[Experimental study of the modified human saphenous vein as a small caliber arterial substitute]

The present study was designed to experimentally evaluate the efficacy of the modified human saphenous vein as a small caliber arterial substitute. In the process of vein preparation, digestion with proteolytic enzyme, ficin, was mandatory in order to increase the diameter of cadaveric veins. However, the tensile strength of the graft was necessarily reduced as the digestion progressed. The optimal time of digestion, therefore, was determined as 60-90 min. For the tanning, 1.5% glutaraldehyde was used. The veins harvested from mild varicose patient seemed to offer a good material, because the varicose veins also exhibited enough strength in the tensile stress test. Twelve glutaraldehyde tanned human saphenous veins (Group A), fourteen ficin treated glutaraldehyde tanned human saphenous veins (Group B) and ten Gore-Tex (Group C) were implanted to the canine abdominal aorta. The patency rate was 83% in Group A, 85% in Group B, and 80% in Group C. One graft in Group B developed a false aneurysm and another was markedly dilated. In Group C, four grafts were calcified about one year following implantation. In contrast with these, in Group A, there was no aneurysm or thrombus formation and the graft surface was very smooth. Therefore, it is reasonable to conclude that glutaraldehyde tanned human saphenous veins (Group A) can be reliably used as a small caliber arterial substitute.