Sound‐guided assessment and localization of pulmonary air leak

Abstract

Pulmonary air leak is the most common complication of lung surgery, with air leaks that persist longer than 5 days representing a major source of post‐surgery morbidity. Clinical management of air leaks is challenging due to limited methods to precisely locate and assess leaks. Here, we present a sound‐guided methodology that enables rapid quantitative assessment and precise localization of air leaks by analyzing the distinct sounds generated as the air escapes through defective lung tissue. Air leaks often present after lung surgery due to loss of tissue integrity at or near a staple line. Accordingly, we investigated air leak sounds from a focal pleural defect in a rat model and from a staple line failure in a clinically relevant swine model to demonstrate the high sensitivity and translational potential of this approach. In rat and swine models of free‐flowing air leak under positive pressure ventilation with intrapleural microphone 1 cm from the lung surface, we identified that: (a) pulmonary air leaks generate sounds that contain distinct harmonic series, (b) acoustic characteristics of air leak sounds can be used to classify leak severity, and (c) precise location of the air leak can be determined with high resolution (within 1 cm) by mapping the sound loudness level across the lung surface. Our findings suggest that sound‐guided assessment and localization of pulmonary air leaks could serve as a diagnostic tool to inform air leak detection and treatment strategies during video‐assisted thoracoscopic surgery (VATS) or thoracotomy procedures.

Lung‐Mimetic Hydrofoam Sealant to Treat Pulmonary Air Leak

“…We also performed a sound‐based air leak detection test established by our group, wherein the intensity and frequency of air leak sounds were analyzed to quantify severity of air leak. [ 69 ] We found that after induction of air leak, sound pressure levels were significantly elevated relative to baseline (baseline: 7.86 ± 0.11 dBA, air leak: 49.4 ± 20.8 dBA, p < 0.05). After sealant application; however, sound pressure levels showed no significant difference compared to baseline levels (sealant: 10.2 ± 3.0 dBA, p = 0.893) (Figure 6F).…”

“…Quantitative Sound Analysis: Quantitative sound analysis algorithms were used to detect presence or absence of air leak in swine lungs, as previously described. [69] Measurements were performed at baseline, after air leak induction, and after sealant application, and analyzed using Audacity and custom MATLAB code. Values were averaged across three breaths.…”