Renal artery malalignment. Cause for reversible and nonreversible renal allograft artery stenosis.

Two cases of renal allograft artery stenosis secondary to circumferential malalignment of the anastomotic site with the recipient external iliac artery are presented. One stenosis was temporary with apparent resolvement by dilatation of the allograft artery; the other was permanent and required operative correction by patch angioplasty. Circumferential malalignment of the arterial anastomotic site, when the renal artery is placed end to side into the recipient external iliac artery, is proposed as an etiologic mechanism for both temporary and permanent renal allograft artery stenosis. Careful attention to the final position of the graft in the retroperitoneum when the site for arterial anastomosis is chosen will prevent this complication of human renal allotransplantation.