Postcaesarean open-heart surgery for Streptococcus sanguinis infective endocarditis

PubMed Central

Kongwattanakul, Kiattisak; Tribuddharat, Sirirat; Prathanee, Sompop; Pachirat, Orathai

2013-01-01

A 33-week pregnant (gravida 3), 29-year-old woman was transferred for management of Streptococcus sanguinis infective endocarditis. A vegetation was present on the posterior leaflet of the mitral valve with moderate mitral regurgitation. On admission (day 1), the ultrasound examination revealed splenic abscesses and retarded intrauterine growth albeit with normal vessels. The fetal heart rate was 140 bpm. On day 11, the baby was delivered by Caesarean, and then the mother underwent tubal ligation followed by a mitral valve repair. The splenic abscess was treated with antibiotics. The woman was clinically stable and recovered uneventfully. This successful outcome was achieved by a strategic (optimal and sequential) timeline for selecting the mode of delivery and type of mitral valve correction. PMID:24234426

Cost-Effectiveness of Transcatheter Aortic Valve Replacement With a Self-Expanding Prosthesis Versus Surgical Aortic Valve Replacement.

PubMed

Reynolds, Matthew R; Lei, Yang; Wang, Kaijun; Chinnakondepalli, Khaja; Vilain, Katherine A; Magnuson, Elizabeth A; Galper, Benjamin Z; Meduri, Christopher U; Arnold, Suzanne V; Baron, Suzanne J; Reardon, Michael J; Adams, David H; Popma, Jeffrey J; Cohen, David J

2016-01-05

Previous studies of the cost-effectiveness of transcatheter aortic valve replacement (TAVR) have been based primarily on a single balloon-expandable system. The goal of this study was to evaluate the cost-effectiveness of TAVR with a self-expanding prosthesis compared with surgical aortic valve replacement (SAVR) for patients with severe aortic stenosis and high surgical risk. We performed a formal economic analysis on the basis of individual, patient-level data from the CoreValve U.S. High Risk Pivotal Trial. Empirical data regarding survival and quality of life over 2 years, and medical resource use and hospital costs through 12 months were used to project life expectancy, quality-adjusted life expectancy, and lifetime medical costs in order to estimate the incremental cost-effectiveness of TAVR versus SAVR from a U.S. Relative to SAVR, TAVR reduced initial length of stay an average of 4.4 days, decreased the need for rehabilitation services at discharge, and resulted in superior 1-month quality of life. Index admission and projected lifetime costs were higher with TAVR than with SAVR (differences $11,260 and $17,849 per patient, respectively), whereas TAVR was projected to provide a lifetime gain of 0.32 quality-adjusted life-years ([QALY]; 0.41 LY) with 3% discounting. Lifetime incremental cost-effectiveness ratios were $55,090 per QALY gained and $43,114 per LY gained. Sensitivity analyses indicated that a reduction in the initial cost of TAVR by ∼$1,650 would lead to an incremental cost-effectiveness ratio <$50,000/QALY gained. In a high-risk clinical trial population, TAVR with a self-expanding prosthesis provided meaningful clinical benefits compared with SAVR, with incremental costs considered acceptable by current U.S. With expected modest reductions in the cost of index TAVR admissions, the value of TAVR compared with SAVR in this patient population would become high. (Safety and Efficacy Study of the Medtronic CoreValve System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement [Medtronic CoreValve U.S. Pivotal Trial]; NCT01240902). Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Effect of Serum C-Reactive Protein Level on Admission to Predict Mortality After Transcatheter Aortic Valve Implantation.

PubMed

Hioki, Hirofumi; Watanabe, Yusuke; Kozuma, Ken; Yamamoto, Masanori; Naganuma, Toru; Araki, Motoharu; Tada, Norio; Shirai, Shinichi; Yamanaka, Futoshi; Higashimori, Akihiro; Mizutani, Kazuki; Tabata, Minoru; Takagi, Kensuke; Ueno, Hiroshi; Hayashida, Kentaro

2018-04-12

The relation between C-reactive protein (CRP) level on admission and mortality after transcatheter aortic valve implantation (TAVI) remains unclear. To evaluate the impact of serum CRP level on mortality after TAVI, we assessed 1,016 patients with CRP who underwent TAVI and 538 patients with high-sensitive CRP (hs-CRP) level who underwent TAVI on admission in the OCEAN (Optimized Transcatheter Valvular Intervention)-TAVI registry. Study population was stratified into 2 groups (high/low), according to the median of CRP and hs-CRP on admission. We assessed the impact of high CRP and hs-CRP level on all-cause death after TAVI. During 2-year follow-up, all-cause death after TAVI was 9.4% in patients with CRP and 11.9% in patients with hs-CRP. Median value of serum CRP was 0.10 mg/dl in both CRP and hs-CRP. Patients with high CRP (>0.10 mg/dl) had significantly higher incidence of all-cause death compared with those with low CRP (11.5% vs 7.6%, log-rank p = 0.015). Multivariate Cox regression analysis with a time-varying covariate demonstrated that high CRP was an independent predictor of all-cause death within the first 3 months (hazard ratio 2.78, 95% CI 1.30 to 5.95) compared with from 3 months to 2 years (hazard ratio 0.80, 95% CI 0.47 to 1.36) (P for interaction = 0.008). Inversely, these results were not observed in the stratification using hs-CRP on admission. In conclusion, high CRP on admission was significantly associated with an increased risk of all-cause death after TAVI, particularly within the first 3 months after TAVI. Risk stratification using CRP may be a simple and useful strategy to identify high-risk patients who undergo TAVI. Copyright © 2018 Elsevier Inc. All rights reserved.

Bellows sealed plug valve

DOEpatents

Dukas, Jr., Stephen J.

1990-01-01

A bellows sealed plug valve includes a valve body having an inlet passage and an outlet passage, a valve chamber between the inlet and outlet passages. A valve plug has substantially the same shape as the valve chamber and is rotatably disposed therein. A shaft is movable linearly in response to a signal from a valve actuator. A bellows is sealingly disposed between the valve chamber and the valve actuator and means are located between the bellows and the valve plug for converting linear movement of the shaft connected to the valve actuator to rotational movement of the plug. Various means are disclosed including helical thread mechanism, clevis mechanism and rack and pinion mechanism, all for converting linear motion to rotational motion.

Leaving Moderate Tricuspid Valve Regurgitation Alone at the Time of Pulmonary Valve Replacement: A Worthwhile Approach.

PubMed

Kogon, Brian; Mori, Makoto; Alsoufi, Bahaaldin; Kanter, Kirk; Oster, Matt

2015-06-01

Pulmonary valve disruption in patients with tetralogy of Fallot and congenital pulmonary stenosis often results in pulmonary insufficiency, right ventricular dilation, and tricuspid valve regurgitation. Management of functional tricuspid regurgitation at the time of subsequent pulmonary valve replacement remains controversial. Our aims were to (1) analyze tricuspid valve function after pulmonary valve replacement through midterm follow-up and (2) determine the benefits, if any, of concomitant tricuspid annuloplasty. Thirty-five patients with tetralogy of Fallot or congenital pulmonary stenosis were analyzed. All patients had been palliated in childhood by disrupting the pulmonary valve, and all patients had at least moderate tricuspid valve regurgitation at the time of subsequent pulmonary valve replacement. Preoperative and serial postoperative echocardiograms were analyzed. Pulmonary and tricuspid regurgitation, along with right ventricular dilation and dysfunction were scored as 0 (none), 1 (mild), 2 (moderate), and 3 (severe). Right ventricular volume and area were also calculated. Comparisons were made between patients who underwent pulmonary valve replacement alone and those who underwent concomitant tricuspid valve annuloplasty. At 1 month after pulmonary valve replacement, there were significant reductions in pulmonary valve regurgitation (mean 3 vs 0.39, p < 0.0001), tricuspid valve regurgitation (mean 2.33 vs 1.3, p < 0.0001), and in right ventricular dilation, volume, and area. There was no difference in the degree of tricuspid regurgitation 1 month postoperatively between patients who underwent concomitant tricuspid annuloplasty and those who underwent pulmonary valve replacement alone (mean 1.31 vs 1.29, p = 0.81). However, at latest follow-up (mean 7.0 ± 2.8 years), the degree of tricuspid regurgitation was significantly higher in the concomitant annuloplasty group (mean 1.87 vs 1.12, p = 0.005). In patients with at least moderate tricuspid valve regurgitation, significant improvement in tricuspid valve function and right ventricular size occurs in the first postoperative month after pulmonary valve replacement, irrespective of concomitant tricuspid valve annuloplasty. The tricuspid valve appears to function better over the midterm if annuloplasty is not performed. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Fatal aortic endocarditis associated with community-acquired Serratia marcescens infection in a dog.

PubMed

Perez, Cristina; Fujii, Yoko; Fauls, Megan; Hummel, James; Breitschwerdt, Edward

2011-01-01

A 12 yr old Dalmatian was referred for evaluation of acute lethargy, fever, neurologic signs, and a recently ausculted heart murmur. Echocardiography in combination with blood cultures resulted in a diagnosis of nonhospital-acquired Serratia marcescens bacteremia and aortic valve endocarditis. Despite early diagnosis and aggressive therapy, the dog failed to respond to antimicrobials and died within 6 hr after admission. Necropsy findings included aortic valve endocarditis, septicemia, and diffuse thromboembolic disease. There was no history of pre-existing underlying disease or immunosuppressive therapy, and the dog had not been hospitalized before referral.

Outcome and prognostic factors of patients with right-sided infective endocarditis requiring intensive care unit admission.

PubMed

Georges, Hugues; Leroy, Olivier; Airapetian, Norair; Lamblin, Nicolas; Zogheib, Elie; Devos, Patrick; Preau, Sebastien

2018-02-21

Right-sided infective endocarditis (RSIE) is an uncommon diagnosis accounting for less than 10% of cases of infective endocarditis. Optimal management for severely ill patients with RSIE remains challenging because few studies reported on management and outcome. The goal of our study was to determine outcome and associated prognostic factors in a population of ICU patients with a diagnosis of definite, active and severe RSIE. We performed a retrospective study in 10 French ICUs between January 2002 and December 2012. Main outcome was mortality at 30 days after ICU admission. Significant variables associated with 30-days mortality in the bivariate analysis were included in a logistic regression analysis. A total of 37 patients were studied. Mean age was 47.9 ± 18.4 years. Mean SAPS II, SOFA score and Charlson comorbidity index were 32.4 ± 17.4, 6.3 ± 4.4 and 3.1 ± 3.4, respectively. Causative pathogens, identified in 34 patients, were mainly staphylococci (n = 29). The source of endocarditis was a catheter related infection in 10 patients, intravenous drug abuse in 8 patients, cutaneous in 7 patients, urinary tract related in one patient and has an unknown origin in 7 patients. Vegetation size was higher than 20 mm for 14 patients. Valve tricuspid regurgitation was classified as severe in 11 patients. All patients received initial appropriate antimicrobial therapy. Aminoglycosides were delivered in combination with β-lactam antibiotics or vancomycin in 22 patients. Surgical procedure was performed in 14 patients. Eight patients (21.6%) died within 30 days following ICU admission. One independent prognostic factor was identified: use of aminoglycosides was associated with improved outcome (OR = 0.1; 95%CI = 0.0017-0.650; p = 0.007). Mortality of patients with RSIE needing ICU admission is high. Aminoglycosides used in combination with β-lactam or vancomycin could reduce 30 days mortality.

Impact of routine cerebral CT angiography on treatment decisions in infective endocarditis.

PubMed

Meshaal, Marwa Sayed; Kassem, Hussein Heshmat; Samir, Ahmad; Zakaria, Ayman; Baghdady, Yasser; Rizk, Hussein Hassan

2015-01-01

Infective endocarditis (IE) is commonly complicated by cerebral embolization and hemorrhage secondary to intracranial mycotic aneurysms (ICMAs). These complications are associated with poor outcome and may require diagnostic and therapeutic plans to be modified. However, routine screening by brain CT and CT angiography (CTA) is not standard practice. We aimed to study the impact of routine cerebral CTA on treatment decisions for patients with IE. From July 2007 to December 2012, we prospectively recruited 81 consecutive patients with definite left-sided IE according to modified Duke's criteria. All patients had routine brain CTA conducted within one week of admission. All patients with ICMA underwent four-vessel conventional angiography. Invasive treatment was performed for ruptured aneurysms, aneurysms ≥ 5 mm, and persistent aneurysms despite appropriate therapy. Surgical clipping was performed for leaking aneurysms if not amenable to intervention. The mean age was 30.43 ± 8.8 years and 60.5% were males. Staph aureus was the most common organism (32.3%). Among the patients, 37% had underlying rheumatic heart disease, 26% had prosthetic valves, 23.5% developed IE on top of a structurally normal heart and 8.6% had underlying congenital heart disease. Brain CT/CTA revealed that 51 patients had evidence of cerebral embolization, of them 17 were clinically silent. Twenty-six patients (32%) had ICMA, of whom 15 were clinically silent. Among the patients with ICMAs, 11 underwent endovascular treatment and 2 underwent neurovascular surgery. The brain CTA findings prompted different treatment choices in 21 patients (25.6%). The choices were aneurysm treatment before cardiac surgery rather than at follow-up, valve replacement by biological valve instead of mechanical valve, and withholding anticoagulation in patients with prosthetic valve endocarditis for fear of aneurysm rupture. Routine brain CT/CTA resulted in changes in the treatment plan in a significant proportion of patients with IE, even those without clinically evident neurological disease. Routine brain CT/CTA may be indicated in all hospitalized patients with IE.

Cost-Effectiveness of Transcatheter Aortic Valve Replacement With a Self-Expanding Prosthesis Versus Surgical Aortic Valve Replacement

PubMed Central

Reynolds, Matthew R.; Lei, Yang; Wang, Kaijun; Chinnakondepalli, Khaja; Vilain, Katherine A.; Magnuson, Elizabeth A.; Galper, Benjamin Z.; Meduri, Christopher U.; Arnold, Suzanne V.; Baron, Suzanne J.; Reardon, Michael J.; Adams, David H.; Popma, Jeffrey J.; Cohen, David J.

2016-01-01

Background Prior studies of the cost-effectiveness of transcatheter aortic valve replacement (TAVR) have been based primarily on a single balloon-expandable system. Objectives The goal of this study was to evaluate the cost-effectiveness of TAVR with a self-expanding prosthesis compared with surgical aortic valve replacement (SAVR) for patients with severe aortic stenosis and high surgical risk. Methods We performed a formal economic analysis on the basis of individual, patient-level data from the CoreValve U.S. High Risk pivotal trial. Empirical data regarding survival and quality of life (QOL) over 2 years, and medical resource use and hospital costs through 12 months were used to project life expectancy, quality-adjusted life expectancy, and lifetime medical costs in order to estimate the incremental cost-effectiveness of TAVR versus SAVR from a U.S. perspective. Results Relative to SAVR, TAVR reduced initial length of stay an average of 4.4 days, decreased the need for rehabilitation services at discharge, and resulted in superior 1-month QOL. Index admission and projected lifetime costs were higher with TAVR than with SAVR (differences $11,260 and $17,849 per patient, respectively), whereas TAVR was projected to provide a lifetime gain of 0.32 quality-adjusted life-years (QALYs; 0.41 life-years [LYs]) with 3% discounting. Lifetime incremental cost-effectiveness ratios (ICERs) were $55,090 per QALY gained and $43,114 per LY gained. Sensitivity analyses indicated that a reduction in the initial cost of TAVR by ~$1,650 would lead to an ICER <$50,000/QALY gained. Conclusions In a high-risk clinical trial population, TAVR with a self-expanding prosthesis provided meaningful clinical benefits compared with SAVR, with incremental costs considered acceptable by current U.S. standards. With expected modest reductions in the cost of index TAVR admissions, the value of TAVR compared with SAVR in this patient population would become high. PMID:26764063

Reoperation for non-structural valvular dysfunction caused by pannus ingrowth in aortic valve prosthesis.

PubMed

Oh, Se Jin; Park, Samina; Kim, Jun Sung; Kim, Kyung-Hwan; Kim, Ki Bong; Ahn, Hyuk

2013-07-01

The authors' clinical experience is presented of non-structural valvular dysfunction of the prosthetic aortic valve caused by pannus ingrowth during the late postoperative period after previous heart valve surgery. Between January 1999 and April 2012, at the authors' institution, a total of 33 patients underwent reoperation for increased mean pressure gradient of the prosthetic aortic valve. All patients were shown to have pannus ingrowth. The mean interval from the previous operation was 16.7 +/- 4.3 years, and the most common etiology for the previous aortic valve replacement (AVR) was rheumatic valve disease. The mean effective orifice area index (EOAI) of the previous prosthetic valve was 0.97 +/- 0.11 cm2/m2, and the mean pressure gradient on the aortic prosthesis before reoperation was 39.1 +/- 10.7 mmHg. Two patients (6.1%) died in-hospital, and late death occurred in six patients (18.2%). At the first operation, 30 patients underwent mitral or tricuspid valve surgery as a concomitant procedure. Among these operations, mitral valve replacement (MVR) was combined in 24 of all 26 patients with rheumatic valve disease. Four patients underwent pannus removal only while the prosthetic aortic valve was left in place. The mean EOAI after reoperation was significantly increased to 1.16 +/- 0.16 cm2/m2 (p < 0.001), and the mean pressure gradient was decreased to 11.9 +/- 1.9 mmHg (p < 0.001). Non-structural valvular dysfunction caused by pannus ingrowth was shown in patients with a small EOAI of the prosthetic aortic valve and combined MVR for rheumatic disease. As reoperation for pannus overgrowth showed good clinical outcomes, an aggressive resection of pannus and repeated AVR should be considered in symptomatic patients to avoid the complications of other cardiac diseases.

Turbulence downstream of subcoronary stentless and stented aortic valves.

PubMed

Funder, Jonas Amstrup; Frost, Markus Winther; Wierup, Per; Klaaborg, Kaj-Erik; Hjortdal, Vibeke; Nygaard, Hans; Hasenkam, J Michael

2011-08-11

Regions of turbulence downstream of bioprosthetic heart valves may cause damage to blood components, vessel wall as well as to aortic valve leaflets. Stentless aortic heart valves are known to posses several hemodynamic benefits such as larger effective orifice areas, lower aortic transvalvular pressure difference and faster left ventricular mass regression compared with their stented counterpart. Whether this is reflected by diminished turbulence formation, remains to be shown. We implanted either stented pericardial valve prostheses (Mitroflow), stentless valve prostheses (Solo or Toronto SPV) in pigs or they preserved their native valves. Following surgery, blood velocity was measured in the cross sectional area downstream of the valves using 10MHz ultrasonic probes connected to a dedicated pulsed Doppler equipment. As a measure of turbulence, Reynolds normal stress (RNS) was calculated at two different blood pressures (baseline and 50% increase). We found no difference in maximum RNS measurements between any of the investigated valve groups. The native valve had significantly lower mean RNS values than the Mitroflow (p=0.004), Toronto SPV (p=0.008) and Solo valve (p=0.02). There were no statistically significant differences between the artificial valve groups (p=0.3). The mean RNS was significantly larger when increasing blood pressure (p=0.0006). We, thus, found no advantages for the stentless aortic valves compared with stented prosthesis in terms of lower maximum or mean RNS values. Native valves have a significantly lower mean RNS value than all investigated bioprostheses. Copyright © 2011 Elsevier Ltd. All rights reserved.

Endocarditis caused by anaerobic bacteria.

PubMed

Kestler, M; Muñoz, P; Marín, M; Goenaga, M A; Idígoras Viedma, P; de Alarcón, A; Lepe, J A; Sousa Regueiro, D; Bravo-Ferrer, J M; Pajarón, M; Costas, C; García-López, M V; Hidalgo-Tenorio, C; Moreno, M; Bouza, E

2017-10-01

Infective endocarditis (IE) caused by anaerobic bacteria is a rare and poorly characterized disease. Most data reported in the literature are from case reports [1-3]. Therefore, we assessed the situation of anaerobic IE (AIE) in Spain using the database of the Spanish Collaboration on Endocarditis (GAMES). We performed a prospective study from 2008 to 2016 in 26 Spanish centers. We included 2491 consecutive cases of definite IE (Duke criteria). Anaerobic bacteria caused 22 cases (0.9%) of definite IE. Median age was 66 years (IQR, 56-73), and 19 (86.4%) patients were men. Most patients (14 [63.6%]) had prosthetic valve IE and all episodes were left-sided: aortic valves, 12 (54.5%); and mitral valves, 8 (36.4%). The most common pathogens were Propionibacterium acnes (14 [63.6%]), Lactobacillus spp (3 [13.63%]), and Clostridium spp. (2 [9.0%]), and the infection was mainly odontogenic. Fifteen of the 22 patients (68.2%) underwent cardiac surgery. Mortality was 18.2% during admission and 5.5% after 1 year of follow-up. When patients with AIE were compared with the rest of the cohort, we found that although those with AIE had a similar age and Charlson comorbidity index, they were more likely to have community-acquired IE (86.4% vs. 60.9%, p = 0.01), have undergone cardiac surgery (68.2% vs 48.7% p = 0.06), and have had lower mortality rates during admission (18.2% vs. 27.3%). IE due to anaerobic bacteria is an uncommon disease that affects mainly prosthetic valves and frequently requires surgery. Otherwise, there are no major differences between AIE and IE caused by other microorganisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Association of Thoracic Aorta Calcium Score With Left Ventricular Hypertrophy and Clinical Outcomes in Patients With Severe Aortic Stenosis After Aortic Valve Replacement.

PubMed

Cho, In-Jeong; Chang, Hyuk-Jae; Heo, Ran; Kim, In-Cheol; Sung, Ji Min; Chang, Byung-Chul; Shim, Chi Young; Hong, Geu-Ru; Chung, Namsik

2017-01-01

Substantial aortic calcification is known to be associated with aortic stiffening and subsequent left ventricular (LV) hypertrophy. This study examined whether the thoracic aorta calcium score (TACS) is related to LV hypertrophy and whether it leads to an adverse prognosis in patients with severe aortic stenosis (AS) after aortic valve replacement (AVR). We retrospectively reviewed 47 patients (mean age, 64 ± 11 years) with isolated severe AS who underwent noncontrast computed tomography of the entire thoracic aorta and who received AVR. TACS was quantified using the volume method with values becoming log transformed ( log [TACS+1]). Transthoracic echocardiography was performed before and 1 year after the operation. Preoperative LV mass index (LVMI) displayed significant positive correlations with male gender (r = 0.430, p = 0.010) and log (TACS+1) (r = 0.556, p = 0.003). In multivariate linear regression analysis, only log (TACS+1) was independently associated with LVMI, even after adjusting for age, gender, transaortic mean pressure gradient, and coronary or valve calcium score. Independent determinants for postoperative LVMI included log (TACS+1) and preoperative LVMI after 1 year of follow-up echocardiography, adjusting for age, gender, indexed effective orifice area, and coronary or valve calcium score. During a median follow-up period of 54 months after AVR, there were 10 events (21%), which included 4 deaths from all-causes, 3 strokes, 2 inpatient admissions for heart failure, and 1 myocardial infarction. The event-free survival rate was significantly lower for patients with TACS of 2,257 mm 3 or higher compared with those whose TACS was lower than 2,257 mm 3 (log-rank p < 0.001). High TACS was associated with increased LVMI among patients with severe AS. Further, high TACS usefully predicted less regression of LVMI and poor clinical outcomes after AVR. TACS may serve as a useful proxy for predicting LV remodeling and adverse prognosis in patients with severe AS undergoing AVR. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

MANAGEMENT OF FAILED MITRAL VALVE REPLACEMENT. THE DURBAN EXPERIENCE.

PubMed

Kistan, D; Booysen, M; Alexander, G; Madiba, T E

2017-06-01

Mitral valve replacement is the procedure of choice in patients with severe mitral valve disease. However, these patients are surviving longer and are thus at an increased risk of prosthesis failure or valve-related complications. Study setting: Inkosi Albert Luthuli Central Hospital, a tertiary referral Hospital in Durban. Study population: All patients undergoing redo mechanical mitral valve replacement surgery between January 2005 and December 2014. Study design: Retrospective analysis of patients undergoing redo mitral valve replacement. Patients were identified from theatre record books, their files were electronically accessed and pertinent information extracted onto a data capture sheet. Information documented included demographics, duration to failure, INR, Albumin, HIV status, clinical findings and outcome. The data was stored on an Excel datasheet. Fifty-eight patients were documented (mean age 32 ± 15.81 years; M:F 1:3). Ten patients (17%) were HIV positive (median CD4 count 478). Mean duration between first surgery and redo was 8.8 years. Thirty-five patients (60%) had no co-morbidities. Presenting features at redo surgery were congestive cardiac failure (27), chest pain (11) and palpitations (17). Mean preoperative Ejection Fraction was 51.65 %. Twenty-nine patients (55%) had emergency redo surgery. Twenty-two patients (75%) had acute prosthetic valve thrombosis. Thirty-two patients had tricuspid regurgitation. Original pathology was documented in 23 patients (40%) as Rheumatic valve disease. Prosthetic valve thrombosis was documented in 31 patients (54%). The most commonly used valve was the On-X. Mean presenting INR was 1.96 + 1.2 and mean presenting serum albumin was 36.7 + 7.8 g/l. Forty-one patients (71%) were found to be compliant to Warfarin therapy prior to redo surgery. Mean ICU stay was 6 +9 days. Two patients died postoperatively. Mean followup was 32 + 26.6 months. Twelve patients (20.7%) developed postoperative complications. Patients were younger than world literature suggests. Rheumatic heart disease was the common underlying pathology. Prosthetic valve thrombosis was common. More than half had emergency surgery. Mortality rate was negligible.

Transapical Mitral Valve Implantation for Native Mitral Valve Stenosis Using a Balloon-Expandable Prosthesis.

PubMed

Kiefer, Philipp; Noack, Thilo; Seeburger, Joerg; Hoyer, Alexandro; Linke, Axel; Mangner, Norman; Lehmkuhl, Lukas; Mohr, Friedrich Wilhelm; Holzhey, David

2017-12-01

Transcatheter mitral valve implantation (TMVI) is still in its infancy and is mainly limited to valve-in-valve or valve-in-ring implantations. We present the early experience with TMVI for severe calcified native MV stenosis. Between January 2014 and June 2015, 6 of 11 patients screened (mean age, 77.4 ± 6.3 years; 66% men) with severe native mitral valve (MV) stenosis (mean gradient [Pmean], 11.1 ± 2.1 mm Hg; mean effective orifice area [EOA], 0.9 ± 0.12 cm 2 ) underwent transcatheter MV replacement at our institution as a bailout procedure. Conventional surgical procedures were denied in all patients because of severe annular calcification and extensive comorbidities (mean logistic EuroScore, 31.4% ± 8.3%). The Edwards SAPIEN 3 (29 mm) (Edwards Lifesciences, Irvine, CA) was used in all cases. Procedural access was transapical in 5 cases and concomitant to aortic valve replacement through the left atrium through a sternotomy in 1 case. Initial implantation was successful in 100% of the cases. Because of early migration, 1 patient needed a valve-in-valve procedure. Postoperative echocardiography showed no residual mitral regurgitation in 4 cases (66%) and mild regurgitation in 2 cases (34%). Mean gradients were reduced to 4.2 ± 0.6 mm Hg (mean EOA, 2.8 ± 0.4 cm 2) . No patient had a stroke during hospitalization, and 30-day mortality was seen in 1 patient (17%) resulting from pneumonia. TMV implantation using the SAPIEN 3 aortic prosthesis in patients with heavy annular calcification is feasible and represents a reasonable bailout option for inoperable patients. However, several limitations need to be considered in this special patient population. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Live 3D TEE demonstrates and guides the management of prosthetic mitral valve obstruction.

PubMed

Chahal, Mangeet; Pandya, Utpal; Adlakha, Satjit; Khouri, Samer J

2011-08-01

A 43-year-old woman, with a remote history of rheumatic mitral stenosis and a St. Jude prosthetic mitral valve replacement, presented with shortness of breath and palpitations, shortly after a long flight. On admission, atrial fibrillation with a rapid ventricular response was noted in the setting of a long history of noncompliance with her anticoagulation. Transesophageal echocardiography (TEE) demonstrated multiple laminated thrombi in the left atrial appendage. Live three-dimensional (3D) TEE confirmed this diagnosis and demonstrated an immobile posterior leaflet of the mitral prosthesis, which had direct implications in her management. She successfully underwent surgery for mitral valve replacement, left atrial appendage ligation, and a Maze procedure on the following day. The multiple thrombi within the atrial appendage were confirmed intraoperatively and pannus formation was determined to be the etiology of the leaflet immobility. © 2011, Wiley Periodicals, Inc.

Air/fuel ratio control system for internal combustion engine having rotary valve and step motor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saito, M.

A system for feedback control of the air/fuel mixing ratio in an internal combustion engine equipped with a carburetor. The control system has an air/fuel ratio detector of a gas sensor type which provides a feedback signal to a control circuit and a rotary valve which is operated by a stepping motor responsive to a control pulse signal produced by the control circuit to regulate the fuel feed rate so as to nullify a deviation of the detected actual air/fuel ratio from a preset air/fuel ratio. The control system may include two auxiliary air-admitting passages respectively connected to a mainmore » fuel passage and a slow fuel passage in the carburetor, and in this case the single rotary valve is designed and arranged so as to simultaneously control the admission of air into both of the two auxiliary air-admitting passages.« less

Anesthetic Management of Cardioband Implantation: Data From a Preliminary Experience and New Insights.

PubMed

Pieri, Marina; Belletti, Alessandro; Oriani, Alessandro; Landoni, Giovanni; Latib, Azeem; Mangieri, Antonio; Colombo, Antonio; Zangrillo, Alberto; Monaco, Fabrizio

2017-04-01

Percutaneous procedures for the treatment of mitral valve disease represent valuable therapeutic options for high-risk patients. The anesthetic management of these patients is complex, as they often suffer from cardiac failure and present multiple comorbidities. A recently developed device for transcatheter mitral valve annuloplasty (Cardioband - Valtech Cardio, Or Yehuda, Israel) is now available in clinical practice. The aim of this study was to present the authors' experience with Cardioband device implantation and to describe their anesthetic strategy. Retrospective study. Cardiac catheterization laboratory of a teaching hospital. Thirteen patients undergoing Cardioband implantation. All the procedures were performed under general anesthesia with continuous transesophageal echocardiographic monitoring. Three-dimensional echocardiography, inotropic therapy, cardiac pacing, and mechanical circulatory support always were available and performed as needed. Mean age was 73±7.1 years, and mean preoperative ejection fraction was 38±7.4%. No complications related to anesthetic management were recorded. The authors observed 1 episode of device malfunction and 1 case of accidental damage to the circumflex artery. Postoperative complications were observed in 3 patients, involving detachment of the anchors, anemia requiring transfusions, vascular injury, and new-onset atrial fibrillation. Six patients (46%) required ICU admission. All patients (100%) were discharged from the hospital. Cardioband device implantation under general anesthesia is a feasible approach when performed by skilled physicians with all the expertise and the resources of high-volume centers used to dealing with severely ill patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of an impedance threshold device in patients receiving active compression-decompression cardiopulmonary resuscitation for out of hospital cardiac arrest.

PubMed

Plaisance, Patrick; Lurie, Keith G; Vicaut, Eric; Martin, Dominique; Gueugniaud, Pierre-Yves; Petit, Jean-Luc; Payen, Didier

2004-06-01

The purpose of this multicentre clinical randomized controlled blinded prospective trial was to determine whether an inspiratory impedance threshold device (ITD), when used in combination with active compression-decompression (ACD) cardiopulmonary resuscitation (CPR), would improve survival rates in patients with out-of-hospital cardiac arrest. Patients were randomized to receive either a sham (n = 200) or an active impedance threshold device (n = 200) during advanced cardiac life support performed with active compression-decompression cardiopulmonary resuscitation. The primary endpoint of this study was 24 h survival. The 24 h survival rates were 44/200 (22%) with the sham valve and 64/200 (32%) with the active valve (P = 0.02). The number of patients who had a return of spontaneous circulation (ROSC), intensive care unit (ICU) admission, and hospital discharge rates was 77 (39%), 57 (29%), and 8 (4%) in the sham valve group versus 96 (48%) (P = 0.05), 79 (40%) (P = 0.02), and 10 (5%) (P = 0.6) in the active valve group. Six out of ten survivors in the active valve group and 1/8 survivors in the sham group had normal neurological function at hospital discharge (P = 0.1). The use of an impedance valve in patients receiving active compression-decompression cardiopulmonary resuscitation for out-of-hospital cardiac arrest significantly improved 24 h survival rates.

Trabeculectomy With Mitomycin C or Ahmed Valve Implantation in Eyes With Uveitic Glaucoma.

PubMed

Bettis, Daniel I; Morshedi, Richard G; Chaya, Craig; Goldsmith, Jason; Crandall, Alan; Zabriskie, Norm

2015-01-01

To report and compare the results of trabeculectomy with mitomycin C (MMC) and Ahmed valve implantation in the management of uveitic glaucoma. The records of 41 eyes of 29 patients who underwent trabeculectomy with MMC or Ahmed valve implantation for uveitic glaucoma were retrospectively reviewed. Seventeen eyes underwent trabeculectomy with MMC, and 24 eyes underwent Ahmed valve implantation. Outcomes included postoperative intraocular pressure (IOP), percent reduction from preoperative IOP, postoperative number of medications, time to failure, and complications. Mean follow-up was 21.2 months in the trabeculectomy group and 23.8 months in the valve group (P=0.06). Mean IOP was reduced from 29.2 to 18.4 mm Hg in the trabeculectomy group (31.3%), compared with a reduction from 33.4 to 15.5 mm Hg in the Ahmed valve group (42.7%, P=0.53). Postoperatively, 1.76 medications were used in the trabeculectomy group, compared with 1.83 medications in the Ahmed valve group (P=0.89). Cumulative success at 1 year was 66.7% in the trabeculectomy group, compared with 100% in the Ahmed valve group (P=0.02). Mean time to failure was 8.36 months with trabeculectomy, and 21.8 months with Ahmed valve (P=0.02). Complications in both groups were typically rare and self-limited, with recurrent inflammation being most common. Although both trabeculectomy with MMC and Ahmed valve implantation are reasonable surgical options in the management of uncontrolled uveitic glaucoma, Ahmed valve implantation was associated with higher cumulative success rate at 1 year and a longer mean time to failure.

Valve repair in aortic regurgitation without root dilatation--aortic valve repair.

PubMed

Lausberg, H F; Aicher, D; Kissinger, A; Langer, F; Fries, R; Schäfers, H-J

2006-02-01

Aortic valve repair was established in the context of aortic root remodeling. Variable results have been reported for isolated valve repair. We analyzed our experience with isolated valve repair and compared the results with those of aortic root remodeling. Between October 1995 and August 2003, isolated repair of the aortic valve was performed in 83 patients (REP), remodeling of the aortic valve in 175 patients (REMO). The demographics of the two groups were comparable (REP: mean age 54.4 +/- 20.7 yrs, male-female ratio 2.1 : 1; REMO: mean age 60.8 +/- 13.6 yrs, male-female ratio 2.4 : 1; p = ns). In both groups the number of bicuspid valves was comparable (REP: 41 %, REMO: 32 %; p = ns). All patients were followed by echocardiography for a cumulative follow-up of 8204 patient months (mean 32 +/- 23 months). Overall in-hospital mortality was 2.4 % in REP and 4.6 % in REMO ( p = 0.62). Systolic gradients were comparable in both groups (REP: 5.8 +/- 2.2, REMO: 6.5 +/- 3.1 mm Hg, p = 0.09). The mean degree of aortic regurgitation 12 months postoperatively was 0.8 +/- 0.7 after REP and 0.7 +/- 0.7 after REMO ( p = 0.29). Freedom from significant regurgitation (> or = II degrees ) after 5 years was 86 % in REP and 89 % in REMO ( p = 0.17). Freedom from re-operation after 5 years was 94.4 % in REP and 98.2 % in REMO ( p = 0.33). Aortic regurgitation without concomitant root dilatation can be treated effectively by aortic valve repair. The functional results are equivalent to those obtained with valve-preserving root replacement. Aortic valve repair appears to be an alternative to valve replacement in aortic regurgitation.

Impact of a multidisciplinary management strategy on the outcome of patients with native valve infective endocarditis.

PubMed

Chirillo, Fabio; Scotton, Piergiorgio; Rocco, Francesco; Rigoli, Roberto; Borsatto, Francesca; Pedrocco, Alessandra; De Leo, Alessandro; Minniti, Giuseppe; Polesel, Elvio; Olivari, Zoran

2013-10-15

Strategies to improve management of patients with native valve endocarditis (NVE) are needed because of persistently high morbidity and mortality. We sought to assess the impact of an operative protocol of multidisciplinary approach on the outcome of patients with NVE. A formal policy for the care of infective endocarditis was introduced at our hospital in 2003 in which patients were referred to and managed by a preexisting team involving a cardiologist, a specialist in infectious diseases, and a cardiac surgeon. The initial multidisciplinary evaluation was performed within 12 hours of admission. Whenever conditions associated with impending hemodynamic impairment, high-risk for systemic embolization, or unsuccessful medical therapy were found, patients were operated on within 48 hours. Stable patients were evaluated weekly by the multidisciplinary team, and on-treatment surgery was performed whenever the above high-risk conditions had developed. Comparing the period 2003 through 2009 with 1996 through 2002 (when a multidisciplinary policy was not followed), patients were more numerous (190 vs 102), older (mean age 59.1 vs 54.2, p = 0.01), and had more co-morbidities (mean Charlson index 3.01 vs 2.31, p = 0.02). The pattern of infection did not change in terms of valve infected or paravalvular complications. In the second period, fewer patients had culture-negative NVE (8% vs 21%, p = 0.01) and worsened renal function (37% vs 58%, p = 0.001). A significant reduction in overall in-hospital mortality (28% to 13%, p = 0.02), mortality for surgery during the active phase (47% to 13%, p ≤0.001), and 3-year mortality (34% vs 16%, p = 0.0007) was observed. In conclusion, formalized, collaborative management led to significant improvement in NVE-related mortality, notwithstanding the less favorable patients' baseline characteristics. Copyright © 2013 Elsevier Inc. All rights reserved.

Early Transcatheter Aortic Valve Function With and Without Therapeutic Anticoagulation.

PubMed

Hiremath, Pranoti G; Kearney, Kathleen; Smith, Bryn; Don, Creighton; Dvir, Danny; Aldea, Gabriel; Reisman, Mark; McCabe, James M

2017-11-01

Prosthetic leaflet thrombosis is a growing concern in transcatheter aortic valve replacement (TAVR). Given the uncertainty of best practices for antiplatelet and anticoagulation therapies in the post-TAVR period, additional evidence regarding the impact of anticoagulation on prosthetic valve function after TAVR is needed. Patients undergoing native-valve TAVR at a single academic institution between 2012 and 2015 were analyzed based on any anticoagulant use at hospital discharge post TAVR. Changes in prosthetic valve peak velocity and mean gradient were assessed based on transthoracic echocardiograms performed immediately following valve implant and at 4-week follow-up. Multivariate regression analyses were performed to explore the impact of anticoagulation status on early TAVR valve performance. For 403 patients, there were no available data to analyze. Of those, 29.6% were discharged on anticoagulation. Following TAVR, the average mean prosthetic valve gradient was 11.8 ± 5.6 mm Hg and peak velocity was 2.33 ± 0.52 m/s. There were no significant differences between anticoagulated and non-anticoagulated groups in the mean or peak gradients or velocity immediately following implant or at 4 weeks, which remained true following multivariate adjustment (P=.80 for delta mean gradient; P=.91 for delta peak velocity). Our data suggest that the absence of anticoagulation is not associated with short-term degradation in TAVR performance and do not support the routine use of anticoagulation following native-valve TAVR.

Percutaneous transcatheter aortic valve implantation for degenerated surgical bioprostheses: the first case series in Asia with one-year follow-up.

PubMed

Chiam, Paul Toon-Lim; Ewe, See-Hooi; Soon, Jia-Lin; Ho, Kay-Woon; Sin, Yong-Koong; Tan, Swee-Yaw; Lim, Soo-Teik; Koh, Tian-Hai; Chua, Yeow-Leng

2016-07-01

Percutaneous transcatheter aortic valve implantation (TAVI) has become an established therapy for inoperable and high-surgical-risk patients with severe aortic stenosis. Although TAVI in patients with degenerated surgical aortic bioprostheses (i.e. valve-in-valve TAVI) is increasingly reported in Western studies, such data is lacking in Asian patients. We describe the initial experience of valve-in-valve TAVI in Asia. Eight patients who underwent valve-in-valve TAVI due to degenerated aortic bioprostheses were enrolled. The mechanism of bioprosthetic valve failure was stenotic, regurgitation or mixed. All procedures were performed via transfemoral arterial access, using the self-expanding CoreValve prosthesis or balloon-expandable SAPIEN XT prosthesis. The mean age of the patients was 71.6 ± 13.2 years and five were male. Mean duration to surgical bioprosthesis degeneration was 10.2 ± 4.1 years. Valve-in-valve TAVI was successfully performed in all patients. CoreValve and SAPIEN XT prostheses were used in six and two patients, respectively. There were no deaths, strokes or permanent pacemaker requirement at 30 days, with one noncardiac mortality at one year. All patients experienced New York Heart Association functional class improvement. Post-procedure mean pressure gradients were 20 ± 11 mmHg and 22 ± 8 mmHg at 30 days and one year, respectively. Residual aortic regurgitation (AR) of more than mild severity occurred in one patient at 30 days. At one year, only one patient had mild residual AR. In our experience of valve-in-valve TAVI, procedural success was achieved in all patients without adverse events at 30 days. Good clinical and haemodynamic outcomes were sustained at one year. Copyright © Singapore Medical Association.

Incidence, Timing, and Predictors of Valve Hemodynamic Deterioration After Transcatheter Aortic Valve Replacement: Multicenter Registry.

PubMed

Del Trigo, Maria; Muñoz-Garcia, Antonio J; Wijeysundera, Harindra C; Nombela-Franco, Luis; Cheema, Asim N; Gutierrez, Enrique; Serra, Vicenç; Kefer, Joelle; Amat-Santos, Ignacio J; Benitez, Luis M; Mewa, Jumana; Jiménez-Quevedo, Pilar; Alnasser, Sami; Garcia Del Blanco, Bruno; Dager, Antonio; Abdul-Jawad Altisent, Omar; Puri, Rishi; Campelo-Parada, Francisco; Dahou, Abdellaziz; Paradis, Jean-Michel; Dumont, Eric; Pibarot, Philippe; Rodés-Cabau, Josep

2016-02-16

Scarce data exist on the incidence of and factors associated with valve hemodynamic deterioration (VHD) after transcatheter aortic valve replacement (TAVR). This study sought to determine the incidence, timing, and predictors of VHD in a large cohort of patients undergoing TAVR. This multicenter registry included 1,521 patients (48% male; 80 ± 7 years of age) who underwent TAVR. Mean echocardiographic follow-up was 20 ± 13 months (minimum: 6 months). Echocardiographic examinations were performed at discharge, at 6 to 12 months, and yearly thereafter. Annualized changes in mean gradient (mm Hg/year) were calculated by dividing the difference between the mean gradient at last follow-up and the gradient at discharge by the time between examinations. VHD was defined as a ≥10 mm Hg increase in transprosthetic mean gradient during follow-up compared with discharge assessment. The overall mean annualized rate of transprosthetic gradient progression during follow-up was 0.30 ± 4.99 mm Hg/year. A total of 68 patients met criteria of VHD (incidence: 4.5% during follow-up). The absence of anticoagulation therapy at hospital discharge (p = 0.002), a valve-in-valve (TAVR in a surgical valve) procedure (p = 0.032), the use of a 23-mm valve (p = 0.016), and a greater body mass index (p = 0.001) were independent predictors of VHD. There was a mild but significant increase in transvalvular gradients over time after TAVR. The lack of anticoagulation therapy, a valve-in-valve procedure, a greater body mass index, and the use of a 23-mm transcatheter valve were associated with higher rates of VHD post-TAVR. Further prospective studies are required to determine whether a specific antithrombotic therapy post-TAVR may reduce the risk of VHD. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

In vitro evaluation of forward and reverse volumetric flow across a regurgitant aortic valve using Doppler power-weighted mean velocities.

PubMed

Minich, L L; Tani, L Y; Pantalos, G M

1997-01-01

To determine the accuracy of using power-weighted mean velocities for quantitating volumetric flow across a cardiac valve, we equipped pulsatile flow-tank systems with a 25 mm porcine or a 27 mm mechanical valve with various sizes of regurgitant orifices. Forward and reverse volumetric flows were measured over a range of hemodynamic conditions using two insonating angles (0 and 45 degrees). Pulsed Doppler power-weighted mean velocity measurements were obtained simultaneously with electromagnetic or ultrasonic transit-time probe measurements. For the porcine valve, Doppler measurements correlated well with electromagnetic flow measurements for all (r = 0.75 to 0.97, p < 0.05) except the smallest (2.7 mm) orifice (r = 0.19). For the mechanical valve, power-weighted mean velocity measurements correlated well with ultrasonic transit-time measurements for each hemodynamic condition defined by pulse rate, mean arterial pressure, and insonating angle (r = 0.93 to 0.99, p < 0.01), but equations varied unpredictably. Thus, although power-weighted mean velocity volumetric flow measurements correlate well with flow probe measurements, equations vary widely as hemodynamic conditions change. Because of this variation, power-weighted mean velocity data are not useful for quantitation of volumetric flow across a cardiac valve at this time. Further investigation may show how different hemodynamic conditions affect power-weighted mean velocity measurements of volumetric flow.

Early Outcomes for Valve-in-valve Transcatheter Aortic Valve Replacement in Degenerative Freestyle Bioprostheses.

PubMed

Sang, Stephane Leung Wai; Beute, Tyler; Heiser, John; Berkompas, Duane; Fanning, Justin; Merhi, William

2017-11-20

Transcatheter aortic valve replacement (TAVR) is used increasingly to treat bioprosthetic valve failure. A paucity of data exists regarding valve-in-valve (ViV) TAVR in degenerated Freestyle stentless bioprostheses (FSBs). This study sought to evaluate the feasibility and short-term outcomes of ViV TAVR in previously placed FSB. From October 2014 to September 2016, 22 patients at a single institution underwent ViV TAVR with a self-expanding transcatheter valve for a failing FSB. Patient baseline characteristics and clinical outcomes data were collected retrospectively and entered into a dedicated database. The mean patient age was 74 ± 9years, and the mean Society of Thoracic Surgeons' Risk score was 9.0 ± 7.4%. Ten patients presented with acute heart failure requiring urgent intervention. The most common mode of failure of the FSB was regurgitation caused by a flail or malcoapting leaflet. Seventeen (77%) patients had a modified subcoronary implantation, 3 (14%) had a full root replacement, and 2 (9%) had a root inclusion. Device success using a self-expanding transcatheter valve was 95%, all via transfemoral approach. The mean implant depth was 7 ± 3 mm. Thirty-day survival was 100%. No patient had more than mild paravalvular regurgitation at 30days, and the permanent pacemaker rate was 9%. The mean hospital stay after intervention was 5 ± 2days. ViV TAVR using a self-expanding transcatheter valve is safe, feasible, and can be used successfully to treat a failed FSB. Procedural challenges suggest referral to valve centers of excellence. Copyright © 2017 Elsevier Inc. All rights reserved.

Outcomes of Solo Smart valve in a single-center experience of 270 patients.

PubMed

Liu, Hao; Khani-Hanjani, Abbas; Yang, Siyuan; Wang, Wei; Sidhu, Surita; Mullen, John; Modry, Dennis; Wang, Shaohua

2018-04-03

The Solo Smart pericardial aortic valve has been widely used in Europe as an option for aortic valve replacement (AVR). We are reporting early and midterm clinical outcomes of AVR with the Solo Smart valve in a single North America center. This is a retrospective study of 270 consecutive patients who had AVR at Mazankowski Alberta Heart Institute from February 2011 to March 2015. Follow-up and echocardiographic data were collected retrospectively from electronic and paper charts. Univariate and multivariate analysis were performed to evaluate the results. The mean age was 71.2±10.0 years, 67.4% were male, and 79.3% had combined procedures. Mean STS Score was 4.18±3.91. Early mortality was 3.7% for the entire group and 0% for isolated aortic valve replacement group. Mean cross-clamp time for isolated AVR and AVR with concomitant procedure was 70.8±12.7min and 117.0±45.0min, respectively. Permanent pacemaker implantation was necessary in 2.2% of patients. Echocardiography demonstrated a reduction in mean gradients from 40.8±17.4mmHg to 7.6±3.7 mmHg and peak gradient from 72.5 ± 48.8 mmHg to 15.5±7.5 mmHg. The 1-, 3-, and 5- year overall survival was 93.0%, 86.5% and 75.9%, respectively. At 5 years, freedom from valve-related death was 92.4%, freedom from structural valve deterioration and freedom from aortic valve reoperation were 96.4% and 98%, respectively. The Solo Smart valve is safe and has excellent hemodynamic performance. Aortic valve reoperation and rates of valve-related adverse events during midterm follow-up were low.

Does positron emission tomography/computed tomography aid the diagnosis of prosthetic valve infective endocarditis?

PubMed

Balmforth, Damian; Chacko, Jacob; Uppal, Rakesh

2016-10-01

A best evidence topic was constructed according to a structured protocol. The question addressed was whether (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) aids the diagnosis of prosthetic valve endocarditis (PVE)? A total of 107 publications were found using the reported search, of which 6 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The reported outcome of all studies was a final diagnosis of confirmed endocarditis on follow-up. All the six studies were non-randomized, single-centre, observational studies and thus represented level 3 evidence. The diagnostic capability of PET/CT for PVE was compared with that of the modified Duke Criteria and echocardiography, and reported in terms of sensitivity, specificity and positive and negative predictive values. All studies demonstrated an increased sensitivity for the diagnosis of PVE when PET/CT was combined with the modified Duke Criteria on admission. A higher SUVmax on PET was found to be significantly associated with a confirmed diagnosis of endocarditis and an additional diagnostic benefit of PET/CT angiography over conventional PET/non-enhanced CT is reported due to improved anatomical resolution. However, PET/CT was found to be unreliable in the early postoperative period due to its inability to distinguish between infection and residual postoperative inflammatory changes. PET/CT was also found to be poor at diagnosing cases of native valve endocarditis. We conclude that PET/CT aids in the diagnosis of PVE when combined with the modified Duke Criteria on admission by increasing the diagnostic sensitivity. The diagnostic ability of PET/CT can be potentiated by the use of PET/CTA; however, its use may be unreliable in the early postoperative period or in native valve endocarditis. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Jet-controlled freeze valve for use in a glass melter

DOEpatents

Routt, Kenneth R.

1986-09-02

A drain valve for use in a furnace for the melting of thermoplastic material. The furnace includes a drain cavity formed in its bottom for withdrawing a flow of thermoplastic material. The drain valve includes a flow member which include a flow tube having an inlet and outlet for the material, and coaxially disposed concentric tubular members defining annuli surrounding the flow tube. The tubular members include heating and cooling means for the flow tube. The flow member is adapted to fit in mating relationship in the drain cavity. A freeze valve member is disposed adjacent the outlet of the flow member. The freeze valve member includes heating means and has a plurality of air jets adapted to direct streams of pressurized air at the outlet to control the flow of thermoplastic material through the flow members. The drain valve can also be used in a furnace of glass melting that includes a drain cavity for withdrawing molten glass from the furnace. The drain valve includes a flow tube member having an inlet and outlet, and having heating and cooling means. The tube member is adapted to fit in mating relationship with the drain cavity. A freeze valve member is disposed at the outlet of the flow tube member. The freeze valve member includes heating means and has a plurality of air jets adapted to direct a stream of pressurized air at the outlet to control the flow of glass through the flow tube member.

Jet-controlled freeze valve for use in a glass melter

DOEpatents

Routt, Kenneth R.

1986-01-01

A drain valve for use in a furnace for the melting of thermoplastic material. The furnace includes a drain cavity formed in its bottom for withdrawing a flow of thermoplastic material. The drain valve includes a flow member which include a flow tube having an inlet and outlet for the material, and coaxially disposed concentric tubular members defining annuli surrounding the flow tube. The tubular members include heating and cooling means for the flow tube. The flow member is adapted to fit in mating relationship in the drain cavity. A freeze valve member is disposed adjacent the outlet of the flow member. The freeze valve member includes heating means and has a plurality of air jets adapted to direct streams of pressurized air at the outlet to control the flow of thermoplastic material through the flow members. The drain valve can also be used in a furnace of glass melting that includes a drain cavity for withdrawing molten glass from the furnace. The drain valve includes a flow tube member having an inlet and outlet, and having heating and cooling means. The tube member is adapted to fit in mating relationship with the drain cavity. A freeze valve member is disposed at the outlet of the flow tube member. The freeze valve member includes heating means and has a plurality of air jets adapted to direct a stream of pressurized air at the outlet to control the flow of glass through the flow tube member.

Hydrogen gas relief valve

DOEpatents

Whittlesey, Curtis C.

1985-01-01

An improved battery stack design for an electrochemical system having at least one cell from which a gas is generated and an electrolyte in communication with the cell is described. The improved battery stack design features means for defining a substantially closed compartment for containing the battery cells and at least a portion of the electrolyte for the system, and means in association with the compartment means for selectively venting gas from the interior of the compartment means in response to the level of the electrolyte within the compartment means. The venting means includes a relief valve having a float member which is actuated in response to the level of the electrolyte within the compartment means. This float member is adapted to close the relief valve when the level of the electrolyte is above a predetermined level and open the relief valve when the level of electrolyte is below this predetermined level.

[Clinical implications and angiographic and electrocardiographic correlation of ST segment elevation in leads V7-V9 in patients with ST elevation myocardial infarction].

PubMed

Adawi, Khaled; Atar, Shaul

2008-07-01

The clinical significance and clinical characteristics of patients with myocardial infarction involving the posterior wall of the left ventricle is not well-defined. The angiographic findings and their correlation with the eletrocardiographic (ECG) findings may be of high therapeutic importance. We retrospectively studied consecutive patients with ST elevation myocardial infarction on the admission ECG to the intensive cardiac care. We studied the clinical and demographic characteristics, the clinical course in-hospital and the clinical outcome (including infarct size, congestive heart failure and significant mitral insufficiency). All patients underwent coronary angiography during the index admission. We correlated the ECG findings on admission to the angiographic findings. We studied 198 patients with mean age of 57 +/- 12 years (range 30-88 years), 158 men (79.8%) and 40 women (20.2%). Myocardial infarction involving the inferior wall was noted in 119 patients, of whom 68 had inferior wall myocardial infarction only, and 51 had inferior and lateral wall involvement (leads I, AVL and/or V5-V6). Only 4 patients (2%) had ST elevation in leads V7-V9 only. The left ventricular ejection fraction was lowest in patients with anterior wall myocardial infarction (41% +/- 6) compared to myocardial infarction with the posterior wall involved (44% +/- 8) or myocardial infarction with the inferior wall only (54% +/- 6) (p = 0.023). The largest infarct size by peak creatine phosphokinase was found in the inferoposterior myocardial infarction group, significantly larger from inferior infarction only, and similar to that of anterior myocardial infarction. The incidence of congestive heart failure was slightly more in anterior myocardial infarction; however, significant mitral valve insufficiency was higher in patients with posterior wall involvement, yet with no statistical significance. The infarct related artery causing posterior myocardial infarction was significantly more frequent in the right coronary artery (57.1%) compared to the left circumflex artery (37.5%) (p < 0.01). The major artery causing involvement of the posterior wall is the right coronary artery. In patients with myocardial infarction involving the posterior wall, infarct size is similar to that of anterior wall myocardial infarction, and with similar complications rate. However, the incidence of significant mitral valve insufficiency and congestive heart failure is high in patients with posterior wall involvement. Posterior leads assessment should be conducted routinely in patients with suspected myocardial infarction.

Obstructive Thebesian valve: anatomical study and implications for invasive cardiologic procedures.

PubMed

Ghosh, Sanjib Kumar; Raheja, Shashi; Tuli, Anita

2014-03-01

Thebesian valve is the embryological remnant of the right sinoatrial valve, guarding the coronary sinus (CS) ostium. Advanced invasive and interventional cardiac diagnostic and management tools involve cannulation of the CS ostium. The presence of obstructive Thebesian valves has been reported to lead to unsuccessful cannulation of the CS. We studied the morphology of the Thebesian valve and CS ostium to assess the possible impact of these structures on invasive cardiological procedures. One hundred fifty randomly selected human cadaveric heart specimens fixed in 10% formalin were dissected in the customary routine manner. The Thebesian valves were classified according to their shape as semilunar/fenestrated/biconcave band like and according to their composition as membranous/fibromuscular/fibrous/muscular, and the extent to which the valve covered the CS ostium was also noted. An obstructive Thebesian valve that could interfere with the cannulation of the CS was defined as non-fenestrated (semilunar/biconcave band like) and non-membranous (fibromuscular/fibrous/muscular) valves covering >75% of the CS ostium. Thebesian valves were present in 118 (79%) heart specimens, of which 27 (18%) met the criteria of being obstructive. Semilunar was the most common type of Thebesian valve in terms of shape and was observed in 65 (65/118; 55%) hearts. This type was associated with the least mean craniocaudal (7.9±0.6 mm) and mean transverse (6.25±0.6 mm) diameters of the CS ostium. The mean craniocaudal diameter of the CS ostium (9.4±2.1 mm) was significantly larger (p=0.004) than the mean transverse diameter (7.15±1.5 mm) in specimens with Thebesian valves, and the cranial margin of the CS ostium was free from any attachment of the Thebesian valve in all the types observed (in terms of shape). Hence, attempts to direct the tip of the catheter toward the cranial margin of the CS ostium under direct vision may lead to successful cannulation of the same when conventional techniques have been unsuccessful because of the presence of an obstructive Thebesian valve.

Conduction Abnormalities and Permanent Pacemaker Implantation After Transcatheter Aortic Valve Replacement Using the Repositionable LOTUS Device: The United Kingdom Experience.

PubMed

Rampat, Rajiv; Khawaja, M Zeeshan; Hilling-Smith, Roland; Byrne, Jonathan; MacCarthy, Philip; Blackman, Daniel J; Krishnamurthy, Arvindra; Gunarathne, Ashan; Kovac, Jan; Banning, Adrian; Kharbanda, Raj; Firoozi, Sami; Brecker, Stephen; Redwood, Simon; Bapat, Vinayak; Mullen, Michael; Aggarwal, Suneil; Manoharan, Ganesh; Spence, Mark S; Khogali, Saib; Dooley, Maureen; Cockburn, James; de Belder, Adam; Trivedi, Uday; Hildick-Smith, David

2017-06-26

The authors report the incidence of pacemaker implantation up to hospital discharge and the factors influencing pacing rate following implantation of the LOTUS bioprosthesis (Boston Scientific, Natick, Massachusetts) in the United Kingdom. Transcatheter aortic valve replacement (TAVR) is associated with a significant need for permanent pacemaker implantation. Pacing rates vary according to the device used. The REPRISE II (Repositionable Percutaneous Replacement of Stenotic Aortic Valve Through Implantation of Lotus Valve System) trial reported a pacing rate of 29% at 30 days after implantation of the LOTUS device. Data were collected retrospectively on 228 patients who had the LOTUS device implanted between March 2013 and February 2015 across 10 centers in the United Kingdom. Twenty-seven patients (12%) had pacemakers implanted pre-procedure and were excluded from the analysis. Patients were aged 81.2 ± 7.7 years; 50.7% were male. The mean pre-procedural QRS duration was 101.7 ± 20.4 ms. More than one-half of the cohort (n = 111, 55%) developed new left bundle branch block (LBBB) following the procedure. Permanent pacemakers were implanted in 64 patients (32%) with a median time to insertion of 3.0 ± 3.4 days. Chief indications for pacing were atrioventricular (AV) block (n = 46, 72%), or LBBB with 1st degree AV block (n = 11, 17%). Amongst those who received a pacemaker following TAVR the pre-procedural electrocardiogram findings included: No conduction disturbance (n = 41, 64%); 1st degree AV block (n = 10, 16%); right bundle branch block (n = 6, 9%) and LBBB (n = 5, 8%). LBBB (but not permanent pacemaker) occurred more frequently in patients who had balloon aortic valvuloplasty before TAVR (odds ratio [OR]: 1.25; p = 0.03). Pre-procedural conduction abnormality (composite of 1st degree AV block, hemiblock, right bundle branch block, LBBB) was independently associated with the need for permanent pacemaker (OR: 2.54; p = 0.048). The absence of aortic valve calcification was also associated with a higher pacing rate (OR: 0.55; p = 0.031). Multivariate regression analysis did not show an independent association between depth of implant, valve oversizing, balloon post-dilatation, and the need for pacing post-procedure. Following implantation of the repositionable LOTUS valve, 55% of patients developed LBBB and 32% of patients required a pacemaker during their index hospital admission. Patients with pre-procedural conduction disturbance and non-calcified aortic valves were more likely to need pacing. No other anatomic features were identified with increased pacing requirement with the LOTUS device. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

[Long-term follow-up in patients with homozygous familial hypercholesterolemia; 13-year experience of a university hospital lipid clinic].

PubMed

Kayıkçıoğlu, Meral; Kısmalı, Erkan; Can, Levent; Payzin, Serdar

2014-10-01

Familiar hypercholesterolemia (FH) is a genetic disease characterized with extremely high levels of cholesterol leading to premature atherosclerosis. In homozygous individuals (HoFH) cardiovascular events could develop in childhood. In this article, long-term clinical experience with adult HoFH patients who are followed in Department of Cardiology, Ege University Faculty of Medicine is presented. Seventeen HoFH patients (11 females, 6 males) who are being followed between the years 2000-2013 were included. All data including clinical characteristics, family history, lipid levels, treatment, lipid-apheresis, cardiovascular events, complications were obtained retrospectively from patient chart records. Mean age was 31 ± 10 years at admission to our clinic. First diagnosis age was 25 ± 14. At diagnosis, mean cholesterol level was 625 ± 136 mg/dl. Admission complaints were dermatologic (41%) and ischemic symptoms (41%). A total of 3 patients (18%) were diagnosed during family screening. 65% of the patients' parents had consanguineous marriage. Xantomas was present in 59%, aortic valve pathology in 59%, and carotid artery plaques in 47%. Coronary artery disease was documented in 59%. Though all patients had indication for apheresis, 10 patients received apheresis due to high refusal rate. Age at the first apheresis was 27 ± 12 (minimum 10-maximum 42) and adherence to apheresis was 60%. With 2 years regular apheresis skin depositions were vanished, however carotid atherosclerosis and aortic pathology progressed. During the 43 ± 42 months follow-up, 4 patients died (mean age: 25 ± 5). Diagnosis is late in HoAH. Due to the delayed treatment of lipid apheresis, atherosclerosis and aortic stenosis progress in these patients. The awareness of the physicians and knowledge of the public is warranted.

From tricuspid to double orifice Morphology: Percutaneous tricuspid regurgitation repair with the MitraClip device in congenitally corrected-transposition of great arteries.

PubMed

Picard, Fabien; Tadros, Victor-Xavier; Asgar, Anita W

2017-09-01

Edge to edge transcatheter mitral valve repair with MitraClip (Abbott Vascular, Menlo Park, CA) is increasing for high-risk surgical patients with significant mitral regurgitation. Patients with congenitally corrected transposition of the great arteries (CCTGA) presenting with tricuspid valve regurgitation of a systemic right ventricle may represent particularly challenging candidates for MitraClip given their anatomy. We report the case of a 67-year-old gentleman with CCTGA and severe tricuspid regurgitation who was referred for MitraClip implantation after heart team consensus. Successful implantation of one clip was performed, achieving a significant reduction of the regurgitation. Similarly, favorable findings were confirmed at 6 months, 1 and 2 years follow-up and the patient had no recurrent heart failure admissions after 2-year follow-up. We describe the technical considerations and the importance of 3D-transoesophageal echocardiography for performing the MitraClip of a trileaflet systemic atrioventricular valve. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Blunt traumatic aortic injuries of the ascending aorta and aortic arch: a clinical multicentre study.

PubMed

Mosquera, Victor X; Marini, Milagros; Muñiz, Javier; Gulias, Daniel; Asorey-Veiga, Vanesa; Adrio-Nazar, Belen; Herrera, José M; Pradas-Montilla, Gonzalo; Cuenca, José J

2013-09-01

To report the clinical and radiological characteristics, management and outcomes of traumatic ascending aorta and aortic arch injuries. Historic cohort multicentre study including 17 major trauma patients with traumatic aortic injury from January 2000 to January 2011. The most common mechanism of blunt trauma was motor-vehicle crash (47%) followed by motorcycle crash (41%). Patients sustaining traumatic ascending aorta or aortic arch injuries presented a high proportion of myocardial contusion (41%); moderate or greater aortic valve regurgitation (12%); haemopericardium (35%); severe head injuries (65%) and spinal cord injury (23%). The 58.8% of the patients presented a high degree aortic injury (types III and IV). Expected in-hospital mortality was over 50% as defined by mean TRISS 59.7 (SD 38.6) and mean ISS 48.2 (SD 21.6) on admission. Observed in-hospital mortality was 53%. The cause of death was directly related to the ATAI in 45% of cases, head and abdominal injuries being the cause of death in the remaining 55% cases. Long-term survival was 46% at 1 year, 39% at 5 years, and 19% at 10 years. Traumatic aortic injuries of the ascending aorta/arch should be considered in any major thoracic trauma patient presenting cardiac tamponade, aortic valve regurgitation and/or myocardial contusion. These aortic injuries are also associated with a high incidence of neurological injuries, which can be just as lethal as the aortic injury, so treatment priorities should be modulated on an individual basis. Copyright © 2012 Elsevier Ltd. All rights reserved.

14 CFR 125.137 - Oil valves.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Oil valves. 125.137 Section 125.137....137 Oil valves. (a) Each oil valve must— (1) Comply with § 125.155; (2) Have positive stops or... the valve. (b) The closing of an oil shutoff means must not prevent feathering the propeller, unless...

14 CFR 125.137 - Oil valves.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Oil valves. 125.137 Section 125.137....137 Oil valves. (a) Each oil valve must— (1) Comply with § 125.155; (2) Have positive stops or... the valve. (b) The closing of an oil shutoff means must not prevent feathering the propeller, unless...

14 CFR 125.137 - Oil valves.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Oil valves. 125.137 Section 125.137....137 Oil valves. (a) Each oil valve must— (1) Comply with § 125.155; (2) Have positive stops or... the valve. (b) The closing of an oil shutoff means must not prevent feathering the propeller, unless...

14 CFR 125.137 - Oil valves.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Oil valves. 125.137 Section 125.137....137 Oil valves. (a) Each oil valve must— (1) Comply with § 125.155; (2) Have positive stops or... the valve. (b) The closing of an oil shutoff means must not prevent feathering the propeller, unless...

14 CFR 125.137 - Oil valves.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Oil valves. 125.137 Section 125.137....137 Oil valves. (a) Each oil valve must— (1) Comply with § 125.155; (2) Have positive stops or... the valve. (b) The closing of an oil shutoff means must not prevent feathering the propeller, unless...

Operating Temperatures of a Sodium-Cooled Exhaust Valve as Measured by a Thermocouple

NASA Technical Reports Server (NTRS)

Sanders, J. C.; Wilsted, H. D.; Mulcahy, B. A.

1943-01-01

A thermocouple was installed in the crown of a sodium-cooled exhaust valve. The valve was then tested in an air-cooled engine cylinder and valve temperatures under various engine operating conditions were determined. A temperature of 1337 F was observed at a fuel-air ratio of 0.064, a brake mean effective pressure of 179 pounds per square inch, and an engine speed of 2000 rpm. Fuel-air ratio was found to have a large influence on valve temperature, but cooling-air pressure and variation in spark advance had little effect. An increase in engine power by change of speed or mean effective pressure increased the valve temperature. It was found that the temperature of the rear spark-plug bushing was not a satisfactory indication of the temperature of the exhaust valve.

ULTRA HIGH VACUUM VALVE

DOEpatents

Fry, W.A.

1962-05-29

A valve for high vacuum applications such as the CStellarator where chamber pressures as low as 2 x 10/sup -10/ mm Hg are necessary is designed with a line-of-sight path through the valve for visual inspection of the contents of reactants in such chambers. The valve comprises a turnable resilient metal ball having an aperture therethrough, means for selectively turning the ball to rotate the axis of its line-of-sight path, and soft, deformable opposing orifices that are movable relatively toward said ball to seal with opposite ball surfaces upon said movement of said axis of said line-of-sight path. The valve also includes a bellows seal connected between said orifices and internal actuating means that eliminates the requirement for gasketed turnable valve closing stems. (AEC)

Fuel supply device for supplying fuel to an engine combustor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindsay, M.H.; Kerr, W.B.

1990-05-29

This patent describes a variable flow rate fuel supply device for supplying fuel to an engine combustor. It comprises: fuel metering means having a fuel valve means for controlling the flow rate of fuel to the combustor; piston means for dividing a first cooling fluid chamber from a second cooling fluid chamber; coupling means for coupling the piston means to the fuel valve means; and cooling fluid supply means in communication with the first and second cooling fluid chamber for producing a first pressure differential across the piston means for actuating the fuel valve means in a first direction, andmore » for producing a second pressure differential across the piston means for actuating the valve means in a second direction opposite the first direction, to control the flow rate of the fuel through the fuel metering means and into the engine combustor; and means for positioning the fuel metering means within the second cooling air chamber enabling the cooling air supply means to both cool the fuel metering means and control the fuel supply rate of fuel supplied by the fuel metering means to the combustor.« less

Cracking a tricuspid perimount bioprosthesis to optimize a second transcatheter sapien valve-in-valve placement.

PubMed

Brown, Stephen C; Cools, Bjorn; Gewillig, Marc

2016-09-01

Bioprosthetic valves degenerate over time. Transcatheter valve-in-valve procedures have become an attractive alternative to surgery. However, every valve increasingly diminishes the diameter of the valvar orifice. We report a 12-year-old female who had a previous transcatheter tricuspid valve-in-valve procedure; cracking the ring of a Carpentier Edwards Perimount valve by means of an ultrahigh pressure balloon allowed implantation of a further larger percutaneous valve. The advantage of this novel approach permits enlarging the inner valve diameter and may facilitate future interventions and prolong time to surgery. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Comparison of acute elastic recoil between the SAPIEN-XT and SAPIEN valves in transfemoral-transcatheter aortic valve replacement.

PubMed

Garg, Aatish; Parashar, Akhil; Agarwal, Shikhar; Aksoy, Olcay; Hammadah, Muhammad; Poddar, Kanhaiya Lal; Puri, Rishi; Svensson, Lars G; Krishnaswamy, Amar; Tuzcu, E Murat; Kapadia, Samir R

2015-02-15

The SAPIEN-XT is a newer generation balloon-expandable valve created of cobalt chromium frame, as opposed to the stainless steel frame used in the older generation SAPIEN valve. We sought to determine if there was difference in acute recoil between the two valves. All patients who underwent transfemoral-transcatheter aortic valve replacement using the SAPIEN-XT valve at the Cleveland Clinic were included. Recoil was measured using biplane cine-angiographic image analysis of valve deployment. Acute recoil was defined as [(valve diameter at maximal balloon inflation) - (valve diameter after deflation)]/valve diameter at maximal balloon inflation (reported as percentage). Patients undergoing SAPIEN valve implantation were used as the comparison group. Among the 23 mm valves, the mean (standard deviation-SD) acute recoil was 2.77% (1.14) for the SAPIEN valve as compared to 3.75% (1.52) for the SAPIEN XT valve (P = 0.04). Among the 26 mm valves, the mean (SD) acute recoil was 2.85% (1.4) for the SAPIEN valve as compared to 4.32% (1.63) for the SAPIEN XT valve (P = 0.01). Multivariable linear regression analysis demonstrated significantly greater adjusted recoil in the SAPIEN XT valves as compared to the SAPIEN valves by 1.43% [(95% CI: 0.69-2.17), P < 0.001]. However, the residual peak gradient was less for SAPIEN XT compared to SAPIEN valves [18.86 mm Hg versus 23.53 mm Hg (P = 0.01)]. Additionally, no difference in paravalvular leak was noted between the two valve types (P = 0.78). The SAPIEN XT valves had significantly greater acute recoil after deployment compared to the SAPIEN valves. Implications of this difference in acute recoil on valve performance need to be investigated in future studies. © 2014 Wiley Periodicals, Inc.

Left ventricular mass regression after aortic valve replacement with the new Mitroflow 12A pericardial bioprosthesis.

PubMed

García-Bengochea, José; Sierra, Juan; González-Juanatey, José R; Rubio, José; Vega, Marino; Fernández, Angel L; Sánchez, Daniel

2006-05-01

The study aim was to evaluate the durability of the new Mitroflow 12A pericardial bioprosthesis and to assess ventricular mass regression after aortic valve replacement (AVR) in patients with small valves. A total of 326 Mitroflow 12A pericardial bioprostheses was implanted without any other associated valve procedure. The mean patient age was 73.5 +/- 6.1 years; 252 patients (78.0%) were in NYHA class III/IV. Small valves (19 and 21 mm) were implanted in 212 patients (65.6%). The total follow up period was 837.1 patient-years (pt-yr). A subset of 61 patients with preoperative stenosis was selected and submitted to conventional echo-Doppler assessment at a mean period of 11.1 months after surgery. Hospital mortality was 8.6%. At eight years of follow up, survival was 57.1%. Freedom from structural valve deterioration (SVD) was 86.5% per pt-yr. Mean gradients were significantly reduced postoperatively for each valve size (to 18 +/- 8 mmHg for 19-mm valves and 12 +/- 4 mmHg for 25-mm valves). The effective orifice area (EOA) was also increased significantly for all valve sizes (to 1.1 +/- 0.1 cm2 for 19-mm valves and 1.8 +/- 0.2 cm2 for 25-mm valves). The left ventricular mass index (LVMI) decreased significantly, from 177 +/- 29 to 136 +/- 22 g/m2 for the 19-mm valve, and from 200 +/- 42 to 132 +/- 22 g/m2 for the 25-mm valve. The EOA index (EOAI) showed mismatch for the 19- and 21-mm valves (0.74 and 0.82 cm2/m2, respectively). The diagrammatic calculation between LVMI and relative wall thickness after surgery showed that 29.7% of patients achieved a normal pattern of remodeling (including 19- and 21-mm valves), despite various degrees of mismatch. The new Mitroflow 12A pericardial bioprosthesis showed an absence of mechanical failure after an eight-year follow up, with a satisfactory rate of SVD. Significant reductions in LVMI and improved ventricular geometry were observed, despite the small valve sizes implanted.

Multiple source/multiple target fluid transfer apparatus

DOEpatents

Turner, Terry D.

1997-01-01

A fluid transfer apparatus includes: a) a plurality of orifices for connection with fluid sources; b) a plurality of orifices for connection with fluid targets; c) a set of fluid source conduits and fluid target conduits associated with the orifices; d) a pump fluidically interposed between the source and target conduits to transfer fluid therebetween; e) a purge gas conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass a purge gas under pressure; f) a solvent conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass solvent, the solvent conduit including a solvent valve; g) pump control means for controlling operation of the pump; h) purge gas valve control means for controlling operation of the purge gas valve to selectively impart flow of purge gas to the fluid source conduits, fluid target conduits and pump; i) solvent valve control means for controlling operation of the solvent valve to selectively impart flow of solvent to the fluid source conduits, fluid target conduits and pump; and j) source and target valve control means for controlling operation of the fluid source conduit valves and the fluid target conduit valves to selectively impart passage of fluid between a selected one of the fluid source conduits and a selected one of the fluid target conduits through the pump and to enable passage of solvent or purge gas through selected fluid source conduits and selected fluid target conduits.

Multiple source/multiple target fluid transfer apparatus

DOEpatents

Turner, T.D.

1997-08-26

A fluid transfer apparatus includes: (a) a plurality of orifices for connection with fluid sources; (b) a plurality of orifices for connection with fluid targets; (c) a set of fluid source conduits and fluid target conduits associated with the orifices; (d) a pump fluidically interposed between the source and target conduits to transfer fluid there between; (e) a purge gas conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass a purge gas under pressure; (f) a solvent conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass solvent, the solvent conduit including a solvent valve; (g) pump control means for controlling operation of the pump; (h) purge gas valve control means for controlling operation of the purge gas valve to selectively impart flow of purge gas to the fluid source conduits, fluid target conduits and pump; (i) solvent valve control means for controlling operation of the solvent valve to selectively impart flow of solvent to the fluid source conduits, fluid target conduits and pump; and (j) source and target valve control means for controlling operation of the fluid source conduit valves and the fluid target conduit valves to selectively impart passage of fluid between a selected one of the fluid source conduits and a selected one of the fluid target conduits through the pump and to enable passage of solvent or purge gas through selected fluid source conduits and selected fluid target conduits. 6 figs.

Trans-catheter aortic valve implantation after previous aortic homograft surgery.

PubMed

Drews, Thorsten; Pasic, Miralem; Buz, Semih; Unbehaun, Axel

2011-12-01

In patients with previous heart surgery, the operative risk is elevated during conventional aortic valve re-operations. Trans-catheter aortic valve implantation is a new method for the treatment of high-risk patients. Nevertheless, this new procedure carries potential risks in patients with previous homograft implantation in aortic position. Between April 2008 and February 2011, 345 consecutive patients (mean EuroSCORE (European System for Cardiac Operative Risk Evaluation): 38 ± 20%; mean Society of Thoracic Surgeons (STS) Mortality Score: 19 ± 16%; mean age: 80 ± 8 years; 111 men and 234 women) underwent trans-apical aortic valve implantation. In three patients, previous aortic homograft implantation had been performed. Homograft degeneration causing combined valve stenosis and incompetence made re-operation necessary. In all three patients, the aortic valve could be implanted using the trans-apical approach, and the procedure was successful. In two patients, there was slight paravalvular leakage of the aortic prosthesis and the other patient had slight central leakage. Neither ostium obstruction nor mitral valve damage was observed. Trans-catheter valve implantation can be performed successfully after previous homograft implantation. Particular care should be taken to achieve optimal valve positioning, not to obstruct the ostium of the coronary vessels due to the changed anatomic situation and not to cause annulus rupture. Copyright © 2011 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Operating Temperatures of a Sodium-Cooled Exhaust Valve as Measured by a Thermocouple

NASA Technical Reports Server (NTRS)

Sanders, J C; Wilsted, H D; Mulcahy, B A

1943-01-01

Report presents the results of a thermocouple installed in the crown of a sodium-cooled exhaust valve. The valve was tested in an air-cooled engine cylinder and valve temperatures under various engine operating conditions were determined. A temperature of 1337 degrees F. was observed at a fuel-air ratio of 0.064, a brake mean effective pressure of 179 pounds per square inch, and an engine speed of 2000 r.p.m. Fuel-air ratio was found to have a large influence on valve temperature, but cooling-air pressure and variation in spark advance had little effect. An increase in engine power by change of speed or mean effective pressure increased the valve temperature. It was found that the temperature of the rear-spark-plug bushing was not a satisfactory indication of the temperature of the exhaust valve.

Reduced-impact sliding pressure control valve for pneumatic hammer drill

DOEpatents

Polsky, Yarom [Oak Ridge, TN; Grubelich, Mark C [Albuquerque, NM; Vaughn, Mark R [Albuquerque, NM

2012-05-15

A method and means of minimizing the effect of elastic valve recoil in impact applications, such as percussive drilling, where sliding spool valves used inside the percussive device are subject to poor positioning control due to elastic recoil effects experienced when the valve impacts a stroke limiting surface. The improved valve design reduces the reflected velocity of the valve by using either an energy damping material, or a valve assembly with internal damping built-in, to dissipate the compression stress wave produced during impact.

Minimally invasive right lateral thoracotomy without aortic cross-clamping: an attractive alternative to repeat sternotomy for reoperative mitral valve surgery.

PubMed

Umakanthan, Ramanan; Petracek, Michael R; Leacche, Marzia; Solenkova, Nataliya V; Eagle, Susan S; Thompson, Annemarie; Ahmad, Rashid M; Greelish, James P; Ball, Stephen K; Hoff, Steven J; Absi, Tarek S; Balaguer, Jorge M; Byrne, John G

2010-03-01

The study aim was to determine the safety and benefits of minimally invasive mitral valve surgery without aortic cross-clamping for mitral valve surgery after previous cardiac surgery. Between January 2006 and August 2008, a total of 90 consecutive patients (38 females, 52 males; mean age 66 +/- 9 years) underwent minimally invasive mitral valve surgery after having undergone previous cardiac surgery. Of these patients, 80 (89%) underwent mitral valve replacement and 10 (11%) mitral valve repair utilizing a small (5 cm) right lateral thoracotomy along the 4th or 5th intercostal space under fibrillatory arrest (mean temperature 28 +/- 2 degrees C). The predicted mortality, calculated using the Society of Thoracic Surgeons (STS) algorithm, was compared to the observed mortality. The mean ejection fraction was 45 +/- 13%, mean NYHA class 3 +/- 1, while 66 patients (73%) had previous coronary artery bypass grafting and 37 (41%) had previous valve surgery. Twenty-six patients (29%) underwent non-elective surgery. Cardiopulmonary bypass was instituted through axillary (n = 19), femoral (n = 70) or direct use aortic (n = 1) cannulation. Operative mortality was 2% (2/90), lower than the STS-predicted mortality of 7%. Three patients (3%) developed acute renal failure postoperatively, one patient (1%) required new-onset hemodialysis, and one (1%) developed postoperative stroke. No patients developed postoperative myocardial infarction. The mean postoperative packed red blood cell transfusion requirement at 48 h was 2 +/- 3 units. Minimally invasive right thoracotomy without aortic cross-clamping is an excellent alternative to conventional redo-sternotomy for reoperative mitral valve surgery. The present study confirmed that this technique is safe and effective in reducing operative mortality in high-risk patients undergoing reoperative cardiac surgery.

Intracranial Hypertension: Medication and Surgery

MedlinePlus

... the atrium (heart). Many shunts used today have programmable valves, which means that the valves are externally adjustable. The advantage of a programmable valve is that after surgery, a physician can ...

[Ministernotomy: a preliminary experience in heart valve surgery].

PubMed

Kovarević, Pavle; Mihajlović, Bogoljub; Velicki, Lazar; Redzek, Aleksandar; Ivanović, Vladimir; Komazec, Nikola

2011-05-01

The last decade of the 20th century brought up a significant development in the field of minimally invasive approaches to the valvular heart surgery. Potential benefits of this method are: good esthetic appearance, reduced pain, reduction of postoperative hemorrhage and incidence of surgical site infection, shorter postoperative intensive care units (ICU) period and overall in-hospital period. Partial upper median stemotomy currently presents as a state-of-the art method for minimally invasive surgery of cardiac valves. The aim of this study was to report on initial experience in application of this surgical method in the surgery of mitral and aortic valves. The study was designed and conducted in a prospective manner and included all the patients who underwent minimally invasive cardiac valve surgery through the partial upper median stemotomy during the period November 2008 - August 2009. We analyzed the data on mean age of patients, mean extubation time, mean postoperative drainage, mean duration of hospital stay, as well as on occurance of postoperative complications (postoperative bleeding, surgical site infection and cerebrovascular insult). During the observed period, in the Institute for Cardiovascular Diseases of Vojvodina, Clinic for Cardiovascular Surgery, 17 ministernotomies were performed, with 14 aortic valve replacements (82.35%) and 3 mitral valve replacements (17.65%). Mean age of the patients was 60.78 +/- 12.99 years (64.71% males, 35.29% females). Mean extubation time was 12.53 +/- 8.87 hours with 23.5% of the patients extubated in less than 8 hours. Mean duration of hospital stay was 12.35 +/- 10.17 days (in 29.4% of the patients less than 8 days). Mean postoperative drainage was 547.06 +/- 335.2 mL. Postoperative complications included: bleeding (5.88%) and cerebrovascular insult (5.88%). One patient (5.88%) required conversion to full stemotomy. Partial upper median sternotomy represents the optimal surgical method for the interventions on the whole ascendant aorta (including aortic valve) and mitral valve through the roof of the left atrium, with a few significant advantages compared to the full stemotomy surgical approach.

Valve thrombosis following transcatheter aortic valve implantation: a systematic review.

PubMed

Córdoba-Soriano, Juan G; Puri, Rishi; Amat-Santos, Ignacio; Ribeiro, Henrique B; Abdul-Jawad Altisent, Omar; del Trigo, María; Paradis, Jean-Michel; Dumont, Eric; Urena, Marina; Rodés-Cabau, Josep

2015-03-01

Despite the rapid global uptake of transcatheter aortic valve implantation, valve trombosis has yet to be systematically evaluated in this field. The aim of this study was to determine the clinical characteristics, diagnostic criteria, and treatment outcomes of patients diagnosed with valve thrombosis following transcatheter aortic valve implantation through a systematic review of published data. Literature published between 2002 and 2012 on valve thrombosis as a complication of transcatheter aortic valve implantation was identified through a systematic electronic search. A total of 11 publications were identified, describing 16 patients (mean age, 80 [5] years, 65% men). All but 1 patient (94%) received a balloon-expandable valve. All patients received dual antiplatelet therapy immediately following the procedure and continued to take either mono- or dual antiplatelet therapy at the time of valve thrombosis diagnosis. Valve thrombosis was diagnosed at a median of 6 months post-procedure, with progressive dyspnea being the most common symptom. A significant increase in transvalvular gradient (from 10 [4] to 40 [12] mmHg) was the most common echocardiographic feature, in addition to leaflet thickening. Thrombus was not directly visualized with echocardiography. Three patients underwent valve explantation, and the remaining received warfarin, which effectively restored the mean transvalvular gradient to baseline within 2 months. Systemic embolism was not a feature of valve thrombosis post-transcatheter aortic valve implantation. Although a rare, yet likely under-reported complication of post-transcatheter aortic valve implantation, progressive dyspnea coupled with an increasing transvalvular gradient on echocardiography within the months following the intervention likely signifies valve thrombosis. While direct thrombus visualization appears difficult, prompt initiation of oral anticoagulation therapy effectively restores baseline valve function. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

One-year outcomes after rapid-deployment aortic valve replacement.

