annual meeting of rcst kittichai luengtaviboon m.d. king chulalongkalongkorn memorial hospital 16...

Annual meeting of RCST

Kittichai Luengtaviboon M.D.King Chulalongkalongkorn Memorial Hospital16 July 2011

Aortic dissection – what is the current situation?

• Still one of the most leathal disease of the aorta.

• Acute type A aortic dissection is a surgical disease.

• Acute type B is medical disease unless it is complicated.

Acute type A aortic dissection

• Diagnosis – markers-plassma smooth muscle heavy chain myosin, D-dimer, CRP –diagnostic promise but lack of large prospective studies.

• Extent of surgical management

definition

• Disruption of medial layer of aorta with bleeding within, resulting in separation of the layers of the wall

• Intimal tear is present in 90%

• This may rupture through adventitia or back through the intima into the lumen.

• Non invasive imaging, IMH is present in 15%

• In autopsy only 4% did not have intimal tear

Cardiac complications

• 1. acute aortic valve regurgitation

• 2. myocardial ischemia and infarction

• 3. pericardial effusion and tamponade

Extent of surgical management of acute type A aortic dissection

• Proximal part or aortic root : aortic commissure resuspension if not severely involved not annulo aortic ectasia otherwise replacement = modified Bentall’s operation aortic valve sparing = David’s reimplantation• Distal part or aortic arch ascending aorta replacement with aortic cross clamping aortic arch replacement hemiarch total arch with elephant trunk frozen elephant trunk

Surgical principle

• Remain the same :

resection of the intimal tear

obliteration of false lumen

replace aorta with prosthetic vascular graft

resuspension of aortic commissures

Result of surgical repair of aortic dissection

• In experienced center, mortality is 3.5-10%, but much higher overall.

• Causes of death- stroke, mesenteric ischemia, renal failure and myocardial ischemia.

Aortic dissection type B

• Phases

acute within 14 days

subacute from 14 days to 2 months

chronic after 2 months

behave like aneurysm

rupture is the risk

malperfusion is rare

Natural history of acute type B dissection

• Not as lethal as acute type A aortic dissection

• 85% of patients will be successfully managed medically.

• Only 15% require interventional or surgical treatment

• The most common indications are

aortic rupture – pain, hemothorax, frank rupture with shock

malperfusion syndrome

abdominal

lower extremity

spinal cord

• Patients with complicated acute type B aortic dissections have a very high (>50%)likelihood of dying and require emergency surgical or interventional treatment

Svensson et al

Expert concensus document

Ann Thorac Surg 2008;85:S1-41

Clinical profiles and outcomes of acute type B aortic dissection in the current era: Lessons from the International Registry of Aortic Dissection (IRAD)

• Toru Suzuki, et al• Circulation 2003;108;II-312-II-317. 384patients (65 +- 13 years, male 71%) with acute type B aortic dissection in hospital mortality 13% most death occurred within the first week. factors associated with increased in hospital mortality on univariate analysis

were hypotension/ shock widened mediastinum periaortic hematoma excessive dilated aorta >6cm inhospital complications of coma, altered consciousness,

mesenteric/limb ischemia, acute renal failure, and surgical management.

• Branch vessel involvement or malperfusion was an independent predictor of early death, odd ratio = 2.9

• Options for type B malperfusion are open surgical repair percutaneous fenestration + bare metal stenting to create

a reentry tear TEVAR to cover the primary tear will reverse dynamic

obstruction• The early mortality for those requiring operative repair

ranges from 18% to 36%.

Management of malperfusion syndrome

• What is the mechanism?

dynamic – high pressure in false lumen with collapse of true lumen ( due to lack of re entry intimal tear)

- aortic fenestration – open vs balloon is treatment of choice

- some groups recommend TEVAR to prevent flow into false lumen

Dynamic obstruction

• Static malperfusion

aortic branch stenting is treatment of choice

extra anatomical bypass is the alternative.

