Strain Analysis for Assessment of Myocardic Dysfunction During Orthotopic Liver Transplantation

Overview

Mycocardial systolic function (contractility) is an essential element of cardio-circulatory physiology during major visceral surgery, in particular during liver transplantation during which several factors are likely to be at the origin of a ventricular dysfunction: acute hemorrhage, major volume changes, acute pulmonary arterial hypertension and ischemia-reperfusion syndrome. Ventricular dysfunction is an underestimated intraoperative liver transplantation phenomenon while it constitutes a risk factor for peroperative and postoperative morbidity and mortality established that graft function can be compromised through the phenomena of low cardiac output and hepatic congestion. Also, better analyzing myocardial systolic function during liver transplantation could guide practitioners in the treatments to be undertaken, evaluate their effects and diagnose various complications. In addition, the usual cardiac output measurement systems (transpulmonary thermodilution techniques and pulse wave contour analysis) are poorly suited to liver transplantation. Frequent variations in blood volume, vasomotor tone and temperature require regular recalibrations and prevent a continuous and reliable estimate of cardiac output. Thus, the choice of hemodynamic monitoring during liver transplantation performed in our center is transesophageal ultrasound, a semi-invasive method with a favorable benefit-risk ratio in this category of the population. However, analysis of right ventricular systolic function by classical indices is difficult in transesophageal ultrasound for reasons of alignment of the ultrasound shot on the right ventricular. The analysis of left ventricular systolic function is complex due to the sudden variations in volume and the difficulty in carrying out planimetry measurements in real time. Myocardial strain imaging has been developed in recent years and is widely validated for the assessment of left ventricular contractile function. It was subsequently applied to the exploration of the right ventricular. Its measurement can be performed from recordings on dedicated software. Thus, the strain could make it possible to better assess myocardial systolic dysfunction in liver per-transplantation from the transesophageal echographic loops recorded in current practice at the different operating times. Strain measurements will be carried out a posteriori from the images which are acquired in a standard way during the operation.