Intraoperative intercostal nerve cryoablation During the Nuss procedure reduces length of stay and opioid requirement: A randomized clinical trial.

ABSTRACT

PURPOSE: Minimally-invasive repair of pectus excavatum by the Nuss procedure is associated with significant postoperative pain, prolonged hospital stay, and high opiate requirement. We hypothesized that intercostal nerve cryoablation during the Nuss procedure reduces hospital length of stay (LOS) compared to thoracic epidural analgesia. DESIGN: This randomized clinical trial evaluated 20 consecutive patients undergoing the Nuss procedure for pectus excavatum between May 2016 and March 2018. Patients were randomized evenly via closed-envelope method to receive either cryoanalgesia or thoracic epidural analgesia. Patients and physicians were blinded to study arm until immediately preoperatively. SETTING: Single institution, UCSF-Benioff Children's Hospital. PARTICIPANTS: 20 consecutive patients were recruited from those scheduled for the Nuss procedure. Exclusion criteria were age < 13 years, chest wall anomaly other than pectus excavatum, previous repair or other thoracic surgery, and chronic use of pain medications. MAIN OUTCOMES AND MEASURES: Primary outcome was postoperative LOS. Secondary outcomes included total operative time, total/daily opioid requirement, inpatient/outpatient pain score, and complications. Primary outcome data were analyzed by the Mann-Whitney U-test for nonparametric continuous variables. Other continuous variables were analyzed by two-tailed t-test, while categorical data were compared via Chi-squared test, with alpha = 0.05 for significance. RESULTS: 20 patients were randomized to receive either cryoablation (n = 10) or thoracic epidural (n = 10). Mean operating room time was 46.5 min longer in the cryoanalgesia group (p = 0.0001). Median LOS decreased by 2 days in patients undergoing cryoablation, to 3 days from 5 days (Mann-Whitney U, p = 0.0001). Cryoablation patients required significantly less inpatient opioid analgesia with a mean decrease of 416 mg oral morphine equivalent per patient (p = 0.0001), requiring 52%-82% fewer milligrams on postoperative days 1-3 (p < 0.01 each day). There was no difference in mean pain score between the groups at any point postoperatively, up to one year, and no increased incidence of neuropathic pain in the cryoablation group. No complications were noted in the cryoablation group; among patients with epidurals, one patient experienced a symptomatic pneumothorax and another had urinary retention. CONCLUSIONS AND RELEVANCE Intercostal nerve cryoablation during the Nuss procedure decreases hospital length of stay and opiate requirement versus thoracic epidural analgesia, while offering equivalent pain control. TYPE OF STUDY Treatment study. LEVEL OF EVIDENCE Level I.