Diagnostic Performance and Safety of Endobronchial Ultrasound-guided Transbronchial Mediastinal Cryobiopsy in Diagnosing Tuberculous Mediastinal Lymphadenitis: a Randomised Controlled Trial

The goal of this clinical trial is to compare the diagnostic efficacy and safety of Endobronchial Ultrasound-guided Transbronchial Mediastinal Cryobiopsy (EBUS-TBMC) versus standard EBUS-guided Transbronchial Needle Aspiration (EBUS-TBNA) in adult patients with suspected mediastinal lymph node tuberculosis. The main questions it aims to answer are:

Does EBUS-TBMC provide a superior diagnostic yield for detecting granulomatous inflammation compared to EBUS-TBNA in the same target lymph node? Does the cryopreservation process affect the viability of Mycobacterium tuberculosis for culture, and does the larger tissue sample obtained via EBUS-TBMC enhance the sensitivity of molecular tests such as Xpert MTB/RIF? Is the safety profile of EBUS-TBMC, particularly regarding bleeding complications, comparable to that of EBUS-TBNA in this patient population? Researchers will compare the two biopsy techniques using a paired design within the same patient to see if EBUS-TBMC results in higher rates of positive pathology, microbiology, and molecular diagnoses.

Participants will:

Undergo both EBUS-TBNA and EBUS-TBMC procedures on the same mediastinal lymph node during a single bronchoscopy session, with the order of procedures randomized.

Provide blood and tissue samples for comprehensive testing, including histology, mycobacterial culture, and Xpert MTB/RIF assay.

Complete short-term (within 2 hours post-procedure) and 7-day follow-up assessments to monitor for any adverse events.

Participate in a 6-month clinical follow-up to establish a final diagnosis, which will serve as the reference standard for evaluating the diagnostic tests.

Study Overview

• Status: Not yet recruiting
• Conditions: Tuberculosis; Mediastinal and Hilar Lymph Node Enlargement
• Intervention / Treatment: Procedure: EBUS-TBMC; Procedure: EBUS-TBNA

• Study Type: Interventional
• Enrollment (Estimated): 108
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Mingming Deng, M.D., Ph.D.; Phone Number: +86 18801336854; Email: isdeng1017@163.com

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100029
      • 2nd Yinghuadong Street, Beijing, China
      • Contact: Mingming Deng; Phone Number: +86 18801336854; Email: isdeng1017@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18 years or older;
• Presence of unexplained mediastinal lymphadenopathy (short-axis diameter ≥1 cm on chest computed tomography) with clinical suspicion of tuberculosis;
• Completion of routine pre-procedural evaluations including blood tests (complete blood count, coagulation profile), electrocardiogram, and chest CT;
• Absence of contraindications for EBUS-TBNA or EBUS-TBMC procedures;
• Provision of written informed consent after being fully informed of the study purpose and procedures.

Exclusion Criteria:

• Known allergy to lidocaine or midazolam;
• Presence of bronchial artery penetration into the target lesion or high risk of bleeding as detected by contrast-enhanced CT or EBUS Doppler mode prior to the procedure;
• Unstable angina, congestive heart failure, or severe bronchial asthma;
• Evidence of significant liquefaction necrosis in the target mediastinal lymph node on pre-procedural CT or EBUS;
• Patient refusal to participate in the study;
• Participation in another clinical trial within the past three months that may interfere with the outcomes of this study;
• Any other condition that, in the opinion of the investigator, makes the patient unsuitable for study participation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: EBUS-TBMC; Participants undergoing EBUS-TBMC for suspected mediastinal lymph node tuberculosis. The procedure is performed under moderate sedation or general anesthesia. After locating the target lymph node via EBUS, a tunnel is created using a puncture dilation catheter. The outer sheath is left in place to maintain the tunnel. A cryoprobe is then inserted through the sheath into the lymph node, ensuring the tip is at least 5 mm from the node edge and visible vessels. Freezing is activated using carbon dioxide to obtain tissue samples. A total of three independent cryobiopsy specimens are collected from the same target node. A portion of each specimen is sent for mycobacterial culture and Xpert MTB/RIF testing; the remaining tissue is fixed in formalin for histopathological evaluation. In this paired design study, all participants undergo both EBUS-TBMC and EBUS-TBNA procedures on the same lymph node during a single session, with the sequence determined by randomization.	Procedure: EBUS-TBMC; EBUS-TBMC is a minimally invasive bronchoscopic procedure performed under moderate sedation or general anesthesia to obtain larger and more intact tissue samples from mediastinal lymph nodes compared to conventional needle aspiration. A convex probe EBUS scope is used to identify the target lymph node, and Doppler mode is employed to map vascular structures for safe puncture path planning. A dedicated puncture dilation catheter is inserted under real-time EBUS guidance to puncture the airway wall and enter the target lymph node; the needle stylet is then removed, leaving the outer sheath in place to establish a "tunnel" from the airway lumen into the lymph node parenchyma. A flexible cryoprobe is advanced through the sheath into the lymph node, with ultrasound confirmation ensuring the probe tip is positioned within the node while maintaining a safety distance of at least 5 mm from the nodal edge and any visible blood vessels. The freezing system is activated using carbon dioxide as th
Active Comparator: EBUS-TBNA; Participants undergoing standard EBUS-TBNA for suspected mediastinal lymph node tuberculosis. The procedure is performed under moderate sedation or general anesthesia. Using a 22G EBUS aspiration needle, the target lymph node is punctured under real-time ultrasound guidance. Standard "to-and-fro" movements are performed approximately 30 times per pass. A total of five independent needle passes are performed on the same target node. The first pass specimen is collected directly into sterile saline for mycobacterial culture. The remaining specimens are rinsed into formalin for cell block preparation. The rinsing fluid from the needle and specimen container is also collected for Xpert MTB/RIF testing and culture. In this paired design study, all participants undergo both EBUS-TBNA and EBUS-TBMC procedures on the same lymph node during a single session, with the sequence determined by randomization.	Procedure: EBUS-TBNA; EBUS-TBNA is a standard minimally invasive bronchoscopic procedure performed under moderate sedation or general anesthesia to obtain cytological samples from mediastinal lymph nodes. A convex probe EBUS scope is used to identify the target lymph node, and Doppler mode is employed to map vascular structures for safe puncture path planning. A dedicated 22G EBUS aspiration needle is inserted under real-time ultrasound guidance to puncture the airway wall and enter the target lymph node. Standard "to-and-fro" movements are performed approximately 30 times per pass to aspirate cellular material. For this trial, a total of five independent needle passes are performed on the same target node. The specimen from the first pass is collected directly into sterile saline for mycobacterial culture. The remaining specimens are rinsed into 10% neutral buffered formalin for cell block preparation and histopathological evaluation. The rinsing fluid from the needle and specimen container is also collect

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Granuloma Detection Rate	The proportion of patients in whom granulomatous inflammation is detected on histopathological examination of the biopsy specimens obtained from the target mediastinal lymph node. Assessment will be performed by pathologists blinded to the biopsy technique used for each specimen.	Within 2 weeks post-procedure (upon completion of histopathological processing and reporting)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mycobacterium tuberculosis Culture Positivity Rate	The proportion of patients with a positive culture for Mycobacterium tuberculosis from the biopsy specimens obtained from the target mediastinal lymph node.	Up to 6 weeks post-procedure (standard mycobacterial culture reporting time)
Acid-Fast Bacilli (AFB) Smear Positivity Rate	The proportion of patients with a positive AFB smear from the biopsy specimens obtained from the target mediastinal lymph node.	Within 1 week post-procedure
Xpert MTB/RIF Ultra Positivity Rate	The proportion of patients with a positive Xpert MTB/RIF Ultra test result from the biopsy specimens obtained from the target mediastinal lymph node.	Within 3 days post-procedure
Procedure-Related Complication Rate	The proportion of patients experiencing any adverse event related to the biopsy procedure. This includes, but is not limited to, bleeding (graded according to CHEST consensus criteria), pneumothorax, and mediastinal emphysema.	From start of procedure through 7 days post-procedure

Collaborators and Investigators

• Sponsor: China-Japan Friendship Hospital
• Collaborators: Anhui Chest Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: March 5, 2026
• First Submitted That Met QC Criteria: March 5, 2026
• First Posted (Actual): March 9, 2026

Study Record Updates

• Last Update Posted (Actual): March 9, 2026
• Last Update Submitted That Met QC Criteria: March 5, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Infections; Gram-Positive Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Actinomycetales Infections; Mycobacterium Infections; Tuberculosis
• Other Study ID Numbers: DETECTION-LYM-TB

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No