Numerical analysis of effects of stent implementation on the arterial wall

Ateroskleroza je bolest krvnih žila pri kojoj dolazi do nakupljanja aterosklerotskog plaka i posljedično povećanja krutosti stijenke krvnih žila. Plak se sastoji od lipida, upalnih stanica, kalcija i stanica vezivnog tkiva. Zbog rasta ili rupture plaka dolazi do opstrukcije krvnog protoka (stenoza), a kao komplikacija može doći i do stvaranja tromba koji može uzrokovati moždani ili srčani udar, ovisno o zahvaćenoj krvnoj žili. Umetanje stenta u krvne žile koristi se kao tretman za povrat normalnog protoka krvi. Tijekom liječenja, proširivi kardiovaskularni stent endovaskularno se ugrađuje u krvnu žilu. Širenje stenta uzrokuje povećanje naprezanja u stijenci krvne žile što može potaknuti rast arterijskog tkiva i ponovno sužavanje (restenoza). U ovom radu izvršena je analiza raspodjele naprezanja i pomaka uslijed ugradnje stenta u krvnu žilu. Na temelju proučene medicinske literature i sakupljenih podataka, izrađen je numerički model krvne žile s aterosklerotskim plakom i numerički model stenta. Uspoređeni su utjecaji različitih krvnih tlakova u žili na različite materijale i debljine plaka prije i nakon ugradnje stenta.Atherosclerosis is a disease of the blood vessels that causes atherosclerotic plaque to accumulate and consequently to increase the stiffness of the vessel wall. The plaque is composed of lipids, inflammatory cells, smooth muscle cells, and connective tissue cells. Due to the growth or rupture of the plaque, blood flow is obstructed (stenosis). As a complication, it can lead to the formation of a thrombus that can cause a stroke, depending on the affected blood vessel. Insertion of the stent into the blood vessels is used as a treatment to restore normal blood flow. During treatment, an expandable cardiovascular stent is inserted endovascularly into the blood vessel. Stent widening causes an increase in stresses in the vessel wall, which can promote arterial tissue growth and re-narrowing (restenosis). In this paper, an analysis of the stress and displacement distribution due to the implantation of a stent into the blood vessel was performed. Based on the reviewed medical literature and collected data, a numerical model of a blood vessel with atherosclerotic plaque and a numerical model of the stent was developed. The effects of different blood pressure in the vessel on different materials and plaque thickness before and after stent placement were compared