Endoscopic ultrasound in the diagnosis of mediastinal diseases

Comprehensive analysis of endoscopic ultrasound (EUS) in mediastinal lesions: patient characteristics, diagnostic outcomes, safety, and efficacy: a multi-country study

Background

Mediastinal lesions are tumors that develop mainly from structures commonly located in the three compartments of the mediastinum and the paravertebral areas. The diagnosis of these lesions is primarily based on imaging studies such as computed tomography and magnetic resonance imaging, which confirm the presence of the lesions and suspected metastatic disease. The study aims to determine the factors that determine the diagnostic accuracy and yield of endoscopic ultrasound (EUS) in diagnosing mediastinal lesions.

Methods

This multi-country study involved a list of centers providing EUS services across ten countries—the United Kingdom, Algeria, Egypt, Iraq, Kingdom of Saudi Arabia (KSA), Lebanon, Morocco, Pakistan, Romania, and Thailand. The appropriate information was collected regarding EUS-FNA and EUS-FNB procedures, including needle types, nature of lesion, needle passes, and complications of the techniques. The frequency/percentage conveyed data on the qualitative variables. The p-values were obtained using the Chi-square two-tailed exact test. The significance of the analysis was defined as p < 0.05. All the syntheses were performed using the Statistical Package for the Social Sciences (SPSS version 27; SPSS Inc., Chicago, IL, USA).

Results

A total of 439 participants were involved in this study, 255 (58.1%) males and 184 (41.9%) females, with a mean age of 55.73 $$\pm$$ ±  14.93 years. EUS-FNA and EUS-FNB diagnostic yield was influenced by needle types, needle size, number of needle passes, and lesion size. Among females, 44.6% were diagnosed with EUS-FNA, 42.8% with EUS-FNB, and 50.0% with EUS-FNA and FNB. Conversely, 55.4% of males were diagnosed using EUS-FNA and 57.2% with EUS-FNB. The association between gender and the diagnostic method, however, was statistically insignificant (p = 0.197). Needles with smaller diameters (22G) offered greater diagnostic yield than needles with larger diameters (19G). A minimal number of needle passes (between 2 and 4) showed a higher diagnostic yield than a higher number of needle passes (> 5). EUS-FNB accounted for a 0.5% complication incidence rate each for fever, pain, thoracic pain, and hemorrhage. EUS-FNA had no complication rate. Patients undergoing EUS-FNA, EUS-FNB, or both procedural examinations had no significant complications (p = 0.085).

Conclusion

The diagnostic yield of EUS procedures is affected by needle types, number of needle passes, lesion size, and needle size. Besides, EUS-FNA and EUS-FNB are infrequently associated with various complication rates. These techniques are safe and offer higher diagnostic yield when utilized responsibly by endosonographers.

Minimally Invasive Sampling of Mediastinal Lesions

This narrative review examines the existing literature on minimally invasive image-guided sampling techniques of mediastinal lesions gathered from international databases (Medline, PubMed, Scopus, and Google Scholar). Original studies, systematic reviews with meta-analyses, randomized controlled trials, and case reports published between January 2009 and November 2023 were included. Four authors independently conducted the search to minimize bias, removed duplicates, and selected and evaluated the studies. The review focuses on the recent advancements in mediastinal sampling techniques, including EBUS-TBNA, EUS-FNA and FNB, IFB, and nodal cryobiopsy. The review highlights the advantages of an integrated approach using these techniques for diagnosing and staging mediastinal diseases, which, when used competently, significantly increase diagnostic yield and accuracy.

Role of Bronchoscopic Techniques in the Diagnosis of Thoracic Sarcoidosis

The diagnosis of sarcoidosis relies on clinical and radiological presentation, evidence of non-caseating granulomas in histopathology and exclusion of alternative causes of granulomatous inflammation. Currently, a proper diagnosis, with a high level of confidence, is considered as key to the appropriate diagnosis and management of the disease. In this sense, this review aims to provide a brief overview on the role of bronchoscopy in the diagnosis of thoracic sarcoidosis, incorporating newer techniques to establish, including endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), transesophageal ultrasound-guided needle aspiration with the use of an echo bronchoscope (EUS-B-FNA) and transbronchial lung cryobiopsy (TBLC). Most of the literature reports the diagnostic superiority of endosonographic techniques, such as EBUS-TBNA alone or in combination with EUS-FNA, over conventional bronchoscopic modalities in diagnosing Scadding stages I and II of the disease. Moreover, TBLC may be considered a useful and safe diagnostic tool for thoracic sarcoidosis, overcoming some limitations of transbronchial lung biopsy (TBLB), avoiding more invasive modalities and being complementary to endosonographic procedures such as EBUS-TBNA.