Science.gov

Sample records for aortic cross clamping

  1. Acute aortic dissection from cross-clamp injury.

    PubMed

    Litchford, B; Okies, J E; Sugimura, S; Starr, A

    1976-11-01

    Acute dissection of the ascending aorta secondary to cross-clamp injury can be successfully managed if the problem is recognized immediately. Bypass must be instituted after recannulation at a point distal to the innominate artery so that proper exposure of the site of injury can be obtained. Systemic as well as local hypothermia for myocardial preservation are both necessary. Direct suture closure of all layers at the site of dissection over Teflon felt can terminate this process. PMID:979312

  2. The effects of thoracic aortic cross-clamping and declamping on visceral organ blood flow.

    PubMed Central

    Oyama, M; McNamara, J J; Suehiro, G T; Suehiro, A; Sue-Ako, K

    1983-01-01

    Blood flow was measured using radioactive microspheres in 11 macaque monkeys 1) before hemorrhage shock, 2) after onset of shock, 3) after aortic cross-clamping and resuscitation, and 4) after release of the cross-clamp and stabilization. Hemodynamic parameters (cardiac output, arterial, right atrial and left atrial pressure) and blood gases were also monitored. Total abdominal organ flow fell with hemorrhage and fell further with aortic clamping. Reinfusion of shed volume did not restore abdominal organ flow (4.7% baselines) but increased LAP and cardiac output to the upper body. Release of the cross-clamp produced profound acidosis that was treated effectively with NcHCO3. After stabilization of blood, flow to kidney remained low (49% baseline) although intestinal flow was increased threefold (320% of baseline). It is clear that thoracic aortic cross-clamping in shock further compromises already reduced visceral blood flow and may contribute to the problem of ischemic multiple organ failure after resuscitation from hemorrhagic shock. PMID:6830352

  3. Haemodynamic effects of thoracic epidural anaesthesia during proximal aortic cross-clamping in pigs.

    PubMed

    Aadahl, P; Saether, O D; Stenseth, R; Myhre, H O

    1995-01-01

    Cross-clamping (XC) of the thoracic aorta induces a hyperdynamic circulation proximal to the aortic clamp. In this investigation, the effects of thoracic epidural anaesthesia (TEA) on the haemodynamic response to XC were studied in pigs. Seventeen pigs were anaesthetized with ketamine, and the thoracic aorta was cross-clamped for 30 minutes. In eight of the animals (TEA-group) a thoracic epidural block (3 ml 0.5% bupivacaine) was added to the general anaesthesia. Prior to XC there was a lower heart rate (HR), cardiac output (CO) and mixed venous oxygen saturation (SvO2) in the TEA-group compared to the nine animals with general anasthesia only (control-group). During XC there was an increase in HR, CO, SvO2 and proximal aortic blood pressure (PPROX) in both groups, without differences between groups. Following aortic declamping central venous pressure (CVP), pulmonary artery pressure (PAP) and pulmonary capillary wedge pressure (PCWP) increased in both groups. Fifteen minutes after declamping, one animal in each group died. It was concluded that in this experimental model, TEA combined with general anaesthesia did not modify the haemodynamic response to XC of the thoracic aorta. PMID:7725879

  4. Aortic compression and cross clamping in a case of placenta percreta and amniotic fluid embolism: a case report.

    PubMed

    Belfort, Michael A; Zimmerman, John; Schemmer, Glenn; Oldroyd, Ronald; Smilanich, Robert; Pearce, Michael

    2011-09-01

    Amniotic fluid embolism (AFE, also known as anaphylactoid syndrome of pregnancy) at the time of surgery for placenta percreta has been previously reported. We report here a case in which AFE and associated cardiac arrest occurred following a hysterectomy for placenta percreta. In this case, subhepatic manual aortic compression during the cardiac arrest and chest compressions followed by infrarenal aortic cross-clamping during volume infusion and reversal of the coagulopathy were associated with a successful resuscitation and good maternal outcome. PMID:23705082

  5. Physiologic Responses to Infrarenal Aortic Cross-Clamping during Laparoscopic or Conventional Vascular Surgery in Experimental Animal Model: Comparative Study

    PubMed Central

    Martín-Cancho, María F.; Crisóstomo, Verónica; Soria, Federico; Calles, Carmen; Sánchez-Margallo, Francisco M.; Díaz-Güemes, Idoia; Usón-Gargallo, Jesús

    2008-01-01

    The aim of this study was to compare the hemodynamic and ventilatory effects of prolonged infrarenal aortic cross-clamping in pigs undergoing either laparotomy or laparoscopy. 18 pigs were used for this study. Infrarenal aortic crossclamping was performed for 60 minutes in groups I (laparotomy, n = 6) and II (laparoscopy, n = 6). Group III (laparoscopy, n = 6) underwent a 120-minute long pneumoperitoneum in absence of aortic clamping (sham group). Ventilatory and hemodynamic parameters and renal function were serially determined in all groups. A significant decrease in pH and significant increase in PaCO2 were observed in group II, whereas no changes in these parameters were seen in group I and III. All variables returned to values similar to baseline in groups I and II 60 minutes after declamping. A significant increase in renal resistive index was evidenced during laparoscopy, with significantly higher values seen in Group II. Thus a synergic effect of pneumoperitoneum and aortic cross-clamping was seen in this study. These two factors together cause decreased renal perfusion and acidosis, thus negatively affecting the patient's general state during this type of surgery. PMID:21197458

  6. Cross-clamping of the thoracic aorta. Influence of aortic shunts, laminectomy, papaverine, calcium channel blocker, allopurinol, and superoxide dismutase on spinal cord blood flow and paraplegia in baboons.

    PubMed

    Svensson, L G; Von Ritter, C M; Groeneveld, H T; Rickards, E S; Hunter, S J; Robinson, M F; Hinder, R A

    1986-07-01

    There is a high incidence of paraplegia associated with thoracic aortic cross-clamping, even when cardiopulmonary bypass or shunts are used. In 56 adult baboons, spinal cord blood flow (SCBF), vascular anatomy, and paraplegia rates were evaluated. Tissue blood flow was measured by radioactive microspheres. Various procedures were used to increase SCBF and to prevent ischemia-reperfusion injury. It was found that the rate of paraplegia was inversely correlated with neural tissue ischemia (SCBF) and directly correlated with reperfusion hyperemia. Two methods completely prevented paraplegia. These two methods were a thoracic shunt with occlusion of the infrarenal aorta or cerebrospinal fluid drainage plus intrathecal papaverine injection, both of which were associated with an increased SCBF. Furthermore, papaverine dilated the anterior spinal artery (ASA) (p = 0.007) and increased the blood flow through the lower ASA. Whereas procedures utilizing a calcium channel blocker (flunarizine), allopurinol, superoxide dismutase (SOD), laminectomy alone, and a thoracoabdominal shunt not perfusing the arteria radicularis magna (ARM) all failed to prevent paraplegia, allopurinol (p = 0.026) and SOD (p = 0.004) did prevent gastric stress lesions, indicating that their failure to prevent paraplegia was not due to a lack of activity. Of great clinical interest is that, if a shunt is used and the ARM is perfused, infrarenal aortic cross-clamping increases SCBF, thus preventing paraplegia. Intrathecal application of papaverine proved to be even more effective in increasing SCBF and also completely prevented paraplegia. As this is a safer procedure than the insertion of shunts, this is the method of choice for the prevention of paraplegia associated with thoracic aortic cross-clamping. The preliminary trial using intrathecal papaverine in human beings has thus far shown no adverse side effects from the drug, and no paraplegia has occurred. PMID:3729582

  7. Cross-clamping of the thoracic aorta. Influence of aortic shunts, laminectomy, papaverine, calcium channel blocker, allopurinol, and superoxide dismutase on spinal cord blood flow and paraplegia in baboons.

    PubMed Central

    Svensson, L G; Von Ritter, C M; Groeneveld, H T; Rickards, E S; Hunter, S J; Robinson, M F; Hinder, R A

    1986-01-01

    There is a high incidence of paraplegia associated with thoracic aortic cross-clamping, even when cardiopulmonary bypass or shunts are used. In 56 adult baboons, spinal cord blood flow (SCBF), vascular anatomy, and paraplegia rates were evaluated. Tissue blood flow was measured by radioactive microspheres. Various procedures were used to increase SCBF and to prevent ischemia-reperfusion injury. It was found that the rate of paraplegia was inversely correlated with neural tissue ischemia (SCBF) and directly correlated with reperfusion hyperemia. Two methods completely prevented paraplegia. These two methods were a thoracic shunt with occlusion of the infrarenal aorta or cerebrospinal fluid drainage plus intrathecal papaverine injection, both of which were associated with an increased SCBF. Furthermore, papaverine dilated the anterior spinal artery (ASA) (p = 0.007) and increased the blood flow through the lower ASA. Whereas procedures utilizing a calcium channel blocker (flunarizine), allopurinol, superoxide dismutase (SOD), laminectomy alone, and a thoracoabdominal shunt not perfusing the arteria radicularis magna (ARM) all failed to prevent paraplegia, allopurinol (p = 0.026) and SOD (p = 0.004) did prevent gastric stress lesions, indicating that their failure to prevent paraplegia was not due to a lack of activity. Of great clinical interest is that, if a shunt is used and the ARM is perfused, infrarenal aortic cross-clamping increases SCBF, thus preventing paraplegia. Intrathecal application of papaverine proved to be even more effective in increasing SCBF and also completely prevented paraplegia. As this is a safer procedure than the insertion of shunts, this is the method of choice for the prevention of paraplegia associated with thoracic aortic cross-clamping. The preliminary trial using intrathecal papaverine in human beings has thus far shown no adverse side effects from the drug, and no paraplegia has occurred. PMID:3729582

  8. Free-floating left atrial ball thrombus after mitral valve replacement with patent coronary artery bypass grafts: successful removal by a right minithoracotomy approach without aortic cross-clamp.

    PubMed

    Hisatomi, Kazuki; Hashizume, Koji; Tanigawa, Kazuyoshi; Miura, Takashi; Matsukuma, Seiji; Yokose, Shogo; Kitamura, Tessho; Shimada, Takashi; Eishi, Kiyoyuki

    2016-06-01

    A free-floating thrombus in the left atrium without attachment to either the atrial wall or the mitral valve is extremely rare. We describe a case in a 79-year-old woman with chronic atrial fibrillation and a recent stroke who had undergone mitral valve replacement 25 years previously and coronary artery bypass grafting 5 years previously. Redo cardiac surgery represents a clinical challenge due to a higher rate of peri-operative morbidity and mortality. Median re-sternotomy can be particularly difficult in patients with functioning coronary artery grafts, where the risk of graft injury is a significant concern. Prompt surgical intervention was carried out, and to avoid the challenge of re-sternotomy in this patient with two prior thoracotomies, we successfully removed the thrombus by a right minithoracotomy approach without aortic cross-clamping. There was no postoperative occurrence of a new stroke or aggravation of the pre-existing stroke. PMID:25098689

  9. Local and remote ischemic preconditioning protect against intestinal ischemic/reperfusion injury after supraceliac aortic clamping

    PubMed Central

    Erling, Nilon; de Souza Montero, Edna Frasson; Sannomiya, Paulina; Poli-de-Figueiredo (in memoriam), Luiz Francisco

    2013-01-01

    OBJECTIVES: This study tests the hypothesis that local or remote ischemic preconditioning may protect the intestinal mucosa against ischemia and reperfusion injuries resulting from temporary supraceliac aortic clamping. METHODS: Twenty-eight Wistar rats were divided into four groups: the sham surgery group, the supraceliac aortic occlusion group, the local ischemic preconditioning prior to supraceliac aortic occlusion group, and the remote ischemic preconditioning prior to supraceliac aortic occlusion group. Tissue samples from the small bowel were used for quantitative morphometric analysis of mucosal injury, and blood samples were collected for laboratory analyses. RESULTS: Supraceliac aortic occlusion decreased intestinal mucosal length by reducing villous height and elevated serum lactic dehydrogenase and lactate levels. Both local and remote ischemic preconditioning mitigated these histopathological and laboratory changes. CONCLUSIONS: Both local and remote ischemic preconditioning protect intestinal mucosa against ischemia and reperfusion injury following supraceliac aortic clamping. PMID:24473514

  10. Fatal Delayed Esophageal Rupture Following Aortic Clamping for Treatment of Stanford Type B Dissection

    SciTech Connect

    Ito, Hisao; Yamada, Takayuki; Ishibashi, Tadashi; Akiyama, Masatoshi; Nakame, Takahiko; Ito, Yasuhiro; Konnai, Toshiaki

    2003-11-15

    A 65-year-old man underwent a thromboexclusionoperation for management of chronic Stanford type B dissecting aneurysmin 1991. However, long-term follow-up CT scans after the operation revealed that the ascending aorta gradually enlarged and was eventually complicated by recurrent aortic dissection. The patient complained of frequent bloody sputum, whereas chest roentogenography showed no pulmonary abnormalities. Subsequent swallow esophagogram demonstrated that the upper esophagus was deviated to the right and the middle esophagus was greatly compressed by the aortic clamp. Esophageal endoscopy showed a bloody inner surface and marked swelling of the middle esophagus. The patient eventually died of massive hematemesis in 2001. We describe the imaging features of unanticipated complications such as recurrent dissecting aneurysm or impending esophageal rupture.Furthermore, we discuss the cause of hematemesis and document that the aortic clamp migrated and resulted in development of a recurrent aneurysmal dissection, which in turn resulted in esophageal rupture with aneurysmal disruption.

  11. Investigating the effect of glucose on aortic pulse wave velocity using pancreatic clamping methodology.

    PubMed

    Puzantian, Houry; Teff, Karen; Townsend, Raymond R

    2015-05-01

    Aortic stiffness, determined by carotid-femoral pulse wave velocity (cfPWV), independently predicts cardiovascular outcomes. Recent studies suggest that glucose levels influence arterial stiffness indices. It is not clear, however, whether glucose affects cfPWV independently of glucoregulatory hormones. The aim of this study was to utilize a pancreatic clamping approach to determine whether plasma glucose independently predicts cfPWV. Healthy participants (N = 10) underwent pancreatic clamping to control glucose at varying concentrations using a 20% dextrose infusion while suppressing endogenous glucagon, insulin, and growth hormone by octreotide and replacing the hormones intravenously to achieve basal concentrations. Tonometric cfPWV, blood pressure, heart rate, plasma glucose, glucagon, insulin, growth hormone, and vasoactive biomarkers were measured. Plasma glucose levels of 150 mg/dl at 1 hr and 200 mg/dl at 2 hr postbaseline were achieved. There were no significant changes in cfPWV (5.8 m/s at 0 hr, 5.9 m/s at 1 hr, and 5.9 m/s at 2 hr) with increased glucose levels. There were small increases in insulin secretion. A definitive role for glucose in cfPWV modulation was not determined; there is a potential role for insulin as a cfPWV modulator. Continued efforts in clarifying the independent roles of glucose and insulin can elucidate novel vessel-related targets for cardiovascular disease prevention and management in patients with impaired glucose tolerance and diabetes. PMID:25802385

  12. Asystole to cross-clamp period predicts development of biliary complications in liver transplantation using donation after cardiac death donors.

    PubMed

    Taner, C Burcin; Bulatao, Ilynn G; Perry, Dana K; Sibulesky, Lena; Willingham, Darrin L; Kramer, David J; Nguyen, Justin H

    2012-08-01

    This study sought to determine the procurement factors that lead to development of intrahepatic bile duct strictures (ITBS) and overall biliary complications in recipients of donation after cardiac death (DCD) liver grafts. Detailed information for different time points during procurement (withdrawal of support; SBP < 50 mmHg; oxygen saturation <30%; mandatory wait period; asystole; incision; aortic cross clamp) and their association with the development of ITBS and overall biliary complications were examined using logistic regression. Two hundred and fifteen liver transplants using DCD donors were performed between 1998 and 2010 at Mayo Clinic Florida. Of all the time periods during procurement, only asystole-cross clamp period was significantly different between patients with ITBS versus no ITBS (P = 0.048) and between the patients who had overall biliary complications versus no biliary complications (P = 0.047). On multivariate analysis, only asystole-cross clamp period was significant predictor for development of ITBS (P = 0.015) and development of overall biliary complications (P = 0.029). Hemodynamic changes in the agonal period did not emerge as risk factors. The results of the study raise the possibility of utilizing asystole-cross-clamp period in place of or in conjunction with donor warm ischemia time in determining viability or quality of liver grafts. PMID:22703372

  13. Stroke Volume estimation using aortic pressure measurements and aortic cross sectional area: Proof of concept.

    PubMed

    Kamoi, S; Pretty, C G; Chiew, Y S; Pironet, A; Davidson, S; Desaive, T; Shaw, G M; Chase, J G

    2015-08-01

    Accurate Stroke Volume (SV) monitoring is essential for patient with cardiovascular dysfunction patients. However, direct SV measurements are not clinically feasible due to the highly invasive nature of measurement devices. Current devices for indirect monitoring of SV are shown to be inaccurate during sudden hemodynamic changes. This paper presents a novel SV estimation using readily available aortic pressure measurements and aortic cross sectional area, using data from a porcine experiment where medical interventions such as fluid replacement, dobutamine infusions, and recruitment maneuvers induced SV changes in a pig with circulatory shock. Measurement of left ventricular volume, proximal aortic pressure, and descending aortic pressure waveforms were made simultaneously during the experiment. From measured data, proximal aortic pressure was separated into reservoir and excess pressures. Beat-to-beat aortic characteristic impedance values were calculated using both aortic pressure measurements and an estimate of the aortic cross sectional area. SV was estimated using the calculated aortic characteristic impedance and excess component of the proximal aorta. The median difference between directly measured SV and estimated SV was -1.4ml with 95% limit of agreement +/- 6.6ml. This method demonstrates that SV can be accurately captured beat-to-beat during sudden changes in hemodynamic state. This novel SV estimation could enable improved cardiac and circulatory treatment in the critical care environment by titrating treatment to the effect on SV. PMID:26736434

  14. [Completion pneumonectomy combined with graft replacement of thoracic aortic aneurysm by simple clamping].

    PubMed

    Shimamoto, A; Takao, M; Kanemitsu, S; Fujinaga, K; Yan, G; Cruz, B P; Onoda, K; Shimono, T; Shimpo, H; Namikawa, S; Yuasa, H; Yada, I

    1999-01-01

    A 59-years-old male patient who had left upper lobe partial resection 30 years ago. He was seen at the family physician because of cough. A chest X-ray was showing an abnormal mass shadow measuring 3 x 4 cm in left lower lobe like honey comb. And squamous cell carcinoma (SCC) was detected in his sputum. He was diagnosed as primary lung cancer and introduced to our department to have operation. Chest CT-scan was showing lung tumor suspected SCC measuring 4.3 x 2.6 cm in segment 8 faced chest wall. At the same time, we detected thoracic aortic aneurysm and subcarinal lymph node, but could not see where the boundary is, so it was hard to distinguish between parietal thrombus with thoracic aortic aneurysm and swelling subcarinal lymph node. We decided it swelling subcarinal lymph node by three-dimensional treated CT-scan. Aortic angiography was showing proximal descending aortic aneurysm measuring diameter was 4.5 cm. Abdominal CT-scan was showing infrarenal abdominal aortic aneurysm measuring diameter was 5.5 cm. He was diagnosed as primary lung cancer (It. S8, SCC) (cT2N2M0, Stage IIIB), thoracic aortic aneurysm, abdominal aortic aneurysm, and idiopathic pulmonary fibrosis, and had completion pneumonectomy (R 2 b) for primary lung cancer and graft replacement with aneurysm dissection for thoracic aortic aneurysm without extracorporeal circulation. In this operation, we could find swelling subcarinal lymph node measuring 5 x 3 cm instead of parietal thrombus with thoracic aortic aneurysm. Pathological examination diagnosed middle differential SCC and no metastasis from dissected lymph node (PT2N0M0, Stage I A). PMID:10024802

  15. A Modified Epicardial Radiofrequency Ablation for Preoperative Atrial Fibrillation Combined With Isolated Aortic Valve Disease.

    PubMed

    Jiang, Zhaolei; Ma, Nan; Liu, Hao; Tang, Min; Ding, Fangbao; Bao, Chunrong; Mei, Ju

    2016-06-01

    Isolated aortic valve diseases can lead to atrial fibrillation (AF) by causing left atrium pressure overload and enlargement. At present, most patients with preoperative AF and isolated aortic valve disease have undergone a Cox-maze IV procedure through a left atriotomy under cardiopulmonary bypass with aortic cross-clamping. Here, we describe a novel modified epicardial radiofrequency ablation procedure performed on a beating heart without aortic cross-clamping or opening the left atrium. This technique has proved to be safe and feasible, with good clinical outcomes. It may be useful in selecting the best ablation approaches for patients with AF and aortic valve disease. PMID:27211963

  16. Endovascular Repair of Abdominal Aortic Aneurysm in a Patient with Renal Transplant

    SciTech Connect

    Rao, M.; Arya, N. Lee, B.; Hannon, R.J.; Loan, W.; Soong, C.V.

    2004-09-15

    Patients with functioning renal transplant who develop abdominal aortic aneurysm can safely be treated with endovascular repair. Endovascular repair of aneurysm avoids renal ischemia associated with cross-clamping of aorta.

  17. Post clamp

    NASA Technical Reports Server (NTRS)

    Ramsey, John K. (Inventor); Meyn, Erwin H. (Inventor)

    1990-01-01

    A pair of spaced collars are mounted at right angles on a clamp body by retaining rings which enable the collars to rotate with respect to the clamp body. Mounting posts extend through aligned holes in the collars and clamp body. Each collar can be clamped onto the inserted post while the clamp body remains free to rotate about the post and collar. The clamp body is selectively clamped onto each post.

  18. del Nido versus St. Thomas Cardioplegia Solutions: A Single-Center Retrospective Analysis of Post Cross-Clamp Defibrillation Rates.

    PubMed

    Buel, Shane T; Striker, Carrie Whittaker; O'Brien, James E

    2016-06-01

    There are many cardioplegia solutions currently in use for pediatric cardiopulmonary bypass (CPB). The most common being del Nido solution. Another common cardioplegia solution used for pediatric CPB is St. Thomas. In October 2014, Children's Mercy Kansas City changed from the use of modified St. Thomas to del Nido. This study compared rates of post cross-clamp fibrillation requiring defibrillation between del Nido solution and modified St. Thomas solution stratified by weight at Children's Mercy Kansas City. This retrospective study consisted of 394 patients who underwent cardiac surgery requiring cardioplegia between January 1, 2014 and July 31, 2015. The outcome measured was defibrillation upon cross-clamp removal. Statistical significance was determined using Fishers exact test with a two-sided significance level of .05. Incidence of defibrillation post cross-clamp removal was 4.4% in the del Nido group and 26.8% in the St. Thomas group (p < .0001). Analysis by weight stratifications displays a reduction in post cross-clamp defibrillation rates in groups using the del Nido solution. The 0- to 6-kg category had an incidence of fibrillation of 1.23% in the del Nido group and 17.5% in the St. Thomas group (p < .0003). The 6- to 15-kg category had an incidence of defibrillation of 1.82% in the del Nido group and 14% in the St. Thomas group (p < .0198). The 15- to 60-kg category had an incidence of defibrillation of 8.9% in the del Nido group and 61% in the St. Thomas group (p < .0001). The >60-kg category had an incidence of defibrillation of 16.7% in the del Nido group and 63% in the St. Thomas group (p < .0623). This study demonstrates a 6-fold decrease in the overall rate of defibrillation post cross-clamp removal between St. Thomas and del Nido cardioplegia solutions. Analyses of weight stratifications demonstrate a decrease in the rate of defibrillation post cross-clamp removal in all categories within the del Nido group. PMID:27578896

  19. Sutureless aortic valve replacement

    PubMed Central

    Phan, Kevin

    2015-01-01

    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

  20. Valve Replacement with a Sutureless Aortic Prosthesis in a Patient with Concomitant Mitral Valve Disease and Severe Aortic Root Calcification

    PubMed Central

    Scafuri, Antonio; Nicolò, Francesca; Chiariello, Luigi

    2016-01-01

    Aortic valve replacement with concomitant mitral valve surgery in the presence of severe aortic root calcification is technically difficult, with long cardiopulmonary bypass and aortic cross-clamp times. We performed sutureless aortic valve replacement and mitral valve annuloplasty in a 68-year-old man who had severe aortic stenosis and moderate-to-severe mitral regurgitation. Intraoperatively, we found severe calcification of the aortic root. We approached the aortic valve through a transverse aortotomy, performed in a higher position than usual, and we replaced the valve with a Sorin Perceval S sutureless prosthesis. In addition, we performed mitral annuloplasty with use of an open rigid ring. The aortic cross-clamp time was 63 minutes, and the cardiopulmonary bypass time was 83 minutes. No paravalvular leakage of the aortic prosthesis was detected 30 days postoperatively. Our case shows that the Perceval S sutureless bioprosthesis can be safely implanted in patients with aortic root calcification, even when mitral valve disease needs surgical correction. PMID:27127442

  1. Mannitol Infusion Within 15 Min of Cross-Clamp Improves Living Donor Kidney Preservation

    PubMed Central

    Andrews, Peter M.; Cooper, Matthew; Verbesey, Jennifer; Ghasemian, Seyed; Rogalsky, Derek; Moody, Patrick; Chen, Allen; Alexandrov, Peter; Wang, Hsing-Wen; Chen, Yu

    2014-01-01

    Background Optical coherence tomography (OCT) revealed that cells lining proximal convoluted tubules of living donor kidneys (LDKs) procured by laparoscopic procedures were very swollen in response to the brief period of ischemia experienced between the time of arterial vessel clamping and flushing the excised kidney with cold preservation solution. Damage to the tubules as a result of this cell swelling resulted in varying degrees of acute tubular necrosis (ATN) that slowed the recovery of the donor kidneys during the first 2 weeks after their transplantation. Methods To prevent this cell damage during LDK procurement, we changed the protocol for intravenous administration of mannitol (i.e., 12.5 or 25 g) to the donor. Specifically, we reduced the time of mannitol administration from 30 to 15 min or less before clamping the renal artery. Result OCT revealed that this change in the timing of mannitol administration protected the human donor proximal tubules from normothermic-induced cell swelling. An evaluation of posttransplant recovery of renal function showed that patients treated with this modified protocol returned to normal renal function significantly faster than those treated with mannitol 30 min or more before clamping the renal artery. Conclusion Because slow graft recovery in the first weeks after transplantation represents a risk factor for long-term graft function and survival, we believe that this change in pretreatment protocol will improve renal transplants in patients receiving LDK. PMID:24831920

  2. Polymer coating of porcine decellularized and cross-linked aortic grafts.

    PubMed

    Heidenhain, Christoph; Weichert, Wilko; Schmidmaier, Gerhard; Wildemann, Britt; Hein, Moritz; Neuhaus, Peter; Heise, Michael

    2010-07-01

    This article investigates a method of modifying and optimizing the biocompatibility of decellularized vascular bioimplants when treated with a specialized, drug eluting coating. For this purpose, we carried out aortic transplantations using a porcine model. Decellularized, cross-linked aortic grafts were coated with poly(D,L-lactide) (PDLLA). To this coating, we added the anticoagulant drug lepirudin which, following transplantation, would be linearly eluted. These aortic grafts are easily manipulated in surgery. It was shown that, as a result of the lepirudin-eluting coating, the rate of thrombogenesis was reduced and the patency rate was significantly improved. However, lumen-stenosing pseudointima developed in all of the transplants and was not effected by PDLLA coating. Furthermore, no evidence of recellularisation was documented. This trial demonstrates that polymer coating of decellularized tissue is possible. Neointimal hyperplasia and the absence of cellular repopulation mark the negative consequences of this concept. PMID:20524202

  3. Technical adjunct for abdominal aortic aneurysm repair in patient with renal transplant.

    PubMed

    Rizzo, Anna R; Sirignano, Pasqualino; Capoccia, Laura; Menna, Danilo; Ippoliti, Francesco; Speziale, Francesco

    2014-10-01

    One of the most discussed issues in abdominal aortic surgery in kidney-transplanted patients is represented by organ protection during aortic cross-clamping. We report the case of a kidney-transplanted woman who underwent surgical correction for an abdominal aortic aneurysm after she refused any endovascular approach. To maintain kidney perfusion, during surgical aortic reconstruction, a biopump was chosen. Nowadays, abdominal aortic aneurysm endovascular repair, when feasible, allows avoiding cross-clamping-related renal ischemia, although a potential risk for contrast-induced nephrotoxicity still exists. When open surgical repair is chosen, several different techniques to protect the transplanted organ have been proposed, with different potential advantages and results. In the case we reported, the use of biopump allowed an effective protection from ischemia, minimizing perioperative stress and complications. PMID:24531028

  4. [Use of sutureless prosthetic aortic valves in cardiac surgery].

    PubMed

    Santarpino, Giuseppe; Fischlein, Theodor

    2014-03-01

    In the last years, an increasing proportion of high-risk patients undergo surgical aortic valve replacement. In order to reduce the risk associated with cross-clamp time or cardioplegic ischemic time, sutureless aortic prostheses have been developed. These bioprosthetic valves are not hand sewn, and this technological advance translates into reduced implantation times, thus improving outcome of patients referred for aortic valve replacement. At present, three sutureless bioprostheses are available on the market: 3f Enable (Medtronic Inc., Minneapolis, Minnesota, USA), Perceval (Sorin Group, Saluggia, Italy) and Intuity (Edwards Lifesciences, Irvine, California, USA). This article provides an overview of the available literature on sutureless aortic valves with the aim to better define current role and future perspectives of sutureless aortic bioprostheses for the treatment of aortic valve stenosis. PMID:24770430

  5. Rigid clamp

    DOEpatents

    Benavides, G.L.; Burt, J.D.

    1994-07-12

    The invention relates to a clamp mechanism that can be used to attach or temporarily support objects inside of tubular goods. The clamp mechanism can also be modified so that it grips objects. The clamp has a self-centering feature to accommodate out-of-roundness or other internal defections in tubular objects such as pipe. A plurality of clamping shoes are expanded by a linkage which is preferably powered by a motor to contact the inside of a pipe. The motion can be reversed and jaw elements can be connected to the linkage so as to bring the jaws together to grab an object. 12 figs.

  6. Rigid clamp

    DOEpatents

    Benavides, Gilbert L.; Burt, Jack D.

