Endobronchial Ultrasound for Detecting Central Pulmonary Emboli: A Pilot Study

Abstract

Background: Contrast-enhanced, computed tomography of the chest (angio-CT) is the preferred modality for evaluating central pulmonary embolism (PE). However, acute PE must be diagnosed quickly, and contraindications to contrast agents, hemodynamic instability preventing transport and radiation exposure may limit its use. Because the mediastinal vessels lie within 5 mm of the trachea and central airways, endobronchial ultrasound (EBUS) imaging may be a feasible alternative to detecting PE. Objectives: To demonstrate the feasibility of detecting PE in the central airways by EBUS. Methods: In a prospective, multicenter pilot study, consecutive patients underwent flexible bronchoscopy with a convex EBUS probe under local anesthesia and moderate sedation within 24 h after angio-CT had documented a central PE. The EBUS images were compared to the CT findings. Results: Among 32 patients (mean age 69 years, 20 men), angio-CT documented 101 PE, of which 97 (96%) were also detected with EBUS. The 4 emboli not detected consisted of 1 in a middle lobe and 3 in a left upper lobe artery. At least 1 embolus was detected with EBUS in every patient, which is sufficient to confirm a diagnosis of central PE. No bronchoscopic complications were observed. Mean procedure time was reduced from 5 min in the first 16 patients to 3 min in the last 16. Conclusions: In this pilot study, EBUS was a feasible and safe approach to detecting central pulmonary emboli. Blinded, comparative trials will be necessary to evaluate its use as a primary tool for diagnosing these emboli.