Static obstruction

Results of a new surgical paradigm: endovascular repair for acute complicated type B aortic dissection

• Wilson Y Szeto, et al U. of Pennsylvania• Ann Thorac Surg 2008;86:87-94 from 2004-2007 35 patients with acute complicated type B aortic

dissection were treated with TEVAR 18 (51.4%) for rupture 17 (48.6% )for malperfusion – mesenteric or renal 5 lower extremities 3 both 9 in malperfusion group distal adjunct to expand the true lumen include infrarenal aortic stent 4 mesenteric/renal stent 4 iliofemoral stent 7

• Results

technical success (coverage of primary tear) was achieved in 34 (97.1%)

coverage of left subclavian 25 (71.4%)

30 day mortality = 2.8%

stroke = 2.8%

spinal cord ischemia 5.7% - transient 2.8% permanent

vascular access 14.2%

Treatment for malperfusion syndrome in acute type A and B aortic dissection: A long term analysis

G Michael Deeb, Himanshu J. Patel, David M WilliamsU of MichiganJ Thorac Cardiovasc Surg 2010;140:S98-S100. Malperfusion – adverse risk factor for survival in both type a and b dissection 1/3 of acute type A, if delayed diagnosis with organ failure -> aortic repair has poor outcome treated malperfusion first = overall mortality 25% including a 15%mortality from rupture. ( compared to 89% of historical control)

• 196 patients with acute type A dissection, 70 with organ malperfusion and end organ dysfunction

percutaneous end organ reperfusion and medical stabilization, followed by surgical repair

95% success rate in opening obstructed vessel percutaneously

38% died before surgical repair 19% of rupture 19% of malperfusion complication126 patients without malperfusion or end organ dysfunction ->

early operative mortality = 9.5%

Endovascular technique for acute type B aortic dissection

• Meta analysis of 39 studies 609 patients with type B dissection procedure success 98% major complications 21% in acute 9.1% in chronic mortality 5.2%

Eggebrecht, H, Eur Heart J 2006;27:489.

• TEVAR for acute dissection with malperfusion 90% success excluding the entry tear and reestablishing perfusion 20% mortality 30% complication• Long term results for percutaneous fenestration with bare metal

stenting to recreate a reentry tear and establish reperfusion in acute type B dissection with malperfusion

69 patients technical success rate 96% 17% mortality, 7% from false lumen rupture, 10% of malperfusion

syndrome complication 1 yr survival 76%, 5 yr survival 65% freedom from open repair or rupture at 1 yr = 80%, 5 yr = 55%

Management of ruptured acute dissection type B

• The most common site of rupture is at the intimal tear ( proximal descending aorta)

• Options of treatment

1- TEVAR

principle of treatment

coverage of intimal tear with stent graft

reexpansion of true lumen

aortic remodelling with healing of false lumen.

Endovascular treatment of acute type B aortic dissection

• Stent graft

• Stent

• composite

2- Open repair for acute type B dissection with rupture

• Principle of open repair for acute type B dissection

resect intimal tear and segment of descending aorta prone to rupture or has ruptured

obliteration of proximal and distal false lumen

direct flow into true lumen only

usually replace proximal ½ or ¾ of descending aorta

• Incision – left thoracotomy

• Technique- under deep hypothermia with circulatory arrest

Type B aortic dissection

• Medical management hospital mortality 10-15% survival at 1 yr 73% 5 yr 58% Surgical treatment hospital mortality 28-65% paraplegia 30-36% survival at 1 yr 48% 5 yr 29%Elefteriades JA, Ann Thorac Surg 1999;67(6):2002

Thoracic Endovascular aortic repair for acute complicated type B aortic dissection: superiority relative to conventional open surgical and medical therapy

• Ahmad Zeeshan, et al• J Thorac Cardiovasc Surg 2010;140:109-1152002-2010 170 patients with type B dissection, U of Pennsylvania data

base – 147 acute – 70 uncomplicated , 77 complicated group A – endovascular repair =45 group B – surgical treatment = 20 (mostly resection of aorta under

DHCA) medical treatment = 12Mortality 30 day A = 4%, B surgical = 40% and medical 33%Survival 1,3,5 yrs A = 82,79, 79% vs B = 58, 52, 44%

Society of Thoracic Surgeons Recommendations

for Thoracic Stent Graft Insertion (summary)Entity/Subgroup Classification Level of Evidence

