內漏 (Endoleak) 被定義為在腹主動脈瘤囊內與支架間產生血液滲漏的狀況，內漏於腹主動脈瘤中的產生及惡化有可能導致動脈瘤的破裂使致死率攀升並增加併發症發生的機會。內漏的發生亦為血管支架植入術治療失敗的一項指標，及早控制內漏產生及惡化發生，能更有效降低手術再次治療的機會，本研究對八位支架植入治療病患分析，建造具有病人特徵之腹主動脈瘤模型，利用流固耦合的數值分析法，對血液作用於腹主動脈瘤支架管壁進行應力受力分佈相關研究，發現所管壁之最大壁面應力與內漏位置具高度相關，經由影像處理比較截面差異，大部分截面比較之角度誤差在10 %以內，透過此方法在未來可應用於血管支架植入術治療後之病人進行觀察，對電腦斷層掃描影像和血管造影等暫態病況影像作內漏點預測分析與治療。

Endoleaks can evolve and become severe complications in patients with Abdominal Aortic Aneurysm (AAA). Endoleak is defined as the seepage of blood into the cavity between aneurysm and stent graft wall. Endoleak is usually considered as a check point after the endovascular aneurysm repair (EVAR). Therefore, the early detection and management of endoleak may effectively reduce the need for surgical reoperation of EVAR. A fluid-structure-interaction (FSI) method was employed and performed in this study to quantify the hemodynamics in eight patient-specific AAA models with stent graft implanted. Throughout the stress analysis in conjunction with the image processing, it was found that the location of endoleak is highly correlated with the location of peak wall stress. The presented analytical paradigm offers a reliable alternative for endoleak prediction and detection, and is beneficial for AAA post-treatment.

[1] Kent, K. C., Zwolak, R. M., Egorova, N. N., Riles, T. S., Manganaro, A., Moskowitz, A. J., Gelijns, A. C., and Greco, G., 2010, "Analysis of risk factors for abdominal aortic aneurysm in a cohort of more than 3 million individuals," Journal of vascular surgery, Vol. 52, pp. 539-548.
[2] Bonamigo, T. P. and Siqueira, I., 2003, "Screening for abdominal aortic aneurysms," Revista do Hospital das Clinicas, Vol. 58, pp. 63-68.
[3] Biasi, L., Ali, T., Hinchliffe, R., Morgan, R., Loftus, I., and Thompson, M., 2009, "Intraoperative DynaCT detection and immediate correction of a type 1a endoleak following endovascular repair of abdominal aortic aneurysm," Cardiovascular and Interventional Radiology, Vol. 32, pp. 535-538.
[4] Karaman, K., Dokdok, A. M., and Karadeniz, O., 2013, "CT-and Fluoroscopy-Guided Percutaneous Transabdominal Embolization of Type II Endoleak," Eurasian Journal of Medicine, Vol. 45, pp. 132-4.
[5] White, G. H., May, J., Waugh, R. C., Chaufour, X., and Yu, W., 1998, "Type III and type IV endoleak: toward a complete definition of blood flow in the sac after endoluminal AAA repair," Journal of Endovascular Surgery, Vol. 5, pp. 305-309.
[6] Veith, F. J., Baum, R. A., Ohki, T., Amor, M., Adiseshiah, M., Blankensteijn, J. D., Buth, J., Chuter, T. A., Fairman, R. M., and Gilling-Smith, G., 2002, "Nature and significance of endoleaks and endotension: summary of opinions expressed at an international conference," Journal of Vascular Surgery, Vol. 35, pp. 1029-1035.
[7] White, S. B. and Stavropoulos, S. W., 2009, "Management of endoleaks following endovascular aneurysm repair," in Seminars in Interventional Radiology, Vol. 26, p. 33.
[8] Expert Panel on Detection, E., 2001, "Executive summary of the third report of the National Cholesterol Education Program (NCEP) expert panel on Detection, Evaluation, and Treatment of high blood cholesterol in adults (Adult Treatment Panel III)," JAMA: the journal of the American Medical Association, Vol. 285, pp. 2486.