PubMed

Young, Christopher; Laufer, Günther; Kocher, Alfred; Solinas, Marco; Alamanni, Francesco; Polvani, Gianluca; Podesser, Bruno K; Aramendi, Jose Ignacio; Arribas, Jose; Bouchot, Olivier; Livi, Ugolino; Massetti, Massimo; Terp, Kim; Giot, Christophe; Glauber, Mattia

2018-02-01

The goals of rapid-deployment aortic valve replacement include facilitation of minimally invasive surgery and reduced aortic crossclamp time. We report the short-term outcomes of a series of 493 patients undergoing rapid-deployment aortic valve replacement with the EDWARDS INTUITY valve system (Edwards Lifesciences, LLC, Irvine, Calif). Assessing Standard oF Care and Clinical Outcomes UsiNg the EDWARDS INTUITY VAlve SysTem in a European multI-center, Active, pOst-market surveillaNce Study was a prospective, multicenter (n = 26) European registry designed to evaluate the safety and performance of the valve system. During rapid-deployment aortic valve replacement, device technical success and crossclamp time were assessed. Procedural outcomes, hemodynamic performance, and various adverse events and clinical outcomes were evaluated up to 2 years. Between 2012 and 2014, 493 of 517 enrolled patients successfully received implants with the study valve (95.4% technical success). Mean crossclamp times for 163 full sternotomies, 128 mini-upper sternotomies, and 36 right anterior thoracotomies isolated aortic valve replacements were 47.3, 52.0, and 73.3 minutes, respectively. Mean follow-up was 1.8 years, with 870 total patient-years of follow-up. Mean effective orifice area increased from 0.72 (baseline) to 1.88 cm 2 , and mean pressure gradient decreased from 47.6 to 9.6 mm Hg (1 year). Mean effective orifice area index increased (0.39-1.01 cm 2 /m 2 ), and 28 of 287 patients (9.8%) exhibited severe prosthesis-patient mismatch at 1 year. After 1 year, 68.1% and 21.7% of patients were in New York Heart Association class I and II, respectively. Freedom from death, major bleeding, major perivalvular leak, reoperation, and device explant at 1 year were 0.935, 0.939, 0.976, 0.975, and 0.983, respectively. These results demonstrate commendable safety and performance of the test valve system over the short term in a broad European setting. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Clinical Implication of Transaortic Mitral Pannus Removal During Repeat Cardiac Surgery for Patients With Mechanical Mitral Valve.

PubMed

Park, Byungjoon; Sung, Kiick; Park, Pyo Won

2018-01-25

This study aimed to evaluate the safety and feasibility of transaortic mitral pannus removal (TMPR).Methods and Results:Between 2004 and 2016, 34 patients (median age, 57 years; 30 women) with rheumatic disease underwent pannus removal on the ventricular side of a mechanical mitral valve through the aortic valve during reoperation. The median time interval from the previous surgery was 14 years. TMPR was performed after removal of the mechanical aortic valve (n=21) or diseased native aortic valve (n=11). TMPR was performed in 2 patients through a normal aortic valve. The mitral transprosthetic mean pressure gradient (TMPG) was ≥5 mmHg in 11 patients, including 3 with prosthetic valve malfunction. Prophylactic TMPR was performed in 23 patients. There were no early deaths. Concomitant operations included 22 tricuspid valve surgeries (13 replacements, 15 repairs) and 32 aortic valve replacements (24 repeats, 8 primary). The mean gradient in patients who had mitral TMPG ≥5 mmHg was significantly decreased from 6.46±1.1 to 4.37±1.17 mmHg at discharge (P<0.001). No mechanical valve malfunction was apparent on last echocardiography. TMPR is a safe and effective procedure for patients with malfunction or stenosis of a mechanical mitral valve and may be considered an alternative approach in patients with pannus overgrowth in such valves.

Consequences of intravascular lymphatic valve properties: a study of contraction timing in a multi-lymphangion model

PubMed Central

Macaskill, Charlie; Davis, Michael J.; Moore, James E.

2016-01-01

The observed properties of valves in collecting lymphatic vessels include transmural pressure-dependent bias to the open state and hysteresis. The bias may reduce resistance to flow when the vessel is functioning as a conduit. However, lymphatic pumping implies a streamwise increase in mean pressure across each valve, suggesting that the bias is then potentially unhelpful. Lymph pumping by a model of several collecting lymphatic vessel segments (lymphangions) in series, which incorporated these properties, was investigated under conditions of adverse pressure difference while varying the refractory period between active muscular contractions and the inter-lymphangion contraction delay. It was found that many combinations of the timing parameters and the adverse pressure difference led to one or more intermediate valves remaining open instead of switching between open and closed states during repetitive contraction cycles. Cyclic valve switching was reliably indicated if the mean pressure in a lymphangion over a cycle was higher than that in the lymphangion upstream, but either lack of or very brief valve closure could cause mean pressure to be lower downstream. Widely separated combinations of refractory period and delay time were found to produce the greatest flow-rate for a given pressure difference. The efficiency of pumping was always maximized by a long refractory period and lymphangion contraction starting when the contraction of the lymphangion immediately upstream was peaking. By means of an ex vivo experiment, it was verified that intermediate valves in a chain of pumping lymphangions can remain open, while the lymphangions on either side of the open valve continue to execute contractions. PMID:26747501

Valve assembly for internal combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wakeman, R.J.; Shea, S.F.

1989-09-05

This patent describes an improvement in a valve assembly for an internal combustion engine of the type including a valve having a valve stem, a valve guideway for mounting this valve for reciprocal strokes between opened and seated position, and spring means for biasing the valve into the seated position. The improvement comprising a valve spool of greater cross-sectional diameter as compared to the valve stem, and a valve spool guideway within which the valve spool is movable during the strokes of the valve, an upper surface of the valve spool and a portion of the spool guideway collectively establishingmore » a damper chamber which varies in volume during the valve strokes. a feed passage for introducing oil into the damper chamber, and a bleed passage for discharging oil from the damper chamber. The bleed passages each laterally opening into the valve spool guideway.« less

Dual-latching solenoid-actuated valve assembly

NASA Technical Reports Server (NTRS)

Brudnicki, Myron J. (Inventor); Yang, Jeff (Inventor)

1994-01-01

A tube-type shutoff valve is electrically positioned to its open or closed position by a concentric electromagnetic solenoid. The valve is dual latching in that the armature of the solenoid maintains the sliding tube of the valve in an open or closed position by means of permanent magnets which are effective when current is not supplied to the solenoid. The valve may also be actuated manually.

Study on the characters of control valve for ammonia injection in selective catalytic reduction (SCR) system of coal-fired power plant

NASA Astrophysics Data System (ADS)

Yao, Che; Li, Tao; Zhang, Hong; Zhou, Yanming

2017-08-01

In this paper, the characters of two control valves used for ammonia injection in SCR system are discussed. The linear/quadratic character between pressure drop/outlet flow rate and valve opening/dynamic pressure inlet are investigated using computational fluid dynamic (CFD) and response surface analysis (RSA) methods. The results show that the linear character of brake valve is significantly better than butterfly valve, which means that the brake valve is more suitable for ammonia injection adjustment than the butterfly valve.

All metal valve structure for gas systems

DOEpatents

Baker, Ray W.; Pawlak, Donald A.; Ramey, Alford J.

1984-11-13

A valve assembly with a resilient metal seat member is disclosed for providing a gas-tight seal in a gas handling system. The valve assembly also includes a valve element for sealing against the valve seat member; and an actuating means for operating the valve element. The valve seat member is a one-piece stainless steel ring having a central valve port and peripheral mounting flange, and an annular corrugation in between. A groove between the first and second ridges serves as a flexure zone during operation of the valve member and thus provides the seating pressure between the inner ridge or valve seat and the valve element. The outer annular ridge has a diameter less than said valve element to limit the seating motion of the valve element, preventing non-elastic deformation of the seat member.

All-metal valve structure for gas systems

DOEpatents

Baker, R.W.; Pawlak, D.A.; Ramey, A.J.

1982-06-10

A valve assembly with a resilient metal seat member is disclosed for providing a gas-tight seal in a gas handling system. The valve assembly also includes a valve element for sealing against the valve seat member; and an actuating means for operating the valve element. The valve seat member is a one-piece stainless steel ring having a central valve port and peripheral mounting flange, and an annular corrugation in between. A groove between the first and second ridges serves as a flexure zone during operation of the valve member and thus provides the seating pressure between the inner ridge or valve seat and the valve element. The outer annular ridge has a diameter less than said valve element to limit the seating motion of the valve element, preventing non-elastic deformation of the seat member.

Valve stem and packing assembly

DOEpatents

Wordin, J.J.

1991-09-03

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

Valve stem and packing assembly

DOEpatents

Wordin, John J.

1991-01-01

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

Impact of Chronic Rheumatic Valve Diseases on Large Vessels.

PubMed

Altunbas, Gokhan; Yuce, Murat; Ozer, Hasan O; Davutoglu, Vedat; Ercan, Suleyman; Kizilkan, Nese; Bilici, Muhammet

2016-01-01

BACKGROUND AND AIM OF STUDY: Rheumatic valvular heart disease, which remains a common health problem in developing countries, has numerous consequences on the heart chambers and circulation. The study aim was to investigate the effects of chronic rheumatic valve disease on the diameters of the descending aorta (DA) and inferior vena cava (IVC). METHODS: A total of 88 patients with echocardiographically documented rheumatic valvular heart disease and 112 healthy controls were enrolled into the study. All patients underwent detailed echocardiographic examinations, while their height and body weight were recorded and adjusted to their body surface area. RESULTS: The most common involvement was mitral valve disease, followed by aortic valve disease and tricuspid valve disease. The mean diameter of the DA (indexed to BSA) was 1.79 ± 0.49 cm for patients and 1.53 ± 0.41 for controls (p <0.001). The mean diameter of the IVC (indexed to BSA) was 1.69 ± 0.73 for patients and 1.38 ± 0.35 cm for controls (p <0.001). There was a significant positive correlation between mitral valve mean gradient and IVC diameter (p = 0.01, r = 0.18). There were also strong associations between the mitral valve area and the diameters of the DA (p = 0.001, r = -0.239) and IVC (p <0.001, r = -0.246). CONCLUSION: Rheumatic valve disease, especially mitral stenosis, was closely related to remodeling of the great vessels.

40 CFR 60.481 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... bypassing of equipment without stopping production. Quarter means a 3-month period; the first quarter... process. Connector means flanged, screwed, or other joined fittings used to connect two pipe lines or a... means two block valves connected in series with a bleed valve or line that can vent the line between the...

40 CFR 60.481 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... bypassing of equipment without stopping production. Quarter means a 3-month period; the first quarter... process. Connector means flanged, screwed, or other joined fittings used to connect two pipe lines or a... means two block valves connected in series with a bleed valve or line that can vent the line between the...

40 CFR 60.481 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... bypassing of equipment without stopping production. Quarter means a 3-month period; the first quarter... process. Connector means flanged, screwed, or other joined fittings used to connect two pipe lines or a... means two block valves connected in series with a bleed valve or line that can vent the line between the...

40 CFR 60.481 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... bypassing of equipment without stopping production. Quarter means a 3-month period; the first quarter... process. Connector means flanged, screwed, or other joined fittings used to connect two pipe lines or a... means two block valves connected in series with a bleed valve or line that can vent the line between the...

40 CFR 60.481 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... bypassing of equipment without stopping production. Quarter means a 3-month period; the first quarter... process. Connector means flanged, screwed, or other joined fittings used to connect two pipe lines or a... means two block valves connected in series with a bleed valve or line that can vent the line between the...

Development and Characterization a Single-Active-Chamber Piezoelectric Membrane Pump with Multiple Passive Check Valves.

PubMed

Zhang, Ronghui; You, Feng; Lv, Zhihan; He, Zhaocheng; Wang, Haiwei; Huang, Ling

2016-12-12

In order to prevent the backward flow of piezoelectric pumps, this paper presents a single-active-chamber piezoelectric membrane pump with multiple passive check valves. Under the condition of a fixed total number of passive check valves, by means of changing the inlet valves and outlet valves' configuration, the pumping characteristics in terms of flow rate and backpressure are experimentally investigated. Like the maximum flow rate and backpressure, the testing results show that the optimal frequencies are significantly affected by changes in the number inlet valves and outlet valves. The variation ratios of the maximum flow rate and the maximum backpressure are up to 66% and less than 20%, respectively. Furthermore, the piezoelectric pump generally demonstrates very similar flow rate and backpressure characteristics when the number of inlet valves in one kind of configuration is the same as that of outlet valves in another configuration. The comparison indicates that the backflow from the pumping chamber to inlet is basically the same as the backflow from the outlet to the pumping chamber. No matter whether the number of inlet valves or the number of outlet valves is increased, the backflow can be effectively reduced. In addition, the backpressure fluctuation can be significantly suppressed with an increase of either inlet valves or outlet valves. It also means that the pump can prevent the backflow more effectively at the cost of power consumption. The pump is very suitable for conditions where more accurate flow rates are needed and wear and fatigue of check valves often occur.

Measurements of droplet velocity and size downstream of the moving valves of a four-valve engine with manifold injection, operated under isothermal steady suction conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Posylkin, M.; Taylor, A.M.K.P.; Whitelaw, J.H.

The four-valve head of a VTEC engine was mounted on an open cylinder and the valves and fuel injection system operated as in the engine with a rotational speed of 1,200 rpm. Local measurements of droplet characteristics were obtained with a phase-Doppler velocimeter and iso-octane injected over 5 ms intervals, corresponding to 36 crank angle degrees, with manifold depression of 20 mbar. The results show that most of the fuel droplets were located close to the liner and on the side of the cylinder adjacent to the exhaust valves. In the plane of the measurement, 10 mm below TDC, themore » liquid flux diminished as the initiation of injection was advanced before opening of the inlet valves. With injection with the inlet valves closed, there were two waves of droplets, one from each of the two valves and separated by 60 deg CA and both with the Sauter mean diameter of about 120 {micro}m. With injection with the inlet valves open, most of the droplets emerged from the main inlet valve and with Sauter mean diameters of about 50 {micro}m, smaller than those of the unconfined spray.« less

The Contegra bovine valved jugular vein conduit for pediatric RVOT reconstruction: 4 years experience with 108 patients.

PubMed

Breymann, Thomas; Boethig, Dietmar; Goerg, Reiner; Thies, Wolf-Rüdiger

2004-01-01

Porcine xenografts for pediatric right ventricular outflow tractus (RVOT) reconstruction lack durability, homografts lack availability. The Contegra is a valve bearing bovine jugular vein. It is tear resistant, well pliable, and permits RVOT reconstruction without further foreign material. The 108 Contegras implanted in Bad Oeynhausen from May 1999 until January 2003 represent the largest single-center Contegra experience. The study gives the preliminary results from a controlled prospective multicenter trial aiming at FDA admission. The patients' diagnoses were truncus arteriosus (27%), double outlet right ventricle (14%), tetralogy of Fallot (48%), transposition of great arteries (6%), rare complex malformation (2%), and Ross procedure (1%). Fifty-eight were female. Age: 2 days to 20.1 years, mean: 4.3 +/- 5.2, median: 1.8 years. Thirty-three had primary implantations, 38 previous repairs, 37 conduit exchange. Total follow-up time: 227.7 years, mean: 2.1. About 848 echos were evaluated. Early mortality: 7.4% (8 patients); 1 late death. None was Contegra-related. Echocardiographic controls showed no relevant average valvular gradient development. Trace and mild-grade insufficiency is frequent, without tendency to increase. Average insufficiency is between trace and mild unless RV pressure remains under 100 mmHg. Average individual right/left ventricle length ratios did not increase over time. We saw no relevant conduit dilatation and no leaflet calcification. Pulmonary artery stenoses had mainly extrinsic reasons. At 4 years, freedom- from- event rates were: reoperation for Conduit inflow or valvular degeneration: 100%; reoperation for pulmonary artery branch stenoses (n = 10) 86%, explantation (n = 4): 92%. Survival: 91.7%. Contegra is worth being considered as an alternative to homografts.

[Simultaneous interventions on the ascending portion, arch of the aorta and cardiac valves in patients with Marfan's syndrome].

PubMed

Belov, Iu V; Stepanenko, A B; Gens, A P; Charchian, E R; Savichev, D D

2007-01-01

Simultaneous surgical interventions on the aorta and valvular system of the heart were performed in four patients presenting with aortic dissections and aneurysms conditioned by Marfan's syndrome. The following reconstructive operations were carried out: 1) prosthetic repair of the aortic valve and the ascending portion of the aorta by means of a valve-containing conduit with replantation of the openings of the coronary arteries into the side of the prosthesis according to the Benthall - De Bono technique, annuloplasty of the tricuspid valve according to the De Vega technique, valvuloplasty of the mitral valve by the Alferi technique; 2) grafting of the aortic valve and the ascending portion of the aorta by means of a valve-containing conduit with replantation of the openings of the coronary arteries according to the Kabrol's technique, plasty of the tricuspid valve by the De Vega technique; 3) prosthetic repair of the aortic arch with distal wedge-like excision of the membrane of the dissection and directing the blood flow along the both channels, plasty of the mitral valve, plasty of the aortic valve and the ascending portion of the aorta with a valve-containing conduit, accompanied by replantation of the openings of the coronary arteries into the side of the graft according to the Benthall - De Bono technique; (4) plasty of the mitral valve with a disk graft through the fibrous ring of the aortic valve, prosthetic repair of the aortic valve and the ascending portion of the aorta with a valve-containing conduit, accompanied by replantation of the openings of the coronary arteries into the side according to the Benthall-De Bono technique.

Drug-Induced by Systemic Lupus Erythematosus Presenting as Recurrent Pericardial Effusion After Mitral Valve Repair.

PubMed

Haydari, Aghigh; Sabzi, Feridoun; Dabiri, Samsam; Poormotaabed, Alireza

2017-09-01

We report a patient presented with recurrent pericardial effusion caused by drug-induced systemic lupus Erythematosus (SLE) following mitral valve repair. The surgery was complicated by hemiparesis and convulsion in early postoperative period. The patient had been received carbamazepine for a paroxysmal seizure that occurred following mitral valve repair. The post operative computed tomography showed embolic stroke and its sequel (seizure) that treated with carbamazepine. In the 3rd month of follow-up, however, hemiparesis recovered by physiotherapy but carbamazepine was not discontinued as by request of neurologist. In the 6th month of surgery, the patient admitted by dyspnea and massive pericardial effusion that treated by subxiphoid drainage. This event was re occurred in two times in a short time frame and each event treated by surgical approach. The serologic exam in the last admission revealed drug-induced lupus erythematosus. The carbamazepine as an anti convulsive drug has been described to cause LE like disease in multiple case reports. Laboratory exam exhibited the possibility of carbamazepine-induced lupus in our case, with the extremely rare presentation of recurrent massive pericardial effusion.

Fracture of the wire stent in a Carpentier-Edwards porcine bioprosthesis.

PubMed

Griffin, S; Bouboulis, N; Holden, M P

1993-05-01

A 60-year-old woman underwent mitral and aortic valve replacement with Carpentier-Edwards supra-annular bioprosthesis in 1986. Six years later rapidly progressing exercise dyspnea and orthopnea made hospital admission necessary. At chest x-ray and cardiac catheter examination one of the wire struts of the mitral bioprosthesis was found completely broken causing cusp prolapse. Surgical findings at reoperation confirmed the diagnosis. No apparent cause of the stent fracture was found.

Valve system incorporating single failure protection logic

DOEpatents

Ryan, Rodger; Timmerman, Walter J. H.

1980-01-01

A valve system incorporating single failure protective logic. The system consists of a valve combination or composite valve which allows actuation or de-actuation of a device such as a hydraulic cylinder or other mechanism, integral with or separate from the valve assembly, by means of three independent input signals combined in a function commonly known as two-out-of-three logic. Using the input signals as independent and redundant actuation/de-actuation signals, a single signal failure, or failure of the corresponding valve or valve set, will neither prevent the desired action, nor cause the undesired action of the mechanism.

46 CFR 105.10-20 - Pressure vacuum relief valve.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in enclosed... 46 Shipping 4 2011-10-01 2011-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10...

46 CFR 105.10-20 - Pressure vacuum relief valve.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in enclosed... 46 Shipping 4 2010-10-01 2010-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10...

46 CFR 105.10-20 - Pressure vacuum relief valve.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in enclosed... 46 Shipping 4 2014-10-01 2014-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10...

46 CFR 105.10-20 - Pressure vacuum relief valve.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in enclosed... 46 Shipping 4 2012-10-01 2012-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10...

46 CFR 105.10-20 - Pressure vacuum relief valve.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Pressure vacuum relief valve. (a) The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of pressure or vacuum in enclosed... 46 Shipping 4 2013-10-01 2013-10-01 false Pressure vacuum relief valve. 105.10-20 Section 105.10...

Mechanical valve replacement in congenital heart disease.

PubMed

Fiane, A E; Lindberg, H L; Saatvedt, K; Svennevig, J L

1996-05-01

Mechanical valves are the prosthesis of choice in valve replacement in children. However, the problem of somatic growth leading to patient-valve mismatch remains present, and the appropriate anticoagulation regimen remains controversial. We present our experience of valve replacement in a young population over 20 years. Between 1972 and 1992, 48 patients (34 males and 14 females), mean age 11.2 years (range 0.4-27.4 years), underwent mechanical valve replacement at our institution. Aortic valve replacement was performed in 28 patients (58.3%), mitral valve replacement in 13 (27.1%), tricuspid valve replacement in six (12.5%) and pulmonary valve replacement in one patient (2.1%). The prostheses used were: St. Jude Medical (n = 2), Björk-Shiley (n = 14), Medtronic Hall (n = 16), Duromedics (n = 2) and CarboMedics (n = 14). Early mortality was 14.3%, 10.7% for aortic valve replacement and 30.8% for mitral valve replacement. Mean follow up for all patients was 8.3 years (range 0-22 years), with a total of 398 patient-years. Seven patients died during the follow up (17.1%). Survival after 10 years, including operative mortality, was 81% for aortic valve replacement, 33% for mitral valve replacement, 83% for tricuspid valve replacement and 100% for pulmonary valve replacement. All patients were anticoagulated with warfarin. In eight patients (16.7%) an antiplatelet drug (aspirin or dipyridamole) was added. Major events included paravalvular leak in six patients (1.5%/pty), valve thrombosis in five (mitral position in two, tricuspid in three) (1.3%/pty) and endocarditis in one patient (0.3%/pty). Minor thromboembolic events occurred in three patients (0.8%/pty) and minor hemorrhagic events in three (0.8%/pty). No patients developed hemolytic anemia and there was no case of structural failure. In our experience, mechanical prostheses in congenital heart disease were associated with significant morbidity and mortality, however long term survival after aortic valve replacement was good (81% at 10 years). Thromboembolic and hemorrhagic events were of minor significance. Atrio-ventricular valve replacement carried the highest risk of valve thrombosis and we now give warfarin and an antiplatelet drug to children undergoing mechanical valve implantation in this position.

THERMALLY OPERATED VAPOR VALVE

DOEpatents

Dorward, J.G. Jr.

1959-02-10

A valve is presented for use in a calutron to supply and control the vapor to be ionized. The invention provides a means readily operable from the exterior of the vacuum tank of the apparatuss without mechanical transmission of forces for the quick and accurate control of the ionizing arc by a corresponding control of gas flow theretos thereby producing an effective way of carefully regulating the operation of the calutron. The invention consists essentially of a tube member extending into the charge bottle of a calutron devices having a poppet type valve closing the lower end of the tube. An electrical heating means is provided in the valve stem to thermally vary the length of the stem to regulate the valve opening to control the flow of material from the charge bottle.

Transapical aortic valve implantation without angiography: proof of concept.

PubMed

Ferrari, Enrico; Sulzer, Christopher; Marcucci, Carlo; Rizzo, Elena; Tozzi, Piergiorgio; von Segesser, Ludwig K

2010-06-01

Cardiac computed tomographic scans, coronary angiograms, and aortographies are routinely performed in transcatheter heart valve therapies. Consequently, all patients are exposed to multiple contrast injections with a following risk of nephrotoxicity and postoperative renal failure. The transapical aortic valve implantation without angiography can prevent contrast-related complications. Between November 2008 and November 2009, 30 consecutive high-risk patients (16 female, 53.3%) underwent transapical aortic valve implantation without angiography. The landmarks identification, the stent-valve positioning, and the postoperative control were routinely performed under transesophageal echocardiogram and fluoroscopic visualization without contrast injections. Mean age was 80.1 +/- 8.7 years. Mean valve gradient, aortic orifice area, and ejection fraction were 60.3 +/- 20.9 mm Hg, 0.7 +/- 0.16 cm(2), and 0.526 +/- 0.128, respectively. Risk factors were pulmonary hypertension (60%), peripheral vascular disease (70%), chronic pulmonary disease (50%), previous cardiac surgery (13.3%), and chronic renal insufficiency (40%) (mean blood creatinine and urea levels: 96.8 +/- 54 microg/dL and 8.45 +/- 5.15 mmol/L). Average European System for Cardiac Operative Risk Evaluation was 32.2 +/- 13.3%. Valve deployment in the ideal landing zone was 96.7% successful and valve embolization occurred once. Thirty-day mortality was 10% (3 patients). Causes of death were the following: intraoperative ventricular rupture (conversion to sternotomy), right ventricular failure, and bilateral pneumonia. Stroke occurred in one patient at postoperative day 9. Renal failure (postoperative mean blood creatinine and urea levels: 91.1 +/- 66.8 microg/dL and 7.27 +/- 3.45 mmol/L), myocardial infarction, and atrioventricular block were not detected. Transapical aortic valve implantation without angiography requires a short learning curve and can be performed routinely by experienced teams. Our report confirms that this procedure is feasible and safe, and provides good results with low incidence of postoperative renal disorders. 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Prosthetic urinary sphincter

NASA Technical Reports Server (NTRS)

Helms, C. R.; Smyly, H. M. (Inventor)

1981-01-01

A pump/valve unit for controlling the inflation and deflation of a urethral collar in a prosthetic urinary sphincter device is described. A compressible bulb pump defining a reservoir was integrated with a valve unit for implantation. The valve unit includes a movable valve member operable by depression of a flexible portion of the valve unit housing for controlling fluid flow between the reservoir and collar; and a pressure sensing means which operates the valve member to relieve an excess pressure in the collar should too much pressure be applied by the patient.

Cost-effectiveness of homograft heart valve replacement surgery: an introductory study.

PubMed

Yaghoubi, Mohsen; Aghayan, Hamid Reza; Arjmand, Babak; Emami-Razavi, Seyed Hassan

2011-05-01

The clinical effectiveness of heart valve replacement surgery has been well documented. Mechanical and homograft valves are used routinely for replacement of damaged heart valves. Homograft valves are produced in our country but we import the mechanical valves. To our knowledge the cost-effectiveness of homograft valve has not been assessed. The objective of the present study was to compare the cost-effectiveness of homograft valve replacement with mechanical valve replacement surgery. Our samples were selected from 200 patients that underwent homograft and mechanical heart valve replacement surgery in Imam-Khomeini hospital (2000-2005). In each group we enrolled 30 patients. Quality of life was measured using the SF-36 questionnaire and utility was measured in quality-adjusted life years (QALYs). For each group we calculated the price of heart valve and hospitalization charges. Finally the cost-effectiveness of each treatment modalities were summarized as costs per QALYs gained. Forty male and twenty female participated in the study. The mean score of quality of life was 66.06 (SD = 9.22) in homograft group and 57.85 (SD = 11.30) in mechanical group (P < 0.05). The mean QALYs gained in homograft group was 0.67 more than mechanical group. The incremental cost-effectiveness ratio (ICER) revealed a cost savings of 1,067 US$ for each QALY gained in homograft group. Despite limitation of this introductory study, we concluded that homograft valve replacement was more effective and less expensive than mechanical valve. These findings can encourage healthcare managers and policy makers to support the production of homograft valves and allocate more recourse for developing such activities.

Lymphangiogenesis is increased in heart valve endocarditis.

PubMed

Niinimäki, Eetu; Mennander, Ari A; Paavonen, Timo; Kholová, Ivana

2016-09-15

Inflammation-associated lymphangiogenesis (IAL) has been identified as part of several acute and chronic inflammation. Sparse data exist on lymphatics during endocarditis. Fifty-two patients with surgically resected valves were included. Endocarditis was present in 18 aortic and 10 mitral valves. Controls consisted of 15 degenerative aortic and 9 degenerative mitral valves. There were 22 males with endocarditis and 17 males in controls. The mean age was 58 (SD 15) years with endocarditis vs. 62 (SD 13) years for controls. Lymphatics were detected by podoplanin antibody immunohistochemistry and morphometrical analysis was performed. The lymphatic density in endocarditis was 833 (SD 529) vessels/mm(2) (range 0-1707) as compared with 39 (SD 60) vessels/mm(2) (range 0-250) in controls (p=0.000). In endocarditis, the mean lymphatic size was 153 (SD 372) μm(2) ranging from 1 to 2034μm(2), whereas it was 30 (SD 29) μm(2), with maximum 90μm(2) and minimum 2μm(2) in controls (p=0.000). IAL is increased in valves with endocarditis as compared with controls. Lymphatics in heart valves may provide a novel means for treatment strategies against endocarditis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Advanced technology for space shuttle auxiliary propellant valves

NASA Technical Reports Server (NTRS)

Wichmann, H.

1973-01-01

Valves for the gaseous hydrogen/gaseous oxygen shuttle auxiliary propulsion system are required to feature low leakage over a wide temperature range coupled with high cycle life, long term compatibility and minimum maintenance. In addition, those valves used as thruster shutoff valves must feature fast response characteristics to achieve small, repeatable minimum impulse bits. These valve technology problems are solved by developing unique valve components such as sealing closures, guidance devices, and actuation means and by demonstrating two prototype valve concepts. One of the prototype valves is cycled over one million cycles without exceeding a leakage rate of 27 scc's per hour at 450 psia helium inlet pressure throughout the cycling program.

Pulse-modulated dual-gas control subsystem for space cabin atmosphere

NASA Technical Reports Server (NTRS)

Jackson, J. K.

1974-01-01

An atmosphere control subsystem (ACS) was developed for use in a closed manned cabin, such as the Space Shuttle Orbiter. This subsystem uses the Perkin Elmer mass spectrometer for continuous measurement of major atmospheric constituents (H2, H2O, N2, O2, and CO2). The O2 and N2 analog signals are used as inputs to the controller, which produces a pulse-frequency-modulated output to operate the N2 gas admission solenoid valve and an on-off signal to operate the O2 valve. The proportional controller characteristic results in improved control accuracy as compared with previously used on-off controllers having significant dead-band. A 60-day evaluation test was performed on the ACS during which operation was measured at various values of control setpoint and simulated cabin leakage.

FLUID PRESSURE AND CAM OPERATED VACUUM VALVE

DOEpatents

Batzer, T.H.

1963-11-26

An ultra-high vacuum valve that is bakable, reusable, and capable of being quickly opened and closed is described. A translationally movable valve gate having an annular ridge is adapted to contact an annular soft metal gasket disposed at the valve seat such that the soft metal gasket extends beyond the annular ridge on all sides. The valve gate is closed, by first laterally aligning the valve gate with the valve seat and then bringing the valve gate and valve seat into seating contact by the translational movement of a ramp-like wedging means that engages similar ramp-like stractures at the base of the valve gate to force the valve gate into essentially pressureless contact with the annular soft metal gasket. This gasket is then pressurized from beneath by a fluid thereby effecting a vacuura tight seal between the gasket and the ridge. (AEC)

Identical tricuspid ring sizing in simultaneous functional tricuspid and mitral valve repair: A simple and effective strategy.

PubMed

Huffman, Lynn C; Nelson, Jennifer S; Lehman, April N; Krajacic, Marguerite C; Bolling, Steven F

2014-02-01

Mitral valve repair for functional mitral regurgitation is common. Concomitant tricuspid valve repair for associated functional tricuspid regurgitation has gained favor. Controversy exists regarding annuloplasty sizing for tricuspid valve repair. Patients with heart failure having functional mitral regurgitation at the University of Michigan and undergoing mitral valve repair and tricuspid valve repair using identical sized annuloplasty rings between April 2007 and January 2012 were identified. Demographic and clinical records were retrospectively reviewed. Institutional review board approval was obtained for this study. Fifty-three patients met inclusion criteria. Mean age was 65 ± 1.7 years. Preoperative New York Heart Association class was III or IV in 81% (43) and mean left ventricular ejection fraction was 33% ± 2.2%. All patients had moderate or greater mitral regurgitation preoperatively and moderate or severe tricuspid regurgitation or a preoperative tricuspid annulus diameter greater than 40 mm. There was no 30-day mortality. Mean immediate postoperative tricuspid valve gradient was 1.75 ± 0.12 mm Hg and was 2.3 ± 0.19 mm Hg at 4 weeks. Four weeks postoperatively 88% (42/48) of patients had tricuspid regurgitation considered to be mild or less. There was no significant decline in right ventricular function by echocardiography over this time period. Functional tricuspid regurgitation can be repaired using an undersized rigid annuloplasty ring. Our data suggest that an identical sizing strategy can be used for tricuspid valve repair, as was used for mitral valve repair, without development of tricuspid stenosis or negative effect on right ventricular function. This method seems to prevent recurrence of significant tricuspid regurgitation. The technique we describe provides effective and reproducible results. Copyright © 2014 The American Association for Thoracic Surgery. All rights reserved.

Valve-sparing aortic root replacement in bicuspid aortic valves: a reasonable option?

PubMed

Aicher, Diana; Langer, Frank; Kissinger, Anke; Lausberg, Henning; Fries, Roland; Schäfers, Hans-Joachim

2004-11-01

Aortic dilatation occurs in many patients with bicuspid aortic valves. We have added root replacement using the remodeling technique originally designed for tricuspid aortic valves to bicuspid aortic valve repair for treatment of the dilated root. We compared the results of remodeling in bicuspid aortic valves with those in tricuspid aortic valves. From October 1995 through January 2004, 60 patients underwent root remodeling for bicuspid aortic valves (group A), and 130 patients underwent root remodeling for tricuspid aortic valves (group B). Correction of cusp prolapse was more often performed in group A (group A, 50/60; group B, 47/130; P < .0001). Transthoracic echocardiography was performed at 1 week, 6 and 12 months, and every year thereafter. Cumulative follow-up was 527 patient-years (mean, 2.9 +/- 2 years). No patient died in group A. Hospital mortality in group B was 5% (5/100; 95% confidence interval,1.6%-11.3%) after elective operations and 10% (3/30; 95% confidence interval, 2.1%-26.5%) after emergency operations. Mean systolic gradients were identical at 1 year (group A, 4.8 +/- 2.1 mm Hg; group B, 4.0 +/- 2 mm Hg) and 5 years (group A, 4.5 +/- 2.3 mm Hg; group B, 3.9 +/- 2.2 mm Hg). Freedom from aortic regurgitation of grade 2 or higher at 5 years was 96% in group A and 83% in group B ( P = .07), and freedom from reoperation at 5 years was 98% in group A and 98% in group B ( P = .73). Valve-sparing aortic replacement with root remodeling can be applied to aortic dilatation and a regurgitant bicuspid aortic valve. Hemodynamic function and valve stability of a repaired bicuspid aortic valve are comparable with those seen in cases of tricuspid anatomy.

14 CFR 121.239 - Oil valves.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Oil valves. 121.239 Section 121.239..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.239 Oil valves. (a) Each oil... oil shutoff means must not prevent feathering the propeller, unless equivalent safety provisions are...

14 CFR 121.239 - Oil valves.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Oil valves. 121.239 Section 121.239..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.239 Oil valves. (a) Each oil... oil shutoff means must not prevent feathering the propeller, unless equivalent safety provisions are...

49 CFR 195.450 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... remote control valve as follows: (1) Check valve means a valve that permits fluid to flow freely in one direction and contains a mechanism to automatically prevent flow in the other direction. (2) Remote control.... The RCV is usually operated by the supervisory control and data acquisition (SCADA) system. The...

49 CFR 195.450 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... remote control valve as follows: (1) Check valve means a valve that permits fluid to flow freely in one direction and contains a mechanism to automatically prevent flow in the other direction. (2) Remote control.... The RCV is usually operated by the supervisory control and data acquisition (SCADA) system. The...

49 CFR 195.450 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... remote control valve as follows: (1) Check valve means a valve that permits fluid to flow freely in one direction and contains a mechanism to automatically prevent flow in the other direction. (2) Remote control.... The RCV is usually operated by the supervisory control and data acquisition (SCADA) system. The...

49 CFR 195.450 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... remote control valve as follows: (1) Check valve means a valve that permits fluid to flow freely in one direction and contains a mechanism to automatically prevent flow in the other direction. (2) Remote control.... The RCV is usually operated by the supervisory control and data acquisition (SCADA) system. The...

49 CFR 195.450 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... remote control valve as follows: (1) Check valve means a valve that permits fluid to flow freely in one direction and contains a mechanism to automatically prevent flow in the other direction. (2) Remote control.... The RCV is usually operated by the supervisory control and data acquisition (SCADA) system. The...

14 CFR 121.239 - Oil valves.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Oil valves. 121.239 Section 121.239..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.239 Oil valves. (a) Each oil... oil shutoff means must not prevent feathering the propeller, unless equivalent safety provisions are...

14 CFR 121.239 - Oil valves.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Oil valves. 121.239 Section 121.239..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.239 Oil valves. (a) Each oil... oil shutoff means must not prevent feathering the propeller, unless equivalent safety provisions are...

14 CFR 121.239 - Oil valves.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Oil valves. 121.239 Section 121.239..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.239 Oil valves. (a) Each oil... oil shutoff means must not prevent feathering the propeller, unless equivalent safety provisions are...

The silent and apparent neurological injury in transcatheter aortic valve implantation study (SANITY): concept, design and rationale.

PubMed

Fanning, Jonathon P; Wesley, Allan J; Platts, David G; Walters, Darren L; Eeles, Eamonn M; Seco, Michael; Tronstad, Oystein; Strugnell, Wendy; Barnett, Adrian G; Clarke, Andrew J; Bellapart, Judith; Vallely, Michael P; Tesar, Peter J; Fraser, John F

2014-04-05

The incidence of clinically apparent stroke in transcatheter aortic valve implantation (TAVI) exceeds that of any other procedure performed by interventional cardiologists and, in the index admission, occurs more than twice as frequently with TAVI than with surgical aortic valve replacement (SAVR). However, this represents only a small component of the vast burden of neurological injury that occurs during TAVI, with recent evidence suggesting that many strokes are clinically silent or only subtly apparent. Additionally, insult may manifest as slight neurocognitive dysfunction rather than overt neurological deficits. Characterisation of the incidence and underlying aetiology of these neurological events may lead to identification of currently unrecognised neuroprotective strategies. The Silent and Apparent Neurological Injury in TAVI (SANITY) Study is a prospective, multicentre, observational study comparing the incidence of neurological injury after TAVI versus SAVR. It introduces an intensive, standardised, formal neurologic and neurocognitive disease assessment for all aortic valve recipients, regardless of intervention (SAVR, TAVI), valve-type (bioprosthetic, Edwards SAPIEN-XT) or access route (sternotomy, transfemoral, transapical or transaortic). Comprehensive monitoring of neurological insult will also be recorded to more fully define and compare the neurological burden of the procedures and identify targets for harm minimisation strategies. The SANITY study undertakes the most rigorous assessment of neurological injury reported in the literature to date. It attempts to accurately characterise the insult and sustained injury associated with both TAVI and SAVR in an attempt to advance understanding of this complication and associations thus allowing for improved patient selection and procedural modification.

The silent and apparent neurological injury in transcatheter aortic valve implantation study (SANITY): concept, design and rationale

PubMed Central

2014-01-01

Background The incidence of clinically apparent stroke in transcatheter aortic valve implantation (TAVI) exceeds that of any other procedure performed by interventional cardiologists and, in the index admission, occurs more than twice as frequently with TAVI than with surgical aortic valve replacement (SAVR). However, this represents only a small component of the vast burden of neurological injury that occurs during TAVI, with recent evidence suggesting that many strokes are clinically silent or only subtly apparent. Additionally, insult may manifest as slight neurocognitive dysfunction rather than overt neurological deficits. Characterisation of the incidence and underlying aetiology of these neurological events may lead to identification of currently unrecognised neuroprotective strategies. Methods The Silent and Apparent Neurological Injury in TAVI (SANITY) Study is a prospective, multicentre, observational study comparing the incidence of neurological injury after TAVI versus SAVR. It introduces an intensive, standardised, formal neurologic and neurocognitive disease assessment for all aortic valve recipients, regardless of intervention (SAVR, TAVI), valve-type (bioprosthetic, Edwards SAPIEN-XT) or access route (sternotomy, transfemoral, transapical or transaortic). Comprehensive monitoring of neurological insult will also be recorded to more fully define and compare the neurological burden of the procedures and identify targets for harm minimisation strategies. Discussion The SANITY study undertakes the most rigorous assessment of neurological injury reported in the literature to date. It attempts to accurately characterise the insult and sustained injury associated with both TAVI and SAVR in an attempt to advance understanding of this complication and associations thus allowing for improved patient selection and procedural modification. PMID:24708720

Rotary distributor type fuel injection pump

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klopfer, K.H.; Dordjevic, I.; Higgins, M.C.

1993-07-20

In a fuel injection pump having a pump body and distributor rotor in coaxial alignment, the pump body is described having a pumping chamber provided by an annular arrangement of pumping plunger bores with axes extending generally radially outwardly from the axis of the distributor rotor, a pumping plunger mounted in each plunger bore for reciprocation, annular cam means surrounding the annular arrangement of plunger bores for reciprocating the pumping plungers to provide alternating intake and pumping strokes thereof for respectively supplying intake charges of fuel to the pumping chamber and delivering high pressure charges of fuel from the pumpingmore » chamber for fuel injection, a distributor head with a plurality of distributor outlets, the distributor rotor being rotatably mounted in the distributor head for distributing the high pressure charges of fuel to the distributor outlets; the improvement wherein the pump body and distributor rotor have a central coaxial bore extending there through and providing a valve bore intersecting the annular arrangement of plunger bores, the pump body providing an annular valve seat around the central bore between one end thereof away from the distributor rotor and the intersection of the valve bore and annular arrangement of plunger bores, an elongated valve member mounted in the valve bore having a sealing head at one end thereof engageable with the annular valve seat and extending from the sealing head toward the other end of the central bore, a fuel supply chamber connected to the one end of the central bore for supplying fuel to the pumping chamber, valve actuating means comprising an electromagnet at the other end of the valve member from the sealing head and operable when energized to shift the valve member in one axial direction thereof to one of its the positions, and means for shifting the valve member in the opposite axial direction thereof to its other position when the electromagnet is deenergized.« less

Impact of pannus formation on hemodynamic dysfunction of prosthetic aortic valve: pannus extent and its relationship to prosthetic valve motion and degree of stenosis.

PubMed

Koo, Hyun Jung; Ha, Hojin; Kang, Joon-Won; Kim, Jeong A; Song, Jae-Kwan; Kim, Hwa Jung; Lim, Tae-Hwan; Yang, Dong Hyun

2018-02-19

Although pannus is an important cause of prosthetic valve dysfunction, the minimum pannus size that can induce hemodynamic dysfunction has not yet been determined. This study investigated the correlation between the limitation of motion (LOM) of the prosthetic valve and pannus extent and determined the pannus extent that could induce severe aortic stenosis. This study included 49 patients who underwent mechanical aortic valve replacement (AVR) and showed pannus on cardiac computed tomography (CT). Pannus width, ratio of pannus width to valve diameter, pannus area, effective orifice area, encroachment ratio by pannus, pannus involvement angle and percent LOM of mechanical valves were evaluated on CT. Transvalvular peak velocity (TPV) and transvalvular pressure gradient (TPG) were measured by transesophageal echocardiography to determine the degree of aortic stenosis. The relationship between percent LOM of the prosthetic valve and pannus extent and the cut-off of pannus extent required to induce severe aortic stenosis were evaluated. The mean interval between AVR and pannus formation was 11 years and was longer in patients with than without severe aortic stenosis (14.0 vs. 7.3 years). On CT, the percent LOM of the prosthetic valve was significantly associated with the extent of pannus only in patients with pannus involvement angle > 180° (r = 0.55-0.68, P < 0.01). Pannus width, effective orifice area, and encroachment ratio were significantly associated with increased TPV and TPG (r = 0.51-0.62, P < 0.01). Pannus width > 3.5 mm, pannus width/valve inner diameter > 0.15, and encroachment ratio > 0.14 were significantly associated with severe aortic stenosis (TPV > 4 m/s; mean TPG ≥ 35 mmHg), with c-indices of 0.74-079 (P < 0.005). CT-derived pannus extent parameters are good indicators of significant hemodynamic changes with increased TPV and mean TPG.

Triple-orifice valve repair in severe Barlow disease with multiple-jet mitral regurgitation: report of mid-term experience.

PubMed

Fucci, Carlo; Faggiano, Pompilio; Nardi, Matilde; D'Aloia, Antonio; Coletti, Giuseppe; De Cicco, Giuseppe; Latini, Leonardo; Vizzardi, Enrico; Lorusso, Roberto

2013-09-10

Barlow disease represents a surgical challenge for mitral valve repair (MR) in the presence of mitral insufficiency (MI) with multiple regurgitant jets. We hereby present our mid-term experience using a modified edge-to-edge technique to address this peculiar MI. From March 2003 till December 2010, 25 consecutive patients (mean age 54 ± 7 years, 14 males) affected by severe Barlow disease with multiple regurgitant jets were submitted to MR. Preoperative transesophageal echo (TEE) in all the cases showed at least 2 regurgitant jets, involving one or both leaflets in more than one segment. In all the patients, a triple orifice valve (TOV) repair with annuloplasty was performed. Intra-operative TEE and postoperative transthoracic echocardiography (TTE) were carried out to evaluate results of the TOV repair. There was no in-hospital death and one late death (non-cardiac related). At intra-operative TEE, the three orifices showed a mean total valve area of 2.9 ± 0.1cm(2) (range 2.5-3.3 cm(2)) with no residual regurgitation (2 cases of trivial MI) and no sign of valve stenosis (mean transvalvular gradient 4.6 ± 1.5 mmHg). At follow up (mean 38 ± 22 months), TTE showed favourable MR and no recurrence of significant MI (6 cases of trivial and 1 of mild MI). Stress TTE was performed in 5 cases showing persistent effective valve function (2 cases of trivial MI at peak exercise). All the patients showed significant NYHA functional class improvement. This report indicates that the TOV technique is effective in correcting complex Barlow mitral valves with multiple jets. Further studies are required to confirm long-term applicability and durability in more numerous clinical cases. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Ross operation using a bovine bioprosthetic valve with autologous pericardial conduit in the pulmonary position.

PubMed Central

Urrea, M S; Herrera, V; Rey, A; Vargas, J

1993-01-01

Between 1 February 1992 and 1 March 1993, we performed Ross's aortic replacement in 7 men and 4 women with rheumatic heart disease. The patients' ages ranged from 22 to 60 years (mean, 41 years). All 11 patients had aortic valve disease; 2 also had mitral valve disease. In all patients, the right ventricular outflow tract was reconstructed using an autologous pericardial conduit containing a bovine cardiac valve bioprosthesis manufactured at our institution. The 2 patients who had mitral valve disease underwent a concomitant mitral valvuloplasty. In 1 patient, minimal aortic regurgitation was documented by means of transesophageal echocardiography immediately after the cessation of cardiopulmonary bypass, but no hemodynamic compromise was noted. In another patient, mediastinal exploration was required for bleeding, 3.5 hours postoperatively. The follow-up period ranged from 6 to 16 months (mean, 11.3 months). Results were assessed by means of clinical and transesophageal echocardiographic studies. No infection or technical failure was encountered. No patient died. All patients remain asymptomatic, and follow-up echocardiography has revealed no transaortic or transpulmonary gradient. The Ross operation was chosen for this group of patients because it avoids the use of mechanical valves and subsequent anticoagulant therapy. Most of our patients have a low income and a history of noncompliance with the strict postoperative drug regimen. Although the short-term results have been excellent with the Ross operation and our combination bioprosthesis, long-term evaluation is needed. PMID:8298323

Bioprosthetic Aortic Valve Durability: A Meta-Regression of Published Studies.

PubMed

Wang, Mansen; Furnary, Anthony P; Li, Hsin-Fang; Grunkemeier, Gary L

2017-09-01

To compare structural valve deterioration (SVD) among bioprosthetic aortic valve types, a PubMed search found 54 papers containing SVD-free curves extending to at least 10 years. The curves were digitized and fit to Weibull distributions, and the mean times to valve failure (MTTF) were calculated. Twelve valve models were collapsed into four valve types: Medtronic (Medtronic, Minneapolis, MN) and Edwards (Edwards Lifesciences, Irvine, CA) porcine; and Sorin (Sorin Group [now LivaNova], London, United Kingdom) and Edwards pericardial. Meta-regression found MTTF was associated with the patient's age, publication year, SVD definition, and valve type. Sorin pericardial valves had significantly lower risk-adjusted MTTF (higher SVD risk), and there were no significant differences in MTTF among the other three valve types. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Optimal prosthesis sizing in transcatheter aortic valve implantation by exclusive use of three-dimensional transoesophageal echocardiography.

PubMed

Kretzschmar, Daniel; Lauten, Alexander; Goebel, Bjoern; Doenst, Torsten; Poerner, Tudor C; Ferrari, Markus; Figulla, Hans R; Hamadanchi, Ali

2016-03-01

The assessment of aortic annular size is critical, and inappropriate sizing is thought to be a main reason of paravalvular aortic regurgitation. Multidetector computed tomograph is associated with the risk of contrast nephropathy. For optimal evaluation of the complex structure of the aortic annulus, three-dimensional (3D)-methods should be used. We therefore sought to determine the value of 3D-transoesophageal echocardiography (3D-TEE) for appropriate sizing. Hundred and one patients (mean age 81·4 years) with symptomatic aortic valve stenosis (AS) and high surgical risk profile (mean log. EuroScore 28·8%) being scheduled for transcatheter aortic valve implantation (TAVI) were included. 2D- and 3D-TEE were performed before the procedure to evaluate the aortic annulus diameter. Maximum, minimum and mean (max diameter + min diameter/2) annulus diameters were 24·7, 23·1 and 23. 9 mm in 3D-TEE and compared to 22·6 mm in 2D-TEE (P<0·001; 0·07; <0·001). The interobserver variability for 3D-TEE was low with a mean difference of 0·18 mm compared to 2D-TEE with 0·59 mm. The application of 3D-TEE caused a change of prosthesis size selection in 40% of patients compared to 2D-TEE. In this study, we implanted three different types of catheter-mounted valves (Edwards-SAPIEN(™) XT valve, CoreValve(™) and JenaValve(™) ). Final angiography confirmed valve competence (mild insufficiency) in 91%, and there was no aortic regurgitation greater than moderate in the follow-up echocardiographic evaluation. Assessment of aortic annulus dimensions for TAVI size selection can safely be performed with 3D-TEE only. Based on our results with significantly higher annulus diameter compared to 2D-TEE, we recommend 3D-TEE to reduce prosthesis undersizing. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Structural deterioration of the Freestyle aortic valve: mode of presentation and mechanisms.

PubMed

Mohammadi, Siamak; Baillot, Richard; Voisine, Pierre; Mathieu, Patrick; Dagenais, François

2006-08-01

Structural valve deterioration is the major cause of bioprosthetic valve failure. Because of the unique design features and anti-calcification treatment of the Freestyle (Medtronic Inc, Minneapolis, Minn) stentless bioprosthesis, development of structural valve deterioration may differ in comparison with other bioprosthetic valves. This study evaluates the mechanisms and clinical presentation of structural valve deterioration in the Freestyle stentless bioprosthesis. Between January 1993 and August 2005, 608 patients underwent aortic valve replacement with a Freestyle stentless bioprosthesis. The implantation technique was subcoronary in 475 patients and a root replacement in 133 patients. Mean overall follow-up was 5.6 +/- 3.4 years. Follow-up was complete in all patients. Clinical and echocardiographic follow-ups were conducted prospectively. Freedom from structural valve deterioration was 95.8% at 10 years. Twelve patients showed evidence of structural valve deterioration and underwent reoperation for aortic regurgitation (n = 10) or aortic stenosis (n = 2). The mean age of patients with structural valve deterioration was significantly lower than patients without structural valve deterioration (62.6 +/- 8.2 years vs 68.6 +/- 8.3 years, P = .02). The median time between implantation and explantation was 8.7 years (range: 1.9-13.3 years). Eleven structural valve deteriorations occurred after subcoronary implantation, and 1 structural valve deterioration occurred after root implantation (P = .4). The mechanisms of structural valve deterioration were leaflet tears in 10 patients (6 in the left coronary cusp and 4 in the right coronary cusp), severe valve calcification in 1 patient, and cusp fibrosis in 1 patient. The interval between onset of symptoms and reoperation was acute or subacute in 10 patients. At 10 years, the Freestyle stentless bioprosthesis shows excellent freedom from structural valve deterioration. Structural valve deterioration in the Freestyle stentless bioprosthesis relates to leaflet tear with minimal calcification in the majority of cases. Because of the fast onset of symptoms with leaflet tear, patients with a Freestyle stentless bioprosthesis should be informed of the preferential mode of failure and time-frame of symptoms.

Society of Thoracic Surgeons Risk Score predicts hospital charges and resource use after aortic valve replacement.

PubMed

Arnaoutakis, George J; George, Timothy J; Alejo, Diane E; Merlo, Christian A; Baumgartner, William A; Cameron, Duke E; Shah, Ashish S

2011-09-01

The impact of Society of Thoracic Surgeons predicted mortality risk score on resource use has not been previously studied. We hypothesize that increasing Society of Thoracic Surgeons risk scores in patients undergoing aortic valve replacement are associated with greater hospital charges. Clinical and financial data for patients undergoing aortic valve replacement at The Johns Hopkins Hospital over a 10-year period (January 2000 to December 2009) were reviewed. The current Society of Thoracic Surgeons formula (v2.61) for in-hospital mortality was used for all patients. After stratification into risk quartiles, index admission hospital charges were compared across risk strata with rank-sum and Kruskal-Wallis tests. Linear regression and Spearman's coefficient assessed correlation and goodness of fit. Multivariable analysis assessed relative contributions of individual variables on overall charges. A total of 553 patients underwent aortic valve replacement during the study period. Average predicted mortality was 2.9% (±3.4) and actual mortality was 3.4% for aortic valve replacement. Median charges were greater in the upper quartile of patients undergoing aortic valve replacement (quartiles 1-3, $39,949 [interquartile range, 32,708-51,323] vs quartile 4, $62,301 [interquartile range, 45,952-97,103], P < .01]. On univariate linear regression, there was a positive correlation between Society of Thoracic Surgeons risk score and log-transformed charges (coefficient, 0.06; 95% confidence interval, 0.05-0.07; P < .01). Spearman's correlation R-value was 0.51. This positive correlation persisted in risk-adjusted multivariable linear regression. Each 1% increase in Society of Thoracic Surgeons risk score was associated with an added $3000 in hospital charges. This is the first study to show that increasing Society of Thoracic Surgeons risk score predicts greater charges after aortic valve replacement. As competing therapies, such as percutaneous valve replacement, emerge to treat high-risk patients, these results serve as a benchmark to compare resource use. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Downhole surge valve for earth boring apparatus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, D.W.

1990-05-29

This patent describes a boring tool assembly having an underground percussion mole boring tool powered by a working fluid, the tool being driven through the earth by a rigid drill string pushed by a drilling frame, and a downhole valve assembly fixed between the downhole end of the drill string and the too, the improved downhole valve assembly. It comprises: a valve spool having an open first end, a closed second end and a peripheral sidewall, an axial bore extending partly through the valve spool from the open first end; a radial passage adjacent the closed second and of themore » valve spool, the radial passage extending radially from the valve spool axial bore through the valve spool peripheral sidewall; an axial groove in the peripheral sidewall of the valve spool; a valve body having a first end, a second end and a peripheral sidewall, an axial bore extending through the valve body, the valve spool extending through the valve body axial bore so that the second end of the valve body is adjacent the closed second end of the valve spool, the valve spool being axially moveable within the valve body axial bore; an axial slot; a free-floating key element; a valve housing; and seal means.« less

Longitudinal Hemodynamics of Transcatheter and Surgical Aortic Valves in the PARTNER Trial.

PubMed

Douglas, Pamela S; Leon, Martin B; Mack, Michael J; Svensson, Lars G; Webb, John G; Hahn, Rebecca T; Pibarot, Philippe; Weissman, Neil J; Miller, D Craig; Kapadia, Samir; Herrmann, Howard C; Kodali, Susheel K; Makkar, Raj R; Thourani, Vinod H; Lerakis, Stamatios; Lowry, Ashley M; Rajeswaran, Jeevanantham; Finn, Matthew T; Alu, Maria C; Smith, Craig R; Blackstone, Eugene H

2017-11-01

Use of transcatheter aortic valve replacement (TAVR) for severe aortic stenosis is growing rapidly. However, to our knowledge, the durability of these prostheses is incompletely defined. To determine the midterm hemodynamic performance of balloon-expandable transcatheter heart valves. In this study, we analyzed core laboratory-generated data from echocardiograms of all patients enrolled in the Placement of Aortic Transcatheter Valves (PARTNER) 1 Trial with successful TAVR or surgical AVR (SAVR) obtained preimplantation and at 7 days, 1 and 6 months, and 1, 2, 3, 4, and 5 years postimplantation. Patients from continued access observational studies were included for comparison. Successful implantation after randomization to TAVR vs SAVR (PARTNER 1A; TAVR, n = 321; SAVR, n = 313), TAVR vs medical treatment (PARTNER 1B; TAVR, n = 165), and continued access (TAVR, n = 1996). Five-year echocardiogram data were available for 424 patients after TAVR and 49 after SAVR. Death or reintervention for aortic valve structural indications, measured using aortic valve mean gradient, effective orifice area, Doppler velocity index, and evidence of hemodynamic deterioration by reintervention, adverse hemodynamics, or transvalvular regurgitation. Of 2795 included patients, the mean (SD) age was 84.5 (7.1) years, and 1313 (47.0%) were female. Population hemodynamic trends derived from nonlinear mixed-effects models showed small early favorable changes in the first few months post-TAVR, with a decrease of -2.9 mm Hg in aortic valve mean gradient, an increase of 0.028 in Doppler velocity index, and an increase of 0.09 cm2 in effective orifice area. There was relative stability at a median follow-up of 3.1 (maximum, 5) years. Moderate/severe transvalvular regurgitation was noted in 89 patients (3.7%) after TAVR and increased over time. Patients with SAVR showed no significant changes. In TAVR, death/reintervention was associated with lower ejection fraction, stroke volume index, and aortic valve mean gradient up to 3 years, with no association with Doppler velocity index or valve area. Reintervention occurred in 20 patients (0.8%) after TAVR and in 1 (0.3%) after SAVR and became less frequent over time. Reintervention was caused by structural deterioration of transcatheter heart valves in only 5 patients. Severely abnormal hemodynamics on echocardiograms were also infrequent and not associated with excess death or reintervention for either TAVR or SAVR. This large, core laboratory-based study of transcatheter heart valves revealed excellent durability of the transcatheter heart valves and SAVR. Abnormal findings in individual patients, suggestive of valve thrombosis or structural deterioration, were rare in this protocol-driven database and require further investigation. clinicaltrials.gov Identifier: NCT00530894.

Hydraulically-actuated operating system for an electric circuit breaker

DOEpatents

Barkan, Philip; Imam, Imdad

1978-01-01

This hydraulically-actuated operating system comprises a cylinder, a piston movable therein in an opening direction to open a circuit breaker, and an accumulator for supplying pressurized liquid to a piston-actuating space within the cylinder. A normally-closed valve between the accumulator and the actuating space is openable to allow pressurized liquid from the accumulator to flow through the valve into the actuating space to drive the piston in an opening direction. A vent is located hydraulically between the actuating space and the valve for affording communication between said actuating space and a low pressure region. Flow control means is provided for restricting leakage through said vent to a rate that prevents said leakage from substantially detracting from the development of pressure within said actuatng space during the period from initial opening of the valve to the time when said piston has moved through most of its opening stroke. Following such period and while the valve is still open, said flow control means allows effective leakage through said vent. The accumulator has a limited capacity that results in the pressure within said actuating space decaying promptly to a low value as a result of effective leakage through said vent after the piston has moved through a circuit-breaker opening stroke and while the valve is in its open state. Means is provided for resetting the valve to its closed state in response to said pressure decay in the actuating space.

CT predictors of post-procedural aortic regurgitation in patients referred for transcatheter aortic valve implantation: an analysis of 105 patients.

PubMed

Marwan, Mohamed; Achenbach, Stephan; Ensminger, Stefan M; Pflederer, Tobias; Ropers, Dieter; Ludwig, Josef; Weyand, Michael; Daniel, Werner G; Arnold, Martin

2013-06-01

Cardiac computed tomography (CT) allows accurate and detailed analysis of the anatomy of the aortic root and valve, including quantification of calcium. We evaluated the correlation between different CT parameters and the degree of post-procedural aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) using the balloon-expandable Edwards Sapien prosthesis. Pre-intervention contrast-enhanced dual source CT data sets of 105 consecutive patients (48 males, mean age 81 ± 6 years, mean logEuroSCORE 34 ± 13%) with symptomatic severe aortic valve stenosis referred for TAVI using the Edwards Sapien prosthesis (Edwards lifesciences, Inc., CA, USA) were analysed. The degrees of aortic valve commissural calcification and annular calcification were visually assessed on a scale from 0 to 3. Furthermore, the degree of aortic valve calcification as quantified by the Agatston score, aortic annulus eccentricity, aortic diameter at the level of the sinus of valsalva and at the sinotubular junction were assessed. Early post-procedural AR was assessed using aortography. Significant AR was defined as angiographic AR of at least moderate degree (AR ≥ 2). Visual assessment of the degree of aortic annular calcification as well as the Agatston score of aortic valve calcium correlated weakly, yet significantly with the degree of post-procedural AR (r = 0.31 and 0.24, p = 0.001 and 0.013, respectively). Compared to patients with AR < 2, patients with AR ≥ 2 showed more severe calcification of the aortic annulus (mean visual scores 1.9 ± 0.6 vs. 1.5 ± 0.6, p = 0.003) as well as higher aortic valve Agatston scores (1,517 ± 861 vs. 1,062 ± 688, p = 0.005). Visual score for commissural calcification did not differ significantly between both groups (mean scores 2.4 ± 0.5 vs. 2.5 ± 0.5, respectively, p = 0.117). No significant correlation was observed between the degree of AR and commissural calcification, aortic annulus eccentricity index or aortic diameters. The extent of aortic valve annular calcification, but not of commissural calcification, predicts significant post-procedural AR in patients referred for TAVI using the balloon-expandable Edwards Sapiens prosthesis.

Kelly mud saver valve sub

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reddoch, J.A.

1986-12-02

A mud saver valve is described for preventing drilling mud from escaping from a kelly when a drill string is broken below the kelly, the valve comprising: a tubular valve body having first and second ends, the first end being provided with means for attachment in fluid communicating relationship with the kelly, the second end being provided with means for attachment to the drill string; an annular seat fixed in the interior of the valve body adjacent its first end; a tubular closure member within the valve body. The closure member is provided with a selectively closed seating end formore » seating in valve closing engagement with the annular seat, an open non-seating end in fluid communicating relationship with the drill string, and an annular expansion in the outer diameter of the closure member adjacent the seating end; a top and bottom spacer ring disposed in sliding relationship around the tubular closure member intermediate the annular expansion and the non-seating end of the closure member. The spacer ring and annular expansion cooperatively define an annular chamber around the closure member; and a helical spring disposed around the closure member towards the annular seat.« less

Additively Manufactured Main Fuel Valve Housing

NASA Technical Reports Server (NTRS)

Eddleman, David; Richard, Jim

2015-01-01

Selective Laser Melting (SLM) was utilized to fabricate a liquid hydrogen valve housing typical of those found in rocket engines and main propulsion systems. The SLM process allowed for a valve geometry that would be difficult, if not impossible to fabricate by traditional means. Several valve bodies were built by different SLM suppliers and assembled with valve internals. The assemblies were then tested with liquid nitrogen and operated as desired. One unit was also burst tested and sectioned for materials analysis. The design, test results, and planned testing are presented herein.

Cerebral hemorrhage in infective endocarditis caused by Actinobacillus actinomycetemcomitans.

PubMed

Lin, Gen-Min; Chu, Kai-Min; Juan, Chun-Jung; Chang, Feng-Yee

2007-11-01

Cerebral hemorrhage occurs rarely in endocarditis caused by Actinobacillus actinomycetemcomitans. A 51-year-old man with a prosthetic mitral valve, who had been prophylactically treated (7 years) with warfarin, presented with intermittent fever. On admission, a Levine grade II/VI systolic cardiac murmur was detected. A transthoracic echocardiogram was negative for valve vegetation. Cefepime (1 g every 8 hours) was administered intravenously. On day 4, culturing of Gram-negative bacilli from blood and a transesophageal echocardiogram revealed a small oscillating filament attached to lateral mitral prosthetic ring on the atrial side. Ceftriaxone (2 g once daily) was started. Gait instability and left-side weakness developed abruptly 2 weeks later; brain magnetic resonance imaging revealed a hematoma over the right parietal-occipital lobe. Ceftriaxone was adjusted to 2 g every 12 hours. Actinobacillus actinomycetemcomitans was identified 3 weeks later. Recovery was achieved, with significant interval improvement and resolution of the cerebral lesions evident on CT.

Cardiac findings in Quarter Horses with heritable equine regional dermal asthenia.

PubMed

Brinkman, Erin L; Weed, Benjamin C; Patnaik, Sourav S; Brazile, Bryn L; Centini, Ryan M; Wills, Robert W; Olivier, Bari; Sledge, Dodd G; Cooley, Jim; Liao, Jun; Rashmir-Raven, Ann M

2017-03-01

OBJECTIVE To compare biomechanical and histologic features of heart valves and echocardiographic findings between Quarter Horses with and without heritable equine regional dermal asthenia (HERDA). DESIGN Prospective case-control study. ANIMALS 41 Quarter Horses. PROCEDURES Ultimate tensile strength (UTS) of aortic and mitral valve leaflets was assessed by biomechanical testing in 5 horses with HERDA and 5 horses without HERDA (controls). Histologic evaluation of aortic and mitral valves was performed for 6 HERDA-affected and 3 control horses. Echocardiography was performed in 14 HERDA-affected and 11 control horses. Biomechanical data and echocardiographic variables of interest were compared between groups by statistical analyses, RESULTS Mean values for mean and maximum UTS of heart valves were significantly lower in HERDA-affected horses than in controls. Blood vessels were identified in aortic valve leaflets of HERDA-affected but not control horses. Most echocardiographic data did not differ between groups. When the statistical model for echocardiographic measures was controlled for body weight, mean and maximum height and width of the aorta at the valve annulus in short-axis images were significantly associated with HERDA status and were smaller for affected horses. CONCLUSIONS AND CLINICAL RELEVANCE Lower UTS of heart valves in HERDA-affected horses, compared with those of control horses, supported that tissues other than skin with high fibrillar collagen content are abnormal in horses with HERDA. Lack of significant differences in most echocardiographic variables between affected and control horses suggested that echocardiography may not be useful to detect a substantial loss of heart valve tensile strength. Further investigation is warranted to confirm these findings. Studies in horses with HERDA may provide insight into cardiac abnormalities in people with collagen disorders.

Modified Ross procedure using a conduit with a synthetic valve.

PubMed

Takabayashi, Shin; Kado, Hideaki; Shiokawa, Yuichi; Fukae, Kouji; Nakano, Toshihide

2004-12-01

In the Ross procedure, a homograft conduit is commonly used in place of an autotransplanted pulmonary valve. Homograft availability may be a problem and has resulted in a search for alternatives. We performed a modified Ross procedure for right ventricular outflow tract reconstruction with a synthetic valved conduit as an alternative to homograft. Our early results of valvular and right ventricular function were evaluated in patients who used a conduit with a synthetic valve. Subjects consisted of 11 patients, who ranged in age from 5 to 22 years (12.0+/-4.9), and whose body weight ranged from 15.1 to 52.5 (34.3+/-14.4) kg. Indications for surgery were aortic stenosis (n=3), aortic stenosis and regurgitation (n=4), and aortic regurgitation (n=4). Right ventricular outflow tract reconstruction was performed using a hand-fashioned valved conduit prepared by sewing a 0.1 mm thick polytetrafluoroethylene sheet onto the luminal cavity of the 20-28 mm conduit. A conduit made with polytetrafluoroethylene was used in 8 patients, and a Dacron graft was used in 3 patients. There was no in-hospital or late mortality and angiocardiography at discharge revealed that all artificial valves remained active. The mean right atrial pressure and right ventricular end-diastolic pressure were not statistically different from preoperative values. The latest echocardiography (mean interval, 12.6 months) revealed that a mean pressure gradient across the synthetic valve was 11.4+/-11.1 mmHg and none of the patients had moderate or severe regurgitation. We demonstrated that a modified Ross procedure for right ventricular outflow tract reconstruction using a conduit with an appropriate synthetic valve is particularly effective in older children.

Serum gamma-glutamyltransferase activity is increased in patients with calcific aortic valve stenosis.

PubMed

Bozbas, Huseyin; Yildirir, Aylin; Demir, Ozlem; Cakmak, Abdulkadir; Karacaglar, Emir; Yilmaz, Mustafa; Eroglu, Serpil; Pirat, Bahar; Ozin, Bulent; Muderrisoglu, Haldun

2008-07-01

A growing body of data indicates an independent association between serum gamma-glutamyltransferase (GGT) activity, a marker of increased oxidative stress, and cardiovascular diseases. The process of calcific aortic valve disease has been shown to present characteristics of atherosclerosis. The study aim was to evaluate the possible role of serum GGT in patients with calcific aortic valve disease. The results of patients' echocardiography studies from 2005 for the presence of calcific aortic valve disease in the forms of aortic stenosis (AS) and aortic valve calcification (AVC) without significant valve stenosis, were retrospectively evaluated. Age-and gender-matched patients with normal aortic valve morphology were selected at random as a control group. A total of 383 patients was enrolled into the study (126 with AS, 133 with AVC, 124 controls). Serum GGT activity, along with other liver enzyme analyses and laboratory results, were determined and compared among the groups. Age, gender and clinical and laboratory results were similar among the three groups. Median serum GGT levels in the AS, AVC and control groups were 23.0 U/1 (mean 31.5 +/- 24.9 U/1), 22.0 U/1 (mean 27.6 +/- 18.6 U/) and 18.0 U/l (mean 22.4 +/- 16.4 U/l), respectively. Compared to controls, AS patients had significantly higher serum GGT and C-reactive protein levels, while the differences between AVC patients and controls for these parameters were not significant. The study results suggest that serum GGT activity is increased in patients with calcific AS. These increases seem to occur in advanced rather than milder forms of calcific aortic valve disease.

14 CFR 25.1025 - Oil valves.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Oil valves. 25.1025 Section 25.1025... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1025 Oil valves. (a) Each oil shutoff must meet the requirements of § 25.1189. (b) The closing of oil shutoff means may not prevent propeller...

14 CFR 25.1025 - Oil valves.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil valves. 25.1025 Section 25.1025... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1025 Oil valves. (a) Each oil shutoff must meet the requirements of § 25.1189. (b) The closing of oil shutoff means may not prevent propeller...

46 CFR 154.519 - Piping relief valves.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Process Piping Systems § 154.519 Piping relief valves. (a) The liquid relief valve that protects the cargo piping system from liquid pressure exceeding the design pressure must discharge into: (1) A cargo tank; or (2) A cargo vent mast if that vent mast has a means for the detection and removal of the liquid...

46 CFR 154.519 - Piping relief valves.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Process Piping Systems § 154.519 Piping relief valves. (a) The liquid relief valve that protects the cargo piping system from liquid pressure exceeding the design pressure must discharge into: (1) A cargo tank; or (2) A cargo vent mast if that vent mast has a means for the detection and removal of the liquid...

46 CFR 154.519 - Piping relief valves.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Process Piping Systems § 154.519 Piping relief valves. (a) The liquid relief valve that protects the cargo piping system from liquid pressure exceeding the design pressure must discharge into: (1) A cargo tank; or (2) A cargo vent mast if that vent mast has a means for the detection and removal of the liquid...

46 CFR 154.519 - Piping relief valves.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Process Piping Systems § 154.519 Piping relief valves. (a) The liquid relief valve that protects the cargo piping system from liquid pressure exceeding the design pressure must discharge into: (1) A cargo tank; or (2) A cargo vent mast if that vent mast has a means for the detection and removal of the liquid...

14 CFR 25.1025 - Oil valves.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oil valves. 25.1025 Section 25.1025... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1025 Oil valves. (a) Each oil shutoff must meet the requirements of § 25.1189. (b) The closing of oil shutoff means may not prevent propeller...

14 CFR 25.1025 - Oil valves.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Oil valves. 25.1025 Section 25.1025... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1025 Oil valves. (a) Each oil shutoff must meet the requirements of § 25.1189. (b) The closing of oil shutoff means may not prevent propeller...

14 CFR 25.1025 - Oil valves.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oil valves. 25.1025 Section 25.1025... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1025 Oil valves. (a) Each oil shutoff must meet the requirements of § 25.1189. (b) The closing of oil shutoff means may not prevent propeller...

49 CFR 236.508 - Interference with application of brakes by means of brake valve.

Code of Federal Regulations, 2011 CFR

2011-10-01

... GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.508 Interference with application of brakes by means of brake valve. The automatic train stop, train control, or...

49 CFR 236.508 - Interference with application of brakes by means of brake valve.

Code of Federal Regulations, 2010 CFR

2010-10-01

... GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.508 Interference with application of brakes by means of brake valve. The automatic train stop, train control, or...

Transcatheter aortic valve-in-valve treatment of degenerative stentless supra-annular Freedom Solo valves: A single centre experience.

PubMed

Cockburn, James; Dooley, Maureen; Parker, Jessica; Hill, Andrew; Hutchinson, Nevil; de Belder, Adam; Trivedi, Uday; Hildick-Smith, David

2017-02-15

Redo surgery for degenerative bioprosthetic aortic valves is associated with significant morbidity and mortality. Report results of valve-in-valve therapy (ViV-TAVI) in failed supra-annular stentless Freedom Solo (FS) bioprostheses, which are the highest risk for coronary occlusion. Six patients with FS valves (mean age 78.5 years, 50% males). Five had valvular restenosis (peak gradient 87.2 mm Hg, valve area 0.63 cm 2 ), one had severe regurgitation (AR). Median time to failure was 7 years. Patients were high risk (mean STS/Logistic EuroScore 10.6 15.8, respectively). FS valves ranged from 21 to 25 mm. Successful ViV-TAVI was achieved in 4/6 patients (67%). Of the unsuccessful cases, (patient 1 and 2 of series) patient 1 underwent BAV with simultaneous aortography which revealed left main stem occlusion. The procedure was stopped and the patient went forward for repeat surgery. Patient 2 underwent successful ViV-TAVI with a 26-mm CoreValve with a guide catheter in the left main, but on removal coronary obstruction occurred, necessitating valve snaring into the aorta. Among the successful cases, (patients 3, 4, 5, 6) the TAVIs used were CoreValve Evolut R 23 mm (n = 3), and Lotus 23 mm (n = 1). In the successful cases the peak gradient fell from 83.0 to 38.3 mm Hg. No patient was left with >1+ AR. One patient had a stroke on Day 2, with full neurological recovery. Two patients underwent semi-elective pacing for LBBB and PR >280 ms. ViV-TAVI in stentless Freedom Solo valves is high risk. The risk of coronary occlusion is high. The smallest possible prosthesis (1:1 sizing) should be used, and strategies to protect the coronary vessels must be considered. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Intermediate results of isolated mitral valve replacement with a Biocor porcine valve.

PubMed

Rizzoli, Giulio; Bottio, Tomaso; Vida, Vladimiro; Nesseris, Georgios; Caprili, Luca; Thiene, Gaetano; Gerosa, Gino

2005-02-01

We analyzed the intermediate experience, survival, and prosthetic complications of patients who received the Biocor valve, a new-generation porcine valve, in the mitral position. At the University of Padua, between May 1992 and January 2004, 154 consecutive patients (102 female and 52 male patients; mean age, 72.3 +/- 6 years; age range, 37-86 years) received 158 mitral Biocor prostheses (Biocor Industria e Pesguisa Ltda, Belo Horizonte, Brazil). Thirty-five percent of the patients had previous mitral operations, 24% had coronary artery bypass grafting, and 34.6% had other procedures. Median preoperative New York Heart Association class was III. Echocardiography was performed in 75% of the long-term survivors. Follow-up included 609.4 patient-years and was 100% complete, with a median time of 4 patient-years (range, 0.02-11.3 years). At 8 years, 20 (14%) of 142 operative survivors were still at risk. Early mortality was 13.6%. According to univariate analysis, New York Heart Association class III to IV, ejection fraction of less than 40%, urgency, male sex, and coronary artery bypass grafting were significant perioperative risk factors. Eight- and 10-year actuarial survival was 51.1% +/- 5.6% (40 deaths). Eight-year actuarial freedom from valve-related death, thromboembolism, anticoagulant-related hemorrhage, endocarditis, paravalvular leak, and valve-related complications were 85.2% +/- 5%, 85.7% +/- 4.4%, 92.6% +/- 3.7%, 94.1% +/- 3%, 91.8% +/- 3%, and 70.2% +/- 5.7%, respectively. Freedom from structural valve deterioration was 100%. Actual freedom from reoperation was 93.2% +/- 2.2%. By Doppler echocardiography, the peak and mean transprosthetic gradients were 15 +/- 5 mm Hg and 6.3 +/- 3 mm Hg, respectively (mean follow-up, 4.2 +/- 2.7 years). At intermediate follow-up, the Biocor prosthesis in the mitral position showed excellent results in terms of valve durability when compared with other second-generation tissue valves.

Transcatheter aortic valve implantation for failing surgical aortic bioprosthetic valve: from concept to clinical application and evaluation (part 2).

PubMed

Piazza, Nicolo; Bleiziffer, Sabine; Brockmann, Gernot; Hendrick, Ruge; Deutsch, Marcus-André; Opitz, Anke; Mazzitelli, Domenico; Tassani-Prell, Peter; Schreiber, Christian; Lange, Rüdiger

2011-07-01

This study sought to review the acute procedural outcomes of patients who underwent transcatheter aortic valve (TAV)-in-surgical aortic valve (SAV) implantation at the German Heart Center, Munich, and to summarize the existing literature on TAV-in-SAV implantation (n = 47). There are several case reports and small case series describing transcatheter aortic valve implantation for a failing surgical aortic valve bioprosthesis (TAV-in-SAV implantation). From January 2007 to March 2011, 20 out of 556 patients underwent a TAV-in-SAV implantation at the German Heart Center Munich. Baseline characteristics and clinical outcome data were prospectively entered into a dedicated database. The mean patient age was 75 ± 13 years, and the mean logistic European System for Cardiac Operative Risk Evaluation and Society of Thoracic Surgeons' Risk Model scores were 27 ± 13% and 7 ± 4%, respectively. Of the 20 patients, 14 had stented and 6 had stentless surgical bioprostheses. Most cases (12 of 20) were performed via the transapical route using a 23-mm Edwards Sapien prosthesis (Edwards Lifesciences, Irvine, California). Successful implantation of a TAV in a SAV with the patient leaving the catheterization laboratory alive was achieved in 18 of 20 patients. The mean transaortic valve gradient was 20.0 ± 7.5 mm Hg. None-to-trivial, mild, and mild-to-moderate paravalvular aortic regurgitation was observed in 10, 6, and 2 patients, respectively. We experienced 1 intraprocedural death following pre-implant balloon aortic valvuloplasty ("stone heart") and 2 further in-hospital deaths due to myocardial infarction. TAV-in-SAV implantation is a safe and feasible treatment for high-risk patients with failing aortic bioprosthetic valves and should be considered as part of the armamentarium in the treatment of aortic bioprosthetic valve failure. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Late outcomes for aortic valve replacement with the Carpentier-Edwards pericardial bioprosthesis: up to 17-year follow-up in 1,000 patients.

PubMed

McClure, R Scott; Narayanasamy, Narendren; Wiegerinck, Esther; Lipsitz, Stuart; Maloney, Ann; Byrne, John G; Aranki, Sary F; Couper, Gregory S; Cohn, Lawrence H

2010-05-01

This study reviews a single institution experience with the Carpentier-Edwards pericardial aortic valve bioprosthesis, concentrating on late outcomes. From December 1991 to June 2002, 1,000 patients underwent aortic valve replacement with the Carpentier-Edwards pericardial valve (mean follow-up 6.01 +/- 3.56 years). The institutional database was reviewed. Follow-up data were acquired through telephone interviews and mail-in questionnaires. Time-to-event analyses were performed by the Kaplan-Meier method. Mean age was 74.1 years; 545 patients (54.5%) were male. Mean preoperative ejection fraction was 52.5%. Isolated aortic valve replacement occurred in 372 cases (37.2%). Combined aortic valve replacement with coronary artery bypass grafting occurred in 443 cases (44.3%). The remaining 185 patients (18.5%) underwent complex procedures with concomitant mitral, tricuspid, or arch repair. One hundred forty patients (14.0%) had prior aortic valve surgery. Follow-up was 99.4% complete. Overall operative mortality was 7.2% (72 of 1,000). There were 503 late deaths (50.3%). Age-stratified survival at 15 years was 43.7% for patients less than 65 years of age; 18.2% for patients aged 65 to 75; and 9.4% for patients aged more than 75 years. There were 26 failed bioprostheses (2.6%) requiring reoperation. Structural valve deterioration was the cause in 13 of 26 cases (50%), endocarditis in 11 of 26 (42%), and perivalvular leak in 2 of 26 (7.6%). Age-stratified freedom from reoperation due to structural valve deterioration at 15 years was 34.7% for patients less than 65 years of age; 89.4% for patients aged 65 to 75; and 99.5% for patients aged more than 75 years. The Carpentier-Edwards pericardial bioprosthesis shows long-term durability with low rates of structural failure. Copyright (c) 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Long-Term Outcome of the Sorin Freedom SOLO Stentless Aortic Valve.

PubMed

Christ, Torsten; Claus, Benjamin; Zielinski, Christina; Falk, Volkmar; Grubitzsch, Herko

2016-11-01

The Sorin Freedom SOLO valve is a third-generation stentless aortic valve which shows beneficial hemodynamic performance compared to stented bioprostheses. Long-term results regarding hemodynamics, the durability of the valve, and patient outcome are scarce, and their acquisition was the aim of this single-center study. Between 2005 and 2006, a total of 68 consecutive patients (30 males, 38 females; mean age at surgery 76.1 ± 6.3 years) underwent aortic valve replacement with a Sorin Freedom SOLO prosthesis. Indications were aortic stenosis (n = 50), aortic regurgitation (n = 1) and mixed lesions (n = 17). Associated procedures were performed in 31 patients (45.6%), most of which were coronary artery bypass grafting (68.8 %). The follow up was performed by telephone interviews, and clinical and echocardiographic examinations. Morbidity, mortality and echocardiographic data were analyzed. The total follow up was 501.1 patient-years, with a mean follow up of 7.4 ± 3.4 years (maximum 11.2 years). The follow up was 100% complete. Hospital mortality was 4.4% (n = 3). Actuarial survival at five and 10 years was 76.5 ± 5.1% and 41.5 ± 6.5%, respectively. Reinterventions were performed in eight patients; these included three reoperations due to endocarditis, four transcatheter aortic valve implantations, and one reoperation due to structural valve deterioration (SVD). The overall freedom from valve reintervention due to SVD at five and 10 years was 97.8 ± 2.2% and 82.9 ± 7.5%, respectively. After eight years, echocardiography demonstrated peak and mean transvalvular gradients of 18 ± 11 and 10 ± 7 mmHg, respectively. The overall effective and indexed aortic valve orifice areas were 1.73 ± 0.58 cm2 and 0.92 ± 0.33 cm2/m2, respectively. At long-term follow up the Sorin Freedom SOLO bioprosthesis was associated with favourable hemodynamic results and survival. Freedom from SVD was not superior to that occurring with stented bioprostheses.

Surgical results of trabeculectomy and Ahmed valve implantation following a previous failed trabeculectomy in primary congenital glaucoma patients.

PubMed

Lee, Naeun; Ma, Kyoung Tak; Bae, Hyoung Won; Hong, Samin; Seong, Gong Je; Hong, Young Jae; Kim, Chan Yun

2015-04-01

To compare the surgical results of trabeculectomy and Ahmed glaucoma valve implantation after a previous failed trabeculectomy. A retrospective comparative case series review was performed on 31 eye surgeries in 20 patients with primary congenital glaucoma who underwent trabeculectomy or Ahmed glaucoma valve implantation after a previous failed trabeculectomy with mitomycin C. The preoperative mean intraocular pressure was 25.5 mmHg in the trabeculectomy group and 26.9 mmHg in the Ahmed glaucoma valve implantation group (p = 0.73). The 48-month postoperative mean intraocular pressure was 19.6 mmHg in the trabeculectomy group and 20.2 mmHg in the Ahmed glaucoma valve implantation group (p = 0.95). The 12-month trabeculectomy success rate was 69%, compared with 64% for Ahmed glaucoma valve implantation, and the 48-month success rates were 42% and 36% for trabeculectomy and valve implantation, respectively. The success rates following the entire follow-up period were not significantly different between the two groups (p > 0.05 by log rank test). Postoperative complications occurred in 25% of the trabeculectomy-operated eyes and 9% of the Ahmed-implanted eyes (p = 0.38). There was no significant difference in surgical outcome between the trabeculectomy and Ahmed glaucoma valve implantation groups, neither of which had favorable results. However, the trabeculectomy group demonstrated a higher prevalence of adverse complications such as post-operative endophthalmitis.

Does the valve regulated release of urine from the bladder decrease encrustation and blockage of indwelling catheters by crystalline proteus mirabilis biofilms?

PubMed

Sabbuba, N A; Stickler, D J; Long, M J; Dong, Z; Short, T D; Feneley, R J C

2005-01-01

We tested whether valve regulated, intermittent flow of urine from catheterized bladders decreases catheter encrustation. Laboratory models of the catheterized bladder were infected with Proteus mirabilis. Urine was allowed to drain continuously through the catheters or regulated by valves to drain intermittently at predetermined intervals. The time that catheters required to become blocked was recorded and encrustation was visualized by scanning electron microscopy. When a manual valve was used to drain urine from the bladder at 2-hour intervals 4 times during the day, catheters required significantly longer to become blocked than those on continuous drainage (mean 62.6 vs 35.9 hours, p = 0.039). A similar 1.7-fold increase occurred when urine was drained at 4-hour intervals 3 times daily. Experiments with an automatic valve in which urine was released at 2 or 4-hour intervals through the day and night also showed a significant increase in mean time to blockage compared with continuous drainage (p = 0.001). Scanning electron microscopy confirmed that crystalline biofilm was less extensive on valve regulated catheters. Valve regulated, intermittent flow of urine through catheters increases the time that catheters require to become blocked with crystalline biofilm. The most beneficial effect was recorded when urine was released from the bladder at 4-hour intervals throughout the day and night by an automatic valve.

Use of the proGAV shunt valve in normal-pressure hydrocephalus.

PubMed

Toma, Ahmed K; Tarnaris, Andrew; Kitchen, Neil D; Watkins, Laurence D

2011-06-01

Overdrainage is a common complication associated with shunt insertion in normal-pressure hydrocephalus (NPH) patients. Using adjustable valves with antigravity devices has been shown to reduce its incidence. The optimal starting setting of an adjustable shunt valve in NPH is debatable. To audit our single-center practice of setting adjustable valves. We performed a retrospective review of clinical records of all NPH patients treated in our unit between 2006 and 2009 by the insertion of shunts with a proGAV valve, recording demographic and clinical data, shunt complications, and revision rates. Radiological reports of postoperative follow-up computed tomography scans of the brain were reviewed for detected subdural hematomas. A proGAV adjustable valve was inserted in 50 probable NPH patients between July 2006 and November 2009. Mean ± SD age was 76 ± 7 years. Mean follow-up was 15 months. The initial shunt setting was 6 ± 3 cm H2O, and the final setting was 4.9 ± 1.9 cm H2O. Nineteen patients required 24 readjustment procedures (readjustment rate, 38%; readjustment number, 0.48 times per patient). One patient (2%) developed delayed bilateral subdural hematoma after readjustment of his shunt valve setting as an outpatient. Starting with a low opening pressure setting on a proGAV adjustable shunt valve does not increase the chances of overdrainage complications and reduces the need for repeated readjustments.

