Long-term metabolic advantages of a gastrointestinal composite urinary reservoir

We investigated the long-term metabolic impact of gastrointestinal composite reservoirs.

Nine patients underwent construction of a gastroileal (7) or gastrocolonic (2) reservoir for continent urinary diversion. Four cases of metabolic acidosis were converted from a preexisting conduit and the other 5 patients had diversion for either preexisting metabolic acidosis or the short bowel syndrome. All were reconstructed using a medium sized gastric segment (8 x 4 cm.) from the greater curvature of the stomach. The anti-incontinence segment was constructed from a tapered and reimplanted ileal segment. All patients underwent preoperative and postoperative measurements of serum pH, serum electrolytes, and urinalysis. Serum gastrin was measured in all patients postoperatively. Followup from surgery ranged from 47 to 61 months (mean 54.4).

All 9 patients demonstrated electrolyte neutrality in serum on long-term followup. Postoperative serum pH (mean 7.40) was significantly different (p < 0.01) from preoperative serum pH (mean 7.36) and serum bicarbonate was also significantly different (p < 0.01) preoperatively versus postoperatively (mean 22.3 versus 25.14). Urine pH values were not significantly different throughout the study. One patient with mildly acidic urinary pH (6.0 to 6.5) had ulcerative skin changes at the stoma site. Three patients had elevated serum gastrin levels on short-term followup but all patients had normal serum gastrin levels on long-term followup. One patient, with persistent alkaline urine, had urolithiasis and symptomatic urinary tract infections.

Our results demonstrate that a composite urinary reservoir constructed using gastric and intestinal segments achieved serum electrolyte neutrality on long-term followup. These results indicate a long-term metabolic advantage over other intestinal reservoirs associated with hyperchloremic metabolic acidosis and may be beneficial in patients compromised by either preexisting metabolic acidosis or the short bowel syndrome.