South African Thoracic Society consensus statement on transbronchial lung cryobiopsy for interstitial lung disease

Surgical lung biopsy (SLB), performed via open lung biopsy or video-assisted thoracoscopic surgery, has traditionally been the gold standard for diagnosing interstitial lung disease (ILD) when histological confirmation is necessary. Transbronchial forceps biopsy, while less invasive, often yields small, artifact-prone specimens that are insufficient for conclusive histopathological analysis. Transbronchial lung cryobiopsy (TBLC) has emerged as a minimally invasive alternative, offering a higher diagnostic yield and superior tissue integrity due to the retrieval of larger, en bloc samples. International societies currently conditionally recommended TBLC as a potential first-line diagnostic tool for ILD, citing its favourable safety profile and diagnostic performance.

TBLC may be performed via flexible bronchoscopy with or without an artificial airway. When an artificial airway is used, general anaesthesia is administered, and a supraglottic device or endotracheal tube facilitates bronchoscope and blocker access. Without an artificial airway, the procedure is conducted under conscious sedation using an oral bite guard. A bronchial blocker is deployed to control bleeding, and biopsies are obtained under fluoroscopic guidance with freezing times of 6 - 10 seconds. At least four adequate samples (>5 mm) are collected. Post-procedure care includes positioning the patient with the biopsied lung in the dependent position and performing imaging to detect pneumothorax. While bleeding and pneumothorax are potential risks, they are generally manageable. Definitive exclusion criteria for TBLC have not yet been established, but characteristics such as severely impaired lung function, pulmonary hypertension and significant comorbidity are associated with adverse events.

Although TBLC yields marginally lower diagnostic rates compared with SLB, it remains a cost-effective and safer alternative, particularly in resource-limited settings. The South African Thoracic Society strongly advocates for TBLC as the first-line diagnostic modality in all cases of ILD, where histology is required, provided there are no contraindications. This recommendation is based on the lower cost and morbidity associated with TBLC compared with SLB. An exception is made for patients with non-diffuse or non-peribronchiolar disease who are suitable candidates for SLB and where the procedure is readily available. Strengthening local capacity and expertise in TBLC is crucial for improving ILD diagnostic accuracy in South Africa.