Bronchoscopic management of peripheral pulmonary lesions: robotic approach paves the way to the future

Abstract

Editorial Detection and diagnosis of peripheral pulmonary lesions (PPLs), mainly those whose long axis is sized < 3 cm (i.e. nodules), challenges specialists in oncology, radiology, thoracic surgery and respiratory medicine. Their detection has increased during the last three decades owing to the widespread and frequent prescription of computed tomography (CT) [1, 2]. The early PPL diagnosis through low-dose CT was found to be associated with a 20% reduction of lung cancer specific mortality in the National Lung Screening Trial; nodules were peripheral and benign in the majority of the patients with lung nodular lesions [3]. The implementation of national screening programs will increase their notification rate (which will be closer to the real incidence rate), and, simultaneously, issues associated to their clinical management [4]. Differential diagnosis should be prioritized to exclude malignant lesions, as well as collection of sufficient tissue for molecular analysis to tailor therapies based on molecular patterns [2, 5]. A part from those nodules which deserve only radiological surveillance or which should be surgically resected, solid lesions > 8mm should undergo non-surgical biopsies as recommended by international Guidelines, with few exceptions (e.g., in patients with low/moderate probability of malignancy, if a benign diagnosis is suspected, when clinical pretest probability and imaging findings are discordant, and when patients requires the proof of malignancy before surgical resection) [2]. Endoscopic and transthoracic approaches are available, but their prescription depends on variable covariates: lesions size, anatomical location, relation to a patent airway (i.e., CT bronchus sign), technological advances (e.g., endoscopic guidance methods), risk of complications, which could be associated with patients’ comorbidities [1, 2, 6]. Transthoracic techniques, which are mostly CT-guided, have showed the best diagnostic accuracy (≥90%) with a highest rate of adverse events (e.g., pneumothorax in > 25% of the cases) in old smokers with emphysema and with central pulmonary lesions [6, 7]. On the contrary, a lower rate of adverse events was found in patients undergoing bronchoscopy (e.g., pneumothorax in 2–5% of the cases), particularly in those with emphysema [6, 8–10]. Furthermore, endoscopic examination can investigate upper and central airways, ruling out synchronous malignancies, and favoring the collection of samples of mediastinal adenopathies [1, 2, 6, 11–13]. Bronchoscopy has showed high accuracy when prescribed for endobronchial lesions and for mediastinal staging of non-small cell lung cancer (NSCLC) [1, 6, 13]. Undeniably, ultrasound guidance and the availability of the esophageal route approach (i.e., endoscopic ultrasound with bronchoscope fine needle aspiration, EUS-B-FNA) made bronchoscopy the key procedure in mediastinal staging of NSCLC [13, 14]. PPLs investigated by fluoroscopy-guided endoscopic techniques are poorly diagnosed (sensitivity: 34–63%), particularly when the size is < 2 cm [6]. The rapid introduction of technologically advanced bronchoscopic modalities has been requested by their diagnostic effectiveness and by the healthcare need of a safe collection of clinical samples [1, 6, 8–10]. Electromagnetic navigation (EMN), radial probes endobronchial ultrasound (R-EBUS), cone beam CT, virtual bronchoscopy and ultrathin instruments, showed higher diagnostic yield (67.1–73%) in comparison with the conventional technique [1, 6, 8–10]. However, they are less accurate than CT-