Surgical Strategy for type A dissection

1. Surgical Management
Aortic Aneurysm & Dissection
Dicky Aligheri ,MD
National Cardiovascular Centre Harapan Kita
2014

2. Introduction
• Usually asymptomatic until complication-
imaging required for detection and monitoring
– Masking diagnostic (CAD, malperfusions)
• Identification of genetic alterations
– Potential for early detection
– Targeted therapy

3. • Aneurysm:permanent localized dilatation of
an artery with at least 50% increase in
diameter compared with the expected normal
diameter.Covered by all 3 layers
• Aortic dissection:disruption of media layer of
aorta with bleeding within and along the wall
of aorta

10. Class I rec.for medical management
• i.v beta blockade titrated to HR<60/min
• CCB alternative if beta blocker contra.
• After HR controlled,i.v vasodilators to reduce
B.P to a level that maintains organ perfusion
• Beta blocker used cautiously in setting of a/c
AR
• Vasodilator should not be given prior to rate
control(classIII)

11. Recommendation for definitive
management(classI)
• Ascending aorta involved-emergent surgical
repair
• Desc. Aorta involved-managed medically
unless lifethreatening complications
– Malperfusion syndrome
– Progression of dissection
– Enlarging aneurysm
– Inability to control BP or symptoms

12. Recommendations for surgical
management(classI)
• Ascending ao.dissection-aneurysmal aorta and
proximal extent of dissection should be resected
• Prtially dissected root-repaired with valve
resuspension
• Extensive dissection of aortic root-aortic root
replacement with a composite graft or with a
valve sparing root replacement
• DeBakey type II-entire dissected aorta should be
replaced

13. • Use of beta blockers slowed aortic root
dilatation(Shores J et al;nejm 1994,Ladouceur M
et al;Am J Cardiol 2007)
• Beta blockers reduced aortic dilatation in c/c type
B dissection(Genoni M et al;2001)
• ACEI perindopril-reduced aortic root dilatation in
marfans(Ahimastos AA et al;JAMA2007)
• ARB-reduced aortic root dilatation in Marfans
syn(Brooks BS et al;nejm2008)
• Statin use a/w decreased long term mortality in
abd aortic aneurysm(Diehm N et al;2008)

14. Thoracic aortic aneurysms
• Rec.for medical Rx:classI
– Antihypertensives to a goal<140/90(goal<130/80 for
DM&CKD)
– Beta blocker in Marfans syn.&aortic aneurysm
– Smoking cessation
• classIIa-
– Reduce B.P to the lowest point pt can tolerate with
beta blocker and ACEI or ARB
– ARB (losartan) for pt with Marfans syn.
– Treatment with statin to target LDL-C<70mg%

15. Surgical management-asymptomatic
pt.(classI)
• Ascending aortic aneurysm degenerative
etiology-surgical repair if diameter>5.5cm
• Genetic syn.-elective surgery at diameter 4.0
to 5.0 cm
• Growth rate>0.5cm/yr
• Patients undergoing AVR at a diameter>4.5cm

16. Rec.for surgery-classII a
• Genetic syn.-ratio of aortic root
area(cm²)devided by height (m)>10-surgery
indicated
• Loeys Diets syn,TGFBR1&2 mutation-diameter
>4.2 by TEE,or >4.4 by CT or MRI

17. Recommendations for desc.thoracic
aorta(classI)
• Endovascular stent grafting-
– Degenerative or traumatic aneurysm>5.5cm
– Saccular aneurysm
– Post op.pseudoaneurysm
• Open repair
– c/c dissection
– a/w connective tissue d/s
– Desc.thoracic aorta>5.5 cm

19. Organ protection
• Class II a-
– deep hypothermic circulatory arrest for brain
protection
– Optimisation of spinal cord perfusion pressure and
moerate systemic hypothermia
• Class II b-preop.hydration and intra
op.mannitol for preservation of renal fn
during open repairs of desc.aorta

24. Mortality risk
• Composite valve graft,AVR with asc.aortic
repair-1-5%
• Valve sparing aortic root reconstruction-less
than1.5%
• BAV &asc.aorta repair-1.5%
• a/c AoD-3.5-10%
• Total arch replacement-2-6%mortality,2-7%
risk of stroke

25. CT
• Advantages
– Availability
– Entire aorta imaged
– Short time
– Branch vessel invt.
• Ecg gating,MDCT

26. Acute aortic syndromes
• Consists of 3 conditions-aortic
dissection,IMH,PAU
• 15% of AoD have an IMH without an intimal
tear
• Incidence 2-3.5/1,00,000 person years
• Mean age of presentation 63yrs
• Male predominance-65%

27. • Acute dissection-within 2 weeks of onset of
pain
• Subacute-b/w 2-6wks
• Chronic->6 wks

28. • DeBakey classification:
– Type I: Dissection originates in Asc.aorta and
propagates to include at least the aortic arch
– Type II: Dissection originates in and confined to the
Asc.aorta
– Type III: Dissection originates in the desc.aorta and
propagates most often distally
• Stanford classification system
– Type A:dissections involving the asc.aorta regardless
of the site of origin
– Type B:dissections that do not involve the asc.aorta

29. Evaluation
• High risk conditions-(class I)
– Genetic syndromes like Marfan syn.,Ehlers-Danlos
– Connective tissue diseases
– F/h of aortic dissection
– Known aortic valve disease
– Recent aortic manipulation
– Known aortic aneurysm

30. • High risk pain features(classI)
– Chest,back or abdominal pain
– Abrupt in onset
– Severe intensity
– Ripping,tearing,stabbing or sharp

