探討利用胸腹主動脈覆膜支架治療主動脈瘤的臨床幾何學及生物標誌

Analysis of Clinical Geometry and Biomarkers of Thoracic and Abdominal Aortic Stent Grafts in the Treatment of Aortic Aneurysms

吳毅暉(I-Hui Wu)

指導教授 ： 楊偉勛

國立臺灣大學/醫學院/臨床醫學研究所/博士(2015年)

https://doi.org/10.6342/NTU.2015.11322

摘要

本篇論文主要是探討胸腹主動脈覆膜支架治療主動脈瘤的臨床幾何學的臨床運用。內容包括(1)腹主動脈血管內支架植入後支架內血栓沉積物(2)破裂腹主動脈血管瘤(3)胸腹主動脈瘤(4)複雜性腹主動脈及骼動脈瘤，以及(5)煙囪式置放術中決定主要主動脈內套膜支架尺寸的方法
(1)腹主動脈血管內支架植入後支架內血栓沉積物
研究目的：探究腹主動脈內套膜支架的支架內血栓沉積物之發生率與危險因子。
研究方法：回溯性檢視51名於2002年至2008年間接受經股植入分叉血管支架之腹主動脈瘤病患（44名男性；平均年齡76.3歲，全距：63-90歲）的臨床紀錄。病患於術後接受電腦斷層評估，執行時間為術後第1、3、6及12個月，此後每年一次。抗血小板藥物使用相關之支架內血栓、術前動脈瘤內之壁血栓、支架主體�雙側肢截面積比值以及主體長度皆經過評估。
研究結果：平均超過10個月的追蹤顯示，51名病患中有8名（15.6%，95%信賴區間：8.2-28）出現管腔內血栓沉積物，血栓形成的最初徵候平均發生於內套膜支架植入後9.8個月（全距：1-24個月），支架內血栓沉積物與術前壁血栓形成（p = 0.38）或術後抗血小板或抗凝血藥物使用（p = 0.40）無關聯性。然而，其與支架主體�雙側肢截面積比值以及主體長度則有明顯關聯性（分別為p = 0.04及p = 0.01）。有三例因支架扭曲造成的支架肢體阻塞，此三例病患於阻塞前之電腦斷層掃描未測得支架內血栓。一名病患在電腦斷層掃瞄追蹤測得支架內主體血栓後4個月，其左側淺股動脈之遠端出現栓塞。追蹤期間沒有個案的支架管腔內血栓沉積物完全清除。
結論：此短期經驗證實，發現腹主動脈內套膜支架內有血栓沉積物相當普遍。血栓沈積大多受到主動脈血管支架的幾何構造影響，主體直徑較寬且肢體較小及主體較大者比較容易發生。大部分血栓皆無臨床症狀而不需要進一步治療
(2)破裂腹主動脈血管瘤
針對一中國人族群探究緊急性血管內修復是否適合用於替代開放性動脈瘤修復術治療解剖構造合適之已破裂腹主動脈瘤，以回溯性分式分析2005至2012年在國立臺灣大學附設醫院接受開放性手術或緊急血管內手術修復術的36名破裂腹主動脈血管瘤病患。總計有35名病患（97.2%）接受治療，其中20名病患（57.1%）接受開放性手術治療，15名（42.9%）接受緊急血管內手術修復術治療。整體30天存活率為77.1%，兩組的30天死亡率（開放性手術15.0%比緊急血管內手術修復術33.3%，p = 0.201）與中期死亡率（開放性手術20.0%比緊急血管內手術修復術 46.7%，p = 0.093）並無明顯差異。單變數分析顯示，在兩種修復手術中，破裂至腹膜腔內出血（p<0.001）、術前休克（p = 0.001）及女性（p = 0.016）與30天死亡率較高有關，破裂至腹膜腔內出血（p = 0.012）及術前休克（p = 0.001）則與中期死亡率較高有關。多變數分析顯示破裂至腹膜腔內出血與30天死亡率（危險比例:26.0，95% 信賴區間:2.2–295.6，p = 0.009）及中期死亡率（危險比例:13.1，95%信賴區間:1.2–37.6，p = 0.032）較高有關。本研究顯示，在破裂腹主動脈血管瘤病患方面，緊急血管內手術修復術與開放性手術組的30天死亡率與中期死亡率並無差異，對中國人族群而言，緊急血管內手術修復術對解剖構造合適之破裂腹主動脈血管瘤病患可能是可行的替代治療。
