Korean J Vasc Endovasc Surg 2012;28(3):109-114 http://dx.doi.org/10.5758/kjves.2012.28.3.109 복부대동맥류치료의최신지견 : 혈관내치료를중심으로 경북대학교의학전문대학원외과학교실 허 승 Current Endovascular Treatment of Abdominal Aortic Aneurysm Seung Huh, M.D. Department of Surgery, Kyungpook National University School of Medicine, Daegu, Korea Open aneurysm repair (OAR) of abdominal aortic aneurysm (AAA) is still an important component of vascular surgery. Notwithstanding refinement of operative techniques and perioperative care, many centers report significant operative mortality rates after elective AAA repair, especially in operative high-risk patients. Therefore, endovascular aneurysm repair (EVAR), initially proposed for patients with excessively high risk for OAR, has now become the primary therapy of elective AAA repair. Although showing high rates of graft-related complications, with more re-interventions, and no benefit of total or aneurysm-related mortalities in the long-term, EVAR is associated with a significantly lower operative mortality than OAR. Many patients are anatomically unfit for EVAR, however newly developed fenestrated or branched stent-grafts have been used in patients with a complex aortic neck. In addition, the use of EVAR has been expanded to the treatment of ruptured or small AAA. With progressive development of endovascular devices and techniques, EVAR will be more properly used in the near future. Key Words: Abdominal aortic aneurysm, Endovascular treatment 중심단어 : 복부대동맥류, 혈관내치료 서 현재복부대동맥류의치료는고전적인개복수술 (open aneurysm repair, OAR) 과혈관내동맥류재건술 (endovascular aneurysm repair, EVAR) 두가지로대별된다. 1951 년 Dubost 등 (1) 은흉부대동맥동종이식편을사용하여근대적인 OAR의최초성공례를보고하였으며, 1954년에 Blakemore와 Voorhees (2) 가 Vinyon N 이라는인공혈관이식편을이용한 OAR을보고하였다. 이후수술기법및수술전후치료법의발달과새로운인공혈관의개발로근래에는복부대동맥류의정규수술수술사망률이비교적많은수의증례를가진우수한기관들에서는평균 론 책임저자 : 허승, 대구시중구동덕로 130 700-721, 경북대학교병원외과 Tel: 053-420-6520, Fax: 053-421-0510 E-mail: shuh@knu.ac.kr 3.2% 로보고되고있으며 (3-5), 이는국내에서도유사한결과를보고하고있다 (6,7). 그러나환자의수술위험도가높은경우나비교적경험이적은기관들을포함한전체조사에서는여전히높은수술사망률이관찰되고있다 (4,8,9). EVAR는 1991년 Parodi 등 (10) 이최초증례를보고한후시술의용이성과수술사망률의감소로현재는복부대동맥류의우선적치료법으로사용되고있으며 (11,12), 이러한경향은국내에서도차츰관찰되고있다 (13). 그러나이전 EVAR의성적이단지수술후초기결과에서만우수하고장기적으로는합병증발생률이나재수술률에서기존의 OAR보다못하다는것이보고되었으며 (14,15), 또한복부대동맥류의해부학적형태가 EVAR 의큰제한점으로작용한다는것도주지의사실이다 (7,16,17). 이연구에서는이러한사실을바탕으로최근발달된다양한형태의 EVAR와복부대동맥류치료의최신지견에대하여고찰하고자한다. 109
