Liposomal Bupivacaine vs Ropivacaine for Post-hemorrhoidectomy Analgesia

Milligan-Morgan open hemorrhoidectomy is associated with substantial postoperative pain due to rich somatic innervation of the perianal region, wound exposure, anal sphincter spasm, and stimulation during defecation. Optimizing postoperative analgesia is critical for enhanced recovery. Local wound infiltration with ropivacaine is commonly used but provides limited duration of analgesia. Liposomal bupivacaine, formulated with a multivesicular liposomal delivery system, enables sustained release of bupivacaine at the injection site and may prolong local analgesia. However, high-quality comparative evidence between liposomal bupivacaine and ropivacaine for wound infiltration after open hemorrhoidectomy remains limited.

This single-center, prospective, randomized, double-blind controlled trial enrolled patients aged 18-60 years with grade III-IV internal hemorrhoids or mixed hemorrhoids scheduled for elective Milligan-Morgan open hemorrhoidectomy at Tongliao People's Hospital between November 2025 and May 2026. Patients were randomized 1:1 to receive perianal wound infiltration with either 266 mg of liposomal bupivacaine or 200 mg of ropivacaine hydrochloride, both diluted to 30 mL with normal saline and divided into six 5-mL aliquots infiltrated at six predefined perianal clock-face positions. All patients received spinal anesthesia with 15 mg of 0.5% hyperbaric bupivacaine. Rescue analgesia with oral diclofenac sodium 50 mg was provided when VAS pain score was ≥4.

The primary outcome is resting VAS pain score at 24 hours postoperatively. Secondary outcomes include resting and movement-evoked VAS pain scores at 4, 6, 12, 24, and 48 hours, cumulative diclofenac sodium consumption during postoperative days 1-3, QoR-40 total scores on postoperative days 1-3, and adverse events (nausea and vomiting, rash, lower-extremity numbness or weakness, local anesthetic systemic toxicity, perianal hematoma, surgical-site infection) within 72 hours.