Comparison of Botulinum Toxin Injection and Lateral Internal Sphincterotomy in Chronic Anal Fissure Management

NCT07568314 | Recruiting

• 1 other identifier: ANTH-GS-CAF-2026
• Study Type: interventional
• Target: 90
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to compare two commonly used treatments for chronic anal fissure: botulinum toxin injection and lateral internal sphincterotomy. Chronic anal fissure is a painful condition that causes severe discomfort during bowel movements and can significantly affect a patient's quality of life. Botulinum toxin injection is a minimally invasive procedure that temporarily relaxes the anal sphincter muscle to promote healing. In contrast, lateral internal sphincterotomy is a minor surgical procedure that permanently reduces sphincter pressure and is considered the standard treatment with high healing rates. A total of 90 adult patients with chronic anal fissure will be enrolled and divided into two groups. One group will receive botulinum toxin injection, while the other group will undergo lateral internal sphincterotomy. Patients will be followed up regularly to assess healing, pain relief, recurrence of the fissure, and any complications such as incontinence. The purpose of this study is to determine which treatment provides better outcomes in terms of effectiveness and safety, helping doctors choose the most appropriate treatment for patients.

Conditions

Anal Fissure Chronic

Outcome Measures

Primary Outcomes (1)

• Proportion of patients with complete fissure healing at 3 months after treatment (Botulinum toxin vs. Lateral Internal Sphincterotomy). This is the main endpoint on which your sample size calculation and comparative effectiveness analysis are based.

  3 months for healing after intervention

Study Arms (2)

Botulinum Toxin Injection

EXPERIMENTAL

Participants in this arm will receive an intrasphincteric injection of 20 units of botulinum toxin type A. The toxin will be diluted in 1 ml of normal saline and administered as two injections of 10 units each at the 3 o'clock and 9 o'clock positions in the intersphincteric plane under aseptic conditions using a 26-30 gauge needle.

Drug: Botulinum Toxin Type A (BOTOX) Injection

Lateral Internal Sphincterotomy

ACTIVE COMPARATOR

Participants in this arm will undergo open lateral internal sphincterotomy under spinal anesthesia. A small incision will be made at the lateral position (3 o'clock), and the lower one-third of the internal anal sphincter will be divided under direct vision. Hemostasis will be secured, and the wound will be left open for secondary healing

Procedure: Lateral Internal Sphincterotomy

Interventions

Botulinum Toxin Type A (BOTOX) Injection DRUG

A total dose of 20 units of botulinum toxin type A will be administered via intrasphincteric injection. The toxin will be diluted in 1 ml of normal saline and injected into the internal anal sphincter in two equal doses of 10 units each at the 3 o'clock and 9 o'clock positions in the intersphincteric plane using a 26-30 gauge needle under aseptic conditions.

Botulinum Toxin Injection

Lateral Internal Sphincterotomy PROCEDURE

An open lateral internal sphincterotomy will be performed under spinal anesthesia. A small lateral incision will be made at the 3 o'clock position, and the lower one-third of the internal anal sphincter will be divided under direct vision. Hemostasis will be achieved, and the wound will be left open to heal by secondary intention.

Lateral Internal Sphincterotomy

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

Sponsors & Collaborators

• Islamabad Medical and Dental College: lead

Study Sites (1)

Islamabad Medical and Dental College

Islamabad, Federal, 44000, Pakistan

RECRUITING

MeSH Terms

Interventions

Botulinum Toxins, Type A; Lateral Internal Sphincterotomy

Intervention Hierarchy (Ancestors)

Botulinum Toxins; Metalloendopeptidases; Endopeptidases; Peptide Hydrolases; Hydrolases; Enzymes; Enzymes and Coenzymes; Metalloproteases; Bacterial Proteins; Proteins; Amino Acids, Peptides, and Proteins; Bacterial Toxins; Toxins, Biological; Biological Factors; Digestive System Surgical Procedures; Surgical Procedures, Operative; Sphincterotomy; Myotomy

Central Study Contacts

Prof.Dr Rizwan Aziz

CONTACT

+923008444229; aziz.rizwan@imdcollege.edu.pk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 28, 2026
• First Posted: May 5, 2026
• Study Start: March 2, 2026
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): August 31, 2026
• Last Updated: May 5, 2026

Record last verified: 2026-04

Locations

PA (1)