Renal function change after refluxing type orthotopic ileal substitution

Purpose: We investigated the impact of the presence and severity of vesicoureteral reflux on renal function in patients with an ileal orthotopic bladder substitute without an antirefluxing mechanism after radical cystectomy. We compared results in patients with an ileal conduit.

Materials and methods: In 101 patients (195 renal units) who underwent radical cystectomy, including 73 (142 renal units) with an ileal orthotopic substitute and 28 (53 renal units) with a conduit between July 2004 and August 2009, we evaluated (99m)technetium diethylenetetramine pentaacetic acid renal scans to measure individual glomerular filtration rates preoperatively. This was followed annually along with postoperative voiding cystourethrography. We analyzed factors influencing a change in the postoperative glomerular filtration rate, including reflux presence and severity.

Results: In patients with an orthotopic substitute vesicoureteral reflux was observed in 104 renal units (73.2%). Reflux was bilateral in 80.8% of renal units and grade 3 or higher in 45 (31.7%). The mean glomerular filtration rate of all renal units remained unchanged perioperatively and was not influenced by reflux presence or severity. The percent change in the glomerular filtration rate was similar between patients with an orthotopic substitute and an ileal conduit. Post-void residual urine was a significant risk factor for febrile urinary tract infection and subsequent hydronephrosis in the absence of obstruction as well as an independent predictor of a significant glomerular filtration rate decrease (p = 0.009).

Conclusions: Vesicoureteral reflux that develops in refluxing type urinary diversions does not significantly alter renal function regardless of its severity unless it is coupled with post-void residual urine. Post-void residual urine carries a significant risk of febrile urinary tract infection and it is an independent predictor of renal function deterioration.