THE IMPORTANCE OF TRANSESOPHAGEAL ECHOCARDIOGRAPHY DURING SURGERY OF THE THORACIC AORTA

Objectives: To assess left ventricular dimensions and cardiac output d uring thoracic and thoracoabdominal aortic aneurysm repair. Material a nd methods: Nine patients undergoing thoracic and thoracoabdominal ane urysm repair using direct cross-clamping without shunt or by-pass were studied prospectively. Prior to, during cross-clamping (XC) and after declamping left ventricular cross-sectional areas were monitored with transesophageal echocardiography. A pulmonary artery catheter was use d for measurements of cardiac output with the thermodilution technique . Results: Cardiac output increased 43% from baseline during XC (p < 0 .01) and was still 55% above baseline at declamping(p < 0.05). Left ve ntricular end-systolic inner area was reduced 32% during XC (p < 0.01) . Pulmonary artery pressures and central venous pressure increased dur ing declamping (p < 0.05). Heart rate increased 38% from 66 beats/min to 92 beats/min (p < 0.01) and was still 30% elevated at declamping (p < 0.01). Conclusion: During thoracic aortic XC, cardiac output is inc reased and left ventricular end-systolic dimension is reduced. TEE is a valuable supplement to pressure measurements for the evaluation of c ardiac Junction during surgery of the thoracic aorta.