Bae, Jae-O

Introduction: Cryoablation of intercostal nerves is performed for pain control after minimally invasive repair of pectus excavatum (MIRPE). Cryoablation affects both sensory and motor neurons, resulting in temporary anesthesia to the chest wall and loss of intercostal motor function. The study objective is to determine the effect of cryoablation on incentive spirometry (IS) volumes, as a measure of pulmonary function, after MIRPE. Materials and Methods: A single-institution retrospective review of pediatric patients undergoing MIRPE was performed. All patients received a multimodal regimen (MMR) of analgesics postoperatively. Three groups were compared—cryoablation (CRYO), elastomeric pain pump (EPP), and MMR alone. The primary outcomes were postoperative IS volumes and IS volumes as a ratio of preoperative forced vital capacity (FVC). Secondary outcomes included pain scores, opioid use, length of stay (LOS), and infectious complications. Results: MIRPE was performed in 115 patients: 50 CRYO, 50 EPP, and 15 MMR alone. Groups were similar for demographics and pectus excavatum severity. Postoperative spirometry measurements were similar across groups: IS (CRYO 750 mL [500,961] versus EPP 750 mL [590,1019] versus MMR 696 mL [500,1037], P = .77); IS/FVC (CRYO 0.19 [0.14,0.26] versus EPP 0.20 [0.16,0.26] versus MMR 0.16 [0.15,0.24], P = .69). Although pain scores were also similar across groups, CRYO patients used less opioid ( P < .05) and had shorter LOS ( P < .05). Postoperative pneumonia was rare and similar across groups ( P = 1.00). Conclusion: Intercostal nerve cryoablation during MIRPE does not adversely affect postoperative IS volumes or increase pneumonia rate, despite the temporary loss of motor innervation to intercostal muscles. Cryoablation provides effective pain control with less opioid use.

Abstract Introduction: Cryoanalgesia has been applied to minimally invasive repair of pectus excavatum (MIRPE). After implementation of cryoanalgesia at our institution, we had several cases of delayed postoperative pneumothorax. The purpose of this study was to critically evaluate the complications and efficacy of cryoanalgesia in MIRPE. Materials and Methods: We performed a single institution retrospective review of pediatric patients undergoing MIRPE from June 2017 to July 2018. Multimodal (MM) analgesia was used in all patients. In addition, most patients received either cryoanalgesia or elastomeric pain pumps (EPPs) as adjuncts to postoperative analgesia. Primary outcome was clinically significant late pneumothorax. Secondary outcomes included length of stay, pain scores, opiate use, and bar displacement requiring reoperation. Results: A total of 101 patients undergoing MIRPE were included: 45 had cryoanalgesia + MM, 45 EPP + MM, and 11 MM alone. Postoperative tube thoracostomy was placed in 5 patients with cryoanalgesia (4 pneumothorax; 1 effusion), 1 patient with EPP (1 pneumothorax), and none in MM alone ( P = .25). Pain scores at discharge were similar in all groups. Cryoanalgesia patients received less overall inpatient opioids than other groups ( P < .05). No patient required reoperation for bar displacement. Conclusion: Cryoanalgesia is an effective therapy for pain control in MIRPE. Because thermal injury can occur on the lung and chest wall with cryoanalgesia, we implemented techniques to limit and prevent this injury. Cryoanalgesia offers a safe alternative for postoperative analgesia with significant reduction in inpatient opioid requirement. Larger prospective studies are required to assess the long-term impact and complications of cryoanalgesia.