FLUID SELECTING APPARATUS

DOEpatents

Stinson, W.J.

1958-09-16

A valve designed to selectively sample fluids from a number of sources is described. The valve comprises a rotatable operating lever connected through a bellows seal to a rotatable assembly containing a needle valve, bearings, and a rotational lock. The needle valve is connected through a flexible tube to the sample fluid outlet. By rotating the lever the needle valve is placed over . one of several fluid sources and locked in position so that the fluid is traasferred through the flexible tubing and outlet to a remote sampling system. The fluids from the nonselected sources are exhausted to a waste line. This valve constitutes a simple, dependable means of selecting a sample from one of several scurces.

Evaluation of manual resuscitators used in ICUs in Brazil*

PubMed Central

Ortiz, Tatiana de Arruda; Forti, Germano; Volpe, Márcia Souza; Beraldo, Marcelo do Amaral; Amato, Marcelo Britto Passos; Carvalho, Carlos Roberto Ribeiro; Tucci, Mauro Roberto

2013-01-01

OBJECTIVE: To evaluate the performance of manual resuscitators (MRs) used in Brazil in accordance with international standards. METHODS: Using a respiratory system simulator, four volunteer physiotherapists employed eight MRs (five produced in Brazil and three produced abroad), which were tested for inspiratory and expiratory resistance of the patient valve; functioning of the pressure-limiting valve; and tidal volume (VT) generated when the one-handed and two-handed techniques were used. The tests were performed and analyzed in accordance with the American Society for Testing and Materials (ASTM) F920-93 criteria. RESULTS: Expiratory resistance was greater than 6 cmH2O . L−1 . s−1 in only one MR. The pressure-limiting valve, a feature of five of the MRs, opened at low pressures (< 17 cmH2O), and the maximal pressure was 32.0-55.9 cmH2O. Mean VT varied greatly among the MRs tested. The mean VT values generated with the one-handed technique were lower than the 600 mL recommended by the ASTM. In the situations studied, mean VT was generally lower from the Brazilian-made MRs that had a pressure-limiting valve. CONCLUSIONS: The resistances imposed by the patient valve met the ASTM criteria in all but one of the MRs tested. The pressure-limiting valves of the Brazilian-made MRs usually opened at low pressures, providing lower VT values in the situations studied, especially when the one-handed technique was used, suggesting that both hands should be used and that the pressure-limiting valve should be closed whenever possible. PMID:24310633

Midterm results after aortic valve replacement with freehand stentless xenografts: a comparison of three prostheses.

PubMed

Luciani, G B; Bertolini, P; Vecchi, B; Mazzucco, A

1998-06-01

The ideal substitute for the diseased aortic valve is yet to be found. For the assessment and comparison of the midterm results after aortic valve replacement with three different types of freehand stentless xenografts, all patients who underwent the operation between October 1992 and April 1997 were reviewed. Of 231 patients undergoing aortic valve replacement, 106 patients (group 1) were given the Biocor PSB (Biocor Industria e Pesquisa Ltda, Belo Horizonte, MG, Brazil); 76 patients (group 2) were given the Toronto SPV (St. Jude Medical, Inc., St. Paul, Minn.), and 49 patients (group 3) were given the O'Brien-Angell valve (Bravo Cardiovascular model 300, Cryolife, Inc., Marietta, Ga.). The first two xenografts require inflow and outflow suturelines; the third xenograft needs a single-sutureline implantation. Mean age (70 +/- 6 years; 70 +/- 7 years; 72 +/- 9 years; p = 0.6), prevalence of male sex (56 patients, 53%; 37 patients, 49%; 22 patients, 45%; p = 0.7), of aortic stenosis (72 patients, 68%; 54 patients, 71%; 37 patients, 73%; p = 0.6), and need for associated procedures (51 patients, 48%; 30 patients, 40%; 21 patients, 43%; p = 0.1) were comparable among groups. Mean aortic crossclamp time was shorter in group 3 (96 +/- 24 minutes; 100 +/- 23 minutes; 88 +/- 25 minutes;p = 0.01). Early deaths were 3 of 106 (3%) in group 1, 2 of 76 (3%) in group 2, and 2 of 49 (4%) in group 3. Follow-up of survivors ranged from 1 to 54 months (mean 32 +/- 13 months). Survival at 4 years was 90% +/- 3% in group 1, 95% +/- 3% in group 2, 85% +/- 8% in group 3 (p = 0.3). At 4 years, freedom from valve-related events was 95% +/- 6%, 100%, 70% +/- 8% (p = 0.004), while freedom from valve deterioration was 99% +/- 1%, 100%, 73% +/- 8% (p = 0.001), in group 1, 2, and 3, respectively (p = 0.001). At follow-up, reintervention on the xenograft was necessary in one patient (endocarditis) in group 1, none in group 2, and six in group 3 (technical cause, group 3; valve tear, group 2; pannus, group 1). Regression analysis showed O'Brien-Angell type of xenograft to be predictive of valve-related events (p = 0.02), valve deterioration (p = 0.001), and reoperation (p = 0.001) during follow-up. Midterm survival after stentless aortic valve replacement is good with all three xenografts. Freedom from valve-related events, valve deterioration, and reoperation are excellent with the Biocor PSB or the Toronto SPV stentless valves but less satisfactory with the O'Brien-Angell valve.

Successful Feasibility Human Trial of a New Self-Expandable Percutaneous Pulmonary Valve (Pulsta Valve) Implantation Using Knitted Nitinol Wire Backbone and Trileaflet α-Gal-Free Porcine Pericardial Valve in the Native Right Ventricular Outflow Tract.

PubMed

Kim, Gi Beom; Song, Mi Kyoung; Bae, Eun Jung; Park, Eun-Ah; Lee, Whal; Lim, Hong-Gook; Kim, Yong Jin

2018-06-01

Self-expandable percutaneous pulmonary valve implantation (PPVI) for native right ventricular outflow tract lesions is still in the clinical trial phase. The aim of this study is to present the result of feasibility study of a novel self-expandable knitted nitinol wire stent mounted with a treated trileaflet α-Gal-free porcine pericardial valve for PPVI. A feasibility study using Pulsta valve (TaeWoong Medical Co, Gyeonggi-do, South Korea) was designed for patients with severe pulmonary regurgitation in the native right ventricular outflow tract, and 6-month follow-up outcomes were reviewed. Ten tetralogy of Fallot patients were enrolled. Before PPVI, severe pulmonary regurgitation (mean pulmonary regurgitation fraction, 45.5%±7.2%; range, 34.9%-56%) and enlarged right ventricular volume (mean indexed right ventricular end-diastolic volume, 176.7±14.3 mL/m 2 ; range, 158.9-205.9 mL/m 2 ) were present. The median age at PPVI was 21.7±6.5 years (range, 13-36 years). Five patients were successfully implanted with 28 mm and the other 5 with 26 mm valves loaded on the 18F delivery cable. No significant periprocedural complications were noted in any patient. At the 6-month follow-up, indexed right ventricular end-diastolic volume was dramatically decreased to 126.3±20.3 mL/m 2 (range, 99-164.2 mL/m 2 ), and the mean value of peak instantaneous pressure gradient between the right ventricle and the pulmonary artery decreased from 6.8±3.5 mm Hg (range, 2-12 mm Hg) before PPVI to 5.7±6.7 mm Hg (range, 2-12 mm Hg) without significant pulmonary regurgitation. There was no adverse event associated with the valve. A feasibility study of the Pulsta valve for native right ventricular outflow tract lesions was completed successfully with planned Pulsta valve implantation and demonstrated good short-term effectiveness without serious adverse events. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02555319. © 2018 American Heart Association, Inc.

Transapical Transcatheter Aortic Valve Implantation Using the JenaValve: A One-Year Follow-up.

PubMed

Reuthebuch, Oliver; Koechlin, Luca; Kaufmann, Beat A; Kessel-Schaefer, Arnheid; Gahl, Brigitta; Eckstein, Friedrich S

2015-09-01

Since the first transcatheter aortic valve implantation (TAVI) in 2002, TAVI technique has gained an increasing popularity especially in high-risk patients. In this study, we present the first echocardiographic midterm outcome with the second-generation transapical JenaValve TAVI system (JenaValve Technology GmbH, Munich, Germany) in patients with aortic stenosis (AS). Between November 2011 and November 2012, a total of 28 patients received transapical TAVI using the JenaValve. Primary endpoint was a combined efficacy endpoint after 1 year, which included all-cause mortality after more than 30 days, failure of current therapy for AS requiring hospitalization for symptoms of valve-related cardiac decompensation or prosthetic heart valve dysfunction. Moreover, we analyzed secondary endpoints after 3 and 12 months including cardiovascular mortality; major stroke; and life-threatening, disabling, or major bleeding. Mean echocardiographic follow-up was 471.35 ± 102.72 days. Mean age was 80.43 ± 6.03 years and EuroSCORE II was 8.80 ± 7.21%. Successful implantation was accomplished in 100% (n = 28). Median transvalvular aortic mean pressure gradient was 44.5 mm Hg (interquartile range [IQR]: 34.5; 55.5) preoperatively, 12 mm Hg (IQR: 9; 16) postoperatively, and 11 mm Hg (IQR: 8; 16) after 1 year. After 12 months, no paravalvular leakage was seen in 52.38% of the patients and grade 1 paravalvular leakage was seen in 47.62% of the patients. There was no grade 2 or 3 leakage detected. Stroke, valve thrombosis or dislocation, myocardial infarction, or bleeding was also not observed. However, criteria for the combined efficacy endpoint after 1 year were met in five patients (17.86%). Thirty-day mortality was 14.29% (n = 4) and all-cause mortality after 1 year was 21.43% (n = 6). The JenaValve transapical TAVI system is a safe and feasible procedure with low peri- and postoperative complications and convincing midterm performance of the prosthesis. Georg Thieme Verlag KG Stuttgart · New York.

Comparative durability and costs analysis of ventricular shunts.

PubMed

Agarwal, Nitin; Kashkoush, Ahmed; McDowell, Michael M; Lariviere, William R; Ismail, Naveed; Friedlander, Robert M

2018-05-11

OBJECTIVE Ventricular shunt (VS) durability has been well studied in the pediatric population and in patients with normal pressure hydrocephalus; however, further evaluation in a more heterogeneous adult population is needed. This study aims to evaluate the effect of diagnosis and valve type-fixed versus programmable-on shunt durability and cost for placement of shunts in adult patients. METHODS The authors retrospectively reviewed the medical records of all patients who underwent implantation of a VS for hydrocephalus at their institution over a 3-year period between August 2013 and October 2016 with a minimum postoperative follow-up of 6 months. The primary outcome was shunt revision, which was defined as reoperation for any indication after the initial procedure. Supply costs, shunt durability, and hydrocephalus etiologies were compared between fixed and programmable valves. RESULTS A total of 417 patients underwent shunt placement during the index time frame, consisting of 62 fixed shunts (15%) and 355 programmable shunts (85%). The mean follow-up was 30 ± 12 (SD) months. The shunt revision rate was 22% for programmable pressure valves and 21% for fixed pressure valves (HR 1.1 [95% CI 0.6-1.8]). Shunt complications, such as valve failure, infection, and overdrainage, occurred with similar frequency across valve types. Kaplan-Meier survival curve analysis showed no difference in durability between fixed (mean 39 months) and programmable (mean 40 months) shunts (p = 0.980, log-rank test). The median shunt supply cost per index case and accounting for subsequent revisions was $3438 (interquartile range $2938-$3876) and $1504 (interquartile range $753-$1584) for programmable and fixed shunts, respectively (p < 0.001, Wilcoxon rank-sum test). Of all hydrocephalus etiologies, pseudotumor cerebri (HR 1.9 [95% CI 1.2-3.1]) and previous shunt malfunction (HR 1.8 [95% CI 1.2-2.7]) were found to significantly increase the risk of shunt revision. Within each diagnosis, there were no significant differences in revision rates between shunts with a fixed valve and shunts with a programmable valve. CONCLUSIONS Long-term shunt revision rates are similar for fixed and programmable shunt pressure valves in adult patients. Hydrocephalus etiology may play a significant role in predicting shunt revision, although programmable valves incur higher supply costs regardless of initial diagnosis. Utilization of fixed pressure valves versus programmable pressure valves may reduce supply costs while maintaining similar revision rates. Given the importance of developing cost-effective management protocols, this study highlights the critical need for large-scale prospective observational studies and randomized clinical trials of ventricular shunt valve revisions and additional patient-centered outcomes.

Self-powered automatic secondary air controllers for woodstoves and small furnaces

DOEpatents

Siemer, Darryl D.

1991-01-01

A controller for automatically regulating the supply of secondary combustion air to woodstoves and small furnaces. The controller includes a movable air valve for controlling the amount of secondary air admitted into the chamber. A self powered means monitors the concentration of combustible gases and vapors and actuates the movable air valve to increase the supply of secondary air in response to increasing concentrations of the combustible gases and vapors. The self-powered means can be two fluid filled sensor bulbs, one of which has a coating of a combustion catalyst. Alternatively, the self powered means can be two metallic stripes laminated together, one of which is coated with a combustion catalyst, and when heated, causes the air valve to actuate.

Aortic valve repair with autologous pericardial patch.

PubMed

Lausberg, Henning F; Aicher, Diana; Langer, Frank; Schäfers, Hans-Joachim

2006-08-01

Isolated aortic valve repair (AVR) has been gaining increasing interest in recent times. Results of isolated aortic valve repair have been reported to be variable. Various techniques have been utilized. We analyzed our experience with isolated valve repair using autologous pericardial patch plasty and compared the results to an age-matched collective with aortic valve repair without the use of additional material. Between January 1997 and June 2005, pericardial patch plasty of the aortic valve was performed in 42 patients (PATCH). During the same period, 42 patients after AVR without the use of additional material were age matched (NO-PATCH). Mean age in both groups was 52 years with a majority of male patients (PATCH ratio, 3.7:1; NO-PATCH ratio, 5:1). Valve anatomy was similar in both groups. All patients were followed by echocardiography for a cumulative follow-up of 2341 patient months (mean 28+/-23 months). No patient died in the hospital in neither group. The average systolic gradient was 5.9+/-2.2 mmHg in PATCH and 4.8+/-2.1 mmHg in NO-PATCH; p=0.17). Freedom from aortic regurgitation > or = II degrees was 87.8% in PATCH and 95.0% in NO-PATCH after 5 years (p=0.21). Freedom from reoperation was 97.6% in PATCH and 97.4% in NO-PATCH (p=0.96). Aortic regurgitation can be treated effectively by aortic valve repair using pericardial patch plasty. The functional results are satisfactory. With the application of this technique also more complex pathologies of the aortic valve can be addressed adequately thus extending the concept of valve preservation in patients with aortic regurgitation.

Redo aortic valve surgery versus transcatheter valve-in-valve implantation for failing surgical bioprosthetic valves: consecutive patients in a single-center setting

PubMed Central

Wottke, Michael; Deutsch, Marcus-André; Krane, Markus; Piazza, Nicolo; Lange, Ruediger; Bleiziffer, Sabine

2015-01-01

Background Due to a considerable rise in bioprosthetic as opposed to mechanical valve implantations, an increase of patients presenting with failing bioprosthetic surgical valves in need of a reoperation is to be expected. Redo surgery may pose a high-risk procedure. Transcatheter aortic valve-in-valve implantation is an innovative, less-invasive treatment alternative for these patients. However, a comprehensive evaluation of the outcome of consecutive patients after a valve-in-valve TAVI [transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV)] as compared to a standard reoperation [surgical aortic valve redo-operation (SAV-in-SAV)] has not yet been performed. The goal of this study was to compare postoperative outcomes after TAV-in-SAV and SAV-in-SAV in a single center setting. Methods All SAV-in-SAV and TAV-in-SAV patients from January 2001 to October 2014 were retrospectively reviewed. Patients with previous mechanical or transcatheter valves, active endocarditis and concomitant cardiac procedures were excluded. Patient characteristics, preoperative data, post-procedural complications, and 30-day mortality were collected from a designated database. Mean values ± SD were calculated for all continuous variables. Counts and percentages were calculated for categorical variables. The Chi-square and Fisher exact tests were used to compare categorical variables. Continuous variables were compared using the t-test for independent samples. A 2-sided P value <0.05 was considered statistically significant. Results A total of 102 patients fulfilled the inclusion criteria, 50 patients (49%) underwent a transcatheter valve-in-valve procedure, while 52 patients (51%) underwent redo-surgery. Patients in the TAV-in-SAV group were significantly older, had a higher mean logistic EuroSCORE and exhibited a lower mean left ventricular ejection fraction than patients in the SAV-in-SAV group (78.1±6.7 vs. 66.2±13.1, P<0.001; 27.4±18.7 vs. 14.4±10, P<0.001; and 49.8±13.1 vs. 56.7±15.8, P=0.019 respectively). Postoperative pacemaker implantation and chest tube output were higher in the SAV-in-SAV group compared to the TAV-in-SAV group [11 (21%) vs. 3 (6%), P=0.042 and 0.9±1.0 vs. 0.6±0.9, P=0.047, respectively]. There was no significant difference in myocardial infarction, stroke or dialysis postoperatively. Thirty-day mortality was not significantly different between the two groups [TAV-in-SAV2 (4%) vs. SAV-in-SAV0, P=0.238]. Kaplan-Meier (KM) 1-year survival was significantly lower in the TAV-in-SAV group than in the SAV-in-SAV group (83% vs. 96%, P<0.001). Conclusions The present investigation shows that both groups, irrespective of different baseline comorbidities, show very good early clinical outcomes. While redo surgery is still the standard of care, a subgroup of patients may profit from the transcatheter valve-in-valve procedure. PMID:26543594

Ten-year results of the Freedom Solo stentless heart valve: excellent haemodynamics but progressive valve dysfunction in the long term.

PubMed

Sponga, Sandro; Barbera, Mila Della; Pavoni, Daisy; Lechiancole, Andrea; Mazzaro, Enzo; Valente, Marialuisa; Nucifora, Gaetano; Thiene, Gaetano; Livi, Ugolino

2017-05-01

Freedom Solo (FS) is a pericardial stentless heart valve showing excellent haemodynamic performance at mid-term. The aim of this study was to evaluate the long-term performance of such bioprostheses. Between December 2004 and November 2009, 109 patients (31 men; mean age 76 ± 6 years) underwent aortic valve replacement with FS. Preoperatively, the mean NYHA class was 2.5 ± 0.7, the mean EuroSCORE II, 2.8 ± 2.5. Mean prosthesis size was 22.7 ± 1.9 mm; concomitant procedures were performed in 65 patients. Structural valve deterioration (SVD) was diagnosed according to the Valve Academic Research Consortium-2 definition. Two patients (1.8%) died within 30 days. Follow-up (72 ± 36 months) was 100% completed. The 1-, 5- and 10-year actuarial survival rates were 89, 73 and 42%, respectively, with 8 valve-related deaths; the actuarial freedom from SVD was 99, 93 and 76%. During 61 ± 39 months of follow-up, echocardiographic findings worsened progressively: At discharge, 3-5 and 7-9 years, the mean gradient was 8 ± 4, 12 ± 11 and 19 ± 19 mmHg ( P  < 0.01); the indexed effective orifice area was 1.0 ± 0.2, 0.9 ± 0.2 and 0.8 ± 0.3 cm 2 /m 2 ( P  < 0.01). Of the 13 patients who developed SVD, it was due to aortic stenosis in 11. SVD was a predictor of cardiovascular mortality at univariate analysis (HR 2.87, 1.12-7.29); 2 explanted prostheses showed massive calcium deposits with mean calcium and phosphorus contents of 234 ± 16 and 116 ± 7 mg/g dry weight, respectively. The FS bioprosthesis shows excellent mid-term clinical and haemodynamic results and offers an alternative to other valves, particularly in the case of a small aortic annulus. Worsening of FS performance was observed at late follow-up because of progressive SVD with stenosis, questioning whether it should be used in patients with a long life expectancy. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

A modified repair technique for tricuspid incompetence in Ebstein's anomaly.

PubMed

Hetzer, R; Nagdyman, N; Ewert, P; Weng, Y G; Alexi-Meskhisvili, V; Berger, F; Pasic, M; Lange, P E

1998-04-01

A modified technique for tricuspid valve repair in Ebstein's anomaly restructures the valve mechanism at the level of the true tricuspid anulus by using the most mobile leaflet for valve closure without plication of the atrialized chamber. Midterm results of this therapeutic approach for patients with Ebstein's anomaly and tricuspid valve incompetence are reported. Between October 1988 and April 1997, the incompetent tricuspid valve was repaired with our technique in 19 patients (12 female, 7 male; 2 to 54 years, mean 21 years). The indication for operation was congestive heart failure of various degrees in all patients. Tricuspid incompetence was grade II in two patients, grade III in 14, and grade IV in three. Associated congenital malformations were simultaneously repaired (interatrial communication in 18, ventricular septal defect in two, pulmonary stenosis in two, mitral valve prolapse in one). Follow-up ranged between 10 and 103 months (median 28 months) and was complete for all patients. There were no operative deaths. One patient with active endocarditis and pulmonary abscess died 2 months after the operation of recurrent sepsis; there were no late deaths. During follow-up, New York Heart Association functional class improved from 2.8 before the operation to 1.9 without recurrent cyanosis, and tricuspid incompetence decreased from a mean grade of 3.1 to one of 0.9, without any echocardiographic deterioration of the tricuspid valve function or right ventricular dilation. Our technique allows tricuspid valve repair in patients with Ebstein's anomaly, even in cases usually reserved for primary valve replacement, without late functional deterioration.

Initial experience with xenograft bioconduit for the treatment of complex prosthetic valve endocarditis.

PubMed

Roubelakis, Apostolos; Karangelis, Dimos; Sadeque, Syed; Yanagawa, Bobby; Modi, Amit; Barlow, Clifford W; Livesey, Steven A; Ohri, Sunil K

2017-07-01

The treatment of complex prosthetic valve endocarditis (PVE) with aortic root abscess remains a surgical challenge. Several studies support the use of biological tissues to minimize the risk of recurrent infection. We present our initial surgical experience with the use of an aortic xenograft conduit for aortic valve and root replacement. Between October 2013 and August 2015, 15 xenograft bioconduits were implanted for complex PVE with abscess (13.3% female). In 6 patients, concomitant procedures were performed: coronary bypass (n=1), mitral valve replacement (n=5) and tricuspid annuloplasty (n=1). The mean age at operation was 60.3±15.5 years. The mean Logistic European system for cardiac operating risk evaluation (EuroSCORE) was 46.6±23.6. The median follow-up time was 607±328 days (range: 172-1074 days). There were two in-hospital deaths (14.3% mortality), two strokes (14.3%) and seven patients required permanent pacemaker insertion for conduction abnormalities (46.7%). The mean length of hospital stay was 26 days. At pre-discharge echocardiography, the conduit mean gradient was 9.3±3.3mmHg and there was either none (n=6), trace (n=6) or mild aortic insufficiency (n=1). There was no incidence of mid-term death, prosthesis-related complications or recurrent endocarditis. Xenograft bioconduits may be safe and effective for aortic valve and root replacement for complex PVE with aortic root abscess. Although excess early mortality reflects the complexity of the patient population, there was good valve hemodynamics, with no incidence of recurrent endocarditis or prosthesis failure in the mid-term. Our data support the continued use and evaluation of this biological prosthesis in this high-risk patient cohort.

Durability Tests of Ball Valve Prototype with Flowmeter Operation

NASA Astrophysics Data System (ADS)

Rogula, J.; Romanik, G.

2018-02-01

The results of the investigation of the prototypical ball valve are presented in this article. The innovation of the tested valve is a ball with a built-in measuring orifice. The valve has been subjected to durability tests. Leakage under three temperatures: ambient, -30°C and +100°C was analyzed. Sealing elements of the valve were tested for roughness and deviation of shape before and after the cycles of operation. Ball valve operation means cycles of open/close. It was planned to perform 1000 cycles at each temperature condition accordingly. Tests of the valve were performed under gas pressure equal to 10 MPa. The research was carried out under the Operational Program "Intelligent Development" (POIR 01.01.01-00-0013 / 15 "Development of devices for measurement of media flow on industrial trunk-lines".

46 CFR 30.10-55 - Pressure vacuum relief valve-TB/ALL.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Pressure vacuum relief valve-TB/ALL. 30.10-55 Section 30... Definitions § 30.10-55 Pressure vacuum relief valve—TB/ALL. The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of...

46 CFR 30.10-55 - Pressure vacuum relief valve-TB/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Pressure vacuum relief valve-TB/ALL. 30.10-55 Section 30... Definitions § 30.10-55 Pressure vacuum relief valve—TB/ALL. The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of...

46 CFR 30.10-55 - Pressure vacuum relief valve-TB/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Pressure vacuum relief valve-TB/ALL. 30.10-55 Section 30... Definitions § 30.10-55 Pressure vacuum relief valve—TB/ALL. The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of...

46 CFR 30.10-55 - Pressure vacuum relief valve-TB/ALL.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Pressure vacuum relief valve-TB/ALL. 30.10-55 Section 30... Definitions § 30.10-55 Pressure vacuum relief valve—TB/ALL. The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of...

46 CFR 30.10-55 - Pressure vacuum relief valve-TB/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Pressure vacuum relief valve-TB/ALL. 30.10-55 Section 30... Definitions § 30.10-55 Pressure vacuum relief valve—TB/ALL. The term pressure vacuum relief valve means any device or assembly of a mechanical, liquid, weight, or other type used for the automatic regulation of...

HIV disease burden, cost, and length of stay in Portuguese hospitals from 2000 to 2010: a cross-sectional study.

PubMed

Catumbela, Emanuel; Freitas, Alberto; Lopes, Fernando; Mendoza, Maria Del Carmen Torres; Costa, Carlos; Sarmento, António; da Costa-Pereira, Altamiro

2015-04-08

The number of HIV-related hospitalizations has decreased worldwide in recent years owing to the availability of highly active antiretroviral therapy. However, the change in HIV-related hospitalizations in Portugal has not been studied. Using comprehensive hospital discharge data from mainland Portuguese hospitals, we examined trends in HIV-related inpatient admissions, length of stay (LOS), Elixhauser comorbidity measures, in-hospital mortality, and mean cost from 2000 to 2010. The hospital administrative data from inpatient admissions and discharges at 75 public acute care hospitals in the Portuguese National Health Service from 2000 to 2010 were included. HIV-related admissions were identified using the International Classification of Diseases, 9(th) Revision, Clinical Modification diagnosis codes 042.x-044.x. The effect of Elixhauser comorbidity measures on extending the LOS was assessed by comparing admissions in HIV patients with and without comorbidities using the Mann-Whitney U test. Multivariate logistic regression was performed to estimate the odds of having a decreased discharge. A total of 57,027 hospital admissions were analyzed; 73% of patients were male, and the mean age was 39 years. The median LOS was 11 days, and the in-hospital mortality was 14%. The mean cost per hospitalization was 5,148.7€. A total of 83% of admissions were through the emergency room. During the period, inpatient HIV admissions decreased by 22%, LOS decreased by 9%, and in-hospital mortality dropped by 12%. Elixhauser comorbidities increased the median LOS in nearly all admissions. Despite small regional variations, a strong, consistent decrease was observed in the hospital admission rate, mean cost, length of stay, and mortality rate for HIV-related admissions in Portugal during 2000-2010.

Aortic biological valve thrombosis in an HIV positive patient.

PubMed

Achouh, Paul; Jemel, Amine; Chaudeurge, Aurélie; Redheuil, Alban; Zegdi, Rachid; Fabiani, Jean-Noël

2011-06-01

Biological aortic valve thrombosis is an exceptional complication. A 64-year-old patient positive for human immunodeficiency virus presented for syncope on exertion, 2 years after an aortic bioprosthetic valve replacement and double coronary artery bypass. Transvalvular aortic mean gradient was approximately 50 mm Hg on echocardiogram and catheterization. Cardiac computed tomography scan showed a limited opening of the bioprosthesis cusps. Surgical exploration revealed thrombosis of the three cusps on the aortic side, limiting the opening of the valve. No relation could be established between the patient's human immunodeficiency virus status and valve thrombosis. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Surgical Results of Trabeculectomy and Ahmed Valve Implantation Following a Previous Failed Trabeculectomy in Primary Congenital Glaucoma Patients

PubMed Central

Lee, Naeun; Ma, Kyoung Tak; Bae, Hyoung Won; Hong, Samin; Seong, Gong Je; Hong, Young Jae

2015-01-01

Purpose To compare the surgical results of trabeculectomy and Ahmed glaucoma valve implantation after a previous failed trabeculectomy. Methods A retrospective comparative case series review was performed on 31 eye surgeries in 20 patients with primary congenital glaucoma who underwent trabeculectomy or Ahmed glaucoma valve implantation after a previous failed trabeculectomy with mitomycin C. Results The preoperative mean intraocular pressure was 25.5 mmHg in the trabeculectomy group and 26.9 mmHg in the Ahmed glaucoma valve implantation group (p = 0.73). The 48-month postoperative mean intraocular pressure was 19.6 mmHg in the trabeculectomy group and 20.2 mmHg in the Ahmed glaucoma valve implantation group (p = 0.95). The 12-month trabeculectomy success rate was 69%, compared with 64% for Ahmed glaucoma valve implantation, and the 48-month success rates were 42% and 36% for trabeculectomy and valve implantation, respectively. The success rates following the entire follow-up period were not significantly different between the two groups (p > 0.05 by log rank test). Postoperative complications occurred in 25% of the trabeculectomy-operated eyes and 9% of the Ahmed-implanted eyes (p = 0.38). Conclusions There was no significant difference in surgical outcome between the trabeculectomy and Ahmed glaucoma valve implantation groups, neither of which had favorable results. However, the trabeculectomy group demonstrated a higher prevalence of adverse complications such as post-operative endophthalmitis. PMID:25829827

Cardiac rehabilitation and mid-term follow-up after transcatheter aortic valve implantation

PubMed Central

Zanettini, Renzo; Gatto, Gemma; Mori, Ileana; Pozzoni, Maria Beatrice; Pelenghi, Stefano; Martinelli, Luigi; Klugmann, Silvio

2014-01-01

Background Evaluation of patient outcomes following transcatheter aortic valve implantation (TAVI) has usually been based on survival and clinical improvement. Studies on quality of life are limited, and data from comprehensive assessments after the procedure are lacking. Methods Sixty patients referred for cardiac rehabilitation after TAVI underwent in-hospital and after-discharge multidimensional assessments to evaluate clinical, functional, and nutritional statuses, degree of autonomy, cognitive impairment, depression and quality of life. Results On admission to rehabilitation, approximately half of the patients had severe functional impairment and dependence for basic activities of daily living. During their hospital stay, one-third of the patients suffered significant clinical complications and two had to be transferred to the implantation center. Despite this, the overall outcome was very good. All of the remaining patients were clinically stable at discharge and functional status, autonomy and quality of life were improved in most. During a mean follow-up of 540 days (range: 192–738 days), five patients died from noncardiac causes, three were hospitalized for cardiac events, and nine for non cardiac reasons. Functional status and autonomy remained satisfactory in the majority of patients and most continued to live independently. Conclusions Patients referred for rehabilitation after TAVI are often very frail, with a high grade of functional impairment, dependence on others and high risk of clinical complications. During a rehabilitation programme, based on a multidimensional assessment and intervention, most patients showed significant improvement in functional status, quality of life, and autonomy, which remained stable in the majority of subjects during mid-term follow-up. PMID:25593575

Polymicrobial Infective Endocarditis: Clinical Features and Prognosis

PubMed Central

García-Granja, Pablo Elpidio; López, Javier; Vilacosta, Isidre; Ortiz-Bautista, Carlos; Sevilla, Teresa; Olmos, Carmen; Sarriá, Cristina; Ferrera, Carlos; Gómez, Itziar; Román, José Alberto San

2015-01-01

Abstract To describe the profile of left-sided polymicrobial endocarditis (PE) and to compare it with monomicrobial endocarditis (ME). Among 1011 episodes of left-sided endocarditis consecutively diagnosed in 3 tertiary centers, between January 1, 1996 and December 31, 2014, 60 were polymicrobial (5.9%), 821 monomicrobial (81.7%), and in 123 no microorganism was detected (12.2%). Seven patients (0.7%) were excluded from the analysis because contamination of biologic tissue could not be discarded. The authors described the clinical, microbiologic, echocardiographic, and outcome of patients with PE and compared it with ME. Mean age was 64 years SD 16 years, 67% were men and 30% nosocomial. Diabetes mellitus (35%) were the most frequent comorbidities, fever (67%) and heart failure (43%) the most common symptoms at admission. Prosthetic valves (50%) were the most frequent infection location and coagulase-negative Staphylococci (48%) and enterococci (37%) the leading etiologies. The most repeated combination was coagulase-negative Staphylococci with enterococci (n = 9). Polymicrobial endocarditis appeared more frequently in patients with underlying disease (70% versus 56%, P = 0.036), mostly diabetics (35% versus 24%, P = 0.044) with previous cardiac surgery (15% versus 8% P = 0.049) and prosthetic valves (50% versus 37%, P = 0.038). Coagulase-negative Staphylococci, enterococci, Gram-negative bacilli, anaerobes, and fungi were more frequent in PE. No differences on age, sex, symptoms, need of surgery, and in-hospital mortality were detected. Polymicrobial endocarditis represents 5.9% of episodes of left-sided endocarditis in our series. Despite relevant demographic and microbiologic differences between PE and ME, short-term outcome is similar. PMID:26656328

Semi-automation of Doppler Spectrum Image Analysis for Grading Aortic Valve Stenosis Severity.

PubMed

Niakšu, O; Balčiunaitė, G; Kizlaitis, R J; Treigys, P

2016-01-01

Doppler echocardiography analysis has become a golden standard in the modern diagnosis of heart diseases. In this paper, we propose a set of techniques for semi-automated parameter extraction for aortic valve stenosis severity grading. The main objectives of the study is to create echocardiography image processing techniques, which minimize manual image processing work of clinicians and leads to reduced human error rates. Aortic valve and left ventricle output tract spectrogram images have been processed and analyzed. A novel method was developed to trace systoles and to extract diagnostic relevant features. The results of the introduced method have been compared to the findings of the participating cardiologists. The experimental results showed the accuracy of the proposed method is comparable to the manual measurement performed by medical professionals. Linear regression analysis of the calculated parameters and the measurements manually obtained by the cardiologists resulted in the strongly correlated values: peak systolic velocity's and mean pressure gradient's R2 both equal to 0.99, their means' differences equal to 0.02 m/s and 4.09 mmHg, respectively, and aortic valve area's R2 of 0.89 with the two methods means' difference of 0.19 mm. The introduced Doppler echocardiography images processing method can be used as a computer-aided assistance in the aortic valve stenosis diagnostics. In our future work, we intend to improve precision of left ventricular outflow tract spectrogram measurements and apply data mining methods to propose a clinical decision support system for diagnosing aortic valve stenosis.

Pledget-Armed Sutures Affect the Haemodynamic Performance of Biologic Aortic Valve Substitutes: A Preliminary Experimental and Computational Study.

PubMed

Capelli, Claudio; Corsini, Chiara; Biscarini, Dario; Ruffini, Francesco; Migliavacca, Francesco; Kocher, Alfred; Laufer, Guenther; Taylor, Andrew M; Schievano, Silvia; Andreas, Martin; Burriesci, Gaetano; Rath, Claus

2017-03-01

Surgical aortic valve replacement is the most common procedure of choice for the treatment of severe aortic stenosis. Bioprosthetic valves are traditionally sewed-in the aortic root by means of pledget-armed sutures during open-heart surgery. Recently, novel bioprostheses which include a stent-based anchoring system have been introduced to allow rapid implantation, therefore reducing the duration and invasiveness of the intervention. Different effects on the hemodynamics were clinically reported associated with the two technologies. The aim of this study was therefore to investigate whether the differences in hemodynamic performances are an effect of different anchoring systems. Two commercially available bio-prosthetic aortic valves, one sewed-in with pledget-armed sutures and one rapid-deployment, were thus tested in this study by means of a combined approach of experimental and computational tools. In vitro experiments were performed to evaluate the overall hydrodynamic performance under identical standard conditions; computational fluid dynamics analyses were set-up to explore local flow variations due to different design of the anchoring system. The results showed how the performance of cardiac valve substitutes is negatively affected by the presence of pledget-armed sutures. These are causing flow disturbances, which in turn increase the mean pressure gradient and decrease the effective orifice area. The combined approach of experiments and numerical simulations can be effectively used to quantify the detailed relationship between local fluid-dynamics and overall performances associated with different valve technologies.

Long-term results of pulmonary valve annular enlargement with valve repair in tetralogy of Fallot.

PubMed

Kim, Hyungtae; Sung, Si Chan; Choi, Kwang Ho; Lee, Hyoung Doo; Kim, Geena; Ko, Hoon; Lee, Young Seok

2018-06-01

We adopted an operative technique of pulmonary valve (PV) annular enlargement with valve repair in tetralogy of Fallot (TOF) correction to reduce postoperative pulmonary regurgitation (PR) 16 years ago. Here, we have evaluated the long-term results. Between April 2000 and August 2005, 43 patients (26 men) with tetralogy of Fallot with pulmonary stenosis underwent PV annular enlargement with valve repair. The median age and body weight at the time of surgery were 14 months and 10.2 kg, respectively. There was no operative mortality. Mean postoperative PR grade at discharge was 0.93 ± 0.40 (none or trivial in 10 patients, mild in 27 patients, mild to moderate in 5 patients and moderate in 1 patient), and the mean postoperative pressure gradient across PV was 13.0 ± 10.9 mmHg. The mean follow-up duration was 131.9 ± 42.9 months. During follow-up, 1 reoperation was performed for residual ventricular septal defect. The mean PR grade at the last follow-up echocardiography was 1.59 ± 0.60 (mild in 17 patients, mild to moderate in 8 patients, moderate in 14 patients, moderate to severe in 1 patient and severe in 3 patients), and the mean pressure gradient was 22.7 ± 9.9 mmHg. We have compared the incidence of moderate or more PR with the incidence of patients who underwent simple transannular patch enlargement through propensity score matching. The PV repair group had a lower incidence of moderate or more PR compared with the simple transannular patch group (40% vs 68%, P = 0.04). PV annular enlargement with valve repair has reasonable long-term results and yields a lower long-term incidence of significant PR compared with the simple transannular patch enlargement technique.

Effectiveness of rivaroxaban for thromboprophylaxis of prosthetic heart valves in a porcine heterotopic valve model.

PubMed

Greiten, Lawrence E; McKellar, Stephen H; Rysavy, Joseph; Schaff, Hartzell V

2014-05-01

Warfarin is used to reduce the risk of stroke and thromboembolic complications in patients with mechanical heart valves. Yet, despite frequent blood testing, its poor pharmacokinetic and pharmacodynamic profiles often result in variable therapeutic levels. Rivaroxaban is a direct competitive factor Xa inhibitor that is taken orally. It inhibits the active site of factor Xa without the need for the cofactor antithrombin, and thus, its mechanism of action is differentiated from that of the fractionated heparins and indirect factor Xa inhibitors. No in vivo data exist regarding the effectiveness of rivaroxaban in preventing thromboembolic complications of mechanical heart valves. We tested the hypothesis that rivaroxaban is as effective as enoxaparin for thromboprophylaxis of mechanical valves that use a previously described heterotopic aortic valve porcine model. A modified bileaflet mechanical valved conduit that bypassed the native, ligated descending thoracic aorta was implanted into 30 swine. Postoperatively, the animals were randomly assigned to groups receiving no anticoagulation (n = 10), enoxaparin at 2 mg/kg subcutaneously twice daily (n = 10) or rivaroxaban at 2 mg/kg orally twice daily (n = 10). The amount of valve thrombus was measured on post-implantation day 30 as the primary end point. Quantitative evaluation of radiolabelled platelet deposition on the valve prostheses was done and embolic and haemorrhagic events were measured as secondary end points. Animals with no anticoagulation had a thrombus mean of 759.9 mg compared with 716.8 mg with enoxaparin treatment and 209.6 mg with rivaroxaban treatment (P = 0.05 for enoxaparin vs rivaroxaban). Similarly, the mean number of platelets deposited on the valve prosthesis was lower in the rivaroxaban group (6.13 × 10(9)) than in the enoxaparin group (3.03 × 10(10)) (P = 0.03). In this study, rivaroxaban was more effective than enoxaparin for short-term thromboprophylaxis of mechanical valve prosthetics in the heterotopic aortic position. It reduced valve thrombus and platelet deposition on day 30 following implantation without increased adverse events. Future studies would provide additional support for clinical trials evaluating rivaroxaban as an alternative to warfarin for appropriately selected patients with prosthetic aortic valves.

North American trial results at 1 year with the Sorin Freedom SOLO pericardial aortic valve.

PubMed

Heimansohn, David; Roselli, Eric E; Thourani, Vinod H; Wang, Shaohua; Voisine, Pierre; Ye, Jian; Dabir, Reza; Moon, Michael

2016-02-01

A North American prospective, 15-centre Food and Drug Administration (FDA) valve trial was designed to assess the safety and effectiveness of the Freedom SOLO stentless pericardial aortic valve in the treatment of surgical aortic valve disease. Beginning in 2010, 251 patients (mean: 74.7 ± 7.5 years), were recruited in the Freedom SOLO aortic valve trial. One hundred eighty-nine patients have been followed for at least 1 year and are the basis for this review. Preoperatively, 54% of patients had NYHA functional class III or IV symptoms, and the majority of patients had a normal ejection fraction (EF) (median EF = 61%). Concomitant procedures were performed in 61.9% of patients, with coronary artery bypass grafting (CABG) (48.7%) being the most common followed by a MAZE procedure (13.7%). Reoperations were performed in 8.5% of patients in the study. The entire cohort of 251 patients enrolled had 7 deaths prior to 30 days, 2 of which were valve-related (aspiration pneumonia and sudden death) and 5 were not valve-related. There were 11 deaths after 30 days, 1 valve-related (unknown cardiac death) and 10 not valve-related. Five valves were explanted, 3 early (endocarditis, acute insufficiency and possible root dissection) and 2 late (endocarditis). Thirty-day adverse events include arrhythmias requiring permanent pacemaker (4.2%), thromboembolic events (3.7%) and thrombocytopenia (7.4%). One-year follow-up of all 189 patients demonstrated mean gradients for valve sizes 19, 21, 23, 25 and 27 mm of 11.7, 7.8, 6.3, 4.6 and 5.0 mmHg, respectively. Effective orifice areas for the same valve sizes were 1.2, 1.3, 1.6, 1.8 and 1.9 cm(2), respectively. Ninety-six percent of patients (181/189) were in NYHA class I or II at the 1-year follow-up. The Freedom SOLO stentless pericardial aortic valve demonstrated excellent haemodynamics and a good safety profile out to the 1 year of follow-up. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Aortic valve function after bicuspidization of the unicuspid aortic valve.

PubMed

Aicher, Diana; Bewarder, Moritz; Kindermann, Michael; Abdul-Khalique, Hashim; Schäfers, Hans-Joachim

2013-05-01

Unicuspid aortic valve (UAV) anatomy leads to dysfunction of the valve in young individuals. We introduced a reconstructive technique of bicuspidizing the UAV. Initially we copied the typical asymmetry of a normal bicuspid aortic valve (BAV) (I), later we created a symmetric BAV (II). This study compared the hemodynamic function of the two designs of a bicuspidized UAV. Aortic valve function was studied at rest and during exercise in 28 patients after repair of UAV (group I, n = 8; group II, n = 20). There were no differences among the groups I and II with respect to gender, age, body size, or weight. All patients were in New York Heart Association class I. Six healthy adults served as control individuals. All patients were studied with transthoracic echocardiography between 4 and 65 months postoperatively. Systolic gradients were assessed by continuous wave Doppler while patients were at rest and exercising on a bicycle ergometer. Aortic regurgitation was grade I or less in all patients. Resting gradients were significantly elevated in group I compared with group II and control individuals (group I, peak 33.8 ± 7.8 mm Hg; mean 19.1 ± 5.4 mm Hg; group II, peak 15.8 ± 5.4, mean 8.2 ± 2.8 mm Hg; control individuals, peak 6.0 ± 1.6, mean 3.2 ± 0.8 mm Hg; p < 0.001). At 100 W peak gradients were highest in group I (group I, 62.7 ± 16.7 mm Hg; group II, 28.1 ± 7.6 mm Hg; control individuals, 15.4 ± 4.6 mm Hg; p < 0.001). Converting a UAV into a symmetric bicuspid design results in adequate valve competence. A symmetric repair design leads to improved systolic aortic valve function at rest and during exercise. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

A second prosthesis as a procedural rescue option in trans-apical aortic valve implantation.

PubMed

Kempfert, Jörg; Rastan, Ardawan J; Schuler, Gerhard; Linke, Axel; Holzhey, David; van Linden, Arnaud; Mohr, Friedrich-W; Walther, Thomas

2011-07-01

Trans-apical aortic valve implantation (TA-AVI) using the Edwards SAPIEN™ prosthesis has evolved to a routine procedure for selected high-risk elderly patients. In rare cases, misplacement of the SAPIEN™ valve (too low a position), dysfunction of the leaflets or perforation of the interventricular septum (ventricular septal defect, VSD) occurs and requires immediate implantation of a second prosthesis within the first one. Results of this 'bailout' maneuver have not been reported yet. Of 305 TA-AVI procedures, 15 patients required a second prosthesis due to dysfunctional leaflets (n = 6), low position (n = 7), or VSD (n = 2). Mean age was 82.5 ± 1.3 years, mean logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) was 45.5 ± 5.4, and Society of Thoracic Surgeons (STS) Score was 13.5 ± 1.5. All second SAPIEN™ valves could be implanted successfully within the first one. The second prosthesis solved leaflet dysfunction, sealed the VSD (lower position of the second prosthesis), or corrected the initial misplacement (higher position of the second prosthesis) in all patients. Within 30 days, four patients died (low cardiac output n = 3, all with preoperative ejection fraction (EF) <35%; intestinal ischemia n = 1). Intra-operative echocardiogram and angiogram revealed mild paravalvular leak in three and none/trace in 12 patients. Transvalvular gradients were low despite the implantation of the second valve (P(max)/mean 13.7 ± 4.3/6.4 ± 2.0). Placement of a second SAPIEN™ valve is a valuable 'bailout' technique in case of VSD, dysfunctional leaflets, or too low placement of the first prosthesis. The technique leads to an excellent functional result with low transvalvular gradients. The simple, straight, tubular stent design of the SAPIEN™ prosthesis may be the ideal design for such valve-in-valve procedures. Copyright © 2011 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Snare-assisted anterograde balloon mitral and aortic valvotomy using Inoue balloon catheter.

PubMed

Krishnan, Mangalath N; Syamkumar, M D; Sajeev, C G; Venugopal, K; Johnson, Francis; Vinaykumar, D; Velayudhan, C C; Jayakumar, T G

2007-01-02

We performed concurrent antegrade mitral and aortic valvotomy using Inoue dilatation catheter in 3 cases of combined rheumatic mitral and aortic stenosis. Following mitral valvotomy by standard procedure, aortic valve was crossed with the help of a floatation catheter. Stiff long length guide wire was fixed in descending aorta using a snare. Inoue catheter was threaded over the wire across the aortic valve and aortic valvotomy completed. Mitral valve area increased from mean 1 cm2 to 2 cm2; aortic gradient dropped from mean of 97 mm to 36 mm. Concurrent anterograde balloon mitral and aortic valvotomy may be effective and safe.

A Prospective Cohort Study of Outpatient Interdisciplinary Rehabilitation of Chronic Headache Patients.

PubMed

Krause, Steven J; Stillman, Mark J; Tepper, Deborah E; Zajac, Deborah

2017-03-01

To evaluate the efficacy of an intensive outpatient program designed to improve functioning and reduce psychological impairment in chronic headache patients. Chronic headaches, occurring 15 or more days per month, for three or more months, may arise from multiple International Classification of Headache Disorders diagnoses: Chronic Migraine, Chronic Tension Type Headache, New Daily Persistent Headache, Chronic Post Traumatic Headaches, and Medication Overuse Headache. Several interdisciplinary programs that treat patients with chronic headaches have reported decreases in headache frequency. This study sought to evaluate the effect of a 3 week interdisciplinary treatment program for patients with chronic headache disorders on headache severity, functional status, and psychological impairment. Subjects were 379 patients admitted to an outpatient chronic headache treatment program. Assessments of headache severity, psychological status, and functional impairment were completed by 371 (97.8%) of these at the time of admission. At discharge, 340 subjects (89.7%) provided assessment data, and 152 (40.1%) provided data at 1-year follow-up. Subjects' mean ratings on a 0-10 scale for their headache pain in the prior week declined, and these improvements were maintained at follow-up. (Estimated marginal means on a 0-10 scale for Average pain: admission 6.1, discharge 3.5, follow-up 3.3; for Least pain: admission 3.2; discharge 1.5; follow-up 1.3; for Worst pain: admission 8.2; discharge 6.4; follow-up 5.7), and similar results were found for current pain (admission 4.7; discharge 2.8; follow-up 2.4): Measures of functional impairment also improved following treatment, and these gains were maintained at 12 month follow up (Estimated marginal mean Headache Impact Test-6 score: admission 66.1, discharge 55.4, follow-up 51.9; Estimated marginal mean Pain Disability Index score: admission 36.2, discharge 14.1, follow-up 11.6). As measured by the Depression, Anxiety and Stress Scale, anxiety and reactivity to stress decreased following treatment, and remained improved at follow-up (Estimated marginal mean score for Anxiety: admission 8.7, discharge 5.2, follow-up 4.4; Estimated marginal mean score for stress: admission 14.9, discharge 7.2, follow-up 7.6). Depression decreased with treatment, but while 1-year follow-up depression scores remained significantly lower than at admission, they were also significantly higher than at discharge (Estimated marginal means: admission 13.3, discharge 4.1, follow-up 6.6). The study supports the efficacy of the treatment model. Limitations of the study and suggestions for future research are also discussed. © 2017 American Headache Society.

The Ross operation: the autologous pulmonary valve in the aortic position.

PubMed

Gonzalez-Lavin, L; Robles, A; Graf, D

1988-03-01

Aortic valve replacement (AVR) with a pulmonary valve autograft (PVA) was first reported by Donald N. Ross (DNR) in 1967. The expectation of this procedure was to avoid degenerative changes seen in other biological tissue valves such as calcification, attenuation, and rupture of the leaflets. Recent reports by the original investigator's group have confirmed the lack of degenerative changes in PVA. To corroborate their conclusions, the fate of 12 patients undergoing AVR with PVA by one of us (LGL) has been ascertained. From March 1969 to June 1971, 12 patients underwent AVR with PVA. The right ventricular outflow tract (RVOT) was reconstructed with an aortic homograft valved conduit. The mean age was 42.7 years (range 21 to 52 years). The mean follow-up for 11 hospital survivors is 12.4 years. Three PVA have been replaced; one following infective endocarditis at 13 years, and two at 15 and 73 months due to technical malalignment. There was no evidence of PVA degeneration during histological examination of these explanted PVAs. Six patients are alive and retain the original PVA at 12 years (55%). This analysis corroborates the conclusions of the DNR report and strongly suggests an immunological mechanism in the process of calcification of other biological tissue valves. The Ross operation is advocated for AVR in young patients as valve durability is of paramount importance especially in this group.

Engine Valve Actuation For Combustion Enhancement

DOEpatents

Reitz, Rolf Deneys; Rutland, Christopher J.; Jhavar, Rahul

2004-05-18

A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-stroke combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Engine valve actuation for combustion enhancement

DOEpatents

Reitz, Rolf Deneys [Madison, WI; Rutland, Christopher J [Madison, WI; Jhavar, Rahul [Madison, WI

2008-03-04

A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-strokes combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Self-expanding Portico Valve Versus Balloon-expandable SAPIEN XT Valve in Patients With Small Aortic Annuli: Comparison of Hemodynamic Performance.

PubMed

Del Trigo, María; Dahou, Abdellaziz; Webb, John G; Dvir, Danny; Puri, Rishi; Abdul-Jawad Altisent, Omar; Campelo-Parada, Francisco; Thompson, Chris; Leipsic, Jonathon; Stub, Dion; DeLarochellière, Robert; Paradis, Jean-Michel; Dumont, Eric; Doyle, Daniel; Mohammadi, Siamak; Pasian, Sergio; Côté, Melanie; Pibarot, Philippe; Rodés-Cabau, Josep

2016-05-01

The self-expanding Portico valve is a new transcatheter aortic valve system yielding promising preliminary results, yet there are no comparative data against earlier generation transcatheter aortic valve systems. The aim of this study was to compare the hemodynamic performance of the Portico and balloon-expandable SAPIEN XT valves in a case-matched study with echocardiographic core laboratory analysis. Twenty-two patients underwent transcatheter aortic valve implantation with the Portico 23-mm valve and were matched for aortic annulus area and mean diameter measured by multidetector computed tomography, left ventricular ejection fraction, body surface area, and body mass index with 40 patients treated with the 23-mm SAPIEN XT. Mean aortic annulus diameters were 19.6±1.3mm by transthoracic echocardiography and 21.4±1.2mm by computed tomography, with no significant between-group differences. Doppler echocardiographic images were collected at baseline and at 1-month of follow-up and were analyzed in a central echocardiography core laboratory. There were no significant between-group differences in residual mean transaortic gradients (SAPIEN XT: 10.4±3.7mmHg; Portico: 9.8±1.1mmHg; P=.49) and effective orifice areas (SAPIEN XT: 1.36±0.27cm(2); Portico, 1.37±.29cm(2); P=.54). Rates of severe prosthesis-patient mismatch (effective orifice area<0.65cm(2)/m(2)) were similar (SAPIEN XT: 13.5%; Portico: 10.0%; P=.56). No between-group differences were found in the occurrence of moderate-severe paravalvular leaks (5.0% vs 4.8% of SAPIEN XT and Portico respectively; P=.90). Transcatheter aortic valve implantation with the self-expanding Portico system yielded similar short-term hemodynamic performance compared with the balloon-expandable SAPIEN XT system for treating patients with severe aortic stenosis and small annuli. Further prospective studies with longer-term follow-up and in patients with larger aortic annuli are required. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Long-term Results After Open Mitral Commissurotomy for a One-Month-Old Infant With Mitral Stenosis.

PubMed

Kitaichi, Takashi; Sugano, Mikio; Arase, Hiroki; Kawatani, Yohei; Kameta, Kanako; Kurobe, Hirotsugu; Fujimoto, Eiki; Ono, Akemi; Hayabuchi, Yasunobu; Fujita, Hiroshi; Sogabe, Hitoshi; Kitagawa, Tetsuya

2017-01-01

The strategy for an infant with congenital mitral stenosis should be determined by three important factors: left ventricular volume, the degree of the systemic outflow tract obstruction, and the type of mitral valve dysfunction. A successful staged biventricular repair in early infancy for a patient who had congenital mitral stenosis with short chordae, hypoplastic left ventricle and coarctation of the aorta, and the long-term results are described. There were the following important hemodynamic factors that led to the successful biventricular repair in the patient. Total systemic output was barely supplied through the hypoplastic left ventricle after closure of the ductus arteriosus on admission. The neonate underwent repair of coarctation of the aorta alone as the initial stage at 9 days after birth. Also, spontaneous closure of the foramen ovale following repair of coarctation of the aorta accelerated the progressive left ventricular growth. Open mitral commissurotomy with an interatrial fenestration using the modified Brawley's approach was performed for a 40-day-old infant. Good left ventricular growth and good mitral valve function have been observed for 18 years after open mitral commissurotomy. Appropriate early augmentation of left ventricular inflow through the mitral valve might be effective for growth of a hypoplastic left ventricle. J. Med. Invest. 64: 187-191, February, 2017.

Analysis of fatigue reliability for high temperature and high pressure multi-stage decompression control valve

NASA Astrophysics Data System (ADS)

Yu, Long; Xu, Juanjuan; Zhang, Lifang; Xu, Xiaogang

2018-03-01

Based on stress-strength interference theory to establish the reliability mathematical model for high temperature and high pressure multi-stage decompression control valve (HMDCV), and introduced to the temperature correction coefficient for revising material fatigue limit at high temperature. Reliability of key dangerous components and fatigue sensitivity curve of each component are calculated and analyzed by the means, which are analyzed the fatigue life of control valve and combined with reliability theory of control valve model. The impact proportion of each component on the control valve system fatigue failure was obtained. The results is shown that temperature correction factor makes the theoretical calculations of reliability more accurate, prediction life expectancy of main pressure parts accords with the technical requirements, and valve body and the sleeve have obvious influence on control system reliability, the stress concentration in key part of control valve can be reduced in the design process by improving structure.

A 3D velocimetry study of the flow through prosthetic heart valves

NASA Astrophysics Data System (ADS)

Ledesma, R.; Zenit, R.; Pulos, G.; Sanchez, E.; Juarez, A.

2006-11-01

Blood damage commonly appears in medical valve prothesis. It is a mayor concern for the designers and surgeons. It is well known that this damage and other complications result from the modified fluid dynamics through the replacement valve. To evaluate the performance of prosthetic heart valves, it is necessary to study the flow through them. To conduct this study , we have built a flow channel that emulates cardiac conditions and allows optical access such that a 3D-PIV velocimetry system could be used. The experiments are aimed to reconstruct the downstream structure of the flow through a mechanical and a bio-material tricuspid heart valve prothesis. Preliminary results show that the observed coherent structures can be related with haemolysis and trombosis, illnesses commonly found in valve prothesis recipients. The mean flow, the levels of strain rate and the turbulence intensity generated by the valves can also be directly related to blood damage. In general, bio-material made valves tend to reduce these complications.

Changes in turbulence with rotation of the omnicarbon prosthesis.

PubMed

Travis, Brandon R; Nyboe, Camilla; Christensen, Thomas D; Smerup, Morten; Johansen, Peter; Nygaard, Hans; Hasenkam, J Michael

2007-01-01

This study was performed to determine whether annular plane orientation of the Omnicarbon aortic valve influences forward flow turbulence. The Omnicarbon prostheses was modified to allow in situ manual rotation of the valve when implanted in the aortic position of eight 90 kg pigs. Pulsed Doppler ultrasound was used to acquire velocity measurements at 17 locations within the cross-sectional area of the ascending aorta. In each animal, 12 valve rotations were tested in this manner. Reynolds normal stresses were estimated from the velocity measurements. High Reynolds normal stresses were concentrated between left and posterior-right sides of the aortic wall for all orientations studied. No trends in mean or maximum Reynolds normal stresses with respect to valve rotation were consistent in the experiments. Unlike previous experiments with the Medtronic-Hall tilting disc valve, these experiments showed no notable changes in Reynolds normal stress with respect to orientation of the Omnicarbon valve. This suggests that the tendency of turbulent stresses to change with tilting disc valve orientation may be dependent on valve design.

Bioprosthetic Valve Fracture Improves the Hemodynamic Results of Valve-in-Valve Transcatheter Aortic Valve Replacement.

PubMed

Chhatriwalla, Adnan K; Allen, Keith B; Saxon, John T; Cohen, David J; Aggarwal, Sanjeev; Hart, Anthony J; Baron, Suzanne J; Dvir, Danny; Borkon, A Michael

2017-07-01

Valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR) may be less effective in small surgical valves because of patient/prosthesis mismatch. Bioprosthetic valve fracture (BVF) using a high-pressure balloon can be performed to facilitate VIV TAVR. We report data from 20 consecutive clinical cases in which BVF was successfully performed before or after VIV TAVR by inflation of a high-pressure balloon positioned across the valve ring during rapid ventricular pacing. Hemodynamic measurements and calculation of the valve effective orifice area were performed at baseline, immediately after VIV TAVR, and after BVF. BVF was successfully performed in 20 patients undergoing VIV TAVR with balloon-expandable (n=8) or self-expanding (n=12) transcatheter valves in Mitroflow, Carpentier-Edwards Perimount, Magna and Magna Ease, Biocor Epic and Biocor Epic Supra, and Mosaic surgical valves. Successful fracture was noted fluoroscopically when the waist of the balloon released and by a sudden drop in inflation pressure, often accompanied by an audible snap. BVF resulted in a reduction in the mean transvalvular gradient (from 20.5±7.4 to 6.7±3.7 mm Hg, P <0.001) and an increase in valve effective orifice area (from 1.0±0.4 to 1.8±0.6 cm 2 , P <0.001). No procedural complications were reported. BVF can be performed safely in small surgical valves to facilitate VIV TAVR with either balloon-expandable or self-expanding transcatheter valves and results in reduced residual transvalvular gradients and increased valve effective orifice area. © 2017 American Heart Association, Inc.

Correction of congenital heart defects in Jehovah's Witness children.

PubMed

Alexi-Meskishvili, V; Stiller, B; Koster, A; Böttcher, W; Hübler, M; Photiadis, J; Lange, P E; Hetzer, R

2004-06-01

Between August 1989 and July 2003 14 Jehovah's Witness children with congenital heart defects (CHD) aged under 14 years (median 2.9 years) and with a median weight of 14 kg underwent 16 operations with cardiopulmonary bypass (CPB). Five children had been operated on previously between one to three times. Preoperatively, 7 children were prepared with oral iron supplementation and 10 received erythropoietin. Mean hemoglobin (Hb) at admission was 14.4 g/dl (range 10.9 - 19.2). The cardiopulmonary bypass (CPB) circuit was modified to reduce total priming volume. High doses of aprotinin were administered. The modified ultrafiltration (MUF) circuit, used in 7 patients, was parallel to the ECC circuit with continuous circulation of the blood through a small shunt between the arterial and venous lines. Operations performed consisted of VSD closure (3 pts.), ASD closure (3 pts.), Fontan operation (2 pts.), and complete AV canal correction, aortic commissurotomy, Ross operation, Glenn shunt, cor triatriatum correction, MV reconstruction combined with left outflow tract stenosis resection, correction of absent pulmonary valve syndrome, and correction of tetralogy of Fallot in one patient each. There were no deaths. Mean duration of CPB was 192 min and mean aortic cross-clamp time 40 min. The Hb value at the end of the operation was 4.9 - 14.5 g/dl (mean 9.6) and at discharge it was 7.1 - 14.5 g/dl (mean 15.5). No blood or blood products were used in any patient. Bloodless cardiac surgery with and without CPB can be safely performed in Jehovah's Witness infants and children.

Bioprosthetic Valve Fracture During Valve-in-valve TAVR: Bench to Bedside.

PubMed

Saxon, John T; Allen, Keith B; Cohen, David J; Chhatriwalla, Adnan K

2018-01-01

Valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR) has been established as a safe and effective means of treating failed surgical bioprosthetic valves (BPVs) in patients at high risk for complications related to reoperation. Patients who undergo VIV TAVR are at risk of patient-prosthesis mismatch, as the transcatheter heart valve (THV) is implanted within the ring of the existing BPV, limiting full expansion and reducing the maximum achievable effective orifice area of the THV. Importantly, patient-prosthesis mismatch and high residual transvalvular gradients are associated with reduced survival following VIV TAVR. Bioprosthetic valve fracture (BVF) is as a novel technique to address this problem. During BPV, a non-compliant valvuloplasty balloon is positioned within the BPV frame, and a highpressure balloon inflation is performed to fracture the surgical sewing ring of the BPV. This allows for further expansion of the BPV as well as the implanted THV, thus increasing the maximum effective orifice area that can be achieved after VIV TAVR. This review focuses on the current evidence base for BVF to facilitate VIV TAVR, including initial bench testing, procedural technique, clinical experience and future directions.

Datagram: Medical College Admission Test

ERIC Educational Resources Information Center

Nelson, Bonnie C.

1974-01-01

Presents data concerning the Medical College Admission Test (MCAT): number of MCAT examinations, 1968-73; characteristics of examinee population; comparison of percentages; mean MCAT scores by sex; and mean score by undergraduate major. (Author/PG)

Pericardial tissue valves and Gore-Tex conduits as an alternative for right ventricular outflow tract replacement in children.

PubMed

Allen, Bradley S; El-Zein, Chawki; Cuneo, Betina; Cava, Joseph P; Barth, Mary Jane; Ilbawi, Michel N

2002-09-01

There is still no perfect conduit for reconstruction of the right ventricular outflow tract (RVOT) in children. Homografts are not always available in the appropriate size, and degenerate in a few years. This study evaluates the pericardial valve with Gore-Tex conduit as an alternative for RVOT construction. From January 1, 1993, to September 30, 1999, a pericardial tissue valve was inserted in all patients undergoing RVOT reconstruction or pulmonary valve replacement (PVR) who were large enough to accommodate a tissue valve. In patients without a native main pulmonary artery, a new technique was used to construct an RV-PA conduit out of a flat sheet of Gore-Tex, as Dacron frequently leads to stenosis. Data were collected by retrospective review, follow-up echocardiograms, and assessment by a single cardiologist. There were 48 patients, 22 undergoing a PVR alone and 26 a RV-PA valved Gore-Tex conduit. Diagnosis included tetralogy of Fallot (n = 25); truncus arteriosis (n = 9); ventricular septal defect with PA (n = 5); DORV (n = 4); D-TGA with PS (n = 2); and 1 each IAA with sub AS, VSD with PI, and PS s/p Ross procedure. Patient age ranged from 3 to 33 years and 98% were reoperations. The valve sizes ranged from 19 to 33 mm and the median hospital length of stay was 4 days. There were 2 (4.2%) perioperative and 1 (2.1%) late deaths, none related to the valve or Gore-Tex conduit. At a follow-up of 15 to 86 months (mean 43 +/- 16 months), all remaining 45 patients are New York Heart Association class I, all valves are functional, and no patient has required valve or conduit replacement or revision; more importantly, echocardiogram revealed no significant valve or conduit stenosis (mean gradient 16 +/- 8 mm Hg) and no evidence of regurgitation or structural degeneration. A pericardial tissue valve and Gore-Tex conduit provides a reliable alternative for RVOT reconstruction in pediatric patients. It is readily available, molds in the limited retrosternal space, and has outstanding intermediate results with no evidence of failure or deterioration up to 7 years after insertion.

Acute aortic dissection involving the root: operative and long-term outcome after curative proximal repair†

PubMed Central

Urbanski, Paul P.; Lenos, Aristidis; Irimie, Vadim; Bougioukakis, Petros; Zacher, Michael; Diegeler, Anno

2016-01-01

OBJECTIVES The aim of the study was to evaluate operative and long-term results after surgery of acute aortic dissection involving the root, in which the proximal repair consisted of curative resection of all dissected aortic sinuses and was performed using either valve-sparing root repair or complete root replacement with a valve conduit. METHODS Between August 2002 and March 2013, 162 consecutive patients (mean age 63 ± 14 years) underwent surgery for acute type A aortic dissection. Eighty-six patients with an involvement of the aortic root underwent curative surgery of the proximal aorta consisting of valve-sparing root repair (n = 54, 62.8%) or complete valve and root replacement using composite valve grafts (n = 32, 37.2%). In patients with root repair, all dissected aortic walls were resected and root remodelling using the single patch technique (n = 53) or root repair with valve reimplantation (n = 1) was performed without the use of any glue. All perioperative data were collected prospectively and retrospective statistical examination was performed using univariate and multivariate analyses. RESULTS The mean follow-up was 5.2 ± 3.5 years for all patients (range 0–12 years) and 6.1 ± 3.3 years for survivors. The 30-day mortality rate was 5.8% (5 patients), being considerably lower in the repair sub-cohort (1.9 vs 12.5%). The estimated survival rate at 5 and 10 years was 80.0 ± 4.5 and 69.1 ± 6.7%, respectively. No patient required reoperation on the proximal aorta and/or aortic valve during the follow-up time and there were only two valve-related events (both embolic, one in each group). Among those patients with repaired valves, the last echocardiography available showed no insufficiency in 40 and an irrelevant insufficiency (1+) in 14. CONCLUSIONS Curative repair of the proximal aorta in acute dissection involving the root provides favourable operative and long-term outcome with very low risk of aortic complications and/or reoperations, regardless if a valve-sparing procedure or replacement with a valve conduit is used. Valve-sparing surgery is frequently suitable, providing excellent outcome and very high durability. PMID:26848190

The first fifty consecutive Bentall operations with a prefabricated tissue-valved aortic conduit: a single-center experience.

PubMed

Baraki, Hassina; Al Ahmad, Ammar; Sarikouch, Samir; Koigeldiev, Nurbol; Khaladj, Nawid; Hagl, Christian; Pichlmaier, Maximillian; Haverich, Axel; Shrestha, Malakh

2010-05-01

Composite replacement is the standard treatment for the repair of aortic aneurysm with aortic valve pathology. With improved long-term durability and no requirement for long-term anticoagulation, tissue-valved conduits have become increasingly popular. Herein are reported the results achieved with 50 consecutive 'Bentall' operations, using the first commercially available prefabricated stentless tissue-valved conduit (Vascutek BioValsalva). Between September 2007 and September 2009, a total of 50 patients (10 females, 40 males; mean age 65 +/- 7 years) received a BioValsalva conduit. Concomitant procedures included coronary artery bypass grafting (CABG; n = 15), other valve (n = 5), and aortic arch replacement with circulatory arrest (n = 20; three of these had an additional frozen elephant trunk). Four of the procedures were re-operations. A six-month follow up with echocardiography and clinical examination was completed in 25 patients. The 30-day mortality was 8% (4/50). Three of these patients underwent concomitant procedures. The cardiopulmonary bypass (CPB) and cross-clamp times were 178 +/- 30 min and 106 +/- 7 min, respectively. The triple-layered vascular graft proved to be hemostatic, without suture-line bleeding. Both, the initial and follow up echocardiography showed no valvular insufficiency, with a mean gradient of 13 +/- 5 mmHg. All patients were in NYHA class I-II. The BioValsalva prefabricated tissue-valved conduit showed very good early results. The ischemic time required to construct a 'home-made' stentless tissue-valved conduit was eliminated, thus reducing the cross-clamp time. The conduit also offered the hemodynamic advantages of a stentless valve.

Coronary flow reserve is impaired in patients with aortic valve calcification.

PubMed

Bozbas, Huseyin; Pirat, Bahar; Yildirir, Aylin; Simşek, Vahide; Sade, Elif; Eroglu, Serpil; Atar, Ilyas; Altin, Cihan; Demirtas, Saadet; Ozin, Bulent; Muderrisoglu, Haldun

2008-04-01

Calcific aortic valve disease is an active and progressive condition. Data indicate that aortic valve calcification (AVC) is associated with endothelial dysfunction and accepted as a manifestation of atherosclerosis. Coronary flow reserve (CFR) determined by transthoracic echocardiography has been introduced as a reliable indicator for coronary microvascular function. In this study we aimed to evaluate CFR in patients with AVC. Eighty patients, aged more than 60 years, without coronary heart disease or diabetes mellitus were included: 40 had AVC without significant stenosis (peak gradient across the valve <25 mm Hg) and 40 had normal aortic valves (controls). Using transthoracic Doppler echocardiography, we measured coronary diastolic peak flow velocities (PFV) at baseline and after dipyridamole infusion. CFR was calculated as the ratio of hyperemic to baseline diastolic PFV and was compared between groups. Mean ages for patients with AVC and controls were 68.9+/-6.2 and 67.6+/-5.9 years (P=.3). There were no significant differences regarding clinical characteristics, laboratory findings, ejection fraction, or peak aortic valve gradients. Mean diastolic PFV at baseline and during hyperemia were 28.4+/-4.2 and 59.2+/-7.8 cm/s for AVC and 27.7+/-3.9 and 68.5+/-10.5 cm/s for controls. Compared with controls, patients with AVC had significantly lower CFR values (2.12+/-0.41 versus 2.51+/-0.51; P<.0001). CFR is impaired in patients with AVC before valve stenosis develops, suggesting that microvascular-endothelial dysfunction is present during the early stages of the calcific aortic valve disease.

Spectrum of Aortic Valve Abnormalities Associated with Aortic Dilation Across Age Groups in Turner Syndrome

PubMed Central

Olivieri, Laura J.; Baba, Ridhwan Y.; Arai, Andrew E.; Bandettini, W. Patricia; Rosing, Douglas R.; Bakalov, Vladimir; Sachdev, Vandana; Bondy, Carolyn A.

2014-01-01

Background Congenital aortic valve fusion is associated with aortic dilation, aneurysm and rupture in girls and women with Turner syndrome (TS). Our objective was to characterize aortic valve structure in subjects with TS, and determine the prevalence of aortic dilation and valve dysfunction associated with different types of aortic valves. Methods and Results The aortic valve and thoracic aorta were characterized by cardiovascular magnetic resonance imaging in 208 subjects with TS in an IRB-approved natural history study. Echocardiography was used to measure peak velocities across the aortic valve, and the degree of aortic regurgitation. Four distinct valve morphologies were identified: tricuspid aortic valve (TAV) 64%(n=133), partially fused aortic valve (PF) 12%(n=25), bicuspid aortic valve (BAV) 23%(n=47), and unicuspid aortic valve (UAV) 1%(n=3). Age and body surface area (BSA) were similar in the 4 valve morphology groups. There was a significant trend, independent of age, towards larger BSA-indexed ascending aortic diameters (AADi) with increasing valve fusion. AADi were (mean +/− SD) 16.9 +/− 3.3 mm/m2, 18.3 +/− 3.3 mm/m2, and 19.8 +/− 3.9 mm/m2 (p<0.0001) for TAV, PF and BAV+UAV respectively. PF, BAV, and UAV were significantly associated with mild aortic regurgitation and elevated peak velocities across the aortic valve. Conclusions Aortic valve abnormalities in TS occur with a spectrum of severity, and are associated with aortic root dilation across age groups. Partial fusion of the aortic valve, traditionally regarded as an acquired valve problem, had an equal age distribution and was associated with an increased AADi. PMID:24084490

Aortic valve replacement and concomitant right coronary artery bypass grafting performed via a right minithoracotomy approach.

PubMed

Mihos, Christos G; Santana, Orlando; Pineda, Andres M; La Pietra, Angelo; Lamelas, Joseph

2014-01-01

We present our experience of concomitant right coronary artery bypass grafting (CABG) and aortic valve replacement performed via a right minithoracotomy in patients with coronary lesions not amenable to percutaneous intervention. A total of 17 patients underwent concomitant aortic valve replacement and right CABG between April 2008 and July 2013. A 5- to 6-cm minithoracotomy incision was made over the right second or third intercostal space, and the costochondral cartilage was transected. A saphenous vein bypass to the right coronary artery was then performed, initiating the anastomosis from the toe of the graft. Subsequently, the aortic valve was replaced using standard techniques. There were 6 men and 11 women. The median European System for Cardiac Operative Risk Evaluation II score mortality risk was 5% [interquartile range (IQR), 2%-8%]. The mean (SD) age was 77 (10) years, the left ventricular ejection fraction was 59% (8%), and the New York Heart Association functional class was 2.4 (0.8). One patient had a history of CABG. The mean (SD) cardiopulmonary bypass time was 168 (57) minutes, and the aortic cross-clamp time was 133 (36) minutes. Three patients underwent concomitant mitral valve surgery (replacement, 2; repair, 1). The median intensive care unit and hospital lengths of stay were 47 hours (IQR, 24-90) and 9 days (IQR, 5-13), respectively. There was one reoperation for bleeding, and there was one postoperative stroke. All patients were alive at a mean (SD) follow-up of 2 (1.1) years. Aortic valve replacement with concomitant CABG performed via a right minithoracotomy approach is feasible.

Extended range heat pump system and centrifugal compressor for use therewith

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shoemaker, J.F.

1988-04-26

Improvements in heat pump systems having indoor and outdoor heat exchangers and at least two compressors for supplying a refrigerant medium under pressure thereto, and means for circulating the medium through the heat exchangers, the improvement is described comprising a selector valve associated with each of the compressors. The selector valves provide that any combination and any one or more of the compressors can be selected for operation, each of the selector valves having a first operating condition placing the associated compressor in series with the heat exchangers and a second operating condition whereby the associated compressor is bypassed, whenmore » the selector valves for at least two of the compressors are simultaneously in their first positions a flow path is established through the associated compressors and through the heat exchangers all in series, a two position changeover valve and associated conduit means. The changeover valve has a first position wherein at least one of the compressors is connected in series with the first and second heat exchangers to produce flow of the medium in one direction therethrough and a second position whereby at least one compressor is connected to produce flow of the medium in the opposite direction through the heat exchangers.« less

Initial experience with the Freedom Solo® stentless aortic valve in a low volume centre.

PubMed

Kolseth, Solveig Moss; Nordhaug, Dag; Stenseth, Roar; Wahba, Alexander

2010-10-01

Freedom Solo is a stentless biological aortic valve which is implanted supra-annularly with a single suture line. An increased risk of postoperative thrombocytopenia in the early postoperative period has been reported in recent studies. In our study we evaluated postoperative haemodynamic performance and thrombocyte-levels. Thirty seven patients who underwent valve implantation of the Sorin Freedom Solo stentless valve were included. The haemodynamic performance of the valve was evaluated by transthoracic echocardiography postoperatively at the fourth day (mean) and after a median of 4.2 months. The mean gradient (mmHg) of Freedom Solo was 7.5 at four days and 8.6 at 4.2 months. Postoperatively no patient had more than grade 1 leakage. Seven percent of the patients had a reduction of thrombocytes to less than 20% of the preoperative level. Seventy six percent had a minimum postoperative thrombocyte level less than 100*10(9)/L. The 30 days mortality in our patient material was zero. Implantation of the Freedom Solo valve was uncomplicated in our experience. Favourable transvalvular gradients and no significant leaks were found. In accordance with the literature, we found a high percentage of patients having a postoperative level of thrombocytes less than 100*10(9)/L after implantation of Freedom Solo.

Incidence, predictors and outcomes of infective endocarditis in a contemporary adult congenital heart disease population.

PubMed

Moore, Benjamin; Cao, Jacob; Kotchetkova, Irina; Celermajer, David S

2017-12-15

The prevalence of congenital heart disease (CHD) in the adult population is steadily increasing. A substrate of prosthetic material and residual lesions, constantly evolving as surgical techniques change over time, predispose these patients to the potentially devastating complication of infective endocarditis (IE). We retrospectively reviewed 2935 patients in our adult CHD database for all cases of endocarditis between 1991 and 2016. Incidence, clinical course and predictors of outcomes were analysed. We document 74 episodes in 62 patients, with an incidence of 0.9 cases/1000 patient years (py). IE was more common in complex CHD (1.4 cases/1000py) and ventricular septal defects (VSDs) (1.9 cases/1000py). Prosthetic material was involved in 47% and left-sided infection predominated (66%). The incidence in bicuspid aortic valves post aortic valve replacement (AVR) was significantly higher than in unoperated valves, being 1.8 and 1.1 cases/1000 patient years respectively. Streptococcus was the most frequently implicated causative organism (37%). Emboli occurred in 34% of cases with a cerebral predilection. 46% of patients required surgery during the admission for IE, most frequently to replace a severely regurgitant bicuspid aortic valve. Early endocarditis-related mortality was 15%, associated with cerebral emboli and acute renal failure. In a contemporary adult CHD cohort, those with complex underlying lesions, VSDs or an AVR were at higher risk for IE. Mortality remains substantial and is more likely in patients with cerebral emboli and/or acute renal failure. Copyright © 2017 Elsevier B.V. All rights reserved.

Systematic Engine Uprate Technology Development and Deployment for Pipeline Compressor Engines through Increased Torque

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dennis Schmitt; Daniel Olsen

2005-09-30

Three methods were utilized to analyze key components of slow-speed, large-bore, natural gas integral engines. These three methods included the application of computational fluid dynamics (CFD), dynamic modal analysis using finite element analysis (FEA), and a stress analysis method also using FEA. The CFD analysis focuses primarily on the fuel mixing in the combustion chamber of a TLA engine. Results indicate a significant increase in the homogeneity of the air and fuel using high-pressure fuel injection (HPFI) instead of standard low-pressure mechanical gas admission valve (MGAV). A modal analysis of three engine crankshafts (TLA-6, HBA-6, and GMV-10) is developed andmore » presented. Results indicate that each crankshaft has a natural frequency and corresponding speed that is well away from the typical engine operating speed. A frame stress analysis method is also developed and presented. Two different crankcases are examined. A TLA-6 crankcase is modeled and a stress analysis is performed. The method of dynamic load determination, model setup, and the results from the stress analysis are discussed. Preliminary results indicate a 10%-15% maximum increase in frame stress due to a 20% increase in HP. However, the high stress regions were localized. A new hydraulically actuated mechanical fuel valve is also developed and presented. This valve provides equivalent high-energy (supersonic) fuel injection comparable to a HPFI system, at 1/5th of the natural gas fuel pressure. This valve was developed in cooperation with the Dresser-Rand Corporation.« less

3D velocity field characterization of prosthetic heart valve with two different valve testers by means of stereo-PIV.

PubMed

D'Avenio, Giuseppe; Grigioni, Mauro; Daniele, Carla; Morbiducci, Umberto; Hamilton, Kathrin

2015-01-01

Prosthetic heart valves can be associated to mechanical loading of blood, potentially linked to complications (hemolysis and thrombogenicity) which can be clinically relevant. In order to test such devices in pulsatile mode, pulse duplicators (PDs) have been designed and built according to different concepts. This study was carried out to compare anemometric measurements made on the same prosthetic device, with two widely used PDs. The valve (a 27-mm bileaflet valve) was mounted in the aortic section of the PD. The Sheffield University PD and the RWTH Aachen PD were selected as physical models of the circulation. These two PDs differ mainly in the vertical vs horizontal realization, and in the ventricular section, which in the RWTH PD allows for storage of potential energy in the elastic walls of the ventricle. A glassblown aorta, realized according to the geometric data of the same anatomical district in healthy individuals, was positioned downstream of the valve, obtaining 1:1 geometric similarity conditions. A NaI-glycerol-water solution of suitable kinematic viscosity and, at the same time, the proper refractive index, was selected. The flow field downstream of the valve was measured by means of the stereo-PIV (Particle Image Velocimetry) technique, capable of providing the complete 3D velocity field as well as the entire Reynolds stress tensor. The measurements were carried out at the plane intersecting the valve axis. A three-jet profile was clearly found in the plane crossing the leaflets, with both PDs. The extent of the typical recirculation zone in the Valsalva sinus was much larger in the RWTH PD, on account of the different duration of the swirling motion in the ventricular chamber, caused by the elasticity of the ventricle and its geometry. The comparison of the hemodynamical behaviour of the same bileaflet valve tested in two PDs demonstrated the role of the mock loop in affecting the valve performance.

Aortic valve replacement with the Biocor PSB stentless xenograft.

PubMed

Bertolini, P; Luciani, G B; Vecchi, B; Pugliese, P; Mazzucco, A

1998-08-01

The midterm clinical results after aortic valve replacement with the Biocor PSB stentless xenograft on all patients operated between October 1992 and October 1996 were reviewed. One hundred six patients, aged 70+/-6 years, had aortic valve replacement for aortic stenosis (67%), regurgitation (11%), or both (22%). Associated procedures were done in 49 patients (46%), including coronary artery bypass in 30 patients, mitral valve repair/replacement in 16, and ascending aorta replacement in 5 patients. Aortic cross-clamp and cardiopulmonary bypass times were 96+/-24 and 129+/-31 minutes, respectively. There were 3 (3%) early deaths due to low output (2 patients) and cerebrovascular accident (1 patient). Follow-up of survivors ranged from 6 to 66 months (mean, 39+/-14 months). Survival was 94%+/-2% and 90%+/-3% at 1 and 5 years. There were 5 late deaths due to cardiac cause (2), cancer (2), and pulmonary embolism (1 patient). No patient had structural valve deterioration, whereas 100% and 95%+/-3% were free from valve-related events at 1 and 5 years. There were two reoperations due to narrowing of the left coronary ostium and endocarditis, with an actuarial freedom from reoperation of 99%+/-1% and 98+/-1% at 1 and 5 years, respectively. Functional results demonstrated a mean peak transprosthetic gradient of 16+/-12 mm Hg, with only 1 patient (1%) with a 55 mm Hg gradient. No cases of valve regurgitation greater than mild were recorded at follow-up. Assessment of New York Heart Association functional class demonstrated a significant improvement (2.9+/-0.6 versus 1.4+/-0.7; p=0.01). All patients were free from anticoagulation. Aortic valve replacement using the Biocor PSB stentless xenograft offers excellent midterm survival, negligible valve deterioration, and a very low rate of valve-related events, which are comparable to estimates reported with other models of stentless xenografts and currently available stented xenografts. Hemodynamic performance is favorable and quality of life satisfactory.

Treatment of aortic stenosis with aortic valve bypass (apicoaortic conduit) surgery: an assessment using computational modeling.

PubMed

Balaras, Elias; Cha, K S; Griffith, Bartley P; Gammie, James S

2009-03-01

Aortic valve bypass surgery treats aortic valve stenosis with a valve-containing conduit that connects the left ventricular apex to the descending thoracic aorta. After aortic valve bypass, blood is ejected from the left ventricle via both the native stenotic aortic valve and the conduit. We performed computational modeling to determine the effects of aortic valve bypass on aortic and cerebral blood flow, as well as the effect of conduit size on relative blood flow through the conduit and the native valve. The interaction of blood flow with the vascular boundary was modeled using a hybrid Eurelian-Lagrangian formulation, where an unstructured Galerkin finite element method was coupled with an immersed boundary approach. Our model predicted native (stenotic) valve to conduit flow ratios of 45:55, 52:48, and 60:40 for conduits with diameters of 20, 16, and 10 mm, respectively. Mean gradients across the native aortic valve were calculated to be 12.5, 13.8, and 17.6 mm Hg, respectively. Post-aortic valve bypass cerebral blood flow was unchanged from preoperative aortic valve stenosis configurations and was constant across all conduit sizes. In all cases modeled, cerebral blood flow was completely supplied by blood ejected across the native aortic valve. An aortic valve bypass conduit as small as 10 mm results in excellent relief of left ventricular outflow tract obstruction in critical aortic valve stenosis. The presence of an aortic valve bypass conduit has no effect on cerebral blood flow. All blood flow to the brain occurs via antegrade flow across the native stenotic valve; this configuration may decrease the long-term risk of cerebral thromboembolism.

Heart valve replacement with the Sorin tilting-disc prosthesis. A 10-year experience.

