Ozkokeli, Mehmet; Ates, Mehmet; Ekinci, Abdurrahman; Akcar, Murat
We report the case of a patient who was diagnosed with prosthetic valve endocarditis caused by Staphylococcus aureus. He had undergone aortic valve replacement with a Starr-Edwards prosthesis 37 years earlier. Because of uncontrolled infection despite antibiotic treatment, the patient underwent successful surgical replacement of the prosthetic valve. PMID:15902834
Slater, S. D.; Sallam, I. A.; Bain, W. H.; Turner, M. A.; Lawrie, T. D. V.
Slater, S. D., Sallam, I. A., Bain, W. H., Turner, M. A., and Lawrie, T. D. V. (1974).Thorax, 29, 624-632. Haemolysis with Björk-Shiley and Starr-Edwards prosthetic heart valves: a comparative study. A comparison was made of the haemolytic complications in 85 patients with two different types of Starr-Edwards cloth-covered ball and cage prosthesis with those in 44 patients with the Björk-Shiley tilting disc valve. Intravascular haemolysis, as detected by the presence of haemosiderinuria, occurred significantly less often with the Björk-Shiley than with the Starr-Edwards valve, the overall incidence with aortic, mitral or multiple replacements being 31%, 15%, and 20% for Björk-Shiley and 94%, 92%, and 88% for Starr-Edwards valves respectively. There was no significant difference in the frequency of haemolysis between each of the two types of Starr-Edwards prosthesis studied at either the aortic (2300 versus 2310 model) or mitral (6300 versus 6310) site. Haemolytic anaemia developed in only one patient with a Björk-Shiley valve but was common though usually mild with Starr-Edwards prostheses, particularly aortic valve replacements with the 2300 model and in aortic plus mitral (± tricuspid) replacements. The greater severity of haemolysis produced by Starr-Edwards valves, again especially of the latter types, was further demonstrated by higher serum lactate dehydrogenase and 24-hour urinary iron levels. It is concluded that the Björk-Shiley tilting disc valve represents a significant advance in the amelioration of the haemolytic complications of prosthetic valves. PMID:4450173
Alimov, Victor K.; Rousou, John A.; Pluchino, Fabrizio I.
We report the case of a 61-year-old obese male patient in whom we found a well-functioning 33-year-old Starr-Edwards aortic prosthesis during repeat aortic surgery. Rather than explant the prosthesis, we remodeled the aortic root, almost completely removing the aortic sinuses and leaving only a pillar of aortic tissue around the coronary ostia. The proximal end of a Hemashield tube-graft was then scalloped to accommodate the remaining aortic tissue. The patient's heart function was excellent after his weaning from cardiopulmonary bypass. Simplifying the repeat aortic root repair, by preserving a well-functioning Starr-Edwards valve, might lead to a better outcome in similar cases. We also discuss other instances of this valve's durability. PMID:28100977
Hackett, D; Fessatidis, I; Sapsford, R; Oakley, C
The long term performance characteristics of the 2400 and 1260 series of Starr-Edwards aortic prostheses were investigated by a follow up study of clinical outcome of 327 patients discharged from hospital with isolated aortic valve replacement. Follow up lasted for up to 10 years and was based on 1616 patient-years. The 2400 series cloth covered tracked valve was implanted in 182 patients from 1974 to 1980 and the 1260 series bare strut silastic ball valve was inserted in 145 patients from 1979 to 1983. Total 10 year mortality and valve related morbidity were low and no cases of mechanical valve failure were recorded. There were no significant actuarial differences in mortality or valve related morbidity between the 2400 and 1260 valves. Starr-Edwards models 2400 and 1260 aortic valve prostheses showed excellent durability without any mechanical failures over a 10 year period. The long term outcome of isolated aortic valve replacement with these models is associated with a low frequency of valve related complications. PMID:3580223
Cleland, J.; Molloy, P. J.
The thrombo-embolic complications of the cloth-covered Starr-Edwards prostheses No. 2300 aortic and No. 6300 mitral followed for an average of 14 months in 155 patients are reviewed. There was a high incidence of early fatal and disabling thrombo-embolus in patients having mitral valve replacement. Late emboli were more common after aortic valve replacement. Anticoagulant control was unsatisfactory and not without hazards. PMID:4685210
Mächler, H E; Schmidt, C H; Neuner, P; Iberer, F; Anelli-Monti, M; Dacar, D; Rigler, B; Kraft-Kinz, J
Six years after the first aortic valve replacement with the Starr-Edwards Silastic ball prosthesis at Oregon Health Sciences University, the model 1260 was implanted in a 44-year-old patient at our department. During 24 years no signs of dysfunction, thromboembolism, thrombosis, periprosthetic leaks or hemolysis were observed. Material test showed no signs of fatigue. The dimension of the Silastic poppet was found to be one millimeter less than the original specifications of these poppets and there were some lipid infiltrations. Functionally the poppet was found to be nonvariant. Histologic findings detected focal hyalinization and giant cells without signs of acute inflammation or ulceration. With regard to its reliability and durability, the Starr-Edwards valve prosthesis should not be viewed with disfavor.
Grunkemeier, G L; Starr, A
The first generation of aortic ball-valve prostheses, used until 1965, was associated with poppet damage owing to fatty infiltration of the silicone rubber ball, a phenomenon termed ball variance. For the Model 1000 Starr-Edwards valves, almost all cases were discovered before 8 years. However, a review of our patients still at risk with the original valve and poppet, prompted by other recent reports of late ball variance, has shown that severe variance can exist up to 20 years after implantation. There is a relationship between the year of valve implantation and the timing and severity of ball variance for the overall series of patients surviving operation, but for the subgroup currently at risk the sample sizes are too small to detect any difference, if one still exists. Only three of 12 patients in the current subset were found to have severe variance. Simple ball change has been the operation of choice. Prophylactic reoperation is not indicated in the current subset, but patients require careful follow-up and should be considered for reoperation should symptoms develop.
Schaffer, R A; McAnulty, J H; Starr, A; Rahimtoola, S H
Diastolic murmurs associated with the Starr-Edwards mitral prosthesis have not been described previously. In this report, five patients with mitral prostheses are described in whom apical mid-diastolic and presystolic murmurs resulted from two different causes. Three patients had clots obstructing the prosthetic orifice. The other two had normally functioning protheses and moderately severe aortic insufficiency. The occurrence of mid-diastolic and presystolic murmurs in the presence of a normally functioning prosthetic mitral valve demonstrates that 1) the mid-diastolic Austin Flint murmur can occur in the absence of incomplete mitral valve opening, premature mitral valve closure, vibrating mitral leaflets, or relative mitral stenosis and 2) the presystolic Austin Flint murmur can occur in the absence of incomplete valve opening or presystolic mitral regurgitation. However, the presystolic murmur was associated with early closure movement of the presthetic poppet.
Matthews, A M
Development of the Starr-Edwards heart valve marked a new era in the treatment of valvular heart disease. Until the development of the Starr-Edwards valve, there were no published reports of patients who had lived longer than 3 months with a prosthetic valve in the mitral position. This valve was the result of a unique partnership between a young surgeon, Dr. Albert Starr, and an experienced engineer, Mr. Lowell Edwards. Working as a team, these 2 men developed and successfully implanted the 1st Starr-Edwards valve within less than 2 years of their 1st meeting. Their key to success was their willingness and ability to make repeated modifications to their design to solve each clinical problem as it arose. Their constant focus on the clinical goal aided the rapid transformation of their design from a leaflet valve to a shielded ball valve, and finally to an unshielded ball valve suitable for implantation in a human being. Along the way, they abandoned the idea of imitating the appearance of native valves, in favor of developing valves that would be clinically successful. Their work has provided help and hope for patients who otherwise would have died from the complications of rheumatic heart disease and other valvular disorders for which valve replacement is the only treatment. Images PMID:9885105
Sakata, K; Ishikawa, S; Ohtaki, A; Otani, Y; Suzuki, M; Kawashima, O; Morishita, Y
Two cases of malfunctioning Starr-Edwards cloth-covered mitral valve prostheses requiring reoperation are presented. Both cases underwent successful surgical repair 21 years after the valve replacement. The causes were a disturbance of the poppet during the opening movement due to excessive tissue ingrowth and a paravalvular leak associated with a tear of the valve seat. Replacement of the Starr-Edwards valve prosthesis more than 20 years after the initial installation has not been reported.
Masilonyane-Jones, Taolo Vijay; Blackham, Ruth; Alvarez, John
The Starr-Edwards valve was the first manufactured valve to be used successfully as a cardiac valve replacement in 1960. Although superseded by newer valves over the decades it has achieved an excellent track record. It has unique features, namely a protective metal casing around the ball poppet and a large and thick sewing ring. We describe the last implant of this valve in Australia; it has now been withdrawn by the manufacturer. In this particular case, the unique features of this valve made the required surgery quite simple and avoided the need for complex mitral valve surgery in a very high-risk patient.
Grondin, Pierre; Lepage, Gilles; Castonguay, Yves
Acquired aortic disease is now currently corrected by total prosthetic replacement of the aortic valve. Aortic valve replacement was performed in 13 cases at the Montreal Heart Institute in 1963. In the first four cases, Bahnson aortic leaflets were used; in the remaining nine, the Starr-Edwards semirigid aortic valve prosthesis. The surgical technique employed is described. There were two operative deaths and two late deaths. The results have been excellent in all of the survivors but one. They have returned to full-time activities and four of them to strenuous physical work. It is the contention of the authors that aortic valve replacement is a surgical procedure with acceptable risks, offering hope for a near-normal life to patients crippled by severe aortic valvular lesions. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7 PMID:14179061
Schottenfeld, M.; Wisheart, J. D.; Ross, J. K.; Lincoln, J. C. R.; Ross, D. N.
Four cases are described in which totally cloth-covered Starr-Edwards valves (model 2300) had to be removed. All were causing significant haemolysis, two in the absence of a peripheral leak. The principal operative finding was destruction of the Dacron covering the struts. Following replacement of these prostheses there was complete resolution of signs and symptoms. The possible causes of haemolysis and consequences of cloth destruction are discussed. Images PMID:5576531
Santini, F; Borghetti, V; Amalfitano, G; Mazzucco, A
A 73-year old man developed an acute prosthetic aortic valve dehiscence for which emergent operation was undertaken. The intraoperative evidence of an aortic annular disruption and of a subannular abscess led to the hypothesis that an endocarditis process was involved. The aortic valve was replaced with a stentless porcine bioprosthesis. Cultures taken intraoperatively from the aortic area had a pure growth of aerobic, spore-forming, gram-positive bacilli identified as Bacillus licheniformis. The patient responded to specific antibiotic therapy with no relapse at a 20-month follow-up. The potentiality of B. licheniformis as a pathogen should be reconsidered. PMID:8576381
Malouf, J F; Hannoush, H M; Odell, J A
Fracture of the occluder disc of a low-profile Starr-Edwards prosthesis is a hitherto unrecognized complication. We describe a patient who presented with right heart failure and severe pulmonary hypertension 27 years after mitral valve replacement with a model 6520 caged-disc prosthesis. At surgery, there was a longitudinal split in the occluder disc, and organized thrombus was lodged between the split segments. This case offers a unique opportunity to study the long-term effects of wear on the polyethylene poppet and Stellite cage.
Carey, J S
One hundred patients in whom cloth-covered Starr-Edwards prostheses were implanted have now been followed for 3 to 7 years. The hospital mortality rate was 5 per cent, and survival at five years was 70 per cent. Complications related to valve design occurred in 8 per cent (4 per cent fatal). The majority of late deaths and poor results were related to progressive cardiac disease rather than valve-related complications. The results indicate that cloth-covered prostheses have significantly lowered the incidence of thromboembolism and eliminated poppet dysfunction. The problem of strut cloth wear was clinically observed only twice in 500 patient-years of follow-up.
Karara, H. M.
Photogrammetric measurements of the surface topography of the aortic valves obtained from silicon rubber molds of freshly excised human aortic valves are presented. The data are part of an investigation into the design of a new prosthetic valve which will be a central-flow device, like the real valve and unlike previous central-occluding prostheses. Since the maximum stress on the heart valve is induced when the valve is closed and subject to diastolic back-pressure, it was decided to determine the valve geometry during diastole. That is, the molds were formed by pouring the rubber down the excised aortas, causing the valves to close. The molds were made under different pressures (20-120 torr); photogrammetry served as a vehicle for the assessment of the mold topography through the following outputs: digital models, surface profiles, and contour maps.
Pine, M; Hahn, G; Paton, B; Pappas, G; Davies, H; Steele, P; Pryor, R; Blount, S G
Homograft aortic valve replacement was done in 103 patients and prosthetic aortic valve replacement in 106 between January 1962 and December 1973. Patients who received homograft and prosthetic valves were compared with respect to age, sex, preoperative functional impairment, infection, dyspnea, angina, hemodynamics, chest X-ray, electrocardiogram, associated operations, early and late mortality, and valve failure. Combined total mortality was 28% (12% operative, 8% first postoperative year, 8% late). Ten percent of valve required replacement. One year after operation, 70% of survivors were asymptomatic, 27% were improved, and 3% were unchanged or between homograft and prosthetic valve replacement. Valve-related failure and infections were more common after homograft aortic valve replacement. Emboli, hemorrhage, and hemolysis were commoner after prosthetic valve replacement. Fungal infections occurred in five homograft patients but in no patient with a prosthetic aortic valve. Severe properative symptoms or recent endocarditis was associated with greater mortality and valve failure in both the homograft and the prosthetic series. Increased mortality and failure was also seen in patients with either preoperative aortic regurgitation with high left ventricular end-diastolic pressure and low cardiac index, or aortic stenosis with cardiomegaly or roentgenographic evidence of congestive heart failure. Therefore, in two series of patients at equal risk, mortality and valve failure were similar for homograft and prosthetic aortic valve replacement.
Mohammadi, Hadi; Mequanint, Kibret
Although heart valve replacement is among the most common cardiovascular surgical procedures, their outcome is often difficult to predict. One of the reasons is the design and choice of the materials used for the fabrication of the prostheses. This review paper describes the use of modeling techniques in prosthetic heart valve (HV) design and aims at the justification and development of a polymer based trileaflet mechanical heart valve (MHV). The closing/opening phase behavior of the bileaflet MHV was investigated. The potential problem of valve failure due to crack propagation in the brittle pyrolytic carbon leaflet was also discussed. These studies suggest that although bileaflet MHV performs satisfactorily, there are justifications for improvement. Since the native aortic HV is trileaflet and made of anisotropic and hyperelastic tissue, one possible approach to a better MHV design is based on our ability to closely mimic the natural geometry and biomaterial properties.
Salem, B I; Pechacek, L W; Leachman, R D
A 21-year-old man had acute aortic insufficiency three months after insertion of an aortic valve prosthesis. Chest roentgenography demonstrated abnormal orientation of the prosthesis. M-mode echocardiography showed dense, linear echoes from the prosthetic valve between the interventricular septum and the mitral valve, along with loss of normal poppet motion within the aortic root. At surgery, the prosthesis was found to be extensively disrupted, resulting in prolapse into the left ventricular outflow tract. Another valve replacement was performed with patient survival. Echocardiography appears to be a useful adjunct to established roentgenographic procedures in the diagnosis of major dehiscence of prosthetic aortic valves.
Mossad, S B; Tomford, J W; Stewart, R; Ratliff, N B; Hall, G S
We describe the first case of prosthetic valve endocarditis due to a Streptomyces sp. The patient presented with fever, cutaneous embolic lesions, and bacteremia 3 months after aortic valve replacement. Treatment required valve replacement and a long course of parenteral imipenem. PMID:8586732
DiSesa, V J; Lachman, P; Collins, J J; Cohn, L H
Improved assessment of valve area is essential to understanding the performance of prosthetic valves. The authors studied six patients undergoing aortic valve replacement using mechanical (ME) or porcine (PO) prostheses. Instantaneous cardiac output (CO) (L/min) was measured in the aorta using an ultrasonic flow probe. Left ventricular and aortic pressures (mmHg) were measured using Millar catheters. Data were analyzed using an IBM PC-AT. Valve area (cm2) was determined using Gorlin's formula (AG) and a new formula for instantaneous area derived mathematically and using a theoretic constant. AG, mean (AI) and peak (Apk) instantaneous areas were compared to geometric measures of area (Aactual) in vitro. Peak instantaneous area correlates best with measured area. Intraoperative assessment using the ultrasonic flow probe and computer analysis is helpful in understanding the dynamic properties of prosthetic valves in vivo.
Tiesenhausen, Kurt; Hausegger, Klaus A.; Tauss, Josef; Amann, Wilfried; Koch, Guenter
Purpose: To describe the efficacy and value of endovascular stent-grafts for the treatment of aortic anastomotic pseudo-aneurysms.Methods: Three patients with proximal aortic anastomotic pseudoaneurysms 8-15 years after prosthetic reconstruction were treated by transfemoral stent-graft implantation. In two patients the pseudoaneurysms were excluded by Talent prostheses [tube graft (n=1), bifurcated graft (n=s1)]. In one patient an uniiliac Zenith stent-graft was implanted and an extra-anatomic crossover bypass for revascularization of the contralateral lower extremity was performed.Results: All procedures were successful with primary exclusion of the pseudoaneurysms. During the follow-up (mean 16 months) one endoleak occurred due to migration of the tube stent-graft. The endoleak was sealed successfully by implanting an additional bifurcated stent-graft.Conclusion: Stent-graft exclusion of aortic pseudoaneurysms offers a minimally invasive and safe alternative to open surgical reconstruction.
Tiesenhausen, Kurt; Hausegger, Klaus A.; Tauss, Josef; Amann, Wilfried; Koch, Guenter
Purpose: To describe the efficacy and value of endovascular stent-grafts for the treatment of aortic anastomotic pseudoaneurysms.Methods: Three patients with proximal aortic anastomotic pseudoaneurysms 8-15 years after prosthetic reconstruction were treated by transfemoral stent-graft implantation. In two patients the pseudoaneurysms were excluded by Talent prostheses [tube graft (n = 1), bifurcated graft (n = 1)]. In one patient an uni iliac Zenith stent-graft was implanted and an extra-anatomic crossover bypass for revascularization of the contralateral lower extremity was performed.Results: All procedures were successful with primary exclusion of the pseudoaneurysms. During the follow-up (mean 16 months) one endoleak occurred due to migration of the tube stent-graft. The endoleak was sealed successfully by implanting an additional bifurcated stent-graft.Conclusion: Stent-graft exclusion of aortic pseudoaneurysms offers a minimally invasive and safe alternative to open surgical reconstruction.
Shemin, R J; Guadiani, V A; Conkle, D M; Morrow, A G
During a 15-year period from January 1962 through December 1976, 42 patients who had undergone a previous aortic valve replacement underwent reoperation. The mean interval between operations was 4.4 years. The indications for reoperation were aortic regurgitation resulting from mechanical malfunction (12 patients), ball variance (15 patients), perivalvular leaks (five patients), prosthetic stenosis (eight patients), anemia (one patient), and recurrent emboli (one patient). The indications were characteristic of a specific valve series. The most common reoperation was aortic valve replacement (29/42), which had a 10.3% operative mortality. Poppet change (10/42) carried a 10% operative mortality and no operative deaths followed suture closure of perivalvular leaks. Eighty-eight percent of patients alive six months after reoperation were New York Heart Association functional class 1 or 2. At last follow-up, 95% of surviving patients were still functional class 1 or 2, with a mean cumulative survival of 4.7 years after reoperation. This experience demonstrates that those patients surviving long enough to undergo reoperation can expect a reasonable operative risk, long-term survival, and excellent clinical improvement.
Oates, E.; Sarno, R.C.
An unsuspected annular abscess at the base of a prosthetic aortic valve in a patient with endocarditis was identified by indium-111-labeled leukocyte scintigraphy alone. This highly sensitive and specific technique expediently demonstrated the surgically proven inflammatory focus.
Nicks, Rowan; Cartmill, T.; Bernstein, L.
We report a technique for the enlargement of a hypoplastic aortic root by an operation whereby the hypoplastic aortic root has been so enlarged by the insertion of a Dacron fabric gusset that it will accommodate a size 9A or larger Starr-Edwards prosthesis. Our experience in five patients is described. No matter what type of valve is used for replacement of a diseased aortic valve, and no matter what improved designs of valvular prosthesis are ultimately developed, it will be necessary (in the particular group described) to enlarge the aortic ring to accommodate a size which will function correctly without causing left ventricular outflow obstruction. Images PMID:5452289
Bradley, Scott M
The contents of this article were presented in the session "Aortic insufficiency in the teenager" at the congenital parallel symposium of the 2013 Society of Thoracic Surgeons (STS) annual meeting. The accompanying articles detail the approaches of aortic valve repair and the Ross procedure.(1,2) The current article focuses on prosthetic valve replacement. For many young patients requiring aortic valve surgery, either aortic valve repair or a Ross procedure provides a good option. The advantages include avoidance of anticoagulation and potential for growth. In other patients, a prosthetic valve is an appropriate alternative. This article discusses the current state of knowledge regarding mechanical and bioprosthetic valve prostheses and their specific advantages relative to valve repair or a Ross procedure. In current practice, young patients requiring aortic valve surgery frequently undergo valve replacement with a prosthetic valve. In STS adult cardiac database, among patients ≤30 years of age undergoing aortic valve surgery, 34% had placement of a mechanical valve, 51% had placement of a bioprosthetic valve, 9% had aortic valve repair, and 2% had a Ross procedure. In the STS congenital database, among patients 12 to 30 years of age undergoing aortic valve surgery, 21% had placement of a mechanical valve, 18% had placement of a bioprosthetic valve, 30% had aortic valve repair, and 24% had a Ross procedure. In the future, the balance among these options may be altered by design improvements in prosthetic valves, alternatives to warfarin, the development of new patch materials for valve repair, and techniques to avoid Ross autograft failure.
Klaaborg, Kaj Erik; Hjortdal, Vibeke; Nørgaard, Bjarne Linde; Terkelsen, Christian Juhl; Jensen, Kaare; Christiansen, Evald Høj; Terp, Kim Allan; Andersen, Gratien; Hvitfeldt, Steen; Andersen, Henning Rud
Prosthetic valve endocarditis (PVE) after transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement (SAVR) is a potential life threatening complication. Better understanding of the incidence, predictors, clinical presentation, diagnostic measures, complications and management of PVE may help improve TAVI long-term outcome. We report a case of TAVI-PVE in an 80-year-old high risk patient in whom SAVR was successfully performed. We have reviewed literature regarding TAVI-PVE. PMID:27867590
Shehatha, Jaffar S; Taha, Abdulsalam Y
A 66-year-old Australian man underwent elective replacement of a severely stenotic aortic valve with a 22-mm Medtronic-Hall valve. Six weeks later, he was readmitted with worsening dyspnea, fever, and mild anemia. Investigations confirmed pulmonary edema and moderate periprosthetic aortic regurgitation. The pulmonary edema was managed conservatively, and a second 22-mm Medtronic-Hall valve was implanted. Infective endocarditis was suspected in the aortic annulus below the orifice of the right coronary artery. A bacteriological study revealed a rare bacteria of Streptomyces species. The patient received intensive antibiotic therapy over a 6-week period of hospitalization, and the aortic regurgitation disappeared one week postoperatively.
Sari, Ibrahim; Delil, Kenan; Ileri, Cigdem; Samadov, Fuad
ST elevation acute myocardial infarction in patients with a mechanical prosthetic valve is rare and usually due to inadequate anticoagulation. We present a case of acute inferior myocardial infarction in a patient with a prosthetic aortic valve and high international normalized ratio, which has not been reported previously. PMID:24799934
Blackstone, E H; Kirklin, J W; Pluth, J R; Turner, M E; Parr, G V
Four hundred seventy-five patients underwent aortic valve replacement with the Braunwald-Cutter ball-valve prosthesis at two institutions. The early (30-day) hospital mortality was 4.7% for those with isolated aortic valve replacement and 6.9% for the entire group. For the former, 5-year actuarial survival of the hospital survivors was 72 +/- 5.7%; for the latter group it was 71 +/- 4.4%. Eleven patients (5 since the date of follow-up inquiry) have suffered poppet escape, 9 of whom died. The actuarial incidence of known poppet escape is 4 +/- 2.6% at 47 months; when the 5 patients suffering poppet escape since the date of follow-up inquiry are included, with certain assumptions, the incidence is 3.7 +/- 1.14%. The projected probability of poppet escape using all 11 patients is 12.2% at 5 years; the 70% confidence bands of projected probability of poppet escape separate from those of the risk of re-replacement at 61 months. This and other analyses indicate that in general, patients with the Braunwald-Cutter aortic prosthesis should have it replaced 4 1/2 to 5 years after its insertion.
Hylen, J C; Kloster, F E; Herr, R H; Hull, P Q; Ames, A W; Starr, A; Griswold, H E
Fatty infiltration causing changes in the silastic poppet of the Model 1000 series Starr-Edwards aortic valve prostheses (ball variance) has been detected with increasing frequency and can result in sudden death. Phonocardiograms were recorded on 12 patients with ball variance confirmed by operation and of 31 controls. Ten of the 12 patients with ball variance were distinguished from the controls by an aortic opening sound (AO) less than half as intense as the aortic closure sound (AC) at the second right intercostal space (AO/AC ratio less than 0.5). Both AO and AC were decreased in two patients with ball variance, with the loss of the characteristic high frequency and amplitude of these sounds. The only patient having a diminished AO/AC ratio (0.42) without ball variance at reoperation had a clot extending over the aortic valve struts. The phonocardiographic findings have been the most reliable objective evidence of ball variance in patients with Starr-Edwards aortic prosthesis of the Model 1000 series.
Langerhuus, S N; Tønnesen, E K; Jensen, K H; Damgaard, B M; Heegaard, P M H; Halekoh, U; Lauridsen, C
Aortic vascular prosthetic graft infection (AVPGI) with Staphylococcus aureus is a feared post-operative complication. This study was conducted to evaluate the clinical signs and potential biomarkers of infection in a porcine AVPGI model. The biomarkers evaluated were: C-reactive protein (CRP), fibrinogen, white blood cells (WBC), major histocompatibility complex II (MHC II) density, lymphocyte CD4:CD8 ratio and tumour necrosis factor-alpha (TNF-α) in vitro responsiveness. Sixteen pigs were included in the study, and randomly assigned into four groups (n = 4): "SHAM" pigs had their infra-renal aorta exposed by laparotomy; "CLEAN" pigs had an aortic graft inserted; "LOW" and "HIGH" pigs had an aortic graft inserted and, subsequently, S. aureus were inoculated on the graft material (5 × 10(4) colony-forming units [CFU] and 1 × 10(6) CFU, respectively). Biomarkers were evaluated prior to surgery and on day 2, 5, 7, and 14 post-operatively in blood samples. Of all biomarkers evaluated, CRP was superior for diagnosing S. aureus AVPGI in pigs, with a sensitivity of 0.86 and a specificity of 0.75.
Spellings, K.; Lourenco, L.
The objective of this study is to provide a precise means of evaluating the hydrodynamic performance of prosthetic aortic and mitral valves. Particle Image Velocimetry is used to measure the in-plane velocity components in selected planes of the flow, from which the turbulent shear stress is derived. The experimental facility used in this study is made of plexiglas tube, and has a circular cross section with a diameter that matches that of the valve. To ensure optical access the test fluid used matches the refractive index of plexiglas and the test section incorporates a square housing filled with the same fluid. The fluid used in this experiment is a mixture of glycerol, water and sodium iodide. Pulsatile flow is achieved by means of a pump and monitored in real time by means of an electronic flowmeter. Dynamic similarity is ensured in these experiments as the viscosity of the fluid mixture closely approximates that of blood.
de Tullio, Marco D.
The flowfield through prosthetic heart valves is investigated by means of direct numerical simulations, considering the fully coupled fluid-structure interaction problem. Two different aortic valve models are modeled: a bileaflet mechanical and a biological one. In order to reveal fluid flow structures and to better understand the transport mechanics, Lagrangian coherent structures (LCS) are used. LCS are distinguished material surfaces that can be identified as boundaries to regions with dynamically distinct behavior, and are revealed as hypersurfaces that locally maximize the finite-time Lyapunov exponent (FTLE) fields. Post-processing the flow simulation data, first FTLE fields are calculated integrating dense meshes of Lagrangian particles backward in time, and then attracting LCS are extracted. A three-jet configuration is distinctive of bi-leaflet mechanical valves, with higher turbulent shear stresses immediately distal to the valve leaflets, while a jet-like flow emerges from the central orifice of bio-prosthetic valves, with high turbulent shear stresses occurring at the edge of the jet. Details of the numerical methodology along with a thorough analysis of the different flow structures developing during the cardiac cycle for the two configurations will be provided.
Bailey, Jonathon; Curzen, Nick; Bressloff, Neil W
TAVI devices are manufactured with cylindrical frames. However, the frames are rarely cylindrical post-deployment since deformation due to localised under expansion can be induced by calcified material on the native valve leaflets exerting irregular forces upon the frame. Consequently, the leaflets within a deformed TAVI device may undergo elevated stress during operation, which may lead to premature device failure. Using computational analysis a complete TAVI device model was simulated undergoing deployment into an aortic root model derived from CT data for a patient with severe calcific aortic stenosis, followed by a pressure simulated cardiac cycle. The complete analysis was performed eight times, each with the device at a different rotational orientation relative to the native valve, with an increment spacing of 15°. The TAVI device frames consistently featured significant distortions associated with bulky calcified material at the base of the non-coronary sinus. It was found that the average von Mises stress in the prosthetic valves was only increased in one of the cases relative to an idealised device. However, the maximum von Mises stress in the prosthetic valves was elevated in the majority of the cases. Furthermore, it was found that there were preferable orientations to deploy the prosthetic device, in this case, when the prosthetic leaflets were aligned with the native leaflets. As device orientation deviated from this orientation, the stresses in the valve increased because the distance between the prosthetic commissures decreased. This potentially could represent a sufficient increase in stress to induce variation in device lifespan.
Maluenda, Gabriel; Caorsi, Carlos; Baeza, Cristian
Transcatheter aortic valve replacement remains challenge in patients with ball-cage-type mechanical valve in mitral position. Potential under-expansion of the percutaneous valve and interaction between the mitral ball-cage mechanical valve tilted towards the left ventricular outflow tract and the percutaneous valve adds risk during and after implantation. We report a successful implantation of the novel CoreValve Evolut-R self-expanding in a patient with severe aortic stenosis and a mitral Starr-Edwards mechanical valve implanted 28years ago.
Eldar, M; Motro, M; Rath, S; Schy, N; Neufeld, H N
Systolic closure of the aortic valve was found in 10 of 36 patients who underwent mitral valve replacement. Eight patients had early systolic closure, and two had mid-systolic closure. The left ventricular outflow tract dimension on M-mode and two dimensional echocardiograms, left ventricular posterior wall and septal thickness, left ventricular dimensions in systole and diastole, aortic valve opening, and mitral to aortic valve distance were not significantly different between patients with and without systolic closure of the aortic valve. Two of the 10 patients with systolic aortic valve closure were catheterised and in neither was there a gradient between the left ventricle and the aorta. The two patients with mid-systolic closure, however, were the patients who had the narrowest left ventricular outflow tract which could cause significant distortion of blood flow. Systolic closure of the aortic valve in patients with mitral valve replacement is probably not caused by left ventricular outflow tract obstruction, though abnormalities in laminar flow from the left ventricular outflow tract may be involved. Images PMID:7082513
Karara, H. M.
The cooperative effort towards the development of a tri-leaflet prosthetic heart valve is described. The photogrammetric studies were conducted on silicone rubber molds. Information on data acquisition and data reduction phases is given, and certain accuracy aspects of the project are explained. The various outputs which are discussed include digital models, profiles, and contour maps.
O'Brien, K.; Barnes, D.; Martin, R.H.; Rae, J.R. )
A 52-yr-old man who had a bioprosthetic aortic valve developed Staphylococcus aureus bacteremia. Despite antibiotic therapy he had persistent pyrexia and developed new conduction system disturbances. Echocardiography did not demonstrate vegetations on the valve or an abscess, but gallium scintigraphy using SPECT clearly identified a focus of intense activity in the region of the aortic valve. The presence of valvular vegetations and a septal abscess was confirmed at autopsy. Gallium scintigraphy, using SPECT, provided a useful noninvasive method for the demonstration of endocarditis and the associated valve ring abscess.
Enoch, D A; Phillimore, N; Karas, J A; Horswill, L; Mlangeni, D A
Daptomycin is a novel lipopeptide with activity against Gram-positive organisms including enterococci. It is licensed for the treatment of Staphylococcus aureus bacteraemia and right-sided endocarditis, but not endocarditis due to Enterococcus spp. We report a case of enterococcal prosthetic valve endocarditis with an aortic root abscess in an elderly patient who was not fit for surgery. The patient's endocarditis relapsed 9 weeks after a 6 week course of daptomycin.
Palmer, Sonny; Mariani, Justin A; Newcomb, Andrew; Stokes, Michael B; Burns, Andrew T
Assessment of the left ventricular pressure measured across an aortic valve prosthesis is occasionally necessary when noninvasive imaging and Doppler echocardiographic data are inconclusive or differ from the clinical findings for specific scenarios, such as diagnosing constrictive or restrictive physiology. We present a case in which we safely and effectively replicate the previous successful application of a PressureWire in diagnosing constrictive pericarditis in a patient with a bileafltet mechanical aortic and mitral valves.
Kaminsky, R; Morbiducci, U; Rossi, M; Scalise, L; Verdonck, P; Grigioni, M
Prosthetic heart valves (PHVs) have been used to replace diseased native valves for more than five decades. Among these, mechanical PHVs are the most frequently implanted. Unfortunately, these devices still do not achieve ideal behavior and lead to many complications, many of which are related to fluid mechanics. The fluid dynamics of mechanical PHVs are particularly complex and the fine-scale characteristics of such flows call for very accurate experimental techniques. Adequate temporal resolution can be reached by applying time-resolved PIV, a high-resolution dynamic technique which is able to capture detailed chronological changes in the velocity field. The aim of this experimental study is to investigate the evolution of the flow field in a detailed time domain of a commercial bileaflet PHV in a mock-loop mimicking unsteady conditions, by means of time-resolved 2D Particle Image Velocimetry (PIV). The investigated flow field corresponded to the region immediately downstream of the valve plane. Spatial resolution as in "standard" PIV analysis of prosthetic valve fluid dynamics was used. The combination of a Nd:YLF high-repetition-rate double-cavity laser with a high frame rate CMOS camera allowed a detailed, highly temporally resolved acquisition (up to 10000 fps depending on the resolution) of the flow downstream of the PHV. Features that were observed include the non-homogeneity and unsteadiness of the phenomenon and the presence of large-scale vortices within the field, especially in the wake of the valve leaflets. Furthermore, we observed that highly temporally cycle-resolved analysis allowed the different behaviors exhibited by the bileaflet valve at closure to be captured in different acquired cardiac cycles. By accurately capturing hemodynamically relevant time scales of motion, time-resolved PIV characterization can realistically be expected to help designers in improving PHV performance and in furnishing comprehensive validation with experimental data
Pasic, Miralem; Dreysse, Stephan; Drews, Thorsten; Buz, Semih; Unbehaun, Axel; Kukucka, Marian; Mladenow, Alexandar; Hetzer, Roland
Transapical aortic valve implantation carries some degree of uncertainty regarding the definitive valve position. We added angiographic visualization of the aortic root while the prosthetic valve is being slowly deployed. It enables easy correction of the position of the valve so that perfect alignment can be achieved of the relationships between the prosthetic valve, aortic valve annulus, aortic cusps, and the coronary arteries.
... to: Abdominal aortic aneurysm Aortic dissection Aortic regurgitation Aortic stenosis Congenital (present from birth) problems Double aortic arch ... Aortic aneurysm repair - endovascular Aortic dissection Aortic insufficiency Aortic stenosis Magnetic resonance ... Patient Instructions Abdominal ...
... lightweight materials such as plastic, metal alloys and carbon-fiber composites. Prosthetic feet can be basic (unmoving), ... feet: store and release energy during the walking cycle give a sense of push-off, a more ...
... Z) Hepatitis HIV Mental Health Mental Health Home Suicide Prevention Substance Abuse Military Sexual Trauma PTSD Research ( ... for measurement of moisture, temperature, pressure, and shear stress; (2) integration of this array into a prosthetic ...
... torque adapter in the pylons of transtibial amputees. Energy Storage & Release Many ambulatory lower limb amputees exhibit ... Future Directions Current Project Summaries Development of Controlled Energy Storage and Release Prosthetic Foot Development of Inverting- ...
Mizoguchi, Hiroki; Sakaki, Masayuki; Inoue, Kazushige; Iwata, Takashi; Tei, Keikou; Miura, Takuya
Prosthesis-patient mismatch (PPM) is always of concern when performing aortic valve replacement (AVR) in patients with a small aortic annulus. Although bioprosthetic AVR is preferred in patients older than 65 years, we have experienced cases in elderly patients with a small aortic annulus whereby we could not implant small-sized bioprosthetic valves. We have implanted St. Jude Medical Regent (SJMR) mechanical valves (St. Jude Medical, St. Paul, MN, USA) as necessary, even in elderly patients with no aortic annulus enlargement. We investigated our experiences of AVR with SJMR mechanical valves of 21 mm or less in size. Between January 2006 and December 2009, 40 patients underwent AVR with SJMR mechanical valves ≤21 mm in size: 9 patients received 21-mm valves, 19 received 19-mm valves, and 12 received 17-mm valves. The mean age was 65.9 ± 9.5 years, and 25 patients (62.5 %) were 65 years or older. We evaluated the clinical outcome and the echocardiographic data for each valve size. There was no operative or hospital mortality. The mean duration of clinical follow-up was 31.2 ± 17.6 months. During follow-up, there were no hospitalizations due to heart failure. The cumulative valve-related event-free survival was 93 % at 33 months, and the cumulative hemorrhagic event-free survival was 93 % at 33 months and 84 % at 43 months, using the Kaplan-Meier method. At follow-up, the mean values of the measured effective orifice area (EOA) for the 21-, 19-, and 17-mm prostheses were 2.00 ± 0.22, 1.74 ± 0.37, and 1.25 ± 0.26 cm(2), and the mean measured EOA index (EOAI) were 1.17 ± 0.12, 1.11 ± 0.21 and 0.90 ± 0.22 cm(2)/m(2), respectively. A PPM (EOAI ≤0.85) was documented in 5 patients, all of whom had received a 17-mm SJMR valve. AVR with SJMR valves of 21 mm or less in size appears to show satisfactory clinical and hemodynamic results.
Ben Ismail, M; Hannachi, N; Abid, F; Kaabar, Z; Rougé, J F
Fifty eight patients (aged 8-59 years, mean 27) treated for prosthetic valve endocarditis from January 1966 to January 1985 were studied retrospectively by review of case notes. There were 12 cases of early and 46 cases of late prosthetic valve endocarditis. These developed in 28 patients with an isolated aortic valve, in 26 with an isolated mitral valve, and in four with both aortic and mitral prosthetic valves. Streptococci were the most commonly isolated microorganisms, followed by staphylococci, Gram negative bacteria, and fungi. A surgical (34 cases) or a necropsy specimen (10 cases) from 44 cases was examined. Eighty two per cent of the patients had congestive heart failure. Twenty four of the 58 patients were medically treated and 17 died (70% mortality). Combined medical and surgical treatment was used in 34 patients; the main indication for surgery was congestive heart failure. Fourteen patients on combined treatment died (40% mortality). Persistent sepsis and prosthetic valve dehiscence were the most common early and late operative complications. The most important influences on outcome were congestive heart failure, the type of micro-organism, the severity and extent of anatomical lesions, the time of onset of prosthetic valve endocarditis, and the type of treatment. This survey indicates that only patients without congestive heart failure or embolic complications and with sensitive micro-organism should be treated medically. In view of the poor prognosis patients with prosthetic valve endocarditis associated with congestive heart failure, persistent sepsis, and repeat arterial emboli should be treated by early surgical intervention. PMID:3620246
Iannaccone, Francesco; Degroote, Joris; Vierendeels, Jan; Segers, Patrick
In recent years the role of FSI (fluid-structure interaction) simulations in the analysis of the fluid-mechanics of heart valves is becoming more and more important, being able to capture the interaction between the blood and both the surrounding biological tissues and the valve itself. When setting up an FSI simulation, several choices have to be made to select the most suitable approach for the case of interest: in particular, to simulate flexible leaflet cardiac valves, the type of discretization of the fluid domain is crucial, which can be described with an ALE (Arbitrary Lagrangian-Eulerian) or an Eulerian formulation. The majority of the reported 3D heart valve FSI simulations are performed with the Eulerian formulation, allowing for large deformations of the domains without compromising the quality of the fluid grid. Nevertheless, it is known that the ALE-FSI approach guarantees more accurate results at the interface between the solid and the fluid. The goal of this paper is to describe the same aortic valve model in the two cases, comparing the performances of an ALE-based FSI solution and an Eulerian-based FSI approach. After a first simplified 2D case, the aortic geometry was considered in a full 3D set-up. The model was kept as similar as possible in the two settings, to better compare the simulations’ outcomes. Although for the 2D case the differences were unsubstantial, in our experience the performance of a full 3D ALE-FSI simulation was significantly limited by the technical problems and requirements inherent to the ALE formulation, mainly related to the mesh motion and deformation of the fluid domain. As a secondary outcome of this work, it is important to point out that the choice of the solver also influenced the reliability of the final results. PMID:27128798
Blauwet, Lori A; Miller, Fletcher A
Valvular heart disease is a global health problem. It is estimated that more than 280,000 prosthetic heart valves are implanted worldwide each year. As the world's population is aging, the incidence of prosthetic heart valve implantation and the prevalence of prosthetic heart valves continue to increase. Assessing heart valve prosthesis function remains challenging, as prosthesis malfunction is unpredictable but not uncommon. Transthoracic two-dimensional and Doppler echocardiography is the preferred method for assessing prosthetic valve function. Clinically useful Doppler-derived measures for assessing prosthetic valve hemodynamic profiles have been reported for aortic, mitral, and tricuspid valve prostheses, but echocardiographic data regarding pulmonary valve prostheses remain limited. Complete prosthetic valve evaluation by transthoracic echocardiography (TTE) is sometimes challenging due to acoustic shadowing and artifacts. In these cases, further imaging with transesophageal echocardiography, fluoroscopy and/or gated CT may be warranted, particularly if prosthetic valve dysfunction is suspected. Being able to differentiate pathologic versus functional obstruction of an individual prosthesis is extremely important, as this distinction affects management decisions. Transprosthetic and periprosthetic regurgitation may be difficult to visualize on TTE, so careful review of Doppler-derived data combined with a high index of suspicion is warranted, particularly in symptomatic patients. A baseline TTE soon after valve implantation is indicated in order to "fingerprint" the prosthesis hemodynamic profile. It remains unclear how frequently serial imaging should be performed in order to assess prosthetic valve function, as this issue has not been systematically studied.
Miller, S.W.; Dinsmore, R.E.
Abscesses in the aortic root are a serious complication of infective endocarditis and require accurate diagnosis for antibiotic and surgical management. Nineteen cases of endocarditis of a native valve or prosthetic valve and adjacent abscess cavities were identified with angiography. Of 6 patients with endocarditis of a native valve, 5 had bicuspid aortic valves and all had severe aortic regurgitation. Of 13 patients with endocarditis of a prosthetic aortic valve, all had paravalvular regurgitation. Fistulas were detected into the mitral anulus in 8 patients, and into the right ventricle in 3 patients. No complications from the catheterization were recorded during the 48-hour follow-up.
Ozker, Emre; Vuran, Can; Saritas, Bülent; Türköz, Riza
We describe a successful surgical treatment in a 2.5-year old boy with Loeys-Dietz syndrome, in whom we performed aortic arch and ascending aorta replacement with a valve-sparing operation (VSO) of the aortic root because of significant aortic insufficiency and dilation of the aortic root. We believe that VSO is ideal for treating young patients with aortic root aneurysm with normal or minimally diseased aortic cusps to avoid the disadvantages of prosthetic valve replacements.
Guihaire, Julien; Kloeckner, Martin; Deleuze, Philippe
Destructive aortic valve endocarditis is a serious condition that can result in aortoventricular disjunction. The appropriate surgical approach for severe excavating lesions remains a matter of debate. Homografts, prosthetic valves associated with a pericardial patch for annulus repair, and prosthetic valve conduits can be used. We report the technical issue of subcoronary inclusion of the full root Freestyle xenograft for complicated aortic endocarditis extending to the left ventricular outflow tract.
Purnell, G.L.; Walker, C.W.; Allison, J.W.; Dalrymple, G.V. )
Infective endocarditis can be difficult to prove, even in the face of strong clinical suspicion. A case in which standard methods of diagnosis failed to demonstrate endocarditis in a patient with recurrent Staphylococcus aureus bacteremia and porcine aortic valve is reported. An In-111 labelled leukocyte SPECT study demonstrated uptake in the aortic root and leaflets, and autopsy demonstrated vegetations on the leaflets. In-111 may prove useful in demonstrating endocarditis in patients with prosthetic valve infection.
Aortic prosthetic valve endocarditis (PVE) is a potentially life-threatening disease. Mortality and incidence of infective endocarditis have been reduced in the past 30 years. Medical treatment of aortic PVE may be successful in patients who have a prompt response after antibiotic treatment and who do not have prosthetic dysfunction. In advanced stages, antibiotic therapy alone is insufficient to control the disease, and surgical intervention is necessary. Surgical treatment may be lifesaving, but it is still associated with considerable morbidity and mortality. The aim of surgery is to perform a radical excision of all infected and necrotic tissue, reconstruction of the left ventricle outflow tract, and replacement of the aortic valve. There is no unanimous consensus on which is the optimal prosthesis to implant in this context, and several surgical techniques have been suggested. We aim to analyze the efficacy of the surgical treatment and discuss the issue of valve selection in patients with aortic valve endocarditis. PMID:27785132
This article traces the development of microprocessor prosthetic knees from early research in the 1970s to the present. Read about how microprocessor knees work, functional options, patient selection, and the future of this prosthetic.
Mahesh, Balakrishnan; Deville, Claude; Nashef, Samer
Valve-sparing aortic root replacement (ARR) is the procedure of choice in young patients with aortic root aneurysm and preserved aortic valve leaflets; however, coronary ostial anastomoses remain an issue. Troublesome bleeding sometimes occurs during surgery, and in the long term, there is a risk of aneurysmal formation in the residual aortic wall of the ostial "button." We describe a technique of valve-sparing ARR wherein each coronary button along with its flange of aortic tissue is implanted within the prosthetic graft used for ARR, thereby eliminating the risk of both immediate surgical bleeding and late coronary button aneurysms.
Hatori, Kyohei; Ohki, Satoshi; Obayashi, Tamiyuki; Koyano, Tetsuya; Yasuhara, Kiyomitsu; Hirai, Hanako
We describe the case of an 82-year-old woman who had undergone aortic mechanical valve replacement for aortic stenosis with a small annulus, and coronary artery bypass grafting. Four years after the operation, she began to experience hemolysis. Prosthetic valve obstruction was observed but there was no paravalvular leakage or aortic regurgitation through the mechanical valve. We elected to perform apicoaortic bypass in this patient with severe hemolytic anemia secondary to a mechanical valve malfunction.
Kannan, Arun; Smith, Cristy; Subramanian, Sreekumar; Janardhanan, Rajesh
A middle-aged adult patient with a history of aortic root replacement with a mechanical valved conduit and remote chest trauma was referred to our institution with prosthetic endocarditis. Transoesophageal echocardiogram at our institution confirmed a near-complete dehiscence of the prosthetic aortic valve from the conduit, with significant perivalvular flow forming a pseudoaneurysm. The patient underwent a high-risk re-operation, involving redo aortic root replacement with a homograft after extensive debridement of the infected tissue. The patient was discharged to an outside facility after an uncomplicated hospital course, and remains stable. PMID:24510692
Ghista, Dhanjoo N.; Reul, Helmut; Ray, Gautam; Chandran, K. B.
The design criteria for an optimum prosthetic-aortic leaflet valve are a smooth washout in the valve cusps, minimal leaflet stress, minimal transmembrane pressure for the valve to open, an adequate lifetime (for a given blood-compatible leaflet material's fatigue data). A rigorous design analysis is presented to obtain the prosthetic tri-leaflet aortic valve leaflet's optimum design parameters. Four alternative optimum leaflet geometries are obtained to satisfy the criteria of a smooth washout and minimal leaflet stress. The leaflet thicknesses of these four optimum designs are determined by satisfying the two remaining design criteria for minimal transmembrane opening pressure and adequate fatigue lifetime, which are formulated in terms of the elastic and fatigue properties of the selected leaflet material - Avcothane-51 (of the Avco-Everett Co. of Massachusetts). Prosthetic valves are fabricated on the basis of the optimum analysis and the resulting detailed engineering drawings of the designs are also presented in the paper.
Horstkotte, D; Körfer, R; Loogen, F; Rosin, H; Bircks, W
Prosthetic valve endocarditis (PVE) was shown in 46 patients out of a group of 2163 carrying prosthetic heart valves. The cumulative rate of early PVE was 1.4% and 1.5% for PVE occurring between the 60th day and 10 years after surgery. In 37% of all cases this was caused by staphylococci, 20% by streptococci, and 13% Gram negative species. Fungi were found in 9% and mixed infections in 21%. The incidence of staphylococci, Gram negative pathogens and fungi was significantly higher in early PVE. In 5 patients, valve involvement consisted in echocardiographically shown vegetations and/or obstructive thromboendocarditis. In 90% of 37 patients who developed paravalvular leakages, there was high intravascular haemolysis uncharacteristic of the type of prosthesis implanted. In 70% fluoroscopy revealed disproportionate tilting of the prosthetic annulus, and in 75% there was a distinct echocardiographic pattern in the closing movement of the valve poppet. The cumulative survival rate after six months was 31% for the conservatively treated, and 66% for the medically plus surgically treated patients. Survival rates at the end of a maximum follow-up of 20 years was 15% with conservative treatment and 51% after primary surgical therapy. The prognosis was worse (P less than 0.01) in patients who, during aortic PVE, developed heart failure refractant to therapy due to haemodynamically significant prosthetic valve dysfunction, to sepsis that persisted for more than 72 h despite antibiotic therapy, to major septic embolism or to acute renal failure. The retrospective prognosis was more favourable for patients with early aortic (P less than 0.02) or mitral (P less than 0.05) valve re-replacement than for patients who had been treated medically only.
... Ventricle Normal Heart Select Disease To Learn More Aortic Stenosis Aortic Insufficiency Aorta The aorta is the main ... the rest of your body. Aortic Valve In aortic stenosis, the aortic valve becomes narrowed and does not ...
Kron, Irving L.