31. • High risk exam features(classI)
– Pulse deficit
– Syst.BP limb diff.>20mmHg
– Focal neurological deficit
– Murmur of AR(new)
– shock

33. Recommendations for screening
tests(classI)
• STEMI in ECG should be treated as primary
cardiac event without delay for aortic imaging
unless pt. is high risk
• Low and intermediate risk patients should be
screened by CXR-
– Findings s/o aortic d/s-definitive aortic imaging
– Alternate diagnosis-manage accordingly
• High risk patients should directly undergo TEE,CT
or MRI
• Class III- negative CXR should not delay definitive
aortic imaging in high risk pt

34. Diagnostic imaging studies(classI)
• Selection of imaging modality based on pt
variables and institutional capabilities
• If high clinical suspicion exists in spite of
negative initial imaging a second study should
be performed

35. Recommendations for management
• BP mesured in both arms-treatment strategy
based on highest reading
• Patient not in shock-i.v drugs for rate and B.P
control

37. Class IIa
• IMH-treated similar to aortic dissection in the
corresponding segment

38. • Endovascular interventions-not approved for
dissection involving asc.aorta or arch
• Intimal defect without IMH-
– Asc.aorta-emergency surgery
– Desc.aorta-endograft
• Intimal defect with IMH
– Stable pt-delay def.Rx until IMH resorbs
– Desc.aorta-endovascular Rx

41. • Patients with symptoms s/o expansion of
aneurysm-prompt surgical intervention(classI)
• Endovascular stent grafts have not been
approved by the US FDA for treatment of
aneurysms or other conditions of asc. aorta.

42. Rec.for open surgery(asc.aortic
aneurysm)-class I
• Separate valve and asc.aortic replacement in
patients without significant root dilatation
• Patients with significant root dilatation-
excision of sinuses&modified David
reimplantation or root replacement with
valved graft conduit

43. Rec. for arch aneurysms-classII
• Partial arch replacement-asc.aortic aneurysm
involves proximal arch
• Replacement of entire aortic arch-
– A/c or c/c dissection in an aneurysmal arch
– Aneurysm of entire arch
– Distal arch aneurysm that involves prox.desc.aorta
– Asymptomatic pts. With diameter>5.5cm
• Annual reimaging-aneurysms<4cm
• Endovascular stent graft not approved

44. • Thoraco abdominal aneurysm-surgery when
diameter >6cm
• End organ ischemia-additional
revascularisation procedure recommended

45. Recommendations for genetic syn.
• classI-
– Marfan syn.-echo to assess aortic root and asc.aorta at
diagnosis &6 months after to determine rate of growth
• Annual imaging if stable and <4.5cm
• More frequent imaging otherwise
– Loeys-Dietz syn,other gen. mutations –complete aortic
imaging at diagnosis,6months
– Loeys-Dietz syn-annual MRI from cerebrovasc.circulation
to pelvis
– Turner syn-imaging at diagnosis for BAV,CoA,dilatation of
asc.aorta.
• If any abnormalities-annual imaging
• Otherwise-repeat 5 to 10yr

46. • Class IIa
– Marfan syn planning pregnancy-replacement of
aortic root and asc.aorta if >4.5cm

48. Recommendations for familial thoracic
aortic aneurysms
• ClassI
– Aortic imaging for first degree relatives of pts with
thoracic aortic aneurysm or dissection
– If a mutant gene a/w aneurysm identified-first
degree relatives should undergo genetic
screening-those with genetic mutation undergo
imaging

49. • classIIa
– If one or more first degree relatives of a patient
affected-imaging of second degree relatives
– Sequencing of ACTA2 gene in patients with f/h of
thoracic aortic aneurysm or dissection

51. Recommendations for BAV
(class I)
• First degree relatives of pts with
BAV,premature onset of thoracic aortic
d/s,familial form of aortic aneurysm and
dissection-should be evaluated for presence
of BAV&aortic d/s
• All pts with BAV should be evaluated for aortic
dilatation

52. Recommendations for takayasu
arteritis &GCA(classI)
• Initial evaluation should include CT or MRI of
thoracic aorta and branches
• Initial therapy-corticosteroids at high dose
• Periodic evaluation-physical examination&ESR
or CRP
• Elective revasc.after a/c inflammatory state is
quiescent
• Class II a –use of anti inflammatory agents

53. Recommendations in pregnancy
• classI
– Marfans syn and aortic d/s-counselled about risk
of dissection,heritable nature
– Strict BP control for pts with predisposition to
dissection
– Aortic root or asc.aortic dilatation-monthly echo
– Arch,descending or abd.aortic dilatation-MRI

54. • ClassIIa
– CS for pts with significant aortic dilatation
• Class IIb
– If progressive aortic dilatation-prophylactic
surgery recommended

55. Aortic dissection in pregnancy
• Type A-
– 1st
or 2nd
TM-urgent surgical repair and fetal
monitoring
– 3rd
TM-urgent CS f/b aortic repair
• Type B-medical therapy preferred

56. Aortic arch atheroma
• classIIa-Rx with a statin
• Class IIb-oral anticoagulation with warfarin or
antiplatelets in stroke pts with atheroma≥ 4
mm

57. Pre op evaluation for CAD
• Class I-
– thoracic aortic d/s undergoing intervention-evaluated
for CAD
– unstable cor syn-undergo revascularisation prior to at
time of aortic surgery or intervention
• classIIa-
– Asc.aortic or arch d/s undergoing surgery-
concomitant CABG for stable significant CAD
• Class IIb-
– Descending thoracic aortic d/s-stable significant CAD-
benefits not certain