    1994-01-01

    The invention relates to a clamp mechanism that can be used to attach or temporarily support objects inside of tubular goods. The clamp mechanism can also be modified so that it grips objects. The clamp has a self-centering feature to accommodate out-of-roundness or other internal defections in tubular objects such as pipe. A plurality of clamping shoes are expanded by a linkage which is preferably powered by a motor to contact the inside of a pipe. The motion can be reversed and jaw elements can be connected to the linkage so as to bring the jaws together to grab an object.

  7. [MINIMALLY INVASIVE AORTIC VALVE REPLACEMENT].

    PubMed

    Tabata, Minoru

    2016-03-01

    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. PMID:27295772

  8. Charlie's Clamp.

    ERIC Educational Resources Information Center

    Tarino, Janet Z.

    1998-01-01

    Presents a version of the crush-the-can demonstration which is a hands-on activity in which students use an inexpensive, easily made holder for the can called Charlie's clamp. Includes some suggestions for the follow-up discussion. (DDR)

  9. Hydrodynamic characteristics of porcine aortic valves cross-linked with glutaraldehyde and polyepoxy compounds.

    PubMed

    Soda, Aiko; Tanaka, Ryou; Saida, Yuuto; Takashima, Kazuaki; Hirayama, Tomohiro; Umezu, Mitsuo; Yamane, Yoshihisa

    2009-01-01

    Porcine aortic valve (AoF) tissues cross-linked with glutaraldehyde and epoxy compounds were reported to have high anticalcification properties, but their hydrodynamic characteristics have not been evaluated. The aim of the present study was to investigate the hydrodynamic differences between porcine AoFs, cross-linked with concomitant use of an epoxy compound and glutaraldehyde, at different fixation periods. The valves were mounted on a pulsatile flow circulation mimicking a left heart. The left atrial and left ventricular pressures and mitral and aortic flows were measured at every 0.002 seconds, and the hydrodynamic factor of the valves mounted on the mitral position was estimated. Effective orifice area and the regurgitation volume, which are used as indicators of valve efficiency, failed to detect significant differences due to glutaraldehyde fixation time. In addition, the pressure gradient across the bioprosthetic valve and the variation of mitral flow also had no significant differences. The flow circuit model of the present study was mimicking of a left heart. The evaluation of the mitral valvular function with different glutaraldehyde fixation times was accomplished by relating the pressure with the flow, and by estimating the time lag between valve motion and transvalvular flow. PMID:19092670

  10. External aortic wrap for repair of type 1 endoleak☆

    PubMed Central

    Dean, Anastasia; Yap, Swee Leong; Bhamidipaty, Venu; Pond, Franklin

    2014-01-01

    INTRODUCTION Type 1 endoleak is a rare complication after endovascular abdominal aortic aneurysm repair (EVAR) with a reported frequency up to 2.88%. It is a major risk factor for aneurysmal enlargement and rupture. PRESENTATION OF CASE We present a case of a 68 year old gentleman who was found to have a proximal type 1 endoleak with loss of graft wall apposition on routine surveillance imaging post-EVAR. An initial attempt at endovascular repair was unsuccessful. Given the patient's multiple medical co-morbidities, which precluded the possibility of conventional graft explantation and open repair, we performed a novel surgical technique which did not require aortic cross-clamping. A double-layered Dacron wrap was secured around the infra-renal aorta with Prolene sutures, effectively hoisting the posterior bulge to allow wall to graft apposition and excluding the endoleak. Post-operative CT angiogram showed resolution of the endoleak and a stable sac size. DISCUSSION Several anatomical factors need to be considered when this technique is proposed including aortic neck angulation, position of lumbar arteries and peri-aortic venous anatomy. While an external wrap technique has been investigated sporadically for vascular aneurysms, to our knowledge there is only one similar case in the literature. CONCLUSION Provided certain anatomical features are present, an external aortic wrap is a useful and successful option to manage type 1 endoleak in high-risk patients who are unsuitable for aortic clamping. PMID:25217878

  11. Endovascular Abdominal Aortic Aneurysm Repair by Means of the Chimney Technique in a Patient with Crossed Fused Renal Ectopia

    PubMed Central

    Kfoury, Elias; Almanfi, Abdelkader; Dougherty, Kathryn G.

    2016-01-01

    Crossed fused renal ectopia, a congenital anomaly in 1 of 7,000 individuals, presents a challenge during endovascular treatment of abdominal aortic aneurysm. Most treatment approaches in these patients have involved open surgical repair of the aneurysm or endovascular repair with coverage of the ectopic renal artery. We present what we think is the first case of endovascular abdominal aortic aneurysm repair with use of the chimney technique (parallel stent-grafting) to preserve an ectopic renal artery, in an 88-year-old man who was at high risk for open surgery. In addition to the patient's case, we discuss the relevant medical literature. PMID:27303239

  12. Endovascular Abdominal Aortic Aneurysm Repair by Means of the Chimney Technique in a Patient with Crossed Fused Renal Ectopia.

    PubMed

    Kfoury, Elias; Almanfi, Abdelkader; Dougherty, Kathryn G; Krajcer, Zvonimir

    2016-06-01

    Crossed fused renal ectopia, a congenital anomaly in 1 of 7,000 individuals, presents a challenge during endovascular treatment of abdominal aortic aneurysm. Most treatment approaches in these patients have involved open surgical repair of the aneurysm or endovascular repair with coverage of the ectopic renal artery. We present what we think is the first case of endovascular abdominal aortic aneurysm repair with use of the chimney technique (parallel stent-grafting) to preserve an ectopic renal artery, in an 88-year-old man who was at high risk for open surgery. In addition to the patient's case, we discuss the relevant medical literature. PMID:27303239

  13. Aortic angiography

    MedlinePlus

    ... with the aorta or its branches, including: Aortic aneurysm Aortic dissection Congenital (present from birth) problems AV ... Abnormal results may be due to: Abdominal aortic aneurysm Aortic dissection Aortic regurgitation Aortic stenosis Congenital (present ...

  14. Chylous Ascites after Abdominal Aortic Aneurysm Repair

    PubMed Central

    Ohki, Shinichi; Kurumisawa, Soki

    2015-01-01

    A 73-year-old man was transferred for treatment of abdominal aortic aneurysm. He had no history of abdominal surgeries. Grafting between the infra-renal abdominal aorta and the bilateral common iliac arteries was performed. Proximal and distal cross clamps were applied for grafting. He developed chylous ascites on the 5th post-operative day, 2 days after initiation of oral intake. Fortunately, he responded to treatment with total parenteral hyper-alimentation for 10 days, followed by a low-fat diet. There was no recurrence of ascites. PMID:27087873

  15. Chylous Ascites after Abdominal Aortic Aneurysm Repair.

    PubMed

    Ohki, Shinichi; Kurumisawa, Soki; Misawa, Yoshio

    2016-01-01

    A 73-year-old man was transferred for treatment of abdominal aortic aneurysm. He had no history of abdominal surgeries. Grafting between the infra-renal abdominal aorta and the bilateral common iliac arteries was performed. Proximal and distal cross clamps were applied for grafting. He developed chylous ascites on the 5th post-operative day, 2 days after initiation of oral intake. Fortunately, he responded to treatment with total parenteral hyper-alimentation for 10 days, followed by a low-fat diet. There was no recurrence of ascites. PMID:27087873

  16. Clamp usable as jig and lifting clamp

    DOEpatents

    Tsuyama, Yoshizo

    1976-01-01

    There is provided a clamp which is well suited for use as a lifting clamp for lifting and moving materials of assembly in a shipyard, etc. and as a pulling jig in welding and other operations. The clamp comprises a clamp body including a shackle for engagement with a pulling device and a slot for receiving an article, and a pair of jaws provided on the leg portions of the clamp body on the opposite sides of the slot to grip the article in the slot, one of said jaws consisting of a screw rod and the other jaw consisting of a swivel jaw with a spherical surface, whereby when the article clamped in the slot by the pair of jaws tends to slide in any direction with respect to the clamp body, the article is more positively gripped by the pair of jaws.

  17. Transcatheter aortic valve implantation in a young heart transplant recipient crossing the traditional boundaries

    PubMed Central

    Terkelsen, Christian Juhl; Terp, Kim Allan; Mathiassen, Ole Norling; Nørgaard, Bjarne Linde; Andersen, Henning Rud; Poulsen, Steen Hvitfeldt

    2016-01-01

    Transcatheter aortic valve implantation (TAVI) is an established therapeutic alternative to surgical aortic valve replacement (SAVR) in high-risk or inoperable patients with symptomatic aortic valve stenosis. Hitherto, TAVI is not recommended in young and low-intermediate risk patients. However, TAVI may also serve as an alternative to SAVR in selected young patients, e.g., patients who have previously undergone multiple cardiac surgery procedures. We report a case of trans-femoral TAVI in a 25-year-old heart transplant (HTx) recipient with prior surgery for congenital heart disease. PMID:27621906

  18. In the era of the valve-in-valve: is transcatheter aortic valve implantation (TAVI) in sutureless valves feasible?

    PubMed Central

    Saia, Francesco; Pellicciari, Giovanni; Phan, Kevin; Ferlito, Marinella; Dall’Ara, Gianni; Di Bartolomeo, Roberto; Marzocchi, Antonio

    2015-01-01

    Sutureless aortic valve implantation has emerged as an innovative alternative for treatment of aortic stenosis. By avoiding the placement of sutures, this approach aims to improve surgical outcomes by facilitating less traumatic minimally invasive approaches and reducing cross-clamp and cardiopulmonary bypass duration. However, the absence of sutures may have detrimental effects after sutureless interventions, including paravalvular leakages, valve dislocation, and stent-infolding. Transcatheter aortic valve-in-valve implantation (A-ViV) is emerging as a valuable procedure in patients with dysfunctioning biological aortic valves who are deemed inoperable with conventional surgery. Here we present the first-in-man case of trans-femoral implant of a balloon expandable aortic valve in a leaking sutureless self-expandable valve. PMID:25870827

  19. In the era of the valve-in-valve: is transcatheter aortic valve implantation (TAVI) in sutureless valves feasible?

    PubMed

    Di Eusanio, Marco; Saia, Francesco; Pellicciari, Giovanni; Phan, Kevin; Ferlito, Marinella; Dall'Ara, Gianni; Di Bartolomeo, Roberto; Marzocchi, Antonio

    2015-03-01

    Sutureless aortic valve implantation has emerged as an innovative alternative for treatment of aortic stenosis. By avoiding the placement of sutures, this approach aims to improve surgical outcomes by facilitating less traumatic minimally invasive approaches and reducing cross-clamp and cardiopulmonary bypass duration. However, the absence of sutures may have detrimental effects after sutureless interventions, including paravalvular leakages, valve dislocation, and stent-infolding. Transcatheter aortic valve-in-valve implantation (A-ViV) is emerging as a valuable procedure in patients with dysfunctioning biological aortic valves who are deemed inoperable with conventional surgery. Here we present the first-in-man case of trans-femoral implant of a balloon expandable aortic valve in a leaking sutureless self-expandable valve. PMID:25870827

  20. Endovascular thoracic aortic repair and risk of spinal cord ischemia: the role of previous or concomitant treatment for aortic aneurysm.

    PubMed

    Setacci, F; Sirignano, P; De Donato, G; Chisci, E; Galzerano, G; Massaroni, R; Setacci, C

    2010-04-01

    Spinal cord ischemia (SCI) is one of the most devastating complications undergoing surgical or endovascular repair of the thoracic aorta. The incidence of SCI after thoracic aorta open repair varies from 2% to 21%, depending on the extent of the descending thoracic aorta replacement compared with as high as 12% of cases after endovascular aortic repair. Endoluminal repair allows the avoidance of aortic cross clamping and its sequelae; however, the intercostal arteries covered by the stent graft cannot be reimplanted. Perioperative risk factors contributing to SCI have been reported to include length of aortic coverage, prior abdominal aortic aneurysm (AAA) repair, hypotension, and left subclavian artery coverage. Although the putative mechanism of loss of lumbar collateral perfusion in those who had prior aortic repairs appears reasonable, occurrence of SCI in this subset of patients has not been consistent. Spinal cord perfusion is dependent on the net pressure of the mean arterial pressure minus the mean intrathecal pressure. Systemic pressure can be maximized by volume resuscitation and vasopressors. Intrathecal spinal pressure can be minimized by drainage of the spinal cord, although this is not without its potential risks. More recently, there have been attempts at attenuating the cellular damage caused by SCI, either with systemic or intrathecal administration of pharmacologic agents, which attempt to mitigate the inflammatory response of cellular reperfusion. This is a review of the risk factors for SCI during TEVAR in patients with previous or concomitant treatment for aortic aneurysm. PMID:20354486

  1. Axillofemoral bypass for kidney transplant protection during open repair of abdominal aortic aneurysm.

    PubMed

    Monnot, Antoine; Rouer, Martin; Horion, Julien; Plissonnier, Didier

    2015-08-01

    The need to treat an abdominal aortic aneurysm (AAA) in kidney transplanted patient is a rare event. To date, no method to protect the kidney during the aneurysm treatment has been identified as undeniably relevant. On the other hand, the advantage of endovascular treatment of the aneurysm (EVAR) is to avoid transplanted kidney injury. Unfortunately, EVAR is not always available leading to open repair and then aortic cross clamping. We report here 3 cases of AAA open repair in kidney transplanted patients using a temporary axillofemoral bypass to protect the renal function. PMID:25958120

  2. Force-Measuring Clamp

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark (Inventor)

    2004-01-01

    A precision clamp that accurately measures force over a wide range of conditions is described. Using a full bridge or other strain gage configuration. the elastic deformation of the clamp is measured or detected by the strain gages. Thc strain gages transmit a signal that corresponds to the degree of stress upon the clamp. Thc strain gage signal is converted to a numeric display. Calibration is achieved by ero and span potentiometers which enable accurate measurements by the force-measuring clamp.

  3. Decellularized aortic homografts for aortic valve and aorta ascendens replacement†

    PubMed Central

    Tudorache, Igor; Horke, Alexander; Cebotari, Serghei; Sarikouch, Samir; Boethig, Dietmar; Breymann, Thomas; Beerbaum, Philipp; Bertram, Harald; Westhoff-Bleck, Mechthild; Theodoridis, Karolina; Bobylev, Dmitry; Cheptanaru, Eduard; Ciubotaru, Anatol; Haverich, Axel

    2016-01-01

    OBJECTIVES The choice of valve prosthesis for aortic valve replacement (AVR) in young patients is challenging. Decellularized pulmonary homografts (DPHs) have shown excellent results in pulmonary position. Here, we report our early clinical results using decellularized aortic valve homografts (DAHs) for AVR in children and mainly young adults. METHODS This prospective observational study included all 69 patients (44 males) operated from February 2008 to September 2015, with a mean age of 19.7 ± 14.6 years (range 0.2–65.3 years). In 18 patients, a long DAH was used for simultaneous replacement of a dilated ascending aorta as an extended aortic root replacement (EARR). Four patients received simultaneous pulmonary valve replacement with DPH. RESULTS Thirty-nine patients (57%) had a total of 62 previous operations. The mean aortic cross-clamp time in isolated cases was 129 ± 41 min. There was 1 conduit-unrelated death. The mean DAH diameter was 22.4 ± 3.7 mm (range, 10–29 mm), the average peak gradient was 14 ± 15 mmHg and the mean aortic regurgitation grade (0.5 = trace, 1 = mild) was 0.6 ± 0.5. The mean effective orifice area (EOA) of 25 mm diameter DAH was 3.07 ± 0.7 cm2. DAH annulus z-values were 1.1 ± 1.1 at implantation and 0.7 ± 1.3 at the last follow-up. The last mean left ventricle ejection fraction and left ventricle end diastolic volume index was 63 ± 7% and 78 ± 16 ml/m2 body surface area, respectively. To date, no dilatation has been observed at any level of the graft during follow-up; however, the observational time is short (140.4 years in total, mean 2.0 ± 1.8 years, maximum 7.6 years). One small DAH (10 mm at implantation) had to be explanted due to subvalvular stenosis and developing regurgitation after 4.5 years and was replaced with a 17 mm DAH without complication. No calcification of the explanted graft was noticed intraoperatively and after histological analysis, which revealed extensive recellularization without inflammation

  4. [Traumatic rupture of the aortic isthmus in a patient with severe head injury].

    PubMed

    Lassié, P; Tentillier, E; Thicoïpé, M; Pinaquy, C; Laborde, N

    1993-01-01

    A 32-year-old man sustained a severe head injury in a road traffic accident. On admission, he was in deep coma (6 on the Glasgow coma scale). The aortic knuckle was difficult to identify on a plain chest film. Twenty hours after admission, the aortic knuckle had completely disappeared and the mediastinal shadow had become enlarged. The diagnosis of a ruptured aortic isthmus was confirmed by angiography. Surgical repair of this lesion may be carried out either with simple aortic cross-clamping, or by using cardiopulmonary bypass (CPB). Either technique may worsen other injuries, especially head injury, by initiating severe arterial hypertension or coagulation disturbances. In this patient, the technique chosen was aortic cross-clamping with permanent monitoring of the intracranial and cerebral perfusion pressures. Anaesthesia was obtained with 5 mg.kg-1 of thiopentone, 30 mg.kg-1 x h-1 of sodium gamma hydroxybutyrate and 8 micrograms.kg-1 x h-1 of fentanyl. Surgery lasted for 90 min, with 33 min of aortic clamping. The increase in arterial blood pressure was controlled with 0.25 mg.kg-1 x h-1 of thiopentone and nicardipine which was stopped 8 min before unclamping. The postoperative course was uneventful. Sedation was stopped after 8 days, and the patient regained consciousness two days later. These remained a paraplegia with no sensory deficit, which had totally receded 15 months later. Carrying out this emergency surgery without CPB means that the intracranial pressure must imperatively be monitored during surgery. Any intracranial hypertension should delay the surgery. PMID:8338263

  5. Photovoltaic panel clamp

    DOEpatents

    Mittan, Margaret Birmingham; Miros, Robert H. J.; Brown, Malcolm P.; Stancel, Robert

    2012-06-05

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  6. Photovoltaic panel clamp

    DOEpatents

    Brown, Malcolm P.; Mittan, Margaret Birmingham; Miros, Robert H. J.; Stancel, Robert

    2013-03-19

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  7. Aortic cusp extension valvuloplasty: repair with an extracellular patch

    PubMed Central

    Pawlak, Szymon; Śliwka, Joanna; Urlik, Maciej; Maruszewski, Marcin; Kukulski, Tomasz; Nożyński, Jerzy; Zembala, Marian

    2015-01-01

    Introduction The proportion of valve repair procedures is increasing in experienced centers. The aim of the study was to assess the clinical and echocardiographic outcomes after aortic valve reconstruction with a novel surgical technique. Material and methods The study group consisted of 30 patients (23 male and 7 female) at a mean age of 35 ± 14 years. In patients with aortic root aneurysm the reimplantation or Florida sleeve technique was used. A sub-commissural annuloplasty, plication of the free edge of the cusp, shaving, and commissurotomy were performed. At this stage of surgery aortic repair was then attempted by cusp extension. Since 2013 the strips have been tailored from extracellular matrix. Results The mean aortic cross-clamp time was 90 ± 32 min. The mean cardiopulmonary bypass time was 126 ± 38 min. There was no in-hospital death. Re-exploration for bleeding was required in 1 patient. During follow-up, 1 patient needed reoperation at 1 year due to endocarditis. All patients remained alive in New York Heart Association (NYHA) functional class I. The echocardiographic findings remained unchanged in all cases during follow-up. Conclusions Our modification of aortic valve repair results in a good outcome. PMID:26855646

  8. Radial wedge flange clamp

    DOEpatents

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  9. Early Outcomes of Sutureless Aortic Valves

    PubMed Central

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

    2016-01-01

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

  10. Dual Functions, Clamp Opening and Primer-Template Recognition, Define a Key Clamp Loader Subunit

    PubMed Central

    Coman, Maria Magdalena; Jin, Mi; Ceapa, Razvan; Finkelstein, Jeff; O'Donnell, Michael; Chait, Brian T.; Hingorani, Manju M.

    2010-01-01

    Clamp loader proteins catalyze assembly of circular sliding clamps on DNA to enable processive DNA replication. During the reaction, the clamp loader binds primer-template DNA and positions it in the center of a clamp to form a topological link between the two. Clamp loaders are multi-protein complexes, such as the five protein Escherichia coli, Saccharomyces cerevisiae, and human clamp loaders, and the two protein Pyrococcus furiosus and Methanobacterium thermoautotrophicum clamp loaders, and thus far the site(s) responsible for binding and selecting primer-template DNA as the target for clamp assembly remain unknown. To address this issue, we analyzed the interaction between the E. coli γ complex clamp loader and DNA using UV-induced protein–DNA cross-linking and mass spectrometry. The results show that the δ subunit in the γ complex makes close contact with the primer-template junction. Tryptophan 279 in the δ C-terminal domain lies near the 3′-OH primer end and may play a key role in primer-template recognition. Previous studies have shown that δ also binds and opens the β clamp (hydrophobic residues in the N-terminal domain of δ contact β. The clamp-binding and DNA-binding sites on δ appear positioned for facile entry of primer-template into the center of the clamp and exit of the template strand from the complex. A similar analysis of the S. cerevisiae RFC complex suggests that the dual functionality observed for δ in the γ complex may be true also for clamp loaders from other organisms. PMID:15364574

  11. Aortic insufficiency

    MedlinePlus

    ... Heart valve - aortic regurgitation; Valvular disease - aortic regurgitation; AI - aortic insufficiency ... BA. Valvular heart disease. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: ...

  12. Aortic Aneurysm

    MedlinePlus

    ... chest and abdomen. There are two types of aortic aneurysm: Thoracic aortic aneurysms - these occur in the part of the aorta running through the chest Abdominal aortic aneurysms - these occur in the part of the aorta ...

  13. Aortic Aneurysm

    MedlinePlus

    ... chest and abdomen. There are two types of aortic aneurysm: Thoracic aortic aneurysms (TAA) - these occur in the part of the aorta running through the chest Abdominal aortic aneurysms (AAA) - these occur in the part of the ...

  14. Aortic insufficiency

    MedlinePlus

    Aortic valve prolapse; Aortic regurgitation ... Any condition that prevents the aortic valve from closing completely can cause this problem. When the valve doesn't close all the way, a small amount of blood comes ...

  15. Quick action clamp

    NASA Technical Reports Server (NTRS)

    Calco, Frank S. (Inventor)

    1991-01-01

    A quick release toggle clamp that utilizes a spring that requires a deliberate positive action for disengagement is presented. The clamp has a sliding bolt that provides a latching mechanism. The bolt is moved by a handle that tends to remain in an engaged position while under tension.

  16. Reusable thermal cycling clamp

    NASA Technical Reports Server (NTRS)

    Debnam, W. J., Jr.; Fripp, A. L.; Crouch, R. K. (Inventor)

    1985-01-01

    A reusable metal clamp for retaining a fused quartz ampoule during temperature cycling in the range of 20 deg C to 1000 deg C is described. A compressible graphite foil having a high radial coefficient of thermal expansion is interposed between the fused quartz ampoule and metal clamp to maintain a snug fit between these components at all temperature levels in the cycle.

  17. Minimally Invasive Versus Conventional Aortic Valve Replacement

    PubMed Central

    Attia, Rizwan Q.; Hickey, Graeme L.; Grant, Stuart W.; Bridgewater, Ben; Roxburgh, James C.; Kumar, Pankaj; Ridley, Paul; Bhabra, Moninder; Millner, Russell W. J.; Athanasiou, Thanos; Casula, Roberto; Chukwuemka, Andrew; Pillay, Thasee; Young, Christopher P.

    2016-01-01

    Objective Minimally invasive aortic valve replacement (MIAVR) has been demonstrated as a safe and effective option but remains underused. We aimed to evaluate outcomes of isolated MIAVR compared with conventional aortic valve replacement (CAVR). Methods Data from The National Institute for Cardiovascular Outcomes Research (NICOR) were analyzed at seven volunteer centers (2006–2012). Primary outcomes were in-hospital mortality and midterm survival. Secondary outcomes were postoperative length of stay as well as cumulative bypass and cross-clamp times. Propensity modeling with matched cohort analysis was used. Results Of 307 consecutive MIAVR patients, 151 (49%) were performed during the last 2 years of study with a continued increase in numbers. The 307 MIAVR patients were matched on a 1:1 ratio. In the matched CAVR group, there was no statistically significant difference in in-hospital mortality [MIAVR, 4/307,(1.3%); 95% confidence interval (CI), 0.4%–3.4% vs CAVR, 6/307 (2.0%); 95% CI, 0.8%–4.3%; P = 0.752]. One-year survival rates in the MIAVR and CAVR groups were 94.4% and 94.6%, respectively. There was no statistically significant difference in midterm survival (P = 0.677; hazard ratio, 0.90; 95% CI, 0.56–1.46). Median postoperative length of stay was lower in the MIAVR patients by 1 day (P = 0.009). The mean cumulative bypass time (94.8 vs 91.3 minutes; P = 0.333) and cross-clamp time (74.6 vs 68.4 minutes; P = 0.006) were longer in the MIAVR group; however, this was significant only in the cross-clamp time comparison. Conclusions Minimally invasive aortic valve replacement is a safe alternative to CAVR with respect to operative and 1-year mortality and is associated with a shorter postoperative stay. Further studies are required in high-risk (logistic EuroSCORE > 10) patients to define the role of MIAVR. PMID:26926521

  18. Formation, Characterization, and O-O Bond Activation of a Peroxomanganese(III) Complex Supported by a Cross-Clamped Cyclam Ligand.

    PubMed

    Colmer, Hannah E; Howcroft, Anthony W; Jackson, Timothy A

    2016-03-01

    Although there have been reports describing the nucleophilic reactivity of peroxomanganese(III) intermediates, as well as their conversion to high-valent oxo-bridged dimers, it remains a challenge to activate peroxomanganese(III) species for conversion to high-valent, mononuclear manganese complexes. Herein, we report the generation, characterization, and activation of a peroxomanganese(III) adduct supported by the cross-clamped, macrocyclic Me2EBC ligand (4,11-dimethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane). This ligand is known to support high-valent, mononuclear Mn(IV) species with well-defined spectroscopic properties, which provides an opportunity to identify mononuclear Mn(IV) products from O-O bond activation of the corresponding Mn(III)-peroxo adduct. The peroxomanganese(III) intermediate, [Mn(III)(O2)(Me2EBC)](+), was prepared at low-temperature by the addition of KO2 to [Mn(II)(Cl)2(Me2EBC)] in CH2Cl2, and this complex was characterized by electronic absorption, electron paramagnetic resonance (EPR), and Mn K-edge X-ray absorption (XAS) spectroscopies. The electronic structure of the [Mn(III)(O2)(Me2EBC)](+) intermediate was examined by density functional theory (DFT) and time-dependent (TD) DFT calculations. Detailed spectroscopic investigations of the decay products of [Mn(III)(O2)(Me2EBC)](+) revealed the presence of mononuclear Mn(III)-hydroxo species or a mixture of mononuclear Mn(IV) and Mn(III)-hydroxo species. The nature of the observed decay products depended on the amount of KO2 used to generate [Mn(III)(O2)(Me2EBC)](+). The Mn(III)-hydroxo product was characterized by Mn K-edge XAS, and shifts in the pre-edge transition energies and intensities relative to [Mn(III)(O2)(Me2EBC)](+) provide a marker for differences in covalency between peroxo and nonperoxo ligands. To the best of our knowledge, this work represents the first observation of a mononuclear Mn(IV) center upon decay of a nonporphyrinoid Mn(III)-peroxo center. PMID:26908013

  19. CT of acute abdominal aortic disorders.

    PubMed

    Bhalla, Sanjeev; Menias, Christine O; Heiken, Jay P

    2003-11-01

    Aortic aneurysm rupture, aortic dissection, PAU, acute aortic occlusion, traumatic aortic injury, and aortic fistula represent acute abdominal aortic conditions. Because of its speed and proximity to the emergency department, helical CT is the imaging test of choice for these conditions. MR imaging also plays an important role in the imaging of aortic dissection and PAU, particularly when the patient is unable to receive intravenous contrast material. In this era of MDCT, conventional angiography is used as a secondary diagnostic tool to clarify equivocal findings on cross-sectional imaging. Ultrasound is helpful when CT is not readily available and the patient is unable or too unstable to undergo MR imaging. PMID:14661663

  20. Laser beam guard clamps

    DOEpatents

    Dickson, Richard K.

    2010-09-07

    A quick insert and release laser beam guard panel clamping apparatus having a base plate mountable on an optical table, a first jaw affixed to the base plate, and a spring-loaded second jaw slidably carried by the base plate to exert a clamping force. The first and second jaws each having a face acutely angled relative to the other face to form a V-shaped, open channel mouth, which enables wedge-action jaw separation by and subsequent clamping of a laser beam guard panel inserted through the open channel mouth. Preferably, the clamping apparatus also includes a support structure having an open slot aperture which is positioned over and parallel with the open channel mouth.

  1. A monogenean without clamps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ectoparasites face a daily challenge: to remain attached to their host. Polyopisthocotylean monogeneans attach to the surface of fish gills by highly specialized structures, the sclerotized clamps. In the original description of the protomicrocotylid species Lethacotyle fijiensis, described 50 years...

