Every anatomical lung resection requires the airtight closure of at least one bronchus. In current clinical practice, these bronchi are sealed with sutures or staplers. This study investigated in an ex vivo pig model whether a new bipolar sealing device MARSEAL (KLS Martin, Tuttlingen, Germany) could be an alternative for this purpose. Complete bronchial trees were prepared free from pig heart-lung blocks that were removed at a slaughterhouse. These preparations were taken to the laboratory, and main, lobar, and segmental bronchi were closed using sutures, staples, or bipolar sealing. Each trachea was then intubated and connected to a ventilating device. The initial airtight closure of the bronchus was first tested with lung-protective ventilation. After 15 minutes of ventilation, the inspiratory ventilation pressure was slowly increased and the burst pressure (in mbar) was recorded. Each group included 12 bronchus closures. Group mean burst pressures were compared using a nonparametric test (Mann-Whitney test). The significance level was < 0.05. The main bronchi closed both stapler magazines or sutures were all initially airtight during ventilation. The mean burst pressure was 60 ± 0 mbar for staplers and 57.92 ± 5.8 mbar for sutures. In contrast, 50% of main bronchi sealed with MARSEAL devices (5 or 10 mm) leaked air from the beginning. This was also noted in all lobar bronchi sealed with the MARSEAL 5-mm device and 80% of those sealed with the MARSEAL 10-mm device. The mean burst pressure of initially airtight lobar bronchi was 12.7 ± 7.25 mbar. In contrast, all segmental bronchi (mean width: 1.6 cm) were airtight when ventilated. Mean burst pressure was 14.64 ± 9.1 mbar with the MARSEAL 5-mm device and 29.64 ± 21.3 mbar with the MARSEAL 10-mm device. Histological investigation of the preparations (with hematoxylin and eosin staining) showed intact cartilaginous structures that were largely unaffected by bipolar coagulation. The airtight sealing of the segmental bronchi resulted from fusion of the peribronchial tissue and not the cartilage. Bipolar sealing is an inappropriate tool for the closure of the bronchi in comparison to suture or stapling.
