Large vessel disease

بسم الله الرحمن الرحيم

Large Vessel Disease

By

Ahmed Shafie AmmarMD, FACC

Aorta

Anatomy

Ascending, arch, descending thoracic, abdominal aorta

Aortic isthmus: arch-descending junction

Histology

Aortic Aneurysm

Epidemiology

Aneurysm rupture: 80% into left retroperitonium cavity

Most common site of AAA is infrarenal, because no vasa vasora in the media of this region

Types of aneurysm

AAAClinical presentation

• Pain: most common, at hypogastrium or back, not affected by movement

• Asymptomatic• Bruit (+/-)• Rupture triad:

♠ abdominal or back pain;

♠ palpable/ pulsatile abdominal mass;

♠ hypotension (<1/3 cases)

AAA

Beyond Grey Hair and Back Pain

Diagnosis & Screening

Essential Elements of Aortic Imaging Reports

1. The location at which the aorta is abnormal.

2. The maximum diameter of any dilatation, measured from the external wall of the aorta, perpendicular to the axis of flow, and the length of the aorta that is abnormal.

3. For patients with presumed or documented genetic syndromes at risk for aortic root disease measurements of aortic valve, sinuses of Valsalva, sinotubular junction, and ascending aorta.

4. The presence of internal filling defects consistent with thrombus or atheroma.

5. The presence of intramural hematoma (IMH), penetrating atherosclerotic ulcer (PAU), and calcification.

6. Extension of aortic abnormality into branch vessels, including dissection and aneurysm, and secondary evidence of end-organ injury (eg, renal or bowel hypoperfusion).

7. Evidence of aortic rupture, including periaortic and mediastinal hematoma, pericardial and pleural fluid, and contrast extravasation from the aortic lumen.

8. When a prior examination is available, direct image to image comparison to determine if there has been any increase in diameter.

Note: This is Table 5 in the full-text version of the TAD Guideline

AAAManagement

• Medications :

Control of hyperlipidemia, hypertension (β- blockers), cigarette smoking

• CT follow up every 3—6 months

• Surgical indication: >rupture;

>size >5.5 cm;

>expanding rapidly (>0.5 cm/year)

• Coronary angio (before surgery)

AAA Repair

• Two types of repair performed

OPEN ENDOVASCULAR

First performed 1951•Now involves placement of Dacron or PTFE graft•2-4% operative death rate, •5-10% complication rate

First performed 1991• Less invasive, done through femoral vessels• Only certain types of AAA can be repaired

Bifurcated Endograft Placement

Katzen, et al

Thoracic Aortic Aneurysms

Etiology

• Cystic medial degeneration

• Genetic

• Atherosclerosis

• Uncommon causes

Genetic Syndromes Associated With Thoracic Aortic Aneurysm and Dissection

Genetic Syndrome

Genetic

Common Clinical Features Defect Diagnostic Test Comments on Aortic Disease

Marfan syndrome

Skeletal features (see text);

Ectopia Lentis; Dural ectasia

FBN1 mutations*

Ghent diagnostic

criteria

DNA for

sequencing

Surgical repair when the aorta reaches 5.0 cm unless there is a family history of AoD at <5.0 cm, a rapidly expanding aneurysm or presence or significant aortic valve regurgitation

Loeys-Dietz syndrome

Bifid uvula or cleft palate;

Arterial tortuosity; Hypertelorism;

Skeletal features similar to MFS;

Craniosynostosis; Aneurysms

and dissections of other arteries

TGFBR2 or TGFBR1 mutations

DNA for

sequencing

Surgical repair recommended at an aortic diameter of ≥4.2 cm by TEE (internal diameter) or 4.4 to ≥4.6 cm by CT and/or MR (external diameter)

Ehlers-Danlos syndrome (vascular form)

Thin, translucent skin;

Gastrointestinal rupture; Rupture of

the gravid uterus; Rupture of

medium-sized to large arteries

COL3A1 mutations

DNA for

sequencing

Dermal fibroblasts

for analysis of

type 3 collagen

Surgical repair is complicated by

friable tissues

Noninvasive imaging recommended

Turner syndrome

Short stature; Primary amenorrhea;

Bicuspid aortic valve; Aortic

coarctation; Webbed neck, low-set

ears, low hairline, broad chest

45,X karyotype Blood (cells) for

karyotype analysis

AoD risk is increased in patients with bicuspid aortic valve, aortic coarctation, hypertension, or pregnancy

* The defective gene at a second locus for MFS is TGFBR2 but the clinical phenotype as MFS is debated. AoD = aortic dissection; COL3A1, type III collagen; FBN1, fibrillin 1; MFS, Marfan syndrome; TGFBR1, transforming growth factor-beta receptor type 1; and TGFBR2, transforming growth factor beta receptor type 2.

