Non-inferiority of 1-minute versus 2-minutes cryoanalgesia cycles during minimally invasive repair of pectus excavatum: A propensity score-matched analysis.

BACKGROUND AND AIM: Thoracoscopic cryoanalgesia reduces opioid requirements and hospital stay after minimally invasive repair of pectus excavatum (MIRPE), but increases operative time. Since the optimal freeze duration remains undefined, our protocol changed from 2-min to 1-min cycles in December 2024. Thus, we aimed to compare the effectiveness of 1-min vs 2-min cryoanalgesia cycles in MIRPE patients.

METHODS

Patients treated with 1-min cryoanalgesia were matched to 2-min controls using Propensity Score-Matched (nearest-neighbor method) to improve the reliability of the comparison. Thirty-four patients were matched for demographic characteristics, pectus severity indices, and surgical variables. Postoperative opioid use, expressed as oral morphine equivalents (OME), and length of stay were compared using the Wilcoxon test and a non-inferiority analysis, with thresholds set at 10 mg OME and 0.5 days.

RESULTS

Cryoanalgesia time was significantly shorter in the 1-min group (20.0 min [IQR: 18; 21] vs 29.0 min [IQR: 27; 31]; p < 0.001). No significant differences were observed in median length of stay (1 day [IQR: 1; 2] vs 1 day [IQR: 1; 1], p = 0.25) or in opioid requirement (10 mg OME [IQR: 0; 20] vs 2.5 mg OME [IQR: 0; 5], p = 0.21). Non-inferiority was confirmed for length of stay, as the upper one-sided 95 % confidence limit remained below the 0.5-day margin. For opioid consumption, the observed median difference remained clinically small, although the upper confidence limit slightly exceeded the predefined 10-mg margin.

CONCLUSION

One-minute cryoanalgesia cycles represent an effective and efficient alternative to 2-min cycles in MIRPE, reducing operative time without increasing postoperative opioid use or length of stay. While non-inferiority was statistically confirmed for length of stay, opioid requirements showed clinically minimal differences that approached-but did not formally meet-the predefined non-inferiority margin.

TYPE OF STUDY: Retrospective comparative study.

LEVEL OF EVIDENCE: III.