An aneurysm is a permanent, localized, abnormal dilation of a blood vessel Occurring due to congenital or acquired weakening or destruction of the vessel wall.

Most commonly aneurysm involve large elastic arteries.

It causes serious ill effects like

1). Thrombosis and Thromboembolism. 2). Alteration in the flow of blood. 3). Rupture of the vessel resulting in sever fatal haemorrhages. 4). Compression of neighbouring structures.

Aneurysms are classified by three ways i.e

1).Depending upon the composition of wall.

2).Depending upon the shape.

3).Depending upon pathogenic mechanisms

Depending upon composition of vessel wall there are 2 types of aneurysm i.e

1). True aneurysm when all the 3 normal layers of the blood vessel are

involved.

2). False aneurysm When only fibrous layer of the wall is involved and

the rest of the layers are damaged due to trauma.

There are 5 types i.e1).spherical having spherical outpouching.

2).Fusiform having spindle shape dilatation

.

3).Cylindrical having continuous parallel

dilatation.

3).varicose having tortuous dilation of the vessel.

4).Racemose having mass of intercommunicating small arteries and veins.

1).Atherosclerotic aneurysms.

2).Syphilitic aneurysms.

3).Mycotic aneurysms.

4).Berry aneurysms.

5).Dissecting aneurysms.

Aneurysms can occur when the the structure and function of the connective tissue within vascular wall is compromised, and it occurs in the following conditions i.e.

1)Marfan syndrome. 2)Loeys_Dietz syndrome. 3)Ehler_Danlos syndrome. 4) Vitamin C deficiency 5)Increased MMP production by macrophages in vasculitis. 6)Ischemia of the media by athersclerotic thickness of the intima and systemic hypertension. 7)Direct trauma to the vessel.

• More common in men

• Frequency increases after 50 years of age.

• Most common in abdominal aorta especially infrarenal , and other sites include thoracic aorta, iliac arteries,

• Clinical features include,

• 1.rupture

• 2.Obstruction

• 3.Embolism

• 4.Abdominal mass

Syphilitic aneurysm occurs usually in tertiary stage of syphilis.

• More common in men after the age of 50 years.• The predominant site of involvement is thoracic

aorta.• Pathogenesis; Inflammatory infiltrate around the

vasa vasorum endarteritis obliterans destruction of smooth muscle and elastic tissue

Of media weakening of vessel wall formation of aneurysm

1. Respiratory difficulties.

2. Difficulty in swallowing

3. Persistent cough due to pressure on recurrent laryngeal nerve.

4. Pain caused by erosion of vertebral bodies.

5. Cardiac disease

6. Rupture

Usually death occurs due to cardiac diseases…….

It results from weakening of arterial wall by microbial infection.

It originates from,1. Embolization of a septic embolus as a

complication of infective endocarditis.2. Extention of adjacent suppurative

process.3. Circulating organisms directly infecting

the arterial wall

Berry aneurysms are saccularOr lobulated bulge arising at the bifurcation of intracranial arteries.

They are genetically Determined.

They are important cause of Subarachnoid hemorrhage And infarction .

When the blood enters the dissected wall of the vessel and spreads for varying distance longitudinally.

• It may and may not be associated with aortic dilatation.

• It can be fatal if dissection ruptures through adventitia leading to sever hemorrhage

It is common in men of 40_60 yr ageWith hypertension and young patients with Connective tissue abnormalities.

The major risk factor is hypertension.

Intimal tear is the 1st step.

Hypertension causes aortic medial degeneration by pressure related ischemic injury.

Inherited or acquired connective tissue disorders also contributory factors.

Dissection occurs b/w inner 2/3 and outer 1/3 of media.

There are 2 types of classifications

1.DeBakey classification.

2. Recent classification.

1.Chest pain2.Myocardial infarction3.Aortic insufficiency4.Vascular obstruction5.Cardiac tamponade6.Death due to rupture of dissection into

pericardial ,peritoneal ,and pleural cavities.

Rapid diagnosis and institution of antihypertensive therapy coupled with surgical procedures permit 65_75% of individuals to be saved.

The most common site of involvement of atherosclerotic aneurysm is???????

A. Arch of aorta

B.) Thoracic aorta

C. Suprarenal abdominal aorta

D.infrarenal abdominal aorta

The most common cause of dissecting haematoma is????????

A.Cystic medial necrosis.

B.Traumatic during cardic catherization.

C.Systemic hypertension.

D.Marfan syndrome.

Dissecting heamatoma causes separation of aortic wall as under.

A. Between intima and media

B. Between inner 1/3of media and outer 2/3 of media

C. Between inner 2/3 of media and outer 1/3

D. Between media and adventitia.