# Is the Thin Bronchoscope the Right Compromise Between Ultrathin and Conventional Bronchoscopy for Peripheral Pulmonary Lesions (PPLs)? A Retrospective Study

## TL;DR

This study evaluates the effectiveness of thin bronchoscopes in diagnosing peripheral lung lesions that are hard to reach with conventional methods.

## Contribution

The study introduces the thin bronchoscope as a promising compromise for accessing and diagnosing peripheral pulmonary lesions.

## Key findings

- The thin bronchoscope achieved a 65% diagnostic yield for peripheral pulmonary lesions.
- Diagnostic performance improved to 76.5% when lesions had a bronchus sign on CT scans.
- Lesion size above 20 mm was associated with higher diagnostic success using the thin bronchoscope.

## Abstract

Background/Objectives: Peripheral pulmonary lesions (PPLs) are the current challenge in bronchoscopy. Novel endoscopic approaches allow us to reach PPLs better than a few years ago. In patients with resectable non-small cell lung cancer (NSCLC), perioperative chemotherapy is associated with significantly greater event-free survival; this means that histological assessment before the resectable surgery of PPLs is becoming mandatory. Our objective was to evaluate the diagnostic yield (DY) of a thin bronchoscope (TB) for PPLs suspected for lung cancer that are not reachable with conventional bronchoscopy. Methods: A total of 176 patients with PPLs were evaluated from January 2022 to July 2023. Of the patients, 26 presented with not reachable PPLs with conventional bronchoscopy, and underwent the procedure again with a TB. When possible, R-EBUS was used. PPLs’ dimensions were recorded via chest computed tomography (CT) scan. DY was evaluated. Results: Mean lesion size was 29 mm, and overall DY for TB was 65% (17/26). When the lesion was bigger than 20 mm, DY was 76.5% (13/17), whereas in lesions smaller than 20 mm, DY was 55% (5/9). When PPLs presented a bronchus sign in the CT scan, diagnostic performance of TB was significantly better (76.5% vs. 40%, p = 0.04) compared to PPLs without a bronchus sign, independent from PPL dimensions. R-EBUS did not change DY. Conclusions: TB easily allows us to reach and sample PPLs with a high DY if a bronchus sign is positive, independently from PPL dimensions. Further studies are needed to evaluate if more flexible and penetrating bronchial wall biopsy tools can augment DY for PPLs with TB.