[Pelvioureteral function after ureterotomy--experimental study simulating endopyeloureterotomy].

Abstract

BACKGROUND: Endopyeloureterotomy has been established as a valuable procedure for ureteropelvic junction or upper ureteral stenosis. In order to evaluate ureteropelvic function after endopyeloureterotomy, I examined electromyographic change in ureteral peristalsis, measured urine bolue volume, and monitored ureteral compliance in dogs following ureterotomy. METHODS: Twelve adult mongrel dogs were anesthetized with pentobarbital, and the upper part of the left ureters was incised longitudinally for a distance of 2 cm. After the incision of the left ureter, a polyurethane splint was inserted through the kidney to the lower part of the ureter and left for four weeks. At 5 (n = 4), 12 (n = 4), and 24 (n = 4) weeks after the operation, electromyography in ureteral peristalsis, urine bolue volume, and ureteral compliance at the incised part of the ureter were investigated. During the measurement of peristaltic frequency and urine bolus volume, saline was infused to the renal pelvis at a constant rate through a nephrostomy. I also investigated these factors in 4 dogs without ureterotomy and defined this group as control. RESULTS: When the infusion rate increased, ureteral peristaltic frequency and/or urine bolus volume gradually increased in the groups of 12, 24 weeks and control group after the operation; in the group of 5 weeks, ureteral peristaltic frequency and bolus volume had not increased significantly. Peristaltic velocity at the incised area decreased significantly at 5 weeks and 12 weeks following the operation compared to the velocity in the control group, but recovered at 24 weeks. Ureteral compliance decreased significantly at 5 weeks compared to that in the incised area of control dog ureter, but increased gradually and recovered at 12 weeks. In the incised ureter the defect was healed with granulation tissue within 5 weeks, and covered by smooth muscle within 12 weeks. CONCLUSION: These results indicate that ureterotomy had harmful effects on ureteral peristalsis 5 weeks following surgery, but that ureteral function generally returned at 12 weeks, and recovered completely at 24 weeks. It was supposed that endopyeloureterotomy would improve ureteral function in patients with ureteropelvic junction and upper ureteral stenosis.