Does reflux in orthotopic diversion matter? A randomized prospective comparison of the Studer and T-pouch ileal neobladders

Orthotopic neobladder reconstruction has become a standard form of urinary diversion in many centers for patients undergoing radical cystectomy for bladder cancer. There is still controversy about the best technique for construction of the neobladder, and especially whether it is necessary to include an antireflux mechanism. We designed a prospective randomized clinical trial comparing two forms of ileal neobladder: the Studer pouch and the T-pouch. The latter includes an extraserosal tunneled afferent limb which prevents reflux from the pouch to the kidneys. The primary endpoint of the study is renal function and anatomy at 3 years following surgery, with secondary endpoints including early and late postoperative complications, renal infections and need for secondary procedures. To date we have randomized 462 patients over approximately 6 years, with a planned full enrollment of 550 patients. Ten percent of patients have been withdrawn because they did not undergo the planned orthotopic diversion due to a positive urethral margin on frozen section. We expect approximately 70% of patients to be alive and available for follow-up at 3 years, which will give us ample power to detect clinically meaningful differences in the outcome of these two diversions. This trial has been feasible and randomization has been acceptable to most patients. Long-term follow-up of the patients on this trial should be able to definitively answer the question of the importance of an antireflux mechanism in the orthotopic neobladders construction.