Annual Report 2010–11

26 New Hope for Stroke Patients Seeing their research results benefiting people may be one of the most rewarding experiences for researchers. Prof. Wong Ka- sing Lawrence, Mok Hing Yiu Professor of Medicine, chief of the Division of Neurology, Department of Medicine and Therapeutics, has studied stroke for two decades. He is the first to confirm that the most common cause of stroke in Asian patients is intracranial atherosclerosis (narrowing of vessel around the brain), while in western countries it is the narrowing of the vessel in the neck. After pinpointing the cause, Professor Wong studied the technique of stent-assisted angioplasty of the brain vessel to minimize the rate of recurrent stroke. The minimally invasive procedure involves transporting a wire mesh tube (a stent) from large supra-aortic arteries to minute intra-cranial arteries through an incision at the groin by means of a small catheter and with the help of imaging tools. The stent will form a rigid support to hold the artery open. This procedure is much more complex than coronary artery stenting. The distance between the thigh to the heart is relatively short and the artery path is quite straight. By contrast, the cerebral vessel has many twists and turns and the narrowed one has a diameter of only 1 mm. Complete technical mastery is a must. Professor Wong and Prof. Leung Wai-hong Thomas from the Department of Medicine and Therapeutics, Prof. Yu Chun-ho Simon from the Department of Imaging and Interventional Radiology published the result of their study on ‘Intracranial Stenting for Prevention of Ischaemic Stroke’ in the American Journal of Neuroradiology in April 2011. Aimed at evaluating the safety and effectiveness of the treatment, the study showed that the success rate of stenting procedure was 95.7% and the risk of stroke after treatment was 6.1% per year, much lower than the 23% observed in patients treated by medical therapy alone. 中風病人的新希望 研究成果能造福人類，也許是令研究 人員最感欣慰的事情。內科及藥物治 療學系莫慶堯內科醫學講座教授、腦 神經科主任黃家星教授，二十多年前 已開始研究中風。他率先確定了顱內 動脈粥樣硬化（腦血管收窄）是亞洲 中風患者最常見的血管病變，與西方 人中風的主因頸部血管狹窄有別。 了解病因後，黃教授就研究利用支架 將中風病人腦血管狹窄部分撐開，減 低病人再次中風的風險。該微創手術 要在大腿動脈開啟一個切口，以影像 引導，透過微型導管將支架沿血管運 送到顱內動脈的狹窄部分，以擴大血 管口徑和維持暢通。 在腦血管安裝支架遠較在心臟安裝支 架複雜，因為從大腿離心臟較近，血 管也較直；而腦血管較彎曲，導管要多 繞數圈才可到達目的地，加上收窄後 的血管直徑只有一毫米，故手術要求 很高技巧。 黃家星教授與同是內科及藥物治療 學系的梁慧康教授，以及影像及介入 放射學系余俊豪教授在 2011 年 4 月的 《美國神經放射學雜誌》上發表名 為「以腦血管支架預防缺血性中風」 的研究成果，該研究旨在評估支架 擴闊治療的成效與安全，結果顯示手 術成功率達百分之九十五點七，而支 架治療後中風的風險僅為每年百分 之六點一，遠較純藥物治療的百分之 二十三為低。