Desire to void and force of micturition in patients with intestinal neobladders

Purpose: We attempted to determine how patients with an orthotopic bladder perceive the desire to void and the force achieved to evacuate the bladder. Materials and Methods: A total of 24 men who had undergone post-cystectomy bladder substitution (ileocecal in 12, sigmoid in 6 and ileal in 6) was evaluated subjectively and objectively by pressure-flow study 1 to 3 years postoperatively. Results: Desire to void was felt at the base of the penis or in the perineum by 20 men (83%). Abdominal pressure contributed to intra-reservoir pressure by 51 to 54% in ileocecal, 20 to 24% in sigmoid and 23 to 25% in ileal neobladders. Conclusions: Patients perceive the desire to void when drops of urine leak into the proximal urethra from an overfilled neobladder. Urine is evacuated mainly by abdominal straining for ileal neobladders, mainly by contraction for sigmoid neobladders, and by approximately equal contributions of contraction and straining for ileocecal neobladders.