ACUTE AORTIC SYNDROMES
RAJESH K F
• Acute aortic syndromes
consist of 3 interrelated
conditions with similar
clinical characteristics
• Aortic dissection
• Intramural hematoma
• Penetrating aortic ulcer
Erbel R, Alfonso F, Boileau C, Dirsch O, Eber B, Haverich A, et al. Diagnosis and
management of aortic dissection. Eur Heart J 2001;22:1642-81.
AORTIC DISSECTION
• Most common aortic
catastrophe
• Incidence - 5 to 30 per 1
million people/year
• Primary tear in aortic
intima with bleed into
diseased media
• Rupture of vasa vasorum Hemorrhage in aortic wall
with subsequent intimal
disruption
• Most ascending aortic
dissections begin within
a few centimeters of
aortic valve
• Most descending aortic
dissections have their
origin just distal to left
subclavian artery
DeBakey classification
• I: Ascending aorta ->
arch +/- descending
aorta
• II: Ascending aorta only
• III:Descending aorta
• IIIa: Limited to
descending thoracic
aorta
• IIIb: Extending below
diaphragm
Stanford classification
Type A
• Affect ascending aorta,
regardless of site of
origin
Type B
• Do not affect ascending
aorta
Classification
• Based on time of onset of initial symptoms to
time of presentation
• Acute dissection < 2 weeks
• Subacute- between 2 and 6 weeks
• Chronic > 6 weeks
Behave like aneurysm
Rupture is the risk
Malperfusion is rare
RISK FACTORS
Hypertension (75%)
Genetically triggered
• Marfan syndrome
• Bicuspid aortic valve (5 to 10 times risk)
• Loeys-Dietz syndrome
• Hereditary thoracic AA or dissection
• Vascular Ehlers-Danlos syndrome
Congenital diseases or syndromes
• Coarctation of the aorta
• Turner syndrome(dissection at small aortic
dimensions)
• Tetralogy of Fallot
Atherosclerosis
• Penetrating atherosclerotic ulcer
Trauma, blunt or iatrogenic
• Catheter or stent
• Intra-aortic balloon pump
• Aortic or vascular surgery
• Motor vehicle accident
• CABG or AVR
Cocaine use
Inflammatory or infectious disease
• Giant cell arteritis
• Takayasu arteritis
• Behcet disease
• Aortitis
• Syphilis
Pregnancy (typically in third trimester)
• Patients <40years are less likely to have HTN(34%) and more likely to have
Marfan’s syndrome, bicuspid aortic valve, or prior aortic surgery
IRAD registery
Marfan syndrome -Ghent criteria
CARDIOVASCULAR SYSTEM
MAJOR CRITERIA
•Dilation of ascending aorta
•Aortic dissection
MINOR CRITERIA
•MVP
•Dilation of MPA
•Premature mitral annular
calcification (<40yrs)
•Descending thoracic or Abdominal
aortic aneurysm(< 50 yrs)
CVS involvement:one minor criterion
OCULAR SYSTEM-MAJOR CRITERION
• Ectopia lentis
SKELETAL SYSTEM
MAJOR CRITERIA
Presence of at least four of the following
• Pectus carinatum
• Pectus excavatum requiring surgery
• Reduced US to LS ratio (.85to 0.95) or arm
span to height ratio > 1.05
• Wrist and thumb signs
•Scoliosis > 20° or spondylolisthesis
•Reduced extension at elbows (<170°)
• Medial displacement of medial malleolus
causing pes planus
• Protusio acetabulae of any degree
Marfan syndrome -Ghent criteria
• INDEX CASE: Major criteria in two systems and
involvement of a third system
• FAMILY MEMBER: One major criterion in an
organ system and involvement of a second
organ system
Revised Ghent criteria
J Med Genet 2010 47: 476-485
Loeys-Dietz aneurysm syndrome
• Autosomal dominant
• Mutations in TGFBR1 or
TGFBR2
• Arterial tortuosity,
hypertelorism, bifid or
broad uvula,cleft palate
• Soft, velvety skin and
easily visible veins
• Aortic dissection and
aneurysm involving
branch vessels
Familial thoracic aortic aneurysm and
