Anastomosis Surgical/adverse effects/instrumentation/methods Constriction Pathologic/etiology Cystectomy/*instrumentation/methods Humans Ileum/surgery Incidence Postoperative Complications/etiology Stents/*adverse effects Ureter/surgery Ureteral Obstruction/*etiology Urinary Bladder Neoplasms/surgery Urinary Catheters/adverse effects Urinary Diversion/adverse effects/*instrumentation/methods Cystectomy Internal double-J stent Orthotopic neobladder Ureteroileal anastomosis stricture Urinary diversion