Long-term renal function after urinary diversion by ileal conduit or orthotopic ileal bladder substitution

Abstract

Background: Data on long-term renal function are scarce for ileal conduit diversion (ICD) and even rarer for orthotopic ileal bladder substitution (BS).

Objective: Explore the changes in renal function of patients who lived≥10 yr with an ICD or BS and determine the risk factors contributing to renal function deterioration.

Design, setting, and participants: Fifty consecutive ICD patients and 111 consecutive BS patients who lived ≥10 yr after undergoing surgery between January 1985 and December 2000 were retrospectively analyzed.

Measurements: The glomerular filtration rate (GFR) was calculated with the Modification of Diet in Renal Disease (MDRD) equation before and 10 yr after surgery. Decreased renal function was defined as a decrease in GFR>10 ml/min per 1.73 m2 in 10 yr.

Results and limitations: Median GFR values in patients with ICD or BS decreased from 65.5 (range: 23-90) to 57 (range: 7-100) ml/min per 1.73 m2 and from 68 (range: 33-106) to 66 (range: 16-100) ml/min per 1.73 m2, respectively. Eighteen ICD patients (36%) and 23 BS patients (21%) had deteriorating renal function. Seven of 12 ICD patients with obstruction (ureteroileal stricture, stomal stenosis/parastomal hernia) (58%) had renal function deterioration, as did 17 of 46 BS patients with obstruction (ureteroileal/nipple stricture and/or bladder outlet obstruction) (37%). Logistic regression analysis confirmed that obstruction was the leading, and an independent, risk factor for renal function deterioration for both ICD patients (p=0.045) and BS patients (p=0.002). Patients with diabetes or hypertension were significantly more likely to have deterioration of renal function if they had ICD (p=0.002 and p=0.05, respectively). The limitation of the study is its retrospective nature and its composition that included many patients who did not survive 10 yr.

Conclusions: Urinary tract obstruction was the leading cause of long-term renal function impairment, regardless of whether the patient had ICD or BS. ICD patients with predisposing risk factors, such as diabetes or hypertension, were at increased risk for impaired renal function.