Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been recommended for diagnosis of suspected sarcoidosis or suspected tuberculosis with adenopathy and may be used as an initial diagnostic test for suspected lymphoma, according to guidelines issued by CHEST (the American College of Chest Physicians).
The guidelines, which are primarily focused on technical aspects of EBUS-TBNA, also advise obtaining additional samples for the purpose of molecular analysis in patients who undergo the procedure for the diagnosis or staging of non–small cell lung cancer.
The guidelines are based on a systematic review and critical analysis of the literature by an expert panel chaired by Dr. Momen M. Wahidi of Duke University Medical Center, Durham, N.C. Of the 12 guideline statements by the panel, 7 were graded evidence-based recommendations and 5 were ungraded consensus-based statements.
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A biopsy window is found and an FNA needle advanced into the mass with EUS guidance.
The guideline (Chest. 2016 Mar;149[3]:816-35) has been endorsed by the American Association of Bronchology and Interventional Pulmonology, American Association for Thoracic Surgery, Canadian Thoracic Society, European Association for Bronchology and Interventional Pulmonology, and Society of Thoracic Surgeons.
Use of EBUS-TBNA for diagnosis in patients with suspected sarcoidosis with mediastinal and/or hilar adenopathy is ranked Grade 1C (strong recommendation, low-quality evidence, benefits outweigh risks). The guideline writers concluded that EBUS-TBNA provides safe and minimally invasive access to the mediastinal and hilar lymph nodes with a pooled diagnostic accuracy of 79.1%. They qualified, however, that it may be difficult to use EBUS-TBNA to obtain adequate tissue from fibrotic lymph nodes and conventional bronchoscopic techniques such as transbronchial lung biopsy and endobronchial biopsy may be needed in selected patients.
One systematic review and meta-analysis study included 15 studies with a total of 553 patients with sarcoidosis. The diagnostic yield of EBUS-TBNA ranged from 54% to 93%, with the pooled diagnostic accuracy of 79% (95% confidence interval, 71-86). Ten additional studies including 573 combined patients were identified through updated searches of the systematic review, and led to a pooled diagnostic accuracy of 78.2%.
Similarly, a Grade 1C recommendation was made for using EBUS-TBNA for diagnosis in when other modalities are not diagnostic in patients with suspected tuberculosis with mediastinal and/or hilar adenopathy who require lymph node sampling. However, “it must be noted that no single study assessed the role of EBUS-TBNA for the diagnosis of TB [tuberculosis] as the primary outcome measure,” they wrote. Various techniques are available for the diagnosis of TB and should be incorporated during the diagnostic evaluation.
In patients with suspected lymphoma, EBUS-TBNA is an acceptable initial, minimally invasive diagnostic test, the guideline writers said in an Ungraded Consensus-Based Statement.
In some conditions, minimally invasive EBUS-TBNA may be preferred over surgical intervention. Repeat mediastinoscopy or surgical biopsy after treatment for relapsed lymphoma can be challenging, for example, with a lower diagnostic yield and higher complication rate.
Because treatment regimens for both non-Hodgkin and Hodgkin lymphoma depend on the specific subtype and histologic grade, a definitive diagnosis of lymphoma requires the evaluation of cell morphology, immunophenotype, and the overall architecture of the tissue. Reed-Sternberg cells, diagnostic of Hodgkin lymphoma, are usually scarce in cytologic aspirates, and it often is impossible to evaluate the overall background architecture. Currently available EBUS-TBNA needles provide only cytologic specimens, with reported high discordance between cytologic specimens and histologic specimens.
In five retrospective studies with a total of 212 patients undergoing EBUS-TBNA for suspected lymphoma, the pooled diagnostic accuracy was 68.7%, and there was heterogeneity across studies in the proportion of patients with de novo lymphoma and relapsed lymphoma. Higher diagnostic yield was noted for relapsed lymphoma, compared with de novo lymphoma. Also, the two studies with the highest yield included cases as diagnostic, even when additional tissue sampling was necessary to subclassify the lymphoma for clinical management.
The panel gave a weak recommendation (Grade 2C) based on low-quality evidence to their conclusion that moderate or deep sedation is acceptable for EBUS-TBNA, based on three studies. Moderate sedation allows patients to respond purposefully to verbal commands while maintaining a functional airway, spontaneous ventilation, and cardiovascular function. In deep sedation, patients cannot be easily aroused but respond purposefully to repeated or painful stimulation and may have compromised airway function and spontaneous ventilation; cardiovascular function usually is maintained.
In one retrospective multivariable analysis of 309 patients at two centers, deep sedation had a statistically significant benefit on diagnostic yield. In a prospective randomized, controlled study of 149 patients at a single center with a single operator, there was no difference in diagnostic yield for moderate and deep sedation. However, fewer patients in the moderate sedation group were able to complete the procedure, compared with the deep-sedation group. Patient comfort and satisfaction were similar for the two sedation groups, and no patients had major complications or needed escalation of care.