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 resection of a 5 cm-long middle segment.

MATERIALS AND

METHODS

Eight dogs underwent resection of the middle segment of the ureter, after which a 6-8 F Bard ureteric stent modelling catheter was inserted into both remaining portions of the ureter for 3 months. One month after removal of the stent the animals were killed and their ureters examined both grossly and microscopically. Paraffin-embedded sections were subjected to microscopic and immunohistochemical studies.

RESULTS

The continuity of the ureter was restored but the reconstructed segment was narrowed to a variable extent. The wall of the ureter was lined by normal urothelium but consisted of fibrous connective tissue which failed to produce a regular coat. The reconstructed segment showed no smooth muscle cells (negative staining with azan and a negative reaction with monoclonal antibodies against desmin). A few smooth myocytes were found only 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.