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| Aneurysm |
Aneurysm
DEF.
Its a localired or diffuse dilatation of an artery.
TYPES.
1. True: It contains all 3 layers of artery wall.
2. False: it has a pinke layer of fibrous tissue as the wall of the sac and does not contain the three layers of the artery wall as the
covering
majority of false types follow trauma. A mycotic aneurysm which is produced by growth of micro organisms in the vessel wall is of false variety.
3. Arteriovenous: It is a communication betn an artery and adjacent vein.
CAUSES.
Except traumatic all other aneurysms are caused by weakening of the wall of artery.
A]CONGENITAL
1. In circle of willis due to congenital efficiency of elastic lamina at d river of branching. This is called as berry aneurysm.
2. A crisoid aneurysm is the mass of dilated pulsating serpiginous vessels
3. Congenital arteriovenous fistula
4. It is associted with some inherited connective tissue disorder like Marfan and Ehler-Danlos
5. Proximal to coarctation of aorta.
6. Congenital intrimomedial mucoid degeneration.
B]ACQUIRED.
1. Traumatic.
Eg. Direct trauma such as penetrating wound, irradiation or indirect trauma.
2. Degenerative.
This is d most commonest cause majority of them caused by atherosclerosis
3. Infective..
Syphilis, acute infections, mycotic aneurysm, infective endocarditis, tb, arteritis
4. Iatrogenic as in renal dialysis for AV type.
It can also be classified according to shape.
A] Fusiform. It is d commonest variety. It is a spindle shared enlargement.
B] Saccular. It is an expansion of a part of circumference of the artery wall. Usually traumatic.
C] Dissecting. It occurs when the initima ruptures usually beneath an atheromatus plaque & blood is forced through d intima to enter betn inner and outer coats of tunica media.
C/F.
1. May be asymptomatic.
2. Commonest presentation is with dull aching pain.
3. Pulsatile mass
4. severe ischemia of lower limb.
5. Enlargement of artery may block the veins by direct pressure or may cause it to thrombose.
6. severe AV type, may precipitate CCF.
7. Increased limb length in AV type.
8. In AV type below d fistula there may muscle wasting, ulcer formation & cold temp.
O/E
1. Expansile pulsation of d swelling.
2. Pulsation diminishes if pressure is applied proximal to d swelling. It refills again in few beats if pressure is released.
3. Swelling is compressible.
4. Thrill may palpable
5. Systolic bruit
6. Branham's sign:(for AV type)
If a finger is pressed on the artery proximal to the fistula there will be slowing of pulse rate and rise in d diastolic pressure
COMPLICATIONS.
1. Pressure on adjacent structures.
2. Thrombosis & emboli formation.
3. Infection.
4. Rupture.
5. Spontaneous cure.
D/D.
1. Swelling over an artery
2. swelling beneath an artery
3. Pulsating tumor
4. Abscess.
INVESTIGATIONS.
1. Blood is examined for cholesterol levels.
2. W.R. & Kahn tests to exclude syphilis.
3. Straight x-ray.
4. Arteriography
5. Investigations for anesthetic & surgical fitness.
TREATMENT.
1. Arterial Ligation:
suitable for splenic a. or intracranial aneurysm.
#Anel's- applied just proximal to sac
#Brasdor's- applied just distal to sac.
#Hunter's- applied immediately above a branch of artery.
#Wardrop's- applied immediately below a branch of artery.
#Antylus's- applied one proximal & one distal to sac.
2. Wiring of aneurysm sac.
Indicated in elderly and poor risk patients and in difficulty placed aneurysm.
3. Wrapping of aneurysm sac.
Used in intracranial aneurysms.
A strip of fascia lata, polytiene or cellophane is wrapped round d aneurysm to strengthen its wall
4. Mata's aneurysmorrhaphy.
Suitable in femoral or popliteal artery.
Sac is totally excised & defect in d wall is closed by suturing adjacent healthy artery wall.
5. Exclusion & bypass grafting.
Used where excision of sac is not safe due to adhesions with neighbouring vital structures.
6. Excision and grafting.
Most popular & should be done wherever possible. Dacron graft or autogenous vein is used.
7 .Excision and end to end suturing.
Possible only in cases of peripheral aneurysm. Two cut ends are approximated..
8. For AV type:
# reconstructive operation is the treatment of choice
# Quadruple ligation
# selective intra-arterial embolisation
# amputation of limb in cases of severe ischaemia.
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