The Thoracic Aorta
Everything You Wanted to
Know….but were afraid to ask
September 8, 2010
Bruce Margolis, DO, MBA
©2010 Genworth Financial, Inc. All rights reserved.
Thoracic Aorta
Company Confidential
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Agenda
Anatomy
Definitions
Epidemiology
Etiology
Pathophysiology
Presentation
Diagnosis
Natural History
Treatment
Prognosis
Underwriting Considerations
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Anatomy
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Definitions
Normal Dimensions
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– Mid-descending 26-28 mm
Dilation (Ballooning, Bulging, Ectasia)
Aneurysm
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– Types
• Saccular
• Fusiform
– Definition
• When the diameter exceeds 4 cm or diameter exceeds 1.5 times normal
Dissection
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– Tear in vessel wall results in false lumen
– Types
• Type A – involves ascending aorta
• Type B – involves descending aorta
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Normal Aortic Dimensions
Hager A. et al.; J Thorac Cardiovasc Surg 2002;123:1060-1066
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Aortic Aneurysm
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Aortic Aneurysm
(A) Tomodensitometric and (B) echocardiographic views of an aortic root
aneurysm.
Nataf P , Lansac E Heart 2006;92:1345-1352
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Aortic Aneurysm
Figure 23. Atherosclerotic vascular dis-ease in an
aortic aneurysm. Axial postcontrast image
(window = 440, level = 40) reveals a large
contrast collection projecting from the
undersurface of the aortic arch, consistent with
aneurysm (arrow). the low attention material
within the aneurysm represents thrombus
http://www.medscape.com/viewarticle/406630_15
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Aortic Aneurysm
Figure 24. Aortic aneurysm
rupture. Axial postcontrast image
(window = 440, level = 40)
through the aortic arch reveals
an aortic aneurysm with contrast
penetrating the thrombus within
the aneurysm (open arrow).
http://www.medscape.com/viewarticle/406630_15
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Aortic Dissection
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Aortic Dissection
Figure 12. Stanford type B (Debakey Type III)
aortic dissection: descending thoracic aorta.
(A) Axial postcontrast image (window = 440,
level = 40) reveals intimal flap (arrow), t = true
lumen, f = false lumen. (B) Oblique sagittal
reconstruction reveals complex nature of the
intimal flap (arrows).
http://www.medscape.com/viewarticle/406630_15
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Epidemiology
Thoracic aneurysms
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– Prevalence greater than 3-4% of those over 65
– 6 cases per 100,000 person-years
– Incidence increasing
– In the top 15 causes of death
– Thoracic aortic aneurysm – rupture 3.5/100,000 persons
Thoracic aortic dissection
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– 2000 new cases/year
– Acute - 3.5/100,000 persons
– Male:Female ratio 2:1
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Etiologies
Underlying Etiologies
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– Atherosclerosis
– Marfan’s
– Type IV Ehlers-Danlos
– Infection (syphillis)
– Arteritis (giant cell, Takayasu, Behcet’s)
– Trauma
Risk Factors
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– Smoking
– COPD
– HTN
– Male gender
– Older age
– High BMI
– Abnormal aortic valve (e.g., bicuspid valve)
– Family history
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Presentation
Aneurysm
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– Most asymptomatic
– Superior vena cava syndrome
– Hoarseness
– Bronchial obstruction
– Dysphagia
– Hemoptysis
– Paralysis/paraplegia
– Lower extremity embolism
Dissection
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– Chest/back/neck pain
– Neurologic signs
– Horner syndrome
– Hoarseness
– Acute aortic regurgitation
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Diagnosis
Chest x-ray
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– Widened mediastinum
Echocardiogram
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– Transthoracic – aortic root
– Transesophageal – ascending and descending
Aortography
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– Delineates the lumen
CT scan
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– Most widely used diagnostic tool
MRI
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– Avoids contrast dye
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Echocardiography
Nataf P , Lansac E Heart 2006;92:1345-1352
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Natural History
Annual Risk of Rupture
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ASI = aortic dia (cm)/body surface area (m2)
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15
10
5
0
<2.75
cm/m2
2.75-4.25
cm/m2
>4.25
cm/m2
Aortic Size Index (ASI)
http://emedicine.medscape.com/article/242904=print
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Natural History
Yearly Rupture or Dissection Rates for Thoracic Aortic Aneurysms: Simple
Prediction Based on Size
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– 304 patients; 58.9% male; median age 65.8
– Aneurysm size – 43.7% were 4.0-4.9 cm
– Location – 72% ascending
– Follow up – average 43.1 months
– End points
Events
No. Patients
Dissection, rupture and death
2
Dissection, rupture (no death)
2
Dissection, death (no rupture)
5
Rupture and death (no dissection)
4
Rupture alone
5
Dissection alone
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Death alone
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Davies RR, et al. Ann Thorac Surg 2002;73:17
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Natural History
Cumulative incidence of acute dissection or rupture as a function of initial aneurysm size.
