R-EBUS procedure

Before each r-EBUS procedure, the lesion was located using the planner of the virtual bronchoscopy software to identify the optimal bronchial path to the lesion (LungPoint planner, Broncus Medical, San Jose, California, USA), from a CT scan of the millimetre slice chest. Bronchoscopy was then carried out using local or general anaesthesia with either an MP160F video bronchoscope or a BF-MP60F bronchofiberscope (Olympus Tokyo, Japan), with a 4 mm outer diameter and a 2 mm working channel.

The ultrasonographic probe was the 1.4 mm UM-S20-17S probe (Olympus, Tokyo, Japan), introduced into the dedicated 1.9 mm diameter guide catheter (K201, Olympus) with a 1.5 mm biopsy forceps.

The procedure was performed without ‘navigation system’ or fluoroscopy. After having memorised the endobronchial route from the planning, the operator reached the most distal subsegmental bronchus. The r-EBUS probe, covered with the guide sheath, was then inserted into the working channel and gently pushed until a lesion-specific ultrasonographic image could be obtained, as described elsewhere.^{27 28} R-EBUS views of peripheral lesions were characterised as ‘concentric’, when the radial probe appeared within and completely surrounded by the lesion and ‘eccentric’, when the probe was adjacent to the lesion, without tissue completely surrounding the probe.

Once the nodule ultrasound signal was obtained, the probe was removed and the guide sheath was left in place in the lesion. The sampling, including brush cytology and forceps biopsy, was then performed. Rapid on-site evaluation was not used.

Radiographs of the chest were obtained only in case of chest pain or respiratory symptoms following the procedure.

Specimens were considered diagnostic when a cytologic, histologic or microbiologic diagnosis was confirmed and consistent with the clinical presentation. Patients for whom the procedures were not diagnostic were referred for other sampling methods or surgery or were followed by surveillance CT scan of the chest, when appropriate. Data on the final diagnosis were collected from our centre’s electronic medical records and/or by interviewing the patient’s pulmonologist when clinical follow-up was performed elsewhere.