小林 朋佳¹, 土井尻 遼介^{2, 3}, 今野 未菜¹, 武田 貞徳¹, 伊藤 祐希¹, 渋谷 ゆう紀¹, 高橋 健¹, 宇沼 香奈¹, 山口 枝里子⁴

Tomoka KOBAYASHI¹, Ryosuke DOIJIRI^{2, 3}, Mina KONNO¹, Sadanori TAKEDA¹, Yuki ITO¹, Yuki SHIBUYA¹, Ken TAKAHASHI¹, Kana UNUMA¹, Eriko YAMAGUCHI⁴

¹秋田県立循環器・脳脊髄センター臨床検査部, ²秋田県立循環器・脳脊髄センター脳血管内科, ³岩手県立中央病院脳神経内科, ⁴国立循環器病研究センター脳血管部門脳神経内科

¹Department of Clinical Laboratory, Akita Cerebrospinal and Cardiovascular Center, ²Department of Cerebrovascular Medicine, Akita Cerebrospinal and Cardiovascular Center, ³Department of Neurology, Iwate Prefectural Central Hospital, ⁴Department of Neurology, National Cerebral and Cardiovascular Center

キーワード : Paget-Schroetter syndrome, ultrasonography, thoracic outlet syndrome, deep vein thrombosis, anticoagulation

上肢深部静脈血栓症は深部静脈血栓症の中でも稀であり，本症例ではその一つであるPaget-Schroetter症候群を超音波検査で診断し得たので報告する．症例は37歳女性，超音波検査に従事する臨床検査技師である．X年5月に肩こりの左右差，5月下旬より左上肢の軽度しびれ，腫脹および前腕の色調変化を認めた．超音波検査にて左鎖骨下静脈血栓を指摘され受診．既往歴・家族歴に特記なく，D-dimer 0.53 μg/mLで血栓性素因を認めなかった．direct oral anticoagulant（DOAC）にて一時血栓は消失したが，その後同部位で再発を2回認めた．X＋1年9月の再評価でRoosテスト陽性．超音波検査にて上肢挙上時，左肋間隙で左鎖骨下静脈が明らかに圧迫され血流停滞を呈し，血栓形成部位と一致していた．体位変換に伴う血流変化を動的に評価できたことから，胸郭出口症候群を背景としたPaget-Schroetter症候群と診断し得た．造影CTでも同所見を確認した．現在，外科的治療は行わずDOAC継続で経過観察中である．

Paget-Schroetter syndrome （PSS） is a relatively rare form of upper extremity deep vein thrombosis （UEDVT）, often associated with thoracic outlet syndrome （TOS）. We report a case in which ultrasonography was useful not only for detecting thrombosis but also for dynamically evaluating venous compression during symptom-provoking maneuvers. The patient was a 37-year-old female sonographer who developed left shoulder discomfort in May, followed by mild swelling, numbness, and discoloration of the left forearm. Ultrasonography performed by the patient herself revealed thrombosis in the left subclavian vein, leading to hospital referral. Laboratory testing demonstrated no thrombophilic predisposition （D-dimer 0.53 μg/mL）. Anticoagulation with a direct oral anticoagulant （DOAC） was initiated, and thrombus resolution was confirmed after 2 months. However, recurrent thrombosis was documented in the same location in December and again the following May, prompting resumption of anticoagulant therapy. At reevaluation in September of the following year, there was no muscle weakness or resting circulatory disturbance, but the Roos test was positive. Ultrasonography during arm elevation demonstrated venous compression and flow stasis at the costoclavicular space, corresponding to the site of prior thrombosis. Contrast-enhanced CT confirmed compression of the left subclavian vessels in the same posture. The patient was diagnosed with Paget-Schroetter syndrome. Notably, her occupational activity as a sonographer, which required repetitive use of the left upper limb to operate the ultrasound device, was considered a potential contributing factor to chronic venous compression. The case highlights the utility of ultrasonography performed under symptom-inducing conditions, allowing real-time assessment of venous hemodynamics, which may be overlooked in supine imaging. This case demonstrates that ultrasonography is not only effective in detecting thrombosis but also valuable in assessing dynamic positional venous compression. Ultrasonographic evaluation under symptom-provoking conditions may therefore play a critical role in the diagnosis of Paget-Schroetter syndrome.