L5: Aneurysms & diseases of veins

Question 1

What is the definition of aneurysms?

Answer 1

• Localized abnormal dilatation of arterial wall forming a sac.

Question 2

What is the iteology of aneurysms?

Answer 2

 Due to weakening of the wall and/or increase of blood pressure.

 It may be true or false.

Question 3

What is the pathogenesis of aneurysms?

Answer 3

• Two processes are responsible for aneurysm formation:
  1. Weakening of arterial wall which may be: “سديت”
  congenital: As Berry aneurysms of brain (cerebral arteries).
  traumatic: As arterio-venous fistula. “Like a bullet”

Inflammation: As polyarteritis nodosa, T.B. syphilis, emboli of subacute bacterial endocarditis, and bilharziasis.

Degenerative: As atheroma and intracerebral microaneurysm in hypertension.

2. Stretching of the weakened wall: by increased pressure (hypertension)

Question 4

What are the types of aneurysms?

Answer 4

• True & false

Question 5

What is the definition of true aneurysm?

Answer 5

• The wall of the aneurysmal sac is part of the arterial wall.

Question 6

What is the definition of false aneurysm?

Answer 6

• The wall of the sac is not the vessel wall.

Question 7

What is the shape of true aneurysm?

Answer 7

• It may be saccular or fusiform.

Question 8

What are examples of true aneurysm?

Answer 8

❖ Syphilitic aneurysm of thoracic aorta: It may be saccular or fusiform.

❖ Atherosclerotic aneurysm of abdominal “weaker than thoracic” aorta: It is fusiform.

Question 9

What are examples of false aneurysm?

Answer 9

• It may be of fibrous tissue after traumatic rupture of artery and organization of the hematoma, or arterio-venous fistula.

Question 10

What are the complications of aneurysm?

Answer 10

1- Pressure on surrounding: More with syphilitic and produce superior mediastinal syndrome manifested by dyspnea, dysphagia and hoarseness of voice.

2- Rupture: More with atheromatous (internal heamorrhage)

3- Thrombosis and organization and may be embolization.

Question 11

What is the site of dissecting aneurysm?

Answer 11

• Occurs only in the aorta with splitting of the media into two parts inner and outer and in between blood accumulates (producing 2 telescoped tubes).

Question 12

What is the cause of dissecting aneurysm?

Answer 12

• It is due to medial damage by Erdheim’s medial necrosis, Marfan’s syndrome and may be atherosclerosis.

Question 13

What is the pathogenesis of dissecting aneurysm?

Answer 13

Weakness of the aortic media.
1- Blood enters the media either from tear in the sliding intima over a weak loose media.

2- Due to rupture of unsupported vasa vasorum.

3- The blood accumulates and splits the weak media into outer and inner layers forming the walls of the aneurysm.

Question 14

What is the fate of dissecting aneurysm?

Answer 14

1- Healing may occur either by clotting and organization of the blood in the media or rupture into the lumen of Aorta.

2- Rupture of the aneurysm with fatal hemorrhage.

3- Extension into the aortic branches and may narrow their opening leading to ischemia.

Question 15

What are the types of aortic aneurysms?

“ASD”

Answer 15

1- Atheromatous aneurysms: Commonest, occur in descending abdominal aorta below the level of renal artery, It is fusiform.

2- Syphilitic due to diffuse syphilitic lesions in tertiary syphilis: It occurs in arch of aorta and may be saccular or fusiform.

3- Dissecting.

Question 16

What are the types of cerebral aneurysms?

“My Coin”

Answer 16

1- Congenital berry aneurysms at circle of Willis (small, multiple):

• Occur in the circle of Willis at sites of medial weakness at the bifurcations.
• They are the most common cause of subarachnoid hemorrhage.

2- Intra-cerebral micro-aneurysms of benign hypertension.

3- Mycotic aneurysms due to emboli of subacute bacterial endocarditis.

4- Atheromatous.

Question 17

What is the definition of varicose veins?

Answer 17

• It is dilatation, elongation, thickening and tortousity of veins.

Question 18

What are the sites of varicose Viens?

Answer 18

1- Superficial veins of the lower limbs (Long saphenous vein): in persons who spend much of their time standing.

2- Varices of the esophagus:

• Veins of lower 1/3 oesophagus and cardia of the stomach.
• Found in portal hypertension as in liver cirrhosis or bilharzial fibrosis.

3- Hemorrhoids: varices of the internal or external hemorrhoidal plexus of the rectum (piles )

4- Varicocele: varices of the pampiniform plexus of the spermatic cord

5- Caput Medusa: around the umbilicus.

Question 19

What is the pathogenesis of varicose veins?

Answer 19

Is divided into Predisposing & exciting factors

Question 20

What are the predisposing factors for varicose veins?

Answer 20

• Congenital weakening of veins or valves.

- Familial tendency.

Question 21

What are the exciting factors for varicose veins?

Answer 21

• The increased venous pressure leads to stretching of the venous wall.

This may be due to either:
1- Prolonged standing (effect of gravity) as in police soldiers: It affects long saphenous vein.

2- Chronic constipation and straining at stool: It leads to piles

3- Obstruction of venous return: As in cases of liver cirrhosis, bilharzial fibrosis, pressure by pregnant uterus, enlarged prostate, cancer rectum ….. Etc.

Question 22

What are the complications of varicose veins?

Answer 22

• Local chronic venous congestion and persistent edema in limbs and secondary ischemic skin changes, including stasis dermatitis and ulcerations.
• Hemorrhage: Haematemesis and melena from esophageal varices.
• Thrombosis and embolism.
• Varicose ulcers which are premalignant (gives rise to squamous cell carciroma).
  ❖ It occurs in the lower inner part of the leg above medial malleolus.
• Inflammations leading to septic thrombophilibitis, septic emboli and pyemia.