Quantification of Collateral Flows in Patients with Severe Coronaropathies

Abstract

Received: 10 May 2019 Accepted: 24 September 2019 The aim of this work is to obtain an indirect evaluation of the pressures and flow rates in the coronary network, in locations where direct measurements are not possible, or invasive, or too expansive, ... More precisely, the study is focused on the role of collateral flows in three-vessel disease patients, before and after bypass grafting, depending on the severity of the stenoses and thromboses. A model of the coronary circulation based on hydraulic / electric analogy has been developed; it is patient’s specific because some of the parameters are determined using per-operative classical measurements. Results show that the complete revascularization is fully justified for these patients, that collateral flows remain low in any cases, and that capillary and collateral resistances have a major impact on the flows and pressures everywhere in the network. The simulations also bring some arguments to current medical debates, such as flow competitions between the grafts and native vessels, or long-term effect of Drug Eluting Stents, or the use of the FFR index to evaluate the severity of stenoses.