Davies RR, et al. Ann Thorac Surg 2002;73:17
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Natural History
Kaplan-Meier cumulative hazard function of rupture or dissection.
Davies RR, et al. Ann Thorac Surg 2002;73:17
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Natural History
Average yearly rates of negative outcomes during the first 5 years after presentation
Davies RR, et al. Ann Thorac Surg 2002;73:17
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Natural History
Kaplan-Meier cumulative hazard function of rupture.
Davies RR, et al. Ann Thorac Surg 2002;73:17
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Natural History
Kaplan-Meier cumulative survival before operative repair.
Davies RR, et al. Ann Thorac Surg 2002;73:17
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Natural History
Kaplan-Meier cumulative survival
Davies RR, et al. Ann Thorac Surg 2002;73:17
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Natural History
Kaplan-Meier cumulative survival
Davies RR, et al. Ann Thorac Surg 2002;73:17
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Natural History
Kaplan-Meier cumulative survival
Davies RR, et al. Ann Thorac Surg 2002;73:17
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Treatment - Aneurysm
Medical
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– BP control
– Smoking cessation
– No heavy lifting
Surgical
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– Dacron tube graft
– Ascending – may need to replace valve
– Arch – graft
– Descending – graft, stent grafts
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Treatment - Dissection
Type A
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– Surgical
Type B
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– Medical
– Surgical
• Acute with rupture, leak or distal ischemia.
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Treatment – Indications for Intervention
Aortic size
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– Ascending diameter >5.5 cm
– Descending diameter >6.5 cm
– Growth rate >1 cm/yr (avg ascending 0.07 cm/yr; descending 0.19 cm/yr)
Symptomatic aneurysm
Traumatic rupture
Pseudoaneurysm
Large saccular aneurysm
Mycotic aneurysm
Aortic coarctation
Bronchial compression
Aortobronchial or aortoesophageal fistuala
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Treatment - Surgical
Composite valve and graft replacement.
Nataf P , Lansac E Heart 2006;92:1345-1352
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Complications
Bleeding
CVA – 2-5%
CHF
Respiratory failure
Graft leaks
Fistula formation
Spinal cord damage
Renal failure
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Prognosis
Aneurysm
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– Early post-op mortality 4-10%; lower for descending aneurysm repair; much
higher for aortic arch repair
– Stroke occurs 2-5%
– Renal failure requiring dialysis – 7%
– Spinal cord injury – 3%
Dissection
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– Treated 10-yr survival rate 60%
– Type A
• 30% mortality surgical
• 60% mortality medical
– Type B
• 10% mortality medical
• 30% mortality surgical
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Underwriting Approach and Considerations
Obtain cardiology and/or vascular medical records
Review serial echos/scans as available
Review blood pressure control
Higher Risk
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– Aneurysm >5 cm
– Poorly controlled blood pressure
– Increase in size >0.5 cm/yr
– Ongoing tobacco usage
– Associated cardiovascular disease (CAD, PVD, carotid disease)
– Non-atherosclerotic vascular disorders (Marfan’s, Ehlers-Danlos, etc)
Lower Risk
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– Aneurysm <5 cm/stable/ well followed
– Aneurysm repaired/stable
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Summary
Thoracic aortic dilation/aneurysm fairly common with age
Risk factors are traditional cardiovascular risk factors
Most are asymptomatic
Thoracic aortic rupture rare
Thoracic dissection rare
Ascending aorta most common site of aneurysm formation
Low risk for aneurysms less than 4 cm
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REMEMBER
In the end, it’s not what you call it………it’s size that matters!
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