From Valve to Arch: How s Your Aorta? March 7, 2011

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Leonard Strickland
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of Michigan Ann Arbor, Michigan The Aorta: Anatomic Definitions Aortic root: Includes AV annulus, AV cusps, sinuses of Valsalva Ascending aorta: Begins at STJ and extends to brachiocephalic artery

1 From Valve to Arch: How s Your Aorta? March 7, 2011 Susan Housholder-Hughes, RN, MSN, ANP-BC, FAHA, AACC Nurse Practitioner, Multidisciplinary Aortic Program Cardiovascular Center Adjunct Clinical Instructor, School of Nursing University of Michigan Ann Arbor, Michigan The Aorta: Anatomic Definitions Aortic root: Includes AV annulus, AV cusps, sinuses of Valsalva Ascending aorta: Begins at STJ and extends to brachiocephalic artery Aortic arch: Begins at brachiocephaliic artery, origin of head and neck arteries Descending thoracic aorta: From origin of left subclavian artery coursing anterior to vertebral column and through diaphragm Abdominal aorta: Diaphragm to iliacs Circulation. 2010;121:e266-e369 Normal Aorta: 3 layers Intima: Endothelial layer Minimal connective tissue Media: Fenestrated sheet of elastic fibers Smooth muscle cells Muscular layer Adventitia: Resilient layer of collagen containing the vasa vasorum

Normal Aortic Diameters Influenced by many factors Age Gender Body size Location of measurement Type of imaging method used Typical Aortic Pathologies Aortic valve disease Aortic regurgitation Aortic

2 Normal Aortic Diameters Influenced by many factors Age Gender Body size Location of measurement Type of imaging method used Typical Aortic Pathologies Aortic valve disease Aortic regurgitation Aortic stenosis Aortic dissection Thoracic aortic aneurysm Ascending Arch Aortic Regurgitation Definition: Leaky aortic valve leaflets Leaflets do not close completely Causes return of blood from the aorta into the left ventricle Practical Cardiology, Philadelphia:Lippincott Williams & Wilkins, 2003, N Engl J Med. 2004;351:

3 Aortic Regurgitation: Causes Congenital bicuspid valve Degenerative calcification Rheumatic fever (rare) Marfan s syndrome Infective endocarditis Trauma Aortic dissection Prosthetic valve dysfunction Causes of acute aortic regurgitation N Engl J Med. 2004;351: , Practical Cardiology, Philadelphia:Lippincott Williams & Wilkins, 2003, Aortic Regurgitation: Symptoms Gradual over time, may be asymptomatic Shortness of breath on exertion Fatigue/weakness (exertion) Chest discomfort (angina) Fainting Palpitations (rapid/irregular pulse) Edema N Engl J Med. 2004;351: , Practical Cardiology, Philadelphia:Lippincott Williams & Wilkins, 2003 Aortic Regurgitation: Diagnosis Physical examination: Presence of a murmur High-pitched, blowing Decrescendo, diastolic murmur Left or right upper sternal border Wide pulse pressure Prominent/bounding arterial pulses Third heart sound Echocardiogram with doppler Excellent to assess presence & severity N Engl J Med. 2004;351: , Practical Cardiology, Philadelphia:Lippincott Williams & Wilkins, 2003.

Aortic Regurgitation: Treatment Medical Management Usually for mild to moderate Medications Endocarditis prohylaxis Follow up echocardiograms Surgical Management Aortic valve replacement N Engl J Med.

4 Aortic Regurgitation: Treatment Medical Management Usually for mild to moderate Medications Endocarditis prohylaxis Follow up echocardiograms Surgical Management Aortic valve replacement N Engl J Med. 2004;351: , Practical Cardiology, Philadelphia:Lippincott Williams & Wilkins, Aortic Stenosis Aortic Stenosis Definition: Stiff leaflets of the aortic valve Causes narrowing of the aortic valve Cannot open and close normally Obstructs flow of blood outward into the aorta

5 Aortic Stenosis: Causes Calcification of the aortic valve Age related Calcium accumulates on leaflets Over time may stiffen leaflets and cause narrowing Rheumatic fever Complication of strep throat Scare tissue forms on valve Congenital heart abnormality Bicuspid aortic valve (1-2%) Practical Cardiology, Philadelphia:Lippincott Williams & Wilkins, 2003 Aortic Stenosis: Symptoms Depends on severity of valve disease Many individuals are asymptomatic Typical: Chest pain (angina) Dizziness Syncope (during or after physical exertion) Fatigue, especially with physical activity Shortness of breath with exertion Palpitations Lower extremity edema Practical Cardiology, Philadelphia:Lippincott Williams & Wilkins, 2003 Aortic Stenosis: Diagnosis Physical examination: Murmur Mid-systolic, diamond shaped, radiating to neck, decreasing in intensity with worsening stenosis Split S 2 single sound (severe disease) S 3 (LVD), S 4 (severe AS) Diminished carotid pulse upstroke Diagnostic studies: ECG: non-diagnostic, may show enlarged heart (LVH) CXR: non-specific Echocardiogram with doppler Useful in diagnosis and assessment of AS Practical Cardiology, Philadelphia:Lippincott Williams & Wilkins, 2003

