Convex probe endobronchial ultrasound: applications beyond conventional indications

Endobronchial ultrasound-guided transbronchial needle aspiration in diagnosing intrathoracic lymphadenopathy in patients with nasopharyngeal cancer

OBJECTIVE

This study aimed to assess the efficacy of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in detecting intrathoracic lymph nodes in patients with nasopharyngeal carcinoma (NPC).

METHODS

Retrospective data analysis was conducted on individuals who underwent EBUS-TBNA between June 2015 and June 2022. Patients with NPC and enlarged intrathoracic lymph nodes were included. Specimens were categorized as malignant or non-malignant, with final non-malignancy confirmation procedures, or 12 months of clinical follow-up.

RESULTS

Among 97 patients, 59 (60.8%) had NPC with intrathoracic lymph node metastasis, 3 (3.1%) had primary lung cancer involving nodes, and 25 (25.8%) showed benign characteristics. Ten cases (10.3%) were false-negative on initial EBUS-TBNA but confirmed as metastatic on follow-up. For NPC patients with intrathoracic lymphadenopathy, EBUS-TBNA exhibited 86.1% sensitivity (62/72), 71.4% negative predictive value (25/35), and 89.7% accuracy (87/97). Multivariate analysis identified increased lymph node short axis (OR: 1.200, 95% CI: 1.024-1.407; P = 0.041), metachronous NPC (OR: 11.274, 95% CI: 2.289-55.528; P = 0.003), and synchronous lung lesions (OR: 19.449, 95% CI: 1.875-201.753; P = 0.001) as independent predictors of malignant intrathoracic lymphadenopathy. Longer lymph node short axis (OR: 1.305, 95% CI: 1.044-1.631; P = 0.019) was independently associated with EBUS-TBNA accuracy.

CONCLUSION

EBUS-TBNA effectively diagnoses intrathoracic lymphadenopathy in NPC patients.

Additional EBUS-guided intralesional amphotericin B injection combined systemic intravenous therapy in pulmonary mucormycosis: a case report

Mucormycosis is an invasive fungal infection that can result in severe lung infections, with pulmonary mucormycosis (PM) being one of the most prevalent manifestations. Prompt diagnosis is crucial for patient survival, as PM often exhibits rapid clinical progression and carries a high fatality rate. Broncho-alveolar lavage fluid or endobronchial biopsy (EBB) has been commonly employed for diagnosing PM, although there is limited mention of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in the literature. In this report, we present a case of PM in a patient with diabetes. While EBB did not yield evidence of Rhizopus infection, a definitive diagnosis was obtained through EBUS-TBNA. The patient underwent combination therapy, including oral medication, nebulization, and EBUS-guided intrafocal amphotericin B injection, which resulted in significant improvement following the failure of initial therapy with amphotericin B injection cholesterol sulfate complex. Our case highlights the potential of EBUS-TBNA not only for mediastinal lymphadenopathy but also for obtaining extraluminal lesion specimens. Furthermore, for patients with an inadequate response to mono-therapy and no access to surgical therapy, the addition of EBUS-guided intralesional amphotericin B injection to systemic intravenous therapy may yield unexpected effects.

The evolution of endobronchial ultrasound usage in modern era

Over the past two decades, endobronchial ultrasound (EBUS) has become a crucial tool for diagnosing pulmonary diseases. The most common indication of EBUS usage is the diagnosis and staging of lung cancer. Additionally, there have been significant improvements in the application of convex probe EBUS in line with the increase in experience and knowledge about EBUS and the developments in medicine and technology. To enhance diagnostic accuracy and acquire larger tissue samples, techniques such as cryo-biopsy guided by endobronchial ultrasound (EBUS) and intranodal forceps biopsy have been developed. Additionally, elastography functionality has been integrated into the EBUS application to improve the assessment of targeted lesions. Moreover, its utilization for evaluating and sampling pulmonary vascular structures has expanded. It has also found applications in guiding intratumoral therapy, positioning fiducial markers, and facilitating the drainage of pleural or pericardial effusions. This review aims to provide an overview of the extended applications of convex probe EBUS beyond its conventional uses.

