Feasibility of a Modified Bronchoscopic Transparenchymal Nodule Access Technique ('Essen Tunnel') for Improving the Diagnosis of Intraparenchymal Pulmonary Lesions.

Abstract

Background and objective: Diagnosing intraparenchymal pulmonary lesions lacking a bronchus sign remains challenging. Bronchoscopic transparenchymal nodule access (BTPNA) for reaching such lesions has seen limited clinical adoption due to insufficient evidence and practical challenges. This study evaluates the feasibility and diagnostic yield of a modified BTPNA (mBTPNA) technique-referred to as the 'Essen tunnel'-which eliminates the need for a guide sheath.

Methods: A retrospective analysis was conducted on patients undergoing virtual bronchoscopic navigation (VBN) incorporating the mBTPNA technique at our centre, from December 2019 to March 2024. The 'Essen tunnel' was created by a needle under virtual navigation guidance, enabling direct insertion of an ultrathin bronchoscope (UTB) or radial endobronchial ultrasound (R-EBUS) probe to biopsy intraparechymal lesions.

Results: Among 266 lesions targeted via VBN, 37 (14%) intraparenchymal lesions (mean target length: 12.7 ± 4.1 mm) were accessed using mBTPNA. The tunnel was successfully created in 97.3% of cases with UTB intubation in 51.4%. R-EBUS was inserted into the tunnel in 83.8% of cases. Semicircular to circular patterns (SCP) were detected in 19.4% before and 61.3% after tunnel creation (p < 0.01). SCP presence on R-EBUS following mBTPNA was associated with a diagnostic accuracy of 66.7%, comparable to that observed in non-tunnel lesions exhibiting a bronchus sign (72.9%, p = 0.58). No severe complications were observed.

Conclusion: The mBTPNA technique is a feasible and safe method that enhances endosonographic lesion detection and achieves promising diagnostic accuracy for challenging intraparenchymal lesions.