Functional angiographic evaluation of individual, sequential, and composite arterial grafts.

Background: To help optimize graft arrangement, we examined the effects of target vessel characteristics, conduit type, and interactions between the target vessels on the occurrence of flow reversal or occlusion.

Methods: The postoperative angiograms of 458 patients after total arterial revascularization with an off-pump, no aortic manipulation technique beginning in December 2000 were reviewed. Reverse flow was defined as the lack of opacification of a distal anastomotic site during graft angiography, but clear retrograde graft opacification during native coronary angiography. We analyzed characteristics of the target coronary branches, and bypass conduits. The potential interactions between coronary branches and sequential anastomoses were categorized as those with two 75% stenotic branches (situation 1); one 75% stenotic branch at the end of the graft and a 99% to 100% stenotic branch at the middle of the graft (situation 2); and a composite Y (or K) graft with one end to a 75% stenotic branch and the other to a 99% to 100% stenotic branch (situation 3).

Results: A total of 18 bypasses (1.1%) were occluded while reverse flow was found in 4.5% (74 of 1,627). In a multivariate analysis of the 521 bypass conduits having more than two distal anastomoses, the predictors of reverse flow or occlusion were a right coronary artery target with 75% or less stenosis (p = 0.006), more than three distal anastomoses with a conduit (p = 0.005), situation 1 (p = 0.04), situation 2 (p < 0.0001), and situation 3 (p < 0.0001).

Conclusions: Interactions between coronary branches and graft arrangement play important roles in flow distribution. Graft arrangement should be adjusted for each patient to minimize reverse flow.