Image-Guided Percutaneous Technique for Direct Pleural Pressure Measurement in a Swine Model

Pleural pressure measurement enables advanced physiologic assessment, including partitioning respiratory system mechanics into lung and chest wall components, calculating transpulmonary pressure, and quantifying regional pleural pressure gradients. This information is essential for optimizing mechanical ventilation, assessing the impact of altered chest wall physiology, and advancing translational research in lung injury. However, current techniques for direct pleural pressure measurement often require open-chest surgical implantation of pleural pressure transducers via thoracotomy, which is time-consuming, high-risk, and may impair chest wall mechanics. To overcome these limitations, we developed a minimally invasive, percutaneous, image-guided technique for pleural catheter placement. The procedure was performed in anesthetized, mechanically ventilated swine. Under ultrasound guidance, a Tuohy needle was advanced into the pleural space, and a small artificial pneumothorax (50-100 mL of oxygen) was created to separate the pleural layers. Over a guidewire, a 9 Fr sheath introducer was placed, allowing advancement of a balloon-tipped catheter into the anterior pleura. The animal was then turned in a semiprone position, and a second catheter was inserted dorsally after increasing the same pneumothorax by an additional 50-100 mL of oxygen. Placement was confirmed by computed tomography (CT) and physiologic tracings. After evacuation of the pneumothorax and lung re-expansion, imaging verified the position. Successful anterior and posterior catheter placement was achieved in 16 of 20 animals (80%), supporting the procedural feasibility of this approach. Unsuccessful procedures were due to unintended pneumothorax during anterior pleural access or anterior catheter malposition outside the target ventral region. This method provides a less invasive and reproducible approach for direct regional pleural pressure monitoring in large-animal models. By avoiding surgical access, this percutaneous, image-guided technique is well-suited for experimental protocols investigating respiratory mechanics, lung and chest wall physiology, and mechanical ventilation in translational research.