Comparing collagen paste and mucosal advancement flap for treating fistula-in-ano

Collagen Paste Injection Compared With Mucosal Advancement Flap for the Treatment of Fistula-in-ano: Single Centre Non-inferiority Randomised Controlled Trial

This study tests whether using collagen paste or surgery works better for healing high anal fistulas while keeping the anal sphincter functioning well.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 118 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Chinese University of Hong Kong (Academic / other)
• Locations: 2 sites (Shatin, New Territories and 1 other locations)
• Trial ID: NCT06386835 on ClinicalTrials.gov

What this trial studies

This clinical trial evaluates the effectiveness of collagen paste injection versus mucosal advancement flap surgery for treating high anal fistulas. The study aims to determine which method provides better healing and lower complication rates while preserving anal sphincter function. Collagen paste is a novel treatment that promotes healing through a matrix that enhances tissue contact and neovascularization. The trial includes patients with specific criteria, such as having undergone prior evaluation and treatment with a draining seton. The outcomes will help establish a more effective first-line treatment for fistula-in-ano.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older with a clinical diagnosis of high cryptoglandular fistula-in-ano who have undergone prior evaluation and treatment.

Not a fit: Patients with low trans-sphincteric fistulas or non-cryptoglandular fistulas, such as those related to Crohn's disease or malignancy, may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a more effective and less invasive treatment option for patients suffering from fistula-in-ano.

How similar studies have performed: Limited data exists on collagen paste, but previous studies on similar surgical techniques have shown varying success rates, indicating potential for improvement.

Eligibility criteria

Inclusion Criteria:

* Clinical diagnosis of high cryptoglandular fistula-in-ano.
* Patients must have undergone a prior EUA to characterise the nature of the fistula.
* The fistula tract should be ≥ 2 cm in length.
* Only a single internal fistula opening should be present at EUA, such that the fistula is suitable for treatment by insertion of a seton drain.
* Patients must have been treated with a draining seton for a minimum period of 6 weeks prior to randomisation.
* Patients must be aged ≥ 18 years and able to provide informed consent.
* Fistulas must be of cryptoglandular aetiology.

Exclusion Criteria:

* Unable/unwilling to provide informed consent.
* Contraindication to general anaesthesia or spinal anaesthesia.
* Low trans-sphincteric fistulas.
* Non-cryptoglandular fistulas (e.g. Crohn's disease, obstetric, irradiation, malignant, etc.).
* Other perineal fistulas (e.g. rectovaginal fistulas, pouch-vaginal fistulas, etc.).
* Complex disease in which more than one internal fistula opening is present and requiring concurrent insertion of more than one fistula plug.
* Clinical evidence of active perianal sepsis. In the event that there is disagreement between clinical and radiological assessment of active sepsis/collection, the clinical opinion will prevail.
* Cultural or religious objection to the use of pig tissue.
* Absolute contraindication to magnetic resonance imaging (MRI) (e.g. cardiac pacemaker).
* Patients with recurrent anal fistulas previously treated with a fistula plug.

Where this trial is running

Shatin, New Territories and 1 other locations

• Department of Surgery, Chinese University of Hong Kong — Shatin, New Territories, Hong Kong (Recruiting)
• Prince of Wlaes Hospital — Shatin, Hong Kong (Recruiting)

Study contacts

• Study coordinator: Kaori Futaba, FRCS

Conditions Fistula-in-ano