  2. Sperm Patch-Clamp

    PubMed Central

    Lishko, Polina; Clapham, David E.; Navarro, Betsy; Kirichok, Yuriy

    2014-01-01

    Sperm intracellular pH and calcium concentration ([Ca2+]i) are two central factors that control sperm activity within the female reproductive tract. As such, the ion channels of the sperm plasma membrane that alter intracellular sperm [Ca2+] and pH play important roles in sperm physiology and the process of fertilization. Indeed, sperm ion channels regulate sperm motility, control sperm chemotaxis toward the egg in some species, and may trigger the acrosome reaction. Until recently, our understanding of these important molecules was rudimentary due to the inability to patch-clamp spermatozoa and directly record the activity of these ion channels under voltage clamp. Recently, we overcame this technical barrier and developed a method for reproducible application of the patch-clamp technique to mouse and human spermatozoa. This chapter covers important aspects of application of the patch-clamp technique to spermatozoa, such as selection of the electrophysiological equipment, isolation of spermatozoa for patch-clamp experiments, formation of the gigaohm seal with spermatozoa, and transition into the whole-cell mode of recording. We also discuss potential pitfalls in application of the patch-clamp technique to flagellar ion channels. PMID:23522465

  3. Traumatic rupture of the aortic isthmus: program of selective management.

    PubMed

    Pate, J W; Gavant, M L; Weiman, D S; Fabian, T C

    1999-01-01

    Two hypotheses were investigated: (1) helical computed tomography (CT) of the chest on victims of decelerating trauma can yield a diagnosis of, or "rule out," a traumatic rupture of the aorta (TRA) without the need for an aortogram; and (2) selective delay of aortic repair can be safely accomplished through a medical management protocol. Screening helical CT examinations were done on 6169 victims of blunt thoracic trauma; 47 were found to have TRA; in 8, indirect but nondiagnostic findings not clarified by an aortogram led to surgical exploration. The sensitivity of helical CT was higher than that of aortograms, and a "normal" helical CT scan was never associated with a proved TRA. It is estimated that the use of helical CT has resulted in at least a 40% to 50% decrease in the need for aortograms, in addition to yielding rapid, noninvasive valuable information about other injuries. Drugs (beta-blockers +/- vasodilators) to decrease the stress in the aortic wall were used in 93 patients when the diagnosis was suspected and were continued as necessary through the evaluation, stabilization, and until the aorta was cross-clamped at operation. Elective, delayed operation was done between 2 days and 25 months in 15 patients who were deemed to be excessive risks for emergency aortic repair; there were 2 deaths (13. 3%). Eleven patients never had aortic repair. No patient maintained on this protocol, whether repaired emergently, electively, or not at all, developed free rupture of the periaortic hematoma and death from TRA. PMID:9841764

  4. Clamp for arctic pipeline support

    SciTech Connect

    Morton, A.W.

    1988-11-29

    This patent describes a ring clamp for supporting and anchoring a large diameter metallic arctic pipeline comprising substantially rigid, curved clamp portions adapted to completely encircle the pipeline and fastening means connecting the clamp portions, the clamp portions having inner and outer layers of fiber reinforced rigid polymer material and an intermediate core layer of honeycomb-form aramid paper.

  5. Clamping characteristics study on different types of clamping unit

    SciTech Connect

    Jiao, Zhiwei; Liu, Haichao; Xie, Pengcheng; Yang, Weimin

    2015-05-22

    Plastic products are becoming more and more widely used in aerospace, IT, digital electronics and many other fields. With the development of technology, the requirement of product precision is getting higher and higher. However, type and working performance of clamping unit play a decisive role in product precision. Clamping characteristics of different types of clamping unit are discussed in this article, which use finite element numerical analysis method through the software ABAQUS to study the clamping uniformity, and detect the clamping force repeatability precision. The result shows that compared with toggled three-platen clamping unit, clamping characteristics of internal circulation two-platen clamping unit are better, for instance, its mold cavity deformation and force that bars and mold parting surface suffered are more uniform, and its clamping uniformity and repeatability precision is also better.

  6. Minimally invasive valve sparing aortic root replacement (David procedure) is safe

    PubMed Central

    Krueger, Heike; Umminger, Julia; Koigeldiyev, Nurbol; Beckmann, Erik; Haverich, Axel; Martens, Andreas

    2015-01-01

    Objective Even though minimally invasive cardiac surgery may reduce morbidity, this approach is not routinely performed for aortic root replacements. The purpose of this pilot study was to assess the safety and feasibility of valve sparing aortic root replacement via an upper mini-sternotomy up to the 3rd intercostal space. Methods Between April 2011 and March 2014, 26 patients (22 males, age 47.6±13 years) underwent elective minimally invasive aortic valve sparing root replacement (David procedure, group A). Twelve patients underwent additional leaflet repair. Concomitant procedures were: four proximal aortic arch replacements and one coronary artery bypass grafting (CABG) to the proximal right coronary artery (RCA). During the same time period, 14 patients (ten males, age 64.2±9.5 years) underwent elective David procedure via median full sternotomy (group B). Concomitant procedures included six proximal aortic arch replacements. Although the patient cohorts were small, the results of these two groups were compared. Results In group A, there were no intra-operative conversions to full sternotomy. The aortic cross-clamp and cardiopulmonary bypass (CPB) times were 115.6±30.3 and 175.8±41.9 min, respectively. One patient was re-opened (via same access) due to post-operative bleeding. The post-operative ventilation time and hospital stay were 0.5±0.3 and 10.4±6.8 days, respectively. There was no 30-day mortality. The patient questionnaire showed that the convalescence time was approximately two weeks. In group B: the cross-clamp and CPB times were 114.1±19.9 and 163.0±24.5 min, respectively. One patient was re-opened (7.1%) due to post-operative bleeding. The post-operative ventilation time and hospital stay were 0.6±0.7 and 14.2±16.7 days, respectively. There was no 30-day mortality. Conclusions Minimally invasive valve sparing aortic root replacement can be safely performed in selected patients. The results are comparable to those operated via a full

  7. Clamp for detonating fuze

    NASA Technical Reports Server (NTRS)

    Holderman, E. J.

    1968-01-01

    Quick acting clamp provides physical support for a closely confined detonating fuse in an application requiring removal and replacement at frequent intervals during test. It can be designed with a base of any required strength and configuration to permit the insertion of an object.

  8. Re-visiting the trans insertion model for complexin clamping.

    PubMed

    Krishnakumar, Shyam S; Li, Feng; Coleman, Jeff; Schauder, Curtis M; Kümmel, Daniel; Pincet, Frederic; Rothman, James E; Reinisch, Karin M

    2015-01-01

    We have previously proposed that complexin cross-links multiple pre-fusion SNARE complexes via a trans interaction to function as a clamp on SNARE-mediated neurotransmitter release. A recent NMR study was unable to detect the trans clamping interaction of complexin and therefore questioned the previous interpretation of the fluorescence resonance energy transfer and isothermal titration calorimetry data on which the trans clamping model was originally based. Here we present new biochemical data that underscore the validity of our previous interpretation and the continued relevancy of the trans insertion model for complexin clamping. PMID:25831964

  9. Endovascular treatment of blunt traumatic thoracic aortic injury.

    PubMed

    Nicolaou, Georghios

    2009-06-01

    Blunt traumatic thoracic aortic injury (BTTAI) is a lethal injury associated with a prehospital mortality of 80% to 90%. Patients arriving in the emergency room and considered appropriate to undergo emergency open surgical repair still have a mortality rate of 15% to 30% because of severe associated injuries. Conventional open surgical repair requires a left thoracotomy, single lung ventilation, aortic-cross clamping and unclamping, with or without the adjunct use of partial or full cardiopulmonary bypass and systemic heparinization. All this leads to significant physiological stress and surgical trauma resulting in perioperative complications such as major blood loss, coagulopathy, myocardial infarction, stroke, respiratory failure, renal failure, bowel infarction, and paraplegia. Despite advances in anesthesia, critical care medicine, and surgical techniques, a recent meta-analysis showed no definite improvement in operative mortality over the past decade, following open surgical repair in patients with BTTAI. Endovascular repair of BTTAI does not require a thoracotomy, single lung ventilation, aorticcross clamping and unclamping, or systemic heparinization. As a result, endovascular repair of BTTAI has emerged as an effective, minimally invasive treatment alternative, especially in patients with severe concomitant injuries, which may be prohibitive to open surgical repair. Recent published studies have shown that endovascular repair of BTTAI is associated with lower morbidity, mortality, stroke, and paraplegia/paraparesis rates, when compared with open surgical repair of BTTAI. PMID:19617250

  10. Branched and fenestrated options to treat aortic arch aneurysms.

    PubMed

    Maurel, Blandine; Mastracci, Tara M; Spear, Rafaelle; Hertault, Adrien; Azzaoui, Richard; Sobocinski, Jonathan; Haulon, Stephan

    2016-10-01

    Conventional surgical repair of aortic arch aneurysms using cardiopulmonary bypass and hypothermic circulatory arrest remains the gold standard, however it is associated with a substantial mortality and morbidity rate, especially in the elderly. Hybrid techniques avoid aortic cross-clamping and circulatory arrest, but are of limited use and are only applicable to selected patients. The development of new devices to treat aortic arch aneurysms endovascularly has the potential to offer a treatment modality to patients unfit for an open repair. We present the challenges specific to endovascular arch repair based on our experience and the literature available from the first experience in 1999 to the third generation graft currently commonly used. Following an initial learning curve associated with the use of the third generation arch branch device, along with careful patient selection and operator experience, early results are promising. Technical success was achieved in all cases, there was no early mortality and strokes were noted in 11%. As with branched and fenestrated technology for thoracoabdominal aneurysm repair, the use of total endovascular repair for arch pathology will require an evolution in endovascular practice and device design. However, at present, the early use of the latest generation device offers a novel approach to patients who previously had no surgical options. PMID:27332680

  11. Atheroembolization and potential air embolization during aortic declamping in open repair of a pararenal aortic aneurysm: A case report

    PubMed Central

    Dregelid, Einar Børre; Lilleng, Peer Kåre

    2016-01-01

    Introduction When ischemic events ascribable to microembolization occur during open repair of proximal abdominal aortic aneurysms, a likely origin of atheroembolism is not always found. Presentation of case A 78-year old man with enlargement of the entire aorta underwent open repair for a pararenal abdominal aortic aneurysm using supraceliac aortic clamping for 20 min. Then the graft was clamped, the supraceliac clamp was removed, and the distal and right renal anastomoses were also completed. The patient was stable throughout the operation with only transient drop in blood pressure on reperfusion. Postoperatively the patient developed ischemia, attributable to microembolization, in legs, small intestine, gall bladder and kidneys. He underwent fasciotomy, small bowel and gall bladder resections. Intestinal absorptive function did not recover adequately and he died after 4 months. Microscopic examination of hundreds of intestinal, juxtaintestinal mesenteric, and gall bladder arteries showed a few ones containing cholesterol emboli. Discussion It is unsure whether a few occluded small arteries out of several hundred could have caused the ischemic injury alone. There had been only moderate backbleeding from aortic branches above the proximal anastomosis while it was sutured. Inadvertently, remaining air in the graft, aorta, and aortic branches may have been whipped into the pulsating blood, resulting in air microbubbles, when the aortic clamp was removed. Conclusion Although both atheromatous particles and air microbubbles are well-known causes of iatrogenic microembolization, the importance of air microembolization in open repair of pararenal aortic aneurysms is not known and need to be studied. PMID:27100956

  12. Cantilever clamp fitting

    NASA Technical Reports Server (NTRS)

    Melton, Patrick B. (Inventor)

    1989-01-01

    A device is disclosed for sealing and clamping a cylindrical element which is to be attached to an object such as a wall, a pressurized vessel or another cylindrical element. The device includes a gland having an inner cylindrical wall, which is threaded at one end and is attached at a bendable end to a deformable portion, which in turn is attached to one end of a conical cantilever structure. The other end of the cantilever structure connects at a bendable area to one end of an outer cylindrical wall. The opposite end of cylindrical wall terminates in a thickened portion, the radially outer surface of which is adapted to accommodate a tool for rotating the gland. The terminal end of cylindrical wall also includes an abutment surface, which is adapted to engage a seal, which in turn engages a surface of a receiver. The receiver further includes a threaded portion for engagement with the threaded portion of gland whereby a tightening rotation of gland relative to receiver will cause relative movement between cylindrical walls and of gland. This movement causes a rotation of the conical structure and thus a bending action at bending area and at the bending end of the upper end of inner cylindrical wall. These rotational and bending actions result in a forcing of the deformable portion radially inwardly so as to contact and deform a pipe. This forcible contact creates a seal between gland and pipe, and simultaneously clamps the pipe in position.

  13. Energy harvesting under excitation of clamped-clamped beam

    NASA Astrophysics Data System (ADS)

    Batra, Ashok; Alomari, Almuatasim; Aggarwal, Mohan; Bandyopadhyay, Alak

    2016-04-01

    In this article, a piezoelectric energy harvesting has been developed experimentally and theoretically based on Euler- Bernoulli Theory. A PVDF piezoelectric thick film has attached along of clamped-clamped beam under sinusoidal base excitation of shaker. The results showed a good agreement between the experimental and simulation of suggested model. The voltage output frequency response function (FRF), current FRF, and output power has been studied under short and open circuit conditions at first vibration mode. The mode shape of the clamped-clamped beam for first three resonance frequency has been modeled and investigated using COMSOL Multiphysics and MATLAB.

  14. Hand-Held Power Clamp

    NASA Technical Reports Server (NTRS)

    Clancy, J. P.

    1985-01-01

    Tool furnishes large pushing or pulling forces. Device includes two clamping blocks, two clamping plates, and a motor-driven linear actuator with selflocking screw shaft. Power clamp exerts opening or closing force at push of switch. Tool approximately 1 m long. Originally designed to secure payload aboard Space Shuttle, operated with one hand to apply opening or closing force of up to 1,000 lb (4,400 N). Clamp has potential applications as end effector for industrial robots and in rescue work to push or pull wreckage with great force.

  15. Changing strategy for aortic stenosis with coronary artery disease by transcatheter aortic valve implantation.

    PubMed

    Kobayashi, Junjiro

    2013-12-01

    Coronary artery disease (CAD) is combined with aortic stenosis (AS) in 40-50 % of patients with typical angina. Recently, transcatheter aortic valve implantation (TAVI) has changed the guideline for AS in patients with high comorbidity. At the same time more than 60 % of isolated CABG has been performed without cardiopulmonary bypass in Japan. CABG is recommended and should be considered in patients with primary indication for AVR and luminal stenosis >70 % in major coronary arteries and the left internal thoracic artery (LITA) by guidelines. AVR is indicated for severe AS undergoing CABG. It is generally accepted to perform AVR for moderate AS at the time of CABG by valve guidelines. However, prophylactic AVR for moderate AS associated with CABG may increase the early operative risk and expose the patients to postoperative long-term valve related complications. AVR after previous CABG poses potential risk for mortality and morbidity. The presence of patent ITA is a significant risk of its injury and difficulty of myocardial protection during aortic cross-clamping. Therefore, at present, for severe AS previous CABG with patent ITA should be one of the definite indications of TAVI. Rationale of TAVI in patients with severe AS and CAD has not been clearly delineated. The safety of TAVI irrespective of the extent and anatomy of CAD is still controversial. PCI is not appropriate before TAVI in high-risk patients with CAD. In the near future hybrid TAVI will be realistic considering least operative mortality and morbidity in high-risk patients. PMID:23546769

  16. Aortic Aneurysm Statistics

    MedlinePlus

    ... Blood Pressure Salt Cholesterol Million Hearts® WISEWOMAN Aortic Aneurysm Fact Sheet Recommend on Facebook Tweet Share Compartir ... cause of most deaths from aortic aneurysms. Aortic Aneurysm in the United States Aortic aneurysms were the ...

  17. Abdominal Aortic Aneurysm (AAA)

    MedlinePlus

    ... Resources Professions Site Index A-Z Abdominal Aortic Aneurysm (AAA) Abdominal aortic aneurysm (AAA) occurs when atherosclerosis ... aortic aneurysm treated? What is an abdominal aortic aneurysm? The aorta, the largest artery in the body, ...

  18. Aortic stenting.

    PubMed

    Droc, Ionel; Calinescu, Francisca Blanca; Droc, Gabriela; Blaj, Catalin; Dammrau, Rolf

    2015-01-01

    The approach to aortic pathology is nowadays more and more endovascular at both thoracic and abdominal levels. Thoracic stenting has gained worldwide acceptance as first intention to treat pathologies of the descending thoracic aorta. Indications have been extended to aortic arch aneurysms and also to diseases of the ascending aorta. The current devices in use for thoracic endovascular repair (TEVAR) are Medtronic Valiant, Gore TAG, Cook Tx2 and Jotec. The choice of the endograft depends on the thoracic aortic pathology and the anatomical suitability. The technological evolution of the abdominal aortic endografts was very rapid, arriving now at the fourth generation. We report the results of 55 elective cases of endovascular abdominal aortic repair (EVAR) performed in two vascular surgical centers in Romania and Germany. The prostheses used were 16 E-vita Abdominal XT, 12 Excluder, eight Talent, seven PowerLink, three Endurant and nine custom-made, fenestrated or branched from Jotec. The mean follow-up was 18 months with CT-scan, duplex ultrasound and contrast-enhanced ultrasound. The mortality was 2%. EVAR tends to become the gold standard for abdominal aortic aneurysm repair. Technological development of the devices with lowest profile introduction systems will permit to extend the anatomical indications to new frontiers. PMID:26200430

  19. Aortic dissection.

    PubMed

    Nienaber, Christoph A; Clough, Rachel E; Sakalihasan, Natzi; Suzuki, Toru; Gibbs, Richard; Mussa, Firas; Jenkins, Michael T; Thompson, Matt M; Evangelista, Arturo; Yeh, James S M; Cheshire, Nicholas; Rosendahl, Ulrich; Pepper, John

    2016-01-01

    Aortic dissection is a life-threatening condition caused by a tear in the intimal layer of the aorta or bleeding within the aortic wall, resulting in the separation (dissection) of the layers of the aortic wall. Aortic dissection is most common in those 65-75 years of age, with an incidence of 35 cases per 100,000 people per year in this population. Other risk factors include hypertension, dyslipidaemia and genetic disorders that involve the connective tissue, such as Marfan syndrome. Swift diagnostic confirmation and adequate treatment are crucial in managing affected patients. Contemporary management is multidisciplinary and includes serial non-invasive imaging, biomarker testing and genetic risk profiling for aortopathy. The choice of approach for repairing or replacing the damaged region of the aorta depends on the severity and the location of the dissection and the risks of complication from surgery. Open surgical repair is most commonly used for dissections involving the ascending aorta and the aortic arch, whereas minimally invasive endovascular intervention is appropriate for descending aorta dissections that are complicated by rupture, malperfusion, ongoing pain, hypotension or imaging features of high risk. Recent advances in the understanding of the underlying pathophysiology of aortic dissection have led to more patients being considered at substantial risk of complications and, therefore, in need of endovascular intervention rather than only medical or surgical intervention. PMID:27440162

  20. International Expert Consensus on Sutureless and Rapid Deployment Valves in Aortic Valve Replacement Using Minimally Invasive Approaches

    PubMed Central

    Glauber, Mattia; Moten, Simon C.; Quaini, Eugenio; Solinas, Marco; Folliguet, Thierry A.; Meuris, Bart; Miceli, Antonio; Oberwalder, Peter J.; Rambaldini, Manfredo; Teoh, Kevin H. T.; Bhatnagar, Gopal; Borger, Michael A.; Bouchard, Denis; Bouchot, Olivier; Clark, Stephen C.; Dapunt, Otto E.; Ferrarini, Matteo; Fischlein, Theodor J. M.; Laufer, Guenther; Mignosa, Carmelo; Millner, Russell; Noirhomme, Philippe; Pfeiffer, Steffen; Ruyra-Baliarda, Xavier; Shrestha, Malakh Lal; Suri, Rakesh M.; Troise, Giovanni; Gersak, Borut

    2016-01-01

    Objective To define the benefit of sutureless and rapid deployment valves in current minimally invasive approaches in isolated aortic valve replacement. Methods A panel of 28 international experts with expertise in both minimally invasive aortic valve replacement and rapid deployment valves was constituted. After thorough literature review, the experts rated evidence-based recommendations in a modified Delphi approach. Results No guideline could be retrieved. Thirty-three clinical trials and 9 systematic reviews could be identified for detailed text analysis to obtain a total of 24 recommendations. After rating by the experts 12, final recommendations were identified: preoperative computed tomographic scan as well as intraoperative transesophageal echocardiography are highly recommended. Suitable annular sizes are 19 to 27 mm. There is a contraindication for bicuspid valves only for type 0 and for annular abscess or destruction due to infective endocarditis. The use of sutureless and rapid deployment valves reduces extracorporeal circulation and aortic cross-clamp time and leads to less early complications as prolonged ventilation, blood transfusion, atrial fibrillation, pleural effusions, paravalvular leakages and aortic regurgitation, and renal replacement therapy, respectively. These clinical outcomes result in reduced intensive care unit and hospital stay and reduced costs. The use of sutureless and rapid deployment valves will lead to a higher adoption rate of minimally invasive approaches in aortic valve replacement. Respect should be taken to a necessary short learning curve for both sutureless and minimally invasive programs. Conclusions Sutureless and rapid deployment aortic valve replacement together with minimally invasive approaches offers an attractive option in aortic valve placement for patients requiring biological valve replacement. PMID:27540996

  1. New device for saphenous vein-to-aorta proximal anastomosis without side-clamping

    PubMed Central

    Tappainer, Ernesto

    2007-01-01

    Background Side clamping to perform saphenous vein-to-aorta proximal anastomosis is a well known cause of cerebral embolization during coronary bypass surgery. Automatic and manual devices have been introduced to avoid aortic clamping and facilitate proximal anastomosis but the manual ones only allow the traditional hand-sewing running suture. Nevertheless, they are not easy to use and very expensive to buy. Methods We developed a simple object that helps to perform a manual proximal anastomosis without the need to clamp the side of the aorta. This device is a steel bar which blocks the aortic hole and simultaneously it provides a slit to receive the needle. Through the slit comes out a thin, sharp, straight, but also well directed and predictable jet of blood which could be easily controlled during the suture. Results The function of the object is quite different from other devices. Nothing is deployed in the aorta. The object is only placed on the aorta with the small appendage slipped into the hole. The main advantage of the device is that while manipulation of the aorta is avoided no foreign bodies are incorporated in the suture and – most importantly – the aortic intima is not touched at all. The main drawback of the device is the blood jet coming from the slit so that the blood pressure has to be lowered by vasodilators during the anastomosis. Moreover, the suture has to change direction and the needle has to enter the aortic wall first to slip out through the slit. Conclusion The object was named "Slit Device" and is not a routine instrument. It would be only an alternative to other anastomotic devices with the same surgical indications. In the case of ascending aortic disease and saphenous vein grafting, the Slit Device avoids aortic clamping thereby preventing atheroembolism and also avoiding the need for hypothermic circulatory arrest in patients with unclampable aorta. PMID:17480222

  2. Internal V-Band Clamp

    DOEpatents

    Vaughn, Mark R.; Hafenrichter, Everett S.; Chapa, Agapito C.; Harris, Steven M.; Martinez, Marcus J.; Baty, Roy S.

    2006-02-28

    A system for clamping two tubular members together in an end-to-end relationship uses a split ring with a V-shaped outer rim that can engage a clamping surface on each member. The split ring has a relaxed closed state where the ends of the ring are adjacent and the outside diameter of the split ring is less than the minimum inside diameter of the members at their ends. The members are clamped when the split ring is spread into an elastically stretched position where the ring rim is pressed tightly against the interior surfaces of the members. Mechanisms are provided for removing the spreader so the split ring will return to the relaxed state, releasing the clamped members.

  3. The Effect of Perioperative Ischemia and Reperfusion on Multiorgan Dysfunction following Abdominal Aortic Aneurysm Repair.

    PubMed

    Katseni, Konstantina; Chalkias, Athanasios; Kotsis, Thomas; Dafnios, Nikolaos; Arapoglou, Vassilis; Kaparos, Georgios; Logothetis, Emmanuel; Iacovidou, Nicoletta; Karvouni, Eleni; Katsenis, Konstantinos

    2015-01-01

    Abdominal aortic aneurysms (AAAs) are relatively common and are potentially life-threatening medical problems. The aim of this review is to provide an overview of the effect of I/R injury on multiorgan failure following AAA repair. The PubMed, CINAHL, EMBASE, Medline, Cochrane Review, and Scopus databases were comprehensively searched for articles concerning the pathophysiology of I/R and its systemic effects. Cross-referencing was performed using the bibliographies from the articles obtained. Articles retrieved were restricted to those published in English. One of the most prominent characteristics of AAA open repair is the double physiological phenomenon of ischemia-reperfusion (I/R) that happens either at the time of clamping or following the aortic clamp removal. Ischemia-reperfusion injury causes significant pathophysiological disturbances to distant organs, increasing the possibility for postoperative multiorgan failure. Although tissue injury is mediated by diverse mechanisms, microvascular dysfunction seems to be the final outcome of I/R. PMID:26798637

  4. The Effect of Perioperative Ischemia and Reperfusion on Multiorgan Dysfunction following Abdominal Aortic Aneurysm Repair

    PubMed Central

    Katseni, Konstantina; Kotsis, Thomas; Dafnios, Nikolaos; Arapoglou, Vassilis; Kaparos, Georgios; Logothetis, Emmanuel; Karvouni, Eleni; Katsenis, Konstantinos

    2015-01-01

    Abdominal aortic aneurysms (AAAs) are relatively common and are potentially life-threatening medical problems. The aim of this review is to provide an overview of the effect of I/R injury on multiorgan failure following AAA repair. The PubMed, CINAHL, EMBASE, Medline, Cochrane Review, and Scopus databases were comprehensively searched for articles concerning the pathophysiology of I/R and its systemic effects. Cross-referencing was performed using the bibliographies from the articles obtained. Articles retrieved were restricted to those published in English. One of the most prominent characteristics of AAA open repair is the double physiological phenomenon of ischemia-reperfusion (I/R) that happens either at the time of clamping or following the aortic clamp removal. Ischemia-reperfusion injury causes significant pathophysiological disturbances to distant organs, increasing the possibility for postoperative multiorgan failure. Although tissue injury is mediated by diverse mechanisms, microvascular dysfunction seems to be the final outcome of I/R. PMID:26798637

  5. Lifting clamp positively grips structural shapes

    NASA Technical Reports Server (NTRS)

    Reinhardt, E. C.

    1966-01-01

    Welded steel clamps securely grip structural shapes of various sizes for crane operations. The clamp has adjustable clamping jaws and screw-operated internal v-jaws and provides greater safety than hoisting slings presently used. The structural member can be rotated in any manner, angle, or direction without being released by the clamp.

  6. Modulation by propranolol of the lysyl cross-links in aortic elastin and collagen of the aneurysm-prone turkey.

    PubMed

    Boucek, R J; Gunja-Smith, Z; Noble, N L; Simpson, C F

    1983-01-15

    dl-Propranolol (propranolol) fed to immature and mature aneurysm-prone turkeys (Broad-Breasted White, BBW) for 6 weeks significantly raised the tensile strength of tissue rings from the abdominal aorta. The drug-mediated increase in tensile strength values was dose-related and independent of its heart rate- and arterial pressure-lowering effects. Propranolol acts, in part, by (a) stimulating lysyl oxidase to produce greater amounts of reactive aldehydes for intermolecular cross-links, (b) enhancing the progression of chemically unstable to stable forms of intermolecular elastin cross-links (lysinonorleucine and the desmosines), and (c) reducing the density of the age-related intermolecular cross-linking of collagen (pyridinoline). These propranolol effects on the lysyl cross-links were demonstrated in both the immature and mature animals and suggest a heretofore unrecognized potential for this widely used cardiovascular drug. PMID:6409122

  7. Split-tapered joint clamping device

    DOEpatents

    Olsen, Max J.; Schwartz, Jr., John F.

    1988-01-01

    This invention relates to a clamping device for removably attaching a tool element to a bracket element wherein a bracket element is disposed in a groove in the tool and a clamping member is disposed in said groove and in engagement with a clamping face of the bracket and a wall of the groove and with the clamping member having pivot means engaging the bracket and about which the clamping member rotates.

  8. Acute Aortic Syndromes and Thoracic Aortic Aneurysm

    PubMed Central

    Ramanath, Vijay S.; Oh, Jae K.; Sundt, Thoralf M.; Eagle, Kim A.

    2009-01-01

    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

  9. How to Assess the Quality of Glucose Clamps? Evaluation of Clamps Performed With ClampArt, a Novel Automated Clamp Device

    PubMed Central

    Benesch, Carsten; Heise, Tim; Klein, Oliver; Heinemann, Lutz; Arnolds, Sabine

    2015-01-01

    Background: There are no widely accepted parameters to assess the quality of glucose clamps. Thus, we selected different parameters describing clamp quality. These parameters were then evaluated in glucose clamps carried out with ClampArt, a novel CE-marked, state-of-the-art fully automated glucose clamp device employing continuous blood glucose (BG) measurements and minute-by-minute adaptations of glucose infusion rate (GIR). Methods: Thirty-nine glucose clamps were performed in 10 healthy and 29 subjects with type 1 diabetes (T1DM) (total duration 583 h). ClampArt-based BG measurements were compared with those obtained with a laboratory reference method. Clamp quality was assessed by 5 parameters: (1) difference (mg/dl) of all paired BG measurements of ClampArt versus reference method (“trueness”), (2) coefficient of variation (CV, %) of ClampArt’s BG measurements at target clamp level (“precision”), (3) mean absolute relative difference (MARD, %) at target clamp level (“accuracy”), (4) difference (mg/dl) between ClampArt and target BG (“control deviation”), and (5) percentage operational time (“utility”). Results: ClampArt-based BG measurements showed a trueness of 1.2 ± 2.5 mg/dl. CV and MARD at target BG were 5.5 ± 2.1% and 5.3 ± 2.3%, respectively. There were only small deviations from target level (1.2 ± 1.6 mg/dl). Operational time was as high as 95.4% ± 4.1% (means ± SD). Conclusions: The selected parameters seem to be adequate to characterize clamp quality. The novel, fully automated clamp device ClampArt achieves high clamp quality, which in future trials should be compared with other (automated and manual) clamp methods. PMID:25852075

  10. Aortic Valve Disease

    MedlinePlus

    ... Disease Tricuspid Valve Disease Cardiac Rhythm Disturbances Thoracic Aortic Aneurysm Pediatric and Congenital Heart Disease Heart abnormalities that ... Disease Tricuspid Valve Disease Cardiac Rhythm Disturbances Thoracic Aortic Aneurysm Aortic Valve Disease Overview The human heart has ...

  11. Thoracic aortic aneurysm

    MedlinePlus

    Aortic aneurysm - thoracic; Syphilitic aneurysm; Aneurysm - thoracic aortic ... The most common cause of a thoracic aortic aneurysm is hardening of the ... with high cholesterol, long-term high blood pressure, or who ...

  12. Myocardial protection during aortic valve replacement. Cardiac metabolism and enzyme release following hypothermic cardioplegia.