An evolving role for endobronchial ultrasonography in the intensive care unit

Endobronchial ultrasound (EBUS) bronchoscopy is an established minimally-invasive modality for visualization, characterization, and guidance of sampling of paratracheal and parabronchial structures and tissues. In the intensive care unit (ICU), rapidly obtaining an accurate diagnosis is paramount to the management of critically ill patients. In some instances, diagnosing and confirming terminal illness in a critically ill patient provides needed closure for patients and their loved ones. Currently available data on feasibility, safety, and yield of EBUS bronchoscopy in critically ill patients is based on single center experiences. These data suggest that in select ICU patients convex and radial probe-EBUS bronchoscopy can serve as useful tools in the evaluation of mediastinal lymphadenopathy, central airway obstruction, pulmonary embolism, and peripheral lung lesions. Barriers to the use of EBUS bronchoscopy in the ICU include: (I) requirement for dedicated equipment, prolonged procedure time, and bronchoscopy team expertise that may not be available; (II) applicability to a limited number of patients and conditions in the ICU; and (III) technical difficulty related to the relatively large outer diameter of the convex probe-EBUS bronchoscope and an increased risk for adverse cardiopulmonary consequences due to intermittent obstruction of the artificial airway. While the prospects for EBUS bronchoscopy in critically ill patients appear promising, judicious patient selection in combination with bronchoscopy team expertise are of utmost importance when considering performance of EBUS bronchoscopy in the ICU setting.

Recent advances in convex probe endobronchial ultrasound: a narrative review

Convex probe endobronchial ultrasound (CP-EBUS) has been widely used in the lymph node staging and restaging of lung tumors and the diagnosis of mediastinal diseases. Recent years have seen continuous progress in this technology. For diagnosis, elastography technology can preliminarily distinguish between benign and malignant lesions, so that reduce the number of punctures. CP-EBUS can also be used as an endoscopic ultrasound (EUS) to guide needle aspirations of liver lesions, retroperitoneal lymph nodes and left adrenal gland (LAG) lesions sometimes. Some advances help diagnosing more accurately and effectively, such as the intranodal forceps biopsy (IFB), the new type of 22G needle, the rapid on-site evaluation (ROSE) and the cancer gene methylation, etc. In addition, special advances are being made in diagnosis using artificial intelligence (AI). For treatment, CP-EBUS has yielded novel research results when applied to transbronchial needle injection (TBNI) and radioactive seed implantation in clinical cases, and blocking of the cardiac plexus in animal studies. The next-generation CP-EBUS is also ready for use in the clinic and the technology will be improving continuously. Through this review, we hope to educate clinicians on the latest uses of CP-EBUS and open up further research ideas for readers interested in this technology.

The role of endobronchial ultrasonography elastography for predicting malignancy

Background

This study aims to investigate the role of endobronchial ultrasonography elastography in predicting malignancy.

Methods

Between January 2016 and December 2016, a total of 221 lymph nodes were biopsied using the endobronchial ultrasonography-guided transbronchial needle aspiration from 119 consecutive patients (69 males, 50 females; mean age 63.2±12.4 years; range, 16 to 86 years) were included. Lymph nodes were scored by elastography according to their colors in four categories before the procedure. The strain ratio was calculated based on the region of interest after three measurements.

Results

Of the patients, 93 were diagnosed with a malignancy through endobronchial ultrasonography-guided transbronchial needle aspiration biopsy. The mean lymph node score of benign versus malignant lesions was 2.2±1.0 and 3.2±1, respectively (p<0.001). There was a positive correlation between the lymph node scores and lymph node diameter, strain ratio, ≥3 of lymph node scoring, the sensitivity for malignancy was 79% and specificity was 60%. The mean strain ratio for malignant and benign lymph nodes was 22.2±30.1 and 5.2±1.7, respectively (p<0.001). With a cut-off value of ≥2.47 of strain ratio, the sensitivity for malignancy was 75% and specificity was 65%. The combined use of positron emission tomography and lymph node score or strain ratio yielded 80.4% and 61.2% sensitivity and 80% and 70.3% specificity for malignancy, respectively.

Conclusion

Endobronchial ultrasonography elastography is useful in predicting malignancy of the lymph nodes. When combined with positron emission tomography, specificity and positive predictive value for malignancy increase.

Role of Convex Probe Endobronchial Ultrasound in the Diagnosis and Treatment of Nonmalignant Diseases

Here we present a comprehensive review of the literature concerning the utility of convex probe endobronchial ultrasound (CP-EBUS) in the diagnosis and treatment of nonmalignant conditions and discuss the associated complications. CP-EBUS has been conventionally used for the staging of lung cancer and sampling of mediastinal and hilar nodes. However, its application is not limited to malignant conditions, and it is gaining acceptance as a diagnostic modality of choice for nonmalignant conditions such as tuberculosis, sarcoidosis, pulmonary embolism, thyroid lesions, and cysts. Moreover, its therapeutic value allows for extended applications such as mediastinal and thyroid cyst drainage, fiducial marker placement for radiation therapy, and transbronchial needle injection. The noninvasiveness, low complication rate, high diagnostic yield, and satisfactory sensitivity and specificity values are the main attributes that lend credence to the use of CP-EBUS as a standalone primary diagnostic and therapeutic tool in pulmonary medicine in the foreseeable future.

