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

NCT ID: NCT07081373

Last Updated: 2025-07-23

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 408 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-07-16
• Study Completion Date: 2027-06-30

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Liposomal Bupivacaine Repeat Dosing Group

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

Group Type: 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.

Intervention Type: 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 Single-Injection Group

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

Group Type: NO_INTERVENTION

No interventions assigned to this group

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.

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.

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• 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.

Exclusion Criteria

• 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;
• Other clinical/laboratory conditions deemed by investigators to preclude trial participation.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine

UNKNOWN

Sponsor Role: collaborator

Maoming People's Hospital

OTHER

Sponsor Role: collaborator

Dongguan Hospital of Traditional Chinese Medicine

OTHER

Sponsor Role: collaborator

Xingyi People's Hospital

UNKNOWN

Sponsor Role: collaborator

Nanjing Hospital of C. M.

UNKNOWN

Sponsor Role: collaborator

People's Hospital of Xinjiang Uygur Autonomous Region

OTHER

Sponsor Role: collaborator

Sixth Affiliated Hospital, Sun Yat-sen University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

The Sixth Affiliated Hospital of Sun Yat-sen University

Guangzhou, Guangdong, China

Site Status: RECRUITING

Countries

China

Central Contacts

Hongcheng Lin, MD

Role: CONTACT

lhcheng@mail.sysu.edu.cn

+86 15915815776

Facility Contacts

Hongcheng Lin, MD

Role: primary

lhcheng@mail.sysu.edu.cn

+86 15915815776

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Other Identifiers

2025ZSLYEC-365

Identifier Type: -

Identifier Source: org_study_id