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Biomedical subjects

L Gonzalez-Lavin

Publications and source records attributed to L Gonzalez-Lavin.

At least 55 records · Page 3Linked to original sources

A new bioprosthesis for aortic and mitral valve replacement: preliminary evaluation of the Tascon valve.

The Tascon valve, a new porcine bioprosthesis, features a detachable sewing ring designed to facilitate insertion and removal. Between April 1984 and June 1986, we implanted the Tascon valve in 25 patients, 12 of whom underwent aortic valve replacement (AVR), and 13 of whom had mitral valve replacement (MVR). Most of the patients were in NYHA class III or IV. Four MVR patients had had previous mitral valve operations, and three AVR patients required composite graft valved conduits. The valve's screw-locking mechanism worked well in all cases, especially in the AVR cases. There were no hospital deaths, and no significant morbidity or valve-related complications were encountered. One late death occurred 3 months after surgery, owing to causes unrelated to the valve. At the end of the study period, most of the survivors had improved by at least two NYHA functional classes. Postoperative aortic and mitral valve gradients and mitral valve areas, as measured by Doppler methods, were excellent. No significant regurgitation was detected. These favorable results indicate that the Tascon valve is a safe, useful bioprosthesis, with satisfactory hemodynamic characteristics.

Journal Article↗

Strut fracture and other events after valve replacement with the 60 degree convexoconcave Björk-Shiley prosthesis.

A total of 688 patients received 808 Björk-Shiley prostheses during a 5 year span. Cumulative duration of follow-up totaled 1175.4 patient-years (1368 valve-years). Linearized rates in percent per patient-year for valve-related events (95% confidence limits) were: strut fracture, 0.5 (0.00 to 1.03); infective endocarditis, 0.94 (0.39 to 1.49); thromboembolism, 2.2 (1.37 to 3.052); valve impingement, 0.3 (0.00 to 0.77); and anticoagulant-related hemorrhage, 3.1 (2.15 to 4.14). No valve thrombosis occurred. Actuarial patient survival, including in-hospital mortality, was: aortic valve replacement, 79.8 +/- 3.4%; mitral valve replacement, 71.7 +/- 4.9%; double valve replacement, 59.8 +/- 7.5%. Incremental risk factors for death were age over 65 (p = .001), preoperative infective endocarditis (p = .04), and associated procedures (p = .0002). Although this prosthesis carries a low risk of infective endocarditis and thromboembolism, concern has been raised regarding its structural integrity.

Actuarial Analysis↗

Actuarial survival, freedom from reoperation, and other events after repair of atrioventricular septal defects.

Repair of an atrioventricular septal defect was performed in 134 patients from 1973 to 1985. Interventricular communication was present in 54 (40%) and none was present in 80 (60%). There were 12 hospital deaths (9%; 70% confidence limits 6%-12%). Earlier date of operation (p = 0.03) and younger age at repair (p = 0.005) were incremental risk factors for hospital death after repair of partial atrioventricular septal defect. Smaller size (p = 0.003) and longer cross-clamp time (p = 0.002) were risk factors for hospital death in those patients with complete atrioventricular septal defect. Higher preoperative pulmonary vascular resistance was a risk factor for death in both groups (p = 0.007). The 10 year actuarial survival rate was 82% overall. Increasing preoperative severity of left atrioventricular valve incompetence was not a risk factor for early (p = 0.001) or late (p = 0.002) death. The 10 year actuarial freedom from reoperation after repair of partial atrioventricular defects was 85%, and it was 68% for complete atrioventricular defects (p = 0.06). We conclude that the intermediate term results after repair of atrioventricular septal defects are good. Incompetence of the left atrioventricular valve has apparently been neutralized as a risk factor for hospital death in this series. However, the durability of the repair has been disappointing. A policy of earlier repair has been adopted and should improve hospital mortality and permit better preservation of the atrioventricular valve structures with resultant improved late term functional status.

Actuarial Analysis↗

Clinical results after bioprosthetic aortic valve replacement in patients with and without coronary artery disease: value of concomitant myocardial revascularization.

The present study analyzes a 7-year experience of two concurrent groups of patients, one with and one without coronary artery disease. These groups underwent aortic valve replacement within the same time frame. They had the same method of myocardial protection and type of valve substitute, and there was no postoperative anticoagulant therapy. There was no statistically significant difference in hospital and late mortality, or in actuarial survival of the two groups after 4 years. Bypass grafting in patients with coronary artery disease undergoing aortic valve replacement reverts these groups of patients to the longterm prognostic level of patients with isolated aortic valve disease undergoing aortic valve replacement.

Journal Article↗

Thromboembolism and bleeding after mitral valve replacement with porcine valves: influence of thromboembolic risk factors.