110 Korean J Vasc Endovasc Surg Vol. 28, No. 3, 2012 파열의위험인자및예방복부대동맥류치료의궁극적인목적은파열의예방에있으나대부분무증상인환자들의수술시기를결정하기는용이하지않다. 현재까지동맥류의최대직경이동맥류파열을예측할수있는가장일반적인기준으로여겨지고있다. 영국에서시행된연구 (United Kingdom Small Aneurysm Trial) 에따르면연간파열위험도는동맥류의최대직경이 3.9 cm 미만인경우에는 0.3%, 4.0 4.9 cm인경우에는 1.5%, 5.0 5.9 cm인경우에는 6.5% 로보고되고있으며 (18), 동맥류의최대직경이 4.0 5.5 cm인상태에서조기에시행한 OAR이환자들의장기생존에긍정적인영향을주지못했음을보여주고있다 (19). 그러나비교적작은크기의동맥류라도그형태에따라동맥류벽에미치는스트레스가증가하면파열의위험이증가하는것으로보고되고있고 (20), 같은크기라도여성인경우남성보다파열의위험이높다 (18). 그외동맥류의확장속도, 흡연유무, 가족력, 고혈압의조절유무, 동맥류의형태등이파열위험도와관련이있는것으로잘알려져있다 (21). 근래기질금속단백분해효소-9(matrix metalloproteinase-9) 의작용을억제하는 statin이동맥류의확장속도를감소시킨다는보고가있다 (22,23). 비록아직대규모의전향적연구결과는없으나금연과함께임상에서비교적안전하게사용할수있다는점에서복부대동맥류환자의관찰기간및수술전후에추천할만한치료법이라고하겠다. 작은동맥류의치료최근 Open Versus Endovascular Repair (OVER) trial에서 EVAR의수술사망률이 0.5% 정도로낮게보고되면서복부대동맥류치료의기준이던최대직경 5.5 cm보다작은동맥류에대한조기치료가주목받고있다 (24). Zarins 등 (25) 은 EVAR 시행후복부대동맥류수술당시의최대직경에따른장기간성적을분석한결과로직경 5 cm 미만의환자군에서가장낮은사망률과동맥류파열률및가장높은해부학적적합도를보고하였다. 이후에시행된 Positive Impact of Endovascular Options for Treating Aneurysms Early trial (26) 과 Comparison of Surveillance versus Aortic Endografting for Small Aneurysm Repair (CAESAR) trial (27) 에서는작은동맥류에서조기에 EVAR를시행한환자들과주기적으로엄격한영상학적관찰을시행하여선택적으로치료를시행한환자들과비교하여술후중기 ( 각각 36개월, 54개월 ) 사망률또는동맥류파열률에서차이를보이지않았다고보고하며, 보다장기적인관찰이필요함을기술하였다. 다만 CAESAR trial에서는관찰 군의 59.7% 가관찰 36개월내지연치료를받았는데, 이들중 16.4% 에서 EVAR를시행하기에는해부학적으로부적합하여 OAR을시행하였음을보고하였다 (27). Paraskevas 등 (28) 은문헌고찰을통하여 EVAR의전체적인수술사망률이 0.5% 정도로낮은상황에서동맥류의크기가작을수록해부학적적합도가높고, 술후재수술률이낮은데비하여수술이지연될수록동맥류의크기및환자의연령증가로수술후사망률이증가하고장기결과가좋지못하므로복부대동맥류치료의최대직경기준을낮추어야함을역설하였다. 반면에 Avgerinos 등 (29) 은비록작은동맥류에서시행한 EVAR의성적이우수하나아직장기간의결과가보고된바없으며, 또한 EVAR 후재수술의빈도가높고이로인한경제적부담이필요한상황에서치료기준을낮추는것은시기상조임을주장하였다. 현재국내에서시행되는 EVAR의보험기준은복부대동맥류의최대직경이 5.0 cm 이상으로정해져있다. 환자의상황을고려하지않은획일적기준이라불합리한면도있지만지나치게작은동맥류에대한치료를무분별하게시행하는것을제한하는효과도있는것으로보인다. 장기간의대규모연구결과가보고되고, 보다개선된기구가개발되면복부대동맥류의치료기준에변화가있을것으로여겨진다. 파열된복부대동맥류에서 EVAR의역할파열된복부대동맥류에서 EVAR는일단개복을피할수있고, 원위부장기및말초의허혈상태를최소화할수있으며, OAR 시발생할수있는주변혈관이나장기의손상을막을수있는장점이있다. 근래 EVAR는파열된복부대동맥류환자의약 10% (11.9%, 10.7%) 에서시행되었으며 (30,31), OAR에비하여 30일수술사망률이유의하게낮은것으로보고되고있으나 (OAR vs. EVAR: 52% vs. 33%, 40.8% vs. 32.3%; P<0.001), 여전히높은수술사망률을보이고있다 (30,31). 최근유럽 9개국에서공동으로시행된 2011년 Vascunet 보고서 (32) 에따르면 7,040명의파열된복부대동맥류환자의 11.7% 에서 EVAR 가시행되었으며, 이들의수술사망률은 19.7% 로 OAR의 32.6% 보다유의하게낮고, 또한이전의보고 (30,31) 보다개선된것을알수있다. 아직까지파열된복부대동맥류에서 EVAR의시행빈도가낮은이유로많은환자에서형태학적으로 EVAR를시행하기에부적합하며, 비록적합하다고하더라도이에맞는기구가잘갖춰져있지않아서응급으로 EVAR를시행하기어려운경우등을들수있겠다. 따라서파열된복부대동맥류에서 EVAR를적절히시행하기위해서는빠른시간내에환자의해부학적적합도를검사하고이에맞는기구를사용할수있어야한다. 그리고파열된복부대동맥류에서일단 EVAR가
