EBUS-guided transbronchial mediastinal cryobiopsy in the diagnosis of mediastinal lesions: safety, feasibility and diagnostic yield – experience in 50 cases

Background

Endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) is the technique of choice in the study of mediastinal and hilar lesions; however, it can be affected by the insufficiency of intact biopsy samples, which might decrease its diagnostic yield for certain conditions, thus requiring re-biopsies or additional diagnostic procedures such as mediastinoscopy when probability of malignancy remains high.

Objectives

Our objectives were to 1) attempt to reproduce this technique in the same conditions that we performed EBUS-TBNA, that is, in the bronchoscopy suite and under moderate sedation; 2) describe the method used for its execution; 3) determine its feasibility by accessing different lymph node stations applying our method; 4) analyze the diagnostic yield and its complications.

Methods

Prospective study of 50 patients who underwent EBUS-TBNA and EBUS-guided TMC in a single procedure using a 22-G TBNA needle and a 1.1 mm cryo-probe subsequently between January and August 2022. Patients with mediastinal lesions greater than 1 cm were recruited and EBUS-TBNA and TMC were performed in the same lymph node station.

Results

The diagnostic yield was 82% and 96% for TBNA and transbronchial mediastinal cryobiopsy, respectively. Diagnostic yields were similar for sarcoidosis, while cryobiopsy was more sensitive than TBNA in lymphomas and metastatic lymph nodes. As for complications, there was no pneumothorax and in no case was there significant bleeding. There were no complications during the procedure or in the follow-up of these patients.

Conclusions

TMC following our method is a minimally invasive, rapid, and safe technique that can be performed in a bronchoscopy suite under moderate sedation, with a higher diagnostic yield than EBUS-TBNA, especially in cases of lymphoproliferative disorders and mestastatic lymph nodes, or when more biopsy sample is needed for molecular determinations.

Transbronchial cryobiopsy in interstitial lung disease: experience in 106 cases - how to do it

Transbronchial biopsy using forceps (TBB) is the first diagnostic technique performed on patients with interstitial lung disease (ILD). However, the small size of the samples and the presence of artefacts in the tissue obtained make the yield variable. Our objectives were 1) to attempt to reproduce transbronchial cryobiopsy under the same conditions with which we performed conventional TBB, that is, in the bronchoscopy unit without intubating the patient and without fluoroscopy or general anaesthesia; 2) to describe the method used for its execution; and 3) to analyse the diagnostic yield and its complications. We carried out a prospective study that included 106 patients with clinical and radiological features suggestive of ILD who underwent cryo-transbronchial lung biopsy (cryo-TBB) under moderate sedation without endotracheal intubation, general anaesthesia or use of fluoroscopy. We performed the procedure using two flexible bronchoscopes connected to two video processors, which we alternated until obtaining the number of desired samples. A definitive diagnosis was obtained in 91 patients (86%). As for complications, there were five pneumothoraces (4.7%) and in no case was there severe haemorrhage or exacerbation of the underlying interstitial disease. Cryo-TBB following our method is a minimally invasive, rapid, safe and economic technique that can be performed in a bronchoscopy suite under moderate sedation without the need for intubating the patient or using fluoroscopy and without requiring general anaesthesia.