dissection
• Autosomal dominant
disorder
• Mutations in various
genes including ACTA 2,
MYH11, TGFBR1 and
TGFBR2, FBN1
• Thoracic aortic aneurysm
and dissection
• May be associated with
PDA, cerebral aneurysm,
BAV or livedo reticularis
Vascular Ehlers-Danlos syndrome
(type 4)
• Autosomal dominant
• Mutation in gene COL3A1
• Abnormal type III
procollagen synthesis
• Hyperflexible fingers,
hyperlucent skin with visible
veins, easy bruisability and
varicose veins
• Hisk for spontaneous
arterial dissection and
rupture, often in medium
sized arteries
Aortic dissection clinical presentation
•
•
•
•
•
•
Usual age is sixth or seventh decades of life
Chestpain or backpain or both
Most severe at its onset
Migratory Pain
Ripping, tearing, stabbing, or sharp quality
Patients on steroids and Marfan syndrome
prone for painless presentation (6.4%)
High-risk examination features
• Loss of peripheral pulse
• SBP limb differential
greater than 20 mm Hg
• Focal neurologic deficit
• New AR murmur
International Registry of
Acute Aortic Dissection
(IRAD) Physical Findings
of 591 Patients With
Type A Aortic Dissection
• Most type B dissection are
hypertensive on
presentation
• Type A dissection may
present with normal BP or
hypotension
• Loss of peripheral pulse
• are reported in 10% to 30%
of acute dissections
• May be intermittent Dynamic movement of
dissection flap
Dynamic obstruction
Aortic regurgitation
• In 40% with acute type
A dissection
• Mechnisms of AR
• Malcoaptation of aortic
leaflets - dilation of
aortic root and annulus
• Distortion of alignment
• Aortic leaflet prolapse
• Prolapse of intimal flap
across aortic valve
Neurologic manifestations
• Most common in dissection type A
• May dominate clinical presentation
• Neurologic syndromes include
• Persistent or transient ischemic stroke
• Spinal cord ischemia
• Ischemic neuropathy
• Hypoxic encephalopathy
Syncope
• Reported in 13% of patients in IRAD
• Indicate development of dangerous
complications
• Acute hypotension - Cardiac tamponade (10% of
acute type A dissections) or aortic rupture
• Cerebral vessel obstruction or activation of
cerebral baroreceptors
Vascular insufficiency
• Renal artery - 5% to 10%
• Renal ischemia,infarction,
renal insufficiency or
refractory hypertension
• Mesenteric ischemia or
infarction in 5%
• Extension to iliac arteries
-acute limb ischemia
Acute myocardial infarction
• Flap causing
malperfusion of
coronary artery
• Occurs in 1% to 7% of
acute type A dissections
• RCA is most commonly
involved
• Left-sided pleural
effusion
• Usually related to
inflammatory response
• Acute hemothorax
Chest radiography
• Widening mediastinum (80%
to 90% of cases (83%, type A;
72%, type B)
• Obliteration of aortic knob
• Displaced intimal calcification
(>5 mm) -calcium sign 20%
• Displacement of trachea to
right
• Distortion of left main-stem
bronchus
• Pleural effusion (more
common left sided)
• Cardiomegaly
• Normal in 12% to 15% of cases
D-dimer levels
• Rise in acute aortic dissection as in pulmonary
embolism
• Level >1,600 ng/mL within first 6 hours positive likelihood ratio of 12.8 for dissection
• In first 24 hours after symptom onset - Ddimer level < 500 ng/Ml has negative
predictive value of 95%
IMAGING
1
2
3
Establish presence of AD or variant (IMH,PAU)
Location of the dissection (Type A, Type B)
Anatomical features
a
b
c
4
Extent of dissection
Sites of entry and reentry
False lumen patency, partial thrombosis, thrombosis
Complications of dissection
a
