Hydronephrosis following aorto-femoral bypass grafts.

Hydronephrosis is reported to be an infrequent late complication of aortofemoral bypass operations. To more clearly define the true incidence of the problem, excretory urograms were performed on 53 asymptomatic patients following successful aortic reconstruction. Unilateral hydronephrosis was found in seven of 50 patients (14%) in whom aortofemoral bifurcation grafts were placed. In each instance, the ureteral obstruction occurred at the point where the ureter crossed the graft limb. Dilatation was mild or moderate in all cases, with no significant deterioration of renal function. All seven patients underwent extensive urologic evaluation and have been followed nonoperatively to date. Hydronephrosis produced in a canine aortic-graft model suggests that a dense fibrotic reaction occurs surrounding the prosthesis, and invades the muscular wall of the ureter. Ureteral obstruction after aortofemoral bypass appears to occur more often than previously thought. Routine pre- and post-operative IVP studies are indicated. If renal function remains good, careful follow-up without re-operation seems warranted.