RESTORATION OF THE CONTINUITY OF DOG URETER AFTER RESECTION OF ITS 5 CM MIDDLE SEGMENT

Objective To evaluate the restoration of the ureter of the dog after r esection of a 5 cm-long middle segment. Materials and methods Eight do gs underwent resection of the middle segment of the ureter, after whic h a 6-8 F Bard ureteric stent modelling catheter was inserted into bot h remaining portions of the ureter for 3 months. One month after remov al of the stent the animals were killed and their ureters examined bot h grossly and microscopically. Paraffin-embedded sections were subject ed to microscopic and immunohistochemical studies. Results The continu ity of the ureter was restored but the reconstructed segment was narro wed to a variable extent. The wall of the ureter was lined by normal u rothelium but consisted of fibrous connective tissue which failed to p roduce a regular coat. The reconstructed segment showed no smooth musc le cells (negative staining with azan and a negative reaction with mon oclonal antibodies against desmin). A few smooth myocytes were found o nly at the border with intact portions of the ureter. Conclusions The surgical procedure resulted in the restoration of ureteric continuity by repair and not by regeneration of its wall.