Coronary Flow in Patients with Three-Vessel Disease: Simulated Hemodynamic Variables in relation to Angiographically Assessed Collaterality and History of Myocardial Infarction.

International audienceWe study patients with stenoses of the left main coronary artery (LMCA), left anterior descending artery (LAD), and left circumflex branch (LCx) and with chronic occlusion of the right coronary artery (RCA), undergoing off-pump coronary surgery. An analog electrical model is used to provide quantitative estimations of the distribution of flows and pressures across the coronary network (in the stenosed native arteries, the collateral branches, the capillary areas, and so forth). The present paper demonstrates that the clinical information collected for the 10 patients included in the study (Rentrop score, history of myocardial infarction, left ventricular ejection fraction (LVEF)) are well correlated with the predicted hydrodynamic data. Patients with a good collaterality (Rentrop score = 3) or patients without anterior myocardial infarction have (i) less severe stenoses on the LMCA, (ii) lower microvascular resistances, (iii) higher grafts flow rates when the revascularization is performed, (iv) higher collateral flow rates towards the territory of the occluded artery, (v) better perfusion of this area, and (vi) better total perfusion of the heart

Acute Mesenteric Ischemia after Cardiopulmonary Bypass.

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A surprising tumor after cardiac surgery

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Blunt traumatic aortic rupture of the proximal ascending aorta repaired by resection and direct anastomosis.

International audienceTraumatic aortic injury represents 15% of motor vehicle related deaths with death occurring at the scene in 85% of the cases. Aortic disruptions usually occur at the isthmus in a transverse fashion with all three of the aortic layers being involved. Herein, we report the case of a 68-year old man with no prior medical history who was struck by a vehicle while riding his bicycle. The ruptured segment of aorta was resected circumferentially and interrupted horizontal mattress pledgeted prolene sutures were used to ensure full thickness aortic integrity of the proximal and distal aortic segments. The aorta was closed with a single-layer technique using 4/0 prolene suture. There were no postoperative complications and patient was discharged on Day 44. The case here discussed demonstrates a rare presentation of blunt aortic injury. The proximal ascending aorta is an unusual site of transection following blunt trauma with few reports in the literature. We were able to repair the aorta with direct suture, thus avoiding the use of artificial material

Coronary collaterals and graft failure

International audienceIn this chapter, we recall the role of the coronary collateral circulation in severe obstructive coronary diseases, and, based on the literature review, we try to provide an answer to the question: when the patients undergo aorto-coronary bypass graft surgery, does good collateral flow reduce the risk of graft disease or, on the contrary, does it increase the risk of graft disease? In order to get additional arguments, a review of the numerical models and simulations addressing this problem is also included in the chapter

Evaluation of Fractional Flow Reserve in Patients with coronary three-vessel disease using a simulating tool

Congrès sous l’égide de la Société Française de Génie Biologique et Médical (SFGBM).National audienceFractional Flow Reserve is an index based on pressure measurements that is clinically used to estimate whether coronary artery stenoses induce ischemia or not. In this paper, we use a simulating tool developed by our group in order to evaluate and analyze FFR values obtained in patients with three vessel disease

A more sensitive pressure-based index to estimate collateral blood supply in case of coronary three-vessel disease.

International audienceWith progressive occlusion of a coronary main artery, some anastomotic vessels are recruited in order to supply blood to the ischemic region. This collateral circulation is an important factor in the preservation of the myocardium until reperfusion of the area at risk. An accurate estimation of collateral flow is crucial in surgical bypass planning as it alters the blood flow distribution in the coronary network and can influence the outcome of a given treatment for a given patient. The evaluation of collateral flow is frequently achieved using an index based on pressure measurements. It is named Collateral Flow Index (CFI) and defined as: (P(w)-P(v))/(P(ao)-P(v)), where P(w) is the pressure distal to the thrombosis, P(ao) the aortic pressure and P(v) the central venous pressure. We propose here another index, that is more sensitive to the P(w) value and could thus describe the role of collateral flow with more precision. We illustrate this idea using some clinical pressure measurements in patients with severe coronary disease (stenoses on the left branches and total occlusion of the right coronary artery)

Extracorporeal membrane oxygenation support for abdominal aortic aneurysms surgery in high-risk patients.

International audienceSurgical treatment of an abdominal aortic aneurysm in patients with a heart disease is risky. Aortic cross-clamping is featured by important consequences on cardiac, renal and gastrointestinal functions. Endovascular aortic repair is considered to be the gold standard in patients with severe comorbidities. However, in the case of unsuccessful endovascular treatment, surgery can be reconsidered with the use of extracorporeal membrane oxygenation, which seems to be a new tool for the management of cardiac and gastrointestinal events ensuring better post-operative outcomes

Theoretical study of the flow rate toward the right heart territory in case of total occlusion of the right coronary artery.

International audienceIn this work, patients with severe coronary disease and chronic occlusion of the right coronary artery (RCA) are studied. In this clinical situation, the collateral circulation is an important factor in the preservation of the myocardium until reperfusion of the area at risk. An accurate estimation of collateral flow is crucial in surgical bypass planning as it can influence the outcome of a given treatment for a given patient. The evaluation of collateral flow is frequently achieved using an index (CFI, Collateral Flow Index) based on pressure measurements. Using a model of the coronary circulation based on hydraulic/electric analogy, we demonstrate, through theoretical simulations, that a wide range of fractional collateral flow values can be obtained for any given distal pressure difference depending on the values of the capillary and collateral resistances

Patients' specific simulations of coronary fluxes in case of three-vessel disease.

International audienceIn this work, we propose a model of the coronary circulation based on hydraulic/electric analogy. This model aims to provide quantitative estimations of the distribution of flows and pressures across the coro-nary network for patients with stenoses of the left main coronary artery (LMCA), left anterior de-scending artery (LAD) and left circumflex branch (LCx), and chronic occlusion of the right coronary artery (RCA), undergoing off-pump coronary sur-gery. The results of the simulations are presented for 10 patients with various stenoses grades and collat-eral supply. For each patient, the four revasculariza-tion situations (no graft operating, pathological situa-tion (0G); right graft only (1G), left grafts only (2G), complete revascularization (3G)) are considered. It is shown that: 1) the complete revascularization is fully justified for these patients because neither the right graft alone, nor the left grafts alone can ensure a suf-ficient perfusion improvement for the heart; 2) the capillary and collateral resistances (and the propor-tion between them) have a major impact on the flows and pressures everywhere in the network; 3) in the presence of the left grafts, the flows in the native stenosed arteries become low and this could promote the development of the native disease in these branches