Continuous transesophageal echocardiographic (TEE) monitoring during port-access cardiac surgery

Since the introduction of the closed-chest minimally invasive heart surgery using the Port-Access system a variety of monitoring techniques including fluoroscopy, transesophageal echocardiography (TEE) and invasive pressure measurements have been described. We investigated whether or not single TEE is feasible for perioperative monitoring of the placement, localization and proper function of the endovascular cardiopulmonary bypass (CPB) devices.

Fifty-one patients (35 mitral valve repair or replacement [MVR], 8 coronary artery bypass grafting [CABG], 5 atrial septal defects [ASD] and 3 left atrial myxoma) were subjected to Port-Access surgery (PAS). Intraoperative Omniplane-TEE (2D- and color-flow Doppler techniques) was used as the leading monitoring device for correct positioning of the endopulmonary vent catheter and the venous cannula, and for the visualization of the guide wire and the endoaortic occlusion catheter (Endoclamp). After balloon inflation, its proper positioning and function during endo-aortic occlusion, sufficient delivery of cardioplegia into the coronary ostia, absence of leakage flow and adequate venting were controlled. Left and right radial artery catheters as well as aortic root pressure measurements served as controls. Additional fluoroscopy was used as standby device.

In 46 patients (90.1%) sufficient perioperative monitoring was provided by single TEE. In five cases additional intermittent fluoroscopy was necessary for correct positioning of the guide wire (CABG) and the Endoclamp (three MVR and one ASD). Dislocation of the Endoclamp into the left ventricle was observed once but was successfully corrected by TEE guidance. Weaning from CPB and de-airing were easily guided with TEE. We did not observe balloon-mediated aortic injury or aortic valve dysfunction, and myocardial recovery from CPB was uneventful. All cases of MVRs showed sufficient results (68% without evidence of regurgitation, 32% showed residual mitral valve incompetence of less than grade II). Neither perivalvular leakage (MV-replacement) nor shunt- (residual ASD) flow were detectable.

We recommend single TEE as a safe and effective on-line imaging device for monitoring the endovascular CPB system during PAS. Fluoroscopy with its potential risk for the patients and the staff due to x-ray exposure should only be used in the presence of peripheral vascular disease or when echocardiographic imaging is insufficient.