Biodegradation and Aneurysm Formation in Umbilical Vein Grafts

Abstract

In a series of 756 glutaraldehyde-stabilized umbilical vein grafts implanted over a 7 1/2-year period, aneurysms were identified in seven cases. The earliest aneurysm was seen at 31 months after implantation and the remainder between 43 and 79 months after surgery. Corrective surgery was performed in five cases and succeeded in four. Although definite mechanisms have not been identified, mechanical fatigue, reversal of aldehyde crosslinks, and immunologic factors may be operative. The pathologic changes include: (1) actual dilation of both graft and mesh with or without intraluminal thrombus and, (2) maintenance of graft diameter with erosion of the umbilical vein and polyester mesh rupture leading to perigraft hematoma and false aneurysm formation. Microscopic examination and infrared spectral analysis confirmed the presence of host-contributed lipid in some specimens. Although this is a low incidence of aneurysm formation, umbilical vein grafts should be selected primarily for patients with limited life expectancy or for whom alternative materials with comparable or superior patency rates are not available or acceptable. Periodic angiography, particularly after 3 or 4 years, is recommended as a routine part of follow-up examinations. Improved graft materials and control of host environmental factors are potential means to reduce the noted degradation.

Aneurysm Formation and Perforation in Glutaraldehyde-Tanned Umbilical Vein Grafts

“…'2 However, aneurysm formation remains a major concern in all types of biologic material used as arterial substitutes. Although Dardik' claimed retention of the original HUV graft structure for periods as long as four years, aneurysm development within functioning HUV prostheses has been repeatedly reported.6-9 In 1982, Giordano first published 3 cases of dilatation in HUV grafts.6 In 1984, Dardik reported 9 cases of HUV aneurysm formation, 8 Layer' 3 cases, and Hirsch 13 2 cases. In 1985, Boontye'4 described 9 HUV aneurysms and Hafnerl5 5 further aneurysms.…”

Mural degeneration in the glutaraldehydetanned umbilical vein graft: Incidence and implications

“…When the results of these two series are combined, the incidence of GTUV aneurysms rises from 14% (5 of 34 grafts) at 2 to 4 years to 53% (7 of 13 grafts) at 4 to 6 years (p = 0.01). Cranley et al) 8 have recently reported that patent GTUV grafts studied by ultrasonography 5 or more years after implantation had a 44% incidence of frank aneurysm (grade 3 change) and a 34% incidence of diffuse dilation (presumably grade 2 change).…”

Chemically Fixed Human Umbilical Cord Vein Grafts as Arterial Substitutes: Potential and Limits

“…The stability of the processed human um bilical vein is less than expected since fail ures, aneurysms and other problems in com mercially available grafts such as Dardik Bio graft and Mindich Bioflow® have been re ported [34,38,[39][40][41], Although minimized by Dardik et al [42]. they raise serious doubts on the long-term prognosis of the pro cessed human umbilical vein [43].…”