PubMed

Milano, A; Bortolotti, U; Mazzucco, A; Mossuto, E; Testolin, L; Thiene, G; Gallucci, V

1992-02-01

From 1978 to 1988, 697 patients with a mean age of 48 +/- 11 years (range 5 to 75 years) received a Sorin tilting-disc prosthesis; 358 had had aortic valve replacement, 247 mitral valve replacement, and 92 mitral and aortic valve replacement. Operative mortality rates were 7.8%, 11.3%, and 10.8%, respectively, in the three groups. Cumulative duration of follow-up is 1650 patient-years for aortic valve replacement (maximum follow-up 11.4 years), 963 patient-years for mitral valve replacement (maximum follow-up 9.9 years) and 328 patient-years for mitral and aortic valve replacement (maximum follow-up 9.4 years). Actuarial survival at 9 years is 72% +/- 4% after mitral valve replacement, 70% +/- 3% after aortic valve replacement, and 50% +/- 12% after mitral and aortic valve replacement, and actuarial freedom from valve-related deaths is 97% +/- 2% after mitral valve replacement, 92% +/- 2% after aortic valve replacement, and 62% +/- 15% after mitral and aortic valve replacement. Thromboembolic events occurred in 21 patients with aortic valve replacement (1.3% +/- 0.2%/pt-yr), in 12 with mitral valve replacement (1.2% +/- 0.3% pt-yr), and in seven with mitral and aortic valve replacement (2.1% +/- 0.8%), with one case of prosthetic thrombosis in each group; actuarial freedom from thromboembolism at 9 years is 92% +/- 3% after mitral valve replacement, 91% +/- 3% after aortic valve replacement, and 74% +/- 16% after mitral and aortic valve replacement. Anticoagulant-related hemorrhage was observed in 15 patients after aortic valve replacement (0.9% +/- 0.2%/pt-yr), in 9 after mitral valve replacement (0.9% +/- 0.3%/pt-yr), and in 6 with mitral and aortic valve replacement (0.9% +/- 0.5%/pt-yr); actuarial freedom from this complication at 9 years is 94% +/- 2% after aortic valve replacement, 91% +/- 4% after mitral valve replacement, and 68% +/- 16% after mitral and aortic valve replacement. Actuarial freedom from reoperation at 9 years is 97% +/- 2% after mitral and aortic valve replacement, 92% +/- 4% after mitral valve replacement, and 89% +/- 3% after aortic valve replacement, with no cases of mechanical fracture. The Sorin valve has shown a satisfactory long-term overall performance, comparable with other mechanical prostheses, and an excellent durability that renders it a reliable heart valve substitute for the mitral and aortic positions.

Aortic expansion rate in patients with dilated post-stenotic ascending aorta submitted only to aortic valve replacement long-term follow-up.

PubMed

Gaudino, Mario; Anselmi, Amedeo; Morelli, Mauro; Pragliola, Claudio; Tsiopoulos, Vasileios; Glieca, Franco; Possati, Gianfederico

2011-08-02

This study was conceived to describe the evolution of aortic dimensions in patients with moderate post-stenotic ascending aorta dilation (50 to 59 mm) submitted to aortic valve replacement (AVR) alone. The appropriate treatment of post-stenotic ascending aorta dilation has been poorly investigated. Ninety-three patients affected by severe isolated calcific aortic valve stenosis in the tricuspid aortic valve accompanied by moderate dilation of the ascending aorta (50 to 59 mm) were submitted to AVR only. All patients were followed for a mean of 14.7 ± 4.8 years by means of periodic clinical evaluations and echocardiography and tomography scans of the thorax. Operative mortality was 1.0% (1 patient). During the follow-up, 16 patients died and 2 had to be reoperated for valve dysfunction. No patients experienced acute aortic events (rupture, dissection, pseudoaneurysm), and no patient had to be reoperated on the aorta. There was not a substantial increase in aortic dimensions: mean aortic diameter was 57 ± 11 mm at the end of the follow-up versus 56 ± 02 mm pre-operatively (p = NS). The mean ascending aorta expansion rate was 0.3 ± 0.2 mm/year. In the absence of connective tissue disorders, AVR alone is sufficient to prevent further aortic expansion in patients with moderate post-stenotic dilation of the ascending aorta. Aortic replacement can probably be reserved for patients with a long life expectancy. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Jet-controlled freeze valve for use in a glass melter

DOEpatents

Routt, K.R.

1985-07-29

A drain valve for use in furnace for the melting of thermoplastic material is disclosed. The furnace includes a drain cavity formed in its bottom for withdrawing a flow of thermoplastic material. The drain valve includes a flow member which include a flow tube having an inlet and outlet for the material, and coaxially disposed concentric tubular members defining annuli surrounding the flow tube. The tubular members include heating and cooling means for the flow tube. The drain valve can also be used in a furnace of glass melting that includes a drain cavity for withdrawing molten glass from the furnace.

Complications and 2-year valve survival following Ahmed valve implantation during the first 2 years of life.

PubMed

Almobarak, F; Al-Mobarak, F; Khan, A O

2009-06-01

To report complications and 2-year valve survival following Ahmed valve implantation during the first 2 years of life. Retrospective institutional case series. Forty-two eyes of 36 patients with Ahmed valve implantation (without prior drainage device surgery) during the first 2 years of life and 2 years' postsurgical follow-up were identified. Most eyes had primary congenital glaucoma (28/42, 66.7%), aphakic glaucoma (5/42, 11.9%) or Peters anomaly (5/42, 11.9%). All but three eyes had prior ocular surgery. Surgery was at a mean age of 11.83 months (m) (SD 5.63). The most common significant postoperative complications were tube malpositioning requiring intervention (11/42, 26.2%), endophthalmitis (3/42, 7.1%; one with tube exposure) and retinal detachment (3/42, 7.1%). Thirty-six eyes (85.8%) required resumption of antiglaucoma medications to maintain intraocular pressure (IOP) < or =22 mm Hg a mean of 7.2 m (SD 6.8) postoperatively. Cumulative probabilities of valve survival (IOP< or =22 mm Hg with or without medication) by Kaplan-Meier analysis were 73.8% and 63.3% at 12 months and 24 months, respectively. Postoperative tube malpositioning that required surgical revision was common in this age group. Infectious endophthalmitis and retinal detachment are known potential complications following any incisional surgery for advanced buphthalmos; however, tube exposure is a unique potential problem following aqueous shunt implantation that can lead to intraocular infection. Cumulative valve survival 2 years following implantation was 63.3%.

The JUPITER registry: 1-year results of transapical aortic valve implantation using a second-generation transcatheter heart valve in patients with aortic stenosis.

PubMed

Silaschi, Miriam; Treede, Hendrik; Rastan, Ardawan J; Baumbach, Hardy; Beyersdorf, Friedhelm; Kappert, Utz; Eichinger, Walter; Rüter, Florian; de Kroon, Thomas L; Lange, Rüdiger; Ensminger, Stephan; Wendler, Olaf

2016-11-01

Transcatheter aortic valve replacement (TAVR) is an established therapy for patients with aortic stenosis (AS) at high surgical risk. The JenaValve™ is a second-generation, self-expanding transcatheter heart valve (THV), implanted through transapical access (TA). During stent deployment, a specific 'clipping-mechanism' engages native aortic valve cusps for fixation. We present 1-year outcomes of the JUPITER registry, a post-market registry of the JenaValve for TA-TAVR. The JUPITER registry is a prospective, multicentre, uncontrolled and observational European study to evaluate the long-term safety and effectiveness of the Conformité Européenne-marked JenaValve THV. A total of 180 patients with AS were enrolled between 2012 and 2014. End-points were adjudicated in accordance with the valve academic research consortium document no. 1 definitions. The mean age was 80.4 ± 5.9 years and the mean logistic European system for cardiac operative risk evaluation I 21.2 ± 14.7%. The procedure was successful in 95.0% (171/180), implantation of a second THV (valve-in-valve) was performed in 2.2% (4/180) and conversion to surgical aortic valve replacement (SAVR) was necessary in 2.8% (5/180). No annular rupture or coronary ostia obstruction occurred. Two patients required SAVR after the day of index procedure (1.1%). All-cause mortality at 30 days was 11.1% (20/180), being cardiovascular in 7.2% (13/180). A major stroke occurred in 1.1% (2/180) at 30 days, no additional major strokes were observed during 1 year. All-cause mortality after 30 days was 13.1% (21/160) and combined efficacy at 1 year was 80.8% (122/151). At 1-year follow-up, no patient presented with more than moderate paravalvular leakage, while 2 patients (3.2%) showed moderate, 12 (19.0%) mild and 49 (82.4%) trace/none paravalvular regurgitation. In a high-risk cohort of patients undergoing TA-TAVR for AS, the use of the JenaValve THV is safe and effective. In patients at higher risk for coronary ostia obstruction, annular rupture or with limited aortic valve calcification, the JenaValve might be preferable for implantation due to its clipping-mechanism engaging native aortic valve cusps for fixation with reduced radial forces of the self-expanding stent. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Use of bovine pericardial tissue for aortic valve and aortic root replacement: long-term results.

PubMed

Vrandecic, M; Gontijo Filho, B; Fantini, F; Barbosa, J; Martins, I; de Oliveira, O C; Martins, C; Max, R; Drumond, L; Oliveira, C; Ferrufino, A; Alcocer, E; Silva, J A; Vrandecic, E

1998-03-01

The study aimed to determine the clinical performance of bovine pericardial aldehyde-treated products alone or in combination with aortic leaflets of porcine origin. These included a composite porcine stentless aortic valve attached to a scalloped pericardial tube (BSAV), and valved and non-valved bovine pericardial conduits for use in left-sided heart lesions (BPG). For BSAV grafts, between January 1990 and August 1996, 163 patients (119 males) had their aortic valves replaced by SJM Biocor BASV. Mean age was 37.9 +/- 17.6 years (range: 1 to 76 years). Rheumatic heart disease sequelae (n = 72) and replacement of a prosthetic heart valve (n = 46) were predominant. Preoperative NYHA functional class showed 90 patients (55.2%) in class III and 50 (30.7%) in class IV. BPVC and NVPC grafts were used in 166 patients: acute aortic dissection was the main indication in 52 (31.3%) and chronic in 36 (21/7%). The ascending aorta was involved in 141 patients (84.9%); grafts were seldom used at other sites. In most patients the graft implanted was either a non-valved (n = 79) or a valved (n = 75) pericardial conduit. Twelve patients had a localized lesion and required a patch repair. For BASV grafts, the non-valve-related hospital mortality rate was 4.9%. There were 14.7% non-fatal complications with full recovery of all patients. Mean follow up in 141 patients was 3.0 +/- 1.4 years (range: 1 month to 7.2 years); 14 patients were lost to follow up. Late, non-conduit-related, mortality occurred in seven patients (4.9%). Eight patients underwent reoperation. The current clinical follow up of 127 patients has shown 118 (92.9%) with competent valves and nine (7.0%) with mild stable aortic insufficiency. For BPVC and NVPC grafts, hospital mortality rate was 16.9%, death being related to poor preoperative clinical condition. Postoperative follow up was accomplished in 125 patients; reoperation was necessary in seven patients. Histology showed good tissue preservation up to five years; echocardiography revealed satisfactory findings. No valved conduit had to be reoperated for valve or pericardial tissue wear. Clinical results of left-sided heterologous pericardial grafts have shown excellent performance over time. The BASV (over seven years) and BPVC and NVPC (eight years) have demonstrated superior results as aortic valves alone or in combination with a pericardial conduit.

Frostless heat pump having thermal expansion valves

DOEpatents

Chen, Fang C [Knoxville, TN; Mei, Viung C [Oak Ridge, TN

2002-10-22

A heat pump system having an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant and further having a compressor, an interior heat exchanger, an exterior heat exchanger, a heat pump reversing valve, an accumulator, a thermal expansion valve having a remote sensing bulb disposed in heat transferable contact with the refrigerant piping section between said accumulator and said reversing valve, an outdoor temperature sensor, and a first means for heating said remote sensing bulb in response to said outdoor temperature sensor thereby opening said thermal expansion valve to raise suction pressure in order to mitigate defrosting of said exterior heat exchanger wherein said heat pump continues to operate in a heating mode.

True external diameter better predicts hemodynamic performance of bioprosthetic aortic valves than the manufacturers' stated size.

PubMed

Cevasco, Marisa; Mick, Stephanie L; Kwon, Michael; Lee, Lawrence S; Chen, Edward P; Chen, Frederick Y

2013-05-01

Currently, there is no universal standard for sizing bioprosthetic aortic valves. Hence, a standardized comparison was performed to clarify this issue. Every size of four commercially available bioprosthetic aortic valves marketed in the United States (Biocor Supra; Mosaic Ultra; Magna Ease; Mitroflow) was obtained. Subsequently, custom sizers were created that were accurate to 0.0025 mm to represent aortic roots 18 mm through 32 mm, and these were used to measure the external diameter of each valve. Using the effective orifice area (EOA) and transvalvular pressure gradient (TPG) data submitted to the FDA, a comparison was made between the hemodynamic properties of valves with equivalent manufacturer stated sizes and valves with equivalent measured external diameters. Based on manufacturer size alone, the valves at first seemed to be hemodynamically different from each other, with Mitroflow valves appearing to be hemodynamically superior, having a large EOA and equivalent or superior TPG (p < 0.05). However, Mitroflow valves had a larger measured external diameter than the other valves of a given numerical manufacturer size. Valves with equivalent external diameters were then compared, regardless of the stated manufacturer sizes. For truly equivalently sized valves (i.e., by measured external diameter) there was no clear hemodynamic difference. There was no statistical difference in the EOAs between the Biocor Supra, Mosaic Ultra, and Mitroflow valves, and the Magna Ease valve had a statistically smaller EOA (p < 0.05). On comparing the mean TPG, the Biocor Supra and Mitroflow valves had statistically equivalent gradients to each other, as did the Mosaic Ultra and Magna Ease valves. When comparing valves of the same numerical manufacturer size, there appears to be a difference in hemodynamic performance across different manufacturers' valves according to FDA data. However, comparing equivalently measured valves eliminates the differences between valves produced by different manufacturers.

Transapical transcatheter aortic valve implantation using a new second-generation TAVI system - J-Valve™ for high-risk patients with aortic valve diseases: Initial results with 90-day follow-up.

PubMed

Zhu, Da; Chen, Yucheng; Guo, Yingqiang; Hu, Jia; Zhang, Ji; Wei, Xin; Tang, Hong; Shi, Yingkang

2015-11-15

To evaluate the safety and efficacy of transcatheter aortic valve implantation (TAVI) for patients with aortic stenosis (AS) or pure/dominant aortic regurgitation (AR) using the J-Valve™ system. Twenty patients with isolated aortic valve disease (11 with pure/dominant AR and 9 with AS) at high risk for open-heart surgery were enrolled in this study. The mean Logistic Euro-SCORE I was 27.2±8.2% (mean age 74.5±4.7years). Four sizes of prosthesis were used for annular size up to 21 mm (n=1), 23mm (n=2), 25mm (n=10) and 27mm (n=7). Clinical and echocardiographic evaluations were performed at baseline, post-procedure and follow-up. The primary endpoint was all-cause mortality. Secondary endpoints were procedural success, major adverse events as well as echocardiographic performance. TAVI with the J-Valve™ device was successfully performed in 19 patients (95%). Conversion to surgical valve replacement was necessary in one patient due to prosthesis embolization. No mortality occurred during 90 days follow-up. Pacemaker implantation for new onset conduction disorders was necessary in one patient (5%). For patient with severe AS, post-procedure TAVI resulted in favorable reduction of mean transvalvular gradients (55.3±8.5 vs. 16.4±13.3 mmHg, P<0.01). Mean transvalvular gradient was also favorable in AR patients after valve implantation (6.9±1mmHg). The majority of patients had none or trivial paravalvular regurgitation (17/19) while none had moderate or severe paravalvular regurgitation. Trans-apical TAVI using the J-Valve™ prosthesis is potentially an effective treatment option for patients with AS or pure/dominant AR at high risk for open-heart surgery. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Single-center experience and short-term outcome with the JenaValve: a second-generation transapical transcatheter aortic valve implantation device.

PubMed

Reuthebuch, Oliver; Inderbitzin, Devdas Thomas; Rüter, Florian; Jeger, Raban; Kaiser, Christoph; Buser, Peter; Fassl, Jens; Eckstein, Friedrich S

2014-01-01

We present the post-CE(Conformité Européenne)-mark single-center implantation experience and short-term outcome with the second-generation transapical JenaValve transcatheter aortic valve implantation system. Patients [N = 27; 9 women; mean (SD) age, 80.3 (5.5) years] were operated on between November 2011 and August 2012. Via a transapical approach, the valve was positioned, in some cases, repositioned, and finally implanted. All data were collected during the hospital stay. The implantation success rate was 100%; the mean (SD) operation time was 124.7 (43.2) minutes; and the size of the implanted prosthesis was 23 mm (n = 6), 25 mm (n = 14), and 27 mm (n = 7). The in-hospital major adverse cardiac and cerebrovascular events were as follows: intraoperative resuscitation with subsequent aortic rupture (n = 1), postoperative hemorrhage needing revision (n = 1), myocardial infarction (n = 1), atrioventricular block needing a definitive pacemaker (n = 1), new-onset renal failure needing hemodialysis (n = 1), and stroke (n = 1). The 30-day mortality was 11.1% (n = 3). The mean (SD) intensive care unit/total stay was 2.2 (1.7)/11.7 (7.9) days. Postoperative echocardiography [day 6.7 (4.8)] revealed residual paravalvular leakage of trace to grade 1 in 12 patients (44.5%) and no leakage in 15 patients, with a mean (SD) transvalvular pressure gradient of 11.6 (5.6) mm Hg with significant reduction by 36.0 (17.7) mm Hg (P = 0.0001, Wilcoxon signed rank test). This second-generation repositionable transcatheter aortic valve implantation device could safely and successfully be implanted with a fast learning curve, significant reduction in pressure gradients, overall clinical improvement at discharge, as well as an acceptable morbidity and mortality rate in this highest-risk patient cohort.

Statins for aortic valve stenosis.

PubMed

Thiago, Luciana; Tsuji, Selma Rumiko; Nyong, Jonathan; Puga, Maria Eduarda Dos Santos; Góis, Aécio Flávio Teixeira de; Macedo, Cristiane Rufino; Valente, Orsine; Atallah, Álvaro Nagib

2016-01-01

Aortic valve stenosis is the most common type of valvular heart disease in the USA and Europe. Aortic valve stenosis is considered similar to atherosclerotic disease. Some studies have evaluated statins for aortic valve stenosis. To evaluate the effectiveness and safety of statins in aortic valve stenosis. Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS - IBECS, Web of Science and CINAHL Plus. These databases were searched from their inception to 24 November 2015. We also searched trials in registers for ongoing trials. We used no language restrictions.Selection criteria: Randomized controlled clinical trials (RCTs) comparing statins alone or in association with other systemic drugs to reduce cholesterol levels versus placebo or usual care. Data collection and analysis: Primary outcomes were severity of aortic valve stenosis (evaluated by echocardiographic criteria: mean pressure gradient, valve area and aortic jet velocity), freedom from valve replacement and death from cardiovascular cause. Secondary outcomes were hospitalization for any reason, overall mortality, adverse events and patient quality of life.Two review authors independently selected trials for inclusion, extracted data and assessed the risk of bias. The GRADE methodology was employed to assess the quality of result findings and the GRADE profiler (GRADEPRO) was used to import data from Review Manager 5.3 to create a 'Summary of findings' table. We included four RCTs with 2360 participants comparing statins (1185 participants) with placebo (1175 participants). We found low-quality evidence for our primary outcome of severity of aortic valve stenosis, evaluated by mean pressure gradient (mean difference (MD) -0.54, 95% confidence interval (CI) -1.88 to 0.80; participants = 1935; studies = 2), valve area (MD -0.07, 95% CI -0.28 to 0.14; participants = 127; studies = 2), and aortic jet velocity (MD -0.06, 95% CI -0.26 to 0.14; participants = 155; study = 1). Moderate-quality evidence showed no effect on freedom from valve replacement with statins (risk ratio (RR) 0.93, 95% CI 0.81 to 1.06; participants = 2360; studies = 4), and no effect on muscle pain as an adverse event (RR 0.91, 95% CI 0.75 to 1.09; participants = 2204; studies = 3; moderate-quality evidence). Low- and very low-quality evidence showed uncertainty around the effect of statins on death from cardiovascular cause (RR 0.80, 95% CI 0.56 to 1.15; participants = 2297; studies = 3; low-quality evidence) and hospitalization for any reason (RR 0.84, 95% CI 0.39 to 1.84; participants = 155; study = 1; very low-quality evidence). None of the four included studies reported on overall mortality and patient quality of life. Result findings showed uncertainty surrounding the effect of statins for aortic valve stenosis. The quality of evidence from the reported outcomes ranged from moderate to very low. These results give support to European and USA guidelines (2012 and 2014, respectively) that so far there is no clinical treatment option for aortic valve stenosis.

The Double-Orifice Valve Technique to Treat Tricuspid Valve Incompetence.

PubMed

Hetzer, Roland; Javier, Mariano; Delmo Walter, Eva Maria

2016-01-01

A straightforward tricuspid valve (TV) repair technique was used to treat either moderate or severe functional (normal valve with dilated annulus) or for primary/organic (Ebstein's anomaly, leaflet retraction/tethering and chordal malposition/tethering, with annular dilatation) TV incompetence, and its long-term outcome assessed. A double-orifice valve technique was employed in 91 patients (mean age 52.6 ± 23.2 years; median age 56 years; range: 0.6-82 years) with severe tricuspid regurgitation. Among the patients, three had post-transplant iatrogenic chordal rupture, five had infective endocarditis, 11 had mitral valve insufficiency, 23 had Ebstein's anomaly, and 47 had isolated severe TV incompetence. The basic principle was to reduce the distance between the coapting leaflets, wherein the most mobile leaflet could coapt to the opposite leaflet, by creating two orifices, ensuring valve competence. The TV repair was performed through a median sternotomy or right anterior thoracotomy in the fifth intercostal space under cardiopulmonary bypass. The degree and extent of creating a double-valve orifice was determined by considering the minimal body surface area (BSA)-related acceptable TV diameter. Repair was accomplished by passing pledgeted mattress sutures from the middle of the true anterior annulus to a spot on the opposite septal annulus, located approximately two-thirds of the length of the septal annulus to avoid injury to the bundle of His. The annular apposition divides the TV into a larger anterior and a smaller posterior orifices, enabling valve closure, on both sides. In adults, the diameter of the anterior valve orifice should be 23-25 mm, and the posterior orifice 15-18 mm; thus, the total valve orifice area is 5-6 cm2. In children, the total valve orifice should be a standard deviation of 1.7 mm for a BSA of <1. 0m2, and 1.5 mm for a BSA of >1.0m2. During a mean follow up of 8.7 ± 1.34 years (median 10 years; range: 1.5-25.9 years) there have been no reoperations for TV insufficiency or stenosis. Reoperations on three patients (mean age 42.5 ± 8.7 years) were indicated for aortic valve replacement at 14 months postoperatively (n = 1) and for assist device implantation (n = 2) who eventually underwent heart transplant at 18 and 20 months after TV repair, respectively. The cumulative 12-year survival rate was 86.9%. This double-orifice technique is technically a straightforward repair to abolish TV incompetence with highly satisfactory results, particularly in patients with severe annular dilatation or with leaflet and chordal tethering. In the present series, the technique provided no pitfalls (if the location of the conduction system was borne in mind), requiring only a gentle placement of sutures. It also led to no residual regurgitation or reoperation during the follow up period.

A D-Shaped Bileaflet Bioprosthesis which Replicates Physiological Left Ventricular Flow Patterns

PubMed Central

Tan, Sean Guo-Dong; Kim, Sangho; Hon, Jimmy Kim Fatt; Leo, Hwa Liang

2016-01-01

Prior studies have shown that in a healthy heart, there exist a large asymmetric vortex structure that aids in establishing a steady flow field in the left ventricle. However, the implantation of existing artificial heart valves at the mitral position is found to have a negative effect on this physiological flow pattern. In light of this, a novel D-shaped bileaflet porcine bioprosthesis (GD valve) has been designed based on the native geometry mitral valve, with the hypothesis that biomimicry in valve design can restore physiological left ventricle flow patterns after valve implantation. An in-vitro experiment using two dimensional particle velocimetry imaging was carried out to determine the hemodynamic performance of the new bileaflet design and then compared to that of the well-established St. Jude Epic valve which functioned as a control in the experiment. Although both valves were found to have similar Reynolds shear stress and Turbulent Kinetic Energy levels, the novel D-shape valve was found to have lower turbulence intensity and greater mean kinetic energy conservation. PMID:27258099

Fluid-structure interaction dynamic simulation of spring-loaded pressure relief valves under seismic wave

NASA Astrophysics Data System (ADS)

Lv, Dongwei; Zhang, Jian; Yu, Xinhai

2018-05-01

In this paper, a fluid-structure interaction dynamic simulation method of spring-loaded pressure relief valve was established. The dynamic performances of the fluid regions and the stress and strain of the structure regions were calculated at the same time by accurately setting up the contact pairs between the solid parts and the coupling surfaces between the fluid regions and the structure regions. A two way fluid-structure interaction dynamic simulation of a simplified pressure relief valve model was carried out. The influence of vertical sinusoidal seismic waves on the performance of the pressure relief valve was preliminarily investigated by loading sine waves. Under vertical seismic waves, the pressure relief valve will flutter, and the reseating pressure was affected by the amplitude and frequency of the seismic waves. This simulation method of the pressure relief valve under vertical seismic waves can provide effective means for investigating the seismic performances of the valves, and make up for the shortcomings of the experiment.

Bioprosthetic Valve Fracture During Valve-in-valve TAVR: Bench to Bedside

PubMed Central

Saxon, John T; Allen, Keith B; Cohen, David J

2018-01-01

Valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR) has been established as a safe and effective means of treating failed surgical bioprosthetic valves (BPVs) in patients at high risk for complications related to reoperation. Patients who undergo VIV TAVR are at risk of patient–prosthesis mismatch, as the transcatheter heart valve (THV) is implanted within the ring of the existing BPV, limiting full expansion and reducing the maximum achievable effective orifice area of the THV. Importantly, patient–prosthesis mismatch and high residual transvalvular gradients are associated with reduced survival following VIV TAVR. Bioprosthetic valve fracture (BVF) is as a novel technique to address this problem. During BPV, a non-compliant valvuloplasty balloon is positioned within the BPV frame, and a highpressure balloon inflation is performed to fracture the surgical sewing ring of the BPV. This allows for further expansion of the BPV as well as the implanted THV, thus increasing the maximum effective orifice area that can be achieved after VIV TAVR. This review focuses on the current evidence base for BVF to facilitate VIV TAVR, including initial bench testing, procedural technique, clinical experience and future directions. PMID:29593832

Engine restart aid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fedewa, Andrew

A system is disclosed comprising an engine having coolant passages defined therethrough, a first coolant pump, and a first radiator. The system additionally comprises a second coolant pump, a second radiator, and a liquid-to-air heat exchanger configured to condition the temperature of intake air to the engine. The system further includes a coolant valve means. For a first configuration of the coolant valve means the first coolant pump is configured to urge coolant through the coolant passages in the engine and through the first radiator, and the second coolant pump is configured to urge coolant through the liquid-to-air heat exchangermore » and through the second radiator. For a second configuration of the coolant valve means the second coolant pump is configured to urge coolant through the coolant passages in the engine and through the liquid-to-air heat exchanger. A method for controlling the system is also disclosed.« less

Transfemoral transcatheter aortic valve insertion-related intraoperative morbidity: Implications of the minimalist approach.

PubMed

Greason, Kevin L; Pochettino, Alberto; Sandhu, Gurpreet S; King, Katherine S; Holmes, David R

2016-04-01

Transfemoral transcatheter aortic valve insertion may be performed in a catheterization laboratory (ie, the minimalist approach). It seems reasonable when considering this approach to avoid it in patients at risk for intraoperative morbidity that would require surgical intervention. We hypothesized that it would be possible to associate baseline characteristics with such morbidity, which would help heart teams select patients for the minimalist approach. We reviewed the records of 215 consecutive patients who underwent transfemoral transcatheter aortic valve insertion with a current commercially available device from November 2008 through July 2015. Demographic characteristics of the patients included a mean age of 78.9 ± 10.6 years, female sex in 73 patients (34.0%), and a mean Society of Thoracic Surgeons predicted risk of mortality of 8.7% ± 5.4%. Valve prostheses were balloon-expandable in 126 patients (58.6%) and self-expanding in 89 patients (41.4%). Significant intraoperative morbidity occurred in 22 patients (10.2%) and included major vascular injury in 12 patients (5.6%), hemodynamic compromise requiring cardiopulmonary bypass support in 4 patients (1.9%), cardiac tamponade requiring intervention in 3 patients (1.4%), ventricular valve embolization in 2 patients (0.9%), and inability to obtain percutaneous access requiring open vascular access in 1 patient (0.5%). Intraoperative morbidity was similarly distributed across all valve types (P = .556) and sheath sizes (P = .369). There were no baseline patient characteristics predictive of intraoperative morbidity. Patient and valve characteristics are not predictive of significant intraoperative morbidity during transfemoral transcatheter aortic valve insertion. The finding has implications for patient selection for the minimalist approach. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Midterm Follow-Up of the Stentless Freedom Solo Bioprosthesis in 350 Patients.

PubMed

Wollersheim, Laurens W; Li, Wilson W; Bouma, Berto J; Kaya, Abdullah; van Boven, Wim J; van der Meulen, Jan; de Mol, Bas A

2016-07-01

The stentless Freedom Solo aortic bioprosthesis is implanted supraannularly using one running suture line in the sinuses of Valsalva. We report our 9-year experience with this bioprosthesis. From April 2005 to July 2014, 350 consecutive patients at our institution underwent aortic valve replacement with the Freedom Solo bioprosthesis. Follow-up and echocardiographic data were collected retrospectively from referring cardiology centers. The mean age was 76 ± 6 years, 48% were male, and 46% underwent a concomitant procedure. Median EuroSCORE II was 3.0 (interquartile range, 1.9 to 4.9). Operative mortality was 5.1% for all procedures and 2.1% for isolated aortic valve replacement. The 1-, 5-, and 9-year overall survival was 92%, 74%, and 47%, respectively. At 6 years, freedom from structural valve deterioration and freedom from aortic valve reoperation were 98% and 96%, respectively. Prosthetic valve endocarditis occurred at a rate of 0.8% per patient-year. Permanent pacemaker implantation was necessary in 2.3% (n = 8), and moderate and severe prosthesis-patient mismatch occurred in 30 patients overall (9.6%). Postoperative maximum and mean valvular gradients were 17 mm Hg and 10 mm Hg, respectively, and remained stable during follow-up. Aortic valve replacement with the Freedom Solo is safe and has a low rate of permanent pacemaker implantations and prosthesis-patient mismatch. Survival is comparable to that with other aortic bioprostheses, and structural valve deterioration and aortic valve reoperation are infrequent during midterm follow-up. Hemodynamic performance is excellent, with low valvular gradients that remain stable during follow-up. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Poor clinical performance of the Wessex porcine heart valve bioprosthesis at nine years' follow up.

PubMed Central

Hurlé, A.; Nistal, J. F.; Revuelta, J. M.

1997-01-01

OBJECTIVE: To assess the long term performance of the Wessex porcine bioprostheses implanted in a consecutive series of patients. DESIGN: A retrospective case series. PATIENTS: Between January 1985 and July 1991, 184 Wessex bioprostheses (78 mitral, 102 aortic, and 4 tricuspid) were implanted in 150 patients. The patients were 55% (83/150) male and 45% (67/150) female; mean age was 60 (SD 10) years. RESULTS: Hospital mortality was 9.3% (14/150). Total follow up was 696 patient-years (mean 4.7 years per patient). Linearised rates (events per 100 patient-years (SEM) for postoperative complications for patients with isolated mitral valve replacement, isolated aortic valve replacement, and multiple valve replacement were, respectively: late mortality: 4.7 (1.6), 3.3 (0.9), and 4.9 (1.9); thromboembolism: 5.8 (1.8), 3.0 (0.9), and 2.8 (1.4); valve thrombosis: 1.0 (0.7), 0.3 (0.3), and 0.7 (0.7); structural failure: 5.8 (1.7), 1.9 (0.7), and 7.1 (2.2). Actuarial freedom from complications at nine years (70% confidence interval) was: late mortality: 61 (9)%, 57 (13)%, and 59 (12)%; thromboembolism and valve thrombosis: 71 (9)%, 79 (6)%, and 81 (8)%; structural failure: 33 (14)%, 50 (16)%, and 12 (14)%; all valve related morbidity/mortality: 31 (10)%, 21 (11)%, and 7 (9)%. Stent fractures appeared in 11 of 17 explanted prostheses; actuarial freedom from stent fracture at nine years was 66 (12)%. CONCLUSIONS: The Wessex bioprosthesis is associated with high thrombogenicity, early structural dysfunction, and a high valve related morbidity/mortality which justifies very close follow up of patients fitted with them. Images PMID:9155609

Final 5-year clinical and echocardiographic results for treatment of severe aortic stenosis with a self-expanding bioprosthesis from the ADVANCE Study

PubMed Central

Gerckens, Ulrich; Tamburino, Corrado; Bleiziffer, Sabine; Bosmans, Johan; Wenaweser, Peter; Brecker, Stephen; Guo, Jia; Linke, Axel

2017-01-01

Abstract Aims The ADVANCE study was designed to evaluate the safety and effectiveness of transcatheter aortic valve implantation (TAVI) with a self-expanding bioprosthesis in real-world patients with symptomatic, severe aortic stenosis at high surgical risk for valve replacement. Methods and results Study participants were enrolled from 44 experienced centres in 12 countries. Patient eligibility, treatment approach, and choice of anaesthesia were determined by the local Heart Team. The study was 100% monitored, and adverse events were adjudicated by an independent clinical events committee using Valve Academic Research Consortium (VARC-1) criteria. There were 1015 patients enrolled with 996 attempted TAVI procedures. Mean age was 81 years, and mean logistic EuroSCORE was 19.3 ± 12.3%. Five-year follow-up was available on 465 (46.7%) patients. At 5 years, the rate of all-cause mortality was 50.7% (95% confidence interval: 46.7%, 54.5%), and the rate of major stroke was 5.4%. Haemodynamic measures remained consistent for paired patients with a mean aortic valve gradient of 8.8 ± 4.4 mmHg (n = 198) and an effective orifice area of 1.7 ± 0.4 cm2 (n = 123). Aortic regurgitation (AR) decreased over time and among paired patients dropped from 12.8% to 8.0% moderate AR at 5 years (n = 125). Of the 860 patients with echocardiographic data or a reintervention after 30 days, there were 22 (2.6%) patients meeting the VARC-2 criteria for valve dysfunction and 10 (1.2%) patients with a reintervention >30 days. Conclusion Five-year results in real-world, elderly, high-risk patients undergoing TAVI with a self-expanding bioprosthesis provided evidence for continued valve durability with low rates of reinterventions and haemodynamic valve dysfunction. Trial registration ClinicalTrials.gov, NCT01074658. PMID:28633375

Tricuspid annuloplasty versus a conservative approach in patients with functional tricuspid regurgitation undergoing left-sided heart valve surgery: A study-level meta-analysis.

PubMed

Pagnesi, Matteo; Montalto, Claudio; Mangieri, Antonio; Agricola, Eustachio; Puri, Rishi; Chiarito, Mauro; Ancona, Marco B; Regazzoli, Damiano; Testa, Luca; De Bonis, Michele; Moat, Neil E; Rodés-Cabau, Josep; Colombo, Antonio; Latib, Azeem

2017-08-01

Tricuspid valve (TV) repair at the time of left-sided valve surgery is indicated in patients with either severe functional tricuspid regurgitation (TR) or mild-to-moderate TR with coexistent tricuspid annular dilation or right heart failure. We assessed the benefits of a concomitant TV repair strategy during left-sided surgical valve interventions, focusing on mortality and echocardiographic TR-related outcomes. A meta-analysis was performed of studies reporting outcomes of patients who underwent left-sided (mitral and/or aortic) valve surgery with or without concomitant TV repair. Primary endpoints were all-cause and cardiac-related mortality; secondary endpoints were the presence of more-than-moderate TR, TR progression, and TR severity grade. All endpoints were evaluated at the longest available follow-up. Fifteen studies were included for a total of 2840 patients. TV repair at the time of left-sided valve surgery was associated with a significantly lower risk of cardiac-related mortality (odds ratio [OR] 0.38; 95% confidence interval [CI]: 0.25-0.58; p<0.001), with a trend towards a lower risk of all-cause mortality (OR 0.57; 95% CI: 0.32-1.05; p=0.07) at a mean weighted follow-up of 6years. The presence of more-than-moderate TR (OR 0.19; 95% CI: 0.12-0.30; p<0.001), TR progression (OR 0.03; 95% CI: 0.01-0.05; p<0.001), and TR grade (standardized mean difference -1.11; 95% CI: -1.57 to -0.65; p<0.001) were significantly lower in the TV repair group at a mean weighted follow-up of 4.7years. A concomitant TV repair strategy during left-sided valve surgery is associated with a reduction in cardiac-related mortality and improved echocardiographic TR outcomes at follow-up. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Early Outcomes of Sutureless Aortic Valves.

PubMed

Hanedan, Muhammet Onur; Mataracı, İlker; Yürük, Mehmet Ali; Özer, Tanıl; Sayar, Ufuk; Arslan, Ali Kemal; Ziyrek, Uğur; Yücel, Murat

2016-06-01

In elderly high-risk surgical patients, sutureless aortic valve replacement (AVR) should be an alternative to standard AVR. The potential advantages of sutureless aortic prostheses include reducing cross-clamping and cardiopulmonary bypass (CPB) time and facilitating minimally invasive surgery and complex cardiac interventions, while maintaining satisfactory hemodynamic outcomes and low rates of paravalvular leakage. The current study reports our single-center experience regarding the early outcomes of sutureless aortic valve implantation. Between October 2012 and June 2015, 65 patients scheduled for surgical valve replacement with symptomatic aortic valve disease and New York Heart Association function of class II or higher were included to this study. Perceval S (Sorin Biomedica Cardio Srl, Sallugia, Italy) and Edwards Intuity (Edwards Lifesciences, Irvine, CA, USA) valves were used. The mean age of the patients was 71.15±8.60 years. Forty-four patients (67.7%) were female. The average preoperative left ventricular ejection fraction was 56.9±9.93. The CPB time was 96.51±41.27 minutes and the cross-clamping time was 60.85±27.08 minutes. The intubation time was 8.95±4.19 hours, and the intensive care unit and hospital stays were 2.89±1.42 days and 7.86±1.42 days, respectively. The mean quantity of drainage from chest tubes was 407.69±149.28 mL. The hospital mortality rate was 3.1%. A total of five patients (7.69%) died during follow-up. The mean follow-up time was 687.24±24.76 days. The one-year survival rate was over 90%. In the last few years, several models of valvular sutureless bioprostheses have been developed. The present study evaluating the single-center early outcomes of sutureless aortic valve implantation presents the results of an innovative surgical technique, finding that it resulted in appropriate hemodynamic conditions with acceptable ischemic time.

Early Outcomes of Sutureless Aortic Valves

PubMed Central

Hanedan, Muhammet Onur; Mataracı, İlker; Yürük, Mehmet Ali; Özer, Tanıl; Sayar, Ufuk; Arslan, Ali Kemal; Ziyrek, Uğur; Yücel, Murat

2016-01-01

Background In elderly high-risk surgical patients, sutureless aortic valve replacement (AVR) should be an alternative to standard AVR. The potential advantages of sutureless aortic prostheses include reducing cross-clamping and cardiopulmonary bypass (CPB) time and facilitating minimally invasive surgery and complex cardiac interventions, while maintaining satisfactory hemodynamic outcomes and low rates of paravalvular leakage. The current study reports our single-center experience regarding the early outcomes of sutureless aortic valve implantation. Methods Between October 2012 and June 2015, 65 patients scheduled for surgical valve replacement with symptomatic aortic valve disease and New York Heart Association function of class II or higher were included to this study. Perceval S (Sorin Biomedica Cardio Srl, Sallugia, Italy) and Edwards Intuity (Edwards Lifesciences, Irvine, CA, USA) valves were used. Results The mean age of the patients was 71.15±8.60 years. Forty-four patients (67.7%) were female. The average preoperative left ventricular ejection fraction was 56.9±9.93. The CPB time was 96.51±41.27 minutes and the cross-clamping time was 60.85±27.08 minutes. The intubation time was 8.95±4.19 hours, and the intensive care unit and hospital stays were 2.89±1.42 days and 7.86±1.42 days, respectively. The mean quantity of drainage from chest tubes was 407.69±149.28 mL. The hospital mortality rate was 3.1%. A total of five patients (7.69%) died during follow-up. The mean follow-up time was 687.24±24.76 days. The one-year survival rate was over 90%. Conclusion In the last few years, several models of valvular sutureless bioprostheses have been developed. The present study evaluating the single-center early outcomes of sutureless aortic valve implantation presents the results of an innovative surgical technique, finding that it resulted in appropriate hemodynamic conditions with acceptable ischemic time. PMID:27298793

Surgical management of traumatic tricuspid insufficiency.

PubMed

Zhang, Zhiqi; Yin, Kanhua; Dong, Lili; Sun, Yongxin; Guo, Changfa; Lin, Yi; Wang, Chunsheng

2017-06-01

This study reviews our experience with traumatic tricuspid insufficiency (TTI) following blunt chest trauma. From January 2010 to June 2016, 10 patients (nine males, mean age 49.0 ± 12.4 years) underwent surgical treatment of TTI following blunt chest trauma. The mean intervals between trauma and diagnosis and between trauma and surgery were 74.1 and 81.8 months, respectively. Preoperatively, all patients exhibited severe tricuspid regurgitation. Five patients underwent tricuspid valve repair, and the remaining patients underwent valve replacement. The mean follow-up duration (with echocardiography) was 29.7 months. There was no early or late death. Seven patients had anterior chordal rupture, two patients had anterior papillary muscle rupture, and one patient had both anterior chordal and anterior leaflet rupture. The median postoperative intensive care unit and hospital stays were 1 and 6 days, respectively. There were no severe postoperative complications. During follow-up, four patients exhibited trivial to mild tricuspid regurgitation, and the remaining six patients exhibited no regurgitation. Surgical treatment of TTI via either valve repair or replacement can be performed with low perioperative morbidity and mortality. Early surgery is recommended for achieving a successful valve repair and preserving right ventricular function. © 2017 Wiley Periodicals, Inc.

Maximal Aortic Valve Cusp Separation and Severity of Aortic Stenosis

PubMed Central

Dilu, VP; George, Raju

2017-01-01

Introduction An integrated approach that incorporates two dimensional, M mode and Doppler echocardiographic evaluation has become the standard means for accurate quantification of severity of valvular aortic stenosis. Maximal separation of the aortic valve cusps during systole has been shown to correlate well with the severity of aortic stenosis measured by other echocardiographic parameters. Aim To study the correlation between Maximal Aortic valve Cusp Separation (MACS) and severity of aortic valve stenosis and to find cut-off values of MACS for detecting severe and mild aortic stenosis. Materials and Methods In the present prospective observational study, we have compared the accuracy of MACS distance and the aortic valve area calculated by continuity equation in 59 patients with varying degrees of aortic valve stenosis. Aortic leaflet separation in M mode was identified as the distance between the inner edges of the tips of these structures at mid systole in the parasternal long axis view. Cuspal separation was also measured in 2D echocardiography from the parasternal long axis view and the average of the two values was taken as the MACS. Patients were grouped into mild, moderate and severe aortic stenosis based on the aortic valve area calculated by continuity equation. The resultant data regarding maximal leaflet separation on cross-sectional echocardiogram was then subjected to linear regression analysis in regard to correlation with the peak transvalvular aortic gradient as well as the calculated aortic valve area. A cut-off value for each group was derived using ROC curve. Results There was a strong correlation between MACS and aortic valve area measured by continuity equation and the peak and mean transvalvular aortic gradients. Mean MACS was 6.89 mm in severe aortic stenosis, 9.97 mm in moderate aortic stenosis and 12.36 mm in mild aortic stenosis. MACS below 8.25 mm reliably predicted severe aortic stenosis, with high sensitivity, specificity and positive predictive value. MACS above 11.25 mm practically ruled out significant aortic stenosis. Conclusion Measurement of MACS is a simple echocardio-graphic method to assess the severity of valvular aortic stenosis, with high sensitivity and specificity. MACS can be extremely useful in two clinical situations as a simple screening tool for assessment of stenosis severity and also helps in decision making non invasively when there is discordance between the other echocardiographic parameters of severity of aortic stenosis. PMID:28764221

Gargantuan left atrium: a sequela of mitral regurgitation and mitral stenosis.

PubMed

Omslaer, Brian T; Biederman, Robert W W

2015-06-01

Cardiac magnetic resonance imaging and echocardiography revealed a gargantuan left atrium measuring 18.9 cm × 15.7 cm × 11.3 cm in a 56-year-old patient diagnosed with severe rheumatic mitral stenosis, severe pulmonary hypertension, and permanent atrial fibrillation. A chest x-ray also revealed a cardiothoracic ratio approaching 1.0 and a transthoracic echocardiogram measured diameters as large as 19.2 cm. The patient then underwent mitral valve replacement and left atrial reduction surgery and has had no further admissions or complications. © 2015, Wiley Periodicals, Inc.

Evaluation of prosthetic valve obstruction on electrocardiographically gated multidetector-row computed tomography--identification of subprosthetic pannus in the aortic position.

PubMed

Ueda, Tomohiro; Teshima, Hideki; Fukunaga, Shuji; Aoyagi, Shigeaki; Tanaka, Hiroyuki

2013-01-01

This study was performed to evaluate the diagnostic role of electrocardiographically gated multidetector-row computed tomography (MDCT) for prosthetic valve obstruction (PVO) in the aortic position. Between 2002 and 2006, 9 patients were diagnosed with PVO of an aortic bileaflet mechanical valve based on echocardiographic and cineradiographic criteria. These 9 patients were examined using MDCT before replacement of the mechanical valve, and intraoperative findings were compared to morphologic periprosthetic abnormalities observed on MDCT. CT attenuation (Hounsfield units; HU) of the periprosthetic abnormalities was measured to investigate the underlying cause of the PVO. MDCT showed subprosthetic masses extending beyond the prosthetic ring into the orifice of the valve. At reoperation, presence of subprosthetic pannus was confirmed in all of the 9 patients, but no periprosthetic thrombus was found. The mean CT attenuation of the subprosthetic pannus was 170 HU, and it was significantly greater than that obtained from the interventricular septum (108 HU; P<0.0001). MDCT can be used to clearly visualize subprosthetic pannus causing PVO and the mean CT attenuation of subprosthetic pannus is significantly higher than that of the interventricular septum on MDCT.

Trauma: An Unusual Cause of Endocarditis.

PubMed

Braga, Ana; Marques, Marta; Abecacis, Miguel; Neves, José Pedro

2017-01-01

Infective endocarditis (IE) remains a dangerous condition with considerable associated mortality. Usual risk factors for IE include the presence of a prosthetic heart valve, structural or congenital heart disease, intravenous drug use, and a recent history of invasive procedures. The authors describe the case report of a patient with IE having trauma as an unusual risk factor. A 33-year old male patient was referred to our department due to infective endocarditis. The patient had a fever of unknown origin for 15 days before going to the emergency department. After admission it was identified by transthoracic echocardiography a 14mm posterior abscess of the aortic valve provoking major aortic regurgitation with moderate LV dysfunction. After careful evaluation of the clinical history it was found that the patient had a known bicuspid aortic valve with follow-up since the age of 14. All other usual risk factors for IE were excluded, including intravenous drug use and recent history of invasive procedures. The only relevant previous event was a traumatic haemathoma in his left jaw caused by a working accident with an iron beam in a construction site as the patient is a civil engineer. Vancomycin plus gentamicin were empirically started after blood cultures taken. The isolated infective agent was Staphylococcus lugdunensis methicillin sensitive and the antibiotherapy was de-escalated to flucloxacilin plus gentamicin. Due to cardiac dysfunction the patient was submitted to cardiac surgery on the fourth day of directed antibiotic therapy and a replacement of the aortic valve by a mechanical prosthetic valve and closure of the abscess with bovine pericardial patch was performed. The valve sent to microbiology evaluation showed the same infective provocative agent. The patient had a good clinical and laboratorial recovery completing the 42-day antibiotic scheme. After antibiotherapy period completion, echocardiography was repeated and the abscess found was larger then the previous one, presenting itself like an aortic pseudo aneurysm. The patient was resubmitted to surgery with re-closure of the initial abscess with autologous pericardial patch and replacement of the prosthetic mechanical valve for an undersized one. The patient was discharger clinically well, having a complete normal life at the moment. This clinical case illustrates trauma as an unusual cause of endocarditis and emphasizes the importance of a detailed clinical history.

Impact of preprocedural atrial fibrillation on immediate and long-term outcomes after successful percutaneous mitral valvuloplasty of significant mitral stenosis.

PubMed

Miura, Shiro; Arita, Takeshi; Domei, Takenori; Yamaji, Kyohei; Soga, Yoshimitsu; Hyodo, Makoto; Shirai, Shinichi; Ando, Kenji

2018-01-01

Optimal time to perform percutaneous mitral valvuloplasty (PMV) for patients with significant mitral stenosis (MS) and atrial fibrillation (AF) remains controversial. We sought to identify prognostic factors and evaluate long-term clinical outcomes after PMV of 77 consecutive patients with MS with a mitral valve area (MVA) <1.5 cm 2 . According to baseline heart rhythm, these patients were divided into sinus rhythm (SR; n = 24) and AF (n = 53) groups. The study endpoint was defined as a composite of all-cause mortality, admission for heart failure, mitral valve surgery, repeated PMV, and major cerebral vascular accident during follow-up. After successful PMV, there was no significant difference between the two groups in post-MVA and post-mitral mean pressure gradient. However, the New York Heart Association Functional Classification post-procedure was worse in the AF group (p < 0.01). In the AF group, event-free survival during follow-up was significantly lower compared with that of the SR group (p = 0.016). Independent predictors of clinical events were AF [hazard ratio (HR), 2.73; 95 % confidence interval (CI), 1.04-9.36; p = 0.03] and pulmonary artery systolic pressure (HR 2.57; 95 % CI 1.18-5.47; p = 0.017). Patients with AF at baseline were significantly associated with worse symptoms and higher event rates after successful PMV compared with those with SR. The clinical benefit of PMV may be considered for patients with MVA <1.5 cm 2 before the onset of AF.

Left ventricle to aorta valved conduit for relief of diffuse left ventricular outflow tract obstruction.

PubMed

Reder, R F; Dimich, I; Steinfeld, L; Litwak, R S

1977-06-01

Operative relief of congenital tunnel subaortic stenosis by means of local incision or excision, or both, has generally been unsatisfactory. The use of a valve-bearing conduit between the left ventricular apex and thoracic aorta offers a predictable means of bypassing the left ventricular outflow obstruction. The procedure was used in a 17 year old girl with an excellent hemodynamic result. The history of operative management with diverting plantation of valved conduits in this position have not been defined, but use of these prostheses appears advisable in severe subvalvular, valvular and supravalvular obstructions that are not readily amenable to predictable and safe surgical palliation. The operation may prove useful in selected cases of idiopathic hypertrophic obstructive cardiomyopathy.

Clinical features, microbiology and surgical outcomes of infective endocarditis: a 13-year study from a UK tertiary cardiothoracic referral centre.

PubMed

Marks, D J B; Hyams, C; Koo, C Y; Pavlou, M; Robbins, J; Koo, C S; Rodger, G; Huggett, J F; Yap, J; Macrae, M B; Swanton, R H; Zumla, A I; Miller, R F

2015-03-01

Infective endocarditis (IE) causes substantial morbidity and mortality. Patient and pathogen profiles, as well as microbiological and operative strategies, continue to evolve. The impact of these changes requires evaluation to inform optimum management and identify individuals at high risk of early mortality. Identification of clinical and microbiological features, and surgical outcomes, among patients presenting to a UK tertiary cardiothoracic centre for surgical management of IE between 1998 and 2010. Retrospective observational cohort study. Clinical, biochemical, microbiological and echocardiographic data were identified from clinical records. Principal outcomes were all-cause 28-day mortality and duration of post-operative admission. Patients (n = 336) were predominantly male (75.0%); median age 52 years (IQR = 41-67). Most cases involved the aortic (56.0%) or mitral (53.9%) valves. Microbiological diagnoses, obtained in 288 (85.7%) patients, included streptococci (45.2%); staphylococci (34.5%); Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella (HACEK) organisms (3.0%); and fungi (1.8%); 11.3% had polymicrobial infection. Valve replacement in 308 (91.7%) patients included mechanical prostheses (69.8%), xenografts (24.0%) and homografts (6.2%). Early mortality was 12.2%, but fell progressively during the study (P = 0.02), as did median duration of post-operative admission (33.5 to 10.5 days; P = 0.0003). Multivariable analysis showed previous cardiothoracic surgery (OR = 3.85, P = 0.03), neutrophil count (OR = 2.27, P = 0.05), albumin (OR = 0.94, P = 0.04) and urea (OR = 2.63, P < 0.001) predicted early mortality. This study demonstrates reduced post-operative early mortality and duration of hospital admission for IE patients over the past 13 years. Biomarkers (previous cardiothoracic surgery, neutrophil count, albumin and urea), predictive of early post-operative mortality, require prospective evaluation to refine algorithms, further improve outcomes and reduce healthcare costs associated with IE. © The Author 2014. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Percutaneous transluminal mitral commissurotomy for rheumatic mitral stenosis in a 5-year-old child.

PubMed

Ullah, Maad; Sultan, Mehboob; Akbar, Hajira; Sadiq, Nadeem

2012-06-01

We report a 5-year-old boy weighing 11 kg, with severe mitral valve stenosis of rheumatic aetiology, who underwent successful percutaneous transluminal mitral commissurotomy (PTMC) with valvuloplasty balloon. Postprocedural mean pressure gradient across the mitral valve decreased to 6 mmHg from an initially recorded value of 22 mmHg. In addition to symptomatic improvement, the mitral valvular area increased from 0.4 to 0.8 cm(2) without significant change in mitral regurgitation. At 1- and 3-month follow up, transthoracic echocardiography revealed further improvement with an increase in mitral valve area to 1.0 cm(2), a decrease in pulmonary arterial pressure, and a mean mitral valve pressure gradient of 8 mmHg with trivial mitral regurgitation. To best of our knowledge, this is the first successful PTMC procedure performed in the youngest and smallest ever reported child with rheumatic mitral stenosis (MS). We conclude that PTMC with valvuloplasty balloon could be a logical alternative to surgery in young patients with rheumatic MS.

Factors influencing mortality after bioprosthetic valve replacement; a midterm outcome.

PubMed

Javadzadegan, Hassan; Javadzadegan, Amir; Mehdizadeh Baghbani, Jafar

2013-01-01

Although valve repair is applied routinely nowadays, particularly for mitral regurgitation (MR) or tricuspid regurgitation (TR), valve replacement using prosthetic valves is also common especially in adults. Unfortunately the valve with ideal hemodynamic performance and long-term durability without increasing the risk of bleeding due to long-term anticoagulant therapy has not been introduced. Therefore, patients and physicians must choose either bioprosthetic or mechanical valves. Currently, there is an increasing clinical trend of using bioprosthetic valves instead of mechanical valves even in young patients apparently because of their advantages. Seventy patients undergone valvular replacement using bioprosthetic valves were evaluated by ECG and Echocardiography to assess the rhythm and ejection fracture. Mean follow-up time was 33 months (min 9, max 92). Mortality rate was 25.9% (n=18) within 8 years of follow-up. Statistical analysis showed a significant relation between atrial fibrillation rhythm and mortality (P=0.02). Morbidities occurred in 30 patients (42.8%). Significant statistical relation was found between the morbidities and age over 65 years old (P=0.005). In follow-up period, 4 cases (5.7%) underwent re-operation due to global valve dysfunction. Our study shows that using biprosthetic valve could reduce the risk of morbidity occurrence in patient who needs valve replacement. However, if medical treatments fail, patients should be referred for surgery. This would reduce the risk of mortality because of lower incident of complications such as atrial fibrillation and morbidities due to younger patients' population.

Factors Influencing Mortality after Bioprosthetic Valve Replacement; A Midterm Outcome

PubMed Central

Javadzadegan, Hassan; Javadzadegan, Amir; Mehdizadeh Baghbani, Jafar

2013-01-01

Introduction: Although valve repair is applied routinely nowadays, particularly for mitral regurgitation (MR) or tricuspid regurgitation (TR), valve replacement using prosthetic valves is also common especially in adults. Unfortunately the valve with ideal hemodynamic performance and long-term durability without increasing the risk of bleeding due to long-term anticoagulant therapy has not been introduced. Therefore, patients and physicians must choose either bioprosthetic or mechanical valves. Currently, there is an increasing clinical trend of using bioprosthetic valves instead of mechanical valves even in young patients apparently because of their advantages. Methods: Seventy patients undergone valvular replacement using bioprosthetic valves were evaluated by ECG and Echocardiography to assess the rhythm and ejection fracture. Mean follow-up time was 33 months (min 9, max 92). Results: Mortality rate was 25.9% (n=18) within 8 years of follow-up. Statistical analysis showed a significant relation between atrial fibrillation rhythm and mortality (P=0.02). Morbidities occurred in 30 patients (42.8%). Significant statistical relation was found between the morbidities and age over 65 years old (P=0.005). In follow-up period, 4 cases (5.7%) underwent re-operation due to global valve dysfunction. Conclusion: Our study shows that using biprosthetic valve could reduce the risk of morbidity occurrence in patient who needs valve replacement. However, if medical treatments fail, patients should be referred for surgery. This would reduce the risk of mortality because of lower incident of complications such as atrial fibrillation and morbidities due to younger patients' population. PMID:24404348

Valve Cap For An Electric Storage Cell

DOEpatents

Verhoog, Roelof; Genton, Alain

2000-04-18

The valve cap for an electric storage cell includes a central annular valve seat (23) and a membrane (5) fixed by its peripheral edge and urged against the seat by a piston (10) bearing thereagainst by means of a spring (12), the rear end of said spring (12) bearing on the endwall (8) of a chamber (20) formed in the cap and containing the piston (10) and the spring. A vent (19) puts the chamber (20) into communication with the atmosphere. A central orifice (26, 28) through the piston (10) and the membrane (5), enables gas from within the cell to escape via the top vent (19) when the valve opens.

[Plastic repair of tricuspid valve: Carpentier's ring annuloplasty versus De VEGA technique].

PubMed

Charfeddine, Salma; Hammami, Rania; Triki, Faten; Abid, Leila; Hentati, Mourad; Frikha, Imed; Kammoun, Samir

2017-01-01

Tricuspid valve disease has been neglected for a long time by cardiologists and surgeons, but for some years now leakage of tricuspid valve has been demonstrated as a prognostic factor in the evolution of patients with left heart valve disease undergoing surgery. Several techniques for plastic repair of tricuspid valve have been developed and the published studies differ on the results of these techniques; we conducted this study to assess the results of plastic repair of tricuspid valve in a population of patients with a high prevalence of rheumatic disease and to compare Carpentier's ring annuloplasty techniques with DEVEGA plasty. We conducted a retrospective study of patients undergoing plastic repair of tricuspid valve in the Department of Cardiology at the Medicine University of Sfax over a period of 25 years. We compared the results from the Group 1 (Carpentier's ring annuloplasty) with Group 2 (DeVEGA plasty). 91 patients were included in our study, 45 patients in the Group 1 and 46 patients in the Group 2. Most patients had mean or severe TI (83%) before surgery, ring dilation was observed in 90% of patients with no significant difference between the two groups. Immediate results were comparable between the two techniques but during monitoring recurrent, at least mean, insufficiency was significantly more frequent in the DeVEGA plasty Group. The predictive factors for significant recurring long term TI were DeVEGA technique (OR=3.26[1.12-9.28]) in multivariate study and preoperative pulmonary artery systolic pressure (OR=1.06 (1.01-1.12)). Plastic repair of tricuspid valve using Carpentier's ring seems to guarantee better results than DeVEGA plasty. On the other hand, preoperative high PASP is predictive of recurrent leakage of tricuspid valve even after plasty; hence the importance of surgery in the treatment of patients at an early stage of the disease.

Transcatheter aortic valve implantation using anatomically oriented, marrow stromal cell-based, stented, tissue-engineered heart valves: technical considerations and implications for translational cell-based heart valve concepts.

PubMed

Emmert, Maximilian Y; Weber, Benedikt; Behr, Luc; Sammut, Sebastien; Frauenfelder, Thomas; Wolint, Petra; Scherman, Jacques; Bettex, Dominique; Grünenfelder, Jürg; Falk, Volkmar; Hoerstrup, Simon P

2014-01-01

While transcatheter aortic valve implantation (TAVI) has rapidly evolved for the treatment of aortic valve disease, the currently used bioprostheses are prone to continuous calcific degeneration. Thus, autologous, cell-based, living, tissue-engineered heart valves (TEHVs) with regeneration potential have been suggested to overcome these limitations. We investigate the technical feasibility of combining the concept of TEHV with transapical implantation technology using a state-of-the-art transcatheter delivery system facilitating the exact anatomical position in the systemic circulation. Trileaflet TEHVs fabricated from biodegradable synthetic scaffolds were sewn onto self-expanding Nitinol stents seeded with autologous marrow stromal cells, crimped and transapically delivered into the orthotopic aortic valve position of adult sheep (n = 4) using the JenaValve transapical TAVI System (JenaValve, Munich, Germany). Delivery, positioning and functionality were assessed by angiography and echocardiography before the TEHV underwent post-mortem gross examination. For three-dimensional reconstruction of the stent position of the anatomically oriented system, a computed tomography analysis was performed post-mortem. Anatomically oriented, transapical delivery of marrow stromal cell-based TEHV into the orthotopic aortic valve position was successful in all animals (n = 4), with a duration from cell harvest to TEHV implantation of 101 ± 6 min. Fluoroscopy and echocardiography displayed sufficient positioning, thereby entirely excluding the native leaflets. There were no signs of coronary obstruction. All TEHV tolerated the loading pressure of the systemic circulation and no acute ruptures occurred. Animals displayed intact and mobile leaflets with an adequate functionality. The mean transvalvular gradient was 7.8 ± 0.9 mmHg, and the mean effective orifice area was 1.73 ± 0.02 cm(2). Paravalvular leakage was present in two animals, and central aortic regurgitation due to a single-leaflet prolapse was detected in two, which was primarily related to the leaflet design. No stent dislocation, migration or affection of the mitral valve was observed. For the first time, we demonstrate the technical feasibility of a transapical TEHV delivery into the aortic valve position using a commercially available and clinically applied transapical implantation system that allows for exact anatomical positioning. Our data indicate that the combination of TEHV and a state-of-the-art transapical delivery system is feasible, representing an important step towards translational, transcatheter-based TEHV concepts.

The effect of intravitreal bevacizumab injection before Ahmed valve implantation in patients with neovascular glaucoma.

PubMed

Kang, Jung Youb; Nam, Ki Yup; Lee, Sang Joon; Lee, Seung Uk

2014-08-01

To evaluate the effect of intravitreal bevacizumab (IVB) before Ahmed valve implantation for treatment of neovascular glaucoma (NVG). This study is a retrospective, comparative, consecutive case series. The study group consisted of 27 eyes of 26 patients with NVG who underwent an Ahmed valve implantation. Thirteen eyes were treated with Ahmed valve implantation alone (control group), and 14 eyes were treated with a combination of preoperative IVB injection and Ahmed valve implantation (IVB group). Visual acuity, intraocular pressure (IOP), number of anti-glaucoma medications, surgical complications, and success rate were compared between the two groups. There were no significant differences in preoperative characteristics between the two groups. Visual acuity at 1, 2 weeks, and 1 month after surgery were significantly better in the IVB group (p = 0.038, 0.034, and 0.032, respectively). Hyphema associated with Ahmed valve implantation occurred significantly less in the IVB group (p = 0.016). On the other hand, the mean IOP and number of anti-glaucoma medications at all follow-up periods were similar between the two groups. Kaplan-Meier survival analysis showed the probability of success 6 months after surgery as 71.4 % in the IVB group and 84.6 % in the control group. No significant difference in success rate was found between the groups (p = 0.422). IVB before Ahmed valve implantation for treatment of NVG reduced the incidence of hyphema. In this retrospective study, IVB provided better visual outcome in the early postoperative periods but did not significantly improve mean IOP, number of anti-glaucoma medications, or success rate.

Aortic Root Replacement for Children With Loeys-Dietz Syndrome.

PubMed

Patel, Nishant D; Alejo, Diane; Crawford, Todd; Hibino, Narutoshi; Dietz, Harry C; Cameron, Duke E; Vricella, Luca A

2017-05-01

Loeys-Dietz syndrome (LDS) is an aggressive aortopathy with a proclivity for aortic aneurysm rupture and dissection at smaller diameters than other connective tissue disorders. We reviewed our surgical experience of children with LDS to validate our guidelines for prophylactic aortic root replacement (ARR). We reviewed all children (younger than 18 years) with a diagnosis of LDS who underwent ARR at our institution. The primary endpoint was mortality, and secondary endpoints included complications and the need for further interventions. Thirty-four children with LDS underwent ARR. Mean age at operation was 10 years, and 15 (44%) were female. Mean preoperative root diameter was 4 cm. Three children (9%) had composite ARR with a mechanical prosthesis, and 31 (91%) underwent valve-sparing ARR. Concomitant procedures included arch replacement in 2 (6%), aortic valve repair in 1 (3%), and patent foramen ovale closure in 16 (47%). There was no operative mortality. Two children (6%) required late replacement of the ascending aorta, 5 (15%) required arch replacement, 1 (3%) required mitral valve replacement, and 2 (6%) had coronary button aneurysms/pseudoaneurysms requiring repair. Three children required redo valve-sparing ARR after a Florida sleeve procedure, and 2 had progressive aortic insufficiency requiring aortic valve replacement after a valve-sparing procedure. There were 2 late deaths (6%). These data confirm the aggressive aortopathy of LDS. Valve-sparing ARR should be performed when feasible to avoid the risks of prostheses. Serial imaging of the arterial tree is critical, given the rate of subsequent intervention. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Single-center experience using the Freedom SOLO aortic bioprosthesis.

PubMed

Iliopoulos, Dimitrios C; Deveja, Aris Rezar; Androutsopoulou, Vasiliki; Filias, Vasilios; Kastelanos, Eleftherios; Satratzemis, Vasilios; Khalpey, Zain; Koudoumas, Dimitrios

2013-07-01

This study reviews a single institution experience with the Freedom SOLO (Sorin Group, Saluggia, Italy) aortic bioprosthesis. Between October 2006 and February 2010, 128 patients (64 men, 64 women; mean age, 75.8 ± 5.1 years) underwent aortic valve replacement using the Freedom SOLO stentless aortic valve. The follow-up time was 36.7 ± 1.2 months and 100% complete. Concomitant procedures were performed in 77 patients (60%). The mean standard European System for Cardiac Operative Risk Evaluation was 9 ± 2.7. Grade 3 aortic stenosis was present in 73% of patients, mixed aortic stenosis and regurgitation were present in 40% of patients, and mitral regurgitation was present in 46% of patients. The mean crossclamp time was 53 ± 12 minutes for isolated Freedom SOLO aortic valve implantation and 80 ± 28 minutes for concomitant procedures, and the mean cardiopulmonary bypass time was 103 ± 31 minutes. The mean implanted valve size was 22.6 ± 1.4 mm. The mean intensive care unit and hospital stays were 2.4 ± 1.1 days and 8.8 ± 2.6 days, respectively. Three patients underwent reoperation for bleeding. The 15-day, 30-day, and perioperative mortality were all 4.6%. The 36-month survival was 95.4% ± 1.6% for the cohort with a low European System for Cardiac Operative Risk Evaluation (<9) and 88.6% ± 1.7% for the cohort with a high European System for Cardiac Operative Risk Evaluation (>9). Echocardiographic data preoperatively, immediately postoperatively, and at 3, 6, and 12 months postoperatively showed peak transvalvular gradients of 75 ± 23, 17 ± 6, 18 ± 6.5, 16 ± 6, and 16 ± 9 mm Hg, respectively (P < .001), and a mean left ventricular end-diastolic diameter of 51 ± 7, 50 ± 6, 48 ± 8, 47 ± 6, and 46.5 ± 7.5 mm, respectively (P < .05). There were only 3 cases of early mild aortic regurgitation (grade 1), which remained stable at 12 months. The Freedom SOLO stentless aortic valve has excellent early and intermediate-term results. Published by Mosby, Inc.

6 CFR 17.105 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 17.105 Definitions..., department, or college of an educational institution (other than a local educational agency) admission to which is independent of admission to any other component of such institution. (b) Admission means...

40 CFR 5.105 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 5.105 Definitions. As..., or college of an educational institution (other than a local educational agency) admission to which is independent of admission to any other component of such institution. Admission means selection for...

CardiaMed mechanical valve: mid-term results of a multicenter clinical trial.

PubMed

Nazarov, Vladimir M; Zheleznev, Sergey I; Bogachev-Prokophiev, Alexandr V; Afanasyev, Alexandr V; Nemchenko, Eugene V; Jeltovskiy, Yuri V; Lavinyukov, Sergey O

2014-01-01

Prosthesis choice is a major concern in valvular surgery. A multicenter clinical trial was performed to assess the efficacy and safety of the CardiaMed prosthetic heart valve. The study enrolled 420 patients who underwent mitral (209) or aortic (211) valve replacement from 2003 to 2004 at 7 institutions in Russia, and who were followed up from 2006 to 2011. The mean age was 52.2 ± 10.2 years (range, 12-78 years), 47.4% were female, and 99.05% completed the study. The maximum observation term was 7.5 years (2188.5 patient-years); 1081.6 patient-years for aortic and 1106.9 patient-years for mitral valve replacement. The overall 7-year survival rate was 85.1%  ± 3.7%; 86.1%  ± 4.8% and 84.4%  ± 5.4% for aortic and mitral valve replacement, respectively. The 7-year freedom from valve-related death was 93.9%  ± 3.7% and 94.5%  ± 3.2% for aortic and mitral valve replacement, respectively. When early mortality (<30 days) was excluded, these rates were 94.8%  ± 3.1% and 93.8%  ± 3.82%, respectively. Linearized valve-dependent complication rates were determined for structural valve failure (0%/patient-year overall), thrombosis (0.63%/patient-year, all for mitral valve replacement), thromboembolic complications including transient neurologic deficits (0.13%/patient-year overall, 0.5%/patient-year for aortic valve replacement, 0.8%/patient-year for mitral valve replacement), hemorrhagic bleeding (0.64%/patient-year overall, 0.55%/patient-year for aortic valve replacement, 0.09%/patient-year for mitral valve replacement), prosthetic endocarditis (0.28%/patient-year overall, 0.28%/patient-year for aortic valve replacement, 0%/patient-year for mitral valve replacement), and hemolysis (0%/patient-year overall). The CardiaMed mechanical heart valve prostheses meets world standards of safety and efficacy.

Direct Comparison of the Edwards Intuity Elite and Sorin Perceval S Rapid Deployment Aortic Valves.

PubMed

Liakopoulos, Oliver J; Gerfer, Stephen; Weider, Simone; Rahmanian, Parwis; Zeriouh, Mohamed; Eghbalzadeh, Kaveh; Sabashnikov, Anton; Choi, Yeong-Hoon; Wippermann, Jens; Wahlers, Thorsten

2018-01-01

Rapid deployment aortic valve replacement (RDAVR) has emerged as an attractive alternative to conventional aortic valve replacement. This single-center study directly compared two commercially available rapid deployment valves with regard to clinical outcomes, valve-related complications, and hemodynamic performance. A total of consecutive 156 patients underwent RDAVR with the Intuity Elite (Edwards Lifesciences, Irvine, CA [Intuity group, n = 117] or the Perceval S (Sorin Group Italia Srl, Saluggia, Italy [Perceval group, n = 39]) between September 2012 and March 2016 at our institution. Perioperative data, including 30-day all-cause mortality, and echocardiographic measurements were assessed and retrospectively analyzed from our institutional database. Preoperative variables, including mean age (77 ± 5 years), European System for Cardiac Operative Risk Evaluation (6.8 ± 2.1), and body mass index (27 ± 5 kg/m 2 ), did not differ between groups. More male patients (60% versus 15%) with a higher body surface area (1.9 ± 0.2 m 2 versus 1.7 ± 0.2 m 2 ) and body weight (78 ± 13 kg versus 71 ± 15 kg) were in the Intuity group compared with the Perceval group, respectively (p < 0.05). Implanted RDAVR size (23.3 ± 1.8 mm versus 23.4 ± 1.5 mm), concomitant coronary artery bypass graft surgery (48% versus 33%), number of grafts, cardiopulmonary bypass, and aortic clamp time were comparable between the Intuity group and the Perceval group. Thirty-day mortality (Intuity 2.6% versus Perceval 5.1%) and valve-related complications (Intuity 12.0% versus Perceval 20.5%), including postoperative pacemaker implantation (Intuity 8.5% versus Perceval 12.8%), did not differ between groups. At discharge echocardiography, indexed effective orifice area was higher in the Intuity group, but peak or mean pressure gradients were comparable between groups. Performing RDAVR with the Intuity and Perceval rapid deployment valves provides comparable good clinical outcomes and valve hemodynamics, with low valve-related complication rates. The rate of pacemaker implantation was comparable for both rapid deployment valves, ranging from 8% to 13%. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Assessment of structural valve deterioration of transcatheter aortic bioprosthetic balloon-expandable valves using the new European consensus definition.

PubMed

Eltchaninoff, Hélène; Durand, Eric; Avinée, Guillaume; Tron, Christophe; Litzler, Pierre-Yves; Bauer, Fabrice; Dacher, Jean-Nicolas; Werhlin, Camille; Bouhzam, Najime; Bettinger, Nicolas; Candolfi, Pascal; Cribier, Alain

2018-03-30

Durability of transcatheter aortic bioprosthetic valves remains a major issue. Standardised definitions of deterioration and failure of bioprosthetic valves have recently been proposed. The aim of this study was to assess structural transcatheter valve deterioration (SVD) and bioprosthetic valve failure (BVF) using these new definitions. All TAVI patients implanted up to September 2012 with a minimal theoretical five-year follow-up were included. Systematic clinical and echocardiographic follow-up was performed annually. New standardised definitions were used to assess durability of transcatheter aortic bioprosthetic valves. From 2002 to 2012, 378 patients were included. Mean age and logistic EuroSCORE were 83.3±6.8 years and 22.8±13.1%. Thirty-day mortality was 13.2%. Nine patients had SVD including two severe forms and two patients had definite late BVF. The incidence of SVD and BVF at eight years was 3.2% (95% CI: 1.45-6.11) and 0.58% (95% CI: 0.15-2.75), respectively. Even though limited by the poor survival of the very high-risk/compassionate early population, our data do not demonstrate any alarm concerning transcatheter aortic valve durability. Careful prospective assessment in younger and lower-risk patients and comparison with surgical bioprosthetic valves are required for further assessment of the long-term durability of transcatheter valves.

Aortic annulus eccentricity before and after transcatheter aortic valve implantation: Comparison of balloon-expandable and self-expanding prostheses.

PubMed

Schuhbaeck, Annika; Weingartner, Christina; Arnold, Martin; Schmid, Jasmin; Pflederer, Tobias; Marwan, Mohamed; Rixe, Johannes; Nef, Holger; Schneider, Christian; Lell, Michael; Uder, Michael; Ensminger, Stephan; Feyrer, Richard; Weyand, Michael; Achenbach, Stephan

2015-07-01

The geometry of the aortic annulus and implanted transcatheter aortic valve prosthesis might influence valve function. We investigated the influence of valve type and aortic valve calcification on post-implant geometry of catheter-based aortic valve prostheses. Eighty consecutive patients with severe aortic valve stenosis (mean age 82 ± 6 years) underwent computed tomography before and after TAVI. Aortic annulus diameters were determined. Influence of prosthesis type and degree of aortic valve calcification on post-implant eccentricity were analysed. Aortic annulus eccentricity was reduced in patients after TAVI (0.21 ± 0.06 vs. 0.08 ± 0.06, p<0.0001). Post-TAVI eccentricity was significantly lower in 65 patients following implantation of a balloon-expandable prosthesis as compared to 15 patients who received a self-expanding prosthesis (0.06 ± 0.05 vs. 0.15 ± 0.07, p<0.0001), even though the extent of aortic valve calcification was not different. After TAVI, patients with a higher calcium amount retained a significantly higher eccentricity compared to patients with lower amounts of calcium. Patients undergoing TAVI with a balloon-expandable prosthesis show a more circular shape of the implanted prosthesis as compared to patients with a self-expanding prosthesis. Eccentricity of the deployed prosthesis is affected by the extent of aortic valve calcification. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

44 CFR 19.105 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 19.105 Definitions. As used in these Title IX... institution (other than a local educational agency) admission to which is independent of admission to any other component of such institution. Admission means selection for part-time, full-time, special...

49 CFR 25.105 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 25.105 Definitions. As used in these Title... educational institution (other than a local educational agency) admission to which is independent of admission to any other component of such institution. Admission means selection for part-time, full-time...

29 CFR 36.105 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... FEDERAL FINANCIAL ASSISTANCE Introduction § 36.105 Definitions. As used in these Title IX regulations, the... institution (other than a local educational agency) admission to which is independent of admission to any other component of such institution. Admission means selection for part-time, full-time, special...

10 CFR 1042.105 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 1042.105 Definitions. As used in these Title... educational institution (other than a local educational agency) admission to which is independent of admission to any other component of such institution. Admission means selection for part-time, full-time...

Gentamicin may have no effect on mortality of staphylococcal prosthetic valve endocarditis.

PubMed

Ramos-Martínez, Antonio; Muñoz Serrano, Alejandro; de Alarcón González, Arístides; Muñoz, Patricia; Fernández-Cruz, Ana; Valerio, Maricela; Fariñas, María Carmen; Gutiérrez-Cuadra, Manuel; Miró, José Ma; Ruiz-Morales, Josefa; Sousa-Regueiro, Dolores; Montejo, José Miguel; Gálvez-Acebal, Juan; HidalgoTenorio, Carmen; Domínguez, Fernando

2018-07-01

To analyze the influence of adding gentamicin to a regimen consisting of β-lactam or vancomycin plus rifampicin on survival in patients suffering from Staphylococcal prosthetic valve endocarditis (SPVE). From January 2008 to September 2016, 334 patients with definite SPVE were attended in the participating hospitals. Ninety-four patients (28.1%) received treatment based on β-lactam or vancomycin plus rifampicin and were included in the study. Variables were analyzed which related to patient survival during admission, including having received treatment with gentamicin. Seventy-seven (81.9%) were treated with cloxacillin (or vancomycin) plus rifampicin plus gentamicin, and 17 patients (18.1%) received the same regimen without gentamicin. The causative microorganism was Staphylococcus aureus in 40 cases (42.6%) and coagulase-negative staphylococci in 54 cases (57.4%). Overall, 40 patients (42.6%) died during hospital admission, 33 patients (42.9%) in the group receiving gentamicin and 7 patients in the group that did not (41.2%, P = 0.899). Worsening renal function was observed in 42 patients (54.5%) who received gentamicin and in 9 patients (52.9%) who did not (p = 0.904). Heart failure as a complication of endocarditis (OR: 4.58; CI 95%: 1.84-11.42) and not performing surgery when indicated (OR: 2.68; CI 95%: 1.03-6.94) increased mortality. Gentamicin administration remained unrelated to mortality (OR: 1.001; CI 95%: 0.29-3.38) in the multivariable analysis. The addition of gentamicin to a regimen containing vancomycin or cloxacillin plus rifampicin in SPVE was not associated to better outcome. Copyright © 2018. Published by Elsevier Ltd.

46 CFR 154.1125 - Pipes, fittings, and valves.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., fitting, and valve for the water spray system must be made of fire resistant and corrosion resistant materials, such as galvanized steel or galvanized iron pipe. (e) Each water spray system must have a means of drainage to prevent corrosion of the system and freezing of accumulated water in subfreezing...

46 CFR 154.1125 - Pipes, fittings, and valves.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., fitting, and valve for the water spray system must be made of fire resistant and corrosion resistant materials, such as galvanized steel or galvanized iron pipe. (e) Each water spray system must have a means of drainage to prevent corrosion of the system and freezing of accumulated water in subfreezing...

Potable water dispenser

NASA Technical Reports Server (NTRS)

Cunningham, H. R. (Inventor)

1973-01-01

A dispenser particularly suited for use in dispensing potable water into food and beverage reconstitution bags is described. The dispenser is characterized by an expansible chamber, selectively adjustable stop means for varying the maximum dimensions, a rotary valve, and a linear valve coupled in a cooperating relation for delivering potable water to and from the chamber.

Control of respiration-driven retrograde flow in the subdiaphragmatic venous return of the Fontan circulation

PubMed Central

Vukicevic, M; Conover, T; Jaeggli, M; Zhou, J; Pennati, G; Hsia, TY; Figliola, RS

2014-01-01

Respiration influences the subdiaphragmatic venous return in the total cavopulmonary connection (TCPC) of the Fontan circulation whereby both the inferior vena cava (IVC) and hepatic vein flows can experience retrograde motion. Controlling retrograde flows could improve patient outcomes. Using a patient-specific model within a Fontan mock circulatory system with respiration, we inserted a valve into the IVC to examine its effects on local hemodynamics while varying retrograde volumes by changing vascular impedances. A bovine valved conduit reduced IVC retrograde flow to within 3% of antegrade flow in all cases. The valve closed only under conditions supporting retrograde flow and its effects on local hemodynamics increased with larger retrograde volume. Liver and TCPC pressures improved only while the valve leaflets were closed while cycle-averaged pressures improved only slightly (italic>1 mm Hg). Increased pulmonary vascular resistance raised mean circulation pressures but the valve functioned and cardiac output improved and stabilized. Power loss across the TCPC improved by 12–15% (pbold>0.05) with a valve. The effectiveness of valve therapy is dependent on patient vascular impedance. PMID:24814833

Segmentation of the Aortic Valve Apparatus in 3D Echocardiographic Images: Deformable Modeling of a Branching Medial Structure

PubMed Central

Pouch, Alison M.; Tian, Sijie; Takabe, Manabu; Wang, Hongzhi; Yuan, Jiefu; Cheung, Albert T.; Jackson, Benjamin M.; Gorman, Joseph H.; Gorman, Robert C.; Yushkevich, Paul A.

2015-01-01

3D echocardiographic (3DE) imaging is a useful tool for assessing the complex geometry of the aortic valve apparatus. Segmentation of this structure in 3DE images is a challenging task that benefits from shape-guided deformable modeling methods, which enable inter-subject statistical shape comparison. Prior work demonstrates the efficacy of using continuous medial representation (cm-rep) as a shape descriptor for valve leaflets. However, its application to the entire aortic valve apparatus is limited since the structure has a branching medial geometry that cannot be explicitly parameterized in the original cm-rep framework. In this work, we show that the aortic valve apparatus can be accurately segmented using a new branching medial modeling paradigm. The segmentation method achieves a mean boundary displacement of 0.6 ± 0.1 mm (approximately one voxel) relative to manual segmentation on 11 3DE images of normal open aortic valves. This study demonstrates a promising approach for quantitative 3DE analysis of aortic valve morphology. PMID:26247062

Radiant energy receiver having improved coolant flow control means

DOEpatents

Hinterberger, H.

1980-10-29

An improved coolant flow control for use in radiant energy receivers of the type having parallel flow paths is disclosed. A coolant performs as a temperature dependent valve means, increasing flow in the warmer flow paths of the receiver, and impeding flow in the cooler paths of the receiver. The coolant has a negative temperature coefficient of viscosity which is high enough such that only an insignificant flow through the receiver is experienced at the minimum operating temperature of the receiver, and such that a maximum flow is experienced at the maximum operating temperature of the receiver. The valving is accomplished by changes in viscosity of the coolant in response to the coolant being heated and cooled. No remotely operated valves, comparators or the like are needed.

Triple valve surgery: a 25-year experience.

PubMed

Yilmaz, Mustafa; Ozkan, Murat; Böke, Erkmen

2004-09-01

Surgical treatment of rheumatic valvular disease still constitutes a significant number of cardiac operations in developing countries. Despite improvements in myocardial protection and cardiopulmonary bypass techniques, triple valve operations (aortic, mitral and tricuspid valves) are still challenging because of longer duration of cardiopulmonary bypass and higher degree of myocardial decompensation. This study was instituted in order to assess results of triple valve surgery. Between 1977 and 2002, 34 patients underwent triple valve surgery in our clinic by the same surgeon (EB). Eleven patients underwent triple valve replacement (32.4%) and 23 underwent tricuspid valve annuloplasty with aortic and mitral valve replacements (67.6%). There was no significant difference between the two groups of patients who underwent triple valve replacement and aortic and mitral valve replacement with tricuspid valve annuloplasty. There were 4 hospital deaths (11.8%) occurring within 30 days. The duration of follow-up for 30 survivors ranged from 6 to 202 months (mean 97 months). The actuarial survival rates were 85%, 72%, and 48% at 5, 10, and 15 years respectively. Actuarial freedom from reoperation rates at 5, 10, and 15 years was 86.3%, 71.9%, and 51.2%, respectively. Freedom from cerebral thromboembolism and anticoagulation-related hemorrhage rates, expressed in actuarial terms was 75.9% and 62.9% at 5 and 10 years. Major cerebral complications occurred in 10 of the 30 patients. We prefer replacing, if repairing is not possible, the tricuspid valve, with a bileaflet mechanical prosthesis in a patient with valve replacement of the left heart who will be anticoagulated in order to avoid unfavorable properties of bioprosthesis like degeneration and of old generation mechanical prosthesis like thrombosis and poor hemodynamic function. In recent years, results of triple valve surgery either with tricuspid valve conservation or valve replacement in suitable cases have become encouraging with improvements in surgical techniques and myocardial preservation methods.

Trans-apical aortic valve implantation in patients with severe calcification of the ascending aorta.

PubMed

Buz, Semih; Pasic, Miralem; Unbehaun, Axel; Drews, Thorsten; Dreysse, Stephan; Kukucka, Marian; Mladenow, Alexander; Hetzer, Roland

2011-08-01

In patients with calcification of the ascending aorta, postoperative stroke and mortality rates remain high after conventional aortic valve replacement, but the results of trans-apical aortic valve implantation in these patients are not known. We evaluate the outcome of trans-apical aortic valve implantation in patients with severely calcified ascending aorta in a single center with expanded procedural experience. Between April 2008 and July 2010, 258 patients underwent trans-apical aortic valve implantation using Edwards Sapien valve. By computed tomography (CT) scan, we identified 46 (18%) patients with severe calcification of the ascending aorta (16 with porcelain aorta and 30 with severe, but not complete, calcification). Of 46 patients (mean age 77 ± 10 years, range 63-90 years; EuroSCORE (European System for Cardiac Operative Risk Evaluation) 45 ± 22%; STS (Society of Thoracic Surgeons) score 23 ± 13) with calcified aorta, 15 received 23-mm valves and 31 patients 26-mm valves. Primary valve implantation was successful in 44 patients and a second valve was implanted (valve-in-valve) in two. Six patients underwent concomitant interventions (three elective percutaneous coronary intervention (PCI), one off-pump coronary artery bypass (OPCAB), one tricuspid valve reconstruction, and one left-ventricular (LV) aneurysmectomy). The final procedural results showed valve incompetence (trace or grade 1) in 17 (37%) patients and paravalvular leak in 15 (32.6%) (trace in 10 and grade 1 in five). There was no 30-day mortality. Postoperatively, cranial CT showed new cerebral ischemia areas in three patients (6.2%), but only one patient (2.1%) experienced postoperative neurological deficit (temporary aphasia). Survival at 6 and 12 months was 88% and 85.2%, respectively. Trans-apical aortic valve implantation can be performed safely in patients with aortic valve stenosis and severe calcification of the ascending aorta. Copyright © 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Echocardiographic features of the normofunctional Labcor-Santiago pericardial bioprosthesis.

