What is the goal reservoir volume for a neobladder?

• A. Max 100-200 cc
• B. Max 400-500 cc
• C. Max 700-800 cc
• D. Max 1200 cc

Answer: (B)

In an orthotopic ileal neobladder, the storage capacity must balance adequate intervals between voiding with keeping intraluminal pressures low to protect the kidneys. The target reservoir volume is about 400–500 mL. This range provides enough space to hold urine comfortably without forcing frequent trips to the bathroom, while still allowing the outlet to function with low-pressure storage. If the reservoir is too small (around 100–200 mL), voiding becomes very frequent and inconvenient. If it’s too large (700–800 or 1200 mL), it risks high storage pressures and potential leakage or impaired emptying, which can endanger upper tract function. Individual patients may vary, but 400–500 mL is the commonly cited goal.