Repeat liposomal bupivacaine for pain after anal fistula surgery.

Efficacy of Repeat Dosing of Liposomal Bupivacaine on Postoperative Pain in Patients With Anal Fistula: A Multicenter, Randomized, Open-Label, Controlled Study

We will see if giving a second dose of liposomal bupivacaine 72 hours after anal fistula surgery reduces postoperative pain in adults.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 408 (estimated)
• Ages: 18 Years to 60 Years
• Sex: All
• Sponsor: Sixth Affiliated Hospital, Sun Yat-sen University (Academic / other)
• Drugs / interventions: chemotherapy
• Locations: 1 site (Guangzhou, Guangdong)
• Trial ID: NCT07081373 on ClinicalTrials.gov

What this trial studies

This interventional protocol tests whether an initial intraoperative dose of liposomal bupivacaine followed by a supplemental dose at 72 hours improves postoperative analgesia after anal fistula repair. Eligible adults (18–60 years, ASA I–II) receive a single dose at the end of surgery without adjunctive analgesics and a planned repeat dose 72 hours postoperatively. Pain scores, rescue analgesic use, wound healing, and length of hospital stay will be recorded during the postoperative period. Patients with active perianal infection, poorly controlled diabetes, recent chemo/radiotherapy, pregnancy/lactation, or hypersensitivity to local anesthetics are excluded.

Who should consider this trial

Good fit: Adults aged 18–60 with an anal fistula scheduled for surgical repair who are ASA physical status I–II and can provide informed consent.

Not a fit: Patients who are pregnant or breastfeeding, have poorly controlled diabetes, active perianal infection, or known hypersensitivity to local anesthetics are unlikely to benefit or are excluded from participation.

Why it matters

Potential benefit: If successful, this approach could reduce postoperative pain, decrease opioid requirements, and shorten hospitalization after anal fistula surgery.

How similar studies have performed: Liposomal bupivacaine has shown prolonged analgesia up to 72 hours in other surgical settings, but repeat dosing at 72 hours is novel and has limited prior evidence.

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.

Where this trial is running

Guangzhou, Guangdong

• The Sixth Affiliated Hospital of Sun Yat-sen University — Guangzhou, Guangdong, China (Recruiting)

Study contacts

• Study coordinator: Hongcheng Lin, MD

Conditions Anal Fistula; Anal fistula; Bupivacaine liposome; Postoperative pain; Repeat dosing