    PubMed

    Bomfim, V; Kaijser, L; Bendz, R; Sylvén, C; Olin, C

    1980-01-01

    Cardiac metabolism following hypothermic potassium cardioplegia was studied in 23 patients undergoing isolated aortic valve replacement. All had normal coronary arteries. Cardioplegia was induced by infusing 700-1 000 ml of cold Ringer's acetate containing 20 mekv K+ selectively into the left coronary artery. Simultaneous blood samples were taken from the radial artery, a central vein and from the coronary sinus before and after cardioplegia. The PO2, O2-saturation and content, PCO2, pH, lactate, glucose, potassium, myoglobin, total creatine kinase (CK), its isoenzyme CK-MB, aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) were assessed. Before bypass lactate was extracted by the heart. During the initial 10 to 20 min after cardioplegia there was a marked release of lactate in the coronary sinus. Myoglobin concentration and CK-MB serum activity peaked during the first 4 hours after the release of the aortic cross-clamping. In order to determine the best indicator of myocardial damage after cardioplegia, duration of extracorporeal circulation (ECC-time), aortic occlusion time (AOT), mean myocardial temperature (MMT) and the product of AOT and MMT, referred to as time-temperature area (TTA), were related to possible indicators of myocardial injury, such as enzyme and myoglobin release. The TTA was the best way of expressing the degree of exposure of the heart to ischaemia. The CK-MB to peak area (CK-MB max area) was the best indicator of the degree of ischaemic injury sustained by the heart during operation. PMID:7375890

  13. Limit analysis of pipe clamps

    SciTech Connect

    Flanders, H.E. Jr.

    1990-01-01

    The Service Level D (faulted) load capacity of a conventional three-bolt pipe-clamp based upon the limit analysis method is presented. The load distribution, plastic hinge locations, and collapse load are developed for the lower bound limit load method. The results of the limit analysis are compared with the manufacturer's rated loads. 3 refs.

  14. Hemiarch versus total aortic arch replacement in acute type A dissection: a systematic review and meta-analysis

    PubMed Central

    Poon, Shi Sum; Theologou, Thomas; Harrington, Deborah; Kuduvalli, Manoj; Oo, Aung

    2016-01-01

    Background Despite recent advances in aortic surgery, acute type A aortic dissection remains a surgical emergency associated with high mortality and morbidity. Appropriate management is crucial to achieve satisfactory outcomes but the optimal surgical approach is controversial. The present systematic review and meta-analysis sought to access cumulative data from comparative studies between hemiarch and total aortic arch replacement in patients with acute type A aortic dissection. Methods A systematic review of the literature using six databases. Eligible studies include comparative studies on hemiarch versus total arch replacement reporting short, medium and long term outcomes. A meta-analysis was performed on eligible studies reporting outcome of interest to quantify the effects of hemiarch replacement on mortality and morbidity risk compared to total arch replacement. Result Fourteen retrospective studies met the inclusion criteria and 2,221 patients were included in the final analysis. Pooled analysis showed that hemiarch replacement was associated with a lower risk of post-operative renal dialysis [risk ratio (RR) =0.72; 95% confidence interval (CI): 0.56–0.94; P=0.02; I2=0%]. There was no significant difference in terms of in-hospital mortality between the two groups (RR =0.84; 95% CI: 0.65–1.09; P=0.20; I2=0%). Cardiopulmonary bypass, aortic cross clamp and circulatory arrest times were significantly longer in total arch replacement. During follow up, no significant difference was reported from current studies between the two operative approaches in terms of aortic re-intervention and freedom from aortic reoperation. Conclusions Within the context of publication bias by high volume aortic centres and non-randomized data sets, there was no difference in mortality outcomes between the two groups. This analysis serves to demonstrate that for those centers doing sufficient total aortic arch activity to allow for publication, excellent and equivalent outcomes

  15. Experimental Study and Early Clinical Application Of a Sutureless Aortic Bioprosthesis

    PubMed Central

    Gomes, Walter J.; Leal, João Carlos; Jatene, Fabio Biscegli; Hossne Jr, Nelson A.; Gabaldi, Renata; Frazzato, Glaucia Basso; Agreli, Guilherme; Braile, Domingo M.

    2015-01-01

    INTRODUCTION The conventional aortic valve replacement is the treatment of choice for symptomatic severe aortic stenosis. Transcatheter technique is a viable alternative with promising results for inoperable patients. Sutureless bioprostheses have shown benefits in high-risk patients, such as reduction of aortic clamping and cardiopulmonary bypass, decreasing risks and adverse effects. OBJECTIVE The objective of this study was to experimentally evaluate the implantation of a novel balloon-expandable aortic valve with sutureless bioprosthesis in sheep and report the early clinical application. METHODS The bioprosthesis is made of a metal frame and bovine pericardium leaflets, encapsulated in a catheter. The animals underwent left thoracotomy and the cardiopulmonary bypass was established. The sutureless bioprosthesis was deployed to the aortic valve, with 1/3 of the structure on the left ventricular face. Cardiopulmonary bypass, aortic clamping and deployment times were recorded. Echocardiograms were performed before, during and after the surgery. The bioprosthesis was initially implanted in an 85 year-old patient with aortic stenosis and high risk for conventional surgery, EuroSCORE 40 and multiple comorbidities. RESULTS The sutureless bioprosthesis was rapidly deployed (50-170 seconds; average=95 seconds). The aortic clamping time ranged from 6-10 minutes, average of 7 minutes; the mean cardiopulmonary bypass time was 71 minutes. Bioprostheses were properly positioned without perivalvar leak. In the first operated patient the aortic clamp time was 39 minutes and the patient had good postoperative course. CONCLUSION The deployment of the sutureless bioprosthesis was safe and effective, thereby representing a new alternative to conventional surgery or transcatheter in moderate- to high-risk patients with severe aortic stenosis. PMID:26735597

  16. Aortic Baroreceptors Display Higher Mechanosensitivity than Carotid Baroreceptors

    PubMed Central

    Lau, Eva On-Chai; Lo, Chun-Yin; Yao, Yifei; Mak, Arthur Fuk-Tat; Jiang, Liwen; Huang, Yu; Yao, Xiaoqiang

    2016-01-01

    Arterial baroreceptors are mechanical sensors that detect blood pressure changes. It has long been suggested that the two arterial baroreceptors, aortic and carotid baroreceptors, have different pressure sensitivities. However, there is no consensus as to which of the arterial baroreceptors are more sensitive to changes in blood pressure. In the present study, we employed independent methods to compare the pressure sensitivity of the two arterial baroreceptors. Firstly, pressure-activated action potential firing was measured by whole-cell current clamp with a high-speed pressure clamp system in primary cultured baroreceptor neurons. The results show that aortic depressor neurons possessed a higher percentage of mechano-sensitive neurons. Furthermore, aortic baroreceptor neurons show a lower pressure threshold than that of carotid baroreceptor neurons. Secondly, uniaxial stretching of baroreceptor neurons, that mimics the forces exerted on blood vessels, elicited a larger increase in intracellular Ca2+ rise in aortic baroreceptor neurons than in carotid baroreceptor neurons. Thirdly, the pressure-induced action potential firing in the aortic depressor nerve recorded in vivo was also higher. The present study therefore provides for a basic physiological understanding on the pressure sensitivity of the two baroreceptor neurons and suggests that aortic baroreceptors have a higher pressure sensitivity than carotid baroreceptors.

  17. A clamped rectangular plate containing a crack

    NASA Technical Reports Server (NTRS)

    Tang, R.; Erdogan, F.

    1985-01-01

    The general problem of a rectangular plate clamped along two parallel sides and containing a crack parallel to the clamps is considered. The problem is formulated in terms of a system of singular integral equations and the asymptotic behavior of the stress state near the corners is investigated. Numerical examples are considered for a clamped plate without a crack and with a centrally located crack, and the stress intensity factors and the stresses along the clamps are calculated.

  18. Aortic valve decalcification revisited.

    PubMed

    Marty, A T; Mufti, S; Murabit, I

    1989-11-01

    A 75-year-old woman with a small calcified aortic root, severe aortic stenosis and triple vessel coronary artery disease developed angina at rest. Aortic valve decalcification and quadruple aorto-coronary bypass were done as her aortic root was too small and calcified to do anything else. Postoperative clinical and hemodynamic results have been excellent. Literature review supports application of this therapy in selected patients with trileaflet senescent aortic stenosis. PMID:2614067

  19. Solution structure of an "open" E. coli Pol III clamp loader sliding clamp complex.

    PubMed

    Tondnevis, Farzaneh; Weiss, Thomas M; Matsui, Tsutomu; Bloom, Linda B; McKenna, Robert

    2016-06-01

    Sliding clamps are opened and loaded onto primer template junctions by clamp loaders, and once loaded on DNA, confer processivity to replicative polymerases. Previously determined crystal structures of eukaryotic and T4 clamp loader-clamp complexes have captured the sliding clamps in either closed or only partially open interface conformations. In these solution structure studies, we have captured for the first time the clamp loader-sliding clamp complex from Escherichia coli using size exclusion chromatography coupled to small angle X-ray scattering (SEC-SAXS). The data suggests the sliding clamp is in an open conformation which is wide enough to permit duplex DNA binding. The data also provides information about spatial arrangement of the sliding clamp with respect to the clamp loader subunits and is compared to complex crystal structures determined from other organisms. PMID:26968362

  20. Dynamics of Open DNA Sliding Clamps.

    PubMed

    Oakley, Aaron J

    2016-01-01

    A range of enzymes in DNA replication and repair bind to DNA-clamps: torus-shaped proteins that encircle double-stranded DNA and act as mobile tethers. Clamps from viruses (such as gp45 from the T4 bacteriophage) and eukaryotes (PCNAs) are homotrimers, each protomer containing two repeats of the DNA-clamp motif, while bacterial clamps (pol III β) are homodimers, each protomer containing three DNA-clamp motifs. Clamps need to be flexible enough to allow opening and loading onto primed DNA by clamp loader complexes. Equilibrium and steered molecular dynamics simulations have been used to study DNA-clamp conformation in open and closed forms. The E. coli and PCNA clamps appear to prefer closed, planar conformations. Remarkably, gp45 appears to prefer an open right-handed spiral conformation in solution, in agreement with previously reported biophysical data. The structural preferences of DNA clamps in solution have implications for understanding the duty cycle of clamp-loaders. PMID:27148748

  1. Dynamics of Open DNA Sliding Clamps

    PubMed Central

    Oakley, Aaron J.

    2016-01-01

    A range of enzymes in DNA replication and repair bind to DNA-clamps: torus-shaped proteins that encircle double-stranded DNA and act as mobile tethers. Clamps from viruses (such as gp45 from the T4 bacteriophage) and eukaryotes (PCNAs) are homotrimers, each protomer containing two repeats of the DNA-clamp motif, while bacterial clamps (pol III β) are homodimers, each protomer containing three DNA-clamp motifs. Clamps need to be flexible enough to allow opening and loading onto primed DNA by clamp loader complexes. Equilibrium and steered molecular dynamics simulations have been used to study DNA-clamp conformation in open and closed forms. The E. coli and PCNA clamps appear to prefer closed, planar conformations. Remarkably, gp45 appears to prefer an open right-handed spiral conformation in solution, in agreement with previously reported biophysical data. The structural preferences of DNA clamps in solution have implications for understanding the duty cycle of clamp-loaders. PMID:27148748

  2. Moderate hypothermic circulatory arrest in total arch repair for acute type A aortic dissection: clinical safety and efficacy

    PubMed Central

    Gong, Ming; Ma, Wei-Guo; Guan, Xin-Liang; Wang, Long-Fei; Li, Jia-Chen; Lan, Feng

    2016-01-01

    Background Continued debates exist regarding the optimal temperature during hypothermic circulatory arrest (HCA) in aortic arch repair for patients with type A aortic dissection (TAAD). This study seeks to examine whether the use of moderate HCA in emergency aortic arch surgery provides comparable operative outcomes to deep HCA for patients with acute TAAD. Methods We prospectively enrolled 74 consecutive patients (mean age 47.7±9.8 years, 54 males) with acute TAAD, who underwent emergency total arch replacement and frozen elephant trunk implantation under HCA (18–28 °C) with unilateral selective antegrade cerebral perfusion (uSACP). Patients were divided into two groups based on the nasopharyngeal temperature at the initiation of HCA: deep HCA (DHCA, <20 °C) in 35 (47.3%) and moderate HCA (MHCA, 20–28 °C) in 39 (52.7%). Operative outcomes including mortality, morbidity and visceral organ functions were compared between the two groups. Results The mean times of cardiopulmonary bypass (CPB) and aortic cross-clamp were 211±54 and 238±62 minutes (P=0.053) and 118±27 and 142±45 minutes (P=0.005) in the MHCA and DHCA groups, respectively. Operative mortality did not differ between two groups (10.2% in MHCA vs. 14.3% in DHCA groups, P=0.862). Nor did the incidence of morbidities differ between the two groups (P>0.05). The temporal trend in the changes of postoperative levels of creatinine, aspartate aminotransferase, total bilirubin and lactate did not differ between two groups (P>0.05). Multivariate analysis found that the temperature during HCA (MHCA vs. DHCA) did not affect operative mortality, morbidities and neurologic complications. Instead, CPB time (in minutes) was the risk factor for operative mortality (odds ratio, 1.032; 95% confidence interval, 1.004–1.061; P=0.023). Conclusions: Moderate HCA is associated with equivalent operative mortality and morbidity and visceral organ functions compared to deep HCA in patients with acute TAAD undergoing

  3. Aortic valve replacement in rheumatoid aortic incompetence.

    PubMed Central

    Devlin, A B; Goldstraw, P; Caves, P K

    1978-01-01

    Rheumatoid aortic valve disease is uncommon. and there are few reports of valve replacement in this condition. Aortic valve replacement and partial pericardiectomy was performed in a patient with acute rheumatoid aortitis and aortic incompetence. Previous reports suggest that any patient with rheumatoid arthritis who develops cardiac symptoms should be carefully assessed for surgically treatable involvement of the pericardium or heart valves. Images PMID:725829

  4. High-speed pressure clamp.

    PubMed

    Besch, Stephen R; Suchyna, Thomas; Sachs, Frederick

    2002-10-01

    We built a high-speed, pneumatic pressure clamp to stimulate patch-clamped membranes mechanically. The key control element is a newly designed differential valve that uses a single, nickel-plated piezoelectric bending element to control both pressure and vacuum. To minimize response time, the valve body was designed with minimum dead volume. The result is improved response time and stability with a threefold decrease in actuation latency. Tight valve clearances minimize the steady-state air flow, permitting us to use small resonant-piston pumps to supply pressure and vacuum. To protect the valve from water contamination in the event of a broken pipette, an optical sensor detects water entering the valve and increases pressure rapidly to clear the system. The open-loop time constant for pressure is 2.5 ms for a 100-mmHg step, and the closed-loop settling time is 500-600 micros. Valve actuation latency is 120 micros. The system performance is illustrated for mechanically induced changes in patch capacitance. PMID:12397401

  5. Selective cerebro-myocardial perfusion in complex congenital aortic arch pathology: a novel technique.

    PubMed

    De Rita, Fabrizio; Lucchese, Gianluca; Barozzi, Luca; Menon, Tiziano; Faggian, Giuseppe; Mazzucco, Alessandro; Luciani, Giovanni Battista

    2011-11-01

    Simultaneous cerebro-myocardial perfusion has been described in neonatal and infant arch surgery, suggesting a reduction in cardiac morbidity. Here reported is a novel technique for selective cerebral perfusion combined with controlled and independent myocardial perfusion during surgery for complex or recurrent aortic arch lesions. From April 2008 to April 2011, 10 patients with arch pathology underwent surgery (two hypoplastic left heart syndrome [HLHS], four recurrent arch obstruction, two aortic arch hypoplasia + ventricular septal defect [VSD], one single ventricle + transposition of the great arteries + arch hypoplasia, one interrupted aortic arch type B + VSD). Median age was 63 days (6 days-36 years) and median weight 4.0 kg (1.6-52). Via midline sternotomy, an arterial cannula (6 or 8 Fr for infants) was directly inserted into the innominate artery or through a polytetrafluoroethylene (PTFE) graft (for neonates <2.0 kg). A cardioplegia delivery system was inserted into the aortic root. Under moderate hypothermia, ascending and descending aorta were cross-clamped, and "beating heart and brain" aortic arch repair was performed. Arch repair was composed of patch augmentation in five, end-to-side anastomosis in three, and replacement in two patients. Average cardiopulmonary bypass time was 163 ± 68 min (71-310). In two patients only (one HLHS, one complex single ventricle), a period of cardiac arrest was required to complete intracardiac repair. In such cases, antegrade blood cardioplegia was delivered directly via the same catheter used for selective myocardial perfusion. Average time of splanchnic ischemia during cerebro-myocardial perfusion was 39 ± 18 min (17-69). Weaning from cardiopulmonary bypass was achieved without inotropic support in three and with low dose in seven patients. One patient required veno-arterial extracorporeal membrane oxygenation. Four patients, body weight <3.0 kg, needed delayed sternal closure. No neurologic dysfunction was noted

  6. Influence of Municipality-Level Mean Income on Access to Aortic Valve Surgery: A Cross-Sectional Observational Study under Japan's Universal Health-Care Coverage

    PubMed Central

    Lee, Seitetsu L.; Hashimoto, Hideki; Kohro, Takahide; Horiguchi, Hiromasa; Koide, Daisuke; Komuro, Issei; Fushimi, Kiyohide; Yamazaki, Tsutomu; Yasunaga, Hideo

    2014-01-01

    Background Universal health-care coverage has attracted the interest of policy makers as a way of achieving health equity. However, previous reports have shown that despite universal coverage, socioeconomic disparity persists in access to high-tech invasive care, such as cardiac treatment. In this study, we aimed to investigate the association between socioeconomic status and care of aortic stenosis in the context of Japan's health-care system, which is mainly publicly funded. Methods We chose aortic stenosis in older people as a target because such patients are likely to be affected by socioeconomic disparity. Using a large Japanese claim-based inpatient database, we identified 12,893 isolated aortic stenosis patients aged over 65 years who were hospitalized between July 2010 and March 2012. Municipality socioeconomic status was represented by the mean household income of the patients' residential municipality, categorized into quartiles. The likelihood of undergoing aortic valve surgery and in-hospital mortality was regressed against socioeconomic status level with adjustments for hospital volume, regional number of cardiac surgeons per 1 million population, and patients' clinical status. Results We found no significant differences between the highest and lowest quartile groups in surgical indication (odds ratio, 0.84; 95% confidence interval, 0.69–1.03) or in-hospital mortality (1.00; 0.68–1.48). Hospital volume was significantly associated with lower postoperative mortality (odds ratio of the highest volume tertile to the lowest, 0.49; 0.34–0.71). Conclusions Under Japan's current universal health-care coverage, municipality socioeconomic status did not appear to have a systematic relationship with either treatment decision for surgical intervention or postoperative survival following aortic valve surgery among older patients. Our results imply that universal health-care coverage with high publicly funded coverage offers equal access to high

  7. Abdominal aortic aneurysm

    MedlinePlus

    ... to the abdomen, pelvis, and legs. An abdominal aortic aneurysm occurs when an area of the aorta becomes ... blood pressure Male gender Genetic factors An abdominal aortic aneurysm is most often seen in males over age ...

  8. Aortic aneurysm repair - endovascular

    MedlinePlus

    ... Endovascular aneurysm repair - aorta; AAA repair - endovascular; Repair - aortic aneurysm - endovascular ... leaking or bleeding. You may have an abdominal aortic aneurysm that is not causing any symptoms or problems. ...

  9. Aortic aneurysm repair - endovascular

    MedlinePlus

    EVAR; Endovascular aneurysm repair - aorta; AAA repair - endovascular; Repair - aortic aneurysm - endovascular ... leaking or bleeding. You may have an abdominal aortic aneurysm that is not causing any symptoms or problems. ...

  10. Advanced motor driven clamped borehole seismic receiver

    DOEpatents

    Engler, Bruce P.; Sleefe, Gerard E.; Striker, Richard P.

    1993-01-01

    A borehole seismic tool including a borehole clamp which only moves perpendicular to the borehole. The clamp is driven by an electric motor, via a right angle drive. When used as a seismic receiver, the tool has a three part housing, two of which are hermetically sealed. Accelerometers or geophones are mounted in one hermetically sealed part, the electric meter in the other hermetically sealed part, and the clamp and right angle drive in the third part. Preferably the tool includes cable connectors at both ends. Optionally a shear plate can be added to the clamp to extend the range of the tool.

  11. Advanced motor driven clamped borehole seismic receiver

    DOEpatents

    Engler, B.P.; Sleefe, G.E.; Striker, R.P.

    1993-02-23

    A borehole seismic tool is described including a borehole clamp which only moves perpendicular to the borehole. The clamp is driven by an electric motor, via a right angle drive. When used as a seismic receiver, the tool has a three part housing, two of which are hermetically sealed. Accelerometers or geophones are mounted in one hermetically sealed part, the electric motor in the other hermetically sealed part, and the clamp and right angle drive in the third part. Preferably the tool includes cable connectors at both ends. Optionally a shear plate can be added to the clamp to extend the range of the tool.

  12. Regional aortic distensibility and its relationship with age and aortic stenosis: a computed tomography study.

    PubMed

    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

    2015-06-01

    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. PMID:25855464

  13. Abdominal Aortic Aneurysms: Treatments

    MedlinePlus

    ... information Membership Directory (SIR login) Interventional Radiology Abdominal Aortic Aneurysms Interventional Radiologists Treat Abdominal Aneurysms Nonsurgically Interventional radiologists ...

  14. Diverless pipeline repair clamp: Phase 2

    SciTech Connect

    Miller, J.E.; Lane, B. )

    1992-04-01

    The objective of this project sponsored by the Pipeline Research Committee of the American Gas Association, is to develop a system suitable for repairing small leaks on deepwater pipelines. Phase I of the project, completed in 1990 by Stress Engineering Services, Inc. investigated the types of problems that would have to be overcome to effect a diverless clamp-type repair. Several repair systems were investigated and ten mechanisms were proposed that could be used to secure two clamp halves together. This current Phase 11 effort, is to take two most promising clamp concepts from Phase 1, further evaluate hardware and installation issues, develop conceptual designs, and determine which concept should be carried forward to detailed design. The two concepts evaluated were (1) a bolted split-sleeve clamp suited for ROV installation, and (2) a hydraulically self-actuating clamp requiring only placement on the pipe and actuation by ROV hydraulic hot stabs. Both concepts were evaluated for a 12-inch (324 mm) nominal pipe diameter with an ANSI 900 (15.3 mPa) pressure rating, presuming either system could be adapted to a wider range of pipe sizes and design pressures. Based on the results of this investigation a modified bolted split-sleeve clamp was recommended over the hydraulically self-actuating clamp. The main reasons are (1) the bolted split-sleeve clamp can be adapted to installation by a ROV, (2) sealing and clamping mechanisms borrow from available proven technology, (3) it would require less development effort than the hydraulically self-actuating clamp, and (4) the bolted split-sleeve clamp would probably result in a simpler, less costly design.

  15. Monoparesis after graft replacement of non-ruptured abdominal aortic aneurysm.

    PubMed

    Matsuda, Hitoshi; Ogino, Hitoshi; Saito, Shunsuke; Sasaki, Hiroaki; Minatoya, Kenji; Kobayashi, Junjiro; Yagihara, Toshikatsu; Kitamura, Soichiro

    2006-10-01

    A 67-year-old man was admitted with a saccular aneurysm of the abdominal aorta. Preoperative CT revealed cylindrical calcification of the abdominal aorta and the patent internal iliac arteries (IIAs). At the elective surgery, a cylinder-shaped and severely calcified intimal layer was found, and the lumbar arteries were totally occluded. Hypotension caused by the loose iliac clamp due to severe calcification continued for 15 minutes and long-time cross clamp was necessary. Monoparesis of the left lower extremity and dysuria occurred postoperatively. Spinal MRI revealed small infarction at the Th10 level. Symptoms improved and he could walk with a cane and within a few months no uninary catheter support was needed. Thoracic spinal cord infarction after abdominal aortic aneurysm (AAA) surgery and a severely calcified abdominal aorta indicated the importance of the blood flow in the IIA as the significant source of spinal blood supply. To prevent spinal cord injury (SCI) which is rare but significant complication of AAA surgery, understanding of the spinal blood supply, quick surgery, and complete revascularization of pelvic arteries are important. PMID:17095985

  16. Transcatheter aortic valve implantation

    PubMed Central

    Oliemy, Ahmed

    2014-01-01

    Transcatheter aortic valve implantation was developed to offer a therapeutic solution to patients with severe symptomatic aortic stenosis who are not candidates for conventional aortic valve replacement. The improvement in transcatheter aortic valve implantation outcomes is still of concern in the areas of stroke, vascular injury, heart block, paravalvular regurgitation and valve durability. Concomitantly, the progress, both technical and in terms of material advances of transcatheter valve systems, as well as in patient selection, renders transcatheter aortic valve implantation an increasingly viable treatment for more and more patients with structural heart disease. PMID:25374670

  17. 24-hour central aortic systolic pressure and 24-hour central pulse pressure are related to diabetic complications in type 1 diabetes – a cross-sectional study

    PubMed Central

    2013-01-01

    Background Non-invasive measurements of 24 hour ambulatory central aortic systolic pressure (24 h-CASP) and central pulse pressure (24 h-CPP) are now feasible. We evaluate the relationship between 24 h central blood pressure and diabetes-related complications in patients with type 1 diabetes. Methods The study was cross-sectional, including 715 subjects: 86 controls (C), 69 patients with short diabetes duration (< 10 years), normoalbuminuria (< 30 mg/24 h) without receiving antihypertensive treatment (SN), 211 with longstanding diabetes (≥ 10 years) and normoalbuminuria (LN), 163 with microalbuminuria (30-299 mg/24 h) (Mi) and 186 with macroalbuminuria (> 300 mg/24 h) (Ma). 24 h-CASP and 24 h-CPP was measured using a tonometric wrist-watch-like device (BPro, HealthStats, Singapore) and derived using N-point moving average. Results In C, SN, LN, Mi and Ma mean ± SD 24 h-CASP was: 114 ± 17, 115 ± 13, 121 ± 13, 119 ± 16 and 121 ± 13 mmHg (p < 0.001); and 24 h-CPP: 38 ± 8, 38 ± 7, 44 ± 10, 46 ± 11 and 46 ± 11 mmHg, (p < 0.001). Following rigorous adjustment (24 h mean arterial pressure and conventional risk factors), 24 h-CASP and 24 h-CPP increased with diabetes, albuminuria degree, previous cardiovascular disease (CVD), retinopathy and autonomic dysfunction (p ≤ 0.031). Odds ratios per 1 standard deviation increase in 24 h-CASP, 24 h-CPP and 24 h systolic blood pressure (24 h-SBP) were for CVD: 3.19 (1.68-6.05), 1.43 (1.01-2.02) and 2.39 (1.32-4.33), retinopathy: 4.41 (2.03-9.57), 1.77 (1.17-2.68) and 3.72 (1.85-7.47) and autonomic dysfunction: 3.25 (1.65-6.41), 1.64 (1.12-2.39) and 2.89 (1.54-5.42). Conclusions 24 h-CASP and 24 h-CPP was higher in patients vs. controls and increased with diabetic complications independently of covariates. Furthermore, 24 h-CASP was stronger associated to complications than 24 h-SBP. The prognostic significance of 24 h-CASP and 24 h-CPP needs to be determined in follow-up studies. Trial

  18. Protein folding in a force clamp

    NASA Astrophysics Data System (ADS)

    Cieplak, Marek; Szymczak, P.

    2006-05-01

    Kinetics of folding of a protein held in a force clamp are compared to an unconstrained folding. The comparison is made within a simple topology-based dynamical model of ubiquitin. We demonstrate that the experimentally observed variations in the end-to-end distance reflect microscopic events during folding. However, the folding scenarios in and out of the force clamp are distinct.

  19. [Minimally Invasive Aortic Valve Replacement Via Right Mini-thoracotomy].

    PubMed

    Totsugawa, Toshinori

    2016-07-01

    Here we demonstrate our surgical procedure of minimally invasive aortic valve replacement through right anterolateral mini-thoracotomy. Preoperative evaluation of the whole aorta by contrast-enhanced computed tomography scan is important to prevent cerebrovascular complications. The patient is set in a mild left lateral decubitus position. A skin incision is made along the anterior axillary line to the inframammary fold and the chest is opened at the 3rd or 4th intercostal space. Cardiopulmonary bypass is usually established by femoro-femoral bypass. The ascending aorta is clamped with a Chitwood clamp and antegrade or selective cardioplegia is administered. Four traction sutures placed at the aortotomy widely open the aortotomy and offer fine surgical view of the aortic valve. The annular calcifications are excised using a cavitron ultrasonic surgical aspirator. Double-needle braided sutures with pledgets are placed in a non-everting mattress manner. Then the prosthetic valve is sewn onto the aortic annulus. Finger knot tying through anterolateral mini-thoracotomy is usually challenging;therefore, all sutures are tied using a knot pusher. The aortotomy is closed and the aorta is de-clamped. The pericardium is loosely closed;chest tubes are placed;and the thoracotomy is closed in a usual manner. PMID:27440021

  20. Aortic Valve Sparing in Different Aortic Valve and Aortic Root Conditions.

    PubMed

    David, Tirone E

    2016-08-01

    The development of aortic valve-sparing operations (reimplantation of the aortic valve and remodeling of the aortic root) expanded the surgical armamentarium for treating patients with aortic root dilation caused by a variety of disorders. Young adults with aortic root aneurysms associated with genetic syndromes are ideal candidates for reimplantation of the aortic valve, and the long-term results have been excellent. Incompetent bicuspid aortic valves with dilated aortic annuli are also satisfactorily treated with the same type of operation. Older patients with ascending aortic aneurysm and aortic insufficiency secondary to dilated sinotubular junction and a normal aortic annulus can be treated with remodeling of the aortic root or with reimplantation of the aortic valve. The first procedure is simpler, and both procedures are likely equally effective. As with any heart valve-preserving procedure, patient selection and surgical expertise are keys to successful and durable repairs. PMID:27491910

  1. Simultaneous Open Surgical Treatment of Aortic Coral Reef and Leriche Syndrome: Case Report and Literature Review.

    PubMed

    Pranteda, Chiara; Menna, Danilo; Capoccia, Laura; Sirignano, Pasqualino; Mansour, Wassim; Speziale, Francesco

    2016-04-01

    The coral reef aorta (CRA) is a rare syndrome commonly referred to a distribution of calcified plaques in the visceral part of the aorta. Because those plaques can cause malperfusion of the lower limbs, visceral ischemia or renovascular hypertension, surgical treatment is recommended. Transaortic endarterectomy is accepted as a standard repair and it is often performed through an extensive thoracoabdominal approach. CRA has been reported in association with polidistrectual atherosclerotic disease, such as Leriche syndrome. When these 2 conditions coexist, surgical invasivity increases raising several issues concerning the type of surgical access and the revascularization techniques. We report the case of a patient with CRA and Leriche syndrome treated by simultaneous aortic endarterectomy and aortibifemoral bypass at our institution. Intervention was performed through left lumbotomy at 10th intercostal space extended by a left pararectal abdominal incision with section of 11th rib. Through extraperitoneal access visceral vessels were isolated. Aortic cross-clamping was performed at supraceliac and infrarenal levels and a longitudinal arteriotomy was performed on the posterolateral wall of visceral aorta for an overall 4-cm extension. Aortic endarterectomy was then performed and complete plaque excision was easily achieved. Superior mesenteric artery angioplasty was then performed by a DeBakey dilator, gaining an optimal backflow. The aortotomy was then closed with running 3-0 polypropylene suture. Subsequently, through a transperitoneal access an aortobi-femoral bypass was performed by a Dacron knitted graft. Postoperative course was uneventful. At a 6-month follow-up, the patient is in good clinical condition with normal patency of visceral vessels. PMID:26806247

  2. The Monogenean Which Lost Its Clamps

    PubMed Central

    Justine, Jean-Lou; Rahmouni, Chahrazed; Gey, Delphine; Schoelinck, Charlotte; Hoberg, Eric P.

