TROPIS Versus Coring Out Fistulectomy in High Anal Fistula (TROCO-HAF)

Early Results of Transanal Opening of the Intersphincteric Space (TROPIS) Versus Coring Out Fistulectomy in Management of High Anal Fistulas: A Randomized Clinical Trial

High anal fistulas represent a surgical challenge due to high recurrence rates and risk of postoperative fecal incontinence. Several sphincter-preserving techniques have been developed to address these issues. Coring Out fistulectomy is a traditional sphincter-saving approach, while Transanal Opening of the Intersphincteric Space (TROPIS) is a recently introduced technique with promising outcomes. This randomized clinical trial aims to compare the efficacy, safety, and patient outcomes of TROPIS versus coring out fistulectomy in the management of high complex anal fistulas.

Study Overview

• Status: Recruiting
• Conditions: High Anal Fistula
• Intervention / Treatment: Procedure: Transanal opening of intersphincteric space (TROPIS); Procedure: Coring Out Fistulectomy

Detailed Description

Fistula-in-ano is an abnormal epithelialized tract connecting the anal canal to the perianal skin, most commonly caused by cryptoglandular infection. High anal fistulas, involving more than one-third of the sphincter complex, carry a significant risk of postoperative incontinence when treated with fistulotomy. As a result, sphincter-preserving techniques have introduced.

Coring out fistulectomy allows excision of the fistulous tract while preserving sphincter integrity but has variable recurrence rates. TROPIS involves transanal opening of the intersphincteric space with complete preservation of the external anal sphincter and has shown high success rates in recent studies.

This prospective randomized clinical trial compares TROPIS and coring out fistulectomy regarding Failure rate (defined as failure of healing or recurrence of anal fistula), operative time, time for wound healing and postoperative complications including fecal incontinence.

• Study Type: Interventional
• Enrollment (Estimated): 64
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ahmed Mohamed Abdelaal, Lecturer; Phone Number: +201118732767; Email: drabdelaal90@gmail.com

Study Locations

• Egypt
  • Al-Manial Cairo
    • Cairo, Al-Manial Cairo, Egypt, 11451
      • Recruiting
      • Faculty of medicine Cairo University
      • Contact: Ahmed Mohamed Abdelaal, Lecturer; Phone Number: +201118732767; Email: drabdelaal90@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients with high anal fistula ( involving more than 1/3 of the sphincter complex), whether de novo or recurrent

Exclusion Criteria:

• Patients with fistula secondary to malignancy, inflammatory bowel disease, trauma or radiation
• Patients with Low anal fistula
• Patient with preoperative fecal incontinence
• Previous levator ani muscle injury

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Transanal Opening of the Intersphincteric Space (TROPIS); patient with high anal fistula will be treated with Transanal Opening of the Intersphincteric Space (TROPIS)	Procedure: Transanal opening of intersphincteric space (TROPIS); The fistula tracts on both sides of the External anal sphincter (EAS) are separately dealt with. A curved artery forceps is inserted in the fistula tract in the intersphincteric space through the internal opening.The mucosa and the internal sphincter overlying the artery forceps are then incised with electrocautery. The edges of the resulting wound are trimmed and A gutter is made inferiorly from the opened-up intersphincteric space to the anal verge to facilitate drainage from the intersphincteric space wound in the postoperative period.The fistula tract lateral to (outside) the EAS will be excised till the external anal sphincter.
Active Comparator: Coring Out Fistulectomy; patient with high anal fistula will be treated with Coring Out Fistulectomy	Procedure: Coring Out Fistulectomy; Incision was made around external opening.Coring out the fistulous track using a combination of cutting and coagulation diathermy from external opening to internal opening with closure of internal opening

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Compares Failure rate of TROPIS versus Coring Out fistulectomy in high fistula	Compares Failure rate of TROPIS versus Coring Out fistulectomy in high fistula (failure of healing or recurrence of anal fistula), Early results	Up to 4 months postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Operative time	compare time of operation between both procedure	During surgery
Hospitalization period	compare how many days patients stay in hospital postoperatively in both groups	From surgery until discharge
surgical site infection	compare surgical site infection in both groups	Up to 4 months postoperatively
Time for wound Healing	Time for wound Healing in both groups	Up to 4 months postoperatively
Postoperative bleeding	compare Postoperative bleeding in both groups	Up to 4 months postoperatively
postoperative fecal incontinence	compare post postoperative fecal incontinence in both groups	Up to 4 months postoperatively
Time to return to normal activity	Compare Time to return to normal activity in both groups	Up to 4 months postoperatively
Postoperative urine retention	compare postoperative urine retention in both groups	Within 48 hours postoperatively
Pain intensity	Compare Pain intensity measured using Visual Analogue Scale between both groups (Visual Analogue Scale for Pain: ranges from 0 to 10 . Higher scores indicate a worse outcome {greater pain intensity}).	At day 1 and day 7 postoperatively

Collaborators and Investigators

• Sponsor: Cairo University
• Investigators: Study Director: Haitham M.Azmy Basiouny, Lecturer, Cairo university

Study record dates

Study Major Dates

• Study Start (Actual): July 8, 2025
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: December 31, 2025
• First Submitted That Met QC Criteria: December 31, 2025
• First Posted (Actual): January 12, 2026

Study Record Updates

• Last Update Posted (Actual): May 27, 2026
• Last Update Submitted That Met QC Criteria: May 23, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: TROPIS; Intersphincteric Space; Coring Out Fistulectomy; High anal fistulas; Sphincter-Preserving Surgery
• Other Study ID Numbers: MS-311-2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared because this is a small surgical trial with a limited number of participants, and sharing raw data could lead to identification of participants

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No