Patient prosthesis mismatch (PPM) can occur when a prosthetic aortic valve has an effective orifice area (EOA) less than that of a native valve. A recent study by Zorn and colleagues evaluated the incidence and significance of PPM in high risk patients with severe aortic stenosis who were randomized to transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR). TAVR is associated with decreased incidence of severe PPM compared to traditional SAVR valves. Severe PPM increases risk for death at 1 year postoperatively in high risk patients. The increased incidence of PPM is largely due to differences in valve design and should encourage development of newer SAVR valves to reduce risk for PPM. In addition more vigorous approaches to root enlargement in small annulus should be performed with SAVR to prevent PPM. PMID:27867654
Ghanta, Ravi K; Kron, Irving L
Patient prosthesis mismatch (PPM) can occur when a prosthetic aortic valve has an effective orifice area (EOA) less than that of a native valve. A recent study by Zorn and colleagues evaluated the incidence and significance of PPM in high risk patients with severe aortic stenosis who were randomized to transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR). TAVR is associated with decreased incidence of severe PPM compared to traditional SAVR valves. Severe PPM increases risk for death at 1 year postoperatively in high risk patients. The increased incidence of PPM is largely due to differences in valve design and should encourage development of newer SAVR valves to reduce risk for PPM. In addition more vigorous approaches to root enlargement in small annulus should be performed with SAVR to prevent PPM.
DARPA Revolutionizing Prosthetics 2009 Michael P. McLoughlin January 2009 Distribution Statements per DoD Directive 5230.24 Distribution Statement...DATE JAN 2009 2. REPORT TYPE 3. DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND SUBTITLE DARPA Revolutionizing Prosthetics 2009 5a...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 CLO-05-003 RevI2 22-Feb-10 DARPA Revolutionizing Prosthetics 2009 Program Vision
... Guide and Service Dogs Contact VA Central Office Prosthetic & Sensory Aids Service If you have a general question regarding artificial limbs/orthotics, automobile adaptive equipment, clothing allowance, durable medical ...
Bartley, Patricia; Angelakis, Emmanouil; Raoult, Didier; Sampath, Rangarajan; Bonomo, Robert A.
Identifying the pathogen responsible for culture-negative valve endocarditis often depends on molecular studies performed on surgical specimens. A patient with Ehlers-Danlos syndrome who had an aortic graft, a mechanical aortic valve, and a mitral anulloplasty ring presented with culture-negative prosthetic valve endocarditis and aortic graft infection. Research-based polymerase chain reaction (PCR)/electrospray ionization mass spectrometry on peripheral blood samples identified Bartonella henselae. Quantitative PCR targeting the16S-23S ribonucleic acid intergenic region and Western immunoblotting confirmed this result. This, in turn, permitted early initiation of pathogen-directed therapy and subsequent successful medical management of B henselae prosthetic valve endocarditis and aortic graft infection. PMID:27844027
Ott, David A.; Cooley, Denton A.; Norman, John C.
A 66-year-old woman developed severe hemolysis after undergoing aortic valve replacement. A diminutive annulus and extensive calcification of the aorta precluded further surgery of the aortic root. Hemolysis was completely reversed by the implantation of a woven Dacron apicoabdominal aortic conduit incorporating a Cooley-Cutter prosthetic valve. Fractionation of stroke volume by means of a second ventricular outlet can reduce shear stresses and turbulence associated with unfavorable hemodynamic conditions, thereby successfully correcting hemolysis. Images PMID:15216312
... these occur in the part of the aorta running through the chest Abdominal aortic aneurysms (AAA) - these occur in the part of the aorta running through the abdomen Most aneurysms are found during ...
... By Mayo Clinic Staff Aortic valve stenosis — or aortic stenosis — occurs when the heart's aortic valve narrows. This ... pressure may prevent or slow the development of aortic stenosis. Ask your doctor if you need to lower ...
Moldovan, Maria-Sînziana; Bedeleanu, Daniela; Kovacs, Emese; Ciumărnean, Lorena; Molnar, Adrian
Pannus-related prosthetic valve dysfunction, a complication of mechanical prosthetic valve replacement, is rare, with a slowly progressive evolution, but it can be acute, severe, requiring surgical reintervention. We present the case of a patient with a mechanical single disc aortic prosthesis, with moderate prosthesis-patient mismatch, minor pannus found on previous ultrasound examinations, who presented to our service with angina pain with a duration of 1 hour, subsequently interpreted as non-ST segment elevation myocardial infarction (NSTEMI) syndrome. Coronarography showed normal epicardial coronary arteries, an ample movement of the prosthetic disc, without evidence of coronary thromboembolism, and Gated Single-Photon Emission Computerized Tomography (SPECT) with Technetium (Tc)-99m detected no perfusion defects. Transthoracic echocardiography (TTE) evidenced a dysfunctional prosthesis due to a subvalvular mass; transesophageal echocardiography (TOE) showed the interference of this mass, with a pannus appearance, with the closure of the prosthetic disc. Under conditions of repeated angina episodes, under anticoagulant treatment, surgery was performed, with the intraoperative confirmation of pannus and its removal. Postoperative evolution was favorable. This case reflects the diagnostic and therapeutic management problems of pannus-related prosthetic valve dysfunction.
Taniyasu, N; Kou, E; Hiramatsu, T; Yokoyama, S; Takenaka, A; Ikawa, O
The patient was a 48-year-old woman with aortic stenosis and regurgitation and mitral stenosis. Preoperative cardiac catheterization revealed LV-Ao pressure gradient of 30 mmHg and regurgitation of Sellers III. The aortic annulus was measured less than 19 mm. As operative findings, the aortic annulus seemed to be too small to be replaced with 19 mm prosthetic valve. Aortic valvuloplasty (AVP) with rasping technique was performed for the aortic valve and valve replacement was carried out for the mitral valve. After aortic declamping and occurring her beat, the transesophageal echocardiographic evaluation for AVP was effective. Postoperative course was uneventful. Postoperative cardiac catheterization have shown decreased transvalvular pressure gradient up to 10 mmHg and aortic regurgitation of Sellers I.
The invention relates to an improved electrically driven prosthetic elbow wherein the elbow is capable of being rigidly locked into place in any...desired position, and upon driving the arm to the fully extended position, the elbow is automatically unlocked.
Norton, William E.; Belcher, Jewell G., Jr.; Carden, James R.; Vest, Thomas W.
Prosthetic hand attached to end of remaining part of forearm and to upper arm just above elbow. Pincerlike fingers pushed apart to degree depending on rotation of forearm. Simpler in design, simpler to operate, weighs less, and takes up less space.
Srinivasan, Sathish; Ting, Darren S J; Snyder, Michael E; Prasad, Somdutt; Koch, Hans-Reinhard
Congenital iris defects may usually present either as subtotal aniridia or colobomatous iris defects. Acquired iris defects are secondary to penetrating iris injury, iatrogenic after surgical excision of iris tumours, collateral trauma after anterior segment surgery, or can be postinflammatory in nature. These iris defects can cause severe visual disability in the form of glare, loss of contrast sensitivity, and loss of best corrected visual acuity. The structural loss of iris can be reconstructed with iris suturing, use of prosthetic iris implants, or by a combination of these, depending on the relative amount of residual iris stromal tissue and health of the underlying pigment epithelium. Since the first implant of a black iris diaphragm posterior chamber intraocular lens in 1994, advances in material and design technology over the last decade have led to advances in the prosthetic material, surgical technique, and instrumentation in the field of prosthetic iris implants. In this article, we review the classification of iris defects, types of iris prosthetic devices, implantation techniques, and complications.
Isomura, T; Hisatomi, K; Yanagi, I; Shimada, S; Uraguchi, K; Aoyagi, S; Kosuga, K; Ohishi, K
We describe the operative and perioperative management of 11 patients with aortic regurgitation due to aortitis. All patients required aortic valve replacement because of severely uncoapted cusps secondary to dilatation of the ascending aorta. The right coronary ostium was narrowed in 5 patients and consequently necessitated a smaller coronary tip for the administration of cardioplegic solution. To implant the prosthetic valve, pledgeted 2-0 Tevdek sutures were placed through the aortic valve annulus either from the ventricular side or from outside the aortic wall. Steroids were administered to 4 patients preoperatively and 8 patients postoperatively. Postoperative dehiscence of the prosthesis was seen in 1 of the 3 patients not given any steriods. We conclude that it is important to arrest the inflammatory reaction before operation and if the aortic valve must be replaced, to reinforce the implanted prosthesis with pledgeted sutures. Also, we suggest the possible importance of steroid therapy.
Acute aortic dissection suddenly occurrs and results in a variety of catastrophic sequelae including cardiac tamponade, rupture, and organ malperfusion. In acute stage (< 2 weeks), according to the classifications on the region of aortic dissection, the condition of the false channel and the onset, appropriate medical, surgical, or endovascular treatments including endovascular aneurysm repair followed by the rapid and accurate diagnosis of aortic dissection using computed tomography and ultrasound should be performed without delay. In the chronic stage (> 2 weeks), the behavior of the chronic dissection or residual distal dissection after the initial treatment should be followed-up carefully with best medical treatment at the regular intervals. If necessary, appropriate surgical and endovascular treatment should be carried out in the proper timing before rupture.
severe aortic stenosis . Figure 1F. Oblique axial cine bright blood imaging through the valve plane of the aorta, demonstrates the aortic valve to...the ascending aorta. This moderate to large jet is consistent with moderate to severe aortic stenosis . No diastolic jet to suggest aortic ...conditions. Functional impairment of the aortic valve—namely aortic stenosis and aortic regurgitation—is the most common complication (in up to 68-85% of
The presence of patent vein grafts on the proximal aorta may cause technical difficulties during reoperations for aortic valve replacement after previous coronary artery bypass surgery. A 65-year-old man underwent reoperation for aortic valve replacement two years after his first open heart surgery (valve-sparing aortic root replacement and aorta-right coronary artery saphenous vein graft). The aortotomy incision was started approximately 2 cm above the proximal anastomosis and continued down at both sides until the prosthetic graft. The reverse U aortotomy prevents unnecessary and risky manipulations of proximal anastomoses, provides perfect exposure, and can be used securely during reoperative aortic valve surgery.
Tenny, John B., Jr
People who lost muscular control of urinary canal through disease or injury aided by prosthetic sphincter. Implanted so it surrounds uretha, sphincter deflated and inflated at will by wearer to start and stop urina tion. Operating pressure adjusted after implantation to accommodate growth or atrophy of urinary canal and prevent tissue damage from excess pressure. Principle adapted to other organs, such as colon, ureter, or ileum.
The objective of this research was to embed tactile sensors in polyimides. This novel method could be utilized to realize prosthetic skin for sensing different kinds of mechanical stimuli. Tactile sensors have an increasing demand in medical sectors: upper and lower-limb prosthetics and in the industrial sectors: robot end-effectors, grippers and manipulators. The sensors developed are targeted for prosthetic arm tactile sensing applications. Current work presents piezoresistive differential pressure sensors fabricated on flexible polyimide film or substrate. A unique technique to bond a flexible superstrate polyimide layer to a MEMS tactile sensor array is presented in this thesis. The sensor is made of aluminium oxide membrane layer with nichrome piezoresistors as the half-Wheatstone bridge elements. Four different types of sensor designs have been characterized to obtain gauge factor of thin film nichrome. The sensor arrays with and without the superstrate film were simulated for obtaining the maximum stress, average strain and deflection of the membrane. The maximum change in output voltage was 0.8 mV. The gauge factors calculated for tactile sensor with superstrate range between 2.2 to 7.8 and without superstrate range 1.5 to 5.7.
AD_________________ Award Number: W81XWH-10-1-0870 TITLE: Advanced Prosthetic Gait Training Tool...Advanced Prosthetic Gait Training Tool 5b. GRANT NUMBER W81XWH-10-1-0870 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Rajankumar...produce a computer-based Advanced Prosthetic Gait Training Tool to aid in the training of clinicians at military treatment facilities providing care for
Ovadia, Steven A.; Askari, Morad
Upper extremity amputations are most frequently indicated by severe traumatic injuries. The location of the injury will determine the level of amputation. Preservation of extremity length is often a goal. The amputation site will have important implications on the functional status of the patient and options for prosthetic reconstruction. Advances in amputation techniques and prosthetic reconstructions promote improved quality of life. In this article, the authors review the principles of upper extremity amputation, including techniques, amputation sites, and prosthetic reconstructions. PMID:25685104
Ovadia, Steven A; Askari, Morad
Upper extremity amputations are most frequently indicated by severe traumatic injuries. The location of the injury will determine the level of amputation. Preservation of extremity length is often a goal. The amputation site will have important implications on the functional status of the patient and options for prosthetic reconstruction. Advances in amputation techniques and prosthetic reconstructions promote improved quality of life. In this article, the authors review the principles of upper extremity amputation, including techniques, amputation sites, and prosthetic reconstructions.
Ramanath, Vijay S.; Oh, Jae K.; Sundt, Thoralf M.; Eagle, Kim A.
Acute and chronic aortic diseases have been diagnosed and studied by physicians for centuries. Both the diagnosis and treatment of aortic diseases have been steadily improving over time, largely because of increased physician awareness and improvements in diagnostic modalities. This comprehensive review discusses the pathophysiology and risk factors, classification schemes, epidemiology, clinical presentations, diagnostic modalities, management options, and outcomes of various aortic conditions, including acute aortic dissection (and its variants intramural hematoma and penetrating aortic ulcers) and thoracic aortic aneurysms. Literature searches of the PubMed database were conducted using the following keywords: aortic dissection, intramural hematoma, aortic ulcer, and thoracic aortic aneurysm. Retrospective and prospective studies performed within the past 20 years were included in the review; however, most data are from the past 15 years. PMID:19411444
... to fellow requirements for affiliate fellow requirements for dental and/or maxillofacial prosthetic technicians requirements for life ... 2016 Member Survey Dr. Gordon Kent Mahanna Obituary Dr. ...
Moss, Alastair J; Dweck, Marc R; Dreisbach, John G; Williams, Michelle C; Mak, Sze Mun; Cartlidge, Timothy; Nicol, Edward D; Morgan-Hughes, Gareth J
Aortic valve replacement is the second most common cardiothoracic procedure in the UK. With an ageing population, there are an increasing number of patients with prosthetic valves that require follow-up. Imaging of prosthetic valves is challenging with conventional echocardiographic techniques making early detection of valve dysfunction or complications difficult. CT has recently emerged as a complementary approach offering excellent spatial resolution and the ability to identify a range of aortic valve replacement complications including structural valve dysfunction, thrombus development, pannus formation and prosthetic valve infective endocarditis. This review discusses each and how CT might be incorporated into a multimodal cardiovascular imaging pathway for the assessment of aortic valve replacements and in guiding clinical management. PMID:27843568
... common cause of a thoracic aortic aneurysm is hardening of the arteries . This condition is more common ... aortic aneurysm repair - open Aortic aneurysm repair - endovascular Hardening of the arteries High blood pressure Marfan syndrome ...
... valve. Also, a narrowing of the aortic valve (aortic stenosis) can be associated with leaking. High blood pressure (hypertension). High blood pressure may stretch the root of the aorta where the aortic valve sits. The valve flaps ( ...
Kim, Kyung Hwa; Choi, Jong Bum; Kim, Min Ho; Kim, Won Ho; Lee, Mi Kyung; Lee, Sam Youn
Valve replacement is typically the most appropriate option for treating aortic valve stenotic insufficiency. However, neither mechanical nor bioprosthetic replacement components preserve the circumferential expansion and contraction of a native aortic annulus during the cardiac cycle, because the prosthetic ring is affixed to the annulus. A 64-year-old man presented with a bicuspid and stenotic aortic valve, and the native annulus was too small to accommodate a porcine replacement valve. We fashioned new aortic leaflets from bovine pericardium with use of a template, and we affixed the sinotubular junction with use of inner and outer stabilization rings. Postoperative echocardiograms revealed coaptation of the 3 new leaflets with no regurgitation. At the patient's 5.5-year follow-up examination, echocardiograms showed flexible leaflet movement with a coaptation height of 7 mm, and expansion and contraction of the aortic annulus similar to that of a normal native annulus. The transvalvular pressure gradient was insignificant. If long-term durability of the new leaflets is confirmed, this method of leaflet replacement and fixation of the sinotubular junction might serve as an acceptable alternative to valve replacement in the treatment of aortic valve stenosis. We describe the patient's case and present our methods and observations.
Kim, Kyung Hwa; Kim, Min Ho; Kim, Won Ho; Lee, Mi Kyung; Lee, Sam Youn
Valve replacement is typically the most appropriate option for treating aortic valve stenotic insufficiency. However, neither mechanical nor bioprosthetic replacement components preserve the circumferential expansion and contraction of a native aortic annulus during the cardiac cycle, because the prosthetic ring is affixed to the annulus. A 64-year-old man presented with a bicuspid and stenotic aortic valve, and the native annulus was too small to accommodate a porcine replacement valve. We fashioned new aortic leaflets from bovine pericardium with use of a template, and we affixed the sinotubular junction with use of inner and outer stabilization rings. Postoperative echocardiograms revealed coaptation of the 3 new leaflets with no regurgitation. At the patient's 5.5-year follow-up examination, echocardiograms showed flexible leaflet movement with a coaptation height of 7 mm, and expansion and contraction of the aortic annulus similar to that of a normal native annulus. The transvalvular pressure gradient was insignificant. If long-term durability of the new leaflets is confirmed, this method of leaflet replacement and fixation of the sinotubular junction might serve as an acceptable alternative to valve replacement in the treatment of aortic valve stenosis. We describe the patient's case and present our methods and observations. PMID:24512414
Bakaeen, Faisal G; Rosengart, Todd K; Carabello, Blase A
This issue provides a clinical overview of aortic stenosis, focusing on screening, diagnosis, treatment, and practice improvement. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.
Weddendorf, Bruce C. (Inventor)
An artificial, manually positionable elbow joint for use in an upper extremity, above-elbow, prosthetic is described. The prosthesis provides a locking feature that is easily controlled by the wearer. The instant elbow joint is very strong and durable enough to withstand the repeated heavy loadings encountered by a wearer who works in an industrial, construction, farming, or similar environment. The elbow joint of the present invention comprises a turntable, a frame, a forearm, and a locking assembly. The frame generally includes a housing for the locking assembly and two protruding ears. The forearm includes an elongated beam having a cup-shaped cylindrical member at one end and a locking wheel having a plurality of holes along a circular arc on its other end with a central bore for pivotal attachment to the protruding ears of the frame. The locking assembly includes a collar having a central opening with a plurality of internal grooves, a plurality of internal cam members each having a chamfered surface at one end and a V-shaped slot at its other end; an elongated locking pin having a crown wheel with cam surfaces and locking lugs secured thereto; two coiled compression springs; and a flexible filament attached to one end of the elongated locking pin and extending from the locking assembly for extending and retracting the locking pin into the holes in the locking wheel to permit selective adjustment of the forearm relative to the frame. In use, the turntable is affixed to the upper arm part of the prosthetic in the conventional manner, and the cup-shaped cylindrical member on one end of the forearm is affixed to the forearm piece of the prosthetic in the conventional manner. The elbow joint is easily adjusted and locked between maximum flex and extended positions.
Helms, C. R.; Smyly, H. M. (Inventor)
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.
Tande, Aaron J.
SUMMARY Prosthetic joint infection (PJI) is a tremendous burden for individual patients as well as the global health care industry. While a small minority of joint arthroplasties will become infected, appropriate recognition and management are critical to preserve or restore adequate function and prevent excess morbidity. In this review, we describe the reported risk factors for and clinical manifestations of PJI. We discuss the pathogenesis of PJI and the numerous microorganisms that can cause this devastating infection. The recently proposed consensus definitions of PJI and approaches to accurate diagnosis are reviewed in detail. An overview of the treatment and prevention of this challenging condition is provided. PMID:24696437
Lawrence, R B; Davies, R M
The rapid and accurate thermoforming of plastics for prosthetic applications has been the subject of considerable research and development by the Bioengineering Centre. This paper outlines the progress in the general concepts that have been effected to date. The original below knee (B/K) socket vacuum forming technique has been extended to above knee (A/K) and supracondylar cases, and there have been developments in rotational casting technology. The work is necessarily based on a sound understanding of the properties of the materials concerned and of the associated manufacturing processes. The contribution of the Bioengineering Centre is outlined together with summaries of collaborative work carried out with other organizations.
Morse, D.; Steiner, R.M.; Fernandez, J.
This book contains 10 chapters. Some of the chapter titles are: The development of artificial heart valves: Introduction and historical perspective; The radiology of prosthetic heart valves; The evaluation of patients for prosthetic valve implantation; Pathology of cardiac valve replacement; and Bioengineering of mechanical and biological heart valve substitutes.
Smith, Craig R; Stamou, Sotiris C; Boeve, Theodore J; Hooker, Robert C
Penetrating ascending aortic ulcers are rarely encountered, yet they present significant risk of hemorrhage and aortic dissection. Expedient recognition and repair is of vital importance. The current management of penetrating ulcer of the ascending aorta includes replacement of the ascending aorta with a prosthetic graft. We describe our technique of repairing a penetrating ulcer of the ascending aorta with localized ulcer resection and extracellular matrix patch aortoplasty.
Healy, Aaron H; Reid, Bruce B; Allred, Bryce D; Doty, John R
Infection of a prosthetic graft after replacement of the ascending aorta is an uncommon but life-threatening complication of surgery. We report the use of antibiotic-impregnated calcium sulfate beads in a patient with ascending aortic graft infection to provide localized, high-dose therapy to the infected region. Perigraft placement of antibiotic beads provides an alternative method for the treatment of aortic graft infection.
Passik, C S; Ackermann, D M; Piehler, J M; Edwards, W D
A 74-year-old woman who had undergone aortic valve replacement with an Ionescu-Shiley bioprosthesis was evaluated and treated because aortic insufficiency developed after the application of the Heimlich maneuver. Pathologic examination of the explanted valve disclosed a cuspid perforation and an adjacent tear of a second cusp at its insertion into the valve strut. Patients with unexplained acute prosthetic insufficiency should be questioned as to whether the Heimlich maneuver has been previously performed.
Nilsson, B; Rølla, G
An account is given of the author's experience in the prosthetic treatment (removable appliances) of children. The authors consider that prosthetic treatment in the primary dentition can be both justified and indicated due to absence or loss of primary teeth. Treatment must take into consideration the growth of the jaws as well as eruption of the permanent teeth. Prosthetic treatment of the young permanent dentition and of the erupting secondary dentition may particularly be necessary, but one must absolutely take into consideration the continuous growth of the jaws. It is important that the dental surgeon have to activate the parents to participate in their child's oral home care.
Zlotolow, Dan A; Kozin, Scott H
Until recently, upper extremity prostheses had changed little since World War II. In 2006, the Defense Advanced Research Projects Agency responded to an increasing number of military amputees with the Revolutionizing Prosthetics program. The program has yielded several breakthroughs both in the engineering of new prosthetic arms and in the control of those arms. Direct brain-wave control of a limb with 22° of freedom may be within reach. In the meantime, advances such as individually powered digits have opened the door to multifunctional full and partial hand prostheses. Restoring sensation to the prosthetic limb remains a major challenge to full integration of the limb into a patient's self-image.
Brinkman, P; Seipel, C; Juers, A
An improved approach to inventory management in the Operating Theatre has been initiated at Princess Alexandra Hospital. A Clinical Resource Co-ordinator (CRC) position was created to provide access to expertise in purchasing and materials management at the clinical level. A review of existing inventory management practices conducted by the CRC revealed reporting inadequacies, lack of product specialisation and inadequate control over pricing, stock levels and product usage. Through liaison with key stakeholders, a competitive tendering process was introduced which resulted in a standing offer arrangement being installed for three specialty orthopaedic areas. Outcomes of this arrangement are discussed. The importance of raising the area of prosthetic inventory management for debate in the Australian literature is also highlighted.
Chortos, Alex; Liu, Jia; Bao, Zhenan
Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals.
Jonckheere, Stijn; De Baere, Thierry; Schroeyers, Pascal; Soetens, Oriane; De Bel, Annelies; Surmont, Ignace
We report a case of fulminant endocarditis on a prosthetic homograft aortic valve caused by Bordetella holmesii, which was successfully managed by surgical valve replacement and antibiotic treatment. B. holmesii, a strictly aerobic, small, Gram-negative coccobacillus, has been implicated as an infrequent cause of a pertussis-like syndrome and other respiratory illnesses. However, B. holmesii is also a rare cause of septicaemia and infective endocarditis, mostly in immunocompromised patients. To our knowledge, this is the first report of B. holmesii endocarditis on a prosthetic aortic valve. Routine laboratory testing initially misidentified the strain as Acinetobacter sp. Correct identification was achieved by 16S rRNA gene and outer-membrane protein A (ompA) gene sequencing. Interestingly, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry also produced an accurate species-level identification. Subsequent susceptibility testing and review of the literature revealed ceftazidime, cefepime, carbapenems, aminoglycosides, fluoroquinolones, piperacillin/tazobactam, tigecycline and colistin as possible candidates to treat infections caused by B. holmesii.
Cardoso, Gonçalo; Trabulo, Marisa; Andrade, Maria João; Ribeiras, Regina; Rodrigues, Rui; Neves, José Pedro; Queiróz e Melo, João; Mendes, Miguel
Prosthetic valve dysfunction is a significant clinical event. Determining its etiological mechanism and severity can be difficult. The authors present the case of a 50-year-old man, with two mechanical valve prostheses in aortic and mitral positions, hospitalized for decompensated heart failure. He had a long history of rheumatic multivalvular disease and had undergone three heart surgeries. On admission, investigation led to a diagnosis of severe dysfunction of both mechanical prostheses with different etiologies and mechanisms: pannus formation in the prosthetic aortic valve and intermittent dysfunction of the mitral prosthesis due to interference of a ruptured chorda tendinea in closure of the disks. The patient was reoperated, leading to significant improvement in functional class.
Ogino, Yoichiro; Ayukawa, Yasunori; Tomita, Yoko; Koyano, Kiyoshi
Osteopetrosis (OP) is a rare condition characterized by skeletal sclerosis caused by dysfunctional osteoclasts. Though many reports have described severe infantile-malignant autosomal recessive OP, few have described the prosthetic management of adult OP. This report discusses the prosthetic treatment of adult OP. Although prosthodontists should try to reconstruct occlusal function as much as possible, a conservative prosthodontic approach may be a reasonable and recommended treatment option for minimizing the risk of further osteomyelitis and osteonecrosis.
study is to produce a computer-based Advanced Prosthetic Gait Training Tool to aid in the training of clinicians at military treatment facilities...providing care for wounded service members. In Phase I of the effort, significant work was completed at the University of Iowa Center for Computer- Aided ...Gait Training Tool Introduction The objective of our study is to produce a computer-based Advanced Prosthetic Gait Training Tool (APGTT) to aid in
Pinzur, M S
The author presents in a condensed way an overview of the principles of limb amputations and further treatment of patients who underwent such a procedure. The metabolic cost of walking, load transfer, and wound healing are reviewed in a concise manner. Particular attention is given to blood supply to the wound and methods to determine adequate perfusion with a clear analysis of the pro and cons of the Doppler method. Pediatric amputations, because of their specificity, are considered apart. Disarticulation of limbs is the method of choice in children, because of it retains growth potential of the bone and prevents bony overgrowth of the stump. The article discusses the main indications for limb amputations: trauma, peripheral vascular disease, musculoskeletal tumors and gas gangrene. In every case the specificity of the amputation is considered by the author. Postoperative care is also presented, with a short description of possible complications. Pain is the most common and treatment strategies should be similar to those used in treating patients with major reflex sympathetic causalgia. Edema, joint contracture, wound failure and dermatologic problems are all shortly reviewed. The last part of the article treats with the principles of prosthetics in both the upper and lower limb. These principles are presented basing on the level of amputation: for the upper limb hand, transradial, transhumeral amputations and shoulder disarticulation. For the lower limb foot and ankle, transtibial and transfemoral amputations are considered.
Vest, Thomas W. (Inventor); Carden, James R. (Inventor); Norton, William E. (Inventor); Belcher, Jewell G. (Inventor)
A prosthetic device for below-the-elbow amputees, having a C-shaped clamping mechanism for grasping cylindrical objects, is described. The clamping mechanism is pivotally mounted to a cuff that fits on the amputee's lower arm. The present invention is utilized by placing an arm that has been amputated below the elbow into the cuff. The clamping mechanism then serves as a hand whenever it becomes necessary for the amputee to grasp a cylindrical object such as a handle, a bar, a rod, etc. To grasp the cylindrical object, the object is jammed against the opening in the C-shaped spring, causing the spring to open, the object to pass to the center of the spring, and the spring to snap shut behind the object. Various sizes of clamping mechanisms can be provided and easily interchanged to accommodate a variety of diameters. With the extension that pivots and rotates, the clamping mechanism can be used in a variety of orientations. Thus, this invention provides the amputee with a clamping mechanism that can be used to perform a number of tasks.
... Professions Site Index A-Z Abdominal Aortic Aneurysm (AAA) Abdominal aortic aneurysm (AAA) occurs when atherosclerosis or plaque buildup causes the ... weak and bulge outward like a balloon. An AAA develops slowly over time and has few noticeable ...
... this page: //medlineplus.gov/ency/article/000162.htm Abdominal aortic aneurysm To use the sharing features on this page, ... blood to the abdomen, pelvis, and legs. An abdominal aortic aneurysm occurs when an area of the aorta becomes ...
Gnann, J W; Dismukes, W E
Infection of an intracardiac prosthesis, the incidence of which is about 2.5% among patients having undergone valve replacement, is a serious complication with considerable morbidity and mortality. Early prosthetic valve endocarditis (PVE), with an onset within 60 days of valve replacement, accounts for approximately one-third of all cases, while the remaining two-thirds, occur more than two months postoperatively (late prosthetic valve endocarditis). Prosthetic valve endocarditis is most commonly caused by Staphylococcus epidermidis, less frequently by viridans streptococci, Staphylococcus aureus, and gram-negative bacilli. The most likely pathogenetic mechanisms in prosthetic valve endocarditis are intraoperative contamination and postoperative infections at extracardiac sites. Prominent clinical features include fever, new or changing heart murmurs, leukocytosis, anemia and hematuria. The etiologic microorganism can be isolated in more than 90% of all cases. Patients with proven prosthetic valve endocarditis should be examined daily to detect signs of congestive heart failure and changes in murmurs; electrocardiographic monitoring is essential for documentation of arrhythmias. With limitations, echocardiography, especially two-dimensional, may help to demonstrate vegetations or valvular dehiscence. Cinefluoroscopy may reveal loosening or dehiscence of the sewing ring or impaired motion of a radio-opaque poppet due to thrombus or vegetation. Cardiac catheterization, not always necessary even when surgical intervention is anticipated, may provide valuable information on the degree of dysfunction, multiple valve involvement, left ventricular function and extent of concomitant coronary artery disease. In patients with mechanical valves, prosthetic valve endocarditis may be associated with a high incidence of valve ring and myocardial abscesses; the reported frequency of valve ring abscesses is lower with porcine heterografts. Infections on mechanical valves
Purpose: Over the past 30 years there have been experimental efforts at catheter-based management of aortic valve regurgitation with the idea of extending treatment to nonsurgical candidates. A new catheter-based aortic valve design is described.Methods: The new catheter-delivered valve consists of a stent-based valve cage with locking mechanism and a prosthetic flexible tilting valve disc. The valve cage is delivered first followed by deployment and locking of the disc. In acute experiments, valve implantation was done in four dogs.Results: Valve implantation was successful in all four animals. The implanted valve functioned well for the duration of the experiments (up to 3 hr).Conclusion: The study showed the implantation feasibility and short-term function of the tested catheter-based aortic disc valve. Further experimental studies are warranted.
Weisburst, M R; Singh, A K; Riley, R S
A case of aortic ball valve prosthesis malfunction is described in which the poppet became alternately stuck in the open and closed position. The patient experienced chest pain followed by pulmonary edema and cardiac arrest. Malfunction of prosthetic valve was diagnosed on echocardiogram and cardiopulmonary resuscitation was carried out until a Bjork-Shiley valve could be inserted in place of the faulty prosthesis. At the time of the operation, poppet migration had occurred and the poppet could not be found. Subsequent Bjork-Shiley aortic valve prosthesis dysfunction was suggested by variation in the intensity of the aortic opening sound and in the duration of the systolic ejection period. Fluoroscopy revealed the missing poppet in the left ventricle. Following surgical removal of the poppet, "normal" Bjork-Shiley valve function was restored.
... fully will restrict blood flow. This is called aortic stenosis. If there is also a leak, it is ... TAVR is used for people with severe aortic stenosis who aren't ... valve . In adults, aortic stenosis usually occurs due to calcium ...
Fetterly, K; Mathew, V
Purpose: Transcatheter aortic valve replacement (TAVR) procedures provide a method to implant a prosthetic aortic valve via a minimallyinvasive, catheter-based procedure. TAVR procedures require use of interventional fluoroscopy c-arm projection angles which are aligned with the aortic valve plane to minimize prosthetic valve positioning error due to x-ray imaging parallax. The purpose of this work is to calculate the continuous range of interventional fluoroscopy c-arm projection angles which are aligned with the aortic valve plane from a single planar image of a valvuloplasty balloon inflated across the aortic valve. Methods: Computational methods to measure the 3D angular orientation of the aortic valve were developed. Required inputs include a planar x-ray image of a known valvuloplasty balloon inflated across the aortic valve and specifications of x-ray imaging geometry from the DICOM header of the image. A-priori knowledge of the species-specific typical range of aortic orientation is required to specify the sign of the angle of the long axis of the balloon with respect to the x-ray beam. The methods were validated ex-vivo and in a live pig. Results: Ex-vivo experiments demonstrated that the angular orientation of a stationary inflated valvuloplasty balloon can be measured with precision less than 1 degree. In-vivo pig experiments demonstrated that cardiac motion contributed to measurement variability, with precision less than 3 degrees. Error in specification of x-ray geometry directly influences measurement accuracy. Conclusion: This work demonstrates that the 3D angular orientation of the aortic valve can be calculated precisely from a planar image of a valvuloplasty balloon inflated across the aortic valve and known x-ray geometry. This method could be used to determine appropriate c-arm angular projections during TAVR procedures to minimize x-ray imaging parallax and thereby minimize prosthetic valve positioning errors.
Kawahara, Yu; Inage, Yuichi; Masaki, Naoki; Toyama, Shuji; Fukasawa, Manabu
56-year-old male, who had undergone re-aortic valve replacement (AVR) 33 years ago, received preoperative study for pancreatic surgery. Computed tomography (CT) revealed a giant pseudoaneurysm (7 cm diameter) of the ascending aorta. The ascending aorta was not dilated. A midline skin incision was performed, followed by full sternotomy. A tight pericardial adhesion was carefully dissected. Cardiopulmonary bypass was established by femoral arterial and bicaval venous cannulation. The pseudoaneurysm was incised under the retrograde cardioplegic protection. A communication between ascending aorta and aneurysm was found 1 cm distal to the previous aortic suture line. This communication coincided with the cardioplegic root cannulation site. The aortic prosthetic valve was intact. The ascending aorta was replaced with 26 mm prosthetic graft. Postoperative course was uneventful. In this case, CT was useful to select the approach to the complicated postoperative surgical site.
Miura, Y; Miyairi, T; Kitamura, T; Kigawa, I; Fukuda, S
We studied cardiac function, clinical outcome and quality of life (QOL) long after aortic valve replacement for pure aortic stenosis. Forty-four patients in small group [St. Jude Medical (SJM) 17 HP, 19 A], and 69 patients in non-small group (19 HP, 21 A, 23 A) operated on from 1984 to 2004 were enrolled in this study. We assessed the clinical data, aortic pressure gradient, left ventricular mass index (LVMI), and ejection fraction (EF) by preoperative and postoperative echocardiography. Moreover to evaluate QOL after the operation, we performed SF-36 used for the evaluation of health and QOL worldwide. Mean follow-up is 7.1 +/- 4.8 years in small group, and 6.8 +/- 4.6 years in non-small group. There were 2 hospital deaths in small group, and 1 in non-small group. The actual survival rate at 10-year were 89.2% in small group, and 85.6% in non-small group. There was no significant difference in hospital mortality, LVMI, long-term survival rate, and the scores of SF-36 between the 2 groups. The use of small sized prosthetic valves in patients with small aortic annulus might be justified when there is no patient-prosthesis mismatch.
Ban, Tetsuaki; Aizawa, Kei; Oki, Shin-ichi; Misawa, Yoshio
We report a case of thoracic aortic aneurysm and aortic valve stenosis with chronic renal failure requiring hemodialysis. A 75-year-old man complained of back pain and hoarseness. He had been on dialysis for 15 years. A computed tomography scan of the chest showed marked calcification in the thoracic aortic arch, which is known as a porcelain aorta, and a distal arch aneurysm. Echocardiographic examination showed moderate aortic valve stenosis with calcification. An operation was scheduled, and both the aortic valve and the aortic arch aneurysm were successfully replaced with a mechanical valve and a prosthetic graft. Cardiovascular surgery for patients complicated by a porcelain aorta requires extra cares for the establishment of cardiopulmonary bypass and anastomoses of the aorta.
Fowler, Roy S., Jr.; And Others
A set of artifical reminders'' are developed to compensate for a profound memory deficit in a young brain damaged male. The prosthetic memory techniques are described, and his increase in functional level is documented. A report of a 15-month follow-up is included. (Author)
Carden, James R.; Norton, William; Belcher, Jewell G.; Vest, Thomas W.
Prosthetic hand designed to enable amputee to lift diverse heavy objects like rocks and logs. Has simple serrated end effector with no moving parts. Prosthesis held on forearm by system of flexible straps. Features include ruggedness, simplicity, and relatively low cost.
Bozeman, Richard J., Jr. (Inventor)
A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the moveable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the moveable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective moveable prosthesis device and its sub-prosthesis.
Jones, W. C.; Owens, L. J.
Device is installed in standard 30 millimeter tubing used for lower leg prosthetics. Unit allows proper rotation (about 3 degrees) of foot relative to the hip, during normal walking or running. Limited rotational movement with restoring force results in a more natural gait.
Valente, Acrisio Sales; Alencar, Polyanna; Santos, Alana Neiva; Lobo, Roberto Augusto de Mesquita; de Mesquita, Fernando Antônio; Guimarães, Aloyra Guedis
The supravalvular aortic stenosis is a rare congenital heart defect being very uncommon in adults. We present a case of supravalvular aortic stenosis in adult associated with anomalies of the aortic arch vessels and aortic regurgitation, which was submitted to aortic valve replacement and arterioplasty of the ascending aorta with a good postoperative course. PMID:24598962
... of the heart is reduced. This is called aortic stenosis. The aortic valve can be replaced using: Minimally ... RN, Wang A. Percutaneous heart valve replacement for aortic stenosis: state of the evidence. Ann Intern Med . 2010; ...
Hodgkiss-Harlow, Kelley D; Bandyk, Dennis F
Surgical site infection (SSI) after aortic intervention, an uncommon but serious vascular condition, requires patient-specific antibiotic therapy. Effective treatment and prevention requires the vascular surgeon to be cognizant of changing SSI microbiology, advances in antibiotic delivery, and patient characteristics. The majority of aortic graft infections are caused by Gram-positive bacteria, with methicillin-resistant Staphylococcus aureus now the prevalent pathogen. Nasal carriage of methicillin-sensitive or methicillin-resistant S aureus strains, diabetes mellitus, recent hospitalization, a failed arterial reconstruction, and the presence of a groin incision are important SSI risk factors. Overall, the aortic SSI rate is higher than predicted by the Centers for Disease Control and Prevention's National Nosocomial Infections Surveillance risk category system; ranging from 5% after open or endovascular aortic interventions to as high as 10% to 15% after aortofemoral bypass or uni-aortoiliac grafting with femorofemoral bypass. Perioperative measures to reduce S aureus nares and skin colonization, administration of antibiotic prophylaxis, meticulous wound closure/care, and therapy directed to optimize patient host defense regulation mechanisms (eg, temperature, oxygenation, blood sugar) can minimize SSI occurrence. Antibiotic therapy for aortic graft infection should utilize bactericidal drugs that penetrate bacteria biofilms and can be delivered to the surgical site both parenterally and locally in the form of antibiotic-impregnated beads or prosthetic grafts.
Sutherland, R D; Guynes, W A; Nichols, C T; Martinez, H E
Excessive cage strut wear allowing ball-poppet embolization caused the sudden death of a 47 year old lady in whom a DeBakey-Surgitool aortic prosthesis had been implanted nine years earlier. Patients with this type of prosthesis should have periodic valvular cine fluoroscopy with image intensification to allow visualization of significant strut wear or fracture, and appropriate prosthetic valve replacement.
Bazan, Ovandir; Ortiz, Jayme Pinto
Objective This work describes the experimental validation of a cardiac simulator for three heart rates (60, 80 and 100 beats per minute), under physiological conditions, as a suitable environment for prosthetic heart valves testing in the mitral or aortic position. Methods In the experiment, an aortic bileaflet mechanical valve and a mitral bioprosthesis were employed in the left ventricular model. A test fluid of 47.6% by volume of glycerin solution in water at 36.5ºC was used as blood analogue fluid. A supervisory control and data acquisition system implemented previously in LabVIEW was applied to induce the ventricular operation and to acquire the ventricular signals. The parameters of the left ventricular model operation were based on in vivo and in vitro data. The waves of ventricular and systemic pressures, aortic flow, stroke volume, among others, were acquired while manual adjustments in the arterial impedance model were also established. Results The acquired waves showed good results concerning some in vivo data and requirements from the ISO 5840 standard. Conclusion The experimental validation was performed, allowing, in future studies, characterizing the hydrodynamic performance of prosthetic heart valves. PMID:27556315
Zimmermann, Corina A; Weber, Roland; Greutmann, Matthias; Dave, Hitendu; Müller, Christoph; Prêtre, René; Seifert, Burkhardt; Buechel, Emanuela Valsangiacomo; Kretschmar, Oliver; Attenhofer Jost, Christine H
Pulmonary autograft replacement (Ross procedure) is used as an alternative to prosthetic aortic valve replacement patients with aortic valve disease. There are limited data on incidence and risk factors for dilatation and dysfunction of the neo-aortic after the Ross procedure. Ross procedure was performed in 100 patients at our institution between 1993 and 2011. In 76 patients, complete follow-up data were available. Their median age at surgery was 16 (0.4-58) years (76 % males; 95 % with congenital aortic valve disease). Median follow-up duration was 5.2 years (0.3-16.0 years). We analyzed their clinical and echocardiographic follow-up to identify possible risk factors for neo-aortic root dilatation and dysfunction. Ross procedure included reduction plasty of the native ascending aorta in 25 % of patients. During follow-up, 21 patients (28 %) developed neo-aortic root dilatation, 38 patients (50 %) dilatation oft the native ascending aorta and 7 patients (9 %) at least moderate neo-aortic regurgitation. Univariate risk factors for neo-aortic root dilatation were preoperative aortic regurgitation (p = 0.04), concomitant reduction plasty of the ascending aorta (p = 0.009) and a longer duration of follow-up (p = 0.005). Younger age at surgery was associated with dilatation of the ascending aorta (p = 0.03). Reoperation on the neo-aortic root because of severe dilatation was necessary in 6 patients (8 %), where 2 patients had at least moderate neo-aortic root regurgitation. Neo-aortic root and aortic dilatation are common after the Ross procedure. This is often combined with neo-aortic valve dysfunction. Close follow-up of these patients is mandatory.
Burnett, Arthur L.
Penile implant usage dates to the 16th century yet penile implants to treat erectile dysfunction did not occur until nearly four centuries later. The modern era of penile implants has progressed rapidly over the past 50 years as physicians' knowledge of effective materials for penile prostheses and surgical techniques has improved. Herein, we describe the history of penile prosthetics and the constant quest to improve the technology. Elements of the design from the first inflatable penile prosthesis by Scott and colleagues and the Small-Carrion malleable penile prosthesis are still found in present iterations of these devices. While there have been significant improvements in penile prosthesis design, the promise of an ideal prosthetic device remains elusive. As other erectile dysfunction therapies emerge, penile prostheses will have to continue to demonstrate a competitive advantage. A particular strength of penile prostheses is their efficacy regardless of etiology, thus allowing treatment of even the most refractory cases. PMID:25763121
Panduranga, Prashanth; El-Deeb, Mohammed; Jha, Chitra
Choosing the best anticoagulant therapy for a pregnant patient with a mechanical prosthetic valve is controversial and the published international guidelines contain no clear-cut consensus on the best approach. This is due to the fact that there is presently no anticoagulant which can reliably decrease thromboembolic events while avoiding damage to the fetus. Current treatments include either continuing oral warfarin or substituting warfarin for subcutaneous unfractionated heparin or low-molecular-weight heparin (LMWH) in the first trimester (6–12 weeks) or at any point throughout the pregnancy. However, LMWH, while widely-prescribed, requires close monitoring of the blood anti-factor Xa levels. Unfortunately, facilities for such monitoring are not universally available, such as within hospitals in developing countries. This review evaluates the leading international guidelines concerning anticoagulant therapy in pregnant patients with mechanical prosthetic valves as well as proposing a simplified guideline which may be more relevant to hospitals in this region. PMID:25364545
Vest, Thomas W. (Inventor); Norton, William E. (Inventor); Belcher, Jewell G. (Inventor); Carden, James R. (Inventor)
A prosthetic device for below-the-elbow amputees is disclosed. The device has a removable effector, which is attached to the end of an arm cuff. The effector is comprised of a pair of C-shaped members that are oriented so as to face each other. Working in concert, the C-shaped members are able to hold a bar such as a chainsaw handle. A flat spring is fitted around the C-shaped members to hold them together.
Bozeman, Richard J. (Inventor)
A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that of movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the moveable body part through the full-shrg position of the moveable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the moveable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective moveable prosthesis device and its sub-prosthesis.
Elzi, Luigia; Gurke, Lorenz; Battegay, Manuel; Widmer, Andreas F.; Weisser, Maja
Objective Little is known about optimal management of prosthetic vascular graft infections, which are a rare but serious complication associated with graft implants. The goal of this study was to compare and characterize these infections with respect to the location of the graft and to identify factors associated with outcome. Methods This was a retrospective study over more than a decade at a tertiary care university hospital that has an established multidisciplinary approach to treating graft infections. Cases of possible prosthetic vascular graft infection were identified from the hospital's infectious diseases database and evaluated against strict diagnostic criteria. Patients were divided into groups according to the locations of their grafts: thoracic-aortic, abdominal-aortic, or peripheral-arterial. Statistical analyses included evaluation of patient and infection characteristics, time to treatment failure, and factors associated specifically with cure rates in aortic graft infections. The primary endpoint was cure at one year after diagnosis of the infection. Results Characterization of graft infections according to the graft location did show that these infections differ in terms of their characteristics and that the prognosis for treatment seems to be influenced by the location of the infection. Cure rate and all-cause mortality at one year were 87.5% and 12.5% in 24 patients with thoracic-aortic graft infections, 37.0% and 55.6% in 27 patients with abdominal-aortic graft infections, and 70.0% and 30.0% in 10 patients with peripheral-arterial graft infections. In uni- and multivariate analysis, the type of surgical intervention used in managing infections (graft retention versus graft replacement) did not affect primary outcome, whereas a rifampicin-based antimicrobial regimen was associated with a higher cure rate. Conclusions We recommend that future prospective studies differentiate prosthetic vascular graft infections according to the location of the
Bozeman, Richard J., Jr.
Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.
Duan, Bin; Hockaday, Laura A.; Kang, Kevin H.; Butcher, Jonathan T.
Heart valve disease is a serious and growing public health problem for which prosthetic replacement is most commonly indicated. Current prosthetic devices are inadequate for younger adults and growing children. Tissue engineered living aortic valve conduits have potential for remodeling, regeneration, and growth, but fabricating natural anatomical complexity with cellular heterogeneity remain challenging. In the current study, we implement 3D bioprinting to fabricate living alginate/gelatin hydrogel valve conduits with anatomical architecture and direct incorporation of dual cell types in a regionally constrained manner. Encapsulated aortic root sinus smooth muscle cells (SMC) and aortic valve leaflet interstitial cells (VIC) were viable within alginate/gelatin hydrogel discs over 7 days in culture. Acellular 3D printed hydrogels exhibited reduced modulus, ultimate strength, and peak strain reducing slightly over 7-day culture, while the tensile biomechanics of cell-laden hydrogels were maintained. Aortic valve conduits were successfully bioprinted with direct encapsulation of SMC in the valve root and VIC in the leaflets. Both cell types were viable (81.4±3.4% for SMC and 83.2±4.0% for VIC) within 3D printed tissues. Encapsulated SMC expressed elevated alpha-smooth muscle actin when printed in stiff matrix, while VIC expressed elevated vimentin in soft matrix. These results demonstrate that anatomically complex, heterogeneously encapsulated aortic valve hydrogel conduits can be fabricated with 3D bioprinting. PMID:23015540
Idhrees, Mohammed; Cherian, Vijay Thomas; Menon, Sabarinath; Mathew, Thomas; Dharan, Baiju S; Jayakumar, K
A 5-year-old boy was diagnosed to have supravalvular aortic stenosis (SVAS). On evaluation of CT angiogram, there was associated bovine aortic arch (BAA). Association of BAA with SVAS has not been previously reported in literature, and to best of our knowledge, this is the first case report of SVAS with BAA. Recent studies show BAA as a marker for aortopathy. SVAS is also an arteriopathy. In light of this, SVAS can also possibly be a manifestation of aortopathy associated with BAA.
Erdem, Can C; Park, Soon J
Structural prosthetic valve deterioration and nonstructural dysfunction are two common causes of nonfatal valve events following implantation of a bioprosthetic valve. Using caution and skill, implantation of a bioprosthesis is relatively easy. On the other hand, explantation of a bioprosthesis is a challenging and time-consuming procedure. We have developed a surgical technique by which we were able to ameliorate this troublesome situation in a 79-year-old man with aortic stenosis in whom we had to intraoperatively explant the bioprosthesis that we have put in initially. Another bioprosthesis of the same kind was used to replace the old prosthesis with the rest of his postoperative course until dismissal being eventless.
Fagman, Erika; van Essen, Martijn; Fredén Lindqvist, Johan; Snygg-Martin, Ulrika; Bech-Hanssen, Odd; Svensson, Gunnar
Recent studies have shown promising results using (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in the diagnosis of prosthetic valve endocarditis (PVE). However, previous studies did not include negative controls. The aim of this study was to compare (18)F-FDG-uptake around prosthetic aortic valves in patients with and without PVE and to determine the diagnostic performance of (18)F-FDG PET/CT in the diagnosis of PVE. (18)F-FDG PET/CT examinations in patients with a prosthetic aortic valve performed 2008-2014 were retrieved. Eight patients with a final diagnosis of definite PVE were included in the analysis of the diagnostic performance of (18)F-FDG PET/CT. Examinations performed on suspicion of malignancy in patients without PVE (n = 19) were used as negative controls. Visual and semi-quantitative analysis was performed. Maximal standardized uptake value (SUVmax) in the valve area was measured and SUVratio was calculated by dividing valve SUVmax by SUVmax in the descending aorta. The sensitivity was 75 %, specificity 84 %, positive likelihood ratio [LR(+)] 4.8 and negative likelihood ratio [LR(-)] 0.3 on visual analysis. Both SUVmax and SUVratio were significantly higher in PVE patients [5.8 (IQR 3.5-6.5) and 2.4 (IQR 1.7-3.0)] compared to non-PVE patients [3.2 (IQR 2.8-3.8) and 1.5 (IQR 1.3-1.6)] (p < 0.001). ROC-curve analysis of SUVratio yielded an area under the curve of 0.90 (95 % CI 0.74-1.0). (18)F-FDG-uptake around non-infected aortic prosthetic valves was low. The level of (18)F-FDG-uptake in the prosthetic valve area showed a good diagnostic performance in the diagnosis of PVE.