(3)胸腹主動脈瘤
研究背景：開放性胸腹主動脈瘤修復術的致病率與致死率皆高。本研究檢視了本院高風險病患的複合型胸腹主動脈瘤修復術中期預後。
研究方法：我們回溯分析了2007年6月至2011年6月間接受一階式複合型胸腹主動脈瘤修復術之病患的臨床資料。本研究呈現我們在單一中心為10名複雜性胸腹主動脈病變病患執行一階段式複合型內臟動脈處置程序的經驗。其中9名病患為男性、1名為女性，平均年齡為65.7歲。平均術後《歐洲心臟手術危險評估》分數為34.1%。研究結果：手術完成時之技術成功率為100%。並未因主動脈事件而放棄任何手術。本研究的30天死亡率為10%。整體嚴重手術前後併發症發生率為20%。嚴重併發症包括需要永久性支持之腎功能不全（1名病患，10%）以及截癱（1名病患，10%）。追蹤期中位數為20.1個月（全距0.3-39個月），整體存活率為70%。主要內臟血管移植物通暢率為96.8%（32/33）。僅有1例腎動脈支架阻塞。
結論：選定接受一階段式複合型修復術之高風險胸腹主動脈瘤病患的中期結果令人振奮。當開放性手術有害且無法使用分支血管支架時，複合型修復術是可行的替代治療方案。然而，必須以較大型研究世代進行較長期的追蹤，才能夠獲得主動脈支架與內臟動脈重建之耐久性的相關資料
(4)複雜性腹主動脈及骼動脈瘤
研究目的：發表我們以翻山煙囪技術保留腹主動脈瘤及骼總動脈瘤病患之骼內動脈的中期結果。
研究方法：將2012年5月及2014年1月間所有先後於我們醫學中心接受選擇性血管內動脈瘤修復術及翻山煙囪技術保留骼內動脈的複雜性腹主動脈及骼動脈瘤病患及腹主動脈瘤伴隨短骼總動脈之病患納入本研究。電腦斷層血管攝影及複合型超音波追蹤評估於術後第1、6及12個月執行，其後每年執行一次。
研究結果：14名病患（100%男性，平均年齡77.3歲）平均接受14.3個月的追蹤（全距：6-21個月），總計執行14次翻山煙囪技術。成功保留骼內動脈且無第I型或第III型內漏的技術成功率為100%。在平均14.3個月的追蹤中，初期通暢率為92.8%。無早期或晚期手術相關死亡。在17例骼動脈瘤中，3例（17.7%）動脈瘤囊顯示直徑明顯縮短（至少5 mm），10例直徑縮短小於5 mm（58.9%），4例直徑無變化（23.4%）。
結論：翻山煙囪技術是簡單安全的保留骼內動脈替代性血管內重建技術，技術成功率高，且中期通暢率令人滿意。
(5) 煙囪式置放術中決定主要主動脈內套膜支架尺寸的方法
在近腎、腎旁或胸腹主動脈瘤等難以處理的位置執行主動脈血管內修復的方法有限。為了處理此難題，煙囪置放術應運而生，且已廣泛施用。然而，對於如何選擇與內臟血管煙囪支架平行之主要主動脈支架的合適尺寸、以使兩者可並存於原生主動脈中，目前並無共識，一切僅憑外科醫師的個人經驗與偏好。等周不等式顯示，在所有固定周長之平面內的所有封閉曲線中，圓形所包圍的面積為最大。在本研究中，我們根據等周不等式提出了一個數學公式，以便為已知直徑的主動脈與內臟煙囪支架選擇要置入主體覆膜支架其內的尺寸，
R'≥√((1.44R^2-r^2))
其中，R’為主體覆膜支架之半徑，R為主動脈之半徑，而r為內臟煙囪支架之半徑。

