Acute aortic syndrome: Imaging & endovascular

treatmentVesna Đurović Sarajlic

Clinic of Radiology

University Clinical Center Sarajevo

BCR 2017, Budapest , Hungary

The term “AAS” was first introduced into the literature in

1998 to describe a variety of acute aortic pathologies:

• Aortic dissection (AD)

• Intramural hematoma (IMH)

• Penetrating ulcer (PAU)

• Clinically usually indistinguishable

• They are interrelated, and one condition may evolve into

another, or coexists with another

IMH � AD

PAU � AD

The common denominator of AAS is disruption of the media layer of the aorta

Clinical signs and symptoms

• Sudden onset of tearing and ripping chest, neck or back pain

• Pulse differences

• Acute congestive heart failure

• Neurological deficit

• Abdominal pain

• Shock

• Multi - detector CTA is the modality of choice in AAS

Sensitivity up to 100%, specificity of 98 – 99%

I. Non CE phase

II. CE arterial phase (with ECG gating)

III. CE delayed phase

• TTE & TEE in unstable patients (aortic valve insufficiency,

pericardial effusion..)

• Magnetic resonance and catheter angiography are seldom

used in acute conditions

Aortic dissection

• Represents the majority of the AAS

• Prevalence 10 – 30/million/ year, twice that of AAA rupture

• Male predominance, but in women has a higher mortality rate

• Ascending aorta app. 60%, descending aorta app. 40%

• > 40 y, hypertension

Risk factors

• Congenital & hereditary

Bicuspid aortic valve, coarctation, Connective tissue disorders

Marfan syndrom, Ehl. Danlos , policystic kidney disease

• Acquired

hypertension

aneurysms, atherosclerosis

• Iatrogenic

cardiac surgery, wires and catheter caused

• Other conditions

smoking, dyslipidemia, cocain and amphetamine abuse

Classification systems for AD

• Stanford classification (extension of dissection):

Stanford type A – Affects Ascending Aorta

Stanford type B – Distal to the left subclavian artery

• DeBakey classification (location of the entry tear):

DeBakey type I – ascending & descending aorta

DeBakey type II – ascending aorta

DeBakey type III – descending aorta

Stanford A Stanford B

• There is no consensus about

the classification of arch AD

without involvement of the

ascending aorta

ESVS Guidelines Descending Thoracic

Aorta

Diagnostic features of AD:

Intimomedial flap and double lumen

True lumen

• Smaller

• Brighter in the arterial phase

• Outer wall calcification

False lumen

• Larger (as more pressurized)

• Wrapping at the level of the

aortic arch

• Thrombosis

Intimomedial flap Double lumen

Coronal plane VR reconstruction

What do we report in AD?

• Primary entry tear

• Re - entry tear

• Complications:

- malperfusion of the aortic branches

- pericardial effusion & tamponade

- rupture

Stanford A Stanford B

63-year old female, hypertension, chest pain, weaknes in the left hand, confusion

Brain malperfusion – bad prognostic factor

68 year-old male, chest pain, left arm and left leg pulse deficite

Right kidny and left leg malperfusion

53 year female, hypertensive crisis, sudden onset of back pain

Intramural hematoma IMH

A hematoma within the aortic wall

• without intimomedial flap

• no visible intimal tear

• no flow in hematoma

- The classical theory of

pathogenesis of IMH is that of

“rupture of the vasa vasorum”

• Incidence – app. 12% of all suspected AAD cases are IMH

(IRAD)

• A significant number of IMH will progress to plain dissection

• Up to 10% of IMH will resolve spontaneously

• The higher incidence in Asians than in Europeans and

Americans

Diagnostic feature and classification

• > 0.5mm crescentic or

circular thickening of the

media, hyperdense on the

non CE scans

• Stanford classification to

IMH type A and type B

IMH vs. AD

• Descending aorta

• Older patients

• Rupture is more frequent

• No compression of the

lumen

• No involvement of the

branch arteries

• Ascending aorta

• Patients with Marfan Sy.