Note: Table 7 in full-text version of TAD Guidelines

Aortic Dissection

Epidemiology• 2-3X more in male• Majority between 50-70 years of age• Relatively rare before 40 y/o except in

association with : Marfan’s syndrome, Ehlers-Danlos syndrome, congenital heart disease, familial incidence, pregnancy, coarctation of aorta, Turner’s syndrome and trauma

• History of systemic hypertension occur in more than 2/3 of patients

Risk Factors for Development of Thoracic Aortic Dissection

Conditions Associated With Increased Aortic Wall Stress

• Hypertension, particularly if uncontrolled• Pheochromocytoma• Cocaine or other stimulant use• Weight lifting or other Valsalva maneuver• Trauma• Deceleration or torsional injury (eg, motor vehicle crash,

fall)• Coarctation of the aorta

Note: Information on this slide is adapted from Table 9 in full-text version of TAD Guidelines

Risk Factors for Development of Thoracic Aortic Dissection (continued)

Conditions Associated With Aortic Media Abnormalities Genetic

• Marfan syndrome• Ehlers-Danlos syndrome, vascular form• Bicuspid aortic valve (including prior aortic valve replacement)• Turner syndrome• Loeys-Dietz syndrome• Familial thoracic aortic aneurysm and dissection syndrome

Note: Information on this slide is adapted from Table 9 in full-text version of TAD Guidelines

Risk Factors for Development of Thoracic Aortic Dissection (continued)

Conditions Associated With Aortic Media Abnormalities (continued)

Inflammatory vasculitides• Takayasu arteritis• Giant cell arteritis• Behçet arteritis

Other• Pregnancy• Autosomal dominant polycystic kidney disease• Chronic corticosteroid or immunosuppression agent

administration• Infections involving the aortic wall either from bacteremia or

extension of adjacent infection

Note: Information on this slide is adapted from Table 9 in full-text version of TAD Guidelines 2010

Pathophysiology and pathoanatomy• Medial degeneration (cystic medial necrosis is no longer used) : a process

of degeneration characterized by loss of smooth muscle cells and elastic tissue that is accompanied by scarring, fibrosis, hyalin-like changes. > mechanism: medial degeneration, repeated flexion of the aorta,

and hydrodynamic stresses on the aortic intima, an aortic dissection occurs

• 2 important factors determine the continued dissection of aorta:

> degree of hypertension and

> the steepness (slope) of the pulse wave (dP/dT)

PAIn

Proximal Distal

Acute: less than 2 weeksChronic: more than 2 weeks

Physical Examination

– Pulse deficits and discrepancies in BP between limbs are key diagnostic clues

– Pulse deficits (50%)

– Aortic regurgitation (50%)

– Neurologic findings (20%): altered sensorium, hemiplegia, hemianesthesia, gaze preference to the affected side

Estimation of Pretest Risk of Thoracic Aortic Dissection

* Loeys-Dietz syndrome, vascular Ehlers-Danlos syndrome, Turner syndrome, or other connective tissue disease.

†Patients with mutations in genes known to predispose to thoracic aortic aneurysms and dissection, such as FBN1, TGFBR1, TGFBR2, ACTA2, and MYH11.

High Risk Conditions

• Marfan Syndrome• Connective tissue disease*• Family history of aortic disease• Known aortic valve disease• Recent aortic manipulation (surgical or catheter-based)• Known thoracic aortic aneurysm• Genetic conditions that predispose to AoD†

1


High Risk Pain FeaturesChest, back, or abdominal pain features described as pain that:• is abrupt or instantaneous in onset. • is severe in intensity. • has a ripping, tearing, stabbing, or sharp quality.•Patients are restless, cannot get comfortable

2

Anterior pain only: 90% ascendingInterscapular pain only: 90% descending


High Risk Examination Features

• Pulse deficit• Systolic BP limb differential > 20mm Hg• Focal neurologic deficit • Murmur of aortic regurgitation (new or not known to be old and in conjunction with pain)

3

Risk-based Diagnostic Evaluation:Patients with Low Risk of TAD

Patients with no high-risk features of TAD present are considered atlow risk for TAD. The following clinical steps are recommended for low-riskTAD patients:

Proceed with diagnosticevaluation as clinically

indicated by presentation.

