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Diseases of the Great Vessels
Susan A. Raaymakers, MPAS, PA-C, RDCS (AE)(PE)Radiologic and Imaging Sciences - Echocardiography
Grand Valley State University, Grand Rapids, [email protected]
Tyler Kahle Story(20 minutes duration)
http://media.bestcare.org/TylerKahleStory
Normal Aortic Anatomy Six Segments
1. Annulus2. Sinuses of Valsalva 3. Sinotubular Junction4. Ascending Tubular Aorta5. Arch6. Descending Thoracic
Aorta
Normal Aortic Anatomy Six Segments
Annulus Represents the junction of the
prox. Ao and the LVOT.
Part of fibrous skeleton of the heart and is contiguous with the anterior mitral valve leaflet and perimembranous septum
Fibrinous structure so relatively stable and resistant to dilation:useful for indexing to remaining aortic sizing
NL 13 +/-1 mm/m2 NL size 2.0-3.1cm
Normal Aortic Anatomy Six Segments
Sinuses of Valsalva Normal aorta dilates at
the level of the sinuses by approximately 6 mm/m2
Three sinuses of Valsalva of equivalent size
Right and left contain ostia of right and left coronaries respectively
Non
Normal Aortic Anatomy Six Segments
Sinotubular Junction Aorta tapers to within 2 to 3 mm
of annular size Crucial to nature of aortic valve
coaptation Insertion of aortic valve cusps:
continuous from the level of the annuls up through the sinuses to the level of the sinotubular junction
Dilatation of sinotubular junction may result in splaying of coaptation line of the aortic cusps leading to secondary aortic insufficiency
Normal Aortic Anatomy Six Segments
Ascending Tubular Aorta Dimension similar to sinotubular
junction
Ascending aorta terminates at the left innominate artery (brachiocephalic) where aortic arch begins and continuous to the left subclavian and ligamentum arteriosum
Normal Aortic Anatomy Six Segments
Arch Three major branch vessels
Innominate artery (brachiocephalic), left common carotid and left subclavian
Descending Thoracic Aorta
Walls of the Aorta Intima
Thin and smooth Media
Elastic and muscular Adventitia
Outer layer
Echocardiographic Evaluation
Echocardiographic Evaluation Evaluation of the intrathoracic portion of
the aorta and of aortic disease TTE: limited to proximal ascending aorta and a
small portion of the descending aorta behind LA
Major use of TEE: high-resolution view of entire length of aorta form aortic valve to approximately the diaphragm
Accuracy equivalent to computed tomography (CT) and magnetic resonance imaging (MRI)
Echocardiographic Evaluation Superior angulation in parasternal long-
axis view Emphasizes visualization of normal ascending
aorta (typically 4 -5 cm may be seen)
20.03 Feigenbaum
Echocardiographic Evaluation Suprasternal notch view
Images more feasible in children and adolescents
Occasional discomfort of ultrasound probe in this area
20.4 Feigenbaum
Echocardiographic Evaluation Descending thoracic aorta seen in
Parasternal long axis behind LA Level of the gastroesophageal junction,
posterior apical four chamber view
Non-dynamic
Echocardiographic Evaluation
Echocardiographic Evaluation Transesophageal
Broader window than transthoracic Visualization from annulus through ascending and
arch to level of gastroesophageal
Non-dynamic
Echocardiographic Evaluation Transesophageal
Typically imaging begins with imaging of the ascending aorta with probe behind the left atrium
Proximal 5 to 10 cm of the ascending aorta can be visualized
Scanning at a 120-degree imaging plane
Non-dynamic
Echocardiographic Evaluation Transesophageal
Rotate probe 30-60° Series of short-axis views of
proximal ascending aorta including short axis of aortic valve
Non-dynamic
Echocardiographic Evaluation Transesophageal
Descending aorta Insertion of TEE probe deeper
toward gastroesophageal junction
Non-dynamic
Intravascular Ultrasound Performed with high-frequency: 20-30 MHz
Used in diagnosis and management of aortic dissection and as a primary imaging tool
Allows highly detailed, high-resolution
Aortic rupturePlaque
Diseases of the Aorta Aortic Dilatation Aortic Dissection Thoracic Aortic Aneurysms Traumatic Injury Aortic Atherosclerosis Sinus of Valsalva Aneurysms
Aortic Dilatation Dilatation can occur at any point along
aorta Primary Secondary
Idiopathic dilatation Also referred to as Anuloaortic ectasia Unclear whether distinct disease entity due
to aging, hypertension or unrecognized disease of aorta
Aortic Aneurysm Definition: Localized abnormal dilatation of aorta
