*1.2.1 Sporadic*

Not associated with any known congenital or genetically mediated syndromes.

**65**

*Aortic Dissection*

**1.3 Newer classification**

*1.3.1 Dissect classification*

*1.3.2 Penn ABC classification*

evolution of complications:

generalized ischemia)

• Acute—less than 2 weeks

• Chronic—>92 days

**2. Pathophysiology**

• Subacute—2 weeks to 92 days

symptom onset [2]:

lumen [1].

*DOI: http://dx.doi.org/10.5772/intechopen.89210*

tion of complications, and extent of involved segments.

• Ab—Branch vessel malperfusion with ischemia

*1.3.3 Classification based on duration of symptoms*

With advancement of treatment approach in cases previously managed conservatively, especially with endovascular interventions, recent classifications have taken into consideration other factors like, the duration of symptom onset, evolu-

The DISSECT classification system is a mnemonic-based approach with relevance to the therapeutic considerations, including endovascular management. The six features of aortic dissection include duration of disease, intimal tear location, size of the dissected aorta, segmental extent of aortic involvement, clinical complications of the dissection, and thrombus within the aortic false

The Penn ABC classification further divides type A aortic dissection based on

• Abc—Both branch vessel malperfusion and circulatory collapse (localized and

More recently type B aortic dissection has been classified based on duration of

The pathophysiology of AD involves the breakdown of the intima and/or the media. The initiating event is an intimal tear. Less commonly rupture of the vasa vasorum may be the initiating event. Initial tear is commonly at the site of greatest hydraulic stress which are the right lateral wall of the ascending aorta in about 50–65% of the cases and the proximal segment of the descending aorta (20–30%) [3]. Subsequently, intramural extension of the bleeding both longitudinally and circumferentially causes the separation of aortic wall layers creating a true lumen and a false lumen. A further intimal tear may create a communication between the false lumen and true lumen. The dissection can extend in antegrade or retrograde

• Aa—Absence of branch vessel malperfusion or circulatory collapse

• Ac—Circulatory collapse with or without cardiac involvement

### *1.2.2 Genetically mediated*

Associated with known genetic syndromes like Marfan's syndrome, Ehlers-Danlos syndrome, Turner syndrome, and Loeys-Dietz syndrome.

### *1.2.3 Congenital cardiovascular defects*

Bicuspid aortic valve, coarctation of aorta, and annuloaortic ectasia.

### *1.2.4 Traumatic*

Prior cardiac surgery, blunt injury, and cardiac catheterization.
