Ureteroscopic and scanning electron microscopical findings in ureteral anastomoses after segment resection

In an experimental study on 8 canine ureters, end-to-end anastomoses were performed after segmental resection between 9 and 13 cm, using two different surgical techniques. After 3 months of observation the three-dimensional structure of the anastomosis and the surrounding areas was investigated by ureteroscopy and scanning electron microscopy. 3 types could be differentiated by the morphologic features of the ureteral lumen: normal width, segmental stricture, and circumferential stricture. The results offer a plausible explanation for the occasional discrepancy between histologic findings of relatively normal lumen width, and functional disorders apparently reflecting ureteral stenosis. They further support that excellent functional and morphologic reconstruction can be achieved even under the extreme conditions of 13 cm segmental resection with obligatory anastomosis under tension. The findings connected with dilatations observed distal to the anastomotic site appear rather contradictory, their interpretation is difficult.