[9] Shapiro, S., Endicott, S., Province, M., Pierce, J., and Campbell, E., 1991, "Marked longevity of human lung parenchymal elastic fibers deduced from prevalence of D-aspartate and nuclear weapons-related radiocarbon," Journal of Clinical Investigation, Vol. 87, pp. 1828.
[10] Habermehl, J., 2005, "Development and validation of a collagen-based scaffold for vascular tissue engineering," Universite Laval, Quebec, Canada.
[11] Hallett Jr, J. W., Marshall, D. M., Petterson, T. M., Gray, D. T., Bower, T. C., Cherry Jr, K. J., Gloviczki, P., and Pairolero, P. C., 1997, "Graft-related complications after abdominal aortic aneurysm repair: reassurance from a 36-year population-based experience," Journal of vascular surgery, Vol. 25, pp. 277-286.
[12] Biasetti, J., Gasser, T. C., Auer, M., Hedin, U., and Labruto, F., 2010, "Hemodynamics of the normal aorta compared to fusiform and saccular abdominal aortic aneurysms with emphasis on a potential thrombus formation mechanism," Annals of biomedical engineering, Vol. 38, pp. 380-390.
[13] Li, Z. and Kleinstreuer, C., 2006, "Analysis of biomechanical factors affecting stent-graft migration in an abdominal aortic aneurysm model," Journal of biomechanics, Vol. 39, pp. 2264-2273.
[14] Greenhalgh, R. M. and Powell, J. T., 2008, "Endovascular repair of abdominal aortic aneurysm," New England Journal of Medicine, Vol. 358, pp. 494-501.
[15] Bastos, R. M., Razuk Filho, A., Blasbalg, R., Caffaro, R. A., Karakhanian, W. K., and Rocha, A. J., 2011, "A multidetector tomography protocol for follow-up of endovascular aortic aneurysm repair," Clinics, Vol. 66, pp. 2025-2029.
[16] Desai, M., Eaton-Evans, J., Hillery, C., Bakhshi, R., You, Z., Lu, J., Hamilton, G., and Seifalian, A. M., 2010, "AAA stent–grafts: past problems and future prospects," Annals of biomedical engineering, Vol. 38, pp. 1259-1275.
[17] Greenberga, R. K., Lawrence-Brownb, M., Bhandaria, G., Hartleyb, D., Stelterc, W., Umscheidc, T., Chuterd, T., Ivanceve, K., Greenf, R., and Hopkinsong, B., 2001, "An update of the Zenith endovascular graft for abdominal aortic aneurysms: initial implantation and mid-term follow-up data," Journal of vascular surgery, Vol. 33, pp. 157-164.
[18] Jordan Jr, W. D., Moore Jr, W. M., Melton, J. G., Brown, O. W., and Carpenter, J. P., 2009, "Secure fixation following EVAR with the Powerlink XL System in wide aortic necks: results of a prospective, multicenter trial," Journal of Vascular Surgery, Vol. 50, pp. 979-986.
[19] Qu, L., Hetzel, G., and Raithel, D., 2007, "Seven years' single center experience of Powerlink unibody bifurcated endograft for endovascular aortic aneurysm repair," The Journal of cardiovascular surgery, Vol. 48, pp. 13-19.
[20] Malina, M., Lindblad, B., Ivancev, K., Lindh, M., Malina, J., and Brunkwall, J., 1998, "Endovascular AAA exclusion: will stents with hooks and barbs prevent stent-graft migration?," Journal of endovascular surgery, Vol. 5, pp. 310-317.
[21] Raghavan, M. and Vorp, D. A., 2000, "Toward a biomechanical tool to evaluate rupture potential of abdominal aortic aneurysm: identification of a finite strain constitutive model and evaluation of its applicability," Journal of biomechanics, Vol. 33, pp. 475-482.
[22] Papaharilaou, Y., Ekaterinaris, J. A., Manousaki, E., and Katsamouris, A. N., 2007, "A decoupled fluid structure approach for estimating wall stress in abdominal aortic aneurysms," Journal of Biomechanics, Vol. 40, pp. 367-377.
[23] Valencia, A., Ledermann, D., Rivera, R., Bravo, E., and Galvez, M., 2008, "Blood flow dynamics and fluid-structure interaction in patient-specific bifurcating cerebral aneurysms," International Journal for Numerical Methods in Fluids, Vol. 58, pp. 1081-1100.
