Aortic Aneurysms

1
Aortic Aneurysms

• Mark A. Farber, MD

2
Aortic AneurysmsIncidence

• 30-60/1000
• Increasing incidence over past 3 decades
• Incidence of AAA
• Autopsy 1.5-3.0
• U/S Screening 3.2
• Pts with CAD 5.0
• Pts with PVD 10.0
• Pts with femoral and pop.aneurysms 50.0

3
Aortic AneurysmsDefinition

• Pseudoaneurysm
• True Aneurysm

4
Definitions

• Aneurysm - Increase in diameter of 50 (1.5x) its
  normal diameter Focal region
• Ectasia - Diffuse dilatation of an artery with
  increase in diameter gt50
• Arteriomegaly - Diffuse enlargement of an artery,
  but not lg. Enough to meet criteria for an
  aneurysm

5
Aortic AneurysmsAssociated Aneurysms

• Iliac - 41
• Femoro-popliteal - 15
• Pts with unilateral popliteal aneurysms--gt8 AAA
• Pts with bilateral popliteal aneurysms--gt 30-50
  AAA

6
Aortic AneurysmsAssociated Medical Conditions

• Carotid Artery Stenosis - 10 have AAA
• SmokerNonsmoker - 81
• MaleFemale - 41
• HTN - 40 of pts with AAA have HTN

7
Aortic AneurysmsEtiology

• Atherosclerosis
• Cystic Medial Necrosis
• Dissection
• Ehlers-Danlos Syndrome
• Syphilis
• Familial Associated
• Lysyl Oxidase deficiency

8
Aortic AneurysmsEtiology

• Decrease in elastin and collagen in arterial wall
• Elastin becomes fragmented--gtarterial elongation
  and dilatation
• Increase in the collagenase and elastase activity

9
Aortic AneurysmsEtiology

• Multifactorial

10
Aortic AneurysmsPhysics

• Laplaces Law
• T P x R
• T - Tension
• P - Pressure
• R - Radius

11
Aortic AneurysmsClinical Presentation

• Asymptomatic - 70-75
• Symptoms
• Early satiety, N,V
• Abd., Flank, or Back pain
• 1/3 of pts experience abd. And flank pain
• Abrupt onset of pain --gtRupture or expansion of
  aneurysm

12
Aortic AneurysmsRuptured Aneurysms

• Small tear-gt pain, followed by frank rupture
• Usually occurs postero-laterally
• Can rupture in Vena Cava creating Aorto-Caval
  Fistula
• Occasionally can rupture anterior - usually fatal

13
Ruptured AneurysmThumbnail Sketch

• 60-70 y/o who presents with c/o abd pain,
  hypotension and a pulsatile abdominal mass

14
Aortic AneurysmsDiagnosis

• Physical Exam
• If lt5cm in diameter, then cannot be detected by
  routine physical exam
• Radiographs
• Calcified wall. Can determine size in 2/3
• Cannot rule out and AAA

15
Aortic AneurysmsDiagnosis

• Arteriography
• Cannot determine aneurysm size because of mural
  thrombus
• Indications for obtaining arteriography
• Suspicion of visceral ischemia
• Occlusive disease of iliac and femoral arteries
• Severe HTN, or impair renal function
• ? Horseshoe Kidney
• Suprarenal of TAAA component
• Femoro-Popliteal Aneurysms

16
Aortic AneurysmsDiagnosis

• Ultrasound
• Establishes diagnosis easily
• Accurately measures infrarenal diameter
• Difficult to visualize thoracic or suprarenal
  aneurysms
• Difficult to establish relationship to renal
  arteries
• Technician dependent
• Widely available, quick, no risk, cheap

17
Aortic AneurysmsCT Scan

• Very reliable and reproducible
• Can image entire aorta
• Can visualize relation ship to visceral vessels
• Longer to obtain and is more costly than U/S
• Most useful
• Requires contrast agent - renal toxicity

18
Aortic AneurysmsMRA

• Now widely available
• More expensive than CT
• No contrast agent required
• Spacial resolution less than CT

19
Aortic AneurysmsRisks

• Complications of AAA
• Thrombosis
• Distal embolization
• Rupture

23.4 of aneurysms 4-5 cm will rupture
20
Aortic AneurysmsRupture Risks

• Patients with COPD and HTN have increased risk of
  rupture
• Rate of enlargement
• 0.5 cm/ year
• Survival
• 50 die prior to reaching hospital, and an
  additional 24 prior to repair.

21
Aortic AneurysmsTreatment Risks

• Mortality
• 0.9 - 5 with current surgical techniques
• Morbidity
• 5-10 usually associated with cardiac events
• Endovascular Techniques are significantly
  reducing morbidity and mortality associated with
  repair

22
Aortic AneurysmsIndications for Treatment

• Presence of an infrarenal aneurysm gt 5cm without
  associated co-morbid medical conditions
• Repair smaller aneurysms if rate of enlargement
  is greater than expected
• Repair all symptomatic aneurysms
• If co-morbid conditions exist wait until risk of
  repair and rupture are equal (approx. 6 cm)

23
Aortic AneurysmsTreatment-Surgical

• Standard Surgical Repair
• Replace diseased aorta with artificial artery
• Requires 7 day hospital stay
• Recovery time 3-6 months
• Proven method with good long term results

24
Aortic AneurysmsTreatment - Endovascular

• Repair through an incision in the groin with
  expandable prosthesis under fluoroscopic guidance
• Requires both surgical and radiological
  assistance
• Significantly reduced mm
• Long tern result unknown
• Hospital stay 2 days, Recovery time 1-2 weeks