Initiate appropriateTherapy.

Alternative diagnosisidentified?

Unexplainedhypotension or

widenedmediastinum on CXR?

Consider aortic imaging study for TAD based onclinical scenario (particularly in patients with advanced

age, risk factors for aortic disease, or syncope)

• TEE (preferred if clinically unstable)• CT scan (image entire aorta: chest to pelvis)• MR (image entire aorta: chest to pelvis)

Expedited aortic imaging

Yes

No

No

Yes

Yes

Risk-based Diagnostic Evaluation:Patients with Intermediate Risk of TAD

EKG consistentwith STEMI?

CXR with clearAlternate diagnosis?

History and physical exam stronglysuggestive of specific alternate diagnosis?

Initiate appropriate therapy.

Alternate diagnosis confirmed by further testing?

Likely primary ACS. In absence of otherperfusion deficits, strongly consider

immediate coronary re-perfusion therapy. IfPTCA performed, is culprit lesion identified?

The following steps for patients with intermediate risk of TAD should be followed when any single high-risk feature is present.

Yes

Yes

Yes

No

No

No


Expedited aortic imagingNo

Risk-based Diagnostic Evaluation:Patients with High Risk of TAD

Patients at high-risk for TAD are those that present with at least 2 high-risk features.

The recommended course of action for high-risk TAD patients is to seek immediate surgical consultation and arrange for expedited aortic imaging.


Expedited aortic imaging

Radiography (I)• Chest X ray

– mediastinal widening(75%)

– “calcium sign” -uncommon but highly specific, >5mm– double-density appearance of the aorta– a localized bulge along a normally smooth aortic contour– a disparity in the caliber between the descending and

ascending aorta– obliteration of the aortic knob– displacement of the trachea or nasogastric tube to the

right by the dissection– pleural effusions(left)

Radiography(II)

• Echocardiography– transthoracic approach: M-mode & 2-D=low

sensitivity and specificity– transesophageal = more accuracy and very

sensitive, can be done in ER (safer).

Radiography (III)

• Computed Tomography– dilatation of the aorta– identification of an intimal flap– differential rates of flow in true and false lumina– the clear demonstration of both the true and false lumina

Radiography(IV)• limitations of CT scan:

– no information about the presence of AR– no information about the relationship of the dissection to

the major branches of the aorta– time-consuming and requires the patient to be outside ER

• advantages over aortography:– greater contrast resolution and detects small or delayed

differences in the opacification of true and false channels– may be able to detect a thrombosed false lumen despite

nonopacification– does not require arterial catheterization

Radiology(V)• Aortography

– filling of a false channel or channels with or without an intervening intimal flap

– distortion of the true lumen by either a patent or thrombosed false lumen

– thickening of the aortic wall by more than 5-6 mm caused by a thrombosed false lumen

– displaced intimal calcification

Radiography(VI)• disadvantages of aortography:

– most invasive, most expensive– risks of intravenous contrast material– inadequate detection of pleural leak

• advantages of aortography:– accurate for determining the site of the initmal

tear and extent of the dissection– easily demonstrated aortic regurgitation– the only procedure that demonstrates the extent

and location of dissection into aortic side branches

Radiography(VII)

• Magnetic Resonance Imaging– shows the site of intimal tear, type and extent of

dissection, presence of aortic insufficiency, and differential flow velocities in the true and false channels and in the aortic side branches

• advantages:– no contrast material, no ionizing radiation,

noninvasive

Diagnostic Imaging

Recommendations for Screening Tests (continued)

Urgent and definitive imaging of the aorta using transesophageal echocardiogram, computed tomographic imaging, or magnetic resonance imaging is recommended to identify or exclude thoracic aortic dissection in patients at high risk for the disease by initial screening.

A negative chest x-ray should not delay definitive aortic imaging in patients determined to be high risk for aortic dissection by initial screening.

