Approximately how much intestinal length is required to form a neobladder reservoir?

• A. Approximately 30 centimeters of intestine
• B. Approximately 60 centimeters of intestine
• C. Approximately 120 centimeters of intestine
• D. Approximately 10 centimeters of intestine

Answer: (B)

Forming an orthotopic neobladder relies on creating a roomy, low-pressure urine reservoir from a segment of ileum. The segment must be long enough to provide sufficient capacity while keeping enough bowel length intact for digestion and absorption. About 60 centimeters of ileum is typically used because it yields a reservoir that can hold several hundred milliliters (roughly 400–600 mL) and remains compliant after detubularization.

Using too short a segment would produce a smaller, higher-pressure reservoir with limited continence and storage capacity. Using a much longer segment—around a meter or more—could increase mucus production, lead to greater absorption of urinary solutes, and worsen metabolic and electrolyte issues, making the diversion harder to manage. The 60 cm length strikes a balance between adequate storage and metabolic stability, which is why it’s commonly cited as the standard.