Sigmoid cystoplasty was described by Lemoine in 1912 and has been used extensively. The sigmoid colon’s proximity to the bladder and reliable blood supply has made it an attractive option for cystoplasty. A suitable segment can be used with minimal, if any, effect on native bowel function. Use of sigmoid colon does not influence vitamin B metabolism as might the use of ileum, and it is the technique of enterocystoplasty least likely to result in chronic diarrhea. Good results can be anticipated when an adequate sized segment is used, reconfigured, and anastomosed to bladder properly. Nonetheless, potential morbidity does accompany colocystoplasty and should be familiar to urologists interested in reconstructive surgery.
After thorough preoperative evaluation, the patient should undergo effective mechanical bowel preparation, and urine culture should document the absence of infection. Exposure is achieved by a lower midline abdominal incision, although some patients may be candidates for sigmoid cystoplasty through a low transverse incision. Laparoscopic mobilization of the intestine may facilitate use of a smaller incision. Augmentation cystoplasty may be performed completely by laparoscopy with or without use of a robotic system; up to four working ports may be needed in such cases, with one being large enough to admit an endostapler.
The sigmoid colon has greater circumference than ileum, and a shorter segment may be used for cystoplasty. The length of segment chosen should be determined by the size of the native bladder and the additional volume needed. In general, a 15- to 20-cm segment is used. To choose the particular segment, transilluminate the colonic mesentery to identify an adequate blood supply based on branches of the inferior mesenteric artery. Likewise, the surgeon should inspect the mobility of the potential segment to ensure that it will reach the bladder without tension ( Fig. 61.1, A ). Windows in the mesentery at either end of the intended segment are created by clearing the mesenteric border of its mesentery for 2 cm at each of those positions. The colon is incised at each end between atraumatic bowel clamps after the abdominal cavity is packed with moist sponges to prevent contamination. Colocolostomy using either a two-layer handsewn anastomosis or stapled side-to-side (functional end-to-end) anastomosis is performed lateral to the isolated segment. The lumen of the isolated segment is rinsed clear with irrigation, and the segment incised for its entire length along the antimesenteric border using the electrosurgical cautery.
There are advantages to effective reconfiguration of any bowel segment used in cystoplasty. Such manipulation maximizes the volume achieved using a given surface area of bowel and blunts effective pressure contractions inherent in any intact gastrointestinal segment. The colon has powerful unit contractions that would be problematic if persistent. Mitchell suggested that the two open ends of the sigmoid segment could be oversewn when the antimesenteric border was incised completely (see Fig. 61.1, B ); most surgeons, however, have chosen to fold the opened segment in a U shape similar to that described for ileocystoplasty to more effectively reconfigure the colonic patch (see Fig. 61.1, C ). Longer segments may be folded in an S shape. After folding, the common limbs of bowel wall are sewn together using absorbable suture. This is easily done in a single full-thickness layer from within the luminal side using a running locked suture. Each purchase of bowel wall should contain more of the seromuscular layer than mucosa to ensure that the mucosa is inverted into the lumen. The native bladder is usually incised longitudinally or bivalved from a point just short of the bladder neck anteriorly to within centimeters of the interureteric ridge posteriorly. It is critical that a wide anastomosis of bowel to bladder be achieved, and a second transverse incision into the bladder near the dome can be performed when necessary to increase the area of anastomosis. The reconfigured colonic patch is mobilized to the open bladder and, at times, rotated 90 degrees to better fit onto the bladder without tension. Watertight approximation of the colonic segment to the bladder is performed using absorbable suture in one or two running layers, again taking care to invert the mucosa of both bowel and bladder ( Fig. 61.2 ).
A large caliber suprapubic cystostomy tube is left in place and usually brought out through the native bladder wall. It is left in place for approximately 3 weeks to keep the bladder decompressed during healing. Cystography is performed at that point to document healing and the absence of any leakage. The tube can be removed when clean intermittent catheterization (CIC) is performed on a regular and reliable basis. Most patients requiring cystoplasty will perform CIC long term to empty and should be ready and capable to do so before any consideration of cystoplasty. Nasogastric suction may be used for the first few days after sigmoid cystoplasty until bowel motility resumes.
Seromuscular colocystoplasty lined with urothelium (SCLU) has been performed in relatively small series in an effort to avoid some morbidity of conventional sigmoid cystoplasty. A segment of sigmoid similar to that described earlier is isolated in an identical fashion, but the colonic mucosa is then sharply excised. Care should be taken to completely excise the mucosa to prevent colonic mucosal regrowth while preserving the submucosa. Preservation of the submucosa may be important to avoid contracture of the intestinal segment. The demucosalized sigmoid segment is reconfigured before approximation to bladder. Preparation of the bladder is entirely different ( Fig. 61.3 ). The bladder muscle of the dome is excised to a position just short of the level of the interureteric ridge circumferentially while the underlying bladder mucosa is preserved. The seromuscular sigmoid patch is applied over the bulging mucosa and approximated to the bladder muscle circumferentially.