PubMed

Gonzalez-Juanatey, J R; Garcia-Bengoechea, J B; Vega, M; Rubio, J; Sierra, J; Duran, D; Amaro, A; Gil, M

1994-09-01

Echocardiography was performed in 94 patients with a total of 99 normally functioning Labcor-Santiago bioprostheses, 62 in the aortic and 37 in the mitral position. The following variables were measured: peak and mean transvalvular velocities, peak and mean instantaneous pressure gradients as calculated from the modified Bernoulli equation, pressure half-time, cardiac index, stroke volume and effective orifice area (using continuity and Hatle equations). Regurgitation patterns were sought by transthoracic echocardiography (all valves) and, for selected mitral bioprostheses, by transesophageal echocardiography. Calculated mean aortic pressure gradient ranged from six to 10 mmHg and calculated effective aortic orifice area increased with ring diameter, with means of 1.27 cm2 for the 19 mm valve and 2.58 cm2 for the 27 mm valve. For mitral bioprostheses, mean pressure gradient ranged from 3.0 to 4.5 mmHg and calculated effective orifice area from 2.27 to 2.73 cm2. Only central regurgitation was observed. The Labcor-Santiago pericardial bioprostheses created little resistance to forward flow. In the small aortic root their hemodynamic performance was as good or better than that of other currently available devices. It is hoped that this new design will contribute increased in vivo mechanical durability.

The development of a microprocessor-controlled linearly-actuated valve assembly

NASA Technical Reports Server (NTRS)

Wall, R. H.

1984-01-01

The development of a proportional fluid control valve assembly is presented. This electromechanical system is needed for space applications to replace the current proportional flow controllers. The flow is controlled by a microprocessor system that monitors the control parameters of upstream pressure and requested volumetric flow rate. The microprocessor achieves the proper valve stem displacement by means of a digital linear actuator. A linear displacement sensor is used to measure the valve stem position. This displacement is monitored by the microprocessor system as a feedback signal to close the control loop. With an upstream pressure between 15 and 47 psig, the developed system operates between 779 standard CU cm/sec (SCCS) and 1543 SCCS.

Multi-detector CT angiography of the aortic valve—Part 2: disease specific findings

PubMed Central

Ganeshan, Arul

2014-01-01

The aortic valve and adjacent structures should be routinely evaluated on all thoracic cross-sectional imaging studies. Echocardiography and magnetic resonance imaging (MRI) are the main imaging techniques used for assessment of the aortic valve and related pathology but multi-detector computed tomography (MDCT) can offer valuable complimentary information in some clinical scenarios. MDCT is the definite means of assessing aortic valvular calcification, acute aortic syndrome and for non-invasive assessment of the coronary arteries. MDCT also has an emerging role in the planning and follow-up of trans-catheter aortic valve replacement. This article reviews the spectrum of aortic valve disease highlighting the key MDCT imaging features. PMID:25202663

Recovery of atrial function after atrial compartment operation for chronic atrial fibrillation in mitral valve disease.

PubMed

Shyu, K G; Cheng, J J; Chen, J J; Lin, J L; Lin, F Y; Tseng, Y Z; Kuan, P; Lien, W P

1994-08-01

We prospectively studied the recovery of atrial function after atrial compartment operation and mitral valve surgery in patients with chronic atrial fibrillation caused by mitral valve disease. Chronic atrial fibrillation is the most common arrhythmia in mitral valve disease. This arrhythmia is associated with excessive morbidity and mortality. Mitral valve surgery alone rarely eliminates it. Twenty-two patients underwent mitral valve surgery and a new surgical method, atrial compartment operation. Doppler echocardiography was performed in all patients before operation and at 1 week and 2 and 6 months after operation in the successful cardioversion group. Peak early diastolic (E) and atrial (A) filling velocities, peak A/E velocity ratio and A/E integral ratio of the mitral and tricuspid valves were measured. Sinus rhythm was restored immediately after operation in 91% of patients and was maintained for > 1 week in 15 (68%) of 22 patients and > 6 months in 14 (64%) of 22. Eleven of 15 patients had left atrial paralysis (A/E integral ratio 0) at 1 week and 6 of 14 patients at 2 months. Nine of 15 patients had right atrial paralysis (A/E integral ratio 0) at 1 week and 1 of 14 patients at 2 months. Both left and right atrial contractile function (presence of an A wave on Doppler findings) was detected at 6 months in 14 patients. Mean (+/- SD) peak atrial filling velocity of the mitral valve was 15 +/- 26 cm/s at 1 week, 38 +/- 39 cm/s at 2 months and 93 +/- 32 cm/s at 6 months (p < 0.001). Mean peak atrial filling velocity of the tricuspid valve was 14 +/- 19 cm/s at 1 week, 33 +/- 19 cm/s at 2 months and 50 +/- 19 cm/s at 6 months (p < 0.001). Peak early diastolic and atrial filling velocities, peak A/E velocity ratio and A/E integral ratio of the mitral and tricuspid valves increased significantly from 1 week to 6 months. Chronic atrial fibrillation in mitral valve disease can often be eliminated by atrial compartment operation. No surgical mortality or significant complications were encountered. Both left and right atrial function, as manifested by Doppler findings, recover after compartment operation and improve over time. The mechanical function of the right atrium recovers earlier than that of the left.

Surgical treatment of Behçet's disease involving aortic regurgitation.

PubMed

Ando, M; Kosakai, Y; Okita, Y; Nakano, K; Kitamura, S

1999-12-01

Behçet's disease involving aortic regurgitation is rare, and prosthetic valve detachment after aortic valve replacement is one of the most serious complications reported. We investigated the surgical results in 10 patients with aortic regurgitation caused by Behçet's disease. Between 1981 and 1997, 10 patients with aortic regurgitation secondary to Behçet's disease had surgery. There were 8 men and 2 women, and their ages ranged from 33 to 60 years (mean, 46+/-8 years). The surgical procedures for aortic regurgitation were aortic valve replacement in 6 patients and Bentall type operation in 4. No patient died during the hospital stay. The follow-up periods ranged from 11 to 185 months (mean, 87 months). Two patients died during the follow-up period. The acturial survival rate was 89% at 5 years and 67% at 10 years. Prosthetic valve detachment or suture detachment requiring redo operation occurred in 4 patients, 3 of whom had redo operations twice. Four patients had a composite graft replacement, and 1 patient died after the operation. No prosthetic valve detachment was noted in 64% of the patients at 5 years and in 43% at 10 years. The rate of prosthetic valve detachment was 40% (4 of 10 patients), with a higher incidence in patients with Behçet's disease than in those treated during the same period at the same hospital for aortitis caused by other diseases. Surgical techniques for treatment of this condition should be modified to improve the surgical outcome in these patients.

Flow compensating pressure regulator

NASA Technical Reports Server (NTRS)

Baehr, E. F. (Inventor)

1978-01-01

An apparatus for regulating pressure of treatment fluid during ophthalmic procedures is described. Flow sensing and pressure regulating diaphragms are used to modulate a flow control valve. The pressure regulating diaphragm is connected to the flow control valve to urge the valve to an open position due to pressure being applied to the diaphragm by bias means such as a spring. The flow sensing diaphragm is mechanically connected to the flow control valve and urges it to an opened position because of the differential pressure on the diaphragm generated by a flow of incoming treatment fluid through an orifice in the diaphragm. A bypass connection with a variable restriction is connected in parallel relationship to the orifice to provide for adjusting the sensitivity of the flow sensing diaphragm. A multiple lever linkage system is utilized between the center of the second diaphragm and the flow control valve to multiply the force applied to the valve by the other diaphragm and reverse the direction of the force.

Non-Dimensional Formulation of Ventricular Work-Load Severity Under Concomitant Heart Valve Disease

NASA Astrophysics Data System (ADS)

Dong, Melody; Simon-Walker, Rachael; Dasi, Lakshmi

2012-11-01

Current guidelines on assessing the severity of heart valve disease rely on dimensional disease specific measures and are thus unable to capture severity under a concomitant heart valve disease scenario. Experiments were conducted to measure ventricular work-load in an in-house in-vitro left heart simulator. In-house tri-leaflet heart valves were built and parameterized to model concomitant heart valve disease. Measured ventricular power varied non-linearly with cardiac output and mean aortic pressure. Significant data collapse could be achieved by the non-dimensionalization of ventricular power with cardiac output, fluid density, and a length scale. The dimensionless power, Circulation Energy Dissipation Index (CEDI), indicates that concomitant conditions require a significant increase in the amount of work needed to sustain cardiac function. It predicts severity without the need to quantify individual disease severities. This indicates the need for new fluid-dynamics similitude based clinical guidelines to assist patients with multiple heart valve diseases. Funded by the American Heart Association.

Valve gape behaviour of mussels (Mytilus edulis) exposed to dispersed crude oil as an environmental monitoring endpoint.

PubMed

Redmond, Kirsten J; Berry, Mark; Pampanin, Daniela M; Andersen, Odd Ketil

2017-04-15

Environmental monitoring requires cost-effective and efficient methods for detecting potential effects of pollution, and valve gape behaviour has been used with this purpose for a range of contaminants in freshwater and marine bivalves. The current study investigated the use of a new method for measuring valve behaviour responses in mussels (Mytilus edulis) exposed to dispersed crude oil (DCO). Results confirmed that valve gape is a sensitive parameter; at the high DCO concentration (0.25mgL -1 ) the mean valve gape was reduced from 49 to 31%, and mussels increased shell movement (measured as distance travelled) or spent more time closed to avoid contact with the oil. At the low DCO concentration (0.015mgL -1 ) the distance travelled parameter was the most sensitive endpoint. Results also demonstrated that valve gape behaviour is a valid endpoint when monitoring mussels for exposure to DCO. Copyright © 2017 Elsevier Ltd. All rights reserved.

Morbidity following the Ross operation.

PubMed

Gonzalez-Lavin, L; Robles, A; Graf, D

1988-09-01

Aortic valve replacement (AVR) with a pulmonary valve autograft (PVA) was first reported by Donald N. Ross in 1967. The expectation of this procedure was to avoid degenerative changes seen in other biological tissue valves such as calcification, attenuation, and rupture of the leaflets. Recent reports by the original investigator's group have confirmed the lack of degenerative changes in PVA. To corroborate their conclusions, the fate of 12 patients undergoing AVR with PVA by Dr. Gonzalez-Lavin has been ascertained. From March 1969 to June 1971, 12 patients underwent AVR with PVA. The right ventricular outflow tract (RVOT) was reconstructed with an aortic homograft valved conduit. The mean age was 42.7 years (range 21 to 52 years). The mean follow-up for 11 hospital survivors is 12.4 years. Three PVAs have been replaced; one following infective endocarditis at 13 years, and two at 15 and 73 months due to technical malalignment. There was no evidence of PVA degeneration during histologic examination of these explanted PVA. Six patients are alive and retain the original PVA at 12 years (55%). This analysis corroborates the conclusions of Dr. Ross and strongly suggests an immunological mechanism in the process of calcification of other biological tissue valves. The Ross operation is believed to be the preferred method of AVR in young patients.

Air intake side secondary air supply system for an internal combustion engine with a duty ratio control operation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawanabe, T.; Asakura, M.; Shina, T.

1987-09-01

An air intake side secondary air supply system is described for an internal combustion engine having an air intake passage with a carburetor and an exhaust passage, comprising: an air intake side secondary air supply passage communicating with the air intake passage on the downstream side of the carburetor; an open/close valve disposed in the air intake side secondary air supply passage; an oxygen concentration sensor disposed in the exhaust passage; and detection and control means for detecting whether an air-fuel ratio of mixture to be supplied to the engine is leaner or richer with respect to a target air-fuelmore » ratio through a level of an output signal of the oxygen concentration sensor and for periodically actuating the open/close valve, the detection and control means decreasing a valve open period of the open/close valve within each cyclic period by a first predetermined amount when a detected air-fuel ratio of mixture is leaner than the target air-fuel ratio and increasing the valve open period by a second predetermined amount when the detected air-fuel ratio of mixture is richer than the target air-fuel ratio. The second predetermined amount is different from the first predetermined amount.« less

Outcome of aortic valve replacement for active infective endocarditis in patients on chronic hemodialysis.

PubMed

Dohmen, Pascal M; Binner, Christian; Mende, Meinhart; Bakhtiary, Farhad; Etz, Christian; Pfannmüller, Bettina; Davierwala, Piroze; Borger, Michael A; Misfeld, Martin; Mohr, Friedrich W

2015-02-01

The high risk of morbidity and mortality for patients on hemodialysis who are undergoing cardiac surgery is increased for those with active infective endocarditis (AIE). This retrospective observational single-center study evaluated the impact of chronic hemodialysis on the outcome of aortic valve replacement in patients with aortic AIE. Data were retrospectively collected for consecutive patients undergoing aortic valve surgery for AIE diagnosed according to modified Duke criteria between October 1994 and January 2011. Characteristics and outcomes of patients receiving preoperative chronic hemodialysis were analyzed. Aortic valve AIE was present in 992 patients. Forty-five (4.5%) of the aortic valve AIE patients were receiving long-term hemodialysis preoperatively, 19 of whom (42.2%) had diabetes mellitus. Mean logistic EuroSCORE was 64.2% ± 32.2%. Twenty-four preoperative septic emboli were found in 15 patients. Results of microbiologic cultures were positive in 36 patients, with the major causative organisms identified as Staphylococcus aureus (n = 17) and Enterococcus faecalis (n = 10). Isolated aortic valve replacement was performed in 19 patients (42.2%), and 26 patients (57.8%) underwent concomitant procedures. The mean follow-up was 5.3 ± 5.2 years (range, 0.1 to 17.1 years). Postoperative complications occurred in 30 patients (66.7%). Nineteen patients (42.2%) died within 30 days of surgery, which in 8 patients was attributable to a cardiac cause. In patients receiving chronic hemodialysis who undergo aortic valve replacement for acute AIE, postoperative mortality is high, especially in patients undergoing aortic root replacement or culture-negative AIE. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Evaluating the effect of three-dimensional visualization on force application and performance time during robotics-assisted mitral valve repair.

PubMed

Currie, Maria E; Trejos, Ana Luisa; Rayman, Reiza; Chu, Michael W A; Patel, Rajni; Peters, Terry; Kiaii, Bob B

2013-01-01

The purpose of this study was to determine the effect of three-dimensional (3D) binocular, stereoscopic, and two-dimensional (2D) monocular visualization on robotics-assisted mitral valve annuloplasty versus conventional techniques in an ex vivo animal model. In addition, we sought to determine whether these effects were consistent between novices and experts in robotics-assisted cardiac surgery. A cardiac surgery test-bed was constructed to measure forces applied during mitral valve annuloplasty. Sutures were passed through the porcine mitral valve annulus by the participants with different levels of experience in robotics-assisted surgery and tied in place using both robotics-assisted and conventional surgery techniques. The mean time for both the experts and the novices using 3D visualization was significantly less than that required using 2D vision (P < 0.001). However, there was no significant difference in the maximum force applied by the novices to the mitral valve during suturing (P = 0.7) and suture tying (P = 0.6) using either 2D or 3D visualization. The mean time required and forces applied by both the experts and the novices were significantly less using the conventional surgical technique than when using the robotic system with either 2D or 3D vision (P < 0.001). Despite high-quality binocular images, both the experts and the novices applied significantly more force to the cardiac tissue during 3D robotics-assisted mitral valve annuloplasty than during conventional open mitral valve annuloplasty. This finding suggests that 3D visualization does not fully compensate for the absence of haptic feedback in robotics-assisted cardiac surgery.

Evaluation of tricuspid valve regurgitation following laser lead extraction†.

PubMed

Pecha, Simon; Castro, Liesa; Gosau, Nils; Linder, Matthias; Vogler, Julia; Willems, Stephan; Reichenspurner, Hermann; Hakmi, Samer

2017-06-01

The objective of this study was to examine the effect of laser lead extraction (LLE) on the development of post-procedural tricuspid regurgitation (TR). Some reports have suggested an increase in TR associated with LLE. We present a series of patients who underwent both, LLE and complete echocardiographic evaluation for TR. A single centre analysis of consecutive patients referred for LLE between January 2012 and August 2015. One hundred and three patients had tricuspid valve function evaluated before the procedure with a transthoracic echocardiography (TTE), during the procedure using transoesophageal echocardiography and postoperatively using a TTE. TR was graded from 0 (none) to 4 (severe). We treated 235 leads in 103 patients, including 118 ventricular leads. Seventy-seven were male (74.8%) and 26 female (25.2%), with a mean age of 65.6 ± 15.4 years. Mean time from initial lead implantation was 98.0 ± 67.3 months. Twenty-one patients (20.4%) had ejection fraction below 30%. No intra-procedural worsening of tricuspid valve function was seen with TEE in any of the patients. Ten patients (9.7%) were found to have TR before LLE that returned to normal valve function after the procedure. Two patients (1.9%) experienced mild TR after the procedure (both with tricuspid valve endocarditis). Ninety-one patients (88.3%) did not experience any significant change of the tricuspid valve function after LLE. Transthoracic and transoesophageal echocardiography findings showed that laser lead extraction was not associated with a significant increase in the incidence of tricuspid valve regurgitation. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Posterior leaflet preservation during mitral valve replacement for rheumatic mitral stenosis.

PubMed

Djukić, P L; Obrenović-Kirćanski, B B; Vranes, M R; Kocica, M J; Mikić, A Dj; Velinović, M M; Kacar, S M; Kovacević, N S; Parapid, B J

2006-01-01

Mitral valve replacement with posterior leaflet preservation was shown beneficial for postoperative left vetricular (LV) performance in patients with mitral regurgitation. Some authors find it beneficial even for the long term LV function. We investigated a long term effect of this technique in patients with rheumatic mitral stenosis. We studied 20 patents with mitral valve replacement due to rheumatic mitral stenosis, in the period from January 1988 to December 1989. In group A (10 patients) both leaflets and coresponding chordal excision was performed, while in group B (10 patients) the posterior leaflet was preserved. In all patients a Carbomedics valve was inserted. We compared clinical pre and postoperative status, as well as hemodynamic characteristics of the valve and left ventricle in both groups. Control echocardiographyc analysis included: maximal (PG) and mean (MG) gradients; effective valve area (AREA); telediastolic (TDV) and telesystolic (TSV) LV volume; stroke volume (SV); ejection fraction (EF); fractional shortening (FS) and segmental LV motion. The mean size of inserted valve was 26.6 in group A and 27.2 in group B. Hemodynamic data: PG (10.12 vs 11.1); MG (3.57 vs 3.87); AREA (2.35 vs 2.30); TDV 126.0 vs 114.5); TSV (42.2 vs 36.62); SV (83.7 vs 77.75); EF (63.66 vs 67.12); FS (32.66 vs 38.25). Diaphragmal segmental hypokinesis was evident in one patient from group A and in two patients from group B. In patients with rheumatic stenosis, posterior leaflet preservation did not have increased beneficial effect on left ventricular performance during long-term follow-up. An adequate posterior leaflet preservation does not change hemodynamic valvular characteristics even after long-term follow-up.

Vct system having closed loop control employing spool valve actuated by a stepper motor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quin, S.B. Jr.; Siemon, E.C.

1993-06-15

An internal combustion engine is described comprising: a crankshaft, the crankshaft being rotable about an axis; a cam shaft, the cam shaft being rotatable about a second axis, the second axis being parallel to the axis, the cam shaft being subject to torque reversals during the rotation thereof; a vane, the vane having at least one lobe, the vane being attached to the cam shaft, being rotatable with the cam shaft and being non-oscillatable with respect to the cam shaft; a housing, the housing being rotatable with the cam shaft and being oscillatable with respect to the cam shaft, themore » housing having at least one recess, the recess receiving the lobe, the lobe being oscillatable within the recess; rotary movement transmitting means for transmitting rotary movement from the crankshaft to the housing; actuating means for varying the position of the housing relative to the cam shaft in reaction to torque reversals in the cam shaft, the actuating means comprising a stepper motor, a lead screw and a proportional spool valve, the position of the spool valve being controlled by the position of the lead screw driven by the stepper motor, the actuating means also delivering hydraulic fluid to the vane; and processing means for controlling the position of the actuating means.« less

Effectiveness of Student Admission Essays in Identifying Attrition.

ERIC Educational Resources Information Center

Sadler, Judith

2003-01-01

From a longitudinal sample of nursing students, 193 completers and 43 noncompleters were compared, revealing significant differences in the groups' mean scores on admission essays but not admission grade point averages. Content analysis revealed how completers had internalized the role of nurse. (Contains 12 references.) (SK)

Surgical outcomes in native valve infectious endocarditis: the experience of the Cardiovascular Surgery Department - Cluj-Napoca Heart Institute.

PubMed

Molnar, Adrian; Muresan, Ioan; Trifan, Catalin; Pop, Dana; Sacui, Diana

2015-01-01

The introduction of Duke's criteria and the improvement of imaging methods has lead to an earlier and a more accurate diagnosis of infectious endocarditis (IE). The options for the best therapeutic approach and the timing of surgery are still a matter of debate and require a close colaboration between the cardiologist, the infectionist and the cardiac surgeon. We undertook a retrospective, descriptive study, spanning over a period of five years (from January 1st, 2007 to December 31st, 2012), on 100 patients who underwent surgery for native valve infectious endocarditis in our unit. The patients' age varied between 13 and 77 years (with a mean of 54 years), of which 85 were males (85%). The main microorganisms responsible for IE were: Streptococcus Spp. (21 cases - 21%), Staphylococcus Spp. (15 cases - 15%), and Enterococcus Spp. (9 cases - 9%). The potential source of infection was identified in 26 patients (26%), with most cases being in the dental area (16 cases - 16%). The lesions caused by IE were situated in the left heart in 96 patients (96%), mostly on the aortic valve (50 cases - 50%). In most cases (82%) we found preexisting endocardial lesions which predisposed to the development of IE, most of them being degenerative valvular lesions (38 cases - 38%). We performed the following surgical procedures: surgery on a single valve - aortic valve replacement (40 cases), mitral valve replacement (19 cases), mitral valve repair (1 case), surgery on more than one valve - mitral and aortic valve replacement (20 cases), aortic and tricuspid valve replacement (1 case), aortic valve replacement with a mechanical valve associated with mitral valve repair (5 cases), aortic valve replacement with a biological valve associated with mitral valve repair (2 cases), and mitral valve replacement with a mechanical valve combined with De Vega procedure on the tricuspid valve (1 case). In 5 patients (5%) the bacteriological examination of valve pieces excised during surgery was positive. In 3 cases it matched the germ identified in the hemocultures, and in 2 cases it evidenced another bacterium. The overall mortality of 5% is well between the limits presented in literature, being higher (30%) in patients who required emergency surgery. For the patients who return into our clinic with prosthetic valve endocarditis, the mortality after surgery was even higher (50%).

Minimally invasive redo mitral valve surgery without aortic crossclamp.

PubMed

Milani, Rodrigo; Brofman, Paulo Roberto Slud; Oliveira, Sergio; Patrial Neto, Luiz; Rosa, Matheus; Lima, Victor Hugo; Binder, Luis Fernando; Sanches, Aline

2013-01-01

Reoperations of the mitral valve have a higher rate of complications when compared with the first surgery. With the field of video-assisted techniques for the first surgery of mitral valve became routine, reoperation cases began to arouse interest for this less invasive procedures. To assess the results and the technical difficulties in 10 patients undergoing minimally invasive redo mitral valve surgery. Cardiopulmonary bypass was installed through a cannula placed in the femoral vessels and right internal jugular vein, conducted in 28 degrees of temperature in ventricular fibrillation. A right lateral thoracotomy with 5 to 6 cm in the third or fourth intercostal space was done, pericardium was displaced only at the point of atriotomy. The aorta was not clamped. Ten patients with mean age of 56.9 ± 10.5 years, four were in atrial fibrilation rhythm and six in sinusal. Average time between first operation and reoperations was 11 ± 3.43 years. The mean EuroSCORE group was 8.3 ± 1.82. The mean ventricular fibrillation and cardiopulmonary bypass was respectively 70.9 ± 17.66 min and 109.4 ± 25.37 min. The average length of stay was 7.6 ± 1.5 days. There were no deaths in this series. Mitral valve reoperation can be performed through less invasive techniques with good immediate results, low morbidity and mortality. However, this type of surgery requires a longer duration of cardiopulmonary bypass, especially in cases where the patient already has prosthesis. The presence of a minimal aortic insufficiency also makes this procedure technically more challenging.

Hemodynamic Evaluation of a Biological and Mechanical Aortic Valve Prosthesis Using Patient-Specific MRI-Based CFD.

PubMed

Hellmeier, Florian; Nordmeyer, Sarah; Yevtushenko, Pavlo; Bruening, Jan; Berger, Felix; Kuehne, Titus; Goubergrits, Leonid; Kelm, Marcus

2018-01-01

Modeling different treatment options before a procedure is performed is a promising approach for surgical decision making and patient care in heart valve disease. This study investigated the hemodynamic impact of different prostheses through patient-specific MRI-based CFD simulations. Ten time-resolved MRI data sets with and without velocity encoding were obtained to reconstruct the aorta and set hemodynamic boundary conditions for simulations. Aortic hemodynamics after virtual valve replacement with a biological and mechanical valve prosthesis were investigated. Wall shear stress (WSS), secondary flow degree (SFD), transvalvular pressure drop (TPD), turbulent kinetic energy (TKE), and normalized flow displacement (NFD) were evaluated to characterize valve-induced hemodynamics. The biological prostheses induced significantly higher WSS (medians: 9.3 vs. 8.6 Pa, P = 0.027) and SFD (means: 0.78 vs. 0.49, P = 0.002) in the ascending aorta, TPD (medians: 11.4 vs. 2.7 mm Hg, P = 0.002), TKE (means: 400 vs. 283 cm 2 /s 2 , P = 0.037), and NFD (means: 0.0994 vs. 0.0607, P = 0.020) than the mechanical prostheses. The differences between the prosthesis types showed great inter-patient variability, however. Given this variability, a patient-specific evaluation is warranted. In conclusion, MRI-based CFD offers an opportunity to assess the interactions between prosthesis and patient-specific boundary conditions, which may help in optimizing surgical decision making and providing additional guidance to clinicians. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Comparison of Outcomes of Resident-performed Ahmed Valve Implantation vs Trabeculectomy

PubMed Central

Kammerdiener, Leah L; Wannamaker, Kendall W; Fan, Jie; Sharpe, Elizabeth D

2016-01-01

ABSTRACT Aims: To compare outcomes of resident-performed Ahmed valve surgery vs trabeculectomy in a Veteran Affairs medical facility. Materials and methods: A retrospective cohort of 103 eyes in 91 patients receiving Ahmed valve (valve) or trabeculectomy (trab) performed at a Veterans Administration Medical Center by residents in their third year of training. The primary outcomes included intraocular pressure (IOP), treatment failure, and complications over 1 year. Results: Of 103 eyes, 44 received valve and 59 received trab. Primary open-angle glaucoma was primary diagnosis more often in trab, while neovascular glaucoma predominated in the valve group (p < 0.001). Preoperative mean IOP was 35.1 ± 11.8 and 24.5 ± 7.1 mm Hg for valve and trabeculectomy respectively (p < 0.001), but at 1 year the IOP difference between groups was not statistically significant (p = 0.064). Overall, 11 (25.0%) and 11 (18.6%) eyes met any criteria for failure for valve and trab respectively. At 1 year, 22.5% of valves had IOP > 21 mm Hg vs only 4.3% of trab (p = 0.02). Complications were infrequent. There were no intraoperative complications for valve, whereas five for trab. Most common immediate complication for valve was hyphema. Both groups had low rates of choroidal effusions and reoperation. Conclusion: Ahmed valve implantation and trabeculectomy produce significant reductions in IOP when performed by residents-in-training. Valves tend to be used more frequently in patients with secondary glaucoma. Although complication profiles differ between procedures, both are safe and well tolerated when performed by resident physicians. Clinical significance: This study provides support for evidence-based patient counseling that supervised, resident-performed Ahmed valve implantation and trabeculectomy are indeed safe and effective. How to cite this article: Sharpe RA, Kammerdiener LL, Wannamaker KW, Fan J, Sharpe ED. Comparison of Outcomes of Resident-performed Ahmed Valve Implantation vs Trabeculectomy. J Curr Glaucoma Pract 2016;10(2):60-67. PMID:27536049

Validation of continuous-wave Doppler echocardiographic measurements of mitral and tricuspid prosthetic valve gradients: a simultaneous Doppler-catheter study.

PubMed

Wilkins, G T; Gillam, L D; Kritzer, G L; Levine, R A; Palacios, I F; Weyman, A E

1986-10-01

For patients with stenotic native valves, the modified Bernoulli equation (delta P = 4V2) may be applied to Doppler-measured transvalvular velocities to yield an accurate estimate of transvalvular gradients. Although it would be useful if the same approach could be used for those with stenotic prosthetic valves, no previous study has validated the Doppler technique in this setting. We therefore recorded simultaneous continuous-wave Doppler flow profiles and transvalvular manometric gradients in 12 catheterized patients in whom all atrial and ventricular pressures were directly measured (transseptal left atrial catheterization and transthoracic ventricular puncture were performed where necessary). A total of 13 prostheses were studied: 11 mitral (seven porcine, three Starr-Edwards, and one Björk-Shiley) and two tricuspid (one porcine and one Björk-Shiley). The Doppler-determined mean gradient was calculated as the mean of the instantaneous gradients (delta P = 4V2) at 10 msec intervals throughout diastole. The correlation of simultaneous Doppler (DMG) and manometric mean gradients (MG) for the whole group (n = 13) demonstrated a highly significant relationship (MG = 1.07 DMG + 0.28; r = .96, p = .0001). The correlation was equally good for porcine valves alone (n = 8) (MG = 1.06 DMG + 0.55; r = .96, p = .001) and for mechanical valves alone (n = 5) (MG = 1.06 DMG - 0.04; r = .93, p = .02). In a subset of patients without regurgitation (n = 8), prosthetic valve areas were estimated by two Doppler methods originally described by Holen and Hatle, as well as by the invasive Gorlin method. As expected from theoretical considerations, a close correlation was not demonstrated between results of the Gorlin method and those of either Hatle's Doppler method (r = .65, fp = NS) or Holen's method (r = .14, p = NS). Comparison of the results of the two Doppler methods yielded a somewhat closer correlation (r = .73, p less than or equal to .05). These results suggest that in patients with disk-occluder, ball-occluder, and porcine prosthetic valves, Doppler estimates of transvalvular gradients are virtually identical to those obtained invasively.

Quality of Life and Anxiety in Younger Patients after Biological versus Mechanical Aortic Valve Replacement.

PubMed

Kottmaier, Marc; Hettich, Ina; Deutsch, Marcus-André; Badiu, Catalin; Krane, Markus; Lange, Ruediger; Bleiziffer, Sabine

2017-04-01

Background  Since biological valve recipients are likely to need a redo procedure in the future for valve deterioration, we hypothesized patients might be more fearful about the progression of their disease than patients after aortic valve replacement (AVR) with a mechanical valve. The aim of this study is to compare the quality of life (QOL) and anxiety in patients who have undergone biological versus mechanical AVR. Method  A total of 56 patients after mechanical AVR (mean age: 64.4 ± 8.17 years) and 66 patients after biological AVR (mean age: 64.8 ± 11.05 years) received three questionnaires 5.66 (± 2.68) years after surgery, including: The short form-36 (SF-36) to assess QOL, the fear of progression questionnaire (FOP), and the cardiac anxiety questionnaire (CAQ) to assess general anxiety, anxiety related to cardiac symptoms, and anxiety about progression of heart disease and valve and anticoagulation-specific questions. Results  No significant differences were found for all categories of the SF-36. The FOP showed significantly favorable values for the biological AVR group. The CAQ showed a tendency in the subscale "avoidance" (i.e., avoidance of pulse increase) and "attention" towards more favorable values for the biological AVR group. Conclusions  In contrast to our hypothesis, patients after mechanical AVR show significantly higher anxiety values for the FOP, and a tendency toward higher values for "avoidance" (i.e., avoidance of pulse increase). Partnership concerns, especially in terms of sexuality can be explained by factors that are recognizable for the partner, such as valve sound. These data provide evidence that factors that are continuously present after mechanical AVR, such as valve sound or anticoagulation might affect wellbeing stronger than the certainty of reoperation in the future after biological AVR. We conclude that implantation of a biological prosthesis can be justified in younger patients with regards to QOL. Georg Thieme Verlag KG Stuttgart · New York.

46 CFR 169.231 - Definitions relating to hull examinations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Definitions relating to hull examinations. 169.231... hull examinations. As used in the part— (a) Drydock examination means hauling out a vessel or placing a... and all through-hull fittings, sea chests, sea valves, sea strainers, and valves for the emergency...

The Effect of a Smoking Ban on Hospitalization Rates for Cardiovascular and Respiratory Conditions in Prince Edward Island, Canada

PubMed Central

Gaudreau, Katherine; Sanford, Carolyn J.; Cheverie, Connie; McClure, Carol

2013-01-01

Background This is the first study to have examined the effect of smoking bans on hospitalizations in the Atlantic Canadian socio-economic, cultural and climatic context. On June 1, 2003 Prince Edward Island (PEI) enacted a province-wide smoking ban in public places and workplaces. Changes in hospital admission rates for cardiovascular (acute myocardial infarction, angina, and stroke) and respiratory (chronic obstructive pulmonary disease and asthma) conditions were examined before and after the smoking ban. Methods Crude annual and monthly admission rates for the above conditions were calculated from April 1, 1995 to December 31, 2008 in all PEI acute care hospitals. Autoregressive Integrated Moving Average time series models were used to test for changes in mean and trend of monthly admission rates for study conditions, control conditions and a control province after the comprehensive smoking ban. Age- and sex-based analyses were completed. Results The mean rate of acute myocardial infarctions was reduced by 5.92 cases per 100,000 person-months (P = 0.04) immediately after the smoking ban. The trend of monthly angina admissions in men was reduced by −0.44 cases per 100,000 person-months (P = 0.01) in the 67 months after the smoking ban. All other cardiovascular and respiratory admission changes were non-significant. Conclusions A comprehensive smoking ban in PEI reduced the overall mean number of acute myocardial infarction admissions and the trend of angina hospital admissions. PMID:23520450

The effect of a smoking ban on hospitalization rates for cardiovascular and respiratory conditions in Prince Edward Island, Canada.

PubMed

Gaudreau, Katherine; Sanford, Carolyn J; Cheverie, Connie; McClure, Carol

2013-01-01

This is the first study to have examined the effect of smoking bans on hospitalizations in the Atlantic Canadian socio-economic, cultural and climatic context. On June 1, 2003 Prince Edward Island (PEI) enacted a province-wide smoking ban in public places and workplaces. Changes in hospital admission rates for cardiovascular (acute myocardial infarction, angina, and stroke) and respiratory (chronic obstructive pulmonary disease and asthma) conditions were examined before and after the smoking ban. Crude annual and monthly admission rates for the above conditions were calculated from April 1, 1995 to December 31, 2008 in all PEI acute care hospitals. Autoregressive Integrated Moving Average time series models were used to test for changes in mean and trend of monthly admission rates for study conditions, control conditions and a control province after the comprehensive smoking ban. Age- and sex-based analyses were completed. The mean rate of acute myocardial infarctions was reduced by 5.92 cases per 100,000 person-months (P = 0.04) immediately after the smoking ban. The trend of monthly angina admissions in men was reduced by -0.44 cases per 100,000 person-months (P = 0.01) in the 67 months after the smoking ban. All other cardiovascular and respiratory admission changes were non-significant. A comprehensive smoking ban in PEI reduced the overall mean number of acute myocardial infarction admissions and the trend of angina hospital admissions.

Leaflet escape in a new bileaflet mechanical valve: TRI technologies.

PubMed

Bottio, Tomaso; Casarotto, Dino; Thiene, Gaetano; Caprili, Luca; Angelini, Annalisa; Gerosa, Gino

2003-05-13

Leaflet escape is a mode of structural valve failure for mechanical prostheses. This complication previously has been reported for both monoleaflet and bileaflet valve models. We report 2 leaflet escape occurrences observed in 2 patients who underwent valve replacement with a TRI Technologies valve prosthesis. At the University of Padua, between November 2000 and February 2002, 36 TRI Technologies valve prostheses (26 aortic and 10 mitral) were implanted in 34 patients (12 women and 22 men) with a mean age of 59.9+/-10.3 years (range, 30 to 75 years). There were 5 deaths: 3 in hospital, 1 early after discharge, and 1 late. Two patients experienced a catastrophic prosthetic leaflet escape; the first patient was a 52-year-old man who died 10 days after aortic valve and ascending aorta replacement, and the second was a 58-year-old man who underwent a successful emergency reoperation 20 months after mitral valve replacement. Examination of the explanted prostheses showed in both cases a leaflet escape caused by a leaflet's pivoting system fracture. Prophylactic replacement was then successfully accomplished so far in 12 patients, without evidence of structural valve failure in any of them. Among other significant postoperative complications, we observed 3 major thromboembolisms, 1 hemorrhage, and 1 paravalvular leak. These catastrophes prompted us to interrupt the implantation program, and they cast a shadow on the durability of the TRI Technologies valve prosthesis because of its high risk of structural failure.

Spool-type control valve assembly with reduced spool stroke for hydraulic belt-and-pulley type continuously variable transmission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Itoh, H.; Akashi, T.; Takada, M.

1987-03-31

This patent describes a hydraulic control system for controlling a speed ratio of a hydraulically-operated continuously variable transmission of belt-and-pulley type having a variable-diameter pulley and a hydraulic cylinder for changing an effective diameter of the variable diameter-pulley of the transmission. The hydraulic control system includes a speed-ratio control valve assembly for controlling the supply and discharge of a pressurized fluid to and from the hydraulic cylinder to thereby change the speed ratio of the transmission. The speed-ratio control valve assembly comprises: a shift-direction switching valve unit disposed in fluid supply and discharge conduits communicating with the hydraulic cylinder, formore » controlling a direction in which the speed ratio of the transmission is varied; a shift-speed control valve unit of spool-valve type connected to the shift-direction switching valve unit. The shift-speed control valve unit is selectively placed in a first state in which the fluid supply and discharge flows to and from the hydraulic cylinder through the conduits are permitted, or in a second state in which the fluid supply flow is restricted while the fluid discharge flow is inhibited; an actuator means for placing the shift speed control valve unit alternately in the first and second states to control a rate of variation in the speed ratio of the transmission in the direction established by the shift-direction switching valve unit.« less

Equal Protection in Special Admissions Programs: Forward from Bakke.

ERIC Educational Resources Information Center

Stone, Julius

1979-01-01

Bakke's equal protection holding is analyzed and an assessment is offered of what the decisions mean for academic special admissions programs. Discussion focuses on how race may be used as a factor in admissions decisions consistently with the equal protection clause of the Federal Constitution. (Author/MSE)

Temperature dependence of giant magneto-resistance in PtMn- and Fe 2O 3-based specular spin valves

NASA Astrophysics Data System (ADS)

Kato, T.; Miyashita, K.; Iwata, S.; Tsunashima, S.; Sakakima, H.; Sugita, Y.; Kawawake, Y.

2002-02-01

Temperature dependence of the giant magneto-resistance (MR) was measured for spin valves with and without nano-oxide layer (NOL). In spin valves with NOL, the MR ratio increased more remarkably on lowering the temperature than in those without NOL. The temperature dependence of MR ratio and that of the resistivity were explained by using two-current model. The MR ratio enhanced with NOL is attributed to the increase of the mean free path of up-spin electrons.

Control methods and valve arrangement for start-up and shutdown of pressurized combustion and gasification systems integrated with a gas turbine

DOEpatents

Provol, Steve J.; Russell, David B.; Isaksson, Matti J.

1994-01-01

A power plant having a system for converting coal to power in a gas turbine comprises a coal fed pressurized circulating bed for converting coal to pressurized gases, a gas turbine having a compressor for pressurizing air for the pressurized circulating bed and expander for receiving and expanding hot combustion gases for powering a generator, a first fast acting valve for controlling the pressurized air, a second fast acting valve means for controlling pressurized gas from the compressor to the expander.

Outcomes After Operations for Unicuspid Aortic Valve With or Without Ascending Repair in Adults

PubMed Central

Zhu, Yuanjia; Roselli, Eric E.; Idrees, Jay J.; Wojnarski, Charles M.; Griffin, Brian; Kalahasti, Vidyasagar; Pettersson, Gosta; Svensson, Lars G.

2016-01-01

Background Unicuspid aortic valve is an important subset of bicuspid aortic valve, and knowledge regarding its aortopathy pattern and surgical outcomes is limited. Our objectives were to characterize unicuspid aortic valve patients, associated aortopathy, and surgical outcomes. Methods From January 1990 to May 2013, 149 adult unicuspid aortic valve patients underwent aortic valve replacement or repair for aortic stenosis (n = 13), regurgitation (n = 13), or both (n = 123), and in 91 (61%) the aortic valve operation was combined with aortic repair. Data were obtained from the Cardiovascular Information Registry and medical record review. Three-dimensional imaging analysis was performed from preoperative computed tomography and magnetic resonance imaging scans. The Kaplan-Meier method was used for survival analysis. Results Patients had a mean maximum aortic diameter of 44 ± 8 mm and variably involved the aortic root, ascending, or arch, or both. Patients with valve operations alone were more likely to be hypertensive (p = 0.01) and to have severe aortic stenosis (p = 0.07) than those who underwent concurrent aortic operations. There were no operative deaths, strokes, or myocardial infarctions. Patients undergoing aortic repair had better long-term survival. Estimated survival at 1, 5, and 10 years was 100%, 100%, and 100% after combined operations and was 100%, 88%, and 88% after valve operations alone (p = 0.01). Conclusions Patients with a dysfunctional unicuspid aortic valve frequently present with an ascending aneurysm that requires repair. Combined aortic valve operations and aortic repair was associated with significantly better long-term survival than a valve operation alone. Further study of this association may direct decisions about timing of surgical intervention. PMID:26453423

Novel self-expandable, stent-based transcatheter pulmonic valve: a preclinical animal study.

PubMed

Kim, Gi Beom; Lim, Hong-Gook; Kim, Yong Jin; Choi, Eun Young; Kwon, Bo Sang; Jeong, Saeromi

2014-04-15

Because transcatheter implantation of pulmonary valve is indicated for limited-size dysfunctional right ventricular outflow tract only as a balloon-expandable stent, we investigated the feasibility of a large-diameter self-expandable valved stent and the durability of the valve after >6 months. We made a nitinol-wire-based, self-expandable valved stent with leaflets made from porcine pericardium. The porcine pericardium was treated with α-galactosidase, glutaraldehyde, and glycine after decellularization. After cutting the inguinal or cervical area, we implanted a valved stent in 12 sheep through the femoral or jugular vein by using an 18-Fr delivery catheter, controlling the catheter handles and hook block under fluoroscopic and echocardiographic guidance. The mean body weight of sheep was 43.9 kg. We successfully implanted valved stents (diameter: 24 mm in 7 sheep, 26 mm in 5 sheep) in good position in 8 sheep, in the main pulmonary artery (PA) in 2 sheep, and in the right ventricular outlet tract (RVOT) in 2 sheep. We sacrificed 8 sheep (6 sheep in good position, 1 sheep in the main PA, and 1 sheep in the RVOT) after >6 months. Five of the 6 sheep implanted in good position showed well-preserved valve morphology at the time of sacrifice. Histologic findings after routine sacrifice showed well-maintained collagen wave structure and no visible calcification in all explanted valve leaflets. Transcatheter implantation of a nitinol-wire-based, self-expandable valved stent in the pulmonic valve was feasible, and stents implanted in good position showed well-preserved valve leaflets with functional competence in the mid-term results. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Transapical implantation of a second-generation transcatheter heart valve in patients with noncalcified aortic regurgitation.

PubMed

Seiffert, Moritz; Diemert, Patrick; Koschyk, Dietmar; Schirmer, Johannes; Conradi, Lenard; Schnabel, Renate; Blankenberg, Stefan; Reichenspurner, Hermann; Baldus, Stephan; Treede, Hendrik

2013-06-01

This study sought to report on the feasibility and early results of transcatheter aortic valve implantation employing a second-generation device in a series of patients with pure aortic regurgitation. Efficacy and safety of transcatheter aortic valve implantation in patients with calcific aortic stenosis and high surgical risk has been demonstrated. However, experience with implantation for severe noncalcified aortic regurgitation has been limited due to increased risk for valve dislocation or annular rupture. Five patients (mean age: 66.6 ± 7 years) underwent transapical implantation of a JenaValve (JenaValve Technology GmbH, Munich, Germany) transcatheter heart valve for moderate to severe, noncalcified aortic regurgitation. All patients were considered high risk for surgical aortic valve replacement after evaluation by an interdisciplinary heart team (logistic EuroSCORE [European System for Cardiac Operative Risk Evaluation] range 3.1% to 38.9%). Procedural and acute clinical outcomes were analyzed. Implantation was successful in all cases without relevant remaining aortic regurgitation or signs of stenosis in any of the patients. No major device- or procedure-related adverse events occurred and all 5 patients were alive with improved exercise tolerance at 3-month follow-up. Noncalcified aortic regurgitation continues to be a challenging pathology for transcatheter aortic valve implantation due to the risk for insufficient anchoring of the valve stent within the aortic annulus. This report provides first evidence that the JenaValve prosthesis may be a reasonable option in these specific patients due to its unique stent design, clipping the native aortic valve leaflets, and offering promising early results. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Calcification Characteristics of Low-Flow Low-Gradient Severe Aortic Stenosis in Patients Undergoing Transcatheter Aortic Valve Replacement

PubMed Central

Stähli, Barbara E.; Nguyen-Kim, Thi Dan Linh; Gebhard, Cathérine; Frauenfelder, Thomas; Tanner, Felix C.; Nietlispach, Fabian; Maisano, Francesco; Falk, Volkmar; Lüscher, Thomas F.; Maier, Willibald; Binder, Ronald K.

2015-01-01

Low-flow low-gradient severe aortic stenosis (LFLGAS) is associated with worse outcomes. Aortic valve calcification patterns of LFLGAS as compared to non-LFLGAS have not yet been thoroughly assessed. 137 patients undergoing transcatheter aortic valve replacement (TAVR) with preprocedural multidetector computed tomography (MDCT) and postprocedural transthoracic echocardiography were enrolled. Calcification characteristics were assessed by MDCT both for the total aortic valve and separately for each leaflet. 34 patients had LFLGAS and 103 non-LFLGAS. Total aortic valve calcification volume (p < 0.001), mass (p < 0.001), and density (p = 0.004) were lower in LFLGAS as compared to non-LFLGAS patients. At 30-day follow-up, mean transaortic pressure gradients and more than mild paravalvular regurgitation did not differ between groups. In conclusion, LFLGAS and non-LFLGAS express different calcification patterns which, however, did not impact on device success after TAVR. PMID:26435875

Aeroacoustics of automotive vents

NASA Astrophysics Data System (ADS)

Guérin, S.; Thomy, E.; Wright, M. C. M.

2005-08-01

This paper studies the generation of noise by car ventilation systems whose outlet rates are controlled by a butterfly valve and whose directions are controlled by grilles. First the noise created by the valve alone is analysed with the theory formulated by Nelson and Morfey for spoiler-generated noise in-duct flow. To confirm this theory the fluctuating force experienced by the valve is measured experimentally and the mean drag force is deduced from analytical work presented by Sarpkaya. Then the noise generated by the grille and its effect on sound transmission is investigated. Finally, it is shown that a strong and complex interaction between the wake shed behind the valve and the grille occurs when both elements are placed close together. This is responsible for an overall increase in the noise level although some sound reduction is measured at low frequency. It is found that moving the valve further upstream can reduce the noise by several decibels.

Design and Performance Evaluation of an Electro-Hydraulic Camless Engine Valve Actuator for Future Vehicle Applications

PubMed Central

Nam, Kanghyun; Cho, Kwanghyun; Park, Sang-Shin; Choi, Seibum B.

2017-01-01

This paper details the new design and dynamic simulation of an electro-hydraulic camless engine valve actuator (EH-CEVA) and experimental verification with lift position sensors. In general, camless engine technologies have been known for improving fuel efficiency, enhancing power output, and reducing emissions of internal combustion engines. Electro-hydraulic valve actuators are used to eliminate the camshaft of an existing internal combustion engines and used to control the valve timing and valve duration independently. This paper presents novel electro-hydraulic actuator design, dynamic simulations, and analysis based on design specifications required to satisfy the operation performances. An EH-CEVA has initially been designed and modeled by means of a powerful hydraulic simulation software, AMESim, which is useful for the dynamic simulations and analysis of hydraulic systems. Fundamental functions and performances of the EH-CEVA have been validated through comparisons with experimental results obtained in a prototype test bench. PMID:29258270

Design and Performance Evaluation of an Electro-Hydraulic Camless Engine Valve Actuator for Future Vehicle Applications.

PubMed

Nam, Kanghyun; Cho, Kwanghyun; Park, Sang-Shin; Choi, Seibum B

2017-12-18

This paper details the new design and dynamic simulation of an electro-hydraulic camless engine valve actuator (EH-CEVA) and experimental verification with lift position sensors. In general, camless engine technologies have been known for improving fuel efficiency, enhancing power output, and reducing emissions of internal combustion engines. Electro-hydraulic valve actuators are used to eliminate the camshaft of an existing internal combustion engines and used to control the valve timing and valve duration independently. This paper presents novel electro-hydraulic actuator design, dynamic simulations, and analysis based on design specifications required to satisfy the operation performances. An EH-CEVA has initially been designed and modeled by means of a powerful hydraulic simulation software, AMESim, which is useful for the dynamic simulations and analysis of hydraulic systems. Fundamental functions and performances of the EH-CEVA have been validated through comparisons with experimental results obtained in a prototype test bench.

Black Clouds vs Random Variation in Hospital Admissions.

PubMed

Ong, Luei Wern; Dawson, Jeffrey D; Ely, John W

2018-06-01

Physicians often accuse their peers of being "black clouds" if they repeatedly have more than the average number of hospital admissions while on call. Our purpose was to determine whether the black-cloud phenomenon is real or explainable by random variation. We analyzed hospital admissions to the University of Iowa family medicine service from July 1, 2010 to June 30, 2015. Analyses were stratified by peer group (eg, night shift attending physicians, day shift senior residents). We analyzed admission numbers to find evidence of black-cloud physicians (those with significantly more admissions than their peers) and white-cloud physicians (those with significantly fewer admissions). The statistical significance of whether there were actual differences across physicians was tested with mixed-effects negative binomial regression. The 5-year study included 96 physicians and 6,194 admissions. The number of daytime admissions ranged from 0 to 10 (mean 2.17, SD 1.63). Night admissions ranged from 0 to 11 (mean 1.23, SD 1.22). Admissions increased from 1,016 in the first year to 1,523 in the fifth year. We found 18 white-cloud and 16 black-cloud physicians in simple regression models that did not control for this upward trend. After including study year and other potential confounding variables in the regression models, there were no significant associations between physicians and admission numbers and therefore no true black or white clouds. In this study, apparent black-cloud and white-cloud physicians could be explained by random variation in hospital admissions. However, this randomness incorporated a wide range in workload among physicians, with potential impact on resident education at the low end and patient safety at the high end.

Low Transvalvular Flow Rate Predicts Mortality in Patients With Low-Gradient Aortic Stenosis Following Aortic Valve Intervention.

PubMed

Vamvakidou, Anastasia; Jin, Wenying; Danylenko, Oleksandr; Chahal, Navtej; Khattar, Rajdeep; Senior, Roxy

2018-03-09

This study aimed to assess the value of low transvalvular flow rate (FR) for the prediction of mortality compared with low stroke volume index (SVi) in patients with low-gradient (mean gradient: <40 mm Hg), low aortic valve area (<1 cm 2 ) aortic stenosis (AS) following aortic valve intervention. Transaortic FR defined as stroke volume/left ventricular ejection time is also a marker of flow; however, no data exist comparing the relative prognostic value of these 2 transvalvular flow markers in patients with low-gradient AS who had undergone valve intervention. We retrospectively followed prospectively assessed consecutive patients with low-gradient, low aortic valve area AS who underwent aortic valve intervention between 2010 and 2014 for all-cause mortality. Of the 218 patients with mean age 75 ± 12 years, 102 (46.8%) had low stroke volume index (SVi) (<35 ml/m 2 ), 95 (43.6%) had low FR (<200 ml/s), and 58 (26.6%) had low left ventricular ejection fraction <50%. The concordance between FR and SVi was 78.8% (p < 0.005). Over a median follow-up of 46.8 ± 21 months, 52 (23.9%) deaths occurred. Patients with low FR had significantly worse outcome compared with those with normal FR (p < 0.005). In patients with low SVi, a low FR conferred a worse outcome than a normal FR (p = 0.005), but FR status did not discriminate outcome in patients with normal SVi. By contrast, SVi did not discriminate survival either in patients with normal or low FR. Low FR was an independent predictor of mortality (p = 0.013) after adjusting for age, clinical prognostic factors, European System for Cardiac Operative Risk Evaluation II, dimensionless velocity index, left ventricular mass index, left ventricular ejection fraction, heart rate, time, type of aortic valve intervention, and SVi (p = 0.59). In patients with low-gradient, low valve area aortic stenosis undergoing aortic valve intervention, low FR, not low SVi, was an independent predictor of medium-term mortality. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Stentless vs. stented bioprosthesis for aortic valve replacement: A case matched comparison of long-term follow-up and subgroup analysis of patients with native valve endocarditis.

PubMed

Schaefer, Andreas; Dickow, Jannis; Schoen, Gerhard; Westhofen, Sumi; Kloss, Lisa; Al-Saydali, Tarik; Reichenspurner, Hermann; Philipp, Sebastian A; Detter, Christian

2018-01-01

Current retrospective evidence suggests similar clinical and superior hemodynamic outcomes of the Sorin Freedom Solo stentless aortic valve (SFS) (LivaNova PLC, London, UK) compared to the Carpentier Edwards Perimount stented aortic valve (CEP) (Edwards Lifesciences Inc., Irvine, California, USA). To date, no reports exist describing case-matched long-term outcomes and analysis for treatment of native valve endocarditis (NVE). From 2004 through 2014, 77 consecutive patients (study group, 59.7% male, 68.9 ± 12.5 years, logEuroSCORE II 7.6 ± 12.3%) received surgical aortic valve replacement (SAVR) with the SFS. A control group of patients after SAVR with the CEP was retrieved from our database and matched to the study group regarding 15 parameters including preoperative endocarditis. Acute perioperative outcomes and follow-up data (mean follow-up time 48.7±29.8 months, 95% complete) were retrospectively analyzed. No differences in early mortality occurred during 30-day follow up (3/77; 3.9% vs. 4/77; 5.2%; p = 0.699). Echocardiographic findings revealed lower postprocedural transvalvular pressure gradients (max. 17.0 ± 8.2 vs. 24.5 ± 9.2 mmHg, p< 0.001/ mean pressure of 8.4 ± 4.1 vs. 13.1 ± 5.9 mmHg, p< 0.001) in the SFS group. Structural valve degeneration (SVD) (5.2% vs. 0%; p = 0.04) and valve explantation due to SVD or prosthetic valve endocarditis (PVE) (9.1% vs. 1.3%; p = 0.04) was more frequent in the SFS group. All-cause mortality during follow-up was 20.8% vs. 14.3% (p = 0.397). When patients were divided into subgroups of NVE and respective utilized bioprosthesis, the SFS presented impaired outcomes regarding mortality in NVE cases (p = 0.031). The hemodynamic superiority of the SFS was confirmed in this comparison. However, clinical outcomes in terms of SVD and PVE rates, as well as survival after NVE, were inferior in this study. Therefore, we are reluctant to recommend utilization of the SFS for treatment of NVE.

AN INVERSE MODELING APPROACH FOR STRESS ESTIMATION IN MITRAL VALVE ANTERIOR LEAFLET VALVULOPLASTY FOR IN-VIVO VALVULAR BIOMATERIAL ASSESSMENT

PubMed Central

Lee, Chung-Hao; Amini, Rouzbeh; Gorman, Robert C.; Gorman, Joseph H.; Sacks, Michael S.

2013-01-01

Estimation of regional tissue stresses in the functioning heart valve remains an important goal in our understanding of normal valve function and in developing novel engineered tissue strategies for valvular repair and replacement. Methods to accurately estimate regional tissue stresses are thus needed for this purpose, and in particular to develop accurate, statistically informed means to validate computational models of valve function. Moreover, there exists no currently accepted method to evaluate engineered heart valve tissues and replacement heart valve biomaterials undergoing valvular stresses in blood contact. While we have utilized mitral valve anterior leaflet valvuloplasty as an experimental approach to address this limitation, robust computational techniques to estimate implant stresses are required. In the present study, we developed a novel numerical analysis approach for estimation of the in-vivo stresses of the central region of the mitral valve anterior leaflet (MVAL) delimited by a sonocrystal transducer array. The in-vivo material properties of the MVAL were simulated using an inverse FE modeling approach based on three pseudo-hyperelastic constitutive models: the neo-Hookean, exponential-type isotropic, and full collagen-fiber mapped transversely isotropic models. A series of numerical replications with varying structural configurations were developed by incorporating measured statistical variations in MVAL local preferred fiber directions and fiber splay. These model replications were then used to investigate how known variations in the valve tissue microstructure influence the estimated ROI stresses and its variation at each time point during a cardiac cycle. Simulations were also able to include estimates of the variation in tissue stresses for an individual specimen dataset over the cardiac cycle. Of the three material models, the transversely anisotropic model produced the most accurate results, with ROI averaged stresses at the fully-loaded state of 432.6±46.5 kPa and 241.4±40.5 kPa in the radial and circumferential directions, respectively. We conclude that the present approach can provide robust instantaneous mean and variation estimates of tissue stresses of the central regions of the MVAL. PMID:24275434

Design of the Endobronchial Valve for Emphysema Palliation Trial (VENT): a non-surgical method of lung volume reduction.

PubMed

Strange, Charlie; Herth, Felix J F; Kovitz, Kevin L; McLennan, Geoffrey; Ernst, Armin; Goldin, Jonathan; Noppen, Marc; Criner, Gerard J; Sciurba, Frank C

2007-07-03

Lung volume reduction surgery is effective at improving lung function, quality of life, and mortality in carefully selected individuals with advanced emphysema. Recently, less invasive bronchoscopic approaches have been designed to utilize these principles while avoiding the associated perioperative risks. The Endobronchial Valve for Emphysema PalliatioN Trial (VENT) posits that occlusion of a single pulmonary lobe through bronchoscopically placed Zephyr endobronchial valves will effect significant improvements in lung function and exercise tolerance with an acceptable risk profile in advanced emphysema. The trial design posted on Clinical trials.gov, on August 10, 2005 proposed an enrollment of 270 subjects. Inclusion criteria included: diagnosis of emphysema with forced expiratory volume in one second (FEV1) < 45% of predicted, hyperinflation (total lung capacity measured by body plethysmography > 100%; residual volume > 150% predicted), and heterogeneous emphysema defined using a quantitative chest computed tomography algorithm. Following standardized pulmonary rehabilitation, patients were randomized 2:1 to receive unilateral lobar placement of endobronchial valves plus optimal medical management or optimal medical management alone. The co-primary endpoint was the mean percent change in FEV1 and six minute walk distance at 180 days. Secondary end-points included mean percent change in St. George's Respiratory Questionnaire score and the mean absolute changes in the maximal work load measured by cycle ergometry, dyspnea (mMRC) score, and total oxygen use per day. Per patient response rates in clinically significant improvement/maintenance of FEV1 and six minute walk distance and technical success rates of valve placement were recorded. Apriori response predictors based on quantitative CT and lung physiology were defined. If endobronchial valves improve FEV1 and health status with an acceptable safety profile in advanced emphysema, they would offer a novel intervention for this progressive and debilitating disease. ClinicalTrials.gov: NCT00129584.

Cardiac autotransplantation for the treatment of permanent atrial fibrillation combined with mitral valve disease.

PubMed

Troise, Giovanni; Brunelli, Federico; Cirillo, Marco; Amaducci, Andrea; Mhagna, Zen; Tomba, Margherita Dalla; Tasca, Giordano; Quaini, Eugenio

2003-01-01

The results of current surgical options for the treatment of permanent atrial fibrillation associated with mitral valve surgery are widely different, particularly for extremely dilated left atria. The aim of this study is to assess the efficacy of cardiac autotransplantation in restoring a normal sinus rhythm via a consistent reduction in the left atrium volume associated with a complete isolation of the pulmonary veins. From April 2000 to April 2002, 28 patients (men/women, 5/23) underwent cardiac autotransplantation for the treatment of mitral disease and concomitant permanent atrial fibrillation (>1 year). A modified surgical technique derived from bicaval heart transplantation procedures maintained the connection of the right atrium with the inferior vena cava in all but 3 cases. In 2 patients, the mitral valve was repaired, and it was replaced in 26 patients. Associated procedures were 6 aortic valve replacements, 2 tricuspid valve annuloplasties, and 2 coronary revascularizations. No hospital deaths were recorded, but 1 patient died of pneumonia 3 months postoperatively. At a mean follow-up period of 17.2 +/- 6.7 months (range, 6-30 months), 24 patients (88.9%) were in sinus rhythm, and 3 (11.1%) were in atrial fibrillation. The Santa Cruz Score was 0 for 3 patients, 2 for 1 patient, and 4 for the remaining 23 patients (85.2%). The mean left atrial diameter decreased from 65.4 +/- 17.1 mm (range, 50-130 mm) before the operation to 48.4 +/- 5.6 mm (range, 37-78 mm) postoperatively (P <.001), and the mean left atrial volume decreased from 119 +/- 70.5 mL (range, 60-426 mL) to 69.1 +/- 35.1 mL (range, 31-226 mL) (P <.0001). Cardiac autotransplantation is a safe and effective surgical option for the treatment of permanent atrial fibrillation in patients with long-lasting mitral valve disease and severe enlargement of the left atrium.

Short-term and mid-term results with the Sorin Freedom Solo aortic valve.

PubMed

Ustunsoy, Hasim; Yasim, Alptekin; Deniz, Hayati; Gokaslan, Gokhan; Ozcaliskan, Ozerdem

2013-03-01

The study aim was to present the short- and mid-term results for patients who underwent aortic valve replacement (AVR) with the Sorin Freedom Solo third-generation stentless prosthetic valve. AVR with a Sorin Freedom Solo valve was performed in 14 patients between March 2006 and March 2011. Patients aged > or = 60 years (male:female ratio 6:8; mean age 73.28 +/- 5.42 years) who required AVR with the Sorin Freedom Solo valve according to the surgeon's choice were included in the study. The valvular prosthesis was implanted in the supra-annular position, using a single suture line. Eight patients underwent an isolated AVR; combined interventions were carried out in the other patients due to concomitant cardiac disease. One patient died during the immediate perioperative period, and two more during the follow up, from non-cardiac causes. The mean maximum transvalvular gradient of patients with aortic stenosis was 88.1 +/- 20.2 mmHg, and this fell to 26.4 +/- 7.6 mmHg during the early postoperative period. The mean gradient at one year of follow up was further decreased to 19.4 +/- 5.3 mmHg. The left ventricular end-diastolic and end-systolic diameters were also significantly reduced, from 4.8 +/- 0.9 to 4.3 +/- 0.6 cm and from 3.2 +/- 0.6 to 2.8 +/- 5.3 cm, respectively. The average left ventricular ejection fraction was 60.2 +/- 4.9% preoperatively, and 63.2 +/- 2.1% at one year after surgery (p = NS). No paravalvular leakage, endocarditis, prosthesis failure or neurologic events were reported among patients. The Sorin Freedom Solo stentless valve has provided good early and intermediate-term results. Implantation of the prosthesis is straightforward, with low rates of morbidity and mortality. However, these data require further support from larger patient series and long-term follow up.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alderfer, R.R.; Futa, P.W.

This patent describes a fuel system for an engine having a filter through which fuel from a pump passes to a regulator in response to an operator input. The regulator controls the flow of fuel presented to a combustion chamber in the engine, the regulator having a feedback apparatus to provide an operator with a signal indicative of the fuel supplied to the combustion chamber. It comprises: bypass means having a housing with a chamber therein, the chamber having an entrance port connected to the pump and an exit port connected to the regulator; piston means located in the chambermore » for separating the entrance port from the exit port, the piston having a face with a projection extending therefrom; stop means located in the chamber; resilient means located is the chamber for urging the piston means toward the stop means to prevent the flow of fuel from the pump through the housing to the regulator; and indicator means having a body retained in the housing with a first end which extends through the housing into the from a full-open position at which the closed circuit is fully opened to a full-closed position at which the closed circuit is fully blocked; ratio detecting means which detects the speed reduction ratio to find if the speed reduction ratio becomes substantially 1; and valve position detecting means which detects position of the direct clutch valve to find if the direct clutch valve is moved to a slight-open position at which the closed circuit is slightly opened.« less

Optimal surgical management of severe tricuspid regurgitation in cardiac transplant patients.

PubMed

Filsoufi, Farzan; Salzberg, Sacha P; Anderson, Curtis A; Couper, Gregory S; Cohn, Lawrence H; Adams, David H

2006-03-01

Severe tricuspid regurgitation (TR) with signs of right-sided heart failure is rare after orthotopic heart transplantation (OHT). In some instances, this condition will require surgical correction using reconstructive surgery or prosthetic valve replacement. Repair techniques of atrioventricular valves are now well described. However, the results of the different surgical procedures in this setting have not been widely reported and may depend on the type of valvular dysfunction and lesions present. Herein we report our experience in a group of patients requiring surgical correction of symptomatic severe TR after OHT. We reviewed our transplant experience during the period from July 1992 to July 1999 (n = 138 cardiac transplants). Eight patients (5.8%) developed symptomatic severe TR requiring surgical correction after a mean duration of 21 months after OHT. Patients were divided into 2 groups based on the mechanism of regurgitation using Carpentier's functional classification. In Group 1 (n = 4), the mechanism of tricuspid regurgitation was Carpentier's Type I, secondary to annular dilation. In Group 2 (n = 4) the mechanism of TR was leaflet prolapse (Type II), due to chordal rupture after biopsy injury. Initially, tricuspid valve integrity was surgically restored in all 8 patients with either valve repair (n = 6) or replacement (n = 2). In Group 1, 2 patients underwent valve repair using a ring annuloplasty and 2 patients underwent valve replacement with a bioprosthetic valve (n = 1) or pulmonary allograft (n = 1). In Group 2, all patients underwent valve repair using a variety of techniques in combination with tricuspid annuloplasty. During the follow-up period, 3 of the 6 (50%) primary repairs (1 patient in Group 1 and 2 in Group 2) failed and required replacement with a bioprosthesis at 8 days, 14 days and 4 years, respectively. The pulmonary allograft failed secondary to valvular stenosis and was replaced with a bioprosthesis after 10 months. Overall, no failures occurred in any of the 5 bioprosthetic valves placed at the primary operation (n = 1) or after failed tricuspid repair/pulmonary allograft (n = 4), after a mean follow-up of 55 months. TR requiring surgical correction after OHT is a rare condition and requires a tailored surgical strategy. This strategy should take into account the mechanism of valve dysfunction and specific valvular lesions. In patients with Type I dysfunction secondary to annular dilation, valve repair with a remodeling annuloplasty should be performed; however, in the presence of any residual TR on transesophageal echocardiography (TEE) at the completion of cardiopulmonary bypass (CPB), a valve replacement with a bioprosthesis is warranted during the same procedure. In patients with Type II dysfunction with leaflet prolapse and biopsy-induced chordal injury, a bioprosthetic valve replacement seems a reliable surgical option.

Inter-ethnic differences in valve morphology, valvular dysfunction, and aortopathy between Asian and European patients with bicuspid aortic valve.

PubMed

Kong, William K F; Regeer, Madelien V; Poh, Kian K; Yip, James W; van Rosendael, Philippe J; Yeo, Tiong C; Tay, Edgar; Kamperidis, Vasileios; van der Velde, Enno T; Mertens, Bart; Ajmone Marsan, Nina; Delgado, Victoria; Bax, Jeroen J

2018-04-14

Transcatheter aortic valve replacement (TAVR) has been shown safe and feasible in patients with bicuspid aortic valve (BAV) morphology. Evaluation of inter-ethnic differences in valve morphology and function and aortic root dimensions in patients with BAV is important for the worldwide spread of this therapy in this subgroup of patients. Comparisons between large European and Asian cohorts of patients with BAV have not been performed, and potential differences between populations may have important implications for TAVR. The present study evaluated the differences in valve morphology and function and aortic root dimensions between two large cohorts of European and Asian patients with BAV. Aortic valve morphology was defined on transthoracic echocardiography according to the number of commissures and raphe: type 0 = no raphe and two commissures, type 1 = one raphe and two commissures, type 2 = two raphes and one commissure. Aortic stenosis and regurgitation were graded according to current recommendations. For this study, aortic root dimensions were manually measured on transthoracic echocardiograms at the level of the aortic annulus, sinus of Valsalva (SOV), sinotubular junction (STJ), and ascending aorta (AA). Of 1427 patients with BAV (45.2 ± 18.1 years, 71.9% men), 794 (55.6%) were Europeans and 633 (44.4%) were Asians. The groups were comparable in age and proportion of male sex. Asians had higher prevalence of type 1 BAV with raphe between right and non-coronary cusps than Europeans (19.7% vs. 13.6%, respectively; P < 0.001), whereas the Europeans had higher prevalence of type 0 BAV (two commissures, no raphe) than Asians (14.5% vs. 6.8%, respectively; P < 0.001). The prevalence of moderate and severe aortic regurgitation was higher in Europeans than Asians (44.2% vs. 26.8%, respectively; P < 0.001) whereas there were no differences in BAV with normal function or aortic stenosis. After adjusting for demographics, comorbidities, and valve function, the dimensions of the aortic annulus [mean difference 1.17 mm/m2, 95% confidence interval (CI) 0.96-1.39], SOV (mean difference 1.86 mm/m2, 95% CI 1.47-2.24), STJ (mean difference 0.52 mm/m2, 95% CI 0.14-0.90) and AA (mean difference 1.05 mm/m2, 95% CI 0.57-1.52) were significantly larger among Asians compared with Europeans. This large multicentre registry reports for the first time that Asians with BAV showed more frequently type 1 BAV (with fusion between right and non-coronary cusp) and have larger aortic dimensions than Europeans. These findings have important implications for prosthesis type and size selection for TAVR.

VALVE

DOEpatents

Arkelyan, A.M.; Rickard, C.L.

1962-04-17

A gate valve for controlling the flow of fluid in separate concentric ducts or channels by means of a single valve is described. In one position, the valve sealing discs engage opposed sets of concentric ducts leading to the concentric pipes defining the flow channels to block flow therethrough. In another position, the discs are withdrawn from engagement with the opposed ducts and at the same time a bridging section is interposed therebetween to define concentric paths coextensive with and connecting the opposed ducts to facilitate flow therebetween. A wedge block arrangement is employed with each sealing disc to enable it to engage the ducts. The wedge block arrangement also facilitates unobstructcd withdrawal of the discs out of the intervening space between the sets of ducts. (AEC)

'Caput medusae': tension reduction on a dehiscent native annulus in valve implantation in an endocarditis case.

PubMed

Albes, Johannes M

2017-12-01

Interrupted pledget-armed braided sutures are widely used for valve implantation. In a 74-year-old woman with aortic valve endocarditis and shallow annular abscess, annulus dehiscence resulted after resection. As resistance was too high for sufficient primary approximation, a snug fit of the valve by means of circumferential application of curbed tourniquets resembling Medusa's head after suture placement was achieved. Closest possible approximation of the upper and lower part of the annulus with the prosthesis prior to final fixation was thus possible, so that application of too much tension on a single suture could be avoided. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Levosimendan improves hemodynamic status in critically ill patients with severe aortic stenosis and left ventricular dysfunction: an interventional study.

PubMed

García-González, Martín J; Jorge-Pérez, Pablo; Jiménez-Sosa, Alejandro; Acea, Antonio Barragán; Lacalzada Almeida, Juan B; Ferrer Hita, Julio J

2015-08-01

To study the hemodynamic effect of levosimendan administration in acute heart failure patients with severe aortic stenosis (AS) and reduced left ventricular ejection fraction (LVEF). Hemodynamic response to 24 h intravenous levosimendan infusion (0.1 μg/kg/min without a loading dose) in patients with severe AS (aortic valve area ≤1 cm(2) , time-velocity integral between left ventricular out-flow tract and aortic valve <0.25), reduced LVEF (≤40%), and a depressed cardiac index (CI) <2.2 L/min/m(2) was determined in a sequential group of nine patients aged 76 ± 10 years (5 men). Baseline mean ejection fraction was 33 ± 0.7%; mean aortic valve area was 0.37 ±0.11 cm(2) /m(2) ; peak and mean gradients of 63.6 ± 20.53 and 36.7 ± 12.62 mmHg, respectively; and mean CI was 1.65 ± 0.20 L/min/m(2) . At 6 and 12 h of levosimendan therapy, mean CI had increased to 2.00 ± 0.41 L/min/m(2) (P = 0.02) and 2.17 ± 0.40 L/min/m(2) (P = 0.01), respectively. At 24 h, mean CI had increased further to 2.37 ± 0.49 L/min/m(2) (P = 0.01). A significant beneficial effect was also observed in pulmonary capillary wedge pressure, pulmonary artery mean pressure, central venous pressure, systemic vascular resistances, pulmonary vascular resistances, stroke volume index, left ventricular stroke work index. NTproBNP levels decreased at 24 h of levosimendan treatment. Levosimendan infusion was also well tolerated. Five patients subsequently underwent aortic valve surgery replacement. One died (of postoperative multiorgan failure). At 30 days, overall survival was 75%. Levosimendan administration improves hemodynamic parameters in critically ill patients with severe AS and reduced LVEF. In our study, it provides a safe and effective bridge to aortic-valve replacement or oral vasodilator therapy in surgical contraindicated patients. A controlled study is needed to confirm these preliminary findings. © 2015 John Wiley & Sons Ltd.

Immediate Outcome of Balloon Mitral Valvuloplasty with JOMIVA Balloon during Pregnancy

PubMed Central

Ramasamy, Ramona; Kaliappan, Tamilarasu; Gopalan, Rajendiran; Palanimuthu, Ramasmy; Anandhan, Premkrishna

2017-01-01

Introduction Rheumatic mitral stenosis is the most common Valvular Heart Disease encountered during pregnancy. Balloon Mitral Valvuloplasty (BMV) is one of the treatment option available if the symptoms are refractory to the medical management and the valve anatomy is suitable for balloon dilatation. BMV with Inoue balloon is the most common technique being followed worldwide. Over the wire BMV is a modified technique using Joseph Mitral Valvuloplasty (JOMIVA) balloon catheter which is being followed in certain centres. Aim To assess the immediate post procedure outcome of over the wire BMV with JOMIVA balloon. Materials and Methods Clinical and echocardiographic parameters of pregnant women with significant mitral stenosis who underwent elective BMV with JOMIVA balloon in our institute from 2005 to 2015 were analysed retrospectively. Severity of breathlessness (New York Heart Association Functional Class), and duration of pregnancy was included in the analysis. Pre procedural echocardiographic parameters which included severity of mitral stenosis and Wilkin’s scoring were analysed. Clinical, haemodynamic and echocardiographic outcomes immediately after the procedure were analysed. Results Among the patients who underwent BMV in our Institute 38 were pregnant women. Twenty four patients (63%) were in New York Heart Association (NYHA) Class III. All of them were in sinus rhythm except two (5%) who had atrial fibrillation. Thirty four patients (89.5%) were in second trimester of pregnancy at the time of presentation and four (10.5%) were in third trimester. Echocardiographic analysis of the mitral valve showed that the mean Wilkin’s score was 7.3. Mean mitral valve area pre procedure was 0.8 cm2. Mean gradient across the valve was 18 mmHg. Ten patients (26.5%) had mild mitral regurgitation and none had more than mild mitral regurgitation. Thirty six patients had pulmonary hypertension as assessed by tricuspid regurgitation jet velocity. All of them underwent BMV with JOMIVA balloon. Post procedure mean mitral valve area was 1.7 cm2 as assessed by echocardiography. Post procedure mean gradient across the mitral valve as assessed by echocardiography was 5 mmHg. Two patients had moderate to severe mitral regurgitation after the procedure and the rest had either no mitral regurgitation or mild mitral regurgitation after the procedure. None of the patients warranted mitral valve replacement after BMV. No patients had any manifestations of systemic embolism like cerebrovascular accident or limb ischemia after the procedure. None of the patients had preterm delivery or adverse fetal outcome during index hospitalisation. Conclusion Over the wire BMV is safe and effective method during pregnancy. The results are comparable to that of Inoue technique. BMV offers a good symptomatic improvement in pregnant women presenting with symptoms of pulmonary congestion because of Rheumatic mitral stenosis. PMID:28384909

Interventional Treatment of Severe Tricuspid Regurgitation: Early Clinical Experience in a Multicenter, Observational, First-in-Man Study.

PubMed

Lauten, Alexander; Figulla, Hans R; Unbehaun, Axel; Fam, Neil; Schofer, Joachim; Doenst, Torsten; Hausleiter, Joerg; Franz, Marcus; Jung, Christian; Dreger, Henryk; Leistner, David; Alushi, Brunilda; Stundl, Anja; Landmesser, Ulf; Falk, Volkmar; Stangl, Karl; Laule, Michael

2018-02-01

Transcatheter caval valve implantation is under evaluation as a treatment option for inoperable patients with severe tricuspid regurgitation (TR). The procedure involves the catheter-based implantation of bioprosthetic valves in the inferior vena cava and superior vena cava to treat symptoms associated with TR. This study is the first to evaluate the feasibility, safety, and efficacy of this interventional concept. Twenty-five patients (mean age, 73.9±7.6 years; women, 52.0%) with severe symptomatic TR despite optimal medical treatment deemed unsuitable for surgery were treated with caval valve implantation under a compassionate clinical use program. Technical feasibility defined as procedural success, hemodynamic effect defined as venous pressure reduction, and safety defined as periprocedural adverse events were evaluated, with clinical follow-up at discharge and up to 12 months. The functional impact was evaluated by assessment of New York Heart Association class at the time of hospital discharge. The total number of valves implanted in the caval position was 31. Patients were treated with single (inferior vena cava-only; n=19; 76.0%) or bicaval valve implantation (inferior vena cava+superior vena cava; n=6; 24.0%). Either balloon-expandable valves (Sapien XT/3: n=18; 72.0%) or self-expandable valves (TricValve: n=6; 24.0%; Directflow: n=1; 4.0%) were used. Procedural success was achieved in 96% (n=24). Early and late valve migration requiring surgical intervention occurred in 1 patient each. Thirty-day and in-hospital mortality were 8% (2 of 25) and 16% (4 of 25). Causes of in-hospital mortality included respiratory (n=1) or multiple organ failure (n=3) and were not linked to the procedure. Mean overall survival in the study cohort was 316±453 days (14-1540 days). Caval valve implantation for the treatment of severe TR and advanced right ventricular failure is associated with a high procedural success rate and seems safe and feasible in an excessive-risk cohort. The study demonstrates hemodynamic efficacy with consistent elimination of TR-associated venous backflow and initial clinical improvement. These results encourage further trials to determine which patients benefit most from this interventional approach. © 2018 American Heart Association, Inc.

A comparison of conventional surgery, transcatheter aortic valve replacement, and sutureless valves in "real-world" patients with aortic stenosis and intermediate- to high-risk profile.

PubMed

Muneretto, Claudio; Alfieri, Ottavio; Cesana, Bruno Mario; Bisleri, Gianluigi; De Bonis, Michele; Di Bartolomeo, Roberto; Savini, Carlo; Folesani, Gianluca; Di Bacco, Lorenzo; Rambaldini, Manfredo; Maureira, Juan Pablo; Laborde, Francois; Tespili, Maurizio; Repossini, Alberto; Folliguet, Thierry

2015-12-01

We sought to investigate the clinical outcomes of patients with isolated severe aortic stenosis and an intermediate- to high-risk profile treated by means of conventional surgery (surgical aortic valve replacement), sutureless valve implantation, or transcatheter aortic valve replacement in a multicenter evaluation. Among 991 consecutive patients with isolated severe aortic stenosis and an intermediate- to high-risk profile (Society of Thoracic Surgeons score >4 and logistic European System for Cardiac Operative Risk Evaluation I >10), a propensity score analysis was performed on the basis of the therapeutic strategy: surgical aortic valve replacement (n = 204), sutureless valve implantation (n = 204), and transcatheter aortic valve replacement (n = 204). Primary end points were 30-day mortality and overall survival at 24-month follow-up; the secondary end point was survival free from a composite end point of major adverse cardiac events (defined as cardiac-related mortality, myocardial infarction, cerebrovascular accidents, and major hemorrhagic events) and periprosthetic regurgitation greater than 2. Thirty-day mortality was significantly higher in the transcatheter aortic valve replacement group (surgical aortic valve replacement = 3.4% vs sutureless = 5.8% vs transcatheter aortic valve replacement = 9.8%; P = .005). The incidence of postprocedural was 3.9% in asurgical aortic valve replacement vs 9.8% in sutureless vs 14.7% in transcatheter aortic valve replacement (P< .001) and peripheral vascular complications occurred in 0% of surgicalaortic valve replacement vs 0% of sutureless vs 9.8% transcatheter aortic valve replacement (P< .001). At 24-month follow-up, overall survival (surgical aortic valve replacement = 91.3% ± 2.4% vs sutureless = 94.9% ± 2.1% vs transcatheter aortic valve replacement = 79.5% ± 4.3%; P < .001) and survival free from the composite end point of major adverse cardiovascular events and periprosthetic regurgitation were significantly better in patients undergoing surgical aortic valve replacement and sutureless valve implantation than in patients undergoing transcatheter aortic valve replacement (surgical aortic valve replacement = 92.6% ± 2.3% vs sutureless = 96% ± 1.8% vs transcatheter aortic valve replacement = 77.1% ± 4.2%; P < .001). Multivariate Cox regression analysis identified transcatheter aortic valve replacement as an independent risk factor for overall mortality hazard ratio (hazard ratio, 2.5; confidence interval, 1.1-4.2; P = .018). The use of transcatheter aortic valve replacement in patients with an intermediate- to high-risk profile was associated with a significantly higher incidence of perioperative complications and decreased survival at short- and mid-term when compared with conventional surgery and sutureless valve implantation. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

The effects of a low international normalized ratio on thromboembolic and bleeding complications in patients with mechanical mitral valve replacement

PubMed Central

2014-01-01

Background Mechanical heart valve replacement has an inherent risk of thromboembolic events (TEs). Current guidelines recommend an international normalized ratio (INR) of at least 2.5 after mechanical mitral valve replacement (MVR). This study aimed to evaluate the effects of a low INR (2.0–2.5) on thromboembolic and bleeding complications in patients with mechanical MVR on warfarin therapy. Methods One hundred and thirty-five patients who underwent mechanical MVR were enrolled in this study. The end points of this study were defined as TEs (valve thrombosis, transient ischemic attack, stroke) and bleeding (all minor and major bleeding) complications. Patients were followed up for a mean of 39.6 months and the mean INR of the patients was calculated. After data collection, patients were divided into 3 groups according to their mean INR, as follows: group 1 (n = 34), INR <2.0; group 2 (n = 49), INR 2.0–2.5; and group 3 (n = 52), INR >2.5. Results A total of 22 events (10 [7.4%] thromboembolic and 12 [8.8%] bleeding events) occurred in the follow-up period. The mean INR was an independent risk factor for the development of TEs. Mean INR and neurological dysfunction were independent risk factors for the development of bleeding events. A statistically significant positive correlation was found between the log mean INR and all bleeding events, and a negative correlation was found between the log mean INR and all TEs. The total number of events was significantly lower in group 2 than in groups 1 and 3 (P = 0.036). Conclusions This study showed that a target INRs of 2.0–2.5 are acceptable for preventing TEs and safe in terms of bleeding complications in patients with mechanical MVR. PMID:24885719

Balloon aortic valvuloplasty to improve candidacy of patients evaluated for transcatheter aortic valve replacement.

PubMed

Arsalan, Mani; Khan, Samir; Golman, Jake; Szerlip, Molly; Mahoney, Cecile; Herbert, Morley; Brown, David; Mack, Michael; Holper, Elizabeth M

2018-02-01

Evaluate the role of balloon aortic valvuloplasty (BAV) in improving candidacy of patients for transcatheter aortic valve replacement (TAVR). Patients who are not candidates for TAVR may undergo BAV to improve functional and clinical status. 117 inoperable or high-risk patients with critical aortic stenosis underwent BAV as a bridge-to-decision for TAVR. Frailty measures including gait speed, serum albumin, hand grip, activities of daily living (ADL); and NYHA functional class before and after BAV were compared. Mean age was 81.6 ± 8.5 years and the mean Society of Thoracic Surgeons predicted risk of mortality was 9.57 ± 5.51, with 19/117 (16.2%) patients non-ambulatory. There was no significant change in mean GS post-BAV, but all non-ambulatory patients completed GS testing at follow-up. Albumin and hand grip did not change after BAV, but there was a significant improvement in mean ADL score (4.85 ± 1.41 baseline to 5.20 ± 1.17, P = 0.021). The number of patients with Class IV congestive heart failure (CHF) was significantly lower post BAV (71/117 [60.7%] baseline versus 18/117 [15.4%], P = 0.008). 78/117 (66.7%) of patients were referred to definitive valve therapy after BAV. When evaluating frailty measures post BAV, we saw no significant improvement in mean GS, however, we observed a significant improvement in non-ambulatory patients and ADL scores. We also describe improved Class IV CHF symptoms. With this improved health status, the majority of patients underwent subsequent valve therapy, demonstrating that BAV may improve candidacy of patients for TAVR. © 2017, Wiley Periodicals, Inc.

Admission Volunteer Programs: Are They Really Worth the Effort?

ERIC Educational Resources Information Center

Symmonds, Ian

2002-01-01

Developing and using volunteers in the admission process is an age-old topic for those in the admission field. A good volunteer program allows an institution to provide more audience-based marketing messages rather than institutional-based marketing messages. Such programs can mean a more engaged, supportive, and enthusiastic set of key…

Aortic valve prosthesis-patient mismatch and exercise capacity in adult patients with congenital heart disease.

