Controlled capnothorax creation for stapled diaphragm resection: a safe maneuver for en-bloc liver and frenic resection without diaphragm opening

Background Full-thickness diaphragmatic resection during minimally invasive liver surgery remains technically demanding, particularly for tumors located in posterosuperior segments with suspected diaphragmatic invasion. Stapled en-bloc resection avoids pleural opening but is limited by negative intrathoracic pressure, which increases tension and complicates safe stapler placement. We present a capnothorax-assisted technique and provide a video demonstration. Methods A retrospective analysis of consecutive patients undergoing minimally invasive liver resection with en-bloc diaphragmatic resection between July 2022 and May 2025 was conducted following IDEAL recommendations. The technique consists of inducing a controlled capnothorax using CO 2 insufflation (8 mmHg) via a Veress needle inserted into the pleural cavity under direct visualization. This neutralizes thoracic negative pressure and facilitates tension-free stapled diaphragmatic transection. A supplementary video illustrates the key technical steps. Results Six patients underwent capnothorax-assisted diaphragmatic resection. A minimally invasive approach was completed in all cases, with one conversion unrelated to the technique. R0 resection was achieved in all patients. No intraoperative complications or pulmonary adverse events were observed. Median operative time was 473 minutes (range 288–825), and median blood loss was 10 mL (range 10–200). Median length of stay was 4 days (range 3–7), with no postoperative complications (Clavien–Dindo ≥ I). No pleural drainage was required in capnothorax cases. No diaphragmatic recurrences were observed at follow-up. Conclusions Capnothorax-assisted diaphragmatic resection is a simple and reproducible technique that facilitates stapled en-bloc resection by transforming a traction-dependent maneuver into a pressure-neutralized approach. The accompanying video provides a practical guide for implementation. These findings are hypothesis-generating and require validation in larger comparative studies.