The functional and structural effects of hypothermic storage on ischaemic arterial grafts.

The effects of hypothermic ischaemia on blood vessels are unknown. This study aimed to determine the 3 week patency rate and the pathology of 9 experimental groups of hypothermically stored ischaemic arteries and one control group in a rabbit femoral artery model. Ischaemia times were 0 h, 24 h, 1, 2, 4, 6, 8 and 10 weeks (Groups 1-8). Patency was over 80% in all groups after 3 weeks reinsertion. Following reinsertion control grafts maintained normal arterial structure, but cellular degeneration had occurred in all ischaemic grafts and appeared complete after 4 weeks ischaemia. The graft connective tissue framework frequently remained intact. Repair was evident in central graft regions after 2 weeks ischaemia and 3 weeks reinsertion, but occurred only adjacent to the anastomosis in 4-10 week ischaemic arteries. Four week ischaemic arteries (Groups 9 and 10) reinserted for 6 and 12 weeks respectively exhibited near complete repair but patency dropped to 60% in the 12 week group.