containing all three layers of the aortic wall Pathophysiology: Weakened media of the aorta
Tunica externa
Tunica media
Tunica intima
Aortic AneurysmTypes
Saccular Fusiform
Locations Ascending aorta 45% Aortic Arch 10% Descending Thoracic Aorta 35% Abdominal Aorta 10%
Causes for Aortic Aneurysms Atherosclerosis Medial Degeneration
Idiopathic (annuloaortic ectasia) Marfan's Syndrome Other heritable disorders Associated with Bicuspid Aortic Valve
More Causes Aortic Dissection with Dilitation of
persisting false lumen Trauma with incomplete aortic rupture Syphilis Mycotic (Bacterial, Fungal, Tuberculous
aortitis) Noninfectious aortitis (Giant-cell,
Takayasu’s Syndrome)
Aortic Dilatation Primary
Occurs with cystic medial necrosis Typified by Marfan’s
May be seen in other connective ts disorders Results in weakening of medial layers
Subsequent dilation and aneurysm formation
Aortic DilatationPrimary
Marfan’s Characteristically involves ascending aorta and sinuses Imaging recommendations:
Radiography for skeletal abnormalities Serial chest radiography for demonstration of progressive
aortic dilation 2D echocardiography for early dx and monitoring of aortic
dilation CT or MRI for evaluation of aortic disease
Aortic DilatationSecondary
Volume or pressure overload states AI or HTN
Post stenotic aortic dilation Valvular aortic stenosis
20.11 Feigenbaum
Aortic Dilatation Dilated ascending aorta
Effacement (loss of tapering) of the sinotubular junction
Classic effacement Sinotubular junction: same dimension as Valsalva sinus
Non-dynamic
Aortic ANEURYSMS May occur in ascending aorta
Typically past sinotubular junction Better visualized with TEE
20.11 Feigenbaum
Aortic ANEURYSMS
20.13 Feigenbaum
Aortic ANEURYSMS and DILATION Rupture or dissection
Directly related to degree of dilation Indication for prophylactic aortic surgery
55 mm Many centers use 50 mm
Rapid change in dilation (<than 5 mm per year)
Non-dynamic images
Marfan’s Syndrome Inherited connective tissue disorder Echocardiography: initial screening tool for
patients or first-degree relatives TEE for more specific information
Marked dilation of ascending aorta Disproportionate involvement of sinuses of
Valsalva Early cases
Mild dilation of sinus Sinotubular effacement
Malcoaptation of aortic cusps Resultant in AI
Marfan’s Syndrome
Level of sinuses: 5.8 cm
Aortic annulus: 2.8 cm
Patient #2
Patient #1
20.20b Feigenbaum
20.21a Feigenbaum
Valsalva Sinus Aneurysm May form from any of the three
Valsalva sinuses Most often arise form the right sinus
Size: highly variable Aneurysms arising from the right
Valsalva sinus typically protrude down into the right atrium Appear as “windsock” structure in the
right atrium
Valsalva Sinus Aneurysm Right sinus of Valsalva aneurysm
Protruding into right ventricular outflow tract
20.24a Feigenbaum
20.24b Feigenbaum
Valsalva Sinus Aneurysm Right sinus of Valsalva aneurysm
Protruding into right ventricular outflow tract
20.24a-c Feigenbaum
Valsalva Sinus Aneurysm Colorflow
Major complication of Valsalva Sinus Aneurysm: rupture Most common location for rupture: right atrium
Results in instantaneous elevation of right heart pressures Jugular distension Loud continuous murmur
20.26 Feigenbaum 20.27 Feigenbaum
Valsalva Sinus Aneurysm Colorflow
Major complication of Valsalva Sinus Aneurysm: rupture Most common location for rupture: right atrium
Results in: Instantaneous elevation of right heart pressures
Aortic DissectionAcute Symptoms
Sudden onset of severe chest pain and/or back pain
Wide range of secondary cardiovascular and physiologic abnormalities
Typically occurs with pre-existing Aortic dilation Cystic medial fibrosis due to Marfan’s
syndrome Long standing hypertension
Any aspect of the aorta may dissect
Aortic Dissection
Two Basic Variants Classic Spontaneous hematoma
Aortic Dissection Classic
Tear from lumen through the intima into the medial layer with subsequent propagation of a column of blood
Further dissect the intima away form the media Propagation may be both proximal and distal to the
initial intimal tear
Aortic Dissection Classic
Typically begins either At the area of the ligamentum arteriosum
Propagates through the arch and into the ascending aorta
Or starts in ascending aorta and propagate distally
Aortic Dissection Spontaneous Intramural Hematoma
Clinical presentation with respect to nature of symptoms: virtually identical to classic dissection