Penetrating ulcer/intramural hematoma

Asymptomatic III C

Symptomatic IIa C

Acute traumatic I B

Chronic traumatic IIa C

Acute Type B dissection

Ischemia I A

No ischemia IIb C

Subacute dissection IIb B

Chronic dissection IIb B

Degenerative descending

>5.5 cm, comorbidity IIa B

>5.5 cm, no comorbidity IIb C

<5.5 cm III C

Arch

Reasonable open risk III A

Severe comorbidity IIb C

Thoracoabdominal/Severe comorbidity IIb C

Note: Table 15 in full-text version of TAD Guidelines. Reprinted from Svensson et al. Expertconsensus document on the treatment of descending thoracic aortic disease using endovascular stentgrafts. Ann Thorac Surg. 2008;85:S1– 41.

Chronic type b dissection

• Although primary medical therapy for uncomplicted type B dissection may improve hospital survival, it has NOT changed long term survival.

• Most deaths are related to comorbid conditions.• Late complications from distal aortic dissection are estimated

to occur in 20-50% of patients.• The sequelae include new dissection rupture of a weak false channel most commonly saccular or fusiform aneurysmal degeneration

of the thinned walls of the false channel.

• Growth rate of chronically dissected distal aorta = 0.1-0.74 cm per year.

strongly dependent on initial diameter of aorta after dissection and control of hypertension

• Genoni freedom from aortic events at a mean of 4.2 years was 80% in those treated with beta blocker VS 47% in those treated with other antihypertensive regimens.

• False lumen patency due to presence of distal fenestrations

thrombosis of false lumen may be associated with a slower rate of aortic growth – controversial.

Chronic dissection type B

• Same principle of treatment as degenerative descending thoracic aortic aneurysm , BUT

more likely to rupture, indication for surgery at diameter 5.5 cm. almost always required replacement from distal aortic arch to

lower descending or thoraco abdominal aorta common technique is via left thoraco abdominal incision under

DHCA distal anastomosis to aorta with diameter < 4 cm. resect dissecting membrane distally to perfuse both lumina remove clots from false lumen distally

• This principle of open repair allows removal of the portion of aorta at risk of rupture, but does not eliminate risk of subsequent aneurysmal degeneration of the residual distal aortic false lumen.

• Nienaber reported results of stent graft in subacute and chronic type B dissection in 1999.

• The rationale is covering the primary intimal tear with stent graft promotes false lumen thrombosis and subsequent aortic remodelling by eliminating antegrade (or occasionally retrograde) flow into the false lumen.

• Based on the INSTEAD (Investigation of STEnt grafts in patients with type B Aortic Dissection) study, it appears that stent-graft treatment of patients with chronic aortic dissection offers no benefit in terms of reducing the risk of aortic rupture or enhancing life expectancy.

• Regardless of the approach used, as long as patients have residual dissected aorta, they remain at risk for late aneurysmal degeration and rupture of the false lumen and require indefinite serial imaging surveillance, close blood pressure monitoring and negative inotropic medication.

Applying Classification of Recommendations and Level of Evidence

Level A: Data derived from multiple randomized clinical trials or meta-analyses

Multiple populations evaluated;

Level B: Data derived from a single randomized trial or nonrandomized studies

Limited populations evaluated

Level C: Only consensus of experts opinion, case studies, or standard of care

Very limited populations evaluated

Level of Evidence:

Class I Benefit >>> Risk

Procedure/ Treatment SHOULD be performed/ administered

Class IIa Benefit >> RiskAdditional studies with focused objectives needed

IT IS REASONABLE to perform procedure/administer treatment

Class IIb Benefit ≥ RiskAdditional studies with broad objectives needed; Additional registry data would be helpful

Procedure/Treatment MAY BE CONSIDERED

Class III Risk ≥ BenefitNo additional studies needed

Procedure/Treatment should NOT be performed/administered SINCE IT IS NOT HELPFUL AND MAY BE HARMFUL

2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM Guidelines for the Diagnosis and Management of Patients with Thoracic Aortic Disease

Developed in partnership with the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, American Association for Thoracic Surgery, American College of Radiology, American Stroke Association, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of Thoracic Surgeons, and Society for Vascular Medicine.

