Hemodynamic Modeling of Surgically Repaired Coarctation of the Aorta
- 213 Downloads
Late morbidity of surgically repaired coarctation of the aorta includes early cardiovascular and cerebrovascular disease, shortened life expectancy, abnormal vasomodulator response, hypertension and exercise-induced hypertension in the absence of recurrent coarctation. Observational studies have linked patterns of arch remodeling (Gothic, Crenel, and Romanesque) to late morbidity, with Gothic arches having the highest incidence. We evaluated flow in native and surgically repaired aortic arches to correlate respective hemodynamic indices with incidence of late morbidity. Three dimensional reconstructions of each remodeled arch were created from an anatomic stack of magnetic resonance (MR) images. A structured mesh core with a boundary layer was generated. Computational fluid dynamic (CFD) analysis was performed assuming peak flow conditions with a uniform velocity profile and unsteady turbulent flow. Wall shear stress (WSS), pressure and velocity data were extracted. The region of maximum WSS was located in the mid-transverse arch for the Crenel, Romanesque and Native arches. Peak WSS was located in the isthmus of the Gothic model. Variations in descending aorta flow patterns were also observed among the models. The location of peak WSS is a primary difference among the models tested, and may have clinical relevance. Specifically, the Gothic arch had a unique location of peak WSS with flow disorganization in the descending aorta. Our results suggest that varied patterns and locations of WSS resulting from abnormal arch remodeling may exhibit a primary effect on clinical vascular dysfunction.
KeywordsAorta Coarctation Congenital heart disease Magnetic resonance imaging Wall shear stress
This work is supported by National Institutes of Health/National Heart, Lung and Blood Institute Grant HL67622.
- 3.Warnes, C. A., R. G. Williams, T. M. Bashore, et al. ACC/AHA 2008 guidelines for the management of adults with congenital heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Develop Guidelines on the Management of Adults With Congenital Heart Disease). Developed in Collaboration With the American Society of Echocardiography, Heart Rhythm Society, International Society for Adult Congenital Heart Disease, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J. Am. Coll. Cardiol. 52:e1–e121, 2008.CrossRefGoogle Scholar
- 4.de Divitiis, M., C. Pilla, M. Kattenhorn, et al. Vascular dysfunction after repair of coarctation of the aorta: impact of early surgery. Circulation 104:I165–I170, 2001.Google Scholar
- 9.Hager, A., S. Kanz, H. Kaemmerer, C. Schreiber, and J. Hess. Coarctation Long-term Assessment (COALA): significance of arterial hypertension in a cohort of 404 patients up to 27 years after surgical repair of isolated coarctation of the aorta, even in the absence of restenosis and prosthetic material. J. Thorac. Cardiovasc. Surg. 134:738–745, 2007.CrossRefGoogle Scholar
- 14.Leuprecht, A., K. Perktold, S. Kozerke, and P. Boesiger. Combined CFD and MRI study of blood flow in a human ascending aorta model. Biorheology 39:425–429, 2002.Google Scholar
- 19.Pizarro, C., and M. R. De Leval. Surgical variations and flow dynamics in cavopulmonary connections: a historical review. Semin. Thorac. Cardiovasc. Surg. Pediatr. Card Surg. Annu. 1:53–60, 1998.Google Scholar
- 25.DeGroff, C. G., R. Shandas, and L. Valdes-Cruz. Analysis of the effect of flow rate on the Doppler continuity equation for stenotic orifice area calculations: a numerical study. Circulation 97:1597–1605, 1998.Google Scholar
- 27.Barbee, K. A., T. Mundel, R. Lal, and P. F. Davies. Subcellular distribution of shear stress at the surface of flow-aligned and nonaligned endothelial monolayers. Am. J. Physiol. 268:H1765–H1772, 1995.Google Scholar
- 28.Kilner, P. J., G. Z. Yang, R. H. Mohiaddin, D. N. Firmin, and D. B. Longmore. Helical and retrograde secondary flow patterns in the aortic arch studied by three-directional magnetic resonance velocity mapping. Circulation 88:2235–2247, 1993.Google Scholar
- 30.Ou, P., D. Celermajer, and O. Raisky. Angular (Gothic) aortic arch leads to enhanced systolic wave reflection, central aortic stiffness, and increased left ventricular mass late after aortic coarctation repair: evaluation with magnetic resonance flow mapping. J. Thorac. Cardiovasc. Surg. 135:62–68, 2008.CrossRefGoogle Scholar