OP4 EBUS-MEDIASTINAL CRYOBIOPSY VERSUS CONVENTIONAL EBUS-NEEDLE ASPIRATION: A 24 MONTHS RETROSPECTIVE COMPARATIVE STUDY IN UNIVERSITY OF MALAYA

Chun Ian Soo1, Vijayan Munusamy1, Leng Cheng Sia1, Diana Bee-Lan Ong2, Seow Fan Chiew2, Wai Ling Leong3, Hazwan Amzar Khairul Annuar3, Nur Husna Ibrahim1, Thian Chee Loh1, Juinn Liang Tan1, Mau Ern Poh1, Chee Kuan Wong1, Yong Kek Pang1, Chong Kin Liam1
1 Division of Respiratory Medicine, Department of Medicine, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
2 Department of Pathology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
3 Department of Biomedical Imaging, Universiti Malaya Research Imaging Centre, Universiti Malaya, 50603, Kuala Lumpur, Malaysia

Background :

Endobronchial Ultrasound-Guided Transbronchial Mediastinal Cryobiopsy (EBUS-TMC) has
emerged as a popular supplementary technique for EBUS-TBNA in obtaining diagnostic tissue samples. The degree to which EBUS-TMC enhances clinical decision-making remains a subject of ongoing debate

Method:

A single-center retrospective analysis of EBUS-TBNA and EBUS-TMC cases over 24 months to determine the diagnostic yield and safety of EBUS-TMC. TBNA was performed using a 22G needle as per guidelines.1 Cytology samples were air-dried to form tissue cell block (TCB). Extra samples used for liquid cell block (LCB) in Cytolyt® fixation. For EBUS-TMC, cryobiopsy (CB) was performed using a 1.1mm cryoprobe. CB samples were fixed in formalin.

Results: 

A total of 138 patients. 78 patients underwent EBUS-TBNA, while 60 patients underwent EBUS-TMC. The diagnostic yield from LCB, TCB, and CB were 71.8% (56 patients), 78.2% (61 patients), and 88.3% (53 patients) (P = 0.62). A significant difference in diagnostic yield was observed between CB to LCB (P = 0.031). Notably, sample adequacy for Next-generation sequencing (NGS) testing with CB was 96.9% (31 out of 32 samples), in contrast to 26.9% and 46.1% for LCB and TCB, respectively (P < 0.001). The procedure time was significantly shorter for CB at 33 minutes (IQR 25-42.7) compared to TBNA at 46 minutes (IQR 40-52): P < 0.001. Mild bleeding, requiring no intervention, occurred in about 10% of cases. No major complications or mortality reported.

Conclusion:

EBUS-TMC offers a promising advancement in EBUS guided biopsies, especially for NGS testing. It refines precision treatment, especially in the evolving landscape of NSCLC treatment.