The increasing incidence of aortic stenosis and greater co-morbidities and risk profiles of the contemporary patient population has driven the development of minimally invasive aortic valve surgery and percutaneous transcatheter aortic valve implantation (TAVI) techniques to reduce surgical trauma. Recent technological developments have led to an alternative minimally invasive option which avoids the placement and tying of sutures, known as “sutureless” or rapid deployment aortic valves. Potential advantages for sutureless aortic prostheses include reducing cross-clamp and cardiopulmonary bypass (CPB) duration, facilitating minimally invasive surgery and complex cardiac interventions, whilst maintaining satisfactory hemodynamic outcomes and low paravalvular leak rates. However, given its recent developments, the majority of evidence regarding sutureless aortic valve replacement (SU-AVR) is limited to observational studies and there is a paucity of adequately-powered randomized studies. Recently, the International Valvular Surgery Study Group (IVSSG) has formulated to conduct the Sutureless Projects, set to be the largest international collaborative group to investigate this technology. This keynote lecture will overview the use, the potential advantages, the caveats, and current evidence of sutureless and rapid deployment aortic valve replacement (AVR). PMID:25870807
Wing, D C; Hittenberger, D A
At least six brands of energy-storing prosthetic feet (ESPF) are now commercially available in the US. These are designed to permit lower extremity amputees to participate in a wide variety of activities, such as running and jumping sports, as well as vigorous walking. Although kinesiologic studies of these devices have not been completed, clinical experience suggests that the Flex-Foot provides the highest performance, followed by the Carbon Copy II and the Seattle Foot. The S.A.F.E. Foot, the STEN Foot, and the Dynamic Foot provide less energy storage and may be suitable for less active patients or those with special needs such as walking on uneven ground. All of the ESPF except the Flex-Foot may be attached to a realigned conventional prosthesis. The Flex-Foot incorporates a pylon and foot in one unit and requires special fabrication technologies. The additional cost of most of the ESPF (compared to a Solid Ankle Cushion Heel Foot) may add little to the cost of a finished prosthesis although it provides greatly increased function. The Flex-Foot, however, is significantly more expensive. Advances in kinesiology and materials science are being applied in the design of prosthetic components that are lighter, stronger, and more resilient. Clinicians can now choose from a variety of innovative commercially available devices but have been hampered by a lack of published information. This paper will review the design philosophy, materials, and applications of ESPF, and will supplement the information available from individual manufacturers and the prosthetic literature.
Ragolta, Carolina I.; Morford, Megan
Existing materials for prosthetic liners tend to be thick and airtight, causing perspiration to accumulate inside the liner and potentially causing infection and injury that reduce quality of life. The purpose of this project was to examine the suitability of aerogel for prosthetic liner applications. Three tests were performed on several types of aerogel to assess the properties of each material. Moisture vapor permeability was tested by incubating four aerogel varieties with an artificial sweat solution at 37.0 C and less than 20% relative humidity for 24 hours. Two aerogel varieties were eliminated from the study due to difficulties in handling the material, and further testing proceeded with Pyrogel in 2.0 and 6.0 mm thicknesses. Force distribution was tested by compressing samples under a load of 4448 N at a rate of 2.5 mm/min. Biofilm formation was tested in a high-shear CDC Biofilm Reactor. Results showed that 2.0 mm Pyrogel blanket allowed 55.7 plus or minus 28.7% of an artificial sweat solution to transpire, and 35.5 plus or minus 27.8% transpired through 6.0 mm Pyrogel blanket. Samples also outperformed the load-bearing capabilities of existing liner materials. No statistically significant difference was found between the two Pyrogel thicknesses for either moisture vapor permeability or force distribution. In addition, biofilm formation results showed no change between the two Pyrogel thicknesses. The breathability and load bearing properties of aerogel make it a suitable material for application to prosthetic liners.
Kerley, James J.; Eklund, Wayne D.
Rotation partly free and partly restrained by resilience and damping. Joint includes U-shaped x- and y-axis frames joined by cables that cross in at center piece. The y-axis frame rotates about y-axis on roller bearing within predetermined angular range. The y-axis frame rotates slightly farther when arm strikes stop, because cables can twist. This mimics compliant resistance of knee joint reaching limit of its forward or backward motion. Used in prosthetic device to replace diseased or damage human joint, or in robot linkage to limit movement and cushion overloads.
Norton, William E. (Inventor); Belcher, Jewell G., Jr. (Inventor); Carden, James R. (Inventor); West, Thomas W. (Inventor)
A prosthetic device has been developed for below-the-elbow amputees. The device consists of a cuff, a stem, a housing, two hook-like fingers, an elastic band for holding the fingers together, and a brace. The fingers are pivotally mounted on a housing that is secured to the amputee's upper arm with the brace. The stem, which also contains a cam, is rotationally mounted within the housing and is secured to the cuff, which fits over the amputee's stump. By rotating the cammed stem between the fingers with the lower arm, the amputee can open and close the fingers.
Muilenburg, Ted B
This communication will provide an outline of the variety of prosthetics available to suit the functional (and cosmetic) needs of patients with upper and lower extremity amputations. It will also demonstrate that the prosthetist constitutes a vital role in the rehabilitation of the patient and will respond to his different needs as his requirements for external prosthetic devices change with age and circumstances.
Sullivan, M F; Roberts, W C
Clinical and morphologic observations are described in 12 patients who underwent simultaneous replacement of the tricuspid, mitral and aortic valves. All 12 patients had mitral stenosis, 10 aortic valve stenosis and 2 pure aortic valve regurgitation; 5 had tricuspid valve stenosis and 7 pure tricuspid valve regurgitation. Of the 10 patients who died within 60 days of triple valve replacement, 7 had the low cardiac output syndrome, which in 4, and possibly 5, of the 7 was attributed to prosthetic aortic valve stenosis. In none of the 12 patients was the ascending aorta dilated, and in the 4 (possibly 5) patients with low cardiac output, the space between the surface of the caged poppet (4 patients) or margins of the tilting disc (1 patient) in the aortic valve position and the aortic endothelium appeared inadequate to allow unobstructed flow despite small-sized prostheses in all but 1 patient. Thus, aortic valve replacement in the setting of triple valve dysfunction is hazardous or potentially so. The relative small sizes of the hearts in these patients also make valve replacement more difficult (and hazardous) compared to hearts with larger ventricles and aortas.
Kojima, Nozomi; Sakano, Yasuhito; Ohki, Shin-Ichi; Misawa, Yoshio
We present a patient with a nine-year history of Behçet's disease (BD), who developed a rapidly expanding aneurysm of the aortic arch. Three-dimensional computed tomography demonstrated a saccular aortic arch aneurysm with a maximal diameter of 5 cm. No bacteria were detected by serial blood cultures. The aneurysm, however, showed a multi-lobular cavity, mimicking an infectious aneurysm. Therefore, we prescribed antibacterial agents for one week. The patient still had a high-fever and an elevated C-reactive protein level thereafter. Aortic arch replacement was performed emergently. Because we were unable to determine whether the aneurysm was caused by infection or BD, the implanted prosthetic graft and the anastomotic sites were covered with a pedicle graft of the greater omentum, and we continued to administer antibacterial agents for four weeks postoperatively. The pathological examination showed neither bacteria nor cystic medial necrosis in the resected aortic wall. Inflammatory changes with eosinophilic infiltration were recognized mainly around the adventitia near the aneurysm. The patient had a favorable postoperative course without any complications.
Clavel, Marie-Annick; Burwash, Ian G; Pibarot, Philippe
Up to 40% of patients with aortic stenosis (AS) harbor discordant Doppler-echocardiographic findings, the most common of which is the presence of a small aortic valve area (≤1.0 cm(2)) suggesting severe AS, but a low gradient (<40 mm Hg) suggesting nonsevere AS. The purpose of this paper is to present the role of multimodality imaging in the diagnostic and therapeutic management of this challenging entity referred to as low-gradient AS. Doppler-echocardiography is critical to determine the subtype of low-gradient AS: that is, classical low-flow, paradoxical low-flow, or normal-flow. Patients with low-flow, low-gradient AS generally have a worse prognosis compared with patients with high-gradient or with normal-flow, low-gradient AS. Patients with low-gradient AS and evidence of severe AS benefit from aortic valve replacement (AVR). However, confirmation of the presence of severe AS is particularly challenging in these patients and requires a multimodality imaging approach including low-dose dobutamine stress echocardiography and aortic valve calcium scoring by multidetector computed tomography. Transcatheter AVR using a transfemoral approach may be superior to surgical AVR in patients with low-flow, low-gradient AS. Further studies are needed to confirm the best valve replacement procedure and prosthetic valve for each category of low-gradient AS and to identify patients with low-gradient AS in whom AVR is likely to be futile.
... this? Submit What's this? Submit Button Related CDC Web Sites Heart Disease Stroke High Blood Pressure Salt ... to Prevent and Control Chronic Diseases Million HeartsÂ® Web Sites with More Information About Aortic Aneurysm For ...
... stiff and not open up. This is called aortic stenosis , which causes the heart to pump harder than usual to get blood through the valve. The aorta may become enlarged with this condition. BAV is ...
Bitar, Diana; Parvizi, Javad
Joint arthroplasty had revolutionized the outcome of orthopaedic surgery. Extensive and collaborative work of many innovator surgeons had led to the development of durable bearing surfaces, yet no single material is considered absolutely perfect. Generation of wear debris from any part of the prosthesis is unavoidable. Implant loosening secondary to osteolysis is the most common mode of failure of arthroplasty. Osteolysis is the resultant of complex contribution of the generated wear debris and the mechanical instability of the prosthetic components. Roughly speaking, all orthopedic biomaterials may induce a universal biologic host response to generated wear débris with little specific characteristics for each material; but some debris has been shown to be more cytotoxic than others. Prosthetic wear debris induces an extensive biological cascade of adverse cellular responses, where macrophages are the main cellular type involved in this hostile inflammatory process. Macrophages cause osteolysis indirectly by releasing numerous chemotactic inflammatory mediators, and directly by resorbing bone with their membrane microstructures. The bio-reactivity of wear particles depends on two major elements: particle characteristics (size, concentration and composition) and host characteristics. While any particle type may enhance hostile cellular reaction, cytological examination demonstrated that more than 70% of the debris burden is constituted of polyethylene particles. Comprehensive understanding of the intricate process of osteolysis is of utmost importance for future development of therapeutic modalities that may delay or prevent the disease progression. PMID:25793158
Sahin, Mesut; Pikov, Victor
One of the roadblocks in the field of neural prosthetics is the lack of microelectronic devices for neural stimulation that can last a lifetime in the central nervous system. Wireless multi-electrode arrays are being developed to improve the longevity of implants by eliminating the wire interconnects as well as the chronic tissue reactions due to the tethering forces generated by these wires. An area of research that has not been sufficiently investigated is a simple single-channel passive microstimulator that can collect the stimulus energy that is transmitted wirelessly through the tissue and immediately convert it into the stimulus pulse. For example, many neural prosthetic approaches to intraspinal microstimulation require only a few channels of stimulation. Wired spinal cord implants are not practical for human subjects because of the extensive flexions and rotations that the spinal cord experiences. Thus, intraspinal microstimulation may be a pioneering application that can benefit from submillimetersize floating stimulators. Possible means of energizing such a floating microstimulator, such as optical, acoustic, and electromagnetic waves, are discussed. PMID:21488815
Gupta, Shweta; Singh, Shashi kumar; Dubey, Pratik Kumar
This research is based on neural prosthetic device. The oldest and most widely used of these electrical, and often computerized, devices is the cochlear implant, which has provided hearing to thousands of congenitally deaf people in this country. Recently, the use of the cochlear implant is expanding to the elderly, who frequently suffer major hearing loss. More cutting edge are artificial retinas, which are helping dozens of blind people see, and ìsmartî artificial arms and legs that amputees can maneuver by thoughts alone, and that feel more like real limbs.Research, which curiosity led to explore frog legs dancing during thunderstorms, a snail shapedorgan in the inner ear, and how various eye cells react to light, have fostered an understanding of how to ìtalkî to the nervous system. That understanding combined with the miniaturization of electronics and enhanced computer processing has enabled prosthetic devices that often can bridge the gap in nerve signaling that is caused by disease or injury.
Berry, Colin; Oukerraj, Latifa; Asgar, Anita; Lamarche, Yoan; Marcheix, Bertrand; Denault, André Y; Laborde, Jean-Claude; Cartier, Raymond; Ducharme, Anique; Bonan, Raoul; Basmadjian, Arsène J
Percutaneous aortic valve replacement (PAVR) is an emerging therapy for nonsurgical patients with severe aortic stenosis (AS). We examined the role of transesophageal echocardiography (TEE) in PAVR. TEE was used initially to assess the native valve and aortic root, and served as a guide during PAVR. Following prosthetic valve deployment, TEE was used to assess valve function. Eleven patients aged 82 +/- 10 years with NYHA III-IV underwent PAVR. Periprocedural TEE gave immediate information on prosthetic position and function, LV function, mitral regurgitation, pericardium, and thoracic aorta anatomy. There was excellent visual agreement between fluoroscopic and TEE images of prosthetic positioning and deployment. TEE facilitated the detection and management of procedure-related complications. Compared with pre-PAVR, AV area (0.56 +/- 0.19 cm(2) vs. 1.3 +/- 0.4 cm(2); P < 0.001) and LVEF (49 +/- 17% vs. 56 +/- 11%; P < 0.001) increased. TEE provides key anatomical and functional information, and serves as a diagnostic guide for complications, which may arise during PAVR.
Salmane, Chadi; Pandya, Bhavi; Lafferty, Kristen; Patel, Nileshkumar J; McCord, Donald
Sixty percent of the patients going for valve replacement opt for mechanical valves and the remaining 40% choose bioprosthetics. Mechanical valves are known to have a higher risk of thrombosis; this risk further varies depending on the type of valve, its position, and certain individual factors. According to current guidelines, long-term anticoagulation is indicated in patients with metallic prosthetic valve disease. We report two unique cases of patients who survived 27 and 37 years event free, respectively, after mechanical aortic valve replacement (AVR) without being on any form of anticoagulation. The latter case described the longest survival in a human with a prosthetic aortic valve without anticoagulation. A review of literature demonstrated few cases of prosthetic valves with no anticoagulation in the long term without significant embolic events reported as case reports. These cases have been summarized in this article. Some cases of long-term survival (in the absence of anticoagulation) were attributed to good luck, and others as the result of genetic variations. New mechanical prosthetic valves can be promising, such as microporus-surfaced valves that may be used without full anticoagulation. The use of dual antiplatelet agents alone can be currently recommended only when a patient cannot take oral anticoagulation after AVR, and it should be followed with measuring and monitoring of platelet reactivity. PMID:27053922
Ziaja, K; Sedlak, L; Urbanek, T; Kostyra, J; Ludyga, T
The reported incidence of inflammatory abdominal aortic aneurysm (IAAA) is from 2% to 14% of patients with abdominal aortic aneurysm and the etiology of this disease is still discussed--according to the literature several pathogenic theories have been proposed. From 1992 to 1997 32 patients with IAAA were operated on. The patients were mostly symptomatic--abdominal pain was present in 68.75% cases, back pain in 31.25%, fever in 12.5% and weight loss in 6.25% of the operated patients. In all the patients ultrasound examination was performed, in 4 patients CT and in 3 cases urography. All the patients were operated on and characteristic signs of inflammatory abdominal aortic aneurysm like: thickened aortic wall, perianeurysmal infiltration or retroperitoneal fibrosis with involvement of retroperitoneal structures were found. In all cases surgery was performed using transperitoneal approach; in three cases intraoperatively contiguous abdominal organs were injured, which was connected with their involvement into periaortic inflammation. In 4 cases clamping of the aorta was done at the level of the diaphragmatic hiatus. 3 patients (9.37%) died (one patient with ruptured abdominal aortic aneurysm). Authors present diagnostic procedures and the differences in the surgical tactic, emphasizing the necessity of the surgical therapy in patients with inflammatory abdominal aortic aneurysm.
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic heart valve sizer. 870.3945 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3945 Prosthetic heart valve sizer. (a) Identification. A prosthetic heart valve sizer is a device used to measure the size of...
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Prosthetic heart valve sizer. 870.3945 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3945 Prosthetic heart valve sizer. (a) Identification. A prosthetic heart valve sizer is a device used to measure the size of...
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Prosthetic heart valve sizer. 870.3945 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3945 Prosthetic heart valve sizer. (a) Identification. A prosthetic heart valve sizer is a device used to measure the size of...
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Prosthetic heart valve sizer. 870.3945 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3945 Prosthetic heart valve sizer. (a) Identification. A prosthetic heart valve sizer is a device used to measure the size of...
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Prosthetic heart valve sizer. 870.3945 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3945 Prosthetic heart valve sizer. (a) Identification. A prosthetic heart valve sizer is a device used to measure the size of...
Khandanpour, Nader; Mehta, Tapan A.; Adiseshiah, M.; Meyer, Felicity J.
Aortic stent grafts are increasingly used to treat aortic aneurysms and also other aortic pathologies. The safety of aortic stent grafts in pregnancy has never been studied or reported. We report on two cases of aortic stent grafts in pregnant women and discuss the effect of pregnancy on these aortic stent grafts. PMID:26229702
Kawashima, Hideyuki; Watanabe, Yusuke; Kozuma, Ken
The patient was a 91-year-old woman presenting with severe aortic valve stenosis. Pre-procedural computed tomography scan revealed a 45-mm abdominal aortic aneurysm (AAA). Transfemoral transcatheter aortic valve implantation (TF-TAVI) was performed after endovascular aortic repair (EVAR) of the AAA. The 23-mm Edwards Sapien XT system passed through the aortic stent graft smoothly. This is the first case report showing that successful TF-TAVI can be performed through a prior abdominal aortic stent graft. TF-TAVI after EVAR of AAA is a feasible option for patients with extremely poor access.
Zapanta, C M; Liszka, E G; Lamson, T C; Stinebring, D R; Deutsch, S; Geselowitz, D B; Tarbell, J M
A method for real-time in vitro observation of cavitation on a prosthetic heart valve has been developed. Cavitation of four blood analog fluids (distilled water, aqueous glycerin, aqueous polyacrylamide, and aqueous xanthan gum) has been documented for a Medtronic/Hall prosthetic heart valve. This method employed a Penn State Electrical Ventricular Assist Device in a mock circulatory loop that was operated in a partial filling mode associated with reduced atrial filling pressure. The observations were made on a valve that was located in the mitral position, with the cavitation occurring on the inlet side after valve closure on every cycle. Stroboscopic videography was used to document the cavity life cycle. Bubble cavitation was observed on the valve occluder face. Vortex cavitation was observed at two locations in the vicinity of the valve occluder and housing. For each fluid, cavity growth and collapse occurred in less than one millisecond, which provides strong evidence that the cavitation is vaporous rather than gaseous. The cavity duration time was found to decrease with increasing atrial pressure at constant aortic pressure and beat rate. The area of cavitation was found to decrease with increasing delay time at a constant aortic pressure, atrial pressure, and beat rate. Cavitation was found to occur in each of the fluids, with the most cavitation seen in the Newtonian fluids (distilled water and aqueous glycerin).
... MRI scan Aortic aneurysm repair - endovascular Aortic angiography Hardening of ... Center-Shreveport, Shreveport, LA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla ...
da Costa, Francisco Diniz Affonso; Colatusso, Daniele de Fátima Fornazari; da Costa, Ana Claudia Brenner Affonso; Balbi Filho, Eduardo Mendel; Cavicchioli, Vinicius Nesi; Lopes, Sergio Augusto Veiga; Ferreira, Andrea Dumsch de Aragon; Collatusso, Claudinei
Introduction Due to late complications associated with the use of conventional prosthetic heart valves, several centers have advocated aortic valve repair and/or valve sparing aortic root replacement for patients with aortic valve insufficiency, in order to enhance late survival and minimize adverse postoperative events. Methods From March/2012 thru March 2015, 37 patients consecutively underwent conservative operations of the aortic valve and/or aortic root. Mean age was 48±16 years and 81% were males. The aortic valve was bicuspid in 54% and tricuspid in the remaining. All were operated with the aid of intraoperative transesophageal echocardiography. Surgical techniques consisted of replacing the aortic root with a Dacron graft whenever it was dilated or aneurysmatic, using either the remodeling or the reimplantation technique, besides correcting leaflet prolapse when present. Patients were sequentially evaluated with clinical and echocardiographic studies and mean follow-up time was 16±5 months. Results Thirty-day mortality was 2.7%. In addition there were two late deaths, with late survival being 85% (CI 95% - 68%-95%) at two years. Two patients were reoperated due to primary structural valve failure. Freedom from reoperation or from primary structural valve failure was 90% (CI 95% - 66%-97%) and 91% (CI 95% - 69%-97%) at 2 years, respectively. During clinical follow-up up to 3 years, there were no cases of thromboembolism, hemorrhage or endocarditis. Conclusions Although this represents an initial series, these data demonstrates that aortic valve repair and/or valve sparing aortic root surgery can be performed with satisfactory immediate and short-term results. PMID:27556321
Resnik, Linda; Meucci, Marissa R; Lieberman-Klinger, Shana; Fantini, Christopher; Kelty, Debra L; Disla, Roxanne; Sasson, Nicole
The number of catastrophic injuries caused by improvised explosive devices in the Afghanistan and Iraq Wars has increased public, legislative, and research attention to upper limb amputation. The Department of Veterans Affairs (VA) has partnered with the Defense Advanced Research Projects Agency and DEKA Integrated Solutions to optimize the function of an advanced prosthetic arm system that will enable greater independence and function. In this special communication, we examine current practices in prosthetic rehabilitation including trends in adoption and use of prosthetic devices, financial considerations, and the role of rehabilitation team members in light of our experiences with a prototype advanced upper limb prosthesis during a VA study to optimize the device. We discuss key challenges in the adoption of advanced prosthetic technology and make recommendations for service provision and use of advanced upper limb prosthetics. Rates of prosthetic rejection are high among upper limb amputees. However, these rates may be reduced with sufficient training by a highly specialized, multidisciplinary team of clinicians, and a focus on patient education and empowerment throughout the rehabilitation process. There are significant challenges emerging that are unique to implementing the use of advanced upper limb prosthetic technology, and a lack of evidence to establish clinical guidelines regarding prosthetic prescription and treatment. Finally, we make recommendations for future research to aid in the identification of best practices and development of policy decisions regarding insurance coverage of prosthetic rehabilitation.
Becerra, Valentina; Labbé, Javier; Cataldo, Anthony; Becerra, Eduardo
INTRODUCTION Stented bovine pericardial prosthetic valves are a good option for older patients, except when there is a fragile small aortic annulus, when, if there is no contraindication to anticoagulation, a mechanical prosthesis may be indicated. PRESENTATION OF CASE We report a 72 year-old man who underwent coronary bypass grafting and aortic valve replacement with a stentless valve fashioned from bovine pericardium using the Batista technique. Despite early sternal infection and dehiscence, and renal and respiratory failure during 15 years follow-up, he remains alive and self-sufficient. Echocardiography demonstrates a well-functioning aortic valve. DISCUSSION When Batista reported his first 60 patients, concerns were raised about the surgical feasibility of constructing the valve and its long-term durability. Our case perhaps addresses both concerns. CONCLUSION Replacement of the aortic valve with a free-hand Batista pericardial valve is a feasible option in a suitable and carefully selected patient. PMID:25524300
Recent advances in and controversies concerning the management of children with congenital valvular aortic stenosis are discussed. In neonates with critical aortic stenosis, improved survival has recently been reported after surgical open valvotomy and balloon valvuloplasty, although it is difficult at this point to compare the results of the two procedures and determine their differential indications. Good results have also been achieved after extended aortic valvuloplasty for recurrent aortic stenosis and/or insufficiency, but the length of follow-up in these patients is still short. The technique first reported in 1991 for bilateral enlargement fo a small annulus permits the insertion of an aortic valve 3-4 sizes larger than the native annulus. It entails no risk of distorting the mitral valve, damaging the conduction system or important branches of the coronary arteries, or resulting in left ventricular dysfunction. The Ross procedure is now widely applied in the West, with reports of early mortality rates of less than 5% and event-free survival rates of 80-90% during follow-up of 4-8 years. Longer follow-up and continued careful evaluation are required to resolve the issue of possible dilatation and subsequent neoaortic valve dysfunction and pulmonary stenosis due to allograft degeneration after pulmonary autograft root replacement in children.
Dapás, Juan Ignacio; Rivero, Cynthia; Burgos, Pablo; Vila, Andrea
Transcatheter aortic valve implantation (TAVI) is an alternative treatment for severe aortic valve stenosis (AS) in patients with prohibitive risk for surgical aortic valve replacement (SAVR). Prosthetic valve endocarditis (PVE) is a rare complication of this relatively novel procedure and current guidelines do not include specific recommendations for its treatment. We report a case of PVE due to Pseudomonas aeruginosa after TAVI that required SAVR, with successful outcome. PVE usually occurs during the first year after TAVI and entails a high mortality risk because patients eligible for this min-imally invasive procedure are fragile (i.e. advanced age and/or severe comorbidities). Additionally, clinical presentation may be atypical or subtle and transesophageal echocardiogram (TEE) may not be conclusive, which delays diagnosis and treatment worsening the prognosis. This case highlights that open SAVR might be ultimately indicated as part of treatment for TAVI-PVE despite a high-risk surgery score. PMID:27014375
Douglas, Tania; Solomonidis, Stephan; Sandham, William; Spence, William
The biomechanical interaction between the residual limb and the prosthetic socket determines the quality of fit of the socket in lower limb prosthetics. An understanding of this interaction and the development of quantitative measures to predict the quality of fit of the socket are important for optimal socket design. Finite-element modeling is used widely for biomechanical modeling of the limb/socket interaction and requires information on the internal and external geometry of the residual limb. Volumetric imaging methods such as X-ray computed tomography, magnetic resonance imaging, and ultrasound have been used to obtain residual limb shape information. Of these modalities, ultrasound has been introduced most recently and its development for visualization in prosthetics is the least mature. This paper reviews ultrasound image acquisition and processing methods as they have been applied in lower limb prosthetics.
Laferrier, Justin Z; Gailey, Robert
The boundaries once faced by individuals with amputations are quickly being overcome through biotechnology. Although there are currently no prosthetics capable of replicating anatomic function, there have been radical advancements in prosthetic technology, medical science, and rehabilitation in the past 30 years, vastly improving functional mobility and quality of life for individuals with lower-limb amputations. What once seemed impossible is rapidly becoming reality. The future seems limitless, and the replication of anatomic function now seems possible.
Norton, William E.; Carden, James R.; Belcher, Jewell G., Jr.; Vest, Thomas W.
Tool attached to prosthetic hand or arm enables user to hold nails, screws, nuts, rivets, and other small ferromagnetic objects on small magnetic tip. Device adjusted to hold nail or screw at proper angle for hammering or for use of screwdriver, respectively. Includes base connector with threaded outer surface and lower male member inserted in standard spring-action, quick-connect/quick-disconnect wrist adapter on prosthetic hand or arm.
Carlino, Paolo; Pettini, Francesco; Cantore, Stefania; Grassi, Felice Roberto; Pepe, Valentina
The aim of this report is to analyze the clinical symptoms, ethologic factors, and prosthetic rehabilitation in a case of Combination Syndrome (CS). The treatment of CS can be conventional or surgical, with or without the bone reconstruction of maxilla. The correct prosthetic treatment helps this kind of patients to restore the physiologic occlusion plane to allow a correct masticatory and aesthetic function. Management of this kind of patients can be a challenge for a dental practitioner. PMID:24511397
Owens, L. J.; Jones, W. C. (Inventor)
A rotational joint assembly for a prosthetic leg has been devised, which enables an artificial foot to rotate slightly when a person is walking, running or turning. The prosthetic leg includes upper and lower tubular members with the rotational joint assembly interposed between them. The assembly includes a restrainer mechanism which consists of a pivotably mounted paddle element. This device applies limiting force to control the rotation of the foot and also restores torque to return the foot back to its initial position.
Mikami, Y; Kyogoku, M
Inflammatory abdominal aortic aneurysm (IAAA) is a distinct clinicopathological entity, characterized by: (1) clinical presentation, such as back pain, weight loss, and increased ESR, (2) patchy and/or diffuse lymphoplasmacytic infiltration, and (3) marked periaortic fibrosis resulting in thickening of the aneurysmal wall and occasional retroperitoneal fibrosis. Its pathogenesis is unknown, but some authors support the theory that IAAA is a subtype of atherosclerotic abdominal aortic aneurysm because of close relationship between IAAA and atherosclerotic change. In this article, we describe clinical and histological features of IAAA on the basis of the literature and our review of 6 cases of IAAA, emphasizing the similarity and difference between IAAA and atherosclerotic abdominal aortic aneurysm. Our review supports that marked lamellar fibrosis completely replacing the media and adventitia, patchy lymphocytic infiltration (mostly B cells) and endarteritis obliterans are characteristic features of IAAA.
Duran, Cassidy; Kashef, Elika; El-Sayed, Hosam F; Bismuth, Jean
Surgical robotics was first utilized to facilitate neurosurgical biopsies in 1985, and it has since found application in orthopedics, urology, gynecology, and cardiothoracic, general, and vascular surgery. Surgical assistance systems provide intelligent, versatile tools that augment the physician's ability to treat patients by eliminating hand tremor and enabling dexterous operation inside the patient's body. Surgical robotics systems have enabled surgeons to treat otherwise untreatable conditions while also reducing morbidity and error rates, shortening operative times, reducing radiation exposure, and improving overall workflow. These capabilities have begun to be realized in two important realms of aortic vascular surgery, namely, flexible robotics for exclusion of complex aortic aneurysms using branched endografts, and robot-assisted laparoscopic aortic surgery for occlusive and aneurysmal disease.
Puga, Andrés Enríquez; Rodríguez, Sara Castaño; Pañero, Blanca Mateos; Moreira, Beatriz Castaño; López Almodóvar, Luis Fernando
We describe the case of a 61-year-old male with a giant aortic root aneurysm associated with chronic aortic Type A dissection. The patient had been operated on 16 years before due to aortic annuloectasia with mechanical valve replacement. The patient underwent revision aortic surgery with a Bentall-De Bono operation with Svensson modification, using a #21 On-X Valsalva mechanical valve conduit. The postoperative course was uneventful. PMID:28097190
Lenoe, Edward M.; Radicic, William N.; Knapp, Michael S.
This research reviews common implant materials and suggests smart materials that may be used as substitutes. Current prosthetic technology, including artificial limbs, joints, and soft and hard tissue, falls short in comprehensive characterization of the chemo-mechanics and materials relationships of the natural tissues and their prosthetic materials counterparts. Many of these unknown chemo-mechanical properties in natural tissue systems maintain cooperative function that allows for optimum efficiency in performance and healing. Traditional prosthetic devices have not taken into account the naturally occurring electro-chemo-mechanical stress- strain relationships that normally exist in a tissue system. Direct mechanical deformation of tissue and cell membrane as a possible use of smart materials may lead to improved prosthetic devices once the mechanosensory systems in living tissues are identified and understood. Smart materials may aid in avoiding interfacial atrophy which is a common cause of prosthetic failure. Finally, we note that advanced composite materials have not received sufficient attention, they should be more widely used in prosthetics. Their structural efficiency allows design and construction of truly efficient bionic devices.
Lichter, P A; Lange, E H; Riehle, T H; Anderson, S M; Hedin, D S
Surface electrodes in modern myoelectric prosthetics are often embedded in the prosthesis socket and make contact with the skin. These electrodes detect and amplify muscle action potentials from voluntary contractions of the muscle in the residual limb and are used to control the prosthetic's movement and function. There are a number of performance-related deficiencies associated with external electrodes including the maintenance of sufficient electromyogram (EMG) signal amplitude, extraneous noise acquisition, and proper electrode interface maintenance that are expected to be improved or eliminated using the proposed implanted sensors. This research seeks to investigate the design components for replacing external electrodes with fully-implantable myoelectric sensors that include a wireless interface to the prosthetic limbs. This implanted technology will allow prosthetic limb manufacturers to provide products with increased performance, capability, and patient-comfort. The EMG signals from the intramuscular recording electrode are amplified and wirelessly transmitted to a receiver in the prosthetic limb. Power to the implant is maintained using a rechargeable battery and an inductive energy transfer link from the prosthetic. A full experimental system was developed to demonstrate that a wireless biopotential sensor can be designed that meets the requirements of size, power, and performance for implantation.
Kasprzak, Jaroslaw D.; Salustri, Alessandro; Roelandt, Jos R.T.C.; Ten Cate, Folkert J.
OBJECTIVES: The purpose of our study was to assess the feasibility and potential clinical utility of three-dimensional echocardiography for evaluation of the aortic valve. BACKGROUND: The value of three-dimensional echocardiographic assessment of the aortic valve has not been established yet. METHODS: The study group comprised 32 patients (11 women, 21 men), mean age 56.1 (range 20-82). Seven morphologically normal valves, 5 homografts, 6 mechanical prostheses, and 14 valves of abnormal morphology were evaluated. Images were acquired during a routine multiplane transesophageal echocardiographic examination (rotational scan with 2 degrees interval, respiration, and electrocardiogram [ECG] gating) and postprocessed off-line. A selection of reconstructed cutplanes (anyplane mode) and volume-rendered three-dimensional views of aortic valve anatomy were analyzed by two observers and compared with two-dimensional echocardiography findings. RESULTS: The quality of reconstructions was scored excellent when permitting unrestricted assessment of aortic valve anatomy with optimized planimetric measurements (19 patients, 59%), adequate when aortic valve was partially visualized (7 patients, 22%), or inadequate when no assessment was possible (6 patients, 19%, including 5 with prosthetic valves). Three-dimensional echocardiography provided additional information in ten (31%) patients as compared with the two-dimensional echocardiographic findings. CONCLUSIONS: It can be concluded that three-dimensional echocardiographic reconstruction of the aortic valve is feasible, with excellent or adequate quality in 81% of patients, more frequently in native than in prosthetic valves, P < 0.05. Morphologic information additional to that provided by two-dimensional echocardiography is obtained in a significant proportion of patients.
Marmagkiolis, Konstantinos; Cilingiroglu, Mehmet
Direct measurement of the left ventricular pressure in patients with mechanical prosthetic aortic valve is an important technical challenge. In the past, transseptal puncture or direct left ventricular accesses were the only available methods. The use of a pressure wire through mechanical aortic prosthesis has been described to be feasible and safe. We report the first case report of pressure guidewire entrapment through a single tilting disk valve (Bjork-Shiley), which resulted in hemodynamic collapse, rupture, and embolization of the pressure wire tip to the right common carotid artery and its successful snaring.
Arici, Vittorio; Rodolico, Giuseppe; Brunetto, Massimo Borri; Argenteri, Angelo
The treatment of choice for aortic coarctation in adults remains open surgical repair. Aortobronchial fistula is a rare but potentially fatal late sequela of surgical correction of isthmic aortic coarctation via the interposition of a graft. The endovascular treatment of aortobronchial fistula is still under discussion because of its high risk for infection, especially if the patient has a history of cardiovascular prosthetic implantation. Patients need close monitoring, most notably those with secondary aortobronchial fistula. We discuss the case of a 65-year-old man who presented with the combined conditions, and we briefly review the relevant medical literature. PMID:28265214
Choudhary, Shiv Kumar; Talwar, Sachin; Airan, Balram
Mechanical prostheses and stented xenografts (bioprosthesis) are most commonly used substitutes for aortic and mitral valve replacement. The mechanical valves have the advantage of durability but are accompanied with the risk of thromboembolism, problems of long-term anticoagulation, and associated risk of bleeding. In contrast, bioprosthetic valves do not require long-term anticoagulation, but carry the risk of structural valve degeneration and re-operation. A mechanical valve is favoured in young patients (<40 years) if reliable anticoagulation is ensured. In elderly patients (>60 years), a bioprosthesis is a suitable substitute. In middle-aged patients (40–60 years), risk of re-operation in a bioprosthesis is equal to that of bleeding in a mechanical valve. Traditionally, a bioprosthesis is opted in patients with limited life expectancy. Calculation of life expectancy, based solely upon chronological age, is erroneous. In developing countries, the calculated life expectancy is much lower than that of Western population, hence age related Western cut-offs are not valid in developing countries. Besides age, cardiac condition of the patient, systemic illnesses, socio-economic status, gender and geographical location also decide the life expectancy of the patients. Selection of the prosthetic valve substitute should be based on: aspiration of the patient, life expectancy, socio-economic and educational background, occupation of the patient, availability, cost, monitoring of anti-coagulation, monitoring of valve function and other valve related complications, and possibility of re-operation. PMID:27326237
Barnhart, Glenn R.; Shrestha, Malakh Lal
Abstract Aortic stenosis is the most common valvular heart disease in the Western world. It is caused primarily by age-related degeneration and progressive calcification typically detected in patients 65 years and older. In patients presenting with symptoms of heart failure, the average survival rate is only 2 years without appropriate treatment. Approximately one half of all patients die within the first 2 to 3 years of symptom onset. In addition, the age of the patients presenting for aortic valve replacement (AVR) is increased along with the demographic changes. The Society of Thoracic Surgeons (STS) database shows that the number of patients older than 80 years has increased from 12% to 24% during the past 20 years. At the same time, the percentage of candidates requiring AVR as well as concomitant coronary bypass surgery has increased from 5% to 25%. Surgical AVR continues to be the criterion standard for treatment of aortic stenosis, improving survival and quality of life. Recent advances in prosthetic valve technology, such as transcatheter AVR, have expanded the indication for AVR to the extreme high-risk population, and the most recent surgical innovation, rapid deployment AVR, provides an additional tool to the surgeons’ armamentarium. PMID:26918310
Bode-Oke, Ayodeji; Ren, Yan; Dong, Haibo; Fish, Frank
During entanglement in fishing gear, dolphins can suffer abrasions and amputations of flukes and fins. As a result, if the dolphin survives the ordeal, swimming performance is altered. Current rehabilitation technques is the use of prosthesis to regain swimming ability. In this work, analyses are focused on two dolphins with locomotive impairment; Winter (currently living in Clearwater Marine Aquarium in Florida) and Fuji (lived in Okinawa Churaumi Aquarium in Japan). Fuji lost about 75% of its fluke surface to necrosis (death of cells) and Winter lost its tail due to amputation. Both dolphins are aided by prosthetic tails that mimic the shape of a real dolphin tail. Using 3D surface reconstruction techniques and a high fidelity Computational Fluid Dynamics (CFD) flow solver, we were able to elucidate the kinematics and hydrodynamics and fluke deformation of these swimmers to clarify the effectiveness of prostheses in helping the dolphins regain their swimming ability. Associated with the performance, we identified distinct features in the wake structures that can explain this gap in the performance compared to a healthy dolphin. This work was supported by ONR MURI Grant Number N00014-14-1-0533.
Schwartz, Andrew B.; Kipke, D. W.; Perepelkin, P. D.
The work presented in this session is part of a project to develop an arm-control system based on neuronal activity recorded from the cerebral cortex. This will make it possible for amputees or paralyzed individuals to move a prosthetic arm or, using functional neural stimulation, their own limbs as effortlessly and with as much skill as intact individuals. We are developing and testing this system in monkeys and hope to have a prototype working in the next couple of years. This project has been made more feasible because we have been able, in the last 15 years to extract, from the brain, a signal that represents arm trajectory accurately. In this paper, we describe how this technique was developed and how we use this as the basis for our control signal. An alternative approach using a self-organizing feature map, an algorithm to deduce arm configuration given an endpoint trajectory and the development of a telemetry system to transmit the neuronal data is described in subsequent papers.
Savarese, R P; Rosenfeld, J C; DeLaurentis, D A
Between January 1976 and December 1982, 181 patients with abdominal aortic aneurysms were treated surgically, and in 13 patients the aneurysms were found to be inflammatory. Inflammatory aneurysms of the abdominal aorta (IAAA) share important characteristics with typical atherosclerotic abdominal aortic aneurysms. Diagnosis and surgical management of IAAA are distinctive which suggests that IAAA should be considered separately, as a varient of typical abdominal aortic aneurysms. IAAA occur predominantly in males. The presenting symptoms are often idiosyncratic and include severe abdominal or back pain, or both, and ureteral obstruction; the diagnosis of IAAA should be considered when these symptoms are present. Although grossly and microscopically, the perianeurysmal fibrosis resembles idiopathic retroperitoneal fibrosis, the two conditions can be differentiated. At the present time, ultrasonography and computed tomography appear to offer reliable means for diagnosing IAAA. The presence of IAAA, whether established preoperatively or discovered unexpectedly at operation, necessitate certain modifications in the surgical approach, in order to avoid injuring the duodenum and the venous structures. Most patients can be successfully treated by resection and graft replacement. Rupture of the aneurysm in IAAA appears to be less frequent than in typical atherosclerotic abdominal aortic aneurysm.
The potential for lifestyle recovery is tremendous for most lower extremity amputees. The amazing and ever-expanding array of adaptive prosthetics can help make the devastating loss of amputation more bearable for patients, their families, and their health care team. The new amputee, in a state of shock and grief, does not know what his or her prosthetic options are. It is crucial that the surgeon is knowledgeable about what the patient can have and what the patient needs to ask for. Dana Bowman stated: Ideally, the new amputee should say to their doctor, "I'd like my leg to be lightweight, flexible, durable, comfortable. I want to do sports or I want to ride bikes with my kids." Whatever it is they like to do. I was told I would never be able to wear two dynamic feet and that my sky diving days were over. I said, "Well how do you know? Can't I try?" It took years to find out what I could have and then to find people to help me get it. The prosthetic prescription the physician writes is the patient's gateway to the kind of prosthetics that will enable him or her to pursue the activities of their life. Often, new amputees end up with the bare minimum prosthesis, which can cause problems with comfort and mobility. A poorly designed or badly fitting prosthesis is as disabling as the actual amputation. When the surgeon can help the amputee and his or her family understand what kind of prosthetic choices are available, it establishes an optimistic outlook that is highly beneficial to the entire recovery process physically and mentally. "When I lost my leg, if someone would have told me that I could at least try to run again, that would have meant a lot," said Brian Frasure. "Getting that positive mental attitude is every bit as important as having good medical and prosthetic care." By asking probing questions about the patient's preamputation lifestyle and postamputation goals, the physician can write a prescription for truly adaptive prosthetics. The surgeon should
Santoro, Giuseppe; Caianiello, Giuseppe; Palladino, Maria Teresa; Iacono, Carola; Russo, Maria Giovanna; Calabrò, Raffaele
A neonate with severe aortic coarctation showed a double lumen transverse aorta (persistent fifth aortic arch) with both channels joining at the isthmus where the obstruction was confirmed by echocardiography and cardiac catheterization. Surgical repair was performed with a pantaloon-shaped patch. Persistent fifth aortic arch does not result in a vascular ring and, per se, is not hemodynamically significant unless associated with other cardiac malformations.
Guivier-Curien, Carine; Deplano, Valérie; Bertrand, Eric
A numerical 3-D fluid-structure interaction (FSI) model of a prosthetic aortic valve was developed, based on a commercial computational fluid dynamics (CFD) software program using an Arbitrary Eulerian Lagrangian (ALE) formulation. To make sure of the validity of this numerical model, an equivalent experimental model accounting for both the geometrical features and the hydrodynamic conditions was also developed. The leaflet and the flow behaviours around the bileaflet valve were investigated numerically and experimentally by performing particle image velocimetry (PIV) measurements. Through quantitative and qualitative comparisons, it was shown that the leaflet behaviour and the velocity fields were similar in both models. The present study allows the validation of a fully coupled 3-D FSI numerical model. The promising numerical tool could be therefore used to investigate clinical issues involving the aortic valve.
Trower, Ted A
In recent years, much attention has been given to the revolution in new materials for prosthetics and the components that they have made possible. The average weight of a delivered prosthesis has decreased, currently available components offer improved function and superior symmetry of gait, and limb interfaces provide superior skin protection and comfort. The focus on the features of these components sometimes has led to neglect of the basic elements of prosthetic design--the fit and the alignment. If the fit and alignment are on the mark, an amputee can function at remarkably high levels with rudimentary components. This article discusses the basics of lower extremity prosthetic practice and addresses challenges for the future.
De Luigi, Arthur Jason; Cooper, Rory A
With the technologic advances in medicine and an emphasis on maintaining physical fitness, the population of athletes with impairments is growing. It is incumbent upon health care practitioners to make every effort to inform these individuals of growing and diverse opportunities and to encourage safe exercise and athletic participation through counseling and education. Given the opportunities for participation in sports for persons with a limb deficiency, the demand for new, innovative prosthetic designs is challenging the clinical and technical expertise of the physician and prosthetist. When generating a prosthetic prescription, physicians and prosthetists should consider the needs and preferences of the athlete with limb deficiency, as well as the functional demands of the chosen sporting activity. The intent of this article is to provide information regarding the current advancements in the adaptive sports technology and biomechanics in the field of prosthetics, and to assist clinicians and their patients in facilitating participation in sporting activities.
The purpose of stent graft for aortic dissection is to terminate antegrade blood flow into the false lumen through primary entry. Early intervention for primary entry makes excellent aortic remodeling and emergent stent grafting for complicated acute type B aortic dissection is supported as a class I. On the other hand stent grafting for chronic aortic dissection is controversial. Early stent grafting is considered with in 6 months after on-set if the diameter of the descending aorta is more than 40 mm. Additional interventions for residual false lumen on the downstream aorta are still required. Stent graft for re-entry, candy-plug technique, and double stenting, other effective re-interventions were reported. Best treatment on the basis of each anatomical and physical characteristics should be selected in each institution. Frozen elephant trunk is alternative procedure for aortic dissection without the need to take account of proximal anatomical limitation and effective for acute type A aortic dissection.
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Prosthetic hair fibers. 895.101 Section 895.101...) MEDICAL DEVICES BANNED DEVICES Listing of Banned Devices § 895.101 Prosthetic hair fibers. Prosthetic hair fibers are devices intended for implantation into the human scalp to simulate natural hair or...
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Prosthetic hair fibers. 895.101 Section 895.101...) MEDICAL DEVICES BANNED DEVICES Listing of Banned Devices § 895.101 Prosthetic hair fibers. Prosthetic hair fibers are devices intended for implantation into the human scalp to simulate natural hair or...
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Prosthetic hair fibers. 895.101 Section 895.101...) MEDICAL DEVICES BANNED DEVICES Listing of Banned Devices § 895.101 Prosthetic hair fibers. Prosthetic hair fibers are devices intended for implantation into the human scalp to simulate natural hair or...
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic hair fibers. 895.101 Section 895.101...) MEDICAL DEVICES BANNED DEVICES Listing of Banned Devices § 895.101 Prosthetic hair fibers. Prosthetic hair fibers are devices intended for implantation into the human scalp to simulate natural hair or...
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Prosthetic hair fibers. 895.101 Section 895.101...) MEDICAL DEVICES BANNED DEVICES Listing of Banned Devices § 895.101 Prosthetic hair fibers. Prosthetic hair fibers are devices intended for implantation into the human scalp to simulate natural hair or...
... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Prosthetic and similar appliances. 17.150 Section 17.150 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Prosthetic, Sensory, and Rehabilitative Aids § 17.150 Prosthetic and similar...
... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Prosthetic and similar appliances. 17.150 Section 17.150 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Prosthetic, Sensory, and Rehabilitative Aids § 17.150 Prosthetic and similar...
... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Prosthetic and similar appliances. 17.150 Section 17.150 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Prosthetic, Sensory, and Rehabilitative Aids § 17.150 Prosthetic and similar...
... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Prosthetic and similar appliances. 17.150 Section 17.150 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Prosthetic, Sensory, and Rehabilitative Aids § 17.150 Prosthetic and similar...
... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Prosthetic and similar appliances. 17.150 Section 17.150 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Prosthetic, Sensory, and Rehabilitative Aids § 17.150 Prosthetic and similar...
Masuda, Shigeki; Takeuchi, Nobuhiro; Takada, Masanori; Fujita, Koichi; Nishibori, Yoshiharu; Maruyama, Takao
A 75-year-old male with a history of alcoholic liver cirrhosis, sigmoid colon cancer, and metastatic liver cancer was admitted to our institution with a complaint of a prickly feeling in his chest. On admission, a chest radiograph revealed a normal cardio-thoracic ratio of 47%. Echocardiography revealed pericardial effusion and blood chemical analyses revealed elevated C-reactive protein levels (14.7 mg/dL). On day 3, chest radiography revealed cardiomegaly with a cardio-thoracic ratio of 58% and protrusion of the left first arch. Contrast-enhanced chest computed tomography revealed a saccular aneurysm in the aortic arch with surrounding hematoma; thus, a ruptured thoracic aortic aneurysm was suspected. Emergency surgery was performed, which revealed a ruptured aortic aneurysm with extensive local inflammation. The diagnosis of an infected aortic rupture was therefore confirmed. The aneurysm and abscess were resected, followed by prosthetic graft replacement and omental packing. Histopathology of the resected aneurysm revealed gram-positive bacilli; and Listeria monocytogenes was confirmed as the causative organism by culture. Postoperative course was uneventful; on postoperative day 60, the patient was ambulatory and was discharged. Here we report the case of a male with a ruptured thoracic aortic aneurysm infected with L. monocytogenes. PMID:25512697
Fernandez, G; Fontan, F; Deville, C; Madonna, F; Thibaud, D
Direct repair of traumatic aortic isthmic transection eliminates the late complications of prosthetic graft repair. This study evaluates the long-term fate of direct aortic repair to which little attention has been paid. Among 32 patients operated upon from 1965 to 1987, 27 (84%) underwent direct repair. The tear was circumferential in 15 patients and partial in 12. Multiple traumatic lesions were present in 26 patients, including intracranial injury in 19. Partial cardiopulmonary bypass was used in 15 patients and simple aortic cross-clamping in 12. No paraplegia was observed. There were 4 deaths from associated lesions among the 14 patients operated upon for acute traumatic isthmic transection and no deaths in the others. Among the 23 survivors, 4 were lost to follow-up; the other 19 patients have excellent clinical results. Intravenous digital aortic angiography performed in 14 patients at a mean delay of 5 years 3 months showed excellent aortic reconstruction in all cases. Technically more demanding and faster than a graft interposition, direct repair is recommended as the procedure of choice in the surgical treatment of traumatic isthmic transection, particularly in young patients, the group most at risk from this lesion.
