Replacement of heart valves with frame-mounted tissue grafts

Abstract

patients had heart valve replacement with frame-mounted autologous or homologous fascia lata or with heterologous pericardial grafts. There were 111 single aortic, 95 single mitral, and seven tricuspid valve replacements.The incidence of hospital and late mortality was each 10% for the entire series and the main causes were myocardial failure and infective endocarditis.The majority of patients obtained significant symptomatic improvement. In patients with aortic replacement there was a statistically significant reduction in cardiothoracic ratio and in the voltage of the electrocardiogram.Regurgitant murmurs developed in 11 6y% of aortic patients and in 51'6% after mitral replacement (in 37-5 % the murmur has not increased in intensity while in 14-1 % it has gradually progressed). None of these mitral patients requires reoperation. Grafts in the tricuspid position have not shown signs of dysfunction or failure. Graft failure has not occurred in the aortic replacement series. From the mitral position six grafts have been removed due to failure. All six were made of autologous fascia and all showed varying degrees of thickening and retraction of cusps. There were six episodes of peripheral embolization (five transient) and one left atrial thrombosis. All seven patients are alive. Anticoagulants were not used.The results of haemodynamic studies and in vitro hydrodynamic experiments are discussed and an explanation for graft dysfunction in the mitral position is presented.The actuarial analysis of this series of patients over a period of up to 54 months postoperatively has shown encouraging results.

An Inverse Numerical Approach for Modeling Aortic Heart Valve Leaflet Tissue Oxygenation

“…The fibrosa covers the whole leaflet and is made up of almost 50% collagen (90% Type I) by dry weight and 10% elastin. 3,13 The ventricularis covers the entire leaflet surface except the coaptation region and contains almost 50% collagen (90% Type I) and 20% elastin. 9 The ventricularis is a jelly-like layer composed mainly of glycosaminoglycans (GAGs).…”

Search for the best heart valve- from replacement to repair

“…1), and have covered the stented autograft with pericardium. This stent was earlier used for housing the fascia lata valve [28]. Pericardium was wrapped around the stent, which helped in excluding the stent totally from the blood stream (Fig.…”

Prosthetic aortic heart valves: Modeling and design

“…Heart valve replacement, pioneered in the early 1960s [4], is now a routine surgical procedure that employs devices made of synthetic biomaterials for substitution of the valvular mechanical functions. Replacement of heart valves offers an excellent improvement in the quality of life for thousands of patients and can be considered one of the major accomplishments of biomedical engineering.…”

“…The fibrosa covers the whole leaflet and consists of almost 50% collagen (90% Type I collagen) by dry weight and 10% elastin [3,4]. The ventricularis covers all but the coaptation region where two adjacent leaflets contact and consists of almost 50% collagen (90% Type I collagen), 20% elastin [2].…”