分析置入腹部主動脈瘤中不同尺寸的血管支架對血液動力學的影響

Analysis Of the Influence Of Endograft Geometry On Blood Hemodynamic In Abdominal Aortic Aneurysm

黃章翔(Chang Hsiang Huang)

指導教授 ： 邵耀華

共同指導教授 ： 吳毅暉(I Hui Wu)

國立臺灣大學/工學院/應用力學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.00071

摘要

腹部主動脈瘤成因乃為動脈血管壁病變導致血管彈性疲乏，血管像氣球般向外膨脹隆起，嚴重時血管破裂，病患因出血而死亡。目前主流治療腹部主動脈血管肌瘤的方法為內套膜支架治療法，將血管支架植入血管內以阻隔病變血管來達到治療的效果。

　　腹部主動脈血管瘤的大小、形狀、彎曲度因人而異，而目前市售的支架主要由主體和兩側腸骨動脈所組成，支架的尺寸並無一定的標準，只要達到治療的效果其支架主體的長度可長可短。內套膜支架治療法術後其中的兩項併發症狀為：　　　
1. 支架中形成血栓和支體栓塞。 2. 支架位移。

　　本研究針對上述兩項併發症狀，利用電腦模擬不同主體長度的血管支架在置入腹部主動脈瘤後其支架中的流場，進而分析主體長度的長短對支架中流場的影響，期望能找出最佳的支架尺寸設計以減少支架中血栓發生的機率和支架位移發生的情形。由模擬的結果可得到在血流減速時迴流與渦流容易形成於主體下游處而形成血栓使得支架支體栓塞，而主體長度越長的支架越容易有迴流與渦流的發生。而造成支架位移的拖力則與支架主體長度無關。

關鍵字

腹部主動脈瘤 ； 內套膜支架治療法 ； 血栓 ； 栓塞 ； 支架位移 ； 渦流 ； 拖曳力

並列摘要

Abdominal aortic aneurysm (AAA) is a balloon-like bulge in an abdominal artery that may be caused by infection or congenital weakening of the connective tissue component bring about artery wall elasticity fatigue. In severe aneurysm rupture, the patient died due to bleeding .At present the mainstream treatment of AAA is Endovascular aneurysm repair (EVAR), the stent graft implantation into AAA sac and blocking lesion to achieve therapeutic effect.

　　The size, geometry and curvature of AAA is different from person to person. The current commercially endograft is composed of main body and iliac leg. The geometry of the stent does not have a certain standard. As long as it achieve therapeutic effect, the length of main body can be longer or shorter. The two Complications of EVAR is including：
1. Intraprosthetic thrombosis and endograft limb obstruction.
2. Device migration.

　　This study,In response to these Complications, Analyze the Influence Of Endograft with different main body length On Blood Hemodynamic In AAA by CFD. Expect to find the best geometry design to reduce Intraprosthetic thrombosis and Device migration occurred.The results show that when blood flow deceleration, recirculation and vortex is easily formed in the downstream of main body leading to Intraprosthetic thrombosis and endograft limb obstruction. The longer length of main body, it is more easily formed. And the drag force making Device migration has nothing to do with the main body length.

並列關鍵字

Abdominal aortic aneurys ； Endovascular aneurysm repair ； Thrombosis ； Obstruction ； Device migration ； Vortex ； Drag force

參考文獻

[1] 施俊哲. 胸、腹主動脈瘤微創治療新趨勢-支架血管治療主動脈瘤. 臨床醫學 2007;60:271-282.

[2] M Davis, P R Taylor. Endovascular infrarenal abdominal aortic aneurysm repair. Heart 2008;94:222-228.

[3] Robert B. Rutherford, MD. Open Versus Endovascular Stent Graft Repair for Abdominal Aortic Aneurysms: An Historical View. Seminars Vascular Surgery 2012;25:39-48.

[4] Steinberg I, Stein HL. Arterosclerotic abdominal aortic aneurysms report of 200 consecutive cases diagnosed by intravenous aortography. JAMA 1966;195:1025-9.

[5] F.L. Moll, J.T. Powell, G. Fraedrich, et al. Management of Abdominal Aortic Aneurysms Clinical Practice Guidelines of the European Society for Vascular Surgery. Eur J Vasc Endovasc Surg (2011) 41, S1-S58.