    2013-01-01

    Ectoparasites face a daily challenge: to remain attached to their hosts. Polyopisthocotylean monogeneans usually attach to the surface of fish gills using highly specialized structures, the sclerotized clamps. In the original description of the protomicrocotylid species Lethacotyle fijiensis, described 60 years ago, the clamps were considered to be absent but few specimens were available and this observation was later questioned. In addition, genera within the family Protomicrocotylidae have either clamps of the “gastrocotylid” or the “microcotylid” types; this puzzled systematists because these clamp types are characteristic of distinct, major groups. Discovery of another, new, species of the genus Lethacotyle, has allowed us to explore the nature of the attachment structures in protomicrocotylids. Lethacotyle vera n. sp. is described from the gills of the carangid Caranx papuensis off New Caledonia. It is distinguished from Lethacotyle fijiensis, the only other species of the genus, by the length of the male copulatory spines. Sequences of 28S rDNA were used to build a tree, in which Lethacotyle vera grouped with other protomicrocotylids. The identity of the host fish was confirmed with COI barcodes. We observed that protomicrocotylids have specialized structures associated with their attachment organ, such as lateral flaps and transverse striations, which are not known in other monogeneans. We thus hypothesized that the clamps in protomicrocotylids were sequentially lost during evolution, coinciding with the development of other attachment structures. To test the hypothesis, we calculated the surfaces of clamps and body in 120 species of gastrocotylinean monogeneans, based on published descriptions. The ratio of clamp surface: body surface was the lowest in protomicrocotylids. We conclude that clamps in protomicrocotylids are vestigial organs, and that occurrence of “gastrocotylid” and simpler “microcotylid” clamps within the same family are

  3. 33 CFR 183.560 - Hose clamps: Installation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Hose clamps: Installation. Each hose clamp on a hose from the fuel tank to the fuel inlet connection on..., pipe, or hose fitting; and (d) Not depend solely on the spring tension of the clamp for...

  4. Surface characterization of selected LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Cromer, T. F.; Grammer, H. L.; Wightman, J. P.; Young, Philip R.; Slemp, Wayne S.

    1993-01-01

    The surface characterization of chromic acid anodized 6061-T6 aluminum alloy tray clamps has shown differences in surface chemistry depending upon the position on the Long Duration Exposure Facility (LDEF). Water contact angle results showed no changes in wettability of the tray clamps. The overall surface topography of the control, trailing edge(E3) and leading edge(D9) samples was similar. The thickness of the aluminum oxide layer for all samples determined by Auger depth profiling was less than one micron. X-ray photoelectron spectroscopy (XPS) analysis of the tray clamps showed significant differences in the surface composition. Carbon and silicon containing compounds were the primary contaminants detected.

  5. State-of-the-art aortic imaging: Part II - applications in transcatheter aortic valve replacement and endovascular aortic aneurysm repair.

    PubMed

    Rengier, Fabian; Geisbüsch, Philipp; Schoenhagen, Paul; Müller-Eschner, Matthias; Vosshenrich, Rolf; Karmonik, Christof; von Tengg-Kobligk, Hendrik; Partovi, Sasan

    2014-01-01

    Transcatheter aortic valve replacement (TAVR) as well as thoracic and abdominal endovascular aortic repair (TEVAR and EVAR) rely on accurate pre- and postprocedural imaging. This review article discusses the application of imaging, including preprocedural assessment and measurements as well as postprocedural imaging of complications. Furthermore, the exciting perspective of computational fluid dynamics (CFD) based on cross-sectional imaging is presented. TAVR is a minimally invasive alternative for treatment of aortic valve stenosis in patients with high age and multiple comorbidities who cannot undergo traditional open surgical repair. Given the lack of direct visualization during the procedure, pre- and peri-procedural imaging forms an essential part of the intervention. Computed tomography angiography (CTA) is the imaging modality of choice for preprocedural planning. Routine postprocedural follow-up is performed by echocardiography to confirm treatment success and detect complications. EVAR and TEVAR are minimally invasive alternatives to open surgical repair of aortic pathologies. CTA constitutes the preferred imaging modality for both preoperative planning and postoperative follow-up including detection of endoleaks. Magnetic resonance imaging is an excellent alternative to CT for postoperative follow-up, and is especially beneficial for younger patients given the lack of radiation. Ultrasound is applied in screening and postoperative follow-up of abdominal aortic aneurysms, but cross-sectional imaging is required once abnormalities are detected. Contrast-enhanced ultrasound may be as sensitive as CTA in detecting endoleaks. PMID:24429327

  6. Acute aortic syndrome

    PubMed Central

    2016-01-01

    Acute aortic syndrome (AAS) is a term used to describe a constellation of life-threatening aortic diseases that have similar presentation, but appear to have distinct demographic, clinical, pathological and survival characteristics. Many believe that the three major entities that comprise AAS: aortic dissection (AD), intramural hematoma (IMH) and penetrating aortic ulcer (PAU), make up a spectrum of aortic disease in which one entity may evolve into or coexist with another. Much of the confusion in accurately classifying an AAS is that they present with similar symptoms: typically acute onset of severe chest or back pain, and may have similar radiographic features, since the disease entities all involve injury or disruption of the medial layer of the aortic wall. The accurate diagnosis of an AAS is often made at operation. This manuscript will attempt to clarify the similarities and differences between AD, IMH and PAU of the ascending aorta and describe the challenges in distinguishing them from one another. PMID:27386405

  7. Acute aortic syndrome.

    PubMed

    Corvera, Joel S

    2016-05-01

    Acute aortic syndrome (AAS) is a term used to describe a constellation of life-threatening aortic diseases that have similar presentation, but appear to have distinct demographic, clinical, pathological and survival characteristics. Many believe that the three major entities that comprise AAS: aortic dissection (AD), intramural hematoma (IMH) and penetrating aortic ulcer (PAU), make up a spectrum of aortic disease in which one entity may evolve into or coexist with another. Much of the confusion in accurately classifying an AAS is that they present with similar symptoms: typically acute onset of severe chest or back pain, and may have similar radiographic features, since the disease entities all involve injury or disruption of the medial layer of the aortic wall. The accurate diagnosis of an AAS is often made at operation. This manuscript will attempt to clarify the similarities and differences between AD, IMH and PAU of the ascending aorta and describe the challenges in distinguishing them from one another. PMID:27386405

  8. Dynamic clamp with StdpC software

    PubMed Central

    2011-01-01

    Dynamic clamp is a powerful method that allows the introduction of artificial electrical components into target cells to simulate ionic conductances and synaptic inputs. This method is based on a fast cycle of measuring the membrane potential of a cell, calculating the current of a desired simulated component using an appropriate model and injecting this current into the cell. Here, we present a dynamic clamp protocol using free, fully integrated, open-source software (StdpC, Spike timing dependent plasticity Clamp). Use of this protocol does not require specialist hardware, costly commercial software, experience in real time operating systems or a strong programming background. The software enables the configuration and operation of a wide range of complex and fully automated dynamic clamp experiments via an intuitive and powerful interface with a minimal initial lead-time of a few hours. After initial configuration, experimental results can be generated within minutes of cell impalement. PMID:21372819

  9. Molecular Mechanisms of DNA Polymerase Clamp Loaders

    NASA Astrophysics Data System (ADS)

    Kelch, Brian; Makino, Debora; Simonetta, Kyle; O'Donnell, Mike; Kuriyan, John

    Clamp loaders are ATP-driven multiprotein machines that couple ATP hydrolysis to the opening and closing of a circular protein ring around DNA. This ring-shaped clamp slides along DNA, and interacts with numerous proteins involved in DNA replication, DNA repair and cell cycle control. Recently determined structures of clamp loader complexes from prokaryotic and eukaryotic DNA polymerases have revealed exciting new details of how these complex AAA+ machines perform this essential clamp loading function. This review serves as background to John Kuriyan's lecture at the 2010 Erice School, and is not meant as a comprehensive review of the contributions of the many scientists who have advanced this field. These lecture notes are derived from recent reviews and research papers from our groups.

  10. Patch-Clamp Fluorometry: Electrophysiology meets Fluorescence

    PubMed Central

    Kusch, Jana; Zifarelli, Giovanni

    2014-01-01

    Ion channels and transporters are membrane proteins whose functions are driven by conformational changes. Classical biophysical techniques provide insight into either the structure or the function of these proteins, but a full understanding of their behavior requires a correlation of both these aspects in time. Patch-clamp and voltage-clamp fluorometry combine spectroscopic and electrophysiological techniques to simultaneously detect conformational changes and ionic currents across the membrane. Since its introduction, patch-clamp fluorometry has been responsible for invaluable advances in our knowledge of ion channel biophysics. Over the years, the technique has been applied to many different ion channel families to address several biophysical questions with a variety of spectroscopic approaches and electrophysiological configurations. This review illustrates the strength and the flexibility of patch-clamp fluorometry, demonstrating its potential as a tool for future research. PMID:24655500

  11. Structural analysis of a eukaryotic sliding DNA clamp-clamp loadercomplex.

    SciTech Connect

    Bowman, Gregory D.; O'Donnell, Mike; Kuriyan, John

    2006-06-17

    Sliding clamps are ring-shaped proteins that encircle DNA and confer high processivity on DNA polymerases. Here we report the crystal structure of the five-protein clamp loader complex (replication factor-C, RFC) of the yeast Saccharomyces cerevisiae, bound to the sliding clamp (proliferating cell nuclear antigen, PCNA). Tight interfacial coordination of the ATP analogue ATP-?-S by RFC results in a spiral arrangement of the ATPase domains of the clamp loader above the PCNA ring. Placement of a model for primed DNA within the central hole of PCNA reveals a striking correspondence between the RFC spiral and the grooves of the DNA double helix. This model, in which the clamp loader complex locks onto primed DNA in a screw-cap-like arrangement, provides a simple explanation for the process by which the engagement of primer-template junctions by the RFC:PCNA complex results in ATP hydrolysis and release of the sliding clamp on DNA.

  12. Protein folding in a force-clamp

    NASA Astrophysics Data System (ADS)

    Cieplak, Marek; Szymczak, Piotr

    2006-03-01

    Kinetics of folding of a protein held in a force-clamp are compared to an unconstrained folding. The comparison is made within a simple topology-based dynamical model of ubiquitin. We demonstrate that the experimentally observed rapid changes in the end-to-end distance mirror microscopic events during folding. However, the folding scenarios in and out of the force-clamp are distinct.

  13. FOXE3 mutations predispose to thoracic aortic aneurysms and dissections

    PubMed Central

    Kuang, Shao-Qing; Medina-Martinez, Olga; Guo, Dong-chuan; Gong, Limin; Regalado, Ellen S.; Reynolds, Corey L.; Boileau, Catherine; Jondeau, Guillaume; Prakash, Siddharth K.; Kwartler, Callie S.; Zhu, Lawrence Yang; Peters, Andrew M.; Duan, Xue-Yan; Bamshad, Michael J.; Shendure, Jay; Nickerson, Debbie A.; Santos-Cortez, Regie L.; Dong, Xiurong; Leal, Suzanne M.; Majesky, Mark W.; Swindell, Eric C.; Jamrich, Milan; Milewicz, Dianna M.

    2016-01-01

    The ascending thoracic aorta is designed to withstand biomechanical forces from pulsatile blood. Thoracic aortic aneurysms and acute aortic dissections (TAADs) occur as a result of genetically triggered defects in aortic structure and a dysfunctional response to these forces. Here, we describe mutations in the forkhead transcription factor FOXE3 that predispose mutation-bearing individuals to TAAD. We performed exome sequencing of a large family with multiple members with TAADs and identified a rare variant in FOXE3 with an altered amino acid in the DNA-binding domain (p.Asp153His) that segregated with disease in this family. Additional pathogenic FOXE3 variants were identified in unrelated TAAD families. In mice, Foxe3 deficiency reduced smooth muscle cell (SMC) density and impaired SMC differentiation in the ascending aorta. Foxe3 expression was induced in aortic SMCs after transverse aortic constriction, and Foxe3 deficiency increased SMC apoptosis and ascending aortic rupture with increased aortic pressure. These phenotypes were rescued by inhibiting p53 activity, either by administration of a p53 inhibitor (pifithrin-α), or by crossing Foxe3–/– mice with p53–/– mice. Our data demonstrate that FOXE3 mutations lead to a reduced number of aortic SMCs during development and increased SMC apoptosis in the ascending aorta in response to increased biomechanical forces, thus defining an additional molecular pathway that leads to familial thoracic aortic disease. PMID:26854927

  14. Diverless pipeline repair clamp, Phase 3

    SciTech Connect

    Miller, J.E.

    1993-08-01

    The objective of this project is to develop a system suitable for repairing small leaks in deep water pipelines. It is assumed that leak repair operations at the water depths in question will be performed by Remotely Operated Vehicles (ROV`s). This report summarizes the results of the third and final phase of this project. Phase 3 work included design, manufacture, and dry testing of (1) a one-half scale model of a 12 inch repair clamp, (2) a full-scale bolt test fixture to demonstrate bolt containment and startup under realistic misalignment of the clamp halves, and (3) a full-scale one-way cylinder for end seal activation. Phase 3 also included a study commissioned from Oceaneering directed at defining the interfaces of the clamp package and the ROV, including suggested procedures for deployment and positioning of the clamp package on the pipeline. Issues regarding bolt make-up by the ROV were also studied in detail and limitations in bolting capability were outlined. The conclusion of this work is that the clamping system described herein may be implemented in a direct manner. The design issues causing the most concern have been resolved through laboratory tests. Note however that all testing performed was mechanical in nature and performed in a dry environment. The recommended next development step, prior to declaring the system operational, is to manufacture a fully outfitted clamp package and to perform installation tests in a controlled underwater environment using a typical deepwater ROV. Wet tests are required in order to demonstrate ROV interfaces and installation procedures, however, the major mechanical features represented by the clamp design as well as its operation have been proven.

  15. Juxtarenal aortic occlusion.

    PubMed Central

    Tapper, S S; Jenkins, J M; Edwards, W H; Mulherin, J L; Martin, R S; Edwards, W H

    1992-01-01

    The authors' experience with 113 aortic occlusions in 103 patients during a 26-year period (1965 to 1991) is reviewed. The authors found three distinct patterns of presentation: group I (n = 26) presented with acute aortic occlusion, group II (n = 66) presented with chronic aortic occlusion, and group III (n = 21) presented with complete occlusion of an aortic graft. Perioperative mortality rates were 31%, 9%, and 4.7% for each respective group and achieved statistical significance when comparing group I with group II (p = 0.009) and group I with group III (p = 0.015). Group I presented with profound metabolic insults due to acute ischemia and fared poorly. Group II presented with chronic claudication and did well long-term. Group III presented with acute ischemia but did well because of established collateral circulation. The treatment and expected outcome of aortic occlusion depends on the cause. PMID:1616381

  16. Conservative Management of Chronic Aortic Dissection with Underlying Aortic Aneurysm

    PubMed Central

    Yusuf Beebeejaun, Mohammad; Malec, Aleksandra; Gupta, Ravi

    2013-01-01

    Aortic dissection is one of the most common aortic emergencies affecting around 2000 Americans each year. It usually presents in the acute state but in a small percentage of patients aortic dissections go unnoticed and these patients survive without any adequate therapy. With recent advances in medical care and diagnostic technologies, aortic dissection can be successfully managed through surgical or medical options, consequently increasing the related survival rate. However, little is known about the optimal long-term management of patients suffering from chronic aortic dissection. The purpose of the present report is to review aortic dissection, namely its pathology and the current diagnostic tools available, and to discuss the management options for chronic aortic dissection. We report a patient in which chronic aortic dissection presented with recurring episodes of vomiting and also discuss the management plan of our patient who had a chronic aortic dissection as well as an underlying aortic aneurysm. PMID:24179638

  17. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  18. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  19. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  20. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  1. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  2. An Ultrasonic Clamp for Bloodless Partial Nephrectomy

    NASA Astrophysics Data System (ADS)

    Lafon, Cyril; Bouchoux, Guillaume; Murat, François Joseph; Birer, Alain; Theillère, Yves; Chapelon, Jean Yves; Cathignol, Dominique

    2007-05-01

    Maximum conservation of the kidney is preferable through partial nephrectomy for patients at risk of disease recurrence of renal cancers. Haemostatic tools are needed in order to achieve bloodless surgery and reduce post surgery morbidity. Two piezo-ceramic transducers operating at a frequency of 4 MHz were mounted on each arm of a clamp. When used for coagulation purposes, two transducers situated on opposite arms of the clamp were driven simultaneously. Heat delivery was optimized as each transducers mirrored back to targeted tissues the wave generated by the opposite transducer. Real-time treatment monitoring with an echo-based technique was also envisaged with this clamp. Therapy was periodically interrupted so one transducer could generate a pulse. The echo returning from the opposite transducer was treated. Coagulation necroses were obtained in vitro on substantial thicknesses (23-38mm) of pig liver over exposure durations ranging from 30s to 130s, and with acoustic intensities of less than 15W/cm2 per transducer. Both kidneys of two pigs were treated in vivo with the clamp (14.5W/cm2 for 90s), and the partial nephrectomies performed proved to be bloodless. In vitro and in vivo, wide transfixing lesions corresponded to an echo energy decrease superior to -10dB and parabolic form of the time of flight versus treatment time. In conclusion, this ultrasound clamp has proven to be an excellent mean for achieving monitored haemostasis in kidney.

  3. Piezoresistive cantilever force-clamp system

    SciTech Connect

    Park, Sung-Jin; Petzold, Bryan C.; Pruitt, Beth L.; Goodman, Miriam B.

    2011-04-15

    We present a microelectromechanical device-based tool, namely, a force-clamp system that sets or ''clamps'' the scaled force and can apply designed loading profiles (e.g., constant, sinusoidal) of a desired magnitude. The system implements a piezoresistive cantilever as a force sensor and the built-in capacitive sensor of a piezoelectric actuator as a displacement sensor, such that sample indentation depth can be directly calculated from the force and displacement signals. A programmable real-time controller operating at 100 kHz feedback calculates the driving voltage of the actuator. The system has two distinct modes: a force-clamp mode that controls the force applied to a sample and a displacement-clamp mode that controls the moving distance of the actuator. We demonstrate that the system has a large dynamic range (sub-nN up to tens of {mu}N force and nm up to tens of {mu}m displacement) in both air and water, and excellent dynamic response (fast response time, <2 ms and large bandwidth, 1 Hz up to 1 kHz). In addition, the system has been specifically designed to be integrated with other instruments such as a microscope with patch-clamp electronics. We demonstrate the capabilities of the system by using it to calibrate the stiffness and sensitivity of an electrostatic actuator and to measure the mechanics of a living, freely moving Caenorhabditis elegans nematode.

  4. Compact, Stiff, Remotely-Actuable Quick-Release Clamp

    NASA Technical Reports Server (NTRS)

    Tsai, Ted W. (Inventor)

    2000-01-01

    The present invention provides a clamp that is compact and lightweight, yet provides high holding strength and stiffness or rigidity. The clamp uses a unique double slant interface design which provides mechanical advantages to resist forces applied to the clamp member as the load increases. The clamp allows for rapid and remote-activated release of the clamp jaws by applying only a small operating force to an over-center lock/release mechanism, such as by pulling a manual tether.

  5. Primary Stenting in Infrarenal Aortic Occlusive Disease

    SciTech Connect

    Nyman, Ulf; Uher, Petr; Lindh, Mats; Lindblad, Bengt; Ivancev, Krasnodar

    2000-03-15

    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.

  6. A patent ductus arteriosus complicating cardiopulmonary bypass for combined coronary artery bypass grafting and aortic valve replacement only discovered by computed tomography 3D reconstruction.

    PubMed

    van Middendorp, Lars B; Maessen, Jos G; Sardari Nia, Peyman

    2014-12-01

    We describe the case of a 59-year old male patient undergoing combined coronary artery bypass grafting and aortic valve replacement. Manipulation of the heart during cardiopulmonary bypass significantly decreased venous return. Several measures were necessary to improve venous return to a level at which continuation of the procedure was safe. Based on the initial troubles with venous return, we decided to selectively cross-clamp the aorta. This resulted in a large amount of backflow of oxygenated blood from the left ventricle, necessitating additional vents in the pulmonary artery and directly in the left ventricle. The procedure was continued uneventfully, and postoperative recovery was without significant complications. Postoperative 2D computed tomography did not show any signs of a shunt, but 3D reconstruction showed a small patent ductus arteriosus. PMID:25164136

  7. Abdominal aortic aneurysm.

    PubMed

    Keisler, Brian; Carter, Chuck

    2015-04-15

    Abdominal aortic aneurysm refers to abdominal aortic dilation of 3.0 cm or greater. The main risk factors are age older than 65 years, male sex, and smoking history. Other risk factors include a family history of abdominal aortic aneurysm, coronary artery disease, hypertension, peripheral artery disease, and previous myocardial infarction. Diagnosis may be made by physical examination, an incidental finding on imaging, or ultrasonography. The U.S. Preventive Services Task Force released updated recommendations for abdominal aortic aneurysm screening in 2014. Men 65 to 75 years of age with a history of smoking should undergo one-time screening with ultrasonography based on evidence that screening will improve abdominal aortic aneurysm-related mortality in this population. Men in this age group without a history of smoking may benefit if they have other risk factors (e.g., family history of abdominal aortic aneurysm, other vascular aneurysms, coronary artery disease). There is inconclusive evidence to recommend screening for abdominal aortic aneurysm in women 65 to 75 years of age with a smoking history. Women without a smoking history should not undergo screening because the harms likely outweigh the benefits. Persons who have a stable abdominal aortic aneurysm should undergo regular surveillance or operative intervention depending on aneurysm size. Surgical intervention by open or endovascular repair is the primary option and is typically reserved for aneurysms 5.5 cm in diameter or greater. There are limited options for medical treatment beyond risk factor modification. Ruptured abdominal aortic aneurysm is a medical emergency presenting with hypotension, shooting abdominal or back pain, and a pulsatile abdominal mass. It is associated with high prehospitalization mortality. Emergent surgical intervention is indicated for a rupture but has a high operative mortality rate. PMID:25884861

  8. Kinetic analysis of PCNA clamp binding and release in the clamp loading reaction catalyzed by Saccharomyces cerevisiae replication factor C

    PubMed Central

    Marzahn, Melissa R.; Hayner, Jaclyn N.; Meyer, Jennifer A.; Bloom, Linda B.

    2014-01-01

    DNA polymerases require a sliding clamp to achieve processive DNA synthesis. The toroidal clamps are loaded onto DNA by clamp loaders, members of the AAA+ family of ATPases. These enzymes utilize the energy of ATP binding and hydrolysis to perform a variety of cellular functions. In this study, a clamp loader-clamp binding assay was developed to measure the rates of ATP-dependent clamp binding and ATP-hydrolysis-dependent clamp release for the S. cerevisiae clamp loader (RFC) and clamp (PCNA). Pre-steady-state kinetics of PCNA binding showed that although ATP binding to RFC increases affinity for PCNA, ATP binding rates and ATP-dependent conformational changes in RFC are fast relative to PCNA binding rates. Interestingly, RFC binds PCNA faster than the Escherichia coli γ complex clamp loader binds the β-clamp. In the process of loading clamps on DNA, RFC maintains contact with PCNA while PCNA closes, as the observed rate of PCNA closing is faster than the rate of PCNA release, precluding the possibility of an open clamp dissociating from DNA. Rates of clamp closing and release are not dependent on the rate of the DNA binding step and are also slower than reported rates of ATP hydrolysis, showing that these rates reflect unique intramolecular reaction steps in the clamp loading pathway. PMID:25450506

  9. The usefulness of near-infrared spectroscopy in the anesthetic management of endovascular aortic aneurysm repair.

    PubMed

    Wakimoto, Masahiro M; Kadosaki, Mamoru; Nagata, Hirofumi; Suzuki, Kenji S

    2012-12-01

    Near-infrared spectroscopy (NIRS) may be a useful method for monitoring the regional oxygen saturation (rSO(2)) of the lower extremity during endovascular aortic repair. Eighteen patients with thoracic descending and/or abdominal aortic aneurysm were enrolled in this study. NIRS probes were placed bilaterally on the calves. Muscular rSO(2) (mrSO(2)) was monitored every 30 s throughout the operation. In the leg in which the femoral artery was clamped, mrSO(2) values were selected at 3 or 4 points-just before clamping (control value), 30 min after clamping, 10 min after the first declamping, and 10 min after the second declamping following repair of the femoral artery, if necessary. In all patients, mrSO(2) decreased significantly during clamping, from 64 ± 11 % (mean ± SD) of the control value to 32 ± 15 %. After declamping, mrSO(2) recovered to 69 ± 14 % of the control value in 16 patients. In the 2 other patients, however, mrSO(2) did not recover after the first declamping, because of femoral artery dissection. After additional repair, mrSO(2) recovered quickly to the control value. These data suggested NIRS may objectively and quantitatively reflect oxygenation of the lower extremities, and may indicate an ischemic event that needs additional repair during endovascular aortic repair. PMID:22733429

  10. Aortic valve surgery - open

    MedlinePlus

    ... choose to have your aortic valve surgery at a center that does many of these procedures. ... DA, Harken AH. Acquired heart disease: valvular. In: Townsend CM, ... Textbook of Cardiovascular Medicine . 10th ed. Philadelphia, PA: ...

  11. [Acute aortic syndrome].

    PubMed

    Nienaber, Christoph A

    2016-06-01

    Acute aortic syndrome is the common denominator for acute events to the aortic wall and encompasses dissection of the aorta, intramural hematoma, formation of aortic ulcers and trauma to the aorta with an annual incidence of up to 35 cases/100.000 between 65 and 75 years of age. Both, inflammation and/or microtrauma at the level of the aortic media layer, and a genetic disposition are promoting elements of AAS, while the extent and anatomic involvement of the ascending aorta call for either surgical resection/repair in the proximal part of the aorta, or an endovascular solution for pathologies in the distal aorta; in all cases of dissection (regardless of location) reconstruction/realignment has been proven to portend better long-term outcomes (in addition to medical management of blood pressure). PMID:27254622

  12. Abdominal aortic aneurysm

    MedlinePlus

    ... main blood vessel that supplies blood to the abdomen, pelvis, and legs. An abdominal aortic aneurysm occurs ... dissection). Symptoms of rupture include: Pain in the abdomen or back. The pain may be severe, sudden, ...

  13. Double aortic arch

    MedlinePlus

    ... double aortic arch may press on the windpipe (trachea) and esophagus, leading to trouble breathing and swallowing. ... to relieve pressure on the esophagus and windpipe (trachea). The surgeon ties off the smaller branch and ...

  14. Clamp and Gas Nozzle for TIG Welding

    NASA Technical Reports Server (NTRS)

    Gue, G. B.; Goller, H. L.

    1982-01-01

    Tool that combines clamp with gas nozzle is aid to tungsten/inert-gas (TIG) welding in hard-to-reach spots. Tool holds work to be welded while directing a stream of argon gas at weld joint, providing an oxygen-free environment for tungsten-arc welding.

  15. Limit analysis of pipe clamps. Revision 1

    SciTech Connect

    Flanders, H.E. Jr.

    1990-12-31

    The Service Level D (faulted) load capacity of a conventional three-bolt pipe-clamp based upon the limit analysis method is presented. The load distribution, plastic hinge locations, and collapse load are developed for the lower bound limit load method. The results of the limit analysis are compared with the manufacturer`s rated loads. 3 refs.

  16. Piezoresistive cantilever force-clamp system

    PubMed Central

    Park, Sung-Jin; Petzold, Bryan C.; Goodman, Miriam B.; Pruitt, Beth L.

    2011-01-01

    We present a microelectromechanical device-based tool, namely, a force-clamp system that sets or “clamps” the scaled force and can apply designed loading profiles (e.g., constant, sinusoidal) of a desired magnitude. The system implements a piezoresistive cantilever as a force sensor and the built-in capacitive sensor of a piezoelectric actuator as a displacement sensor, such that sample indentation depth can be directly calculated from the force and displacement signals. A programmable real-time controller operating at 100 kHz feedback calculates the driving voltage of the actuator. The system has two distinct modes: a force-clamp mode that controls the force applied to a sample and a displacement-clamp mode that controls the moving distance of the actuator. We demonstrate that the system has a large dynamic range (sub-nN up to tens of μN force and nm up to tens of μm displacement) in both air and water, and excellent dynamic response (fast response time, <2 ms and large bandwidth, 1 Hz up to 1 kHz). In addition, the system has been specifically designed to be integrated with other instruments such as a microscope with patch-clamp electronics. We demonstrate the capabilities of the system by using it to calibrate the stiffness and sensitivity of an electrostatic actuator and to measure the mechanics of a living, freely moving Caenorhabditis elegans nematode. PMID:21529009

  17. Minimally invasive aortic valve replacement: the Leipzig experience

    PubMed Central

    Merk, Denis R.; Etz, Christian D.; Seeburger, Joerg; Schroeter, Thomas; Oberbach, Andreas; Uhlemann, Madlen; Hoellriegel, Robert; Haensig, Martin; Leontyev, Sergey; Garbade, Jens; Misfeld, Martin; Mohr, Friedrich W.

