Bulletin No. 2, 2011

New Milestone in Stroke Treatment  35  P r o f. L awr ence K . S . Wong , Mok Hing Yiu Professor of Medicine, Chief of Neurology at the Department of Medicine and Therapeutics, is a specialist in the epidemiology, neuroimaging and treatment of stroke. His pioneering work has brought not only fresh hope to stroke sufferers, but also won him a Senior Medical Research Fellowship 2011–12 of the Croucher Foundation. Professor Wong was the first researcher to confirm that intracranial atherosclerosis (narrowing of vessel around the brain) is the most common vascular lesion among Asian stroke patients, and that it is found in one-third to half of Chinese stroke patients. He was the first to establish the high possibility of having another stroke among patients with diffuse intracranial atherosclerosis. 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, right) 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,’ said Professor Wong. T h e c e r e b r a l v e s s e l i s s u r r ound e d b y cerebrospinal fluid instead of flesh. It is very fragile and may burst if overly expanded. He pointed out, ‘Since a few years ago, stents made of shape memory alloys have been available. Stents made of this new material will expand to 70 – 80% of the required diameter when put into the cerebral vessel and expand gradually to the designated size in the following weeks. This is much safer.’ CUHK is the first centre outside the US to perform the stent-assisted angioplasty of the brain vessel. So far, there are about 100 successful cases with a low complication rate. In addition to the local patients who have participated in the research, many patients from overseas, such as India and Malaysia, have come to the University for the treatment. New Milestone in Stroke Treatment