武田 京子, 松山 裕宇, 岩瀬 正嗣, 加藤 千博, 福井 雅子, 長谷川 和生, 木村 美由紀, 森本 紳一郎, 野村 雅則, 菱田 仁

Kyoko TAKEDA, Hiroyuki MATSUYAMA, Masatsugu IWASE, Chihiro KATO, Masako FUKUI, Kazuo HASEGAWA, Miyuki KIMURA, Shin-ichiro MORIMOTO, Masanori NOMURA, Hitoshi HISHIDA

藤田保健衛生大学内科

Department of Internal Medicine Fujita Health University

キーワード : Intravascular ultrasound (IVUS), Mediastinal tumor, Pulmonary artery (PA), Pulmonary hypertension, Pulmonary thromboembolism

The clinical usefulness of intravascular ultrasound (IVUS) in assessing pulmonary artery (PA) lesions was studied in 17 patients with pulmonary disease (13 with pulmonary thromboembolism, 1 with secondary pulmonary hypertension, and 3 with mediastinal tumor) and 7 normal subjects. We used a mechanically scanned 20 MHz catheter-type transducer in conjunction with an ultrasound scanner (CVIS Insight US 1; CVIS Inc., Sunnyvale, USA). IVUS examination added 30 minutes of manipulation to the conventional catheterization procedure; however, the equipment was able to produce images of the PA walls of subjects in the normal group, in which internal PA diameters ranged form 5 to 25 mm. The walls in these images appeared to have one or two layers, and they had good pulsatile extension. IVUS demonstrated a large echo-lucent mass in the proximal PA in the acute phase of pulmonary thromboembolism (PTE), which was frequently accompanied by spontaneous luminal echo contrast. Such findings were thought to indicate the presence of a new thrombus. In the subacute phase of PTE, 1 month after the appearance of embolic evidence, IVUS showed a crescent-shaped low-echoic layer attached to the PA wall, probably produced by a residual thrombus that had not appeared on PA angiography. In the chronic phase, after persistent anticoagulant therapy, IVUS showed that the lesions had disappeared or decreased in size. IVUS showed that the lesions had disappeared or decreased in size. IVUS showed a crescent-shaped high-echoic layer attached to the proximal PA wall and irregular luminal surfaces in chromic PTE accompanied by pulmonary hypertension and in recurrent PTE. These lesions were thought to be organized thrombi. Pulsatile extensions of the PA wall in a patient with ischemic heart disease accompanied by pulmonary hypertension were severely restricted. although no other vascular lesions were apparent. The IVUS image showed an irregular inner surface and a discontinuity in the PA wall of a patient with a mediastinal tumor that had invaded the PA wall. We conclude that IVUS imaging of PA is a feasible procedure: It is safe and can provide detailed complementary information about lesions of the pulmonary artery.