Thrombolysis of Pulmonary Emboli via Endobronchial Ultrasound-Guided Transbronchial Needle Injection

Endobronchial Ultrasound Access to Pulmonary Vasculature in Thoracic Malignancy

Endobronchial ultrasound (EBUS) has evolved beyond conventional applications in mediastinal staging and central pulmonary tumor diagnosis. It encompasses the assessment of pulmonary vasculature in patients with thoracic malignancies. EBUS can visualize major vessels and allow assessment of pulmonary embolism, differential diagnosis of endovascular lesions, and T staging. Additionally, EBUS-guided transvascular needle aspiration (TVNA) has proven valuable for sampling lesions behind vessels and diagnosing conditions such as pulmonary artery sarcoma and tumor embolism, with low complication rates reported. The PubMed and SCOPUS databases were searched up to November 2024 for articles in the English language reporting the use of EBUS for pulmonary vasculature assessment. References were also searched for relevant articles. The integration of EBUS with other modalities enhances staging and diagnostic capabilities in thoracic malignancies. Despite promising findings, limitations include suboptimal image quality and challenges in extensively assessing all the vasculature. Safety concerns, particularly with transvascular biopsy, remain minimal with expert handling, although further studies are needed to assess specific risks like hematogenous tumor seeding. EBUS continues to evolve, suggesting its potential to become the cornerstone in advanced thoracic diagnostics and treatment planning. This review systematically explores the feasibility, safety, and diagnostic utility of EBUS in pulmonary vasculature assessment, highlighting its potential as an indispensable tool in thoracic diagnostics and treatment planning.

Assessment of effectiveness and safety of thrombolytic therapy to pulmonary emboli by endobronchial ultrasound-guided transbronchial needle injection

Objective

Endobronchial ultrasound-guided transbronchial needle injection (EBUS-TBNI) may effectively treat acute pulmonary embolisms (PEs). Here, we assessed the effectiveness of clot dissolution and safety of tissue plasminogen activator (t-PA) injection using EBUS-TBNI in a 1-week survival study of a porcine PE model.

Methods

Six pigs with bilateral PEs were used: 3 for t-PA injection using EBUS-TBNI (TBNI group) and 3 for systemic administration of t-PA (systemic group). Once bilateral PEs were created, each 25 mg of t-PA injection using EBUS-TBNI for bilateral PEs (a total of 50 mg t-PA) and 100 mg of t-PA systemic administration was performed on day 1. Hemodynamic parameters, blood tests, and contrast-enhanced computed tomography scans were carried out at several time points. On day 7, pigs were humanely killed to evaluate the residual clot volume in the pulmonary arteries.

Results

The average of percent change of residual clot volumes was significantly lower in the TBNI group than in the systemic group (%: systemic group 36.6 ± 22.6 vs TBNI group 9.6 ± 6.1, P < .01) on day 3. Considering the elapsed time, the average decrease of clot volume per hour at pre-t-PA to post t-PA was significantly greater in the TBNI group than in the systemic group (mm3/hour: systemic 68.1 ± 68.1 vs TBNI 256.8 ± 148.1, P < .05). No hemorrhage was observed intracranially, intrathoracically, or intraperitoneally on any contrast-enhanced computed tomography images.

Conclusions

This study revealed that t-PA injection using EBUS-TBNI is an effective and safe way to dissolve clots.