Hemorrhage into the medial layer then dissects proximally or distally to a variable degree WITHOUT rupture into the adventitia
Aortic Dissection Two schemes for identification
Stanford (A-B) DeBakey (1, 2, 3)
Types Type A(1): (70% occurrence)
Throughout ascending and descending aorta
Type A(2): (5% occurrence) Confined to ascending aorta
Type B(3): (25% occurrence) Confined to descending aorta
Isolated: Aortic arch
Type II Dissection
20.31 Feigenbaum
20.35 Feigenbaum
20.34 Feigenbaum
Type II Dissection
20.31 Feigenbaum
20.35 Feigenbaum
20.34 Feigenbaum
True and False Lumens True lumen
Pulsatile aortic flow Expand w/systole Circular or ovale typically In descending aorta: usually
smaller of the two lumens False lumen
Continuous flow in venous flow pattern
Often filled with twirling homogenous echoes (stasis of blood or frank thrombus)
Tags of tissue (small muscle remnants where the intima has been sheared from the media)
Non-dynamic
True and False Lumens
True lumen
False lumen
20.36a Feigenbaum
20.36a Feigenbaum
Type III Aortic Dissection Descending aortic dissection
20.39b Feigenbaum
Imaging Goals for Dissection Ascending dissection
Most are detected by TEE rather than TTE
20.30a Feigenbaum
20.30b Feigenbaum
Intramural Hematoma May occur at any point along the aorta More common in the descending aorta and arch Appears as a smooth homogenous concentric
thickening of the wall Typically > 7 mm in thickness
No active flow with the “lumen” and no tear in the intima
20.44 Feigenbaum
Goals of Imaging Confirmation of diagnosis Location Extent of dissection Mechanism of AI Presence of pericardial or pleural effusions Coronary artery involvement Head vessel involvement Detection of rupture Location of:
Intimal tear (entry) Re-entry site
Transesophogeal Echo Superior over transthoracic echo CT, MRI and Aortography are also
common methods of diagnosis Pitt falls of TEE
Reverberations, catheters Mirror image artifacts Thoracic aneurysm with mural thrombus
Echo Findings 2D
Presence of an intimal flap, which may appear as a thin linear structure
A true and a false lumen Pericardial effusion
MM Dilated aorta >4.2cm Increased aortic wall thickness
Color/Doppler AI Flow between the true and false lumen
Role of TEE Best for seeing ascending aortic
aneurysms Helps rule out aortic dissection versus
aortic aneurysm Instant results
Non-dynamic
Mechanisms of AI Dilatation of aortic root Asymmetric dissection causes faulty
coaptation of the aortic valve Prolapsing intimal flap back through the
aorta
Aortic Atheroma Atherosclerosis of the aorta
Frequently encountered in TEE May be identified in SSN view Common in advanced age, HTN, elevated
cholesterol May be a component of atherosclerotic
aneurysm and intramural hematoma of the aorta
Most common in descending aorta Less frequently in ascending aorta
Aortic Atheroma Characterized as symmetric and
crescentic (curved shaped) Smooth, homogenous crescent filling a portion
of the aortic lumen, protruding or complex Complex: defined as atherosclerotic disease with
epedunculated or mobile components
Grading System I = 1 – 3.9mm thickness II = > 4mm thickness III = Debris (mobile regardless of size)
Aortic AtheromaTwo Different Patients
20.50a Feigenbaum
20.50b Feigenbaum
Miscellaneous ConditionsAortic Pseudoaneurysm Contained rupture of the aorta Characterized by an extraluminal aneurysmal sack communicating
with the true lumen by a relatively narrow neck Occur in several situations
Spontaneous rupture of an aortic aneurysm with subsequent sealing off of the hemorrhage
Sequelae of aortic dissection with further rupture through the adventitial layers
Rare occasions: iatrogenic injury
20.55 Feigenbaum
Miscellaneous ConditionsAortic Trauma Wide spread of extent of injury/pathology
Simple contusion Intimal tear Intramural hematoma False Aneurysm Frank rupture (transection) Major dissection NOT a feature of aortic trauma(usually
no underlying medial disease)
Miscellaneous ConditionsAortic Trauma Blunt chest injury
High-speed impact injury (i.e. unrestrained MVA) Partial or complete transection of the descending aorta,
classically at area of ligamentum arteriosum Complete = nearly instantaneous fatal event Partial = hemorrhage and shock CT or MRI typically primary diagnostic tool
Traumatic Injury Cont. Intimal Lacerations (transection)
The mechanism of injury historically was thought to be rapid deceleration with "whipping" of the aorta at points of attachment (i.e., aortic root, ligamentum arteriosus, diaphragmatic hiatus).