• Compression of the true

lumen

• Proximal and distal

malperfusion sindromes

• Longer lesions

Predictors of the adverse IMH outcome

• Age of the patient > 68y

• Location of the IMH –IMH type A

• Coexistance of PAU

• Hematoma thickness

> 10 mm

• Aortic diameter

> 50 mm

Penetrating atherosclerotic ulcer (PAU)

• Progressive erosion of an

atheromatous plaque that

penetrates the elastic lamina

into the aortic media

• It counts for 2- 7% of all

AAS

• Usually asymptomatic

• PAUs are closely associated with

atherosclerosis of the aorta

(hypertension, hyperlipidemia,

AAA)

• 85% -90% are located in the

descending aorta

• PAUs in the ascending aorta and the

arch are more prone to rupture

PAU type A PAU type B

Complications of PAU

PAU > 20 mm x 10 mm

increases the risk of :

• Hematoma formation

• Pseudoaneurysm

• Rupture

Treatment concepts in the ASCENDING thoracic aorta

• Surgical repair - AAS

involving ascending aorta

• Endovascularrepair - in the

early phase of application

Treatment concepts in the DESCENDING thoracic aorta

• Level A evidence does not exist in the management of DTA

• “Management of Descending Thoracic Aorta Diseases”

(Clinical Practice Guidelines of the ESVS 2017)

- offer the best medical evidence available and the best

consensus amongst key experts in the field

Uncomplicatedacute type B dissection

• Acute dissection- within the first 14 days after the onset of

symptoms

• Medical therapy with antihypertensive drugs is widely

accepted to be the first line treatment ( SBP 100-120; HR <60

beats/min)

• Adequate clinical and imaging surveillance (MR or CTA 3m,

6m, yearly)

TEVAR in Uncomplicatedacute type B AD “To treat or not to treat”

Pros

• To prevent late dilatation and

rupture of the aorta

• IRAD reported reduced mortality

in patients treated with TEVAR

(Fattori R at al, 2013)

• ADSORB study – increased false

lumen thrombosis and remodeling

of the aorta after TEVAR

(Brunkwall J at al, 2014)

Cons

• Complications of the

endovascular procedure

• Retrograde dissection of the aorta

• Stroke

• Spinal cord ischemia

• Paraplegia/ paraparesis

• Migration of the stent-graft

Selection of the patients

Radiologic pred. of growth

• One entry tear (ET) , the size

>10mm

• Entry tear at the concavity

• False lumen > 22 mm

• Eliptic true lumen and round false

lumen

• Early thoracic endografting may be considered selectively to

prevent aortic complications in uncomplicated acute type B

dissection, (recommendation 18, ESVS’ CPG)

• To facilitate the patient selection process, important clinical

and anatomical features were summarized in a new

categorization scheme DISSECT (M.Dake at al, 2013)

Complicated acute type B dissection

• Endovascular repair with thoracic endografting should be the first

line therapy (recommendation 16, ESVS CPG)

• Endovascular repair is associated with lower peri-operative

morbidity and mortality rate than OR (2,5 9,8% : 25-50% mortality rate)

• Technical success of TEVAR ranges from 95 to 99%, hospital

mortality from 2,6 to 9,8%, neurological complications from 0,6

to 3,1 % (6,96,97)

The goals of TEVAR are:

- Coverage of the primary

entry tear

- Decreased pressure in the

false lumen/ repressurisation

of the true lumen

- Reperfusion of branch

vessels

- Thrombosis of the false

lumen

• In complicated type B AD,

patients presenting with

malperfusion, experience the

poorest outcome

• Endovascular fenestrationshould

be considered in these patients to

treat malperfusion

(recommendation 17, ESVS CPG)

Acute type B IMH and PAU

• Uncomplicatedtype B IMH

and PAU should be treated

medically, followed by

serial imaging surveillance

(recommendation 20, ESVS CPG)

• Complicated type B IMH

and PAU should be treated

by endovascular approach –

TEVAR

(recommendation 21&22, ESVS CPG)

Future prospectives

• To assess the management controversies of uncomplicated acute

type B dissections, larger randomized controlled trias should be

conducted

• The timing of the procedure is of special interest in

uncomplicated type B aortic dissections

• Definition of early unfavourable clinical and imaging signs to

select the patients who would benefit the most from an early

TEVAR procedure