First described in paediatrics, the formation of a catheterisable channel utilising the Mitrofanoff principle has been used for the past few decades in adult populations. 

The optimal site for the exit stoma of a Mitrofanoff or Monti channel remains unknown. In children there is evidence that the iliac fossa may be a superior site but it remains unclear whether this information can be extrapolated to an adult population.

Our aim was to examine a large adult cohort of patients having creation of a continent catheterisable channel for a variety of indications to elucidate the presence, if any, of an optimal exit stoma site in adults.

We performed a retrospective case note review of 176 consecutive adult patients (median age 42 years) having Mitrofanoff channel formation a median of 142 months (range 54-386) previously. We evaluated outcome in terms of stoma site revision, channel revision, continued use and continence for each stoma exit site. Statistical analysis was by Chi Squared analysis and significance was determined as P<0.05.

175 patients had a median of 62 months (range 2-293) follow-up (FU) available. 1 patient had died during follow up and outcomes could not be assessed. Outcomes at last clinic FU are listed in Table 1 (* P<0.05).

69% (n=121) received a stoma to the umbilicus, 29% (n=50) to the right iliac fossa (RIF), and 2% (n=4) to the left iliac fossa.

The stoma in use rate between all sites averaged at 84%, with a 100% LIF stoma in use rate.

The Dry at last follow up rate averaged 79%, with a 100% LIF dry rate.

Skin revision rate was 72% and 75% for RIF and LIF respectively, but 55% for those stomas sited at the umbilicus.

Umbilical stomas for Mitrofanoff channels are formed significantly more often than stomas in other locations such as the right or left iliac fossae. The site of Mitrofanoff exit stoma did not affect channel usage and continence at last follow up. However, it appears that a Mitrofanoff channel sited at the umbilicus has a significantly lower rate of requiring a skin level revision compared to those in the iliac fossae.

Location of the exit site of a continent catheterisable channel will of course be affected by other factors such as body habitus and prior abdominal surgery but we propose that given the significantly lower rate of skin level revision at an umbilical exit site that this may be the better location in adults.