Abstract. Whether an endobronchial ultrasound (EBUS)is required for transbronchial needle aspiration (TBNA) in the diagnosis of mediastinal masses is currently a disputed subject. Previous studies have demonstrated that EBUS-TBNA performs better compared to conventional TBNA as it is capable of sampling in real-time compared with conventional TBNA. However, some clinicians consider conventional TBNA to be sufficient for diagnosis. In this meta-analysis, we evaluated these two methods according to diagnostic yield. A search was conducted through PubMed, Embase and the proceedings of major conferences, for studies comparing TBNA with EBUS-TBNA in the diagnosis of mediastinal masses. The identified studies were evaluated for publication bias and heterogeneity. The primary outcome was diagnostic yield. Pooled odds ratio (OR) estimated with 95% confidence intervals (CIs) was calculated using the fixed-effects model. Five studies, including a total of 407 patients, were included in the meta-analysis. The EBUS-TBNA arm was associated with a significantly higher OR compared to that of the TBNA arm in terms of diagnostic yield (OR=2.72, 95% CI: 1.72-4.30, P<0.001). There was no evidence of heterogeneity (I 2 =0%, P=0.540) or publication bias (Egger's test, P= 0.568; Begg-Mazumdar test, P=0.806). In conclusion, EBUS-TBNA and conventional TBNA are safe and provide good diagnostic yield in the diagnosis of hilar and mediastinal masses and lymphadenopathies; however, EBUS-TBNA performs better compared to conventional TBNA, with a shorter aspiration time and higher sensitivity.
IntroductionClinically, mediastinal masses are currently a common occurrence. The incidence of certain diseases, such as lung cancer and sarcoidosis, is on the increase. Accurate and early diagnosis of such diseases is crucial for the appropriate treatment and prognosis (1,2). A major concern for clinicians worldwide is the establishment of a diagnostic method that is fast, accurate and minimally invasive.Imaging is crucial in the diagnosis of mediastinal masses. An imaging scan may provide critical information with regard to the location, size and periphery of the lesions and it is fast and non-invasive. Positron emission tomography-computed tomography (PET-CT) may also indicate whether the mass is benign or malignant. However, more precise information is required for staging and typing.Although mediastinoscopy or surgery is considered to be the gold standard for diagnosis (3), some patients are unable to tolerate the procedural injury and intravenous anesthesia. Therefore, efforts are focused on establishing a method that is easy to use, minimally invasive and efficient in providing the critical information required.Transbronchial biopsy is such a method, particularly transbronchial needle aspiration (TBNA), which aspirates masses and pathological lymph nodes through an air tube, with minimal invasion (4). However, conventional TBNA requires the assistance of X-ray, CT or PET-CT; therefore, there remains the need for equipment that may guide real-tim...