The Yang-Monti ileovesicostomy: a problematic channel?

OBJECTIVE: To compare the differences in the quality of Mitrofanoff channels created using appendix and re-tubularized small bowel (the Yang-Monti ileovesicostomy). Patients and methods The case-notes were reviewed retrospectively for all patients who underwent a Mitrofanoff procedure using either appendix or small bowel, over a 5-year period from June 1994 to July 1999. RESULTS: In all, 92 patients underwent 94 Mitrofanoff procedures; the appendix was used in 69 and small bowel in 25. The underlying diagnoses were exstrophy-epispadias complex (38), neuropathic bladder (21), anorectal malformations and cloacal anomalies (15), posterior urethral valves (nine) and miscellaneous (nine). The mean (range) age at operation was 9.2 (1.1-18.3) years. The mean (range) follow-up for the appendix group was 37 (6.7-65) months and for the Monti group 25 (6-66) months. Catheterization problems occurred in 18 (27%) patients from the appendix group; two needed an adjustment of technique, six dilatation and 10 revision. Stomal stenosis occurred in 10 (15%) patients, bladder level stenosis in four (6%) and conduit necrosis in two. Catheterization problems were reported in 15 (60%) patients from the Monti group; five needed revision, three dilatation and seven are being managed conservatively. The incidences of stomal stenosis (four, 16%) and bladder level stenosis (two, 8%) were comparable with the appendix group. In addition, two patients had distal channel (sub-stomal) stenosis and two had mid-channel stenosis. The problem unique to the Yang-Monti channel was a pouch-like dilatation in seven patients (28%), all of whom presented with catheterization problems; five are being managed conservatively and two have needed pouch resection. Stomal prolapse occurred in five (7%) patients in the appendix group, but in none of the Monti group. CONCLUSIONS: The appendix is the conduit of choice for a Mitrofanoff procedure. Re-tubularized small bowel conduits have a considerably higher incidence of catheterization problems. Anatomical factors may contribute to the unique incidence of pouch formation.