Angioscopic detection of pulmonary thromboemboli: with special reference to comparison with angiography, intravascular ultrasonography, and computed tomography angiography.

Introduction: Pulmonary embolism (PE) is often fatal and its incidence is increasing worldwide. Detection of thromboemboli (TEi) is essential for a definitive diagnosis of PE. The detection of TEi using most imaging methods is low in patients clinically suspected of having PE. This study was carried out to detect TEi in the pulmonary arterial trees by angioscopy (AS); to classify TEi; and to compare the sensitivity of detection for TEi among AS, angiography (AG), intravascular ultrasonography (IVUS), and computed tomography angiography (CTA) in patients with clinically suspected PE.

Methods: After CTA, AG, and IVUS, the pulmonary arterial trees were surveyed by AS in 49 patients clinically suspected of having PE.

Results: TEi were found by AS, AG, IVUS, and CTA in 81.6%, 24.4%, 34.8%, and 22.5% of 49 patients, respectively. The 48 TEi classified by AS were globular (35%), mural (10%), cap-like (8%), web-like (4%), patchy (33%), and micro (18%). Cap-like, patchy, and micro-TEi were not detectable by AG, IVUS, and CTA in any subjects. TEi color was classified as red, white, yellow, and red-and-yellow in a mosaic pattern in 10%, 31%, 38%, and 18%, respectively. Red and white globular TEi were observed in acute, and red-and-yellow TEi in both acute and chronic PE patients. TEi other than globular were observed in both patient groups.

Conclusion: Although invasive, AS is superior to AG, IVUS, and CTA for the detection of TEi, and therefore is a helpful imaging method for the definitive diagnosis of PE.