A comparison of the Monti and spiral Monti procedures: A long-term analysis

The Monti ileovesicostomy provides an excellent substitution for an appendicovesicostomy when the appendix is unavailable or suitable for use. The spiral Monti is a useful modification to the traditional Monti as it allows creation of a longer channel when needed. In 2007, the short-term outcomes were reported; they compared traditional and spiral Monti in 188 patients with an average follow-up of 43 months. In the present population, a total of 25 subfasical revisions were performed in 21 patients: nine (8.3%) subfascial revisions in the traditional Monti (TM) patients and 12 (15.2%) subfascial revisions in the spiral Monti (SM) patients. The study found an increased risk of subfascial revisions of either TM or SM when the stoma was located at the umbilicus versus right lower quadrant (16.8% vs 6.3%, P < 0.05). On subgroup analysis, this increased subfascial revision rate appeared to be driven by SM channels to the umbilicus rather than other stomal locations, but this trend was not statistically significant.

It was hypothesized that with longer follow-up, the spiral Monti would require more subfascial revisions due to progressive lengthening of the channel.

A retrospective chart review was performed for all patients undergoing a traditional Monti (TM) or spiral Monti (SM) procedure at the present institution (1997-2013). Patient demographics, bowel segment used, stomal location, channel or stomal revisions, number of anesthetic endoscopic procedures performed, and indications for revision were reviewed. Kaplan-Meier analysis and Cox proportional hazards modeling was used for analysis.

Of the 296 patients identified, 146 had Monti procedures and 150 had spiral Monti procedures (median follow-up 7.7 years). Median age at surgery was 10.6 years. Myelomeningocele was the most common underlying cause of neuropathic bladder, totaling 169 (57.1%) patients. Stomas were located at the umbilicus (106, 35.8%), right lower quadrant (183, 61.8%) and left lower quadrant (seven, 2.4%). Median follow-up for the entire cohort was 7.7 years (range: 1 month-15.7 years). Stomal stenosis rate was 7.4%, and 96.6% of the channels were continent. A total of 87 revisions were performed in 74 patients (25.0%). Of these, 55 were subfascial revisions in 49 patients (16.6%). The umbilical spiral Monti on univariate and multivariate analysis was found to be over twice as likely to undergo subfascial revision.

The majority of patients with a Monti channel had durable results and did not require further channel surgery with long-term follow-up. Spiral Monti channels to the umbilicus were more than twice as likely to undergo subfascial revision compared to all other Monti channels. Overall, one in three umbilical SM channels required a subfascial revision at 10 years after the initial surgery, compared to one in six of all other Monti channels. The study was limited by being a retrospective, single-center series; however, it does represent the largest series of pure SM and TM patients. It focused only on surgical interventions, thus was likely to underestimate the overall risk of complications, as some complications were managed conservatively. As in all studies, some patients were lost to follow-up and inevitably some of these may have had complications. Correction for this was attempted through survival analysis.

The present study reported durable and reliable long-term results with Monti and spiral Monti procedures based on a large patient cohort. Spiral Monti to the umbilicus was more than twice as likely to require a subfascial revision.