Urodynamic study of enhanced continent mechanism using tapered ileum as continent urinary reservoir

OBJECTIVE: To investigate the effect of extramural support from the pouch and abdominal wall to enhance the continent mechanism of tapered ileum. METHODS: A total of 24 patients underwent a procedure in which an ileal segment was tapered into an efferent tube, of which a part was placed between the back surface of the rectus muscle and the ileal pouch wall. The internal orifice of the tapered ileum was anastomosed to the ileal pouch and its external orifice was anastomosed to the umbilicus. A urodynamic study of the efferent tubes and pouch was done 1.5 to 3 months and 6 to 24 months postoperatively. RESULTS: One patient died of heart disease 55 days postoperatively, while 22 of the remaining 23 were completely continent day and night. At 1.5 to 3 months, the urodynamic study of the efferent tubes demonstrated that the maximum closure pressure with a full pouch was 46 - 124 cmH(2)O (91.26 +/- 15.71 cmH(2)O) and with an empty pouch was 34 - 84 cmH(2)O (67 +/- 10.60 cmH(2)O). The difference in mean maximum closure pressure in the full and empty pouches was statistically significant (t = -11.78 and P = 0.00001). At 6 to 24 months, a second urodynamic study was performed on 18 cases, demonstrating a reservoir capacity of 420 to 750 ml (481.67 +/- 78.83 ml). Reservoir pressure was 6 to 9 cmH(2)O (7.17 +/- 1.17 cmH(2)O) when the pouch was filled to 50 ml, and 16 to 35 cmH(2)O (24.12 +/- 5.61 cmH(2)O) when it was filled to maximum capacity. There was no contractive wave during the filling in any patient. Maximum closure pressure in the efferent tube was 80 to 194 cm H(2)O (98.89 +/- 26.34 cmH(2)O) when the pouch was filled with saline, and 64 to 128 cmH(2)O (74.78 +/- 14.54 cmH(2)O) when the pouch was empty. The difference in mean maximum closure pressure in the full and empty pouches was statistically significant (t = -7.58 and P = 0.00003). CONCLUSIONS: This study indicates that the continent mechanism of tapered ileum may be greatly enhanced by extramural support from the abdominal and pouch walls.

Reinforcing the continent mechanism of continent cutaneous diversions by wrapped rectus abdominis muscle flap： a preliminary experimental study

Background Continent cutaneous diversion （CCD） has been widely used in almost any lower urinary reconstruction. We have been continually trying to modify this procedure because of the high complications rate, especially as they relate to the efferent tube. In this study, we reported a modified procedure with a tapered ileum wrapped by the rectus abdominalis flap （RAMF） and assessed the feasibility of this new technique to achieve urinary continence. Methods A procedure in which two ileal segments were tapered and connected to a U-shaped reservoir was performed in ten dogs. A RAMF with its blood supply was wrapped around one of the tapered ileum. In control groups, the tapered ileum was brought to the abdominal skin. Urodynamic studies were conducted In the 1st, 3rd and 6th months post-operatively. The data of maximum inner pressure （MIP） and functional pressure length （FPL） in every group at each phase were recorded. Retrograde radiograms of the efferent limbs were performed before sacrifice. Results MIP in the study group was significantly higher than that in the control group at each phase （P 〈0.05）. However no significant differences in MIP or FPL were found in the study group between an empty and full reservoir. In the control group, MIP increased （P 〈0.05） and FPL decreased significantly （P 〈0.05） compared with an empty and full reservoir. Retrograde radiograms confirmed that efferent limbs were positioned straigh beneath the abdominal wall. Histological examination of the study group demonstrated a layer of striated muscle around the outside surface of the ileum. Conclusion The continent mechanism of tapered ileum can be enhanced by extra support from wrapped RAMF.