EDUCATIONAL REVIEW What is the efficacy of circumcision in boys with complex urinary tract abnormalities? Mohammed Bader & Liam McCarthy Received: 21 November 2011 / Revised: 27 November 2012 / Accepted: 13 December 2012 # IPNA 2013 Abstract The risk of urinary tract infection (UTI) in normal boys is 1%. This risk is significantly increased in boys with congenital abnormalities of the urinary tract, which includes such abnormalities as vesico-ureteric reflux, obstructive megaureter (VUJO) and posterior urethral valves. UTI in these boys can lead to urosepsis, a potentially life-threaten- ing complication, and in the longer term renal scarring complicating pyelonephritis can lead to chronic renal im- pairment or even end-stage renal disease. Circumcision has been shown in normal boys to reduce the risk of UTI by 90%, and potentially could be a simple intervention to reduce the risk of urosepsis and renal scarring. In order to make this decision a clinician really needs to have the answers to two questions: 1) What is the risk of UTI in this particular boy? 2) What is the evidence of efficacy of circumcision in this particular condition? This article reviews what evidence exists to make a calculation of the risk/benefit ratio for circumcision in boys with abnormali- ties of the urinary tract. Keywords Circumcision . Complications . Vesicoureteric reflux . Megaureter . Vesicoureteric junction obstruction . Posterior urethral valves . Bladder outlet obstruction . Urinary tract infection Introduction The risk of urinary tract infection (UTI) in a boy with an anatomically normal urinary tract is 1 %. Circumcision in a normal boy will reduce the risk of UTI by 90 % [1], but the number of boys who need to be circumcised to prevent 1 UTI is 111 [ 2 ]. With a complication rate of 2 %, circumcision is not indicated in the normal population, as more harm than good will result. However, in boys with complex abnormalities of the urinary tract, the risk of UTI is increased and the benefit may be much increased [2]. In order to make this decision, a clinician really needs to have the answers to two questions: (1) What is the risk of UTI in this particular boy? (2) What is the evidence of efficacy of circumcision in this particular condition? Particularly when making a risk/benefit calculation for a particular patient, knowledge of the number of boys that would need to be treated (NNT) to prevent one UTI is crucial. Making the leap from an observation in a normal population to an abnormal population needs to be justified. This article reviews what evidence exists to make a calculation of the risk/benefit ratio for circumcision in boys with abnormalities of the urinary tract. Specifically the risk of UTI is considered for the following conditions: 1. Vesico-ureteric reflux (VUR) 2. Primary non-refluxing obstructive megaureter (PNROM), also known as vesico-ureteric junction obstruction (VUJO) 3. Pelvi-ureteric junction obstruction (PUJO) 4. Posterior urethral valves (PUV) This article will then consider the particular case of PUV in greater detail, as there is specific information on the efficacy of circumcision in this condition [3]. The risk of UTI and evidence for the benefit of circumcision is tabulat- ed for each anatomical abnormality in Table 1. Circumcision is briefly described and the complications that can occur listed. Circumcision Circumcision is the operation to remove the foreskin (prepuce) in males. It is one of the commonest surgical procedures performed, and one of the few procedures that M. Bader : L. McCarthy (*) Birmingham Children’ s Hospital, Steelhouse Lane, Birmingham B4 6NH, UK e-mail: liam.mccarthy@bch.nhs.uk Pediatr Nephrol DOI 10.1007/s00467-013-2410-2