Seung Huh: Current Endovascular Treatment of Abdominal Aortic Aneurysm 111 성공적으로시행되었다하더라도후복막강에남아있는혈종의정도에따른전신적인부작용과대장허혈증같은심각한합병증이발생할수있으므로수술후환자의상태에따라적절한치료가뒤따라야할것이다. 해부학적으로적합하지않은복부대동맥류의치료에서 EVAR 의역할 엄격한사용자지침서 (instructions for user, IFU) 에벗어나서 EVAR를시행한경우에는그결과가좋지못하다. Abbruzzese 등 (33) 은세가지기구 (Cook Zenith, Gore Excluder, Medtronic AneuRx) 를사용하여 EVAR를시행한환자들을대상으로적어도 IFU를한가지이상벗어난환자군 (outside IFU) 과 IFU에적합한환자군 (within IFU) 을비교한연구에서수술사망률은두군간에유의한차이가없었으나 (1.8% outside IFU, 1.7% within IFU; P=1.00), 1년 (94% outside IFU, 100% within IFU) 과 5년 (89% outside IFU, 100% within IFU; P<0.001) 의동맥류-관련사망자유도 (freedom from aneurysm-related mortality) 는 within IFU 군에서유의하게우수한것을관찰하였다. 또한 1년 (96% outside IFU, 95% within IFU) 과 5년 (76% outside IFU, 85% within IFU; P<0.39) 의전체적인재수술자유도 (freedom from reintervention) 에서는차이가없었으나, IFU를벗어난경우가많을수록재수술의빈도가높은것을관찰하였다 (freedom from reintervention: 87% outside 3 IFU, 95% within IFU at 1 year; 21% outside IFU, 85% within IFU at 5 year; P<0.01). 외국의보고에서는 EVAR를시행하지못한해부학적부적합의주요한원인으로스텐트-이식편의근위부가부착되는신장동맥하방의대동맥 (proximal neck of aorta) 이 IFU에벗어난경우가많았다 (proximal neck of aorta vs. iliac artery: 52% vs. 22%, 74% vs. 16%) (16,17). 주요원인이아닌해부학적부적합성의모든경우를조사하여전술한외국의자료와직접적인비교는어렵지만국내에서후향적으로관찰한보고에따르면대동맥부착부및장골동맥의해부학적부적합비율이동일하게관찰된다 (proximal neck of aorta vs. iliac artery: 69.6% vs. 68.6%) (34). 해부학적부적합부위가스텐트- 이식편의원위부부착부인장골동맥의경우에는내장골동맥색전술, 내장골동맥전치술, 총장골동맥색전술및대퇴-대퇴동맥간우회술등의다양한술식을통하여비교적쉽게해결될수있으나, 근위부부착부인대동맥의경우에는주변의주요내장동맥들을보존하기위하여 OAR에준하는수술이필요하므로이를 EVAR로해결하기위한시도들이활발히진행되고있다. 이들중대표적인것이 fenestrated stent-graft (f-sg), branched stent-graft (b-sg), chimney graft (ch-g) 등이다. 1) Fenestrated stent-grafts 1996년국내의 Park 등 (35) 에의해 f-sg가처음소개된이후에 1999년 Browne 등 (36) 과 Frauqi 등 (37) 이보다개선된형태의 f-sg를보고하였다. 이수술법은복부대동맥류의이환부위에따라양측신장동맥이외에도상장간막동맥과복강동맥에도추가적인스텐트-이식편을삽입하여야한다. 이를위해서는수술전 3-dimension-computed tomography를이용한동맥류와내장동맥간의정확한해부학적내비게이션이필수적이며, 수술방법또한전문가의숙련된혈관내치료술기를필요로한다. 이러한이유로 f-sg가최초로소개된이후에도드물게시행되다가근래비교적많은수의증례를가진연구들이보고되었다. O Neill 등 (38) 은 119예의 f-sg에서계획된 302개의내장동맥중 299개에성공적으로스텐트-이식편을삽입하였으며, 1% 미만 (1/119) 의수술사망률, 92% 와 83% 의 1 년과 3년생존율을보고하였다. 69% 의환자에서양측신장동맥과상장간동맥을포함하는 f-sg가시행되었으며, 평균 19개월의추적관찰기간동안총 231개의신장동맥스텐트-이식편중 10개가폐색되었으며, 12개에서협착이발견되었다고한다. 신장동맥스텐트-이식편의협착이나폐색으로야기된신부전증은투석이나환자의사망을초래할수있으므로 f-sg 후이에대한엄밀한관찰이필요하다. Haddad 등 (39) 의보고에따르면 f-sg 후이전에신기능부전증이없던환자의 16% 에서술후 2년간의관찰기간 ( 평균 5.8개월 ) 동안신기능이상이발생하였다고한다. 