Acute aortic dissections: Surgical versus medical therapy

With computed tomography, accurate diagnosis of acute aortic dissection is improving. This may help reduce the number of patients dying untreated, which in some series has reached 25% of the total. Improved surgical results and a variety of modified techniques have increased the one-month survival rate to 75% generally, and to 90% to 95% in smaller series from single institutions. Significant postoperative complications-renal failure, redissections, or neurological deficits-develop in approximately one of three patients and continue to be causes for concern. Uncontrolled postoperative hypertension is a significant problem, resulting in new disease elsewhere in the aorta in almost half the patients treated surgically. Fortunately, new disease is easily assessed by computed tomographic scanning. Until surgical therapy achieves a uniform 90% to 95% survival rate and a total delayed complication rate of less than 20%, the subset of patients who are at a low risk for rupture or major arterial occlusion can best be handled according to the Wheat medical therapy protocol. Expected short-term results are equal to those currently reported for the surgical management of high-risk dissections. Patients with dissections not likely to rupture-for example, sheathlike descending aortic dissections without expansion or rupture in those with severe hypertension and small, limited dissections anywhere within the aorta-are still best treated medically for a prolonged period. Long-term survival at one, five, and ten years for patients who have lower-risk acute aortic dissection appears to be competitive with survival achieved with surgical treatment for patients with higher-risk dissections. The unanswered questions remain. Is surgical therapy appropriate for the patient with acute aortic dissection who is at low risk for rupture? Is medical therapy appropriate for the patient at operative risk, regardless of the risk of rupture? Certainly the operative mortality expectations would be unfavorable for patients with respiratory insufficiency, concomitant myocardial infarction, and low-output failure without tamponade. Expectations would also be unfavorable for patients with descending dissections or complicated dissections such as arch dissections with stroke and for those without a clear-cut origin of the false lumen in the absence of tamponade or severe congestive heart failure. Serious consideration of prolonged medical therapy in these cases seems appropriate. We need to pursue further avenues of investigation and innovation before we can say confidently that acute aortic dissection is always a 'surgical' disease and the case for prolonged medical therapy is closed.