| Home | About | Brochure | Committee | Experts | Venue | Programme | Accommodation |
| List of Problems (2014) |
| Problem 4 : Coronary Bifurcation - Effects of Stent on Blood Flow |
BACKGROUND Cardiovascular disease is used most often to describe damage caused to the heart or blood vessels by atherosclerosis (arterial disease). The development of atherosclerotic lesions is strongly disturbing the blood flow at the coronary artery bifurcations. Coronary bifurcation lesions represent an area of ongoing challenge in interventional cardiology. Contemporary studies using drug-eluting stents report a reduction in main vessel restenosis, residual stenosis and restenosis at the side branch remain an issue [1]. Nowadays stent placement becomes a common interventional procedure for treatment of coronary artery disease and its clinical outcome was better when compared to standard angioplasty. However, bifurcation lesions have always represented a major challenge for placement of stents for treatment of stenosis. Conventional bare metal stents are mostly used in clinical practice of bifurcation lesion treatments since there is no specific commercially available stent dedicated for treating bifurcations. Stent design is strongly influenced by the specific hemodynamic conditions in a given vessel. Therefore, in principal, what was previously assessed for standard stent design, should be re-assessed for stenting bifurcations [2]. Stent implantation affects wall shear stress (WSS) values which might lead to in-stent restenosis, and plaque formation in pre-stent and post-stent regions. Alteration of arterial WSS may cause endothelial damage which is believed to be a major cause of plaque and thrombus formation. An investigation on the effects of stent geometry and bifurcation angle on blood flow pattern in a stented coronary artery has to be considered [3]. Problem Statement: If the doctor insert stent in main vessel, the doctor may see the lesions at the side branch grow up to 90%. Is it a true blockage or it is just carina (angle shift)? If it is a true blockage, then the intervention is required. But, if it is just carina, how can the doctor detect this without going through another procedure (another scan, flow meter, intervention)? Reference: [1] Victor H.T. Chen & Samin K. Sharma, SIS 2006 Yearbook Chapter 3 BIFURCATION STENTING, http://www.sis.org/yearbook_2006.php. [2] Marjan Molavi Zarandi, Rosaire Mongrain, Olivier F. Bertrand and Ali Bonakdar, Non-Newtonian Effects on Blood Flow Dynamics in Stented Coronary Artery Bifurcations, ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting: Volume 1, Symposia - Parts A, B, and C, Montreal, Quebec, Canada, August 1-5, 2010 [3] JOHN F. LADISA JR., DOUGLAS A. HETTRICK,LARS E. OLSON,ISMAIL GULER, ERIC R. GROSS,1 TOBIAS T. KRESS,1 JUDY R. KERSTEN,DAVID C. WARLTIER, AND PAUL S. PAGEL, Stent implantation alters coronary artery hemodynamics and wall shear stress during maximal vasodilation, J Appl Physiol 93: 1939-1946, 2002. |