이외에 Ziegler 등 (40) 은 87.3% 의수술성공률과 96.7% 의내장동맥스텐트-이식편삽입률, 1% 의수술사망률, 평균 23개월 (6 77개월) 의추적관찰기간동안 9.7% 의내장동맥스텐트-이식편실패율등을보고하였으며, Scurr 등 (41) 은 100% 의수술성공률및내장동맥스텐트-이식편삽입률 2.2% (2/45) 의수술사망률, 1 48 개월 ( 중앙값 24) 의추적관찰기간동안내장동맥스텐트- 이식편개존율 96.6% 를보고하였다. 비록전술한보고들이낮은수술사망률과우수한초기및중기내장동맥스텐트-이식편개존율을보이고있으나, 보다많은수의환자들을대상으로한장기적인연구결과가있어야하겠다. 2) Branched stent-grafts 2000년 3형흉복부대동맥류에서 Chuter 등 (42) 이 b-sg 를시행한이후로대동맥전반에걸쳐서 b-sg가시행되고있으나, 수술전정확한해부학적내비게이션, 특수하게제작되어야하는스텐트-이식편, 숙련된전문가의필요등으로아직보편적으로시행되고있지는못하다. 저자의미국 University California at San Francisco (UCSF) 연수경험에의하면 b-sg는흉복부대동맥류뿐만아니라
112 Korean J Vasc Endovasc Surg Vol. 28, No. 3, 2012 대동맥궁및상행대동맥의일부에서도하이브리드수술과함께시행되었다. 단순히스텐트-이식편의본체 (main body) 에내장동맥분지부에맞춘구멍을뚫어제작된 f-sg에비하여 b-sg는스텐트-이식편본체의근위부에내장동맥분지부의각도에맞추어 5 10 mm 정도의소매 (cuff) 부가부착되어있다는것이차이점이라고하겠다. 이렇게근위부에소매를둠으로써내장동맥분지부와본체사이에여유거리가있어서스텐트-이식편을삽입하기에 f-sg보다용이한것으로생각된다. 또한내장동맥스텐트-이식편은좌측액와동맥을통하여아래로삽입되어원래의해부학적구조와비교적동일한형태를갖추게된다. 아직장기간의연구결과는보고되지않았으나저자가조사한바에의하면거의모든예에서내장동맥스텐트-이식편의삽입을포함한전반적인수술은성공적이었으며, 낮은수술사망률과초기및중기의높은내장동맥스텐트-이식편개존률이관찰되었다. 현재표준화되어있는신장동맥하방복부대동맥류용스텐트- 이식편과같이 b-sg의기본형을제작하기위한연구가시도되고있으며 (43-45), 이러한연구가결실을맺으면대동맥류치료에새로운전기가마련될것으로보인다. 3) Chimney graft 2008년 Ohrlander 등 (46) 이 EVAR 시대동맥분지의혈류를유지하기위한 ch-g 10예를보고하였다. 이술식은비교적응급한상황에서표준화된스텐트-이식편에맞지않는신장동맥근접복부대동맥류나대동맥궁및이에근접한흉부대동맥류의스텐트-이식편삽입시대동맥분지의혈류를보존하기위하여고안되었다. Moulakakis 등 (47) 이 2011년까지 15개의문헌, 93명의환자들을고찰한바에따르면이들중 77.4% 가복부대동맥류에서, 24.7% 가동맥류의파열이나증상이있는준응급상황에서 ch-g를시행받았다. 134개의내장동맥스텐트-이식편중신장동맥에 108개, 상장간막동맥에 20개, 복강동맥에 5개, 하장간막동맥에 1개의이식편이삽입되었으며, 초기수술성공률은 100% 였다. 스텐트-이식편삽입후 13 예 (14.0%) 에서 1형관내누출 (endoleak) 이발생하였으며, 수술사망률 4.3%, 수술후신기능이상 11.8%, 심근경색증 2.1%, 허혈성뇌졸중 3.2% 등이관찰되었고, 평균추적관찰기간 9개월동안내장동맥스텐트-이식편의 97.8% 가개존되어있었다. 아직까지대규모연구나장기간의결과가없어서이술식의유용성에대해서명확하게기술할수없지만 OAR의위험이상당히높고, 해부학적으로표준화된 EVAR에부적합한신장근접복부대동맥류환자들을대상으로시행할수있을것으로여겨진다. 결 이전의연구에서 EVAR는 OAR에비하여초기수술후의빈번한재수술및환자의장기생존에서별다른이득이없는것으로보고되고있지만낮은수술사망률은복부대동맥류치료에 EVAR가우선적으로시행되는데가장큰역할을하고있다. 스텐트-이식편의지속적인발달로최근에는보다개선된초기및장기결과를기대하게되었으며, 이러한결과를바탕으로보다작은크기의복부대동맥류에서도안전하게 EVAR를시행할수있을것이다. 그러나아직까지동맥류의형태가해부학적으로부적합할경우에는 EVAR를안전하게시행하기어려우며, 이러한 EVAR의제한점은향후에도 OAR의역할이중요함을시사하고있다. 비록일부에서 f-sg 또는 b-sg로이문제점을해결하려고하나, 이러한술식을국내에서안전하게시행하기에는아직사회-경제적인제약이많이존재하고있다. 향후표준화된 b-sg가개발되고이를유용하게사용할수있으면복부대동맥류의치료에또다른전기가마련될것이다. 