微創手術如何關閉卵圓孔,減低中風風險?

訪問:張誠謙心臟科醫生

(一)什麼是卵圓孔未閉症?卵圓孔未閉症與中風有關?

卵圓孔是每個人都有的心臟結構,位於左心房和右心房之間的一道小門。有些情況身體有機會形成血塊,特別在靜脈系統當中。當血塊出現在腿部靜脈系統,便會隨著血流運送到心臟。如果正常卵圓孔關閉,這些血塊會流入肺部作為隔濾,但如果患者有卵圓孔未閉症,血塊便會經由右心房通過卵圓孔到達左心房,隨著血流運送全身,如果血塊去到腦血管,便會形成阻塞,造成缺血性中風。

(二)如何診斷卵圓孔未閉症?

在超聲波檢查中,醫生會放置顏色,看看會否有不正常的血流。就像這個病人的個案,他的右心房和左心房中間有不正常的血流,因此懷疑病人有卵圓孔未閉症。

(三)微創手術如何關閉卵圓孔?

透過X光片段錄影的微創導管封閉卵圓孔手術過程,醫生會在病人大腿股溝切一個很小的傷口,利用一條長導管,由大腿股溝靜脈上到病人右心臟。在X光和超聲波機指引下,導管就會穿過卵圓孔,接着在導管中,醫生會引入封堵器到病人左邊心臟。

過程首先會在左邊心房慢慢放置左心房心碟,然後放置右碟,在X光和超聲波指引下,醫生會把整個系統慢慢拉後,當左碟慢慢去到卵圓孔位置,醫生便會放置封堵器的右碟,封堵器便會永久而穩固地放置在卵圓孔上。

完成後,醫生會將封堵器和導管脫離,讓導管和鋼絲慢慢分離,離開身體,只有封堵器永久植入病人身體。

(四)封堵器如何減低中風風險?

從影片中的食道超聲波影像,可以看到為病人置放封堵器後半年後所錄得的影像從影像可見,封堵器已永久植入在病人卵圓孔上,位於左右心房中間。醫生在檢查時亦會放置一些顏色,看看病人會否有不正常的血流。此病人已經無任何血流橫跨封堵器附近,即代表如果病人將來不幸再有血塊出現,這些血塊也不會經過卵圓孔,由右心臟直接去左心臟。這些血塊只會由心臟經過肺部進行過濾。


參考資料 :

1. Hospital Authority  (2021). Smart Patient-Stroke.  Retrieved 30 March 2021, from https://www21.ha.org.hk/smartpatient/SPW/en-us/Disease-Information/Disease/?guid=29ac1219-3d68-4378-a2bd-09e111da3650

2. National Health Service. (3 August 2021). Stroke. Retrieved from

https://www.nhs.uk/conditions/stroke/

3. Jeffrey L. Saver, M.D., John D. Carroll, M.D, et al Long-Term Outcomes of Patent Foramen Ovale Closure or Medical Therapy after Stroke. N Engl J Med 2017; 377:1022-1032/DOI: 10.1056/NEJMoa1610057. 

4. Mohammad K Mojadidi, Muhammad O Zaman, Islam Y Elgendy et al Cryptogenic Stroke and Patent Foramen Ovale. J AM Coll Cardiol 2018 Mar 6;71(9):1035-1043.  doi: 10.1016/j.jacc.2017.12.059.

5. Mayo Clinic. (2 September 2021). Patent foramen ovale. Retrieved from

https://www.mayoclinic.org/zh-hans/diseases-conditions/patent-foramen-ovale/symptoms-causes/syc-20353487

6. Cleveland Clinic. (15 July 2022). Patent Foramen Ovale (PFO). Retrieved from

https://my.clevelandclinic.org/health/diseases/17326-patent-foramen-ovale-pfo

7. American Stroke Association. (18 September 2022). Cryptogenic Stroke or Stroke of Unknown Cause. Retrieved from

https://www.stroke.org/en/about-stroke/types-of-stroke/cryptogenic-stroke

8. Rothwell P. M. (2007). Making the most of secondary prevention. Stroke, 38(6), 1726. https://doi.org/10.1161/STROKEAHA.107.482265

9. Walter N Kernan, Bruce Ovbiagele, Henry R Black et al Guidelines for the prevention of stroke in patients with stroke and transient ischemic attack. 2014 Jul;45(7):2160-236.  doi: 10.1161/STR.0000000000000024. 

10. Esther Boot, Merel Sanne Ekker, Junkanoo Putaala et al Ischaemic stroke in young adults: a global perspective. Journal of Neurology, Neurosurgery & Psychiatry 2020; 91: 411-417.

11. Ebrahimi, H. A., Moghadam, A. H., & Aredestani, E. (2011). Evaluation of patent foramen ovale in young adults with cryptogenic stroke. ARYA atherosclerosis, 7(2), 74.

12. Patent Foramen Ovale Closure or Anticoagulation vs. Antiplatelets after Stroke. Article in New England Journal of Medicine. September 2017, DOI: 10.1056/NEJMoal1705915.

13. Fleissner F, Frank P, Haverich A, Ismail I. Echocardiographic guided, transatrial closure of a patent foramen ovale. J Cardiothorac Surg. 2020;15(1):255. Published 2020 Sep 14. doi:10.1186/s13019-020-01289-7.

14. Cleveland Clinic. (2 May 2022). Thoracotomy. Retrieved from https://my.clevelandclinic.org/health/treatments/22981-thoracotomy

15. Brown KN, ElBebawy B, Shah AH, et al. Catheter Management Of Patent Foramen Ovale. [Updated 2022 May 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan.

16. Steven R. Messé, Gary S. Gronseth, David M. Kent et al Practice advisory update summary: Patent foramen ovale and secondary stroke prevention. First published April 29, 2020, DOI: https://doi.org/10.1212/WNL.0000000000009443.