Modified Human Ureter and Human Saphenous Vein Grafts Tanned with a Polyepoxy Compound or Glutaraldehyde for Small-Diameter Arterial Substitution

Abstract

The polyepoxy compound is a new cross-linking agent that is now replacing glutaraldehyde, and human ureter is a new potential substitute for small-caliber arterial prostheses. The present study was performed to compare the use of human ureter grafts tanned with a polyepoxy compound, human ureter grafts tanned with glutaraldehyde, and human saphenous vein grafts tanned with a polyepoxy compound for small-diameter arterial substitutions. Human ureter grafts tanned with a polyepoxy compound (n= eight), human ureter grafts tanned with glutaraldehyde (n=six), and human saphenous vein grafts tanned with a polyepoxy compound (n=eight) were implanted in the carotid arteries of Japanese white rabbits. These grafts were sacrificed after either 1 month's or 6 months' observation. There was no evidence of rejection, aneurysmal formation, and/or infection. Human ureter gcafts tanned with a polyepoxy compound after 1 month's observation (n=six) showed excellent patency without stenosis at the anastomotic sites as well as function, and the histologic findings revealed monolayer endothelial-like cells covering the surface of the graft. Human ureter grafts tanned with glutaraldehyde after 1 month's observation (n=six) were completely occluded with severe intimal hyperplasia. Human saphenous vein grafts tanned with a polyepoxy compound after 1 month's observation (n= six) were patent at the time of explantation, but moderate stenosis caused by intimal hyperplasia at the anastomotic sites was observed. The preliminary data also suggest that, with longer observation of up to 6 months, human ureter grafts tanned with a polyepoxy compound (n=two) showed excellent patency. However, a longer observation of up to 6 months for human saphenous vein grafts tanned with a polyepoxy compound (n=two) revealed severe intimal hyperplasia with intramural thrombosis and/or severe calcification. This study suggests that human ureter grafts tanned with a polyepoxy compound could serve as more satisfactory bioprostheses for the reconstruction of smallcaliber vessels than human ureter grafts tanned with glutaraldehyde or human saphenous vein grafts tanned with a polyepoxy compound.