Surgeons Report Modified Channel Substitution Technique for Leaking Catheterizable Channels in Children

Surgeons in Egypt have described a modified technique for completely replacing a leaking continent cutaneous catheterizable channel in children, using a single short segment of ileum to rebuild both the channel and its continence mechanism. In a preliminary report published in the African Journal of Urology, Mohamed Hussiny, Ashraf T. Hafez and Tamer Helmy detail how the operation was performed in two boys whose channels leaked after previous reconstructive surgery, with no major complications recorded and continence maintained at the last follow-up.

A continent cutaneous catheterizable channel is a surgically created conduit that allows children, and often their caregivers, to empty the bladder through a small abdominal stoma using clean intermittent catheterization. It is typically offered when catheterization through the urethra fails or is impossible. The channel is connected to a bladder reservoir, frequently one that has been enlarged with bowel, and a continence mechanism keeps urine from leaking out through the stoma between catheterizations.

While many studies confirm excellent short-term outcomes for these channels in children and adolescents, the authors note that surgical reintervention rates remain high for channel-related complications. These include stomal stenosis, parastomal hernia, channel diverticulum, fistula formation, difficult catheterization and leakage. A leaking channel is far more than a nuisance: the report describes peristomal dermatitis, recurrent skin excoriation and urinary tract infection on the medical side, alongside low self-esteem, anxiety during school activities and social isolation on the psychological side.

Before any surgery is considered, conservative measures come first. These include catheterizing at shorter intervals, adding anticholinergic medications or beta-3 agonists, and treating constipation where present. When leakage stems from disruption of the continence mechanism itself, in a bladder with adequate capacity, surgical options range from submucosal bulking agents and trimming of a dilated Monti tube to closure of a fistula or reinforcement of the mechanism with anterior or posterior packing or a rectus fascia sling. Total channel substitution is reserved for cases of complete disruption of the original channel or its continence mechanism, and conversion to an incontinent conduit remains the last resort when everything else fails.

The first patient in the report was an 11-year-old boy with a neuropathic bladder due to meningomyelocele. He had undergone augmentation ileocystoplasty and bladder neck reconstruction with a Mitrofanoff channel, built from appendix, at age six at another institution. He presented with total urinary incontinence through both the urethra and the channel. Ultrasound showed a normal upper tract with an empty augmented bladder, and a cystogram showed good augmented bladder capacity without vesicoureteric reflux. Because the continence mechanism was completely disrupted, the team decided on bladder neck closure with total channel substitution.

The second patient was a boy who had presented at age six with total urinary incontinence after abdominoperineal rectal pull-through surgery for imperforate anus. Repeated hypospadias repairs had left multiple urethral kinks, and his appendix was too short to serve as a channel, so he received an augmentation with bladder neck reconstruction and a Monti channel. Two years later, after traumatic failed catheterization, he developed a leaking channel with a large false passage at its distal part. A follow-up cystogram showed a mildly reduced augmented bladder capacity, downgrading of right vesicoureteric reflux from grade V to grade III, and a shortened Monti channel. The operative plan was revision of the continence mechanism without repeat augmentation.

The modified technique itself is the core of the report. After exposing and longitudinally opening only the anterior wall of the augmented bladder, the surgeons isolated a six-centimeter ileal segment and divided it into two equal parts. The distal half was reconfigured into a spiral Monti tube, a configuration in which a three-centimeter bowel segment is opened and re-tubed spirally to yield a channel of roughly nine to ten centimeters, considerably longer than a standard Monti tube. This allows a tension-free anastomosis to the bladder, greater flexibility, and avoidance of the tube-to-tube anastomosis required in a double-tube Monti, though the spiral configuration carries a long suture line and a higher risk of fistula. To reduce that risk, the team created unequal-width flaps so the tunnel and channel suture lines do not overlap.

The proximal half of the segment was sutured to the anterior wall of the pouch with seromuscular sutures to form a trough, opened along its antimesenteric border, and the spiral Monti channel was then inlaid within it. The edges of the trough were approximated over the channel, creating a serous-lined extramural tunnel. The remaining free flap of opened ileum closed the defect in the pouch, adding capacity to the augmented bladder. The distal end of the new channel was brought out at the umbilicus. A key advantage, the authors emphasize, is the minimal dissection involved: only the anterior wall of the augment is exposed, avoiding posterior or lateral dissection that could injure the mesenteric blood supply, cause ischemia and further compromise bladder capacity.

The continence provided by this arrangement rests on two mechanisms. A passive component arises from the tubular resistance of the reconfigured ileal segment, preventing leakage at low pressures, while a dynamic component comes from embedding the outlet within the wall of the reservoir, preventing leakage as the reservoir fills or pressures rise. The serous-lined extramural tunnel technique was originally developed for antireflux ureteral reimplantation in detubularized ileal neobladders and later adopted for catheterizable channels in children and adolescents. In a retrospective study of 60 patients aged three to 18 who received channels built this way, 55 achieved continence after a median follow-up of 43 months, catheterizing every three to four hours during the day. In a more recent study of 52 children, leaking stoma occurred in 19 percent and was treated by endoscopic injection, with redo surgery required in three patients.

The results in these two cases were encouraging but preliminary. No major complications were recorded, and both patients were discharged after three days. After one year of follow-up in the first boy and six months in the second, the channels remained continent, defined as dryness with three-hour catheterization intervals, with no sonographic evidence of hydronephrosis. The authors are candid about the limitations: only two patients, short follow-up, and no urodynamic assessment, which the patients could not cooperate with. They relied instead on preoperative cystograms to measure bladder capacity. Because roughly a third of channel complications emerge after more than five years, longer observation is needed to assess late problems such as channel stenosis, catheterization difficulties, false passages and recurrent leakage. The team recommends further prospective studies in larger numbers of patients before the technique’s place in the surgical toolkit can be firmly established.

Subject of Research: A modified surgical technique for total channel substitution in children with a leaking continent cutaneous catheterizable channel

Article Title: A modified technique of total channel substitution for management of a leaking continent cutaneous catheterizable channel in children: a preliminary report

Article References: Hussiny, M., T. Hafez, A., & Helmy, T. (2026). A modified technique of total channel substitution for management of a leaking continent cutaneous catheterizable channel in children: a preliminary report. African Journal of Urology, 32(1), Article 63. https://doi.org/10.1186/s12301-026-00613-2

Image Credits: AI Generated

DOI: 10.1186/s12301-026-00613-2

Keywords: continent catheterizable channel, pediatric urology, spiral Monti tube, serous-lined extramural tunnel, bladder augmentation, channel leakage, case report, neuropathic bladder, surgical technique, urinary continence, modified, technique