FREE URETERAL REPLACEMENT IN RATS - REGENERATION OF URETERAL WALL COMPONENTS IN THE ACELLULAR MATRIX GRAFT

Objectives. To evaluate ureteral replacement by a free homologous graf t of acellular matrix in a rat model. Methods. in 30 male Sprague-Dawl ey rats, a 0.3 to 0.8-cm midsegment of the left ureter was resected an d replaced with an acellular matrix graft of equal length placed on a polyethylene stent, The animals were killed at varying intervals, and the grafted specimens were prepared for light and electron microscopy. Results. In all animals, the acellular matrix graft remained in its or iginal position without evidence of incrustation or infection, and his tologic examination showed complete epithelialization and progressive infiltration by vessels. At 10 weeks, smooth muscle fibers were observ ed; at 12 weeks, nerve fibers were first detected; at 4 months, smooth muscle cells had assumed regular configuration. Conclusions. The uret eral acellular matrix graft appears to promote the regeneration of all ureteral wall components. (C) 1997, Elsevier Science Inc. All rights reserved.