This study evaluates the use of liposomal bupivacaine (Exparel), a long-acting local anesthetic, for peri-procedural pain control in patients undergoing interventional radiology (IR) procedures. Effective pain management during and after IR procedures is important for patient comfort, procedural success, and recovery, yet standard local anesthetics (e.g., lidocaine or bupivacaine HCl) provide relatively short durations of analgesia.

Liposomal bupivacaine is an FDA-approved formulation designed to provide extended-release local anesthetic effects over a prolonged period. Its use has been studied in surgical settings, but data in interventional radiology procedures remain limited. This prospective, single-arm quality improvement initiative aims to assess whether incorporation of liposomal bupivacaine into routine procedural care improves patient-reported pain outcomes.

Adult patients undergoing IR procedures will receive liposomal bupivacaine administered by the proceduralist as part of standard care. Pain will be assessed using a structured patient-reported outcome survey at multiple time points, including pre-procedure, during the procedure, 1 hour post-procedure, and within 24 hours post-procedure. The survey also captures use of additional analgesic medications within the first 24 hours.

The primary outcome is patient-reported pain intensity. Secondary outcomes include post-procedural analgesic utilization. Data will be analyzed descriptively given the exploratory nature and small sample size.

Findings from this project may inform future approaches to pain management in interventional radiology and help determine whether longer-acting local anesthetics provide clinically meaningful improvements in patient experience.

Background and Rationale

Effective peri-procedural pain control is an important component of interventional radiology (IR) procedures, influencing patient comfort, procedural tolerance, and recovery. Standard local anesthetics such as lidocaine and bupivacaine hydrochloride provide relatively short durations of analgesia, which may not extend sufficiently into the post-procedural period.

Liposomal bupivacaine (Exparel) is an extended-release formulation of bupivacaine designed to provide prolonged local anesthetic effect following a single administration. While this formulation has been studied in surgical settings, its role in minimally invasive interventional radiology procedures is less well defined.

This quality improvement initiative is designed to evaluate whether the use of liposomal bupivacaine during IR procedures improves patient-reported pain outcomes and reduces the need for additional analgesics in the immediate post-procedural period.

Study Design

This is a prospective, single-arm, open-label quality improvement study conducted in adult patients undergoing interventional radiology procedures. All participants will receive liposomal bupivacaine as part of procedural care.

The study is exploratory in nature and is intended to generate preliminary data on patient-reported pain outcomes associated with the intervention.

Study Population

Inclusion Criteria:

Adults (≥18 years of age) Undergoing an interventional radiology procedure Able to provide informed consent

Exclusion Criteria:

Known allergy to bupivacaine or other amide local anesthetics History of chronic pain conditions Patients under 18 years of age Patients who do not consent to participation

Patients will be identified through routine clinical scheduling and approached on the day of the procedure by study personnel.

Intervention

Participants will receive liposomal bupivacaine administered by the interventional radiology provider at the procedural site.

The study preparation consists of:

10 mL of 0.5% bupivacaine hydrochloride 10 mL of liposomal bupivacaine (Exparel 1.3%, 133 mg/10 mL)

These are combined and administered via local infiltration at the procedural site in accordance with standard clinical practice.

Liposomal bupivacaine is FDA-approved for local infiltration; its use in this context may be considered off-label depending on the specific procedural indication.

Study Procedures and Data Collection Pain Assessment

Pain will be assessed using a structured patient-reported outcome survey developed for this project. The survey is informed by established pain assessment tools and captures pain intensity using a 0-10 numeric rating scale.

Pain scores will be collected at the following time points:

Immediately prior to the procedure During the procedure (maximum pain experienced)

1 hour post-procedure Within 24 hours post-procedure (maximum pain experienced) Analgesic Use

Participants will report whether additional analgesics were required within 24 hours after the procedure. Responses will be categorized as:

No additional analgesics Non-opioid analgesics Opioid analgesics Not sure Follow-Up

Follow-up data collection will occur either:

In person (for hospitalized patients), or Via telephone within 24 hours post-procedure Outcome Measures

Primary Outcome:

Patient-reported pain intensity (0-10 numeric rating scale) across defined peri-procedural time points

Secondary Outcomes:

Use of additional analgesics within 24 hours post-procedure Type of analgesics used (opioid vs non-opioid) Sample Size and Statistical Analysis

Approximately 10 participants will be enrolled. Given the small sample size, analyses will be descriptive and exploratory.

Pain scores will be summarized using measures of central tendency (e.g., mean, median) and variability. Analgesic use will be reported as proportions. No formal hypothesis testing is planned.

Risks and Safety

Risks associated with liposomal bupivacaine are similar to those of standard local anesthetics and include:

Injection site pain, bleeding, or infection Local tissue irritation or inflammation Allergic reactions Rare risk of local anesthetic systemic toxicity

Participation in the survey presents minimal risk and primarily involves minor inconvenience.

Patients will be monitored during procedures using standard clinical monitoring, including heart rate, blood pressure, oxygen saturation, and other routine parameters as indicated.

Benefits

Participants may experience improved peri-procedural pain control. There is no guarantee of direct benefit. The information obtained from this study may help improve pain management strategies for future patients undergoing interventional radiology procedures.

Data Management and Confidentiality

All data will be de-identified and stored in secure, password-protected systems accessible only to authorized study personnel. Data handling will comply with institutional privacy policies and applicable regulations, including HIPAA.

Monitoring

The Principal Investigator will oversee study conduct, data integrity, and safety monitoring. Given the minimal risk and quality improvement nature of the study, no Data Safety Monitoring Board is planned.

Significance

This study aims to generate preliminary data on the feasibility and effectiveness of liposomal bupivacaine for pain control in interventional radiology procedures. Findings may inform future studies and guide improvements in peri-procedural pain management.

Inclusion Criteria:

-

Exclusion Criteria:

• chronic pain condition