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

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.