The risk of postoperative thromboembolism (PTE), anticoagulant related hemorrhage (ARH), and the influence of thromboembolic risk factors ( TERF ) were assessed retrospectively in 206 unselected patients undergoing mitral valve replacement (MVR) with porcine xenobioprotheses ( PXBP ). Other aims were to identify the "high-risk" group with respect to PTE and to assess the effectiveness of long-term anticoagulant therapy (AT) in this subset, as well as to elucidate the most adequate method of AT and ascertain if AT is strictly necessary in patients undergoing MVR with PXBP . Patients were divided in two groups: Group I (N = 115) received long-term AT; there were 22 PTE. Group II (N = 91) with only 8 weeks of AT had 2 PTE (P less than 0.01). ARH was the same in both groups. Actuarially , 71.7% of the patients in group I and 96.3% of the patients in group II were free of PTE at 6 years. Long-term AT proved ineffective in preventing PTE and carried a significant incidence of ARH. ARH surpassed PTE (3.5:1) in patients on short-term AT. Patients without TERF have a low incidence of PTE, and AT is not indicated. The "high-risk" group were patients in postoperative atrial fibrillation and left atrial enlargement. One week heparin therapy and 3 months oral AT is suggested for patients with TERF . PXBP for MVR in patients with TERF is significantly thrombogenic. Early operation is advocated to avoid development of TERF that will affect patient outlook after MVR with PXBP due to the significantly increased risks of PTE and (if placed on AT) ARH.

Adult↗

Tricuspid valve obstruction due to intravenous leiomyomatosis.

A case is discussed of a 65-year-old woman who presented with tricuspid stenosis. She was evaluated with multiple imaging techniques including gated radionuclide angiography, cardiac sector scanning, and abdominal CT imaging. A review of the literature of the entity known as intravenous leiomyomatosis is presented.

Abdominal Neoplasms↗

Thrombosis of an aortic porcine xenobioprosthesis associated with familial antithrombin III deficiency.

Thrombosis of a porcine xenobioprosthesis in the aortic position associated with antithrombin III deficiency has not been reported. Admittedly a rare coagulation abnormality, it should be suspected in patients with previous tendencies or family history toward spontaneous thrombosis, especially in those with Scandinavian ancestry. Special precautions should be taken if a cardiac operation becomes necessary.

Antithrombin III Deficiency↗

The risk of thromboembolism and hemorrhage following mitral valve replacement. A comparative analysis between the porcine xenograft valve and Ionescu-Shiley bovine pericardial valve.

To ascertain the risk of thromboembolism and anticoagulant-related hemorrhage following mitral valve replacement with bioprostheses, an 8 year retrospective study between two groups of patients was analyzed. Group I included 206 patients undergoing mitral valve replacement with porcine xenograft valves. They were placed on a regimen of long-term oral anticoagulation (greater than 8 weeks, mean 6 months). Follow-up was 524.3 patient-years, mean 30.5 months. There were 24 thromboembolic events (4.6% per patient-year), four of which were fatal. Actuarially, 80.7% +/- 4.3% are free of thromboembolism at 8 years. There were 12 instances of major bleeding episodes, for a linearized incidence of 2.5% per patient-year; two were fatal. Group II included 322 patients undergoing mitral valve replacement with a bovine pericardial valve. They were placed on a program of short-term anticoagulation (6 weeks only). Follow-up was 1,106 patient-years, mean 46.4 months. There were four thromboembolic episodes (none fatal), an incidence of 0.36% per patient-year. Seven bleeding episodes occurred, 0.63% per patient-year; none was fatal. The difference between the groups reached statistical significance (p less than 0.001). The low risk of thromboembolism with the bovine pericardial valve appears to be due to its superior hydraulic characteristics. Use of this valve allows mitral valve replacement without long-term oral anticoagulation and the associated risk of anticoagulant-related hemorrhage.

Adolescent↗

Surgical treatment of ventricular septal rupture and mitral regurgitation complicating acute myocardial infarction: report of a case and review of the literature.

Coexisting ventricular septal rupture (VSR) and severe mitral regurgitation following myocardial infarction is rare; only ten cases have been documented in the English literature. Present refinements in myocardial preservation and surgical techniques have markedly improved the results of surgery in this group of desperately ill patients. Early repair of both lesions is advocated and exemplified by a case report.

Aged↗

Five-year experience with the Ionescu-Shiley bovine pericardial valve in the aortic position.

Between February, 1977, and April, 1982, 168 patients underwent aortic valve replacement (AVR) with an Ionescu-Shiley bovine pericardial valve. Concomitant procedures were performed in 71 patients. There were 12 hospital deaths (7.1%). Among patients having AVR only, there were 5 deaths (5.2%). Assessment included valve durability, incidence of thromboembolism, clinical improvement, and patient survival. There was 100% follow-up. Actuarial freedom from intrinsic valve failure at 5 years was 96.3 +/- 3.6%. Intrinsic valve failure occurred only once, 0.3 episodes per 100 patient-years. Four patients had thromboembolic complications. As for clinical status, 99.3% of surviving patients are in New York Heart Association Functional Class I or II, including 79 patients with valve sizes 17, 19, or 21 mm (56%). Among 13 late deaths, 9 were related to the cardiovascular system. Overall patient survival is 84.9 +/- 4.7%. Among the 92 patients with isolated AVR, 87.8 +/- 5.9% are alive at the 5-year follow-up. If the incidence of valve failure is not altered in years to come, the durability of the Ionescu-Shiley bovine pericardial valve will surpass that of previous bioprostheses.

Actuarial Analysis↗

Calcified aortic plug syndrome.

Five women are described with an extremely rare manifestation of atherosclerosis. All presented with upper extremity hypertension and diminished femoral pulses. Three had intermittent claudication. Plain radiography and arteriography demonstrated focal, heavily calcified, mass-like, obstructing lesions that caused a functional coarctation of the aorta. These lesions involved both the thoracic and abdominal aorta. Three patients had visceral artery involvement. Atherosclerosis was diagnosed in the four patients who underwent endarterectomy or bypass surgery.

Adult↗