[Value of intraoperative transesophageal echocardiography during repair of thoracic aorta dissection].

The study was designed to assess the diagnostic accuracy and usefulness of intraoperative transesophageal echocardiography (TEE) during repair of aortic dissection. To this end, 32 patients with ascending aortic dissection, undergoing replacement of the ascending aorta, were examined. The diagnosis was validated in each case by intraoperative and/or autopsy findings. The accuracy of TEE was studied in three different periods of surgical operation: before cardiopulmonary bypass (TEE pre-CPB), during CPB (TEE-CPB) and after CPB (TEE post-CPB). In comparison with TEE performed in the intensive care unit 70 +/- 40 min before surgery, TEE pre-CPB showed a higher diagnostic accuracy (100 vs 96%) in classification of the dissection type, a higher sensibility in the identification of intimal tears (83 vs 75%), involvement of the coronary arteries (71 vs 62%) and of aortic arch branches (81 vs 71%); there was no statistically significant difference in the detection of the aortic valve involvement (100 vs 100%). TEE-CPB showed normal perfusion of the true lumen in all but one patient, in whom TEE-CPB showed retrograde perfusion of the false lumen, promptly resolved by fenestration of the false lumen. TEE post-CPB showed persistence of the intimal flap in non repaired segments in all the patients with type I aortic dissection: in 60% of them there was no communication between the true and false lumen; in 40% of them there was a communication between the two lumina, which was proximal in 25% and distal in 15%; all patients did not show thrombosis of the false lumen. TEE post-CPB allowed also the evaluation of flow in left aortic arch branch vessels in 77% of the patients and in the coronary arteries in 70%, and showed well functioning prosthesis in all patients. In each case aortic regurgitation was mild; however, one case had severe insufficiency which was corrected at the time of surgery with annuloplasty. Ejection fraction was normal in 45% of the patients, whereas it was decreased in the remaining patients. Intraoperative TEE during repair of aortic dissection is accurate and useful: it allows improvement in preoperative diagnosis just before CPB, optimizing surgical technique; it gives also important information for the management of patients immediately after CPB and for the follow-up.