Real-Time Three-Dimensional Optical Coherence Tomography Guidance for Transbronchial Biopsy: A Proof-of-Concept Ex Vivo Study

Background/needConventional bronchoscopy has a limited ability to localize and accurately target peripheral pulmonary lesions (PPLs) because these lesions are not endoscopically visible, and obtaining three-dimensional (3D) images of the position of sampling instruments relative to the target lesion in real time is also difficult. Three-dimensional optical coherence tomography (3D-OCT) which have the special resolution of 10-µm provides higher spatial resolution than intravascular ultrasound of 100-µm for intravascular imaging and is used to support the assessment and treatment of coronary artery stenosis. In the respiratory system, 3D-OCT guidance may enable real-time 3D analysis of the spatial relationship between the sampling instrument and the target lesion during transbronchial lung biopsy (TBB), which is difficult to achieve with two-dimensional radial endobronchial ultrasound (r-EBUS).Methodology and device descriptionWe evaluated whether 3D-OCT could visualize pseudo-lesions and enable real-time assessment of the spatial relationship between the sampling instrument and the pseudo-lesion during TBB.Preliminary resultsIn three excised pig lungs, a 3D-OCT probe and ultrathin biopsy forceps were simultaneously advanced through a guide sheath placed in the bronchus to a pseudo-lesion per an excised pig lung. The probe visualized the spatial relationship between the sampling instrument and the pseudo-lesion in real time. Furthermore, 3D-OCT-guided TBB was successfully performed in three consecutive biopsies per a pseudo-lesion.Current status3D-OCT-guided TBB was feasible in an ex vivo model for sampling target lesions. These results indicate that 3D-OCT-guided bronchoscopy may help to provide the special relationship of targeting and sampling of PPLs.