Villa, Emmanuel; Troise, Giovanni; Cirillo, Marco; Brunelli, Federico; Tomba, Margherita Dalla; Mhagna, Zen; Tasca, Giordano; Quaini, Eugenio
Although a small percentage of patients with critical aortic stenosis do not develop left ventricle hypertrophy, increased ventricular mass is widely observed in conditions of increased afterload. There is growing epidemiological evidence that hypertrophy is associated with excess cardiac mortality and morbidity not only in patients with arterial hypertension, but also in those undergoing aortic valve replacement. Valve replacement surgery relieves the aortic obstruction and prolongs the life of many patients, but favorable or adverse left ventricular remodeling is affected by a large number of factors whose specific roles are still a subject of debate. Age, gender, hemodynamic factors, prosthetic valve types, myocyte alterations, interstitial structures, blood pressure control and ethnicity can all influence the process of left ventricle mass regression, and myocardial metabolism and coronary artery circulation are also involved in the changes occurring after aortic valve replacement. The aim of this overview is to analyze these factors in the light of our experience, elucidate the important question of prosthesis-patient mismatch by considering the method of effective orifice area, and discuss surgical timings and techniques that can improve the management of patients with aortic valve stenosis and maximize the probability of mass regression. PMID:16803632
Toyota, Kosaku; Ota, Takashi; Nagamine, Katsutoshi; Koide, Yasuhiro; Nomura, Takeshi; Yamanaka, Futoshi; Shishido, Koki; Tanaka, Masashi; Saito, Shigeru
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.
Cal-Purriños, Natalia; Arribas-Leal, Jose M; Carnero-Alcazar, Manuel; Gutierrez-Diez, Jose F; Cuenca-Castillo, Jose J
Introduction Rapid deployment valves (RDV) represent a newly introduced approach to aortic valve replacement which facilitates surgical implantation and minimally invasive techniques, shortens surgical times and shows excellent haemodynamic performance. However, evidence on their safety, efficacy and potential complications is mostly fitted with small-volume and retrospective studies. Moreover, no current guidelines exist. To improve our knowledge on this technology, The Rapid Deployment Aortic Replacement (RADAR) Registry will be established across Spain with the aim of assessing RDV outcomes in the real-world setting. Methods and analysis The RADAR Registry is designed as a product registry that would provide information on its use and outcomes in clinical practice. This multicentre, prospective, national effort will initially involve 4 centres in Spain. Any patient undergoing cardiac surgery for aortic valve replacement and receiving an RDV as an isolated operation or in combination with other cardiac procedures may be included. Participation is voluntary. Data collection is equal to information obtained during standard care and is prospectively entered by the participating physicians perioperatively and during subsequent follow-up visits. The primary outcome assessed is in-hospital and up to 5 years of follow-up, prosthetic valve functioning and clinical status. Secondary outcomes are to perform subgroup analysis, to compare outcomes with other existing approaches and to develop future clinical guidelines. The follow-up assessments are timed with routine clinical appointments. Dissociated data will be extracted and collectively analysed. Initial target sample size for the registry is 500 participants entered with complete follow-up information. Different substudies will be implemented within the registry to investigate specific populations undergoing aortic valve replacement. Ethics and dissemination The protocol is approved by all local institutional ethics
Lind, Randall F; Jansen, John F; Love, Lonnie J
A mesofluidic powered robotic and/or prosthetic finger joint includes a first finger section having at least one mesofluidic actuator in fluid communication with a first actuator, a second mesofluidic actuator in fluid communication with a second actuator and a second prosthetic finger section pivotally connected to the first finger section by a joint pivot, wherein the first actuator pivotally cooperates with the second finger to provide a first mechanical advantage relative to the joint point and wherein the second actuator pivotally cooperates with the second finger section to provide a second mechanical advantage relative to the joint point.
Sachs, T; Schermerhorn, M
Ruptured abdominal aortic aneurysm (AAA) continues to be one of the most lethal vascular pathologies we encounter. Its management demands prompt and efficient evaluation and repair. Open repair has traditionally been the mainstay of treatment. However, the introduction of endovascular techniques has altered the treatment algorithm for ruptured AAA in most major medical centers. We present recent literature and techniques for ruptured AAA and its surgical management.
Quezada, Emilio; Lapidus, Jodi; Shaughnessy, Robin; Chen, Zunqiu; Silberbach, Michael
In Turner syndrome, linear growth is less than the general population. Consequently, to assess stature in Turner syndrome, condition-specific comparators have been employed. Similar reference curves for cardiac structures in Turner syndrome are currently unavailable. Accurate assessment of the aorta is particularly critical in Turner syndrome because aortic dissection and rupture occur more frequently than in the general population. Furthermore, comparisons to references calculated from the taller general population with the shorter Turner syndrome population can lead to over-estimation of aortic size causing stigmatization, medicalization, and potentially over-treatment. We used echocardiography to measure aortic diameters at eight levels of the thoracic aorta in 481 healthy girls and women with Turner syndrome who ranged in age from two to seventy years. Univariate and multivariate linear regression analyses were performed to assess the influence of karyotype, age, body mass index, bicuspid aortic valve, blood pressure, history of renal disease, thyroid disease, or growth hormone therapy. Because only bicuspid aortic valve was found to independently affect aortic size, subjects with bicuspid aortic valve were excluded from the analysis. Regression equations for aortic diameters were calculated and Z-scores corresponding to 1, 2, and 3 standard deviations from the mean were plotted against body surface area. The information presented here will allow clinicians and other caregivers to calculate aortic Z-scores using a Turner-based reference population. © 2015 Wiley Periodicals, Inc.
Leon, Luis R
The radiographic finding of air bubbles around a surgically placed prosthetic graft is traditionally assumed to be a sign of infection until proven otherwise. Direct delivery of atmospheric air bubbles, shown in an imaging study performed very soon after a surgical intervention, or percutaneously introduced during an endovascular procedure could be possible causes of air bubble presence and not necessarily infection. However, if air around a prosthetic aortic graft is identified in an imaging study after a previous one did not document its presence, or if the amount of air is increasing on serial imaging studies, the suspicion level should increase. The case presented here is of a 49-year-old male who underwent an endovascular repair of a possible symptomatic penetrating aortic ulcer, who was found to have peri stent-graft air 3 weeks after intervention. Previous imaging postoperative studies did not reveal air around the aortic prosthesis. The diagnosis of endovascular stent-graft infection was very difficult due to several challenging factors that are herein presented.
Akbari, Jayesh G; Varma, Praveen K; Gadhinglajkar, Shrinivas V; Neelakandhan, Kurur S
A 32-year-old female underwent mitral valve replacement with total chordal preservation (Miki's technique) using 26 mm (1M) Starr-Edward prosthesis (SEP) in 1988. The patient was in NYHA class-I until 2001. She progressed to NYHA class-III with paroxysmal nocturnal dyspnoea. Transthoracic echocardiogram showed increased prosthetic valve gradient, and cardiac catheterization confirmed the findings. Intraoperatively, the poppet movement in the cage was found to be restricted due to the preserved subvalvular apparatus entrapping the poppet inside the prosthetic valve cage.
Dohmen, Pascal M.; Lehmkuhl, Lukas; Borger, Michael A.; Misfeld, Martin; Mohr, Friedrich W.
Patient: Female, 61 Final Diagnosis: Tissue degeneration Symptoms: Dyspnea Medication: — Clinical Procedure: Redo valve replacement Specialty: Surgery Objective: Rare disease Background: We present a unique case of a 61-year-old female patient with homograft deterioration after redo surgery for prosthetic valve endocarditis with root abscess. Case Report: The first operation was performed for type A dissection with root, arch, and elephant trunk replacement of the thoracic aorta. The present re-redo surgery was performed as valve-in-valve with a sutureless aortic biopros-thesis. The postoperative course was uneventful and the patient was discharged on day 6. Conclusions: The current case report demonstrates that sutureless bioprostheses are an attractive option for surgical valve-in-valve procedures, which can reduce morbidity and mortality. PMID:27694795
Nordon, Ian M. Hinchliffe, Robert J.; Loftus, Ian M.; Morgan, Robert A.; Thompson, Matt M.
Acute aortic syndrome (AAS) describes several life-threatening aortic pathologies. These include intramural hematoma, penetrating aortic ulcer, and acute aortic dissection (AAD). Advances in both imaging and endovascular treatment have led to an increase in diagnosis and improved management of these often catastrophic pathologies. Patients, who were previously consigned to medical management or high-risk open surgical repair, can now be offered minimally invasive solutions with reduced morbidity and mortality. Information from the International Registry of Acute Aortic Dissection (IRAD) database demonstrates how in selected patients with complicated AAD the 30-day mortality from open surgery is 17% and endovascular stenting is 6%. Despite these improvements in perioperative deaths, the risks of stroke and paraplegia remain with endovascular treatment (combined outcome risk 4%). The pathophysiology of each aspect of AAS is described. The best imaging techniques and the evolving role of endovascular techniques in the definitive management of AAS are discussed incorporating strategies to reduce perioperative morbidity.
Kanaoka, Yuji; Ohki, Takao; Ozawa, Hirotsugu
We report a case in which a stent graft and an Amplatzer(®) vascular plug (AVP) were effective for the treatment of chronic aneurysmal aortic dissection. The patient was a 52-year-old man. At 45 years of age, he developed acute aortic dissection, for which he underwent surgery 4 times with prosthetic graft replacement in the abdominal aorta, descending thoracic, ascending aorta (without neck branch reconstruction), and thoracoabdominal aorta with the reconstruction of the celiac, superior mesenteric, and bilateral renal arteries. At the time of thoracoabdominal aortic surgery, strong adhesion was evident, particularly in the thoracoabdominal area. The adhesion was dissected in a part of the chest, and prosthetic graft replacement was performed the following day. Subsequently, the dissection of the residual distal aortic arch enlarged, and the patient was examined at our hospital. Computed tomography (CT) revealed a small intimal tear at the site of anastomosis distal to the graft in the ascending aorta and a large intimal tear in the descending thoracic aorta with a maximum diameter of 67 mm. Furthermore, open repair by prosthetic graft replacement seemed difficult; therefore, treatment with stent grafting was considered. Because the prosthetic graft in the abdomen was extremely tortuous, stent-graft insertion via the femoral artery seemed to be impossible. The planned treatment involved the placement of a thoracic stent graft using the chimney technique which included reconstruction of the brachiocephalic artery and left common carotid arteries using chimney stent graft and coverage of the left subclavian artery. The thoracic stent graft was planned to be inserted via the abdominal prosthetic graft site because the abdominal prosthetic graft was crooked and was located close to the body surface. However, a small intimal tear distal to the graft in the ascending aorta which had not been revealed by intraoperative aortography was detected by the selective
Jackson, John S., Ed.; DeVore, R. William, Ed.
Presented are 28 papers given at a 1972 conference on electronic prosthetics for the handicapped. Among the papers are the following titles: "Therapy for Cerebral Palsy Employing Artifician Sense Organs for Alternatives to Proprioceptive Feedback"; "Excessive Neuromuscular Time Delay as a Possible Cause of Poor Hand-Eye Coordination and…
Contents: Self-containment and self-suspension of externally powered prostheses for the forearm; Below- elbow control of an externally powered hand...An experiment with the control of a hybrid prosthetic system: electric elbow , body-powered hook; Interfacial couplings for man-machine systems--a
Jaramillo, R; Barabe, J G; Cupp, D
This article describes an effective approach to informing the Latino community about prosthetics. Unlike English, little information on this subject is available in Spanish. The process of obtaining, fabricating, and wearing a prosthesis was interwoven into the teleplay "Milagros." The story concept, video production, and the Latino population's cultural characteristics are discussed. The audience welcomed the opportunity to share the information with others.
Chamogeorgakis, Themistokles; Mountis, Maria; Gonzalez-Stawinski, Gonzalo V.
Left ventricular assist device (LVAD) implantation has become a mainstay of therapy for advanced heart failure patients who are either ineligible for, or awaiting, cardiac transplantation. Controversy remains over the optimal therapeutic strategy for preexisting aortic valvular dysfunction in these patients at the time of LVAD implant. In patients with moderate to severe aortic regurgitation, surgical approaches are center specific and range from variable leaflet closure techniques to concomitant aortic valve replacement (AVR) with a bioprosthesis. In the present study, we retrospectively analyzed our outcomes in patients who underwent simultaneous AVR and LVAD implantation secondary to antecedent aortic valve pathology. Between January 2004 and June 2010, 144 patients underwent LVAD implantation at a single institution. Of these, 7 patients (4.8%) required concomitant AVR. Five of the 7 patients (71%) survived to hospital discharge and suffered no adverse events in the perioperative period. One-year survival for the discharged patients was 80%, and no prosthetic valve-related adverse events were observed in long-term follow-up. Given our experience, we conclude that bioprosthetic AVR is a plausible alternative for end-stage heart failure patients at the time of LVAD implantation. PMID:26424939
Cuddihy, E F; Moacanin, J; Roschke, E J; Harrison, E C
Dynamic shear modulus G' was measured throughout the volume of three nonvariant silicone rubber poppets which were recovered from aortic prosthetic heart valves that had been implanted for 4 days, 52 days, and 8 years. Similar measurements were obtained for two unused silicone rubber poppets. Although the recovered poppets exhibited no obvious physical evidence of damage, the silicone rubber had undergone in vivo degradation throughout the poppet volume as indicated by decreases in modulus. The measurements also indicate that the poppet surface degrades at a rate faster than the core. Further, comparison with data reported in the literature suggests that the surfaces of variant poppets degrade at a rate faster than the surfaces of nonvariant poppets.
Claiborne, Thomas E; Slepian, Marvin J; Hossainy, Syed; Bluestein, Danny
Present prosthetic heart valves, while hemodynamically effective, remain limited by progressive structural deterioration of tissue valves or the burden of chronic anticoagulation for mechanical valves. An idealized valve prosthesis would eliminate these limitations. Polymeric heart valves (PHVs), fabricated from advanced polymeric materials, offer the potential of durability and hemocompatibility. Unfortunately, the clinical realization of PHVs to date has been hampered by findings of in vivo calcification, degradation and thrombosis. Here, the authors review the evolution of PHVs, evaluate the state of the art of this technology and propose a pathway towards clinical reality. In particular, the authors discuss the development of a novel aortic PHV that may be deployed via transcatheter implantation, as well as its optimization via device thrombogenicity emulation. PMID:23249154
Akutsu, T; Modi, V J
Five typical mechanical heart valves (Starr-Edwards, Björk-Shiley convexo-concave (c-c), Björk-Shiley monostrut, Bicer-Val, and St. Jude Medical) were tested in the mitral position under the pulsatile flow condition. The test program included measurements of velocity and turbulent stresses at 5 downstream locations. The study was carried out using a sophisticated cardiac simulator in conjunction with a highly sensitive 2 component laser Doppler anemometer (LDA) system. The continuous monitoring of parametric time histories revealed useful details about the complex flow and helped to establish the locations and times of the peak parameter values. Based upon the nondimensional presentation of data, the following general conclusions can be made. First, all the 5 valve designs created elevated turbulent stresses during the accelerating and peak flow phases, presenting the possibility of thromboembolism and perhaps hemolysis. Second, the difference in valve configuration seemed to affect the flow characteristics; third, the bileaflet design of the St. Jude valve appeared to create a lower turbulence stress level.
Cemri, M; Cengel, A; Timurkaynak, T
Congenital aortic valve anomalies are quite a rare finding in echocardiographic examinations. A case of a 19 year old man with a pentacuspid aortic valve without aortic stenosis and regurgitation, detected by transoesophageal echocardiography, is presented. Keywords: pentacuspid aortic valve; echocardiography PMID:10995427
Oshima, H; Usui, A; Akita, T; Ueda, Y
Aortic valve surgery for the small aortic annulus is still challenging for surgeons. Recently, the new types of high performance prosthesis have been developed and the chance of an aortic root enlargement (ARE) is decreasing. In this study, we propose the ideal strategy of the aortic surgery for the small aortic annulus. We analyzed the clinical records of 158 patients who underwent aortic valve replacement from August 1999 to October 2005 in our institution. The small aortic annulus was observed in 38 patients (24%). Fourteen patients of this group underwent ARE. Patient-prosthesis mismatch (PPM) was less frequently observed in patients with ARE compared to those without ARE. The additional time required for ARE was not considerable, and neither ischemic time nor cardiopulmonary bypass time was significantly prolonged by ARE. In conclusion, we have to select a prosthesis with sufficient orifice area to avoid PPM, otherwise we should choose an option of ARE. For this consideration, we definitely need the chart that demonstrates the relationship between the nominal size of various types of prostheses and the size of a patient's annulus that those prostheses actually fit.
Okamoto, Yuki; Yamamoto, Kazuo; Sugimoto, Tsutomu; Asami, Fuyuki; Nagasawa, Ayako; Shiraiwa, Satoru; Nakamura, Norihito; Yoshii, Shinpei
We encountered a surgical case of middle aortic syndrome (MAS) in a 56-year-old man who had resistant hypertension. Computed tomography showed severe stenosis of the abdominal aorta from below the superior mesenteric artery to above the inferior mesenteric artery. Although bilateral renal artery stenosis was confirmed, renal function was within normal limits. A 10-mm vascular prosthetic graft was used to perform a descending aorta to left external iliac artery bypass. His hypertension was well controlled without medication. This extra-anatomic bypass may be a simple and useful approach for treating MAS if it is not necessary to reconstruct the renal artery or visceral artery.
Badran, Hala Mahfouz; Soltan, Ghada; Faheem, Nagla; Elnoamany, Mohamed Fahmy; Tawfik, Mohamed; Yacoub, Magdi
Background: Ventricular-vascular coupling is an important phenomenon in many cardiovascular diseases. The association between aortic mechanical dysfunction and left ventricular (LV) dysfunction is well characterized in many disease entities, but no data are available on how these changes are related in hypertrophic cardiomyopathy (HCM). Aim of the work: This study examined whether HCM alone is associated with an impaired aortic mechanical function in patients without cardiovascular risk factors and the relation of these changes, if any, to LV deformation and cardiac phenotype. Methods: 141 patients with HCM were recruited and compared to 66 age- and sex-matched healthy subjects as control group. Pulse pressure, aortic strain, stiffness and distensibility were calculated from the aortic diameters measured by M-mode echocardiography and blood pressure obtained by sphygmomanometer. Aortic wall systolic and diastolic velocities were measured using pulsed wave Doppler tissue imaging (DTI). Cardiac assessment included geometric parameters and myocardial deformation (strain and strain rate) and mechanical dyssynchrony. Results: The pulsatile change in the aortic diameter, distensibility and aortic wall systolic velocity (AWS') were significantly decreased and aortic stiffness index was increased in HCM compared to control (P < .001) In HCM AWS' was inversely correlated to age(r = − .32, P < .0001), MWT (r = − .22, P < .008), LVMI (r = − .20, P < .02), E/Ea (r = − .16, P < .03) LVOT gradient (r = − 19, P < .02) and severity of mitral regurg (r = − .18, P < .03) but not to the concealed LV deformation abnormalities or mechanical dyssynchrony. On multivariate analysis, the key determinant of aortic stiffness was LV mass index and LVOT obstruction while the role LV dysfunction in aortic stiffness is not evident in this population. Conclusion: HCM is associated with abnormal aortic mechanical properties. The severity of cardiac
Hamamoto, Masaki; Kobayashi, Taira; Kodama, Hiroshi
We describe a new technique of prosthesis-preserving aortic root replacement for patients who have previously undergone aortic valve replacement. With preservation of the mechanical prosthesis, we implant a Gelweave Valsalva graft using double suture lines. The first suture line is made between the sewing cuff of the mechanical valve and the graft, with mattress sutures of 2/0 braided polyester with pledgets. After the first sutures are tied, the second suture line is created between the graft collar and the aortic root remnant with continuous 4/0 polypropylene sutures.
Scott, S M; Sethi, G K; Paulson, D M; Takaro, T
Recent reports of cage wear occurring in DeBakey-Surgitool aortic valve prostheses prompted us to examine with image intensification all our patients who have had this type of prosthesis implanted. One patient, who was asymptomatic, was discovered to have a prosthesis with two fractured struts. This patient's prosthetic valve was replaced successfully with a stented porcine heterograft prosthesis. Including the valve removed from this patient, 8 DeBakey-Surgitool aortic valves with structural defects have been reported to the manufacturer. In the absence of a catastrophic event, patients with valves having fractured or worn struts may be totally asymptomatic, and routine periodic roentgenographic examination may be the only way of detecting strut wear or fracture.
Grolla, Elisabetta; Dalla Vestra, Michele; Bonanni, Luca; Cutolo, Ada; Rigo, Fausto
Idiopathic hypereosinophilic syndrome (HES) is characterized by persistent eosinophilia and eosinophil-mediated organ-system damage. Cardiac thrombosis and thromboembolic complications represent common causes of morbidity and mortality and usually involve cardiac ventricles or mitral and prosthetic valves, while the involvement of the aortic valve is extremely rare in HES. Here we report peculiar multimodality images of an atypical case of extended thrombosis of the aortic valve, complicated by myocardial ischemia and asymptomatic cerebral ischemia, likely due to thrombus embolization, occurring in a 48-year-old man with HES. Prompt anticoagulant and steroid therapy lead to rapid and complete resolution of the thrombotic lesions, allowing preserving the native valve and preventing further embolic events. PMID:26435854
Siebenmann, R; Schneider, K; von Segesser, L; Turina, M
348 cases of abdominal aortic aneurysm were reviewed for typical features of inflammatory aneurysm (IAAA) (marked thickening of aneurysm wall, retroperitoneal fibrosis and rigid adherence of adjacent structures). IAAA was present in 15 cases (14 male, 1 female). When compared with patients who had ordinary aneurysms, significantly more patients complained of back or abdominal pain (p less than 0.01). Erythrocyte sedimentation rate was highly elevated. Diagnosis was established in 7 of 10 computed tomographies. 2 patients underwent emergency repair for ruptured aneurysm. Unilateral ureteral obstruction was present in 4 cases and bilateral in 1. Repair of IAAA was performed by a modified technique. Histological examination revealed thickening of the aortic wall, mainly of the adventitial layer, infiltrated by plasma cells and lymphocytes. One 71-year-old patient operated on for rupture of IAAA died early, and another 78-year-old patient after 5 1/2 months. Control computed tomographies revealed spontaneous regression of inflammatory infiltration after repair. Equally, hydronephrosis due to ureteral obstruction could be shown to disappear or at least to decrease. IAAA can be diagnosed by computed tomography with high sensitivity. Repair involves low risk, but modification of technique is necessary. The etiology of IAAA remains unclear.
Alterman, Daniel M; Stevens, Scott L
Since its introduction, more than 59000 patients have been treated with Gore Excluder endoprosthesis (GORE) for abdominal aortic aneurysm (AAA) in the past 11 years. It has become clearer that differences in device delivery and design provide certain advantages that may favor one anatomical milieu over another. Behavior of the aneurysm sac also seems to be graft dependent as more long-term data become available. The currently available low-permeability GORE seems to have addressed the problem of endotension noted with previous designs. Cumulative data are reviewed, and the data demonstrate very low perioperative morbidity and mortality and excellent protection from aneurysm-related complications with the GORE device. Superior ease of use, excellent trackability, and rare failures requiring acute open conversion characterize the GORE device. By addressing clinical demands of aortic endografting, Gore has eclipsed other endografts in the industry to now dominate the US market. The aim of this review is to describe the history, experience, advantages, and future goals with the GORE for the treatment of AAA.
Castrovinci, Sebastiano; Emmanuel, Sam; Moscarelli, Marco; Murana, Giacomo; Caccamo, Giuseppa; Bertolino, Emanuela Clara; Nasso, Giuseppe; Speziale, Giuseppe; Fattouch, Khalil
Aortic valve disease is a prevalent disorder that affects approximately 2% of the general adult population. Surgical aortic valve replacement is the gold standard treatment for symptomatic patients. This treatment has demonstrably proven to be both safe and effective. Over the last few decades, in an attempt to reduce surgical trauma, different minimally invasive approaches for aortic valve replacement have been developed and are now being increasingly utilized. A narrative review of the literature was carried out to describe the surgical techniques for minimally invasive aortic valve surgery and report the results from different experienced centers. Minimally invasive aortic valve replacement is associated with low perioperative morbidity, mortality and a low conversion rate to full sternotomy. Long-term survival appears to be at least comparable to that reported for conventional full sternotomy. Minimally invasive aortic valve surgery, either with a partial upper sternotomy or a right anterior minithoracotomy provides early- and long-term benefits. Given these benefits, it may be considered the standard of care for isolated aortic valve disease. PMID:27582764
Rodriguez-Ospina, Luis; Garcia-Morell, Juan; Rodriguez-Monserrate, Carla P; Valentin-Nieves, Julio
Valve replacement is the standard surgical treatment of diseased valves that cannot be repaired. The main goal of replacement is to exchange the diseased valve with one that has the engineering and hemodynamics as close as possible to the disease free native valve. However due to mechanical and fluid dynamic constraints all prosthetic heart valves (PHVs) are smaller than normal and thus are inherently stenotic. This represents a challenge when it comes time to replace a valve. The correct valve with the correct and matching profile has to be selected before the procedure to avoid possible complications. It is well recognized that patients are also prone to patient-prosthesis mismatch at long term which could have consequences in the clinical outcomes (1). The evaluation of patient-prosthesis mismatch (PPM) has not been sufficiently emphasized in common practice. Failure to recognize this fact may lead to significant hemodynamic impairment and worsening of the clinical status over the time. Making efforts to identifying patients at risk may decrease the prevalence of PPM, the economic impact to our health system, the morbidity and mortality involved in these cases as well as creates efforts to standardized pre-operative protocols to minimized risk of PPM. We present a case of a 78 years old male patient who underwent aortic valve replacement due severe aortic stenosis, afterwards his clinical course got complicated with several admissions for shortness of breath and decompensated congestive heart failure (CHF).
Von Der Emde, Jürgen; Eberlein, Ulrich; Breme, Jürgen
From August 1971 through November 1972, we implanted 62 Model 2 DeBakey-Surgitool aortic valve prostheses in 62 patients, 4 of whom later had clinically asymptomatic strut fractures. In 1 case, the patient died suddenly, and autopsy revealed detachment of the ball-cage; in each of the other 3 cases, fractures of 2 struts close to the base of the prosthesis were diagnosed fluoroscopically, and the patients underwent successful reoperation. The interval between implantation and reoperation ranged from 11 months to 16 years, 9 months. In 1 patient, retrospective study of chest radiographs revealed that the fracture had been present for 2½ years. Larger valves (≥ A6) were affected significantly more often than smaller ones. We performed metallurgic analysis of 1 prosthesis: results revealed strut wear from fatigue cracking and secondary abrasion. Strut fracture was also promoted by suspension of the cage at right angles to the prosthetic ring and by use of a pyrolytic carbon ball in a titanium cage (i.e., an occluder harder than its holder). Patients with DeBakey-Surgitool aortic valve prostheses should undergo annual radiologic examinations to enable early detection of strut fractures. Prophylactic valve replacement is not indicated. (Texas Heart Institute Journal 1990;17:223-7) Images PMID:15227175
Bonares, Michael J; Vaisman, Alon; Sharkawy, Abdu
Pseudomonas stutzeri is infrequently isolated from clinical specimens, and if isolated, more likely represents colonization or contamination rather than infection. Despite this, there are dozens of case reports which describe clinically significant P. stutzeri infections at variable sites. A 69-year-old man had a P. stutzeri infection of a prosthetic vascular graft infection, which he received in Panama City. He was successfully treated with a single antipseudomonal agent for 6 weeks and the removal of the infected vascular graft. A 70-year-old man had a P. stutzeri infection of a prosthetic joint, which was successfully treated with a single anti-pseudomonal agent for 6 weeks. There is only one other documented case of a prosthetic vascular graft infection secondary to P. stutzeri. There are 5 documented cases of P. stutzeri prosthetic joint infections. The previous cases were treated with antibiotics and variably, source control with the removal of prosthetic material. Most cases of P. stutzeri infection are due to exposure in health care settings. Immunocompromised states such as HIV or hematological and solid tumor malignancies are risk factors for P. stutzeri infection. Infections caused by P. stutzeri are far less frequent and less fatal than those caused by P. aeruginosa. The etiology of a P. stutzeri infection could be exposure to soil and water, but also contaminated material in the health care setting or an immunocompromised state. Iatrogenic infections that are secondary to health care tourism are a potential cause of fever in the returned traveler.
Smith, Mark W; Su, Pon; Phibbs, Ciaran S
The National Prosthetics Patient Database (NPPD) is the national Department of Veterans Affairs (VA) dataset that records characteristics of individual prosthetic and assistive devices. It remains unknown how well NPPD records can be matched to encounter records for the same individuals in major VA utilization databases. We compared the count of prosthetics records in the NPPD with the count of prosthetics-related procedures for the same individuals recorded in major VA utilization databases. We then attempted to match the NPPD records to the utilization records by person and date. In general, 40% to 60% of the NPPD records could be matched to outpatient utilization records within a 14-day window around the NPPD dataset entry date. Match rates for inpatient data were lower: 10% to 16% within a 14-day window. The NPPD will be particularly important for studies of certain veteran groups, such as those with spinal cord injury or blast-related polytraumatic injury. Health services researchers should use both the NPPD and utilization databases to develop a full understanding of prosthetics use by individual patients.
Hu, X; Johnston, W M; Seghi, R R
Color information from different color-measuring systems varies during color matching in maxillofacial prosthetics. We studied the hypothesis that a non-contact measuring system and 4 contact color-measuring instruments perform comparably in accuracy and precision on measurements of pigmented maxillofacial elastomer specimens having human skin colors. Measurement comparisons in accuracy on opaque standard color patches were made in Phase I. In Phase II, the system with the best accuracy was used as the reference instrument, and comparisons in accuracy and precision on elastomer specimens were made. The CIEDE2000 color difference formula was used. Repeated-measures ANOVA with Tukey testing and linear regression analysis for CIELAB and color differences among the instruments were performed. The contact measuring systems perform differently in accuracy, possibly due to edge loss and other factors, but performed comparably in precision with the non-contact measuring instrument. This non-contact system is recommended for color measurement of maxillofacial prosthetic materials.
The planned scope of research for this reporting period were to: 1) develop and evaluate improved tactile sensors to be used in future clinical...construction of novel robust sensor designs and testing of these designs, 2) development of a controller development board to test the programming and...Quad Chart 37 1. INTRODUCTION: The purpose of this research is to equip a myoelectric prosthetic hand with contact detecting sensors and a
The electrically powered elbow design effort was initiated to develop a useful prosthetic component for severely handicapped persons. Preliminary...minimum static capacity of 300 pound-inches, and a no-load lifting velocity of ten revolutions per minute. In addition, the elbow was to provide continuous...the design criteria were not fulfilled but several elbow units were built for clinical evaluation. Recommendations for future design efforts are given. (Author)
Norton, William E.; Belcher, Jewell B.; Vest, Thomas W.; Carden, James R.
Prosthetic hand developed for amputee who retains significant portion of forearm. Outer end of device is end effector including two fingers, one moved by rotating remaining part of forearm about its longitudinal axis. Main body of end effector is end member supporting fingers, roller bearing assembly, and rack-and-pinion mechanism. Advantage of rack-and-pinion mechanism enables user to open or close gap between fingers with precision and force.
Marc, Robert; Pfeiffer, Rebecca; Jones, Bryan
Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral delivery of type 1 opsin genes from prokaryotes or eukaryote algae to restore light responses in survivor neurons. Targeting and expression remain major problems, but are potentially soluble. Importantly, optogenetics could provide the ultimate in high-resolution vision due to the long persistence of gene expression achieved in animal models. Nevertheless, optogenetics remains challenging to implement in human eyes with large volumes, complex disease progression, and physical barriers to viral penetration. Now, a new generation of photochromic ligands or chemical photoswitches (azobenzene-quaternary ammonium derivatives) can be injected into a degenerated mouse eye and, in minutes to hours, activate light responses in neurons. These photoswitches offer the potential for rapidly and reversibly screening the vision restoration expected in an individual patient. Chemical photoswitch variants that persist in the cell membrane could make them a simple therapy of choice, with resolution and sensitivity equivalent to optogenetics approaches. A major complexity in treating retinal degenerations is retinal remodeling: pathologic network rewiring, molecular reprogramming, and cell death that compromise signaling in the surviving retina. Remodeling forces a choice between upstream and downstream targeting, each engaging different benefits and defects. Prosthetics and optogenetics can be implemented in either mode, but the use of chemical photoswitches is currently limited to downstream
Bozeman, Richard J., Jr. (Inventor)
A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the movable body part through the full-shrug position of the movable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the movable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective movable prosthesis device and its sub-prosthesis.
Joo, Hyung Joon; Hong, Soon Jun; Yu, Cheol Woong
A 43-year-old man presented with severe aortic stenosis. Eight years previously, he had undergone primary surgical aortic valve replacement (AVR) for severe aortic regurgitation, but one year later developed cardiac arrest and complete atrioventricular block as a result of non-bacterial thrombotic endocarditis with severe valvular dehiscence. Following the diagnosis of prosthetic valve failure caused by Behçet's disease, the patient underwent a Bentall operation using 23 mm aortic homograft with permanent pacemaker implantation and coronary artery bypass grafting. Subsequently, he was stable with steroid administration and azathioprine for seven years after the second operation, but recently suffered from severe dyspnea and chest pain. Echocardiography revealed the development of severe aortic stenosis. A preprocedural evaluation demonstrated a porcelain aorta with severe calcification in the previous homograft valve on computed tomography, and critical stenosis at the ostium of the left circumflex artery on coronary angiography. After percutaneous coronary intervention for the ostium of the left circumflex artery, a transcatheter AVR was successfully performed using a 26 mm Edwards SAPIEN XT valve. The patient recovered without any complications after the procedure. This is the first report of a successful transcatheter aortic valve-in valve implantation for severe homograft aortic stenosis after a Bentall operation, using a homograft, in a patient with Behçet's disease.
There are a great number of feet to choose from, some simple and nonadjustable, some more technically sophisticated and adjustable by prosthetist or patient. A foot must meet the lifestyle and prosthetic needs of the patient. One also must consider the maintenance requirements and how they are impacted by the amputees' living environment, distance from a prosthetic facility, and the patient's gadget tolerance. On the practical side, the manufacturer must stand behind their foot and offer a reasonable trial period. Today the physician, prosthetist, and physical therapist must be familiar with Medicare guidelines and K levels. Being informed enables the rehabilitation team to agree upon the componentry best suited for the amputee when generating the prescription. This approach also avoids unnecessary inquiries and helps assure payment. In closing, two statements are added: (1) a well-informed prosthetist with good communication skills and dedication to the details of socket fit and alignment is for the patient the best source of information concerning componentry; and (2) appropriateness, reliability, and convenience are good, general guidelines to follow when helping an amputee choose a prosthetic foot.
The surgical treatment of aortic arch aneurysm including newly developed procedures and their outcomes is reviewed. Major advances in aortic arch repair have been made by meticulous brain protection with antegrade-selective and retrograde cerebral perfusion in addition to hypothermia circulatory arrest and refinement of surgical techniques. Total arch replacement using a multibranched prosthetic graft with antegrade-selective cerebral perfusion (SCP) under hypothermia through a median sternotomy has been standardized, resulting in lower mortality and cerebral mortality rates. In particular, the impact of the use of the axillary artery for cardiopulmonary bypass and of the stepwise or elephant trunk technique for distal anastomosis has recently been assessed. In addition, arch repair under moderate hypothermia in conjunction with SCP has been attempted without any serious problems. The surgical strategy for extended aortic aneurysms is also of concern. A two-stage approach with an elephant trunk procedure is employed predominantly for high-risk patients, while one-stage repair is aggressively applied for relatively young, low-risk patients. In contrast, there has been great progress in stent graft therapy for aortic arch lesions. Arch stent graft repairs including hybrid procedures have been attempted in elderly, high-risk patients. Consequently, these comorbid procedures can be used satisfactorily.
Farid, A; Sullivan, T M
Inflammatory abdominal aortic aneurysms (IAAA) occur infrequently in clinical practice. The reported incidence varies from 2.5-15% of all abdominal aortic aneurysms (AAA). Four percent of all AAA rupture into the vena cava. IAAA rupturing into the vena cava is exceedingly rare. To date, four such cases have been reported. IAAA are associated with a thick, rigid aortic wall which may be thin posteriorly and posterolaterally, where they are likely to rupture. A dense, fibrotic, desmoplastic reaction is found in the periaortic tissues often involving the duodenum, the inferior vena cava, the left renal vein, and ureters. IAAA may present with abdominal, back, or flank pain even in the absence of rupture. The diagnosis of IAAA can be made preoperatively by CT scan and at the time of laparotomy. Aortocaval fistula (ACF) can occur as a complication of AAA. The triad of low back pain, a palpable AAA, and a machinery murmur is diagnostic. ACF in association with IAAA is even more rare. It is amenable to surgical correction using a standard technique of fistula repair from within the aneurysm and prosthetic aortic graft replacement. Two cases of AAA with aortocaval fistula (ACF) are presented. In both, the diagnosis of ACF was made preoperatively. Repair of ACF was performed from within the aneurysm, with subsequent graft replacement. Despite complicated postoperative courses, both patients survived.
Lang, Pencilla; Chen, Elvis C. S.; Guiraudon, Gerard M.; Jones, Doug L.; Bainbridge, Daniel; Chu, Michael W.; Drangova, Maria; Hata, Noby; Jain, Ameet; Peters, Terry M.
A feature-based registration was developed to align biplane and tracked ultrasound images of the aortic root with a preoperative CT volume. In transcatheter aortic valve replacement, a prosthetic valve is inserted into the aortic annulus via a catheter. Poor anatomical visualization of the aortic root region can result in incorrect positioning, leading to significant morbidity and mortality. Registration of pre-operative CT to transesophageal ultrasound and fluoroscopy images is a major step towards providing augmented image guidance for this procedure. The proposed registration approach uses an iterative closest point algorithm to register a surface mesh generated from CT to 3D US points reconstructed from a single biplane US acquisition, or multiple tracked US images. The use of a single simultaneous acquisition biplane image eliminates reconstruction error introduced by cardiac gating and TEE probe tracking, creating potential for real-time intra-operative registration. A simple initialization procedure is used to minimize changes to operating room workflow. The algorithm is tested on images acquired from excised porcine hearts. Results demonstrate a clinically acceptable accuracy of 2.6mm and 5mm for tracked US to CT and biplane US to CT registration respectively.
Petramala, Luigi; Cotesta, Dario; Sapienza, Paolo; Zinnamosca, Laura; Moroni, Enrico; di Marzio, Luca; De Toma, Giorgio; Letizia, Claudio
We report a case of a 63-year-old man, with a previous history of hypertension and glucose intolerance associated troncular obesity that was emergently admitted to our Institution for evaluation of a severe, constant posterior chest pain which radiated anteriorly and dyspnoea with a suspected diagnosis of acute aortic dissection. A CT scan of thorax and abdomen demonstrated a dissection starting just below left succlavian artery and extending downward to the left renal artery, involving the celiac tripod and superior mesenteric artery. The dissection was classified as Stanford B, De Bakey III. Moreover, CT scan of abdomen revealed incidentally a left adrenal tumor of 25 mm of diameter. An emergent prosthetic graft was placed just below the origin of the left succlavian artery up-to the diaphragmatic hiatus. Furthermore, a diagnostic evaluation of the mass revealed an increase of cortisol production, and a diagnosis of Cushing's syndrome was done and the patient underwent an adrenalectomy via laparotomic approach. We report an association of acute aortic dissection of acute aortic dissection type B associated to Cushing's syndrome. Keywords Cushing's syndrome; Adrenocortical adenoma; Aortic dissection type B PMID:22505966
Chitragari, Gautham; Mahler, David B; Sumpio, Brandon J; Blume, Peter A; Sumpio, Bauer E
Although the rate of lower limb amputation in patients with diabetes is decreasing, amputation still remains a major complication of diabetes. Prosthetics have been long used to help amputees ambulate. The last decade has seen many advances in prostheses with the enhanced understanding of the mechanics of ambulation and improved use of technology. This review describes the different types of prosthetic options available for below knee, ankle, and foot amputees, emphasizing the latest advances in prosthetic design.
Ayad, Sherif W.; Hassanein, Mahmoud M.; Mohamed, Elsayed A.; Gohar, Ahmed M.
BACKGROUND Pregnancy is associated with several cardiocirculatory changes that can significantly impact underlying cardiac disease. These changes include an increase in cardiac output, sodium, and water retention leading to blood volume expansion, and reductions in systemic vascular resistance and systemic blood pressure. In addition, pregnancy results in a hypercoagulable state that increases the risk of thromboembolic complications. OBJECTIVES The aim of this study is to assess the maternal and fetal outcomes of pregnant women with mechanical prosthetic heart valves (PHVs). METHODS This is a prospective observational study that included 100 pregnant patients with cardiac mechanical valve prostheses on anticoagulant therapy. The main maternal outcomes included thromboembolic or hemorrhagic complications, prosthetic valve thrombosis, and acute decompensated heart failure. Fetal outcomes included miscarriage, fetal death, live birth, small-for-gestational age, and warfarin embryopathy. The relationship between the following were observed: – Maternal and fetal complications and the site of the replaced valve (mitral, aortic, or double)– Maternal and fetal complications and warfarin dosage (≤5 mg, >5 mg)– Maternal and fetal complications and the type of anticoagulation administered during the first trimester RESULTS This study included 60 patients (60%) with mitral valve replacement (MVR), 22 patients (22%) with aortic valve replacement (AVR), and 18 patients (18%) with double valve replacement (DVR). A total of 65 patients (65%) received >5 mg of oral anticoagulant (warfarin), 33 patients (33%) received ≤5 mg of warfarin, and 2 patients (2%) received low-molecular-weight heparin (LMWH; enoxaparin sodium) throughout the pregnancy. A total of 17 patients (17%) received oral anticoagulant (warfarin) during the first trimester: 9 patients received a daily warfarin dose of >5 mg while the remaining 8 patients received a daily dose of ≤5 mg. Twenty
... signs or symptoms of an abdominal aortic aneurysm (AAA). The final recommendation statement summarizes what the Task ... the potential benefits and harms of screening for AAA: (1) Men ages 65 to 75 who smoke ...
Yetkin, Oguz; Ahluwalia, Simranjit; Silva, Dinithi; Kasi-Okonye, Isioma; Volker, Rachael; Baptist, Joshua R.; Popa, Dan O.
Upper limb prosthetics are currently operated using several electromyography sensors mounted on an amputee's residual limb. In order for any prosthetic driving interface to be widely adopted, it needs to be responsive, lightweight, and out of the way when not being used. In this paper we discuss the possibility of replacing such electrodes with fingernail optical sensor systems mounted on the sound limb. We present a prototype device that can detect pinch gestures and communicate with the prosthetic system. The device detects the relative position of fingers to each other by measuring light transmitted via tissue. Applications are not limited to prosthetic control, but can be extended to other human-machine interfaces.
O'Neill, S C; Queally, J M; Devitt, B M; Doran, P P; O'Byrne, J M
Peri-prosthetic osteolysis and subsequent aseptic loosening is the most common reason for revising total hip replacements. Wear particles originating from the prosthetic components interact with multiple cell types in the peri-prosthetic region resulting in an inflammatory process that ultimately leads to peri-prosthetic bone loss. These cells include macrophages, osteoclasts, osteoblasts and fibroblasts. The majority of research in peri-prosthetic osteolysis has concentrated on the role played by osteoclasts and macrophages. The purpose of this review is to assess the role of the osteoblast in peri-prosthetic osteolysis. In peri-prosthetic osteolysis, wear particles may affect osteoblasts and contribute to the osteolytic process by two mechanisms. First, particles and metallic ions have been shown to inhibit the osteoblast in terms of its ability to secrete mineralised bone matrix, by reducing calcium deposition, alkaline phosphatase activity and its ability to proliferate. Secondly, particles and metallic ions have been shown to stimulate osteoblasts to produce pro inflammatory mediators in vitro. In vivo, these mediators have the potential to attract pro-inflammatory cells to the peri-prosthetic area and stimulate osteoclasts to absorb bone. Further research is needed to fully define the role of the osteoblast in peri-prosthetic osteolysis and to explore its potential role as a therapeutic target in this condition.
Bellows, Charles; Smith, Alison
Biologic prosthetics are increasingly used for the repair of abdominal wall hernia defects but can become infected as a result of peri- or early post-operative bacterial contamination. Data evaluating biofilm formation on biologic prosthetics is lacking. The aim of this study was to investigate the influence of different biologic prosthetics on the growth behavior of two different bacterial species and their ability to form biofilms. Methicillin resistant Staphylococcus aureus (MRSA) or Pseudomrnonas aeruginosa were incubated on disks of two biologic prosthetics-human acellular dermis (ADM), and porcine small intestinal submucosa (SIS). The bacteria were allowed to attach to the prosthetics and propagate into mature biofilms for 24 hours at 370C. Images of biofilms were obtained using confocal microscopy and scanning electron microscopy (SEM). The number of viable cells and the biofilm biomass were quantified by colony forming units (CFUs) and crystal violet staining respectively. Analysis of variance was performed to compare the mean values for the different prosthetics. Each biologic matrix had a distinct surface characteristic. SEM visualized mature biofilms characterized by highly organized multi-cellular structures on surface of both biologic prosthetics. Quantification of bacterial growth over time showed that ADM had the lowest CFUs and biofilm biomass at 24 hours post-inoculation compared to SIS for both bacterial strains. MRSA and P. aeruginosa can form mature biofilms on biologic prosthetics but the relative abundance of the biofilm varies on different prosthetic constructs. Biologic material composition and manufacturing methods may influence bacterial adherence.
Renewed interest for aortic valve disease has evolved in recent years. Aortic valve replacement has become the second most frequent cause of cardiac surgery, following coronary bypass surgery. In addition, the etiologic and physiopathologic knowledge of this disorder has improved. In the present paper we analyze three aspects of the disease which are, at present, the subject of study and controversy: first, we discuss the possible relationship between degenerative aortic stenosis and atherosclerosis; second, the involvement of the aortic root in cases of bicuspid aortic valve; and third, the surgical indications in asymptomatic patients with either aortic stenosis or regurgitation.
Liang, Liang; Martin, Caitlin; Wang, Qian; Sun, Wei; Duncan, James
Aortic valve (AV) disease is a significant cause of morbidity and mortality. The preferred treatment modality for severe AV disease is surgical resection and replacement of the native valve with either a mechanical or tissue prosthetic. In order to develop effective and long-lasting treatment methods, computational analyses, e.g., structural finite element (FE) and computational fluid dynamic simulations, are very effective for studying valve biomechanics. These computational analyses are based on mesh models of the aortic valve, which are usually constructed from 3D CT images though many hours of manual annotation, and therefore an automatic valve shape reconstruction method is desired. In this paper, we present a method for estimating the aortic valve shape from 3D cardiac CT images, which is represented by triangle meshes. We propose a pipeline for aortic valve shape estimation which includes novel algorithms for building local shape dictionaries and for building landmark detectors and curve detectors using local shape dictionaries. The method is evaluated on real patient image dataset using a leave-one-out approach and achieves an average accuracy of 0.69 mm. The work will facilitate automatic patient-specific computational modeling of the aortic valve.
Waller, B.F.; Taliercio, C.P.; Dickos, D.K.; Howard, J.; Adlam, J.H.; Jolly, W. )
Six patients undergoing aortic valve replacement had rare or unusual causes of isolated, pure aortic regurgitation. Two patients had congenitally bicuspid aortic valves with a false commissure (raphe) displaced to the aortic wall (tethered bicuspid aortic valve), two had floppy aortic valves, one had a congenital quadricuspid valve, and one had radiation-induced valve damage.
Moore, Brandon L; Dasi, Lakshmi Prasad
Mechanical stresses on aortic valve leaflets are well-known mediators for initiating processes leading to calcific aortic valve disease. Given that non-coronary leaflets calcify first, it may be hypothesized that coronary flow originating from the ostia significantly influences aortic leaflet mechanics and sinus hemodynamics. High resolution time-resolved particle image velocimetry (PIV) measurements were conducted to map the spatiotemporal characteristics of aortic sinus blood flow and leaflet motion with and without physiological coronary flow in a well-controlled in vitro setup. The in vitro setup consists of a porcine aortic valve mounted in a physiological aorta sinus chamber with dynamically controlled coronary resistance to emulate physiological coronary flow. Results were analyzed using qualitative streak plots illustrating the spatiotemporal complexity of blood flow patterns, and quantitative velocity vector and shear stress contour plots to show differences in the mechanical environments between the coronary and non-coronary sinuses. It is shown that the presence of coronary flow pulls the classical sinus vorticity deeper into the sinus and increases flow velocity near the leaflet base. This creates a beneficial increase in shear stress and washout near the leaflet that is not seen in the non-coronary sinus. Further, leaflet opens approximately 10% farther into the sinus with coronary flow case indicating superior valve opening area. The presence of coronary flow significantly improves leaflet mechanics and sinus hemodynamics in a manner that would reduce low wall shear stress conditions while improving washout at the base of the leaflet.
Hasler, D.; Landolt, A.; Obrist, D.
The instantaneous three-dimensional velocity field past a bioprosthetic heart valve was measured using tomographic particle image velocimetry. Two digital cameras were used together with a mirror setup to record PIV images from four different angles. Measurements were conducted in a transparent silicone phantom with a simplified geometry of the aortic root. The refraction indices of the silicone phantom and the working fluid were matched to minimize optical distortion from the flow field to the cameras. The silicone phantom of the aorta was integrated in a flow loop driven by a piston pump. Measurements were conducted for steady and pulsatile flow conditions. Results of the instantaneous, ensemble and phase-averaged flow field are presented. The three-dimensional velocity field reveals a flow topology, which can be related to features of the aortic valve prosthesis.
Yamanaka, Katsuhiro; Okada, Kenji; Okita, Yutaka
A 67-year old man with ascending aortic aneurysm was referred because of a quadricuspid aortic valve. He underwent aortic root replacement with a valve-sparing technique. Under deep hypothermic circulatory arrest, replacement of the ascending aorta was successfully performed. The postoperative course was uneventful without recurrence of aortic regurgitation.
Limb deficiency has a significant impact on the involved person, with upper limb absence presenting a materially different set of issues than lower limb absence. The primary objectives in fitting a patient with a prosthesis are to enhance their independence in performing daily activities, and to improve their quality of life. For lower limb absence, the primary issues are safety, stability, and the ability to ambulate in a manner consistent with their overall health. The primary objectives in prescribing upper limb prosthetics are function, durability, appearance, comfort, and usability of the device. This article discusses the nuances associated with managing these patients.
Scott, W. L. (Inventor)
An improved prosthetic device characterized by a frame and a socket for mounting on the stump of a truncated human appendage is described. Flexible digits extend from the distal end and transducers located within the digits act as sensing devices for detecting tactile stimuli. The transducers are connected through a power circuit with a slave unit supported by a strap and fixed to the stump. The tactile stimuli detected at the sensing devices are reproduced and applied to the skin of the appendage in order to stimulate the sensory organs located therein.
