Infectious complications of intercostal nerve cryoablation mediated by perioperative hypothermia during pediatric Nuss procedure.

Background: Intercostal nerve cryoablation (cryoanalgesia) is increasingly used for pain control in minimally invasive repair of pectus excavatum (MIRPE) by Nuss procedure. Cryoanalgesia may lower core body temperature and increase the risk of postoperative infectious complications. We investigated cryoanalgesia effects on infectious complications following MIRPE.

Method: We performed a retrospective review of patients undergoing MIRPE at our institution. Patients treated via multimodal analgesia with cryoanalgesia (Cryo) were compared to patients treated via multimodal analgesia +/- elastomeric pain pumps (Non-cryo). Core body and intraoperative minimum/maximum temperatures were recorded. Primary outcomes were wound infection and pneumonia; secondary outcome was length of stay (LOS). Fisher's Exact and Mann-Whitney U tests compared proportions and medians respectively, p-value ≤ 0.05 being significant.

Results: 80 patients were included, 35(43.7%) Cryo and 45(56.3%) Non-cryo. There were no significant differences in median [IQR] for age(15[13.3,16.0];p =0.86), number of bars inserted (2[1,2];p = 0.57), or operative time(123.5[98.3, 148.8]; p = 0.11) between the two groups. We found no significant differences in median [IQR] minimum temperature (35.4°C [35.0,35.8];p = 0.76), median change in intraoperative temperature (-0.13°C [-0.44,0.00];p = 0.94) or median recovery temperature (-1.10°C [-1.56,-0.65]; p = 0.59) between Cryo and Non-cryo. PACU temperature was significantly lower in the Cryo group, 36.4°C [36.2,36.6] p = 0.04. There were no postoperative wound infections in either group and no significant difference in incidence of postoperative pneumonia (8.57% versus 2.22%,p =  0.31) or median[IQR] for LOS (4[3,4];p = 0.57), between Cryo and Non-cryo patients.

Conclusion: Although cryoanalgesia for MIRPE resulted in lower core body temperature, there appears to be no significant difference between Cryo and Non-Cryo patients for LOS or infectious complications.