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

NCT07459569 | Not Yet Recruiting DMC

• 1 other identifier: DETECTION-LYM-TB
• Study Type: interventional
• Target: 108
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Tuberculosis; Mediastinal and Hilar Lymph Node Enlargement

Outcome Measures

Primary Outcomes (1)

• 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 Outcomes (4)

• Mycobacterium tuberculosis Culture Positivity Rate

  Up to 6 weeks post-procedure (standard mycobacterial culture reporting time)

• Acid-Fast Bacilli (AFB) Smear Positivity Rate

  Within 1 week post-procedure

• Xpert MTB/RIF Ultra Positivity Rate

  Within 3 days post-procedure

• Procedure-Related Complication Rate

  From start of procedure through 7 days post-procedure

Study Arms (2)

EBUS-TBMC

EXPERIMENTAL

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-TBNA

ACTIVE COMPARATOR

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

Interventions

EBUS-TBMC PROCEDURE

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

EBUS-TBMC

EBUS-TBNA PROCEDURE

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

EBUS-TBNA

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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

Sponsors & Collaborators

• China-Japan Friendship Hospital: lead
• Anhui Chest Hospital: collaborator

Study Sites (1)

2nd Yinghuadong Street, Beijing, China

Beijing, Beijing Municipality, 100029, China

Location

MeSH Terms

Conditions

Tuberculosis

Condition Hierarchy (Ancestors)

Mycobacterium Infections; Actinomycetales Infections; Gram-Positive Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Infections

Central Study Contacts

Mingming Deng, M.D., Ph.D.

CONTACT

+86 18801336854; isdeng1017@163.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: March 5, 2026
• First Posted: March 9, 2026
• Study Start: May 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027
• Last Updated: March 9, 2026

Record last verified: 2026-03

Locations

CN (1)