Experimental assessment of ureteral free autograft.

OBJECTIVE

To establish the sequence of ureteral events under ischemic and desvascularized conditions but without immunologic interference.

MATERIALS AND METHODS

Sixty-two rats were divided into four groups. NU group (n 20) control group, normal ureter; SC group (n 15) only surgical control ureterolysis; NIAFG group (n 13) ureter used as non integrated autologous free graft; IAFG group (n 14): ureter used as integrated autologous free graft. Urographic, histologic and histomorphometric studies were performed.

RESULTS

We established ureteral changes in the NIAFG and IAFG groups, compared to the control groups (NU, SC). Surgical findings and urographic assessment revealed normal peristalsis with no ectasia in some cases, and no ureteral fistulas or extravasations were found in the IAFG group. Histologic findings showed preservation of the architecture of the three normal layers. Histomorphometric studies showed that ureterolysis caused edema in the lamina propria, while changes in ureter free graft depended on whether the ureter was integrated or not. In the NIAFG group only the urothelial layers showed differences and in the IAFG group the ureteral wall appeared thicker. Histomorphometric studies showed preservation of the normal histologic structures in all cases.

CONCLUSIONS

The rat ureter can be used as a free autologous graft and represents an experimental model for immunologic events. We may assume that the necrosis and fibrosis observed in transplanted ureters are secondary to rejection in some cases.