Aortic Stenosis: Treatment Medical management: Asymptomatic Regular follow up Serial echos based on severity of disease Treatment of HTN, lipids, other

Symptomatic patients Mechanical vs bioprosthetic Aortic balloon valvuloplasty Bridge to surgery Percutaneous aortic valve replacement Pending clinical

6 Aortic Stenosis: Treatment Medical management: Asymptomatic Regular follow up Serial echos based on severity of disease Treatment of HTN, lipids, other risk factors Endocarditis prophylaxis Education Limiting physical activity based on disease severity Surgical management: Aortic valve replacement Symptomatic patients Mechanical vs bioprosthetic Aortic balloon valvuloplasty Bridge to surgery Percutaneous aortic valve replacement Pending clinical trials in US Practical Cardiology, Philadelphia:Lippincott Williams & Wilkins, 2003 AV Balloon Valvuloplasty Aortic Dissection

Aortic Dissection Definition: Tear of the intima causing blood to flow between layers, forcing them apart. Creates a true and false lumen. Blood supply to major organs may be compromised.

Medical emergency, may lead to rupture and death.

7 Aortic Dissection Definition: Tear of the intima causing blood to flow between layers, forcing them apart. Creates a true and false lumen. Blood supply to major organs may be compromised. Can occur without the presence of aneurysm. Can spread in an antegrade or retrograde fashion. Aortic Dissection: Statistics Most common acute problem of the aorta. Medical emergency, may lead to rupture and death. True incidence unknown 2000 new cases reported annually Most common sites: Ascending aorta (cms from the AV) Descending aorta, just beyond origin of left subclavian artery American Nurse Today. 2008;3:31-36, Circulation. 2005;112: Aortic Dissection: Stanford Classification Type A Dissections involving the ascending aorta Highly lethal Mortality 1-2% per hour after symptoms begin If no surgery, 50% mortality at one month. Type B Dissections affecting the descending aorta Uncomplicated cases, 30-day mortality of 10% Can be managed medically Possible stent grafting Circulation. 2005;112:

8 Aortic Dissection: Risk Factors Chronic Hypertension Atherosclerosis History of CABG and/or AVR Male gender (3:1) History of aortic aneurysm Age > 50 years: Elastin tissue damage Loss of smooth mucscle Congenital/connective tissue disorders Bicuspid AV Coarctation of the aorta Turner syndrome Marfan s, Ehlers-Danlos, Loey-Dietz Vascular inflammation Arteritis, syphilis Pregnancy Trauma Crack cocaine Iradonline.org, Circulation. 2005;112: , American Nurse Today. 2008;3:31-36, JAMA. 2000;283: , Emerg Med Clin N Am. 2003;21: Aortic Dissection: Symptoms Symptoms are not universal Abrupt, severe chest, back or abdominal pain (tearing/ripping quality possible) Neck or jaw pain Flank pain if kidneys involved Quality maximum at onset, unrelenting Neurologic symptoms (20%) Syncope, altered mental status, numbness, tingling of extremities, weakness, stroke Hypotension Symptoms of HF Asymptomatic in about 12% Iradonline.org, American Nurse Today. 2008;3:31-36, JAMA. 2000;283: , Emerg Med Clin N Am. 2003;21: , Emerg Med Clin N Am. 2004;22: , Journal of Cardiovascular Nursing. 2005;20: , Circulation. 2005;112: Aortic Dissection: Diagnosis Careful assessment of symptoms Detailed physical examination CXR widening of aorta ECG May have ischemic changes if coronary artery flow disrupted, RCA more commonly involved TTE Useful for proximal dissections TEE Can visualize well the distal ascending, arch, descending aorta CT Good tool for defining aortic anatomy MRI Highest accuracy Limited use Availability, applicability Emerg Med J. 2008;25: , JAMA.2000;283: , Emerg Med Clin N Am. 2004;22: , Emerg Med Clin N Am. 2003;21: , Circulation. 2005;112:

9 Aortic Dissection: Treatment Type A dissection Surgical repair required Graft replacement of diseased aorta Type B dissection Definitive treatment less clear Medical management Aggressive BP management B-blocker, others, goal <120 mm/hg systolic Life-time surveillance required Education vital Circulation. 2005;112: Endovascular Therapy Indications: Pain Growth of aorta Progression of dissection End-organ malperfusion syndromes Circulation. 2005;112: Genetic Syndromes Associated with TAA/Dissection Marfan s Syndrome: FBN1 mutation Distinct physical features Surgical repair at 5.0cm, unless family hx of AoD <5.0cm or rapidly growing or significiant AV regurgitation Loeys-Dietz Syndrome: TGFBR2 or TGFBR1 mutation Distinct physical features Surgical repair at diameter of 4.2 cm by TEE or 4.4 to 4.6 cm by CT Ehlers-Danlos Syndrome: COL3A1 mutation Surgical repair complicated by friable tissues Easy bruising, thin skin, GI rupture, others Turner Syndrome: Absence of 1 sex chromosome 10-25% have BAV 8% coarctation AoD increased

