Prevention of transplant renal artery stenosis.

Transplant renal artery stenosis occurred in 17 of 142 consecutive transplants (12 percent). All stenoses were in the renal artery distal to the anastomosis and two separate forms are recognized: angulation and segmental stenosis. Successful surgical correction in 12 of 17 patients relieved the hypertension and resulted in improved renal function. No patients receiving dipyridamole, a drug which inhibits platelet aggregation and intravascular fibrin deposition, developed segmental renal artery stenosis. No other factors could be identified which were important in either causing or preventing renal artery stenosis. Since intrarenal vascular changes are an integral aspect of rejection, the protection afforded by dipyridamole against segmental renal artery stenosis indicates that segmental stenosis is probably a manifestation of rejection.