Vascular integrity of the distal ureter following combined tapering and cross trigonal reimplantation.

Massive unilateral hydroureteronephrosis was created in 20 female dogs by ligating the urographically normal prevesical ureter. Over a 14-day period the obstructed ureter dilated to an average of 15.3 mm. A ureteral tapering procedure was performed by lateral darting and posterior folding of the resultant flap, followed by a cross-trigonal reimplantation. One anastomotic stricture resulted; in the remaining 19 animals, ureteral peristalsis was restored, the ureteral diameter was reduced 61.9 per cent and hydronephrosis was resolved. Histological studies on the tapered segments of these 19 animals showed that the subadventitial blood supply was preserved with fibrotic occlusion of the folded flaps. These results demonstrate that no significant vascular compromise after ureteral tapering and cross-trigonal reimplantation occurs. Success rates comparable to those of conventional ureteral tailoring can be achieved by this technically simplified form of reconstructive surgery.