近位部鎖骨下動脈および腕頭動脈閉塞症に対するstenting—preliminary results

Stenting for Proximal Subclavian and Brachiocephalic Artery Occlusion : Preliminary Results

I．はじめに

　血管内治療（interventional radiology，以下IVR）は，外科的血行再建術では到達困難な部位の閉塞性血管障害でさえ低侵襲に治療可能な理由から，近年急速に発展した治療分野である．頭頸部動脈狭窄症に対するpercutaneous transluminalangioplasty（以下PTA）やステント併用血管形成術（以下stenting）の有用性は，本邦でも既に確立されつつある．一方，頭頸部動脈閉塞症に対するIVRに関しては，諸外国に比較して本邦における知見は極めて乏しい^{3,5,7-9,13-15,17,20,22,28）}．

　頭頸部領域では閉塞動脈を再開通させる際に必ずdistal embolismを避ける必要があり，狭窄症と異なり頸動脈閉塞症に対するIVRの報告は限られている^{3,11,12,18,20）}．しかし，subclavian stealphenomenon（以下SSP）を伴う近位部鎖骨下および腕頭動脈閉塞性病変では，頭蓋内へのdistalembolismの頻度が低く^{2,4,5,8,9,13,15,20-24,27,28）}，また，遠位側からのapproachも可能であること^{4,5,9,15,17,20,22）}，術後の再狭窄が少ない^15,19）等の特徴から，近位部鎖骨下および腕頭動脈閉塞症に対してstentingが有効な治療法として本邦でも応用されつつある．

The authors report the initial results, between January 1998 and February 2001, of stenting utilizing thebrachial approach in seven patients for total occlusions at the following locations : two right subclavian,one brachiocephalic, and five left subclavian arteries. All lesions were associated with subclavian steal syn-drome. Indications for the treatment included ischemic symptoms in the affected arm (seven patients), andvertebrobasilar insufficiency (five patients).

A total of eight stents were implanted in six occluded arteries, resulting in a 75% procedural successrate. Procedural complications encountered were two subintimal dissections by a 0.035-inch guide wire dur-ing recanalization , and one stent dislodgement with migration. There was no stroke, presumably becauseof the previously reported preventive effect of delayed reversal of a stealing vertebral artery. Follow-upover a mean duration of 11 months revealed no sign or symptom of recurrence in cases with initial technic-al success.

The results of the current study, with a literature survey, indicated that percutaneous transluminal angio-plasty with primary stent deployment in an occluded prevertebral segment of the subclavian or thebrachiocephalic artery should be considered as an available choice for treatment. Further points, such assome remaining technical and clinical problems, will require more experience and consideration.