Effects on renal function of obstructive and nonobstructive dilatation of the upper urinary tract in ileal neobladders with refluxing ureteroenteric anastomoses.

AIMS: To investigate the incidence and long-term effects on kidney function of obstructive and nonobstructive dilatation of the upper urinary tract in patients with ileal neobladder with refluxing ureterointestinal anastomoses. METHODS: We retrospectively analyzed a prospectively derived database of 110 patients with bladder cancer and who were treated with an ileal neobladder between 1996 and 2007 using refluxing end-to-side ureterointestinal anastomoses on a short afferent limb. The mean follow up was 65 months. At every follow up visit the patients had an analysis of serum creatinine, urine culture, abdominal CT or ultrasonography, and, if there was dilatation of the upper urinary tract, 99mTc-DTPA renal scintigraphy was requested. RESULTS: In all, 206 renoureteral units were included in the study. Overall, seven had anastomotic stricture and of those, three were symptomatic and were corrected; while four were asymptomatic and of those, only two, with preserved split GFR, were surgically treated, while the remaining two, with a poor split GFR, were followed up. The last 99mTc-DTPA showed a preserved split GFR in the reimplanted units and further split renal function decrease in untreated units. Nonobstructive dilatation of the upper urinary tract, caused by reflux, was diagnosed in 13 units. The dilatation was bilateral in three patients with recurrent UTIs and urosepsis, and the split GFR was bilaterally reduced at diagnosis with a further reduction at the last 99mTc-DTPA. The remaining seven units with sterile urine, showed a preserved split GFR during follow up. CONCLUSIONS: All strictures, regardless of their severity, should be immediately corrected. Reflux per se does not provoke renal impairment unless recurrent UTIs and urosepsis are present