Gilarranz, Raul; Chamizo, Francisco; Horcajada, Iballa; Bordes-Benítez, Ana
Trueperella bernardiae is a Gram-positive coryneform bacilli which role as human pathogen is unknown because it has been usually considered a contaminant. Furthermore its identification by biochemical test was difficult. We describe a prosthetic joint infection in a women who years ago underwent a total knee replacement with superinfection and necrosis of the patellar tendon as major complications. In the sample of synovial fluid collected grew a gram-positive bacilli which was identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) as T. bernardiae. The patient was treated with ciprofloxacin and currently preserves the prosthesis without signs of infection.
Mallapragada, Surya K.; Anderson, Brian C.
The present invention provides novel block copolymers as structural supplements for injectible bodily prosthetics employed in medical or cosmetic procedures. The invention also includes the use of such block copolymers as nucleus pulposus replacement materials for the treatment of degenerative disc disorders and spinal injuries. The copolymers are constructed by polymerization of a tertiary amine methacrylate with either a (poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) polymer, such as the commercially available Pluronic.RTM. polymers, or a poly(ethylene glycol) methyl ether polymer.
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Prosthetic heart valve holder. 870.3935 Section... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold a replacement heart valve while it is being sutured into place. (b) Classification. Class I. The device...
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Prosthetic heart valve holder. 870.3935 Section... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold a replacement heart valve while it is being sutured into place. (b) Classification. Class I. The device...
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic heart valve holder. 870.3935 Section... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold a replacement heart valve while it is being sutured into place. (b) Classification. Class I. The device...
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Prosthetic heart valve holder. 870.3935 Section... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold a replacement heart valve while it is being sutured into place. (b) Classification. Class I. The device...
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Prosthetic heart valve holder. 870.3935 Section... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold a replacement heart valve while it is being sutured into place. (b) Classification. Class I. The device...
Philbin, T M; Leyes, M; Sferra, J J; Donley, B G
With advanced surgical techniques and orthotic, as well as prosthetic devices, partial foot amputations have become a viable alternative. Orthotics can help restore stability, maintain support, and protect function of the residual limb. The authors discuss orthotic and prosthetic management of patients who have undergone toe amputations; ray amputations; transmetatarsal, Lisfranc-, or Chopart-level amputations.
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false External limb prosthetic component. 890.3420 Section 890.3420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Prosthetic and orthotic accessory. 890.3025 Section 890.3025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false External limb prosthetic component. 890.3420 Section 890.3420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Prosthetic and orthotic accessory. 890.3025 Section 890.3025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Prosthetic and orthotic accessory. 890.3025 Section 890.3025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...
... 21 Food and Drugs 8 2013-04-01 2013-04-01 false External limb prosthetic component. 890.3420 Section 890.3420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External limb prosthetic component. 890.3420 Section 890.3420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Prosthetic and orthotic accessory. 890.3025 Section 890.3025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic and orthotic accessory. 890.3025 Section 890.3025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false External limb prosthetic component. 890.3420 Section 890.3420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices §...
American Orthotic and Prosthetic Association, Washington, DC.
The booklet sets forth the National Apprenticeship and Training Standards for the one-year apprenticeship program for orthotic and/or prosthetic technicians, as developed and recommended by the American Orthotic and Prosthetic Association. Standards in various areas--such as qualifications for apprenticeship, hours of work, salaries, records,…
Serov, P G
During prosthetic stomatological reception with the help of portable arterial pressure monitor Kardiotechnika-04AD-01 there were examined patients with normal blood pressure and arterial hypertension. The data were received confirming dependence of arterial pressure lifting with personal anxiety level. Conclusion was drown that close patient's examination was necessary before prosthetic stomatological reception.
Chiappa, Enrico; Greco, Antonella; Fainardi, Valentina; Passantino, Silvia; Serranti, Daniele; Favilli, Silvia
PHACE is a rare congenital neurocutaneous syndrome where posterior fossa malformations, hemangiomas, cerebrovascular anomalies, aortic arch anomalies, cardiac defects, and eye abnormalities are variably associated. We describe the prenatal detection and the postnatal course of a child with PHACE syndrome with a unique type of aortic arch anomaly consisting of proximal interruption of the aortic arch and persistence of the fifth aortic arch. The fifth aortic arch represented in this case a vital systemic-to-systemic connection between the ascending aorta and the transverse portion of the aortic arch allowing adequate forward flow through the aortic arch without surgical treatment.
... aortic aneurysm repair - open Aortic angiography Chest MRI Hardening of the ... Center-Shreveport, Shreveport, LA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla ...
Li, Guorong; Zhao, Hong; Zhu, Xiaodong; Ren, Bing
To achieve the aim of long-term heart-assist with a simple implantable device, we have been trying to develop a minimal intra-aortic impeller blood pump driven by an extracorporeal magnetic device. The purpose of the current study was to evaluate its feasibility by acute in vivo animal tests. The minimal intra-aortic pump was a cage-supported rotor-impeller, 17 mm in diameter with a total length of 30 mm. The driving magnet, mounted extracorporeally, was 55 mm in diameter and 50 mm in length. Seventeen dogs weighing from 28-34 kg were used in the study. After thoracic incision, heparin (50 U/kg) was infused. The impeller pump was inserted into the aortic chamber via a prosthetic vessel and fastened. Thin tubes were inserted into the left ventricular apex and the femoral artery to monitor the left ventricular (LV) and the aortic pressure. After closing the thoracic cavity, the extracorporeal whirling magnet, turned by an electric motor, was placed tightly against the thoracic wall parallel to the intra-aortic pump. The experiments, each lasting for about 40 min, were successful in 7 animals; the other 10 animals died of bleeding during pump implantation and were excluded from the experiment. The peak systolic pressure of the left ventricle could be considerably decreased by the pump and was reduced to as low as 28 mm Hg at a rotational speed of 9,000 rpm, showing that the simple intra-aortic impeller was effective in unloading the natural heart. The novel left ventricular assist device (LVAD) concept of an intra-aortic impeller pump, driven by an extracorporeal magnetic device, is feasible.
Patients with a bicuspid aortic valve (BAV) constitute a heterogeneous population with variable clinical presentation and complications. More than 50% of the patients who require aortic valve replacement have a BAV, a condition that may be associated with dilation of ascending aorta and aortic insufficiency caused by cusp disease or aortic root pathology. Of the potential BAV-related complications, dilation of the aortic root and ascending aorta are among the most serious. The dilation of ascending aorta and aortic root have been the subject of controversy. Whereas some surgeons believe that the dilation of the aorta is caused by the hemodynamic properties of the BAV, others believe that the dilation of the aortic root is secondary to genetic defects associated with the BAV. Management of a BAV should be tailored to each patient's clinical condition. The surgical approach varies from aortic valve replacement to combined aortic valve and root replacement to aortic-valve-sparing root replacement.
Mortimer, Alice Emily
A 79-year-old woman presented to a private medical practice 2 years previously for an elective ultrasound screening scan. This imaging provided the evidence for a diagnosis of an abdominal aortic aneurysm (AAA) to be made. Despite having a number of recognised risk factors for an AAA, her general practitioner at the time did not follow the guidance set out by the private medical professional, that is, to refer the patient to a vascular specialist to be entered into a surveillance programme and surgically evaluated. The patient became symptomatic with her AAA, was admitted to hospital and found to have a tender, symptomatic, 6 cm leaking AAA. She consented for an emergency open AAA repair within a few hours of being admitted to hospital, despite the 50% perioperative mortality risk. The patient spent 4 days in intensive care where she recovered well. She was discharged after a 12 day hospital stay but unfortunately passed away shortly after her discharge from a previously undiagnosed gastric cancer.
Tripathi, Rishi; Sainathan, Sandeep; Ziganshin, Bulat A; Elefteriades, John A
Aortic aneurysms are a common but often undetected pathology prevalent in the population. They are often detected as incidental findings on imaging studies performed for unrelated pathologies. Estrogens have been shown to exert a protective influence on aortic tissue. Pharmacological agents blocking the actions of estrogens may thus be implicated in causing aortic pathologies. We present the case of an elderly woman with breast carcinoma treated for 18 years with antiestrogen therapy who subsequently developed acute thoracic aortic deterioration (enlargement and wall disruption).
Kim, Chang-Young; Kim, Yeon Soo; Ryoo, Ji Yoon
It is expected that the stent graft will become an alternative method for treating aortic diseases or reducing the extent of surgery; therefore, thoracic endovascular aortic repair has widened its indications. However, it can have rare but serious complications such as paraplegia and retrograde type A aortic dissection. Here, we report a surgical repair of retrograde type A aortic dissection that was performed after thoracic endovascular aortic repair. PMID:24570865
Aortic Valve Insufficiency; Aortic Valve Regurgitation; Aortic Valve Stenosis; Aortic Valve Incompetence; Mitral Valve Insufficiency; Mitral Valve Regurgitation; Mitral Valve Stenosis; Mitral Valve Incompetence
It has been reported that 0.5-1% of patients undergoing carotid endarterectomy with prosthetic patch closure of the arteriotomy will develop patch infection. One third occur within the first 2 months after surgery, while two-thirds occur after >6 months have elapsed. Wound infection and abscess formation is the commonest mode of presentation in early cases, while chronic sinus discharge and false aneurysm formation are the commonest presentations in late cases. The commonest infecting organisms are Staphylococci/Streptococci (90%) and this should be borne in mind when planning antibiotic therapy before cultures are available. Most patch infections present (semi)-electively and patch rupture is relatively rare (10%), thereby enabling the surgeon to undertake careful evaluation of the patients overall clinical and anatomical status, whilst planning the optimal treatment strategy. If necessary, the patient should be transferred to a tertiary center for treatment. This is not an operation to be undertaken by an inexperienced surgeon. Operative planning should involve checking the original operation note (did the patient tolerate carotid clamping under locoregional anesthesia and therefore might tolerate carotid ligation), is there evidence of contralateral cranial nerve lesions (a contraindication to major open surgery) and has the surgeon planned for adequate distal exposure of the internal carotid artery. Patch excision and autologous reconstruction (usually vein) is the current 'gold standard' treatment, but highly selected patients can be successfully treated by less invasive surgery (including insertion of a covered stent). Patch excision and prosthetic reconstruction should be avoided.
Henderson, Emma; Buis, Arjan
As global populations age, conditions such as stroke and diabetes require individuals to use rehabilitation technology for many years to come due to chronic musculoskeletal, sensory, and other physical impairments. One in four males currently aged 45 will experience a stroke within 40 years and will often require access to prolonged rehabilitation. In addition, worldwide, one individual loses a limb every 30 s due to the complications of diabetes. As a result, innovative ideas are required to devise more effective prosthetic and orthotic devices to enhance quality of life. While Nitinol has already found much favor within the biomedical industry, one area, which has not yet exploited its unique properties, is in the field of physical rehabilitation, ranging from prosthetic and orthotic devices to assistive technology such as wheelchairs. Improved intervention capabilities based on materials such as Nitinol have the potential to vastly improve patients' quality of life and in the case of orthoses, may even reduce the severity of the condition over time. It is hoped that this study will spark discussion and interest for the materials community in a field which has yet to be fully exploited.
De Franco, Michele; Bosetti, Giovanni
The purpose of this retrospective study was to clinically evaluate the benefits of adopting a full digital workflow for the implementation of fixed prosthetic restorations on natural teeth. To evaluate the effectiveness of these protocols, treatment plans were drawn up for 15 patients requiring rehabilitation of one or more natural teeth. All the dental impressions were taken using a Planmeca PlanScan® (Planmeca OY, Helsinki, Finland) intraoral scanner, which provided digital casts on which the restorations were digitally designed using Exocad® (Exocad GmbH, Germany, 2010) software and fabricated by CAM processing on 5-axis milling machines. A total of 28 single crowns were made from monolithic zirconia, 12 vestibular veneers from lithium disilicate, and 4 three-quarter vestibular veneers with palatal extension. While the restorations were applied, the authors could clinically appreciate the excellent match between the digitally produced prosthetic design and the cemented prostheses, which never required any occlusal or proximal adjustment. Out of all the restorations applied, only one exhibited premature failure and was replaced with no other complications or need for further scanning. From the clinical experience gained using a full digital workflow, the authors can confirm that these work processes enable the fabrication of clinically reliable restorations, with all the benefits that digital methods bring to the dentist, the dental laboratory, and the patient. PMID:27829834
Dornfeld, Chelsea; Swanston, Michelle; Cassella, Joseph; Beasley, Casey; Green, Jacob; Moshayev, Yonatan; Wininger, Michael
Embodiment is the process by which patients with limb loss come to accept their peripheral device as a natural extension of self. However, there is little guidance as to how exacting the prosthesis must be in order for embodiment to take place: is it necessary for the prosthetic hand to look just like the absent hand? Here, we describe a protocol for testing whether an individual would select a hand that looks like their own from among a selection of five hands, and whether the hand selection (regardless of homology) is consistent across multiple exposures to the same (but reordered) set of candidate hands. Pilot results using healthy volunteers reveals that hand selection is only modestly consistent, and that selection of the prosthetic homologue is atypical (61 of 192 total exposures). Our protocol can be executed in minutes, and makes use of readily available equipment and softwares. We present both a face-to-face and a virtual protocol, for maximum flexibility of implementation. PMID:28066228
Dancey, A; Titley, OG
Introduction Metal detectors have been present in airports and points of departure for some time. With the introduction of heightened security measures in response to fears of an increased threat of terrorism, they may become more prevalent in other public locations. The aim of this study was to ascertain which prosthetic devices activated metal detector devices used for security purposes. Methods A range of prosthetic devices used commonly in orthopaedic and plastic surgery procedures were passed through an arch metal detector at Birmingham Airport in the UK. Additionally, each item was passed under a wand detector. Items tested included expandable breast prostheses, plates used in wrist and hand surgery, screws, K-wires, Autosuture™ ligation clips and staples. Results No prostheses were detected by the arch detector. The expandable implants and wrist plates were the only devices detected by passing the wand directly over them. No device was detected by the wand when it was under cover of the axillary soft tissue. Screws, K-wires, Autosuture™ clips and staples were not detected under any of the study conditions. Conclusions Although unlikely to trigger a detector, it is possible that an expandable breast prosthesis or larger plate may do so. It is therefore best to warn patients of this so they can anticipate detection and further examination. PMID:23827294
Urban, Marian; Pirk, Jan; Szarszoi, Ondrej; Skalsky, Ivo; Maly, Jiri; Netuka, Ivan
BACKGROUND: Double valve replacement for concomitant aortic and mitral valve disease is associated with substantial morbidity and mortality. Excellent results with valve repair in isolated mitral valve lesions have been reported; therefore, whether its potential benefits would translate into better outcomes in patients with combined mitral-aortic disease was investigated. METHODS: A retrospective observational study was performed involving 341 patients who underwent aortic valve replacement with either mitral valve repair (n=42) or double valve replacement (n=299). Data were analyzed for early mortality, late valve-related complications and survival. RESULTS: The early mortality rate was 11.9% for valve repair and 11.0% for replacement (P=0.797). Survival (± SD) was 67±11% in mitral valve repair with aortic valve replacement and 81±3% in double valve replacement at five years of follow-up (P=0.187). The percentage of patients who did not experience major adverse valve-related events at five years of follow-up was 83±9% in those who underwent mitral valve repair with aortic valve replacement and 89±2% in patients who underwent double valve replacement (P=0.412). Age >70 years (HR 2.4 [95% CI 1.1 to 4.9]; P=0.023) and renal dysfunction (HR 1.9 [95% CI 1.2 to 3.7]; P=0.01) were independent predictors of decreased survival. CONCLUSIONS: In patients with double valve disease, both mitral valve repair and replacement provided comparable early outcomes. There were no significant differences in valve-related reoperations, anticoagulation-related complications or prosthetic valve endocarditis. Patient-related factors appear to be the major determinant of late survival, irrespective of the type of operation. PMID:24294032
Querzoli, Giorgio; Fortini, Stefania; Espa, Stefania; Melchionna, Simone
Cardiovascular flows have been extensively investigated by means of in vitro models to assess the prosthetic valve performances and to provide insight into the fluid dynamics of the heart and proximal aorta. In particular, the models for the study of the flow past the aortic valve have been continuously improved by including, among other things, the compliance of the vessel and more realistic geometries. The flow within the sinuses of Valsalva is known to play a fundamental role in the dynamics of the aortic valve since they host a recirculation region that interacts with the leaflets. The coronary arteries originate from the ostia located within two of the three sinuses, and their presence may significantly affect the fluid dynamics of the aortic root. In spite of their importance, to the extent of the authors' knowledge, coronary arteries were not included so far when modeling in vitro the transvalvular aortic flow. We present a pulse duplicator consisting of a passively pulsing ventricle, a compliant proximal aorta, and coronary arteries connected to the sinuses of Valsalva. The coronary flow is modulated by a self-regulating device mimicking the physiological mechanism, which is based on the contraction and relaxation of the heart muscle during the cardiac cycle. Results show that the model reproduces satisfyingly the coronary flow. The analysis of the time evolution of the velocity and vorticity fields within the aortic root reveals the main characteristics of the backflow generated through the aorta in order to feed the coronaries during the diastole. Experiments without coronary flow have been run for comparison. Interestingly, the lifetime of the vortex forming in the sinus of Valsalva during the systole is reduced by the presence of the coronaries. As a matter of fact, at the end of the systole, that vortex is washed out because of the suction generated by the coronary flow. Correspondingly, the valve closure is delayed and faster compared to the case with
Swinkels, B.M.; Jaarsma, W.; Wely, L. Relik-van; van Swieten, H.A.; Ernst, J.M.P.G.; Plokker, H.W.M.
This case report describes a patient with severe calcific aortic stenosis who was initially considered inoperable because of a very poor left ventricular function and severe pulmonary hypertension. After balloon aortic valvuloplasty, the clinical and haemodynamic status of the patient improved to such an extent that subsequent aortic valve replacement was considered possible and eventually proved to be successful. Balloon aortic valvuloplasty has value as a potential bridge to aortic valve replacement when the risks for surgery are considered to be too high. ImagesFigure 1 PMID:25696195
Minimally invasive aortic valve replacement (MIAVR) is defined as aortic valve replacement avoiding full sternotomy. Common approaches include a partial sternotomy right thoracotomy, and a parasternal approach. MIAVR has been shown to have advantages over conventional AVR such as shorter length of stay and smaller amount of blood transfusion and better cosmesis. However, it is also known to have disadvantages such as longer cardiopulmonary bypass and aortic cross-clamp times and potential complications related to peripheral cannulation. Appropriate patient selection is very important. Since the procedure is more complex than conventional AVR, more intensive teamwork in the operating room is essential. Additionally, a team approach during postoperative management is critical to maximize the benefits of MIAVR.
Lu, Yuan-Qiang; Yao, Feng; Shang, An-Dong; Pan, Jian
Abstract Background: Pseudoaneurysm of the aortic arch is uncommonly associated with cancer, and is extremely rare in pulmonary cancer. Here, we report an unusual and successfully treated case of aortic arch pseudoaneurysm in a male patient with lung squamous cell carcinoma. Methods: A 64-year-old male patient was admitted to the Emergency Department, presenting with massive hemoptysis (>500 mL blood during the 12 hours prior to treatment). The diagnosis of aortic arch pseudoaneurysm was confirmed after inspection of computed tomographic angiography and three-dimensional reconstruction. We processed the immediate endovascular stent-grafting for this patient. Results: This patient recovered with no filling or enlargement of the pseudoaneurysm, no episodes of hemoptysis, and no neurological complications during the 4-week follow-up period. Conclusion: Herein, we compare our case with other cancer-related pseudoaneurysms in the medical literature and summarize the clinical features and treatment of this unusual case. PMID:27495079
Godinho, Ana Rita; Amorim, Sandra; Campelo, Manuel; Martins, Elisabete; Lopez Rodriguez, Elisa; Coelho, Rosa; Macedo, Guilherme; Maciel, Maria Júlia
The authors present the case of a 68-year-old man with predominantly right heart failure in the context of severe aortic stenosis associated with pulmonary hypertension. Anemia was diagnosed which, after endoscopic study, was considered to be secondary to angiodysplasia and a diagnosis of Heyde syndrome was made. After valve replacement surgery the patient's heart failure improved and hemoglobin levels stabilized. We present this case to show the need to recognize less common associations of severe aortic stenosis, in order to provide immediate and appropriate treatment.
Ramzisham, A R M; Arief, H; Ngoo, K S; Zamrin, D M; Joanna, O S M
Acute aortic dissection is a life-threatening condition, warranting prompt diagnosis and treatment. Management of which incorporates multidisciplinary expertise from the medical, surgical and intensive care. If left untreated, the mortality rate of acute aortic disease exceeds 50% within 48 hours and 80% within two weeks, with a 5-year survival rate of 19%. The most common cause of death in untreated acute aortic dissection, regardless of aetiology, is aortic rupture. We would like to share our successful experience of cases at the two extreme ages of acute aortic dissection. Literature review with their pathogenesis are discussed.
Tscheuschler, Anke; Meffert, Philipp; Beyersdorf, Friedhelm; Heilmann, Claudia; Kocher, Nadja; Uffelmann, Xenia; Discher, Philipp; Siepe, Matthias; Kari, Fabian A.
Objective The need for biological markers of aortic wall stress and risk of rupture or dissection of ascending aortic aneurysms is obvious. To date, wall stress cannot be related to a certain biological marker. We analyzed aortic tissue and serum for the presence of different MMP-2 isoforms to find a connection between serum and tissue MMP-2 and to evaluate the potential of different MMP-2 isoforms as markers of high wall stress. Methods Serum and aortic tissue from n = 24 patients and serum from n = 19 healthy controls was analyzed by ELISA and gelatin zymography. 24 patients had ascending aortic aneurysms, 10 of them also had aortic root aneurysms. Three patients had normally functioning valves, 12 had regurgitation alone, eight had regurgitation and stenosis and one had only stenosis. Patients had bicuspid and tricuspid aortic valves (9/15). Serum samples were taken preoperatively, and the aortic wall specimen collected during surgical aortic repair. Results Pro-MMP-2 was identified in all serum and tissue samples. Pro-MMP-2 was detected in all tissue and serum samples from patients with ascending aortic/aortic root aneurysms, irrespective of valve morphology or other clinical parameters and in serum from healthy controls. We also identified active MMP-2 in all tissue samples from patients with ascending aortic/aortic root aneurysms. None of the analyzed serum samples revealed signals relatable to active MMP-2. No correlation between aortic tissue total MMP-2 or tissue pro-MMP-2 or tissue active MMP-2 and serum MMP-2 was found and tissue MMP-2/pro-MMP-2/active MMP-2 did not correlate with aortic diameter. This evidence shows that pro-MMP-2 is the predominant MMP-2 species in serum of patients and healthy individuals and in aneurysmatic aortic tissue, irrespective of aortic valve configuration. Active MMP-2 species are either not released into systemic circulation or not detectable in serum. There is no reliable connection between aortic tissue—and serum MMP-2
Miskon, Azizi; A/L Thanakodi, Suresh; Raihan Mazlan, Mohd; Mohd Haziq Azhar, Satria; Nooraya Mohd Tawil, Siti
This project presents the development of an artificial hand controlled by Electroencephalograph (EEG) signal datasets for the prosthetic application. The EEG signal datasets were used as to improvise the way to control the prosthetic hand compared to the Electromyograph (EMG). The EMG has disadvantages to a person, who has not used the muscle for a long time and also to person with degenerative issues due to age factor. Thus, the EEG datasets found to be an alternative for EMG. The datasets used in this work were taken from Brain Computer Interface (BCI) Project. The datasets were already classified for open, close and combined movement operations. It served the purpose as an input to control the prosthetic hand by using an Interface system between Microsoft Visual Studio and Arduino. The obtained results reveal the prosthetic hand to be more efficient and faster in response to the EEG datasets with an additional LiPo (Lithium Polymer) battery attached to the prosthetic. Some limitations were also identified in terms of the hand movements, weight of the prosthetic, and the suggestions to improve were concluded in this paper. Overall, the objective of this paper were achieved when the prosthetic hand found to be feasible in operation utilizing the EEG datasets.
Resnik, Linda; Borgia, Matthew
We describe prosthetic limb prescription in the first year following lower-limb amputation and examine the relationship between amputation level, geographic region, and prosthetic prescription. We analyzed 2005 to 2010 Department of Veterans Affairs (VA) Inpatient and Medical Encounters SAS data sets, Vital Status death data, and National Prosthetic Patient Database data for 9,994 Veterans who underwent lower-limb amputation at a VA hospital. Descriptive statistics and bivariates were examined. Cox proportional hazard models identified factors associated with prosthetic prescription. Analyses showed that amputation level was associated with prosthetic prescription. The hazard ratios (HRs) were 1.41 for ankle amputation and 0.46 for transfemoral amputation compared with transtibial amputation. HRs for geographic region were Northeast = 1.49, Upper Midwest = 1.26, and West = 1.39 compared with the South (p < 0.001). African American race, longer length of hospital stay, older age, congestive heart failure, paralysis, other neurological disease, renal failure, and admission from a nursing facility were negatively associated with prosthetic prescription. Being married was positively associated. After adjusting for patient characteristics, people with ankle amputation were most likely to be prescribed a prosthesis and people with transfemoral amputation were least likely. Geographic variation in prosthetic prescription exists in the VA and further research is needed to explain why.
Chik, William; Chen, Sharon; Kok, Jen
Introduction. Listeria monocytogenes is an uncommon cause of prosthetic valve endocarditis (PVE). Recommended antimicrobial therapy typically includes intravenous β-lactams with or without synergistic aminoglycosides. In vitro studies have previously identified antagonism when rifampicin has been used in combination with β-lactams. However, in vivo data of rifampicin use are limited despite its enhanced anti-biofilm activity. Case presentation. A 63-year-old male presented with fever and back pain. L. monocytogenes bacteraemia and bioprosthetic aortic valve endocarditis was confirmed, along with spinal discitis and osteomyelitis. He was successfully treated with benzylpenicillin and rifampicin, in conjunction with valve replacement. Conclusion. Rifampicin remains an alternate agent to use, when there are contraindications to traditional aminoglycoside therapy. Further data on rifampicin use in L. monocytogenes PVE are awaited. PMID:28348807
Kostina, Aleksandra S; Uspensky, Vladimir Е; Irtyuga, Olga B; Ignatieva, Elena V; Freylikhman, Olga; Gavriliuk, Natalia D; Moiseeva, Olga M; Zhuk, Sergey; Tomilin, Alexey; Kostareva, Аnna А; Malashicheva, Anna B
Bicuspid aortic valve is the most common congenital heart malformation and the reasons for the aortopathies associated with bicuspid aortic valve remain unclear. NOTCH1 mutations are associated with bicuspid aortic valve and have been found in individuals with various left ventricular outflow tract abnormalities. Notch is a key signaling during cardiac valve formation that promotes the endothelial-to-mesenchymal transition. We address the role of Notch signaling in human aortic endothelial cells from patients with bicuspid aortic valve and aortic aneurysm. Aortic endothelial cells were isolated from tissue fragments of bicuspid aortic valve-associated thoracic aortic aneurysm patients and from healthy donors. Endothelial-to-mesenchymal transition was induced by activation of Notch signaling. Effectiveness of the transition was estimated by loss of endothelial and gain of mesenchymal markers by immunocytochemistry and qPCR. We show that aortic endothelial cells from the patients with aortic aneurysm and bicuspid aortic valve have down regulated Notch signaling and fail to activate Notch-dependent endothelial-to-mesenchymal transition in response to its stimulation by different Notch ligands. Our findings support the idea that bicuspid aortic valve and associated aortic aneurysm is associated with dysregulation of the entire Notch signaling pathway independently on the specific gene mutation.
Baikoussis, Nikolaos G.; Dedeilias, Panagiotis; Argiriou, Michalis
Aortic valve replacement (AVR) in patients with a small aortic annulus is a challenging issue. The importance of prosthesis–patient mismatch (PPM) post aortic valve replacement (AVR) is controversial but has to be avoided. Many studies support the fact that PPM has a negative impact on short and long term survival. In order to avoid PPM, aortic root enlargement may be performed. Alternatively and keeping in mind that often some comorbidities are present in old patients with small aortic root, the Perceval S suturelles valve implantation could be a perfect solution. The Perceval sutureless bioprosthesis provides reasonable hemodynamic performance avoiding the PPM and providing the maximum of aortic orifice area. We would like to see in the near future the role of the aortic root enlargement techniques in the era of surgical implantation of the sutureless valve (SAVR) and the transcatheter valve implantation (TAVI). PMID:28028424
Kim, Ha Won
Aneurysms are characterized by structural deterioration of the vascular wall leading to progressive dilatation and, potentially, rupture of the aorta. While aortic aneurysms often remain clinically silent, the morbidity and mortality associated with aneurysm expansion and rupture are considerable. Over 13,000 deaths annually in the United States are attributable to aortic aneurysm rupture with less than 1 in 3 persons with aortic aneurysm rupture surviving to surgical intervention. Environmental and epidemiologic risk factors including smoking, male gender, hypertension, older age, dyslipidemia, atherosclerosis, and family history are highly associated with abdominal aortic aneurysms, while heritable genetic mutations are commonly associated with aneurysms of the thoracic aorta. Similar to other forms of cardiovascular disease, family history, genetic variation, and heritable mutations modify the risk of aortic aneurysm formation and provide mechanistic insight into the pathogenesis of human aortic aneurysms. This review will examine the relationship between heritable genetic and epigenetic influences on thoracic and abdominal aortic aneurysm formation and rupture. PMID:28116311
Pluth, J R; Broadbent, J C; Barnhorst, D A; Danielson, G K
From February, 1971, through February, 1974, heart valves of 510 patients were replaced with cloth-covered Braunwald-Cutter prostheses. The data indicate that cloth encapsulation of the prosthetic cage is associated with a reduction in thromboembolic complications, particularly for mitral valves. Cloth wear on the distal strut, however, is not prevented by use of a Silastic poppet and appears to be a typical finding in aortic valves recovered or inspected after 3 months. Excessive poppet wear has also been noted in the aortic position; poppet embolization has occurred on 2 occasions, and a third patient was found, at the time of reoperation for periprosthetic leak, to have opppet wear sufficient to permit embolization. Although there have been no reports of clinical malfunction of the mitral prosthesis at the time of this writing, further long-term observation of these patients appears warranted.
Tretter, Justin T; Jones, Thomas K; McElhinney, Doff B
Aortic wall complications can occur in unrepaired aortic coarctation (CoA) and after surgical repair or endovascular treatment. This review summarizes the available literature and current understanding of aortic wall injury (AWI) surrounding the management of CoA, focusing specifically on acute and follow-up AWI after endovascular treatment. There have been 23 reported cases of aortic rupture after endovascular treatment for CoA, including angioplasty alone, bare metal stenting, and primary covered stent therapy. Even if these published cases represent only a minority of ruptures that have actually occurred, the incidence is substantially <1%. The incidence of acute aneurysm formation was 0% to 13% after angioplasty, 0% to 5% after bare metal stent placement, and <1% after covered stent placement. The reported incidence and natural history of both acute and new AWI during follow-up after endovascular therapy for CoA varies considerably, likely secondary to ascertainment and reporting biases and inconsistent definitions. Although important AWI after endovascular treatment of CoA seems to be declining in frequency with increasing experience and improving technology, it remains one of the most important potential adverse outcomes. Long-term surveillance for new AWI and monitoring of existing AWI is mandatory, with institution of appropriate treatment when necessary. A central research focus in this population should be determination of the appropriate treatment for both native and recurrent CoA across various ages with regard to limiting recurrent CoA and preventing associated aortic wall complications, in addition to determining the appropriate treatment of various AWI. Consistent definitions and reporting are necessary to truly understand the incidence of, risk factors for, and measures protective against AWI after angioplasty or stent implantation for CoA.
Barral, X; Gay, J L; Favre, J P; Gournier, J P
The purpose of this study was to evaluate the benefits of collagen-impregnated Dacron grafts in patients undergoing infrarenal aortic reconstruction. We therefore prospectively compared two consecutive series of patients undergoing infrarenal aortic reconstruction with Dacron grafts between January 1991 and December 1992. The first group (group A) included 83 high-density knitted prosthetic grafts (Dialine I), whereas the second included 82 grafts of the same type but impregnated with collagen (Dialine II). The two groups were comparable with regard to age, sex, and operative risk factors. They were also comparable in terms of the proportion of patients with occlusive disease or aneurysms, that is, there were 39 and 36 patients with occlusive disease and 44 and 46 patients with aneurysms in groups A and B, respectively. The type of bypass was similar in both groups with 17 and 19 tubular grafts and 66 and 63 bifurcated grafts being inserted in groups A and B, respectively. Thirteen parameters were studied and compared within each group including (1) number of infected grafts, (2) number of postoperative occlusions, (3) maximum postoperative temperature, (4) number of positive postoperative blood cultures, (5) number of postoperative deaths, (6) intraoperative and (7) postoperative quantities of blood transfused, (8) difference between pre- and postoperative hemoglobin concentrations, (9) difference between pre- and postoperative fibrinogen levels, (10) difference between pre- and postoperative platelet counts, (11) duration of aortic clamping, (12) date of return of intestinal function, and (13) mean duration of pre- and postoperative hospital stays.(ABSTRACT TRUNCATED AT 250 WORDS)
Dosumu, O O; Ogunrinde, T J; Ogundipe, O T
The treatment of cleft in the soft palate can be achieved essentially by surgical reconstruction or prosthetic obturation. The goals of prosthetic intervention are to prevent food and liquid leakage into the nose and to improve speech intelligibility by ensuring functional velopharyngeal port closure. In this report, the prosthetic management of a 5-year-old child with soft palatal cleft is presented. The impression of the cleft was taken with tissue conditioner, Visco -gel, TM (De Trey, Amalgamated Dental London) and the pharyngeal obturator (speech bulb) was made in clear acrylic resin. Patient tolerated the appliance well and was referred to speech therapist for speech articulation.
Gait analysis combined with sound clinical judgment plays an important role in elucidating the factors involved in the pathologic prosthetic gait and the selection and effects of available interventions to optimize it. Detailed clinical evaluation of walking contributes to the analysis of the prosthetic gait, but evaluation in the gait laboratory using kinetic and kinematic data is often necessary to quantify and identify the particular contributions of the variables impacting the gait with confidence and assess the results of such intervention. The same approach can be considered when selecting prosthetic components and assessing leg length in this patient population.
Lavien, Garjae; Zaid, Uwais; Peterson, Andrew C
Genitourinary prosthetics are used for correction of functional deficits and to improve the quality of lives of affected patients. General surgeons must evaluate patients scheduled for nonurologic surgery with urologic devices that can impact their perioperative management. Lack of recognition of these prosthetics preoperatively can lead to unnecessary morbidity for the patient and have legal implications for the surgeon. Close consultation with a urologist may avoid common complications associated with these devices and allows for surgical assistance when operative misadventures do occur. This article reviews 3 common urologic prosthetics: testicular prosthesis, artificial urinary sphincter, and penile prosthesis.
Hatt, Charles R.; Wagner, Martin; Raval, Amish N.; Speidel, Michael A.
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.
Stalpers, M J; Engelen, M; van der Stappen, J A A M; Weijs, W L J; Takes, R P; van Heumen, C C M
A 12-year-old boy had problems with his speech due to a defect in the soft palate. This defect was caused by the surgical removal of a synovial sarcoma. Testing with a nasometer revealed hypernasality above normal values. Given the size and severity of the defect in the soft palate, the possibility of improving the speech with speech therapy was limited. At a centre for special dentistry an attempt was made with a prosthetic construction to improve the performance of the palate and, in that way, the speech. This construction consisted of a denture with an obturator attached to it. With it, an effective closure of the palate could be achieved. New measurements with acoustic nasometry showed scores within the normal values. The nasality in the speech largely disappeared. The obturator is an effective and relatively easy solution for palatal insufficiency resulting from surgical resection. Intrusive reconstructive surgery can be avoided in this way.
Choudhary, Sunita; Garg, Hemlata; H.G., Jagadeesh
There have been constant searches and researches which are taking place in the field of dental materials to best suit the ideal selection criteria to satisfy the functionality, biocompatibility, aesthetics as well as the durability as a maxillofacial material. Among all the different materials, Silicone is the most popularly used, but still studies are carried out to overcome their weaknesses and to come out with a material which can be labeled as the “ideal maxillofacial prosthetic material”. This article comprises the materials which were and are in use and the reason for their unpopularity. It also gives us a scope to understand the major fields where the materials lack and thus needs improvement to render an individual with the best maxillo-facial prosthesis. PMID:25654054
Coombes, A G; Greenwood, C D
Shrink forming prosthetic sockets from memory plastics offers several advantages over existing techniques. The manual skill requirement is reduced relative to drapeforming flat sheet while compared with the Rapidform process, the requirement for a purpose built vacuum forming machine is eliminated. Two methods for producing thermoplastic sockets from heat shrinkable preforms are described. One uses established heat shrink technology and crosslinked thermoplastics. The second based on blowmoulding simplifies preform manufacture relative to existing techniques by reducing it to a single stage operation. Shrink formed sockets have been produced for three application areas concerned with the lower limb namely load bearing sockets, flexible ISNY type and rigid transparent check sockets. Static testing has demonstrated the ability of shrink formed, load bearing sockets to surpass Philadelphia Static Load Levels (ISPO, 1978) while fatigue testing has indicated a capability for long service life.
Platt, Robert; Chu, Mars; Diftler, Myron; Martin, Toby; Valvo, Michael
Tactile sensing is an important part of the development of new prosthetic hands. A number of approaches to establishing an afferent pathway back to the patient for tactile information are becoming available including tactors and direct stimulation of the afferent nerves. Tactile information can also be used by low-level control systems that perform simple tasks for the patient such as establishing a stable grasp and maintaining the grasping forces needed to hold an object. This abstract reports on the design of a small fingertip load cell based on semi-conductor strain gauges. Since this load cell is so small (measuring only 8.5mm in diameter and 6.25 mm in height), it easily fits into the tip of an anthropomorphic mechatronic hand. This load cell is tested by comparing a time series of force and moment data with reference data acquired from a much larger high-precision commercial load cell.
Johnson, Willard C.; Nabseth, Donald C.
An experience with aortic surgery is reported which reveals that visceral ischemia is more frequent than expected and significantly contributes to operative mortality. Two of five deaths among 84 patients who had aorto-iliac occlusive disease and four of 40 deaths among 103 aneurysmectomies (both ruptured and elective) were related to visceral ischemia. A review of the literature reveals 99 cases of colonic ischemia in more than 6,100 cases of aortic surgery, an incidence of 1.5%. Only 10 cases of small bowel ischemia were recorded. The present experience with 9 cases of colon ischemia and one of small bowel ischemia is presented particularly with reference to pathophysiology and prevention. It is concluded that patients should be identified by appropriate angiography if considered a risk for visceral infarction, and, if present, visceral arterial reconstruction should be performed in addition to aortic reconstructive surgery. Colon infarction following aortic aneurysmal surgery is directly related to ligation of a patent IMA. Thus re-implantation of the patent IMA should be considered. ImagesFig. 1a. PMID:4277757
Allen, Keith B; Davis, J Russell; Cohen, David J
Thoracic endovascular aortic repair (TEVAR) of acute ascending aortic pathology is feasible; however, the unique features of this aortic segment in addition to access challenges restricts its use to a select, high-risk subset of patients. With the advent of TAVR, large device delivery using transapical access has become a well-defined technique. We report a patient with critical aortic stenosis and an acute ascending aortic penetrating ulcer with tamponade managed successfully utilizing transapical TAVR and TEVAR. To our knowledge, this is the first reported case of a hybrid single-stage TAVR and ascending aortic TEVAR using transapical access.
Purpose: In 2014, the American Heart Association (AHA)/American College of Cardiology (ACC) guidelines were largely revised with regard to the selection of prosthetic valves. (1) A mechanical prosthesis is reasonable for aortic valve replacement (AVR) or mitral valve replacement (MVR) in patients less than 60 years of age, (2) A bioprosthesis is reasonable in patients more than 70 years of age, and (3) Either a bioprosthetic or mechanical valve is reasonable in patients between 60 and 70 years of age. Japan faces the unprecedented population aging, and moreover, the average life expectancy is longer among the Japanese than the Westerners. In Japan, whether this choice is appropriate seems questionable. Methods: This time, with the revision of the AHA/ACC guidelines, it might be necessary to take into consideration the average life expectancy of Japanese people and revise the Japanese guidelines accordingly. Results: We should consider whether 60–70 years should be set as a gray zone regarding the age criteria for choosing biological valves, or if the age should be set higher relative to that specified in the western guidelines, given the longer Japanese life expectancy. Conclusion: We believe that the development of unique, Japanese guidelines for the selection of prosthetic valves will allow us to provide appropriate selection and treatment for each patient. PMID:26062580
Claiborne, Thomas E; Sheriff, Jawaad; Kuetting, Maximilian; Steinseifer, Ulrich; Slepian, Marvin J; Bluestein, Danny
Calcific aortic valve disease is the most common and life threatening form of valvular heart disease, characterized by stenosis and regurgitation, which is currently treated at the symptomatic end-stages via open-heart surgical replacement of the diseased valve with, typically, either a xenograft tissue valve or a pyrolytic carbon mechanical heart valve. These options offer the clinician a choice between structural valve deterioration and chronic anticoagulant therapy, respectively, effectively replacing one disease with another. Polymeric prosthetic heart valves (PHV) offer the promise of reducing or eliminating these complications, and they may be better suited for the new transcatheter aortic valve replacement (TAVR) procedure, which currently utilizes tissue valves. New evidence indicates that the latter may incur damage during implantation. Polymer PHVs may also be incorporated into pulsatile circulatory support devices such as total artificial heart and ventricular assist devices that currently employ mechanical PHVs. Development of polymer PHVs, however, has been slow due to the lack of sufficiently durable and biocompatible polymers. We have designed a new trileaflet polymer PHV for surgical implantation employing a novel polymer-xSIBS-that offers superior bio-stability and durability. The design of this polymer PHV was optimized for reduced stresses, improved hemodynamic performance, and reduced thrombogenicity using our device thrombogenicity emulation (DTE) methodology, the results of which have been published separately. Here we present our new design, prototype fabrication methods, hydrodynamics performance testing, and platelet activation measurements performed in the optimized valve prototype and compare it to the performance of a gold standard tissue valve. The hydrodynamic performance of the two valves was comparable in all measures, with a certain advantage to our valve during regurgitation. There was no significant difference between the platelet
Schad, N.; Andrews, E.J.; Fleming, J.W.
This book contains 21 chapters. Some of the titles are: Functional imaging; Fist pass radionuclide studies in evaluation of mitral valve replacement in chronic insufficiency using Bjork-Shiley tilting disc valves; First pass radionuclide studies in evaluation of left and right ventricular function in patients with bioprosthetic mitral valve replacement after 9-11 years; and First pass radionuclide studies in the evaluation of long term (up to about 15 years) follow up of aortic valve replacement using Starr-Edwards ball prosthesis.
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
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.
Kim, Joo Yeon; Kim, Joon Bum; Jung, Sung-Ho; Choo, Suk Jung; Chung, Cheol Hyun; Lee, Jae Won
Background The advantages of using a homograft in valve replacement surgery are the excellent hemodynamic profile, low risk of thromboembolism, and low risk of prosthetic valve infection. The aim of this study was to evaluate the long-term outcomes of homograft implantation in the aortic valve position. Methods This is a retrospective study of 33 patients (>20 years old) who underwent aortic valve replacement or root replacement with homografts between April 1995 and May 2015. Valves were collected within 24 hours from explanted hearts of heart transplant recipients (<60 years) and organ donors who were not suitable for heart transplantation. The median follow-up duration was 35.6 months (range, 0 to 168 months). Results Aortic homografts were used in all patients. The 30-day mortality rate was 9.1%. The 1- and 5-year survival rates were 80.0%±7.3% and 60.8%±10.1%, respectively. The 1-, 5-, and 10-year freedom from reoperation rates were 92.3%±5.2%, 68.9%±10.2%, and 50.3%±13.6%, respectively. The 1-, 5-, and 10-year freedom from significant aortic dysfunction rates were 91.7%±8.0%, 41.7%±14.2%, and 25.0%±12.5%, respectively. Conclusion Homografts had the advantages of a good hemodynamic profile and low risk of thromboembolic events, and with good outcomes in cases of aortitis. PMID:27525234
... for the New Amputee Prosthetic FAQs for the New Amputee Web Development June 5, 2015 Fact Sheet ... step in your journey toward returning to your new normal after surgery. It is important to make ...
Chun, P K; Nelson, W P
The development of prosthetic heart valves has been an important advance in the treatment of patients with serious valvular cardiac disease. Because there are many types of prosthetic valves, we have prepared a diagram of the valves currently or previously used and list their potential complications. Prosthetic valves were identified according to photographic and radiologic features, valve replacement location, and reported associated complications. Data have been compiled in tabular form for quick reference; valves have been identified according to valve base, cage, and poppet. They may be categorized as caged-ball or low-profile valves. Such information helps to provide recognition of the valve that has been inserted and permits the clinician or radiologist to be alert to possible complications with the various prosthetic devices.
Iannotti, Joseph P; Lippitt, Steven B; Williams, Gerald R
Surgeons performing anatomical reconstruction of the shoulder during prosthetic replacement should consider the size of the humeral head and the placement of the head within the humerus. Prosthetic systems with a wide range of modular head sizes, eccentric tapers, and adjustable neck-shaft angles and versions help surgeons to better adapt a prosthesis to a patient's bone anatomy. Surgical technique remains critical for proper placement of the prosthesis and for correction of other soft-tissue and bony abnormalities associated with the pathology. In this article, we review some principles of prosthetic design and surgical technique to anatomically reconstruct the humeral head. We also review the clinical consequences of prosthetic humeral head malpositioning.
Fredrick, Jeff; Fletcher, Donna
Guidelines are offered to help teachers understand the nature and use of orthotic and prosthetic appliances for disabled students. Classroom behavior observations are noted so that teachers can help monitor the child's adjustment to the appliance. (CL)
Atasoy, A; Kaya, E; Toptas, E; Kuchimov, S; Kaplanoglu, E; Ozkan, M
A complete mechanical design concept of an electromyogram (EMG) controlled hybrid prosthetic hand, with 24 degree of freedom (DOF) anthropomorphic structure is presented. Brushless DC motors along with Shape Memory Alloy (SMA) actuators are used to achieve dexterous functionality. An 8 channel EMG is used for detecting 7 basic hand gestures for control purposes. The prosthetic hand will be integrated with the Neural Network (NNE) based controller in the next phase of the study.
Cooper, D K; Sturridge, M F
Two cases of prosthetic valve dysfunction resulting in acute massive mitral regurgitation are reported; emergency operation was successful in both cases. Survival following complete dislodgement of the occluder of a disc valve, as occurred in one case, does not appear to have been reported before. The diffculty in diagnosis of sudden cardiac decompensation in patients with prosthetic valves is stressed, as is the need for urgent operation. Images PMID:973894
The author on the basis of clinical and laboratory methods justified, that the use of locally cream "Solcoseryl-Denta" persons suffering from arterial hypertension, increase the speed of recovery of normal epithelial layer of the cells of the mucous membranes of the oral cavity, and, consequently, prevents the development of complications in prosthetics. On the basis of research identified the need in developing a method of prevention of inflammatory complications in prosthetic patients with arterial hypertension.
Gupta, Prateek K.; Gupta, Himani; Khoynezhad, Ali
Over the last few decades, treatment for aortic dissection and thoracic aortic aneurysms has evolved significantly with improvement in outcomes. Treatment paradigms include medical, endovascular and surgical options. As aortic dissection presents as a hypertensive emergency, diligent control of BP is of utmost importance in order to reduce the progression of dissection with possible aortic branch malperfusion. Treatment should begin on arrival to the emergency department and continues in the intensive care unit, endovascular suite or the operating room. Novel antihypertensive medications with improved pharmacological profile and improved surgical techniques, have improved the prognosis of patients with aortic aneurysm and/or aortic dissection. Nevertheless, morbidity and mortality remain high and hypertensive emergency poses a significant challenge in aortic dissection and thoracic aortic aneurysms. PMID:27713224
Hata, T; Fujiwara, K; Furukawa, H; Tsushima, Y; Yoshitaka, H; Kuinose, M; Minami, H; Ishida, A; Tamura, K; Totsugawa, T; Kanemitsu, H; Ozawa, M
Recent reports have shown that aortic valve replacement in elderly patients over 65 years with atherosclerotic aortic stenosis and a small aortic annulus is possible by using a small sized bioprosthesis (Carpentier-Edwards pericardial valve). Here we present out surgical technique. Firstly, the native calcified aortic valve was removed completely to gain total exposure of the surrounding aortic root and sinus of Valsalva like Bentall procedure. Secondly, a small sized bioprosthesis was implanted with intermittent noneverting mattress 2-0 sutures with spaghetti and small polytetrafluoroethylene (PTFE) felt. Aortic annulus is the dilated by inserting Hegar dilator sizing from 25 to 27 mm. Therefore, aortic valve replacement for small aortic annulus in intra- or supra-annular position should be easily accomplished. Good surgical results and hemodynamic state were achieved in 25 consecutive cases using this technique.
Kitano, Mitsuru; Teranishi, Hiroo; Kudo, Masahumi; Matsuura, Makoto
Objective: To our knowledge, no previous study has described the measurement of the tensile strength of the human aortic adventitia. In the present study, we examined the relationship between the tension and length of the aortic adventitia resected from the aortic wall of patients with acute aortic dissection. Methods: We obtained rectangular specimens from the aortic adventitia that was resected in patients with acute aortic dissection during surgery. The specimens were placed on a tension meter (Digital Force Gauge FGS-10, SHIMPO, Kyoto, Japan) within 15 min after resection and stretched until they were pulled apart, and the tension and length were recorded. Results: We obtained 18 specimens during surgery from 11 cases of acute aortic dissection. When the specimen was being pulled apart, the mean tension recorded was 10.2 ± 4.9 N/cm specimen width, whereas the mean elongated length recorded was 4.2 ± 1.1 mm/cm specimen length. Discussion: We determined that the aortic adventitia is elastic and expandable up to 140% of its original length. This indicates that dilation of the aorta to >4.2 cm in diameter may result in a rupture if the original aortic diameter prior to dissection was 3 cm. (*English translation of J Jpn Coll Angiol 2013; 53: 77-81) PMID:25298826
Kwon, Hee-Jin; Kim, Song Soo; Sun, Byung Joo; Jin, Sun Ah; Kim, Jun-Hyung; Lee, Jae-Hwan; Choi, Siwan; Jeong, Jin-Ok; Seong, In-Whan
Unicuspid aortic valve (UAV) is an extremely rare form of congenital aortic valvular abnormality. Although UAV shows similar clinical characteristics to bicuspid aortic valve, the clinical symptoms develop at earlier age and progress at a faster pace in UAV. In this report, we are presenting a 42-year-old male with severe aortic stenosis associated with unicommissural UAV. The patients underwent a successful Bentall operation. PMID:27721957
Joseph, Jessica; Naqvi, Syed Yaseen; Giri, Jay; Goldberg, Sheldon
The incidence of aortic stenosis increases with age, affecting up to 10% of the population by the eighth decade. Once symptoms develop, aortic stenosis is rapidly fatal. Proper management requires an understanding of the physiology and criteria used to define disease severity. There is no effective pharmacologic treatment. Surgical aortic valve replacement has been the gold standard treatment for decades. However, over the last 10 years transcatheter aortic valve replacement has emerged as an attractive, less-invasive option for appropriately selected patients. Refinements in valve design and delivery systems have led to widespread use of this breakthrough technology in selected patients. We review the pathophysiology, criteria for valve replacement, and the results of the trials comparing transcatheter aortic valve replacement with surgical aortic valve replacement.
