Ultrasound-Guided Percutaneous Cryoneurolysis to Treat Pain Following Thoracic Trauma

Summary

Thoracic trauma frequently involve rib fractures which can be very painful for 2-3 months. Unfortunately, pain is not simply a "symptom" of the injuries, but a significant cause of additional medical problems: pain causes people to breath and cough less deeply/often which increases the risk of collapsing little parts of the lung. These collapsed areas often lead to complications which can increase the risk of death. In addition, the higher the amount of pain in the weeks following the fracture, the higher the risk of developing persistent, chronic pain that can last indefinitely. So, providing excellent pain control is very important for a variety of reasons. Various nerve blocks can greatly decrease pain, but even the longest acting are measured in hours or days, and not the weeks and months for which rib fracture pain can last. Therefore, opioids-"narcotics"-are the most common pain control method provided to patients; but they frequently do not provide enough pain control, have undesirable side effects like nausea and vomiting, and are sometimes misused which can lead to addiction or overdose.

A prolonged nerve block lasting multiple months from a single treatment may be provided by freezing the nerve using a process called "cryoneurolysis". With cryoneurolysis and ultrasound machines, a very small "probe" may be placed through anesthetized skin and guided to the target nerve to allow freezing. The procedure takes about 5 minutes for each nerve, involves little discomfort, has no side effects, and cannot be misused or addictive. After 2-3 months, the nerve returns to normal functioning. The investigators have completed a small study suggesting that a single cryoneurolysis treatment provides potent short- and long-term pain relief following thoracic trauma with rib fractures. The ultimate objective of the proposed research is to determine if percutaneous cryoneurolysis is an effective non-opioid, single-application treatment for pain following traumatic rib fracture.

The current project is a pragmatic, multicenter, randomized, triple-masked (investigators, participants, statisticians), sham/placebo-controlled, parallel-arm, human-subjects, post-market clinical trial to determine if cryoneurolysis is an effective non-opioid treatment for pain following traumatic rib fractures.

Conditions

• Rib Fracture
• Rib Fracture Multiple

Interventions

DEVICE

Cryoneurolysis

Active cryoneurolysis of the intercostal nerve of each fractured rib along with one cephalad and one caudad will be targeted: for each nerve the cryoneurolysis device will be triggered using 3 cycles of 2-minute nitrous oxide activation separated by 1-minute defrost periods (Epimed) or for the Varian: 5.5-minute \[all but 5 participants\] or 3-minute \[5th - 12th participants; changes based on new laboratory and subsequently clinical data\] argon activation (2000 psi starting at 100% power but decreased to keep return gas flow temperature warmer than -100C) followed by a 30-second helium defrost. For the active comparator, the gas will be deployed to the tip where a drop in temperature will result in cryoneurolysis.

PROCEDURE

Local anesthetic peripheral nerve block

Due to the pragmatic design of this trial, study participation will not alter an institution's current practice. Examples of peripheral nerve blocks include paravertebral, erector spinae plane, and serratus anterior nerve blocks. The injectate through the introducer will depend on the treatment group: for participants of the control group, ropivacaine 0.5% or bupivacaine 0.375% (both with epinephrine 1:400,000) will be injected (volume determined by institutional standard-of-care). This will provide a peripheral nerve block for the control group.

DEVICE

Sham Cryoneurolysis

Sham cryoneurolysis of the intercostal nerve of each fractured rib along with one cephalad and one caudad will be targeted: for each nerve the cryoneurolysis device will be triggered using 3 cycles of 2-minute nitrous oxide activation separated by 1-minute defrost periods (Epimed) or for the Varian: 1 cycle of 5.5 minutes \[all but 5 participants\] or 3 minutes \[5th - 12th participants; changes based on new laboratory and subsequently clinical data\] of argon and 30 seconds of helium. However, for the sham comparator, the gas will NOT be deployed to the tip, there will NOT be a drop in temperature, and NO cryoneurolysis will occur.

PROCEDURE

Sham peripheral nerve block

Due to the pragmatic design of this trial, study participation will not alter an institution's current practice. Examples of peripheral nerve blocks include paravertebral, erector spinae plane, and serratus anterior nerve blocks: for participants allocated to the cryoneurolysis group (experimental group), normal saline will be injected for the peripheral nerve block. This will result in a sham/placebo nerve block for the experimental group.

Sponsors & Collaborators

• Congressionally Directed Medical Research Programs

  collaborator FED

• University of California, San Diego

  lead OTHER

Principal Investigators

• Brian Ilfeld, MD, MS · University of California, San Diego

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-10-30

Primary Completion

2026-12-31

Completion

2027-12-31

FDA Device

Yes

Countries

• United States

Study Locations