PubMed

van Slooten, Ymkje J; van Melle, Joost P; Freling, Hendrik G; Bouma, Berto J; van Dijk, Arie Pj; Jongbloed, Monique Rm; Post, Martijn C; Sieswerda, Gertjan T; Huis In 't Veld, Anna; Ebels, Tjark; Voors, Adriaan A; Pieper, Petronella G

2016-01-01

To report the prevalence of aortic valve prosthesis-patient mismatch (PPM) in an adult population with congenital heart disease (CHD) and its impact on exercise capacity. Adults with congenital heart disease (ACHD) with a history of aortic valve replacement may outgrow their prosthesis later in life. However, the prevalence and clinical consequences of aortic PPM in ACHD are presently unknown. From the national Dutch Congenital Corvitia (CONCOR) registry, we identified 207 ACHD with an aortic valve prosthesis for this cross-sectional cohort study. Severe PPM was defined as an indexed effective orifice area ≤0.65 cm2/m2 and moderate PPM as an indexed orifice area ≤0.85 cm2/m2 measured using echocardiography. Exercise capacity was reported as percentage of predicted exercise capacity (PPEC). Of the 207 patients, 68% was male, 71% had a mechanical prosthesis and mean age at inclusion was 43.9 years ±11.4. The prevalence of PPM was 42%, comprising 23% severe PPM and 19% moderate PPM. Prevalence of PPM was higher in patients with mechanical prostheses (p<0.001). PPM was associated with poorer exercise capacity (mean PPEC 84% vs. 92%; p=0.048, mean difference =-8.3%, p=0.047). Mean follow-up was 2.6±1.1 years during which New York Heart Association (NYHA) class remained stable in most patients. PPM showed no significant effect on death or hospitalisation during follow-up (p=0.218). In this study we report a high prevalence (42%) of PPM in ACHD with an aortic valve prosthesis and an independent association of PPM with diminished exercise capacity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Apical closure device for full-percutaneous transapical valve implantation: stress-test in an animal model†.

PubMed

Ferrari, Enrico; Demertzis, Stefanos; Angelella, Jennifer; Berdajs, Denis; Tozzi, Piergiorgio; Moccetti, Tiziano; Maisano, Francesco; von Segesser, Ludwig K

2017-05-01

Transapical valve implantation is traditionally performed through a left antero-lateral mini-thoracotomy. A self-expandable apical closure device has recently been developed for full-percutaneous transapical valve implantation. We performed haemodynamics stress-tests on an animal model to evaluate the sealing properties. Under general anaesthesia 5 pigs (mean weight: 67 ± 6 Kg) received full heparinization (100 IU/Kg; activated clotting time >250 s and, through inferior mini-sternotomies, 21-Fr introducer sheaths for transapical aortic valve implantation (outer diameter: 25-Fr) were placed over-the-wire in the apexes. Delivery-catheters carrying folded occluders (SAFEX TM final design) were inserted in the introducer sheaths and plugs were then deployed under fluoroscopic guidance. Phase 1: after protamine injection, apical bleeding was monitored for 1 h with standard haemodynamics condition. Phase 2: we induced systemic hypertension with adrenaline infusion to test the sealing properties under stress. Animals were sacrificed after Phase 2 and hearts were removed and inspected. Five plugs were successfully introduced and deployed in 5 pig hearts. Plugs provided good apical sealing in each animal and a mean of 7 ± 4 ml of blood lost per animal was collected during Phase 1: haemodynamics remained stable and no plug dislodgement was detected (mean blood pressure: 52 ± 9 mmHg). During Phase 2, mean systolic and diastolic peak levels reached 268 ± 24 mmHg and 175 ± 17 mmHg, respectively, without plug dislodgment or bleeding. Post-mortem inspection showed good plug deployment and fixation without myocardial damage. The new apical occluder seals large-sized apical access sites in animal models also during induced systemic hypertension. This pilot study is a further step towards full-percutaneous transapical valve procedures in the clinical setting. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Self-actuating and locking control for nuclear reactor

DOEpatents

Chung, Dong K.

1982-01-01

A self-actuating, self-locking flow cutoff valve particularly suited for use in a nuclear reactor of the type which utilizes a plurality of fluid support neutron absorber elements to provide for the safe shutdown of the reactor. The valve comprises a substantially vertical elongated housing and an aperture plate located in the housing for the flow of fluid therethrough, a substantially vertical elongated nozzle member located in the housing and affixed to the housing with an opening in the bottom for receiving fluid and apertures adjacent a top end for discharging fluid. The nozzle further includes two sealing means, one located above and the other below the apertures. Also located in the housing and having walls surrounding the nozzle is a flow cutoff sleeve having a fluid opening adjacent an upper end of the sleeve, the sleeve being moveable between an upper open position wherein the nozzle apertures are substantially unobstructed and a closed position wherein the sleeve and nozzle sealing surfaces are mated such that the flow of fluid through the apertures is obstructed. It is a particular feature of the present invention that the valve further includes a means for utilizing any increase in fluid pressure to maintain the cutoff sleeve in a closed position. It is another feature of the invention that there is provided a means for automatically closing the valve whenever the flow of fluid drops below a predetermined level.

Coupling of HRT II and AS-OCT to evaluate corneal endothelial cell loss and in vivo visualization of the Ahmed glaucoma valve implant.

PubMed

Mendrinos, E; Dosso, A; Sommerhalder, J; Shaarawy, T

2009-09-01

To report corneal endothelial cell loss and in vivo visualization of the Ahmed glaucoma valve implant in eyes with refractory glaucoma. Ten eyes underwent Ahmed valve implant surgery and were followed-up for 12 months. Data collected included intraocular pressure (IOP), number of antiglaucoma medications and surgery-related complications. At 6 and 12 months postoperatively, the intracameral length of the drainage tube (ICL) and the distance between the tube and the cornea (T-C distance), and the iris (T-I distance) were assessed using anterior segment optical coherence tomography (AS-OCT). Heidelberg cornea tomograph II (HRT II) was used to measure the corneal endothelial cell density. Mean (+/-SEM) preoperative IOP was 29.5+/-4 mmHg. Mean postoperative IOP was 11.6+/-2 at 12 months (P<0.01). Over a 6-month period, mean corneal endothelial loss was 7.9%+/-2.5 in the central and 7.5%+/-2.4 in the peripheral cornea (P<0.01). There was no correlation between central or peripheral corneal endothelial cell loss and the T-C, T-I distance or the ICL of the tube. Corneal endothelial cell loss occurs following Ahmed valve implant surgery, this appears to be multifactorial. AS-OCT and HRT II are promising methods for the follow-up of patients with a glaucoma drainage device.

Surgical outcomes in native valve infectious endocarditis: the experience of the Cardiovascular Surgery Department – Cluj-Napoca Heart Institute

PubMed Central

MOLNAR, ADRIAN; MURESAN, IOAN; TRIFAN, CATALIN; POP, DANA; SACUI, DIANA

2015-01-01

Background and aims The introduction of Duke’s criteria and the improvement of imaging methods has lead to an earlier and a more accurate diagnosis of infectious endocarditis (IE). The options for the best therapeutic approach and the timing of surgery are still a matter of debate and require a close colaboration between the cardiologist, the infectionist and the cardiac surgeon. Methods We undertook a retrospective, descriptive study, spanning over a period of five years (from January 1st, 2007 to December 31st, 2012), on 100 patients who underwent surgery for native valve infectious endocarditis in our unit. Results The patients’ age varied between 13 and 77 years (with a mean of 54 years), of which 85 were males (85%). The main microorganisms responsible for IE were: Streptococcus Spp. (21 cases – 21%), Staphylococcus Spp. (15 cases – 15%), and Enterococcus Spp. (9 cases – 9%). The potential source of infection was identified in 26 patients (26%), with most cases being in the dental area (16 cases – 16%). The lesions caused by IE were situated in the left heart in 96 patients (96%), mostly on the aortic valve (50 cases – 50%). In most cases (82%) we found preexisting endocardial lesions which predisposed to the development of IE, most of them being degenerative valvular lesions (38 cases – 38%). We performed the following surgical procedures: surgery on a single valve - aortic valve replacement (40 cases), mitral valve replacement (19 cases), mitral valve repair (1 case), surgery on more than one valve – mitral and aortic valve replacement (20 cases), aortic and tricuspid valve replacement (1 case), aortic valve replacement with a mechanical valve associated with mitral valve repair (5 cases), aortic valve replacement with a biological valve associated with mitral valve repair (2 cases), and mitral valve replacement with a mechanical valve combined with De Vega procedure on the tricuspid valve (1 case). In 5 patients (5%) the bacteriological examination of valve pieces excised during surgery was positive. In 3 cases it matched the germ identified in the hemocultures, and in 2 cases it evidenced another bacterium. Conclusion The overall mortality of 5% is well between the limits presented in literature, being higher (30%) in patients who required emergency surgery. For the patients who return into our clinic with prosthetic valve endocarditis, the mortality after surgery was even higher (50%). PMID:26609267

Early and Mid-Term Outcome of Pediatric Congenital Mitral Valve Surgery

PubMed Central

Baghaei, Ramin; Tabib, Avisa; Jalili, Farshad; Totonchi, Ziae; Mahdavi, Mohammad; Ghadrdoost, Behshid

2015-01-01

Background: Congenital lesions of the mitral valve are relatively rare and are associated with a wide spectrum of cardiac malformations. The surgical management of congenital mitral valve malformations has been a great challenge. Objectives: The aim of this study was to evaluate the early and intermediate-term outcome of congenital mitral valve (MV) surgery in children and to identify the predictors for poor postoperative outcomes and death. Patients and Methods: In this retrospective study, 100 consecutive patients with congenital MV disease undergoing mitral valve surgery were reviewed in 60-month follow-up (mean, 42.4 ± 16.4 months) during 2008 - 2013. Twenty-six patients (26%) were under one-year old. The mean age and weight of the patients were 41.63 ± 38.18 months and 11.92 ± 6.12 kg, respectively. The predominant lesion of the mitral valve was MV stenosis (MS group) seen in 21% and MR (MR group) seen in 79% of the patients. All patients underwent preoperative two-dimensional echocardiography and then every six months after surgery Results: Significant improvement in degree of MR was noted in all patients with MR during postoperative and follow-up period in both patients with or without atrioventricular septal defect (AVSD) (P = 0.045 in patients with AVSD and P = 0.008 in patients without AVSD). Decreasing trend of mean gradient (MG) in MS group was statistically significant (P = 0.005). In patients with MR, the mean pulmonary artery pressure (PAP) had improved postoperatively (P < 0.001). Although PAP in patients with MV stenosis was reduced, this reduction was not statistically significant (P = 0.17). In-hospital mortality was 7%. Multivariate analysis demonstrated that age (P < 0.001), weight (P < 0.001), and pulmonary stenosis (P = 0.03) are strong predictors for mortality. Based on the echocardiography report at the day of discharge from hospital, surgical results were optimal (up to moderate degree for MR group and up to mild degree for MS group) in 85.7% of patients with MS and in 76.6% of patients with MR. Age (P = 0.002) and weight (P = 0.003) of patients are strong predictors for surgical success in multivariate analysis. Conclusions: Surgical repair of the congenital MV disease yields acceptable early and intermediate-term satisfactory valve function and good survival at intermediate-term follow-up. Strong predictors for poor surgical outcome and death were age smaller than 1 year, weight smaller or equal than 6 kg, and associated cardiac anomalies such as pulmonary stenosis. PMID:26446282

Incidence and impact of prosthesis-patient mismatch after transcatheter aortic valve implantation.

PubMed

Bleiziffer, Sabine; Hettich, Ina; Hutter, Andrea; Wagner, Anke; Deutsch, Marcus-André; Piazza, Nicolo; Lange, Rüdiger

2013-05-01

The study aim was to investigate the incidence of patient-prosthesis mismatch (PPM) with new catheter valves, and its influence on the patients' clinical state. At present, few echocardiographic data are available on the incidence and impact of PPM with the CoreValve and Sapien prostheses for transcatheter aortic valve implantation (TAVI). The reliability of effective orifice area (EOA) measurements was assured by awaiting an interval of six months after TAVI. Of 256 survivors after TAVI, 149 complete echocardiographic data sets were available for the assessment of the indexed EOA (iEOA). In total, 106 CoreValve prostheses and 43 Sapien prostheses were implanted in this high-risk cohort (mean age 81 +/- 6 years, mean logistic EuroSCORE 20 +/- 13%). The overall incidence of PPM (iEOA < 0.85 cm2/m2) was 61%. Patients with a larger body surface area were more likely to develop PPM (p = 0.001), while the prosthesis type, native annulus diameter, preoperative EOA, gender and prosthesis size had no influence. The mean aortic gradient was significantly higher in patients with PPM. A reduction in the left ventricular end-diastolic diameter was seen in all patients, without significant differences between groups. There were no differences in postoperative NYHA class or self-assessed health state between patients with or without PPM. PPM was common after TAVI in the presented cohort, presumably because the native calcium masses narrow the outflow area available for blood flow. As expected for low gradients, there was no impairment of left ventricular dimension regression or clinical state of the patients, even if severe PPM was present. Based on the presented data, it is assumed that PPM might be less relevant in TAVI patients.

Safety of minimally invasive mitral valve surgery without aortic cross-clamp.

PubMed

Umakanthan, Ramanan; Leacche, Marzia; Petracek, Michael R; Kumar, Sathappan; Solenkova, Nataliya V; Kaiser, Clayton A; Greelish, James P; Balaguer, Jorge M; Ahmad, Rashid M; Ball, Stephen K; Hoff, Steven J; Absi, Tarek S; Kim, Betty S; Byrne, John G

2008-05-01

We developed a technique for open heart surgery through a small (5 cm) right-anterolateral thoracotomy without aortic cross-clamp. One hundred and ninety-five consecutive patients (103 male and 92 female), age 69 +/- 8 years, underwent surgery between January 2006 and July 2007. Mean preoperative New York Heart Association function class was 2.2 +/- 0.7. Thirty-five patients (18%) had an ejection fraction 0.35 or less. Cardiopulmonary bypass was instituted through femoral (176 of 195, 90%), axillary (18 of 195, 9%), or direct aortic (1 of 195, 0.5%) cannulation. Under cold fibrillatory arrest (mean temperature 28.2 degrees C) without aortic cross-clamp, mitral valve repair (72 of 195, 37%), mitral valve replacement (117 of 195, 60%), or other (6 of 195, 3%) procedures were performed. Concomitant procedures included maze (45 of 195, 23%), patent foramen ovale closure (42 of 195, 22%) and tricuspid valve repair (16 of 195, 8%), or replacement (4 of 195, 2%). Thirty-day mortality was 3% (6 of 195). Duration of fibrillatory arrest, cardiopulmonary bypass, and "skin to skin" surgery were 88 +/- 32, 118 +/- 52, and 280 +/- 78 minutes, respectively. Ten patients (5%) underwent reexploration for bleeding and 44% did not receive any blood transfusions. Six patients (3%) sustained a postoperative stroke, eight (4%) developed low cardiac output syndrome, and two (1%) developed renal failure requiring hemodialysis. Mean length of hospital stay was 7 +/- 4.8 days. This simplified technique of minimally invasive open heart surgery is safe and easily reproducible. Fibrillatory arrest without aortic cross-clamping, with coronary perfusion against an intact aortic valve, does not increase the risk of stroke or low cardiac output. It may be particularly useful in higher risk patients in whom sternotomy with aortic clamping is less desirable.

Reasons for conversion and adverse intraoperative events in Endoscopic Port Access™ atrioventricular valve surgery and minimally invasive aortic valve surgery.

PubMed

van der Merwe, Johan; Van Praet, Frank; Stockman, Bernard; Degrieck, Ivan; Vermeulen, Yvette; Casselman, Filip

2018-02-14

This study reports the factors that contribute to sternotomy conversions (SCs) and adverse intraoperative events in minimally invasive aortic valve surgery (MI-AVS) and minimally invasive Endoscopic Port Access™ atrioventricular valve surgery (MI-PAS). In total, 3780 consecutive patients with either aortic valve disease or atrioventricular valve disease underwent minimally invasive valve surgery (MIVS) at our institution between 1 February 1997 and 31 March 2016. MI-AVS was performed in 908 patients (mean age 69.2 ± 11.3 years, 45.2% women, 6.2% redo cardiac surgery) and MI-PAS in 2872 patients (mean age 64.1 ± 13.3 years, 46.7% women, 12.2% redo cardiac surgery). A cumulative total of 4415 MIVS procedures (MI-AVS = 908, MI-PAS = 3507) included 1537 valve replacements (MI-AVS = 896, MI-PAS = 641) and 2878 isolated or combined valve repairs (MI-AVS = 12, MI-PAS = 2866). SC was required in 3.0% (n = 114 of 3780) of MIVS patients, which occurred in 3.1% (n = 28 of 908) of MI-AVS patients and 3.0% (n = 86 of 2872) of MI-PAS patients, respectively. Reasons for SC in MI-AVS included inadequate visualization (n = 4, 0.4%) and arterial cannulation difficulty (n = 7, 0.8%). For MI-PAS, SC was required in 54 (2.5%) isolated mitral valve procedures (n = 2183). Factors that contributed to SC in MI-PAS included lung adhesions (n = 35, 1.2%), inadequate visualization (n = 2, 0.1%), ventricular bleeding (n = 3, 0.1%) and atrioventricular dehiscence (n = 5, 0.2%). Neurological deficit occurred in 1 (0.1%) and 3 (3.5%) MI-AVS and MI-PAS conversions, respectively. No operative or 30-day mortalities were observed in MI-AVS conversions (n = 28). The 30-day mortality associated with SC in MI-PAS (n = 86) was 10.5% (n = 9). MIVS is increasingly being recognized as the 'gold-standard' for surgical valve interventions in the context of rapidly expanding catheter-based technology and increasing patient expectations. Surgeons need to be aware of factors that contribute to SC and adverse intraoperative outcomes to ensure that patients enjoy the maximum potential benefit of MIVS and to apply effective risk reduction strategies that encourage safer and sustainable MIVS programmes.

The role of visual and direct force feedback in robotics-assisted mitral valve annuloplasty.

PubMed

Currie, Maria E; Talasaz, Ali; Rayman, Reiza; Chu, Michael W A; Kiaii, Bob; Peters, Terry; Trejos, Ana Luisa; Patel, Rajni

2017-09-01

The objective of this work was to determine the effect of both direct force feedback and visual force feedback on the amount of force applied to mitral valve tissue during ex vivo robotics-assisted mitral valve annuloplasty. A force feedback-enabled master-slave surgical system was developed to provide both visual and direct force feedback during robotics-assisted cardiac surgery. This system measured the amount of force applied by novice and expert surgeons to cardiac tissue during ex vivo mitral valve annuloplasty repair. The addition of visual (2.16 ± 1.67), direct (1.62 ± 0.86), or both visual and direct force feedback (2.15 ± 1.08) resulted in lower mean maximum force applied to mitral valve tissue while suturing compared with no force feedback (3.34 ± 1.93 N; P < 0.05). To achieve better control of interaction forces on cardiac tissue during robotics-assisted mitral valve annuloplasty suturing, force feedback may be required. Copyright © 2016 John Wiley & Sons, Ltd.

Valve movement response of the freshwater clam Corbicula fluminea following exposure to waterborne arsenic.

PubMed

Liao, Chung-Min; Jau, Sheng-Feng; Lin, Chieh-Ming; Jou, Li-John; Liu, Chen-Wuing; Liao, Vivian Hsiu-Chuan; Chang, Fi-John

2009-07-01

We developed an inductance-based valvometry technique as a detection system to measure the valve daily activity in freshwater clam Corbicula fluminea in response to waterborne arsenic. Our findings reveal that C. fluminea experiences a valve opening in the absence of arsenic predominantly in the morning hours (03:00-08:00) with a mean daily opening/closing period of 21.32 (95% CI: 20.58-22.05) h. Amplification of daily activity occurred in the presence of arsenic. Behavioral toxicity assays revealed arsenic detection thresholds of 0.60 (95% CI: 0.53-0.66) mg l(-1) and 0.35 (95% CI: 0.30-0.40) mg l(-1) for response times of 60 and 300 min, respectively. The proposed valve daily activity model was linked with response time-specific Hill dose-response functions to predict valve opening/closing behavior in response to arsenic. The predictive capabilities were verified satisfactory with the measurements. Our results implicate a biomonitoring system by valve daily activity in C. fluminea to identify safe water uses in areas with elevated arsenic.

Dynamic tracking of prosthetic valve motion and deformation from bi-plane x-ray views: feasibility study

NASA Astrophysics Data System (ADS)

Hatt, Charles R.; Wagner, Martin; Raval, Amish N.; Speidel, Michael A.

2016-03-01

Transcatheter aortic valve replacement (TAVR) requires navigation and deployment of a prosthetic valve within the aortic annulus under fluoroscopic guidance. To support improved device visualization in this procedure, this study investigates the feasibility of frame-by-frame 3D reconstruction of a moving and expanding prosthetic valve structure from simultaneous bi-plane x-ray views. In the proposed method, a dynamic 3D model of the valve is used in a 2D/3D registration framework to obtain a reconstruction of the valve. For each frame, valve model parameters describing position, orientation, expansion state, and deformation are iteratively adjusted until forward projections of the model match both bi-plane views. Simulated bi-plane imaging of a valve at different signal-difference-to-noise ratio (SDNR) levels was performed to test the approach. 20 image sequences with 50 frames of valve deployment were simulated at each SDNR. The simulation achieved a target registration error (TRE) of the estimated valve model of 0.93 +/- 2.6 mm (mean +/- S.D.) for the lowest SDNR of 2. For higher SDNRs (5 to 50) a TRE of 0.04 mm +/- 0.23 mm was achieved. A tabletop phantom study was then conducted using a TAVR valve. The dynamic 3D model was constructed from high resolution CT scans and a simple expansion model. TRE was 1.22 +/- 0.35 mm for expansion states varying from undeployed to fully deployed, and for moderate amounts of inter-frame motion. Results indicate that it is feasible to use bi-plane imaging to recover the 3D structure of deformable catheter devices.

Dynamic tracking of prosthetic valve motion and deformation from bi-plane x-ray views: feasibility study.

PubMed

Hatt, Charles R; Wagner, Martin; Raval, Amish N; Speidel, Michael A

2016-01-01

Transcatheter aortic valve replacement (TAVR) requires navigation and deployment of a prosthetic valve within the aortic annulus under fluoroscopic guidance. To support improved device visualization in this procedure, this study investigates the feasibility of frame-by-frame 3D reconstruction of a moving and expanding prosthetic valve structure from simultaneous bi-plane x-ray views. In the proposed method, a dynamic 3D model of the valve is used in a 2D/3D registration framework to obtain a reconstruction of the valve. For each frame, valve model parameters describing position, orientation, expansion state, and deformation are iteratively adjusted until forward projections of the model match both bi-plane views. Simulated bi-plane imaging of a valve at different signal-difference-to-noise ratio (SDNR) levels was performed to test the approach. 20 image sequences with 50 frames of valve deployment were simulated at each SDNR. The simulation achieved a target registration error (TRE) of the estimated valve model of 0.93 ± 2.6 mm (mean ± S.D.) for the lowest SDNR of 2. For higher SDNRs (5 to 50) a TRE of 0.04 mm ± 0.23 mm was achieved. A tabletop phantom study was then conducted using a TAVR valve. The dynamic 3D model was constructed from high resolution CT scans and a simple expansion model. TRE was 1.22 ± 0.35 mm for expansion states varying from undeployed to fully deployed, and for moderate amounts of inter-frame motion. Results indicate that it is feasible to use bi-plane imaging to recover the 3D structure of deformable catheter devices.

Thromboembolism in patients with pericardial valves in the absence of chronic anticoagulation: 12 years' experience.

PubMed

García-Bengoechea, J B; González-Juanatey, J R; Rubio, J; Durán, D; Sierra, J

1991-01-01

Between January 1977 and January 1989, 465 pericardial bioprostheses were implanted in 424 patients. The mean age of patients was 59.1 years (range 16-81 y.) At the time of surgery, 68% of the patients suffered from chronic atrial fibrillation. Mitral valve replacement was performed in 167 patients, aortic valve replacement in 216, multiple replacement in 40 (36 mitral and aortic, 3 mitral and tricuspid, and 1 mitral, aortic and tricuspid), and 1 pulmonary valve replacement. The different types of pericardial valve used were: Ionescu-Shiley 408, Mitral Medical 23, Bioflo 30, and Hancock 4. Hospital mortality was 10.1% with an attrition rate of 1.8 episodes per 100 patients/year. The 12-year actuarial survival rate was 65.1%. No patient underwent long-term anticoagulant treatment. The first 144 patients undergoing mitral and multiple valve replacements received temporary anticoagulation for the first 8 weeks after surgery. There was no valve thrombosis observed. Altogether 19 thromboembolic events (6 early and 13 late) were clinically documented. One patient died after an embolic event. The linearized rates of thromboembolism were 1.64 episodes per 100 patients/year for mitral and multiple valve replacements and 0.33 episodes per 100 patients/year for aortic valve replacement, with an overall rate of 1.0 episodes per 100 patients/year. Excluding early thromboembolism, the linearized rate was 1.02 episodes per 100 patients/year overall. The actuarial freedom from embolism was 92.4% overall, 88.2% for the mitral and multiple valve replacement group, and 97.6% for the aortic valve replacement group at a maximum follow-up of 12 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Valve assembly for use with high temperature and high pressure fluids

DOEpatents

De Feo, Angelo

1982-01-01

The valve assembly for use with high temperature and high pressure fluids has inner and outer spaced shells and a valve actuator support of inner and outer spaced members which are connected at their end portions to the inner and outer shells, respectively, to extend substantially normal to the longitudinal axis of the inner shell. A layer of resilient heat insulating material covers the outer surfaces of the inner shell and the inner actuator support member and is of a thickness to only occupy part of the spaces between the inner and outer shells and inner and outer actuator support members. The remaining portion of the space between the inner and outer shells and the space between the inner and outer members is substantially filled with a body of castable, rigid refractory material. A movable valve member is disposed in the inner shell. A valve actuator assembly is supported in the valve actuator support to extend into the inner shell for connection with the movable valve member for movement of the movable valve member to positions from a fully open to a fully closed position to control flow of fluid through the inner shell. An anchor mneans is disposed adjacent opposite sides of the axis of the valve actuator support and attached to the inner shell so that relative radial movement between the inner and outer shell is permitted by the layer of resilient heat insulating material and relative longitudinal movement of the inner shell to the outer shell is permitted in opposite directions from the anchor means to thereby maintain the functional integrity of the movable valve member by providing an area of the inner shell surrounding the movable valve member longitdinally stationary, but at the same time allowing radial movement.

Mechanics of cryopreserved aortic and pulmonary homografts.

PubMed

Vesely, I; Casarotto, D C; Gerosa, G

2000-01-01

The surgical placement of pulmonary valve grafts into the aortic position (the Ross procedure) has been performed for three decades. Cryopreserved pulmonary valves have had mixed clinical results, however. The objectives of this study were to compare the mechanics of cryopreserved human aortic and pulmonary valve cusps and roots to determine if the pulmonary root can withstand the greater pressures of the aortic position. Six aortic and six pulmonary valve roots were obtained from the Oxford Valve Bank. They were harvested during cardiac transplantation from hearts explanted for dilated cardiomyopathy (mean patient age 68 years). The whole roots were initially stored frozen at -186 degrees C, then shipped packed on dry ice. After complete thawing, the roots were pressurized whole; test strips were then cut from the valve cusps, roots and sinuses and tested for stress/strain, stress relaxation, and ultimate failure strength. The pulmonary roots were more distensible (30% versus 20% strain to lock-up) and less compliant when loaded to aortic pressures. The pulmonary valve cusp and root tissue also showed greater extensibility and greater stiffness (lower compliance) when subjected to the same loads. We conclude that mechanical differences between aortic and pulmonary valve tissues are minimal. The pulmonary root should withstand the forces imposed on it when placed in the aortic position. However, if implanted whole, the pulmonary root will distend about 30% more than the aortic root when subjected to aortic pressures. These geometric changes may affect valve function in the long term and should be appreciated when implanting a pulmonary valve graft.

[Periodontal microbiota and microorganisms isolated from heart valves in patients undergoing valve replacement surgery in a clinic in Cali, Colombia].

PubMed

Moreno, Sandra; Parra, Beatriz; Botero, Javier E; Moreno, Freddy; Vásquez, Daniel; Fernández, Hugo; Alba, Sandra; Gallego, Sara; Castillo, Gilberto; Contreras, Adolfo

2017-12-01

Periodontitis is an infectious disease that affects the support tissue of the teeth and it is associated with different systemic diseases, including cardiovascular disease. Microbiological studies facilitate the detection of microorganisms from subgingival and cardiovascular samples. To describe the cultivable periodontal microbiota and the presence of microorganisms in heart valves from patients undergoing valve replacement surgery in a clinic in Cali. We analyzed 30 subgingival and valvular tissue samples by means of two-phase culture medium, supplemented blood agar and trypticase soy agar with antibiotics. Conventional PCR was performed on samples of valve tissue. The periodontal pathogens isolated from periodontal pockets were: Fusobacterium nucleatum (50%), Prevotella intermedia/ nigrescens (40%), Campylobacter rectus (40%), Eikenella corrodens (36.7%), Gram negative enteric bacilli (36.7%), Porphyromonas gingivalis (33.3%), and Eubacterium spp. (33.3%). The pathogens isolated from the aortic valve were Propionibacterium acnes (12%), Gram negative enteric bacilli (8%), Bacteroides merdae (4%), and Clostridium bifermentans (4%), and from the mitral valve we isolated P. acnes and Clostridium beijerinckii. Conventional PCR did not return positive results for oral pathogens and bacterial DNA was detected only in two samples. Periodontal microbiota of patients undergoing surgery for heart valve replacement consisted of species of Gram-negative bacteria that have been associated with infections in extraoral tissues. However, there is no evidence of the presence of periodontal pathogens in valve tissue, because even though there were valve and subgingival samples positive for Gram-negative enteric bacilli, it is not possible to maintain they corresponded to the same phylogenetic origin.

Histopathology of valves in infective endocarditis, diagnostic criteria and treatment considerations.

PubMed

Brandão, Tatiana J D; Januario-da-Silva, Carolina A; Correia, Marcelo G; Zappa, Monica; Abrantes, Jaime A; Dantas, Angela M R; Golebiovski, Wilma; Barbosa, Giovanna Ianini F; Weksler, Clara; Lamas, Cristiane C

2017-04-01

Infective endocarditis (IE) is a severe disease. Pathogen isolation is fundamental so as to treat effectively and reduce morbidity and mortality. Blood and valve culture and histopathology (HP) are routinely employed for this purpose. Valve HP is the gold standard for diagnosis. To determine the sensitivity and specificity of clinical criteria for IE (the modified Duke and the St Thomas' minor modifications, STH) of blood and valve culture compared to valve HP, and to evaluate antibiotic treatment duration. Prospective case series of patients, from 2006 to 2014 with surgically treated IE. Statistical analysis was done by the R software. There were 136 clinically definite episodes of IE in 133 patients. Mean age ± SD was 43 ± 15.6 years and IE was left sided in 81.6 %. HP was definite in 96 valves examined, which were used as gold standard. Sensitivity of blood culture was 61 % (CI 0.51, 0.71) and of valve culture 15 % (CI 0.07, 0.26). The modified Duke criteria were 65 % (CI 0.55, 0.75) sensitive and 33 % specific, while the STH's sensitivity was 72 % (CI 0.61, 0.80) with similar specificity. In multivariate analysis and logistic regression, the only variable with statistical significance was duration of antibiotic therapy postoperatively. Valve HP had high sensitivity and valve culture low sensitivity in the diagnosis of IE. The STH's criteria were more sensitive than the modified Duke criteria. Valve HP should guide duration of postoperative antibiotic treatment.

A 20-year study on treating childhood infective endocarditis with valve replacement in a single cardiac center in China.

PubMed

Xiao, Jian; Yin, Liang; Lin, Yiyun; Zhang, Yufeng; Wu, Lihui; Wang, Zhinong

2016-07-01

Children with infective endocarditis (IE) have to undergo valve replacement instead of valve repair in China due to severe valve damage. The present study is to review our experience on surgical treatment of children with IE in reference to the incidence, pathologic status, diagnosis, surgical strategies and outcomes. We reviewed 35 patients with a mean age of 13.7±2.2 years who were underwent valve replacement surgery for IE during the period from January 1993 to December 2013. Preoperative transthoracic echocardiographic (TTE) evaluation and transesophageal echocardiography during operation were performed in all patients. All the children underwent chart review and retrospective risk-hazard analysis. Among the patients surveyed congenital cardiac lesions were present in 15 (42.8%), rheumatic heart valve disease in 2 (5.7%) and previous heart surgery in 2 (5.7%). The median stay of intensive care unit was 6 days. Intraoperative findings showed that the endocarditis involved mostly the mitral and aortic valves (88.5%). Triple or quadruple valve involvement was found in one patient each. Ten-year freedom from IE-related death and re-intervention was 94.2% and 91.6%, respectively. Children undergoing surgery for IE frequently have advanced disease with embolic complications. Although valve replacement is not the primary option for pediatric IE, the rate of 5-year survival and freedom from re-operation was optimal prognostically. Pediatric physicians should pay attention to the common clinical features of IE so that the native valve is preserved well.

Evaluation of aortic valve stenosis using cardiovascular magnetic resonance: comparison of an original semiautomated analysis of phase-contrast cardiovascular magnetic resonance with Doppler echocardiography.

PubMed

Defrance, Carine; Bollache, Emilie; Kachenoura, Nadjia; Perdrix, Ludivine; Hrynchyshyn, Nataliya; Bruguière, Eric; Redheuil, Alban; Diebold, Benoit; Mousseaux, Elie

2012-09-01

Accurate quantification of aortic valve stenosis (AVS) is needed for relevant management decisions. However, transthoracic Doppler echocardiography (TTE) remains inconclusive in a significant number of patients. Previous studies demonstrated the usefulness of phase-contrast cardiovascular magnetic resonance (PC-CMR) in noninvasive AVS evaluation. We hypothesized that semiautomated analysis of aortic hemodynamics from PC-CMR might provide reproducible and accurate evaluation of aortic valve area (AVA), aortic velocities, and gradients in agreement with TTE. We studied 53 AVS patients (AVA(TTE)=0.87±0.44 cm(2)) and 21 controls (AVA(TTE)=2.96±0.59 cm(2)) who had TTE and PC-CMR of aortic valve and left ventricular outflow tract on the same day. PC-CMR data analysis included left ventricular outflow tract and aortic valve segmentation, and extraction of velocities, gradients, and flow rates. Three AVA measures were performed: AVA(CMR1) based on Hakki formula, AVA(CMR2) based on continuity equation, AVA(CMR3) simplified continuity equation=left ventricular outflow tract peak flow rate/aortic peak velocity. Our analysis was reproducible, as reflected by low interoperator variability (<4.56±4.40%). Comparison of PC-CMR and TTE aortic peak velocities and mean gradients resulted in good agreement (r=0.92 with mean bias=-29±62 cm/s and r=0.86 with mean bias=-12±15 mm Hg, respectively). Although good agreement was found between TTE and continuity equation-based CMR-AVA (r>0.94 and mean bias=-0.01±0.38 cm(2) for AVA(CMR2), -0.09±0.28 cm(2) for AVA(CMR3)), AVA(CMR1) values were lower than AVA(TTE) especially for higher AVA (mean bias=-0.45±0.52 cm(2)). Besides, ability of PC-CMR to detect severe AVS, defined by TTE, provided the best results for continuity equation-based methods (accuracy >94%). Our PC-CMR semiautomated AVS evaluation provided reproducible measurements that accurately detected severe AVS and were in good agreement with TTE.

Cerebrospinal Fluid Lumbar Tapping Utilization for Suspected Ventriculoperitoneal Shunt Under-Drainage Malfunctions.

PubMed

Lee, Jong-Beom; Ahn, Ho-Young; Lee, Hong-Jae; Yang, Ji-Ho; Yi, Jin-Seok; Lee, Il-Woo

2017-01-01

The diagnosis of shunt malfunction can be challenging since neuroimaging results are not always correlated with clinical outcomes. The purpose of this study was to evaluate the efficacy of a simple, minimally invasive cerebrospinal fluid (CSF) lumbar tapping test that predicts shunt under-drainage in hydrocephalus patients. We retrospectively reviewed the clinical and radiological features of 48 patients who underwent routine CSF lumbar tapping after ventriculoperitoneal shunt (VPS) operation using a programmable shunting device. We compared shunt valve opening pressure and CSF lumbar tapping pressure to check under-drainage. The mean pressure difference between valve opening pressure and CSF lumbar tapping pressure of all patients were 2.21±24.57 mmH 2 O. The frequency of CSF lumbar tapping was 2.06±1.26 times. Eighty five times lumbar tapping of 41 patients showed that their VPS function was normal which was consistent with clinical improvement and decreased ventricle size on computed tomography scan. The mean pressure difference in these patients was -3.69±19.20 mmH 2 O. The mean frequency of CSF lumbar tapping was 2.07±1.25 times. Fourteen cases of 10 patients revealed suspected VPS malfunction which were consistent with radiological results and clinical symptoms, defined as changes in ventricle size and no clinical improvement. The mean pressure difference was 38.07±23.58 mmH 2 O. The mean frequency of CSF lumbar tapping was 1.44±1.01 times. Pressure difference greater than 35 mmH 2 O was shown in 2.35% of the normal VPS function group (2 of 85) whereas it was shown in 64.29% of the suspected VPS malfunction group (9 of 14). The difference was statistically significant ( p =0.000001). Among 10 patients with under-drainage, 5 patients underwent shunt revision. The causes of the shunt malfunction included 3 cases of proximal occlusion and 2 cases of distal obstruction and valve malfunction. Under-drainage of CSF should be suspected if CSF lumbar tapping pressure is 35 mmH 2 O higher than the valve opening pressure and shunt malfunction evaluation or adjustment of the valve opening pressure should be made.

Transcatheter Heart Valve Selection and Permanent Pacemaker Implantation in Patients With Pre-Existent Right Bundle Branch Block.

PubMed

van Gils, Lennart; Tchetche, Didier; Lhermusier, Thibault; Abawi, Masieh; Dumonteil, Nicolas; Rodriguez Olivares, Ramón; Molina-Martin de Nicolas, Javier; Stella, Pieter R; Carrié, Didier; De Jaegere, Peter P; Van Mieghem, Nicolas M

2017-03-03

Right bundle branch block is an established predictor for new conduction disturbances and need for a permanent pacemaker (PPM) after transcatheter aortic valve replacement. The aim of the study was to evaluate the absolute rates of transcatheter aortic valve replacement related PPM implantations in patients with pre-existent right bundle branch block and categorize for different transcatheter heart valves. We pooled data on 306 transcatheter aortic valve replacement patients from 4 high-volume centers in Europe and selected those with right bundle branch block at baseline without a previously implanted PPM. Logistic regression was used to evaluate whether PPM rate differed among transcatheter heart valves after adjustment for confounders. Mean age was 83±7 years and 63% were male. Median Society of Thoracic Surgeons score was 6.3 (interquartile range, 4.1-10.2). The following transcatheter valve designs were used: Medtronic CoreValve (n=130; Medtronic, Minneapolis, MN); Edwards Sapien XT (ES-XT; n=124) and Edwards Sapien 3 (ES-3; n=32; Edwards Lifesciences, Irvine, CA); and Boston Scientific Lotus (n=20; Boston Scientific Corporation, Marlborough, MA). Overall permanent pacemaker implantation rate post-transcatheter aortic valve replacement was 41%, and per valve design: 75% with Lotus, 46% with CoreValve, 32% with ES-XT, and 34% with ES-3. The indication for PPM implantation was total atrioventricular block in 98% of the cases. Lotus was associated with a higher PPM rate than all other valves. PPM rate did not differ between ES-XT and ES-3. Ventricular paced rhythm at 30-day and 1-year follow-up was present in 81% at 89%, respectively. Right bundle branch block at baseline is associated with a high incidence of PPM implantation for all transcatheter heart valves. PPM rate was highest for Lotus and lowest for ES-XT and ES-3. Pacemaker dependency remained high during follow-up. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Performance of stented biological valves for right ventricular outflow tract reconstruction.

PubMed

Buchholz, Christian; Mayr, Andreas; Purbojo, Ariawan; Glöckler, Martin; Toka, Okan; Cesnjevar, Robert A; Rüffer, André

2016-12-01

This retrospective single-centre review presents mid- and long-term results of stented biological valves (SBVs) in the pulmonary position. Fifty-two SBVs (17 Carpentier-Edwards Supraannular; 13 Carpentier-Edwards Perimount; 12 St. Jude Medical Trifecta; 4 Sorin Mitroflow; 4 Sorin Soprano; 2 Sorin More) were implanted between 2000 and 2015. The median valve size, patient age and weight were 23 mm (range 19-27), 22.8 years (range 5-77) and 62.0 kg (range 14-110), respectively. The main cardiac diagnosis was tetralogy of Fallot in 26 patients (50%). Forty-four patients (85%) had previous cardiac surgery; 12 patients (23%) had previous conduit or biological valve replacement. Valve degeneration was defined as a valvular peak pressure gradient >50 mmHg or pulmonary valve regurgitation more than moderate. The mean follow-up was 7.9 ± 5.5 years. Two patients died after 5.8 and 6.1 years of causes not related to SBVs. Eleven SBVs (21%) had to be replaced surgically (n = 6) or interventionally (n = 5) after 9.0 ± 4.1 years due to valve degeneration (n = 8), endocarditis (n = 2) or right ventricular dysfunction (n = 1). The rates of freedom from valve replacement were 100%, 92% [95% confidence interval (CI) 79-97], 81% (CI 64-91) and 60% (CI 40-78) after 1, 5, 10 and 15 years, respectively. Successful interventional valve-in-valve implantation resulted in 100% freedom from surgical valve replacement in all patients older than 19.1 years. Multivariate analysis identified patient age <19.1 years (P = 0.007) as a risk factor for earlier valve degeneration. SBVs in the pulmonary position showed encouraging long-term results in mature patients. The design of SBVs enables interventional valve implantation, postponing the need for reoperation. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Some Factors Affecting the Reproducibility of Penetration and the Cut-Off of Oil Sprays for Fuel-injection Engines

NASA Technical Reports Server (NTRS)

Beardsley, E G

1928-01-01

This investigation was undertaken at the Langley Memorial Aeronautical Laboratory in connection with a general research on fuel-injection for aircraft. The purpose of the investigation was to determine the factors controlling the reproducibility of spray penetration and secondary discharges after cut-off. The development of single sprays from automatic injection valves was recorded by means of special high-speed photographic apparatus capable of taking 25 consecutive pictures of the moving spray at a rate of 4,000 per second. The effect of two types of injection valves, injection-valve tube length, initial pressure in the injection-valve tube, speed of the injection control mechanism, and time of spray cut-off, on the reproducibility of spray penetration, and on secondary discharges were investigated. It was found that neither type of injection valve materially affected spray reproducibility. The initial pressure in the injection-valve tube controlled the reproducibility of spray penetrations. An increase in the initial pressure or in the length of the injection-valve tube slightly increased the spray penetration within the limits of this investigation. The speed of the injection-control mechanism did not affect the penetration. Analysis of the results indicates that secondary discharges were caused in this apparatus by pressure waves initiated by the rapid opening of the cut-off valve. The secondary discharges were eliminated in this investigation by increasing the length of the injection-valve tube. (author)

Trends in hospital admissions and surgical procedures for degenerative lumbar spine disease in England: a 15-year time-series study.

PubMed

Sivasubramaniam, Vinothan; Patel, Hitesh C; Ozdemir, Baris A; Papadopoulos, Marios C

2015-12-15

Low back pain (LBP), from degenerative lumbar spine disease, represents a significant burden on healthcare resources. Studies worldwide report trends attributable to their country's specific demographics and healthcare system. Considering England's specific medico-socioeconomic conditions, we investigate recent trends in hospital admissions and procedures for LBP, and discuss the implications for the allocation of healthcare resources. Retrospective cohort study using Hospital Episode Statistics data relating to degenerative lumbar spine disease in England, between 1999 and 2013. Regression models were used to analyse trends. Trends in the number of admissions and procedures for LBP, mean patient age, gender and length of stay. Hospital admissions and procedures have increased significantly over the study period, from 127.09 to 216.16 and from 24.5 to 48.83 per 100,000, respectively, (p<0.001). The increase was most marked in the oldest age groups with a 1.9 and 2.33-fold increase in admissions for patients aged 60-74 and ≥ 75 years, respectively, and a 2.8-fold increase in procedures for those aged ≥ 60 years. Trends in hospital admissions were characterised by a widening gender gap, increasing mean patient age, and decreasing mean hospital stay (p<0.001). Trends in procedures were characterised by a narrowing gender gap, increasing mean patient age (p=0.014) and decreasing mean hospital stay (p<0.001). Linear regression models estimate that each hospital admission translates to 0.27 procedures, per 100,000 (95% CI 0.25 to 0.30, r 0.99, p<0.001; r, Pearson's correlation coefficient). Hospital admissions are increasing at 3.5 times the rate of surgical procedures (regression gradient 7.63 vs 2.18 per 100,000/year). LBP represents a significant and increasing workload for hospitals in England. These trends demonstrate an increasing demand for specialists involved in the surgical and non-surgical management of this disease, and highlight the need for services capable of dealing with the increased comorbidity burden associated with an ageing patient group. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Direct Enrollments at Twenty-two Colleges and Universities Test Society's Confidence

ERIC Educational Resources Information Center

Chunlin, Yuan

2005-01-01

This article examines the direct admission process and the selection criteria set by the tertiary institutions in China. As the name suggests, "direct admissions" means that it is up to the institution to decide which students to enroll. Tertiary institutions also have the right to decide the number of admissions, and not all schools are…

Prior oral conditions in patients undergoing heart valve surgery

PubMed Central

Gil-Raga, Irene; Martinez-Herrera, Mayte; Lauritano, Dorina; Silvestre-Rangil, Javier

2017-01-01

Background Patients scheduled for heart valve surgery should be free of any oral infectious disorders that might pose a risk in the postoperative period. Few studies have been made on the dental conditions of such patients prior to surgery. The present study describes the most frequent prior oral diseases in this population group. Material and Methods A prospective, observational case-control study was designed involving 60 patients (30 with heart valve disease and 30 controls, with a mean age of 71 years in both groups). A dental exploration was carried out, with calculation of the DMFT (decayed, missing and filled teeth) index and recording of the periodontal parameters (plaque index, gingival bleeding index, periodontal pocket depth, and attachment loss). The oral mucosa was also examined, and panoramic X-rays were used to identify possible intrabony lesions. Results Significant differences in bacterial plaque index were observed between the two groups (p<0.05), with higher scores in the patients with valve disease. Probing depth and the presence of moderate pockets were also greater in the patients with valve disease than among the controls (p<0.01). Sixty percent of the patients with valve disease presented periodontitis. Conclusions Patients scheduled for heart valve surgery should be examined for possible active periodontitis before the operation. Those individuals found to have periodontal disease should receive adequate periodontal treatment before heart surgery. Key words:Valve disease, aortic, mitral, heart surgery, periodontitis. PMID:29302279

Prior oral conditions in patients undergoing heart valve surgery.

PubMed

Silvestre, Francisco-Javier; Gil-Raga, Irene; Martinez-Herrera, Mayte; Lauritano, Dorina; Silvestre-Rangil, Javier

2017-11-01

Patients scheduled for heart valve surgery should be free of any oral infectious disorders that might pose a risk in the postoperative period. Few studies have been made on the dental conditions of such patients prior to surgery. The present study describes the most frequent prior oral diseases in this population group. A prospective, observational case-control study was designed involving 60 patients (30 with heart valve disease and 30 controls, with a mean age of 71 years in both groups). A dental exploration was carried out, with calculation of the DMFT (decayed, missing and filled teeth) index and recording of the periodontal parameters (plaque index, gingival bleeding index, periodontal pocket depth, and attachment loss). The oral mucosa was also examined, and panoramic X-rays were used to identify possible intrabony lesions. Significant differences in bacterial plaque index were observed between the two groups ( p <0.05), with higher scores in the patients with valve disease. Probing depth and the presence of moderate pockets were also greater in the patients with valve disease than among the controls ( p <0.01). Sixty percent of the patients with valve disease presented periodontitis. Patients scheduled for heart valve surgery should be examined for possible active periodontitis before the operation. Those individuals found to have periodontal disease should receive adequate periodontal treatment before heart surgery. Key words: Valve disease, aortic, mitral, heart surgery, periodontitis.

Open heart surgery after renal transplantation.

PubMed

Yamamura, Mitsuhiro; Miyamoto, Yuji; Mitsuno, Masataka; Tanaka, Hiroe; Ryomoto, Masaaki; Fukui, Shinya; Tsujiya, Noriko; Kajiyama, Tetsuya; Nojima, Michio

2014-09-01

to evaluate the strategy for open heart surgery after renal transplantation performed in a single institution in Japan. we reviewed 6 open heart surgeries after renal transplantation in 5 patients, performed between January 1992 and December 2012. The patients were 3 men and 2 women with a mean age of 60 ± 11 years (range 46-68 years). They had old myocardial infarction and unstable angina, aortic and mitral stenosis, left arterial myxoma, aortic stenosis, and native valve endocarditis followed by prosthetic valve endocarditis. Operative procedures included coronary artery bypass grafting, double-valve replacement, resection of left arterial myxoma, 2 aortic valve replacements, and a double-valve replacement. Renal protection consisted of steroid cover (hydrocortisone 100-500 mg or methylprednisolone 1000 mg) and intravenous immunosuppressant infusion (cyclosporine 30-40 mg day(-1) or tacrolimus 1.0 mg day(-1)). 5 cases were uneventful and good renal graft function was maintained at discharge (serum creatinine 2.1 ± 0.5 mg dL(-1)). There was one operative death after emergency double-valve replacement for methicillin-resistant Staphylococcus aureus-associated prosthetic valve endocarditis. Although the endocarditis improved after valve replacement, the patient died of postoperative pneumonia on postoperative day 45. careful perioperative management can allow successful open heart surgery after renal transplantation. However, severe complications, especially methicillin-resistant Staphylococcus aureus infection, may cause renal graft loss. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Determining the spin dependent mean free path in Co90Fe10 using giant magnetoresistance

NASA Astrophysics Data System (ADS)

Shakespear, K. F.; Perdue, K. L.; Moyerman, S. M.; Checkelsky, J. G.; Harberger, S. S.; Tamboli, A. C.; Carey, M. J.; Sparks, P. D.; Eckert, J. C.

2005-05-01

The spin dependent mean free path in Co90Fe10 is determined as a function of temperature down to 5K using two different spin valve structures. At 5K the spin dependent mean free path for one structure was measured to be 9.4±1.4nm, decreasing by a factor of 3 by 350K. For the other structure, it is 7.5±0.5nm at 5K and decreased by a factor of 1.5 by 350K. In both cases, the spin dependent mean free path approaches the typical thickness of ferromagnetic layers in spin valves at room temperature and, thus, has an impact on the choice of design parameters for the development of new spintronic devices.

In-hospital Mobility Variations across Primary Diagnoses among Older Adults

PubMed Central

Valiani, Vincenzo; Gao, Shiyao; Chen, Zhiguo; Swami, Sunil; Harle, Christopher A.; Lipori, Gigi; Sourdet, Sandrine; Wu, Samuel; Nayfield, Susan G.; Sabbá, Carlo; Pahor, Marco; Manini, Todd M.

2016-01-01

Objectives To examine the relationship between primary diagnoses and mobility impairment and recovery among hospitalized older adults. Design Prospective cohort study. Setting UF Health Shands Hospital, an 852-bed level I trauma center located in Gainesville, Florida. Participants 18,551 older adults (≥65 years) with 29,148 hospitalizations between 1/2009 and 4/2014. Measurements Incident and discharge mobility impairment and recovery were assessed using the Braden activity subscale score that was recorded by the nursing staff at every shift change–approximately three times per day. Primary diagnosis ICD-9 codes were used as predictors and re-categorized by using the Agency for Health Care Research and Quality Clinical Classification Software. Results Out of the 15,498 hospital records where the patient was initially observed to “walk frequently”, 3,186 (20.6%) developed incident mobility impairment (chair-fast or bedfast). Primary diagnoses with a surgical or invasive procedure were the most prevalent (77.2 %) among the hospital observations with incident mobility impairment; otherwise primary diagnoses without surgery were much more associated with discharge mobility impairment (59%). The highest incidence of mobility impairment occurred in patients with heart valve disorders and aortic and peripheral/visceral artery aneurysms (6.24 and 6.05 events per 30 person-days, respectively); septicemia showed the highest incidence rate for mobility limitation at discharge (0.94 events per 30 person-days). Mobility impairment was observed in 13,650 (46.8% of total) records at admission and 5,930 (43.44%) were observed to recover to a state of walking occasionally or frequently. Osteoarthritis and cancer of gastrointestinal organs/peritoneum had the highest incidence rate for mobility recovery (7.68 and 5.63 events per 30 person-days respectively). Conclusions Approximately 1 out of 5 patients who were mobile at admission became significantly impaired during hospitalization. However, about half (43.4%) of patients observed to have mobility impairment at admission recovered during hospitalization. Conditions most associated with mobility impairment and recovery are varied, but older patients hospitalized for septicemia and cardiovascular diseases with surgery (heart valve disorders and aortic/peripheral/visceral artery aneurysms) appear to be at most risk for incident mobility impairment that did not recover at discharge. PMID:26971132

Acute medical bed usage by nursing home residents.

PubMed

Beringer, T R; Flanagan, P

1999-05-01

An increasing number of elderly patients in nursing home care appears to be presenting to hospital for acute medical admission. A survey of acute hospital care was undertaken to establish accurately the number and character of such admissions. A total of 1300 acute medical beds was surveyed in Northern Ireland in June 1996 and January 1997 on a single day using a standardised proforma. Demographic details, diagnosis and length of admission were recorded. A total of 84 patients over the age of 65 (mean 79.5 years) admitted from nursing home care was identified in June 1996 and a total of 125 (mean 83.3 years) in January 1997. A total of 88 (70%) of admissions in 1997 were accompanied by a general practitioner's letter. The assessing doctor judged that 12 (9.6%) of admissions in 1997 could have had investigations and or treatment reasonably instituted in a nursing home. The proportion of acute medical beds occupied by nursing home residents was 6% in June 1996 rising to 10% in January 1997. The study accurately identifies the significant contribution of nursing home patients to acute medical admissions and the low proportion in whom admission was unnecessary. Closure of long stay hospital facilities should be accompanied by investment in community medical services and also reinvestment in acute hospital care for elderly people.

Mitral Valve Stenosis after Open Repair Surgery for Non-rheumatic Mitral Valve Regurgitation: A Review.

PubMed

Shabsigh, Muhammad; Lawrence, Cassidy; Rosero-Britton, Byron R; Kumar, Nicolas; Kimura, Satoshi; Durda, Michael Andrew; Essandoh, Michael

2016-01-01

Mitral stenosis (MS) after mitral valve (MV) repair is a slowly progressive condition, usually detected many years after the index MV surgery. It is defined as a mean transmitral pressure gradient (TMPG) >5 mmHg or a mitral valve area (MVA) <1.5 cm(2). Pannus formation around the mitral annulus or extending to the mitral leaflets is suggested as the main mechanism for developing delayed MS after MV repair. On the other hand, early stenosis is thought to be a direct result of an undersized annuloplasty ring. Furthermore, in MS following ischemic mitral regurgitation (MR) repair, subvalvular tethering is the hypothesized pathophysiology. MS after MV repair has an incidence of 9-54%. Several factors have been associated with a higher risk for developing MS after MV repair, including the use of flexible Duran annuloplasty rings versus rigid Carpentier-Edwards rings, complete annuloplasty rings versus partial bands, small versus large anterior leaflet opening angle, and anterior leaflet tip opening length. Intraoperative echocardiography can measure the anterior leaflet opening angle, the anterior leaflet tip opening dimension, the MVA and the mean TMPG, and may help identify patients at risk for developing MS after MV repair.

Mitral Valve Stenosis after Open Repair Surgery for Non-rheumatic Mitral Valve Regurgitation: A Review

PubMed Central

Shabsigh, Muhammad; Lawrence, Cassidy; Rosero-Britton, Byron R.; Kumar, Nicolas; Kimura, Satoshi; Durda, Michael Andrew; Essandoh, Michael

2016-01-01

Mitral stenosis (MS) after mitral valve (MV) repair is a slowly progressive condition, usually detected many years after the index MV surgery. It is defined as a mean transmitral pressure gradient (TMPG) >5 mmHg or a mitral valve area (MVA) <1.5 cm2. Pannus formation around the mitral annulus or extending to the mitral leaflets is suggested as the main mechanism for developing delayed MS after MV repair. On the other hand, early stenosis is thought to be a direct result of an undersized annuloplasty ring. Furthermore, in MS following ischemic mitral regurgitation (MR) repair, subvalvular tethering is the hypothesized pathophysiology. MS after MV repair has an incidence of 9–54%. Several factors have been associated with a higher risk for developing MS after MV repair, including the use of flexible Duran annuloplasty rings versus rigid Carpentier–Edwards rings, complete annuloplasty rings versus partial bands, small versus large anterior leaflet opening angle, and anterior leaflet tip opening length. Intraoperative echocardiography can measure the anterior leaflet opening angle, the anterior leaflet tip opening dimension, the MVA and the mean TMPG, and may help identify patients at risk for developing MS after MV repair. PMID:27148540

Early and late outcomes in minimally invasive mitral valve repair: an eleven-year experience in 707 patients.

PubMed

McClure, R Scott; Cohn, Lawrence H; Wiegerinck, Esther; Couper, Gregory S; Aranki, Sary F; Bolman, R Morton; Davidson, Michael J; Chen, Frederick Y

2009-01-01

This study analyzes a single institution experience with minimally invasive mitral valve repair and evaluates long-term surgical outcomes of morbidity, mortality, and rates of reoperation. Late follow-up of mitral regurgitation and left ventricular function were also assessed. Between August 1996 and October 2007, minimally invasive mitral valve repair was performed in 713 patients (mean follow-up 5.7 years). Excluding 6 repairs with robotic assistance, an perspective analysis of the remaining 707 patients was carried forth. Mean age was 57 +/- 13 years. Mean preoperative ejection fraction was 60% +/- 10%. Surgical access was through a lower ministernotomy (74%), right parasternal incision (24%), right thoracotomy (1.4%), or upper ministernotomy (0.7%). Exposure of the mitral valve was through the left atrium in 58% of the cases and transeptal in 42%. A ring annuloplasty was incorporated into 680 (96%) of 707 repairs. The Kaplan-Meier and Student t test for paired samples were used for statistical analysis. There were 3 (0.4%) operative deaths. Perioperative morbidity included new-onset atrial fibrillation (20%), reoperation for bleeding (2%), stroke (1.9%), permanent pacemaker implantation (1.7%), deep sternal wound infection (0.7%), and aortic dissection (0.4%). Median hospital stay was 5 days. Only 31% of patients required blood transfusion during the hospital course. There were 49 (6.9%) late deaths and 34 (4.8%) failed repairs necessitating reoperation. At 11.2 years, survival was 83% (95% confidence intervals, 76.5-88.1); freedom from reoperation was 92% (95% confidence intervals, 86.2-94.9). Nine (1.3%) patients were lost to follow-up. A total of 2369 patient-years of echocardiography time were obtained in 544 patients (mean 4.36 years, range 0.47-11.09). Mean grade of mitral regurgitation decreased from 3.80 to 1.42 (P < .0001) Mean left ventricular ejection fraction decreased from 60.7% to 56.3% (P < .0001). Combined risk of death, reoperation, and recurrence of moderately severe to severe mitral regurgitation was 7.7% (43/555). Minimally invasive mitral valve repair is safe, with low perioperative morbidity, low rates of recurrent mitral regurgitation, and low rates of reoperation and death at late follow-up.

Advanced CT acquisition protocol with a third-generation dual-source CT scanner and iterative reconstruction technique for comprehensive prosthetic heart valve assessment.

PubMed

Faure, Marguerite E; Swart, Laurens E; Dijkshoorn, Marcel L; Bekkers, Jos A; van Straten, Marcel; Nieman, Koen; Parizel, Paul M; Krestin, Gabriel P; Budde, Ricardo P J

2018-05-01

Multidetector CT (MDCT) is a valuable tool for functional prosthetic heart valve (PHV) assessment. However, radiation exposure remains a concern. We assessed a novel CT-acquisition protocol for comprehensive PHV evaluation at limited dose. Patients with a PHV were scanned using a third-generation dual-source CT scanner (DSCT) and iterative reconstruction technique (IR). Three acquisitions were obtained: a non-enhanced scan; a contrast-enhanced, ECG-triggered, arterial CT angiography (CTA) scan with reconstructions at each 5 % of the R-R interval; and a delayed high-pitch CTA of the entire chest. Image quality was scored on a five-point scale. Radiation dose was obtained from the reported CT dose index (CTDI) and dose length product (DLP). We analysed 43 CT examinations. Mean image quality score was 4.1±1.4, 4.7±0.5 and 4.2±0.6 for the non-contrast-enhanced, arterial and delayed acquisitions, respectively, with a total mean image quality of 4.3±0.7. Mean image quality for leaflet motion was 3.9±1.4. Mean DLP was 28.2±17.1, 457.3±168.6 and 68.5±47.2 mGy.cm for the non-contrast-enhanced (n=40), arterial (n=43) and delayed acquisition (n=43), respectively. The mean total DLP was 569±208 mGy.cm and mean total radiation dose was 8.3±3.0 mSv (n=43). Comprehensive assessment of PHVs is possible using DSCT and IR at moderate radiation dose. • Prosthetic heart valve dysfunction is a potentially life-threatening condition. • Dual-source CT can adequately assess valve leaflet motion and anatomy. • We assessed a comprehensive protocol with three acquisitions for PHV evaluation. • This protocol is associated with good image quality and limited dose.

A valved hepatic portoduodenal intestinal conduit for biliary atresia.

PubMed

Tanaka, K; Shirahase, I; Utsunomiya, H; Katayama, T; Uemoto, S; Asonuma, K; Inomata, Y; Ozawa, K

1991-03-01

Forty-six consecutive patients with biliary atresia were operated on at our institution during the 11-year period between 1978 and 1989. Their ages at operation ranged from 18 to 153 days (mean, 59 days). After dissecting the porta hepatis structures by Kasai operation, a biliointestinal anastomosis was constructed with a valved hepatic portoduodenal intestinal conduit in all cases. The intestinal valve is an intussuscepted muscular valve. Valvular function was examined radiologically. The upper gastrointestinal series demonstrated no reflux of contrast material into the conduit proximal to the valve and liver scintigraphy demonstrated that radioactive isotope drained readily into the duodenum through the valve. Thirty-nine of the forty-six patients (85%) had bile drainage after initial operation. At present 30 patients (65%) are alive without jaundice, 6 (13%) are alive with jaundice, and 10 (22%) are dead. The 5-year jaundice-free survival rate was 64%. Cholangitis occurred in 9 of 39 patients (23%) who had obtained apparent bile drainage: 5 had tractable cholangitis and 4 had refractory cholangitis. Reoperation restored bile flow in 2 of 8 patients who abruptly ceased to have bile drainage without cholangitis. In conclusion, with a valved hepatic portoduodenal intestinal conduit, the incidence of cholangitis was decreased, its medical control became easier, and the survival rate was improved.

Molecular Analysis of Oral Bacteria in Heart Valve of Patients With Cardiovascular Disease by Real-Time Polymerase Chain Reaction

PubMed Central

Oliveira, Francisco Artur Forte; Forte, Clarissa Pessoa Fernandes; Silva, Paulo Goberlânio de Barros; Lopes, Camile B.; Montenegro, Raquel Carvalho; dos Santos, Ândrea Kely Campos Ribeiro; Sobrinho, Carlos Roberto Martins Rodrigues; Mota, Mário Rogério Lima; Sousa, Fabrício Bitu; Alves, Ana Paula Negreiros Nunes

2015-01-01

Abstract Structural deficiencies and functional abnormalities of heart valves represent an important cause of cardiovascular morbidity and mortality, and a number of diseases, such as aortic stenosis, have been recently associated with infectious agents. This study aimed to analyze oral bacteria in dental plaque, saliva, and cardiac valves of patients with cardiovascular disease. Samples of supragingival plaque, subgingival plaque, saliva, and cardiac valve tissue were collected from 42 patients with heart valve disease. Molecular analysis of Streptococcus mutans, Prevotella intermedia, Porphyromonas gingivalis, and Treponema denticola was performed through real-time PCR. The micro-organism most frequently detected in heart valve samples was the S. mutans (89.3%), followed by P. intermedia (19.1%), P. gingivalis (4.2%), and T. denticola (2.1%). The mean decayed, missing, filled teeth (DMFT) was 26.4 ± 6.9 (mean ± SD), and according to the highest score of periodontal disease observed for each patient, periodontal pockets > 4 mm and dental calculus were detected in 43.4% and 34.7% of patients, respectively. In conclusion, oral bacteria, especially S. mutans, were found in the cardiac valve samples of patients with a high rate of caries and gingivitis/periodontitis. PMID:26632711

Surgical or Transcatheter Aortic-Valve Replacement in Intermediate-Risk Patients.

PubMed

Reardon, Michael J; Van Mieghem, Nicolas M; Popma, Jeffrey J; Kleiman, Neal S; Søndergaard, Lars; Mumtaz, Mubashir; Adams, David H; Deeb, G Michael; Maini, Brijeshwar; Gada, Hemal; Chetcuti, Stanley; Gleason, Thomas; Heiser, John; Lange, Rüdiger; Merhi, William; Oh, Jae K; Olsen, Peter S; Piazza, Nicolo; Williams, Mathew; Windecker, Stephan; Yakubov, Steven J; Grube, Eberhard; Makkar, Raj; Lee, Joon S; Conte, John; Vang, Eric; Nguyen, Hang; Chang, Yanping; Mugglin, Andrew S; Serruys, Patrick W J C; Kappetein, Arie P

2017-04-06

Although transcatheter aortic-valve replacement (TAVR) is an accepted alternative to surgery in patients with severe aortic stenosis who are at high surgical risk, less is known about comparative outcomes among patients with aortic stenosis who are at intermediate surgical risk. We evaluated the clinical outcomes in intermediate-risk patients with severe, symptomatic aortic stenosis in a randomized trial comparing TAVR (performed with the use of a self-expanding prosthesis) with surgical aortic-valve replacement. The primary end point was a composite of death from any cause or disabling stroke at 24 months in patients undergoing attempted aortic-valve replacement. We used Bayesian analytical methods (with a margin of 0.07) to evaluate the noninferiority of TAVR as compared with surgical valve replacement. A total of 1746 patients underwent randomization at 87 centers. Of these patients, 1660 underwent an attempted TAVR or surgical procedure. The mean (±SD) age of the patients was 79.8±6.2 years, and all were at intermediate risk for surgery (Society of Thoracic Surgeons Predicted Risk of Mortality, 4.5±1.6%). At 24 months, the estimated incidence of the primary end point was 12.6% in the TAVR group and 14.0% in the surgery group (95% credible interval [Bayesian analysis] for difference, -5.2 to 2.3%; posterior probability of noninferiority, >0.999). Surgery was associated with higher rates of acute kidney injury, atrial fibrillation, and transfusion requirements, whereas TAVR had higher rates of residual aortic regurgitation and need for pacemaker implantation. TAVR resulted in lower mean gradients and larger aortic-valve areas than surgery. Structural valve deterioration at 24 months did not occur in either group. TAVR was a noninferior alternative to surgery in patients with severe aortic stenosis at intermediate surgical risk, with a different pattern of adverse events associated with each procedure. (Funded by Medtronic; SURTAVI ClinicalTrials.gov number, NCT01586910 .).

Totally biological composite aortic stentless valved conduit for aortic root replacement: 10-year experience

PubMed Central

2011-01-01

Objectives To retrospectively analyze the clinical outcome of a totally biological composite stentless aortic valved conduit (No-React® BioConduit) implanted using the Bentall procedure over ten years in a single centre. Methods Between 27/10/99 and 19/01/08, the No-React® BioConduit composite graft was implanted in 67 patients. Data on these patients were collected from the in-hospital database, from patient notes and from questionnaires. A cohort of patients had 2D-echocardiogram with an average of 4.3 ± 0.45 years post-operatively to evaluate valve function, calcification, and the diameter of the conduit. Results Implantation in 67 patients represented a follow-up of 371.3 patient-year. Males were 60% of the operated population, with a mean age of 67.9 ± 1.3 years (range 34.1-83.8 years), 21 of them below the age of 65. After a mean follow-up of 7.1 ± 0.3 years (range of 2.2-10.5 years), more than 50% of the survivors were in NYHA I/II and more than 60% of the survivors were angina-free (CCS 0). The overall 10-year survival following replacement of the aortic valve and root was 51%. During this period, 88% of patients were free from valved-conduit related complications leading to mortality. Post-operative echocardiography studies showed no evidence of stenosis, dilatation, calcification or thrombosis. Importantly, during the 10-year follow-up period no failures of the valved conduit were reported, suggesting that the tissue of the conduit does not structurally change (histology of one explant showed normal cusp and conduit). Conclusions The No-React® BioConduit composite stentless aortic valved conduit provides excellent long-term clinical results for aortic root replacement with few prosthesis-related complications in the first post-operative decade. PMID:21699696

The early and midterm function of decellularized aortic valve allografts.

PubMed

da Costa, Francisco D A; Costa, Ana Claudia B A; Prestes, Roberta; Domanski, Ana Carolina; Balbi, Eduardo Mendel; Ferreira, Andreia D A; Lopes, Sergio Veiga

2010-12-01

This study evaluates the early and midterm results of decellularized aortic valve allografts (DAVA) as an aortic valve replacement. Between October 2005 and February 2010, 41 patients, 28 of whom were male, with a median age of 34 years (range, 0.1 to 71), had aortic valve replacement with DAVA. Decellularization was obtained with a 0.1% sodium dodecyl sulfate solution. Postoperative evaluation was performed with serial echocardiograms, magnetic resonance imaging, and multislice computed tomography studies to evaluate valve hemodynamics, allograft conduit dimensions, and calcification scores. There were 3 early deaths and 1 late death, with a mean follow-up of 19 months (range, 1 to 53). There was 1 reoperation due to a failed mitral valve repair. By echocardiography in all patients, the median immediate postoperative peak gradient was 7 mm Hg (range, 1 to 26 mm Hg), and at last follow-up it was 4 mm Hg (range, 1 to 16 mm Hg); valvular regurgitation was graded as none or trivial in all but 1 patient, who had a regurgitation graded as mild to moderate. By magnetic resonance imaging (n = 4), mean root dimensions were stable at the annulus (24 mm), sinus of Valsalva (33 mm), and sinotubular junction (28 mm). By computed tomography (n = 22), there was only discrete conduit calcification (median calcium score 63 Hounsfield units [HU]; range, 0 to 894 HU) to 3 years of follow-up. Conduit biopsy in the patient who underwent reoperation demonstrated well-preserved wall structure, absence of calcification, and limited in vivo host repopulation. The early and midterm results with DAVA demonstrated stable structural integrity, low rate of calcification, and adequate hemodynamics. Although longer periods of observation are necessary, DAVA appears to be a promising alternative for aortic valve replacement in selected patients. Copyright © 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Mid-term results of mitral valve repair using flexible bands versus complete rings in patients with degenerative mitral valve disease: a prospective, randomized study.

PubMed

Bogachev-Prokophiev, Alexandr V; Afanasyev, Alexandr V; Zheleznev, Sergei I; Nazarov, Vladimir M; Sharifulin, Ravil M; Karaskov, Alexandr M

2017-12-13

We aimed to compare the outcomes of mitral valve repair with flexible band (FB) versus complete semirigid ring (SR) in degenerative mitral valve disease patients. From September 2011 to 2014, 171 patients were randomized and underwent successful mitral valve repair using a SR (n = 85) or FB (n = 86). There were no significant between-group differences at baseline. There were no early mortalities. The mean follow up was 24.7 months. The 2-year survival was 96.0 ± 2.3% (95% confidence interval [CI], 88.6-98.7%) and 94.3 ± 2.8% (95% CI, 85.5-97.9%) in the SR and FB groups, respectively (p = 0.899). The left ventricle remodeling was similar between the groups. Higher transmitral peak (8.5 [3.9-17] vs. 6 [2.1-18] mmHg, p < 0.001), mean pressure gradients (3.7 [1.3-8] vs. 2.8 [0.6-6.8] mmHg, p = 0.001), and systolic pulmonary artery pressure (34.5 [20-68] vs. 29.5 [8-48] mmHg, p < 0.001) was observed in the SR group. The 2-year freedom from recurrence of significant mitral regurgitation was significantly higher in the FB group than the SR group (p = 0.002). Residual mitral regurgitation was an independent prognostic factor of recurrence of mitral regurgitation. The 3-year freedom from reoperation was significantly higher in the FB group than the SR group (p = 0.044). Patients with degenerative mitral valve disease may benefit from valve repair with FBs. Residual mitral regurgitation before discharge is an independent risk factor of late insufficiency recurrence. ClinicalTrials.gov NCT03278574 , retrospectively registered on 06.09.2017.

A magnetorheological fluid locking device

NASA Astrophysics Data System (ADS)

Kavlicoglu, Barkan; Liu, Yanming

2011-04-01

A magnetorheological fluid (MRF) device is designed to provide a static locking force caused by the operation of a controllable MRF valve. The intent is to introduce an MRF device which provides the locking force of a fifth wheel coupler while maintaining the "powerless" locking capability when required. A passive magnetic field supplied by a permanent magnet provides a powerless locking resistance force. The passively closed MRF valve provides sufficient reaction force to eliminate axial displacement to a pre-defined force value. Unlocking of the device is provided by means of an electromagnet which re-routes the magnetic field distribution along the MR valve, and minimizes the resistance. Three dimensional electromagnetic finite element analyses are performed to optimize the MRF lock valve performance. The MRF locking valve is fabricated and tested for installation on a truck fifth wheel application. An experimental setup, resembling actual working conditions, is designed and tests are conducted on vehicle interface schemes. The powerless-locking capacity and the unlocking process with minimal resistance are experimentally demonstrated.

Modification of the Smeloff mitral prosthesis.

PubMed

Smeloff, E A; Davey, T B; Riemenschneider, T A; Epstein, M L; Janos, G; Marshall, R

1982-07-01

The simplicity of the ball valve with its random seating capabilities coupled with its durability, reliability, and predictability has made it the attractive choice of many surgeons. A low incidence of embolic phenomena with the Smeloff full-orifice, double-caged, bare-strutted ball valve has made us reluctant to alter the design over 17 years. Recent evaluation of the reasons for reoperation on the Smeloff mitral valve implantation in 376 cases revealed 16 cases in which development of fibrous subvalvular pannus with signs and symptoms of mitral stenosis occurred. The mean occurrence time was 7.5 years for adults and 4.6 years for children under age 8 years. No such problem has been encountered with the valve in the aortic position. Many of these patients are maintained on aspirin and Persantine alone. Valve design was explored as a possible cause of mitral subvalvular stenosis. Alterations of the design were examined in the engineering laboratory and in dog implantations by catheterization, electrophysiologic evaluation, and echocardiography. The results were encouraging.

Study of the mechanism of diatom cell division by means of 29Si isotope tracing

NASA Astrophysics Data System (ADS)

Audinot, J.-N.; Guignard, C.; Migeon, H.-N.; Hoffmann, L.

2006-07-01

Diatoms are delicate unicellular organisms enclosed in a silica frustule, that is made up of two valves. Multiplication of the diatoms occurs by ordinary mitotic cell division. During cell division each cell produces two daughter cells, each of them keeping one of the two valves of the mother cell and producing a new valve by absorbing the silicon present in the environment. The NanoSIMS 50 allows ion imaging to be performed on diatoms in order to determine the site of fixation of silicon. The aim of this study was to observe and compare the mechanism of the construction of the new valve after cell division. To this end, different types of diatoms have been transferred in a culture medium enriched with 29Si and after several days, the distribution of the different isotopes of silicon has been determined by NanoSIMS50 imaging. The construction of new valves has been observed and the isotopic ratio has been determined.

Long-term performance of the Hancock bioprosthetic valved conduit in the aortic root position.

PubMed

Badiu, Catalin C; Bleiziffer, Sabine; Eichinger, Walter B; Hettich, Ina; Krane, Markus; Bauernschmitt, Robert; Lange, Rüdiger

2011-03-01

The study aim was to assess long-term morbidity and mortality with special regard to prosthesis durability after aortic root replacement with the Hancock bioprosthetic porcine conduit. Between 1975 and 2004, a total of 81 patients (55 males, 26 females; mean age 58 +/- 18 years) underwent aortic root replacement with the Hancock conduit for aortic dissection (n = 22; 27%), ascending aortic aneurysm (n = 57; 70%), or porcelain aorta (n = 2; 3%). Twenty-five patients (31%) underwent an emergency operation, 12 (15%) presented with Marfan syndrome, and eight (10%) had undergone previous cardiac surgery. Concomitant procedures were performed in 26 cases (32%). The follow up was 98% complete; the mean follow up was 4.8 +/- 4.0 years (range: 1 day to 16.7 years), and the cumulative follow up was 403 patient-years. Actuarial event-free rates were calculated, and valve-related complications classified according to guidelines for reporting morbidity and mortality after cardiac valvular operations. There were seven (9%) operative deaths and four (5%) in-hospital deaths. Actuarial survival rates at five and 10 years (excluding operative deaths) were 77.0 +/- 5.3% and 54.0 +/- 7.5%, respectively. Actuarial freedom from aortic valve reoperation at five and 10 years was 98 +/- 1.6% and 64 +/- 10.2%, from structural valve deterioration 88.1 +/- 4.7% and 49.9 +/- 9.6%, from thromboembolic events 87.4 +/- 4.6% and 75.1 +/- 9.5%, and from major bleeding events 90.2 +/- 3.9% and 75.4 +/- 8.1%, respectively. Among redo procedures, the stentless Hancock valve could be excised without separating the synthetic graft from the left ventricular outflow tract, and a stented valve prosthesis thus implanted. Hence, it was possible to avoid a second Bentall operation. The long-term survival rates after aortic root replacement with the bioprosthetic Hancock conduit were reasonable for this demanding patient cohort. However, the durability of the prosthesis was inferior to that reported for the stented Hancock valve substitute. The key benefit of this bioprosthetic valved conduit was the simplified redo procedure.

Transaortic edge-to-edge mitral valve repair for moderate secondary/functional mitral regurgitation in patients undergoing aortic root/valve intervention.

PubMed

Choudhary, Shiv Kumar; Abraham, Atul; Bhoje, Amol; Gharde, Parag; Sahu, Manoj; Talwar, Sachin; Airan, Balram

2017-11-01

The present study evaluates the feasibility, safety, and efficacy of edge-to-edge repair for moderate secondary/functional mitral regurgitation in patients undergoing aortic valve/root interventions. Sixteen patients underwent transaortic edge-to-edge mitral valve repair. Mitral regurgitation was 2+ in 8 patients and 3+ in 6 patients. Two patients in whom cardiac arrest developed preoperatively had severe (4+) mitral regurgitation. Patients underwent operation for severe aortic regurgitation ± aortic root lesions. The mean left ventricular systolic and diastolic diameters were 51.5 ± 12.8 mm and 70.7 ± 10.7 mm, respectively. Left ventricular ejection fraction ranged from 20% to 60%. Primary surgical procedure included Bentall's ± hemiarch replacement in 10 patients, aortic valve replacement in 5 patients, and noncoronary sinus replacement with aortic valve repair in 1 patient. Severity of mitral regurgitation decreased to trivial or zero in 13 patients, 1+ in 2 patients, and 2+ in 1 patient. There were no gradients across the mitral valve in 9 patients, less than 5 mm Hg in 6 patients, and 9 mm Hg in 1 patient. There was no operative mortality. Follow-up ranged from 2 weeks to 54 months. Echocardiography showed trivial or no mitral regurgitation in 12 patients, 1+ in 2 patients, and 2+ in 2 patients. None of the patients had significant mitral stenosis. The mean left ventricular systolic and diastolic diameters decreased to 40.5 ± 10.3 mm and 58.7 ± 11.6 mm, respectively. Ejection fraction also improved slightly (22%-65%). Transaortic edge-to-edge mitral valve repair is a safe and effective technique to abolish secondary/functional mitral regurgitation. However, its impact on overall survival needs to be studied. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Energy dynamics of the intraventricular vortex after mitral valve surgery.

PubMed

Nakashima, Kouki; Itatani, Keiichi; Kitamura, Tadashi; Oka, Norihiko; Horai, Tetsuya; Miyazaki, Shohei; Nie, Masaki; Miyaji, Kagami

2017-09-01

Mitral valve morphology after mitral valve surgery affects postoperative intraventricular flow patterns and long-term cardiac performance. We visualized ventricular flow by echocardiography vector flow mapping (VFM) to reveal the impact of different mitral valve procedures. Eleven cases of mechanical mitral valve replacement (nine in the anti-anatomical and two in the anatomical position), three bioprosthetic mitral valve replacements, and four mitral valve repairs were evaluated. The mean age at the procedure was 57.4 ± 17.8 year, and the echocardiography VFM in the apical long-axis view was performed 119.9 ± 126.7 months later. Flow energy loss (EL), kinetic pressure (KP), and the flow energy efficiency ratio (EL/KP) were measured. The cases with MVR in the anatomical position and with valve repair had normal vortex directionality ("Clockwise"; N = 6), whereas those with MVR in the anti-anatomical position and with a bioprosthetic mitral valve had the vortex in the opposite direction ("Counterclockwise"; N = 12). During diastole, vortex direction had no effect on EL ("Clockwise": 0.080 ± 0.025 W/m; "Counterclockwise": 0.083 ± 0.048 W/m; P = 0.31) or KP ("Clockwise": 0.117 ± 0.021 N; "Counterclockwise": 0.099 ± 0.057 N; P = 0.023). However, during systole, the EL/KP ratio was significantly higher in the "Counterclockwise" vortex than that in the "Clockwise" vortex (1.056 ± 0.463 vs. 0.617 ± 0.158; P = 0.009). MVP and MVR with a mechanical valve in the anatomical position preserve the physiological vortex, whereas MVR with a mechanical valve in the anti-anatomical position and a bioprosthetic mitral valve generate inefficient vortex flow patterns, resulting in a potential increase in excessive cardiac workload.

Suture technique does not affect hemodynamic performance of the small supra-annular Trifecta bioprosthesis.

PubMed

Ugur, Murat; Byrne, John G; Bavaria, Joseph E; Cheung, Anson; Petracek, Michael; Groh, Mark A; Suri, Rakesh M; Borger, Michael A; Schaff, Hartzell V

2014-10-01

The study objective was to evaluate whether aortic valve replacement with the Trifecta valve (St Jude Medical Inc, St Paul, Minn) using simple sutures produces better hemodynamic performance than valve replacement with noneverting pledget-reinforced sutures. We analyzed prospectively acquired 1-year hemodynamic data of patients with small aortic annulus sizes who were enrolled in a multicenter trial of the Trifecta aortic valve bioprosthesis and underwent aortic valve replacement with a 19-mm or 21-mm bioprosthesis between August 2007 and November 2009. We compared preoperative clinical information and 1-year postoperative hemodynamic data for noneverting pledget-reinforced sutures (group 1) versus everting mattress sutures or simple sutures (group 2). A total of 346 patients underwent aortic valve replacement: 269 in group 1 and 77 in group 2. Preoperative demographic characteristics for the 2 groups were similar. For groups 1 and 2, the mean gradient was 10.4±4.7 mm Hg and 11.1±4.4 mm Hg for 19-mm valves, respectively, and 8.4±3.5 mm Hg and 8.8±3.6 mm Hg for 21-mm valves, respectively; the effective orifice area was 1.40 cm2 and 1.25 cm2 for 19-mm valves, respectively, and 1.57 cm2 and 1.50 cm2 for 21-mm valves, respectively. The rate of severe prosthesis-patient mismatch (indexed effective orifice area≤0.65 cm2/m2) was 18.6% (n=11) and 25% (n=6) for 19-mm valves, respectively, and 10.9% (n=20) and 16.3% (n=8) for 21-mm valves, respectively. The suture method did not affect hemodynamic performance of supra-annular bioprostheses in patients with small aortic annulus sizes. Choice of suture technique should be determined by surgeon experience and local anatomic features. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Long-Term Durability of Bioprosthetic Aortic Valves: Implications From 12,569 Implants

PubMed Central

Johnston, Douglas R.; Soltesz, Edward G.; Vakil, Nakul; Rajeswaran, Jeevanantham; Roselli, Eric E.; Sabik, Joseph F.; Smedira, Nicholas G.; Svensson, Lars G.; Lytle, Bruce W.; Blackstone, Eugene H.

2016-01-01

Background Increased life expectancy and younger patients’ desire to avoid lifelong anticoagulation requires a better understanding of bioprosthetic valve failure. This study evaluates risk factors associated with explantation for structural valve deterioration (SVD) in a long-term series of Carpentier-Edwards PERIMOUNT aortic valves (AV). Methods From June 1982 to January 2011, 12,569 patients underwent AV replacement with Edwards Lifesciences Carpentier-Edwards PERIMOUNT stented bovine pericardial prostheses, models 2700PM (n = 310) or 2700 (n = 12,259). Mean age was 71 ± 11 years (range, 18 to 98 years). 93% had native AV disease, 48% underwent concomitant coronary artery bypass grafting, and 26% had additional valve surgery. There were 81,706 patient-years of systematic follow-up data available for analysis. Demographics, intraoperative variables, and 27,386 echocardiographic records were used to identify risks for explant for SVD and assess longitudinal changes in transprosthesis gradients using time-varying covariable analyses. Results Three hundred fifty-four explants were performed, with 41% related to endocarditis and 44% to SVD. Actuarial estimates of explant for SVD at 10 and 20 years were 1.9% and 15% overall, respectively, and in patients younger than 60 years, 5.6% and 46%, respectively. Younger age (p < 0.0001), lipid-lowering drugs (p = 0.002), prosthesis–patient mismatch (p = 0.001), and higher postoperative peak and mean AV gradients were associated with explant for SVD (p < 0.0001). The effect of gradient on SVD was greatest in patients younger than 60 years. Conclusions Durability of the Carpentier-Edwards PERIMOUNT aortic valve is excellent even in younger patients. Explant for SVD is related to gradient at implantation, especially in younger patients. Strategies to reduce early postoperative AV gradients, such as root enlargement or more efficient prostheses, should be considered. PMID:25662439

Valve-sparing aortic root replacement in Loeys-Dietz syndrome.

PubMed

Patel, Nishant D; Arnaoutakis, George J; George, Timothy J; Allen, Jeremiah G; Alejo, Diane E; Dietz, Harry C; Cameron, Duke E; Vricella, Luca A

2011-08-01

Loeys-Dietz syndrome (LDS) is a recently recognized aggressive aortic disorder characterized by root aneurysm, arterial tortuosity, hypertelorism, and bifid uvula or cleft palate. The results of prophylactic root replacement using valve-sparing procedures (valve-sparing root replacement [VSRR]) in patients with LDS is not known. We reviewed all patients with clinical and genetic (transforming growth factor-β receptor mutations) evidence of LDS who underwent VSRR at our institution. Echocardiographic and clinical data were obtained from hospital and follow-up clinic records. From 2002 to 2009, 31 patients with a firm diagnosis of LDS underwent VSRR for aortic root aneurysm. Mean age was 15 years, and 24 (77%) were children. One (3%) patient had a bicuspid aortic valve. Preoperative sinus diameter was 3.9±0.8 cm (z score 7.0±2.9) and 2 (6%) had greater than 2+ aortic insufficiency. Thirty patients (97%) underwent reimplantation procedures using a Valsalva graft. There were no operative deaths. Mean follow-up was 3.6 years (range, 0 to 7 years). One patient required late repair of a pseudoaneurysm at the distal aortic anastomosis, and 1 had a conversion to a David reimplantation procedure after a Florida sleeve operation. No patient suffered thromboembolism or endocarditis, and 1 (3%) patient experienced greater than 2+ late aortic insufficiency. No patient required late aortic valve repair or replacement. Loeys-Dietz syndrome is an aggressive aortic aneurysm syndrome that can be addressed by prophylactic aortic root replacement with low operative risk. Valve-sparing procedures have encouraging early and midterm results, similar to those in Marfan syndrome, and are an attractive option for young patients. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Bench evaluation: three face-shield CPR barrier devices.