Julien, Maureen B; Desai, Nimesh; Brozena, Susan; Herrmann, Howard C
Despite the widespread use of transcatheter aortic valve replacement (TAVR) for moderate and high-risk patients with severe aortic stenosis, it is utilized less frequently in patients with bicuspid aortic valves (BAV). Orthotopic heart transplant (OHT) donors tend to be younger and may have undiagnosed BAV. We present a case of successful TAVR in a patient with BAV thirteen years after OHT.
Irving, J. B.
This case report describes the presentation and treatment of a case of aortic incompetence, resulting from a road traffic accident. The relevant literature is briefly reviewed. Aortic incompetence due to trauma has been described following non-penetrating chest injuries, such as kicks from horses (Barie, 1881), falls from heights and crushing accidents (Kissane, Koons and Clark, 1948; Levine, Roberts and Morrow, 1962). Despite the frequency of road traffic accidents, there have been no recent reports of traumatic aortic valve damage. PMID:4467876
Bokeria, L A; Bokeria, O L; Fadeev, A A; Makhachev, O A; Kosareva, T I; Averina, I I
The analysis of transprosthetic hemodynamics in adults after aortic valve replacement in the Bakoulev Center for Cardiovascular Surgery in 2007-2010 demonstrated the hemodynamic advantage of the concept of new full-flow mechanical aortic valve prosthesis "CorBeat". Having the same size of internal orifice and tissue annulus diameters, the values of transprosthetic parameters (peak and mean gradients, blood flow velocities) through "CorBeat" were close to physiological values of transvalvular native aortic parameters and had a tendency to be not dependent on the size of prosthesis (p = 0.63). In the article for the first time a morphometric database of geometric values of internal orifice area of normal native aortic valves in adults was used taking into account both the gender and the body surface area's of a patient. There was also used the standardized prosthesis size Z-score which represents the number of SDs by which the internal prosthesis area differs from the mean normal native aortic valve area for the patient's body surface area. The article emphasizes the need of the personal selection of the size and the type of prosthesis for any patient as well as the need for new design development of prosthetic heart valves.
Bazan, Ovandir; Ortiz, Jayme Pinto; Vieira Junior, Francisco Ubaldo; Vieira, Reinaldo Wilson; Antunes, Nilson; Tabacow, Fabio Bittencourt Dutra; Costa, Eduardo Tavares; Petrucci Junior, Orlando
Introduction In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench. Objective To compare unidimensional velocity profiles at the central plane of two bi-leaflet aortic prosthesis from St. Jude (AGN 21 - 751 and 21 AJ - 501 models) exposed to a steady flow regime, on four distinct sections, three downstream and one upstream. Methods To provide similar conditions for the flow through each prosthesis by a steady flow workbench (water, flow rate of 17L/min. ) and, for the same sections and sweeps, to obtain the velocity profiles of each heart valve by unidimensional measurements. Results It was found that higher velocities correspond to the prosthesis with smaller inner diameter and instabilities of flow are larger as the section of interest is closer to the valve. Regions of recirculation, stagnation of flow, low pressure, and flow peak velocities were also found. Conclusions Considering the hydrodynamic aspect and for every section measured, it could be concluded that the prosthesis model AGN 21 - 751 (RegentTM) is superior to the 21 AJ - 501 model (Master Series). Based on the results, future studies can choose to focus on specific regions of the these valves. PMID:24598950
Clavel, Marie-Annick; Magne, Julien; Pibarot, Philippe
An important proportion of patients with aortic stenosis (AS) have a 'low-gradient' AS, i.e. a small aortic valve area (AVA <1.0 cm(2)) consistent with severe AS but a low mean transvalvular gradient (<40 mmHg) consistent with non-severe AS. The management of this subset of patients is particularly challenging because the AVA-gradient discrepancy raises uncertainty about the actual stenosis severity and thus about the indication for aortic valve replacement (AVR) if the patient has symptoms and/or left ventricular (LV) systolic dysfunction. The most frequent cause of low-gradient (LG) AS is the presence of a low LV outflow state, which may occur with reduced left ventricular ejection fraction (LVEF), i.e. classical low-flow, low-gradient (LF-LG), or preserved LVEF, i.e. paradoxical LF-LG. Furthermore, a substantial proportion of patients with AS may have a normal-flow, low-gradient (NF-LG) AS: i.e. a small AVA-low-gradient combination but with a normal flow. One of the most important clinical challenges in these three categories of patients with LG AS (classical LF-LG, paradoxical LF-LG, and NF-LG) is to differentiate a true-severe AS that generally benefits from AVR vs. a pseudo-severe AS that should be managed conservatively. A low-dose dobutamine stress echocardiography may be used for this purpose in patients with classical LF-LG AS, whereas aortic valve calcium scoring by multi-detector computed tomography is the preferred modality in those with paradoxical LF-LG or NF-LG AS. Although patients with LF-LG severe AS have worse outcomes than those with high-gradient AS following AVR, they nonetheless display an important survival benefit with this intervention. Some studies suggest that transcatheter AVR may be superior to surgical AVR in patients with LF-LG AS.
Hammer, W J; Hearne, M J; Roberts, W C
Intermittent aortic regurgitation due to cocking is described for the first time after replacement of the aortic valve with a poppet-disc prosthesis. A combination of disc grooving and strut thrombus produced the cocking with resultant aortic regurgitation.
Aortic aneurysm (AA) is one of the life-threatening aortic diseases, leading to aortic rupture of any cause including atherosclerotic and non-atherosclerotic diseases. AA is diagnosed in a variable proportion of patients with dilated aorta by imaging modality. The etiopathogenesis of AA remains unclear in many aortic diseases. Furthermore, although it may be difficult to explain all phenotypes of patients even if genetic mutation could be identified in some proteins such as smooth muscle cell α-actin (ACTA2), myosin heavy chain 11 (MYH11) or SMAD3, individualized consideration of these factors in each patient is essential on the basis of clinicopathological characteristics. PMID:27375798
Gupta-Malhotra, Monesha; Devereux, Richard B; Dave, Archana; Bell, Cynthia; Portman, Ronald; Milewicz, Diana
The aim of the study was to determine the presence of aortic dilatation in hypertensive children, the prevalence of which is 4% to 10% in hypertensive adults. Prospectively enrolled multiethnic children, untreated for their hypertension, underwent an echocardiogram to exclude congenital heart disease and evaluate for end-organ damage and aortic size. The aorta was measured in the parasternal long-axis view at three levels: the sinus of Valsalva, supra-tubular junction, and the ascending aorta. Aortic dilatation was determined by z-score >2 at any one of the levels measured. Hypertension was defined as blood pressure above the 95th percentile based on the Fourth Working Group criteria confirmed by 24-hour ambulatory blood pressure monitoring. Among 142 consecutive hypertensive children (median age, 14 years; 45% females) aortic dilatation was detected in 2.8% (95% confidence interval, 1%-7%; median age, 16 years; 100% females). Children with aortic dilatation, when compared with those without, had significantly more aortic valve insufficiency (P = .005) and left ventricular hypertrophy (P = .018). Prevalence of aortic dilatation was 2.8% and was associated with significantly more aortic insufficiency and left ventricular hypertrophy in comparison to those without aortic dilatation.
Gupta-Malhotra, Monesha; Devereux, Richard B.; Dave, Archana; Bell, Cynthia; Portman, Ronald; Milewicz, Diana
Background The aim of the study was to determine presence of aortic dilatation in hypertensive children, the prevalence of which is 4–10% in hypertensive adults. Methods Prospectively enrolled multiethnic children untreated for their hypertension, underwent an echocardiogram to exclude congenital heart disease and evaluate for end-organ damage and aortic size. The aorta was measured in the parasternal long-axis view at 3 levels: the sinus of Valsalva, supra-tubular junction and the ascending aorta. Aortic dilatation was determined by z-score > 2 at any 1 of the levels measured. Hypertension was defined as blood pressure above the 95th percentile based on the Fourth Working Group criteria confirmed by 24-hour ambulatory blood pressure monitoring. Results Among 142 consecutive hypertensive children (median age 14 years, 45% females) aortic dilatation was detected in 2.8% (95% CI 1% to 7%, median age 16 years, 100% females). Children with aortic dilatation, when compared to those without, had significantly more aortic valve insufficiency (p = 0.005) and left ventricular hypertrophy (p = 0.018). Conclusions Prevalence of aortic dilatation was 2.8% and was associated with significantly more aortic insufficiency and left ventricular hypertrophy in comparison to those without aortic dilatation. PMID:24507486
Aortic stenosis (AS) occurs in almost 10% of adults over age 80 years with a mortality about 50% at 2 years unless outflow obstruction is relieved by aortic valve replacement (AVR). Development of AS is associated with anatomic, clinical and genetic risk factors including a bicuspid valve in 50%; clinical factors that include older age, hypertension, smoking, diabetes and elevated serum lipoprotein(a) [Lp(a)] levels; and genetic factors such as a polymorphism in the Lp(a) locus. Early stages of AS are characterized by focal areas of leaflet thickening and calcification. The rate of hemodynamic progression is variable but eventual severe AS is inevitable once even mild valve obstruction is present. There is no specific medical therapy to prevent leaflet calcification. Basic principles of medical therapy for asymptomatic AS are patient education, periodic echocardiographic and clinical monitoring, standard cardiac risk factor evaluation and modification and treatment of hypertension or other comorbid conditions. When severe AS is present, a careful evaluation for symptoms is needed, often with an exercise test to document symptom status and cardiac reserve. In symptomatic patients with severe AS, AVR improves survival and relieves symptoms. In asymptomatic patients with severe AS, AVR also is appropriate if ejection fraction is < 50%, disease progression is rapid or AS is very severe (aortic velocity > 5 m/s). The choice of surgical or transcatheter AVR depends on the estimated surgical risk plus other factors such as frailty, other organ system disease and procedural specific impediments. PMID:26140146
Pupka, Artur; Lepiesza, Agnieszka; Skóra, Jan; Nega, Katarzyna
The correlation between abdominal hernias and aortic aneurysm has been well documented in literature. The pathophysiology of aneurysm and hernia formation is seen within the abnormal collagen metabolism, resulting in extracellular matrix defects. This study presents a group of 8 men in the age of 36 to 78 years old (average 63, 5 years old) who underwent both an operation for the aneurysm and for the abdominal hernia. Of the reported 8 patients, 7 had postoperative hernias, where 4 of the cases there were recurrent postoperative hernias. The remaining patient had an inguinal hernia. In 7 cases patients underwent an abdominal aortic aneurysm (AAA) operation and in one case a hepatic artery aneurysm endovascular operation was performed. Due to the fact that postoperative hernias are an immense problem, especially within the group of patient with collagen defects, the area of research and improvement of the materials that are used in prosthetic hernia surgery today needs to progress. This study also presents a short review of the various types of prosthetic materials used in the production of hernial meshes. This is to emphasize the necessity of improving operational techniques to minimize the risk of herniation, especially within a group of patients with collagen defects.
Nuñez-Anita, Rosa Elvira; Acosta-Torres, Laura Susana; Vilar-Pineda, Jorge; Martínez-Espinosa, Juan Carlos; de la Fuente-Hernández, Javier; Castaño, Víctor Manuel
Advances in nanotechnology are producing an accelerated proliferation of new nanomaterial composites that are likely to become an important source of engineered health-related products. Nanoparticles with antifungal effects are of great interest in the formulation of microbicidal materials. Fungi are found as innocuous commensals and colonize various habitats in and on humans, especially the skin and mucosa. As growth on surfaces is a natural part of the Candida spp. lifestyle, one can expect that Candida organisms colonize prosthetic devices, such as dentures. Macromolecular systems, due to their properties, allow efficient use of these materials in various fields, including the creation of reinforced nanoparticle polymers with antimicrobial activity. This review briefly summarizes the results of studies conducted during the past decade and especially in the last few years focused on the toxicity of different antimicrobial polymers and factors influencing their activities, as well as the main applications of antimicrobial polymers in dentistry. The present study addresses aspects that are often overlooked in nanotoxicology studies, such as careful time-dependent characterization of agglomeration and ion release. PMID:25187703
Davies, Richard; Nugent, Chris D.; Donnelly, Mark
In the COGKNOW project, a cognitive prosthetic has been developed through the application of Information and Communication Technology (ICT)-based services to address the unmet needs and demands of persons with dementia. The primary aim of the developed solution was to offer guidance with conducting everyday activities for persons with dementia. To encourage a user-centred design process, a three-phased methodology was introduced to facilitate cyclical prototype development. At each phase, user input was used to guide the future development. As a prerequisite to the first phase of development, user requirements were gathered to identify a small set of functional requirements from which a number of services were identified. Following implementation of these initial services, the prototype was evaluated on a cohort of users and, through observing their experiences and recording their feedback, the design was refined and the prototype redeveloped to include a number of additional services in the second phase. The current chapter provides an overview of the services designed and developed in the first two phases.
Castellini, Claudio; van der Smagt, Patrick
One of the major problems when dealing with highly dexterous, active hand prostheses is their control by the patient wearing them. With the advances in mechatronics, building prosthetic hands with multiple active degrees of freedom is realisable, but actively controlling the position and especially the exerted force of each finger cannot yet be done naturally. This paper deals with advanced robotic hand control via surface electromyography. Building upon recent results, we show that machine learning, together with a simple downsampling algorithm, can be effectively used to control on-line, in real time, finger position as well as finger force of a highly dexterous robotic hand. The system determines the type of grasp a human subject is willing to use, and the required amount of force involved, with a high degree of accuracy. This represents a remarkable improvement with respect to the state-of-the-art of feed-forward control of dexterous mechanical hands, and opens up a scenario in which amputees will be able to control hand prostheses in a much finer way than it has so far been possible.
Cruce, Jesse R; Erwin, Jenny R; Remick, Kevin R; Cornwell, Phillip J; Menegini, R. Michael; Racanelli, Joe
The purpose of this study was to establish a test setup and vibration analysis method to predict femoral stem seating and prevent bone fracture using accelerometer and force response data from an instrumented stem and impactor. This study builds upon earlier studies to identify a means to supplement a surgeon's tactile and auditory senses by using damage identification techniques normally used for civil and mechanical structures. Testing was conducted using foam cortical shell sawbones prepared for stems of different geometries. Each stem was instrumented with an accelerometer. Two impactor designs were compared: a monolithic impactor and a two-piece impactor, each with an integrated load cell and accelerometer. Acceleration and force measurements were taken in the direction of impaction. Comparisons between different methods of applying an impacting force were made, including a drop tower and a surgical hammer. The effect of varying compliance on the data was also investigated. The ultimate goal of this study was to assist in the design of an integrated portable data acquisition system capable of being used in future cadaveric testing. This paper will discuss the experimental setup and the subsequent results of the comparisons made between impactors, prosthetic geometries, compliances, and impact methods. The results of this study can be used for both future replicate testing as well as in a cadaveric environment.
Research has tremendously contributed to the developments in both practical and fundamental aspects of limb prosthetics. These advancements are reflected in scientific articles, particularly in the most cited papers. This article aimed to identify the 100 top-cited articles in the field of limb prosthetics and to investigate their main characteristics. Articles related to the field of limb prosthetics and published in the Web of Knowledge database of the Institute for Scientific Information (ISI) from the period of 1980 to 2012. The 100 most cited articles in limb prosthetics were selected based on the citation index report. All types of articles except for proceedings and letters were included in the study. The study design and level of evidence were determined using Sackett’s initial rules of evidence. The level of evidence was categorized either as a systematic review or meta-analysis, randomized controlled trial, cohort study, case–control study, case series, expert opinion, or design and development. The top cited articles in prosthetics were published from 1980 to 2012 with a citation range of 11 to 90 times since publication. The mean citation rate was 24.43 (SD 16.7) times. Eighty-four percent of the articles were original publications and were most commonly prospective (76%) and case series studies (67%) that used human subjects (96%) providing level 4 evidence. Among the various fields, rehabilitation (47%), orthopedics (29%), and sport sciences (28%) were the most common fields of study. The study established that studies conducted in North America and were written in English had the highest citations. Top cited articles primarily dealt with lower limb prosthetics, specifically, on transtibial and transradial prosthetic limbs. Majority of the articles were experimental studies. PMID:24237942
Eshraghi, Arezoo; Osman, Noor Azuan Abu; Gholizadeh, Hossein; Ali, Sadeeq; Shadgan, Babak
Research has tremendously contributed to the developments in both practical and fundamental aspects of limb prosthetics. These advancements are reflected in scientific articles, particularly in the most cited papers. This article aimed to identify the 100 top-cited articles in the field of limb prosthetics and to investigate their main characteristics. Articles related to the field of limb prosthetics and published in the Web of Knowledge database of the Institute for Scientific Information (ISI) from the period of 1980 to 2012. The 100 most cited articles in limb prosthetics were selected based on the citation index report. All types of articles except for proceedings and letters were included in the study. The study design and level of evidence were determined using Sackett's initial rules of evidence. The level of evidence was categorized either as a systematic review or meta-analysis, randomized controlled trial, cohort study, case-control study, case series, expert opinion, or design and development. The top cited articles in prosthetics were published from 1980 to 2012 with a citation range of 11 to 90 times since publication. The mean citation rate was 24.43 (SD 16.7) times. Eighty-four percent of the articles were original publications and were most commonly prospective (76%) and case series studies (67%) that used human subjects (96%) providing level 4 evidence. Among the various fields, rehabilitation (47%), orthopedics (29%), and sport sciences (28%) were the most common fields of study. The study established that studies conducted in North America and were written in English had the highest citations. Top cited articles primarily dealt with lower limb prosthetics, specifically, on transtibial and transradial prosthetic limbs. Majority of the articles were experimental studies.
Etter, Katherine; Borgia, Matthew; Resnik, Linda
Abstract Purpose: To quantify prescription and repair rates of prosthetic limbs in the Department of Veterans Affairs (VA) and explore differences by level, type, and age. Methods: Veterans (N = 32 440) with an initial prosthetic prescription between 2000 and 2010 were classified by amputation level and type. Annual rates of prescription and repair were calculated using person-time and compared by group. Results: Veterans with upper limb amputation had lower annual prescription and repair rates (0.28 and 0.21) compared with those with lower limb amputation (0.40 and 0.56). Myoelectric devices users had higher prescription rates. However, body-powered users had higher repair rates. Prescription and repair rates for microprocessor knee joints were higher than for fluid and friction devices. Veterans under 65 had 0.07 and 0.16 higher rates of prescription and repair than those over 65 (p < 0.0001). Conclusions: Because the VA is unconstrained by co-pays or caps, data on prosthetic prescription and repair can be used to estimate rates that might occur if national prosthetic parity laws were adopted. Given the rates found, it is likely that annual costs would exceed the typical annual and/or lifetime caps in most insurance plans. In states without prosthetic parity laws, such costs likely limit access to needed devices. Implications for Rehabilitation For the almost 2 million people in the United States living with an amputation or congenital limb loss, purchasing and maintaining a prosthetic limb can be costly, with insurances often imposing annual or lifetime caps. Data on prosthetic purchasing and repair is limited and reliant on self-reported information. Because the VA is unconstrained by co-pays or caps, claims data on prosthetic prescription and repair can be used to estimate rates that might occur if national prosthetic parity laws were adopted. Given the rates found, it is likely that annual costs would exceed the typical annual and/or lifetime caps
Sogawa, M; Kasuya, S; Yamamoto, K; Koshika, M; Oguma, F; Hayashi, J
Werner's syndrome is a rare genetic disease characterized by premature aging and scleroderma-like involvement of the skin. We report a case of aortic valve replacement for severely calcified aortic valve stenosis with a small annulus in a patient suffering from Werner's syndrome and liver cirrhosis
Cooper, Leroy L.; Mitchell, Gary F.
Background Aortic stiffness is associated with cardiovascular and cerebrovascular events and cognitive decline. This mini-review focuses on relations of aortic stiffness with microvascular dysfunction and discusses the contribution of abnormal pulsatile hemodynamics to cerebrovascular damage and cognitive decline. We also provide a rationale for considering aortic stiffness as a putative and important contributor to memory impairment in older individuals. Summary Aging is associated with stiffening of the aorta but not the muscular arteries, which reduces wave reflection and increases the transmission of pulsatility into the periphery. Aortic stiffening thereby impairs a protective mechanism that shields the peripheral microcirculation from excessive pulsatility within downstream target organs. Beyond midlife, aortic stiffness increases rapidly and exposes the cerebral microcirculation to abnormal pulsatile mechanical forces that are associated with microvascular damage and remodeling in the brain. Aortic stiffening and high-flow pulsatility are associated with alterations in the microvasculature of the brain; however, a mechanistic link between aortic stiffness and memory has not been established. We showed that in a community-based sample of older individuals, cerebrovascular resistance and white matter hyperintensities - markers of cerebrovascular remodeling and damage - mediated the relation between higher aortic stiffness and lower performance on memory function tests. These data suggest that microvascular and white matter damage associated with excessive aortic stiffness contribute to impaired memory function with advancing age. Key Messages Increasing evidence suggests that vascular etiologies - including aortic stiffness and microvascular damage - contribute to memory impairment and the pathogenesis of dementia, including Alzheimer's disease. Interventions that reduce aortic stiffness may delay memory decline among older individuals. PMID:27752478
Karsh, D L; Michaelson, S P; Langou, R A; Cohen, L S; Wolfson, S
Twenty-seven consecutive patients with an aortic valve prosthesis were evaluated with retrograde left ventricular catheterization. The prosthesis was successfully crossed, permitting hemodynamic and angiographic evaluation of function of the prosthetic valve, left ventricle and mitral valve in all 27 cases. No complications were encountered. In patients with active endocarditis or recent embolization, the retrograde technique was avoided when possible, and attempts were made to utilize other techniques for study. However, three such patients were evaluated with the retrograde technique without complication. Examination of pressure tracings and cineangiographic films suggested only minor interference with valve poppet movement induced by the catheter transversing the valve. In three cases, hemodynamic data were recorded with the catheter crossing the prosthesis at one time and a paraprosthetic valve defect at another time. Identical gradients were recorded. This series documents the safety and efficacy of the retrograde approach, which is proposed as an alternative to the transseptal technique and left ventricular puncture.
Williams, G M
Collections of serous fluid surrounding prosthetic grafts can be caused by infection or transudation of serum, and making the distinction is often troublesome. Bergamini and his colleagues developed a dog model of low-grade prosthetic graft contamination with Staphylococcus epidermatis. All animals developed evidence of graft infection, and 13 of 18 dogs developed a fluid-filled perigraft cyst. Signs of systemic infection, however, were present in only 1 animal, and the Staphylococcus epidermatis study strain was isolated from the tissue surrounding the graft in only 1 dog. The authors had to disrupt the biofilm to achieve positive cultures in 14 of 18 animals. This animal model seemed to conform to clinical experience and placed great emphasis on the role of indolent infections in the pathogenesis of perigraft fluid collection. It is equally clear that perigraft fluid collections may result from transudation of fluid through the prosthetic surfaces, which act similar to a dialysis membrane under certain circumstances. Noninfectious seromas are characterized generally by the accumulation of clear serous fluid with a protein and glucose content of serum and the lack of acute inflammatory cells when the sediment is examined. The need to distinguish between these 2 forms of fluid accumulation became important in the treatment of a 62-year-old man who was seen 2 1/2 years after the repair of an abdominal aortic aneurysm with an aortobiiliac stretch polytetrafluoroethylene (PTFE) prosthesis. There was no evidence of infection, and there was a 12 cm cystic mass surrounding a patent PTFE prosthesis.
Kubota, Takehiro; Wakasa, Satoru; Shingu, Yasushige; Matsui, Yoshiro
Unicuspid aortic valve in an adult is extremely rare. In addition, 90% of the patients with aortic coarctation are reported to die before the age 50. A 60-year-old woman was admitted to our hospital for further examination of exertional dyspnea which had begun one year before. She had been under medical treatment for hypertension since early thirties, and had been also diagnosed with moderate aortic stenosis at 50 years of age. She was at 1st diagnosed with aortic coarctation combined with bicuspid aortic valve stenosis. The aortic valve was then found unicuspid and was replaced under cardiopulmonary bypass with perfusion to both the ascending aorta and the femoral artery. Repair of aortic coarctation was performed 3 months later through left thoracotomy without extracorporeal circulation due to the rich collateral circulation. She had no postoperative complications, and hypertension as well as ankle-brachial index improved to the normal levels.
Hopkins, Richard A
Part of the ongoing argument concerning patient-prosthesis mismatch (PPM) following aortic valve replacement (AVR) is due to the perception that aortic annulus enlargement procedures increase the risk and technical difficulty of aortic valve surgery. Here, an aortic root reconstruction that involves enlargement of the annulus and tailoring of the aortic root to accommodate larger stented prostheses is presented that has been personally performed in 196 patients with no technique-related surgical deaths or complications, and thus can be carried out without additional risk. This aortic root enlargement aortoplasty and annuloplasty method can be calibrated to all AVRs involving stented manufactured prostheses when these are deemed the prosthesis of choice for the patient with a relatively small annulus and/or aortic root, severe left ventricular hypertrophy, compromised LV function or a very active lifestyle, to achieve predicted EOA values > or = 1.00 cm2/m2.
El Fattah, Hisham; Zaghloul, Ashraf; Escuin, Tomas
Objectives: After maxillectomy, prosthetic restoration of the resulting defect is an essential step because it signals the beginning of patient’s rehabilitation. The obturator used to restore the defect should be comfortable, restore adequate speech, deglutition, mastication, and be cosmetically acceptable, success will depend on the size and location of the defect and the quantity and integrity of the remaining structures, in addition to pre-prosthetic surgical preparation of defect site. Preoperative cooperation between the oncologist surgeon and the maxillofacial surgeon may allow obturation of a resultant defect by preservation of the premaxilla or the tuberosity on the defect side and maintaining the alveolar bone or teeth adjacent to the defect. This study evaluates the importance of pre-prosthetic surgical alterations at the time maxillectomy on the enhancement of the prosthetic prognoses as part of the rehabilitation of oral cancer patient. Study Design: The study was carried out between 2003- 2008, on 66 cancer patients(41 male-25 female) age ranged from 33 to 72 years, at National Cancer Institute, Cairo University, whom underwent maxillectomy surgery to remove malignant tumor as a part of cancer treatment. Patients were divided in two groups. Group A: Resection of maxilla followed by preprosthetic surgical preparation. Twenty-four cancer patients (13 male – 11 female). Group B: Resection of maxilla without any preprosthetic surgical preparation. Forty-two cancer patients (28 male-14 female). Results: Outcome variables measured included facial contour and aesthetic results, speech understandability, ability to eat solid foods, oronasal separation, socializing outside the home, and return-to-work status. Flap success and donor site morbidity were also studied. Conclusions: To improve the prosthetic restoration of maxillary defect resulting maxillary resection as part treatment of maxillofacial tumor depends on the close cooperation between
Szymański, Piotr; Hryniewiecki, Tomasz; Dąbrowski, Maciej; Sorysz, Danuta; Kochman, Janusz; Jastrzębski, Jan; Kukulski, Tomasz; Zembala, Marian
Objective To analyse the impact of postprocedural mitral regurgitation (MR), in an interaction with aortic regurgitation (AR), on mortality following transcatheter aortic valve implantation (TAVI). Methods To assess the interaction between MR and AR, we compared the survival rate of patients (i) without both significant MR and AR versus (ii) those with either significant MR or significant AR versus (iii) with significant MR and AR, all postprocedure. 381 participants of the Polish Transcatheter Aortic Valve Implantation Registry (166 males (43.6%) and 215 females (56.4%), age 78.8±7.4 years) were analysed. Follow-up was 94.1±96.5 days. Results Inhospital and midterm mortality were 6.6% and 10.2%, respectively. Significant MR and AR were present in 16% and 8.1% patients, including 3.1% patients with both significant MR and AR. Patients with significant versus insignificant AR differed with respect to mortality (log rank p=0.009). This difference was not apparent in a subgroup of patients without significant MR (log rank p=0.80). In a subgroup of patients without significant AR, there were no significant differences in mortality between individuals with versus without significant MR (log rank p=0.44). Significant MR and AR had a significant impact on mortality only when associated with each other (log rank p<0.0001). At multivariate Cox regression modelling concomitant significant MR and AR were independently associated with mortality (OR 3.2, 95% CI 1.54 to 5.71, p=0.002). Conclusions Significant MR or AR postprocedure, when isolated, had no impact on survival. Combined MR and AR had a significant impact on a patient's prognosis. PMID:26908096
Sattar, Adil; Yu, Siegfried; Koirala, Janak
We report the first case of native and recurrent prosthetic valve endocarditis with Corynebacterium CDC group G, a rarely reported cause of infective endocarditis (IE). Previously, there have been only two cases reported for prosthetic valve IE caused by these organisms. A 69-year-old female with a known history of mitral valve regurgitation presented with a 3-day history of high-grade fever, pleuritic chest pain and cough. Echocardiography confirmed findings of mitral valve thickening consistent with endocarditis, which subsequently progressed to become large and mobile vegetations. Both sets of blood cultures taken on admission were positive for Corynebacterium CDC group G. Despite removal of a long-term venous access port, the patient's presumed source of line associated bacteremia, mitral valve replacement, and aggressive antibiotic therapy, the patient had recurrence of vegetations on the prosthetic valve. She underwent replacement of her prosthetic mitral valve in the subsequent 2 weeks, before she progressed to disseminated intravascular coagulation and expired. Although they are typically considered contaminants, corynebacteria, in the appropriate clinical setting, should be recognized, identified, and treated as potentially life-threatening infections, particularly in the case of line-associated bacteremias, and native and prosthetic valve endocarditis.
Salminger, S; Roche, A D; Sturma, A; Mayer, J A; Aszmann, O C
Composite tissue transplantation and new developments in the field of prosthetics have opened new frontiers in the restoration of function among upper limb amputees. It is now possible to restore hand function in affected patients; however, the indications, advantages, and limitations for either hand transplantation or prosthetic fitting must be carefully considered depending on the level and extent of the limb loss. Hand transplantation allows comprehensive hand function to be restored, yet composite tissue transplantation comes with disadvantages, making this method a controversial topic in the hand surgical community. Alternatively, prosthetic limb replacement represents the standard of care for upper limb amputees, but results in the known limitations of function, sensation, and usage. The indication for hand transplantation or prosthetic fitting strongly depends on the level of amputation, as well as on the extent (unilateral/bilateral) of the amputation. In this review, we discuss the advantages and disadvantages of hand transplantation and prosthetic replacement for upper limb amputees in general, as well as in regard to the different levels of amputation.
Komolafe, Oluseeni; Wood, Sean; Caldwell, Ryan; Hansen, Andrew; Fatone, Stefania
Despite increasingly widespread adoption of vacuum-assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm(3) (2 in.(3)) to 197 cm(3) (12 in.(3)) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.
Sang, Yuanjun; Li, Xiang; Luo, Yun
Traditional function and comfort assessment of transradial prostheses pay scant attention to prosthetic interface. With better understanding of the biomechanics of prosthetic interface comes better efficiency and safety for interface design; in this way, amputees are more likely to accept prosthetic usage. This review attempts to provide design and selection criteria of transradial interface for prosthetists and clinicians. Various transradial socket types in the literature were chronologically reviewed. Biomechanical discussion of transradial prosthetic interface design from an engineering point of view was also done. Suspension control, range of motion, stability, as well as comfort and safety of socket designs have been considered in varying degrees in the literature. The human-machine interface design should change from traditional "socket design" to new "interface design." From anatomy and physiology to biomechanics of the transradial residual limb, the force and motion transfer, together with comfort and safety, are the two main aspects in prosthetic interface design. Load distribution and transmission should mainly rely on achieving additional skeletal control through targeted soft tissue relief. Biomechanics of the residual limb soft tissues should be studied to find the relationship between mechanical properties and the comfort and safety of soft tissues.
Al-Adhami, Ahmed; Al-Attar, Nawwar
Aortic valve replacement is no longer an operation that is approached solely through a median sternotomy. Recent advances in the fields of transcatheter valves have expanded the proportion of patients eligible for intervention. Comparisons between transcatheter valves and conventional surgery have shown non-inferiority of transcatheter valve implants in patients with a high or intermediate pre-operative predictive risk. With advances in our understanding of sutureless valves and their applicability to minimally invasive surgery, the invasiveness and trauma of surgery can be reduced with potential improvements in outcome. The strategy of care has radically changed over the last decade. PMID:27803800
Pham, T; Martin, C; Elefteriades, J; Sun, W
Studies have shown that patients harboring bicuspid aortic valve (BAV) or bovine aortic arch (BAA) are more likely than the general population to develop ascending aortic aneurysm (AsAA). A thorough quantification of the AsAA tissue properties for these patient groups may offer insights into the underlying mechanisms of AsAA development. Thus, the objective of this study was to investigate and compare the mechanical and microstructural properties of aortic tissues from AsAA patients with and without concomitant BAV or BAA. AsAA (n=20), BAV (n=20) and BAA (n=15) human tissues were obtained from patients who underwent elective AsAA surgery. Planar biaxial and uniaxial failure tests were used to characterize the mechanical and failure properties of the tissues, respectively. Histological analysis was performed to detect medial degenerative characteristics of aortic aneurysm. Individual layer thickness and composition were quantified for each patient group. The circumferential stress-strain response of the BAV samples was stiffer than both AsAA (p=0.473) and BAA (p=0.152) tissues at a low load. The BAV samples were nearly isotropic, while AsAA and BAA samples were anisotropic. The areal strain of BAV samples was significantly less than that of AsAA (p=0.041) and BAA (p=0.004) samples at a low load. The BAA samples were similar to the AsAA samples in both mechanical and failure properties. On the microstructural level, all samples displayed moderate medial degeneration, characterized by elastin fragmentation, cell loss, mucoid accumulation and fibrosis. The ultimate tensile strength of BAV and BAA sampleswere also found to decrease with age. Overall, the BAV samples were stiffer than both AsAA and BAA samples, and the BAA samples were similar to the AsAA samples. The BAV samples were thinnest, with less elastin than AsAA and BAA samples, which may be attributed to the loss of extensibility of these tissues at a low load. No apparent difference in failure mechanics among
Souza, André Luiz Silveira; Salgado, Constantino González; Mourilhe-Rocha, Ricardo; Mesquita, Evandro Tinoco; Lima, Luciana Cristina Lima Correia; de Mattos, Nelson Durval Ferreira Gomes; Rabischoffsky, Arnaldo; Fagundes, Francisco Eduardo Sampaio; Colafranceschi, Alexandre Siciliano; Carvalho, Luiz Antonio Ferreira
Background Transcatheter aortic valve implantation has become an option for high-surgical-risk patients with aortic valve disease. Objective To evaluate the in-hospital and one-year follow-up outcomes of transcatheter aortic valve implantation. Methods Prospective cohort study of transcatheter aortic valve implantation cases from July 2009 to February 2015. Analysis of clinical and procedural variables, correlating them with in-hospital and one-year mortality. Results A total of 136 patients with a mean age of 83 years (80-87) underwent heart valve implantation; of these, 49% were women, 131 (96.3%) had aortic stenosis, one (0.7%) had aortic regurgitation and four (2.9%) had prosthetic valve dysfunction. NYHA functional class was III or IV in 129 cases (94.8%). The baseline orifice area was 0.67 ± 0.17 cm2 and the mean left ventricular-aortic pressure gradient was 47.3±18.2 mmHg, with an STS score of 9.3% (4.8%-22.3%). The prostheses implanted were self-expanding in 97% of cases. Perioperative mortality was 1.5%; 30-day mortality, 5.9%; in-hospital mortality, 8.1%; and one-year mortality, 15.5%. Blood transfusion (relative risk of 54; p = 0.0003) and pulmonary arterial hypertension (relative risk of 5.3; p = 0.036) were predictive of in-hospital mortality. Peak C-reactive protein (relative risk of 1.8; p = 0.013) and blood transfusion (relative risk of 8.3; p = 0.0009) were predictive of 1-year mortality. At 30 days, 97% of patients were in NYHA functional class I/II; at one year, this figure reached 96%. Conclusion Transcatheter aortic valve implantation was performed with a high success rate and low mortality. Blood transfusion was associated with higher in-hospital and one-year mortality. Peak C-reactive protein was associated with one-year mortality. PMID:27192383
Iwata, Shinichi; Walker, Marcella Donovan; Di Tullio, Marco R.; Hyodo, Eiichi; Jin, Zhezhen; Liu, Rui; Sacco, Ralph L.; Homma, Shunichi
Context: It is unclear whether cardiovascular disease is present in primary hyperparathyroidism (PHPT). Objective: Aortic valve structure and function were compared in PHPT patients and population-based controls. Design: This is a case-control study. Setting: The study was conducted in a university hospital metabolic bone disease unit. Participants: We studied 51 patients with PHPT and 49 controls. Outcome Measures: We measured the aortic valve calcification area and the transaortic pressure gradient. Results: Aortic valve calcification area was significantly higher in PHPT (0.24 ± 0.02 vs. 0.17 ± 0.02 cm2, p<0.01), although there was no difference in the peak transaortic pressure gradient, a functional measure of valvular calcification (5.6 ± 0.3 vs. 6.0 ± 0.3 mm Hg, P = 0.39). Aortic valve calcification area was positively associated with PTH (r = 0.34; P < 0.05) but not with serum calcium, phosphorus, or 25-hydroxyvitamin D levels or with calcium-phosphate product. Serum PTH level remained an independent predictor of aortic valve calcification area after adjustment for age, sex, body mass index, smoking status, history of hypercholesterolemia and hypertension, and estimated glomerular filtration rate. Conclusions: Mild PHPT is associated with subclinical aortic valve calcification. PTH, but not serum calcium concentration, predicted aortic valve calcification. PTH was a more important predictor of aortic valve calcification than well-accepted cardiovascular risk factors. PMID:22031523
Karmy-Jones, Riyad; Teso, Desarom; Jackson, Nicole; Ferigno, Lisa; Bloch, Robert
Traumatic thoracic aortic injury remains a major cause of death following motor vehicle accidents. Endovascular approaches have begun to supersede open repair, offering the hope of reduced morbidity and mortality. The available endovascular technology is associated with specific anatomic considerations and complications. This paper will review the current status of endovascular management of traumatic thoracic aortic injuries. PMID:21160721
To restore meaningful vision to blind patients requires a retinal prosthetic device that can generate precise spiking patterns in retinal ganglion cells. We sought to develop a stimulus protocol that could reliably elicit one ganglion cell spike for every stimulation pulse over a broad frequency range. Small tipped platinum-iridium epiretinal electrodes were used to deliver biphasic cathodal electrical stimulus pulses at frequencies ranging from 10 to 125 Hz. We measured spiking responses with on-cell patch clamp from ganglion cells in the flat mount rabbit retina, identified by light response and morphology. Single electrical 30 pA cathodal pulses of 1 msec duration elicited both by direct electrical activation of ganglion cells and synaptic excitation and inhibition. Direct activation elicited a single spike that followed the onset of the cathodic pulse by about 100 μsec; presynaptic activation typically elicited multiple spikes which began after 10 msec and could persist for more than 50 ms depending on pulse amplitude levels. Limiting the pulse duration to 100 μsec eliminated all presynaptic activity: only ganglion cells were driven. Each pulse elicited a single pike for stimulation frequencies tested from 10 to125 Hz. Our ability to elicit one spike per pulse provides many important advantages: This protocol can be used to generate temporal patterns of activity in ganglion cells with precision. We can now mimic normal light evoked responses for either transient or sustained cells, and we can modulate spike frequency to simulate changes in intensity, contrast, motion and other essential cues in the visual environment.
Tevell, S; Hellmark, B; Nilsdotter-Augustinsson, Å; Söderquist, B
Further knowledge about the clinical and microbiological characteristics of prosthetic joint infections (PJIs) caused by different coagulase-negative staphylococci (CoNS) may facilitate interpretation of microbiological findings and improve treatment algorithms. Staphylococcus capitis is a CoNS with documented potential for both human disease and nosocomial spread. As data on orthopaedic infections are scarce, our aim was to describe the clinical and microbiological characteristics of PJIs caused by S. capitis. This retrospective cohort study included three centres and 21 patients with significant growth of S. capitis during revision surgery for PJI between 2005 and 2014. Clinical data were extracted and further microbiological characterisation of the S. capitis isolates was performed. Multidrug-resistant (≥3 antibiotic groups) S. capitis was detected in 28.6 % of isolates, methicillin resistance in 38.1 % and fluoroquinolone resistance in 14.3 %; no isolates were rifampin-resistant. Heterogeneous glycopeptide-intermediate resistance was detected in 38.1 %. Biofilm-forming ability was common. All episodes were either early post-interventional or chronic, and there were no haematogenous infections. Ten patients experienced monomicrobial infections. Among patients available for evaluation, 86 % of chronic infections and 70 % of early post-interventional infections achieved clinical cure; 90 % of monomicrobial infections remained infection-free. Genetic fingerprinting with repetitive sequence-based polymerase chain reaction (rep-PCR; DiversiLab®) displayed clustering of isolates, suggesting that nosocomial spread might be present. Staphylococcus capitis has the potential to cause PJIs, with infection most likely being contracted during surgery or in the early postoperative period. As S. capitis might be an emerging nosocomial pathogen, surveillance of the prevalence of PJIs caused by S. capitis could be recommended.
Geertzen, J H B; Gankema, H G J; Groothoff, J W; Dijkstra, P U
The aim of this study was to assess consumer/patient satisfaction with the services of the prosthetics and orthotics (P&O) facilities in the north of the Netherlands, using a modified SERVQUAL questionnaire. In this questionnaire, consumer interests and experiences are assessed on a 5-point Likert scale. The questionnaire consisted of 30 items covering 5 domains: tangibles, reliability, responsiveness, assurance and empathy and the consumers were invited to give an overall rating of satisfaction (scale 1-10). Consumers of four P&O facilities were asked to participate. In total 496 consumers (aged 0-76) participated; 279 consumers received orthopaedic shoes and 217 consumers received either prostheses or orthoses. An overall satisfaction rating of 8 or higher was given by 75% of the consumers (mean 8.0; sd=1.2). Consumers were defined as satisfied with the services of the P&O facility if they rated their experiences on a certain item equal or better than their rating of its importance. Eighty-five percent (85%) or more of the consumers were satisfied with the P&O facility in 24 of the 30 (80%) items of the SERVQUAL questionnaire. Of the 6 less unsatisfying items, 3 were related to the domain "tangibles", 2 were related to the domain "empathy" and 1 to the domain "responsiveness". The management of the P&O facility can use this information to increase consumer satisfaction by improving quality and service at these items. In general, the degree of consumer overall satisfaction was not related to age, gender, and type of assistive device or "length of relationship of consumer" and P&O facility. Only consumers who received orthopaedic shoes rated their overall satisfaction significantly lower (0.3) than consumers who received other types of devices. This difference is clinically not relevant.
Arutiunov, A S; Kitsul, I S; Lebedenko, I Iu; Gazazian, V V
Expericnce of working out of tools of quality management of maxillofacial prosthetics which can be applied in clinical practice of maxillofacial orthopedy is presented. The fragment of the algorithm of maxillofacial prosthetics developed by authors is presented.
Obstructive sleep apnea (OSA) is a common disease, often present in "cardiovascular or metabolic patients". OSA favours the occurrence of arterial lesions, all the more if severe. There is a strong relationship between OSA and acute aortic syndromes (AAS). This relationship is in part explained by aortic dilatation linked to OSA. The presence of repeated episodes of sudden variation of transmural pressure applied on aortic wall seems to play a major role in this dilatation. All OSA patients should have a search of aortic dilatation by ultrasound (at a thoracic and abdominal level). Also, screening of OSA should be systematically performed in patients with aortic disease. The effect of continuous positive airway pressure in apneic patients with AAS has not been studied.
Lamanna, Arvin; Fayers, Trevor; Clarke, Sophie; Parsonage, William
Osteogenesis imperfecta (OI) is an inheritable connective tissue disorder caused by defective collagen synthesis with the principal manifestations of bone fragility. OI has been associated with left sided valvular regurgitation and aortic dilation. Valve and aortic surgery are technically feasible in patients with OI but are inherently high risk due to the underlying connective tissue defect. This report reviews the valvular and aortic pathology associated with OI and their management. We describe two cases of patients with OI who have significant aortic and mitral valve regurgitation, one of whom has been managed conservatively and the other who has undergone successful mitral valve repair and aortic valve replacement. The latter case represents the fifth case of mitral valve repair in a patient with OI reported in the medical literature.
Sundararajan, Sabapathy; Teferi, Abraham
Introduction: Granulicatella adiacens is a Gram-positive bacteria and a normal component of oral flora. It is also found in dental plaques, endodontic abscesses and can rarely cause more serious infections. Case presentation: We describe a prosthetic hip joint infection in an 81-year-old fit and healthy man due to Granulicatella adiacens who underwent a prolonged dental intervention two days earlier without antibiotic prophylaxis. The infection was successfully treated with surgical intervention and a combination of antibiotics. The patient eventually succumbed to severe community-acquired pneumonia two months later. Conclusion: Current guidelines recommend avoidance of antibiotic prophylaxis prior to dental treatment in patients who have no co-morbidities and no prior operation on the index prosthetic joint. This case report indicates that infections of prosthetic joints may be associated with dental procedures even in fit and healthy patients without the recognized risk factors. PMID:28348763
Fukuda, Osamu; Bu, Nan; Ueno, Naohiro
Electromyogram (EMG) signals can be measured from human muscles and can be used to anticipate movements. In fact, many researchers have tried to use these signals as an interface tool for a prosthetic hand. However, most of these studies focused on the discrimination performance of the EMG signals, and only discussed the control method for the prosthetic hand. Evaluation of the operating performance was seldom reported. This paper proposes a virtual prosthetic control system and presents the analyses of a grasp motion under two different EMG control methods: on/off control and proportional control. The proportional control is able to proportionally control the grasping velocity based on the amplitude of the EMG signal. The on/off control controls the hand at a uniform rate while the amplitude of the EMG signal is greater than a predefined threshold. We conducted experiments with five subjects, and confirmed the usefulness of the developed system.
Flowers, D. A.; Ayres, V. M.; Delgado-Rivera, R.; Ahmed, I.; Meiners, S. A.
Preliminary data from in-vivo investigations (rat model) suggest that a nanofiber prosthetic device of fibroblast growth factor-2 (FGF-2)-modified nanofibers can correctly guide regenerating axons across an injury gap with aligned functional recovery. Scanning Probe Recognition Microscopy (SPRM) with auto-tracking of individual nanofibers is used for investigation of the key nanoscale properties of the nanofiber prosthetic device for central nervous system tissue engineering and repair. The key properties under SPRM investigation include nanofiber stiffness and surface roughness, nanofiber curvature, nanofiber mesh density and porosity, and growth factor presentation and distribution. Each of these factors has been demonstrated to have global effects on cell morphology, function, proliferation, morphogenesis, migration, and differentiation. The effect of FGF-2 modification on the key nanoscale properties is investigated. Results from the nanofiber prosthetic properties investigations are correlated with astrocyte response to unmodified and FGF-2 modified scaffolds, using 2D planar substrates as a control.
Goncalves, Thais Marques Simek Vega; de Oliveira, Jonas Alves; Sanchez-Ayala, Alfonso; Rodrigues Garcia, Renata Cunha Matheus
The aim of this case report was to describe the surgical removal of an extensive mandibular torus and the conventional prosthetic treatment that was performed. During surgery, the torus was exposed by a intrasulcular lingual incision from molar to contralateral molar side and displacement of the mucoperiosteal flap. The bone volume was carefully removed in three separate blocks by sculpting a groove in the superior lesion area and chiseling. After a 30-day postoperative period, a prosthetic treatment was performed using a conventional distal extension removable partial denture. The patient's esthetic and functional expectations were achieved. The surgical procedure and prosthetic treatment performed in the treatment of the mandibular torus in this clinical case is a viable treatment that produces few complications and re-establishes normal masticatory function.
Kallenbach, K; Schwill, S; Karck, M
Marfan syndrome is a hereditary disease with a prevalence of 2-3 in 10,000 births, leading to a fibrillin connective tissue disorder with manifestations in the skeleton, eye, skin, dura mater and in particular the cardiovascular system. Since other syndromes demonstrate similar vascular manifestations, but therapy may differ significantly, diagnosis should be established using the revised Ghent nosology in combination with genotypic analysis in specialized Marfan centres. The formation of aortic root aneurysms with the subsequent risk of acute aortic dissection type A (AADA) or aortic rupture limits life expectancy in patients with Marfan syndrome. Therefore, prophylactic replacement of the aortic root needs to be performed before the catastrophic event of AADA can occur. The goal of surgery is the complete resection of pathological aortic tissue. This can be achieved with excellent results by using a (mechanically) valved conduit that replaces both the aortic valve and the aortic root (Bentall operation). However, the need for lifelong anticoagulation with Coumadin can be avoided using the aortic valve sparing reimplantation technique according to David. The long-term durability of the reconstructed valve is favourable, and further technical improvements may improve longevity. Although results of prospective randomised long-term studies comparing surgical techniques are lacking, the David operation has become the surgical method of choice for aortic root aneurysms, not only at the Heidelberg Marfan Centre. Replacement of the aneurysmal dilated aortic arch is performed under moderate hypothermic circulatory arrest combined with antegrade cerebral perfusion using a heart-lung machine, which we also use in thoracic or thoracoabdominal aneurysms. Close post-operative follow-up in a Marfan centre is pivotal for the early detection of pathological changes on the diseased aorta.
Kapustin, Andrew J; Litt, Harold I
Diagnostic imaging for aortic dissection has dramatically changed in recent years. Previously, imaging consisted of conventional X-ray radiography, followed by invasive catheter angiography. Now imaging of dissection is performed primarily with multidetector CT, and to a lesser extent, with ultrasound and MRI. Catheter angiography is used primarily as a means of treating complications. Which modality to choose depends on patient factors, physician preference, and differences in availability of state-of-the-art equipment. All three modalities are highly accurate in experienced hands and have revolutionized the detection and evaluation of this condition.
Cunningham, Anthony J.
