ISSN:0886-0440    

DOI:10.1111/j.1540-8191.1992.tb00785.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractLeft atrial appendage aneurysm is a rare anomaly, which usually presents with arrhythmia or cerebral embolism. Diagnostic evaluation traditionally required cardiac catheterization, and surgical resection required cardiopulmonary bypass. Utilizing intraoperative transesophageal echocardiography and surgical stapling devices, we have streamlined our operative technique, allowing resection of a left atrial appendage aneurysm without cardiopulmonary bypass. This report of two cases treated over the past decade demonstrates the evolution of our surgical technique.

ISSN:0886-0440    

DOI:10.1111/j.1540-8191.1992.tb00786.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe use of the patient's pulmonary valve for replacement of the patient's diseased aortic valve was introduced and developed by Mr. Donald Ross. Its demonstrated durability, freedom from thromboembolism, and potential for growth has led to increased utilization of this technique. Modifications of the earlier techniques have led to a reproducible operation with low operative risk and excellent mid‐term result

ISSN:0886-0440    

DOI:10.1111/j.1540-8191.1992.tb00787.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe problems encountered in coronary artery reattachment when the ascending aorta and aortic valve are replaced with a composite graft induced Gallucci and one of the authors to develop a new aortovalvular prosthesis in clinical practice. The unique transverse ovoidal shape of this graft is intended to conform to the natural aortic root and facilitate the coronary anastomoses and minimize bleeding. We present our 6‐year experience with 56 patients operated upon with this prosthesis. In all patients we were able to connect the coronary arteries directly to the graft without complications including hemorrhage or distortion of the coronary ostia. The survivors were evaluated with chest X ray, two‐dimensional echocardiography, and conventional or digital subtraction angiography to detect the presence of pseudoaneurysms at the site of the coronary anastomosis, reported by others that have used the composite graft technique. The notable absence of this complication in our patients at a mean follow‐up of 41 months (range 3–71) documents that this ovoidal composite graft is a reliable tool in the treatment of aortic root pa

ISSN:0886-0440    

DOI:10.1111/j.1540-8191.1992.tb00788.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractLung transplantation has now become an established form of treatment for end‐stage pulmonary parenchymal and vascular diseases. Despite its wide acceptance, technical aspects are still in discussion. We report on the initiation of our own lung transplant program and the technical changes we have performed during our first 1 ½‐year experience. During that period of time, we have performed 26 lung transplantations (16 single lung [SLTX] and 10 bilateral lung transplantations [BLTX]). Three‐month survival for the whole group was 74% (69% for the SLTX group and 77% for the BLTX group). No instance of bronchial dehiscence was observed; however, there were eight cases of bronchial stenosis: six were managed by silicone stent insertion, one by bronchoplastic correction, and one by retransplantation. Changes in the technique of the bronchial anastomosis together with the addition of prednisone to the immediate postoperative immunosuppressive regime resulted in almost complete avoidance of these pr

ISSN:0886-0440    

DOI:10.1111/j.1540-8191.1992.tb00789.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractDespite widespread use of hypothermic circulatory arrest (HCA) in aneurysm surgery and for repair of congenital heart defects, there is continued concern about possible adverse cerebral sequelae. The search for ways to improve implementation of HCA has inspired retrospective clinical studies to try to identify risk factors for cerebral injury, and clinical and laboratory investigations to explore the physiology of HCA. At present, risk factors associated with less favorable cerebral outcome after HCA include: prolonged duration of HCA (usually>60 min); advanced patient age; rapid cooling (<20 min); hyperglycemia either before HCA or during reperfusion; preoperative cyanosis or lack of adequate hemodilution; evidence of increased oxygen extraction before HCA or during reperfusion; and delayed reappearance of electroencephalogram (EEG) or marked EEG abnormality. Strategies advocated to increase safety of HCA include: pretreatment with barbiturates and steroids; use of alpha‐stat pH regulation during cooling and rewarming; intraoperative monitoring of EEG; slow and adequate cooling, including packing of the head in ice; monitoring of jugular venous oxygen content; hemodilution; and avoidance of hyperglycemia. Current investigation focuses on delineating the relationship of cerebral blood flow (CBF) to cerebral oxygen consumption and glucose metabolism during cooling, HCA, rewarming, and later recovery, and identifying changes in acute intraoperative parameters, including the presence of intracerebral enzymes in cerebral spinal fluid, with cerebral outcome as assessed by neurological evaluation, quantitative EEG, and postmortem histology. Clinically, intraoperative monitoring of EEG and measurement of CBF by tracer washout or Doppler flows are contributing to better understanding of the physiology of HCA, and in the laboratory, nuclear magnetic resonance (NMR) spectroscopy has provided valuable insights into the kinetics of intracerebral energy metabolism. Promising strategies for the future include investigation of other pharmacological agents to increase cerebral protection, and use of “cerebroplegia” or intermittent perfusion between intervals of HCA to improve cerebral tolerance for longer durations o