    2015-01-01

    Background Minimally invasive techniques are progressively challenging traditional approaches in cardiothoracic surgery. Minimally invasive aortic valve replacement (AVR) has become a routine procedure at our institution. Methods We retrospectively analyzed all patients undergoing minimally invasive isolated AVR between January 2003 and March 2014, at our institution. Mean follow-up was 4.7±4.3 years (range: 0-18 years) and was 99.8% complete. Results There were 1,714 patients who received an isolated minimally invasive AVR. The mean (± SD) patient age was 65±12.8 years, ejection fraction 60%±12% and log EuroSCORE 5.3%±5.1%. Mean cross-clamp time was 58±18 minutes and mean cardiopulmonary bypass (CPB) time was 82.9±26.7 minutes. Thirty-day survival was 97.8%±0.4%, and 69.4%±1.7% at 10-years. The multivariate analysis revealed age at surgery [P=0.016; odds ratio (OR), 1.1], length of surgery time (P=0.002; OR, 1.01), female gender (P=0.023; OR, 3.54), preoperative myocardial infarction (MI) (P=0.006; OR, 7.87), preoperative stroke (P=0.001; OR, 13.76) and preoperative liver failure (P=0.015; OR, 10.28) as independent risk factors for mortality. Cox-regression analysis revealed the following predictors for long term mortality: age over 75 years (P<0.001; OR, 3.5), preoperative dialysis (P<0.01; OR, 2.14), ejection fraction less than 30% (P=0.003; OR, 3.28) and urgent or emergency operation (P<0.001; OR, 2.3). Conclusions Minimally invasive AVR can be performed safely and effectively with very few perioperative complications. The early and long-term outcomes in these patients are acceptable. PMID:25694976

  18. Abdominal aortic aneurysm.

    PubMed

    Setacci, Francesco; Galzerano, Giuseppe; De Donato, Gianmarco; Benevento, Domenico; Guerrieri, Massimiliano W; Ruzzi, Umberto; Borrelli, Maria P; Setacci, Carlo

    2016-02-01

    Endovascular repair of abdominal aortic aneurysms has become a milestone in the treatment of patients with abdominal aortic aneurysm. Technological improvement allows treatment in more and more complex cases. This review summarizes all grafts available on the market. A complete review of most important trial on this topic is provided to the best of our knowledge, and technical tips and tricks for standard cases are also included. PMID:26771730

  19. Stress softening and permanent deformation in human aortas: Continuum and computational modeling with application to arterial clamping.

    PubMed

    Fereidoonnezhad, B; Naghdabadi, R; Holzapfel, G A

    2016-08-01

    Inelastic phenomena such as stress softening and unrecoverable inelastic deformations induced by supra-physiological loading have been observed experimentally in soft tissues such as arteries. These phenomena need to be accounted for in constitutive models of arterial tissues so that computational models can properly predict the outcome of interventional procedures such as arterial clamping and balloon angioplasty that involve non-physiological tissue loading. Motivated by experimental data, a novel pseudo-elastic damage model is proposed to describe discontinuous softening and permanent deformation in arterial tissues. The model is fitted to experimental data and specific material parameters for 9 abdominal and 14 thoracic aortas are provided. Furthermore, the model was implemented in a finite element code and numerically analyzed with respect to experimental tests, i.e. cyclic uniaxial tension in circumferential and longitudinal directions. Results showed that the model is able to capture specific features including anisotropy, nonlinearity, and damage-induced inelastic phenomena, i.e. stress softening and permanent deformation. Finite element results of a more complex boundary-value problem, i.e. aortic clamping considering the three aortic layers, residual stress, non-symmetric blood pressure after clamping, and patient-specific data are also presented. PMID:27233103

  20. Surgical Aortic Valvuloplasty Versus Balloon Aortic Valve Dilatation in Children.

    PubMed

    Donald, Julia S; Konstantinov, Igor E

    2016-09-01

    Balloon aortic valve dilatation (BAD : is assumed to provide the same outcomes as surgical aortic valvuloplasty (SAV). However, the development of precise modern surgical valvuloplasty techniques may result in better long-term durability of the aortic valve repair. This review of the recent literature suggests that current SAV provides a safe and durable repair. Furthermore, primary SAV appears to have greater freedom from reintervention and aortic valve replacement when compared to BAD. PMID:27587493

  1. Pentoxifylline inhibits pulmonary inflammation induced by infrarenal aorticcross-clamping dependent of adenosine receptor A2A

    PubMed Central

    Li, Hali; Tan, Gang; Tong, Liquan; Han, Peng; Zhang, Feng; Liu, Bing; Sun, Xueying

    2016-01-01

    Infrarenal aortic cross-clamping (IAC) is commonly used during infrarenal vascular operations. Prolonged IAC causes ischemia-reperfusion injury to local tissues, resulting in the release of inflammatory cytokines and acute lung injury (ALI). Pentoxifylline (PTX) is a clinically used drug for chronic occlusive arterial diseases and exerts protective effects against ALI induced by various factors in experimental models. In this study, we evaluated the protective effects of PTX in a rat model of IAC. Wistar rats underwent IAC for 2 h, followed by 4 h reperfusion. PTX alone, or in combination with ZM-241385 (an adenosine receptor A2A antagonist) or CGS-21680 (an A2A agonist), was pre-administered to rats 1 h prior to IAC, and the severity of lung injury and inflammation were examined. Administration of PTX significantly attenuated ALI induced by IAC, evidenced by reduced histological scores and wet lung contents, improved blood gas parameters, decreased cell counts and protein amounts in bronchoalveolar lavage fluids, and inhibition of MPO activity and ICAM-1 expression in lung tissues, and lower plasma levels of TNF-α, IL-6, IL-1β and soluble ICAM-1. ZM-241385 significantly abrogated, while CGS-21680 slightly enhanced, the effects of PTX in ameliorating ALI and inhibiting pulmonary inflammation. In exploration of the mechanisms, we found that PTX stimulated IL-10 production through the phosphorylation of STAT3, and A2A receptor participated in this regulation. The study indicates PTX plays a protective role in IAC-induced ALI in rats by inhibiting pulmonary inflammation through A2A signaling pathways. PMID:27347328

  2. Aortic regurgitation after transcatheter aortic valve replacement.

    PubMed

    Werner, Nikos; Sinning, Jan-Malte

    2014-01-01

    Paravalvular aortic regurgitation (AR) negatively affects prognosis following transcatheter aortic valve replacement (TAVR). As transcatheter heart valves (THV) are anchored using a certain degree of oversizing at the level of the aortic annulus, incomplete stent frame expansion because of heavily annular calcifications, suboptimal placement of the prosthesis, and/or annulus-prosthesis size-mismatch can contribute to paravalvular AR with subsequent increased mortality risk. Echocardiography is essential to differentiate between transvalvular and paravalvular AR and to further elucidate the etiology of AR during the procedure. However, because echocardiographic quantification of AR in TAVR patients remains challenging, especially in the implantation situation, a multimodal approach to the evaluation of AR with use of hemodynamic measurements and imaging modalities is useful to precisely quantify the severity of AR immediately after valve deployment. "Next-generation" THVs are already on the market and first results show that paravalvular AR related to design modifications (eg, paravalvular space-fillers, full repositionability) are rarely seen in these valve types.  PMID:24632758

  3. Electrical cable connector-clamp has smooth exterior surface

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Electrical cable connector-clamp fitted with a collet has a smooth exterior surface that can be easily gripped. The collet clamps a portion of the cable and provides for connecting it to a standard electrical connector.

  4. Aortic aneurysm repair - endovascular- discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000236.htm Aortic aneurysm repair - endovascular - discharge To use the sharing features ... enable JavaScript. AAA repair - endovascular - discharge; Repair - aortic aneurysm - endovascular - discharge; EVAR - discharge; Endovascular aneurysm repair - discharge ...

  5. Screening for Abdominal Aortic Aneurysm

    MedlinePlus

    Understanding Task Force Recommendations Screening for Abdominal Aortic Aneurysm The U.S. Preventive Services Task Force (Task Force) ... final recommendation statement on Screening for Abdominal Aortic Aneurysm. This final recommendation statement applies to adults ages ...

  6. Mechanical and metallurgical properties of carotid artery clamps.

    PubMed

    Dujovny, M; Kossovsky, N; Kossowsky, R; Segal, R; Diaz, F G; Kaufman, H; Perlin, A; Cook, E E

    1985-11-01

    The mechanical and metallurgical properties of carotid artery clamps were evaluated. The pressure plate retreat propensity, metallurgical composition, surface morphology, magnetic properties, and corrosion resistance of the Crutchfield, Selverstone, Salibi, and Kindt clamps were tested. None of the clamps showed evidence of pressure plate retreat. The clamps differed significantly in their composition, surface cleanliness, magnetic properties, and corrosion resistance. The Crutchfield clamp was the only one manufactured from an ASTM-ANSI-approved implantable stainless steel (AISI 316) and the only clamp in which the surfaces were clean and free of debris. The Selverstone clamp was made principally from AISI 304 stainless steel, as was one Salibi clamp. The pressure plate on another Salibi clamp was made from a 1% chromium and 1% manganese steel. Machining and surface debris consisting principally of aluminum, silicon, and sulfur was abundant on the Selverstone and Salibi clamps. The Kindt clamp was manufactured from AISI 301 stainless steel with a silicate-aluminized outer coating. The Crutchfield and Selverstone clamps were essentially nonferromagnetic, whereas the Salibi and Kindt clamps were sensitive to magnetic flux. In the pitting potential corrosion test, the Crutchfield clamp demonstrated good corrosion resistance with a pitting potential of 310 mV and no surface corrosion or pitting by scanning electron microscopy examination. The Selverstone clamp had lower pitting potentials and showed various degrees of corrosion and surface pitting by scanning electron microscopy. The Salibi pressure plate had a very low pitting potential of -525 mV and showed severe corrosion. By metallurgical criteria, only the Crutchfield clamp is suitable for long term implantation. PMID:4069328

  7. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to... mounted component. Cable grips anchored to the cable may be used in lieu of insulated strain...

  8. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to... mounted component. Cable grips anchored to the cable may be used in lieu of insulated strain...

  9. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to... mounted component. Cable grips anchored to the cable may be used in lieu of insulated strain...

  10. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to... mounted component. Cable grips anchored to the cable may be used in lieu of insulated strain...

  11. Single molecule study of a processivity clamp sliding on DNA

    SciTech Connect

    Laurence, T A; Kwon, Y; Johnson, A; Hollars, C; O?Donnell, M; Camarero, J A; Barsky, D

    2007-07-05

    Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder.

  12. Aneurysms: thoracic aortic aneurysms.

    PubMed

    Chun, Kevin C; Lee, Eugene S

    2015-04-01

    Thoracic aortic aneurysms (TAAs) have many possible etiologies, including congenital heart defects (eg, bicuspid aortic valves, coarctation of the aorta), inherited connective tissue disorders (eg, Marfan, Ehlers-Danlos, Loeys-Dietz syndromes), and degenerative conditions (eg, medial necrosis, atherosclerosis of the aortic wall). Symptoms of rupture include a severe tearing pain in the chest, back, or neck, sometimes associated with cardiovascular collapse. Before rupture, TAAs may exert pressure on other thoracic structures, leading to a variety of symptoms. However, most TAAs are asymptomatic and are found incidentally during imaging for other conditions. Diagnosis is confirmed with computed tomography scan or echocardiography. Asymptomatic TAAs should be monitored with imaging at specified intervals and patients referred for repair if the TAAs are enlarging rapidly (greater than 0.5 cm in diameter over 6 months for heritable etiologies; greater than 0.5 cm over 1 year for degenerative etiologies) or reach a critical aortic diameter threshold for elective surgery (5.5 cm for TAAs due to degenerative etiologies, 5.0 cm when associated with inherited syndromes). Open surgery is used most often to treat asymptomatic TAAs in the ascending aorta and aortic arch. Asymptomatic TAAs in the descending aorta often are treated medically with aggressive blood pressure control, though recent data suggest that endovascular procedures may result in better long-term survival rates. PMID:25860136

  13. [Thoracoabdominal aortic aneurysm].

    PubMed

    Kalder, J; Kotelis, D; Jacobs, M J

    2016-09-01

    Thoracoabdominal aortic aneurysms (TAAA) are rare events with an incidence of 5.9 cases per 100,000 persons per year. In Germany approximately 940 TAAA procedures are performed annually. The cause of TAAA is mostly degenerative but they can also occur on the basis of an aortic dissection or connective tissue disease (e. g. Marfan's syndrome). Patients often have severe comorbidities and suffer from hypertension, coronary heart disease or chronic obstructive pulmonary disease, mostly as a result of smoking. Operative treatment is indicated when the maximum aortic diameter has reached 6 cm (> 5 cm in patients with connective tissue disease) or the aortic diameter rapidly increases (> 5 mm/year). Treatment options are open surgical aortic repair with extracorporeal circulation, endovascular repair with branched/fenestrated endografts and parallel grafts (chimneys) or a combination of open and endovascular procedures (hybrid procedures). Mortality rates after both open and endovascular procedures are approximately 8 % depending on the extent of the repair. Furthermore, there are relevant risks of complications, such as paraplegia (up to 20 %) and the necessity for dialysis. In recent years several approaches to minimize these risks have been proposed. Besides cardiopulmonary risk evaluation, clinical assessment of patients by the physician with respect to the patient-specific anatomy influences the allocation of patients to one treatment option or another. Surgery of TAAA should ideally be performed in high-volume centers in order to achieve better results. PMID:27558261

  14. Temperature-Controlled Clamping and Releasing Mechanism

    NASA Technical Reports Server (NTRS)

    Rosing, David; Ford, Virginia

    2005-01-01

    A report describes the development of a mechanism that automatically clamps upon warming and releases upon cooling between temperature limits of approx. =180 K and approx. =293 K. The mechanism satisfied a need specific to a program that involved repeated excursions of a spectrometer between a room-temperature atmospheric environment and a cryogenic vacuum testing environment. The mechanism was also to be utilized in the intended application of the spectrometer, in which the spectrometer would be clamped for protection during launch of a spacecraft and released in the cold of outer space to allow it to assume its nominal configuration for scientific observations. The mechanism is passive in the sense that its operation does not depend on a control system and does not require any power other than that incidental to heating and cooling. The clamping and releasing action is effected by bolt-preloaded stacks of shape-memory-alloy (SMA) cylinders. In designing this mechanism, as in designing other, similar SMA mechanisms, it was necessary to account for the complex interplay among thermal expansion, elastic and inelastic deformation under load, and SMA thermomechanical properties.

  15. Carbon nanotube-clamped metal atomic chain

    PubMed Central

    Tang, Dai-Ming; Yin, Li-Chang; Li, Feng; Liu, Chang; Yu, Wan-Jing; Hou, Peng-Xiang; Wu, Bo; Lee, Young-Hee; Ma, Xiu-Liang; Cheng, Hui-Ming

    2010-01-01

    Metal atomic chain (MAC) is an ultimate one-dimensional structure with unique physical properties, such as quantized conductance, colossal magnetic anisotropy, and quantized magnetoresistance. Therefore, MACs show great potential as possible components of nanoscale electronic and spintronic devices. However, MACs are usually suspended between two macroscale metallic electrodes; hence obvious technical barriers exist in the interconnection and integration of MACs. Here we report a carbon nanotube (CNT)-clamped MAC, where CNTs play the roles of both nanoconnector and electrodes. This nanostructure is prepared by in situ machining a metal-filled CNT, including peeling off carbon shells by spatially and elementally selective electron beam irradiation and further elongating the exposed metal nanorod. The microstructure and formation process of this CNT-clamped MAC are explored by both transmission electron microscopy observations and theoretical simulations. First-principles calculations indicate that strong covalent bonds are formed between the CNT and MAC. The electrical transport property of the CNT-clamped MAC was experimentally measured, and quantized conductance was observed. PMID:20427743

  16. π-Clamp Mediated Cysteine Conjugation

    PubMed Central

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; Van Voorhis, Troy; Pentelute, Bradley L.

    2016-01-01

    Site-selective functionalization of complex molecules is a grand challenge in chemistry. Protecting groups or catalysts must be used to selectively modify one site among many that are similarly reactive. General strategies are rare such the local chemical environment around the target site is tuned for selective transformation. Here we show a four amino acid sequence (Phe-Cys-Pro-Phe), which we call the “π-clamp”, tunes the reactivity of its cysteine thiol for the site-selective conjugation with perfluoroaromatic reagents. We used the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues (e.g. antibodies and cysteine-based enzymes), which was impossible with prior cysteine modification methods. The modified π-clamp antibodies retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates (ADCs) for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach for site-selective chemistry and provides opportunities to modify biomolecules for research and therapeutics. PMID:26791894

  17. π-Clamp-mediated cysteine conjugation

    NASA Astrophysics Data System (ADS)

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; van Voorhis, Troy; Pentelute, Bradley L.

    2016-02-01

    Site-selective functionalization of complex molecules is one of the most significant challenges in chemistry. Typically, protecting groups or catalysts must be used to enable the selective modification of one site among many that are similarly reactive, and general strategies that selectively tune the local chemical environment around a target site are rare. Here, we show a four-amino-acid sequence (Phe-Cys-Pro-Phe), which we call the ‘π-clamp’, that tunes the reactivity of its cysteine thiol for site-selective conjugation with perfluoroaromatic reagents. We use the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues. These examples include antibodies and cysteine-based enzymes that would be difficult to modify selectively using standard cysteine-based methods. Antibodies modified using the π-clamp retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach to mediate site-selective chemistry and provides new avenues to modify biomolecules for research and therapeutics.

  18. Transcatheter Aortic Valve Implantation.

    PubMed

    Malaisrie, S Chris; Iddriss, Adam; Flaherty, James D; Churyla, Andrei

    2016-05-01

    Severe aortic stenosis (AS) is a life-threatening condition when left untreated. Aortic valve replacement (AVR) is the gold standard treatment for the majority of patients; however, transcatheter aortic valve implantation/replacement (TAVI/TAVR) has emerged as the preferred treatment for high-risk or inoperable patients. The concept of transcatheter heart valves originated in the 1960s and has evolved into the current Edwards Sapien and Medtronic CoreValve platforms available for clinical use. Complications following TAVI, including cerebrovascular events, perivalvular regurgitation, vascular injury, and heart block have decreased with experience and evolving technology, such that ongoing trials studying TAVI in lower risk patients have become tenable. The multidisciplinary team involving the cardiac surgeon and cardiologist plays an essential role in patient selection, procedural conduct, and perioperative care. PMID:27021619

  19. Condition of chromic acid anodized aluminum clamps flown

    NASA Technical Reports Server (NTRS)

    Plagemann, W. L.

    1991-01-01

    A survey of the condition of the chromic acid anodized (CAA) coating on selected LDEF tray clamps was carried out. Measurements of solar absorptance and thermal emittance were carried out at multiple locations on both the space exposed and spacecraft facing sides of the clamps. Multiple clamps from each available angle relative to the ram direction were examined. The diffuse component of the reflectance spectrum was measured for a selected subset of the clamps. The thickness of the CAA was determined for a small set of clamps. Examples of variation in integrity of the coatings from leading to trailing edge will be shown.

  20. Abdominal Aortic Aneurysms

    PubMed Central

    Fortner, George; Johansen, Kaj

    1984-01-01

    Aneurysms are common in our increasingly elderly population, and are a major threat to life and limb. Until the advent of vascular reconstructive techniques, aneurysm patients were subject to an overwhelming risk of death from exsanguination. The first successful repair of an abdominal aortic aneurysm using an interposed arterial homograft was reported by Dubost in 1952. A milestone in the evolution of vascular surgery, this event and subsequent diagnostic, operative and prosthetic graft refinements have permitted patients with an unruptured abdominal aortic aneurysm to enjoy a better prognosis than patients with almost any other form of major systemic illness. Images PMID:6702193

  1. Non-invasive volumetric assessment of aortic atheroma: a core laboratory validation using computed tomography angiography.

    PubMed

    Hammadah, Muhammad; Qintar, Mohammed; Nissen, Steven E; John, Julie St; Alkharabsheh, Saqer; Mobolaji-Lawal, Motunrayo; Philip, Femi; Uno, Kiyoko; Kataoka, Yu; Babb, Brett; Poliszczuk, Roman; Kapadia, Samir R; Tuzcu, E Murat; Schoenhagen, Paul; Nicholls, Stephen J; Puri, Rishi

    2016-01-01

    Aortic atherosclerosis has been linked with worse peri- and post-procedural outcomes following a range of aortic procedures. Yet, there are currently no standardized methods for non-invasive volumetric pan-aortic plaque assessment. We propose a novel means of more accurately assessing plaque volume across whole aortic segments using computed tomography angiography (CTA) imaging. Sixty patients who underwent CTA prior to trans-catheter aortic valve implantation were included in this analysis. Specialized software analysis (3mensio Vascular™, Pie Medical, Maastricht, Netherlands) was used to reconstruct images using a centerline approach, thus creating true cross-sectional aortic images, akin to those images produced with intravascular ultrasonography. Following aortic segmentation (from the aortic valve to the renal artery origin), atheroma areas were measured across multiple contiguous evenly spaced (10 mm) cross-sections. Percent atheroma volume (PAV), total atheroma volume (TAV) and calcium score were calculated. In our populations (age 79.9 ± 8.5 years, male 52 %, diabetes 27 %, CAD 84 %, PVD 20 %), mean ± SD number of cross sections measured for each patient was 35.1 ± 3.5 sections. Mean aortic PAV and TAV were 33.2 ± 2.51 % and 83,509 ± 17,078 mm(3), respectively. Median (IQR) calcium score was 1.5 (0.7-2.5). Mean (SD) inter-observer coefficient of variation and agreement for plaque area among 4 different analysts was 14.1 (5.4), and the mean (95 % CI) Lin's concordance correlation coefficient was 0.79 (0.62-0.89), effectively simulating a Core Laboratory scenario. We provide an initial validation of cross-sectional volumetric aortic atheroma assessment using CTA. This proposed methodology highlights the potential for utilizing non-invasive aortic plaque imaging for risk prediction across a range of clinical scenarios. PMID:25962864

  2. Segmental Aortic Stiffening Contributes to Experimental Abdominal Aortic Aneurysm Development

    PubMed Central

    Raaz, Uwe; Zöllner, Alexander M.; Schellinger, Isabel N.; Toh, Ryuji; Nakagami, Futoshi; Brandt, Moritz; Emrich, Fabian C.; Kayama, Yosuke; Eken, Suzanne; Adam, Matti; Maegdefessel, Lars; Hertel, Thomas; Deng, Alicia; Jagger, Ann; Buerke, Michael; Dalman, Ronald L.; Spin, Joshua M.; Kuhl, Ellen; Tsao, Philip S.

    2015-01-01

    Background Stiffening of the aortic wall is a phenomenon consistently observed in age and in abdominal aortic aneurysm (AAA). However, its role in AAA pathophysiology is largely undefined. Methods and Results Using an established murine elastase-induced AAA model, we demonstrate that segmental aortic stiffening (SAS) precedes aneurysm growth. Finite element analysis (FEA) reveals that early stiffening of the aneurysm-prone aortic segment leads to axial (longitudinal) wall stress generated by cyclic (systolic) tethering of adjacent, more compliant wall segments. Interventional stiffening of AAA-adjacent aortic segments (via external application of surgical adhesive) significantly reduces aneurysm growth. These changes correlate with reduced segmental stiffness of the AAA-prone aorta (due to equalized stiffness in adjacent segments), reduced axial wall stress, decreased production of reactive oxygen species (ROS), attenuated elastin breakdown, and decreased expression of inflammatory cytokines and macrophage infiltration, as well as attenuated apoptosis within the aortic wall. Cyclic pressurization of segmentally stiffened aortic segments ex vivo increases the expression of genes related to inflammation and extracellular matrix (ECM) remodeling. Finally, human ultrasound studies reveal that aging, a significant AAA risk factor, is accompanied by segmental infrarenal aortic stiffening. Conclusions The present study introduces the novel concept of segmental aortic stiffening (SAS) as an early pathomechanism generating aortic wall stress and triggering aneurysmal growth, thereby delineating potential underlying molecular mechanisms and therapeutic targets. In addition, monitoring SAS may aid the identification of patients at risk for AAA. PMID:25904646

  3. Bicuspid aortic valve

    MedlinePlus

    ... is unclear, but it is the most common congenital heart disease . It often runs in families. The bicuspid aortic ... A.M. Editorial team. Related MedlinePlus Health Topics Congenital Heart Defects Heart Valve Diseases Browse the Encyclopedia A.D.A.M., Inc. ...

  4. Biological cell controllable patch-clamp microchip

    NASA Astrophysics Data System (ADS)

    Penmetsa, Siva; Nagrajan, Krithika; Gong, Zhongcheng; Mills, David; Que, Long

    2010-12-01

    A patch-clamp (PC) microchip with cell sorting and positioning functions is reported, which can avoid drawbacks of random cell selection or positioning for a PC microchip. The cell sorting and positioning are enabled by air bubble (AB) actuators. AB actuators are pneumatic actuators, in which air pressure is generated by microheaters within sealed microchambers. The sorting, positioning, and capturing of 3T3 cells by this type of microchip have been demonstrated. Using human breast cancer cells MDA-MB-231 as the model, experiments have been demonstrated by this microchip as a label-free technical platform for real-time monitoring of the cell viability.

  5. Aortic valve annuloplasty: new single suture technique.

    PubMed

    Schöllhorn, Joachim; Rylski, Bartosz; Beyersdorf, Friedhelm

    2014-06-01

    Reconstruction strategies for aortic valve insufficiency in the presence of aortic annulus dilatation are usually surgically challenging. We demonstrate a simple, modified Taylor technique of downsizing and stabilization of the aortic annulus using a single internal base suture. Since April 2011, 22 consecutive patients have undergone safe aortic valve annuloplasty. No reoperations for aortic valve insufficiency and no deaths occurred. PMID:24882316

  6. The Warden procedure can be successfully performed using minimally invasive cardiac surgery without aortic clamping.

    PubMed

    Zubritskiy, Alexey; Arkhipov, Alexey; Khapaev, Timur; Naberukhin, Yuriy; Omelchenko, Alexander; Gorbatykh, Yuriy; Bogachev-Prokophiev, Alexander; Karaskov, Alexander

    2016-02-01

    Currently, minimally invasive cardiac surgery has found widespread use even in congenital heart surgery. The number of defects, which can be corrected through a small incision or totally endoscopic, is on the rise. Nowadays, surgeons can repair atrial septal defect, ventricular septal defect, patent ductus arteriosus and other congenital heart defects using minimally invasive techniques. In this paper, we report 21 cases of successful repair of supracardiac partial anomalous right upper and middle pulmonary venous connection, using the Warden procedure. It was performed in children through the right-sided midaxillary thoracotomy with direct cardiopulmonary bypass cannulation and induction of ventricular fibrillation. There were no operative or early postoperative deaths or complications. All patients were in sinus rhythm at discharge. According to echocardiography, there were no cases of early SVC or pulmonary veins narrowing. The Warden procedure can be performed safely and efficiently using the minimally invasive cardiac surgery. PMID:26541958

  7. Recent advances in aortic valve disease: highlights from a bicuspid aortic valve to transcatheter aortic valve replacement.

    PubMed

    Augoustides, John G T; Wolfe, Yanika; Walsh, Elizabeth K; Szeto, Wilson Y

    2009-08-01

    There have been major advances in the management of aortic valve disease. Because bicuspid aortic valve is common and predicts an increased risk of adverse aortic events, these patients merit aortic surveillance and consideration for ascending aortic replacement when its diameter exceeds 4.0 cm. Serial quantitative echocardiographic analysis, as compared with traditional clinical markers, can result in better timing of surgical intervention for aortic regurgitation. Furthermore, echocardiographic analysis of aortic regurgitation can classify the mechanism based on cusp mobility to guide aortic valve repair. In aortic root replacement, aortic valve preservation with reimplantation is a mainstream surgical option in Marfan syndrome to offer freedom from valve-related anticoagulation. Prosthetic aortic root replacement has further alternatives with the introduction of the aortic neosinus design and acceptable clinical outcomes with the porcine xenograft. Because aortic valve prosthesis-patient mismatch (PPM) may adversely affect patient outcome, its perioperative prevention is important. Furthermore, significant functional mitral regurgitation in association with aortic stenosis often resolves after aortic valve replacement. Echocardiographic assessment of the aortic valve must include valve area because the transaortic pressure gradient may be low in severe stenosis. Aortic valve replacement with partial sternotomy is safe and offers a reasonable less invasive alternative. Transcatheter aortic valve replacement, whether transfemoral or transapical, has revolutionized aortic valve replacement; it remains a major theme in the specialty for 2009 and beyond. PMID:19497768

  8. ClampOn acoustic solid fuel monitor

    SciTech Connect

    Vesterhus, T.

    1999-07-01

    The general idea of the project is to develop a ClampOn Solid Fuel Monitor, enabling optimization of the combustion process in pulverized coal fired boilers. The development will be based on adapting existing technology for measuring the content of sand particles in a flow of natural gas. The Norwegian firm ClampOn AS develops equipment for such measurements, and has already a proven track record as a result of its work with major oil companies throughout the world. The industry wants some sort of fuel indicator, e.g. a piece of equipment that enables the operator to measure and control the amounts of the fuel to each individual burner. The best techniques available today--as far as the author knows--can only offer samples of the fuel stream at discrete points of time. To truly optimize the combustion process, it is vital to continuously monitor the mass of fuel to each burner, and optimize the combustion process through continuous and infinitesimal adjustments of the fuel flow. This will minimize the NO{sub x} created by uneven temperature-distribution in the combustion chamber. In this way maximum power generation can be obtained at minimal emission of pollutants for a given amount of coal burned.

  9. Laser-assisted patch clamping: a methodology

    NASA Technical Reports Server (NTRS)

    Henriksen, G. H.; Assmann, S. M.; Evans, M. L. (Principal Investigator)

    1997-01-01

    Laser microsurgery can be used to perform both cell biological manipulations, such as targeted cell ablation, and molecular genetic manipulations, such as genetic transformation and chromosome dissection. In this report, we describe a laser microsurgical method that can be used either to ablate single cells or to ablate a small area (1-3 microns diameter) of the extracellular matrix. In plants and microorganisms, the extracellular matrix consists of the cell wall. While conventional patch clamping of these cells, as well as of many animal cells, requires enzymatic digestion of the extracellular matrix, we illustrate that laser microsurgery of a portion of the wall enables patch clamp access to the plasma membrane of higher plant cells remaining situated in their tissue environment. What follows is a detailed description of the construction and use of an economical laser microsurgery system, including procedures for single cell and targeted cell wall ablation. This methodology will be of interest to scientists wishing to perform cellular or subcellular ablation with a high degree of accuracy, or wishing to study how the extracellular matrix affects ion channel function.

