First real-time imaging of bronchoscopic lung volume reduction by electrical impedance tomography

• Published in: Respiratory research Vol. 25; no. 1; pp. 264 - 14
• Main Authors: Torsani, Vinicius, Cardoso, Paulo Francisco Guerreiro, Borges, João Batista, Gomes, Susimeire, Moriya, Henrique Takachi, Cruz, Andrea Fonseca da, Santiago, Roberta Ribeiro de Santis, Nagao, Cristopher Kengo, Fitipaldi, Mariana Fernandes, Beraldo, Marcelo do Amaral, Junior, Marcus Henrique Victor, Mlček, Mikuláš, Pego-Fernandes, Paulo Manuel, Amato, Marcelo Britto Passos
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 04.07.2024; BioMed Central; BMC
• Subjects: Absorption atelectasis; Analysis; Animals; Atelectasis; Bronchoscopy; Bronchoscopy - methods; Care and treatment; CT imaging; Diagnosis; Electric Impedance; Electrical impedance tomography; Emphysema; Emphysema, Pulmonary; Endobronchial valves; Impedance, Bioelectric; Lung - diagnostic imaging; Lung - physiology; Lung - physiopathology; Lung - surgery; Lung Volume Measurements - methods; Lung volume reduction; Patient outcomes; Pneumonectomy - methods; Pulmonary Atelectasis - diagnostic imaging; Pulmonary Atelectasis - physiopathology; Risk factors; Swine; Time Factors; Tomography - methods; Valves; United States; Electrical impedance tomography; Lung volume reduction; Absorption atelectasis; Emphysema; Endobronchial valves
• ISSN: 1465-993X; 1465-9921; 1465-993X
• DOI: 10.1186/s12931-024-02877-0

Bronchoscopic lung volume reduction (BLVR) with one-way endobronchial valves (EBV) has better outcomes when the target lobe has poor collateral ventilation, resulting in complete lobe atelectasis. High-inspired oxygen fraction (F O ) promotes atelectasis through faster gas absorption after airway occlusion, but its application during BLVR with EBV has been poorly understood. We aimed to investigate the real-time effects of F O on regional lung volumes and regional ventilation/perfusion by electrical impedance tomography (EIT) during BLVR with EBV. Six piglets were submitted to left lower lobe occlusion by a balloon-catheter and EBV valves with F O 0.5 and 1.0. Regional end-expiratory lung impedances (EELI) and regional ventilation/perfusion were monitored. Local pocket pressure measurements were obtained (balloon occlusion method). One animal underwent simultaneous acquisitions of computed tomography (CT) and EIT. Regions-of-interest (ROIs) were right and left hemithoraces. Following balloon occlusion, a steep decrease in left ROI-EELI with F O 1.0 occurred, 3-fold greater than with 0.5 (p < 0.001). Higher F O also enhanced the final volume reduction (ROI-EELI) achieved by each valve (p < 0.01). CT analysis confirmed the denser atelectasis and greater volume reduction achieved by higher F O (1.0) during balloon occlusion or during valve placement. CT and pocket pressure data agreed well with EIT findings, indicating greater strain redistribution with higher F O . EIT demonstrated in real-time a faster and more complete volume reduction in the occluded lung regions under high F O (1.0), as compared to 0.5. Immediate changes in the ventilation and perfusion of ipsilateral non-target lung regions were also detected, providing better estimates of the full impact of each valve in place. Not applicable.