Does the Geometry of a Distal Vein Graft Anastomosis Affect Patency?

Abstract

Between January, 1988, and December, 1992, 336 autogenous vein bypasses were performed on the vascular service at The University of Iowa Hospital. Routine color duplex surveillance (CDS) identified 25 bypasses with a significant distal anastomotic stenosis that developed between one and thirty-one months postoperatively (mean nine months). These 25 „failing bypasses” underwent a revisional procedure following arteriographic confirmation of the location and severity of the lesion. The intraoperative completion arteriograms performed at the time of the original bypass procedure of these revised bypasses were critically analyzed. The length of the distal anastomosis, as well as the diameter of the distal vein conduit and artery (proximal and distal to the anastomosis) were measured in each case. In addition any anastomotic defect seen on the original intraoperative completion arteriogram was also noted. This same analysis was done for 50 consecutive vein bypasses that have remained primarily patent for two years or more and had normal duplex surveillance studies. Vein/artery diameter, anastomotic length/artery diameter, anastomotic length/vein diameter ratios were calculated for both the groups. Demographic characteristics, risk factors (diabetes mellitus, hypertension, coronary artery disease, renal failure, chronic obstructive pulmonary disease), indications for surgery, type of venous bypass conduit, and the outflow of the bypasses were comparable between these two groups. The results are depicted in the following table: [Table: see text] These data indicate that the geometry of the distal anastomosis does not play a significant role in the development of distal anastomotic stenosis. An uncorrected anastomotic defect on the completion arteriogram is a risk factor for bypass failure. Hence, patients with such defects should have these lesions corrected when they are initially identified at the time of the initial bypass procedure.