Aortic Aneurysms Mark A. Farber, MD

Aortic Aneurysms Incidence 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%

Aortic Aneurysms Definition Pseudoaneurysm True Aneurysm

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

Aortic Aneurysms Associated Aneurysms Iliac - 41% Femoro-popliteal - 15% Pts with unilateral popliteal aneurysms-->8% AAA Pts with bilateral popliteal aneurysms--> 30%-50% AAA

Aortic Aneurysms Associated Medical Conditions Carotid Artery Stenosis - 10% have AAA Smoker:Nonsmoker - 8:1 Male:Female - 4:1 HTN - 40% of pts with AAA have HTN

Aortic Aneurysms Etiology Atherosclerosis Cystic Medial Necrosis Dissection Ehlers-Danlos Syndrome Syphilis Familial Associated Lysyl Oxidase deficiency

Aortic Aneurysms Etiology Decrease in elastin and collagen in arterial wall Elastin becomes fragmented-->arterial elongation and dilatation Increase in the collagenase and elastase activity

Aortic Aneurysms Etiology Multifactorial

Aortic Aneurysms Physics Laplace’s Law T = P x R T - Tension P - Pressure R - Radius

Aortic Aneurysms Clinical 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 -->Rupture or expansion of aneurysm

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

Ruptured Aneurysm Thumbnail Sketch 60-70 y/o who presents with c/o abd pain, hypotension and a pulsatile abdominal mass

Aortic Aneurysms Diagnosis Physical Exam: If <5cm in diameter, then cannot be detected by routine physical exam Radiographs: Calcified wall. Can determine size in 2/3 Cannot rule out and AAA

Aortic Aneurysms Diagnosis 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

Aortic Aneurysms Diagnosis 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

Aortic Aneurysms CT 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

Aortic Aneurysms MRA Now widely available More expensive than CT No contrast agent required Spacial resolution less than CT

Aortic Aneurysms Risks Complications of AAA Thrombosis Distal embolization Rupture 23.4% of aneurysms 4-5 cm will rupture

Aortic Aneurysms Rupture 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.

Aortic Aneurysms Treatment 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

Aortic Aneurysms Indications for Treatment Presence of an infrarenal aneurysm > 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)

Aortic Aneurysms Treatment-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

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