Am experimental study of restrainable small calibre conduits formed with ileum anastomosed directly to the bladder in pigs / 解放军医学杂志

ABSTRACT

Objective To study the restraining capability mechanism of small calibre ileum conduit anastomosed directly to the bladder in pigs. Methods 15 pigs were randomized into 5 groups according to the length of the ileal loop to form the conduit 4cm, 5cm, 6cm, 7cm, and 8cm. In each pig, two ileal segments of the same length were reduced in calibre by opening up longitudinally and closed around a catheter. They were then directly anastomosed to the bladder end to side and placed within rectus abdominis musche in each pig. Urodynamic test, radiological image analysis and histological study were carried out 8 weeks after the procedure. Results No stenosis and twisting of the ileal ileum conduit were observed in 5cm, 6cm, and 7cm groups, in which they could be catheterized with ease. When the bladder was filled with a mean volume of 400ml of saline, the maximum "urethral" pressure ranged from 5.15～12.19kPa and the maximum close pressure (MCP) ranged from 4.83～11.27kPa. The "urethral functional length" of the ileal conduit was longer than 2cm. Among 5cm, 6cm and 7cm groups, there were no significant differences in maximum closure pressure and the urethral functional length, except in maximum "urethral" pressure. In the 4cm group, there was incontinence. Failure was found in the 8cm group because of necrosis of the ileal loop embedded in the abdominal muscle. Conclusion Small calibre conduits formed with ileum in the length of 5cm to 7cm are able to restrain urinary leakage when anastomosed directly to the bladder and and embedded in the by rectus abdominis in pigs.