The objectives of the review are to highlight the clinical characteristics of the patient population; to assess multivariate risk factor analysis and the invasive/non-invasive techniques available for risk factor identification and management in this high-risk surgical population; to assess the major hemodynamic, metabolic, and regional blood flow changes associated with aortic cross-clamping/unclamping procedures and techniques for their modification or attenuation; and to assess the influence of perioperative anesthetic techniques and management on patient outcome. PMID:1814052
Attaran, Saina; Chukwuemeka, Andrew; Punjabi, Prakash P.; Anderson, Jon
A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was ‘do all patients with prosthetic valve endocarditis need surgery?’ Seventeen papers were found using the reported search that 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. These studies compared the outcome and survival between surgically and non-surgically treated patients with prosthetic valve endocarditis. Of these studies, two were prospective observational studies and the rest were retrospective studies. The results of most of these papers were in accordance with the guidelines of the American College of Cardiology and American Heart association. These studies showed that unless a patient is not a surgical candidate, an operation is the treatment of choice in prosthetic valve endocarditis. Surgery should be performed as soon as possible, particularly in haemodynamically unstable patients and those who develop complications such as heart failure, valvular dysfunction, regurgitation/obstruction, dehiscence and annular abscess. In addition to the above indications and cardiac/valvularrelated complications of prosthetic valve endocarditis, infection with Staphylococcus aureus plays an important role in the outcome, and the presence of this micro-organism should be considered an urgent surgical indication in the treatment of prosthetic valve endocarditis. Surgery should be performed before the development of any cerebral or other complications. In contrast, in stable patients with other micro-organisms, particularly those with organisms sensitive to antibiotic treatment who have no structural valvular damage or cardiac complications, surgery can be postponed. The option of surgical intervention can also be revisited if there is a change in response to the treatment. This
Marwan, Mohamed; Achenbach, Stephan
Catheter-based aortic valve implantation is increasingly being performed in high-risk patients with symptomatic aortic valve stenosis. For successful planning of the procedure, CT has been shown to provide crucial information concerning the aortic root as well as the peripheral access vessels. This article illustrates the increasing role of CT before transcatheter aortic valve implantation.
Chang, Rei-Yeuh; Chen, Chien-Chang; Hsu, Wei-Pang; Hsiao, Pei-Ching; Tsai, Han-Lin; Hsiao, Ping-Gune; Wu, Jiann-Der; Guo, How-Ran
Abstract Background: Avulsion of the aortic valve commissure as a cause of acute aortic valve regurgitation is mostly due to trauma, infective endocarditis, or ascending aortic dissection. Nontraumatic avulsion of the aortic valve commissure is very rare. We reviewed the literature and analyzed potential risk factors of nontraumatic avulsion. Case presentation: An 80-year-old male with hypertension was seen in the emergency department with acute onset dyspnea. Echocardiogram revealed left ventricular hypertrophy with adequate systolic function, prolapse of the noncoronary cusp, and incomplete coaptation of the right coronary and noncoronary cusps with severe aortic valve regurgitation. Surgery revealed an avulsion between the left coronary and noncoronary cusps. Histopathology examination of the aortic valve showed myxoid degeneration, fibrosis, and calcification. Examination of the ascending aorta revealed myxoid degeneration and fragmentation of elastic fibers. Aortic valve replacement was performed, and the patient was alive and well 4 years after surgery. A review of the literature showed that more than three-fourths of the similar cases occurred in males, and about half in patients with hypertension and those 60 years of age or older. Conclusions: In the case of acute aortic regurgitation without a history of trauma, infection, or valvotomy, when 2 prolapsed aortic cusps are observed by echocardiography in the absence of an intimal tear of the ascending aorta, an avulsion of the aortic commissure should be suspected, especially in males with hypertension who are 60 years of age or older. PMID:27749570
Tatar, Cihad; Tüzün, İshak Sefa; Karşıdağ, Tamer; Kızılkaya, Mehmet Celal; Yılmaz, Erdem
Background: Incarcerated inguinal hernia is a commonly encountered urgent surgical condition, and tension-free repair is a well-established method for the treatment of non-complicated cases. However, due to the risk of prosthetic material-related infections, the use of mesh in the repair of strangulated or incarcerated hernia has often been subject to debate. Recent studies have demonstrated that biomaterials represent suitable materials for performing urgent hernia repair. Certain studies recommend mesh repair only for cases where no bowel resection is required; other studies, however, recommend mesh repair for patients requiring bowel resection as well. Aim: The aim of this study was to compare the outcomes of different surgical techniques performed for strangulated hernia, and to evaluate the effect of mesh use on postoperative complications. Study Design: Retrospective cross-sectional study. Methods: This retrospective study was performed with 151 patients who had been admitted to our hospital’s emergency department to undergo surgery for a diagnosis of incarcerated inguinal hernia. The patients were divided into two groups based on the applied surgical technique. Group 1 consisted of 112 patients treated with mesh-based repair techniques, while Group 2 consisted of 39 patients treated with tissue repair techniques. Patients in Group 1 were further divided into two sub-groups: one consisting of patients undergoing bowel resection (Group 3), and the other consisting of patients not undergoing bowel resection (Group 4). Results: In Group 1, it was observed that eight (7.14%) of the patients had wound infections, while two (1.78%) had hematomas, four (3.57%) had seromas, and one (0.89%) had relapse. In Group 2, one (2.56%) of the patients had a wound infection, while three (7.69%) had hematomas, one (2.56%) had seroma, and none had relapses. There were no statistically significant differences between the two groups with respect to wound infection, seroma
Park, Ju Hyun; Song, Sung Gook; Kim, Jeong Su; Park, Yong Hyun; Kim, Jun; Choo, Ki Seuk; Kim, June Hong; Lee, Sang Kwon
Aortic coarctation is usually diagnosed and repaired in childhood and early adulthood. Survival of a patient with an uncorrected coarctation to more than 70 years of age is extremely unusual, and management strategies for these cases remain controversial. We present a case of a 75-year-old woman who was first diagnosed with aortic coarctation and severe aortic valve stenosis 5 years ago and who underwent a successful one-stage repair involving valve replacement and insertion of an extra-anatomical bypass graft from the ascending to the descending aorta. PMID:22363387
Illuminati, Giulio; Pacilè, Maria Antonietta; Palumbo, Piergaspare; Salvatori, Filippo Maria; Vietri, Francesco
False aneurysm degeneration is a known complication of patch aortoplasty for coarctation of the aortic isthmus. Open surgical treatment consists of prosthetic graft repair of the involved aorta, often requires circulatory arrest to achieve a safe proximal aortic control and perform proximal anastomosis, and finally is associated with substantial perioperative morbidity. Endografting of the diseased aorta is a valuable alternative to open repair, when feasible, with good short and long term results. We now report one more case of false aneurysm ten years after Dacron patch aortoplasty for isthmic coarctation in a 26-year-old woman, successfully treated by endovascular repair via the left common iliac artery, and a complete exclusion of the aneurysm at two year follow-up.
Deogade, Suryakant C; Vinay, S; Naidu, Sonal
Oral disorders are cumulative throughout life and hence unfavourable outcomes are likely to be greatest among the elderly. A descriptive cross-sectional study was conducted among institutionalized geriatric population in old-age homes of Jabalpur city, Madhya Pradesh, to assess their prosthetic status and prosthetic needs. A cross-sectional survey was conducted in all the four old-age homes of Jabalpur city, Madhya Pradesh state, India. All residents aged 60 years and above formed the study population. The recording of prosthetic status and prosthetic needs was carried out according to the World Health Organisation (WHO) Oral Health Assessment Form (1997). A total of 224 individuals were included in the study of which 123 were females and 101 were males. Seventy five percent of the females and 55 % of the males had no prostheses in their upper arch and 61 % of the females and 76 % of the males had no prostheses in their lower arch. More number of males presented with 'Bridges' in their upper arch when compared to females (P value = 0.006). Highest prosthetic need in males was multi-unit prosthesis (42 % in upper arch and 41 % in lower arch) whereas, females' required full prosthesis (39 % in both the upper arch and lower arches). Ageing presents some formidable challenges, particularly with the institutionalised. This study clearly demonstrates a high insufficiency of prosthetic care among the institutionalized elderly population. Any preparation towards the provision of oral health care should not be limited to treatment alone but, more importantly focus on empowering this elderly community with information and education programmes.
Antunes, M J
The favorable results of mitral valvuloplasty when compared with valve replacement have renewed the interest of many surgeons in aortic valve repair. However, these efforts have, for the most part, been unsuccessful. Also, the results of aortic valve replacement are usually better than those of mitral valve replacement. Yet, some patients appear to derive benefit from a conservative aortic valve procedure. The best examples are mild or moderate aortic valve disease associated with mitral valve or coronary artery disease, which constitute the primary indication for operation, where "prophylactic" aortic valve replacement does not appear justifiable. Other possible indications for aortic valvuloplasty includes patient's lack of compliance or contraindication to anticoagulation in young patients. Senile aortic stenosis, in very old patients with a small annulus, preserved leaflet morphology and nonsignificant commissural fusion should be considered for repair. However, since the procedure is not easily reproducible and the results not uniformly predictable, it cannot be recommended for generalized use. Nonetheless, experienced surgeons should be encouraged to continue these efforts.
Park, Sung Hun; Rha, Seung-Woon
Endovascular aortic repair (EVAR) was relatively safe, and became a widely performed procedure. If aortic dissection (AD) occurred in patient with previous EVAR, it could cause fatal complications like endograft collapse. Surgical treatment was limited in this situation for comorbidities and complex anatomies. Here we report a rare case of acute type B AD developed following trans-radial coronary intervention in a patient with previous EVAR of abdominal aortic aneurysm, which was treated with thoracic EVAR. PMID:28377913
Jain, Rakesh; Kader, Muneer; Sajeev, C.G.; Krishnan, M.N.
Bicuspid aortic valve is the most common congenital cardiac malformation, affecting 1%–2% of the population. Among various complications, incidence of infective endocarditis (IE) in the bicuspid aortic valve population is high with higher rate of periannular extension resulting in conduction disturbances. Here we are reporting a rare case of infective endocarditis of bicuspid aortic valve presented with alternating bundle branch block. PMID:26138186
Wang, Qian; Kodali, Susheel; Primiano, Charles; Sun, Wei
Objectives Aortic root rupture is one of the most severe complications of transcatheter aortic valve implantation (TAVI). The mechanism of this adverse event remains mostly unknown. The purpose of this study was to obtain a better understanding of the biomechanical interaction between the tissue and stent for patients with a high risk of aortic rupture. Methods We simulated the stent deployment process of three TAVI patients with high aortic rupture risk using finite element method. The first case was a retrospective analysis of an aortic rupture case, while the other two cases were prospective studies, which ended with one cancelled procedure and one successful TAVI. Simulation results were evaluated for the risk of aortic root rupture, as well as coronary artery occlusion, and paravalvular leak. Results For Case 1, the simulated aortic rupture location was the same as clinical observations. From the simulation results, it can be seen that the large calcified spot on the interior of the left coronary sinus between coronary ostium and the aortic annulus was pushed by the stent, causing the aortic rupture. For Case 2 and Case 3, predicated results from the simulations were presented to the clinicians at pre-procedure meetings; and they were in agreement with clinician’s observations and decisions. Conclusions Our results indicated that the engineering analysis could provide additional information to help clinicians evaluate complicated, high risk aortic rupture cases. Since a systematic study of a large patient cohort of aortic rupture is currently not available (due to the low occurrence rate) to clearly understand underlying rupture mechanisms, case by case engineering analysis is recommended for evaluating patient-specific aortic rupture risk. PMID:24736808
Ngow, H A; Wan Khairina, W M N
Bacillus cereus endocarditis is rare. It has been implicated in immunocompromised individuals, especially in intravenous drug users as well as in those with a cardiac prosthesis. The patient was a 31-year-old ex-intravenous drug addict with a past history of staphylococcal pulmonary valve endocarditis, who presented with symptoms of decompensated cardiac failure. Echocardiography showed severe aortic regurgitation with an oscillating vegetation seen on the right coronary cusp of the aortic valve. The blood cultures grew Bacillus cereus. We report this as a rare case of Bacillus cereus endocarditis affecting a native aortic valve.
Kuhelj, Dimitrij; Berden, Pavel; Podnar, Tomaž
We report a case of aortic pseudoaneurysm associated with a fractured bare Cheatham-Platinum stent following stenting for aortic coarctation. These complications were recognised 6 years after the implantation procedure and were successfully managed by percutaneous stent graft implantation. Staged approach for stent dilatation might prevent development of aortic pseudoaneurysms. In addition, careful follow-up is warranted after stenting for aortic coarctation, particularly in patients with recognised aortic wall injury.
Tseng, E E; Lee, C A; Cameron, D E; Stuart, R S; Greene, P S; Sussman, M S; Watkins, L; Gardner, T J; Baumgartner, W A
OBJECTIVE: The current study was undertaken to determine long-term results of aortic valve replacement (AVR) in the elderly, to ascertain predictors of poor outcome, and to assess quality of life. SUMMARY BACKGROUND DATA: Aortic valve replacement is the procedure of choice for elderly patients with aortic valve disease. The number of patients aged 70 and older requiring AVR continues to increase. However, controversy exists as to whether surgery devoted to this subset reflect a cost-effective approach to attaining a meaningful quality of life. METHODS: This study reviews data on 247 patients aged 70 to 89 years who underwent isolated AVR between 1980 and 1995; there were 126 men (51%) and 121 women (49%). Follow-up was 97% complete (239/247 patients) for a total of 974.9 patient-years. Mean age was 76.2 +/- 4.8 years. Operative mortality and actuarial survival were determined. Patient age, gender, symptoms, associated diseases, prior conditions, New York Health Association class congestive heart failure, native valve disease, prosthetic valve type, preoperative catheterization data, and early postoperative conditions were analyzed as possible predictors of outcome. Functional recovery was evaluated using the SF-36 quality assessment tool. RESULTS: Operative mortality was 6.1% (15/247). Multivariate logistic regression showed that poor left ventricular function and preoperative pacemaker insertion were independent predictors of early mortality. After surgery, infection was predictive of early mortality. Overall actuarial survival at 1, 5, and 10 years was 89.5 +/- 2% (198 patients at risk), 69.3 +/- 3.4% (89 patients at risk), and 41.2 +/- 6% (13 patients at risk), respectively. Cox proportional hazards model showed that chronic obstructive pulmonary disease and urgency of operation were independent predictors of poor long-term survival. Postoperative renal failure also was predictive of poor outcome. Using the SF-36 quality assessment tool, elderly patients who
Williams, Matthew R.; Walter, Wayne
The loss of a hand can greatly affect quality of life. A prosthetic device that can mimic normal hand function is very important to physical and mental recuperation after hand amputation, but the currently available prosthetics do not fully meet the needs of the amputee community. Most prosthetic hands are not dexterous enough to grasp a variety of shaped objects, and those that are tend to be heavy, leading to discomfort while wearing the device. In order to attempt to better simulate human hand function, a dexterous hand was developed that uses an over-actuated mechanism to form grasp shape using intrinsic joint mounted motors in addition to a finger tendon to produce large flexion force for a tight grip. This novel actuation method allows the hand to use small actuators for grip shape formation, and the tendon to produce high grip strength. The hand was capable of producing fingertip flexion force suitable for most activities of daily living. In addition, it was able to produce a range of grasp shapes with natural, independent finger motion, and appearance similar to that of a human hand. The hand also had a mass distribution more similar to a natural forearm and hand compared to contemporary prosthetics due to the more proximal location of the heavier components of the system. This paper describes the design of the hand and controller, as well as the test results. PMID:25790306
Hagemann, Jürgen Benjamin; Essig, Andreas; Herrmann, Manuel; Liebold, Andreas; Quader, Mohamed Abo
Corynebacterium (C.) kroppenstedtii is a rarely detected agent of bacterial infections in humans. Here, we describe the first case of prosthetic valve endocarditis caused by C. kroppenstedtii. Application of molecular methods using surgically excised valve tissue was a cornerstone for the establishment of the microbiological diagnosis, which is crucial for targeted antimicrobial treatment.
Houdek, Matthew T; Kralovec, Michael E; Andrews, Karen L
The hemipelvectomy, most commonly performed for pelvic tumor resection, is one of the most technically demanding and invasive surgical procedures performed today. Adequate soft tissue coverage and wound complications after hemipelvectomy are important considerations. Rehabilitation after hemipelvectomy is optimally managed by a multidisciplinary integrated team. Understanding the functional outcomes for this population assists the rehabilitation team to counsel patients, plan goals, and determine discharge needs. The most important rehabilitation goal is the optimal restoration of the patient's functional independence. Factors such as age, sex, etiology, level of amputation, and general health play important roles in determining prosthetic use. The three main criteria for successful prosthetic rehabilitation of patients with high-level amputation are comfort, function, and cosmesis. Recent advances in hip and knee joints have contributed to increased function. Prosthetic use after hemipelvectomy improves balance and decreases the need for a gait aid. Using a prosthesis helps maintain muscle strength and tone, cardiovascular health, and functional mobility. With new advances in prosthetic components, patients are choosing to use their prostheses for primary mobility.
Students in the Orthotics and Prosthetics Technician Program at Oklahoma State University (OSU)-Okmulgee are provided with opportunities to develop multiple skill sets coveted by employers that will land them jobs in the industry as technicians, fitters or pedorthists. The program was recently restructured to become a technically based orthotic…
Miro, Rebecca Maria
Students who graduate from a practitioner program in prosthetics & orthotics must achieve certification in order to obtain licensure and practice independently in 16 states. In states where licensure is not mandatory, graduates may choose to pursue certification in order assure patients that they are practicing at the highest level as well as…
Belcher, Jewell G., Jr.; Vest, Thomas W.
Prosthetic hand with quick-grip/quick-release lever broadens range of specialized functions available to lower-arm amputee by providing improved capabilities for gripping rods, tools, handles, and like. Includes two stationary lower fingers opposed by one pivoting upper finger. Lever operates in conjunction with attached bracket.
Abid, Shazia; El-Hayek, Kevin
This article reviews the ever-increasing number of prosthetic devices--both synthetic mesh and biologic grafts--now in use for abdominal wall reconstruction. It also introduces a novel hybrid synthetic/biologic graft (Zenapro) and suture passer device (Novapass).
Donahue, T J
This article presents a history of the Journal of Prosthetic Dentistry from its inception to the present day. Particular emphasis is given to those people who worked towards its formation, and those changes that were made over the years in order to improve it as a medium for the exchange of ideas in prosthodontics.
Chen, S. C.; Suaning, G. J.; Morley, J. W.; Lovell, N. H.
Human trials of prototype visual prostheses have successfully elicited visual percepts (phosphenes) in the visual field of implant recipients blinded through retinitis pigmentosa and age-related macular degeneration. Researchers are progressing rapidly towards a device that utilizes individual phosphenes as the elementary building blocks to compose a visual scene. This form of prosthetic vision is expected, in the near term, to have low resolution, large inter-phosphene gaps, distorted spatial distribution of phosphenes, restricted field of view, an eccentrically located phosphene field and limited number of expressible luminance levels. In order to fully realize the potential of these devices, there needs to be a training and rehabilitation program which aims to assist the prosthesis recipients to understand what they are seeing, and also to adapt their viewing habits to optimize the performance of the device. Based on the literature of psychophysical studies in simulated and real prosthetic vision, this paper proposes a comprehensive, theoretical training regime for a prosthesis recipient: visual search, visual acuity, reading, face/object recognition, hand-eye coordination and navigation. The aim of these tasks is to train the recipients to conduct visual scanning, eccentric viewing and reading, discerning low-contrast visual information, and coordinating bodily actions for visual-guided tasks under prosthetic vision. These skills have been identified as playing an important role in making prosthetic vision functional for the daily activities of their recipients.
van Keeken, Helco G; Vrieling, Aline H; Hof, At L; Postema, Klaas; Otten, Bert
In this study, conditions that enable a prosthetic knee flexion strategy in transfemoral amputee subjects during obstacle avoidance were investigated. This study explored the hip torque principle and the static ground principle as object avoidance strategies. A prosthetic limb simulator device was used to study the influence of applied hip torques and static ground friction on the prosthetic foot trajectory. Inverse dynamics were used to calculate the energy produced by the hip joint. A two-dimensional forward dynamics model was used to investigate the relation between obstacle-foot distance and the necessary hip torques utilized during obstacle avoidance. The study showed that a prosthetic knee flexion strategy was facilitated by the use of ground friction and by larger active hip torques. This strategy required more energy produced by the hip compared to a knee extension strategy. We conclude that when an amputee maintains enough distance between the distal tip of the foot and the obstacle during stance, he or she produces sufficiently high, yet feasible, hip torques and uses static ground friction, the amputee satisfies the conditions for enable stepping over an obstacle using a knee flexion strategy.
Kistenberg, Robert S
New technology and materials have advanced prosthetic designs to enable people who rely on artificial limbs to achieve feats never dreamed before. However, the latest and the greatest technology is not appropriate for everyone. The aim of this article is to present contemporary options that are available for people who rely on artificial limbs to enhance their quality of life for mobility and independence.
Karchak, A., Jr.; Allen, J. R.; Bontrager, E. L.
The powered hook with trigger finger appears to be a useful adaptation of a terminal device for an amputee when performing vocational activities involving the use of a powered tool requiring a trigger control. The proportional control system includes transducers and amplifiers and appears to have widespread application for control of any external power, whether it be in the orthotic or prosthetic field.
Aggarwal, Himanshi; Kumar, Pradeep; Eachempati, Prashanti; Alvi, Habib A
Enucleation is the removal of the entire globe of the eye and a portion of the optic nerve, while evisceration involves the removal of the contents of the globe leaving the sclera, extraocular muscles, and optic nerve. Following enucleation or evisceration, intraorbital implants are routinely placed to enhance the prosthetic outcome in addition to restoring the lost orbital volume. Current practice employs intraorbital implants made of nonporous silicone, hydroxyapatite, or porous polyethylene. Intraorbital implant selection and placement, being a highly demanding procedure in terms of knowledge, skill, and expertise, may be associated with a multiplicity of technical and surgical errors. Complications are usually minimal with these implants, but they do occur. The literature reveals many articles related to intraorbital implants, their benefits, and complications; however, the literature regarding the effect of various intraorbital implant situations on the subsequent prosthetic rehabilitation is markedly scarce. Moreover, the need for interdisciplinary surgical and prosthetic interventions required for successful rehabilitation in cases of compromised implant situations has been underemphasized. Hence, this review aimed to evaluate the effect of different intraorbital implant situations on ocular rehabilitation and the required interdisciplinary surgical and prosthetic treatment approach for rehabilitation of enucleated/eviscerated sockets with compromised implant situations, to provide a critical appraisal, and to present a simplified management strategy.
Imoto, Kiyotaka; Uchida, Keiji; Isoda, Susumu; Karube, Norihisa; Yasuda, Shota; Masuda, Munetaka
A 77-year-old woman underwent emergency ascending aortic replacement for type A acute aortic dissection. Fifteen days after the operation, she had motor and sensory disturbances in the lower limbs. Computed tomography revealed multiple aortic thrombi and disrupted blood flow in the right external iliac and left common iliac arteries. She underwent an emergency thrombectomy for acute limb ischemia. Because heparin- induced-thrombocytopenia (HIT) was suspected to have caused the multiple aortic thrombi, we postoperatively changed the anticoagulant therapy from heparin to argatroban. Seventeen days after the first operation, gastrointestinal bleeding developed, and the patient died of mesenteric ischemia caused by HIT. Arterial embolization caused by HIT after cardiovascular surgery is a rare, but fatal event. To avoid fatal complications, early diagnosis and early treatment are essential. Use of a scoring system would probably facilitate early diagnosis. PMID:26780951
Bashir, Mohamad; Fok, Matthew; Shaw, Matthew; Field, Mark; Kuduvalli, Manoj; Desmond, Michael; Harrington, Deborah; Rashid, Abbas; Oo, Aung
Aortic aneurysm disease is a complex condition that requires a multidisciplinary approach in management. The innovation and collaboration among vascular surgery, cardiothoracic surgery, interventional radiology, and other related specialties is essential for progress in the management of aortic aneurysms. The Fifth Liverpool Aortic Surgery Symposium that was held in May 2013 aimed at bringing national and international experts from across the United Kingdom and the globe to deliver their thoughts, applications, and advances in aortic and vascular surgery. In this report, we present a selected short synopsis of the key topics presented at this symposium. PMID:26798724
Ren, Shiyan; Sun, Guang; Yang, Yuguang; Liu, Peng
Primary large saccular aortic aneurysm with high grade stenosis of aortic arc is rare, and no standard therapy is available. We have encountered one case and successfully treated using a hybrid interventional approach. A 59-year-old woman with a 7-day history of headache, dizziness and chest pain, and a 5-year history of hypertension admitted and was diagnosed with transverse aortic aneurysm with sever aortic stenosis, the huge saccular aneurysm was located behind the transverse aortic arc. During surgery, a bypass with graft from ascending aorta to left external iliac artery was made initially in order to ensure the blood supply to the left leg, afterward, a 40 mm × 160 mm covered stent was implanted to cover the orifice of aneurysm and was used as a supporting anchorage in the descending aorta, a second covered stent (20 mm × 100 mm) was implanted to expand the stenosis of aortic arc. Follow-up at 1.5-year after surgery, the patient has been doing well without any surgical complication. A collateral pathway between internal mammary artery and inferior epigastric artery via the superior epigastric artery was found on3-dimensional reconstruction before surgery. Interruption of the compensatory arterial collateral pathway in the patient with severe stenosis of aortic arc should be prevented if possible in order to ensure the satisfactory perfusion of the lower limbs of the body.In conclusion, a patient with transverse aortic aneurysm accompanied with severe aortic stenosis can be treated by hybrid surgery.
Permanyer, Eduard; Estigarribia, Arnaldo-Javier; Ysasi, Alejandro; Herrero, Enrique; Semper, Omar; Llorens, Rafael
OBJECTIVES The St. Jude Medical Trifecta aortic bioprosthesis (St. Jude Medical, Inc., St. Paul, MN, USA) is a new stented pericardial tissue heart valve. The aim of the study was to evaluate the clinical and haemodynamic performance of the Trifecta bioprosthesis in the early postoperative period. METHODS From July 2010 to September 2012, a total of 200 consecutive patients underwent aortic valve replacement with the Trifecta valve in our institution. All intraoperative and postoperative data were prospectively collected. Mean EuroSCORE II was 3.98%. Echocardiography was performed at discharge in all patients. RESULTS The mean age was 71.2 ± 7.7 (range 39–89 years). Extubation in the operating theatre was successfully performed in 96% of patients. Mean hospital stay was 8.5 days. The prosthesis sizes were 19 mm (n = 33), 21 mm (n = 81), 23 mm (n = 59), 25 mm (n = 23) and 27 mm (n = 4). Mean systolic pressure gradients ranged from 9.4 mmHg (size 19 valve) to 4.8 mmHg (size 27 valve). Mean effective orifice area (EOA) ranged from 1.61 cm2 (size 19 valve) to 2.5 cm2 (size 27 valve). Severe mismatch (<0.65 cm2/m2) did not occur in any patient. Of note, 99.5% of patients had mild or no aortic insufficiency at discharge. The early (30-day) mortality was 2.5% (n = 5). CONCLUSIONS The Trifecta valve offers good clinical results and excellent haemodynamic performance. Special care must be taken to avoid oversizing, which can lead to difficulty in implantation and can produce gradient increases due to an excess of prosthetic leaflet tissue. PMID:23825161
Behzadnia, Neda; Sharif Kashani, Babak; Kiani, Arda; Abedini, Atefe; Seyedi, Seyed Reza; Zargham Ahmadi, Hossein; Naghash Zadeh, Farah; Fakharian, Atefeh
Thrombosis is a life threatening complications of prosthetic mitral valves and is associated with high morbidity and mortality. Even in presence of systemic anticoagulation prosthetic valve thrombosis has an incidence of 0.5% to 8%. Recurrent prosthetic valve thrombosis and the resulting thrombotic occlusion require re-establishment of blood flow across the valve. While surgical repair is considered the classic first line treatment option for prosthetic valve thrombosis, intravenous thrombolysis has emerged as an acceptable alternative for the first episode of prosthetic valve thrombosis. Due to the limitation of using streptokinase in recurrent thrombotic events, fibrin-specific tissue plasminogen activators have been successfully utilized to treat cases of recurrent prosthetic valve thrombosis. In this case-series, we have reported four cases of recurrent prosthetic valve thrombosis that were successfully treated with Reteplase at our hospital.
Lo, Ruby C.; Schermerhorn, Marc L.
Abdominal aortic aneurysm (AAA) has long been recognized as a condition predominantly afflicting males, with sex-associated differences described for almost every aspect of the disease from pathophysiology and epidemiology to morbidity and mortality. Women are generally spared from AAA formation by the immunomodulating effects of estrogen but once they develop, the natural history of AAAs in women appears to be more aggressive, with more rapid expansion, a higher tendency to rupture at smaller diameters, and higher mortality following rupture. However, simply repairing AAA at smaller diameters in women is a debatable solution, as even elective endovascular AAA repair (EVAR) is fraught with higher morbidity and mortality in women compared to men. The goal of this review is to summarize what is currently known about the effect of gender on AAA presentation, treatment, and outcomes. Additionally, we aim to review current controversies over screening recommendations and threshold for repair in women. PMID:26747679
Kuivaniemi, Helena; Ryer, Evan J.; Elmore, James R.; Tromp, Gerard
Summary An aortic aneurysm is a dilatation in which the aortic diameter is ≥ 3.0 cm. If left untreated, the aortic wall continues to weaken and becomes unable to withstand the forces of the luminal blood pressure resulting in progressive dilatation and rupture, a catastrophic event associated with a mortality of 50 – 80%. Smoking and positive family history are important risk factors for the development of abdominal aortic aneurysms (AAA). Several genetic risk factors have also been identified. On the histological level, visible hallmarks of AAA pathogenesis include inflammation, smooth muscle cell apoptosis, extracellular matrix degradation, and oxidative stress. We expect that large genetic, genomic, epigenetic, proteomic and metabolomic studies will be undertaken by international consortia to identify additional risk factors and biomarkers, and to enhance our understanding of the pathobiology of AAA. Collaboration between different research groups will be important in overcoming the challenges to develop pharmacological treatments for AAA. PMID:26308600
Shadden, Shawn C.; Astorino, Matteo; Gerbeau, Jean-Frédéric
In this work we employ a coupled FSI scheme using an immersed boundary method to simulate flow through a realistic deformable, 3D aortic valve model. This data was used to compute Lagrangian coherent structures, which revealed flow separation from the valve leaflets during systole, and correspondingly, the boundary between the jet of ejected fluid and the regions of separated, recirculating flow. Advantages of computing LCS in multi-dimensional FSI models of the aortic valve are twofold. For one, the quality and effectiveness of existing clinical indices used to measure aortic jet size can be tested by taking advantage of the accurate measure of the jet area derived from LCS. Secondly, as an ultimate goal, a reliable computational framework for the assessment of the aortic valve stenosis could be developed.
Ene, Gabriela; Garcia Raso, Aránzazu; Gonzalez-Dominguez Weber, Almudena; Hidalgo-Vega, Álvaro; Llamas, Pilar
Background: The initiation of oral anticoagulation therapy after valve replacement surgery requires strict monitoring because these patients are at high risk for the development of thrombotic complications and present an increased risk of bleeding. Objectives: The aim of this study was to examine the total healthcare costs of oral anticoagulant treatment with vitamin K antagonists in patients with metallic prosthetic valves in the mitral position. Methods: Data from clinical records were used in the study including international normalized ratio results, number of medical visits, type of anticoagulant, use of rescue medication and hospital admissions from related complications. The drug cost was calculated based on the official Spanish Ministry of Health price list. Monitoring expenses were included in the cost of the medical supplies used in the procedures. Hospitalization costs were calculated using the diagnosis-related group price for each case. Results: We collected data from 151 patients receiving oral anticoagulation therapy with vitamin K antagonist who were diagnosed with mitral prosthesis (n = 90), mitro-aortic prosthesis (n = 57), and mitral and tricuspid prosthesis (n = 4). The total direct healthcare cost was €15302.59, with a mean total cost per patient per year of €1558.15 (±2774.58) consisting of 44.38 (±42.30) for drug cost, €71.41 (±21.43) for international normalized ratio monitoring, €429.52 (±126.87) for medical visits, €26.31 (±28.38) for rescue medication and €986.53 (±2735.68) for related complications. Conclusion: Most direct healthcare costs associated with the sampled patients arose from the specialist-care monitoring required for treatment. Good monitoring is inversely related to direct healthcare costs. PMID:27579168
Cardoso, Goncalo; Abecasis, Miguel; Anjos, Rui; Marques, Marta; Koukoulis, Giovanna; Aguiar, Carlos; Neves, José Pedro
Aortic coarctation can be repaired surgically or percutaneously. The decision should be made according to the anatomy and location of the coarctation, age of the patient, presence of other cardiac lesions, and other anatomic determinants (extensive collaterals or aortic calcification). This article reviews the different therapeutic options available, explaining the differences between children and adults, describing different approaches to the same disease, exemplified by three cases of nonclassic surgical approach and one percutaneous treatment.
Wong, Dennis T L; Narayan, Om; Leong, Darryl P; Bertaso, Angela G; Maia, Murilo G; Ko, Brian S H; Baillie, Timothy; Seneviratne, Sujith K; Worthley, Matthew I; Meredith, Ian T; Cameron, James D
Aortic distensibility (AD) decreases with age and increased aortic stiffness is independently associated with adverse cardiovascular outcomes. The association of severe aortic stenosis (AS) with AD in different aortic regions has not been evaluated. Elderly subjects with severe AS and a cohort of patients without AS of similar age were studied. Proximal aortic cross-sectional-area changes during the cardiac cycle were determined using retrospective-ECG-gating on 128-detector row computed-tomography. Using oscillometric-brachial-blood-pressure measurements, the AD at the ascending-aorta (AA), proximal-descending-aorta (PDA) and distal-descending-aorta (DDA) was determined. Linear mixed effects modelling was used to determine the association of age and aortic stenosis on regional AD. 102 patients were evaluated: 36 AS patients (70-85 years), 24 AS patients (>85 years) and 42 patients without AS (9 patients <50 years, 20 patients between 51-70 years and 13 patients 70-85 years). When comparing patients 70-85 years, AA distensibility was significantly lower in those with AS compared to those without AS (0.9 ± 0.9 vs. 1.4 ± 1.1, P = 0.03) while there was no difference in the PDA (1.0 ± 1.1 vs. 1.0 ± 1.2, P = 0.26) and DDA (1.1 ± 1.2 vs. 1.2 ± 0.8, P = 0.97). In patients without AS, AD decreased with age in all aortic regions (P < 0.001). The AA in patients <50 years were the most distensible compared to other aortic regions. There is regional variation in aortic distensibility with aging. Patients with aortic stenosis demonstrated regional differences in aortic distensibility with lower distensibility demonstrated in the proximal ascending aorta compared to an age-matched cohort.
Wimmer, Matthias D; Randau, Thomas M; Friedrich, Max J; Ploeger, Milena M; Schmolder, Jan; Strauss, Andreas C; Pennekamp, Peter H; Vavken, Patrick; Gravius, Sascha
Prosthetic joint infections are a major challenge in total joint arthroplasty, especially in times of accumulating drug resistancies. Even though predictive risk classifications are a widely accepted tool to define a suitable treatment protocol a classification is still missing considering the difficulty in treating the -causative pathogen antibiotically. In this study, we present and evaluate a new predictive risk stratification for prosthetic joint infections in 120 cases, treated with a two-stage exchange. Treatment outcomes in 120 patients with proven prosthetic joint infections in hip and knee prostheses were regressed on time of infection, systemic risk factors, local risk factors and the difficulty in treating the causing pathogen. The main outcome variable was "definitely free of infection" after two years as published. Age, gender, and BMI were included as covariables and analyzed in a logistic regression model. 66 male and 54 female patients, with a mean age at surgery of 68.3 years±12.0 and a mean BMI of 26.05±6.21 were included in our survey and followed for 29.0±11.3 months. We found a significant association (p<0.001) between our score and the outcome parameters evaluated. Age, gender and BMI did not show a significant association with the outcome. These results show that our score is an independent and reliable predictor for the cure rate in prosthetic joint infections in hip and knee prostheses treated within a two-stage exchange protocol. Our score illustrates, that there is a statistically significant, sizable decrease in cure rate with an increase in score. In patients with prosthetic joint infections the validation of a risk score may help to identify patients with local and systemic risk factors or with infectious organisms identified as "difficult to treat" prior to the treatment or the decision about the treatment concept. Thus, appropriate extra care should be considered and provided.
Hannawa, Kevin K.; Eliason, Jonathan L.; Upchurch, Gilbert R.
Abdominal aortic aneurysms (AAAs) comprise the 10th leading cause of death in Caucasian males 65–74 years of age, and accounted for nearly 16,000 deaths overall in the year 2000. Therefore, understanding the pathophysiology of AAAs is an important undertaking. Clinically, multiple risk factors are associated with the development of AAAs, including increasing age, positive smoking history, and hypertension. Male gender is also a well-established risk factor for the development of an AAA with a 4:1 male to female ratio. The reason for this gender disparity is unknown. The pathogenesis of AAAs formation is complex and multifactorial. Histologically, AAAs are characterized by early chemokine driven leukocyte infiltration into the aortic wall. Subsequent destruction of elastin and collagen in the media and adventitia ensues due to excessive local production of matrix degrading enzymes, and is accompanied by smooth muscle cell loss and thinning of the aortic wall. At present, there are no medical therapies available to treat patients with aortic aneurysms, using only the crude measurement of aortic diameter as a threshold for which patients must undergo life-threatening and costly surgery. Defining the early mechanisms underlying gender-related differences in AAA formation are critical, as understanding differences in disease patterns based on gender may allow us to develop new translational approaches to the prevention and treatment of patients with aortic aneurysms. PMID:19426607
Demirci, Stefanie; Manstad-Hulaas, Frode; Navab, Nassir
Quantification of abdominal aortic deformation is an important requirement for the evaluation of endovascular stenting procedures and the further refinement of stent graft design. During endovascular aortic repair (EVAR) treatment, the aortic shape is subject to severe deformation that is imposed by medical instruments such as guide wires, catheters, and, the stent graft. This deformation can affect the flow characteristics and morphology of the aorta which have been shown to be elicitors for stent graft failures and be reason for reappearance of aneurysms. We present a method for quantifying the deformation of an aneurysmatic aorta imposed by an inserted stent graft device. The outline of the procedure includes initial rigid alignment of the two abdominal scans, segmentation of abdominal vessel trees, and automatic reduction of their centerline structures to one specified region of interest around the aorta. This is accomplished by preprocessing and remodeling of the pre- and postoperative aortic shapes before performing a non-rigid registration. We further narrow the resulting displacement fields to only include local non-rigid deformation and therefore, eliminate all remaining global rigid transformations. Finally, deformations for specified locations can be calculated from the resulting displacement fields. In order to evaluate our method, experiments for the extraction of aortic deformation fields are conducted on 15 patient datasets from endovascular aortic repair (EVAR) treatment. A visual assessment of the registration results and evaluation of the usage of deformation quantification were performed by two vascular surgeons and one interventional radiologist who are all experts in EVAR procedures.
Mastrobuoni, Stefano; Tamer, Sadallah; de Kerchove, Laurent; El Khoury, Gebrine
Aortic valve-sparing procedures are alternative options to aortic valve replacement in patients with aortic root aneurysm and/or severe aortic regurgitation reducing the risk of prosthesis-related complications, such as thromboembolism, and have no need for long-term oral anticoagulation. However, these techniques are technically demanding and long-term results are highly dependent on perfect intraoperative restoration of valve function. We describe a systematic approach to aortic valve-sparing aortic root replacement with the reimplantation technique the way it is currently performed in our institution.
Marshall, D A; Jackson, R; Rae, A P; Capell, H A
Aortic regurgitation associated with relapsing polychondritis usually occurs late in the disease as a result of aortic root dilatation. A case where aortic regurgitation occurred early and was due to cusp rupture with a normal aortic root is reported. The patient required urgent aortic valve replacement within six weeks of developing a murmur despite apparent control of inflammation with immunosuppressive treatment. The possibility of cusp rupture with sudden haemodynamic deterioration should be considered in patients with relapsing polychondritis who develop aortic regurgitation. Images PMID:1575597
Liu, Yinxiao; Liao, Rui; Lv, Xudong
Navigation and deployment of the prosthetic valve during trans-catheter aortic valve implantation (TAVI) can be greatly facilitated with 3-D models showing detailed anatomical structures. Fast and robust automatic contrast detection at the aortic root on X-ray images is indispensable for automatically triggering a 2-D/3-D registration to align the 3-D model. Previously, we have proposed an automatic method for contrast detection at the aortic root on fluoroscopic and angiographic sequences . In this paper, we extend that algorithm in several ways, making it more robust to handle more general and difficult cases. Specifically, the histogram likelihood ratio test is multiplied with the histogram portion computation to handle faint contrast cases. Histogram mapping corrects sudden changes in the global brightness, thus avoiding potential false positives. Respiration and heart beating check further reduces the false positive rate. In addition, a probe mask is introduced to enhance the contrast feature curve when the dark ultrasound probe partially occludes the aortic root. Lastly, a semi-global registration method for aligning the aorta shape model is implemented to improve the robustness of the algorithm with respect to the selection of region of interest (ROI) containing the aorta. The extended algorithm was evaluated on 100 sequences, and improved the detection accuracy from 94% to 100%, compared to the original method. Also, the robustness of the extended algorithm was tested with 20 different shifts of the ROI, and the error rate was as low as 0.2%, in comparison to 6.6% for the original method.
Wojnarski, Charles M.; Svensson, Lars G.; Roselli, Eric E.; Idrees, Jay J.; Lowry, Ashley M.; Ehrlinger, John; Pettersson, Gösta B.; Gillinov, A. Marc; Johnston, Douglas R.; Soltesz, Edward G.; Navia, Jose L.; Hammer, Donald F.; Griffin, Brian; Thamilarasan, Maran; Kalahasti, Vidyasagar; Sabik, Joseph F.; Blackstone, Eugene H.; Lytle, Bruce W.
Background Data regarding the risk of aortic dissection in patients with bicuspid aortic valve and large ascending aortic diameter are limited, and appropriate timing of prophylactic ascending aortic replacement lacks consensus. Thus our objectives were to determine the risk of aortic dissection based on initial cross-sectional imaging data and clinical variables and to isolate predictors of aortic intervention in those initially prescribed serial surveillance imaging. Methods From January 1995 to January 2014, 1,181 patients with bicuspid aortic valve underwent cross-sectional computed tomography (CT) or magnetic resonance imaging (MRI) to ascertain sinus or tubular ascending aortic diameter greater than or equal to 4.7 cm. Random Forest classification was used to identify risk factors for aortic dissection, and among patients undergoing surveillance, time-related analysis was used to identify risk factors for aortic intervention. Results Prevalence of type A dissection that was detected by imaging or was found at operation or on follow-up was 5.3% (n = 63). Probability of type A dissection increased gradually at a sinus diameter of 5.0 cm—from 4.1% to 13% at 7.2 cm—and then increased steeply at an ascending aortic diameter of 5.3 cm—from 3.8% to 35% at 8.4 cm—corresponding to a cross-sectional area to height ratio of 10 cm2/m for sinuses of Valsalva and 13 cm2/m for the tubular ascending aorta. Cross-sectional area to height ratio was the best predictor of type A dissection (area under the curve [AUC] = 0.73). Conclusions Early prophylactic ascending aortic replacement in patients with bicuspid aortic valve should be considered at high-volume aortic centers to reduce the high risk of preventable type A dissection in those with aortas larger than approximately 5.0 cm or with a cross-sectional area to height ratio greater than approximately 10 cm2/m. PMID:26209494
Melvan, John Nicholas; DeLaRosa, Jacob; Vasquez, Julio C
Continued enlargement of the aneurysm sac after thoracic endovascular aortic repair (TEVAR) is a known risk after endovascular treatment of thoracic aortic aneurysms. For this reason, periodic outpatient follow-up is required to identify situations that require repair. Here, we describe an aortobronchial fistula (ABF) in a patient lost to follow-up, that presented 3 years after an elective TEVAR done for a primary, descending thoracic aortic aneurysm. Our patient arrived in extremis and suffered massive hemoptysis leading to her demise. Computed tomography (CT) angiogram near the time of her death demonstrated a bleeding ABF immediately distal to her previous TEVAR repair. Aortic aneurysmal disease remains life threatening even after repair. Improved endovascular techniques and devices have resulted in decreased need for reintervention. However, this case demonstrates the risk of thoracic aortic disease progression and highlights the importance of establishing consistent, long-term follow-up after TEVAR.
Keeble, Thomas R; Khokhar, Arif; Akhtar, Mohammed Majid; Mathur, Anthony; Weerackody, Roshan; Kennon, Simon
The role of percutaneous balloon aortic valvuloplasty (BAV) in the management of severe symptomatic aortic stenosis has come under the spotlight following the development of the transcatheter aortic valve implantation (TAVI) technique. Previous indications for BAV were limited to symptom palliation and as a bridge to definitive therapy for patients undergoing conventional surgical aortic valve replacement (AVR). In the TAVI era, BAV may also be undertaken to assess the ‘therapeutic response’ of a reduction in aortic gradient in borderline patients often with multiple comorbidities, to assess symptomatic improvement prior to consideration of definitive TAVI intervention. This narrative review aims to update the reader on the current indications and practical techniques involved in undertaking a BAV procedure. In addition, a summary of the haemodynamic and clinical outcomes, as well as the frequently encountered procedural complications is presented for BAV procedures conducted during both the pre-TAVI and post-TAVI era. PMID:28008354
Morimoto, Naoto; Morimoto, Keisuke; Morimoto, Yoshihisa; Tanaka, Akiko; Sakamoto, Toshihito; Okada, Kenji; Okita, Yutaka
A 39-year-old woman with familial homozygous hypercholesterolemia had supravalvular and valvular aortic stenosis. Modified Nick's procedure and aortic valve replacement was performed to relieve both the supravalvular and annular stenoses. At surgery, the ascending aorta was found to be narrowing at the level of the sinotubular junction, which was compatible with congenital supravalvular aortic stenosis. Histological examination of the aortic cusps showed sclerotic change due to hypercholesterolemia. These findings indicated that familial homozygous hypercholesterolemia caused valvular aortic stenosis and exacerbated congenital supravalvular aortic stenosis.
Regalado, Ellen S.; Guo, Dongchuan; Prakash, Siddharth; Bensend, Tracy A.; Flynn, Kelly; Estrera, Anthony; Safi, Hazim; Liang, David; Hyland, James; Child, Anne; Arno, Gavin; Boileau, Catherine; Jondeau, Guillaume; Braverman, Alan; Moran, Rocio; Morisaki, Takayuki; Morisaki, Hiroko; Consortium, Montalcino Aortic; Pyeritz, Reed; Coselli, Joseph; LeMaire, Scott; Milewicz, Dianna M.
Background ACTA2 mutations are the major cause of familial thoracic aortic aneurysms and dissections. We sought to characterize these aortic diseases in a large case series of individuals with ACTA2 mutations. Methods and Results Aortic disease, management, and outcome associated with the first aortic event (aortic dissection or aneurysm repair) were abstracted from the medical records of 277 individuals with 41 various ACTA2 mutations. Aortic events occurred in 48% of these individuals, with the vast majority presenting with thoracic aortic dissections (88%) associated with 25% mortality. Type A dissections were more common than type B dissections (54% versus 21%), but the median age of onset of type B dissections was significantly younger than type A dissections (27 years, IQR 18–41 versus 36 years, IQR 26–45). Only 12% of aortic events were repair of ascending aortic aneurysms, which variably involved the aortic root, ascending aorta and aortic arch. Overall cumulative risk of an aortic event at age 85 years was 0.76 (95% CI 0.64, 0.86). After adjustment for intra-familial correlation, gender and race, mutations disrupting p.R179 and p.R258 were associated with significantly increased risk for aortic events, whereas p.R185Q and p.R118Q mutations showed significantly lower risk of aortic events compared to other mutations. Conclusions ACTA2 mutations are associated with high risk of presentation with an acute aortic dissection. The lifetime risk for an aortic event is only 76%, suggesting that additional environmental or genetic factors play a role in expression of aortic disease in individuals with ACTA2 mutations. PMID:25759435
Venardos, Neil; Nadlonek, Nicole A.; Zhan, Qiong; Weyant, Michael J.; Reece, T. Brett; Meng, Xianzhong; Fullerton, David A.
Background While calcific aortic stenosis is common, calcification of the other three heart valves is not. The aortic valve interstitial cell (VIC) has been implicated in the pathogenesis of aortic stenosis. Pro-inflammatory stimulation of aortic VICs induces an osteogenic and inflammatory phenotypic change. We hypothesized that the VICs of the other heart valves do not undergo these changes. Using isolated human VICs from normal aortic, mitral, pulmonary and tricuspid valves, our purpose was to compare the osteogenic response to pro-inflammatory stimulation via TLR-4. Materials And Methods Aortic, pulmonic, mitral, and tricuspid (n=4 for each valve type) VICs were isolated from hearts valves explanted from patients undergoing cardiac transplantation. Cells were cultured and grown to confluence in passage 2-6 before treatment with LPS (100-200ng/mL) for 24 or 48 hours. Cells were characterized by immunofluorescent staining. TLR-4 expression was analyzed (immunoblotting, flow cytometry). BMP-2 and intercellular adhesion molecule-1 (ICAM-1) production were determined (immunoblotting). Monocyte chemoattractant protein-1 (MCP-1) levels were determined by ELISA. Statistics were by Mann-Whitney U test. Results TLR-4 stimulation induced BMP-2 production only in aortic VICs (p<0.05). ICAM-1 production and MCP-1 secretion increased in a similar fashion among TLR4-stimulated VICs from all four valves. Conclusions Pro-inflammatory stimulation induces an osteogenic phenotype in aortic VICs but not mitral, pulmonic, or tricuspid VICs. We conclude that this differential osteogenic response of aortic VICs contributes to the pathogenesis of calcific aortic stenosis. PMID:24746950
Background 1-stage prosthetic breast reconstruction is gaining traction as a preferred method of breast reconstruction in select patients who undergo mastectomy for cancer or prevention. Methods Critical elements to the procedure including patient selection, technique, surgical judgment, and postoperative care were reviewed. Results Outcomes series reveal that in properly selected patients, direct-to-implant (DTI) reconstruction has similar low rates of complications and high rates of patient satisfaction compared to traditional 2-stage reconstruction. Conclusions 1-stage prosthetic breast reconstruction may be the procedure of choice in select patients undergoing mastectomy. Advantages include the potential for the entire reconstructive process to be complete in one surgery, the quick return to normal activities, and lack of donor site morbidity. PMID:26005643
Connolly, R.; McEnroe, C.S.; Li, S.; Coleman, J.; Callow, A.D.
