shotaro okachi

Introduction: Accurate diagnosis of peripheral pulmonary lesions is crucial in respiratory medicine. Radial endobronchial ultrasound (R-EBUS), navigation technologies, and ultrathin bronchoscopes have progressively enhanced distal airway access. Mixed reality (MR) offers a hands-free method for visualizing and manipulating CT-derived three-dimensional (3D) anatomy within the operator’s field of view. This retrospective study aimed to describe the technical feasibility and safety of intraprocedural MR-based holographic virtual bronchoscopy (VB) use. Methods: This study included patients who underwent bronchoscopy for peripheral pulmonary lesions using an MR-based 3D holographic VB system. CT datasets were converted into 3D polygon models and displayed on a HoloLens 2 headset. Operators/assistants intraprocedurally referenced and manipulated the hologram while advancing the bronchoscope. Procedural variables, R-EBUS findings, biopsy techniques, diagnostic yield, and complications were evaluated. Results: Eighteen patients were included. A direct bronchus sign was present in 12 lesions. The median bronchial generation that could be visualized on CT and 3D-VB was six, whereas bronchoscopy enabled advancement to a median of five generations. Radial EBUS demonstrated a within-lesion position in 13 cases. Biopsy techniques included forceps biopsy, cryobiopsy, and TBNA. The overall diagnostic yield was 72.2% (13/18), with malignant disease accounting for the majority of diagnoses. One patient developed mild pneumothorax, which resolved without drainage. Conclusion: MR-based holographic VB enabled real-time, hands-free 3D anatomical referencing without interrupting the procedure. Further prospective studies are warranted to assess procedural benefits and potential integration with other bronchoscopic modalities and devices.

BACKGROUND: Data regarding the diagnostic efficacy of radial endobronchial ultrasound (R-EBUS) findings obtained via transbronchial needle aspiration (TBNA)/biopsy (TBB) with endobronchial ultrasonography with a guide sheath (EBUS-GS) for peripheral pulmonary lesions (PPLs) are lacking. We evaluated whether intraoperative probe repositioning improves R-EBUS imaging and affects diagnostic yield and safety of EBUS-guided sampling for PPLs. METHODS: We retrospectively studied 363 patients with PPLs who underwent TBNA/TBB (83 lesions) or TBB (280 lesions) using EBUS-GS. Based on the R-EBUS findings before and after these procedures, patients were categorized into three groups: the improved R-EBUS image (n = 52), unimproved R-EBUS image (n = 69), and initial within-lesion groups (n = 242). The impact of improved R-EBUS findings on diagnostic yield and complications was assessed using multivariable logistic regression, adjusting for lesion size, lesion location, and the presence of a bronchus leading to the lesion on CT. A separate exploratory random-forest model with SHAP analysis was used to explore factors associated with successful repositioning in lesions not initially "within." RESULTS: The diagnostic yield in the improved R-EBUS group was significantly higher than that in the unimproved R-EBUS group (76.9% vs. 46.4%, p = 0.001). The regression model revealed that the improvement in intraoperative R-EBUS findings was associated with a high diagnostic yield (odds ratio: 3.55, 95% confidence interval, 1.57-8.06, p = 0.002). Machine learning analysis indicated that inner lesion location and radiographic visibility were the most influential predictors of successful repositioning. The complication rates were similar across all groups (total complications: 5.8% vs. 4.3% vs. 6.2%, p = 0.943). CONCLUSIONS: Improved R-EBUS findings during TBNA/TBB or TBB with EBUS-GS were associated with a high diagnostic yield without an increase in complications, even when the initial R-EBUS findings were inadequate. This suggests that repeated intraoperative probe repositioning can safely boost outcomes.