Surgical ManagementAortic Aneurysm & Dissection

Dicky Aligheri ,MDNational Cardiovascular Centre Harapan Kita

2014

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

• 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

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)

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

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

• 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)

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%

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

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

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

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

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

CT

• Advantages – Availability– Entire aorta imaged– Short time– Branch vessel invt.

• Ecg gating,MDCT

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%

• Acute dissection-within 2 weeks of onset of pain

• Subacute-b/w 2-6wks• Chronic->6 wks

• 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

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

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

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

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

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

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

Class IIa

• IMH-treated similar to aortic dissection in the corresponding segment

• 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

• 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.

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

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

• Thoraco abdominal aneurysm-surgery when diameter >6cm

• End organ ischemia-additional revascularisation procedure recommended

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

• Class IIa– Marfan syn planning pregnancy-replacement of

aortic root and asc.aorta if >4.5cm

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

• 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

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

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

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

• ClassIIa– CS for pts with significant aortic dilatation

• Class IIb– If progressive aortic dilatation-prophylactic

surgery recommended

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

Aortic arch atheroma

• classIIa-Rx with a statin• Class IIb-oral anticoagulation with warfarin or

antiplatelets in stroke pts with atheroma≥ 4 mm

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