Contributions of Transesophageal Echocardiography in Liver Transplant Surgery

A TEE scan was performed in case of hemodynamic instability episodes defined by a decrease of 30% of the mean arterial pressure (MAP) during at least 1 min, and in all patients during immediate graft reperfusion phase and up 30 minutes.

The instability hemodynamic state was classified into four categories: diastolic failure, systolic failure, hypovolemia and vasodilatation.

The diastolic evaluation was performed at ME 4C view using pulsed doppler of the mitral and tricuspid valve at the level of the leaflet tips and tissue Doppler motion of the mitral and tricuspid annulus. The systolic evaluation was performed using tissue Doppler motion of the mitral and tricuspid annulus evaluating S´. Hypovolemia was registered such low filling pressures (mitral lateral E/e´\<10 m/s), cardiac index \< 2.5 l . min-1 . m-2 and close approximation of the papillary muscles in the TG Mid SAX view. Vasodilatation was registered such low filling pressures (mitral E/e´\< 10 m/s) and CI >2.5 l. min-1 . m-2).

An assessment of cardiac filling volumes and contractility, were obtained at two levels: the mid-esophageal four-chamber view (ME 4C) to evaluate the interaction of left and right ventricles and detect possible venous air embolism; and in the trans-gastric mid short axis view (TG mid SAX), to evaluate left ventricular size for the diagnosis of hypovolemia secondary to hemorrhage or altered venous return due to surgical maneuvers on the liver, and segmental wall motion. If the TG mid SAX view was not possible due to the posterior retraction of the stomach during surgery, the ME 4C view, mid-esophageal two chamber view (ME 2C) and mid-esophageal long axis view (ME LAX) was used for the diagnosis of left ventricle systolic dysfunction, and mid-esophageal bicaval view (ME bicaval) was used for the volemia evaluation.