10 Aortic Aneurysm Aortic Aneurysm Definition Localized dilation of the aortic wall Greater than 50% of normal caliber Typically defined as an outer diameter greater than 3cm, size varies based on age, gender, body habitus MC extracranial location is infrarenal abdominal aorta Aneurysms weaken the aorta and may lead to: Dissection Rupture Generally, aneurysm exceeding 5.0 cm are considered large Thoracic Aortic Aneurysm

11 TAA: Statistics Annual incidence: 6-10/100,000 people Males affected 2-4x more than females 13% of those with TAAs have multiple aneurysms Concern for rupture, mortality 94% Aneurysm may involve: Aortic root Ascending aorta 60% Arch 10% Descending aorta 40% Circulation. 2005;112: , Ann Thorac Surg. 2008;85:S1-41, Circulation. 2005;111: TAA: Causes Congenital bicuspid AV 52% with aortic dilatation Atherosclerosis: Infrequent cause of ascending, predominantly descending Risk factors; hypertension, elevated cholesterol, smoking, others Genetic: Connective disorders; Marfan s syndrome, Ehlers-Danlos syndrome Turner syndrome (sex chromosome absent) Inflammatory/infectious: Arteritis, syphilis Circulation. 2005;111: TAA: Symptoms Most are asymptomatic Found incidentally on imaging for some other reason If symptoms; Typically due to compression of adjacent structures/blood vessels (larger aneurysms) Trachea: cough, dyspnea, wheezing Esophagus: dysphagia Laryngeal nerve: hoarseness Chest, back, flank pain (rare unless dissecting) 3.bp.blogspot.com/.../s320/coughing.jpg J Cardiovascular Nursing. 2005;20: , Circulation. 2005;111:

12 TAA: Dissection/Rupture Feared consequence of TAAs Potentially lethal Risk based on aneurysm size 2% annually if < 5 cm 3% if cm 7% if > or = to 6 cm Symptoms: Abrupt onset neck, chest, back, abdominal pain Severe in nature Circulation. 2005;111: , Ann Thorac Surg. 2002;73:17-28 TAA: Diagnosis Chest x-ray May show evidence of aneurysms CT scan MRA TEE Can visualize entire thoracic aorta TTE can image aortic root Circulation. 2005;111: TAA: Management Medical Management: Goal: slow growth and decrease risk of dissection/rupture Limited therapies Blood pressure control b-blockers, ARBs Target lower: systolic < 120 mm/hg Provide education on proper home BP monitoring Physical activity limitation Aeorbic exercise OK if no hypertensive response Avoid abrupt increase in intrathoracic pressure Symptom education Dissection/rupture What to do (911 ED prompt physician for CT imaging) Circulation. 2005;111:

13 TAA: Management Regular surveillance: CT, frequency individualized Mean growth rate of all TAAs = 0.1 cm per year Growth rate variable, may be challenging to predict Surgical options: Timing somewhat uncertain, typically when risk of dissection/rupture outweigh risks of surgery Ascending diameter 5.0 cm Higher operative risk: 6 cm Higher risk for rupture (Marfan, BAV), cm Circulation. 2005;111: , J Thorac Cardiovasc Surg. 1994;107: TAA: Treatment Surgical Repair: Open resection: Symptomatic patients or those with complications (dissection) Asymptomatic; decision based on risk for rupture and dissection versus surgical risk AV sparing, full root replacement, ascending, arch, descending replacement, need for concomitant CABG Open thoracotomy Aortic cross-clamping Resection of aneurysm and replacement with a prosthetic graft Cardio-pulmonary bypass Associated mortality; 5-20% elective, up to 50% emergent Complications; renal & pulmonary failure, visceral/cardiac ischemia, stroke and paraplegia Minimal imaging required post-operatively J Cardiovascular Nursing. 2005;20: , Coron Artery Dis. 2002;13:93-102, J Cardiovasc Surg. 1978;19: , J Vasc Surg. 1993;17: Summary

Diseases of the aorta

Diseases of the aorta Aneurysm, dissection and aortitis are the main pathologies (Fig. 18.79 ). data:text/html;charset=utf-8,%3ch2%20id%3d%22cc5a0836d6aa490ca26dd7c15632b559%22%20style%3d%22margin%3a%201.3em%200px%200.5em%3b%20padding%3a%200px%3b%20border%3a%200px%3b%20font-fa