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Capillary instability of a two-layer liquid film lining a rigid tube is studied computationally as a model for liquid plug formation and closure of human airways. The two-layer liquid consists of a serous layer, also called the periciliary liquid layer, at the inner side and a mucus layer at the outer side. Together, they form the airway surface liquid lining the airway wall and surrounding an air core. Liquid plug formation occurs due to Plateau-Rayleigh instability when the liquid film thickness exceeds a critical value. Numerical simulations are performed for the entire closure process, including the pre- and post-coalescence phases. The mechanical stresses and their gradients on the airway wall are investigated for physiologically relevant ranges of the mucus-to-serous thickness ratio, the viscosity ratio, and the air-mucus and serous-mucus surface tensions encompassing healthy and pathological conditions of a typical adult human lung. The growth rate of the two-layer model is found to be higher in comparison with a one-layer equivalent configuration. This leads to a much sooner closure in the two-layer model than that in the corresponding one-layer model. Moreover, it is found that the serous layer generally provides an effective protection to the pulmonary epithelium against high shear stress excursions and their gradients. A linear stability analysis is also performed, and the results are found to be in good qualitative agreement with the simulations. Finally, a secondary coalescence that may occur during the post-closure phase is investigated. [ABSTRACT FROM AUTHOR]

Objective: Open decannulation from femoral venoarterial extracorporeal membrane oxygenation (VA-ECMO) carries high risk of morbidity, including groin wound infection. This study evaluated the impact of percutaneous decannulation on rates of groin wound infection in patients decannulated from femoral VA-ECMO., Methods: Between January 1, 2022, and April 30, 2023, 47 consecutive patients received percutaneous femoral VA-ECMO and survived to decannulation. A percutaneous suture-mediated closure device was used for decannulation in patients with relatively smaller arterial cannulas. Patients with larger arterial cannulas or unsuccessful percutaneous closures underwent surgical cutdown and repair of the femoral artery. The primary outcome was arterial site wound infection following decannulation., Results: Among the 47 patients who survived to decannulation from VA-ECMO, 21 underwent percutaneous decannulation and 27 underwent surgical cutdown. One patient underwent 2 VA-ECMO runs, one with percutaneous decannulation and one with surgical cutdown. Percutaneous decannulation was attempted in 22 patients, with 21 of 22 (95.5%) success rate. Decannulation procedure length was significantly shorter in the percutaneous group (79 minutes vs 148 minutes, P  = .0001). The percutaneous group had significantly reduced rates of groin wound complications (0% vs 40.7%, P  = .001) and groin wound infections (0% vs 22.2%, P  = .03) when compared with the surgical cutdown group. Three patients (14.3%) in the percutaneous group experienced vascular complications, including pseudoaneurysm at the distal perfusion catheter site and nonocclusive thrombus of the common femoral artery., Conclusions: Percutaneous decannulation may reduce decannulation procedure length and rate of groin wound infection in patients who survive to decannulation from VA-ECMO., Competing Interests: The authors reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest., (© 2024 The Authors.)