PubMed

Simmons, M; Deao, D; Moon, L; Peters, K; Cavanaugh, S

1995-06-01

Due to the fear of disease transmission, the practice of mouth-to-mouth (M-M) rescue breathing is rarely performed; to address this concern, many types of CPR barrier devices have been developed. These include bag-valve-mask devices, mouth-to-mask devices, and face shields (FS). The purpose of this study was to measure the volumes delivered during mouth-to-face shield (M-FS) breathing, to measure the back pressure and calculate the resistance to flow through their 1-way valves, and to test for backward leak of gas through the valves. Three FS brands were evaluated: Kiss of Life (KOL), MicroSHIELD (Micro) and Res-Cue Key (RCK). Volume delivered during M-M and M-FS breathing was evaluated by 10 rescuers who used the devices while performing rescue breathing on a CPR mannequin. Back pressure was measured and resistance calculated by directing airflow through the 1-way valves. Backward leak was evaluated by measuring the O2 concentration at the rescuer side of the valve while 100% O2 was directed toward the patient side of the valve. Differences among the brands were evaluated using analysis of variance. The mean (SD) values for volumes in L were: M-M 1.00 (0.25), Micro 0.77 (0.20), RCK 0.64 (0.10), and KOL 0.24 (0.11). Mean values for back pressure in cm H2O at 50 L/min were Micro 16.7 (1.29), KOL 7.22 (0.13), and RCK 2.15 (0.16). Significant backward leak only occurred with RCK. Not one of the FSs tested met all of the requirements suggested by the American Heart Association and by the International Standards Organization.

Impact of Annular Size on Outcomes After Surgical or Transcatheter Aortic Valve Replacement.

PubMed

Deeb, G Michael; Chetcuti, Stanley J; Yakubov, Steven J; Patel, Himanshu J; Grossman, P Michael; Kleiman, Neal S; Heiser, John; Merhi, William; Zorn, George L; Tadros, Peter N; Petrossian, George; Robinson, Newell; Mumtaz, Mubashir; Gleason, Thomas G; Huang, Jian; Conte, John V; Popma, Jeffrey J; Reardon, Michael J

2018-04-01

This analysis evaluates the relationship of annular size to hemodynamics and the incidence of prosthesis-patient mismatch (PPM) in surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) patients. The CoreValve US Pivotal High Risk Trial, described previously, compared TAVR using a self-expanding valve with SAVR. Multislice computed tomography was used to categorize TAVR and SAVR subjects according to annular perimeter-derived diameter: large (≥26 mm), medium (23 to <26 mm), and small (<23 mm). Hemodynamics, PPM, and clinical outcomes were assessed. At all postprocedure visits, mean gradients were significantly lower for TAVR compared with SAVR in small and medium size annuli (p < 0.001). Annular size was significantly associated with mean gradient after SAVR, with small annuli having the highest gradients (p < 0.05 at all timepoints); gradients were similar across all annular sizes after TAVR. In subjects receiving SAVR, the frequency of PPM was significantly associated with annular size, with small annuli having the greatest incidence. No difference in PPM incidence by annular sizing was observed with TAVR. In addition, TAVR subjects had significantly less PPM than SAVR subjects in small and medium annuli (p < 0.001), with no difference in the incidence of PPM between TAVR and SAVR in large annuli (p = 0.10). Annular size has a significant effect on hemodynamics and the incidence of PPM in SAVR subjects, not observed in TAVR subjects. With respect to annular size, TAVR results in better hemodynamics and less PPM for annuli less than 26 mm and should be strongly considered when choosing a tissue valve for small and medium size annuli. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

PREVAIL TRANSAPICAL: multicentre trial of transcatheter aortic valve implantation using the newly designed bioprosthesis (SAPIEN-XT) and delivery system (ASCENDRA-II).

PubMed

Walther, Thomas; Thielmann, Matthias; Kempfert, Joerg; Schroefel, Holger; Wimmer-Greinecker, Gerhard; Treede, Hendrik; Wahlers, Thorsten; Wendler, Olaf

2012-08-01

Transapical (TA) aortic valve implantation (AVI) has evolved as an alternative procedure for high-risk patients. We evaluated the second-generation SAPIEN XT™ prosthesis in a prospective multicentre clinical trial. A total of 150 patients (age: 81.6 ± 5.8 years; 40.7% female) were included. Prosthetic valves (diameter: 23 mm (n = 36), 26 mm (n = 57) and 29 mm (n = 57)) were implanted. The ASCENDRA-II™ modified delivery system was used in the smaller sizes. Mean logistic EuroSCORE was 24.3 ± 7.0%, and mean STS score 7.5 ± 4.4%. All patients gave written informed consent. Off-pump AVI was performed using femoral arterial and venous access wires as a safety net. All but two patients received TA-AVI, as planned. The 29-mm valve showed similar function as the values of two other diameters did. Three patients (2%) required temporary cardiopulmonary bypass support. Postoperative complications included renal failure requiring long-term dialysis in four, bleeding requiring rethoracotomy in four, respiratory complication requiring reintubation in eight and sepsis in four patients, respectively. Thirty-day mortality was 13 (8.7%) for the total cohort and 2/57 (3.5%) for patients receiving the 29-mm valve, respectively. Echocardiography at discharge showed none or trivial aortic incompetence (AI) in 71% and mild-AI in 22% of the patients. Post-implantation AI was predominantly paravalvular and ≥ 2+ in 7% of patients. One patient required reoperation for AI within 30 days. The PREVAIL TA multicentre trial demonstrates good functionality and good outcomes for TA-AVI, using the SAPIEN XT™ prosthesis and its second-generation ASCENDRA-II™ delivery system, as well successful introduction of the 29-mm SAPIEN XT™ valve for the benefit of high-risk elderly patients.

One-year multicentre outcomes of transapical aortic valve implantation using the SAPIEN XT™ valve: the PREVAIL transapical study.

PubMed

Walther, Thomas; Thielmann, Matthias; Kempfert, Joerg; Schroefel, Holger; Wimmer-Greinecker, Gerhard; Treede, Hendrik; Wahlers, Thorsten; Wendler, Olaf

2013-05-01

The study aimed to evaluate 1-year outcomes of the multicentre PREVAIL transapical (TA) study of TA-aortic valve implantation (AVI) in high-risk patients. From September 2009 to August 2010, a total of 150 patients, aged 81.6 ± 5.8 years, 40.7% female, were included at 12 European TA-AVI experienced sites. Patients received 23 (n = 36), 26 (n = 57) and 29 mm (n = 57) second-generation SAPIEN XT™ (Edwards Lifesciences, Irvine, CA, USA) valves. The mean logistic EuroSCORE was 24.3 ± 7.0, and mean Society Thoracic Surgeons score was 7.5 ± 4.4%. Survival was 91.3% at 30 days and 77.9% at 1 year. Subgroup analysis revealed survivals of 91.7/88.9, 86.0/70.2, 96.55/91.2% for patients receiving 23-, 26- and 29-mm valves at 30 days and at 1 year, respectively. Transthoracic echocardiography revealed preserved left ventricular ejection fraction and low gradients. Aortic incompetence was none in 41/48, trace 30/36, mild 22/12 and moderate in 7/4% at discharge and 1 year. Walking distance increased from 221 (postimplant) to 284 m (at 1 year, P = 0.0004). Three patients required reoperation due to increasing aortic incompetence during follow-up. Causes of mortality at 1 year were cardiac (n = 7), stroke (n = 1) and others (n = 5). The European PREVAIL multicentre trial demonstrates good functionality and good outcomes for TA-AVI using the second-generation SAPIEN XT prosthesis and the ASCENDRA-II delivery system. The 29-mm SAPIEN XT valve was successfully introduced and showed excellent results.

Relationship of aortic annular eccentricity and paravalvular regurgitation post transcatheter aortic valve implantation with CoreValve.

PubMed

Wong, Dennis T L; Bertaso, Angela G; Liew, Gary Y H; Thomson, Viji S; Cunnington, Michael S; Richardson, James D; Gooley, Robert; Lockwood, Siobhan; Meredith, Ian T; Worthley, Matthew I; Worthley, Stephen G

2013-04-01

Significant paravalvular aortic regurgitation (PAR) after transcatheter aortic valve implantation (TAVI) is associated with negative clinical consequences. We hypothesize that increased eccentricity of the aortic annulus is associated with greater PAR. Patients with severe aortic stenosis underwent multidetector computed tomography (MDCT) before successful TAVI with the Medtronic CoreValve bioprosthesis. The smallest (D(min)) and largest (D(max)) orthogonal diameters in the basal ring of the aortic annulus were determined. We defined circularity of aortic annulus using the eccentricity index (1 - D(min)/D(max)). The primary endpoint was early occurrence of significant PAR, defined as > grade II PAR by postprocedural aortography. Eighty-four patients, mean age 83 ± 4 years with a mean aortic valve area of 0.7 ± 0.2 cm² were included. Twenty patients had postprocedural PAR > grade II. Using a receiver operating characteristic (ROC) analysis, eccentricity index correlated with significant PAR (AUC = 0.834; P=.034). A retrospectively determined eccentricity index cut-off of >0.25 was related to significant PAR with a sensitivity of 80%, specificity of 86%, and negative predictive value of 95% (P<.001). On univariate logistic regression, eccentricity index of >0.25 (P<.001) and device implantation depth (P=.015) correlated with significant PAR, while other parameters such as annular calcification and cover index did not. On multivariate analysis including only parameters with P<.1 on univariate analysis, eccentricity index >0.25 was the sole independent predictor of significant PAR. Eccentricity index is related to significant PAR after TAVI with Medtronic CoreValve. Further larger studies are required to determine the utility of this novel index in screening suitable patients for this procedure.

Mid-term results of cardiac autotransplantation as method to treat permanent atrial fibrillation and mitral disease.

PubMed

Troise, Giovanni; Cirillo, Marco; Brunelli, Federico; Tasca, Giordano; Amaducci, Andrea; Mhagna, Zen; Tomba, Margherita Dalla; Quaini, Eugenio

2004-06-01

The results of current surgical options for the treatment of permanent atrial fibrillation (AF) associated with mitral surgery are widely different, particularly in very enlarged left atria. The aim of this study was to assess the mid-term efficacy of cardiac autotransplantation for this goal, through a consistent reduction of left atrium volume and a complete isolation of the pulmonary veins. From April 2000 to September 2002, 30 patients (male/female 5/25) underwent cardiac autotransplantation for the treatment of mitral valve disease and concomitant permanent AF (>1 year). Surgical technique of bicaval heart transplantation was modified maintaining the connection of inferior vena cava in all but three cases. Twenty-eight patients had mitral valve replacement and two had mitral valve repair. Associated procedures were: aortic valve replacement (6 cases), tricuspid valve repair (2 cases), coronary re-vascularization (2 cases) and right atrium volume reduction (4 cases). No hospital death occurred; 1 patient died 3 months post-operatively for pneumonia. At a mean follow-up of 21.1+/-7.7 months (range 6-35), 26 patients (89.7%) were in sinus rhythm and 3 (10.3%) in AF. Santa Cruz Score was 0 in 3 patients, 2 in 2 patients and 4 in the remaining 24 patients (82.7%). Mean left atrial diameter and volume decreased from 65.1+/-16.4 mm (range 50-130 mm) to 49.9+/-8.4 mm (range 37-78) (P < 0.001) and from 118.3+/-68.4 ml (range 60-426) to 69.4+/-34.1 ml (range 31-226) (P = 0.001), respectively, after the operation. Cardiac autotransplantation is a safe and effective option for the treatment of permanent AF in patients with mitral valve disease and severe dilation of left atrium.

Long-Term Follow-Up Study of Temporary Tricuspid Valve Detachment as Approach to VSD Repair without Consequent Tricuspid Dysfunction.

PubMed

Lucchese, Gianluca; Rossetti, Lucia; Faggian, Giuseppe; Luciani, Giovanni B

2016-10-01

Temporary tricuspid valve detachment improves the operative view of certain congenital ventricular septal defects (VSDs), but its long-term effects on tricuspid valve function are still debated. From 2002 through 2012, we performed a prospective study of 68 children (mean age, 1.28 ± 1.01 yr) who underwent transatrial closure of VSDs following temporary tricuspid valve detachment. Sixty patients had conoventricular and 8 had mid-muscular VSDs. All were in sinus rhythm. Seventeen patients had systemic pulmonary artery pressures. Preoperative echocardiograms showed trivial-to-mild tricuspid regurgitation in 62 patients and tricuspid dysplasia with severe regurgitation in 6 patients. Patients were clinically and echocardiographically monitored at 30 postoperative days, 3 months, 6 months, every 6 months thereafter for the first 2 years, and then once a year. No in-hospital or late death was observed at the median follow-up evaluation of 5.9 years. Mean intensive care unit and hospital stays were 1.6 ± 1.1 and 7.3 ± 2.7 days, respectively. Residual small VSDs occurred in 3 patients, and temporary atrioventricular block in one. After VSD repair, 62 patients (91%) had trivial or mild tricuspid regurgitation, and 6 moderate. Five of these last had severe tricuspid regurgitation preoperatively and had undergone additional tricuspid valve repair during the procedure. The grade of residual tricuspid regurgitation remained stable postoperatively, and no tricuspid stenosis was documented. All patients were in New York Heart Association class I at follow-up. Temporary tricuspid valve detachment is a simple and useful method for a complete visualization of certain VSDs without incurring substantial tricuspid dysfunction.

Long-Term Follow-Up Study of Temporary Tricuspid Valve Detachment as Approach to VSD Repair without Consequent Tricuspid Dysfunction

PubMed Central

Rossetti, Lucia; Faggian, Giuseppe; Luciani, Giovanni B.

2016-01-01

Temporary tricuspid valve detachment improves the operative view of certain congenital ventricular septal defects (VSDs), but its long-term effects on tricuspid valve function are still debated. From 2002 through 2012, we performed a prospective study of 68 children (mean age, 1.28 ± 1.01 yr) who underwent transatrial closure of VSDs following temporary tricuspid valve detachment. Sixty patients had conoventricular and 8 had mid-muscular VSDs. All were in sinus rhythm. Seventeen patients had systemic pulmonary artery pressures. Preoperative echocardiograms showed trivial-to-mild tricuspid regurgitation in 62 patients and tricuspid dysplasia with severe regurgitation in 6 patients. Patients were clinically and echocardiographically monitored at 30 postoperative days, 3 months, 6 months, every 6 months thereafter for the first 2 years, and then once a year. No in-hospital or late death was observed at the median follow-up evaluation of 5.9 years. Mean intensive care unit and hospital stays were 1.6 ± 1.1 and 7.3 ± 2.7 days, respectively. Residual small VSDs occurred in 3 patients, and temporary atrioventricular block in one. After VSD repair, 62 patients (91%) had trivial or mild tricuspid regurgitation, and 6 moderate. Five of these last had severe tricuspid regurgitation preoperatively and had undergone additional tricuspid valve repair during the procedure. The grade of residual tricuspid regurgitation remained stable postoperatively, and no tricuspid stenosis was documented. All patients were in New York Heart Association class I at follow-up. Temporary tricuspid valve detachment is a simple and useful method for a complete visualization of certain VSDs without incurring substantial tricuspid dysfunction. PMID:27777518

Healthcare-Associated Infective Endocarditis: a Case Series in a Referral Hospital from 2006 to 2011

PubMed Central

Francischetto, Oslan; da Silva, Luciana Almenara Pereira; Senna, Katia Marie Simões e; Vasques, Marcia Regina; Barbosa, Giovanna Ferraiuoli; Weksler, Clara; Ramos, Rosana Grandelle; Golebiovski, Wilma Felix; Lamas, Cristiane da Cruz

2014-01-01

Background Healthcare-associated infective endocarditis (HCA-IE), a severe complication of medical care, shows a growing incidence in literature. Objective To evaluate epidemiology, etiology, risk factors for acquisition, complications, surgical treatment, and outcome of HCA-IE. Methods Observational prospective case series study (2006-2011) in a public hospital in Rio de Janeiro. Results Fifty-three patients with HCA-IE from a total of 151 cases of infective endocarditis (IE) were included. There were 26 (49%) males (mean age of 47 ± 18.7 years), 27 (51%) females (mean age of 42 ± 20.1 years). IE was acute in 37 (70%) cases and subacute in 16 (30%) cases. The mitral valve was affected in 19 (36%) patients and the aortic valve in 12 (36%); prosthetic valves were affected in 23 (43%) patients and native valves in 30 (57%). Deep intravenous access was used in 43 (81%) cases. Negative blood cultures were observed in 11 (21%) patients, Enterococcus faecalis in 10 (19%), Staphylococcus aureus in 9 (17%), and Candida sp. in 7 (13%). Fever was present in 49 (92%) patients, splenomegaly in 12 (23%), new regurgitation murmur in 31 (58%), and elevated C-reactive protein in 44/53 (83%). Echocardiograms showed major criteria in 46 (87%) patients, and 34 (64%) patients were submitted to cardiac surgery. Overall mortality was 17/53 (32%). Conclusion In Brazil HCA-IE affected young subjects. Patients with prosthetic and native valves were affected in a similar proportion, and non-cardiac surgery was an infrequent predisposing factor, whereas intravenous access was a common one. S. aureus was significantly frequent in native valve HCA-IE, and overall mortality was high. PMID:25352503

Mitral valve repair for post-myocardial infarction papillary muscle rupture

PubMed Central

Bouma, Wobbe; Wijdh-den Hamer, Inez J.; Klinkenberg, Theo J.; Kuijpers, Michiel; Bijleveld, Aanke; van der Horst, Iwan C.C.; Erasmus, Michiel E.; Gorman, Joseph H.; Gorman, Robert C.; Mariani, Massimo A.

2013-01-01

OBJECTIVES Papillary muscle rupture (PMR) is a rare, but serious mechanical complication of myocardial infarction (MI). Although mitral valve replacement is usually the preferred treatment for this condition, mitral valve repair may offer an improved outcome. In this study, we sought to determine the outcome of mitral valve repair for post-MI PMR and to provide a systematic review of the literature on this topic. METHODS Between January 1990 and December 2010, 9 consecutive patients (mean age 63.5 ± 14.2 years) underwent mitral valve repair for partial post-MI PMR. Clinical data, echocardiographic data, catheterization data and surgical reports were reviewed. Follow-up was obtained in December of 2012 and it was complete; the mean follow-up was 8.7 ± 6.1 (range 0.2–18.8 years). RESULTS Intraoperative and in-hospital mortality were 0%. Intraoperative repair failure rate was 11.1% (n = 1). Freedom from Grade 3+ or 4+ mitral regurgitation and from reoperation at 1, 5, 10 and 15 years was 87.5 ± 11.7%. Estimated 1-, 5-, 10- and 15-year survival rates were 100, 83.3 ± 15.2, 66.7 ± 19.2 and 44.4 ± 22.2%, respectively. There were 3 late deaths, and 2 were cardiac-related. All late survivors were in New York Heart Association Class I or II. No predictors of long-term survival could be identified. CONCLUSIONS Mitral valve repair for partial or incomplete post-MI PMR is reliable and provides good short- and long-term results, provided established repair techniques are used and adjacent tissue is not friable. PMR type and adjacent tissue quality ultimately determine the feasibility and durability of repair. PMID:23520228

Cost of Chronic Obstructive Pulmonary Disease in the Emergency Department and Hospital: An Analysis of Administrative Data from 218 US Hospitals.

PubMed

Stanford, Richard H; Shen, Yingjia; McLaughlin, Trent

2006-01-01

Treatment of chronic obstructive pulmonary disease (COPD) in the emergency department (ED) or hospital accounts for a significant portion of COPD costs. This study estimates the cost of a COPD ED or hospitalization visit in the US. This observational study utilized administrative data from 218 acute care hospitals. ED/hospital discharges for COPD (International Classification of Diseases - Ninth Revision - Clinical Modification codes 491.xx. 492.xx, 496.xx) during 2001 were identified. Costs were determined for three groups: (i) ED only; (ii) standard admission; and (iii) severe admissions (intensive care unit [ICU] or intubation). Severe admissions were stratified into: (i) ICU/no intubation; (ii) intubation/no ICU; and (iii) ICU + intubation. Mean total costs and length of stay (LOS) were calculated for each group. A total of 59 735 ED/hospital encounters were identified: 20 431 ED only, 33 210 standard admissions, and 6094 severe admissions (4456 ICU/no intubation, 496 intubation/no ICU, and 1142 ICU/intubation). ED visits had a mean cost of $US571 +/- 507 (year 2001 value). Inpatient costs ranged from $US5997 (+/- 5752) for a standard admission to $US36 743 (+/- 62 886) for ICU plus intubation admissions, while LOS ranged from 5.1 days (+/- 4.5) to 14.8 days (+/- 16.7), respectively. In addition, only 10% of encounters required an intubation/ICU admission, but these accounted for 34% of the cost. Cost of a COPD hospitalization is substantial in the US, with one-third of those costs being associated with severe admissions, which make up only 10% of all COPD admissions. Treatments aimed at reducing hospitalizations and length of stay could result in substantial cost savings.

Do racial and ethnic group differences in performance on the MCAT exam reflect test bias?

PubMed

Davis, Dwight; Dorsey, J Kevin; Franks, Ronald D; Sackett, Paul R; Searcy, Cynthia A; Zhao, Xiaohui

2013-05-01

The Medical College Admission Test (MCAT) is a standardized examination that assesses fundamental knowledge of scientific concepts, critical reasoning ability, and written communication skills. Medical school admission officers use MCAT scores, along with other measures of academic preparation and personal attributes, to select the applicants they consider the most likely to succeed in medical school. In 2008-2011, the committee charged with conducting a comprehensive review of the MCAT exam examined four issues: (1) whether racial and ethnic groups differ in mean MCAT scores, (2) whether any score differences are due to test bias, (3) how group differences may be explained, and (4) whether the MCAT exam is a barrier to medical school admission for black or Latino applicants. This analysis showed that black and Latino examinees' mean MCAT scores are lower than white examinees', mirroring differences on other standardized admission tests and in the average undergraduate grades of medical school applicants. However, there was no evidence that the MCAT exam is biased against black and Latino applicants as determined by their subsequent performance on selected medical school performance indicators. Among other factors which could contribute to mean differences in MCAT performance, whites, blacks, and Latinos interested in medicine differ with respect to parents' education and income. Admission data indicate that admission committees accept majority and minority applicants at similar rates, which suggests that medical students are selected on the basis of a combination of attributes and competencies rather than on MCAT scores alone.

A new risk prediction model for critical care: the Intensive Care National Audit & Research Centre (ICNARC) model.

PubMed

Harrison, David A; Parry, Gareth J; Carpenter, James R; Short, Alasdair; Rowan, Kathy

2007-04-01

To develop a new model to improve risk prediction for admissions to adult critical care units in the UK. Prospective cohort study. The setting was 163 adult, general critical care units in England, Wales, and Northern Ireland, December 1995 to August 2003. Patients were 216,626 critical care admissions. None. The performance of different approaches to modeling physiologic measurements was evaluated, and the best methods were selected to produce a new physiology score. This physiology score was combined with other information relating to the critical care admission-age, diagnostic category, source of admission, and cardiopulmonary resuscitation before admission-to develop a risk prediction model. Modeling interactions between diagnostic category and physiology score enabled the inclusion of groups of admissions that are frequently excluded from risk prediction models. The new model showed good discrimination (mean c index 0.870) and fit (mean Shapiro's R 0.665, mean Brier's score 0.132) in 200 repeated validation samples and performed well when compared with recalibrated versions of existing published risk prediction models in the cohort of patients eligible for all models. The hypothesis of perfect fit was rejected for all models, including the Intensive Care National Audit & Research Centre (ICNARC) model, as is to be expected in such a large cohort. The ICNARC model demonstrated better discrimination and overall fit than existing risk prediction models, even following recalibration of these models. We recommend it be used to replace previously published models for risk adjustment in the UK.

Sliding-gate valve

DOEpatents

Usnick, George B.; Ward, Gene T.; Blair, Henry O.; Roberts, James W.; Warner, Terry N.

1979-01-01

This invention is a novel valve of the slidable-gate type. The valve is designed especially for long-term use with highly abrasive slurries. The sealing surfaces of the gate are shielded by the valve seats when the valve is fully open or closed, and the gate-to-seat clearance is swept with an inflowing purge gas while the gate is in transit. A preferred form of the valve includes an annular valve body containing an annular seat assembly defining a flow channel. The seat assembly comprises a first seat ring which is slidably and sealably mounted in the body, and a second seat ring which is tightly fitted in the body. These rings cooperatively define an annular gap which, together with passages in the valve body, forms a guideway extending normal to the channel. A plate-type gate is mounted for reciprocation in the guideway between positions where a portion of the plate closes the channel and where a circular aperture in the gate is in register with the channel. The valve casing includes opposed chambers which extend outwardly from the body along the axis of the guideway to accommodate the end portions of the gate. The chambers are sealed from atmosphere; when the gate is in transit, purge gas is admitted to the chambers and flows inwardly through the gate-to-seat-ring, clearance, minimizing buildup of process solids therein. A shaft reciprocated by an external actuator extends into one of the sealed chambers through a shaft seal and is coupled to an end of the gate. Means are provided for adjusting the clearance between the first seat ring and the gate while the valve is in service.

Incidence of cerebrovascular accidents in patients undergoing minimally invasive valve surgery.

PubMed

LaPietra, Angelo; Santana, Orlando; Mihos, Christos G; DeBeer, Steven; Rosen, Gerald P; Lamas, Gervasio A; Lamelas, Joseph

2014-07-01

Minimally invasive valve surgery has been associated with increased cerebrovascular complications. Our objective was to evaluate the incidence of cerebrovascular accidents in patients undergoing minimally invasive valve surgery. We retrospectively reviewed all the minimally invasive valve surgery performed at our institution from January 2009 to June 2012. The operative times, lengths of stay, postoperative complications, and mortality were analyzed. A total of 1501 consecutive patients were identified. The mean age was 73 ± 13 years, and 808 patients (54%) were male. Of the 1501 patients, 206 (13.7%) had a history of a cerebrovascular accident, and 225 (15%) had undergone previous heart surgery. The procedures performed were 617 isolated aortic valve replacements (41.1%), 658 isolated mitral valve operations (43.8%), 6 tricuspid valve repairs (0.4%), 216 double valve surgery (14.4%), and 4 triple valve surgery (0.3%). Femoral cannulation was used in 1359 patients (90.5%) and central cannulation in 142 (9.5%). In 1392 patients (92.7%), the aorta was clamped, and in 109 (7.3%), the surgery was performed with the heart fibrillating. The median aortic crossclamp and cardiopulmonary bypass times were 86 minutes (interquartile range [IQR], 70-107) minutes and 116 minutes (IQR, 96-143), respectively. The median intensive care unit length of stay was 47 hours (IQR, 29-74), and the median postoperative hospital length of stay was 7 days (IQR, 5-10). A total of 23 cerebrovascular accidents (1.53%) and 38 deaths (2.53%) had occurred at 30 days postoperatively. Minimally invasive valve surgery was associated with an acceptable stroke rate, regardless of the cannulation technique. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Aortic cusp extension for surgical correction of rheumatic aortic valve insufficiency in children.

PubMed

Kalangos, Afksendiyos; Myers, Patrick O

2013-10-01

Surgical management of aortic insufficiency in the young is problematic because of the lack of an ideal valve substitute. Potential advantages of aortic valve repair include low incidences of thromboembolism and endocarditis, avoiding conduit replacements, the maintenance of growth potential, and improved quality of life. Aortic valve repair is still far from fulfilling the three key factors that have allowed the phenomenal development of mitral valve repair (standardization, reproducibility, and stable long-term results); however, techniques of aortic valve repair have been refined, and subsets of patients amenable to repair have been identified. We have focused on the oldest technique of aortic valve repair, cusp extension, focusing on children with rheumatic aortic insufficiency. Among 77 children operated from 2003 to 2007, there was one early death from ventricular failure and one late death from sudden cardiac arrhythmia. During a mean follow-up of 12.8 ± 5.9 years, there were 16 (20.5%) reoperations on the aortic valve, at a median of 3.4 years (range, 2 months to 18.3 years) from repair. Freedom from aortic valve reoperation was 96.2% ± 2.2% at 1 year, 94.9% ± 2.5% at 2 years, 88.5% ± 3.6% at 5 years, 81.7% ± 4.4% at 10 years, 79.7% ± 4.8% at 15 years, and 76.2% ± 5.7% at 20 years. Although aortic cusp extension is technically more demanding, it remains particularly more suitable in the context of evolving rheumatic aortic insufficiency in children with a small aortic annulus as a bridge surgical approach to late aortic valve replacement with a larger valvular prosthesis.

Dysfunction of mechanical heart valve prosthesis: experience with surgical management in 48 patients

PubMed Central

Ma, Wei-Guo; Hou, Bin; Abdurusul, Adiljan; Gong, Ding-Xu; Tang, Yue; Chang, Qian; Xu, Jian-Ping

2015-01-01

Background Dysfunction of mechanical heart valve prostheses is an unusual but potentially lethal complication after mechanical prosthetic valve replacement. We seek to report our experience with mechanical valve dysfunction regarding etiology, surgical techniques and early outcomes. Methods Clinical data of 48 patients with mechanical valve dysfunction surgically treated between October 1996 and June 2011 were analyzed. Results Mean age was 43.7±10.9 years and 34 were female (70.8%). The median interval from primary valve implantation to dysfunction was 44.5 months (range, 1 hour to 20 years). There were 21 emergent and 27 elective reoperations. The etiology was thrombosis in 19 cases (39.6%), pannus in 12 (25%), thrombosis and pannus in 11 (22.9%), improper disc orientation in 2 (4.1%), missing leaflet in 1 (2.1%), excessively long knot end in 1 (2.1%), endogenous factor in 1 (2.1%) and unidentified in 1 (2.1%). Surgical procedure was mechanical valve replacement in 37 cases (77.1%), bioprosthetic valve replacement in 7 (14.9%), disc rotation in 2 (4.2%) and excision of excessive knot end in 1 (2.1%). Early deaths occurred in 7 patients (14.6%), due to low cardiac output in 3 (6.3%), multi-organ failure in 2 (4.2%) and refractory ventricular fibrillation in 2 (4.2%). Complications occurred in 10 patients (20.8%). Conclusions Surgical management of mechanical valve dysfunction is associated with significant mortality and morbidity. Earlier identification and prompt reoperation are vital to achieving better clinical outcomes. The high incidence of thrombosis in this series highlights the need for adequate anticoagulation and regular follow-up after mechanical valve replacement. PMID:26793354

[Initial experience of transcatheter implantation with a new aortic valve in sheep].

PubMed

Wang, Jian-ming; Yang, Jian; Yang, Li-fang; Zhang, Xue-xin; Hu, Yun; Liu, Jin-cheng; Yu, Shi-qiang; Yi, Ding-hua

2011-11-01

To evaluate the feasibility and short-term results of transcatheter aortic valve implantation (TAVI) using a new transcatheter valve. Twenty healthy adult sheep received general anesthesia. Under the guidance of X-ray and transthoracic echocardiography (TTE), the new anti-calcification transcatheter valve was released from delivery system and implanted at the level of native aortic annulus via left common carotid artery. Position and function of the new anti-calcification transcatheter valve were evaluated by angiography and TTE immediately after intervention. Thirty day survival rate of animals was obtained. New transcatheter valves were implanted in all sheep. Fifteen sheep (75%) survived up to 30 days and post-operative examination showed that the transcatheter valve was in optimal position without migration and mitral valve impingement. The native coronary artery was patent in these animals. There was a slight paravalvular leak in 5 sheep. Postoperative echocardiography showed reflux percentage was significantly increased (P < 0.05) compared pre-intervention. Effective orifice area, aortic systolic pressure, diastolic aortic pressure, mean aortic pressure, left ventricular systolic pressure, left ventricular end diastolic pressure and heart rate were similar between post and pre-intervention (all P < 0.05). Five sheep died after TAVI within 30 days, including one fatal ventricular fibrillation occurred immediately after releasing the transcatheter valve and another sheep died of acute myocardial infarction due to left main coronary artery occlusion evidenced by angiography. Two sheep died of severe mitral regurgitation at 8 and 12 hours post-operation and one died of infective endocarditis at 26 days after intervention. Our favorable preliminary results showed that it was feasible to perform TAVI using the new transcatheter valve.

Thrombocytopenia following implantation of the stentless biological sorin freedom SOLO valve.

PubMed

Gersak, Borut; Gartner, Urska; Antonic, Miha

2011-07-01

Stentless biological valves have proven advantages in hemodynamic performance and left ventricular function compared to stented biological valves. Following a marked postoperative fall in the platelet count of patients after implantation of the Freedom SOLO valve, the study aim was to confirm clinical observations that this effect was more severe in patients receiving Freedom SOLO valves than in those receiving St. Jude Medical (SJM) mechanical aortic valves. Preoperative and postoperative platelet counts were compared in two groups of patients who underwent aortic valve replacement (AVR) without any concomitant procedures between January and December 2007. Patients received either a Freedom SOLO valve (n = 28) or a SJM mechanical valve (n = 41). Mean values of platelet counts were compared using three multiple linear regression models. Platelet counts were significantly lower in the Freedom SOLO group than in the SJM group from the first postoperative day (POD 1) up to POD 6 (p <0.001). In three patients of the Freedom SOLO group the platelet count fell below 30x10(9)/l, while the lowest level in the SJM group was 75x10(9)/l. Based on multiple linear regression models, the type of valve implanted had a statistically significant influence on postoperative platelet counts on POD 1, POD 3, and POD 5 (p <0.001). Whilst the reason for this phenomenon is unknown, the use of consistent monitoring should prevent severe falls in platelet count from becoming dangerous for the patient. Further studies are required to investigate the phenomenon since, despite a shorter cardiopulmonary bypass time, the fall in platelet count was more profound in the Freedom SOLO group.

Incidence rates of admissions associated with alcohol withdrawal syndrome in Spain: Analysis of minimum basic data set 1999-2010.

PubMed

Gómez-Méndez, Raquel; Monte-Secades, Rafael; Ventura-Valcárcel, Pablo; Rabuñal-Rey, Ramón; Guerrero-Sande, Héctor; Chamorro-Fernández, Antonio J; Pértega-Díaz, Sonia

2017-12-20

There are no data on the incidence of admissions associated with alcohol withdrawal syndrome (AWS) or about its trend over time in Spain. To analyze the characteristics, incidence rates and trends over time of hospital admissions associated with AWS in Spanish public hospitals. Analysis from the Spanish public hospitals minimum basic data set of hospital admissions with AWS (CIE9-MC 291.81), alcohol withdrawal delirium (CIE9-MC 291.0) and alcohol withdrawal hallucinosis (CIE9-MC 291.3), since 1999 to 2010. We identified 56,395 admissions associated with AWS. Mean age was 50.9 (SD 12.5) and 88% were male. The most frequent admission department was Internal Medicine (24.9%). The mean hospital stay was 12.6 days (SD 14.4) and mortality was 4.7%; 62.6% of cases developed AWS during an admission for another reason, mostly due to alcohol-related pathologies. Secondary diagnoses in patients hospitalized for AWS were related to alcohol consumption in more than half of the cases. The incidence rate of admissions associated with AWS in Spain remained stable from 1999 to 2010, with a small decline in the last 3 years of the period. The communities with the highest incidence were the Canary Islands, the Balearic Islands and Galicia. The incidence rate of admissions associated with AWS in Spanish public hospitals in the period 1999-2010 has remained stable with slight changes. There are differences in the incidence of AWS among the different autonomous communities. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Pediatric retropharyngeal abscesses: a national perspective.

PubMed

Lander, Lina; Lu, Sam; Shah, Rahul K

2008-12-01

To determine the resource utilization and national variation in the management of pediatric retropharyngeal abscesses. The Kids' Inpatient Database (KID) 2003 was analyzed. International Classification of Diseases, Ninth Revision code 478.24 was the inclusion criteria. One thousand three hundred and twenty-one admissions with retropharyngeal abscess were sampled from the KID in 2003; there were no deaths. The mean age of patients was 5.1 years (S.D. 4.4 years); 63% were male. Of all admissions, 563 (43%) patients underwent surgical drainage of their infection; surgical patients had longer length of stays and total charges than patients managed medically. The average state spending per admission varied from $5126 (Utah) to $27,776 (California). There was seasonal variation in admissions with the highest percentage of admissions occurring in March (10.7%) and lowest in August (3.8%). Indicators of increased resource utilization included age (older patients), increased length of stay, non-elective admission, discharge quarter, and number of other diagnoses on record. There is a statistically significant decrease in the length of stay and total charges in patients admitted in the Midwest compared to other regions of the country. This study demonstrates national demographics and normative data on a commonly treated pediatric disease process, retropharyngeal space infections. The average demographic of such a patient is a 5-year-old male from an urban location admitted in a non-elective fashion via the emergency department. The mean total charges were $16,377; 90% of admissions had total charges less than $28,511. Patients who underwent surgical procedures had mean total charges of $22,013. There exists significant national variation in resource utilization for this commonly treated disease process.

Transcatheter aortic valve implantation in patients with bicuspid aortic valve stenosis.

PubMed

Wijesinghe, Namal; Ye, Jian; Rodés-Cabau, Josep; Cheung, Anson; Velianou, James L; Natarajan, Madhu K; Dumont, Eric; Nietlispach, Fabian; Gurvitch, Ronen; Wood, David A; Tay, Edgar; Webb, John G

2010-11-01

We evaluated transcatheter aortic valve implantation (TAVI) in high-risk patients with bicuspid aortic valve (BAV) stenosis. TAVI shows promise in the treatment of severe stenosis of triscupid aortic valves, especially in high-risk patients. However, BAV stenosis has been considered a contraindication to TAVI. Eleven patients (age 52 to 90 years) with symptomatic severe BAV stenosis underwent TAVI at 3 Canadian tertiary hospitals between May 2006 and April 2010. All patients were considered high risk for surgical aortic valve replacement. Edwards-SAPIEN transcatheter heart valves (Edwards Lifesciences, Inc., Irvine, California) were used. Transfemoral or transapical access was selected, depending on the adequacy of femoral access. Access was transfemoral in 7 patients and transapical in 4 patients. There were no intraprocedural complications. Significant symptomatic and hemodynamic improvement was observed in 10 of 11 patients. Baseline aortic valve area of 0.65 ± 0.17 cm(2) and mean transaortic pressure gradient of 41 ± 22.4 mm Hg were improved to 1.45 ± 0.3 cm(2) and 13.4 ± 5.7 mm Hg, respectively. Two patients had moderate perivalvular leaks. At the 30-day follow-up there were 2 deaths due to multisystem failure in 2 transapical patients. In 1 patient an undersized, suboptimally positioned, unstable valve required late conversion to open surgery. TAVI in selected high-risk patients with severe BAV stenosis can be successfully performed with acceptable clinical outcomes but will require further evaluation. Copyright © 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

The safety of tracheostomy speaking valve use during sleep in children: a pilot study.

PubMed

Barraza, Giselle Y; Fernandez, Claudia; Halaby, Claudia; Ambrosio, Sara; Simpser, Edwin F; Pirzada, Melodi B

2014-01-01

One of the disadvantages of having a tracheostomy tube is not being able to vocalize. A speaking valve connected to a tracheostomy tube allows patients to vocalize. Some studies have shown that tracheostomy-speaking valve can improve swallowing, respiratory secretion management, and expedite decannulation. There is scant research about speaking valve use during sleep. The aim of this study is to evaluate the safety of tracheostomy-speaking valve overnight, during sleep. Children, ages 1-18 years, with tracheostomy tubes who were using a tracheostomy-speaking valve during daytime/awake periods, were included in this study. The subjects had baseline monitoring of their heart rate, respiratory rate, oxygen saturation, and end tidal carbon dioxide measurement the night prior to the intervention, throughout the night at scheduled intervals. The tracheostomy-speaking valve was placed the following night and the same parameters were monitored and recorded throughout the study night. A total of 9 patients were recruited. In all subjects, the mean values of the overnight parameters showed no significant clinical variations between the baseline night and the study night. Repeated measure ANOVA analysis revealed no significant changes in the parameters over the 8 hours of recorded time. No major adverse events were recorded during the study night. This pilot study reveals that use of a tracheostomy-speaking valve during sleep, was not associated with adverse cardiopulmonary events. This is the first study to show that a tracheostomy-speaking valve might be safely used during sleep, in children. Copyright © 2014 Elsevier Inc. All rights reserved.

Anatomic characteristics of bileaflet mitral valve prolapse--Barlow disease--in patients undergoing mitral valve repair.

PubMed

Rostagno, Carlo; Droandi, Ginevra; Rossi, Alessandra; Bevilacqua, Sergio; Romagnoli, Stefano; Montesi, Gian Franco; Stefàno, Pier Luigi

2014-01-01

Barlow disease is a still challenging pathology for the surgeon. Aim of the present study is to report anatomic abnormalities of mitral valve in patients undergoing mitral valve repair. Between January 1st, 2007, and December 31st, 2010, 85 consecutive patients (54 men and 31 women, mean age 59 +/- 14 years--range: 28-85 years) with the features of a Barlow mitral valve disease underwent mitral repair Forty seven percent of patients were in New York Heart Association functional class III or IV. Preoperative transesophageal echocardiography was compared with anatomical findings at the moment of surgery. Transthoracic echocardiography diagnosis of Barlow disease according to the criteria described by Carpentier was confirmed at anatomical inspection. Annular calcifications were found in 28 patients while 7 patients presented single or multiple clefts. A flail posterior mitral leaflet was detected in 32 subjects, while a flail anterior leaflet in 8. Elongation of chordae tendineae was demonstrated in 45 patients and chordal rupture in 31. All patients showed at trans esophageal echocardiography the typical features of Barlow disease. Seventy-seven (90.6%) patients had severe mitral valve regurgitation, in the remaining 9.4% it was moderate to severe. Transesophageal echocardiography failed to identify clefts in 2/7 and chordal rupture in 4/31. bileaflet prolapse > 2 mm, billowing valve with excess tissue and thickened leaflets > or = 3 mm, and severe annular dilatation, are characteristics of Barlow disease, however the identification of the associated and complex abnormalities of mitral valve is necessary to obtain optimal valve repair.

Manual, semiautomated, and fully automated measurement of the aortic annulus for planning of transcatheter aortic valve replacement (TAVR/TAVI): analysis of interchangeability.

PubMed

Lou, Junyang; Obuchowski, Nancy A; Krishnaswamy, Amar; Popovic, Zoran; Flamm, Scott D; Kapadia, Samir R; Svensson, Lars G; Bolen, Michael A; Desai, Milind Y; Halliburton, Sandra S; Tuzcu, E Murat; Schoenhagen, Paul

2015-01-01

Preprocedural 3-dimensional CT imaging of the aortic annular plane plays a critical role for transcatheter aortic valve replacement (TAVR) planning; however, manual reconstructions are complex. Automated analysis software may improve reproducibility and agreement between readers but is incompletely validated. In 110 TAVR patients (mean age, 81 years; 37% female) undergoing preprocedural multidetector CT, automated reconstruction of the aortic annular plane and planimetry of the annulus was performed with a prototype of now commercially available software (syngo.CT Cardiac Function-Valve Pilot; Siemens Healthcare, Erlangen, Germany). Fully automated, semiautomated, and manual annulus measurements were compared. Intrareader and inter-reader agreement, intermodality agreement, and interchangeability were analyzed. Finally, the impact of these measurements on recommended valve size was evaluated. Semiautomated analysis required major correction in 5 patients (4.5%). In the remaining 95.5%, only minor correction was performed. Mean manual annulus area was significantly smaller than fully automated results (P < .001 for both readers) but similar to semiautomated measurements (5.0 vs 5.4 vs 4.9 cm(2), respectively). The frequency of concordant recommendations for valve size increased if manual analysis was replaced with the semiautomated method (60% agreement was improved to 82.4%; 95% confidence interval for the difference [69.1%-83.4%]). Semiautomated aortic annulus analysis, with minor correction by the user, provides reliable results in the context of TAVR annulus evaluation. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Clinical efficacy of transcatheter aortic valve replacement for severe aortic stenosis in high-risk patients: the PREVAIL JAPAN trial.

PubMed

Sawa, Yoshiki; Takayama, Morimasa; Mitsudo, Kazuaki; Nanto, Shinsuke; Takanashi, Shuichiro; Komiya, Tatsuhiko; Kuratani, Toru; Tobaru, Tetsuya; Goto, Tsuyoshi

2015-01-01

Transcatheter aortic valve replacement (TAVR) is suggested to be less invasive and/or equally effective in comparison to conventional aortic valve replacement for high-risk symptomatic aortic stenosis patients. We herein report the initial results of a pivotal clinical trial of TAVR in Japan (the PREVAIL JAPAN). Sixty-four aortic stenosis patients (mean age 84.3 ± 6.1 years) not suitable for surgery were enrolled at three centers in Japan, with a primary composite endpoint of the 6-month post-procedure improvements in the aortic valve area and New York Heart Association (NYHA) functional classification. A transfemoral approach was used in 37 patients and a transapical approach was used in 27. The device success rate was 91.9 %. After 30 days and 6 months, the rates of mortality from any cause were 8.1 and 11.3 %, respectively. At 6 months, symptomatic stroke was found in 3.1 % of the patients, and silent infarction in 7.8 %. The aortic valve area and mean pressure gradient were significantly improved over time with both approaches (p < 0.001). At 6 months, the NYHA functional classification based on a conventional physician's assessment was improved in 87.9 % of the patients. We found results that were equivalent to those in other major TAVR trials, such as an acceptable 30-day survival (91.9 %), suggesting that balloon-expandable TAVR is effective for small Japanese AS patients classified as high-risk or inoperable.

Tricuspid insufficiency after laser lead extraction.

PubMed

Rodriguez, Yasser; Mesa, Julian; Arguelles, Eric; Carrillo, Roger G

2013-08-01

The use of laser lead extraction (LLE) to remove pacemaker and implantable cardiac defibrillator leads has become more prevalent in the past decade. Though the procedure is associated with a low rate of complications, LLE still poses some risks to patients. Some reports have suggested an increase in tricuspid insufficiency (TI) associated with LLE. We present a series of patients who underwent both LLE and complete evaluation for TI with echocardiographic techniques. From August 2008 to January 2010, 173 prospective, consecutive patients underwent LLE in a single center. All patients had transesophageal echocardiograms (TEE) during the extraction. Fifty-three patients had tricuspid valve function evaluated a day before the procedure with a transthoracic echocardiogram (TTE), during the procedure with a TEE and 2 days postoperatively with a TTE. All 173 patients experienced no change in tricuspid valve function during the procedure with TEE. Of the 53 patients who underwent a complete TI evaluation, 38 were males (72%) and 15 females (38%), with a mean age of 69.45 ± 14.08. Mean ejection fraction was 35.82 ± 14.72. Three (6%) patients experienced TI after the procedure (two mild and one severe, all with tricuspid valve endocarditis); 16 (30%) patients were found to have TI before LLE that returned to normal valve function during or after the procedure. Thirty-four (64%) patients did not experience any significant change of the tricuspid valve performance after LLE. LLE was not associated with increased TI. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

Sutureless versus Conventional Aortic Valve Replacement: Outcomes in 70 High-Risk Patients Undergoing Concomitant Cardiac Procedures.

PubMed

Hanedan, Muhammet Onur; Yuruk, Mehmet Ali; Parlar, Ali Ihsan; Ziyrek, Ugur; Arslan, Ali Kemal; Sayar, Ufuk; Mataraci, Ilker

2018-02-01

In elderly, high-risk surgical patients, sutureless aortic valve replacement (AVR) can often be an alternative to conventional AVR; shorter aortic cross-clamp and cardiopulmonary bypass times are the chief advantages. We compared the outcomes of sutureless AVR with those of conventional AVR in 70 elderly patients who underwent concomitant cardiac surgical procedures. We retrospectively analyzed the cases of 42 men and 28 women (mean age, 70.4 ± 10.3 yr; range, 34-93 yr) who underwent cardiac operations plus AVR with either a sutureless valve (group 1, n=38) or a conventional bioprosthetic or mechanical valve (group 2, n=32). Baseline patient characteristics were similar except for worse New York Heart Association functional status and the prevalence of diabetes mellitus in group 1. In group 1, the operative, cross-clamp, and cardiopulmonary bypass times were shorter (all P =0.001), postoperative drainage amounts were lower ( P =0.009), hospital stays were shorter ( P =0.004), and less red blood cell transfusion was needed ( P =0.037). Echocardiograms before patients' discharge from the hospital showed lower peak and mean aortic gradients in group 1 (mean transvalvular gradient, 8.4 ± 2.8 vs 12.2 ± 5.2 mmHg; P =0.012). We found that elderly, high-risk patients who underwent multiple cardiac surgical procedures and sutureless AVR had better hemodynamic outcomes and shorter ischemic times than did patients who underwent conventional AVR.

Multicomponent cardiac rehabilitation in patients after transcatheter aortic valve implantation: Predictors of functional and psychocognitive recovery.

PubMed

Eichler, Sarah; Salzwedel, Annett; Reibis, Rona; Nothroff, Jörg; Harnath, Axel; Schikora, Martin; Butter, Christian; Wegscheider, Karl; Völler, Heinz

2017-02-01

Background In the last decade, transcatheter aortic valve implantation has become a promising treatment modality for patients with aortic stenosis and a high surgical risk. Little is known about influencing factors of function and quality of life during multicomponent cardiac rehabilitation. Methods From October 2013 to July 2015, patients with elective transcatheter aortic valve implantation and a subsequent inpatient cardiac rehabilitation were enrolled in the prospective cohort multicentre study. Frailty-Index (including cognition, nutrition, autonomy and mobility), Short Form-12 (SF-12), six-minute walk distance (6MWD) and maximum work load in bicycle ergometry were performed at admission and discharge of cardiac rehabilitation. The relation between patient characteristics and improvements in 6MWD, maximum work load or SF-12 scales were studied univariately and multivariately using regression models. Results One hundred and thirty-six patients (80.6 ± 5.0 years, 47.8% male) were enrolled. 6MWD and maximum work load increased by 56.3 ± 65.3 m ( p < 0.001) and 8.0 ± 14.9 watts ( p < 0.001), respectively. An improvement in SF-12 (physical 2.5 ± 8.7, p = 0.001, mental 3.4 ± 10.2, p = 0.003) could be observed. In multivariate analysis, age and higher education were significantly associated with a reduced 6MWD, whereas cognition and obesity showed a positive predictive value. Higher cognition, nutrition and autonomy positively influenced the physical scale of SF-12. Additionally, the baseline values of SF-12 had an inverse impact on the change during cardiac rehabilitation. Conclusions Cardiac rehabilitation can improve functional capacity as well as quality of life and reduce frailty in patients after transcatheter aortic valve implantation. An individually tailored therapy with special consideration of cognition and nutrition is needed to maintain autonomy and empower octogenarians in coping with challenges of everyday life.

The N.A.C.A. Photographic Apparatus for Studying Fuel Sprays from Oil Engine Injection Valves and Test Results from Several Researches

NASA Technical Reports Server (NTRS)

Beardsley, Edward G

1928-01-01

Apparatus for recording photographically the start, growth, and cut-off of oil sprays from injection valves has been developed at the Langley Memorial Aeronautical Laboratory. The apparatus consists of a high-tension transformer by means of which a bank of condensers is charged to a high voltage. The controlled discharge of these condensers in sequence, at a rate of several thousand per second, produces electric sparks of sufficient intensity to illuminate the moving spray for photographing. The sprays are injected from various types of valves into a chamber containing gases at pressures up to 600 pounds per square inch. Several series of pictures are shown. The results give the effects of injection pressure, chamber pressure, specific gravity of the fuel oil used, and injection-valve design, upon spray characteristics.

Osmotic Acoustic Source

DTIC Science & Technology

2017-09-25

sonar range operations (for example, 15000 meters and longer). This means that the two-way travel time is typically at least twenty seconds...in the enclosure through osmosis. Valves open at a specified time after the liquid injection to free flood between the enclosure and the...the timing of the salt jets and the free-flooding valves enables a repeatable Attorney Docket No. 300070 4 of 14 acoustic pulse at low

Long-term outcomes of kidney and bladder function in patients with a posterior urethral valve.

PubMed

Kim, Sung Jin; Jung, Jaeyoon; Lee, Chanwoo; Park, Sejun; Song, Sang Hoon; Won, Hye-Sung; Kim, Kun Suk

2018-06-01

We investigated long-term functional changes in the kidney and bladder of patients with posterior urethral valve (PUV) who underwent fetal intervention or postnatal surgery.We retrospectively reviewed the medical records of 28 consecutive patients treated for PUV at our institution. Detailed data on medical and surgical histories, particularly on pre- and postnatal treatment modality, including fetal vesicoamniotic shunt, endoscopic valve ablation, and vesicostomy, were collected and analyzed. Long-term renal function was evaluated based on serum levels of creatinine (sCr), estimated glomerular filtration rate (eGFR), and renal scans. Voiding function was evaluated in urodynamic tests.Vesicoamniotic shunting was performed in 12 (42.8%) patients. Although the mean initial sCr was significantly higher in patients in whom a fetal shunt was placed than in others (2.04 vs 1.17 mg/L, P = .038), the sCr at long-term follow-up was not significantly different between them (0.64 vs 0.40 mg/L, P = .186). The mean maximum detrusor pressure was significantly lower in patients with a fetal shunt than in others (37.7 vs 73.0 cm H2O, P = .019). Postnatal vesicostomy was performed in 14 patients, and primary valve ablation was performed in 13 patients. The mean initial sCr was higher in patients in the vesicostomy group than in the primary valve ablation group (2.08 vs 0.86 mg/L, P = .014). However, no significant differences were found in sCr (0.9 vs 0.3 mg/L, P = .252) or GFR (59.1 vs 68.5 mL/min/1.73 m, P = .338) at long-term follow-up. Bladder capacity was greater and residual urine volume was less in the vesicostomy group than in the primary valve ablation group, but without statistical significance.Vesicostomy is more beneficial in the recovery of renal function and is not inferior in terms of bladder function, even in patients with severe PUV disorder. It is a reliable surgical option that can spare renal function and guarantee adequate bladder function in the long term.

Effect of Ivabradine on Heart Rate and Duration of Exercise in Patients With Mild-to-Moderate Mitral Stenosis: A Randomized Comparison With Metoprolol.

PubMed

Saggu, Daljeet K; Narain, Varun S; Dwivedi, Sudhanshu K; Sethi, Rishi; Chandra, Sharad; Puri, Aniket; Saran, Ram K

2015-06-01

Symptoms in mitral stenosis (MS) are heart rate (HR) dependent. Increase in HR reduces diastolic filling period with rise in transmitral gradient. By reducing HR, beta-blockers improve hemodynamics and relieve symptoms, but the use may be limited by side effects. The present randomized crossover study looked at comparative efficacy of ivabradine and metoprolol on symptoms, hemodynamics, and exercise parameters in patients with mild-to-moderate MS (mitral valve area, 1-2 cm) in normal sinus rhythm. Baseline clinical assessment, treadmill stress testing, and an echocardiographic Doppler evaluation were performed to determine resting HR, total exercise duration, mean gradient across mitral valve, and mean pulmonary artery systolic pressure (PASP). Patients were then allocated to either metoprolol or ivabradine to maximal tolerated doses over 6 weeks (metoprolol: 100 mg twice a day, ivabradine: 10 mg twice a day). Reevaluation was done at the end of this period, and all drugs stopped for washout over 2 weeks. Thereafter, the 2 groups were crossed over to the other drug that was continued for another 6 weeks. Assessment was again performed at the end of this period. Thirty-three patients of 34 completed the protocol. Fifteen were male, mean age was 28.9 ± 6.6 years, all were in New York Heart Association class 2, and mean resting HR was 103.5 ± 7.2/min. Mean mitral valve area was 1.56 ± 0.16 cm, mean PASP was 38.1 ± 5.1 mm Hg, and mean gradient across mitral valve was 10.6 ± 1.6 mm Hg. Significant decrease in baseline and peak exercise HR was observed at the end of follow-up with both drugs. Reduction in mitral valve gradient after ivabradine (42%) and metoprolol (37%) and reduction in PASP after both ivabradine (23%) and metoprolol (27%) were to a similar extent. Significant reduction in total exercise duration after both ivabradine and metoprolol therapy was observed. One patient developed blurring of vision with ivabradine therapy but did not require discontinuation of drug. An improvement in dyspnea of one grade was observed in all the patients by treatment with both ivabradine and metoprolol. Both metoprolol and ivabradine reduced symptoms and improved hemodynamics significantly from baseline to a similar extent. Ivabradine thus can be used effectively and safely in patients with MS in normal sinus rhythm who are intolerant or contraindicated for beta-blocker therapy.

Tricuspid valve replacement with mechanical prostheses: Short and long-term outcomes.

PubMed

Rossello, Xavier; Muñoz-Guijosa, Christian; Mena, Elisabet; Camprecios, Marta; Mendez, Ana B; Borras, Xavier; Padro, Josep M

2017-09-01

Tricuspid valve replacement has been associated with high mortality and poor long-term outcomes. We report the preoperative risk factors associated with short and long-term outcomes following tricuspid valve replacement with mechanical prostheses. In 62 patients who underwent mechanical tricuspid valve replacement, clinical, laboratory, and echocardiographic findings were analyzed using both univariate and multivariate analyses to describe operative and long-term mortality. In our population (mean age 59 ± 9.7 years, 82.3% female), most common causes of tricuspid valve disease were rheumatic fever (69.4%) and functional regurgitation (19.4%). Operative and long-term mortality were 17.7 and 33.9%, respectively. Age, diabetes mellitus, and coronary artery disease were independently associated with increased long-term mortality. New York Heart Association (NYHA) class and right heart failure symptoms significantly improved during follow-up. In this series of mechanical tricuspid valve replacements in patients with predominately rheumatic heart disease, operative and long-term mortality were increased; however, survivors had significant improvement in their NYHA class and freedom from right heart failure symptoms. Three preoperative factors (age, diabetes mellitus, and coronary artery disease) were independently associated with long-term mortality. © 2017 Wiley Periodicals, Inc.

Very long-term results (more than 20 years) of valve repair with carpentier's techniques in nonrheumatic mitral valve insufficiency.

PubMed

Braunberger, E; Deloche, A; Berrebi, A; Abdallah, F; Celestin, J A; Meimoun, P; Chatellier, G; Chauvaud, S; Fabiani, J N; Carpentier, A

2001-09-18

Mitral valve repair is considered the gold standard in surgery of degenerative mitral valve insufficiency (MVI), but the long-term results (>20 years) are unknown. We reviewed the first 162 consecutive patients who underwent mitral valve repair between 1970 and 1984 for MVI due to nonrheumatic disease. The cause of MVI was degenerative in 146 patients (90%) and bacterial endocarditis in 16 patients (10%). MVI was isolated or, in 18 cases, associated with tricuspid insufficiency. The mean age of the 162 patients (104 men and 58 women) was 56+/-10 years (age range 22 to 77 years). New York Heart Association functional class was I, II, III, and IV in 2%, 39%, 52%, and 7% of patients, respectively. The mean cardiothoracic ratio was 0.58+/-0.07 (0.4 to 0.8), and 72 (45%) patients had atrial fibrillation. Valve analysis showed that the main mechanism of MVI was type II Carpentier's functional classification in 152 patients. The leaflet prolapse involved the posterior leaflet in 93 patients, the anterior leaflet in 28 patients, and both leaflets in 31 patients. Surgical technique included a Carpentier's ring annuloplasty in all cases, a valve resection in 126 patients, and shortening or transposition of chordae in 49 patients. During the first postoperative month, there were 3 deaths (1.9%) and 3 reoperations (2 valve replacements and 1 repeat repair [1.9%]). Six patients were lost to follow-up. The remaining 151 patients with mitral valve repair were followed during a median of 17 years (range 1 to 29 years; 2273 patient-years). The 20-year Kaplan-Meier survival rate was 48% (95% CI 40% to 57%), which is similar to the survival rate for a normal population with the same age structure. The 20-year rates were 19.3% (95% CI 11% to 27%) for cardiac death and 26% (95% CI 17% to 35%) for cardiac morbidity/mortality (including death from a cardiac cause, stroke, and reoperation). During the 20 years of follow-up, 7 patients were underwent surgery at 3, 7, 7, 8, 8, 10, or 12 years after the initial operation. Valve replacement was carried out in 5 patients, and repeat repair was carried out in 2 patients. At the end of the study, 65 patients remained alive (median follow-up 19 years). Their median age was 76 years (age range 41 to 95 years). All except 1 were in New York Heart Association functional class I/II. Mitral valve repair using Carpentier's technique in patients with nonrheumatic MVI provides excellent long-term results with a mortality rate similar to that of the general population and a very low incidence of reoperation.

A booming economy means a bursting trauma system: association between hospital admission for major injury and indicators of economic activity in a large Canadian health region.

PubMed

Roberts, Derek J; Das, Debanjana; Mercado, Michelle; Vis, Christine; Kortbeek, John B; Kirkpatrick, Andrew W; Ball, Chad G

2014-05-01

Injury epidemiology fluctuates with economic activity in many countries. These relationships remain unclear in Canada. The annual risk of admission for major injury (Injury Severity Score ≥12) to a high-volume, level-1 Canadian trauma center was compared with indicators of economic activity over a 16-year period using linear regression. An increased risk of injured patient admissions was associated with rising mean gross domestic product (GDP [millions of chained 2002 dollars]) (.36 person increase per 100,000 population/$1,000 increase in GDP; P = .001) and annual gasoline prices (.47 person increase per 100,000 population/cent increase in gasoline price; P = .001). Recreation-related vehicle injuries were also associated with economic affluence. The risk of trauma patient mortality with increasing mean annual GDP (P = .72) and gasoline prices (P = .32) remained unchanged. Hospital admissions for major injury, but not trauma patient mortality, were associated with economic activity in a large Canadian health care region. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparative study of encapsulated blebs following Ahmed glaucoma valve implantation and trabeculectomy with mitomycin-C.

PubMed

Bae, Kunho; Suh, Wool; Kee, Changwon

2012-08-01

To compare the histopathologic and morphologic findings of encapsulated blebs following Ahmed glaucoma valve implantation and primary standard trabeculectomy with mitomycin-C. We reviewed the records of patients with otherwise uncontrollable glaucoma who had undergone Ahmed glaucoma valve implantation or trabeculectomy with mitomycin-C. Five eyes that underwent Ahmed valve implantation and three eyes that underwent trabeculectomy needed surgical revision of the initial surgery due to encapsulated bleb development with total loss of function. The surgically removed encapsulated blebs were analyzed macroscopically and microscopically. Removal of the encapsulated bleb was performed at a mean follow-up time of 26.6 ± 19.4 weeks in the Ahmed valve implantation group and 12.0 ± 11.4 weeks in the trabeculectomy group. The fibrotic wall of the encapsulated blebs had an overall thickness of 2.48 ± 0.42 mm in the Ahmed valve implantation group and 1.62 ± 0.37 mm in the trabeculectomy group. Macroscopically, the coconut flesh-like smooth surface was split into two layers, and the wall of the capsule was thicker in the Ahmed valve implantation group than in the trabeculectomy group. Histopathologically, the fibrotic capsule was composed of an inner fibrodegenerative layer and an outer fibrovascular layer, and there were no histopathological differences between the two groups. The fibrotic capsule wall was thicker in the Ahmed valve group, but there were no differences in histological findings between the two groups.

A Comparative Result of Ventriculoperitoneal Shunt, Focusing Mainly on Gravity-Assisted Valve and Programmable Valve

PubMed Central

Lee, Won-Chul; Choe, Il-Seung; Park, Sung-Choon; Ha, Young-Soo; Lee, Kyu Chang

2010-01-01

Objective Despite rapid evolution of shunt devices, the complication rates remain high. The most common causes are turning from obstruction, infection, and overdrainage into mainly underdrainage. We investigated the incidence of complications in a consecutive series of hydrocephalic patients. Methods From January 2002 to December 2009, 111 patients underwent ventriculoperitoneal (VP) shunting at our hospital. We documented shunt failures and complications according to valve type, primary disease, and number of revisions. Results Overall shunt survival time was 268 weeks. Mean survival time of gravity-assisted valve (GAV) was 222 weeks versus 286 weeks for other shunts. Survival time of programmable valves (264 weeks) was longer than that of pressure-controlled valves (186 weeks). The most common cause for shunt revision was underdrainage (13 valves). The revision rate due to underdrainage in patients with GAV (7 of 10 patients) was higher than that for other valve types. Of 7 patients requiring revision for GAV underdrainage, 6 patients were bedridden. The overall infection rate was 3.6%, which was lower than reported series. Seven patients demonstrating overdrainage had cranial defects when operations were performed (41%), and overdrainage was improved in 5 patients after cranioplasty. Conclusion Although none of the differences was statistically significant, some of the observations were especially notable. If a candidate for VP shunting is bedridden, GAV may not be indicated because it could lead to underdrainage. Careful procedure and perioperative management can reduce infection rate. Cranioplasty performed prior to VP shunting may be beneficial. PMID:21082054

Tricuspid valve repair for severe tricuspid regurgitation due to pacemaker leads.

PubMed

Uehara, Kyokun; Minakata, Kenji; Watanabe, Kentaro; Sakaguchi, Hisashi; Yamazaki, Kazuhiro; Ikeda, Tadashi; Sakata, Ryuzo

2016-07-01

Tricuspid valve regurgitation due to pacemaker leads is a well-known complication. Although some reports have suggested that pacemaker leads should be surgically explanted, strongly adhered leads cannot always be removed. The aim of this study was to describe our tricuspid valve repair techniques with pacemaker leads left in situ. Our retrospective study investigated 6 consecutive patients who required tricuspid valve surgery for severe regurgitation induced by pacemaker leads. From the operative findings, we identified 3 patterns of tricuspid valve and pacemaker lead involvement. In 3 patients, the leads were caught in the chordae, in 2 patients, tricuspid regurgitation was caused by lead impingement on the septal leaflet, and in 3 patients, tricuspid valve leaflets had been perforated by the pacemaker leads. During surgery, all leads were left in situ after being separated from the leaflet or valvular apparatus. In addition, suture annuloplasty was performed for annular dilatation in all cases. In one patient, the lead was reaffixed to the annulus after the posterior leaflet was cut back towards the annulus, and the leaflet was then closed. There was one hospital death due to sepsis. The degree of tricuspid regurgitation was trivial in all surviving patients at discharge. During a mean follow-up of 21 months, one patient died from pneumonia 20 months after tricuspid valve repair. In patients undergoing tricuspid valve surgery due to severe tricuspid regurgitation caused by pacemaker leads, the leads can be left in situ after proper repair with annuloplasty. © The Author(s) 2016.

Experimental investigations on the fluid-mechanics of an electrospun heart valve by means of particle image velocimetry.

PubMed

Del Gaudio, Costantino; Gasbarroni, Pier Luca; Romano, Giovanni Paolo

2016-12-01

End-stage failing heart valves are currently replaced by mechanical or biological prostheses. Both types positively contribute to restore the physiological function of native valves, but a number of drawbacks limits the expected performances. In order to improve the outcome, tissue engineering can offer an alternative approach to design and fabricate innovative heart valves capable to support the requested function and to promote the formation of a novel, viable and correctly operating physiological structure. This potential result is particularly critical if referred to the aortic valve, being the one mainly exposed to structural and functional degeneration. In this regard, the here proposed study presents the fabrication and in vitro characterization of a bioresorbable electrospun heart valve prosthesis using the particle image velocimetry technique either in physiological and pathological fluid dynamic conditions. The scaffold was designed to reproduce the aortic valve geometry, also mimicking the fibrous structure of the natural extracellular matrix. To evaluate its performances for possible implantation, the flow fields downstream the valve were accurately investigated and compared. The experimental results showed a correct functionality of the device, supported by the formation of vortex structures at the edge of the three cusps, with Reynolds stress values below the threshold for the risk of hemolysis (which can be comprised in the range 400-4000N/m(2) depending on the exposure period), and a good structural resistance to the mechanical loads generated by the driving pressure difference. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of tilting disc valves after fatigue life testing: preliminary results within a comparison program.

PubMed

Barbaro, V; Boccanera, G; Daniele, C; Grigioni, M; Palombo, A

1995-09-01

A fatigue life test, by accelerating the beat rate, simulates several years of virtual life of a prosthetic heart valve in a short period of time. The correlation between the in vivo life of a valve and in vitro testing expectations is as yet not well established, but reproducible test conditions yield precious information about wear and failure. The paper reports a qualitative analysis of mechanical valve wear as part of a comparison program designed to investigate the significance of fatigue testing with the ultimate aim of defining standard guidelines for these type of tests. Two tilting disc valves (29 mm) were subjected to 16 years of fatigue life simulated by means of a Rowan Ash fatigue tester (accelerated rate of 1,200 bpm). Fatigue-induced effects on valve disc and ring surfaces were observed under a monitor microscope to identify wear sites and patterns. A high speed cinematographic system was used to investigate the mechanisms responsible for the wear (wear modes). Valve closure was inspected at a 6,000 frame/s rate. Because of disc rotation during the tilting movement, the points of contact between disc and ring are distributed all around the disc edge but focally on the ring. On both sides of the disc, the surfaces present ring-like concentric grooves. After 16 years of fatigue life the valves showed neither severe wear nor alteration of their fluidodynamic behavior in the pulsatile flow test.

Long-term results of heart valve replacement with the Edwards Duromedics bileaflet prosthesis: a prospective ten-year clinical follow-up.

PubMed

Podesser, B K; Khuenl-Brady, G; Eigenbauer, E; Roedler, S; Schmiedberger, A; Wolner, E; Moritz, A

1998-05-01

The Edwards Duromedics valve (Baxter Healthcare Corp., Edwards Division, Santa Ana, Calif.) was designed with a self-irrigating hinge mechanism to reduce thromboembolic complications. After good initial clinical results, distribution was suspended in 1988 after reports of valve fracture after 20,000 valves had been implanted. The manufacturer conducted extensive studies to improve the Edwards Duromedics and reintroduced a modified version, which is available as Edwards Tekna. The purpose of the study was the evaluation of long-term results of the original Edwards Duromedics that might be important for the current version, the Edwards Tekna valve. A prospective clinical 10-year follow-up was performed of 508 patients who underwent valve replacement with the Edwards Duromedics valve in the aortic (n = 268), mitral (n = 183), and aortic and mitral (n = 56) position. The perioperative mortality rate was 6.9%; follow-up was 98% complete, comprising 3648 patient-years for a mean follow-up of 86 months (range: 33 to 144 months). The actuarial freedom from complications at the 10-year follow-up and the incidence rate (percent per patient-year) were as follows: late mortality rate, 69.2% +/- 2.4% (3.5% per patient-year); thromboembolism, 90.7% +/- 1.6% (0.96% per patient-year); anticoagulation-related hemorrhage, 87.7% +/- 1.7% (1.34% per patient-year); prosthetic valve endocarditis, 96.7% +/- 0.09% (0.38% per patient-year); valve-related mortality rate, 89.3% +/- 1.6% (1.21% per patient-year); valve failure, 86.2% +/- 1.85% (1.54% per patient-year); and valve-related morbidity and mortality rate, 71.1% +/- 2.3% (3.2% per patient-year). Three leaflet escapes were observed (one lethal, two successful reoperations; 99.1% +/- 0.05% freedom, 0.08% per patient-year). All patients functionally improved (86% in New York Heart Association classes I and II), and incidence of anemia was insignificant. These results confirm that the Edwards Duromedics valve shows excellent performance concerning thromboembolism, hemolysis, and functional improvement and will serve as a reference for the last version, the Edwards Tekna valve, where comparable long-term data are currently not available.

Post-introduction observation of transcatheter aortic valve implantation in Galicia (Spain).

PubMed

Varela-Lema, Leonor; Queiro-Verdes, Teresa; Baz-Alonso, José A; Cuenca-Castillo, José J; Durán-Muñoz, Darío; Gónzalez-Juanatey, José R; Herrera Noreña, José M; Iñiguez-Romo, Andrés; López-Otero, Diego; Pradas-Montilla, Gonzalo; Rubio-Álvarez, José; Salgado-Fernández, Jorge; Trillo Nouche, Ramiro; Vázquez-González, Nicolás; López-García, Marisa

2015-02-01

Transcatheter aortic valve implantation constitutes an example of a technology introduced into the Galician Health Care System basket and subjected to a post-introduction observational study after coverage. This paper aims to describe the process and results of this experience, illustrating the main challenges and opportunities in using these studies for supporting decision making. The study protocol was developed by a multidisciplinary team consisting of experts from the Galician HTA Agency (avalia-t), interventional cardiologists and cardiac surgeons. Together they agreed on the information that was relevant and feasible for collection, and planned the study design, data collection and analysis of results. During the 1-year recruitment period, 94 patients underwent percutaneous aortic valve replacement in the three authorized centres. Implantation rate and prosthesis models differed substantially across the centres. Overall, procedural success rate was 96.8% and hospital mortality was 7.4%. Complications during post-surgical admission were recorded in 40.4% of patients. Moderate residual aortic regurgitation was observed in 10% of patients, and the procedure was associated with a stroke rate of 3.3% at 30 days and 5.3% at 1 year. Post-introduction observation has made it feasible to determine the use of this procedure within the SERGAS context and has enabled the assessment of performance in real-life conditions. The proposed strategic actions and interventions have been drawn up based upon the collective judgement of a group of experienced professionals, and have served to establish recommendations on further research that would be required to optimize health benefits. © 2014 John Wiley & Sons, Ltd.

Complete Atrioventricular Block Complicating Mitral Infective Endocarditis Caused by Streptococcus Agalactiae.

PubMed

Arai, Masaru; Nagashima, Koichi; Kato, Mahoto; Akutsu, Naotaka; Hayase, Misa; Ogura, Kanako; Iwasawa, Yukino; Aizawa, Yoshihiro; Saito, Yuki; Okumura, Yasuo; Nishimaki, Haruna; Masuda, Shinobu; Hirayama, Astushi

2016-09-08

BACKGROUND Infective endocarditis (IE) involving the mitral valve can but rarely lead to complete atrioventricular block (CAVB). CASE REPORT A 74-year-old man with a history of infective endocarditis caused by Streptococcus gordonii (S. gordonii) presented to our emergency room with fever and loss of appetite, which had lasted for 5 days. On admission, results of serologic tests pointed to severe infection. Electrocardiography showed normal sinus rhythm with first-degree atrioventricular block and incomplete right bundle branch block, and transthoracic echocardiography and transesophageal echocardiography revealed severe mitral regurgitation caused by posterior leaflet perforation and 2 vegetations (5 mm and 6 mm) on the tricuspid valve. The patient was initially treated with ceftriaxone and gentamycin because blood and cutaneous ulcer cultures yielded S. agalactiae. On hospital day 2, however, sudden CAVB requiring transvenous pacing occurred, and the patient's heart failure and infection worsened. Although an emergent surgery is strongly recommended, even in patients with uncontrolled heart failure or infection, surgery was not performed because of the Child-Pugh class B liver cirrhosis. Despite intensive therapy, the patient's condition further deteriorated, and he died on hospital day 16. On postmortem examination, a 2×1-cm vegetation was seen on the perforated posterior mitral leaflet, and the infection had extended to the interventricular septum. Histologic examination revealed extensive necrosis of the AV node. CONCLUSIONS This rare case of CAVB resulting from S. agalactiae IE points to the fact that in monitoring patients with IE involving the mitral valve, clinicians should be aware of the potential for perivalvular extension of the infection, which can lead to fatal heart block.

Ambient biomass smoke and cardio-respiratory hospital admissions in Darwin, Australia

PubMed Central

Johnston, Fay H; Bailie, Ross S; Pilotto, Louis S; Hanigan, Ivan C

2007-01-01

Background Increasing severe vegetation fires worldwide has been attributed to both global environmental change and land management practices. However there is little evidence concerning the population health effects of outdoor air pollution derived from biomass fires. Frequent seasonal bushfires near Darwin, Australia provide an opportunity to examine this issue. We examined the relationship between atmospheric particle loadings <10 microns in diameter (PM10), and emergency hospital admissions for cardio-respiratory conditions over the three fire seasons of 2000, 2004 and 2005. In addition we examined the differential impacts on Indigenous Australians, a high risk population subgroup. Methods We conducted a case-crossover analysis of emergency hospital admissions with principal ICD10 diagnosis codes J00–J99 and I00–I99. Conditional logistic regression models were used to calculate odds ratios for admission with 10 μg/m3 rises in PM10. These were adjusted for weekly influenza rates, same day mean temperature and humidity, the mean temperature and humidity of the previous three days, days with rainfall > 5 mm, public holidays and holiday periods. Results PM10 ranged from 6.4 – 70.0 μg/m3 (mean 19.1). 2466 admissions were examined of which 23% were for Indigenous people. There was a positive relationship between PM10 and admissions for all respiratory conditions (OR 1.08 95%CI 0.98–1.18) with a larger magnitude in the Indigenous subpopulation (OR1.17 95% CI 0.98–1.40). While there was no relationship between PM10 and cardiovascular admissions overall, there was a positive association with ischaemic heart disease in Indigenous people, greatest at a lag of 3 days (OR 1.71 95%CI 1.14–2.55). Conclusion PM10 derived from vegetation fires was predominantly associated with respiratory rather than cardiovascular admissions. This outcome is consistent with the few available studies of ambient biomass smoke pollution. Indigenous people appear to be at higher risk of cardio-respiratory hospital admissions associated with exposure to PM10. PMID:17854481

Three-dimensional thoracic aorta principal strain analysis from routine ECG-gated computerized tomography: feasibility in patients undergoing transcatheter aortic valve replacement.

PubMed

Satriano, Alessandro; Guenther, Zachary; White, James A; Merchant, Naeem; Di Martino, Elena S; Al-Qoofi, Faisal; Lydell, Carmen P; Fine, Nowell M

2018-05-02

Functional impairment of the aorta is a recognized complication of aortic and aortic valve disease. Aortic strain measurement provides effective quantification of mechanical aortic function, and 3-dimenional (3D) approaches may be desirable for serial evaluation. Computerized tomographic angiography (CTA) is routinely performed for various clinical indications, and offers the unique potential to study 3D aortic deformation. We sought to investigate the feasibility of performing 3D aortic strain analysis in a candidate population of patients undergoing transcatheter aortic valve replacement (TAVR). Twenty-one patients with severe aortic valve stenosis (AS) referred for TAVR underwent ECG-gated CTA and echocardiography. CTA images were analyzed using a 3D feature-tracking based technique to construct a dynamic aortic mesh model to perform peak principal strain amplitude (PPSA) analysis. Segmental strain values were correlated against clinical, hemodynamic and echocardiographic variables. Reproducibility analysis was performed. The mean patient age was 81±6 years. Mean left ventricular ejection fraction was 52±14%, aortic valve area (AVA) 0.6±0.3 cm 2 and mean AS pressure gradient (MG) 44±11 mmHg. CTA-based 3D PPSA analysis was feasible in all subjects. Mean PPSA values for the global thoracic aorta, ascending aorta, aortic arch and descending aorta segments were 6.5±3.0, 10.2±6.0, 6.1±2.9 and 3.3±1.7%, respectively. 3D PSSA values demonstrated significantly more impairment with measures of worsening AS severity, including AVA and MG for the global thoracic aorta and ascending segment (p<0.001 for all). 3D PSSA was independently associated with AVA by multivariable modelling. Coefficients of variation for intra- and inter-observer variability were 5.8 and 7.2%, respectively. Three-dimensional aortic PPSA analysis is clinically feasible from routine ECG-gated CTA. Appropriate reductions in PSSA were identified with increasing AS hemodynamic severity. Expanded study of 3D aortic PSSA for patients with various forms of aortic disease is warranted.

Late outcome analysis of the Braile Biomédica® pericardial valve in the aortic position

PubMed Central

Azeredo, Lisandro Gonçalves; Veronese, Elinthon Tavares; Santiago, José Augusto Duncan; Brandão, Carlos Manuel de Almeida; Pomerantzeff, Pablo Maria Alberto; Jatene, Fabio Biscegli

2014-01-01

Objective Aortic valve replacement with Braile bovine pericardial prosthesis has been routinely done at the Heart Institute of the Universidade de São Paulo Medical School since 2006. The objective of this study is to analyze the results of Braile Biomédica® aortic bioprosthesis in patients with aortic valve disease. Methods We retrospectively evaluated 196 patients with aortic valve disease submitted to aortic valve replacement with Braile Biomédica® bovine pericardial prosthesis, between 2006 and 2010. Mean age was 59.41±16.34 years and 67.3% were male. Before surgery, 73.4% of patients were in NYHA functional class III or IV. Results Hospital mortality was 8.16% (16 patients). Linearized rates of mortality, endocarditis, reintervention, and structural dysfunction were 1.065%, 0.91%, 0.68% and 0.075% patients/year, respectively. Actuarial survival was 90.59±2.56% in 88 months. Freedom from reintervention, endocarditis and structural dysfunction was respectively 91.38±2.79%, 89.84±2.92% and 98.57±0.72% in 88 months. Conclusion The Braile Biomédica® pericardial aortic valve prosthesis demonstrated actuarial survival and durability similar to that described in the literature, but further follow up is required to assess the incidence of prosthetic valve endocarditis and structural dysfunction in the future. PMID:25372903

IL-10 and ET-1 as biomarkers of rheumatic valve disease

PubMed Central

Leão, Sydney Correia; Lima, Maria Regina Menezes; do Nascimento, Hertaline Menezes; Octacilio-Silva, Shirlei; Rodrigues, Tania Maria de Andrade

2014-01-01

Objective To evaluate the immunological profile and gene expression of endothelin-1 (ET-1) in mitral valves of patients with rheumatic fever originated from a reference service in cardiovascular surgery. Methods This was a quantitative, observational and cross-sectional study. Thirty-five subjects (divided into four groups) participated in the study, 25 patients with chronic rheumatic heart disease and ten control subjects. The mean age of the sample studied was 34.5 years. Seventeen of them (48.58%) were male and 18 (51.42%) were female. Inflammatory cytokines (TNF-α, IL-4 and IL-10) were measured and ten mitral valves of patients who underwent first valve replacement were collected for determination of gene expression of endothelin-1 by real time PCR. Results Among the groups studied (patients vs. controls), there was a statistically significant difference in IL-10 levels (P=0.002), and no differences in other cytokines. Expression of endothelin-1 was observed in 70% of samples. Quantitatively, average of ET-1 expression was 62.85±25.63%. Conclusion Inflammatory cytokine IL-10 participates in the maintenance of chronicity of rheumatic fever in patients who underwent valve replacement and those who are undergoing medical treatment. The expression of endothelin-1 in heart valve lesions in patients undergoing mitral valve replacement confirms its association with inflammatory activity in rheumatic fever. PMID:24896159

The role of three-dimensional visualization in robotics-assisted cardiac surgery

NASA Astrophysics Data System (ADS)

Currie, Maria; Trejos, Ana Luisa; Rayman, Reiza; Chu, Michael W. A.; Patel, Rajni; Peters, Terry; Kiaii, Bob

2012-02-01

Objectives: The purpose of this study was to determine the effect of three-dimensional (3D) versus two-dimensional (2D) visualization on the amount of force applied to mitral valve tissue during robotics-assisted mitral valve annuloplasty, and the time to perform the procedure in an ex vivo animal model. In addition, we examined whether these effects are consistent between novices and experts in robotics-assisted cardiac surgery. Methods: A cardiac surgery test-bed was constructed to measure forces applied by the da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA) during mitral valve annuloplasty. Both experts and novices completed roboticsassisted mitral valve annuloplasty with 2D and 3D visualization. Results: The mean time for both experts and novices to suture the mitral valve annulus and to tie sutures using 3D visualization was significantly less than that required to suture the mitral valve annulus and to tie sutures using 2D vision (p∠0.01). However, there was no significant difference in the maximum force applied by novices to the mitral valve during suturing (p = 0.3) and suture tying (p = 0.6) using either 2D or 3D visualization. Conclusion: This finding suggests that 3D visualization does not fully compensate for the absence of haptic feedback in robotics-assisted cardiac surgery. Keywords: Robotics-assisted surgery, visualization, cardiac surgery

Whom We Admit, What We Deny: The Meaning of Selective Admissions

ERIC Educational Resources Information Center

Kohn, Alfie

2012-01-01

What does it mean when a school, having rejected a child who applied for admission, explains that he or she just "isn't a good fit" with the school? At times, it is not clear how the decision to prevent a child from enrolling is best described as a lack of fit, particularly if the school's goals and priorities (a) correspond to what most parents…

Automatically operable self-leveling load table

NASA Technical Reports Server (NTRS)

Burch, J. L. (Inventor)

1974-01-01

A self-leveling load table is described which is automatically maintained level by selectively opening and closing solenoid valves for inserting and removing air from chambers under the table. The table is floated in a fluid by nine air chambers beneath the top of the table. These chambers are open at the bottom and four oppositely located chambers are used for leveling the table by having the air increased or decreased by means of a flexible hose. Air bearing pendulums are used for selectively energizing solenoid valves which either apply pressurized air to the chamber or evacuate air from the chamber by means of a vacuum source.

Dynamics of the inlet system of a four-stroke engine

NASA Technical Reports Server (NTRS)

Boden, R H; Schecter, Harry

1944-01-01

Tests were run on a single-cylinder and a multicylinder four-stroke engine in order to determine the effect of the dynamics of the inlet system upon indicated mean effective pressure. Tests on the single-cylinder engine were made at various speeds, inlet valve timings, and inlet pipe lengths. These tests indicated that the indicated mean effective pressure could be raised considerably at any one speed by the use of a suitably long inlet pipe. Tests at other speeds with this length of pipe showed higher indicated mean effective pressure than with a very short pipe, although not so high as could be obtained with the pipe length adjusted for each speed. A general relation was discovered between optimum time of inlet valve closing and pipe length; namely, that longer pipes require later inlet valve closing in order to be fully effective. Tests were also made on three cylinders connected to a single pipe. With this arrangement, increased volumetric efficiency at low speed was obtainable by using a long pipe, but only with a sacrifice of volumetric efficiency at high speed. Volumetric efficiency at high speed was progressively lower as the pipe length was increased.

