High anal fistula is a complex anorectal condition that can cause persistent pain, purulent discharge, recurrent infection, and a significant reduction in quality of life. The conventional cutting seton technique is an established treatment modality; however, it may be associated with postoperative pain, delayed healing, recurrence, and impairment of anal continence. GLUBRAN® is a synthetic surgical adhesive with antimicrobial and tissue-healing properties that may enhance the performance of the cutting seton and improve clinical outcomes.

This randomized controlled clinical trial aims to compare the efficacy and safety of a conventional cutting seton with a GLUBRAN®-coated cutting seton in adult patients with high anal fistulas. Eligible participants will be randomly allocated to one of the two treatment groups and followed for six months after surgery. The primary and secondary outcome measures will include fistula healing rate, time to complete healing, postoperative pain, anal continence, recurrence, postoperative complications, and length of hospital stay.

The findings of this study may provide evidence regarding whether coating a cutting seton with GLUBRAN® offers clinical advantages over the conventional technique, potentially leading to improved healing, reduced postoperative morbidity, and better preservation of anal continence in the management of high anal fistulas.

High anal fistula is a challenging anorectal disorder characterized by an abnormal communication between the anal canal and the perianal skin that involves a significant portion of the anal sphincter complex. Patients with high anal fistulas commonly present with persistent perianal pain, recurrent abscess formation, purulent discharge, local irritation, and a substantial reduction in quality of life. These fistulas are considered complex because of their anatomical relationship with the anal sphincter muscles and the increased risk of postoperative continence impairment following surgical treatment. Consequently, the ideal management strategy should achieve complete eradication of the fistula tract while preserving sphincter function and minimizing the risk of recurrence.

The cutting seton technique has long been used as a sphincter-preserving surgical approach for the management of high anal fistulas. The procedure involves placement of a seton through the fistula tract, allowing gradual division of the sphincter muscle while promoting fibrosis and controlled healing. Although this technique has demonstrated satisfactory healing rates in numerous studies, concerns remain regarding postoperative pain, prolonged healing time, recurrence, local infection, and varying degrees of fecal incontinence. Therefore, ongoing efforts have focused on identifying modifications that may improve clinical outcomes while maintaining the effectiveness of the procedure.

GLUBRAN® is a synthetic cyanoacrylate-based surgical adhesive that has been used in multiple surgical specialties because of its adhesive, hemostatic, sealing, and bacteriostatic properties. Experimental and clinical evidence suggests that cyanoacrylate-based materials may reduce bacterial colonization, attenuate local inflammatory responses, provide mechanical support to healing tissues, and promote tissue repair. Coating a cutting seton with GLUBRAN® may therefore enhance the therapeutic effect of the procedure by reducing local infection, minimizing tissue irritation, facilitating wound healing, and potentially decreasing postoperative complications. Despite these theoretical advantages, there is currently limited clinical evidence directly comparing GLUBRAN®-coated cutting setons with conventional cutting setons in the management of high anal fistulas.

This study is designed as a prospective, randomized controlled clinical trial conducted at Cairo University Hospitals to evaluate the efficacy and safety of GLUBRAN®-coated cutting setons compared with conventional cutting setons in adult patients with high anal fistulas. Eligible participants will include patients aged 18 years or older with high trans-sphincteric, suprasphincteric, extrasphincteric, or otherwise complex anal fistulas confirmed by clinical examination and magnetic resonance imaging (MRI) fistulography. Patients with Crohn's disease, tuberculosis, malignancy-associated fistulas, radiation-induced fistulas, active perianal abscesses, or significant uncontrolled medical conditions that may interfere with wound healing will be excluded.

Following enrollment, participants will be randomly allocated in a 1:1 ratio to one of two treatment groups. Patients assigned to the control group will undergo conventional cutting seton placement using silk suture material. Patients assigned to the intervention group will undergo placement of a silk cutting seton coated with GLUBRAN® surgical adhesive before insertion through the fistula tract. All procedures will be performed according to standardized operative techniques, and all participants will receive standardized postoperative care, including analgesia, antibiotic therapy when indicated, and scheduled outpatient follow-up.

Participants will be monitored throughout the postoperative period and during a six-month follow-up. Clinical assessments will evaluate wound healing, symptom resolution, postoperative pain, continence status, recurrence, and treatment-related complications. Pain severity will be assessed using the Numerical Rating Scale (NRS), while continence will be evaluated using the validated Wexner Continence Score. Additional outcome measures will include postoperative infection, abscess formation, bleeding, length of hospital stay, need for reintervention, and overall postoperative recovery.

The primary objectives of this study are to compare complete healing rates, time to complete healing, and preservation of anal continence between the two treatment groups. Secondary objectives include comparing postoperative pain, complication rates, recurrence rates, and length of hospital stay. By systematically evaluating these outcomes, this study seeks to determine whether coating a cutting seton with GLUBRAN® provides clinically meaningful benefits over the conventional technique.

The results of this trial are expected to provide valuable evidence regarding the role of GLUBRAN® in the management of high anal fistulas. If shown to improve healing while reducing postoperative complications and preserving anal continence, GLUBRAN®-coated cutting setons may represent a safe and effective modification of the conventional cutting seton technique. The findings may help guide future surgical practice, optimize patient outcomes, and improve the quality of care provided to patients with this challenging condition.

Inclusion Criteria: - Patients diagnosed with high trans-sphincteric/Extrasphinteric/supra-sphincteric/complex Fistula confirmed clinically and MRI Fistulogram

• Age ≥ 18 years
• Patients fit for surgery.

Exclusion Criteria:

• Patients with Crohn's disease, tuberculosis, malignancy, or radiation-associated fistulas (due to different healing patterns and management protocols).
• Presence of acute perianal abscess at the time of surgery
• Patients with uncontrolled comorbidities (e.g., diabetes mellitus, bleeding disorders, immunosuppression) that could affect healing.

Individual participant data will not be shared publicly due to patient confidentiality considerations, the sensitive nature of clinical surgical data, and institutional data protection policies. Only aggregated results will be reported.