MRI postoperative monitoring in patients surgically treated for aortic dissection.

In most cases, surgery of aortic dissections repairs only the ascending portion of the aorta, leaving a residual dissection in the arch and descending aorta. We studied 17 patients operated upon for type A aortic dissection. A total of 42 magnetic resonance imaging (MRI) examinations were performed, with two to five studies per patient (mean 2.47). The studies were done between 5 weeks and 47 months (mean 17.5 months) after surgery. The patients were evaluated by MRI using gated spin-echo and gradient-echo sequences on axial and oblique sagittal views, and in selected cases, coronal views. A high incidence of abnormalities was observed. Pericardial hematoma was observed in 11% of cases, aortic and branch involvement in 41%, abdominal aortic branch involvement in 47%, dilatation of native aorta in 58%, and extension of dissection in 10%. New complications were detected during follow-up in 53% of patients. MRI was helpful in the follow-up of patients operated upon for aortic dissections, owing to its noninvasiveness and multiplanarity. By means of this technique, it was possible to obtain information about the natural history of the disease, as well as information useful for subsequent treatment.