Type A
i Aortic regurgitation
ii Coronary artery involvement
iii Pericardial effusion/hemopericardium
b
c
d
Aortic rupture or leaking
Branch vessel involvement
Malperfusion
Contrast-enhanced CT
• Most commonly used
• Sensitivity and specificity of
95% to 98%
• ECG gating or multi
detector scanning
eliminate pulsation artifacts
• Intravenous contrast is
necessary to visualize true
and false channels
• Visualize hemopericardium,
aortic rupture, and branch
vessel involvement
MRI
• Sensitivity of 98% and
specificity of 98% with
diagnostic odds ratio of 6.8
• Capable of multiplanar
imaging with 3D
reconstruction
• Cine MRI visualize blood
flow, differentiating slow
flow and clot and AR
• MRA -detect and quantify
AR & branch vessel
morphology
TTE
• 78.3% sensitivity and
83.0% specificity for
diagnosing proximal
dissection
• 2 lumens separated by
flap
TEE
• Accurately visualise entire
thoracic aorta (sensitivity
98.0%, specificity 95.0%,
diagnostic odds ratio 6.1)
• 2 lumens separated by flap
• Visualize coronary ostia
• AR
• Pericardial effusion
• LV & RV function
• May not adequately visualize
distal ascending aorta and
aortic arch
Aortography
• Identify intimal flap, true and
false lumen
• Thickened wall (thrombosed
false lumen)
• AR, branch vessel involvement
• Diagnostic accuracy 90-95%
• 5-10% false negative rate
– thrombosed false lumen
– simultaneous opacification
of both lumens
– misses IMH
• Risks of procedure
• Comparative study with
nonhelical CT, 0.5 Tesla
MR and TEE showed
• 100% sensitivity for all
modalities,
• Better specificity of CT
(100%) than for TEE and
MR
• False-negative studies
can and do occur
Shiga T, Wajima Z, Apfel CC, Inoue T, Ohe Y. Diagnostic accuracy of transesohageal
echocardiography, helical computed tomography,and magnetic resonance imaging
for suspected thoracic aortic dissection. Arch Intern Med. 2006;166:1350-6.
INITIAL MANAGEMENT
• IV beta blockade -Target HR of 60 /min or less(LOE : C)
• Esmolol -Initial bolus of 500microg/kg and continuous
infusion of 50 to 200 microg/kg/min
• Labetolol-Initial dose of 20 mg IV over 2 minutes and
40 to 80 mg IV every 15 minutes (max 300 mg),
continuous infusion 2 to 8 mg/min
• Propranolol and metoprolol –IV or oral
• BBs blockers- compensatory tachycardia in acute AR
BB Action
• CIs to BB-Nondihydropyridine CCB(LOE : C)
• IV diltiazem 0.25 mg/kg over 2 minutes > infusion 5
to 15 mg/hr
• SBP > 120 mm Hg after adequate HR control- ACEI
and/or other vasodilators IV (LOE : C)
• Should not be initiated prior to rate control - reflex
tachycardia increase aortic wall stress (LOE : C)
• IV sodium nitroprusside - most established agent, rapidly
titratable , 20 microg/min, with titration to 0.5 to 5
microg/kg/min
• Renal insufficiency or prolonged use-cyanide toxicity
• IV enalaprilat,nitroglycerin,nicardipine,nitroglycerin,
fenoldopam
• Refractory hypertension - consider renal artery
hypertension due to dissection causing renal malperfusion
• Appropriate analgesia – opiate
Surgical Therapy
Acute type A aortic dissection
Retrograde dissection into ascending aorta
Surgical Therapy and/or Endovascular Therapy
Acute type B aortic dissection complicated by
•
•
•
•
•
Medical Therapy
Visceral ischemia
Limb ischemia
Rupture or impending rupture
Aneurysmal dilation
Refractory pain
Uncomplicated type B aortic dissection
Uncomplicated isolated arch dissection
GOALS OF SURGERY
• Excise intimal tear
• Obliterate false channel by oversewing aortic
edges
• Reconstitute aorta,usually by placing a dacron
