Aortic Aneurysm

Dr.mehdi hadadzadeh Cardiovascular surgeon

IN THE NAME OF GOD

Aortic Aneurysm Definition

Permanent focal dilatation of artery greater than 1.5 times its

NL diameter

ClassificationLocation

Wall

shape

location• abdominal aortic aneurysms (AAA).

• thoracic aneurysms (TA).

• thoracoabdominal aneurysms (TAA).

Wall:false or true

• blood vessel has 3 layers: the intima ,media and adventitia

• The wall of a true aneurysm involves all 3 layers

• The wall of a false or pseudoaneurysm only involves the outer layer

shape • saccular

• fusiform

29

  PATHOPHYSIOLOGY

• Most of the elasticity and tensile strength of the aorta is derived from its medial layer

• consists of approximately 45 to 55 lamellar units of elastin, collagen, smooth muscle cells, and ground substance

• elastin content diminishes as one proceeds distally into the descending thoracic and abdominal aorta

• Most aortic aneurysms occur in the infrarenal segment (95%).

The aortic wall is a biologically active environment

tension = pressure x radius

• Larger aneurysms have a greater risk of rupture.

• Larger aneurysms have an increased growth rates (0/08-0/5cm/year)

• prevalence : 3-4% in individuals older than 65 years.

• Begin at approximately age 50years and reaches peak incidence at 80 years

• Men affected 4x more

• Rupture of an AAA usually is a lethal event , carrying an overall mortality rate of 80-90%

Frequency

Etiology Degenerative (arteriosclerotic)(Cystic medial

degeneration )

previous aortic dissection

connective-tissue disease (marfan, Ehler-

Danlos Type IV)

Imflamatory (Autoimmune)

Traumatic

Congenital:15% of first-degree relatives of

patients

Aortic dissection

Mycotic aneurysm

• fewer than 5% of cases

• hematogenous origin

• Sacular

• Most commonly cause:S.aureus and S.epidermidis

Symptoms & Sign1. Mass.

2. Displacement of adjucent structure

3. Compression of adjucent structure:

esophagus,trachea,SVC,nerve,renal,….

4. Erosion of adjucent structure

5. Rupture

6. Distal embolism

Physical examination

• blood pressures • Cervical bruits• Abdominal palpation • Abdominal bruits and trill• peripheral pulses

Diagnosis:• History & PE• X.ray• Sonography• Color duplex scanning• C T• MRI• Angiography

Diagnostic pathways Ultrasound is an excellent screening tool to identify with an AAA in unstable patient,

but is less reliable for detection of vascular rupture . sensitivity and specificity

approaching 100% and 96%

CT is accurate for both detection of an AAA and identifying leak or rupture. CT is

more useful in evaluation of symptomatic but stable patients

Angiography . Represent another option for evaluation of patient with symptomatic

AAA. Its primary function is for consulting surgeons who may obtain anatomic

information that will aid in the surgical plan.

MRI offers the advantages better than CT for defining three-dimensional views of

the aorta and surrounding vascular structures, but limited to patients with metalic

foreign object( I,e. pacemakers, surgical clips.

http://upload.wikimedia.org/wikipedia/commons/7/79/AAA2009.JPG

http://cardiacsurgery.ctsnetbooks.org/content/vol3/issue2008/images/large/1223fig8.jpeg

Treatment:1. Conservative manangment

- Drugs: B-Blockers / Indomethasin

- Monitor growth

- maintain BP

- Frequent CT Scans

2. Intervension:

- Intraluminal stent

- Surgery

Indications for surgery

• Aortic size: Patients with AAAs > 5cm

• Rate of dilatation exceeds 1cm/y

• Symptomatic aneurysm

• Traumatic aortic rupture

• Mycotic aneurysm

Contraindications for surgery

• severe COPD• severe cardiac disease• active infection • medical problems that preclude operative

intervention: advanced cancer, end-stage lung disease ,elderly patient (>80 y) with significant comorbidities

A

B

Thanks for your attention