關鍵字

破裂腹主動脈瘤 ； 血管內動脈瘤修復術 ； 腹主動脈瘤 ； 骼總動脈瘤 ； 骼內動脈 ； 煙囪支架

並列摘要

This thesis mainly focuses on analysis of clinical geometry of thoracic and abdominal aortic stent grafts in the treatment of aortic aneurysms. Including (1) The Significance of Endograft Geometry on the Incidence of Intraprosthetic Thrombus Deposits after Abdominal Endovascular Grafting (2) Outcomes following endovascular or open repair for ruptured abdominal aortic aneurysm in a Chinese population (3) One-stage Hybrid Repair to Thoracoabdominal Aortic Aneurysm (4) Crossover Chimney Technique to Preserve the Internal Iliac Artery During Endovascular Repair of Iliac or Aortoiliac Aneurysms, and (5) How to size the main aortic endograft in a chimney procedure
(1) The Significance of Endograft Geometry on the Incidence of Intraprosthetic Thrombus Deposits after Abdominal Endovascular Grafting
Objectives: To examine the incidence and risk factors of intraprosthetic throm-
botic deposits in abdominal aortic endografts.
Methods: The clinical records of 51 patients (44 males; mean age 76.3 years, range: 63-90years) with abdominal aortic aneurysm treated with transfemoral implantation of bifurcated stent graft between the years 2002 and 2008 were retrospectively reviewed. Patients underwent three-phase helical computed tomographic (CT) examinations at 1-, 3-, 6- and 12-month intervals and then annually. The formation of intraprosthetic thrombus associated with use of anti-platelet, preoperative mural thrombus in the aneurysm, ratio of cross-sectional area between the mainbody and bilateral limb grafts and length of mainbody were evaluated.
Results: Over a 10-month mean follow-up, intraluminal deposits of thrombotic material were observed in eight of 51 patients (15.6%, 95% confidence interval: 8.2-28). The first signs of thrombus formation occurred on average 9.8 months after endografting (range: 1-24 months).Intraprosthetic thrombotic deposits was not related to preoperative mural thrombus formation(p value: 0.38) or postoperative anti-platelet or anticoagulation medication (p﹦0.40). However, it was significantly related to the ratio of the cross-sectional area between the mainbody and the bilateral limb grafts and the length of mainbody (p﹦0.04 and p﹦0.01). There were three graft limbs occlusion owing to kinking with no intraprosthetic thrombus detected on CT scans taken prior to occlusion. One patient developed distal left proximal superior femoral
artery embolisation 4 months after detectable intraprosthetic mainbody thrombus in a CT scan follow-up. In no case did the thrombotic deposits clear completely from the prosthesis lumen during follow-up.
(2) Outcomes following endovascular or open repair for ruptured abdominal aortic aneurysm in a Chinese population
36 patients with RAAA undergoing either OAR or eEVAR in National Taiwan University Hospital from 2005 to 2012 were analyzed retrospectively. Thirty-five (97.2 %) patients were treated. Among them, 20 (57.1 %) were treated by OAR and 15 (42.9 %) by eEVAR. The overall 30-day survival rate was 77.1 %. There was no significant difference in 30-day mortality rate (OAR 15.0 % vs.eEVAR 33.3 %, p = 0.201) and midterm mortality rate (OAR 20.0 % vs. eEVAR 46.7 %, p = 0.093) between these two groups. On univariate analysis, free peritoneal rupture (p =0.001), pre-operative shock (p = 0.001) and female gender (p = 0.016) are related to a higher 30-day mortality rate, while free peritoneal rupture (p = 0.012) and pre-operative shock (p = 0.030) are associated with a higher midterm mortality rate in both repair techniques. On multivariate analysis, free peritoneal rupture was associated with higher 30-day (OR 26.0, 95 % CI 2.2–295.6,p = 0.009) and midterm (OR 13.1, 95 % CI 1.2–37.6,p = 0.032) mortality rates. In patients with RAAA, there is no significant difference in 30-day mortality and midterm mortality between eEVAR and OAR groups in our study. eEVAR could be an alternative therapy for anatomically suitable RAAA in a Chinese population.