interposition graft
Type A aortic dissection
• Replace affected ascending
aorta with or without aortic
arch with prosthetic graft
• In-hospital mortality 15-35%
• Proximal extension of
dissection to aortic valve or
ostia of coronary arteries
may require replacement or
resuspension of aortic valve
(24% )or coronary artery
bypass (15% )
Valve sparing -David or Yacoub Procedures
• AVR required if annular
supports of leaflets
damaged (composite graft
or homograft)
• AVR required if aortic
root >5 cm
Modified Bentall’s operation
Preoperative Prediction Model of
Surgical Mortality Risk
VARIABLE
OVERALL
TYPE A (%)
AMONG
AMONG
SURVIVORS
DEATH (%)
(%)
COEFFICIENT
SCORE
ASSIGNED
P VALUE
ODDS RATIO,
DEATH (95%
CI)
Age ≥ 70 yr
27.3
24.1
37.4
0.68
0.7
<0.01
1.98 (1.193.29)
History of
aortic valve 4.5
replacement
3.8
6.6
1.44
1.5
<0.01
4.21 (1.56.34)
Presenting
hypotension,
28.8
shock, or
tamponade
22.4
49.0
1.17
1.2
<0.01
3.23 (1.955.37)
Migrating
chest pain
13.8
12.1
19.3
0.88
0.9
<0.01
2.42 (1.324.45)
Preoperative
cardiac
15.5
tamponade
11.7
28.2
0.97
1.0
<0.01
2.65 (1.484.75)
Any pulse
deficit
25.7
37.8
0.56
0.6
0.03
1.75 (1.062.88)
28.6
From Rampoldi V, Trimarchi S, Eagle KA, et al: Simple risk models to predict surgical mortality in acute type A aortic dissection: The
International Registry of Acute Aortic Dissection score. Ann Thorac Surg 83:55, 2007.
Uncomplicated acute type B aortic
dissection
• Drug treatment alone
can result in 78% three
year survival
• Medical management
remains the gold
standard
• Endovascular treatment
is increasingly possible
with low mortality
[IRAD]: New insights into an old disease.
JAMA 283:897, 2000.)
ADSORB trial
• Acute Dissection:
Stent graft OR Best
medical therapy
• Acute uncomplicated
type B aortic dissection
• Stent graft OR Best
medical therapy
• 250 subjects ,125 test /
125 control
• Follow-up – 3 years
<55mm
• No 30-day deaths stroke
or paraplegia were
reported in either
treatment group
• Aortic remodelling at 1
year (p<0.001) favoured
TAG+BMT
Complicated acute type B dissection
• Complications such as
malperfusion, shock mortality rate is 25% to
50%
• Conventional open
surgery- 30 day mortality
of 30%
• Meta-analysis has shown
that endovascular
treatment( TEVAR)-30 day
mortality of 9.8%
30-day mortality in patients with acute type B-AD undergoing
stent–graft placement in comparison with medically and
surgically treated type B-AD patients derive d from IRAD
Eggebrecht H, Nienaber CA, Neuhauser M, Baumgart D, Kische S,
Schmermund A, et al. Endovascular stent-graft placement in aortic
dissection: a meta-analysis. Eur Heart J 2006;27:489-98.
TEVAR
• Treatment modality of choice in complicated
acute type B AD
• Focus is occlusion of primary entry tear
• Size of stent graft should be based on diameter of
aorta proximal to dissected segment, applying
almost no oversizing
• Sufficient length (1.5–2 cm) of proximal landing
zone
• Ballooning is not recommended even if stent
graft is not fully expanded-Retrograde dissection
and rupture of dissection membrane
Chronic type B dissection
• Managed conservatively
• 15% complicated by aneurysm
• Conventional open surgery has an appreciable
death rate and poses considerable
physiological challenges
• Endovascular approach is associated with less
morbidity and mortality
• Endovascular surgery 93%; open surgery 79%
Subramanian S, Roselli EE. Thoracic aortic dissection: long-term results of endovascular and open repair. Semin Vasc Surg 2009;22:61-8.
