Experimental Studies on Surgery of the Ureter: Part III. Homologous Ureteral Transplantation

Choo, Kun Weon; Lee, Hak Song

Abstract

Short gaps in the ureter may be spanned by uretero-ureterostomy, or if in proximity to the bladder, by uretero-neocystostomy Longer defects defy such anastomoses and most surgeons have employed nephrostomy, ureterostomy and cutaneous ureterostomy or uretero-sigmoidostomy in this condition to avoid further damage to the affected kidney. These procedures are not ideal, do not solve the problem of reconstructing the ureter and often lead to a diminution of renal function. For the past several decades investigators have attempted to insert or construct a conduit that could adequately substitute for the ureter. For this purpose, inorganic tubes of polyethylene, vitallium, tantalum and autogenous tissues such as ileal loops, oviduct, bladder flaps and blood vessel grafts have been utilized without success. In 1954, Hardin attempted to reconstruct the ureteral detect by homologous ureteral transplantation. He concluded that homologous ureteral grafts failed because of stenosis, dehiscence and leakage. By the time proliferating capillary vascular buds have permeated the free graft, necrosis and scar formation have taken place. He utilized polyethylene tubing as a splint catheter for a maximum of seven days in two of five experimental dogs and no splint catheter at all in the other three. He was unable to observe the dogs for long periods since the animals died on the 30th. 65th and 70th postoperative days. Complete ureteral stenosis had occurred in all dogs. An attempt to reestablish the ureteral defect with autogenous ureteral transplantation is described. Mongrel dogs, weighing from 15~25kg were utilized without special preoperative preparation. Pentothal sodium was administered intravenously for anesthesia. The right ureter was exposed through paravertebral incision retroperitoneally in two dogs simultaneously by two operative groups. The middle third of the right ureter was mobilized. A 3 to 7cm segment of the right ureter was removed and transplantated to the other dog. In 4 of 10 dogs, a splint catheter of polyethylene tubing slightly longer than the transplanted graft was inserted. In 6 dogs, a splint catheter was inserted from the renal pelvis to the bladder making it easy to remove the polyethylene tubing subsequently. The ends of the ureter were anastomosed with 4-0 chromic catgut using for interrupted sutures. The wound was closed without drainage. The splint catheter was removed in the fourth to sixth postoperative week. The animals were sacrificed after one to six months and an autopsy was performed. The results are summarized in Table 1. Gross and microscopic changes in the graft in all dogs were contracture, shrinkage or thickening, calcification or ossification within the graft, and round cell infiltration. Hydronephrosis also was seen in all animals. Animals sacrificed after one to two months postoperatively showed epithelial loge and degenerative changes, but the animals sacrificed after six months showed partial normal epithelial lining and capillarization in the submucosal layer of the transplanted segment. No fistula was seen, and at the time of sacrifice, the NPN and creatinine were elevated.