Effect of medical and surgical therapy on aortic dissection evaluated by transesophageal echocardiography. Implications for prognosis and therapy. The European Cooperative Study Group on Echocardiography.

BACKGROUND

Aortic dissection still has a poor prognosis despite progress in therapy. Therefore, this prospective follow-up study was designed to determine whether the degree of communication between true and false lumen in relation to the type of dissection, analyzed by transesophageal echocardiography, influences the risk after initiation of medical or surgical therapy.

METHODS AND RESULTS

In eight centers, 168 patients (124 men and 44 women) of age range of 23-84 years with proven aortic dissection were examined by transesophageal echocardiography in the acute phase, after start of medical and/or surgical therapy, and during follow-up (0-65 months; mean, 10 months). Analyses were performed prospectively according to a detailed study protocol. Patients were subdivided by transesophageal echocardiography according to a modified DeBakey classification. Type I aortic dissection was found in 35%, type II aortic dissection in 17%, and type III aortic dissection in 48%. Preoperative mortality was 3%, 7%, and 2%, and survival rates were 52%, 69%, and 70%, respectively. Type III aortic dissection could be subdivided into those with communication and antegrade dissection (ca) (50%), with communication and retrograde dissection limited to the descending aorta (cr desc) (10%), with dissection extended to the aortic arch and ascending aorta (cr asc) (27%), and with noncommunicating (nc) aortic dissection (13%). An open false lumen with no thrombus formation was present in types I, II, III ca and III cr asc aortic dissection in 17%, 21%, 39%, and 27% respectively, although it was most pronounced in types III nc and III cr desc (75% and 78%). During follow-up in patients who survived, thrombus was demonstrated in the false lumen in 80% of type I aortic dissection and 81% of types III ca and III cr asc. Open false lumen was seen in type II aortic dissection in 18%. Spontaneous healing was found in 4% with type II and 4% with type III aortic dissection (mainly in patients with type III nc aortic dissection). Patients with fluid extravasation, pleural effusion, pericardial tamponade, and periaortic effusion as well as mediastinal hematoma had a mortality of 52%. Reoperations were necessary in 12-29%, with the highest rate in patients with type III ca aortic dissection. Survival for patients with types III nc and III cr desc aortic dissection was higher than those with types I, II, III ca, and III cr asc.

CONCLUSIONS

Preoperative mortality appears to be reduced by transesophageal echocardiography, allowing rapid initiation of treatment. Intraoperative and postoperative mortality in aortic dissection remains high. Risk factors are fluid extravasation and an open false lumen with high communication. Thrombus formation in the false lumen can be regarded as a good prognostic sign. Surgery appears to be only a first step in the treatment of aortic dissection. Second surgery or closure of entry sites based on intraoperative echocardiography may be considered to induce thrombus formation and reduce aortic wall stress.