大多數人對 冠心病的認知就是血管被堵塞,其實伴隨而來還有其他問題——心臟冠狀動脈因脂肪性物質凝聚形成粥樣斑塊,令血管通道收窄(1),經年累月,這些斑塊有機會鈣化變硬,造成「血管鈣化」問題(2)。可想像一下,若血管內壁封上一層堅硬的水泥,變成一條又窄又硬的通道,要「通波仔」的話就棘手了,需加入其他儀器輔助,近年引入的衝擊波技術是其中一個風險較低的選擇(3,4)。
血管鈣化變硬 通波仔變棘手
血管鈣化是隨年紀增長而出現的問題,難以避免,如有血脂問題、吸煙、高血壓、腎病等人士風險會較高(5,6)。
通波仔(冠狀動脈介入治療術)大家也聽得多,用以治療冠心病,是相對低風險的微創手術(7)。一般情況,醫生會經由手腕或大腿血管引入導管,延伸至冠狀動脈收窄位置,打開球囊擴闊血管,再植入金屬支架撐開通道,令血流回復暢順(8)。若血管已鈣化變硬,傳統通波仔球囊便難以撐開血管,令支架打開幅度變小,增加復發機會(9,10)。以往醫生或會建議病人改做「搭橋」(血管繞道手術),開胸移植另一條自身的血管,連接收窄位置,讓血流繞道而行(11,12),但要在一條已硬化的血管上縫合,同樣有難度(13)。
隨着通波仔技術漸趨成熟,球囊設計亦有不同演化,以應付血管鈣化問題。早期有高壓球囊和刀片球囊,前者增加壓力撐開血管,後者利用附在球囊的刀片𠝹開鈣化物,可是這兩種方式均有機會導致血管破損,亦難以應付較厚的鈣化物(10,14,15)。後來又有「冠狀動脈旋磨術」,先利用高速轉動的鑽頭,如同沙紙般將鈣化物磨薄,再導入球囊放置支架(16)。
衝擊波球囊 對付頑強厚硬鈣化物
近年較為革新的是在球囊加入衝擊波技術,球囊除了脹大,還可釋放衝擊波能量,將一大塊的鈣化物震碎,製造許多微細的裂紋,令原本硬邦邦的管道可再度擴張,有助張開支架(3,4,10)。衝擊波技術已引入香港兩年多,這技術可應付較頑強厚實的鈣化物,特別適合360度鈣化的血管,好處是風險較低,也可降低長遠復發機會(3,4,10,17)。
其實醫生進行通波仔手術時,會先經導管進行介入性的血管造影和血管檢查,利用儀器檢視血管內的狀況,包括鈣化物的厚度和包圍面積等,再評估需要用哪些儀器和球囊來治療,應對不同的血管收窄情況(18,19)。
陸毅康醫生 心臟科專科醫生
MAT-HK-2101251-1.0-12/2021
This article is supported by Sanofi Hong Kong Limited
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