Effect of Local Infiltration of Liposomal Bupivacaine on Postoperative Analgesia in Patients With Craniotomy Microvascular Decompression

Effect of Local Infiltration of Liposomal Bupivacaine on Postoperative Analgesia in Patients With Craniotomy Microvascular Decompression: a Randomized Controlled Study

Background: Approximately 60-84% of patients undergoing craniotomy experience moderate to severe pain within 48 hours postoperatively, with posterior fossa craniotomy patients experiencing more severe pain. Microvascular decompression (MVD) is a type of posterior fossa surgery. Traditional analgesic regimens rely on intravenous opioids, but these have significant side effects. Currently, local infiltration at the incision site is a simple and effective analgesic method in multimodal analgesia protocols after craniotomy. Liposomal bupivacaine (Exparel®) is a new type of sustained-release local anesthetic. Its liposome encapsulation technology can extend the drug release time to 72 hours, covering the entire time window of postoperative acute pain and helping patients better control pain.

Objective: This study aims to explore the efficacy of local infiltration of liposomal bupivacaine at the scalp incision in acute pain after microvascular decompression in neurosurgery and provide evidence for clinical practice.

Methods: This study is a single-center, prospective, randomized controlled trial. A total of 100 patients scheduled for elective craniotomy for microvascular decompression will be enrolled. They will be randomly assigned to the liposomal bupivacaine incision infiltration group (LB group) or the conventional treatment control group (C group). After induction of general anesthesia, in the LB group, after preoperative disinfection and draping, the surgeon will perform layer-by-layer infiltration of the incision (subcutaneous → muscle → periosteum) before skin incision. In the C group, the routine procedure of direct disinfection and draping followed by skin incision will be performed. Both groups will receive standardized multimodal analgesia after returning to the ward. The primary outcome measure is the area under the curve of the numerical rating scale (NRS) for rest pain from 0 to 72 hours postoperatively (AUC NRS-R0-72). Secondary outcome measures include the time to first analgesic request within 72 hours postoperatively; rescue analgesia within 72 hours postoperatively (opioid analgesics converted to morphine milligram equivalents); NRS scores at 6, 12, 24, 48, and 72 hours postoperatively; hemodynamic data: heart rate and blood pressure at skin incision, 1 hour after skin incision, 2 hours after skin incision, at the end of surgery, and 1 hour postoperatively; QoR-15 score at 72 hours postoperatively; and length of hospital stay and hospitalization costs.

Study Overview

• Status: Not yet recruiting
• Conditions: Microvascular Decompression; Liposomal Bupivacaine
• Intervention / Treatment: Other: normal operation; Drug: liposomal bupivacaine local infiltration

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Wen Fan, M.A.; Phone Number: 86-13738142076; Email: mosquitofw@qq.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• (1) Age ≥ 18 years old;
• (2) ASA classification ≤ III grade, patients scheduled to undergo craniotomy and microvascular decompression surgery.

Exclusion Criteria:

• (1) Trauma or emergency patients;
• (2) Patients with cardiac conduction block (sinus node conduction block or atrioventricular conduction block);
• (3) Patients with coagulation dysfunction;
• (4) Patients who have abused alcohol or had severe dependence on anesthetic drugs within the past 2 months;
• (5) Patients with uncontrolled anxiety disorder, schizophrenia or other mental illnesses;
• (6) Patients with a history of allergy to local anesthetics or non-steroidal drugs.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Control group; For this group of patients, after routine disinfection and draping, the incision operation was performed directly.	Other: normal operation; Following the normal procedure, after direct disinfection and draping, the incision operation can be carried out.
Experimental: Liposome bupivacaine group; After the patients in this group underwent preoperative disinfection and draping, the surgical doctor gradually infiltrated the liposomal bupivacaine into the incision layer by layer (subcutaneous → muscle → periosteum), and then proceeded with the incision operation.	Drug: liposomal bupivacaine local infiltration; Before the operation, local infiltration of the scalp incision was performed using liposomal bupivacaine.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
AUC NRS-R0-72	The area under the curve of the resting pain score from 0 to 72 hours after the operation	From 0 to 72 hours after the operation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The time required for the first postoperative analgesic administration within 72 hours after the operation	The time required for the first postoperative analgesic administration within 72 hours after the operation	From 0 to 72 hours after the operation
The situation of emergency pain relief within 72 hours after the operation	The situation of emergency pain relief within 72 hours after the operation(Converting the dosage of opioid painkillers into milligram equivalents of morphine)	From 0 to72 hours after the operation
NRS scores at 6 hours, 12 hours, 24 hours, 48 hours, and 72 hours after the operation	Numerical rating scale（NRS) scores at 6 hours, 12 hours, 24 hours, 48 hours, and 72 hours after the operation	From 0 to 72 hours after the operation
Hemodynamic data 1	Heart rate at the time of incision, 1 hour after incision, 2 hours after incision, at the end of the surgery, and 1 hour after surgery.	From the time of incision to 1 hour after surgery
Hemodynamic data 2	Blood pressure at the time of incision, 1 hour after incision, 2 hours after incision, at the end of the surgery, and 1 hour after surgery.	From the time of incision to 1 hour after surgery
QoR-15 score	The 15-item quality of recovery scale at 72 hours after the operation	At 72 hours after the operation
Length of hospital stay	The duration from admission to discharge	From admission to discharge
Hospital expenses	The medical expenses incurred from admission to discharge	From admission to discharge

Collaborators and Investigators

• Sponsor: Second Affiliated Hospital, School of Medicine, Zhejiang University

Study record dates

Study Major Dates

• Study Start (Estimated): November 1, 2025
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: September 22, 2025
• First Submitted That Met QC Criteria: November 17, 2025
• First Posted (Actual): November 24, 2025

Study Record Updates

• Last Update Posted (Actual): November 24, 2025
• Last Update Submitted That Met QC Criteria: November 17, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Liposomal Bupivacaine; scalp infiltration; Microvascular decompression
• Other Study ID Numbers: 2025-1230

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No