Previous studies have demonstrated the importance of employing prosthetic material with minimal thrombogenicity. However, the role of different suture materials in early thrombotic events on prosthetic materials has not been examined. Experiments were designed to analyze the effects of suture on platelet graft interaction using an in vivo baboon hemocompatability screen. Indium labeled, autologous platelet deposition was determined on expanded polytetrafluoroethylene (ePTFE) containing suture lines of polypropylene (Prolene), polybutester (Novafil), and ePTFE (Gore-Tex). A significant increase in platelet deposition was noted not only at the suture line, but proximal and distal to it as well. The results were different for each of the sutures employed and suggest that the suture line may influence early platelet deposition in the perianastomotic region, not only at the suture line, but proximally and distally as well.
Karrouf, Gamal; Zaghloul, Adel; Abou-Alsaud, Mohamed; Barbour, Elie; Abouelnasr, Khaled
The management of abdominal wall repair continues to present a challenging problem, especially in the repair of major defects. Many abdominal wall defects can be repaired by primary closure; however, if the defect is large and there is a tension on the closure of the wound, the use of prosthetic materials becomes indispensable. Many studies have been performed with various materials and implant techniques, without the comparison of their degrees of success, based on sound meta-analysis and/or inclusive epidemiologic studies. This review covered the effectiveness of recent advances in prosthetic materials and implant procedures used in repair of abdominal wall, based on biomechanical properties and economic aspects of reconstructed large abdominal wall defects and hernias in animals. The presented results in this review helped to reach treatment algorithms that could maximize outcomes and minimize morbidity. PMID:27293982
O'Connor, Cormac T; Kiernan, Thomas J
Infective endocarditis involving prosthetic valves accounts for 20% of all endocarditis cases. Rising in prevalence due to increasing placement of valvular prostheses, prosthetic valve endocarditis (PVE) is more difficult to diagnose by conventional methods, associated with more invasive infection and increased mortality. This report explores the existing literature in identifying a direct approach to the management of PVE; such as adjuncts to establishing a diagnosis (for instance positron emission tomography/computed tomography and radiolabeled leukocyte scintigraphy), the trends in specific pathogens associated with PVE and the recommended antimicrobials for each. The patterns of disease requiring surgical intervention are also highlighted and explored. In addition, a 5-year outlook offers consolidated knowledge on epidemiological trends of both culprit organisms and population subgroups suffering (and projected to suffer) from PVE.
Karrouf, Gamal; Zaghloul, Adel; Abou-Alsaud, Mohamed; Barbour, Elie; Abouelnasr, Khaled
The management of abdominal wall repair continues to present a challenging problem, especially in the repair of major defects. Many abdominal wall defects can be repaired by primary closure; however, if the defect is large and there is a tension on the closure of the wound, the use of prosthetic materials becomes indispensable. Many studies have been performed with various materials and implant techniques, without the comparison of their degrees of success, based on sound meta-analysis and/or inclusive epidemiologic studies. This review covered the effectiveness of recent advances in prosthetic materials and implant procedures used in repair of abdominal wall, based on biomechanical properties and economic aspects of reconstructed large abdominal wall defects and hernias in animals. The presented results in this review helped to reach treatment algorithms that could maximize outcomes and minimize morbidity.
Ciancio, Anna Lisa; Cordella, Francesca; Barone, Roberto; Romeo, Rocco Antonio; Bellingegni, Alberto Dellacasa; Sacchetti, Rinaldo; Davalli, Angelo; Di Pino, Giovanni; Ranieri, Federico; Di Lazzaro, Vincenzo; Guglielmelli, Eugenio; Zollo, Loredana
This paper intends to provide a critical review of the literature on the technological issues on control and sensorization of hand prostheses interfacing with the Peripheral Nervous System (i.e., PNS), and their experimental validation on amputees. The study opens with an in-depth analysis of control solutions and sensorization features of research and commercially available prosthetic hands. Pros and cons of adopted technologies, signal processing techniques and motion control solutions are investigated. Special emphasis is then dedicated to the recent studies on the restoration of tactile perception in amputees through neural interfaces. The paper finally proposes a number of suggestions for designing the prosthetic system able to re-establish a bidirectional communication with the PNS and foster the prosthesis natural control. PMID:27092041
Simpson, John T [Clinton, TN; Ivanov, Ilia N [Knoxville, TN; Shibata, Jason [Manhattan Beach, CA
An external covering and method of making an external covering for hiding the internal endoskeleton of a mechanical (e.g., prosthetic) device that exhibits skin-like qualities is provided. The external covering generally comprises an internal bulk layer in contact with the endoskeleton of the prosthetic device and an external skin layer disposed about the internal bulk layer. The external skin layer is comprised of a polymer composite with carbon nanotubes embedded therein. The outer surface of the skin layer has multiple cone-shaped projections that provide the external skin layer with superhydrophobicity. The carbon nanotubes are preferably vertically aligned between the inner surface and outer surface of the external skin layer in order to provide the skin layer with the ability to transmit heat. Superhydrophobic powders may optionally be used as part of the polymer composite or applied as a coating to the surface of the skin layer to enhance superhydrophobicity.
Takahara, Shingo; Fukasawa, Manabu; Kawahara, Yu; Suzuki, Kotaro; Kobayashi, Yuriko
Congenital bicuspid aortic valve (BAV) is one of the most common congenital heart diseases, with a high incidence of associated valvular lesions and aortic abnormalities including aortic stenosis( AS), aortic regurgitation, aortic dilatation, and aortic dissection. Patients with BAV and AS often have a small aortic annulus. We encountered a case of BAV in which a 51-year-old woman with severe AS having a small aortic annulus and a dilated ascending aorta required surgical intervention. We performed the surgery using new technique that involved concomitant replacement of the aortic valve and the ascending aorta with enlargement of the aortic annulus using a single uniquely-shaped graft to avoid prosthesis patient mismatch. We trimmed the proximal end of the straight graft in shape of 2 teardrops hanging on it to fit the cut annulus. It requires only a single suture line to replace the ascending aorta and enlarge the aortic annulus, which entails a decreased risk of bleeding during surgery. We believe that it could be applicable to many cases requiring concomitant surgery.
Artopoulou, Ioli-Ioanna; Higuera, Stephen; Martin, Jack W; Stal, Samuel; Chambers, Mark S
Patients with cleft lip or palate encounter a myriad of difficulties in their early years of life, some of which begin at birth. The defect often impairs suckling and deglutition in the neonate. It can hinder appropriate speech development and may impose undue social and psychological stresses. Surgical and orthodontic interventions are essential and prosthetic palatal appliances play an important role not only throughout the patient's treatment course, but also in the treatment of unfavorable surgical sequelae.
TERMS Prosthetics, Orthotics, Prosthesis, Orthosis , Amputation, Outcomes Based Evaluation 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...10 in 28) What is the biomechanical system called that this orthosis uses to control genuvarus? ______3 – point pressure...Unloader type orthosis (Fig 2) have to be to statically hold the knee? 31) What would the Moments at M1 & M2 if the system was concentrated at the
Achermann, Yvonne; Rössle, Matthias; Hoffmann, Matthias; Deggim, Vanessa; Kuster, Stefan; Zimmermann, Dieter R.; Hombach, Michael; Hasse, Barbara
Prosthetic valve endocarditis (PVE) due to fast-growing nontuberculous mycobacteria (NTM) has been reported anecdotally. Reports of PVE with slowly growing NTM, however, are lacking. We present here one case of PVE and one case of bloodstream infection caused by Mycobacterium chimaera. Randomly amplified polymorphic DNA (RAPD)-PCR indicated a relatedness of the two M. chimaera strains. Both patients had heart surgery 2 years apart from each other. A nosocomial link was not detected. PMID:23536407
Naidu, D; Chen, Cheng-Hung; Perez, Alba; Schoen, Marco P
A chronological overview of the applications of control theory to prosthetic hand is presented. The overview focuses on hard computing or control techniques such as multivariable feedback, optimal, nonlinear, adaptive and robust and soft computing or control techniques such as artificial intelligence, neural networks, fuzzy logic, genetic algorithms and on the fusion of hard and soft control techniques. This overview is not intended to be an exhaustive survey on this topic and any omissions of other works is purely unintentional.
Buckley, Theresa M.
Electronic neural networks proposed for use in controlling robotic and prosthetic hands and exoskeletal or glovelike electromechanical devices aiding intact but nonfunctional hands. Specific to patient, who activates grasping motion by voice command, by mechanical switch, or by myoelectric impulse. Patient retains higher-level control, while lower-level control provided by neural network analogous to that of miniature brain. During training, patient teaches miniature brain to perform specialized, anthropomorphic movements unique to himself or herself.
from retinitis pigmentosa : Arch Ophthalmol, v. 122, p. 460-9. 8 Dacey, D. M., B. B. Peterson, F. R. Robinson, and P. D. Gamlin, 2003, Fireworks in...with DTL electrodes: a study in patients with retinitis pigmentosa , glaucoma, and homonymous visual field loss and normal subjects: Invest Ophthalmol...outcomes associated with retinal prosthetics. To accomplish this, we are investigating the mechanism(s) by which different types of retinal neurons
Achermann, Yvonne; Rössle, Matthias; Hoffmann, Matthias; Deggim, Vanessa; Kuster, Stefan; Zimmermann, Dieter R; Bloemberg, Guido; Hombach, Michael; Hasse, Barbara
Prosthetic valve endocarditis (PVE) due to fast-growing nontuberculous mycobacteria (NTM) has been reported anecdotally. Reports of PVE with slowly growing NTM, however, are lacking. We present here one case of PVE and one case of bloodstream infection caused by Mycobacterium chimaera. Randomly amplified polymorphic DNA (RAPD)-PCR indicated a relatedness of the two M. chimaera strains. Both patients had heart surgery 2 years apart from each other. A nosocomial link was not detected.
Carberry, Patrick; Lieberman, Brian P.; Ploessl, Karl; Choi, Seok R.; Haase, Danniebelle N.; Kung, Hank F.
A novel fluorine-18 prosthetic ligand, 5-(1,3-dioxolan-2-yl)-2-(2-(2-(2- fluoroethoxy)ethoxy)ethoxy)pyridine [18F]2, has been synthesized. The prosthetic ligand is formed in high radiochemical yield (rcy = 71 ± 2 %, n = 3) with excellent radiochemical purity (rcp = 99 ± 1 %, n = 3) in a short reaction time (10 min). [18F]2 is a small, neutral, organic complex, easily synthesized in four steps from a readily available starting material. It can be anchored onto a target molecule containing an aminooxy functional group under acidic conditions by way of an oxime bond. We report herein two examples [18F]23 and [18F]24, potential imaging agents for β-amyloid plaques, which were labeled with this prosthetic group. This approach could be used for labeling proteins and peptides containing an aminooxy group. Biodistribution in male ICR mice for both oxime labeled complexes [18F]23 and [18F]24 were compared to that of the known β-amyloid plaque indicator, [18F]-AV-45, florbetapir 1. Oximes [18F]23 and [18F]24 are larger in size and therefore should reduce the blood-brain barrier (BBB) penetration. The brain uptake for oxime [18F]23 appeared to be reduced, but still retained some capability to cross the BBB. Oxime [18F]24 showed promising results after 2 min post injection (0.48 % dose/gram), however the uptake increased after 30 min post injection (0.92 % dose/gram) suggesting an in-vivo decomposition/metabolism of compound [18F]24. We have demonstrated a general protocol for the fluoride-18 labeling with a new prosthetic ligand [18F]2 that is tolerant towards several functional groups and is formed via chemoselective oxime coupling. PMID:21452846
Milewicz, Dianna M.
Aortic aneurysms are a common clinical condition that can cause death due to aortic dissection or rupture. The association between aortic aneurysm pathogenesis and altered TGF-β signaling has been the subject of numerous investigations. Recently, a TGF-β–responsive microRNA (miR), miR-29, has been identified to play a role in cellular phenotypic modulation during aortic development and aging. In this issue of JCI, Maegdefessel and colleagues demonstrate that decreasing the levels of miR-29b in the aortic wall can attenuate aortic aneurysm progression in two different mouse models of abdominal aortic aneurysms. This study highlights the relevance of miR-29b in aortic disease but also raises questions about its specific role. PMID:22269322
McClarren-Curry, C; Shaughnessy, K
Acute thoracic aortic dissection is frequently misdiagnosed, and even with surgical intervention, the mortality rate is 50%. This article focuses on assessment, interventions, and postoperative care of patients with aortic dissection.
... español Talk to Your Doctor about Abdominal Aortic Aneurysm Browse Sections The Basics Overview What is AAA? ... doctor about getting screened (tested) for abdominal aortic aneurysm (AAA). If AAA isn't found and treated ...
Veger, H T C; Hedeman Joosten, P Ph; Thoma, S R; Visser, M J T
Infection of endovascular abdominal aneurysm stent grafts is an uncommon but known complication. Inoculation with bacteria of the endovascular abdominal aneurysm stent graft during the actual implantation, in the periprocedural hospitalization or later due to an aortoenteric fistula, has been described in the literature. We report a case of endovascular abdominal aortic aneurysm stent graft infection occurring 40 months after implantation in a patient doing well up to an episode of urosepsis. In conclusion, we postulate that poor intraluminal healing of stent grafts, as observed in several explant studies, may result in a higher susceptibility to episodes of bacteremia than prosthetic vascular grafts inserted during open repair. We therefore consider the administration of prophylactic antibiotics in patients with endovascular stent grafts during periods with a likelihood of bacteremia.
Candy, J V; Meyer, A W
People with serious cardiac problems have had their life span extended with the development of the prosthetic heart valve. However, the valves operate continuously at approximately 39 million cycles per year and are therefore subject to structural failures either by faulty design or material fatigue. The development of a non-invasive technique using an acoustic contact microphone and sophisticated signal processing techniques has been proposed and demonstrated on limited data sets. In this paper we discuss an extension of the techniques to perform the heart valve tests in an anechoic like. Here the objective is to extract a ''pure'' sound or equivalently the acoustical vibration response of the prosthetic valves in a quiet environment. The goal is to demonstrate that there clearly exist differences between values which have a specific mechanical defect known as single leg separation (SLS) and non-defective valves known as intact (INT). We discuss the signal processing and results of anechoic acoustic measurements on 50 prosthetic valves in the tank. Finally, we show the results of the individual runs for each valve, point out any of the meaningful features that could be used to distinguish the SLS from INT and summarize the experiments.
Brunner, M C; Mitchell, R S; Baldwin, J C; James, D R; Olcott, C; Mehigan, J T; McDougall, I R; Miller, D C
The lack of a rapid, noninvasive, and accurate method to confirm or rule out prosthetic graft infection continues to constitute a compelling and vexing clinical problem. A host of adjunctive diagnostic techniques has been used in the past, but early promising results subsequently have usually not yielded acceptable sensitivity (reflecting false negatives) and specificity (reflecting false positive) data. White blood cell (WBC) indium 111 scanning has recently been added to this list. The utility and accuracy of 111In WBC scans were assessed by retrospective review of WBC scan results in 70 patients undergoing evaluation for possible prosthetic graft infection over a 7-year period. Operative and autopsy data (mean follow-up, 18 months for survivors with negative scans) were used to confirm the 22 positive, 45 negative, and three equivocal WBC scans. The false positive rate (+/- 70% confidence limits) was 36% +/- 6% (n = 8) among the 22 patients with positive scans (44% +/- 6% [11 of 25] if the three equivocal scans are included as false positive), yielding a specificity of 85% +/- 5% and an overall accuracy rate of 88% +/- 4% (80% +/- 5% and 84% +/- 5%, respectively, if the three equivocal cases are considered as false positive). All three patients with equivocal scans ultimately were judged not to have prosthetic graft infection. As implied by the high accuracy rate, the sensitivity of the test was absolute (100% [14 of 14]); there were no false negative results. (ABSTRACT TRUNCATED AT 250 WORDS)
Matteucci, Paul B; Byrnes-Preston, Philip; Chen, Spencer C; Lovell, Nigel H; Suaning, Gregg J
A growing number of prosthetic devices have been shown to provide visual perception to the profoundly blind through electrical neural stimulation. These first-generation devices offer promising outcomes to those affected by degenerative disorders such as retinitis pigmentosa. Although prosthetic approaches vary in their placement of the stimulating array (visual cortex, optic-nerve, epi-retinal surface, sub-retinal surface, supra-choroidal space, etc.), most of the solutions incorporate an externally-worn device to acquire and process video to provide the implant with instructions on how to deliver electrical stimulation to the patient, in order to elicit phosphenized vision. With the significant increase in availability and performance of low power-consumption smart phone and personal device processors, the authors investigated the use of a commercially available ARM (Advanced RISC Machine) device as an externally-worn processing unit for a prosthetic neural stimulator for the retina. A 400 MHz Samsung S3C2440A ARM920T single-board computer was programmed to extract 98 values from a 1.3 Megapixel OV9650 CMOS camera using impulse, regional averaging and Gaussian sampling algorithms. Power consumption and speed of video processing were compared to results obtained to similar reported devices. The results show that by using code optimization, the system is capable of driving a 98 channel implantable device for the restoration of visual percepts to the blind.
Brunner, M.C.; Mitchell, R.S.; Baldwin, J.C.; James, D.R.; Olcott C 4; Mehigan, J.T.; McDougall, I.R.; Miller, D.C.
The lack of a rapid, noninvasive, and accurate method to confirm or rule out prosthetic graft infection continues to constitute a compelling and vexing clinical problem. A host of adjunctive diagnostic techniques has been used in the past, but early promising results subsequently have usually not yielded acceptable sensitivity (reflecting false negatives) and specificity (reflecting false positive) data. White blood cell (WBC) indium 111 scanning has recently been added to this list. The utility and accuracy of /sup 111/In WBC scans were assessed by retrospective review of WBC scan results in 70 patients undergoing evaluation for possible prosthetic graft infection over a 7-year period. Operative and autopsy data (mean follow-up, 18 months for survivors with negative scans) were used to confirm the 22 positive, 45 negative, and three equivocal WBC scans. The false positive rate (+/- 70% confidence limits) was 36% +/- 6% (n = 8) among the 22 patients with positive scans (44% +/- 6% (11 of 25) if the three equivocal scans are included as false positive), yielding a specificity of 85% +/- 5% and an overall accuracy rate of 88% +/- 4% (80% +/- 5% and 84% +/- 5%, respectively, if the three equivocal cases are considered as false positive). All three patients with equivocal scans ultimately were judged not to have prosthetic graft infection. As implied by the high accuracy rate, the sensitivity of the test was absolute (100% (14 of 14)); there were no false negative results.
Brewer, A.R.; Stromberg, B.V. )
Adherence of bacteria to prosthetic grafting material is thought to play an important role in the ultimate development of prosthetic infections. To evaluate the role of bacterial adherence in the initiation and colonization of prosthetic materials, Proplast II, Gore-Tex, and silicone were evaluated for adherence of Escherichia coli and Staphylococcus aureus. Bacteria were radiolabeled and incubated with the study material. Adherence was determined by scintillation. Adherence to Proplast II and Gore-Tex reached a maximum at approximately 45 minutes of incubation and demonstrated a detachment phenomenon with E. coli. Similar results were noted with S. aureus, but with a maximal attachment at approximately 30 minutes. Interestingly, bacterial attachment to silicone continued to increase throughout the time of the incubation. In addition, adherence of S. aureus was at a faster rate than E. coli. Attachment of bacteria is a multifactorial process. However, the PTFE graft demonstrates a slower rate of attachment, lower total number of attached bacteria, and faster detachment. The importance of this phenomenon may help explain the foreign body effect of increased susceptibility to infection of foreign materials.
Cagle, John C; Reinhall, Per G; Hafner, Brian J; Sanders, Joan E
A set of protocols was created to characterize prosthetic liners across six clinically relevant material properties. Properties included compressive elasticity, shear elasticity, tensile elasticity, volumetric elasticity, coefficient of friction (CoF), and thermal conductivity. Eighteen prosthetic liners representing the diverse range of commercial products were evaluated to create test procedures that maximized repeatability, minimized error, and provided clinically meaningful results. Shear and tensile elasticity test designs were augmented with finite element analysis (FEA) to optimize specimen geometries. Results showed that because of the wide range of available liner products, the compressive elasticity and tensile elasticity tests required two test maxima; samples were tested until they met either a strain-based or a stress-based maximum, whichever was reached first. The shear and tensile elasticity tests required that no cyclic conditioning be conducted because of limited endurance of the mounting adhesive with some liner materials. The coefficient of friction test was based on dynamic coefficient of friction, as it proved to be a more reliable measurement than static coefficient of friction. The volumetric elasticity test required that air be released beneath samples in the test chamber before testing. The thermal conductivity test best reflected the clinical environment when thermal grease was omitted and when liner samples were placed under pressure consistent with load bearing conditions. The developed procedures provide a standardized approach for evaluating liner products in the prosthetics industry. Test results can be used to improve clinical selection of liners for individual patients and guide development of new liner products.
Zapf, Marc P; Matteucci, Paul B; Lovell, Nigel H; Suaning, Gregg J
The feasibility of implants for prosthetic vision has been demonstrated by research and commercial organizations. In most devices, an essential forerunner to the internal stimulation circuit is an external electronics solution for capturing, processing and relaying image information as well as extracting useful features from the scene surrounding the patient. The capabilities and multitude of image processing algorithms that can be performed by the device in real-time plays a major part in the final quality of the prosthetic vision. It is therefore optimal to use powerful hardware yet to avoid bulky, straining solutions. Recent publications have reported of portable single-board computers fast enough for computationally intensive image processing. Following the rapid evolution of commercial, ultra-portable ARM (Advanced RISC machine) mobile devices, the authors investigated the feasibility of modern smartphones running complex face detection as external processing devices for vision implants. The role of dedicated graphics processors in speeding up computation was evaluated while performing a demanding noise reduction algorithm (image denoising). The time required for face detection was found to decrease by 95% from 2.5 year old to recent devices. In denoising, graphics acceleration played a major role, speeding up denoising by a factor of 18. These results demonstrate that the technology has matured sufficiently to be considered as a valid external electronics platform for visual prosthetic research.
Background Good prosthetic suspension system secures the residual limb inside the prosthetic socket and enables easy donning and doffing. This study aimed to introduce, evaluate and compare a newly designed prosthetic suspension system (HOLO) with the current suspension systems (suction, pin/lock and magnetic systems). Methods All the suspension systems were tested (tensile testing machine) in terms of the degree of the shear strength and the patient’s comfort. Nine transtibial amputees participated in this study. The patients were asked to use four different suspension systems. Afterwards, each participant completed a questionnaire for each system to evaluate their comfort. Furthermore, the systems were compared in terms of the cost. Results The maximum tensile load that the new system could bear was 490 N (SD, 5.5) before the system failed. Pin/lock, magnetic and suction suspension systems could tolerate loads of580 N (SD, 8.5), 350.9 (SD, 7) and 310 N (SD, 8.4), respectively. Our subjects were satisfied with the new hook and loop system, particularly in terms of easy donning and doffing. Furthermore, the new system is considerably cheaper (35 times) than the current locking systems in the market. Conclusions The new suspension system could successfully retain the prosthesis on the residual limb as a good alternative for lower limb amputees. In addition, the new system addresses some problems of the existing systems and is more cost effective than its counterparts. PMID:24410918
Gregg, Robert D.; Martin, Anne E.
Recent work has extended the control method of virtual constraints, originally developed for autonomous walking robots, to powered prosthetic legs for lower-limb amputees. Virtual constraints define desired joint patterns as functions of a mechanical phasing variable, which are typically enforced by torque control laws that linearize the output dynamics associated with the virtual constraints. However, the output dynamics of a powered prosthetic leg generally depend on the human interaction forces, which must be measured and canceled by the feedback linearizing control law. This feedback requires expensive multi-axis load cells, and actively canceling the interaction forces may minimize the human's influence over the prosthesis. To address these limitations, this paper proposes a method for projecting virtual constraints into the nullspace of the human interaction terms in the output dynamics. The projected virtual constraints naturally render the output dynamics invariant with respect to the human interaction forces, which instead enter into the internal dynamics of the partially linearized prosthetic system. This method is illustrated with simulations of a transfemoral amputee model walking with a powered knee-ankle prosthesis that is controlled via virtual constraints with and without the proposed projection. PMID:27746585
Ajduković, Zorica; Janošević, Mirjana; Filipović, Gordana; Arsić, Stojanka; Janošević, Predrag; Petrović, Nenad
Skeletal class III malocclusion is one of the most difficult dentofacial anomalies, characterized by deviation in the development of the mandible and maxilla in the sagittal plane, where the mandible is dominant in relation to the maxilla. In patients with class III malocclusion, anomalies in the dentoalveolar level and esthetic discrepancies are also frequent. The etiology of class III malocclusion is multifactorial due to the interaction of hereditary and environmental factors. Rehabilitation and treatment of malocclusion is one of the major goals of modern dentistry. This article presents the orthodontic-prosthetic therapy and rehabilitation of a 45-year-old patient with an abnormal occlusal vertical dimension and a skeletal class III malocclusion. The patient came to the clinic complaining about degraded esthetics and disordered functions of the orofacial region (functions of eating, swallowing, speech) and also pain in the temporomandibular joint. After the diagnosis was made, the patient was first referred to orthodontic treatment with fixed orthodontic appliances (self-ligating brackets system Rot 0.22). Upon completion of the orthodontic treatment, the patient was sent for further prosthetic treatment. Fixed prosthetic restorations were made in the upper and lower jaw, thus achieving a satisfactory result in terms of esthetics and function of the stomatognathic system.
Bianchi, Thomas; Zambarbieri, Daniela; Beltrami, Giorgio; Verni, Gennaro
The fitting of upper-extremity amputees requires special efforts, and its significance has been increased by the development of the myoelectrically controlled prosthetic arm. This solution is not free of problems due to the nature of the amputation, to the electromagnetic noise affecting the myelectrical signal and to the perspiration due to the contact between socket and the residual limb. Starting from the fact that NIRS and electromyographic signals are similar during a muscle contraction, we have first studied the NIRS signal during forearm muscle contractions in normal and amputee subjects. Then a new system to interface the NIRS unit and the myoelectrical prosthetic hand has been developed. The NIRS unit has been used as optical sensor and all the operations (I/O and signal processing) are performed via software. This system has been tested on normal and amputee subjects performing hand grasping using a visual biofeedback control scheme. All the subjects have been able to perform these operations demonstrating the NIRS technique. This could represent an alternative solution for controlling a prosthetic device.
Hu, Jie; Xia, Peng; Gu, Chaochen; Qi, Jin; Li, Sheng; Peng, Yinghong
Due to the limitations of existing techniques, even the most advanced visual prostheses, using several hundred electrodes to transmit signals to the visual pathway, restrict sensory function and visual information. To identify the bottlenecks and guide prosthesis designing, psychophysics simulations of a visual prosthesis in normally sighted individuals are desirable. In this study, psychophysical experiments of discriminating objects with similar profiles were used to test the effects of phosphene array parameters (spatial resolution, gray scale, distortion, and dropout rate) on visual information using simulated prosthetic vision. The results showed that the increase in spatial resolution and number of gray levels and the decrease in phosphene distortion and dropout rate improved recognition performance, and the accuracy is 78.5% under the optimum condition (resolution: 32 × 32, gray level: 8, distortion: k = 0, dropout: 0%). In combined parameter tests, significant facial recognition accuracy was achieved for all the images with k = 0.1 distortion and 10% dropout. Compared with other experiments, we find that different objects do not show specific sensitivity to the changes of parameters and visual information is not nearly enough even under the optimum condition. The results suggests that higher spatial resolution and more gray levels are required for visual prosthetic devices and further research on image processing strategies to improve prosthetic vision is necessary, especially when the wearers have to accomplish more than simple visual tasks.
Kunisaki, Shaun M.; Barnewolt, Carol E.; Estroff, Judy A.; Nemes, Luanne P.; Jennings, Russell W.; Wilson, Jay M.; Fauza, Dario O.
Objective To determine whether any common maternal-fetal variable has prenatal predictive value of prosthetic repair in congenital diaphragmatic hernia. Methods This was a 5-year single-center retrospective review of fetal congenital diaphragmatic hernia referrals. Multiple prenatal variables were correlated with the need for a prosthetic repair. Statistical analyses were by Fisher's exact and Mann-Whitney U-tests, as appropriate (p < 0.05). Results Fetal liver position was a predictor of prosthetic repair. The presence or absence of liver herniation was correlated with prosthetic repair rates of 83.3 and 23.1%, respectively (p < 0.001). All patients with moderate/severe liver herniation required a prosthetic patch. Conclusion Liver herniation has prenatal predictive value for the need for prosthetic repair in congenital diaphragmatic hernia. This finding should be valuable during prenatal counseling for clinical trials of engineered diaphragmatic repair. PMID:18417990
Loma, Luis; Miller, Paul; Hertzberg, Jean
Coarctation of the aorta is a congenital cardiovascular defect that causes a constriction in the descending thoracic aorta. To gain a better understanding of the cause of post-surgical problems, a rigid glass and a compliant in vitro model of the aortic arch and descending aorta with a coarctation were constructed. Near-physiologic compliance was obtained using a silicone elastomer. Stereoscopic PIV was used to obtain 3D velocity maps. Results show a high speed turbulent jet formed at the exit of the coarctation. Flow in the rigid model was significantly different from in the compliant model. In the rigid model, the jet was symmetric, creating a toroidal recirculation area. In the compliant model, the jet was directed towards the medial wall, inducing flow reversal only at the lateral wall. Peak velocities and turbulence intensities were higher in the rigid model, however shear rate values in the compliant model were significantly above both the rigid model and normal in vivo values at the medial wall. In both models the reattachment region fluctuated, creating oscillatory shear.
Intra-aortic balloon pumps (IABPs) are circulatory assist devices used to treat a number of cardiovascular conditions. IABPs provide temporary circulatory support by reducing the resistance to blood flow out of the heart during systole and by providing added pressure to aid in perfusing the heart during diastole. In this Evaluation, we tested three IABPs from three suppliers. We examined the units' technical performance, safety and monitoring, human factors design, transport operation, and supplier support. Rather than test all the triggering (activation) modes available, we focused our testing on the modes most commonly used on each unit. We also provide information on an IABP currently available only in Japan; although we did not test this unit, we do provide a preliminary judgment based on the information provided to us by the supplier. In the Technology Overview also included in the Evaluation, we describe the basic operation and use of an IABP, as well as review the state of the art of this technology. And in the Selection, Purchasing, and Use Guide at the conclusion of the Evaluation, we discuss such topics as balloon costs and sizing, interfacing IABPs with patient monitors, and the use of IABPs in community hospitals.
Bangeas, Petros; Voulalas, Grigorios; Ktenidis, Kiriakos
3D printing provides the sequential addition of material layers and, thus, the opportunity to print parts and components made of different materials with variable mechanical and physical properties. It helps us create 3D anatomical models for the better planning of surgical procedures when needed, since it can reveal any complex anatomical feature. Images of abdominal aortic aneurysms received by computed tomographic angiography were converted into 3D images using a Google SketchUp free software and saved in stereolithography format. Using a 3D printer (Makerbot), a model made of polylactic acid material (thermoplastic filament) was printed. A 3D model of an abdominal aorta aneurysm was created in 138 min, while the model was a precise copy of the aorta visualized in the computed tomographic images. The total cost (including the initial cost of the printer) reached 1303.00 euros. 3D imaging and modelling using different materials can be very useful in cases when anatomical difficulties are recognized through the computed tomographic images and a tactile approach is demanded preoperatively. In this way, major complications during abdominal aorta aneurysm management can be predicted and prevented. Furthermore, the model can be used as a mould; the development of new, more biocompatible, less antigenic and individualized can become a challenge in the future.
Zhang, Lei; Chen, Xin; Liu, Muhan
Thoracic descending aorta diseases include aortic dissection and aortic aneurysm, of which the natural mortality rate is extremely high. At present, endovascular aneurysm repair (EVAR) has been widely used as an effective means for the treatment of descending aortic disease. Most of the existing coating stents are standard design, which are unable to meet the size or structure of different patients. As a result, failure of treatment would be caused by dimensional discrepancy between stent and vessels, which could lead to internal leakage or rupture of blood vessels. Therefore, based on rapid prototyping sacrificial core – coating forming (RPSC-CF), a customized aortic stent graft manufactured technique has been proposed in this study. The aortic stent graft consists of film and metallic stent, so polyether polyurethane (PU) and nickel-titanium (NiTi) shape memory alloy with good biocompatibility were chosen. To minimum film thickness without degrading performance, effect of different dip coating conditions on the thickness of film were studied. To make the NiTi alloy exhibit super-elasticity at body temperature (37°C), influence of different heat treatment conditions on austenite transformation temperature (Af) and mechanical properties were studied. The results show that the customized stent grafts could meet the demand of personalized therapy, and have good performance in blasting pressure and radial support force, laying the foundation for further animal experiment and clinical experiment.
Kleiman, Neal S.; Reardon, Michael J.
Transcatheter aortic valve replacement (TAVR) is becoming widely used for the treatment of symptomatic severe aortic stenosis in patients with high surgical risk. Data from The PARTNER Trial (Placement of AoRtic TraNscathetER Valves) and the Medtronic CoreValve® U.S. Pivotal Investigational Device Exemption trial indicate that survival for extreme-risk patients is superior to best medical therapy and equivalent or superior to surgical aortic valve replacement (SAVR), although long-term durability remains unknown. Paravalvular leak remains higher in TAVR than SAVR, as does permanent pacemaker implantation in self-expanding valves. New-generation valves are addressing these issues, especially for paravalvular leak. There is strong evidence that TAVR is appropriate for both extreme-risk and high-risk patients with symptomatic severe aortic stenosis, and the continued development of new valves are making implantation more reliable. This review discusses the studies supporting the use of TAVR and explores current advances in the field. PMID:27127560
Azorin, Jacques F; Bertin, Francois; Martinod, Emmanuel; Laskar, Marc
Tracheal replacement after extensive resection remains a challenge for the thoracic surgeon. We propose an innovative solution: the use of an aortic autograft. After an experimental work on animals with aortic autografts and allografts [Martinod E, Seguin A, Pfeuty K, Fornes P, Kambouchner M, Azorin JF, Carpentier AF. Long-term evaluation of the replacement of the trachea with an autologous aortic graft. Ann Thorac Surg 2003;75(5):1572-8; Martinod E, Seguin A, Holder-Espinasse M, Kambouchner M, Duterque-Coquillaud M, Azorin JF, Carpentier AF. Tracheal regeneration following tracheal replacement with an allogenic aorta. Ann Thorac Surg 2005;79(3):942-8], we present the first human case of long tracheal replacement with an aortic autograft. In this case we replaced 7 cm of a tumoral trachea using an aortic infra-renal autograft supported by a silicone stent. The early postoperative course was uneventful. The stent was removed at three months. The patient died at six months from an acute pulmonary infection without any sign of anastomosis leakage or graft rupture. A new field of clinical study has to be investigated.
Nyman, Ulf; Uher, Petr; Lindh, Mats; Lindblad, Bengt; Ivancev, Krasnodar
Purpose: To evaluate the results of primary stenting in aortic occlusive disease.Methods: Thirty patients underwent primary stenting of focal concentric (n = 2) and complex aortic stenoses (n = 19), and aortic or aorto-iliac occlusions (n = 9). Sixteen patients underwent endovascular outflow procedures, three of whom also had distal open surgical reconstructions. Median follow-up was 16 months (range 1-60 months).Results: Guidewire crossing of two aorto-biiliac occlusions failed, resulting in a 93% (28/30) technical success. Major complications included one access hematoma, one myocardial infarction, one death (recurrent thromboembolism) in a patient with widespread malignancy, and one fatal hemorrhage during thrombolysis of distal emboli from a recanalized occluded iliac artery. One patient did not improve his symptoms, resulting in a 1-month clinical success of 83% (25/30). Following restenting the 26 stented survivors changed their clinical limb status to +3 (n = 17) and +2 (n = 9). During follow-up one symptomatic aortic restenosis occurred and was successfully restented.Conclusions: Primary stenting of complex aortic stenoses and short occlusions is an attractive alternative to conventional surgery. Larger studies with longer follow-up and stratification of lesion morphology are warranted to define its role relative to balloon angioplasty. Stenting of aorto-biiliac occlusions is feasible but its role relative to bypass grafting remains to be defined.
Fishbein, Gregory A; Schoen, Frederick J; Fishbein, Michael C
Calcific aortic valve disease of the elderly is the most prevalent hemodynamically-significant valvular disease, and the most common lesion requiring valve replacement in industrialized countries. Transcatheter aortic valve implantation is a less invasive alternative to classical aortic valve replacement that can provide a therapeutic option for high-risk or inoperable patients with aortic stenosis. These devices must be biocompatible, have excellent hemodynamic performance, be easy to insert, be securely anchored without sutures, and be durable, without increased risk of thrombosis or infection. To date, complications are related to the site of entry for insertion, the site of implantation (aorta, coronary ostia, base of left ventricle), and to the structure and design of the inserted device. However, as with any novel technology unanticipated complications will develop. Goals for future development will be to make the devices more effective, more durable, safer, and easier to implant, so as to further improve outcome for patients with severe aortic stenosis. The pathologist participating in research and development, and examination of excised devices will have a critical role in improving outcome for these patients.
Alli, Oluseun; Jacobs, Larry; Amanullah, Aman M
The acute aortic syndromes carry significant morbidity and mortality, especially when detected late. Symptoms may mimic myocardial ischemia, and physical findings may be absent or, if present, can be suggestive of a diverse range of other conditions. Maintaining a high clinical index of suspicion is crucial in establishing the diagnosis. All patients with suspected aortic disease and evidence of acute ischemia on electrocardiogram should undergo diagnostic imaging studies before thrombolytics are administered. The demonstration of an intimal flap separating 2 lumina is the basis for diagnosis. Tear detection and localization are very important because any therapeutic intervention aims to occlude the entry tear. The goals of medical therapy are to reduce the force of left ventricular contractions, decrease the steepness of the rise of the aortic pulse wave, and reduce the systemic arterial pressure to as low a level as possible without compromising perfusion of vital organs. Surgical therapy still remains the gold standard of care for type A aortic dissection, whereas in type B dissection, percutaneous aortic stenting and fenestration techniques have been developed and are sometimes used in conjunction with medical therapy in certain situations.
Maffi, Alberto; Mulè, Chiara; Taveggia, Giovanni
The rehabilitation of amputees requires a multi-discipline approach. Within the work of the team, physiotherapy plays a central role both in terms of the technical skills made available to the patient, as well as in terms of the psychological-motivational support offered to the amputee during treatment. The pre-prosthetic phase of rehabilitation is the beginning of a complex rehabilitative process during which starts with an assessment of the general clinical condition of the patient and their residual capacities, so as to develop personalised rehabilitative strategies based upon the needs of the amputee. This whole process aims to get the amputee standing with a prosthetic as quickly as possible, thus allowing the social reintegration of the amputee.
Santoro, Rosaria; Consolo, Filippo; Spiccia, Marco; Piola, Marco; Kassem, Samer; Prandi, Francesca; Vinci, Maria Cristina; Forti, Elisa; Polvani, Gianluca; Fiore, Gianfranco Beniamino; Soncini, Monica; Pesce, Maurizio
Glutaraldehyde-fixed pericardium of animal origin is the elective material for the fabrication of bio-prosthetic valves for surgical replacement of insufficient/stenotic cardiac valves. However, the pericardial tissue employed to this aim undergoes severe calcification due to chronic inflammation resulting from a non-complete immunological compatibility of the animal-derived pericardial tissue resulting from failure to remove animal-derived xeno-antigens. In the mid/long-term, this leads to structural deterioration, mechanical failure, and prosthesis leaflets rupture, with consequent need for re-intervention. In the search for novel procedures to maximize biological compatibility of the pericardial tissue into immunocompetent background, we have recently devised a procedure to decellularize the human pericardium as an alternative to fixation with aldehydes. In the present contribution, we used this procedure to derive sheets of decellularized pig pericardium. The decellularized tissue was first tested for the presence of 1,3 α-galactose (αGal), one of the main xenoantigens involved in prosthetic valve rejection, as well as for mechanical tensile behavior and distensibility, and finally seeded with pig- and human-derived aortic valve interstitial cells. We demonstrate that the decellularization procedure removed the αGAL antigen, maintained the mechanical characteristics of the native pig pericardium, and ensured an efficient surface colonization of the tissue by animal- and human-derived aortic valve interstitial cells. This establishes, for the first time, the feasibility of fixative-free pericardial tissue seeding with valve competent cells for derivation of tissue engineered heart valve leaflets.
Karataş, Zehra; Karataş, Ahmet; Özlü, Tülay; Goksugur, Sevil B.; Varan, Birgül
The use of antiepileptic drugs increases the risk of major congenital malformations during pregnancy. Here, we report an infant who had a history of in-utero carbamazepine exposure and who was born with a cardiac malformation. The infant was born at 39 weeks of gestation vaginally to an epileptic mother who had been treated with carbamazepine throughout her pregnancy. He was referred due to cardiac murmur in the second week of his life. The mother had not received folic acid supplementation. Transthoracic echocardiography revealed bicuspid aortic valve, mild aortic stenosis, patent ductus arteriosus, patent foramen ovale and the renal ultrasound revealed mild left hydronephrosis. Follow-up echocardiography performed 14 weeks later showed increased severity of aortic stenosis and percutaneous balloon aortic valvuloplasty was performed. To our knowledge, there is only one case report in the literature mentioning the association of a bicuspid aortic valve and aortic stenosis with oxcarbazepine exposure, which is a structural derivative of carbamazepine. However, there are no reports for association with carbamazepine itself. Bicuspid aorta and aortic stenosis may be among the cardiac malformations that result from the teratogenic effect of carbamazepine. PMID:25584038
Belov, Iu V; Komarov, R N; Stepanenko, A B; Gens, A P; Charchian, E R
The paper presents the method of local repair of distal aortic dissections. Local aortic grafting for surgical correction of type B dissecting aortic aneurysms helped to decrease hospital mortality up to 15.4%, the rate of paraparesis and multiorgan failure - up to 11.5%.
... Rekha Mankad, M.D. References AskMayoExpert. Valvular disease – aortic stenosis. Rochester, Minn.: Mayo Foundation for Medical Education and ... Original article: http://www.mayoclinic.org/diseases-conditions/aortic-stenosis/expert-answers/aortic-valve-calcification/FAQ-20058525 . Mayo ...
Park, Jinhyuk; Choi, Seung-Bok
A prosthetic knee for above-knee (AK) amputees is categorized into two types; namely a passive and an active type. The passive prosthetic knee is generally made by elastic materials such as carbon fiber reinforced composite material, titanium and etc. The passive prosthetic knee easy to walk. But, it has disadvantages such that a knee joint motion is not similar to ordinary people. On the other hand, the active prosthetic knee can control the knee joint angle effectively because of mechanical actuator and microprocessor. The actuator should generate large damping force to support the weight of human body. But, generating the large torque using small actuator is difficult. To solve this problem, a semi-active type prosthetic knee has been researched. This paper proposes a semi-active prosthetic knee using a flow mode magneto-rheological (MR) damper for AK amputees. The proposed semi-active type prosthetic knee consists of the flow mode MR damper, hinge and prosthetic knee body. In order to support weight of human body, the required energy of MR damper is smaller than actuator of active prosthetic leg. And it can control the knee joint angle by inducing the magnetic field during the stance phase.
... Rehabilitation Program, Chiropractic Care, Audiology and Speech Pathology, Veterans Benefits, and Prosthetic and.... Long, Designated Federal Officer, Veterans Health Administration, Patient Care Services,...
Butany, J; Collins, M J
Pathologists all over the world increasingly encounter prosthetic cardiac devices. A good evaluation of these devices is a valuable source of information, which can contribute to patient care and the appreciation and understanding of the pathobiology involved in the changes occurring between the host and the implanted prosthetic device. This article summarises the considerations underlying the analysis of prosthetic devices (particularly prosthetic heart valves), including the identification of the devices, the major morphological features of the devices, their modes of failure, and some technical details about evaluation and pitfalls. PMID:15677529
Goujon, H; Bonnet, X; Sautreuil, P; Maurisset, M; Darmon, L; Fode, P; Lavaste, F
This paper reports on a functional evaluation of prosthetic feet based on gait analysis. The aim is to analyse prosthetic feet behaviour under loads applied during gait in order to quantify user benefits for each foot. Ten traumatic amputees (six trans-tibial and four trans-femoral) were tested using their own prosthetic foot. An original protocol is presented to calculate the forefoot kinematics together with the overall body kinematics and ground reaction forces during gait. In this work, sagittal motion of the prosthetic ankle and the forefoot, time-distance parameters and ground reaction forces were examined. It is shown that an analysis of not only trans-tibial but also trans-femoral amputees provides an insight in the performance of prosthetic feet. Symmetry and prosthetic propulsive force were proved to be mainly dependant on amputation level. In contrast, the flexion of the prosthetic forefoot and several time-distance parameters are highly influenced by foot design. Correlations show influential of foot and ankle kinematics on other parameters. These results suggest that prosthetic foot efficiency depends simultaneously on foot design and gait style. The evaluation, proposed in this article, associated to clinical examination should help to achieve the best prosthetic foot match to a patient.
... administered by the Secretary to serve Veterans with spinal cord injuries, blindness or visual impairments... Services, Spinal Cord Injury and Disorders, Orthotic and Prosthetic Program, Clothing Benefits,...
Abeyratne, L R; Kingston, J E; Onadim, Z; Dubrey, S W
Heritable retinoblastoma is associated with a germline mutation in the tumour suppressor gene RBI. The Rb protein (pRb) arises from the RB1 gene, which was the first demonstrated cancer susceptibility gene in humans. 1 Second primary malignancies are recognised complications of retinoblastoma. Furthermore, pRb is implicated in valve remodelling in calcific aortic valve disease. 2 3 We report a family with hereditary retinoblastoma and associated secondary primary malignancies. There are two interesting aspects to this family. The first is the concept of ‘cancer susceptibility genes’; the RBI gene being the first reported in humans. A further feature of note is that two family members also have bicuspid aortic valves. We discuss a potential association between the gene defect responsible for retinoblastoma (with its associated propensity for further malignancies) and accelerated deterioration of the bicuspid aortic valve in the proband carrying this gene defect. PMID:23595191
Darabant, Sergiu; Oberton, Shelby B; Roldan, Luis P; Roldan, Carlos A
Aortic valve infective endocarditis (IE) can be complicated with severe aortic regurgitation (AR) jet-related lesions such as vegetations, pseudoaneurysms, aneurysms or perforations on the anterior mitral leaflet. Herein is reported the case of a 69-year-old male with culture-negative aortic valve endocarditis complicated with aortic valve perforations resulting in severe and eccentric AR and an AR jet-related ventricular septal defect (VSD). Neither transthoracic echocardiography (TTE) nor two-dimensional transesophageal echocardiography (2D-TEE) were unable to clearly discriminate an aorto-right ventricular fistula from a VSD. By contrast, three-dimensional TEE (3D-TEE) demonstrated multiple aortic valve vegetations, aortic valve perforations, severe AR, and an AR jet-related VSD. The 3D-TEE findings were confirmed at surgery, the aortic valve was replaced with a bioprosthetic valve, and the VSD was repaired with a pericardial patch. To the authors' knowledge, this is the first case of a VSD resulting from an AR jet lesion to be detected and characterized using 3D-TEE. The accurate preoperative diagnosis and characterization of the VSD with 3D-TEE contributed to successful surgery and the patient's short- and long-term survival. Video 1A: This four-chamber transthoracic echocardiography (TTE) view with color Doppler shows a color-Doppler jet traversing the basal interventricular septum (IVS) into the right ventricle, predominantly during systole. However, the origin of the jet resulting from an aortic-right ventricular fistula cannot be determined. A mild to moderate degree of tricuspid regurgitation is also noted. Video 1B: Close-up view of the basal IVS demonstrates a color Doppler jet traversing the IVS, predominantly during systole and apparently originating in the left ventricular outflow tract side, as illustrated by a color Doppler acceleration zone. However, and as in Fig. 1A, the origin of the jet resulting from an aortic-right ventricular fistula cannot
Pepine, Carl J.; Nichols, W. W.; Curry, R. C.; Conti, C. Richard
Beneficial effects of nitroprusside infusion in heart failure are purportedly a result of decreased afterload through “impedance” reduction. To study the effect of nitroprusside on vascular factors that determine the total load opposing left ventricular ejection, the total aortic input impedance spectrum was examined in 12 patients with heart failure (cardiac index <2.0 liters/min per m2 and left ventricular end diastolic pressure >20 mm Hg). This input impedance spectrum expresses both mean flow (resistance) and pulsatile flow (compliance and wave reflections) components of vascular load. Aortic root blood flow velocity and pressure were recorded continuously with a catheter-tip electromagnetic velocity probe in addition to left ventricular pressure. Small doses of nitroprusside (9-19 μg/min) altered the total aortic input impedance spectrum as significant (P < 0.05) reductions in both mean and pulsatile components were observed within 60-90 s. With these acute changes in vascular load, left ventricular end diastolic pressure declined (44%) and stroke volume increased (20%, both P < 0.05). Larger nitroprusside doses (20-38 μg/min) caused additional alteration in the aortic input impedance spectrum with further reduction in left ventricular end diastolic pressure and increase in stroke volume but no additional changes in the impedance spectrum or stroke volume occurred with 39-77 μg/min. Improved ventricular function persisted when aortic pressure was restored to control values with simultaneous phenylephrine infusion in three patients. These data indicate that nitroprusside acutely alters both the mean and pulsatile components of vascular load to effect improvement in ventricular function in patients with heart failure. The evidence presented suggests that it may be possible to reduce vascular load and improve ventricular function independent of aortic pressure reduction. PMID:457874
Ryb, Gabriel E; Dischinger, Patricia C; Kleinberger, Michael; McGwin, Gerald; Griffin, Russell L
The occurrence of AI was studied in relation to vehicle model year (MY) among front seat vehicular occupants, age≥16 in vehicles MY≥1994, entered in the National Automotive Sampling System Crashworthiness Data System between 1997 and 2010 to determine whether newer vehicles, due to their crashworthiness improvements, are linked to a lower risk of aortic injuries (AI). MY was categorized as 1994-1997, 1998-2004, or 2005-2010 reflecting the introduction of newer occupant protection technology. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals for the association between AI and MY independent of possible confounders. Analysis was repeated, stratified by frontal and near lateral impacts. AI occurred in 19,187 (0.06%) of the 31,221,007 (weighted) cases, and contributed to 11% of all deaths. AIs were associated with advanced age, male gender, high BMI, near-side impact, rollover, ejection, collision against a fixed object, high ΔV, vehicle mismatch, unrestrained status, and forward track position. Among frontal crashes, MY 98-04 and MY 05-10 showed increased adjusted odds of AI when compared to MY 94-97 [OR 1.84 (1.02-3.32) and 1.99 (0.93-4.26), respectively]. In contrast, among near-side impact crashes, MY 98-04 and MY 05-10 showed decreased adjusted odds of AI [OR 0.50 (0.25-0.99) and 0.27 (0.06-1.31), respectively]. While occupants of newer vehicles experience lower odds of AI in near side impact crashes, a higher AI risk is present in frontal crashes.