  10. First direct aortic retrievable transcatheter aortic valve implantation in humans.

    PubMed

    Chandrasekhar, Jaya; Glover, Chris; Labinaz, Marino; Ruel, Marc

    2014-11-01

    We describe 2 cases in which transcatheter aortic valve implantation was performed with a Portico prosthesis (St Jude Medical, St Paul, MN) through a direct aortic approach. In 1 of the cases, prosthesis retrieval was needed during the procedure and was essential to the successful outcome. This is the first report, to our knowledge, of direct aortic Portico prosthesis implantation, and it highlights the significance of the retrievable nature of this device. PMID:25442452

  11. Paraplegia caused by aortic coarctation complicated with spinal epidural hemorrhage.

    PubMed

    Tsai, Yi-Da; Hsu, Chin-Wang; Hsu, Chia-Ching; Liao, Wen-I; Chen, Sy-Jou

    2016-03-01

    Aortic coarctation complicated with spinal artery aneurysm rupture is exceptionally rare and can be source of intraspinal hemorrhage with markedly poor prognosis. A 21-year-old man visited the emergency department because of chest and back pain along with immobility of bilateral lower limbs immediately after he woke up in the morning. Complete flaccid paraplegia and hypoesthesia in dermatome below bilateral T3 level and pain over axial region from neck to lumbar region were noted. A computed tomography excluded aortic dissection. Magnetic resonance imaging revealed a fusiform lesion involving the anterior epidural space from C7 to T2 level suspected of epidural hemorrhage, causing compression of spinal cord. He started intravenous corticosteroid but refused operation concerning the surgical benefits. Severe chest pain occurred with newly onset right bundle branch block that developed the other day. Coronary artery angiography revealed myocardial bridge of left anterior descending coronary artery at middle third and coarctation of aorta. He underwent thoracic endovascular aortic repair uneventfully. The patient was hemodynamically stable but with slow improvement in neurologic recovery of lower limbs. Aortic coarcation can cause paralysis by ruptured vascular aneurysms with spinal hemorrhage and chest pain that mimics acute aortic dissection. A history of hypertension at young age and aortic regurgitated murmurs may serve as clues for further diagnostic studies. Cautious and prudent evaluation and cross disciplines cares are essential for diagnosis and successful management of the disease. PMID:26275629

  12. [Stent Grafting for Aortic Dissection].

    PubMed

    Uchida, Naomichi

    2016-07-01

    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. PMID:27440026

  13. An Optimal Cell Detection Technique for Automated Patch Clamping

    NASA Technical Reports Server (NTRS)

    McDowell, Mark; Gray, Elizabeth

    2004-01-01

    While there are several hardware techniques for the automated patch clamping of cells that describe the equipment apparatus used for patch clamping, very few explain the science behind the actual technique of locating the ideal cell for a patch clamping procedure. We present a machine vision approach to patch clamping cell selection by developing an intelligent algorithm technique that gives the user the ability to determine the good cell to patch clamp in an image within one second. This technique will aid the user in determining the best candidates for patch clamping and will ultimately save time, increase efficiency and reduce cost. The ultimate goal is to combine intelligent processing with instrumentation and controls in order to produce a complete turnkey automated patch clamping system capable of accurately and reliably patch clamping cells with a minimum amount of human intervention. We present a unique technique that identifies good patch clamping cell candidates based on feature metrics of a cell's (x, y) position, major axis length, minor axis length, area, elongation, roundness, smoothness, angle of orientation, thinness and whether or not the cell is only particularly in the field of view. A patent is pending for this research.

  14. Characterization of the clamp pressure of electrostatic chucks

    NASA Astrophysics Data System (ADS)

    Ziemann, M.; Voss, S.; Baldus, O.; Schmidt, V.

    2010-04-01

    Berliner Glas KGaA is specialized on the manufacturing of high performance wafer and reticle chucks. Electrostatic chucks (ESC) are especially used in vacuum environments e.g. during lithographic processing, coating and etching. The main task of the chuck is to provide a well defined positioning and thermal stabilization of the wafer or reticle. Typical wafer materials are semiconductors like silicon and in some special cases dielectrics like magnesia, alumina or glass. For a functional characterization of the ESC clamps Berliner Glas has developed a measurement method to determine the clamp pressure with a Fizeau interferometer. The setup utilizes the local bending of clamped wafers to determine the effective clamp pressure. The clamp pressure is measured in the range of 20...500 mbar. This new method allows for a lateral resolution of the clamp pressure measurement. It can be calibrated by various methods. Direct computation of the clamp pressure based on the bending height or comparative measurements with vacuum chucking by the same chuck gives evidence for the quantitative results. Transient clamp pressure variation can be measured with a resolution of 2 mbar. The results can be used to qualify and optimize ESĆs and even for a local correction of the clamp force.

  15. Spectral infrared hemispherical reflectance measurements for LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Cromwell, B. K.; Shepherd, S. D.; Pender, C. W.; Wood, B. E.

    1993-01-01

    Infrared hemispherical reflectance measurements that were made on 58 chromic acid anodized tray clamps from LDEF are described. The measurements were made using a hemiellipsoidal mirror reflectometer with interferometer for wavelengths between 2-15 microns. The tray clamps investigated were from locations about the entire spacecraft and provided the opportunity for comparing the effects of atomic oxygen at each location. Results indicate there was essentially no dependence on atomic oxygen fluence for the surfaces studied, but there did appear to be a slight dependence on solar radiation exposure. The reflectances of the front sides of the tray clamps consistently were slightly higher than for the protected rear tray clamp surfaces.

  16. A New Murine Model of Endovascular Aortic Aneurysm Repair

    PubMed Central

    Rouer, Martin; Meilhac, Olivier; Delbosc, Sandrine; Louedec, Liliane; Pavon-Djavid, Graciela; Cross, Jane; Legagneux, Josette; Bouilliant-Linet, Maxime; Michel, Jean-Baptiste; Alsac, Jean-Marc

    2013-01-01

    Endovascular aneurysm exclusion is a validated technique to prevent aneurysm rupture. Long-term results highlight technique limitations and new aspects of Abdominal aortic aneurysm (AAA) pathophysiology. There is no abdominal aortic aneurysm endograft exclusion model cheap and reproducible, which would allow deep investigations of AAA before and after treatment. We hereby describe how to induce, and then to exclude with a covered coronary stentgraft an abdominal aortic aneurysm in a rat. The well known elastase induced AAA model was first reported in 19901 in a rat, then described in mice2. Elastin degradation leads to dilation of the aorta with inflammatory infiltration of the abdominal wall and intra luminal thrombus, matching with human AAA. Endovascular exclusion with small covered stentgraft is then performed, excluding any interactions between circulating blood and the aneurysm thrombus. Appropriate exclusion and stentgraft patency is confirmed before euthanasia by an angiography thought the left carotid artery. Partial control of elastase diffusion makes aneurysm shape different for each animal. It is difficult to create an aneurysm, which will allow an appropriate length of aorta below the aneurysm for an easy stentgraft introduction, and with adequate proximal and distal neck to prevent endoleaks. Lots of failure can result to stentgraft introduction which sometimes lead to aorta tear with pain and troubles to stitch it, and endothelial damage with post op aorta thrombosis. Giving aspirin to rats before stentgraft implantation decreases failure rate without major hemorrhage. Clamping time activates neutrophils, endothelium and platelets, and may interfere with biological analysis. PMID:23851958

  17. Aortic dimensions in Turner syndrome.

    PubMed

    Quezada, Emilio; Lapidus, Jodi; Shaughnessy, Robin; Chen, Zunqiu; Silberbach, Michael

    2015-11-01

    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. PMID:26118429

  18. Micromanaging abdominal aortic aneurysms.

    PubMed

    Maegdefessel, Lars; Spin, Joshua M; Adam, Matti; Raaz, Uwe; Toh, Ryuji; Nakagami, Futoshi; Tsao, Philip S

    2013-01-01

    The contribution of abdominal aortic aneurysm (AAA) disease to human morbidity and mortality has increased in the aging, industrialized world. In response, extraordinary efforts have been launched to determine the molecular and pathophysiological characteristics of the diseased aorta. This work aims to develop novel diagnostic and therapeutic strategies to limit AAA expansion and, ultimately, rupture. Contributions from multiple research groups have uncovered a complex transcriptional and post-transcriptional regulatory milieu, which is believed to be essential for maintaining aortic vascular homeostasis. Recently, novel small noncoding RNAs, called microRNAs, have been identified as important transcriptional and post-transcriptional inhibitors of gene expression. MicroRNAs are thought to "fine tune" the translational output of their target messenger RNAs (mRNAs) by promoting mRNA degradation or inhibiting translation. With the discovery that microRNAs act as powerful regulators in the context of a wide variety of diseases, it is only logical that microRNAs be thoroughly explored as potential therapeutic entities. This current review summarizes interesting findings regarding the intriguing roles and benefits of microRNA expression modulation during AAA initiation and propagation. These studies utilize disease-relevant murine models, as well as human tissue from patients undergoing surgical aortic aneurysm repair. Furthermore, we critically examine future therapeutic strategies with regard to their clinical and translational feasibility. PMID:23852016

  19. Voltage clamp experiments on ventricular myocarial fibres.

    PubMed

    Beeler, G W; Reuter, H

    1970-03-01

    1. A voltage clamp method utilizing a sucrose gap and glass microelectrodes was developed and used to study dog ventricular myocardial fibre bundles. The limitations and the reliability of this method are demonstrated by a series of tests.2. A dynamic sodium current, excited at membrane potentials more positive than -65 mV, was measured. The equilibrium potential for this large, rapid inward current depends directly on [Na](o), shifting 29.0 +/- 2.3 mV (+/- S.E. of mean), as opposed to a theoretically expected value of 30.6 mV, when [Na](o) is reduced to 31% of normal.3. Sodium current is inactivated by conditioning depolarizations. Complete inactivation occurs with conditioning potentials more positive than -45 mV, and 50% inactivation occurs at about -55 mV. The location of the inactivation curve shifts along the voltage axis, when [Ca](o) is varied between 0.2 and 7.2 mM.4. A second, much smaller and slower net inward current, with a threshold around -30 mV, and an equilibrium potential above +40 mV was also observed.5. The ;steady-state' current-voltage relationship (after 300-600 msec) exhibits inward-going (anomalous) rectification with negative slope between -50 and -25 mV.6. A small, very slowly developing component of outward current was observed at inside positive potentials. The equilibrium potential for this current, although slightly dependent on [K](o), is neither identical with the potassium equilibrium potential nor with the resting potential in normal Tyrode solution.7. Anatomical limitations, primarily resistance in the extracellular space within the bundle, prevent complete characterization of the rapid, large sodium current, but do not limit the application of the clamp method to the study of other, smaller and slower currents. The evidence for this is discussed extensively in the Appendix. PMID:5503866

  20. Transcatheter aortic valve implantation.

    PubMed

    Nielsen, Hans Henrik Møller

    2012-12-01

    Transcatheter aortic valve implantation (TAVI) was introduced experimentally in 1989, based on a newly developed heart valve prosthesis - the stentvalve. The valve was invented by a Danish cardiologist named Henning Rud Andersen. The new valve was revolutionary. It was foldable and could be inserted via a catheter through an artery in the groin, without the need for heart lung machine. This allowed for a new valve implantation technique, much less invasive than conventional surgical aortic valve replacement (SAVR). Surgical aortic valve replacement is safe and improves symptoms along with survival. However, up to 1/3 of patients with aortic valve stenosis cannot complete the procedure due to frailty. The catheter technique was hoped to provide a new treatment option for these patients. The first human case was in 2002, but more widespread clinical use did not begin until 2006-2010. Today, in 2011, more than 40,000 valves have been implanted worldwide. Initially, because of the experimental character of the procedure, TAVI was reserved for patients who could not undergo SAVR due to high risk. The results in this group of patients were promising. The procedural safety was acceptable, and the patients experienced significant improvements in their symptoms. Three of the papers in this PhD-thesis are based on the outcome of TAVI at Skejby Hospital, in this high-risk population [I, II and IV]. Along with other international publications, they support TAVI as being superior to standard medical treatment, despite a high risk of prosthetic regurgitation. These results only apply to high-risk patients, who cannot undergo SAVR. The main purpose of this PhD study has been to investigate the quality of TAVI compared to SAVR, in order to define the indications for this new procedure. The article attached [V] describes a prospective clinical randomised controlled trial, between TAVI to SAVR in surgically amenable patients over 75 years of age with isolated aortic valve stenosis

  1. Quadricuspid Aortic Valve: A Rare Congenital Cause of Aortic Insufficiency

    PubMed Central

    Vasudev, Rahul; Shah, Priyank; Bikkina, Mahesh; Shamoon, Fayez

    2016-01-01

    Quadricuspid aortic valve (QAV) is a rare congenital cardiac anomaly causing aortic regurgitation usually in the fifth to sixth decade of life. Earlier, the diagnosis was mostly during postmortem or intraoperative, but now with the advent of better imaging techniques such as transthoracic echocardiography, transesophageal echocardiography (TEE), and cardiac magnetic resonance imaging, more cases are being diagnosed in asymptomatic patients. We present a case of a 39-year-old male who was found to have QAV, with the help of TEE, while undergoing evaluation for a diastolic murmur. The patient was found to have Type B QAV with moderate aortic regurgitation. We also present a brief review of classification, pathophysiology, and embryological basis of this rare congenital anomaly. The importance of diagnosing QAV lies in the fact that majority of these patients will require surgery for aortic regurgitation and close follow-up so that aortic valve replacement/repair is done before the left ventricular decompensation occurs. PMID:27195176

  2. Management of Acute Aortic Syndrome and Chronic Aortic Dissection

    SciTech Connect

    Nordon, Ian M. Hinchliffe, Robert J.; Loftus, Ian M.; Morgan, Robert A.; Thompson, Matt M.

    2011-10-15

    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.

  3. 21 CFR 876.5160 - Urological clamp for males.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urological clamp for males. 876.5160 Section 876.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for males. (a) Identification. A urological...

  4. Combination Space Station Handrail Clamp and Pointing Device

    NASA Technical Reports Server (NTRS)

    Hughes, Stephen J. (Inventor)

    1999-01-01

    A device for attaching an experiment carrier to a space station handrail is provided. The device has two major components, a clamping mechanism for attachment to a space station handrail, and a pointing carrier on which an experiment package can be mounted and oriented. The handrail clamp uses an overcenter mechanism and the carrier mechanism uses an adjustable preload ball and socket for carrier positioning. The handrail clamp uses a stack of disk springs to provide a spring loaded button. This configuration provides consistent clamping force over a range of possible handrail thicknesses. Three load points are incorporated in the clamping mechanism thereby spreading the clamping load onto three separate points on the handrail. A four bar linkage is used to provide for a single actuation lever for all three load points. For additional safety, a secondary lock consisting of a capture plate and push lock keeps the clamp attached to the handrail in the event of main clamp failure. For the carrier positioning mechanism, a ball in a spring loaded socket uses friction to provide locking torque; however. the ball and socket are torque limited so that the ball ran slip under kick loads (125 pounds or greater). A lead screw attached to disk spring stacks is used to provide an adjustable spring force on the socket. A locking knob is attached to the lead screw to allow for hand manipulation of the lead screw.

  5. Off-clamp robotic partial nephrectomy: Technique and outcome

    PubMed Central

    Lamoshi, Abdulraouf Y.; Salkini, Mohamad W.

    2015-01-01

    Introduction: Robotic partial nephrectomy (RPN) is a technically challenging procedure. Advanced skills are needed to accomplish tumor resection, hemostasis, and renorrhaphy within short ischemia time in RPN. Off-clamp RPN with zero ischemia may decrease the risk of ischemic reperfusion injury to the kidney. However, the off-clamp technique has been associated with an increased risk of blood loss. The purpose of this study was to evaluate the outcome of our modified off-clamp technique utilized in certain RPN cases. Patients and Methods: A total of 81 patients underwent RPN between September 2009 and July 2013 for renal masses. We studied a subgroup of patients who underwent off-clamp RPN with zero ischemia time. The off-clamp technique was utilized for exophytic, nonhilar tumors that have a base of 2 cm or less. We developed a novel technique to avoid ischemia reperfusion renal injury while minimizing blood loss in certain cases of RPN. Results: Of the 81 cases of RPN, we reviewed and adopted the off-clamp technique in 34 patients (41.98%). Utilizing off-clamp RPN resulted in an average blood loss of 96.29 ml and 1.56 days (range: 1-3 days) of hospital stay and minimal change in serum creatinine. Conclusions: Off-clamp RPN is safe and feasible approach to excise certain kidney tumors. It carries the benefits of RPN and prevents ischemia reperfusion renal injury. PMID:25835489

  6. 21 CFR 876.5160 - Urological clamp for males.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Urological clamp for males. 876.5160 Section 876.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for...

  7. 21 CFR 876.5160 - Urological clamp for males.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Urological clamp for males. 876.5160 Section 876.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for males. (a) Identification. A urological...

  8. OPTIMAL TIMING FOR CLAMPING THE UMBILICAL CORD AFTER BIRTH

    PubMed Central

    Raju, Tonse N. K.; Singal, Nalini

    2013-01-01

    Synopsis This paper provides a brief overview of pros and cons of clamping the cord too early (within seconds) after birth. It also highlights evolving data that suggests that delaying cord clamping for 30–60 seconds after birth is beneficial to the baby and the mother, with no measurable negative effects. PMID:23164185

  9. Circumferential hoof clamp method of lameness induction in the horse.

    PubMed

    Swaab, M E; Mendez-Angulo, J L; Groschen, D M; Ernst, N S; Brown, M P; Trumble, T N

    2015-07-01

    A circumferential hoof clamp method to induce controlled and reversible lameness in the forelimbs of eight horses was assessed. Peak vertical forces and vertical impulses were recorded using a force plate to verify induced lameness. Video recordings were used by blinded observers to determine subjective lameness using a 0-5 scale and any residual lameness following clamp loosening. Tightening of clamps resulted in consistent, visible lameness in the selected limbs in all horses. Lameness was confirmed by significant decreases from baseline in the peak vertical force (P <0.01). Lameness was also confirmed subjectively by elevated median scores (0 at baseline and 2 during lameness). Lameness was not immediately reversible after clamp loosening (median score 1.5), but horses were not obviously lame after clamp removal and were no different from initial baseline (median score 0.5) approximately 3 days later. PMID:26045357

  10. Thoracic aortic aneurysms and pregnancy.

    PubMed

    Coulon, Capucine

    2015-11-01

    Half of acute aortic dissection in women under the age of 40 occurs during pregnancy or peripartum period. Marfan syndrome is the most common syndromic presentation of ascending aortic aneurysm, but other syndromes such as vascular Ehlers-Danlos syndrome, Loeys-Dietz syndrome and Turner syndrome also have ascending aortic aneurysms and the associated cardiovascular risk of aortic dissection and rupture. Management of aortic root aneurysm has been established in recent recommendations, even if levels of evidence are weak. Pregnancy and postpartum period should be followed very closely and determined to be at high risk. Guidelines suggest that women with aortopathy should be counseled against the risk of pregnancy and about the heritable nature of the disease prior to pregnancy. PMID:26454306

  11. Subclinical Hypothyroidism Might Increase the Risk of Postoperative Atrial Fibrillation after Aortic Valve Replacement.

    PubMed

    Martínez-Comendador, Jose; Marcos-Vidal, Jose Miguel; Gualis, Javier; Martin, Carlos Esteban; Martin, Elio; Otero, Javier; Castaño, Mario

    2016-08-01

    Background To evaluate the influence of subclinical hypothyroidism (SCH) on the development of postoperative atrial fibrillation (AF) in patients undergoing aortic valve replacement surgery with extracorporeal circulation. Methods A prospective study in a tertiary hospital between July 2005 and December 2013 in which all patients undergoing aortic valve replacement with no other valve surgery were consecutively included. Patients who were in preoperative sinus rhythm were selected and they underwent thyroxine (T4) and thyroid-stimulating hormone determination in the month before surgery. Postoperative AF was defined as the development of AF during hospital admittance. Descriptive analysis and binary logistic regression were performed for the target variable. Results A total of 467 patients were studied, with 35 cases of SCH. The incidence of postoperative AF was 57% in the group with SCH versus 30.3% (p = 0.001) in the group without hypothyroidism, without significant differences in other postoperative complications. In the logistic regression analysis, the independent predictors of postoperative AF were SCH, age, and aortic clamping time. SCH multiplies the odds ratio of postoperative AF by 3.14 (95% confidence interval: 1.24-7.96). Conclusion SCH behaves like a risk factor for the development of postoperative AF in patients undergoing aortic valve replacement with extracorporeal circulation. Other studies are needed to determine whether preoperative T4 replacement therapy and/or more aggressive AF prophylaxis can prevent this complication in patients undergoing aortic valve replacement. PMID:26121379

  12. Aortic PWV in Chronic Kidney Disease: A CRIC Ancillary Study

    PubMed Central

    Townsend, Raymond R.; Wimmer, Neil J.; Chirinos, Julio A.; Parsa, Afshin; Weir, Matthew; Perumal, Kalyani; Lash, James P.; Chen, Jing; Steigerwalt, Susan P.; Flack, John; Go, Alan S.; Rafey, Mohammed; Rahman, Mahboob; Sheridan, Angela; Gadegbeku, Crystal A.; Robinson, Nancy A.; Joffe, Marshall

    2009-01-01

    Background Aortic PWV is a measure of arterial stiffness and has proved useful in predicting cardiovascular morbidity and mortality in several populations of patients, including the healthy elderly, hypertensives and those with end stage renal disease receiving hemodialysis. Little data exist characterizing aortic stiffness in patients with chronic kidney disease who are not receiving dialysis, and in particular the effect of reduced kidney function on aortic PWV. Methods We performed measurements of aortic PWV in a cross-sectional cohort of participants enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study to determine factors which predict increased aortic PWV in chronic kidney disease. Results PWV measurements were obtained in 2564 participants. The tertiles of aortic PWV (adjusted for waist circumference) were < 7.7 m/sec, 7.7–10.2 m/sec and > 10.2 m/sec with an overall mean (± S.D.) value of 9.48 ± 3.03 m/sec [95% CI = 9.35–9.61 m/sec]. Multivariable regression identified significant independent positive associations of age, blood glucose concentrations, race, waist circumference, mean arterial blood pressure, gender, and presence of diabetes with aortic PWV and a significant negative association with the level of kidney function. Conclusions The large size of this unique cohort, and the targeted enrollment of chronic kidney disease participants provides an ideal situation to study the role of reduced kidney function as a determinant of arterial stiffness. Arterial stiffness may be a significant component of the enhanced cardiovascular risk associated with kidney failure. PMID:20019670

  13. Intraoperative aortic dissection

    PubMed Central

    Singh, Ajmer; Mehta, Yatin

    2015-01-01

    Intraoperative aortic dissection is a rare but fatal complication of open heart surgery. By recognizing the population at risk and by using a gentle operative technique in such patients, the surgeon can usually avoid iatrogenic injury to the aorta. Intraoperative transesophageal echocardiography and epiaortic scanning are invaluable for prompt diagnosis and determination of the extent of the injury. Prevention lies in the strict control of blood pressure during cannulation/decannulation, construction of proximal anastomosis, or in avoiding manipulation of the aorta in high-risk patients. Immediate repair using interposition graft or Dacron patch graft is warranted to reduce the high mortality associated with this complication. PMID:26440240

  14. Cell-Detection Technique for Automated Patch Clamping

    NASA Technical Reports Server (NTRS)

    McDowell, Mark; Gray, Elizabeth

    2008-01-01

    A unique and customizable machinevision and image-data-processing technique has been developed for use in automated identification of cells that are optimal for patch clamping. [Patch clamping (in which patch electrodes are pressed against cell membranes) is an electrophysiological technique widely applied for the study of ion channels, and of membrane proteins that regulate the flow of ions across the membranes. Patch clamping is used in many biological research fields such as neurobiology, pharmacology, and molecular biology.] While there exist several hardware techniques for automated patch clamping of cells, very few of those techniques incorporate machine vision for locating cells that are ideal subjects for patch clamping. In contrast, the present technique is embodied in a machine-vision algorithm that, in practical application, enables the user to identify good and bad cells for patch clamping in an image captured by a charge-coupled-device (CCD) camera attached to a microscope, within a processing time of one second. Hence, the present technique can save time, thereby increasing efficiency and reducing cost. The present technique involves the utilization of cell-feature metrics to accurately make decisions on the degree to which individual cells are "good" or "bad" candidates for patch clamping. These metrics include position coordinates (x,y) in the image plane, major-axis length, minor-axis length, area, elongation, roundness, smoothness, angle of orientation, and degree of inclusion in the field of view. The present technique does not require any special hardware beyond commercially available, off-the-shelf patch-clamping hardware: A standard patchclamping microscope system with an attached CCD camera, a personal computer with an imagedata- processing board, and some experience in utilizing imagedata- processing software are all that are needed. A cell image is first captured by the microscope CCD camera and image-data-processing board, then the image

  15. Aortic biomechanics in hypertrophic cardiomyopathy

    PubMed Central

    Badran, Hala Mahfouz; Soltan, Ghada; Faheem, Nagla; Elnoamany, Mohamed Fahmy; Tawfik, Mohamed; Yacoub, Magdi

    2015-01-01

    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

  16. Unusual Case of Overt Aortic Dissection Mimicking Aortic Intramural Hematoma

    PubMed Central

    Disha, Kushtrim; Kuntze, Thomas; Girdauskas, Evaldas

    2016-01-01

    We report an interesting case in which overt aortic dissection mimicked two episodes of aortic intramural hematoma (IMH) (Stanford A, DeBakey I). This took place over the course of four days and had a major influence on the surgical treatment strategy. The first episode of IMH regressed completely within 15 hours after it was clinically diagnosed and verified using imaging techniques. The recurrence of IMH was detected three days thereafter, resulting in an urgent surgical intervention. Overt aortic dissection with evidence of an intimal tear was diagnosed intraoperatively. PMID:27066437

  17. Dynamic clamp: a powerful tool in cardiac electrophysiology.

    PubMed

    Wilders, Ronald

    2006-10-15

    Dynamic clamp is a collection of closely related techniques that have been employed in cardiac electrophysiology to provide direct answers to numerous research questions regarding basic cellular mechanisms of action potential formation, action potential transfer and action potential synchronization in health and disease. Building on traditional current clamp, dynamic clamp was initially used to create virtual gap junctions between isolated myocytes. More recent applications include the embedding of a real pacemaking myocyte in a simulated network of atrial or ventricular cells and the insertion of virtual ion channels, either simulated in real time or simultaneously recorded from an expression system, into the membrane of an isolated myocyte. These applications have proven that dynamic clamp, which is characterized by the real-time evaluation and injection of simulated membrane current, is a powerful tool in cardiac electrophysiology. Here, each of the three different experimental configurations used in cardiac electrophysiology is reviewed. Also, directions are given for the implementation of dynamic clamp in the cardiac electrophysiology laboratory. With the growing interest in the application of dynamic clamp in cardiac electrophysiology, it is anticipated that dynamic clamp will also prove to be a powerful tool in basic research on biological pacemakers and in identification of specific ion channels as targets for drug development. PMID:16873403

  18. Minimally invasive aortic valve surgery.

    PubMed

    Castrovinci, Sebastiano; Emmanuel, Sam; Moscarelli, Marco; Murana, Giacomo; Caccamo, Giuseppa; Bertolino, Emanuela Clara; Nasso, Giuseppe; Speziale, Giuseppe; Fattouch, Khalil

    2016-09-01

    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

  19. Minimally invasive aortic valve surgery

    PubMed Central

    Castrovinci, Sebastiano; Emmanuel, Sam; Moscarelli, Marco; Murana, Giacomo; Caccamo, Giuseppa; Bertolino, Emanuela Clara; Nasso, Giuseppe; Speziale, Giuseppe; Fattouch, Khalil

    2016-01-01

    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

  20. Patch voltage clamp of squid axon membrane.

    PubMed

    Fishman, H M

    1975-12-01

    A small area (patch) of the external surface of a squid axon can be "isolated" electrically from the surrounding bath by means of a pair of concentric glass pipettes. The seawater-filled inner pipette makes contact with the axon and constitutes the external access to the patch. The outer pipette is used to direct flowing sucrose solution over the area surrounding the patch of membrane underlying the inner pipette. Typically, sucrose isolated patches remain in good condition (spike amplitude greater than 90 mV) for periods of approximately one half hour. Patches of axon membrane which had previously been exposed to sucrose solution were often excitable. Membrane survival of sucrose treatment apparently arises from an outflow of ions from the axon and perhaps satellite cells into the interstitial cell space surrounding the exolemma. Estimate of the total access resistance (electrode plus series resistance) to the patch is about 100 komega (7 omega cm2). Patch capacitance ranges from 10-100 pF, which suggests areas of 10(-4) to 10(-5) cm2 and resting patch resistances of 10-100 Momega. Shunt resistance through the interstitial space exposed to sucrose solution, which isolates the patch, is typically 1-2 Momega. These parameters indicate that good potential control and response times can be achieved on a patch. Furthermore, spatial uniformity is demonstrated by measurement of an exoplasmic isopotential during voltage clamp of an axon patch. The method may be useful for other preparations in which limited membrane area is available or in special instances such as in the measurement of membrane conduction noise. PMID:1214276

  1. Prediction of Shock Response and Methods to Mitigate the Shock Response Produced by V-Section Band Clamps Using a Simplified Dynamic Model

    NASA Astrophysics Data System (ADS)

    Shi, Qinzhong; Tomoya, Niwa; Wada, Yoshio

    2012-07-01

    V-section band clamps are widely used for connecting payload and launch vehicle in space application. The mechanical principle of V-band clamp uses the clamp nut which tightens the clamp to result in a radial force on the ring flange to generate an axial load to restrain the payload on payload adapter. Release of V-band clamp by pyrotechnic actuator generates high shock acceleration in both magnitude and frequency, which may damage functions of the sensitive electromechanical equipment. Prediction and mitigation technology of shock acceleration of V-band clamps are necessary to the payload design, verification. This paper proposes a simplified model to analysis the shock acceleration of dominating mode which decides the knee frequency and the magnitude of shock response spectrum (SRS). The dominating mode of ring flange may be calculated from the structural parameters of V- band, such as materials, cross-section of the ring flange, and the clamp preload. Besides dominating mode, high modes which may excited depends on load distribution along the ring flange is investigated by mode participating factor of each modes. The envelope tolerance of SRS is calculated statistically based on the deviation between the analysis model and test data, obtained from several satellite shock test. Finally, mitigation of shock acceleration of V-band by the way of extension of load release time is simulated.