More recent evidence suggests that injury at the most common site, the aortic isthmus, is due to
Compression of the anterior chest wall and pinching of the aorta between structures of the anterior bony thorax and the thoracic spine.
Aortic Infections – mentioned earlier under causes of aortic aneurysm Bacterial or fungal infections of the aorta
is rare Manifest as a pedunculated mobile mass Syphilic aortic disease: rare encountered
in contemporary practice Results in inflammatory thickening of the
proximal aorta
Aortic Thrombus Rare Bland mobile thrombus form within the thoracic aorta More common in the proximal descending thoracic aorta
and is often associated with evidence of peripheral embolization
Thrombi are highly mobile echo-dense masses within the lumen, appear attached to the aortic wall by a fairly thin stalk
20.59 Feigenbaum
Takayasu Arteritis Inflammatory disease of the aorta and its proximal branches Occurs in patients <40 years old Results in marked, irregular intimal thickening and accumulation
of inflammatory tissue in the proximal aorta and ostia of major branches including the coronary arteries
Echo: appears similar to atheroclerotic disease
20.61 Feigenbaum
Pulmonary Artery Abnormalities
Pulmonary Artery Abnormalities Most abnormalities of PA: congenital
Postenotic dilation Branch pulmonary artery stenosis Abnormal position of the pulmonary artery Transposition of the great vessels
May also be involved by systemic diseases such as Takayasu arteritis
Pulmonary artery dissection: rare Reported in patients with chronic pulmonary
hypertension
Pulmonary Artery Abnormalities Dilated pulmonary arteries
Right-sided volume overload (e.g., atrial septal defect)
Pulmonary hypertension Idiopathic dilation of the pulmonary artery
(Rare)
Finding of dilated PA mandates careful evaluation for: Right-sided pressure or volume overload
Pulmonary Artery Abnormalities Standard views
PSAX RVOT Subcostal four with severe anterior tilt SSN (right pulmonary artery)
High parasternal short axis
RPA LPA
Non-dynamic
Pulmonary Artery Abnormalities Transesphageal
0° esophageal level superior the LA Long axis of pulmonary artery
May not be obtained in all patients d/t interposition of the air-filled bronchus
AO
SVC
MPA
RPA LPA
12-005 Feigenbaum
Pulmonary Artery Abnormalities Transesphageal
90° plane (analogous to TTE RVOT view) Image quality may be suboptimal due to
distance of PA from transducer in this view
Alternative studies CT MRI Contrast angiography Radionuclide ventilation/perfusion scan for
evaluation for pulmonary embolism
Pulmonary Artery Abnormalities Limitations and alternative approaches
Acoustic access and quality Body habitus and skill of sonographer Interpretation must consider the likelihood of
False-positive findings from beam-width artifacts, reverberations and oblique image planes
False-negative findings due to limited acoustic access and poor resolution
Chest CT Advantages: wide field of view, high accuracy and wide
availability Disadvantages: ionizing radiation and non-portable nature
of the study MRI
Advantages: high resolution, high diagnostic accuracy, wide field of view and ability to orient the images along the long axis of the aorta
Sources Feigenbaum H, Armstrong W. (2004). Echocardiography. (6th
Edition). Indianapolis. Lippincott Williams & Wilkins.
Goldstein S., Harry M., Carney D., Dempsey A., Ehler D., Geiser E., Gillam L., Kraft C., Rigling R., McCallister B., Sisk E., Waggoner A., Witt S., Gresser C.. (2005). Outline of Sonographer Core Curriculum in Echocardiography.
Otto C. (2004). Textbook of Clinical Echocardiography. (3rd Edition). Elsevier & Saunders.
Reynolds T. (2000). The Echocardiographer's Pocket Reference. (2nd Edition). Arizona. Arizona Heart Institute.