Bronchoscopy & EBUS

The convex probe EBUS bronchoscope is passed through the mouth into the trachea; its tip transducer is placed against the tracheal or bronchial wall, and the tip balloon is filled with water when needed. The stations are surveyed in a systematic order on the IASLC map: N3 (contralateral), then N2 (ipsilateral mediastinal), then N1 (hilar and interlobar). For a right upper lobe tumour the order may be 4L, then 7 and 4R, then 10R or 11R; when the same needle is used, this order aims to prevent cells being carried between stations and upstaging the patient. ERS/ESGE/ESTS 2026 suggests systematic rather than targeted staging and, where possible, EBUS combined with EUS(-B) sampling from the oesophagus.

Source: Korevaar DA et al. ERS/ESGE/ESTS, Eur Respir J 2026;68(2) (PMID 42167778)

The subcarinal (7) node is imaged from the medial wall of the right or left main bronchus and its short axis is measured. Round shape, distinct margin, heterogeneous echogenicity and the coagulation necrosis sign were reported as independent predictors of metastasis; when all four were absent, 96% of nodes were not metastatic. The image helps choose the node to sample; it does not replace sampling. The needle path is checked for vessels with colour Doppler; the right pulmonary artery and the left atrium lie around the subcarinal region.

Source: Fujiwara T et al. Chest 2010;138:641-647 (PMID 20382710)

The needle sheath is clicked onto the working channel of the bronchoscope and locked; the sheath is advanced until its tip shows on the endoscopic image, then fixed. The needle is advanced into the node between the cartilage rings, followed as a bright line on the ultrasound image. Per the instructions for use, the stylet is pulled back by no more than 5 mm while advancing and removed completely once the tip is inside the node. ERS/ESGE/ESTS 2026 considers 21G and 22G TBNA needles the standard and finds insufficient evidence for the structural use of other sizes and needle types.

Source: Wahidi MM et al. CHEST, Chest 2016;149:816-835 (PMID 26402427)

With the stylet out, the needle is moved to and fro inside the node; the strokes can be directed to different parts of the node. Suction is the physician's choice: negative pressure with the VacLok syringe, or no suction (capillary technique). Randomised trials found no difference in adequacy or diagnosis between samples taken with and without suction, nor between sampling with and without the stylet. If suction is on, the syringe stopcock is closed before the needle leaves the node.

Source: Casal RF et al. Chest 2012;142:568-573 (PMID 22156610); Scholten EL et al. Chest 2017;151:636-642 (PMID 27769775)

The needle is drawn into the sheath, locked and removed from the bronchoscope; the aspirate is expressed onto slides with the syringe or by reinserting the stylet, and the rest is flushed with saline into a cell block or formalin tube. Rapid on-site evaluation (ROSE) tells adequacy during the procedure; in a randomised trial ROSE reduced the number of punctures and the need for additional procedures, with similar diagnostic sensitivity. If molecular testing is planned, how the material is divided is agreed with pathology beforehand; CHEST 2024 gives separate recommendations on acquisition and handling.

Source: Oki M et al. Respiration 2013;85:486-492 (PMID 23571718); Gilbert CR et al. Chest 2025;167:899-909 (PMID 39343294)

In a study without ROSE, sensitivity for malignant stations reached 95% at the third aspiration and the fourth added nothing. Once the sample is adequate, the next station follows. Where tissue architecture is needed, as in lymphoma, sarcoidosis or rare tumours, a TBNB needle that takes a core or mediastinal cryobiopsy may be considered; in a randomised trial cryobiopsy raised the diagnostic yield in rare tumours and benign disease. ERS/ESGE/ESTS 2026 still finds the evidence insufficient for the structural use of cryobiopsy; the decision is the physician's.

Source: Lee HS et al. Chest 2008;134:368-374 (PMID 18263688); Zhang J et al. Eur Respir J 2021;58(6) (PMID 33958432)

Without an EBUS bronchoscope, large central nodes such as the subcarinal node are sampled on CT landmarks without an ultrasound image: the needle passes through a chosen point on the carina or the bronchial wall, between cartilage rings, and the sample is taken by aspiration. Because the target and the vessels cannot be followed on an image, the entry point is planned beforehand on the CT map.