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http://content.onlinejacc.org/cgi/content/full/j.jacc.2010.02.015/DC1


Differential Diagnosis– Chest pain is the most common symptom in AD– Acute myocardial infarction

• pain is more typically pressurelike but may radiate to the arms or neck

• pain does not typically migrate over time

• CK-MB levels are elevated

– Pulmonary embolus• pain is generally respirophasic

• hypoxemia secondary to ventilation/perfusion mismatch

– Pericarditis• pain typically changes with position

• auscultation may reveal a pericardial friction rub

• EKG is common diagnostic(ST-segment elevation prominent in V5-6 and lead I)

Acute AoD Management Pathway

STEP 1: Immediate post-diagnosis management and disposition considerations

• Arrange for definitive management:– Appropriate surgical consultation– Inter-facility transfer if indicated based on institutional capabilities

• If transfer required, initiate aggressive medical management until transfer occurs.




STEP 2: Initial management of aortic wall stress

• Obtain accurate blood pressure prior to beginning treatment.

• Measure in both arms.• Base treatment goals on highest blood pressure

reading.

Rate/Pressure Control

Intravenous beta blockade or Labetalol

(If contraindication to beta blockadesubstitute diltiazem or verapamil)

Titrate to heart rate <60

1

Pain Control

Intravenous opiates

Titrate to pain control

Intravenous rate and pressure control

2

+

Hypotensionor shock state?

No

Yes

Systolic BP >120mm HG?

BP Control Intravenous vasodilator

Titrate to BP <120mm HG (Goal is lowest possible BP that maintains adequate end organ perfusion)

Secondary pressure control

3

Anatomic based management

Acute AoD Management Pathway STEP 2: Initial management of aortic

wall stress

Acute AoD Management Pathway STEP 2: Initial management of aortic wall stress

Anatomic based management

Urgent surgical consultation +

Arrange for expeditedoperative management

Intravenous fluid bolus•Titrate to MAP of 70mm HG or Euvolemia

(If still hypotensive begin intravenous vasopressor agents)

Review imaging study for:• Pericardial tamponade• Contained rupture• Severe aortic insufficiency

1

2

3

Type A dissection

Intravenous fluid bolus •Titrate to MAP of 70mm HG or Euvolemia

(If still hypotensive begin intravenous vasopressor agents)

Evaluate etiology of hypotension

• Review imaging study for evidence of contained rupture • Consider TTE to evaluate

cardiac function

Urgent surgical consultation

2

3

Type B dissection

1


STEP 3: Definitive management

• Depending on the results from the pressure control or anatomic based management, continued treatment will involve either:

– ongoing medical management, or

– operative or interventional management.

Acute AoD Management Pathway STEP 3: Definitive management

Based on results from intravenousrate and pressure control:

Based on results from anatomicbased management:

Dissection involving the ascending aorta?

Close hemodynamic monitoringMaintain systolic BP < 120mm Hg

(Lowest BP that maintainsend organ perfusion)

Ongoing medical management

Limb or mesenteric ischemiaProgression of dissection

Aneurysm expansionUncontrolled hypertension

Complications requiring operativeor interventional management?

Operative orinterventionalmanagement

Yes

NoEtiology of hypotension Amenable to operative

management?

Operative orinterventionalmanagement

Yes


STEP 4: Transition to outpatient management and disease surveillance

• If no complications present requiring operative or interventional management, transition to:

– Oral medications (beta blockade/ antihypertensives regimen)

– Outpatient disease surveillance imaging

Note: For full algorithm, see Figure 26 in full-text version of TAD Guidelines

Treatment(II)• Definite Therapy– Type A: acute aortic dissections require surgical

treatment– the only contradiction to immediate surgical repair of a

type A dissection is the simultaneous occurrence of a progressing stroke

– Type B : medical management mortality is 15-20%(same as surgery done)

– Surgery indications: persistent pain, uncontrolled hypertension, occlusion of a major arterial trunk, frank aortic leaking or rupture, or development of a localized anerysm.

– Chronic aortic dissection: control of blood pressure using beta-blocking agents(most common)

Acute Surgical Management Pathway for AoD

The following steps outline ascending TAD by imaging study.

STEP 1: Determine patient suitability for surgery

• If not suitable, begin medical management.

STEP 2: Determine stability for pre-op testing

• If not sufficiently stable, proceed with urgent operative management.


STEP 3: Determine likelihood of coexistent CAD

Is patient age >40?Assess need for

preoperative coronaryangiography

Plan for CABG ifappropriate at time

of AoD repair

• Known CAD? • Significant risk factors for CAD?

Significant CAD byangiography?

Urgent operativemanagement

Yes

Yes

Yes

No

No

No

Yes


STEP 4: Intra-operative evaluation of aortic valve

• Perform intra-operative assessment of aortic valve by TEE.

