Correspondence

Isolated Non-A, Non-B Dissection of the Aortic Arch

N Engl J Med 1999; 341:1775December 2, 1999

Article

To the Editor:

Dissection of the aorta involves a tear of the aortic intima with separation of the aortic wall and formation of two perfused channels. There are two generally accepted classifications of aortic dissection: the De Bakey classification (types I, II and III)1 and the Stanford classification (types A and B).2 Both classifications are based on the portions of the aorta involved in the dissection, but an isolated dissection of the aortic arch is not included in either classification system. We report the case of a patient with isolated dissection of the aortic arch, a rare clinical entity, which is neither a type A nor a type B dissection of the aorta.

A 50-year-old woman was admitted to the hospital because of severe chest pain. After an acute ischemic syndrome had been ruled out, further evaluation revealed a localized dissection of the aortic arch (Figure 1Figure 1CT Scan Showing Localized Dissection of the Aortic Arch with an Intimal Tear (Arrows).), with a slightly dilated ascending aorta and a normal descending aorta. The patient was treated with a regimen of antihypertensive medication and bed rest. Computed tomographic (CT) examinations performed one week and three months later showed no progression of the aortic abnormality, and the patient received continued medical therapy, with close surveillance.

Isolated dissection of the aortic arch is neither a type A nor a type B dissection and can therefore be called a non-A, non-B aortic dissection. The prognosis for patients with this type of dissection is still unknown, and the optimal treatment is therefore not well established. Although surgery is obligatory if a patient has an acute type A dissection or complications of a type B dissection, there is no firm indication for surgical treatment of a dissection localized in the aortic arch. The aim of surgery for this type of dissection is to prevent complications, such as enlargement of the aortic arch with the formation of an aneurysm and possible rupture or proximal or distal progression of the dissection combined with dangerous neurologic complications and increased lethality.3 Surgery is considered if the diameter of the aortic arch increases or if follow-up CT studies show that the dissection is progressing.

The surgical procedure for isolated dissection of the aortic arch is replacement of the aortic arch with a graft, with reimplantation of the neck arteries into the graft. The procedure is performed through a median sternotomy with the use of cardiopulmonary bypass, deep hypothermic arrest, and retrograde cerebral protection. So far, there is only limited experience with this surgical problem.

Miralem Pasic, M.D., Ph.D.
Friedrich Knollman, M.D.
Roland Hetzer, M.D., Ph.D.
Deutsches Herzzentrum Berlin, D-13353 Berlin, Germany

3 References

1. 1

   De Bakey ME, Henly WS, Cooley DA, Morris GC Jr, Crawford ES, Beall AC Jr. Surgical management of dissecting aneurysms of the aorta. J Thorac Cardiovasc Surg 1965;49:130-149
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2. 2

   Daily PO, Truebold HW, Stinson EB, Wuerflein RD, Shumway NE. Management of acute aortic dissections. Ann Thorac Surg 1970;10:237-247
   CrossRef | Medline

3. 3

   Carrel T, Pasic M, Vogt P, et al. Retrograde ascending aortic dissection: a diagnostic and therapeutic challenge. Eur J Cardiothorac Surg 1993;7:146-150
   CrossRef | Web of Science | Medline