론 감사의글 지난 1년간의 UCSF 연수에도움을주신경북대학교, 경북대학교병원및대한혈관외과학회에감사드린다. REFERENCES 1) Dubost C, Allary M, Oeconomos N. Treatment of aortic aneurysms; removal of the aneurysm; re-establishment of continuity by grafts of preserved human aorta. Mem Acad Chir (Paris) 1951;77:381-383. 2) Blakemore AH, Voorhees AB Jr. The use of tubes constructed from vinyon N cloth in bridging arterial defects; experimental and clinical. Ann Surg 1954;140:324-334. 3) Krupski WC, Rutherford RB. Update on open repair of abdominal aortic aneurysms: the challenges for endovascular repair. J Am Coll Surg 2004;199:946-960. 4) Menard MT, Chew DK, Chan RK, Conte MS, Donaldson MC, Mannick JA, et al. Outcome in patients at high risk after open surgical repair of abdominal aortic aneurysm. J Vasc Surg 2003;37:285-292. 5) Hertzer NR, Mascha EJ. A personal experience with factors influencing survival after elective open repair of infrarenal aortic aneurysms. J Vasc Surg 2005;42:898-905. 6) Kim HK, Jo MJ, Choi HH, Huh S, Kim YW. The long-term results and causes of death after abdominal aortic aneurysm repair. J Korean Surg Soc 2008;74:54-59. 7) Roh YN, Park YJ, Kim DI, Park KB, Do YS, Choi SH, et
Seung Huh: Current Endovascular Treatment of Abdominal Aortic Aneurysm 113 al. Indications and short-term results of open surgical repair of abdominal aortic aneurysm in an endovascular era. J Korean Surg Soc 2011;80:212-220. 8) Schermerhorn ML, O Malley AJ, Jhaveri A, Cotterill P, Pomposelli F, Landon BE. Endovascular vs. open repair of abdominal aortic aneurysms in the Medicare population. N Engl J Med 2008;358:464-474. 9) Hallin A, Bergqvist D, Holmberg L. Literature review of surgical management of abdominal aortic aneurysm. Eur J Vasc Endovasc Surg 2001;22:197-204. 10) Parodi JC, Palmaz JC, Barone HD. Transfemoral intraluminal graft implantation for abdominal aortic aneurysms. Ann Vasc Surg 1991;5:491-499. 11) Hill JS, McPhee JT, Messina LM, Ciocca RG, Eslami MH. Regionalization of abdominal aortic aneurysm repair: evidence of a shift to high-volume centers in the endovascular era. J Vasc Surg 2008;48:29-36. 12) Levin DC, Rao VM, Parker L, Frangos AJ, Sunshine JH. Endovascular repair vs open surgical repair of abdominal aortic aneurysms: comparative utilization trends from 2001 to 2006. J Am Coll Radiol 2009;6:506-509. 13) Park YJ, Kim N, Kim YW. Investigation of current trend of AAA treatment in Korea. J Korean Surg Soc 2011;80:125-130. 