Aortic Regurgitation?or

Dissection of aortic sinuses?

Graft replacementof ascending aorta

+/- aortic archand

repair/ replacementof aortic valve

Graft replacementof ascending aorta

+/- aortic arch

STEP 5: Surgicalintervention

Yes No

Note: For full algorithm, see Figure 22 in full-text version of TAD Guidelines.

Aortic coarctation

Clinical Features

• c/o : headache, cold feet• o/e :

HPT,

vigorous carotid pulsations

week pulse in the LL

under sized LL relative to the UL

LVH

mid systolic murmur

Echo, CT, MRI > cofirm the diagnosis

Treatment of A. coarctation

• Balloon dilatation

• Stent implantation

• Surgical TTT

Acute aortic occlusion• Infrarenal aorta at bifurcation• Saddle embolus• Af / RHD, MI, DCM, aneurysm• Bilateral leg pain, weakness, numbness, paresthesia, • Cold, cyanosis, absent pulse, diminished or absent deep

tendon reflexes• Aortogram• Heparin, transcatheter, operation • life-long anticoagulant

Ahmed Shafea MD, FACC

Atypical aortic dissection

Intramural hematoma: • rupture of vasa vasorum,

• aortic dissection without intimal flap, • 10% type B dissection, • failed diagnosis in aortography, • high risk for aneurysm formation, • medication (distal) or surgery (proximal)

Recommendation for Intramural Hematoma Without Intimal Defect

It is reasonable to treat intramural hematoma similar to aortic dissection in the corresponding segment of the aorta.

I IIa IIb III

Atypical aortic dissection

Penetrating atherosclerotic ulcer: • old, hypertension• no false lumen, • Aortography is standard• no definite treatment

Aortic atheromatous disease

Aortic atherothrombotic emboli

• Age, hypertension, DM, hyperlipidemia, vascular disease

• Most common in descending thoracic aorta• Coumadin is for high risk patients to prevent

embolic event• Post-operative stroke

Cholesterol embolization syndrome

• Cholesterol crystal from ulcerated atheromatous plaques

• “blue-toe” or “purple-toe” syndrome

• Elevated ESR & eosinophil

• Reduced complement level

• No specific therapy

Primary tumor of aorta

• < 50 Cases

• Equal in thoracic and abdomen aorta

• Back pain

• Aortography, biopsy

• Prevent embolization

Ahmed Shafea MD, FACC

Peripheral artery diseases

< 60 y/o population: <3%> 75 y/o population: >20%

Peripheral artery diseases—risk factors


Peripheral artery diseasesIntermittent claudication: • pain, ache, fatigue, or discomfort in the affected leg

during exercise, particularly walking (oxygen demand)• resolved with rest within few minutes• Buttock, hip, thigh• Gastrocnemius muscle is most common• Walking Impairment Questionnaire

• Arterial embolism, vasculitis / arteritis, secondary compression, lumbar sacroradiculopathy (neurogenic pseudoclaudication, standing)


Rest pain• Inadequate blood flow• Skin fissure, ulceration, or necorsis• DM neuropathy or ischemic neuropathy


Physical examination:

• Absent pulse distal to the stenotic site

• Bruit of the stenotic site

• Muscle atrophy, hair loss, cool skin, poor healing, pressure sore,



Ankle/brachial index (ABI): • SBP ratio (normal: >=1)• ABI <0.9 : 95% sensitive for PAD• ABI 05—0.8 with claudication: critical limb ischemia• ABI <0.5 or ankle BP <55mmHG: poor ulcer healing

MR angiography: 95% sensitivity and specificity

Contrast angiography

Peripheral artery diseases—treatment

Risk factor modification

Control DM, HTN, smoking cessation

Antiplatelet therapy: ticlopidine, plavix

Exercise: improve maximal walking distance than PTA

Angioplasty / stents and surgery• Trental: RBC flexibility and anti-inflammatory• Pletal: unknown• Beta-blocker: controversial

Thromboangitis obliterans

• Young smokers

• Medium and smalll vessels of the arms

• Cause unknown? Type I and III collagen

• Pain, digit ulceration, Raynaud phenomenon

• Abnormal allen test (2/3)

• Tx: Cessation smoking, prostacyclin analogue,

Acute limb ischemia

• Arterial embolism (Af)

• thrombosis with plaque ruprure

• dissection,

• trauma

Health & Medicine

Large vessel disease