INSTEAD trial
• Investigation of Stent
Grafts in Aortic
Dissection
• 140 patients with
uncomplicated type B
dissection >2 weeks
• Compared drug therapy
with endovascular stent
grafting
• 2 years of follow-up
• No difference in rate of
death between two
treatment groups
• Patients receiving
endovascular grafts higher rate of falselumen thrombosis
• Systematic review of mid-term outcomes of
endovascular treatment
Reintervention for late morbidities
• Endoleak (8.1%)
• Formation of a distal aneurysm (7.8%)
• Rupture (3.0%)
• Postoperative surveillance is mandatory
Thrumurthy SG, Karthikesalingam A, Patterson BO, Holt PJ, Hinchliffe RJ, Loftus IM, et al. A
systematic review of mid-term outcomes of Thoracic Endovascular Repair (TEVAR) of chronic
type B aortic dissection. Eur J Vasc Endovasc Surg 2011;42:632-47
Endovascular therapy in aortic
dissection
• Fenestration of aorta
and stenting of branch
vessels -earliest
techniques used in
complicated type B
dissection
• By fenestrating intimal
flap, blood flow from
false lumen into true
lumen,decompressing
distended false lumen
Endovascular stenting
• Acute aortic rupture,
malperfusion
syndromes and rapidly
enlarging false lumens
• Endovascular grafts
cover area of a primary
intimal tear
• Promote false-lumen
thrombosis
STABLE trial
• Petticoat technique-entry
point is sealed with
endograft and remaining
thoracic and potentially
abdominal aorta is
stented open
• Decrease chance of true
lumen collapse, enhance
aortic remodeling, and
promote false lumen
thrombosis
Zenith Dissection Endovascular System,
• Evaluates safety and effectiveness of a unique
composite thoracic endovascular aneurysm repair
(TEVAR) construct (proximal TX2 stent graft and
distal BMS) (Zenith Dissection Endovascular
System; Cook Medical) for treatment of patients
with complicated type B AD
• Enrolled 40 patients
• Acute 24 pts (60%), subacute (15-30 days) six pts
(15%) and chronic (31-90 days) in 10 pts (25%)
( J Vasc Surg 2012;55:629-40)
• 30-day mortality rate was 5% (2 of 40)
• Two deaths occurred after 30 days, leading to
a 1-year survival rate of 90%
• Morbidity occurring within 30 days included
stroke (7.5%), TIA(2.5%), paraplegia (2.5%),
retrograde progression of dissection (5%) and
renal failure (12.5%)
• Four patients (10%) underwent secondary
interventions within 1 year
• Favorable aortic remodeling
was observed during the
course of follow-up
• Increase in true lumen size
and a concomitant decrease
in false lumen size
• Completely thrombosed
thoracic false lumen
observed in 31% of patients
at 12 months as compared
to 0% at baseline
Hybrid approach
• One segment of aorta,
such as the aortic arch,
is treated surgically,
descending aorta
receives an
endovascular graft
Zone 3：
Carotid
Bypass+TEVAR
Zone 2：
Ascending aorta
Bypass(elephant
trunk extension)
+TEVAR
Zone 4:
TEVAR
FOLLOW UP
• ESC recommendations
• Regular cross sectional imaging of aorta,
preferably with MRA, at 1,3 and 12 months
after discharge and every six to 12 months
thereafter, depending on aortic size
• All patients should receive lifelong
antihypertensive treatment, including β
blockers, with a target BP of 120/80 mm Hg
Intramural Hematoma
•
•
•
•
10% to 20% acute aortic syndromes
Common in older patients
Clinical picture of dissection
Imaging show no blood flow in false lumen or intimal
lesion
• Hemorrhage of vasa vasorum in medial layer of aorta
or hematoma arises from microscopic tears in aortic
intima
• Most (50% to 85%) are located in the descending aorta
• Typically associated with hypertension
• Crescentic or circular
thickening of aortic wall
with maximal thickness
> 7 mm on TEE without
intimal flap or tear or
longitudinal flow in
