Ileal Orthotopic Neobladder — Internal Urinary Diversion

Orthotopic ileal neobladder is a continent internal urinary diversion constructed after radical cystectomy for muscle-invasive bladder cancer or selected non-malignant indications. A 40-60 cm segment of distal ileum is harvested, detubularized along its antimesenteric border, and reconfigured into a spherical or cuboidal low-pressure reservoir. The most popular techniques are the Studer ileal neobladder with a chimney for ureteral implantation, and the Hautmann W-shaped pouch with antireflux ureteral implantation.

Bilateral ureters are implanted with antireflux mechanism (e.g., Le Duc or Studer afferent limb) to prevent ureteral reflux and renal damage. The neobladder is anastomosed to the urethral stump, allowing volitional voiding through pelvic floor relaxation and Valsalva maneuver. Pre-operative requirements include adequate renal function (creatinine clearance > 40 mL/min), adequate liver function, motivated patient, and disease-free urethra (no prostatic urethra involvement, negative urethral margin).

Daytime continence is achieved in 80-95% and nocturnal continence in 50-80% over 12-18 months as the reservoir matures. Voiding requires pelvic floor relaxation; clean intermittent self-catheterization is required in 5-15%. Complications include metabolic acidosis (chloride absorption), B12 deficiency, urinary tract infections, mucus production, neobladder rupture, and urethral recurrence. Long-term oncologic and functional follow-up is essential.