Aortic Arch Dissection: A Controversy of Classification

Abstract

Aortic dissections originating in the ascending aorta and descending aorta have been classified as type A and type B dissections, respectively. However, dissections with intimal flap extension into the aortic arch between the innominate and left subclavian arteries are not accounted for adequately in the widely used Stanford classification. This gap has been the subject of controversy in the medical and surgical literature, and there is a tendency among many radiologists to categorize such arch dissections as type A lesions, thus making them an indication for surgery. However, the radiologic perspective is not supported by either standard dissection classification or current clinical management. In this special report, the origin of dissection classification and its evolution into current radiologic interpretation and surgical practice are reviewed. The cause for the widespread misconception about classification and treatment algorithms is identified. Institutional review board approval and waiver of informed consent were obtained as part of this HIPAA-compliant retrospective study to assess all aortic dissection studies performed at the University of Maryland Medical Center, Baltimore between 2010 and 2012 to determine the prevalence of arch dissections. Finally, a unified classification system that reconciles imaging interpretation and management implementation is proposed.

The role of multidetector-row CT in the diagnosis, classification and management of acute aortic syndrome

“…68,69 Some authors have advocated a non-operative management approach in Type A arch dissections that do not involve the ascending aorta, leading to recent proposals to revise the Stanford classification system based on disease involvement proximal to (Type A) and distal to (Type B*) the origin of the brachiocephalic artery and distal to the left subclavian artery (Type B). 70 Type A IMH is also associated with a high risk of progression to aortic dissection and aortic rupture if left untreated, with an early mortality rate of 8% with surgical repair vs 55% with medical therapy in Western populations. 51,71,72 Although there are few published data concerning the outcome of Type A vs Type B PAU, current consensus again is that management based on the Stanford classification is appropriate.…”

Clinical features and prognosis of patients with acute aortic dissection in China

“…The patients were divided into two groups according to the Stanford classification system: those with AAD involving the ascending aorta (type A dissection group) and those with AAD not involving the ascending aorta (type B dissection group). 2 Of all patients, 37 were diagnosed with type A AAD and 68 with type B AAD. The mean age of the patients was 53.39 years (range, 31–87 years).…”

Aortic dissection: medical, interventional and surgical management

“…The most commonly used classification systems are illustrated in figure 4. While the ‘DeBakey Classification’ specifies the extension of the dissection and location of the entry (I, II, III),17 the more commonly used ‘Stanford Classification’ simply informs whether there is involvement of the proximal aorta up to the aortic arch (type A) or only of the descending aorta (type B) 18 19. Although we will, in the following sections of this article, mainly refer to the Stanford Classification, since it is more widely used in clinical practice, the DeBakey Classification still plays a role in surgical treatment, as described below.…”