Experimental Studies on Surgery of the Ureter: Part I. Mobilization and Isolation of the Ureter

Choo, Kun Weon; Lee, Hak Song

Abstract

A number of authors have supported and emphasized that mobilization of the ureter even for a short distance, would lead to injury of this structure. Benson stated that careful preservation of the ureteral would supply and avoidance of gross denudation will prevent delayed necrosis and fistula formation. Similarly Masterson, Hamm and Duffy contended that interference with blood supply during mobilization is the most important cause of injury to the ureter. This most likely can happen in Wertheim operation, Bricker's procedure and ureterocutaneostomy. Bricker, a pioneer in the use of ileum, stated that mobilization of the ureter should be carried out no longer than necessary. Usually 5cm being adequate. This amount of mobilization is safe if the blood supply remains intact. In author's clinical experience, ureteral mobilization even for considerable distance has been carried out without ill effect in ureterocutancostomy and Wertheim operation. To investigate the development of ureteral injury during surgery author undertook following experimental work. Experiments were carried out on healthy mongrel dogs weighing from 15 to 20 kg. Intravenous pentothal sodium was used. The ureter was approached through a right paravertebral incision. The dogs were divided into two groups. In the first series of four dogs (Group A), each ureter was meticulously isolated without ligation of vessels. The wound was closed in layers without drainage. During the fifth and eighth postoperative day, the animals were sacrificed and autopsied after intravenous or retrograde pyelography as well as blood hemistry was done. In the second series of four dogs (Group B), each ureter was isolated as in Group A and wrapped in a rubber tube to evaluate the interference with vascular supply. From the 12th to 24th postoperative day, the animals were sacrificed and autopsied immediately after intravenous or retrograde pyelography was done and blood chemistry examined. Group A: No fistula, infection and necrosis of the ureter was found. There was no hydronephrosis, hydroureter or infection. The croscopic section of the ureter and kidney showed no significant changes. BUN and creatinine just before the sacrifice was within normal limit. Group B: Two out of four dogs developed ureteral fistula and ecrosis associated with marked hydronephrosis and hydroureter. The middle third of the ureter in the remaining two dogs showed mild necrosis in association with marked hydronephrosis and hydroureter. In even clinical cases in ureterocutaneostomy and Wertheim operation, the length of the isolation during operation was measured. The average length of mobilization was about seven to twelve centimeter. perative check up with intravenous or retrograde pyelography and blood chemistry on patients in a period of eight weeks and two and one half years were done. Out of clinical cases, there were no ureteral injury. The functional restoration of the kidney was revealed by intravenous or retrograde pyelography and BUN and creatinine follow up examination. Summary 1. Dog ureter can be isolated from the surrounding tissues, for its entire length without developing fistula, necrosis or infection provided the blood supply as left intact. 2. When the ureter is mobilized and wrapped in a rubber tube, dilatation, necrosis and fistula formation is produced. These alterations are most marked at the middle third of the ureter. 3 In eleven clinical cases, the ureter was mobilized between seven to twelve centimeter in ureterocutaneostomy and Wertheim operation, no ureteral injury was found.