Causes of failure and pathologic findings in surgically removed Ionescu-Shiley standard bovine pericardial heart valve bioprostheses: emphasis on progressive structural deterioration.

Abstract

Twenty-three lonescu-Shiley standard bovine pericardial bioprostheses (15 aortic, seven mitral, and one tricuspid) removed at surgery from 21 adults, 28 to 75 years old (mean 55 at reoperation), were examined after functioning for as long as 84 months (mean 26 BIOPROSTHESES fabricated from glutaraldehydepretreated porcine aortic valves or bovine pericardium are commonly used to replace diseased human cardiac valves. Primary tissue degeneration due to intrinsic cuspal calcification is the most frequent cause of failure of porcine aortic valve bioprostheses. [1][2][3][4][5] Commercially prepared glutaraldehyde-preserved bioprosthetic heart valves fabricated from bovine pericardium, introduced into general clinical practice in 1976, are now widely used. Actuarially determined freedom from primary tissue failure of the popular Ionescu-Shiley standard pericardial valve has been variably reported to be 60% at 6 years,6 80% to 95% at 6 years,7-and 90% at 11 years.

Bioprosthetic Heart Valves: Impact of Implantation on Biomaterials

“…Butany et al [28] in their study of 24 explanted ISLP and others [26,30] observed that primary tissue failure and tears were the predominant mode of failure in ISLP. This was followed by infective endocarditis, thrombus, paravalvular leak, and pannus overgrowth ( Figure 9).…”

“…It had a commissural suture ("alignment suture"), through-and-through stitch at the top of the cusps at each stent post, to hold the adjacent cusps together at the stent (site of highest compressive stress) and to align the cusp free margins with one another. This valve had good hemodynamics but failed prematurely due to factors related to its design, that is, abrasion-related damage at the alignment suture [26].…”

“…Walley et al also observed holes in the cusp away from the stitch site, which could be related to the fact that once tear develops at the stitch site, the cuspal tissues lose their normal fixation and become more prone to abrasive injuries. It was concluded that the alignment stitch was the focus of mechanical stress and degenerative changes in ISS valves [26]. In addition, Schoen et al [26] observed small thrombi at the base of the cusps and inflammatory cells below the cusp surface and near calcific deposits.…”

“…It was concluded that the alignment stitch was the focus of mechanical stress and degenerative changes in ISS valves [26]. In addition, Schoen et al [26] observed small thrombi at the base of the cusps and inflammatory cells below the cusp surface and near calcific deposits.…”

“…The absence of basal tears could be due to different types of cloth (Microvel Dacron) used to cover the stent. On the other hand, this cloth was associated with exuberant pannus overgrowth on ISLP as compared to ISS [26,33]. Butany et al [34] have reported a case in which ISLP valve survived up to 15 years, where pannus had covered the entire stent (both surfaces) and the cusps thus reducing friction and protecting the valve cusp.…”