How much volume can be held over time with a Mitrofanoff procedure?

• A. 50-100 mL
• B. 600-1000 mL
• C. 100-200 mL
• D. 1200-1500 mL

Answer: (B)

In a Mitrofanoff continent urinary diversion, the storage capacity comes from the reservoir that the patient uses (often augmented bowel segment) and the catheterizable channel makes it possible to empty regularly. A mature continent reservoir typically holds about 600–1000 mL of urine between catheterizations. This range provides practical intervals for emptying (not too frequent) while maintaining continence. Capacities well below this (like 50–100 mL or 100–200 mL) would require frequent catheterizations and are not typical for a functioning long-term reservoir. Capacities much larger (1200–1500 mL) are uncommon and carry a higher risk of overdistention or other complications.