(3) One-stage Hybrid Repair to Thoracoabdominal Aortic Aneurysm
This study represents our experience with 10 patients at a single center who underwent 1-stage visceral hybrid procedures for complex thoracoabdominal aortic pathologies. There were 9 men and 1 woman with a median age of 65.7 years. The average preoperative European System for Cardiac Operative Risk Evaluation II score was 34.1%. The technical success rate with completion was 100%. No procedure was abandoned because of any aortic event. The 30-day mortality rate in this study was 10%. Overall major peri-operative complication rates were 20%. Major complications included renal impairment requiring permanent support in 1 patient (10%) and paraplegia in 1 patient (10%). At a median follow-up of 20.1 months (range, 0.3e39 months), the overall survival rate was 70%. The primary graft patency rate was 96.8% (32/33). Only 1 renal artery graft was occluded. The midterm results in selected high-risk patients with TAAA undergoing 1-stage hybrid repair were encouraging. When open repair is hazardous and branched stent grafting is not an option, hybrid repair is a viable treatment alternative.
(4) Crossover Chimney Technique to Preserve the Internal Iliac Artery During Endovascular Repair of Iliac or Aortoiliac Aneurysms
Between May 2012 and January 2014, 14 consecutive patients (mean age 77.3 years; all men) with 17 AIA, isolated CIAAs, or abdominal aortic aneurysms with short CIAs underwent elective endovascular aneurysm repair (EVAR) with the crossover chimney technique to preserve the IIA. Follow-up assessment, including computed tomographic angiography or duplex ultrasound, was performed at 1, 6, and 12 months and annually thereafter. Technical success, defined as successful preservation of IIA without intraoperative type I or III endoleak, was 100%. Over a mean 14.3 months (range 6–21), primary patency was 92.8%. There was no early or late procedure-related mortality. Among the 17 iliac aneurysms excluded, the sac diameter significantly (at least 5 mm) decreased in 3, decreased <5 mm in 10, and did not change in 4. The crossover chimney technique is a simple and safe alternative for IIA endovascular revascularization with high technical success and acceptable midterm patency.
(5) How to size the main aortic endograft in a chimney procedure
The application of endovascular aortic repair in difficult circumstances, such as juxtarenal, pararenal, or thoracoabdominal aortic aneurysms is limited. To address this difficulty, the chimney technique has been expanded and applied widely. Other than the surgeon’s individual experience and preference, however, there is currently no consensus regarding how to choose the appropriate size for the main aortic graft (MAG) parallel to the visceral chimney graft (CG) so that they accommodate each other properly inside the native aorta. Isoperimetric inequality states that among all closed curves in the plane of a fixed perimeter, a circle maximizes the area of its enclosed region. In this study, we propose a mathematical formula that was based on isoperimetric inequality to select the size of the MAG inside a known diameter of the native aorta and visceral CG:
R'≥√((1.44R^2-r^2))
where R’is the radius of the MAG, R is the radius of the native aorta, and r is the radius of the CG.

並列關鍵字

Ruptured abdominal aortic aneurysm ； Endovascular aneurysm repair abdominal aortic aneurysm ； common iliac artery aneurysm ； internal iliac artery ； chimney graft

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