Lisa E. McMahon's research while affiliated with The University of Arizona and other places

Introduction The minimally invasive repair of pectus excavatum (PE) is a painful procedure that can result in long-term hospitalization and opioid use. To mitigate the length of stay and opioid consumption, many different analgesia strategies have been implemented. The aim of this study is to review the use and patient outcomes of intercostal nerve cryoablation (INC) during PE repair reported in the literature. Methods An unfunded literature search using PubMed identifying articles discussing INC during PE repair from 1946 to 1 July 2023 was performed. Articles were included if they discussed patient outcomes with INC use during PE repair. Articles were excluded if they were reviews/meta-analyses, editorials, or not available in English. Each article was reviewed for bias by analyzing the study methods, data analysis, patient selection, and patient follow-up. Articles comparing outcomes of INC were considered significant if p -value was <0.05. Results A total of 34 articles were included in this review that described INC use during pectus repair. Most supported a decreased hospital length of stay and opioid use with INC. Overall, INC was associated with fewer short-term and long-term complications. However, the researchers reported varied results of total hospital costs with the use of INC. Conclusion The review was limited by a paucity of prospective studies and low number of patients who received INC. Despite this, the present data support INC as a safe and effective analgesic strategy during the repair of PE.

Introduction: Minimally invasive repair of pectus excavatum (MIRPE) and cartilaginous rib excision (CRE) for slipping rib syndrome (SRS) are painful procedures. Intercostal nerve cryoablation (Cryo) controls pain and decreases opioid use in MIRPE. Herein, we describe our experience with cryoablation in CRE. Methods: A retrospective chart review was performed of all patients undergoing CRE between 2018 and 2022. Data on demographics, clinical characteristics, operative details, and hospital course were collected. Results: A total of 98 patients underwent CRE: 68 CRE without cryo, 22 CRE + Cryo, and 8 combined MIRPE + CRE + Cryo. Ninety percent of patients underwent bioabsorbable rib plating. Patients were predominantly female (79%, 73%, 50% respectively) with median ages 17.6, 16.9, and 14.2 years respectively. CRE + Cryo patients used significantly less opioids in hospital (0.6 OME/kg [0.1,1.2]) compared to CRE without cryo (1.0 OME/kg [0.6,2.1]), p < 0.05. The median length of stay (LOS) in CRE + Cryo was 1 day [1,2] compared to 2 days in CRE without cryo [1,2], p = 0.09. MIRPE + CRE + Cryo patients used 0.6 OME/kg [0.2,8.0] with a 2 day [1,5.5] LOS. Ninety-one percent of Cryo patients had cryoablation of T9 and/or T10 intercostal nerves, with no documented abdominal wall laxity at median follow-up of 16 days. Cryo was applied extra-thoracically in CRE + cryo without thoracoscopy or lung isolation, while MIRPE + CRE + Cryo used a combination extra-/intra-thoracic cryoablation in with thoracoscopy. Conclusion: Intercostal nerve cryoablation reduces opioid use and LOS in patients undergoing cartilaginous rib excision for slipping rib syndrome. Cryotherapy to as low as T10 did not result in abdominal wall laxity and can be applied extra-thoracically without the need for thoracoscopy. Ongoing prospective studies are required to assess the long-term outcomes. Level of evidence: III.

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.

Introduction Current studies show cryoablation decreases opioid requirements and lengths of stay (LOS) in patients undergoing the Nuss procedure for pectus excavatum. This study evaluated the relationship between cryoablation and clinical outcomes for the Nuss procedure. Methods A retrospective single-center chart review was performed on patients undergoing the Nuss procedure with intercostal cryoablation from December 2017-August 2021. Demographics, hospital course, and postoperative complications were abstracted. To evaluate the evolution of outcomes over time, the earliest quarter (Q1) of cryoablation patients was compared to the last quarter (Q4). Results Over 45 months, 350 Nuss procedures with cryoablation were performed. The mean age at operation was 15.7 ± 2.3 years with an average Haller Index of 5.4 ± 4.2. The mean operative time was 136 ± 40.5 minutes. On average, patients used 2.8 ± 2.5 OME/kg of opioid in hospital with a LOS of 2.7 ± 1.1 days. The Q4 patients were discharged 1.3 days earlier (p<0.05) than Q1 patients, with 80% of Q4 discharged by postoperative day #2 vs. 23% in Q1 (p<0.05). Q4 patients received 74% (p<0.05) less opioid in hospital and 21% (p<0.05) less on discharge. Within 90 days postoperatively, complication rates (chest tube placement, wound infection, readmission, neuropathic pain) were similar. Only two patients (0.6%) required reoperation for bar migration/slippage. Conclusion With increased experience, cryoablation for the Nuss procedure decreased opioid use by 74% and was associated with 80% of patients achieving early discharge. Major complication rates were not increased. Cryoablation can be successfully implemented as an effective method of postoperative analgesia. Level of Evidence Level III