[24] Scotti, C. M. and Finol, E. A., 2007, "Compliant biomechanics of abdominal aortic aneurysms: a fluid–structure interaction study," Computers & structures, Vol. 85, pp. 1097-1113.
[25] Subasic, M., Loncaric, S., and Sorantin, E., 1999, "3-D image analysis of abdominal aortic aneurysm," Studies in health technology and informatics, Vol. 77, pp. 1195-1200.
[26] Leung, J. H., Wright, A. R., Cheshire, N., Crane, J., Thom, S. A., Hughes, A. D., and Xu, Y., 2006, "Fluid structure interaction of patient specific abdominal aortic aneurysms: a comparison with solid stress models," BioMedical Engineering OnLine, Vol. 5, pp. 33.
[27] Chen, C.-Y., Anton, R., Hung, M.-y., Menon, P., Finol, E. A., and Pekkan, K., 2014, "Effects of Intraluminal Thrombus on Patient-Specific Abdominal Aortic Aneurysm Hemodynamics via Stereoscopic Particle Image Velocity and Computational Fluid Dynamics Modeling," Journal of Biomechanical Engineering, Vol. 136, pp. 031001-031001.
[28] Olufsen, M. S., Peskin, C. S., Kim, W. Y., Pedersen, E. M., Nadim, A., and Larsen, J., 2000, "Numerical simulation and experimental validation of blood flow in arteries with structured-tree outflow conditions," Annals of biomedical engineering, Vol. 28, pp. 1281-1299.
[29] Valencia, A., Ledermann, D., Rivera, R., Bravo, E., and Galvez, M., 2008, "Blood flow dynamics and fluid–structure interaction in patient-specific bifurcating cerebral aneurysms," International Journal for Numerical Methods in Fluids, Vol. 58, pp. 1081-1100.
[30] Johnston, B. M., Johnston, P. R., Corney, S., and Kilpatrick, D., 2004, "Non-Newtonian blood flow in human right coronary arteries: steady state simulations," Journal of biomechanics, Vol. 37, pp. 709-720.
[31] Bathe, K.-J. and Dong, J., 1987, "Solution of incompressible viscous fluid flow with heat transfer using ADINA-F," Computers & Structures, Vol. 26, pp. 17-31.
[32] Menon, P. G., Teslovich, N., Chen, C.-Y., Undar, A., and Pekkan, K., 2013, "Characterization of neonatal aortic cannula jet flow regimes for improved cardiopulmonary bypass," Journal of biomechanics, Vol. 46, pp. 362-372.
[33] Brannon, R., "Mohr’s Circle and more circles," in University of New Mexico, 2003.
[34] Volokh, K., 2010, "Comparison of biomechanical failure criteria for abdominal aortic aneurysm," Journal of biomechanics, Vol. 43, pp. 2032-2034.
[35] Kim, N.-H. and Sankar, B. V., Introduction to finite element analysis and design: Wiley, 2009.
[36] Jong, I. C. S., W. T., "GC 2009-267: teaching von Mises stress: from principal axes to nonprincipal axes," American Society for Engineering Education, 2009.
[37] Canny, J., 1986, "A computational approach to edge detection," Pattern Analysis and Machine Intelligence, IEEE Transactions on, Vol. 6, pp. 679-698.
[38] Dong, W. and Shisheng, Z., 2008, "Color image recognition method based on the prewitt operator," 2008 International Conference on Computer Science and Software Engineering, Vol. 6, pp. 170-173.
[39] Roberts, L. G., "Machine perception of three-dimensional solids," Massachusetts Institute of Technology, 1963.
[40] Davis, L. S., 1975, "A survey of edge detection techniques," Computer Graphics and Image Processing, Vol. 4, pp. 248-270.
[41] Vincent, O. and Folorunso, O., 2009, "A descriptive algorithm for sobel image edge detection," Proceedings of Informing Science & IT Education Conference (InSITE), Vol. 40, pp. 97-107.
[42] Van Den Boomgaard, R. and Van Balen, R., 1992, "Methods for fast morphological image transforms using bitmapped binary images," CVGIP: Graphical Models and Image Processing, Vol. 54, pp. 252-258.