Substitution urethroplasty was performed in 9 donkeys. In each donkey a urethral segment was removed and a venous graft from the jugular or saphenous vein was exposed and harvested by ligation of both ends of the vein. In three animals (group I), a suitable sized multifenstrated Ryle tube was introduced to bypass the urethra and the venous graft to drain the urinary bladder. The cut ends of the urethra and those of the graft were approximated and spatulated anastomosis was performed on the tube using simple interrupted suture. In six donkeys (group II) a perineal urethrotomy was done and Foley's catheter was introduced through it to drain the bladder and the anastomosis was separately stented.
The animals were observed for 3 months and the outcome and com plications were recorded. After follow up for 3 months, one animal had a fistula, 2 animals had urethral stricture and the rest of the animals (6 donkeys) had smooth patent pathway. The results indicated that venous graft is a worthy trial for substitution of urethral defects of variable lengths (2-5cm long. The anastomosis should be spatulated and stented with proximal urinary diversion.