Cerebrospinal Fluid Lumbar Tapping Utilization for Suspected Ventriculoperitoneal Shunt Under-Drainage Malfunctions

PubMed Central

Lee, Jong-Beom; Ahn, Ho-Young; Lee, Hong-Jae; Yang, Ji-Ho; Yi, Jin-Seok; Lee, Il-Woo

2017-01-01

Objective The diagnosis of shunt malfunction can be challenging since neuroimaging results are not always correlated with clinical outcomes. The purpose of this study was to evaluate the efficacy of a simple, minimally invasive cerebrospinal fluid (CSF) lumbar tapping test that predicts shunt under-drainage in hydrocephalus patients. Methods We retrospectively reviewed the clinical and radiological features of 48 patients who underwent routine CSF lumbar tapping after ventriculoperitoneal shunt (VPS) operation using a programmable shunting device. We compared shunt valve opening pressure and CSF lumbar tapping pressure to check under-drainage. Results The mean pressure difference between valve opening pressure and CSF lumbar tapping pressure of all patients were 2.21±24.57 mmH2O. The frequency of CSF lumbar tapping was 2.06±1.26 times. Eighty five times lumbar tapping of 41 patients showed that their VPS function was normal which was consistent with clinical improvement and decreased ventricle size on computed tomography scan. The mean pressure difference in these patients was −3.69±19.20 mmH2O. The mean frequency of CSF lumbar tapping was 2.07±1.25 times. Fourteen cases of 10 patients revealed suspected VPS malfunction which were consistent with radiological results and clinical symptoms, defined as changes in ventricle size and no clinical improvement. The mean pressure difference was 38.07±23.58 mmH2O. The mean frequency of CSF lumbar tapping was 1.44±1.01 times. Pressure difference greater than 35 mmH2O was shown in 2.35% of the normal VPS function group (2 of 85) whereas it was shown in 64.29% of the suspected VPS malfunction group (9 of 14). The difference was statistically significant (p=0.000001). Among 10 patients with under-drainage, 5 patients underwent shunt revision. The causes of the shunt malfunction included 3 cases of proximal occlusion and 2 cases of distal obstruction and valve malfunction. Conclusion Under-drainage of CSF should be suspected if CSF lumbar tapping pressure is 35 mmH2O higher than the valve opening pressure and shunt malfunction evaluation or adjustment of the valve opening pressure should be made. PMID:28061484

Do prices reflect the costs of cardiac surgery in the elderly?

PubMed

Coelho, Pedro; Rodrigues, Vanessa; Miranda, Luís; Fragata, José; Pita Barros, Pedro

2017-01-01

Payment for cardiac surgery in Portugal is based on a contract agreement between hospitals and the health ministry. Our aim was to compare the prices paid according to this contract agreement with calculated costs in a population of patients aged ≥65 years undergoing cardiac surgery in one hospital department. Data on 250 patients operated between September 2011 and September 2012 were prospectively collected. The procedures studied were coronary artery bypass graft surgery (CABG) (n=67), valve surgery (n=156) and combined CABG and valve surgery (n=27). Costs were calculated by two methods: micro-costing when feasible and mean length of stay otherwise. Price information was provided by the hospital administration and calculated using the hospital's mean case-mix. Thirty-day mortality was 3.2%. Mean EuroSCORE I was 5.97 (standard deviation [SD] 4.5%), significantly lower for CABG (p<0.01). Mean intensive care unit stay was 3.27 days (SD 4.7) and mean hospital stay was 9.92 days (SD 6.30), both significantly shorter for CABG. Calculated costs for CABG were €6539.17 (SD 3990.26), for valve surgery €8289.72 (SD 3319.93) and for combined CABG and valve surgery €11 498.24 (SD 10 470.57). The payment for each patient was €4732.38 in 2011 and €4678.66 in 2012 based on the case-mix index of the hospital group, which was 2.06 in 2011 and 2.21 in 2012; however, the case-mix in our sample was 6.48 in 2011 and 6.26 in 2012. The price paid for each patient was lower than the calculated costs. Prices would be higher than costs if the case-mix of the sample had been used. Costs were significantly lower for CABG. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Planar solid oxide fuel cell with staged indirect-internal air and fuel preheating and reformation

DOEpatents

Geisbrecht, Rodney A; Williams, Mark C

2003-10-21

A solid oxide fuel cell arrangement and method of use that provides internal preheating of both fuel and air in order to maintain the optimum operating temperature for the production of energy. The internal preheat passes are created by the addition of two plates, one on either side of the bipolar plate, such that these plates create additional passes through the fuel cell. This internal preheat fuel cell configuration and method reduce the requirements for external heat exchanger units and air compressors. Air or fuel may be added to the fuel cell as required to maintain the optimum operating temperature through a cathode control valve or an anode control valve, respectively. A control loop comprises a temperature sensing means within the preheat air and fuel passes, a means to compare the measured temperature to a set point temperature and a determination based on the comparison as to whether the control valves should allow additional air or fuel into the preheat or bypass manifolds of the fuel cell.

Multi-bottle, no compressor, mean pressure control system for a Stirling engine

DOEpatents

Corey, John A.

1990-01-01

The invention relates to an apparatus for mean pressure control of a Stirling engine without the need for a compressor. The invention includes a multi-tank system in which there is at least one high pressure level tank and one low pressure level tank wherein gas flows through a maximum pressure and supply line from the engine to the high pressure tank when a first valve is opened until the maximum pressure of the engine drops below that of the high pressure tank opening an inlet regulator to permit gas flow from the engine to the low pressure tank. When gas flows toward the engine it flows through the minimum pressure supply line 2 when a second valve is opened from the low pressure tank until the tank reaches the engine's minimum pressure level at which time the outlet regulator opens permitting gas to be supplied from the high pressure tank to the engine. Check valves between the two tanks prevent any backflow of gas from occurring.

[Percutaneous stented pulmonary valve implantation].

PubMed

Ersbøll, Mads; Søndergaard, Lars

2010-03-29

A number of congenital cardiac malformations involve the right ventricular outflow tract and are often treated with a biological valved conduit. The longevity of these valves is limited due to graft degeneration, which causes progressive valvular dysfunction and subsequently right ventricular failure. Due to the young age of these patients, repeat surgery can be expected and this has motivated the invention of the percutaneous stented valve implantation (PPVR). We retrospectively examined 13 patients (mean age 26 +/- 10 years) treated with PPVR between 2006 and 2008 at our institution. Indications for PPVR were conduit dysfunction with severe stenosis and/or regurgitation, reduced exercise capacity and right ventricular dilatation. In all patients, immediate haemodynamic improvement occurred with full valvular competence after PPVR. The pressure gradient was reduced from 43 (+/- 15) mmHg to 12 (+/- 7) mmHg (p = 0,05) in patients with combined regurgitation and stenosis and 47 (+/- 14) mmHg to 12 (+/- 2) mmHg (p = 0,05) in patients with isolated stenosis. At mean follow-up after 141 (+/- 140) days, no reintervention had been required. Significant haemodynamic and clinical improvement occurred after PPVR in all patients and no major complications occurred. PPVR remains a safe and minimally invasive treatment modality, and our study demonstrates that PPVR can be safely performed in a low volume setting.

Complex blood flow patterns in an idealized left ventricle: A numerical study

NASA Astrophysics Data System (ADS)

Tagliabue, Anna; Dedè, Luca; Quarteroni, Alfio

2017-09-01

In this paper, we study the blood flow dynamics in a three-dimensional (3D) idealized left ventricle of the human heart whose deformation is driven by muscle contraction and relaxation in coordination with the action of the mitral and aortic valves. We propose a simplified but realistic mathematical treatment of the valves function based on mixed time-varying boundary conditions (BCs) for the Navier-Stokes equations modeling the flow. These switchings in time BCs, from natural to essential and vice versa, model either the open or the closed configurations of the valves. At the numerical level, these BCs are enforced by means of the extended Nitsche's method (Tagliabue et al., Int. J. Numer. Methods Fluids, 2017). Numerical results for the 3D idealized left ventricle obtained by means of Isogeometric Analysis are presented, discussed in terms of both instantaneous and phase-averaged quantities of interest and validated against those available in the literature, both experimental and computational. The complex blood flow patterns are analysed to describe the characteristic fluid properties, to show the transitional nature of the flow, and to highlight its main features inside the left ventricle. The sensitivity of the intraventricular flow patterns to the mitral valve properties is also investigated.

Early outcome of patients undergoing transcatheter aortic valve implantation (TAVI): The Auckland City Hospital experience 2011-2015.

PubMed

Wu, Sylvia S Y; Wang, Tom Kai Ming; Nand, Parma; Ramanathan, Tharumenthiran; Webster, Mark; Stewart, Jim

2016-01-08

Transcatheter aortic valve implantation (TAVI) is an alternative to surgical aortic valve replacement (AVR) in high-risk patients. We report the initial TAVI experience at Auckland City Hospital. The records of patients undergoing TAVI between 2011 and 2015 at Auckland City Hospital were reviewed. We report the procedural success and outcome, including major adverse events (death, stroke, myocardial infarction, bleeding, vascular complications and rehospitalisations), degree of aortic regurgitation and symptom status up to 1-year follow-up. Mean age was 80.7 years and mean Euroscore II and Society of Thoracic Surgeons' scores were 8.2% and 6.3% respectively; 50% had undergone previous cardiac surgery. Successful deployment of the valve was achieved in all patients. The cumulative mortality rates at 30 days, 6 months and 1 year were 2.4%, 6.1% and 12.2% and cumulative stroke rates 1.2%, 3% and 8.2% respectively. Severe aortic regurgitation occurred in 2.3% TAVI is available in the New Zealand public hospital system for patients who are high-risk candidates for AVR. Early results are excellent and indicate that the technology is being used appropriately, according to current access criteria. If the early cost effectiveness data are confirmed, the indications for TAVI may widen.

Crossing the GEM Frontier: Graduate Admissions Professionals' Participation in Enrollment Management

ERIC Educational Resources Information Center

Campbell, C. Dean; Smith, Jahmaine

2014-01-01

Using qualitative inquiry and professional socialization as a framework to draw meaning from the work experiences of graduate admissions professionals, this project examines individual beliefs and organizational behaviors as they relate to enrollment management.

Aortic valve repair using a differentiated surgical strategy.

PubMed

Langer, Frank; Aicher, Diana; Kissinger, Anke; Wendler, Olaf; Lausberg, Henning; Fries, Roland; Schäfers, Hans-Joachim

2004-09-14

Reconstruction of the aortic valve for aortic regurgitation (AR) remains challenging, in part because of not only cusp or root pathology but also a combination of both can be responsible for this valve dysfunction. We have systematically tailored the repair to the individual pathology of cusps and root. Between October 1995 and August 2003, aortic valve repair was performed in 282 of 493 patients undergoing surgery for AR and concomitant disease. Root dilatation was corrected by subcommissural plication (n=59), supracommissural aortic replacement (n=27), root remodeling (n=175), or valve reimplantation within a graft (n=24). Cusp prolapse was corrected by plication of the free margin (n=157) or triangular resection (n =36), cusp defects were closed with a pericardial patch (n=16). Additional procedures were arch replacement (n=114), coronary artery bypass graft (n=60) or mitral repair (n=24). All patients were followed-up (follow-up 99.6% complete), and cumulative follow-up was 8425 patient-months (mean, 33+/-27 months).Results- Eleven patients died in hospital (3.9%). Nine patients underwent reoperation for recurrent AR (3.3%). Actuarial freedom from AR grade > or =II at 5 years was 81% for isolated valve repair, 84% for isolated root replacement, and 94% for combination of both; actuarial freedom from reoperation at 5 years was 93%, 95%, and 98%, respectively. No thromboembolic events occurred, and there was 1 episode of endocarditis 4.5 years postoperatively. Aortic valve repair is feasible even for complex mechanisms of AR with a systematic and individually tailored approach. Operative mortality is low and mid-term durability is encouraging. The incidence of valve-related morbidity is low compared with valve replacement.

Aortic root remodeling: ten-year experience with 274 patients.

PubMed

Aicher, Diana; Langer, Frank; Lausberg, Henning; Bierbach, Benjamin; Schäfers, Hans-Joachim

2007-10-01

Dilatation of the aortic root with concomitant aortic regurgitation can be treated by valve-preserving surgery. We have consistently chosen root remodeling rather than reimplantation whenever the aortoventricular junction was not dilated. We have analyzed our 11-year experience with root remodeling. Between October 1995 and October 2006, 274 patients (201 male; 73 female, aged 59 +/- 15 years) were treated by root remodeling in the presence of a preserved aortoventricular diameter (<30 mm). Acute aortic dissection was present in 46 patients. The valve anatomy was tricuspid in 193 and bicuspid in 81 patients. Cusp disease was additionally corrected in 173 (63%) patients. Follow-up was complete in 99%. Cumulative follow-up was 1045 patient-years (mean of 4.0 +/- 2.7 years). Hospital mortality was 3.6% (elective 3.1%; emergency 6.5%). One patient had endocarditis 2 months postoperatively and subsequently underwent valve replacement. Freedom from aortic regurgitation of grade II or more was 91% and 87% at 10 years for bicuspid and tricuspid aortic valves. Nine patients required reoperation: in 6 patients the valve was replaced and in 3 patients rerepaired. Freedom from reoperation was 96% at 5 and 10 years, and freedom from valve replacement was 98% at 5 and 10 years. A comparison of 3 operative periods (1995-1998, 1999-2002, and 2003-2006) showed that with increasing experience cusp prolapse was diagnosed and corrected more frequently (8/49 = 17%; 62/105 = 59%; 103/108 = 82%; P < .0001), and repair stability significantly improved over time (P = .007). Root remodeling leads to durable restoration of aortic valve function in both tricuspid and bicuspid valve anatomy. Aggressive correction of cusp prolapse seems to have a beneficial effect on aortic valve competence.

Internal Acoustics of a Pintle Valve with Supercritical Helium Flow

NASA Technical Reports Server (NTRS)

Fishbach, Sean R.; Davis, R. Benjamin

2010-01-01

Large amplitude flow unsteadiness is a common phenomenon within the high flow rate ducts and valves associated with propulsion systems. Boundary layer noise, shear layers and vortex shedding are a few of the many sources of flow oscillations. The presence of lightly damped acoustic modes can organize and amplify these sources of flow perturbation, causing undesirable loading of internal parts. The present study investigates the self-induced acoustic environment within a pintle valve subject to high Reynolds Number flow of helium gas. Experiments were conducted to measure the internal pressure oscillations of the Ares I Launch Abort System (LAS) Attitude Control Motor (ACM) valve. The AGM consists of a solid propellant gas generator with eight pintle valves attached to the aft end. The pintle valve is designed to deliver variable upstream conditions to an attache( converging diverging nozzle. In order to investigate the full range of operating conditions 28 separate tests were conducted with varying pintle position and upstream pressure. Helium gas was utilized in order to closely mimic the speed of sound of the gas generator exhaust, minimizing required scaling during data analysis. The recordec pressure measurements were interrogated to multiple ends. The development of root mean square (RMS) value! versus Reynolds Number and Pintle position are important to creating bounding unsteady load curves for valve internal parts. Spectral analysis was also performed, helping to identify power spectral densities (PSD) of acoustic natural frequencies and boundary layer noise. An interesting and unexpected result was the identification of an acoustic mode within the valve which does not respond until the valve was over 60% open. Further, the response amplitude around this mode can be as large or larger than those associated with lower frequency modes.

Mechanisms of valve competency after mitral valve annuloplasty for ischaemic mitral regurgitation using the Geoform ring: insights from three-dimensional echocardiography.

PubMed

Armen, Todd A; Vandse, Rashmi; Crestanello, Juan A; Raman, Subha V; Bickle, Katherine M; Nathan, Nadia S

2009-01-01

Left ventricular remodelling leads to functional mitral regurgitation resulting from annular dilatation, leaflet tethering, tenting, and decreased leaflet coaptation. Mitral valve annuloplasty restores valve competency, improving the patient's functional status and ventricular function. This study was designed to evaluate the mechanisms underlying mitral valve competency after the implantation of a Geoform annuloplasty ring using three-dimensional (3D) echocardiography. Seven patients (mean age of 65 years) with ischaemic mitral regurgitation underwent mitral valve annuloplasty with the Geoform ring and coronary artery bypass surgery. Pre- and post-operative 3D echocardiograms were performed. Following mitral annuloplasty, mitral regurgitation decreased from 3.4+/-0.2 to 0.9+/-0.3 (P-value<0.0001), mitral valve tenting volume from 13+/-1.7 to 3.2+/-0.3 mL (P-value<0.001), annulus area from 12.6+/-1.0 to 3.3+/-0.2 cm2 (P-value<0.0001), valve circumference from 13+/-0.5 to 7.3+/-0.3 cm (P-value<0.0001), septolateral distance from 2.1+/-0.1 to 1.4+/-0.06 cm (P-value<0.01) and intercommissural distance from 3.4+/-0.1 to 2.7+/-0.03 cm (P-value<0.03). There was significant decrease in the septolateral distance at the level of A2-P2 with respect to other regions. These geometric changes were associated with the improvement in the NYHA class from 3.1+/-0.3 to 1.3+/-0.3 (P-value<0.002). The mitral valve annuloplasty with the Geoform ring restores leaflet coaptation and eliminates mitral regurgitation by effectively modifying the mitral annular geometry.

Transfemoral Implantation of a Fully Repositionable and Retrievable Transcatheter Valve for Noncalcified Pure Aortic Regurgitation.

PubMed

Schofer, Joachim; Nietlispach, Fabian; Bijuklic, Klaudija; Colombo, Antonio; Gatto, Fernando; De Marco, Federico; Mangieri, Antonio; Hansen, Lorenz; Bruschi, Giuseppe; Ruparelia, Neil; Rieß, Friedrich-Christian; Maisano, Franscesco; Latib, Azeem

2015-12-21

This study sought to evaluate the use of the Direct Flow Medical (DFM) transcatheter heart valve (Direct Flow Medical, Santa Rosa, California) for the treatment of noncalcific pure aortic regurgitation (AR). The treatment of noncalcific AR has remained a relative contraindication with transcatheter heart valves due to challenges in anchoring devices in the absence of calcium, concerns of valve embolization, and the high risk of significant residual paravalvular leak. The study population consisted of patients treated for severe noncalcific pure AR with transfemoral implantation of a DFM transcatheter heart valve at 6 European centers. The primary endpoint was the composite endpoint of device success and the secondary endpoint was the composite early safety endpoint (according to the VARC-2 criteria). Eleven high-risk (STS score 8.84 ± 8.9, Logistic EuroSCORE 19.9 ± 7.1) patients (mean age 74.7 ± 12.9 years) were included. Device success was achieved in all patients. In 1 patient, the initial valve prosthesis was retrieved after pull-through, and a second valve was successfully deployed. The early safety endpoint was reached in 91% of the patients, with 1 patient requiring surgical aortic valve replacement secondary to downward dislocation of the prosthesis that was successfully managed with surgical aortic valve replacement. DFM implantation resulted in excellent hemodynamics with none or trivial paravalvular regurgitation in 9 patients and a transprosthetic gradient of 7.7 ± 5.1 mm Hg at 30-day follow up. All patients derived symptomatic benefit following the procedure, with 72% in New York Heart Association functional class I or II. This study reports the feasibility of treating severe noncalcific AR with the Direct Flow prosthesis via the transfemoral route. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Morphological variation of dinoflagellate Prorocentrum lima (Ehrenberg) Dodge with geographical difference.

PubMed

Yoo, Jong Su

2004-01-01

Prorocentrum lima (Ehrenberg) Dodge, one of the cosmopolitan dinoflagellates, is basically benthic and is found on the surface of macroalgae and detritus. The identification of this species requires detailed morphological observation because of its close similarity to other benthic Prorocentrum species. The purpose of this study is to detect the morphological variability of P. lima using culture clones collected from several areas to find an adequate way of subdividing the species. In this study, 33 clones of P. lima were collected from Saipan, Tahiti, Indonesia, Japan and Bermuda, and their thecal valves and periflagellar area were observed by means of light microscopy with differential interference contrast optics and scanning electron microscopy. In general cells have two centrally located pyrenoids and a posterior nucleus. The surface of both valves has many valve pores except the center. Evenly spaced marginal pores are located along the edge of the valves. P. lima samples studied herein were subdivided into four major types (ellipsoidal, general, short, and elongate ovoid) according to their shapes, length-to-width ratio and number of valve pores. The length-to-width ratios of ellipsoidal, general, short, and elongate ovoid types were 1.32, 1.33-1.43, 1.20-1.27, and 1.53-1.60 microm respectively. Also there were slight differences in the number of valve pores. The number of valve pores examined in this study ranges from 40 to 97: ellipsoidal, general, and short ovoid types range from 40 to 91, while an elongate ovoid type ranges from 80 to 97. The combination of valve shape, number of valve pores and length-to-width ratio provides useful information on the morphological variation of P. lima.

Does the Use of a Decision Aid Improve Decision Making in Prosthetic Heart Valve Selection? A Multicenter Randomized Trial.

PubMed

Korteland, Nelleke M; Ahmed, Yunus; Koolbergen, David R; Brouwer, Marjan; de Heer, Frederiek; Kluin, Jolanda; Bruggemans, Eline F; Klautz, Robert J M; Stiggelbout, Anne M; Bucx, Jeroen J J; Roos-Hesselink, Jolien W; Polak, Peter; Markou, Thanasie; van den Broek, Inge; Ligthart, Rene; Bogers, Ad J J C; Takkenberg, Johanna J M

2017-02-01

A Dutch online patient decision aid to support prosthetic heart valve selection was recently developed. A multicenter randomized controlled trial was conducted to assess whether use of the patient decision aid results in optimization of shared decision making in prosthetic heart valve selection. In a 5-center randomized controlled trial, patients were allocated to receive either standard preoperative care (control group) or additional access to the patient decision aid (intervention group). Legally capable adult patients accepted for elective isolated or combined aortic and mitral valve replacement were included. Primary outcome was preoperative decisional conflict (Decisional Conflict Scale); secondary outcomes included patient knowledge, involvement in valve selection, anxiety and depression, (valve-specific) quality of life, and regret. Out of 306 eligible patients, 155 were randomized (78 control and 77 intervention). Preoperative decisional conflict did not differ between the groups (34% versus 33%; P =0.834). Intervention patients felt better informed (median Decisional Conflict Scale informed subscore: 8 versus 17; P =0.046) and had a better knowledge of prosthetic valves (85% versus 68%; P =0.004). Intervention patients experienced less anxiety and depression (median Hospital Anxiety and Depression Scale score: 6 versus 9; P =0.015) and better mental well-being (mean Short Form Health Survey score: 54 versus 50; P =0.032). Three months postoperatively, valve-specific quality of life and regret did not differ between the groups. A patient decision aid to support shared decision making in prosthetic heart valve selection does not lower decisional conflict. It does result in more knowledgeable, better informed, and less anxious and depressed patients, with a better mental well-being. http://www.trialregister.nl. Unique identifier: NTR4350. © 2017 American Heart Association, Inc.

Aortic Valve Replacement for Moderate Aortic Stenosis with Severe Calcification and Left Ventricualr Dysfunction-A Case Report and Review of the Literature.

PubMed

Narang, Nikhil; Lang, Roberto M; Liarski, Vladimir M; Jeevanandam, Valluvan; Hofmann Bowman, Marion A

2017-01-01

A 55-year-old man with a history of erosive, seropositive rheumatoid arthritis (RA), and interstitial lung disease presented with shortness of breath. Echocardiography showed new-onset severe left ventricular (LV) dysfunction with an ejection fraction (EF) of 15% and moderately increased mean aortic valve gradient of 20 mmHg in a trileaflet aortic valve with severe sclero-calcific degeneration. Coronary angiography revealed no significant obstructive coronary disease. Invasive hemodynamic studies and dobutamine stress echocardiography were consistent with moderate aortic stenosis. Guideline directed medical therapy for heart failure with reduced EF was initiated; however, diuretics and neurohormonal blockade (beta-blocker and angiotensin receptor blocker) provided minimal improvement, and the patient remained functionally limited. Of interest, echocardiography performed 1 year prior to his presentation showed normal LV EF and mild aortic leaflet calcification with moderate stenosis, suggesting a rapid progressing of calcific aortic valve disease. Subsequently, the patient underwent surgical aortic valve replacement and demonstrated excellent postsurgical recovery of LV EF (55%). Calcific aortic valve disease is commonly associated with aging, bicuspid aortic valve, and chronic kidney disease. Pathophysiological mechanism for valvular calcification is incompletely understood but include osteogenic transformation of valvular interstitial cells mediated by local and systemic inflammatory processes. Several rheumatologic diseases including RA are associated with premature atherosclerosis and arterial calcification, and we speculated a similar role of RA accelerating calcific aortic valve disease. We present a case of accelerated aortic valve calcification with (only) moderate stenosis, complicated by a rapid decline in LV systolic performance. Guidelines for AVR in moderate stenosis without concomitant cardiac surgery are not well established, although it should be considered in selected patients.

The JUPITER registry: One-year outcomes of transapical aortic valve implantation using a second generation transcatheter heart valve for aortic regurgitation.

PubMed

Silaschi, Miriam; Conradi, Lenard; Wendler, Olaf; Schlingloff, Friederike; Kappert, Utz; Rastan, Ardawan J; Baumbach, Hardy; Holzhey, David; Eichinger, Walter; Bader, Ralf; Treede, Hendrik

2018-06-01

We present 1-year outcomes of the post-market registry of a next-generation transcatheter heart valve used for aortic regurgitation (AR). Transcatheter aortic valve replacement (TAVR) is routine in high-risk patients with aortic stenosis but is not recommended for AR. The JenaValve™ (JenaValve Technology GmbH, Munich, Germany) overcomes technical challenges in AR patients through a leaflet clipping mechanism. The JenaValve EvalUation of Long Term Performance and Safety In PaTients with SEvere Aortic Stenosis oR Aortic Insufficiency (JUPITER) Registry is a European study to evaluate safety and effectiveness of this THV. From 2012-2015, 30 patients with AR were enrolled. Mean age was 74.4 ± 9.3 years. Procedural success was 96.7% (29/30). One patient was converted to open surgery. No annular rupture or coronary ostia obstruction occurred. Mortality at 30 days was 10.0% (3/30). Combined safety endpoint was met in 13.3% (4/30). Paravalvular regurgitation was not present/trivial in 84.6% (22/26) and mild in 15.4% (4/26). Rate of permanent pacemaker implantation was 3.8% (1/26). One-year Kaplan-Meier survival was 79.9%, one-year combined efficacy was 73.1% (19/30). No further strokes were observed during 1 year of follow-up. The JenaValve overcomes technical challenges of TAVR in AR through a clipping mechanism. We report satisfactory outcomes of a multicenter registry using the JenaValve for predominant AR, as rate of THV embolization, residual AR and permanent pacemaker implantation was low. One-year results using the JenaValve for AR encourage its use for this indication. © 2017 Wiley Periodicals, Inc.

Pump having pistons and valves made of electroactive actuators

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph (Inventor)

1997-01-01

The present invention provides a pump for inducing a displacement of a fluid from a first medium to a second medium, including a conduit coupled to the first and second media, a transducing material piston defining a pump chamber in the conduit and being transversely displaceable for increasing a volume of the chamber to extract the fluid from the first medium to the chamber and for decreasing the chamber volume to force the fluid from the chamber to the second medium, a first transducing material valve mounted in the conduit between the piston and the first medium and being transversely displaceable from a closed position to an open position to admit the fluid to the chamber, and control means for changing a first field applied to the piston to displace the piston for changing the chamber volume and for changing a second field applied to the first valve to change the position of the first valve.

Non-collinear valve actuator

NASA Technical Reports Server (NTRS)

Richard, James A. (Inventor)

2012-01-01

A non-collinear valve actuator includes a primary actuating system and a return spring system with each applying forces to a linkage system in order to regulate the flow of a quarter-turn valve. The primary actuating system and return spring system are positioned non-collinearly, which simply means the primary actuating system and return spring system are not in line with each other. By positioning the primary actuating system and return spring system in this manner, the primary actuating system can undergo a larger stroke while the return spring system experiences significantly less displacement. This allows the length of the return spring to be reduced due to the minimization of displacement thereby reducing the weight of the return spring system. By allowing the primary actuating system to undergo longer strokes, the weight of the primary actuating system may also be reduced. Accordingly, the weight of the non-collinear valve actuator is reduced.

System for Dispensing a Precise Amount of Fluid

DOEpatents

Benett, William J.; Krulevitch, Peter A.; Visuri, Steven R.; Dzenitis, John M.; Ness, Kevin D.

2008-08-12

A dispensing system delivers a precise amount of fluid for biological or chemical processing and/or analysis. Dispensing means moves the fluid. The dispensing means is operated by a pneumatic force. Connection means delivers the fluid to the desired location. An actuator means provides the pneumatic force to the dispensing means. Valving means transmits the pneumatic force from the actuator means to the dispensing means.

Short-term forecasting of emergency inpatient flow.

PubMed

Abraham, Gad; Byrnes, Graham B; Bain, Christopher A

2009-05-01

Hospital managers have to manage resources effectively, while maintaining a high quality of care. For hospitals where admissions from the emergency department to the wards represent a large proportion of admissions, the ability to forecast these admissions and the resultant ward occupancy is especially useful for resource planning purposes. Since emergency admissions often compete with planned elective admissions, modeling emergency demand may result in improved elective planning as well. We compare several models for forecasting daily emergency inpatient admissions and occupancy. The models are applied to three years of daily data. By measuring their mean square error in a cross-validation framework, we find that emergency admissions are largely random, and hence, unpredictable, whereas emergency occupancy can be forecasted using a model combining regression and autoregressive integrated moving average (ARIMA) model, or a seasonal ARIMA model, for up to one week ahead. Faced with variable admissions and occupancy, hospitals must prepare a reserve capacity of beds and staff. Our approach allows estimation of the required reserve capacity.

Design and Experimental Performance of a Two Stage Partial Admission Turbine, Task B.1/B.4

NASA Technical Reports Server (NTRS)

Sutton, R. F.; Boynton, J. L.; Akian, R. A.; Shea, Dan; Roschak, Edmund; Rojas, Lou; Orr, Linsey; Davis, Linda; King, Brad; Bubel, Bill

1992-01-01

A three-inch mean diameter, two-stage turbine with partial admission in each stage was experimentally investigated over a range of admissions and angular orientations of admission arcs. Three configurations were tested in which first stage admission varied from 37.4 percent (10 of 29 passages open, 5 per side) to 6.9 percent (2 open, 1 per side). Corresponding second stage admissions were 45.2 percent (14 of 31 passages open, 7 per side) and 12.9 percent (4 open, 2 per side). Angular positions of the second stage admission arcs with respect to the first stage varied over a range of 70 degrees. Design and off-design efficiency and flow characteristics for the three configurations are presented. The results indicated that peak efficiency and the corresponding isentropic velocity ratio decreased as the arcs of admission were decreased. Both efficiency and flow characteristics were sensitive to the second stage nozzle orientation angles.

Relation of an Echocardiographic-Based Cardiac Calcium Score to Mitral Stenosis Severity and Coronary Artery Disease in Patients with Severe Aortic Stenosis.

PubMed

Sheng, Siyuan P; Howell, Lucius A; Caughey, Melissa C; Yeung, Michael; Vavalle, John P

2018-01-15

Patients with calcific aortic stenosis (AS) often have diffuse cardiac calcification involving the mitral valve apparatus and coronary arteries. We examined the association between global cardiac calcification quantified by a previously validated echocardiographic calcium score (eCS) with the severity of mitral stenosis (MS) and coronary artery disease (CAD) in patients with a clinical diagnosis of severe calcific AS. In this sample of 147 patients (mean age 81 ± 9 years, 50% male), 81 patients (55%) were determined by echocardiography to have some degree of MS. Higher mean eCS was observed in patients with more severe MS (r = 0.54, p < 0.0001). Higher eCS was also inversely associated with mitral valve area (r = -0.31, p = 0.001) and positively associated with mitral valve mean pressure gradient (r = 0.46, p < 0.0001) and mitral valve peak flow velocity (r = 0.55, p < 0.0001). The area under the receiver operating characteristic curve for using eCS to predict the presence of MS was 0.76. An eCS ≥ 8 predicted MS with a sensitivity of 68%, specificity of 76%, positive predictive value of 77%, and negative predictive value of 66%. High eCS, relative to low eCS, was associated with 2.70 times the adjusted odds of CAD (odds ratio = 2.70, 95% confidence interval 1.02 to 7.17). In conclusion, global cardiac calcification is associated with MS and CAD in patients with severe calcific AS, and eCS shows ability to predict the presence of MS. This study suggests that a simple eCS may be used as part of a risk-stratification tool in patients with severe calcific aortic valve stenosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Mid-term study of transcatheter aortic valve implantation in an Asian population with severe aortic stenosis: two-year Valve Academic Research Consortium-2 outcomes

PubMed Central

Chew, Nicholas; Hon, Jimmy Kim Fatt; Yip, Wei Luen James; Chan, Siew Pang; Poh, Kian-Keong; Kong, William Kok-Fai; Teoh, Kristine Leok Kheng; Yeo, Tiong Cheng; Tan, Huay Cheem; Tay, Edgar Lik Wui

2017-01-01

INTRODUCTION Transcatheter aortic valve implantation (TAVI) is an effective treatment for high-risk or inoperative patients with severe aortic stenosis. Given the unique characteristics of Asian populations, questions regarding mid-term outcomes in Asians undergoing TAVI have yet to be addressed. We evaluated the two-year clinical outcomes of TAVI in an Asian population using Valve Academic Research Consortium-2 definitions. METHODS This prospective study recruited 59 patients from a major academic medical centre in Singapore. The main outcomes were two-year survival rates, peri-procedural complications, symptom improvement, valvular function and assessment of learning curve. RESULTS Mean age was 76.8 years (61.0% male), mean body surface area 1.6 m2 and mean logistic EuroSCORE 18.7%. Survival was 93.2%, 86.0% and 79.1% at 30 days, one year and two years, respectively. At 30 days post TAVI, the rate of stroke was 1.7%, life-threatening bleeding 5.1%, acute kidney injury 25.0%, major vascular complication 5.1%, and new permanent pacemaker implantation 6.8%. 29.3% of TAVI patients were rehospitalised (47.1% cardiovascular-related) within one year. These composite outcomes were measured: device success (93.2%); early safety (79.7%); clinical efficacy (66.1%); and time-related valve safety (84.7%). Univariate analysis found these predictors of two-year all-cause mortality: logistic EuroSCORE (hazard ratio [HR] 1.07; p < 0.001); baseline estimated glomerular filtration rate (HR 0.97; p = 0.048); and acute kidney injury (HR 5.33; p = 0.022). Multivariate analysis identified non-transfemoral TAVI as a predictor of cardiovascular-related two-year mortality (HR 14.64; p = 0.008). CONCLUSION Despite the unique clinical differences in Asian populations, this registry demonstrated favourable mid-term clinical and safety outcomes in Asians undergoing TAVI. PMID:27516113

Mid-term study of transcatheter aortic valve implantation in an Asian population with severe aortic stenosis: two-year Valve Academic Research Consortium-2 outcomes.

PubMed

Chew, Nicholas; Hon, Jimmy Kim Fatt; Yip, Wei Luen James; Chan, Siew Pang; Poh, Kian-Keong; Kong, William Kok-Fai; Teoh, Kristine Leok Kheng; Yeo, Tiong Cheng; Tan, Huay Cheem; Tay, Edgar Lik Wui

2017-09-01

Transcatheter aortic valve implantation (TAVI) is an effective treatment for high-risk or inoperative patients with severe aortic stenosis. Given the unique characteristics of Asian populations, questions regarding mid-term outcomes in Asians undergoing TAVI have yet to be addressed. We evaluated the two-year clinical outcomes of TAVI in an Asian population using Valve Academic Research Consortium-2 definitions. This prospective study recruited 59 patients from a major academic medical centre in Singapore. The main outcomes were two-year survival rates, peri-procedural complications, symptom improvement, valvular function and assessment of learning curve. Mean age was 76.8 years (61.0% male), mean body surface area 1.6 m 2 and mean logistic EuroSCORE 18.7%. Survival was 93.2%, 86.0% and 79.1% at 30 days, one year and two years, respectively. At 30 days post TAVI, the rate of stroke was 1.7%, life-threatening bleeding 5.1%, acute kidney injury 25.0%, major vascular complication 5.1%, and new permanent pacemaker implantation 6.8%. 29.3% of TAVI patients were rehospitalised (47.1% cardiovascular-related) within one year. These composite outcomes were measured: device success (93.2%); early safety (79.7%); clinical efficacy (66.1%); and time-related valve safety (84.7%). Univariate analysis found these predictors of two-year all-cause mortality: logistic EuroSCORE (hazard ratio [HR] 1.07; p < 0.001); baseline estimated glomerular filtration rate (HR 0.97; p = 0.048); and acute kidney injury (HR 5.33; p = 0.022). Multivariate analysis identified non-transfemoral TAVI as a predictor of cardiovascular-related two-year mortality (HR 14.64; p = 0.008). Despite the unique clinical differences in Asian populations, this registry demonstrated favourable mid-term clinical and safety outcomes in Asians undergoing TAVI. Copyright: © Singapore Medical Association

Outcomes following transcatheter aortic valve replacement in patients with native aortic valve regurgitation

PubMed Central

Bob-Manuel, Tamunoinemi; Kadire, Siri; Heckle, Mark R.; Wang, Jiajing

2018-01-01

Due to the absence of annular calcification for device anchoring, it is presumed that transcatheter aortic valve replacement (TAVR) is not suitable for the treatment of native aortic valve regurgitation (NAVR) resulting in very limited data and experience concerning its safety and efficacy. We sought to review published data on the safety and efficacy of TAVR in high-risk patients with NAVR. Studies including case reports, case series and original articles published between 2002 and 2016 on TAVR in patients with NAVR were identified with a systematic electronic search using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Only studies reporting data on demographic and procedural characteristics, management and follow up outcomes were analyzed. A total of 30 publications describing 182 patients were identified. Most patients (54%) were men, with a mean age of 70.1±2.6 years, mean logistic European System for Cardiac Operative Risk Evaluation score (EuroSCORE) of 21.8%±4.5% and mean Society of Thoracic Surgeons (STS) score of 8%±1.8% for mortality. The majority (87%) of patients had severe NAVR with no valvular calcification. TAVR was mostly performed through the femoral (58.8%) and apical (33.1%) approach. Device success, defined by VARC-2, was achieved in 86.3% of our study population. A second valve was required in 17 patients (9.3%) during the index procedure for residual aortic regurgitation or malposition. Post-procedure aortic regurgitation of grade 1 or less was present in 80 patients (81%). Pacemaker implantation was required post procedure in 17 patients (9.3%). The 30-day and 1-year mortality was 11.9% and 16.2%, respectively. TAVR is associated with favorable pacemaker implantation and 1-year mortality rates with a high 30-day mortality among selected patients with NAVR. PMID:29404354

Larry car for a coking oven battery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corry, D.B.

A larry car (3) for transporting a charge of pre-heated coal along the top of a battery of coke ovens, from a storage installation including a group of metering bins (1) at one or more filling stations above the battery, to a corresponding group of charge holes for the oven chamber to be charged, the car including a corresponding group of coal transfer hoppers (4) each having valved inlet and discharge apertures (5,21), a sealed connection (2) between each metering bin and transfer hopper, an inert gas reservoir (10) connectable via a valved manifold (13,14) to each transfer hopper, amore » valved connection (7,8,9) for charging the reservoir, and a valved connection (15,16,17) to permit dusty gas to be displaced into the storage bunkers, and control means for the various valved connections to maintain continuous isolation of the interior of each transfer hopper from the atmosphere, to permit dust-laden gases to escape into the storage installation, and to cause inert medium to displace coal discharged from the transfer hoppers.« less

Open-heart surgery using a centrifugal pump: a case of hereditary spherocytosis.

PubMed

Matsuzaki, Yuichi; Tomioka, Hideyuki; Saso, Masaki; Azuma, Takashi; Saito, Satoshi; Aomi, Shigeyuki; Yamazaki, Kenji

2016-08-26

Hereditary spherocytosis is a genetic, frequently familial hemolytic blood disease characterized by varying degrees of hemolytic anemia, splenomegaly, and jaundice. There are few reports on adult open-heart surgery for patients with hereditary spherocytosis. We report a rare case of an adult open-heart surgery associated with hereditary spherocytosis. A 63-year-old man was admitted for congestive heart failure due to bicuspid aortic valve, aortic valve regurgitation, and sinus of subaortic aneurysm. The family history, the microscopic findings of the blood smear, and the characteristic osmotic fragility confirmed the diagnosis of hereditary spherocytosis. Furthermore, splenectomy had not been undertaken preoperatively. The patient underwent a successful operation by means of a centrifugal pump. Haptoglobin was used during the cardiopulmonary bypass, and a biological valve was selected to prevent hemolysis. No significant hemolysis occurred intraoperatively or postoperatively. There are no previous reports of patients with hereditary spherocytosis, and bicuspid aortic valve. We have successfully performed an adult open-heart surgery using a centrifugal pump in an adult patient suffering from hereditary spherocytosis and bicuspid aortic valve.

CARDIAC SURGERY FOR VALVULAR HEART DISEASE AT A REFERRAL HOSPITAL IN ETHIOPIA: A REVIEW OF CASES OPERATED IN THE LAST 30 YEARS.

PubMed

Guteta, Senbeta; Yadeta, Dejuma; Azazh, Aklilu; Mekonnen, Dufera

2016-04-01

Valvular heart disease has been a significant cause of heart disease worldwide. In Ethiopia, it particularly affects young individuals and constitutes the major cause of cardiovascular disease. Factors associated with choice of treatment for advanced valvular heart disease are variable. The objective of this study is to review surgery done for Ethiopian patients with valvular heart disease. We analyzed data on patients who had valve surgery and follow-up at the Tikur Anbessa Specialized Hospital cardiology unit. We collected data on sociodemographic characteristics, the pre-operative status of effected valves and co-morbidities, and assessed their associations with patient management options. A total of 157 valve surgeries were done from 1983 to 2013. Mean age at time of surgery was 26.7 years and females constituted 66% of the cases. Patients with rheumatic heart disease were younger, more likely to be female and have atrial fibrillation, but less likely to have impaired left ventricular systolic function when compared to patients with non-rheumatic heart disease. More than 75% of the surgical procedures done were mechanical valve replacement. Mechanical valves, compared with bioprosthetic valves, were more likely to be used in patients with rheumatic heart disease. The median age of those receiving mechanical valves, 24 (IQR 22-28) years, was lower than those receiving bioprosthetic valves, 31.5 (IQR 29.9-37.9) years. Mechanical valve replacement was significantly higher in those under the age of 20 years (Adjusted Odds Ratio 41.0, 95% CI: 3.0-557.2) and in those between 20 and 29 years of age (Adjusted Odds Ratio 14.3, 95% CI: 2.3-88.6). Valve surgery for valvular heart diseases has been more common performed for young and female patients. A great majority of the replacements done have been with mechanical valves. As many of the patients have been younger and female, the choice of valve surgery and the need for anticoagulation impacts subsequent management of rheumatic heart disease and associated morbidities, lifestyle plans and pregnancy.

Hospital admissions for viral meningitis in children in England over five decades: a population-based observational study.

PubMed

Martin, Natalie G; Iro, Mildred A; Sadarangani, Manish; Goldacre, Raphael; Pollard, Andrew J; Goldacre, Michael J

2016-11-01

A substantial reduction in bacterial meningitis has occurred in the UK following successful implementation of immunisation programmes. Most childhood meningitis in developed countries is now caused by viruses. Long-term trends in paediatric viral meningitis in England have not previously been reported. The objective of this study is to report on epidemiological trends over time in childhood viral meningitis in England. In this population-based observational study, we used routinely collected hospital discharge records from English National Health Service hospitals from 1968-2011 to analyse annual age-specific admission rates for viral meningitis, including specific viral aetiologies, in children younger than 15 years. We analysed hospital discharge records from Jan 1, 1968, to Dec 31, 2011. Hospital admission rates for viral meningitis from Jan 1, 1968, to Dec 31, 1985, varied annually, with a mean of 13·5 admissions per 100 000 children aged less than 15 years, per year (95% CI 13·0-14·0). Admission rates declined during the late 1980s, and the mean number of admissions from 1989-2011 was 5·2 per 100 000 per year (5·1-5·3). This decrease was entirely in children aged 1-14 years. Admission rates for infants aged less than 1 year increased since 2005, to 70·0 per 100 000 (63·7-76·2) in 2011, which was driven by an increase in admission of infants aged 90 days or less. In 1968-85, the majority of cases in children were in those aged 1-14 years (22 150 [89%] of 24 920 admissions). In 2007-11, 1716 (72%) of 2382 cases were in infants. Admissions for mumps-related meningitis almost disappeared following introduction of the measles-mumps-rubella (MMR) vaccine in 1988. Admissions with a specified viral aetiology have increased since 2000. Trends in viral meningitis admissions have changed substantially over the past 50 years, and probably reflect the impact of the MMR vaccine programme and the use of more sensitive diagnostic techniques. None. Copyright © 2016 Elsevier Ltd. All rights reserved.

The valve choice in tricuspid valve replacement: 25 years of experience.

PubMed

Van Nooten, G J; Caes, F L; François, K J; Taeymans, Y; Primo, G; Wellens, F; Leclerq, J L; Deuvaert, F E

1995-01-01

This study reviews 146 consecutive patients who underwent tricuspid valve replacement (TVR) with 69 bioprostheses (porcine and bovine pericardial) and 77 mechanical ball, disc or bileaflet valves between 1967 and 1987. The mean age was 51.4 +/- 12.1 years. Preoperatively, 97% were in New York Heart Association (NYHA) functional class III or more and over 40% had undergone previous cardiac surgery. Hospital mortality was high (16.1%). Incremental risk factors for hospital death were preoperative icterus (P < 0.01), hepatomegaly (P = 0.02), NYHA functional class IV (P = 0.02) and male sex (P = 0.04) (univariate analysis). Ninety-eight percent of the hospital survivors were followed up for a mean of 92 months. Cumulative follow-up added up to 955 patient-years. There were 70 late deaths. The actuarial survival rate was 74% at 60 months and less than 25% at 14 years. Incremental risk factors for late death indicated by univariate analysis were the type of tricuspid prosthesis (Smel-off-Cutter and Kay-Shiley prostheses) (P = 0.04), the type of operative myocardial protection (normothermia and coronary perfusion) (P = 0.05) and preoperative NYHA functional class IV (P = 0.05). We conclude that TVR carries a high operative risk and poor long-term survival, both influenced by preoperative and perioperative variables. Bearing in mind the poor prognosis for TVR, we prefer a large-sized bioprosthesis, in view of its initial good durability and low risk of valve-related events. However, in patients with good life expectancy, a bileaflet mechanical prosthesis may be an acceptable alternative.

Paper-based microfluidics with an erodible polymeric bridge giving controlled release and timed flow shutoff.

PubMed

Jahanshahi-Anbuhi, Sana; Henry, Aleah; Leung, Vincent; Sicard, Clémence; Pennings, Kevin; Pelton, Robert; Brennan, John D; Filipe, Carlos D M

2014-01-07

Water soluble pullulan films were formatted into paper-based microfluidic devices, serving as a controlled time shutoff valve. The utility of the valve was demonstrated by a one-step, fully automatic implementation of a complex pesticide assay requiring timed, sequential exposure of an immobilized enzyme layer to separate liquid streams. Pullulan film dissolution and the capillary wicking of aqueous solutions through the device were measured and modeled providing valve design criteria. The films dissolve mainly by surface erosion, meaning the film thickness mainly controls the shutoff time. This method can also provide time-dependent sequential release of reagents without compromising the simplicity and low cost of paper-based devices.

Fuel injection of coal slurry using vortex nozzles and valves

DOEpatents

Holmes, Allen B.

1989-01-01

Injection of atomized coal slurry fuel into an engine combustion chamber is achieved at relatively low pressures by means of a vortex swirl nozzle. The outlet opening of the vortex nozzle is considerably larger than conventional nozzle outlets, thereby eliminating major sources of failure due to clogging by contaminants in the fuel. Control fluid, such as air, may be used to impart vorticity to the slurry and/or purge the nozzle of contaminants during the times between measured slurry charges. The measured slurry charges may be produced by a diaphragm pump or by vortex valves controlled by a separate control fluid. Fluidic circuitry, employing vortex valves to alternatively block and pass cool slurry fuel flow, is disclosed.

Relation of Mitral Valve Surgery Volume to Repair Rate, Durability, and Survival.

PubMed

Chikwe, Joanna; Toyoda, Nana; Anyanwu, Anelechi C; Itagaki, Shinobu; Egorova, Natalia N; Boateng, Percy; El-Eshmawi, Ahmed; Adams, David H

2017-04-24

Degenerative mitral valve repair rates remain highly variable, despite established benefits of repair over replacement. The contribution of surgeon-specific factors is poorly defined. This study evaluated the influence of surgeon case volume on degenerative mitral valve repair rates and outcomes. A mandatory New York State database was queried and 5,475 patients were identified with degenerative mitral disease who underwent mitral valve operations between 2002 and 2013. Mitral repair rates, mitral reoperations within 12 months of repair, and survival were analyzed using multivariable Cox modeling and restricted cubic spline function. Median annual surgeon volume of any mitral operations was 10 (range 1 to 230), with a mean repair rate of 55% (n = 20,797 of 38,128). In the subgroup of patients with degenerative disease, the mean repair rate was 67% (n = 3,660 of 5,475), with a range of 0% to 100%. Mean repair rates ranged from 48% (n = 179 of 370) for surgeons with total annual volumes of ≤10 mitral operations to 77% (n = 1,710 of 2,216) for surgeons with total annual volumes of >50 mitral operations (p < 0.001). Higher total annual surgeon volume was associated with increased repair rates of degenerative mitral valve disease (adjusted odds ratio [OR]: 1.13 for every additional 10 mitral operations; 95% confidence interval [CI]: 1.10 to 1.17; p < 0.001); a steady decrease in reoperation risk until 25 total mitral operations annually; and improved 1-year survival (adjusted hazard ratio: 0.95 for every additional 10 operations; 95% CI: 0.92 to 0.98; p = 0.001). For surgeons with a total annual volume of ≤25 mitral operations, repair rates were higher (63.8%; n = 180 of 282) if they operated in the same institution as a surgeon with total annual mitral volumes of >50 and degenerative mitral valve repair rates of >70%, compared with surgeons operating in the other institutions (51.3%; n = 580 of 1,130) (adjusted OR: 1.79; 95% CI: 1.24 to 2.60; p < 0.001). This study suggests that individual surgeon volume is a determinant of not only mitral repair rates, but also freedom from reoperation, and survival. The data from this study support the guideline's concept of reference referral to experienced mitral surgeons to improve outcomes in patients with degenerative mitral valve disease. Copyright © 2017. Published by Elsevier Inc.

Results of transcatheter pulmonary valvulation in native or patched right ventricular outflow tracts.

PubMed

Malekzadeh-Milani, Sophie; Ladouceur, Magalie; Cohen, Sarah; Iserin, Laurence; Boudjemline, Younes

2014-11-01

Although widely accepted worldwide, indications for percutaneous valve replacement are limited to treatment of dysfunction of prosthetic conduits inserted in the right ventricular outflow tract (RVOT). There has been little evaluation of the use of the Melody(®) valve for patched non-circular pulmonary pathways. To evaluate the outcomes of Melody valve insertion in patients with a patched non-circular RVOT. We analysed procedural and outcomes data from 34 patients who underwent Melody valve implantation for a non-circular RVOT. RVOT preparation was done in all patients, using different techniques (conventional, Russian doll and/or PA jailing). Melody valve insertion was performed concomitantly in most patients. All procedures were successful. Sixteen patients had complex additional procedures, including the jailing technique (n=5), the Russian doll technique (n=6) and multiple stent implantations (Russian jailing; n=5). The remaining patients were treated using the conventional technique with systematic prestenting. Three early complications occurred: one haemoptysis; one residual RVOT obstruction needing recatheterization 48 hours after percutaneous pulmonary valve implantation; and one stent embolization during advancement of the Ensemble(®) delivery system. The mean follow-up period was 2.6 years postprocedure. There was no stent fracture, migration or embolization. Two patients developed a significant paraprosthetic leak and one received a second Melody valve. Careful patient selection, balloon sizing and RVOT preparation with prestenting are required to create a safe landing zone for the Melody valve. Short-term follow-up shows excellent results with no stent fracture or migration and appears promising. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Effect of transcatheter aortic valve implantation on intraoperative left ventricular end-diastolic pressure.

PubMed

Toyota, Kosaku; Ota, Takashi; Nagamine, Katsutoshi; Koide, Yasuhiro; Nomura, Takeshi; Yamanaka, Futoshi; Shishido, Koki; Tanaka, Masashi; Saito, Shigeru

2016-12-01

Transcatheter aortic valve implantation (TAVI) for patients with aortic stenosis is a less invasive alternative to surgical aortic valve replacement. Despite this, careful anesthetic management, especially strict control of blood pressure and fluid management, is necessary. During TAVI, normalization of left ventricular afterload due to aortic balloon valvuloplasty and prosthetic valve deployment is expected to result in rapid improvement of systolic function and consequent improvement in diastolic function. However, the early effect of TAVI on left ventricular diastolic function is less clear. We hypothesized that TAVI induces a rapid decrease in left ventricular end-diastolic pressure (LVEDP) after valve deployment. This retrospective observational study included 71 patients who had undergone TAVI using the transfemoral approach with a balloon-expandable valve under general anesthesia. Intraoperative LVEDP was measured using an intracardiac catheter. The severity of residual aortic regurgitation (AR) was assessed using the Sellers criteria. The mean (SD) LVEDP was 17.8 (5.3) mmHg just before TAVI and increased significantly to 27.3 (8.2) mmHg immediately after prosthetic valve deployment (p < 0.0001). The change in LVEDP was 8.7 (8.6) mmHg in patients with low residual AR (Sellers ≤1) and 11.0 (7.1) mmHg in those with high residual AR (Sellers ≥2); however, this difference was not significant. No correlation was found between the LVEDP change and intraoperative fluid balance. In conclusion, LVEDP increased significantly in the early period after valve deployment during TAVI, regardless of residual AR severity. It was suggested that the tolerability of fluid load could be reduced at that time.

Utility of cardiac computed tomography for evaluation of pannus in mechanical aortic valve.

PubMed

Suh, Young Joo; Kim, Young Jin; Lee, Sak; Hong, Yoo Jin; Lee, Hye-Jeong; Hur, Jin; Choi, Byoung Wook; Chang, Byung-Chul

2015-08-01

The clinical significance of pannus detected on computed tomography (CT) has not yet been investigated. The purposes of this study were to investigate the clinical significance of pannus detected on cardiac CT in patients who underwent aortic valve replacement (AVR) with mechanical valves, and to determine predictors for pannus severity. A total of 92 patients who underwent cardiac CT and TTE and who had undergone mechanical AVR were included. The geometric orifice area (GOA), the presence of limitation of motion (LOM) and pannus were evaluated on CT. The GOA, presence of LOM, and presence and severity of pannus were compared with echocardiographic parameters. Logistic regression analysis was performed to determine the predictors for pannus severity. The GOA on CT positively correlated with effective orifice area on TTE (r = 0.733, P < 0.0001). Pannus was found in 77.2% and LOM in 14.0%. With increasing pannus severity, mean transvalvular pressure gradient (PG) was significantly higher (P < 0.0001). Patients with elevated PG showed a smaller GOA, a higher incidence of pannus, more severe pannus and LOM than patients with normal PG (P < 0.05). Small valve size (≤19 mm), Carbomedics valve, rheumatic etiology, and young age at AVR (<48.8 years) were independent predictors of moderate to severe pannus (P < 0.05). Cardiac CT is helpful in the evaluation of pannus formation in patients with mechanical aortic valves. Moderate to severe pannus formation frequently occurred in patients with small mechanical valve size, Carbomedics valves, rheumatic heart disease and young age at AVR.

Hemodynamics of Pericardial Aortic Valves: Contemporary Stented versus Stentless Valves in a Matched Comparison

PubMed Central

Holinski, Sebastian; Zhigalov, Konstantin; Zielinski, Christina Barbara; Grubitzsch, Herko

2017-01-01

Purpose: Hemodynamic performance of aortic valve bioprostheses is essential for reliable function and durability. So far, the supra-annularly implanted stentless Sorin Freedom Solo (SFS) demonstrated unsurpassed hemodynamic properties. As contemporary stented and externally mounted pericardial bioprostheses, like the Labcor Dokimos Plus (LDP), also improve hemodynamic performance, these types of valves were compared in this study. Methods: A total of 218 patients, who underwent aortic valve replacement with the LDP or the SFS, were matched retrospectively 1:1 on variables affecting hemodynamic measurements: implanted valve size, age, sex, and body surface area (BSA). With matching tolerance for valve size and gender of 0%, for age and BSA of 5%, 57 patient-pairs were yielded. Operative data, clinical, and hemodynamic outcome were analyzed. Results: Except for slightly higher left ventricular function and lower procedural times in the SFS group, preoperative, operative, and postoperative characteristics of patient-pairs did not differ significantly. Mean pressure gradients, effective orifice areas (EOAs), and indexed EOAs were comparable. Corresponding to valve sizes of 21, 23, 25, and 27 mm, the indexed EOAs of the LDP and SFS prostheses were 1.08 ± 0.33, 0.92 ± 0.19, 0.93 ± 0.24, 0.99 ± 0.13 cm2/m2 and 0.81 ± 0.13, 0.92 ± 0.28, 0.95 ± 0.20, 1.04 ± 0.27 cm2/m2, respectively. Conclusion: Contemporary stented and stentless pericardial bioprostheses showed excellent hemodynamic properties without significant differences in EOAs and indexed EOAs. PMID:28890465

Tenon advancement and duplication technique to prevent postoperative Ahmed valve tube exposure in patients with refractory glaucoma.

PubMed

Tamcelik, Nevbahar; Ozkok, Ahmet; Sarıcı, Ahmet Murat; Atalay, Eray; Yetik, Huseyin; Gungor, Kivanc

2013-07-01

To present and compare the long-term results of Dr. Tamcelik's previously described technique of Tenon advancement and duplication with the conventional Ahmed glaucoma valve (AGV) implantation technique in patients with refractory glaucoma. This study was a multicenter, retrospective case series that included 303 eyes of 276 patients with refractory glaucoma who underwent glaucoma valve implantation surgery. The patients were divided into three groups according to the surgical technique applied and the outcomes compared. In group 1, 96 eyes of 86 patients underwent AGV implant surgery without patch graft; in group 2, 78 eyes of 72 patients underwent AGV implant surgery with donor scleral patch; in group 3, 129 eyes of 118 patients underwent Ahmed valve implant surgery with "combined short scleral tunnel with Tenon advancement and duplication technique". The endpoint assessed was tube exposure through the conjunctiva. In group 1, conjunctival tube exposure was seen in 11 eyes (12.9 %) after a mean 9.2 ± 3.7 years of follow-up. In group 2, conjunctival tube exposure was seen in six eyes (2.2 %) after a mean 8.9 ± 3.3 years of follow-up. In group 3, there was no conjunctival exposure after a mean 7.8 ± 2.8 years of follow-up. The difference between the groups was statistically significant. (P = 0.0001, Chi-square test). This novel surgical technique combining a short scleral tunnel with Tenon advancement and duplication was found to be effective and safe to prevent conjunctival tube exposure after AGV implantation surgery in patients with refractory glaucoma.

Prospective ECG-triggered, axial 4-D imaging of the aortic root, valvular, and left ventricular structures: a lower radiation dose option for preprocedural TAVR imaging.

PubMed

Bolen, Michael A; Popovic, Zoran B; Dahiya, Arun; Kapadia, Samir R; Tuzcu, E Murat; Flamm, Scott D; Halliburton, Sandra S; Schoenhagen, Paul

2012-01-01

Transcatheter valve interventions rely on imaging for patient selection, preprocedural planning, and intraprocedural guidance. We explored the use of prospective electrocardiogram (ECG)-triggered 4-dimensional (4-D) CT imaging in patients evaluated for transcatheter aortic valve replacement (TAVR). A total of 47 consecutive patients underwent 128-slice dual-source CT with wide-window dose-modulated prospective ECG-triggered, axial acquisition of the aortic root, reconstructed during diastolic and systolic cardiac phases. Image quality was evaluated, aortic root and left ventricular (LV) geometry and function were analyzed, and radiation exposure was estimated. Image quality was generally good, with 41 of 47 (87%) patients scored as good or excellent. The mean aortic valve area was 0.93 ± 0.24 cm(2). Mean LV ejection fraction was 56.8% ± 16.4%, and mean LV mass was 130.4 ± 43.8 g. The minor diameter of the annulus was larger in systole (systole, 2.29 ± 0.24 cm; diastole, 2.14 ± 0.25 cm; P = 0.006), but the mean and major diameters did not vary significantly between systole and diastole. The mean estimated effective dose was 5.9 ± 2.4 mSv. Multiphase, prospective ECG-triggered axial image acquisition is a lower dose acquisition technique for 4-D aortic root imaging in patients being considered for TAVR. Copyright © 2012 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Admission temperature of low birth weight infants: predictors and associated morbidities.

PubMed

Laptook, Abbot R; Salhab, Walid; Bhaskar, Brinda

2007-03-01

There is a paucity of information on the maintenance of body temperature at birth for low birth weight infants. We examined the distribution of temperatures in low birth weight infants on admission to the NICUs in the Neonatal Research Network centers and determined whether admission temperature was associated with antepartum and birth variables and selected morbidities and mortality. Infants without major congenital anomalies born during 2002 and 2003 with birth weights of 401 to 1499 g who were admitted directly from the delivery room to the NICU were included. Bivariate associations between antepartum/birth variables and admission temperature and selected morbidities/mortality and admission temperature were examined, followed by multivariable linear or logistic regressions to detect independent associations. There were 5277 study infants and the mean (+/-SD) birth weight and gestational age were 1036 +/- 286 g and 28 +/- 3 weeks, respectively. The distribution of admission temperatures was 14.3% at < 35 degrees C, 32.6% between 35 and 35.9 degrees C, 42.3% between 36 and 36.9 degrees C, and 10.8% at > or = 37 degrees C. The estimate of birth weight on admission temperature with and without intubation was +0.13 degrees C and +0.04 degrees C per 100-g increase in birth weight, respectively. The mean admission temperature for each center varied from 1.5 degrees C below to 0.3 degrees C above a reference center. On adjusted analyses, admission temperature was inversely related to mortality (28% increase per 1 degrees C decrease) and late-onset sepsis (11% increase per 1 degrees C decrease) but not to intraventricular hemorrhage, necrotizing enterocolitis, or duration of conventional ventilation. Preventing decreases in temperature at birth among low birth weight infants remains a challenge. Associations with intubation and center of birth suggest that assessment of temperature control for infants intubated in the delivery room may be beneficial. Whether the admission temperature is part of the casual path or a marker of mortality needs additional study.

Investigation of Flow Structures Downstream of SAPIEN 3, CoreValve, and PERIMOUNT Magna Using Particle Image Velocimetry

NASA Astrophysics Data System (ADS)

Barakat, Mohammed; Lengsfeld, Corinne; Dvir, Danny; Azadani, Ali

2017-11-01

Transcatheter aortic valves provide superior systolic hemodynamic performance in terms of valvular pressure gradient and effective orifice area compared with equivalent size surgical bioprostheses. However, in depth investigation of the flow field structures is of interest to examine the flow field characteristics and provide experimental evidence necessary for validation of computational models. The goal of this study was to compare flow field characteristics of the three most commonly used transcatheter and surgical valves using phase-locked particle image velocimetry (PIV). 26mm SAPIEN 3, 26mm CoreValve, and 25mm PERIMOUNT Magna were examined in a pulse duplicator with input parameters matching ISO-5840. A 2D PIV system was used to obtain the velocity fields. Flow velocity and shear stress were obtained during the entire cardiac cycle. In-vitro testing showed that mean gradient was lowest for SAPIEN 3, followed by CoreValve and PERIMOUNT Magna. In all the valves, the peak jet velocity and maximum viscous shear stress were 2 m/s and 2 MPa, respectively. In conclusion, PIV was used to investigate flow field downstream of the three bioprostheses. Viscous shear stress was low and consequently shear-induced thrombotic trauma or shear-induced damage to red blood cells is unlikely.

The impact of community-based palliative care on acute hospital use in the last year of life is modified by time to death, age and underlying cause of death. A population-based retrospective cohort study

PubMed Central

Rosenwax, Lorna; Arendts, Glenn; Semmens, James B.

2017-01-01

Objective Community-based palliative care is known to be associated with reduced acute care health service use. Our objective was to investigate how reduced acute care hospital use in the last year of life varied temporally and by patient factors. Methods A retrospective cohort study of the last year of life of 12,763 Western Australians who died from cancer or one of seven non-cancer conditions. Outcome measures were rates of hospital admissions and mean length of hospital stays. Multivariate analyses involved time-to-event and population averaged log-link gamma models. Results There were 28,939 acute care overnight hospital admissions recorded in the last year of life, an average of 2.3 (SD 2.2) per decedent and a mean length of stay of 9.2 (SD 10.3) days. Overall, the rate of hospital admissions was reduced 34% (95%CI 1–66) and the mean length of stay reduced 6% (95%CI 2–10) during periods of time decedents received community-based palliative care compared to periods of time not receiving this care. Decedents aged <70 years receiving community-based palliative care showed a reduced rate of hospital admission around five months before death, whereas for older decedents the reduction in hospital admissions was apparent a year before death. All decedents who were receiving community-based palliative care tended towards shorter hospital stays in the last month of life. Decedents with neoplasms had a mean length of stay three weeks prior to death while not receiving community-based palliative care of 9.6 (95%CI 9.3–9.9) days compared to 8.2 (95% CI 7.9–8.7) days when receiving community-based palliative care. Conclusion Rates of hospital admission during periods of receiving community-based palliative care were reduced with benefits evident five months before death and even earlier for older decedents. The mean length of hospital stay was also reduced while receiving community-based palliative care, mostly in the last month of life. PMID:28934324

The impact of community-based palliative care on acute hospital use in the last year of life is modified by time to death, age and underlying cause of death. A population-based retrospective cohort study.

PubMed

Spilsbury, Katrina; Rosenwax, Lorna; Arendts, Glenn; Semmens, James B

2017-01-01

Community-based palliative care is known to be associated with reduced acute care health service use. Our objective was to investigate how reduced acute care hospital use in the last year of life varied temporally and by patient factors. A retrospective cohort study of the last year of life of 12,763 Western Australians who died from cancer or one of seven non-cancer conditions. Outcome measures were rates of hospital admissions and mean length of hospital stays. Multivariate analyses involved time-to-event and population averaged log-link gamma models. There were 28,939 acute care overnight hospital admissions recorded in the last year of life, an average of 2.3 (SD 2.2) per decedent and a mean length of stay of 9.2 (SD 10.3) days. Overall, the rate of hospital admissions was reduced 34% (95%CI 1-66) and the mean length of stay reduced 6% (95%CI 2-10) during periods of time decedents received community-based palliative care compared to periods of time not receiving this care. Decedents aged <70 years receiving community-based palliative care showed a reduced rate of hospital admission around five months before death, whereas for older decedents the reduction in hospital admissions was apparent a year before death. All decedents who were receiving community-based palliative care tended towards shorter hospital stays in the last month of life. Decedents with neoplasms had a mean length of stay three weeks prior to death while not receiving community-based palliative care of 9.6 (95%CI 9.3-9.9) days compared to 8.2 (95% CI 7.9-8.7) days when receiving community-based palliative care. Rates of hospital admission during periods of receiving community-based palliative care were reduced with benefits evident five months before death and even earlier for older decedents. The mean length of hospital stay was also reduced while receiving community-based palliative care, mostly in the last month of life.

Valve-Sparing Root Replacement Compared With Composite Valve Graft Procedures in Patients With Aortic Root Dilation.

PubMed

Ouzounian, Maral; Rao, Vivek; Manlhiot, Cedric; Abraham, Nachum; David, Carolyn; Feindel, Christopher M; David, Tirone E

2016-10-25

Although aortic valve-sparing (AVS) operations are established alternatives to composite valve graft (CVG) procedures for patients with aortic root aneurysms, comparative long-term outcomes are lacking. This study sought to compare the results of patients undergoing AVS procedures with those undergoing CVG operations. From 1990 to 2010, a total of 616 patients age <70 years and without aortic stenosis underwent elective aortic root surgery (AVS, n = 253; CVG with a bioprosthesis [bio-CVG], n = 180; CVG with a mechanical prosthesis [m-CVG], n = 183). A propensity score was used as a covariate to adjust for unbalanced variables in group comparisons. Mean age was 46 ± 14 years, 83.3% were male, and mean follow-up was 9.8 ± 5.3 years. Patients undergoing AVS had higher rates of Marfan syndrome and lower rates of bicuspid aortic valve than those undergoing bio-CVG or m-CVG procedures. In-hospital mortality (0.3%) and stroke rate (1.3%) were similar among groups. After adjusting for clinical covariates, both bio-CVG and m-CVG procedures were associated with increased long-term major adverse valve-related events compared with patients undergoing AVS (hazard ratio [HR]: 3.4, p = 0.005; and HR: 5.2, p < 0.001, respectively). They were also associated with increased cardiac mortality (HR: 7.0, p = 0.001; and HR: 6.4, p = 0.003). Furthermore, bio-CVG procedures were associated with increased risk of reoperations (HR: 6.9; p = 0.003), and m-CVG procedures were associated with increased risk of anticoagulant-related hemorrhage (HR: 5.6; p = 0.008) compared with AVS procedures. This comparative study showed that AVS procedures were associated with reduced cardiac mortality and valve-related complications when compared with bio-CVG and m-CVG. AVS is the treatment of choice for young patients with aortic root aneurysm and normal or near-normal aortic cusps. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Early outcomes of transcatheter aortic valve replacement in patients with severe aortic stenosis: single center experience

PubMed Central

Bozkurt, Engin; Keleş, Telat; Durmaz, Tahir; Akçay, Murat; Ayhan, Hüseyin; Bayram, Nihal Akar; Aslan, Abdullah Nabi; Baştuğ, Serdal; Bilen, Emine

2014-01-01

Introduction Transcatheter aortic valve implantation is a promising alternative to high risk surgical aortic valve replacement. The procedure is mainly indicated in patients with severe symptomatic aortic stenosis who cannot undergo surgery or who are at very high surgical risk. Aim Description early results of our single-center experience with balloon expandable aortic valve implantation. Material and methods Between July 2011 and August 2012, we screened in total 75 consecutive patients with severe aortic stenosis and high risk for surgery. Twenty-one of them were found ineligible for transcatheter aortic valve implantation (TAVI) because of various reasons, and finally we treated a total of 54 patients with symptomatic severe aortic stenosis (AS) who could not be treated by open heart surgery (inoperable) because of high-risk criteria. The average age of the patients was 77.4 ±7.1; 27.8% were male and 72.2% were female. The number of patients in NYHA class II was 7 while the number of patients in class III and class IV was 47. Results The average mortality score of patients according to the STS scoring system was 8.5%. Pre-implantation mean and maximal aortic valve gradients were measured as 53.2 ±14.1 mm Hg and 85.5 ±18.9 mm Hg, respectively. Post-implantation mean and maximal aortic valve gradients were 9.0 ±3.0 and 18.2 ±5.6, respectively (p < 0.0001). The left ventricular ejection fraction was calculated as 54.7 ±14.4% before the operation and 58.0 ±11.1% after the operation (p < 0.0001). The duration of discharge after the operation was 5.29 days, and a statistically significant correlation between the duration of discharge after the operation and STS was found (r = 0385, p = 0.004). Conclusions We consider that with decreasing cost and increasing treatment experience, TAVI will be used more frequently in broader indications. Our experience with TAVI using the Edwards-Sapien XT (Edwards Lifesciences, Irvine, CA) devices suggests that this is an effective and relatively safe procedure for the treatment of severe aortic stenosis in suitable patients. PMID:25061453

Validation of a noninvasive test routinely used in otology for the diagnosis of cerebrospinal fluid shunt malfunction in patients with normal pressure hydrocephalus.

PubMed

Sakka, Laurent; Chomicki, Alexandre; Gabrillargues, Jean; Khalil, Toufic; Chazal, Jean; Avan, Paul

2016-02-01

Ventriculoperitoneal shunting is the first-line treatment for normal pressure hydrocephalus. Noninvasive auditory tests based on recorded otoacoustic emissions were assessed, as currently used for universal neonatal hearing screenings, for the diagnosis of cerebrospinal fluid shunt malfunction. The test was designed based on previous works, which demonstrated that an intracranial pressure change induces a proportional, characteristic, otoacoustic-emission phase shift. Forty-four patients with normal pressure hydrocephalus (23 idiopathic and 21 secondary cases) were included in this prospective observational study. The male:female sex ratio was 1.44, the age range was 21-87 years (mean age 64.3 years), and the range of the follow-up period was 1-3 years (mean 20 months). Patients were implanted with a Sophy SU8 adjustable-pressure valve as the ventriculoperitoneal shunt. The phase shifts of otoacoustic emissions in response to body tilt were measured preoperatively, immediately postoperatively, and at 3-6 months, 7-15 months, 16-24 months, and more than 24 months postoperatively. Three groups were enrolled: Group 1, 19 patients who required no valve opening-pressure adjustment; Group 2, 18 patients who required valve opening-pressure adjustments; and Group 3, 7 patients who required valve replacement. In Group 1, phase shift, which was positive before surgery, became steadily negative after surgery and during the follow-up. In Group 2, phase shift, which was positive before surgery, became negative immediately after surgery and increasingly negative after a decrease in the valve-opening pressure. In Group 3, phase shift was positive in 6 cases and slightly negative in 1 case before revision, but after revision phase shift became significantly negative in all cases. Otoacoustic emissions noninvasively reflect cerebrospinal fluid shunt function and are impacted by valve-opening pressure adjustments. Otoacoustic emissions consistently diagnosed shunt malfunction and predicted the need for surgical revision. The authors' diagnostic test, which can be repeated without risk or discomfort by an unskilled operator, may address the crucial need of detecting valve dysfunction in patients with poor clinical outcome after shunt surgery.

40 CFR 60.481a - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... stopping production. Quarter means a 3-month period; the first quarter concludes on the last day of the... means flanged, screwed, or other joined fittings used to connect two pipe lines or a pipe line and a..., separating the compressor cylinder from the crankcase. Double block and bleed system means two block valves...

40 CFR 60.481a - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... stopping production. Quarter means a 3-month period; the first quarter concludes on the last day of the... means flanged, screwed, or other joined fittings used to connect two pipe lines or a pipe line and a..., separating the compressor cylinder from the crankcase. Double block and bleed system means two block valves...

40 CFR 60.481a - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... stopping production. Quarter means a 3-month period; the first quarter concludes on the last day of the... means flanged, screwed, or other joined fittings used to connect two pipe lines or a pipe line and a..., separating the compressor cylinder from the crankcase. Double block and bleed system means two block valves...

40 CFR 60.481a - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... stopping production. Quarter means a 3-month period; the first quarter concludes on the last day of the... means flanged, screwed, or other joined fittings used to connect two pipe lines or a pipe line and a..., separating the compressor cylinder from the crankcase. Double block and bleed system means two block valves...

40 CFR 60.481a - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... stopping production. Quarter means a 3-month period; the first quarter concludes on the last day of the... means flanged, screwed, or other joined fittings used to connect two pipe lines or a pipe line and a..., separating the compressor cylinder from the crankcase. Double block and bleed system means two block valves...

45 CFR 618.105 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE... unit means a school, department, or college of an educational institution (other than a local educational agency) admission to which is independent of admission to any other component of such institution...

[Morbidity and hospital cost reduction in cardiac surgery using a presurgery ambulatory strategy].

PubMed

Ávila-Vanzzini, Nydia; Kuri-Alfaro, Jorge; Rodríguez-Chávez, Laura Leticia; Meléndez-Ramírez, Gabriela; Trevethan-Cravioto, Sergio; Quiroz-Martínez, Alejandro; Herrera-Bello, Héctor; Herrera-Alarcón, Valentín; Martínez-Hernández, Humberto; Martínez-Ríos, Marco Antonio

2010-01-01

In our hospital, the patients that need an elective cardiac surgery are admitted through the admission department on the basis of a waiting list. Since 1999, a fast track to hospitalization program has existed in the National Institute of Cardiology Ignacio Chavez for patients with low surgical risk. Later, in 2004, this program was extended to patients to moderate risk, based on rules accepted worldwide, and our own experience. 1) To compare two ways of admission that are used currently: fast track to hospitalization, against admission department waiting list. We compared major events: death or events that increased the hospital stay by more than 14 days (infections, alterations of rhythm and conduction, reoperations and others), 2) To compare the days of hospitalization and money spent by the hospital. We conformed 2 groups of 347 patients. The admission department waiting list group was admitted before doing their preoperative studies, which is the customary form for hospitalization by our admissions department, while the group of fast track to hospitalization was obligated to have their laboratory exams complete and any other diseases resolved or controlled previously. The monetary cost per patient for the hospital was calculated based on the patient's socioeconomic classification. Student t test was conduncted on independent samples and numerical variables, and Chi square for categorical variables. We considered a p <0.05 to be statistically significant. In average in both groups, 75% underwent valve operation and 25% underwent congenital heart disease repair, 49% were women, age 47 15 years. The comparison between the groups fast track to hospitalization and admission department waiting list group were: Mortality: 4.3% vs. 5.8% (p=0.38). Major events that needed a hospital stay of more than 14 days: 73 vs. 97 cases respectively (p = 0.032). Infections: 22 vs. 29 (p = 0.14). Mediastinitis: 2 vs. 9 respectively (p = 0.033). In-hospital stay: were 11 days vs. 20 days (p = 0.0001), the biggest difference was found in the pre-surgical time: 2 vs. 9 days respectively (p = 0.0001). The postoperative morbidity in general was lower in fast track to hospitalization group, and the mediastinitis showed a decrease with statistical significance. The time interval between hospital admission an operation in fast track to hospitalization group was significantly shorter. We believe that the decrease in the exposure time to nosocomial pathogens present in the hospital environment was directly related to the low number of mediastinitis. Finally, the decrease in time of hospital stay represented a 32% monetary savings for the hospital.

Heart failure with preserved left ventricular systolic function: a hospital cohort study

PubMed Central

Berry, C; Hogg, K; Norrie, J; Stevenson, K; Brett, M; McMurray, J

2005-01-01

Objective: To investigate how patients with heart failure with preserved left ventricular systolic function (LVSF) compare with patients with reduced LVSF. Design: Cohort study. Setting: Urban university hospital. Patients: 528 index emergency admissions with heart failure during the year 2000. Information on LVSF and follow up was available for 445 (84%) of these patients. Results: 130 (29%) patients had preserved LVSF (defined as an ejection fraction > 40%). The median follow up was 814 days (range 632–978 days). The average (SD) age was 72 (13) years. Women accounted for 62% and 45% of patients with preserved and reduced LVSF, respectively (p  =  0.001). Patients with preserved LVSF (compared with those with reduced LVSF) had a higher prevalence of left ventricular hypertrophy (56% v 29%) and aortic valve disease (mean gradient > 20 mm Hg; 31% v 9%). Fewer patients with preserved LVSF received an angiotensin converting enzyme inhibitor (65% v 78%, p  =  0.008) or spironolactone (12% v 21%, p  =  0.027). Anaemia tended to occur more often in patients with preserved LVSF than in those with reduced LVSF (43% v 33% for women, p  =  0.12; 59% v 49% for men, p  =  0.22). There was a similarly high prevalence of significant renal dysfunction in both groups (estimated glomerular filtration rate < 60 ml/min/1.73 m2 in 68% with preserved and 64% with reduced LVSF, p  =  0.40). Mortality was similar in both groups (preserved versus reduced 51 (39%) v 132 (42%), p  =  0.51). Compared with patients with reduced LVSF, patients with preserved LVSF tended to have a lower risk of death or hospital admission for heart failure (56 (42%) v 165 (53%), p  =  0.072) but a similar rate of death or readmission for any reason. Conclusion: Patients with preserved LVSF had more co-morbid problems than those with reduced LVSF; however, prognosis was similar for both groups. PMID:15958359

Method and apparatus for controlling the solenoid current of a solenoid valve which controls the amount of suction of air in an internal combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiuchi, T.; Sakurai, H.

1988-09-20

This patent describes an apparatus for controlling the solenoid current of a solenoid valve which controls suction air in an internal combustion engine. The apparatus consists of: (a) engine rotational speed detector means for detecting engine rotational speed; (b) aimed idle speed setting means for generating a signal corresponding to a predetermined idling speed; (c) first calculating means coupled to the engine rotational speed detector means and the aimed idle speed setting means for calculating a feedback control term (Ifb(n)) as a function of an integration term (Iai), a proportion term (Ip), and a differentiation term (Id); (d) first determiningmore » and storing means coupled to the first calculating means, for determining an integration term (Iai(n)) of the the feedback control term (Ifb(n)) and for determining a determined value (Ixref) in accordance therewith; (e) changeover means coupled to the first calculating means and the first determining and storing means for selecting the output of one of the first calculating means or the first determining and storing means; (f) first signal generating means coupled to the changeover means for generating a solenoid current control value (Icmd) as a function of the output of the changeover means.« less

Comparison of aortic media changes in patients with bicuspid aortic valve stenosis versus bicuspid valve insufficiency and proximal aortic aneurysm.

PubMed

Girdauskas, Evaldas; Rouman, Mina; Borger, Michael A; Kuntze, Thomas

2013-12-01

The aim of this study was to evaluate aortic media changes in bicuspid aortic valve (BAV) patients who underwent aortic valve replacement (AVR) and simultaneous replacement of the proximal aorta for BAV stenosis vs BAV insufficiency. Review of our institutional BAV database identified a subgroup of 79 consecutive BAV patients (mean age 52.3 ± 13 years, 81% men) with BAV stenosis or insufficiency and concomitant proximal aortic dilatation of ≥50 mm who underwent AVR and simultaneous replacement of proximal aorta from 1995 through 2005. All cases of BAV disease and concomitant ascending aortic dilatation of 40-50 mm underwent isolated AVR and therefore were excluded from this analysis. Proximal aortic media elastic fibre loss (EFL) was assessed (graded 0 to 3+) and compared between patients with BAV stenosis (Group I, n = 44) vs BAV insufficiency (Group II, n = 35). Follow-up (690 patient-years) was 100% complete and 9.1 ± 4.6 years long. Mean aortic media EFL was 1.3 ± 0.7 in Group I vs 2.5 ± 0.8 in Group II (P = 0.03). Moderate/severe EFL (i.e. defined as grade 2+/3+) was found in 13 patients (29%) in Group I vs 28 patients (80%) in Group II (P < 0.001). Logistic regression identified BAV insufficiency as the strongest predictor of moderate/severe EFL (OR 9.3; 95% CI 3.2-29.8, P < 0.001). Valve-related event-free survival was 64 ± 8% in Group I vs 93% ± 5% in Group II at 10 years postoperatively (P = 0.05). A total of 4 patients (5%, 3 from Group I and 1 from Group II) underwent redo aortic root surgery for prosthetic valve endocarditis during follow-up. Patients with BAV insufficiency and a proximal aorta of ≥50 mm have a significantly higher rate of moderate/severe EFL as compared to their counterparts with BAV stenosis.

Metoprolol Reduces Hemodynamic and Metabolic Overload in Asymptomatic Aortic Valve Stenosis Patients: A Randomized Trial.

PubMed

Hansson, Nils Henrik; Sörensen, Jens; Harms, Hendrik Johannes; Kim, Won Yong; Nielsen, Roni; Tolbod, Lars Poulsen; Frøkiær, Jørgen; Bouchelouche, Kirsten; Dodt, Karen Kaae; Sihm, Inger; Poulsen, Steen Hvitfeldt; Wiggers, Henrik

2017-10-01

Currently, no pharmacological treatment can modify the natural history of aortic valve stenosis (AS). This underlines the critical need to explore novel treatment strategies, which could postpone or prevent the need for aortic valve replacement in patients with asymptomatic AS. The objectives of this study were to investigate whether metoprolol reduce the hemodynamic and metabolic burden imposed by AS. In a double-blinded design, 40 patients with moderate-severe asymptomatic AS (aortic valve area, 0.5±0.1 cm 2 /m 2 ; peak gradient, 53±19 mm Hg) were randomized to placebo or metoprolol treatment for 22 weeks. Patients were evaluated by echocardiography, cardiovascular magnetic resonance, and 11 C-acetate positron emission tomography. Compared with placebo, metoprolol (100±53 mg/d) decreased heart rate; mean difference (95% confidence interval) -8 minute - 1 (-13, -3; P =0.003) and increased ejection time 26 ms (2, 50; P =0.03). Furthermore, metoprolol reduced aortic valve peak -7 mm Hg (-13, 0; P =0.05) and mean -4 mm Hg (-7, -1; P =0.03) gradients, without affecting stroke volume 3 mL/m 2 (-2, 8; P =0.16). Valvuloarterial impedance (ie, global afterload) and myocardial oxygen consumption were reduced by -11% and -12% ( P =0.03 and 0.01), respectively; and decreased heart rate correlated with lower valvuloarterial impedance, myocardial oxygen consumption, and improved myocardial efficiency defined as stroke work/myocardial oxygen consumption ( r =0.63-0.65; all P <0.01). There were 2 adverse cardiovascular events in the metoprolol group and none in the placebo group. In patients with asymptomatic AS, metoprolol increases systolic ejection time and reduces aortic valve gradients, global afterload, and myocardial oxygen requirements. Thus, metoprolol displays favorable hemodynamic and metabolic effects and could improve outcome in patients with asymptomatic AS. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02076711. © 2017 American Heart Association, Inc.

Transseptal antegrade transcatheter aortic valve replacement for patients with no other access approach - a contemporary experience.

PubMed

Cohen, Mauricio G; Singh, Vikas; Martinez, Claudia A; O'Neill, Brian P; Alfonso, Carlos E; Martinezclark, Pedro O; Heldman, Alan W; O'Neill, William W

2013-11-15

To assess the feasibility and outcomes in patients undergoing transvenous transseptal (TS) transcatheter aortic valve replacement (TAVR). TS approach for TAVR was abandoned in favor of retrograde transfemoral, transaortic, or transapical approaches. TS TAVR may still be warranted in patients for whom no other approach is feasible. Observational consecutive case series at a single center, to evaluate technical outcomes in inoperable patients with aortic stenosis who had contraindications for other approaches and who underwent TAVR via a transvenous TS antegrade approach using the Edwards-Sapien (ES) valve. Over a 4-month period, 9 patients underwent TS TAVR with 26 mm (n = 4) and 23 mm (n = 5) ES valves. Mean age was 84.5 ± 6.6 years and Society of Thoracic Surgeons predicted risk of mortality was 7.8 ± 2.8%. Specific contraindications for other access included iliofemoral arterial diameter <7 mm in 9 (100%), porcelain aorta in 6 (66%) patients, multiple (≥2) sternotomies in 2 (22%) patients, severe pulmonary disease in 3 (33%), extreme frailty in 1 (11%), spinal stenosis with impaired ability to rehabilitate postsurgery in 1 (11%) and apical left ventricular thrombus in 1 (11%) patient. Antegrade deployment of the ES prosthetic valve was technically feasible in 8 patients. Major bleeding occurred in 4 patients, two patients suffered acute kidney injury without need for dialysis and one patient required a permanent pacemaker. The median (25th, 75th percentiles) fluoroscopy time was 49 (34, 81) minutes and contrast volume was 150 (120, 225) ml. No patient had hemodynamically significant post-TAVR aortic insufficiency nor damage to the mitral valve. At 6 months follow-up, there were no cerebrovascular events or rehospitalizations and mean NYHA Class improved from 3.4 to 1.7. The antegrade TS approach to TAVR is a technically feasible option for "no-access" patients. Prospective assessment of the safety and efficacy of this approach in the current era warrants further study. Copyright © 2013 Wiley Periodicals, Inc.