Renal function evaluation in patients undergoing orthotopic bladder substitution: a systematic review of literature

Renal function (RFn) after orthotopic bladder substitution (OBS) is a critical point to be assessed. We performed a systematic review of MEDLINE for full length peer reviewed English articles from the year 2000 till January 2013. We included only original articles and excluded reviews, editorials and replies and abstracts presented in conferences. The outcome is formulated in research questions; what is the status of RFn after OBS? Which is better, the direct free-refluxing or anti-refluxing ureteroileal anastomosis (UIA) techniques? Studies reporting RFn as secondary outcome were also reported. A total of 129 publications were reviewed for full text and only 41 were included in this review. All studies were of low level of evidence and grade of recommendations. Only 3 randomized controlled trials were included and were of poor quality. Renal function after OBS was poorly described in the literature with no universal definition about RFn deterioration or outcome with no consensus on the best evaluation method. Urinary obstruction, chemotherapy and pyelonephritis appeared significant factors but with insufficient evidence. There is a universal trend to use the free refluxing technique for UIA to avoid complications of anti-refluxing techniques. However, the anti-reflux technique proved acceptable outcome in experienced hands. There is marked heterogeneity and underestimation of RFn evaluation among reported outcomes after OBS with most publications reporting the incidence of UIA and pyelonephritis with paucity reporting absolute figures about RFn measurements. In conclusion, urinary tract obstruction remains the main factor of RFn deterioration after OBS. Methods evaluating RFn, definitions of RFn outcome and factors predicting it are poorly studied in the literature and the current evidence is relatively weak to draw solid conclusions. Further well-designed studies and consensus about method of assessment and definitions of RFn are warranted.