Microbubble fibrin sealant application technique for prolonged air leak after anatomical lung resection: a retrospective comparative study.

Background: Prolonged air leak (PAL) is a frequent complication of anatomical lung resection. Although fibrin sealants combined with polyglycolic acid sheets are widely used, an optimal application technique has not yet been established. Their effectiveness may be limited because fibrinogen solution is difficult to visualize and tends to run off during the application. To address these limitations, we introduced a simple microbubble fibrin sealant application technique that improves fibrinogen visibility and viscosity by mixing fibrinogen solution with air. This study aimed to compare the incidence of PAL between the conventional and microbubble techniques in patients undergoing anatomical lung resection for lung cancer. Methods: This single-center retrospective study included patients who underwent anatomical lung resection for primary lung cancer between April 2019 and April 2025, and had an intraoperative air leak identified using a water-sealing test. Patients were treated using either the conventional or microbubble technique. The microbubble technique was introduced in April 2022, and the choice of technique was primarily determined by the study period. Multivariable logistic regression analysis was performed to evaluate factors associated with PAL, adjusting for clinically relevant variables. Results: The 356 eligible patients were classified into conventional (n=201) and microbubble (n=155) groups. PAL occurred in 22/201 patients (10.9%) in the conventional group and 7/155 patients (4.5%) in the microbubble group (P=0.03). In the multivariable analysis, the microbubble technique was independently associated with a lower incidence of PAL [odds ratio (OR) 0.36; 95% confidence interval (CI): 0.15-0.90; P=0.03]. Higher intraoperative air leak severity, as assessed by the Macchiarini scale, was independently associated with increased PAL risk (OR, 2.39; 95% CI: 1.20-4.73; P=0.01). Conclusions: The microbubble technique is associated with a reduced incidence of PAL after anatomical lung resection. Given the retrospective design, these findings should be interpreted with caution and warrant further prospective validation.