Pathway and application value of exploration of the pulmonary artery by endobronchial ultrasound

Background

The current standard methods for detecting pulmonary artery diseases are pulmonary artery enhanced computed tomography (CT) scan and pulmonary arteriography. However, some patients cannot tolerate these procedures for various reasons. The present study aimed to investigate the feasibility and operation process of endobronchial ultrasound (EBUS) in exploring the pulmonary artery.

Methods

Based on normal contrast-enhanced chest CT images, the sites and process for exploring the pulmonary arteries were established. Then the feasibility of the exploration by the convex probe EBUS were evaluated, and roadmaps for exploration of the pulmonary arteries were drawn.

Results

Among patients who underwent pulmonary artery exploration, sonograms of the left and right pulmonary artery were obtained by the convex probe EBUS. The above-mentioned pulmonary artery branches can be positioned by means of anatomical markers under the bronchoscopic view and follow a certain route for continuous exploration. Sonograms had a certain degree of identification and can be used as an auxiliary tool for pulmonary artery exploration.

Conclusions

EBUS can be used to explore the main branches of the pulmonary artery continuously. Therefore, EBUS could be considered as a candidate for the diagnosis of pulmonary artery diseases in a selected group of patients, i.e., patient with contrast allergy or renal failure.

Mitral valve vegetation diagnosed with oesophageal ultrasound with bronchoscope (EUS-B)

Oesophageal ultrasound with bronchoscope (EUS-B) is designed to evaluate mediastinal structures. We describe a case of a 78-year-old woman who presented with altered mental status for 2 weeks. CT head revealed a subacute infarct in the right middle cerebral artery distribution. She was also found to have a lung mass on chest imaging. EUS-B-guided fine needle aspiration demonstrated the presence of adenocarcinoma in station 7 lymph node and in the mass. Immunohistochemistry confirmed it to be a lung primary as the Thyroid Transcription Factor-1 (TTF-1) was strongly positive. During the procedure, the cardiac valves were evaluated, and a mitral valve vegetation was noted. Formal echocardiography confirmed the presence of the vegetation. During hospital stay, the patient developed fever. Her blood cultures grew oxacillin-resistant Staphylococcus aureus. She was subsequently treated for infective endocarditis. We suggest that the use of EUS-B to routinely scan adjacent structures during a procedure may help obtain additional clinical information that may be critical to patient management.

The role of endobronchial ultrasonography for mediastinal lymphadenopathy in cases with extrathoracic malignancy

INTRODUCTION

Many extrathoracic malignancies can metastasize to lungs and mediastinal lymph nodes. Whether mediastinal lesions are metastasis in these patients changes staging, prognosis, and treatment strategy. In this study, we aimed to find out the contribution of EBUS-TBNA to the diagnosis in cases with extrathoracic malignancy.

MATERIALS AND METHODS

Patients who had been previously diagnosed as extrapulmonary solid organ malignancy and in whom mediastinal or hilar lymphadenopathy developed during their follow-up and EBUS-TBNA was applied for diagnostic purposes were retrospectively included in this study.

RESULTS

A total of 91 patients consisting of 35 females (38.5 %) and 56 males (61.5 %) were included in the study. The mean age of the patients was 60.5 (±11.4). Malignancy was not observed in 54 (59.3 %) patients; primary malignancy metastasis was detected in 33 (36.3 %) patients, and primary lung cancer was detected in 4 (4.4 %) patients with EBUS-TBNA. The sensitivity of EBUS-TBNA in extrathoracic malignancies was determined as 90.2 %; its specificity was determined as 100 %, its negative predictive value as 92.5 %, its positive predictive value as 100 %, and its diagnostic accuracy as 95.6 %. The highest rate was determined in the left lower paratracheal lymph node when they were examined in terms of malignancy detection rate in lymph node stations.

CONCLUSION

EBUS-TBNA is a minimally invasive method with quite a low complication rate that does not require general anesthesia. It should be the first step method to be used in the diagnosis of mediastinal and hilar lymphadenopathies seen in extrathoracic malignancies since it has high diagnostic accuracy, sensitivity, and specificity. EBUS-TBNA significantly reduces the need for surgical intervention. Further surgical interventions can be planned in patients in whom diagnostic competence is not ensured.