14) Greenhalgh RM, Brown LC, Kwong GP, Powell JT, Thompson SG; EVAR trial participants. Comparison of endovascular aneurysm repair with open repair in patients with abdominal aortic aneurysm (EVAR trial 1), 30-day operative mortality results: randomised controlled trial. Lancet 2004;364: 843-848. 15) Blankensteijn JD, de Jong SE, Prinssen M, van der Ham AC, Buth J, van Sterkenburg SM, et al. Two-year outcomes after conventional or endovascular repair of abdominal aortic aneurysms. N Engl J Med 2005;352:2398-2405. 16) Wolf YG, Fogarty TJ, Olcott C IV, Hill BB, Harris EJ, Mitchell RS, et al. Endovascular repair of abdominal aortic aneurysms: eligibility rate and impact on the rate of open repair. J Vasc Surg 2000;32:519-523. 17) Arko FR, Filis KA, Seidel SA, Gonzalez J, Lengle SJ, Webb R, et al. How many patients with infrarenal aneurysms are candidates for endovascular repair? The Northern California experience. J Endovasc Ther 2004;11:33-40. 18) Brown LC, Powell JT. Risk factors for aneurysm rupture in patients kept under ultrasound surveillance. UK Small Aneurysm Trial Participants. Ann Surg 1999;230:289-296. 19) Mortality results for randomised controlled trial of early elective surgery or ultrasonographic surveillance for small abdominal aortic aneurysms. The UK Small Aneurysm Trial Participants. Lancet 1998;352:1649-1655. 20) Fillinger MF, Marra SP, Raghavan ML, Kennedy FE. Prediction of rupture risk in abdominal aortic aneurysm during observation: wall stress versus diameter. J Vasc Surg 2003;37: 724-732. 21) Brewster DC, Cronenwett JL, Hallett JW Jr, Johnston KW, Krupski WC, Matsumura JS, et al. Guidelines for the treatment of abdominal aortic aneurysms. Report of a subcommittee of the Joint Council of the American Association for Vascular Surgery and Society for Vascular Surgery. J Vasc Surg 2003;37:1106-1117. 22) Schouten O, van Laanen JH, Boersma E, Vidakovic R, Feringa HH, Dunkelgrun M, et al. Statins are associated with a reduced infrarenal abdominal aortic aneurysm growth. Eur J Vasc Endovasc Surg 2006;32:21-26. 23) Schlosser FJ, Tangelder MJ, Verhagen HJ, van der Heijden GJ, Muhs BE, van der Graaf Y, et al. Growth predictors and prognosis of small abdominal aortic aneurysms. J Vasc Surg 2008;47:1127-1133. 24) Lederle FA, Freischlag JA, Kyriakides TC, Padberg FT Jr, Matsumura JS, Kohler TR, et al. Outcomes following endovascular vs open repair of abdominal aortic aneurysm: a randomized trial. JAMA 2009;302:1535-1542. 