Intraoperative Intracavernosal Liposomal Bupivacaine (Exparel) Injection Does Not Affect Systemic Hemodynamics

Hisanori Taniguchi, MD, PhD and John P. Mulhall, MD, MSc, FECSM, FACS

FIRST PUBLISHED: January 23, 2020 – The Journal of Sexual Medicine

DOI: https://doi.org/10.1016/j.jsxm.2019.12.017

Introduction

While penile implants are an effective treatment for medication-refractory erectile dysfunction (ED), perioperative pain management is a great concern.

Local anesthetics, including chloroprocaine, lidocaine, and bupivacaine have been used for pain management.

Exparel, a liposomal formulation of bupivacaine, is a single-dose medication that can be injected into a surgical site. Its effect lasts from 72 to 96 hours, while the effects of traditional bupivacaine last less than 10 hours.

Previous research has shown that men given Exparel during implant procedures needed less narcotic medication within 24 hours of surgery compared to men not given Exparel. Despite previous concerns with local anesthetic systemic toxicity (LAST) that were raised for Exparel, this study did not investigate its effect on systemic hemodynamics.

The current study analyzed whether Exparel injections during implant surgery would have adverse effects on systemic hemodynamics.

Methods

Fifty-six penile implant recipients with a median age of 64 years participated in the study. All of the men had inflatable penile implant procedures. The ASA (American Society of Anesthesiologists) score was 3 in 42 patients, indicating severe systemic disease in the majority of the studied population.

One surgeon performed all procedures at the same institution. Surgery was conducted using a transverse scrotal approach.  About 30 minutes after the start of surgery, Exparel [10mL of 1.3% (13.3 mg/mL) was injected bilaterally intracavernosally with a 25-guage needle. At the end of surgery, 5 mL of Exparel was instilled in the area near the incision.

Before they were discharged from the postanesthesia care unit, all of the men rated their postoperative pain on a standard 10-point scale.

Results

The following highlights were reported:

• Preoperative median systolic blood pressure was 131 mmHg, which decreased 25% to 98 mmHg after anesthesia induction before any incision was made. However, no significant decreases in blood pressure were reported before and after the Exparel injection.
• Perioperative pulse rate and pulse oximetry oxygen saturation were stable.
• No arrythmias or convulsions occurred. There were no complications associated with the Exparel injection.
• The median postoperative pain scale measurement was 0 (IQR: 0-2.25).

Discussion

Exparel was approved by the U.S. Food and Drug Administration in October 2011. It is an extended-release formulation that diffuses over 72 to 96 hours.

Only one other paper has discussed the use of Exparel in penile implant procedures.  In that study, opioid use (morphine equivalent) was significantly lower in men who received Exparel compared to men who did not (5.6 vs 18.0  P < 0.05 ).

Another study has described local anesthetic systemic toxicity (LAST) related to Exparel. LAST is characterized by central nervous system symptoms and cardiovascular symptoms. “[The] report suggested that severe systemic toxicity due to Exparel (seizures with or without cardiac arrest) could possibly occur after peripheral nerve block using Exparel, similar to those occurring with traditional bupivacaine.”  However, “the incidence of serious adverse events is unknown.”

The absence of Exparel blood level data was noted as the study’s main limitation.

Conclusion 

The authors conclude that ”intraoperative intracavernosal Exparel injection does not affect systemic hemodynamics.”