ISSN:0886-0440    

DOI:10.1111/j.1540-8191.1992.tb00790.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe ideal prosthetic conduit for surgical repair of complex congenital heart disease has yet to be found. Twenty conduits were implanted between the right ventricle and pulmonary artery in growing sheep as follows: four Dacron porcine valve conduits (mean time in place, 142 days); four avalved glutaraldehyde‐fixed bovine iliac veins (mean 132 days); and 12 glutaraldehyde‐fixed bovine iliac veins containing a porcine valve (mean 180 days). Fifteen conduits were left in place from 167 to 244 days (mean 204 days), and five were explanted earlier (mean 54 days). Pathological study included gross, x‐ray, histological, and ultrastructural investigation. Five conduits failed because of infective endocarditis. The valved Dacron conduits showed significant tissue ingrowth and calcification of the valve graft. The valved bovine iliac veins presented calcification at the valve level and vein wall, as well as a valvelike calcific fibrous ridge at the proximal anastomosis with the right ventricle. The avalved bovine iliac veins also presented calcific deposits along the wall and a valvelike calcific ridge at the ventricular anastomosis. Histological and ultrastructural studies of the vein tunica media revealed the phenomena of inflammatory rejection and foreign body reaction with loss of smooth muscle cells (medionecrosis) and fibrotic replacement. In conclusion, bovine iliac veins undergo inflammation with medionecrosis indicating that smooth muscle cell antigenicity is not attenuated by glutaraldehyde fix

ISSN:0886-0440    

DOI:10.1111/j.1540-8191.1992.tb00791.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractA canine femoral artery model was used for evaluation of a dialdehyde starch preserved bovine internal mammary artery (BIMA) (3 and 4 mm internal diameter) in comparison to a polytetrafluoroethylene (PTFE) graft. The study comprised three groups for a 2‐hour (n = 7, 3 mm), 3‐month (n = 10, 4 mm), and 6‐month (n = 10, 4 mim) follow‐up. The thrombogenicity of the grafts was measured after 2 hours and 3 months using chromium 51 labeled autologous platelets. In addition, compliance studies were done. To control the wall stability of the xenografts, the collagen content before implantation and after explantation was examined together with the diameter of the grafts. Healing characteristics were studied using appropriate histologic methods. The acute platelet adhesion rate (2 hours) of the BIMA graft was 181 ± 69 × 104platelets/mm2as compared to 57 ± 43 × 104for PTFE (p<0.05, t‐test). However, after 3 months the thrombogenicity of the biograft had decreased whereas the platelet count at the PTFE graft had increased (BIMA: 79 ± 48 × 104; PTFE: 179 ± 102 × 104, p<0.05). At implantation, the compliance of the BIMA graft was 0.028%± 0.009% per mmHg as compared to 0.06%± 0.0025% of the femoral artery. The PTFE graft was uncompliant (0.008 ± 0.005). After 6 months, the compliance of the femoral artery had decreased to 0.039%± 0.013% per mmHg, which was now well matched to the nearly unchanged compliance of the biograft (0.0027 ± 0.005). The external diameters and the collagen contents of the xenografts remained unchanged. In contrast to PTFE, the xenografts developed no diameter‐reducing neointima. After 6 months, six out of ten BIMA grafts and only two out often PTF

ISSN:0886-0440    

DOI:10.1111/j.1540-8191.1992.tb00792.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThere have been numerous attempts to develop prosthetic conduits or utilize al‐lograft saphenous veins for arterial bypass. This article summarizes our experimental and clinical experience with cryopreserved allograft saphenous veins. During these studies, particular attention was paid to vein donor postmortem ischemia time, vein procurement technique, and tissue storage methods. Experimental cryopreserved autograft studies demonstrated that cryopreservation of the veins does not alter subsequent graft patency, the arterialization process, blood flow, or platelet deposition in vein grafts. Endothelium‐derived relaxing and contractile factors are produced by the endothelium of explanted cryopreserved autografts, and smooth muscle contractions and relaxations can be induced. In experimental cryopreserved al‐lografts, the endothelium appears to be removed by an immune response during the first 10 days after transplantation, fibrin deposition is minimal, and re‐endothelialization occurs over 6–9 months. Early clinical results using cryopreserved allograft saphenous veins are encouraging with 1‐year patency rates of 79% for peripheral grafts and 86% for coronary by

ISSN:0886-0440    

DOI:10.1111/j.1540-8191.1992.tb00793.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractIn order to address questions related to cell/biomaterial interactions with respect to cell function and production of extracellular matrix proteins that support or maintain cell/tissue specific properties, we have developed molecular approaches for analysis of in vivo implanted materials and in vitro studies. In an explant of a human left ventricular assist device (LVAD), intact total cellular RNA could be isolated in sufficient quantities for hybridization analyses with gene‐specific probes to evaluate cell growth, cytoskeletal organization, and production of extracellular matrix proteins. Cells harvested from a 132‐day implanted LVAD exhibited proliferative activity and expressed genes for fibronectin and collagen types I, III, and IV. In vitro studies revealed that endothelial cells cultured on two different segmented polyurethane biomaterials (Biomer and Tecoflex 60D) exhibited different patterns of gene expression that reflected differences in cell growth rates, morphology, and composition of the extracellular matrix. These methodologies provide a valuable approach for a detailed evaluation of: (1) the biocompatibility of cells colonizing implanted cardiac assist devices; and (2) the functionality of cells seeded onto biomateri

ISSN:0886-0440    

DOI:10.1111/j.1540-8191.1992.tb00794.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY