Thoracic Aortic Aneurysm and Dissection

15 Pages·2012·0.74 MB·English

JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY VOL. 64, NO. 16, 2014
ª2014 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION ISSN 0735-1097/$36.00
PUBLISHED BY ELSEVIER INC. http://dx.doi.org/10.1016/j.jacc.2014.08.025
THE PRESENT AND FUTURE
STATE-OF-THE-ART REVIEW
Thoracic Aortic Aneurysm and Dissection
JudithZ.Goldfinger,MD,*JonathanL.Halperin,MD,*MichaelL.Marin,MD,yAllanS.Stewart,MD,z
KimA.Eagle,MD,xValentinFuster,MD,PHD*
ABSTRACT
Aorticdissectionisthemostdevastatingcomplicationofthoracicaorticdisease.Inthemorethan250yearssince
thoracicaorticdissectionwasfirstdescribed,muchhasbeenlearnedaboutdiseasesofthethoracicaorta.Inthisreview,
wedescribenormalthoracicaorticsize;riskfactorsfordissection,includinggeneticandinflammatoryconditions;the
underpinningsofgeneticdiseasesassociatedwithaneurysmanddissection,includingMarfansyndromeandtheroleof
transforminggrowthfactorbetasignaling;dataontheroleformedicaltherapiesinaneurysmaldisease,including
beta-blockers,angiotensinreceptorblockers,andangiotensin-convertingenzymeinhibitors;prophylacticsurgeryfor
aneurysm;surgicaltechniquesfortheaorticroot;andsurgicalandendovascularmanagementofaneurysmanddissection
fordifferentaorticsegments. (JAmCollCardiol2014;64:1725–39)©2014bytheAmericanCollegeofCardiology
Foundation.
A
ortic dissection is the most devastating formedicaltherapiestolimitaneurysmgrowth.Sur-
complication of thoracic aortic disease. In gical therapies for aneurysm and dissection were
population-based studies, the annual inci- initially developed in the 1950s and have steadily
dence ranged from 6 cases per 100,000 in a British improved since then. More recently, endovascular
study (1), to 9.1 per 100,000 in women or 16.3 per techniquesanddevicesweredevelopedtotreataneu-
100,000 in men in a Swedish study that included rysms and dissections of the descending thoracic
national healthcare registry diagnoses and autopsies aorta.
for all out-of-hospital deaths (2). The first reported
case was King George II of Great Britain, who died AORTIC SIZE, ANEURYSM, AND DISSECTION
in1760ofpericardialtamponadeduetoacutedissec-
tionoftheascendingaorta,althoughtheterm“aortic AORTIC SIZE. Normal aortic diameter varies by age,
dissection” was not coined for another 40 years (3). sex,andmodality(4,5),increasingwithageandbody
Sincethen,muchhasbeenlearnedaboutriskfactors surface area (Figure 1). At a given age, men typically
for dissection, including aneurysmal disease and have larger aortas than women. Echocardiography,
genetic disorders, like Marfan syndrome, that in- computed tomography (CT) with contrast, and
crease risk for both aneurysm and dissection. An cardiac magnetic resonance (CMR) with gadoli-
animal Marfan syndrome model and later studies nium measure the internal diameter of the aorta,
of patients with Marfan syndrome provided data whereasnoncontrastCTandCMRgenerallymeasure
Fromthe*DepartmentofMedicine,DivisionofCardiology,ZenaandMichaelA.WienerCardiovascularInstituteandMarie-Josée
and Henry R. Kravis Center for Cardiovascular Health, Icahn School of Medicine at Mount Sinai, New York, New York;
yDepartment of Surgery, Division of Vascular Surgery, Icahn School of Medicine at Mount Sinai, New York, New York;
zDepartmentofCardiothoracicSurgery,IcahnSchoolofMedicineatMountSinai,NewYork,NewYork;andthexDepartmentof
Medicine,SamuelandJeanA.FrankelCardiovascularCenter,UniversityofMichiganHealthSystemandMedicalSchool,Ann
Arbor,Michigan.Dr.MarinisaconsultantforW.L.Gore.Dr.EagleisaninvestigatorfortheInternationalRegistryofAcuteAortic
Dissection,whichhasreceivedgrantsupportfromW.L.Gore,Terumo,andMedtronic.Allotherauthorshavereportedthatthey
havenorelationshipsrelevanttothecontentsofthispapertodisclose.
Listentothismanuscript’saudiosummarybyJACCEditor-in-ChiefDr.ValentinFuster.
Youcanalsolistentothisissue’saudiosummarybyJACCEditor-in-ChiefDr.ValentinFuster.
ManuscriptreceivedJuly1,2014;revisedmanuscriptreceivedAugust26,2014,acceptedAugust26,2014.
1726 Goldfingeretal. JACC VOL. 64, NO. 16, 2014
ThoracicAorticAneurysmandDissection OCTOBER 21, 2014:1725–39
ABBREVIATIONS the external diameter. Thus, measurements Medial degeneration may (at least initially) occur
AND ACRONYMS differbytheaorticwallthickness,usually0.2 as an adaptive response to wall stress in the aortic
to0.4cm(4–8). dilation zone. Per Laplace’s law, wall tension (T)
ACC=AmericanCollegeof
equals pressure (P) multiplied by radius (R), or
Cardiology AORTIC ANEURYSM. An aneurysm is a per-
T ¼ PR. Aneurysm formation increases wall tension,
AHA=AmericanHeart manent, localized arterial dilation to more
causing further expansion of the aneurysmal seg-
Association
than50%ofthenormaldiameter.Thehisto-
EACTS=EuropeanAssociation pathologyofsomeaorticaneurysmsinvolves ment. As the aorta enlarges, it loses distensibility.
forCardio-ThoracicSurgery When the tensile limit is reached, dissection may
medial degeneration (formerly called cystic
EAPCI=EuropeanAssociation medialnecrosis),characterizedbyelasticfiber occur, but aneurysms can occur without dissection,
ofPercutaneousCardiovascular anddissectionscanoccurwithoutaneurysms.
Interventions loss from the medial layer, loss of vascular
ESC=EuropeanSocietyof smoothmusclecells,andproteoglycandepo- AORTICDISSECTION. Dissectioninvolvesdisruption
Cardiology sition. Altered microribonucleic acid expres- of the medial layer, with intramural hemorrhage
TEVAR=thoracic sion is implicated in increased activity of leading to propagation (especially when the intimal
endovascularaneurysmrepair matrix metalloproteinase (MMP)-2 and -9 layer is also disrupted) and tracking of blood within
MMP=matrix (9,10), which lyse elastic fibers and break the media. Two commonly used classification
metalloproteinase
down the extracellular matrix. The media schemes are used for thoracic aortic dissection: the
TGF=transforminggrowth
withintheaneurysmisalsoremodeled,with DeBakeyschemecategorizesdissectionsbythesiteof
factor
smooth muscle cells oriented randomly, origin; and the Stanford scheme categorizes dissec-
instead of in organized layers parallel to the aortic tions by involvement of the ascending aorta (Central
lumen.Transforminggrowthfactor(TGF)-b,aregula- Illustration). In the DeBakey classification, dissec-
tory cytokine expressed by arterial wall vascular tions originating in the ascending aorta are sub-
smooth muscle cells, modulates MMP activity. In a divided into those that propagate to the aortic arch
mouse aortic aneurysm model, disrupting TGF-b (type I) and those confined to the ascending aorta
signaling prevented aneurysm formation (11). There (type II), as opposed to those that originate in the
are2TGF-bsignalingpathways,andbothplayrolesin descending aorta (type III), regardless of whether
aneurysmformation(12,13).Inthecanonicalpathway, they propagate distally or retrograde. The Stanford
TGF-bbindsatthecellsurfacetoitstypeIortypeII scheme is divided into type A dissections, which
receptors. The complex phosphorylates Smad2 or involve the ascending aorta, and type B dissections,
Smad3, resulting in Smad4 recruitment and nuclear whichdonot,regardlessofpointoforigin(14).
translocation, and Smad-dependent gene transcrip-
RISK FACTORS FOR AORTIC DISSECTION
tion.Inthenoncanonicalpathway,TGF-bphosphor-
ylatesextracellularsignal-regulatedkinase(ERK),Jun
Clinicalaorticdissectionriskfactorsfallinto2broad
N-terminalkinase,andp38.
categories: conditions that contribute to medial
degenerationandthosethatincreaseaorticwallstress.
Conditions associated with medial degeneration
includeMarfansyndrome,Loeys-Dietzsyndrome,the
vascularformofEhlers-Danlossyndrome,inflamma-
torydiseasesoftheaorta,Turnersyndrome,bicuspid
Ascending thoracic aorta Proximal descending aorticvalve,andfamilialthoracicaorticaneurysmand
thoracic aorta
F 2.7 cm, M 3.0 cm (Echo) F 1.9 cm, M 2.1 cm (CMR) dissection syndrome. The most common condition
F 2.6 cm, M 2.7 cm (CMR)
that increases wall stress is hypertension,present in
more than two-thirds of patients with aortic dissec-
Sinotubular junction tion. Other conditions implicated in dissection are
F 2.6-3.2 cm, M 2.9-3.6 cm (Echo) likely mediated by hypertension, including pheo-
F 2.2 cm, M 2.5 cm (CMR) Mid descending thoracic aorta
F 2.5-2.6 cm, M 2.4-3.0 cm (CMR) chromocytoma, cocaine use (15), and coarctation.
Sinuses of Valsalva Physical trauma can increase wall stress and cause
F 3-3.6 cm, M 3.4-4.0 cm (Echo) dissection, as in weightlifting, deceleration injury in
F 2.8 cm, M 3.2 cm (CMR)
motorvehicleaccidents,orfalls(16,17).Smokingalso
increases dissection risk, likely by affecting TGF-b.
Priorcardiacsurgerymayincreasetheriskofdissec-
FIGURE1 NormalSizesforAorticSegmentsbySexandImagingModality(6–8)
tionandcomplications.OnthebasisofInternational
CMR¼cardiacmagneticresonance;Echo¼echocardiography;F¼female;M¼male. RegistryofAcuteAorticDissection(IRAD)data,15%of
patientswithdissectionhadpriorcardiacsurgery(18),
JACC VOL. 64, NO. 16, 2014 Goldfingeretal. 1727
OCTOBER 21, 2014:1725–39 ThoracicAorticAneurysmandDissection
AORTIC ANEURYSM AND DISSECTION
Heart Tube
Tear Tear Tear graft
Normal True
thoracic lumen
aorta
False
lumen Stent
graft
Kidney
An aortic DeBakey I DeBakey II DeBakey III Endovascular: Open repair:
aneurysm is a (tear in the (tear in the Minimally Traditional
bulge in a section ascending aorta the ascending descending invasive open surgery
of the aorta that propagates aorta) aorta) insertion of with replacement
caused by an to the arch) Stanford B a stent graft of the damaged
underlying (tear in the section with a
weakness in the Stanford A descending tube graft
aortic wall (tear in the ascending aorta) aorta)
RISK FACTORS MANAGEMENT
Genetic diseases: Lifestyle changes: Medical treatment: Surveillance and prophylactic surgery:
• Marfan syndrome • Optimization • Patients should be treated to control • Surveillance of aortic diameter
•• LEoheleyrss--DDiaentzlo ssy snydnrdomroeme • Somf loipkiidnsg hpyrepsesrutreension to the lowest tolerated blood • Rmeefaesrurarle mfoer nstu rrgeaecryh ewsh tehne saeo rctriict idcaial mpoeitnetrs :
•• TB(Vuicarunsscepur ildsay ran fodorrrtomicm) vealve • Acreevssoissiadtti vsiotern enuous • β(Rsat-ertbdeelusnoscoc.ek lSoset lrhu, ydnpaieeddrot ilenon lps oiaort nipe ranontpsd r wapniutolhsl oaMtl)ial erf wana ll Ga≥n5ed.n5 eb crimaclu psopor ipgdur aolaowtrittohicn > v0al.v5e cm/ year
• Familial thoracic aortic (isometric) syndrome Marfan syndrome
•• TGaaniakenautyr aycsseumll a adrrtitseesrreiitctiistsion syndrome • Aeapstnxvoiedmowr idoceuirt lscafheuone lctr as ine • Ate(Lphonneawzgtryii eonmprtdrseeo ol nm(epsAvroiCinelt E leocs) o ra o inoenfvn rhMteaiibrclMtai tiapPnonr-grie2sl u) arnydsm T)G. FL-eβs s(f actors ≥a(L≥≥to54 4e.<.02.y 05 scc .-cm0mDm icfue mointfrz l, ce doosirnss s gtfeearcmomtwipioltlynah th (>ifins0agtm.o 5pri lrycyem ogh/fni sdyateniosacrsryye )co tfi on
• Behçet’s disease • Management aortic dissection or growth >0.5 cm/ year),
Factors that increase of stress and AT2 signaling or >4.5 cm and undergoing surgery for
aortic wall stress: • Angiotensin-II receptor blockers (ARBs) symptomatic severe aortic stenosis
• Hypertension (losartan or irbesartan) Ehlers Danlos, vascular form
• Pheochromocytoma Inhibits levels of TGF-β. Selective blockade Surgery is high risk because of tissue
of AT1. Studied in patients with Marfan fragility
• Cocaine use syndrome
• Coarctation
• Trauma (deceleration injury, falls)
• Weight lifting
• Smoking
CENTRALILLUSTRATION AnOverviewofThoracicAorticAneurysmandDissection
andblackpatientswithanacutedissectionweremore eitherof2cardinalfeaturesispresent:ectopialentisor
likely to present with a type B dissection, were aortic root aneurysm. Without a family history, both
younger, were more likely to have hypertension and cardinalfeaturesarerequired.Withoutthesefeatures,
priorcocaineuse,andwerelesslikelytohavebicuspid diagnosisisbasedontherevised2010Ghentnosology,
aorticvalvesorprioraorticcardiacsurgerythanwhite whichassignspointsforcommonsystemiccorrelates,
patients(19). together with genetic testing for fibrillin gene muta-
GENETIC DISORDERS ASSOCIATED WITH MEDIAL tions. Aortic aneurysm and dissection are the most
DEGENERATION. Marfan syndrome.Marfan syn- life-threateningMarfansyndromemanifestations(22).
drome results from mutations in the FBN-1 gene Loeys-Dietz syndrome. Loeys-Dietz syndrome is
encodingfibrillin-1,alargeglycoproteindepositedin characterized by the triad of: arterial tortuosity and
extracellular matrix microfibrils, including at the aneurysms; orbital hypertelorism (widely-spaced
periphery of elastic fibers in the medial layer of eyes); and bifid uvula or cleft palate. It results from
the ascending aorta. Fibrillin-1 regulates the cyto- mutationsinTGF-breceptors1or2,anddiagnosisis
kine transforming growth factor-b type II receptor confirmed by genotyping. In the largest study of
(TGFbR2)(20).Normalfibrillin-1inhibitsTGF-b;TGF-b Loeys-Dietz patients (n ¼ 90), 98% had aortic root
levels are elevated in Marfan patients, leading to aneurysms. The mean age at death was 26 years
increased MMP activity and extracellular matrix (range 0.5 to 47 years) due to thoracic aortic dissec-
breakdown (21). In patients with a family history of tion (67%), abdominal aortic dissection (22%), and
Marfan syndrome, the diagnosis can be made when intracerebralbleeding(7%)(23).
1728 Goldfingeretal. JACC VOL. 64, NO. 16, 2014
ThoracicAorticAneurysmandDissection OCTOBER 21, 2014:1725–39
The vascular form of Ehlers-Danlos syndrome. Takayasu and giant cell arteritis are both T cell-
The vascular form of Ehlers-Danlos syndrome is mediated panarteritides affecting the vasa vasora in
characterizedby:easybruising;thinskinwithvisible the adventitia and extending inward, with inflam-
veins; characteristic facial features; and rupture of mation resulting in either destruction, leading to
arteries, the uterus, or intestines. Diagnosis requires aneurysm formation, or fibrosis, leading to stenosis.
genetic testing to identify a defect in the COL3A1 Takayasu arteritis has Asian predominance and 10:1
gene,encodingtypeIIIcollagen.Themediansurvival sex predominance for women. Giant cell arteritis, or
is 48 years, with most deaths due to dissection or temporal arteritis, predominantly affects females of
rupture of arteries in the thorax or abdomen, often Northern European ancestry over age 50 years (31).
withoutaneurysms.Becausethesepatientshavesuch Behçet’s disease is characterized by oral mucosal ul-
fragile tissue, bleeding, wound dehiscence, poor cers and 2 of the following features: genital ulcers;
wound healing, fistulae, and adhesions complicate uveitis; retinal vasculitis; or skin lesions. Behçet’s
surgicalrepairofaorticdissections(24). disease affects the aorta infrequently, but can be
Bicuspid aortic valve.Bicuspid aortic valve is the associated with lymphocytic, histiocytic, eosino-
most common congenital abnormality affecting the philic, and giant cell infiltration around the vasa
aorta,occurringin1%to2%ofthepopulation.Bicuspid vasora, with media disruption leading to aneurysm
valves are classified by their anatomic appearance formationoraorticrootnecrosis(4).
(25).Type0ortruebicuspidvalveshavenorapheand
MANAGEMENT OF AORTIC ANEURYSM
2 equally-sized leaflets. More commonly, type I
AND DISSECTION
bicuspidvalveshaveasingleraphe,usuallybetween
therightandleftcoronarycusps.Lesscommonly,the
right and noncoronary cusps are fused. The raphe’s The first step in management of patients with aortic
position may create reproducible flow patterns that aneurysmisriskfactorcontroltoslowtheexpansion
rate and reduce the risk of dissection or rupture.
lead to aortic aneurysm development (26). Patients
Patients should be treated to control hypertension
withbicuspidvalvesareatincreasedriskforascending
to the lowest tolerated blood pressure, to optimize
aortic aneurysm, dissection, and valvular aortic ste-
lipids, and for smoking cessation, as smokers have
nosisandregurgitation(27,28).
twice the aneurysm expansion rate of nonsmokers
Turner syndrome.Turnersyndromeischaracterized
and higher dissection rates (32). Patients should be
bytheabsenceofoneXchromosomeinaphenotypic
cautioned to avoid strenuous resistive (isometric)
female (45X). Patients commonly have short stature
exercise, such as heavy weightlifting, cocaine, and
and ovarian failure. Less commonly, patients have
other powerful stimulants, and to manage stress as
cardiac anomalies, including bicuspid aortic valve,
besttheycan.Lifestressorscanleadtoacutehyper-
aortic coarctation, and aortic dilation, and these pa-
tension and abrupt wall pressure changes over time
tientsareatincreasedriskofdissection.Over90%of
(dp/dt), dramatically affecting aneurysm expansion
dissection cases in Turner syndrome had hyperten-
and increasing dissection risk. Patients with aortic
sionorstructuraldisease(29,30).
aneurysms who become pregnant require close
Familialthoracicaorticaneurysmanddissection monitoring of aortic diameter and strict blood pres-
syndrome.Between11%and19%ofpatientsreferred surecontrol.
for surgery with thoracic aortic aneurysm or dissec-
MEDICAL TREATMENT WITH b-BLOCKERS. In the
tionhavefirst-degreerelativeswitheitheraneurysm
1960s, using Tygon tubing as a model for aortic
ordissection,suggestingafamilialsyndromewithout
dissection, Wheat et al. (33) showed that dissection
specific identifiable genetic defects. Mutations were
was initiated and propagated by hypertension and
identified in: TGFbR2, similar to Loeys-Dietz syn- pulsatile wall stress increasing dp/dt. b-blockers
drome; smooth muscle cell–specific myosin heavy
decrease both (34), and this was proposed as the
chain 11, a protein involved in smooth muscle cell
mechanism by which propranolol decreased dissec-
contraction, where the dissections are associated
tion in a turkey model of aortic aneurysms (35).
with patent ductus arteriosus; and ACTA2, encoding b-blockers may also prevent dissections by prevent-
smooth muscle-specific a-actin, also involved in
ing the acute hypertensive response to emotional or
vascularsmoothmusclecellcontraction(4).
exertionalevents(16).
INFLAMMATORY CONDITIONS ASSOCIATED WITH On the basis of ex vivo and animal data, b-adren-
AORTICANEURYSMANDDISSECTION. Aorticmedial ergic inhibition was studied in an open-label, ran-
disease-associated vasculitides include Takayasu domized trial of 70 Marfan patients: 32 were treated
arteritis, giant cell arteritis, and Behçet’s disease. with propranolol at a dose titrated to a heart rate
JACC VOL. 64, NO. 16, 2014 Goldfingeretal. 1729
OCTOBER 21, 2014:1725–39 ThoracicAorticAneurysmandDissection
below100beats/minduringexerciseoranincreasein with other conditions, suggesting differences in
systolictimeintervalof30%(meandose212mg);38 pathophysiology,tissueintegrity,ordiseaseseverity
patients in the control arm were untreated. Despite (39). Thoracic and abdominal aortic aneurysms are
greater aortic diameter in the propranolol arm at also distinct histologically, with abdominal aneu-
baseline(34.6cmvs.30.2cm),themeanslopeofthe rysms showing an inflammatory infiltrate, apoptosis
aorticratiowas0.023cm/yearinthetreatmentgroup, ofvascularsmoothmusclecells,extracellularmatrix
compared with 0.084 cm/year in the control group fragmentation, and more frequent and extensive
(p<0.001)(Figure2)(36). atherosclerosis (40). Two randomized trials of pa-
Inaretrospectivestudyof155childrenwithMarfan tients with abdominal aortic aneurysms showed no
syndrome,despitegreaterdilationoftheaortaatthe benefitsforb-blockers,andmanytoleratedtreatment
levelofthesinusesofValsalva(29.7mmvs.27.3mm), poorly(41,42).
those who had taken a b-blocker (predominantly Althoughtheroleofb-blockersinpreventingaortic
atenolol, less frequently nadolol or propranolol) dis- dissection has not been elucidated, once dissec-
played a small but statistically significant decrease tion has developed, they have a clearer role in man-
(0.16mm/year;p<0.05)intheaorticexpansionrate agement. Among 1,301 patients with acute aortic
comparedtountreatedcontrols(37). dissection in the IRAD database (722 type A and 579
On the basis of these and other small studies, typeB),b-blockeradministrationwasassociatedwith
b-blocker use for thoracic aortic aneurysms became improvedsurvival,drivenmainlybyimprovementin
standardforMarfanpatientsandcommoninpatients thosewithtypeAdissections(43).
withother forms of thoracic aortic aneurysms.How- ANGIOTENSIN-II RECEPTOR BLOCKERS. Angiotensin-
ever, a meta-analysis of 802 Marfan patients from IIreceptorblockers(ARBs)inhibitTGF-bthroughse-
5 nonrandomized trials and 1 randomized trial lectiveangiotensin-IIreceptorAT1blockade,withno
found no difference with b-blocker use in rates of effect on AT2. Mice heterozygous for the Marfan
aortic dissection or rupture, cardiovascular surgery, syndrome fibrillin-1 C1039G mutation displayed
or death. Using a fixed effects model, b-blockers greater aortic expansion than wild-type mice. When
appearedtocauseharm(38).Therearealsoconcerns mice withthemutationwere treatedwithproprano-
that b-blockers might decrease aortic elasticity and lol,theydisplayedsloweraorticrootexpansionthan
regarding potential side effects during long-term placebo-treated mice, but greater expansion than
therapyinyoungpeople(5). wild-type mice, whereas treatment with losartan
Seminal trials of b-blockers for thoracic aortic resulted in the same aortic diameter, rate of aortic
aneurysmwerelimitedtoMarfanpatients.Although rootexpansion,aorticwallthickness,andelasticfiber
thoracic aneurysms arising in a variety of disease architecture as wild-type mice, suggesting that los-
states may exhibit medial degeneration, Marfan pa- artan corrected the aortic morphology changes asso-
tients have greater aneurysm expansion dissection, ciated with this Marfan syndrome model (11).
whichoccursatsmalleraorticdiametersthaninthose However, losartan’s beneficial effect on aneurysm
growthrequiresintactAT2signaling,andmaybedue
toindirectERKinhibition(12).
Brookeetal.(44)reviewedtherecordsof18pedi-
100
atric Marfan patients who had received ARB therapy
90
80 foroverayear(17losartanand1irbesartan)whilealso
Patients (%) 6453700000 Treatment (n = 32) Control (n = 38) taAyaoeRkarBitrnictg(hprebor-o<abtploy0ec,x.k0tphe0are1ns).es.ixPoTprnhaionerrrsaeittoeonwwAraaasRtsBen3so.tl5ho4sewirgemandpmiyfit,o/cyat0ehn.a4etr6;bmamlofetmoaendr/
20 pressure reduction, suggesting another mechanism
10 for this effect (44). A prospective nonrandomized
0
study with 20 pediatric patients found that losartan
–0.1 0.0 0.1 0.2
decreased aortic root size, and suggested that the
Rate of Change in Aortic Ratio (Per Year) benefit increased when therapy was started at an
earlier age (45). The recently published COMPARE
FIGURE2 RatesofChangeinAorticRatioforMarfan
(COzaar in Marfan patients Reduces Aortic Enlarge-
PatientsTreatedWithPropranololVersusPlacebo
ment)trialwasarandomized,multicenter,open-label
ReprintedwithpermissionfromShoresetal.(36). studythatenrolled233patients(of330planned)and
randomized 116 to losartan and 117 to no additional
1730 Goldfingeretal. JACC VOL. 64, NO. 16, 2014
ThoracicAorticAneurysmandDissection OCTOBER 21, 2014:1725–39
treatment.Mostweretakingb-blockers.Over3years humanstudiessuggestedsomebenefitforabdominal
offollow-up,aorticrootdilationwas0.77mminthe aortic aneurysms, but the results are insufficient to
losartangroup,comparedwith1.35mminthecontrol support clinical recommendations for this line of
group(p¼0.014).Thepercentageofparticipantswith therapy(39,53,54).
a stable aortic root over the 3-year study period was
50% in the losartan group and 31% in the control SURVEILLANCE AND
group (p ¼0.022),withanumber-needed-to-treat of PROPHYLACTIC SURGERY
5.3 patients. The benefit on aortic root size did not
appearrelatedtothebloodpressurereduction(46). Management of patients with aortic aneurysms in-
While intriguing, ARBs’ benefits in Marfan cludes surveillance of aortic diameter and, when it
patientsarenotconclusive.Severaltrialstoevaluate reaches a critical point, referral for surgery. Regard-
losartan in patients with thoracic aneurysms are less of aortic dimensions, symptomatic patients
underway, including the Pediatric Heart Network should be referred for surgery. In asymptomatic
study comparing the effects of atenolol and losartan patients, the size of aneurysm is the main determi-
on aortic root growth over 3 years, which com- nantoftheneedforintervention.
pleted its planned enrollment (47,48), and the Gott et al. (55) described675 Marfan patients who
Ghent Marfan Trial, which will evaluate losartan underwent aortic root replacement at 10 surgical
versus placebo in 174 Marfan patients taking centers between 1968 and 1996. The 30-day post-
b-blockers(49). operative mortality was 1.5% for those undergoing
elective repair (n ¼ 455), 2.6% for urgent repair
ANGIOTENSIN-CONVERTING ENZYME INHIBITORS.
(n ¼ 117), and 11.7% for emergent repair (n ¼ 103).
In a randomized, double-blind, placebo-controlled
Compared to elective repair, the hazard ratio (HR)
trial of 17 Marfan patients who were taking
for death with urgent repair was 3.33 (95% confi-
b-blockers, 24 weeks of perindopril resulted in
dence interval [CI]: 1.14 to 9.79; p < 0.025) and for
smaller aortic root diameters, and lower levels of
death with emergent repair the HR was 7.40 (95%
MMP-2 and TGF-b (50). Angiotensin-converting
CI: 2.84 to 19.30; p < 0.001). For 103 patients un-
enzyme (ACE) inhibitors block angiotensin I conver-
dergoing emergent aortic root replacement within
siontoangiotensinIIupstreamofthesiteofactionof
24 h of surgical consultation, the indications were
ARBs,whichselectivelyblocktheAT1receptorbutnot
acute dissection (n ¼73), chronic dissection (n ¼9),
theAT2receptor.InamouseMarfansyndromemodel,
chest pain, aneurysm diameter >7 cm, or New York
atequivalentdoses,theACEinhibitor,enalapril,was
Heart Association functional class III or IV symp-
lesseffectiveatreducingaorticrootgrowththanlos-
toms. Among 202 patients with acute or chronic
artan (p < 0.0001). This may be due to a protective
dissection, nearly one-half had aortic diameters
effect of AT2 signaling on aneurysms in Marfan syn-
#6.5 cm. Thirty-day mortality after acute aortic
drome, specifically through AT2 receptor-mediated
dissection was 9.1%. The authors concluded that
ERK 1/2 inhibition. However, ACE inhibitors block
surgery should be undertaken electively when the
AT2aswellasAT1signaling(12).Thebenefitofena-
aortic root diameter is “well below” 6.5 cm to
laprilin the mouse modelwas comparabletothat of
reduce surgical mortality (55).
propranololinanearlierstudybythesamegroup(11).
Elefteriades et al. (56–58) found that the risk of
OTHER PHARMACOLOGICAL APPROACHES. In a rupture or dissection increased sharply with aortic
retrospective analysis of 649 patients with thoracic diameters>6cmattheascendingaortaand>7cmin
aortic aneurysm, 147 patients taking statins were thedescendingaorta(Figure3).Atthesedimensions,
comparedto502whowerenot.After3.6years,fewer thelikelihoodofaneurysmruptureordissectionwas
patients taking statins reached the composite 31% for those with ascending aortic aneurysms and
endpoint of death, aortic rupture, dissection, or 43% for aneurysms of the descending aorta. Above
repair, but aneurysm diameter was not affected (51). thesecriticaldimensions,theriskofdeathassociated
In a retrospective analysis of 1,560 patients with withsurgery(2.5%ascendingand8%fordescending
aortic aneurysms, the 369 (24%) taking statins had aortic aneurysms) was exceeded by the risk of com-
lower rates of dissection rupture, death related to plications related to aortic rupture, dissection, or
surgery, or requirement for surgery for those with death(14.1%)(Figure4)(56–58).
aneurysms of the ascending aorta, aortic arch, and Several professional societies, including the
descendingaorta,butnotforaneurysmsoftheaortic American College of Cardiology (ACC), American
root (52). In mice, doxycycline prevented aneurysm Heart Association (AHA), American Association for
formation through MMP-2 and MMP-9 inhibition; ThoracicSurgery,andAmericanCollegeofRadiology,
JACC VOL. 64, NO. 16, 2014 Goldfingeretal. 1731
OCTOBER 21, 2014:1725–39 ThoracicAorticAneurysmandDissection
toreleaseoftheupdatedvalvulardiseaseguidelines,
A there was considerable discussion about the appro-
Point Increase inof Complication 423000 hopvafrigildavhiteesesr(ecc2ucu7tt,tio6oof2nfff–fw6oo4firt)5h.s.u5bIrnicgcmiudcs,aeplfteihrdneefdvaeaiurnlrvtgahelostfh,rosterhcaenitebpewiatcuhucgesiuptlyioiddwoeaflriodnaratetetisacs’
Percentage Probability 100 * H(pin =g 0e .p0o0in5t) at 6.0 cm rdveaisgrsaiaerbcdtiiliniotgnythirneiskdaeogsrruteibcestolaefnvateiovlretli(ycsindiuinlsactrieooafnseaVsta,lwsaahnlivcdah ttvhhsee.
4 5 6 7 8 ascending aorta) at which dilation occurs with
Aneurysm Size (cm) * bicuspidvalves(60).
B Marfanpatientsshouldundergoechocardiography
50
Point Increase inof Complication 4300 * Hinge point at 7.0 cm ad6shtinmodguoilandagtohnrhstoa.as,viIsfethateooannrtnaiacsusarefloososllitomtwdhai-egauimnpageoteretcuirhcnoitscrilaosrotdtathiboelagenr,ddapmiaaamtsiaceefenttneetsrr-
Percentage Probability 2100 (p = 0.006) rfdreeeanqccuheee:nst$Ci4)m..5aPgcamintigoenristcshaadwnvgiiteshesdsiLg(oCneliafiysscs-aDnIi,telytLz,ewveshylenondfmroEomvriee-
0
3 4 5 6 7 8 should have complete aortic imaging at diagnosis
Aneurysm Size (cm) * andafter 6 months (ClassI, Levelof Evidence: C). If
stable, they should undergo yearly CMR from the
FIGURE3 EffectsofAscendingAorticAneurysmSize cerebrovascular circulation to the pelvis (Class I,
Level of Evidence: B). Patients with mutations that
(A)Effectofascendingaorticaneurysmsizeontheriskof predispose to aortic aneurysm formation and/or
complications.(B)Effectofdescendingaorticaneurysmsize
dissection should have complete aortic imaging at
ontheriskofcomplications.Reprintedwithpermissionfrom
diagnosis and 6 months later (Class I, Level of Evi-
Elefteriades(56).
dence: C). Patients with Turner syndrome should
undergo imaging to exclude bicuspid aortic valve,
agree on a 5.5 cm threshold for surgical referral for coarctation, or dilation of the ascending aorta. If
patientswithdilatedaorticroots,onthebasisofthe initial imaging is normal and there are no other risk
relative risks of surgical complications, rupture,
dissection, and death (4,11). This cutoff will not
invariably avoid dissection at smaller diameters.
IRAD investigators found that the mean ascending 3.5 to 3.9 cm
18%
aorticdiameterwas5.3cmin591patientswithtypeA 4.0 to 4.9 cm
15.6%
dissections between 1996 and 2005; 349 (59%) pa- 16% 5.0 to 5.9 cm
tientshaddiameters<5.5cm.Independentpredictors 14% ≥ 6.0 cm
ofdissectionatdiameters<5.5cmincludedhistoryof ate 12% 11.8%
hypertension,radiatingpain,andadvancedage.The R
overall 27% mortality rate was unrelated to aortic arly 10%
e
Y 8%
diameter(59)(Table1). e 6.9%
g
Forabicuspidaorticvalvewithdilatedaorticroot, era 6%
the 2014 ACC/AHA guidelines for valvular disease Av 4% 3.7% 3.9%
recommend surgical referral when the aortic root is
2%
5.5 cm or larger, similar to recommendations for pa-
0%
tientswithoutabicuspidvalve(ClassI,LevelofEvi- Rupture Dissection Rupture or Death Rupture, Dissection
Dissection or Death
dence:B).Forabicuspidvalvewithanadditionalrisk
Outcome
for dissection (family history or rapid growth), there
is a Class IIa recommendation for surgery when the
FIGURE4 RiskofComplications,SpecificallyAorticRupture,Dissection,andDeath,
aorticrootis5.0cm(LevelofEvidence:C)(60).Pre-
IncreasesWithIncreasedAneurysmSize
vious valvular disease guidelines from 2008 and the
thoracicaortaguidelinesusedacutoffof5.0cm,even ReprintedwithpermissionfromElefteriadesandFarkas(5).
intheabsenceofanadditionalriskfactor(4,61).Prior
1732 Goldfingeretal. JACC VOL. 64, NO. 16, 2014
ThoracicAorticAneurysmandDissection OCTOBER 21, 2014:1725–39
conditions (e.g., Marfan syndrome), certain features
TABLE1 RecommendationsforReferraltoSurgerybyDiseaseandAorticRootDiameter
of the presenting symptoms (abrupt onset of severe
AorticRootDiameteratWhichReferral or tearing quality pain), and clinical findings (shock,
Population forSurgeryIsRecommended
new murmur of aortic regurgitation) into a score to
General(4) $5.5cmascendingaortaorgrowth>0.5cm/yr
(ClassI,LevelofEvidence:C) stratifypatientsintolow-,intermediate-,orhigh-risk
Marfansyndrome(4) $5.0cmascendingaorta,unlessfamilyhistoryofdissection groups(66).
at<5.0cm,orgrowth>0.5cm/yror
$4.0cmandcontemplatingpregnancy(ClassIIa,Levelof
SURGICAL MANAGEMENT FOR
Evidence:C)
Loeys-Dietzsyndrome(4) $4.2cmbytransesophagealechocardiogram(internaldiameter)or TYPE A DISSECTION
$4.4to4.6cmbyCTorCMR(externaldiameter)
(ClassIIa,LevelofEvidence:C)
Bicuspidaorticvalve(4,60) Per2014ACC/AHAvalvulardiseaseguidelines: Mortality associated with acute unoperated type A
>5.5cm(ClassI,LevelofEvidence:B) aorticdissectionhasbeenestimatedat1%/hto2%/h
>5.0cmwithariskfactorfordissection(familyhistoryof duringthefirst 48h.Hence,allpatientswithtypeA
aorticdissectionorgrowth>0.5cm/yr)(ClassIIa,Levelof
dissection should be considered for urgent surgical
Evidence:C)
>4.5cmandundergoingsurgeryforsymptomatic repair.IntheIRADdatabase,in-hospitalmortalityfor
severeaorticstenosisorregurgitation(ClassIIa,Levelof patientsmanagedsurgicallywas27%,comparedwith
Evidence:C)
56%forthosemanagedmedically(Figure5)(67).For
Per2010ACC/AHAthoracicaorticdiseaseguidelines:
$5.0cm(ClassI,LevelofEvidence:C) thosesurvivingtohospitaldischarge,1-yearsurvival
Planforaorticvalverepairor >4.5cm(ClassI,LevelofEvidence:C) was 96% in the surgery group versus 89% in the
replacement(4) medicalgroup,andwas91%aftersurgeryversus69%
at 3 years. In multivariable analysis, predictors of
ACC¼AmericanCollegeofCardiology;AHA¼AmericanHeartAssociation;CT¼computedtomography;
CMR¼cardiacmagneticresonance. long-termmortalitywereahistoryofatherosclerosis
(relativerisk:2.17;95%CI:1.08to4.37;p¼0.03)and
previous cardiac surgery (relative risk: 2.54; 95% CI:
factors for dissection, imaging should be repeated 1.16to5.57;p¼0.02)(68).
every 5 to 10 years. If initial imaging is abnormal, Uncertaintysurroundstheappropriatenessofsur-
reimaging is indicated based on clinical deve- gical management in certain populations, such as
lopments (Class I, Level of Evidence: C). those older than age 80 years, with neurological in-
juries, presenting late after the onset of dissection,
PREDICTING DISSECTION. Diseases of the thoracic and with prior cardiac surgery. While 1 study sug-
aortamaybeclinicallysilentuntildissectionbecomes gestedthatpatients>80yearsofagehavepoorout-
an emergency. Surveillance of high-risk populations comes (69), another comparing patients younger or
andprophylacticsurgerydecreasedthefrequencyof olderthan80yearsofagefoundnodifferenceinsur-
dissection,buttheseeventsarestilltoocommonand vival (70). In an analysis of 936 patients in IRAD,
catastrophic. Several biomarkers were investigated one-third were over 70 years of age and 63 were
forearlierdetectionofeventsthatmayprecedeaortic 80 years of age or older; the rate of surgical repair
dissection, including MMP and TGF-b levels (65).
Microribonucleic acid expression and MMP activity
measurements may elucidate distinctive profiles Kaplan-Meier Survival Estimates
0
ad(asisssoterccoiatpitooennd,intwhiectsoheunitnhtceolrrupadcaeirctCa-oroferatsacmtidvoieostepharsoetmseiun(s9,c,cl1ea0)l),p.oaFnnoindr of Death 0.751.0 Surgery
D-dimer, although these have not been studied pro- ee 0 No Surgery
spectively. In a meta-analysis of 11 studies that n Fr 0.5
o
itnivciltuydfeodrd34is9sepcatitoiennotsf,9D4-%diamnedrshpaedciaficpitoyoloefd40se%nstio- oporti 0.25 Median = 1035 days (2.8 yrs)
Pr 0 Log rank p=0.009
100%. These markers remain investigational, and 0
0.
currentguidelinesdonotrecommendbiomarkeruse 0 500 1000 1500 2000
Follow Up Days
inroutineclinicalpractice(4).
Sensitivity and specificity approach 100% for
FIGURE5 Kaplan-MeierSurvivalCurvesforTypeA
diagnosisofaorticdissectionbyCTandCMRimaging,
DissectionsinSurgicalVersusNonsurgicalGroups
but these figures presuppose clinical suspicion. To
improvediagnosis,theIRADinvestigatorsformulated ReprintedwithpermissionfromTsaietal.(67).
a risk prediction tool that incorporates high-risk
JACC VOL. 64, NO. 16, 2014 Goldfingeretal. 1733
OCTOBER 21, 2014:1725–39 ThoracicAorticAneurysmandDissection
decreasedwithage,andsurgical mortality increased ROLE FOR SURGERY OR ENDOVASCULAR
with age >70 years. There were not enough patients REPAIR FOR ANEURYSM AND DISSECTION
>80yearsofagetopermit conclusionsaboutamor-
tality benefit with surgery, and the authors recom- Theroleforendovascularversusopenrepairdifferson
mendconsideringsurgeryinallpatients,regardlessof thebasisoftheaorticsegmentcontainingthelesion.
age(71). Aneurysms or dissections of the ascending aorta are
In single-center reports, surgical repair for type A treated surgically. There is a role for endovascular
dissection was performed in the setting of stroke, repairinthedescendingthoracicaorta,withU.S.Food
without neurologic decline (72,73). Similarly, IRAD andDrugAdministration(FDA)–approveddevicesfor
analyses point to improved outcomes for surgical aneurysm andcomplicated dissection (79).Endovas-
managementofpatientswhopresentwithacutetype cular approaches avoid the pain and recovery time
A dissection and stroke. In an analysis of 1,873 fromthoracotomyandtherisksofaorticclamping,but
patients, 87 (4.7%) presented with stroke and 54 theirusemaybelimitedinpatientswithinadequate
(2.9%) with coma. With stroke, mortality was 76% landing zones for stent placement, excessive aortic
with medical management and 27% with surgical dilation,inadequatevascularaccess,andsevereaortic
management (p < 0.001), and with coma, mortality atherosclerosis, which would increase the risk for
was 100% with medical management and 44% with embolism.Therearealsoconsiderablymorelong-term
surgicalmanagement(p<0.001).Logisticregression dataforopenrepair(4).
analysis pointed to improved survival with surgery 1.ASCENDINGAORTAANEURYSMANDDISSECTION.
afterbraininjury(oddsratio:0.058;p<0.001).Five-
Open repair is the standard of care for patients
year survival rates for patients presenting with meeting the criteria outlined in Table 1. However,
stroke and coma were 23.8% and 0% with initial
thereiscontroversyinthetreatmentapproachtothe
medical management versus 67.1% and 57.1% with aortic root. Myriad options exist (Table 2), and
surgery (log rank, p < 0.001), respectively (74). In
appropriatetreatmentcentersonthenormalityofthe
a later analysis of 2,202 IRAD patients with acute
aorticsinuses.Inolderpatients,thediseaseprocessis
type A dissection over a 16-year period, 132 (6%)
usually effacement at the sinotubular junction. A
presentedwithstroke.Thesepatientswereolder,had
tube graft replacement above the sinuses, including
higher rates of hypertension and atherosclerosis
the proximal portion of the aortic arch, should be
compared to those who did not present with stroke,
used. These operations are reproducibly done, with
weremorelikelytopresentwithshock(13.8%vs.7%;
only modest hypothermia and low risk of death or
p ¼ 0.005), and more likely to have aortic arch
stroke(80).
vesselinvolvement(68%vs.37%;p<0.001),butless
Inpatientswithproximaldiseaseoftheaorticroot,
likely to undergo surgical repair (73.5% vs. 85.4%;
attention to aortic valve integrity is essential. The
p < 0.001). In-hospital mortality was 42.4% for pa- modifiedBentallprocedure,whereacompositevalve
tients with stroke, compared to 24.1% for patients
and graft is used to replace the entire aortic root, is
without stroke (p < 0.001). Among stroke patients,
the standard of care for these patients. However,
5-year mortality was 100% for those managed medi-
many options for composite biological grafts now
callyand22.1%forpatientsmanagedsurgically(75).
exist, including a bioprosthetic valve sewn into a
In a single-institution study of 195 patients with
Dacrongraft,oruseoftheporcinexenograftFreestyle
typeAdissection,93(47%)presentedmorethan48h
(Medtronic,Freely,Minnesota)compositevalvegraft
aftertheonsetofsymptoms.Therewasnodifference
(81). In the last decade, there has been intensive
inlong-termsurvivalafter41.8monthsamongthose
surviving the initial phase of management (76). It is
important to recognize the inherent selection bias
TABLE2 SurgicalOptionsforAscendingAortaRepair
whenanalyzingthosepatientswhosurvivetheinitial
SurgicalProcedure DescriptionoftheProcedure
48hwithoutsurgicalintervention(67,68).
Bentall(115–118) Totalaorticrootreplacementwithacompositevalve
Although some reports suggested that prior aortic
graftconsistingofaDacronaorticrootandaprosthetic
valve surgery might protect againstcomplicationsof aorticvalve(eitherbioprostheticormechanical),with
type A dissection, specifically aortic regurgitation or reimplantationofthecoronaryarteries
Yacoub(rootremodeling)(83) Dacronaorticrootwithascallopeddesign
involvement of the right coronary artery in the
David(valvesparing)(82) NativeaorticvalveisreimplantedintoaDacronaorticgraft
dissection, other reports implicated prior cardiac andcoronaryarteriesarereattached
surgery as increasing operative risk. Prior surgery Rossprocedure(119) Pulmonaryvalveautograftisplacedintheaorticvalveposition,
andahomograftvalvereplacesthepulmonaryvalve
should not delay treatment of a type A dissection
Aortichomograft(120) Consistsofaorticvalveandascendingaorta
(77,78).
1734 Goldfingeretal. JACC VOL. 64, NO. 16, 2014
ThoracicAorticAneurysmandDissection OCTOBER 21, 2014:1725–39
interest in valve-sparing aortic root replacement, proximal arch disease, partial arch replacement and
which allows treatment of the aortic root aneurysm ascending aorta repair are recommended. Total arch
and reimplantation of the aortic valve in both replacement is reasonable for acute dissection when
bicuspid and trileaflet valve patients (82). Another thearchisaneurysmalorthereisextensivedestruc-
valve-preserving option involves remodeling the tion; for aneurysms that involve the entire arch; for
aorticrootinordertorecreatethesinusesofValsalva chronic dissection with arch enlargement; and for
and sinotubular junction (83). Patients presenting distal arch aneurysms that involve the proximal
with type A dissection should be offered immediate descending thoracic aorta. Repair is also recom-
surgery. There is no role for medical stabilization mendedforarchdiameter>5.5cminasymptomatic,
priortosurgery.Pre-operativecoronaryangiography low-risk patients with isolated degenerative or
should not be performed routinely; this delays sur- atheroscleroticaneurysms(4).
gical repair and increases the risk for aortic rupture Although endovascular stent grafts are not FDA-
(84). Moreover, surgeons are unlikely to perform approved for arch aneurysms, and randomized data
coronaryarterybypassgraftinginthesettingofatype are lacking, endovascular or hybrid procedures
A dissection and the risk of wire misadventure in a (combined endovascular and vascular surgery pro-
dissectedaortaisnotinsignificant.Theprimarygoal cedures) are increasingly used for patients at high
of type A dissection surgery is not to entirely elimi- surgical risk due to age or medical comorbidities.
natethedissection,buttoemergewithalivepatient. One type of hybrid procedure involves extra-
Only in DeBakey type II cases can the dissection be anatomic bypass, either carotid-carotid or carotid-
completelyeliminated.Inmostpatients,therewillbe subclavian, to permit a stent graft to cover the
persistent downstream dissection with patent false origin of the carotid artery (90). Hybrid procedures
lumen in the descending and abdominal aorta. The for the aortic arch also include “debranching” pro-
ascending aorta is replaced from the sinotubular cedures,whereaffectedarchvesselsaresequentially
junctiontotheundersurfaceoftheaorticarch.Ifthe surgically anastomosed to aDacron graft,effectively
aortic root is involved, the operation may be removing the branches from the aortic arch (91).
extended proximally to address pathologic or aneu- Because of high morbidity and mortality, these pro-
rysmal aortic sinuses. There is little role to expand cedures are reserved for patients at high surgical
theoperationtoincludefulltransversearchreplace- risk.
ment, as this increases operative risk without elimi-
natingalldiseasedtissue. 3.DESCENDINGTHORACICAORTAANEURYSMAND
There is no role for endovascular repair of DISSECTION. Thedescendingthoracicaortaextends
ascending aortic aneurysms or type A dissections fromafterthearchtoproximaltotheceliacaxis.For
(85,86). saccular aneurysmsordegenerativeortraumatic an-
eurysms of the descending thoracic aorta exceeding
2.AORTICARCHANEURYSMANDDISSECTION. The 5.5 cm, endovascular stent-grafting should be
aortic arch was the last aortic section to be success- considered.Theguidelinesrecommendopensurgical
fully replaced surgically, due to the difficulty of repair for chronic dissection in the setting of a con-
maintaining perfusion of the head, neck, and upper nective tissue disorder and a descending thoracic
extremities. From the 1950s through 1970s, high aortic diameter >5.5 cm. (Class I, Level of Evidence:
mortality and neurologic morbidity rates with surgi- B)(4,92).Citingtheabsenceofrandomizedtrialdata,
calarchreplacementimprovedwiththeintroduction the 2010 ACC/AHA guidelines do not address the
of deep hypothermic circulatory arrest (87) followed relative efficacy of open versus endovascular repair
by advances in intraoperative cerebral perfusion for the descending thoracic aorta. The authors note
(88,89). In a retrospective analysis of 347 patients theFDAapprovalofstentgraftsforaneurysmrepair
whounderwentsurgicalaorticarchreplacementfrom (TEVAR) on the basis of observational data without
1993 to 2007, 95 underwent total arch replacement long-termdurabilitydata(4).
with hypothermia and circulatory arrest. For those The Society of Thoracic Surgeons Endovascular
who also received selective antegrade cerebral SurgeryTaskForceconsensusdocumentrecommends
perfusion, mortality was 6% compared to 34.6% for against endovascular stent grafting in asymptomatic
thosewhodidnot,andstrokeoccurredin6%versus descending aortic aneurysms <5.5 cm because the
19.2%.Electivecaseswereevensafer,withamortal- surgical risk of roughly 5% exceedsthe risk of aneu-
ityrateof2.7%andstrokesin5.4%(89). rysmruptureordissection (92).Similarly,a2012po-
CurrentguidelinesprovideClassIIarecommenda- sition statement from the European Association for
tion for open surgical repair of the aortic arch. For Cardio-Thoracic Surgery (EACTS), European Society