25) Zarins CK, Crabtree T, Bloch DA, Arko FR, Ouriel K, White RA. Endovascular aneurysm repair at 5 years: Does aneurysm diameter predict outcome? J Vasc Surg 2006;44:920-929. 26) Ouriel K, Clair DG, Kent KC, Zarins CK; Positive Impact of Endovascular Options for treating Aneurysms Early (PIVOTAL) Investigators. Endovascular repair compared with surveillance for patients with small abdominal aortic aneurysms. J Vasc Surg 2010;51:1081-1087. 27) Cao P, De Rango P, Verzini F, Parlani G, Romano L, Cieri E, et al. Comparison of surveillance versus aortic endografting for small aneurysm repair (CAESAR): results from a randomised trial. Eur J Vasc Endovasc Surg 2011;41:13-25. 28) Paraskevas KI, Mikhailidis DP, Andrikopoulos V, Bessias N, Bell Sir PR. Should the size threshold for elective abdominal aortic aneurysm repair be lowered in the endovascular era? Yes. Angiology 2010;61:617-619. 29) Avgerinos ED, Katsargyris A, Klonaris C, Papapetrou A, Moulakakis K, Liapis CD. Should the size threshold for elective abdominal aortic aneurysm repair be lowered in the endovascular era? No. Angiology 2010;61:620-623. 30) Dillavou ED, Muluk SC, Makaroun MS. Improving aneurysmrelated outcomes: nationwide benefits of endovascular repair. J Vasc Surg 2006;43:446-451. 31) Giles KA, Pomposelli F, Hamdan A, Wyers M, Jhaveri A, Schermerhorn ML. Decrease in total aneurysm-related deaths in the era of endovascular aneurysm repair. J Vasc Surg 2009; 49:543-550. 32) Mani K, Lees T, Beiles B, Jensen LP, Venermo M, Simo G, et al. Treatment of abdominal aortic aneurysm in nine countries 2005-2009: a vascunet report. Eur J Vasc Endovasc Surg 2011;42:598-607. 33) Abbruzzese TA, Kwolek CJ, Brewster DC, Chung TK, Kang J, Conrad MF, et al. Outcomes following endovascular abdominal aortic aneurysm repair (EVAR): an anatomic and
114 Korean J Vasc Endovasc Surg Vol. 28, No. 3, 2012 device-specific analysis. J Vasc Surg 2008;48:19-28. 34) Park KH, Lim C, Lee JH, Yoo JS. Suitability of endovascular repair with current stent grafts for abdominal aortic aneurysm in Korean patients. J Korean Med Sci 2011;26:1047-1051. 35) Park JH, Chung JW, Choo IW, Kim SJ, Lee JY, Han MC. Fenestrated stent-grafts for preserving visceral arterial branches in the treatment of abdominal aortic aneurysms: preliminary experience. J Vasc Interv Radiol 1996;7:819-823. 