  2. Reoperative Aortic Root Replacement in Patients with Previous Aortic Root or Aortic Valve Procedures

    PubMed Central

    Chong, Byung Kwon; Jung, Sung-Ho; Choo, Suk Jung; Chung, Cheol Hyun; Lee, Jae Won; Kim, Joon Bum

    2016-01-01

    Background Generalization of standardized surgical techniques to treat aortic valve (AV) and aortic root diseases has benefited large numbers of patients. As a consequence of the proliferation of patients receiving aortic root surgeries, surgeons are more frequently challenged by reoperative aortic root procedures. The aim of this study was to evaluate the outcomes of redo-aortic root replacement (ARR). Methods We retrospectively reviewed 66 patients (36 male; mean age, 44.5±9.5 years) who underwent redo-ARR following AV or aortic root procedures between April 1995 and June 2015. Results Emergency surgeries comprised 43.9% (n=29). Indications for the redo-ARR were aneurysm (n=12), pseudoaneurysm (n=1), or dissection (n=6) of the residual native aortic sinus in 19 patients (28.8%), native AV dysfunction in 8 patients (12.1%), structural dysfunction of an implanted bioprosthetic AV in 19 patients (28.8%), and infection of previously replaced AV or proximal aortic grafts in 30 patients (45.5%). There were 3 early deaths (4.5%). During follow-up (median, 54.65 months; quartile 1–3, 17.93 to 95.71 months), there were 14 late deaths (21.2%), and 9 valve-related complications including reoperation of the aortic root in 1 patient, infective endocarditis in 3 patients, and hemorrhagic events in 5 patients. Overall survival and event-free survival rates at 5 years were 81.5%±5.1% and 76.4%±5.4%, respectively. Conclusion Despite technical challenges and a high rate of emergency conditions in patients requiring redo-ARR, early and late outcomes were acceptable in these patients. PMID:27525233

  3. Combined Retrograde/Antegrade Approach to Transcatheter Closure of an Aortic Paravalvular Leak

    PubMed Central

    Damluji, Abdulla A.; Kaynak, Husnu E.

    2015-01-01

    New interventional techniques have made transcatheter closure of aortic paravalvular leaks a viable therapeutic option to treat the sequelae of these defects, including congestive heart failure and hemolysis. We report the transcatheter closure of an aortic paravalvular leak via a combined retrograde/antegrade approach. This was necessary because of difficulty in crossing the defect with a sheath from the retrograde approach. This technique might be useful in application to other difficult structural heart interventions. To our knowledge, this is the first report of a treated paravalvular leak around a Mitroflow® Aortic Pericardial Heart Valve. PMID:26504437

  4. Insulin Tolerance Test and Hyperinsulinemic-Euglycemic Clamp

    PubMed Central

    Paschos, Georgios K.; FitzGerald, Garret A.

    2016-01-01

    The two tests are used to evaluate in vivo sensitivity to insulin in mouse. The hypoerinsulinemic-euglycemic clamp provides information about the sensitivity to insulin in liver and other metabolically relevant tissues.

  5. A clamp-like biohybrid catalyst for DNA oxidation

    NASA Astrophysics Data System (ADS)

    van Dongen, Stijn F. M.; Clerx, Joost; Nørgaard, Kasper; Bloemberg, Tom G.; Cornelissen, Jeroen J. L. M.; Trakselis, Michael A.; Nelson, Scott W.; Benkovic, Stephen J.; Rowan, Alan E.; Nolte, Roeland J. M.

    2013-11-01

    In processive catalysis, a catalyst binds to a substrate and remains bound as it performs several consecutive reactions, as exemplified by DNA polymerases. Processivity is essential in nature and is often mediated by a clamp-like structure that physically tethers the catalyst to its (polymeric) template. In the case of the bacteriophage T4 replisome, a dedicated clamp protein acts as a processivity mediator by encircling DNA and subsequently recruiting its polymerase. Here we use this DNA-binding protein to construct a biohybrid catalyst. Conjugation of the clamp protein to a chemical catalyst with sequence-specific oxidation behaviour formed a catalytic clamp that can be loaded onto a DNA plasmid. The catalytic activity of the biohybrid catalyst was visualized using a procedure based on an atomic force microscopy method that detects and spatially locates oxidized sites in DNA. Varying the experimental conditions enabled switching between processive and distributive catalysis and influencing the sliding direction of this rotaxane-like catalyst.

  6. Aortic dissection--an update.

    PubMed

    Mukherjee, Debabrata; Eagle, Kim A

    2005-06-01

    Acute aortic dissection is a medical emergency with high morbidity and mortality requiring emergent diagnosis and therapy. Rapid advances in noninvasive imaging technology have facilitated the early diagnosis of this condition and should be considered in the differential diagnosis of any patient with chest, back, or abdominal pain. Emergent surgery is the treatment for patients with type A dissection while optimal medical therapy is appropriate in patients with uncomplicated type B dissection. Adequate beta-blockade is the cornerstone of medical therapy. Patients who survive acute aortic dissection need long-term medical therapy with beta-blockers and statins and appropriate serial imaging follow-up. Future advances in this field include biomarkers in the early diagnosis of acute aortic dissection and presymptomatic diagnosis with genetic screening. Overall patients with aortic dissection are at high risk for an adverse outcome and need to be managed aggressively in hospital and long term with frequent follow-up. PMID:15973249

  7. A phage-encoded inhibitor of Escherichia coli DNA replication targets the DNA polymerase clamp loader.

    PubMed

    Yano, Sho T; Rothman-Denes, Lucia B

    2011-03-01

    Coliphage N4 infection leads to shut-off of host DNA replication without inhibition of host transcription or translation. We report the identification and characterization of gp8, the N4 gene product responsible for this phenotype. N4 gp8 is an Escherichia coli bacteriostatic inhibitor that colocalizes with the E. coli replisome in a replication-dependent manner. Gp8 was purified and observed to cross-link to complexes containing the replicative DNA polymerase, DNAP III, in vivo. Purified gp8 inhibits DNA polymerization by DNA polymerase III holoenzyme in vitro by interfering with polymerase processivity. Gp8 specifically inhibits the clamp-loading activity of DNAP III by targeting the delta subunit of the DNAP III clamp loader; E. coli mutations conferring gp8 resistance were identified in the holA gene, encoding delta. Delta and gp8 interact in vitro; no interaction was detected between gp8 inactive mutants and wild-type delta or between delta gp8-resistant mutants and wild-type gp8. Therefore, this work identifies the DNAP III clamp loader as a new target for inhibition of bacterial growth. Finally, we show that gp8 is not essential in N4 development under laboratory conditions, but its activity contributes to phage yield. PMID:21205014

  8. Distal embolization as a presenting symptom of aortic aneurysms.

    PubMed

    Baxter, B T; McGee, G S; Flinn, W R; McCarthy, W J; Pearce, W H; Yao, J S

    1990-08-01

    The records of 302 patients who underwent abdominal aortic aneurysm (AAA) repair between 1985 and 1990 were reviewed. Two hundred and forty-eight patients (82%) were asymptomatic, while 32 patients (11%) had ruptured aneurysms. During this period, 15 patients (5%) presented with distal embolization as the first manifestation of their AAA. The preoperative embolic event resulted in limb-threatening ischemia in 3 patients, digital ischemia in 11, and calf myonecrosis in 1. CT scan was performed in 14 of 15 patients demonstrating irregular, heterogeneous thrombus within the AAA. Only two of the AAAs were larger than 5 cm. Angiography demonstrated occlusive lesions but was not diagnostic for AAA in seven patients and resulted in three episodes of embolization. AAA was repaired with a tube graft in 4 patients while a bifurcated graft was required in 11 patients for aneurysmal (in 4 patients) and occlusive disease (in 7 patients) of the iliac arteries. All cases employed a transperitoneal approach, systemic heparin, and distal occlusion prior to aortic clamping. Complications included three major (below-knee) and five minor amputations, developing or worsening renal failure in five patients (33%), and death in two (13%). In comparison, mortality was 5% for elective repair and 66% for rupture during this same period. CT scan was safer and more informative than angiography. The morbidity of patients with AAA presenting with emboli is comparable with rupture. The risk of embolization does not correlate with size and indicates the potentially dangerous nature of small AAAs. PMID:2200293

  9. [Aortic intramural hematoma. An atypical pattern equivalent to aortic dissection].

    PubMed

    López-Mínguez, J R; Merchán, A; Arrobas, J; Fernández, G; González-Egüaras, M; García-Andoaín, J M; Alonso, M; Gamero, C; Poblador, M A; Alonso, F

    1995-09-01

    A case is presented of a hypertensive woman who had suffered a stabbing back pain for some three hours, with mild irradiation to precordium and accompanied by vegetative signs. A sinusal rhythm and negative T waves of little depth were seen on the ECG. A transthoracic bidimensional echocardiogram (TTE) showed a normal left ventricle with a somewhat dilated aortic root and the existence of a double echo running parallel to the anterior wall of the aorta but non-ondulating and without a visible intimal flap. Because of suspected aortic dissection an urgent contrasted CAT and a transesophageal echocardiogram were performed. These were informed as an aneurysm of the aortic root with mural thrombus from the ascending to descending aorta, but with no existing intimal flap suggesting dissection. A cardiac catheterization showed a mildly some dilated aortic root without dissection signs and normal left ventricle and coronary arteries. The patient was presented for surgical evaluation but, since no dissection was present, was not considered urgent surgery; she was admitted to the coronary unit and died 48 hours later in a situation of acute pericardial tamponade, documented by TTE, surely due to rupture of the aortic root to pericardial sack. This way of presenting threatened aorta rupture that has been only recently recognized is discussed, as well as some misconceptions which must be avoided. PMID:7569267

  10. Coronary Flow Impacts Aortic Leaflet Mechanics and Aortic Sinus Hemodynamics

    PubMed Central

    Moore, Brandon L.; Dasi, Lakshmi Prasad

    2016-01-01

    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. PMID:25636598

  11. Spectral infrared hemispherical reflectance measurements for LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Wood, Bobby E.; Cromwell, Brian K.; Pender, Charles W.; Shepherd, Seth D.

    1992-01-01

    This paper describes infrared hemispherical reflectance measurements (2-15 microns) that were made on 58 chromic acid anodized tray clamps retrieved from the LDEF spacecraft. These clamps were used for maintaining the experiments in place and were located at various locations about the spacecraft. Changes in reflectance of the tray clamps at these locations were compared with atomic oxygen fluxes at the same locations. A decrease in absorption band depth was seen for the surfaces exposed to space indicating that there was some surface layer erosion. In all of the surfaces measured, little evidence of contamination was observed and none of the samples showed evidence of the brown nicotine stain that was so prominent in other experiments. Total emissivity values were calculated for both exposed and unexposed tray clamp surfaces. Only small differences, usually less than 1 percent, were observed. The spectral reflectances were measured using a hemi-ellipsoidal mirror reflectometer matched with an interferometer spectrometer. The rapid scanning capability of the interferometer allowed the reflectance measurements to be made in a timely fashion. The ellipsoidal mirror has its two foci separated by 2 inches and located on the major axis. A blackbody source was located at one focus while the tray clamp samples were located at the conjugate focus. The blackbody radiation was modulated and then focused by the ellipsoid onto the tray clamps. Radiation reflected from the tray clamp was sampled by the interferometer by viewing through a hole in the ellipsoid. A gold mirror (reflectance approximately 98 percent) was used as the reference surface.

  12. Measuring beta-cell function relative to insulin sensitivity in youth: Does the hyperglycemic clamp suffice?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To compare beta-cell function relative to insulin sensitivity, disposition index (DI), calculated from two clamps (2cDI, insulin sensitivity from the hyperinsulinemic-euglycemic clamp and first-phase insulin from the hyperglycemic clamp) with the DI calculated from the hyperglycemic clamp alone (hcD...

  13. Abdominal aortic aneurysm repair - open - discharge

    MedlinePlus

    AAA - open - discharge; Repair - aortic aneurysm - open - discharge ... You had open aortic aneurysm surgery to repair an aneurysm (a widened part) in your aorta, the large artery that carries blood to your ...

  14. Targeted Endovascular Temporary Vessel Occlusion with a Reverse Thermosensitive Polymer for Near-Bloodless Partial Nephrectomy: Comparison to Standard Surgical Clamping Techniques

    SciTech Connect

    Flacke, Sebastian; Harty, Niall J.; Laskey, Daniel H.; Moinzadeh, Alireza; Benn, James A.; Villani, Rosanna; Kalra, Aarti; Libertino, John A.; Madras, Peter N.

    2012-10-15

    Purpose: To determine whether reversible blood flow interruption to a randomly chosen target region of the kidney may be achieved with the injection of a reverse thermoplastic polymer through an angiographic catheter, thereby facilitating partial nephrectomy without compromising blood flow to the remaining kidney or adding risks beyond those encountered by the use of hilar clamping. Methods: Fifteen pigs underwent partial nephrectomy after blood flow interruption by vascular cross-clamping or injection of polymer (Lumagel Trade-Mark-Sign ) into a segmental artery. Five animals were euthanized after surgery (three open and two laparoscopic resection, cross-clamping n = 2), and 10 (open resection, cross-clamping n = 4) were euthanized after 6 weeks' survival. Blood specimens were obtained periodically, and angiogram and necropsy were performed at 6 weeks. Results: Selective renal ischemia was achieved in all cases. Surgical resection time averaged 9 and 24.5 min in the open and laparoscopic groups, respectively. Estimated blood loss was negligible with the exception of one case where an accessory renal artery was originally overlooked. Reversal of the polymer to a liquid state was consistent angiographically and visually in all cases. Time to complete flow return averaged 7.4 and 2 min for polymer and clamping, respectively. Angiography at 6 weeks revealed no evidence of vascular injury. Laboratory data and necropsies revealed no differences between animals undergoing vascular clamping or polymer injection. Conclusion: Lumagel was as effective as vascular clamping in producing a near bloodless operative field for partial nephrectomy while maintaining flow to the uninvolved portion of the affected kidney.

  15. Aortic or Mitral Valve Replacement With the Biocor and Biocor Supra

    ClinicalTrials.gov

    2016-03-09

    Aortic Valve Insufficiency; Aortic Valve Regurgitation; Aortic Valve Stenosis; Aortic Valve Incompetence; Mitral Valve Insufficiency; Mitral Valve Regurgitation; Mitral Valve Stenosis; Mitral Valve Incompetence

  16. Current aortic endografts for the treatment of abdominal aortic aneurysms.

    PubMed

    Colvard, Benjamin; Georg, Yannick; Chakfe, Nabil; Swanstrom, Lee

    2016-05-01

    Endovascular Aneurysm Repair is a widely adopted method of treatment for patients with abdominal aortic aneurysms. The minimally invasive approach offered with EVAR has become popular not only among physicians and patients, but in the medical device industry as well. Over the past 25 years the global market for aortic endografts has increased rapidly, resulting in a wide range of devices from various companies. Currently, there are seven endografts approved by the FDA for the treatment of abdominal aortic aneurysms. These devices offer a wide range of designs intended to increase inclusion criteria while decreasing technical complications such as endoleak and migration. Despite advances in device design, secondary interventions and follow-up requirements remain a significant issue. New devices are currently being studied in the U.S. and abroad and may significantly reduce complications and secondary interventions. PMID:26959727

  17. Ascending Aortic Slide for Interrupted Aortic Arch Repair.

    PubMed

    Urencio, Miguel; Dodge-Khatami, Ali; Greenleaf, Chris E; Aru, Giorgio; Salazar, Jorge D

    2016-09-01

    For repair of interrupted aortic arch, unfavorable anatomy challenges a tension-free anastomosis. We describe a useful alternative surgical technique used in five neonates/infants, involving splitting the ascending aorta from the sinotubular junction to the arch origin, leftward and posterior "sliding" of the flap with anastomosis to the distal arch creating a native tissue bridge, and reconstruction with a patch. With wide interruption gaps between proximal and distal aortic portions, the ascending aortic slide is a safe and reproducible technique, providing a tension-free native tissue bridge with potential for growth, and a scaffold for patch augmentation in biventricular hearts, or for Norwood stage I in univentricular palliation. PMID:27587504

  18. Abdominal aortic feminism.

    PubMed

    Mortimer, Alice Emily

    2014-01-01

    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. PMID:25398912

  19. Dynamic Clamp in Cardiac and Neuronal Systems Using RTXI

    PubMed Central

    Ortega, Francis A.; Butera, Robert J.; Christini, David J.; White, John A.; Dorval, Alan D.

    2016-01-01

    The injection of computer-simulated conductances through the dynamic clamp technique has allowed researchers to probe the intercellular and intracellular dynamics of cardiac and neuronal systems with great precision. By coupling computational models to biological systems, dynamic clamp has become a proven tool in electrophysiology with many applications, such as generating hybrid networks in neurons or simulating channelopathies in cardiomyocytes. While its applications are broad, the approach is straightforward: synthesizing traditional patch clamp, computational modeling, and closed-loop feedback control to simulate a cellular conductance. Here, we present two example applications: artificial blocking of the inward rectifier potassium current in a cardiomyocyte and coupling of a biological neuron to a virtual neuron through a virtual synapse. The design and implementation of the necessary software to administer these dynamic clamp experiments can be difficult. In this chapter, we provide an overview of designing and implementing a dynamic clamp experiment using the Real-Time eXperiment Interface (RTXI), an open- source software system tailored for real-time biological experiments. We present two ways to achieve this using RTXI’s modular format, through the creation of a custom user-made module and through existing modules found in RTXI’s online library. PMID:25023319

  20. Surgical Repair of Retrograde Type A Aortic Dissection after Thoracic Endovascular Aortic Repair

    PubMed Central

    Kim, Chang-Young; Kim, Yeon Soo; Ryoo, Ji Yoon

    2014-01-01

    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

  1. Open aortic surgery after thoracic endovascular aortic repair.

    PubMed

    Coselli, Joseph S; Spiliotopoulos, Konstantinos; Preventza, Ourania; de la Cruz, Kim I; Amarasekara, Hiruni; Green, Susan Y

    2016-08-01

    In the last decade, thoracic endovascular aortic aneurysm repair (TEVAR) has emerged as an appealing alternative to the traditional open aortic aneurysm repair. This is largely due to generally improved early outcomes associated with TEVAR, including lower perioperative mortality and morbidity. However, it is relatively common for patients who undergo TEVAR to need a secondary intervention. In select circumstances, these secondary interventions are performed as an open procedure. Although it is difficult to assess the rate of open repairs after TEVAR, the rates in large series of TEVAR cases (>300) have ranged from 0.4 to 7.9 %. Major complications of TEVAR that typically necessitates open distal aortic repair (i.e., repair of the descending thoracic or thoracoabdominal aorta) include endoleak (especially type I), aortic fistula, endograft infection, device collapse or migration, and continued expansion of the aneurysm sac. Conversion to open repair of the distal aorta may be either elective (as for many endoleaks) or emergent (as for rupture, retrograde complicated dissection, malperfusion, and endograft infection). In addition, in select patients (e.g., those with a chronic aortic dissection), unrepaired sections of the aorta may progressively dilate, resulting in the need for multiple distal aortic repairs. Open repairs after TEVAR can be broadly classified as full extraction, partial extraction, or full salvage of the stent-graft. Although full and partial stent-graft extraction imply failure of TEVAR, such failure is generally absent in cases where the stent-graft can be fully salvaged. We review the literature regarding open repair after TEVAR and highlight operative strategies. PMID:27314956

  2. Turbulence downstream of subcoronary stentless and stented aortic valves.

    PubMed

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

    2011-08-11

    Regions of turbulence downstream of bioprosthetic heart valves may cause damage to blood components, vessel wall as well as to aortic valve leaflets. Stentless aortic heart valves are known to posses several hemodynamic benefits such as larger effective orifice areas, lower aortic transvalvular pressure difference and faster left ventricular mass regression compared with their stented counterpart. Whether this is reflected by diminished turbulence formation, remains to be shown. We implanted either stented pericardial valve prostheses (Mitroflow), stentless valve prostheses (Solo or Toronto SPV) in pigs or they preserved their native valves. Following surgery, blood velocity was measured in the cross sectional area downstream of the valves using 10MHz ultrasonic probes connected to a dedicated pulsed Doppler equipment. As a measure of turbulence, Reynolds normal stress (RNS) was calculated at two different blood pressures (baseline and 50% increase). We found no difference in maximum RNS measurements between any of the investigated valve groups. The native valve had significantly lower mean RNS values than the Mitroflow (p=0.004), Toronto SPV (p=0.008) and Solo valve (p=0.02). There were no statistically significant differences between the artificial valve groups (p=0.3). The mean RNS was significantly larger when increasing blood pressure (p=0.0006). We, thus, found no advantages for the stentless aortic valves compared with stented prosthesis in terms of lower maximum or mean RNS values. Native valves have a significantly lower mean RNS value than all investigated bioprostheses. PMID:21696741

  3. Persistent Fifth Aortic Arch with Coarctation

    PubMed Central

    Kim, Sue Hyun; Choi, Eun-Suk; Cho, Sungkyu; Kim, Woong-Han

    2016-01-01

    Persistent fifth aortic arch (PFAA) is a rare congenital anomaly of the aortic arch frequently associated with other cardiovascular anomalies, such as tetralogy of Fallot and aortic arch coarctation or interruption. We report the case of a neonate with PFAA with coarctation who successfully underwent surgical repair. PMID:26889445

  4. Impact of Aortic Valve Calcification, as Measured by MDCT, on Survival in Patients With Aortic Stenosis

    PubMed Central

    Clavel, Marie-Annick; Pibarot, Philippe; Messika-Zeitoun, David; Capoulade, Romain; Malouf, Joseph; Aggarval, Shivani; Araoz, Phillip A.; Michelena, Hector I.; Cueff, Caroline; Larose, Eric; Miller, Jordan D.; Vahanian, Alec; Enriquez-Sarano, Maurice

    2014-01-01

    BACKGROUND Aortic valve calcification (AVC) load measures lesion severity in aortic stenosis (AS) and is useful for diagnostic purposes. Whether AVC predicts survival after diagnosis, independent of clinical and Doppler echocardiographic AS characteristics, has not been studied. OBJECTIVES This study evaluated the impact of AVC load, absolute and relative to aortic annulus size (AVCdensity), on overall mortality in patients with AS under conservative treatment and without regard to treatment. METHODS In 3 academic centers, we enrolled 794 patients (mean age, 73 ± 12 years; 274 women) diagnosed with AS by Doppler echocardiography who underwent multidetector computed tomography (MDCT) within the same episode of care. Absolute AVC load and AVCdensity (ratio of absolute AVC to cross-sectional area of aortic annulus) were measured, and severe AVC was separately defined in men and women. RESULTS During follow-up, there were 440 aortic valve implantations (AVIs) and 194 deaths (115 under medical treatment). Univariate analysis showed strong association of absolute AVC and AVCdensity with survival (both, p < 0.0001) with a spline curve analysis pattern of threshold and plateau of risk. After adjustment for age, sex, coronary artery disease, diabetes, symptoms, AS severity on hemodynamic assessment, and LV ejection fraction, severe absolute AVC (adjusted hazard ratio [HR]: 1.75; 95% confidence interval [CI]: 1.04 to 2.92; p = 0.03) or severe AVCdensity (adjusted HR: 2.44; 95% CI: 1.37 to 4.37; p = 0.002) independently predicted mortality under medical treatment, with additive model predictive value (all, p ≤ 0.04) and a net reclassification index of 12.5% (p = 0.04). Severe absolute AVC (adjusted HR: 1.71; 95% CI: 1.12 to 2.62; p = 0.01) and severe AVCdensity (adjusted HR: 2.22; 95% CI: 1.40 to 3.52; p = 0.001) also independently predicted overall mortality, even with adjustment for time-dependent AVI. CONCLUSIONS This large-scale, multicenter outcomes study of

  5. Aortic regurgitation caused by rupture of the abnormal fibrous band between the aortic valve and aortic wall.

    PubMed

    Minami, Hiroya; Asada, Tatsuro; Gan, Kunio; Yamada, Akitoshi; Sato, Masanobu

    2011-07-01

    This report documents the sudden onset of aortic regurgitation (AR) by an exceptional cause. A 68-year-old woman suddenly experienced general fatigue, and AR was diagnosed. One year later, we performed aortic valve replacement. At surgery, three aortic cusps with a larger noncoronary cusp had prolapsed along with a free-floating fibrous band that had previously anchored the cusp to the aortic wall. Its rupture had induced the sudden onset of AR. There was no sign of infectious endocarditis. We performed successful aortic valve replacement. PMID:21751110

  6. Timing of clamping and factors associated with iron stores in full-term newborns

    PubMed Central

    Oliveira, Fabiana de Cássia Carvalho; Assis, Karine Franklin; Martins, Mariana Campos; do Prado, Mara Rúbia Maciel Cardoso; Ribeiro, Andréia Queiroz; Sant’Ana, Luciana Ferreira da Rocha; Priore, Silvia Eloiza; Franceschini, Sylvia do Carmo Castro

    2014-01-01

    OBJECTIVE To analyze the impact of timing of clamping and obstetric, biological and socioeconomic factors on the iron stores of full-term newborns. METHODS Cross-sectional study between October 2011 and July 2012 in which hematological parameters were evaluated for newborns in Viçosa, MG, Southeastern Brazil. It involved collecting 7 mL of umbilical cord blood from 144 full-term not underweight newborns. The parameters investigated were complete blood count, serum iron, ferritin and C-reactive protein. The time of umbilical cord clamping was measured using a digital timer without interfering in the procedures of childbirth. The birth data were collected from Live Birth Certificates and other information was obtained from the mother through a questionnaire applied in the first month postpartum. Analysis of multiple linear regression was then used to estimate the influence of biological, obstetrics and socioeconomic factors on the ferritin levels at birth. RESULTS The median ferritin was 130.3 µg/L (n = 129, minimum = 16.4; maximum = 420.5 µg/L), the mean serum iron was 137.9 μg/dL (n = 144, SD = 39.29) and mean hemoglobin was 14.7 g/dL (n = 144, SD = 1.47). The median time of cord clamping was 36 seconds, ranging between 7 and 100. The bivariate analysis detected an association between ferritin levels and color of the child, timing clamping of 60 seconds, type of delivery, the presence of gestational diabetes and per capita family income. In multivariate analysis, the variables per capita income, number of antenatal visits and length at birth accounted for 22.0% of variation in ferritin levels. CONCLUSIONS Iron stores at birth were influenced by biological, obstetric and social characteristics. Tackling anemia should involve creating policies aimed at reducing social inequalities, improving the quality of antenatal care, as well as implementing a criterion of delayed clamping of the umbilical cord within the guidelines of labor. PMID:24789632

  7. Self-locking clamping tool with swivel jaws

    NASA Technical Reports Server (NTRS)

    Redmon, Jr., John W. (Inventor); Jankowski, Fred (Inventor)

    1989-01-01

    A plier-like tool (11) having two plier-like members (13, 15) pivotally joined togther intermediate of their ends and having handle portions (17, 18) and swivel jaw members (29,30). An automatic locking mechanism (27) extending between the members permits an user to clamp the handle portions together so as to clamp the jaw members on an object (25) but holds the position so reached if the clamping action of the user is removed. A release device (65) is provided so that the jaw members may be opened up again. A compression spring (23) extending between the members (19, 20) assists in the opening of the jaw members. The swivel jaw members (29, 30) permit the user to rotate the plier-like members (13,15) relative to the object (25) being grasped.

  8. Hysteresis modeling of clamp band joint with macro-slip

    NASA Astrophysics Data System (ADS)

    Qin, Zhaoye; Cui, Delin; Yan, Shaoze; Chu, Fulei

    2016-01-01

    Clamp band joints are commonly used to connect spacecrafts with launch vehicles. Due to the frictional slippage between the joint components, hysteresis behavior might occur at joint interfaces under cyclic loading. The joint hysteresis will bring friction damping into the launching systems. In this paper, a closed-form hysteresis model for the clamp band joint is developed based on theoretical and numerical analyses of the interactions of the joint components. Then, the hysteresis model is applied to investigating the dynamic response of a payload fastened by the clamp band joint, where the nonlinearity and friction damping effects of the joint is evaluated. The proposed analytical model, which is validated by both finite element analyses and quasi-static experiments, has a simple form with sound accuracy and can be incorporated into the dynamic models of launching systems conveniently.

  9. Pseudoaneurysm of the aortic arch

    PubMed Central

    Lu, Yuan-Qiang; Yao, Feng; Shang, An-Dong; Pan, Jian

    2016-01-01

    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

  10. [Pedicular clamping in major hepatectomies: clamping "of principle" or "of necessity"? A comparative study].

    PubMed

    Le Treut, Y P; Christophe, M; Banti, J C; Berthet, B; Bricot, R

    1995-02-01

    Fifty-two consecutive patients undergoing major hepatic resection for liver tumor were divided into two groups according to the operative procedure. Group A consisted of 34 patients in whom vascular inflow occlusion was performed "de principle" during parenchymal division and intrahepatic approach of the portal structures; the mean duration of the portal triad clamping was 43 mn (ranged 17 to 70 mn). Group B patients (18 cases) had hilar division of the structures of that portion of the liver due to be removed, prior to parenchymal division was performed without vascular arrest, except in five "de necessitate" cases during 5 to 22 mn. Groups A and B were comparable in terms of patient age or status, of king of liver tumors and extent of resection. Mean operating duration (215 vs 263 mn), volume of intraoperative blood transfusion (557 vs 1019 ml), intensive care (2.5 vs 4.2 days) and total hospital stays (19.6 vs 30.5 days) were significantly reduced in group A. A higher but transient increase of amino-transferase level was the only biochemical consequence of liver ischemia in group A, whereas postoperative disturbance in serum bilirubin, prothrombin time, fibrinogen, and total protein were significantly greater in group B, probably because of the greater volume of blood transfusion in this group. Thus, routine vascular inflow occlusion with transhepatic approach of the portal structures may be an effective and innocuous procedure for major liver resection. PMID:7751341