Effect of compliance mismatch on vascular graft patency

The hypothesis that a mismatch in compliance between a vascular graft and its host artery is detrimental to graft patency was tested by implanting paired arterial autografts, prepared with differential glutaraldehyde fixation of carotid arteries in the femoral arteries of dogs. These grafts differed only in circumferential compliance: they were 100% (compliant) vs. 40% (stiff) as compliant as the host artery. Their flow surfaces were equivalent, as determined by physicochemical measurements and scanning electron microscopy; both lacked viable cells, as determined by in vitro cell culture. In 14 dogs, eight stiff and two compliant grafts became occluded within 3 months, the latter doing so within 24 hours after their contralateral counterparts. Cumulative patencies were 85% and 37% for compliant and stiff grafts, respectively (p less than 0.05) and 100% and 43%, excluding the two dogs with bilateral graft failures (p less than 0.01). We conclude that even with near optimal flow surfaces, compliance mismatch is deleterious to graft patency.