36) Browne TF, Hartley D, Purchas S, Rosenberg M, Van Schie G, Lawrence-Brown M. A fenestrated covered suprarenal aortic stent. Eur J Vasc Endovasc Surg 1999;18:445-449. 37) Faruqi RM, Chuter TA, Reilly LM, Sawhney R, Wall S, Canto C, et al. Endovascular repair of abdominal aortic aneurysm using a pararenal fenestrated stent-graft. J Endovasc Surg 1999;6:354-358. 38) O Neill S, Greenberg RK, Haddad F, Resch T, Sereika J, Katz E. A prospective analysis of fenestrated endovascular grafting: intermediate-term outcomes. Eur J Vasc Endovasc Surg 2006; 32:115-123. 39) Haddad F, Greenberg RK, Walker E, Nally J, O Neill S, Kolin G, et al. Fenestrated endovascular grafting: The renal side of the story. J Vasc Surg 2005;41:181-190. 40) Ziegler P, Avgerinos ED, Umscheid T, Perdikides T, Stelter WJ. Fenestrated endografting for aortic aneurysm repair: a 7-year experience. J Endovasc Ther 2007;14:609-618. 41) Scurr JR, Brennan JA, Gilling-Smith GL, Harris PL, Vallabhaneni SR, McWilliams RG. Fenestrated endovascular repair for juxtarenal aortic aneurysm. Br J Surg 2008;95: 326-332. 42) Chuter TA, Gordon RL, Reilly LM, Pak LK, Messina LM. Multi-branched stent-graft for type III thoracoabdominal aortic aneurysm. J Vasc Interv Radiol 2001;12:391-392. 43) Sweet MP, Hiramoto JS, Park KH, Reilly LM, Chuter TA. A standardized multi-branched thoracoabdominal stent-graft for endovascular aneurysm repair. J Endovasc Ther 2009;16:359-364. 44) Park KH, Hiramoto JS, Reilly LM, Sweet M, Chuter TA. Variation in the shape and length of the branches of a thoracoabdominal aortic stent graft: implications for the role of standard off-the-shelf components. J Vasc Surg 2010;51: 572-576. 45) Chuter T, Greenberg RK. Standardized off-the-shelf components for multibranched endovascular repair of thoracoabdominal aortic aneurysms. Perspect Vasc Surg Endovasc Ther 2011;23:195-201. 46) Ohrlander T, Sonesson B, Ivancev K, Resch T, Dias N, Malina M. The chimney graft: a technique for preserving or rescuing aortic branch vessels in stent-graft sealing zones. J Endovasc Ther 2008;15:427-432. 47) Moulakakis KG, Mylonas SN, Avgerinos E, Papapetrou A, Kakisis JD, Brountzos EN, et al. The chimney graft technique for preserving visceral vessels during endovascular treatment of aortic pathologies. J Vasc Surg 2012;55:1497-1503.