CAUSES OF AORTA DISSECTING ANEURYSM

This is seen in cases of Marfan’s syndrome, pregnancy, hypertension, atherosclerosis, coarctation of the aorta and bicuspid aortic valve. Cystic medial necrosis of the aorta is the commonest cause of dissection. The tear usually occurs in
the middle of the medial coat of aorta.
Sixty five per cent of intimal tears occur in the ascending aorta, 20 per cent is the descending aorta, 10 per cent in the aortic arch and 5 per cent in the abdominal aorta.
The two commonly used classification systems are (1) Stanford types A and B and (2) De Bakey types I, II and III.

STANFORD TYPES

Type A: When ascending aorta is involved it is called Type A.
Type B: When dissection occurs in sites other than ascending aorta it is called Type B.

DE BAKEY TYPES

Туре I: It originates in the ascending aorta goes up to aortic
arch and often beyond it distally.
Type II: It starts from and is confined to the ascending aorta.

Type III: Originates in the descending aorta and extends distally down the aorta or rarely retrograde into the
aortic arch and ascending aorta.

CLINICAL FEATURES OFAORTA DISSECTING ANEURYSM

Onset is sudden.
Age: Above 40 years
Sex: Males predominate.
There is severe precordial pain which may extend backwards in the paravertebral region or downwards in the abdomen. It is usually accompanied by severe shock and collapse. Pulse is weak and quick, may be inequal, may be absent or there may be pulse deficits, blood pressure is very low even unrecordable, limbs are cold, profuse sweating and central cyanosis are also present. If the dissection extends further downwards there may be pain in the loin, anuria, or even when iliac arteries are affected lower limbs become pulseless and cold. If the dissection extends upwards there may be pain in the neck, hemiparesis and appearance of systolic or diastolic murmur over the aortic area.AORTA DISSECTING ANEURYSM

INVESTIGATION

X-ray chest, ECG, Angiography, Ultrasonogram, CT scan, MRI are all helpful. CT scan and MRI are very sensitive investigations. Transoesophageal Echo of aorta is recently considered to be of special value in the diagnosis.
Prognosis Many patients die suddenly before diagnosis can be made; 20% die within 24 hours and 60% in 2 weeks.

TREATMENT

If hypertension is present it is to be treated by rapid acting antihypertensive drug. Surgical treatment is very much popular.\

AORTA DISSECTING ANEURYSM