Definitions
Congenital or acquired localised area of
abnormal dilations of blood vessels or the
heart
Whats the importance?
Aneurysm & dissections are important causes of
stasis & subsequent thrombosis, tendency to rupture.
Types of Aneurysm
True aneurysm
- Involves all 3 layers of
the artery
(intima, media, adventitia)
- attenuated wall of the heart
- Eg: atherosclerotic, congenital
aneurysms, syphilitic aneurysm,
ventricular aneurysm from
transmural MI
False Aneurysm
- wall defect that leads to
extravascular hematoma that
communicate with the
intravascular space
(pulsating hematoma)
- Eg: ventricular rupture after MI
contained by pericardial adhesions
& leaks at the junction of a
vascular graft with a natural artery
Spherical outpouching 5cm 20cm Often contain thrombus
Cylindrical dilation
Causes of Aneurysms
1) Loss of smooth muscles cells or change in the smooth muscle cell
synthetic phenotype (ischemia, Marfan syndrome)
Most commonly:
Atherosclerosis (Abdominal aortic aneurysm) and hypertension
(Ascending aortic aneurysm)
2) Excessive connective tissue degradation
(eg. Local inflammatory response Macrophages in atherosclerotic
plaque, MMP, TIMP cystic medial degeneration)
3) Weakened vessel walls (trauma, vasculitis, congenital defects berry
aneurysm, infections mycotic aneurysms, 3syphilis- obliterative
endarteritis esp ascending thoracic aorta)
4) Inadequate or abnormal connective tissue synthesis (eg. Marfan
syndrome-defective synthesis of fibrillin, Ehlers-Danlos syndrome-deficient
synthesis of type III collagen for bv, bowel wall)
Example of Aneurysms Berry aneurysm - replacement of muscular wall by fibrous tissue,
involve Circle of Willis at the point of branching, young to middle age (suspect when young pt have chronic headache)
Predisposing factor : Hypertension
Complication : Subarachnoid hemorrhage
Capillary microaneurysm (Charcoat-Bouchard) - rupture of branches of arteris in brain (eg: middle cerebral artery)
- adult, HPT due to hyaline arteriolosclerosis, cn cause stroke
Syphilitic aneurysm - 3 syphilis, ascending thoracic & arch of aorta
Mycotic aneurysm - Bacterial or fungal infection via blood streeam
- Involve cerebral vessels
Abdominal Aortic Aneurysm
Anteropostero diameter of 3cm is generally accepted as aneurysm
Degeneration of the elastin and collagen
(Local inflammatory infiltrates in atherosclerotic arteries
Excessive ECM degradation, destructive proteolytic
enzymes.Compromise diffusion of nutrients & wastes btw
vascular lumen & arterial wall, compress underlying media)
Degeneration & necrosis, thinning of arterial wall, expansion accelerates, risk of rupture increases
Risk factors:
Men older than 60 y/o
Smoking
Familial predisposition (atherosclerosis/HPT)
Hereditary defects in structural component of aorta ( Marfan syndromes)
Abdominal Aortic Aneurysm
Typically occur btw aortic bifurcation & renal arteries Can be saccular or fusiform Up to 15cm diameter, 25cm in length Variants: i) Inflammatory AAAs
characterized by dense periaortic dense fibrosis containing many macrophages, giant cells
ii) Mycotic AAAs
occur when circulating microorganisms (as in
bacteremia from a Salmonella gastroenteritis),
suppuration accelerate medial destruction, rapid dilation, rupture
Complications (ROCE) :
1) Rupture into peritoneal cavity/ retroperitoneal
tissues massive, fatal hemorrhage!!
2) Obstruction of a vessel branching off the aorta
( i.e. vertebralspinal cord, mesenteric arteries-GI
tract, renal-kidney, iliac-legs, reproductive organs)
3) Compression on adjacent structures ( ureter,
vertebrae)
4) Embolism from atheroma/mural thrombus
Symptoms of Abdominal Aortic Aneurysm
Asymptomatic
- pulsatile mass in abdomen
(incidentally discovered on abdominal examination,
calcification on plain abdominal X-ray, CT, ultrasound scan)
Symptomatic
- Abdominal pain/ back pain (need urgent surgery)
- due to rapid expanding aneurysm that causes pressure on
adjacent structures
- Fainting, hypotension (cardiovascular collapse), pain
that mimic renal colic pain due to leaking/ruptured aneurysm
Investigations for arterial disease Angiography CT scan X ray (chest, abdominal) Exercise ,resting ECG echocardiography Ultrasounds (carotid, abdominal, Doppler s
ultrasound)
Duplex ultrasonography Urine test for sugar, blood glucose Blood test for EST, CRP, serum cholesterol Ankle brachial pressure index (to look for PVD)
Prevention of arterial disease 1) Patients
Quit smoking Control blood sugar level Lower cholesterol & blood pressure level Eat food that are low in saturated fat (healthy diet) Exercise regularly, maintain BMI Sleep regularly (circadian rhythm) Regular body checkup Avoid contraceptive pills (choose alternatives), alcohol
(anti-ADH effects)
Drink lots of water, exercise foot & Wear elastic compression stockings for long flight travel
Take prophylaxis (anticoagulants)
2) Healthcare personnel
Monitor blood pressure, glucose, cholesterol level, body weight of the patient
Ultrasound scan of abdominal aorta for all men reaching 65 y/o
Give local anesthesia than general anesthesia during surgery
Give prophylaxis (anticoagulant) perioperatively
Prevention of arterial disease
Principles of Management of Arterial Disease 1) Non-surgical
Acute:
control ABCs (stop bleeding, resuscitation, treatment of thrombi or emboli)
obtain intravenous access, and administer oxygen, baseline laboratory studies, special investigations like ECG, chest radiograph, treatment of
thrombi or emboli (heparin infusion to increase APTT to 1.5 times normal
levels)
Contraindication in the presence of active internal bleeding, intracranial
bleeding, or bleeding at non-compressible sites.
Chronic:
Treat & monitor underlying diseases (eg.HPT, diabetes mellitus)
Regular risk factors assessment, screening, preventive measures
Principles of Management of Arterial Disease 2) Surgical
- Operative exploration (small vessels ligated, partial tear sutured or closed
with a vein patch, replace injured area with a segment of saphenous vein)
- Fasciotomy (split the deep fascia widely to relieve compartment pressure)
- Reconstructive surgery
- Insert stent-graft (endovascular repair)
- Angioplasty
- CABG
- Lumbar sympathectomy (increase blood supply to allow ulcer healing)
- Amputation