Endorsed by the North American Society for Cardiovascular Imaging.

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 Features

Chest, 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.

2


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

Recommendations for Estimation of Pretest Risk of Thoracic Aortic Dissection

Patients presenting with sudden onset of severechest, back, and/or abdominal pain, particularly those less than 40 years of age, should be questioned about a history and examined for physical features of Marfan syndrome, Loeys-Dietz syndrome, vascular Ehlers-Danlos syndrome, Turner syndrome, or other connective tissue disorder associated with thoracic aortic disease.

III IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIII IIaIIaIIa IIbIIbIIb IIIIIIIIIIIaIIaIIa IIbIIbIIb IIIIIIIII

Recommendations for Estimation of Pretest Risk of Thoracic Aortic Dissection

III IIaIIaIIa IIbIIbIIbIIIIIIIIIIII IIaIIaIIa IIbIIbIIbIIIIIIIIIIII IIaIIaIIa IIbIIbIIbIIIIIIIIIIIaIIaIIa IIbIIbIIbIIIIIIIII

III IIaIIaIIa IIbIIbIIbIIIIIIIIIIII IIaIIaIIa IIbIIbIIbIIIIIIIIIIII IIaIIaIIa IIbIIbIIbIIIIIIIIIIIaIIaIIa IIbIIbIIbIIIIIIIII In patients with suspected or confirmed aortic dissection who have experienced a syncopal episode, a focused examination should be performed to identify associated neurologic injury or the presence of pericardial tamponade.

All patients presenting with acute neurologic complaints should be questioned about the presence of chest, back, and/or abdominal pain and checked for peripheral pulse deficits as patients with dissection-related neurologic pathology are less likely to report thoracic pain than the typical aortic dissection patient.

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 (outlined in more detail in the following slides).

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

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

Expedited aortic imaging

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


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


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.



Recommendations for Diagnostic Imaging Studies

Selection of a specific imaging modality to identify or exclude aortic dissection should be based on patient variables and institutional capabilities, including immediate availability.

If a high clinical suspicion exists for acute aortic dissection but initial aortic imaging is negative, a second imaging study should be obtained.



Recommendations for Initial Management

a. In the absence of contraindications, intravenous beta blockade should be initiated and titrated to a target heart rate of 60 beats per minute or less.

b. In patients with clear contraindications to beta blockade, nondihydropyridine calcium channel–blocking agents should be used as an alternative for rate control.



Initial management of thoracic aortic dissection should bedirected at decreasing aortic wall stress by controlling heartrate and blood pressure as follows:

Recommendations for Initial Management (continued)

c. If systolic blood pressures remain greater than 120mm Hg after adequate heart rate control has been obtained, then angiotensin-converting enzyme inhibitors and/or other vasodilators should be administered intravenously to further reduce blood pressure that maintains adequate end-organ perfusion.

d. Beta blockers should be used cautiously in the setting of acute aortic regurgitation because they will block the compensatory tachycardia.



Recommendations for Initial Management (continued)

Vasodilator therapy should not be initiated prior to rate control so as to avoid associated reflex tachycardia that may increase aortic wall stress, leading to propagation or expansion of a thoracic aortic dissection.


Acute AoD Management Pathway

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 expedited

operative 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 or

interventional

management

Yes

NoEtiology of hypotension Amenable to operative

management?

Operative or

interventional

management

Yes

Recommendations for Definitive Management (continued)

Acute thoracic aortic dissection involving the descending aorta should be managed medically unless life-threatening complications develop (ie, malperfusion syndrome, progression of dissection, enlarging aneurysm, inability to control blood pressure or symptoms).


Guidelines for Thoracic Aortic Disease

Recommendation for Intramural Hematoma Without Intimal Defect

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 IIaIIbIII

Male 76 with Pau of arch and IMH of ascending and severe TVD.


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

annual meeting of rcst kittichai luengtaviboon m.d. king chulalongkalongkorn memorial hospital 16...

Documents

aortic root

aortic dissection proximal

rare slide

tamponade slide

aortic rupture pain

aortic commissure resuspension

intimal tear slide

annulo aortic ectasia