Study on Repeat Liposomal Bupivacaine for Post-Surgery Pain in Anal Fistula Patients.

NCT07081373 | Recruiting DMC

• 1 other identifier: 2025ZSLYEC-365
• Study Type: interventional
• Target: 408
• Locations: 1 country
• Sites: 1

Brief Summary

Anal Fistula refers to an abnormal infectious fistula tract between the anorectum and the perianal skin. The prevalence of anal fistula is approximately 8.6 cases per 100,000 individuals. It can occur at any age but is relatively more common in individuals aged 20-40 years, with a higher incidence in males than females. Postoperative wound management is a critical component of the overall treatment for anal fistula patients. Regular postoperative wound care, such as dressing changes, can reduce recurrence rates, alleviate pain, and shorten hospitalization time. However, postoperative pain remains a major challenge in wound management following anal fistula surgery. This is largely attributed to inadequate current postoperative analgesic protocols. With ongoing advancements in local anesthetics, liposomal bupivacaine has been applied for postoperative analgesia. It offers higher bioavailability and a prolonged half-life, providing up to 72 hours of sustained analgesic effect. Given the limitations of existing analgesic strategies for post-anal fistula surgery, developing more effective pain management approaches to reduce postoperative pain holds significant clinical importance. Therefore, the investigators propose that a repeat-dosing strategy based on liposomal bupivacaine may provide superior postoperative pain control for anal fistula patients. To investigate this, the investigators designed a prospective, multicenter, randomized, open-label, controlled clinical trial. This study aims to evaluate the efficacy and safety of repeat-dose liposomal bupivacaine for postoperative analgesia following anal fistula surgery, thereby generating high-level evidence to support its clinical application in this context.

Conditions

Anal Fistula

Keywords

Anal fistula; Bupivacaine liposome; Postoperative pain; Repeat dosing

Outcome Measures

Primary Outcomes (1)

• Area Under the Curve (AUC) of the Numerical Rating Scale (NRS) for pain within 7 Days postoperatively (NRS-AUC0-168h)

  Numerical rating scale, a numerical rating scale where participants select a number from 0 to 10 based on their subjective pain experience. On this scale: 0 represents no pain; 10 represents the most severe pain imaginable.

  7 days postoperatively

Secondary Outcomes (17)

• Numerical Rating Scale (NRS) for pain during wound dressing changes within 7 days postoperatively

  7 days postoperatively

• Area Under the Curve (AUC) of the Numerical Rating Scale (NRS) for pain from 96 to 168 hours postoperatively (NRS-AUC96h-168h)

  96 to 168 hours postoperatively

• Number of breakthrough pain episodes and corresponding Numerical Rating Scale (NRS) scores during episodes

  7 days postoperatively

• Postoperative 7-day cumulative consumption of all analgesic drugs (calculated as morphine equivalents)

  7 days postoperatively

• Postoperative 7-day cumulative consumption of rescue analgesic drugs (calculated as morphine equivalents)

  7 days postoperatively

Study Arms (2)

Liposomal Bupivacaine Repeat Dosing Group

EXPERIMENTAL

A single dose of liposomal bupivacaine is administered at the conclusion of surgery without adjunctive analgesics, followed by a supplemental dose 72 hours postoperatively.

Drug: A single dose of liposomal bupivacaine is administered at the conclusion of surgery without adjunctive analgesics, followed by a supplemental dose 72 hours postoperatively.

Liposomal Bupivacaine Single-Injection Group

NO INTERVENTION

A single dose of liposomal bupivacaine is administered at the conclusion of surgery without adjunctive analgesics.

Interventions

A single dose of liposomal bupivacaine is administered at the conclusion of surgery without adjunctive analgesics, followed by a supplemental dose 72 hours postoperatively. DRUG

At surgical closure, a single dose of undiluted liposomal bupivacaine (266 mg/20 mL) is administered without concurrent analgesics. The total 20 mL volume is divided into six equal aliquots (≈3.3 mL each) and infiltrated circumferentially around the incision using a 25-gauge or larger-bore needle. Injections target tissue layers above and below the fascia and within the subcutaneous plane, with frequent aspiration during administration to mitigate intravascular injection risk. Seventy-two hours postoperatively, a repeat dose of undiluted liposomal bupivacaine (266 mg/20 mL) is administered. Prior to infiltration, topical lidocaine cream is applied to the per-incisional skin for ≥20 minutes. The full 20 mL volume is then injected uniformly around the incision via circumferential needle advancement into pericicatricial tissues.

Liposomal Bupivacaine Repeat Dosing Group

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Diagnosed with anal fistula and scheduled to undergo anal fistula surgery;
• Aged between 18 and 60 years;
• ASA (American Society of Anesthesiologists) physical status class I-II;
• Patient provides written informed consent after understanding the study protocol.

You may not qualify if:

• Anal fistula caused by specific etiologies (e.g., tuberculosis);
• Concurrent acute perianal skin infection;
• Poorly controlled diabetes (HbA1c \>9%);
• Chronic use of corticosteroids;
• History of radiotherapy or chemotherapy within the past 2 weeks;
• Pregnancy or lactation;
• Hypersensitivity to local anesthetics or any component of the investigational drug;
• History of substance abuse, illicit drug use, or alcohol abuse;
• Use or planned use of non-opioid/opioid analgesics within 12 hours before/during surgery;
• Concurrent treatment with anticonvulsants, MAO inhibitors, antidepressants, neuromuscular blockers, or anticholinergics within 2 weeks prior to surgery;
• Severe hepatic/renal impairment, cardiopulmonary dysfunction, coagulation disorders, or comorbidities contraindicating surgery;
• History of severe psychiatric disorders or cognitive impairment;
• Sensory disorders (e.g., hyperalgesia) or preexisting pain interfering with postoperative pain assessment;
• Contraindications to amide-type local anesthetics, opioids, or propofol;
• Participation in investigational drug trials within 90 days prior to enrollment;

Sponsors & Collaborators

• Sixth Affiliated Hospital, Sun Yat-sen University: lead
• The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine: collaborator
• Maoming People's Hospital: collaborator
• Dongguan Hospital of Traditional Chinese Medicine: collaborator
• Xingyi People's Hospital: collaborator
• Nanjing Hospital of C. M.: collaborator
• People's Hospital of Xinjiang Uygur Autonomous Region: collaborator

Study Sites (1)

The Sixth Affiliated Hospital of Sun Yat-sen University

Guangzhou, Guangdong, China

RECRUITING

MeSH Terms

Conditions

Rectal Fistula; Pain, Postoperative

Condition Hierarchy (Ancestors)

Intestinal Fistula; Digestive System Fistula; Digestive System Diseases; Intestinal Diseases; Gastrointestinal Diseases; Rectal Diseases; Fistula; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms; Postoperative Complications; Pathologic Processes; Pain; Neurologic Manifestations; Signs and Symptoms

Central Study Contacts

Hongcheng Lin, MD

CONTACT

+86 15915815776; lhcheng@mail.sysu.edu.cn

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 26, 2025
• First Posted: July 23, 2025
• Study Start: July 16, 2025
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): June 30, 2027
• Last Updated: July 23, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)