false lumen
type A IMH
Hematoma may
• Entirely resolve (10%)
• Convert to a classic dissection(3% to 14% of
cases of descending aorta and in 11% to 88%
of cases of ascending aorta)
• Aorta may enlarge and potentially rupture
Management
• Surgery in patients with
acute IMH involving
ascending aorta
• Aggressive medical
therapy is advocated in
patients with acute IMH
involving the
descending aorta
IRAD
In-hospital mortality for IMH according to site of origin
PENETRATING AORTIC ULCER
• Atherosclerotic lesion
penetrates internal elastic
lamina into media
• Associated with variable
degree of IMH
• May lead to
pseudoaneurysm
formation, aortic rupture, or
late aneurysm
• Range from 5 mm to 25 mm
in diameter and 4 mm to 30
mm in depth
• More common in thoracic
and abdominal aorta
• 2% to 8% of acute aortic
syndrome
• 25% of PAUs are found
incidentally
• Typical symptoms include
acute chest or back pain,
similar to dissection
• Imaging show crater-like
outpouching with irregular
edges in setting of heavy
atherosclerosis
• 80% of patients have some
degree of IMH
• PAU may stabilize or lead to complications
including
• IMH
• Distal embolization
• Aortic rupture
• Pseudoaneurysm (contained rupture)
• Aortic dissection
• Saccular or fusiform aneurysm
Management
• Ascending PAUs are treated with surgical
resection
• Stable patients with type B PAUs medical
management, with strict follow-up and serial
imaging
• Rrefractory or recurrent pain have increased risk
of disease progression, rapid increase in aortic
dimension are at risk for rupture should be
treated surgically or with endovascular stent
grafts
Indications for surgery or endovascular therapy (imaging )
• Interval development of hemorrhage
• Periaortic hematoma
• Expanding pseudoaneurysm and rupture
• Increasing aortic wall thickness
• Ulcer craters more than 20 mm in diameter or 10 mm in depth
• Increasing aortic hematoma
• Increasing pleural effusion
• More aggressive approach to type B PAU than classic type B
dissection because of concern of increased risk of rupture
• Relatively focal aortic segment involved -suitable for endovascular
therapy
Recommendations
for Thoracic Stent
Graft Insertion
REFERENCES
•
•
•
•
•
•
•
•
•
•
The diagnosis and management of aortic dissection Sri G Thrumurthy, Alan Karthikesalingam,
Benjamin O Patterson, Peter J E Holt,Matt M Thompson BMJ | 14 JANUARY 2012 | VOLUME 344
Aortic dissection:Prompt diagnosis and emergency treatment are critical ALAN C. BRAVERMAN, MD
clevelandclinicjournalofmedicinevolume78•number10october2011
2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM Guidelines for the Diagnosis and
Management of Patients With Thoracic Aortic Disease Circulation April 6, 2010
Acute Aortic Syndromes Thomas T. Tsai, MD; Christoph A. Nienaber, MD; Kim A. Eagle,
MDCirculation. 2005;112:3802-3813
IRAD Registry JAMA February 16th 2000 ,vol 283 no,7
The INvestigation of STEnt Grafts in Aortic Dissection (INSTEAD) Trial Christoph A. Nienaber, MD,
PhD; etalCirculation. 2009;120:2519-2528
Management of Aortic Dissection----New classification and Mid-term results Dinghua Yi, et al,
Division of Cardiovascular Surgery ,Xijing Hospital, Xi’an, China
Thoracic Endovascular Aortic Repair (TEVAR)for the treatment of aortic diseases: a
positionstatement from the European Association for Cardio-Thoracic Surgery (EACTS)and the
European Society of Cardiology (ESC),in collaboration with the European Association of
Percutaneous Cardiovascular Interventions (EAPCI)†Martin Grabenwo¨ ger1, European Heart
Journal Advance Access published May 4, 2012
Braunwald's Heart Disease Ninth Edition
Hurst,s THE HEART 13TH edition
• (CAPTIVIA (NCT01181947) and VIRTUE
(NCT01213589)