# Phrenic Nerve Cryotherapy for Preventing Prolonged Air Leak During VATS Lobectomy

## TL;DR

This study investigates whether phrenic nerve cryotherapy during VATS lobectomy can reduce prolonged air leak after surgery.

## Contribution

The study introduces phrenic nerve cryotherapy as a potential intervention to prevent prolonged air leak during VATS lobectomy.

## Key findings

- PNC did not significantly reduce 24-hour air leak or prolonged air leak rates, but more patients in the PNC group stopped leaking over time.
- PNC caused significant diaphragm elevation post-surgery, which partially recovered by 3 months.
- PNC combined with active lung repair may help high-risk patients reduce prolonged air leak.

## Abstract

背景与目的 电视辅助胸腔镜手术（video-assisted thoracoscopic surgery, VATS）肺叶切除术是目前治疗肺癌的主要术式，术后持续性肺漏气（prolonged air leak, PAL）是影响VATS肺叶切除术后恢复的重要因素之一。尽管目前临床上有很多防治术后PAL的方法，但术后PAL发生率仍较高。膈神经冷冻术（phrenic nerve cryotherapy, PNC）通过可逆性抑制膈神经功能，诱导膈肌暂时性上抬，从而减小胸腔容积、促进脏壁层胸膜贴合，减少漏气。本研究探讨PNC在VATS肺叶切除术中预防术后PAL的效果。方法 纳入2023年6月至2025年1月在内蒙古医科大学附属医院胸外科接受手术的108例符合入组条件的肺癌患者，使用随机数字表法分为对照组（n=54）和试验组（n=54），两组患者均接受VATS肺叶切除及系统性淋巴结清扫术，试验组术中额外行PNC。对两组患者基线特征、术中、术后指标及漏气动态变化进行比较。结果 两组患者临床基线资料无统计学差异（P>0.05），对照组和试验组患者术后24 h肺漏气发生率（31.5% vs 29.6%）和术后PAL发生率（20.4% vs 14.8%）均无统计学差异（P>0.05）。但对照组从术中漏气测试试验到术后24 h肺漏气过程中，共有8例（32.0%）停止漏气，少于试验组的14例（46.7%）；对照组从术后24 h肺漏气者进展为术后PAL过程中，共有6例（35.3%）停止漏气，少于试验组的8例（50.0%），差异有统计学意义（P<0.001）。与对照组相比，试验组术后膈肌上抬更为显著，并在术后3个月恢复，但稍高于术前水平。结论 PNC联合积极肺修补可作为术中漏气高风险患者的重要干预手段，减少术后PAL发生。

A: Before cryotherapy: cryoprobe elevating the phrenic nerve away from the pericardium; B: During cryotherapy: ice ball formation on the cryoprobe; C: After cryotherapy: ice ball on the cryoprobe gradually disappeared.

Comparison of baseline characteristics between the two groups

Analysis of the differences in intraoperative indicators between the two groups

Factor analysis of intraoperative air leakage test

Analysis of the differences in postoperative indicators between the two groups

Analysis of factors causing postoperative air leakage 24 hours after surgery

Analysis of factors of postoperative PAL

Logistic regression analysis of influencing factors for postoperative air leakage after 24 h

Logistic regression analysis of influencing factors for postoperative PAL

A: 1 day before surgery: Normal diaphragmatic position (baseline level); B: 1 day after surgery: left hemidiaphragm elevated (arrow); C: 1 month after surgery: Sustained diaphragmatic elevation (arrow); D: 3 months after surgery: the left diaphragm has recovered.

A: 1 day before surgery: Normal diaphragmatic position (baseline level); B: 1 day after surgery: The chest radiograph showed that the left diaphragm did not elevate (arrow); C: 1 month after surgery: The diaphragm failed to elevate even one month after the surgery (arrow); D: 3 months after surgery: The diaphragm did not elevate.