Coarctation of the AortaP. Syamasundar Rao, MD

AddressDivision of Pediatric Cardiology, The University of Texas/Houston Medical School, 6431 Fannin, MSB 3.130, Houston, TX 77030, USA.E-mail: P.Syamasundar.Rao@uth.tmc.edu

Current Cardiology Reports 2005, 7:425–434Current Science Inc. ISSN 1523-3782Copyright © 2005 by Current Science Inc.

IntroductionCoarctation of the aorta is an important cause of secondaryhypertension and consequently, inclusion of this entitywhen discussing secondary hypertension is appropriate. Inthis review, definition, pathology, prevalence, pathogenesis,pathophysiology, clinical features, noninvasive and invasiveevaluation, treatment, and prognosis of aortic coarctation(AC) in children, adolescents, and adults is discussed.

Definition and PathologyCoarctation of the aorta is defined as a congenital cardiacanomaly consisting of a constricted aortic segment com-prising localized medial thickening with some infolding of

the media and superimposed neointimal tissue. The local-ized constriction may form a shelf-like structure with aneccentric opening or it may be a membranous curtain-likestructure with a central or eccentric opening. The coarcta-tion may be discrete, or a long segment of the aorta may benarrowed; the former is more common. In the past, AC hasbeen described as preductal (or infantile) type and post-ductal (or adult) type, depending upon whether the coarc-tation segment is proximal or distal to the ductusarteriosus, respectively. However, a detailed review of theanatomy suggests that all coarctations are juxtaductal.

Dilatation of the descending aorta immediately distalto the coarctation segment, poststenotic dilatation, is usu-ally present. Varying degrees of hypoplasia of the isthmusof the aorta (the portion of the aorta between the origin ofthe left subclavian artery and ductus arteriosus) and trans-verse aortic arch (the portion of the aorta between the ori-gins of left common carotid and left subclavian artery) arepresent in the majority of patients with thoracic coarcta-tion. Collateral vessels that connect arteries from theupper part of the body to the vessels below the level ofcoarctation may be seen; these may be present as early as afew weeks of life.

PrevalenceThe prevalence of AC was found to vary between 5% to 8%of all congenital heart defects [1,2]. Slight male preponder-ance has been observed in older patients, although it isminimal in infants.

Associated DefectsBicuspid aortic valve may be seen in nearly two thirds ofinfants with AC, whereas only 30% of older children mayhave such an anomaly. Mitral valve anomalies, although lessfrequent than those of the aortic valve, are also seen withAC. Some patients with AC may have cerebral aneurysms,predisposing them to development of cerebrovascular acci-dents with severe hypertension later in life. AC is the mostcommon cardiac defect seen in Turner’s syndrome.

PathogenesisThe exact mechanism by which AC is produced is notclearly understood [3]. Two hypotheses are most com-monly invoked: hemodynamic and ectopic ductal tissue. Inthe first hypothesis, an abnormal preductal flow or abnor-

Coarctation of the aorta is an important, treatable cause of secondary hypertension. Its prevalence varies from 5% to 8% of all congenital heart defects. This condition is most often detected because of a murmur or hypertension found on routine examination. Delayed or absent femoral pulses and an arm/leg systolic blood pressure difference of 20 mm Hg or more in favor of the arms may be considered as evi-dence for aortic coarctation. The coarctation may be dem-onstrated on a suprasternal notch two-dimensional echocardiographic view along with increased Doppler flow velocities across the coarctation site. Cardiac catheteriza-tion reveals significant systolic pressure gradient (> 20 mm Hg) across the coarctation and angiography demonstrates the degree and type of aortic narrowing. Aortic obstruc-tion may be relieved by surgery or by transcatheter tech-niques; the latter include balloon angioplasty and stent implantation. In the past, surgery has been used exclusively, but because of morbidity and complications associated with surgery, catheter techniques are increasingly used in the management of aortic coarctation. Balloon angioplasty in children and stents in adolescents and adults are becoming initial therapeutic options for management of coarctation. Studies evaluating long-term follow-up results of the inter-ventional techniques are needed.

426 Hypertension

mal angle between the ductus and coarctation are invoked.Spontaneous postnatal closure of the ductus arteriosuscompletes the development of aortic obstruction. A highincidence of AC in congenital heart defect patients withdecreased antegrade aortic flow in utero and virtual absenceof AC in patients with right heart obstructions would lendcredence to the hemodynamic hypothesis. Abnormal exten-sion of ductal tissue into the aorta (ectopic ductal tissue)has been postulated to create coarctation shelf, and withductal closure, development of aortic coarctation. This the-ory, however, does not explain the variable degrees of isth-mic and aortic arch hypoplasia seen with AC.

PathophysiologyIn children, adolescents, and adults, the mode of presenta-tion is hypertension or systolic murmur. The aorticobstruction is deemed to have developed slowly with evi-dence for development of left ventricular hypertrophy(LVH) and collateral circulation. The mechanism for devel-opment of hypertension is not clearly understood;mechanical obstruction and rennin-angiotensin–medi-ated humoral mechanisms have been postulated [3].

Mechanical obstruction theory explains the increasedblood pressure by postulating that a higher blood pressureis required to maintain flow through the coarcted segmentand collateral vessels. The stroke volume, ejected into thelimited aortic receptacle, produces a higher pressure proxi-mal to coarctation. However, this theory does not explain1) the lack of relationship between the degree of elevationof blood pressure and the magnitude of obstruction, 2)increased peripheral vascular resistance distal to the site ofobstruction, and 3) delayed or lack of reduction of bloodpressure following relief of obstruction.

Humoral theory postulates activation of the rennin-angiotensin system secondary to reduction of renal bloodflow and appears to explain most of the clinical features.However, measurement of plasma rennin activity both inanimal models and human subjects did not show consis-tently elevated plasma rennin levels. The reason for theinability to demonstrate elevation of rennin levels may berelated to lack of inadequate accounting for salt intake, pos-ture, extracellular fluid volume, and sympathetic influenceson rennin release. More recent studies did demonstrateabnormalities in rennin-angiotensin-aldosterone systems.In addition, activation of central sympathetic nervous sys-tem may also be responsible for hypertension of AC.

Clinical FeaturesMost often, the coarctation is identified because of a murmuror hypertension detected on routine examination. The AC isnot frequently recognized by the primary care physician [4,5],and consequently it is recommended that palpation of femo-ral pulses and measurement blood pressure be undertakenduring routine examination to avoid delay in the diagnosis.

Palpation of the brachial and femoral artery pulses simulta-neously will reveal decreased and delayed or absent femoralpulses. Blood pressure in both arms and one leg must bedetermined; a pressure difference of more than 20 mm Hg infavor of the arms may be considered evidence for AC.

The LV impulse may be increased. A thrill is usually feltin the suprasternal notch. The first and second heartsounds are usually normal in isolated aortic coarctation.Because of the large percentage (up to 60%) of patientswith AC have associated bicuspid aortic valve, an ejectionsystolic click may be heard at the apex and left mid andright upper sternal borders; this click is constant and doesnot change with respiration. An ejection systolic murmurmay be heard best at the left or right upper sternal borders,but is usually heard best over the back in the left interscap-ular region. Sometimes, a faint continuous murmur maybe heard in the left interscapular region, secondary to con-tinuous flow in the coarcted segment or on the back (sec-ondary to flow in the collateral vessels).

Noninvasive AssessmentChest radiographChest roentgenogram may show significant cardiomegalyor the heart size may be normal. Rib-notching secondaryto collateral vessels may also be seen. Other roentgeno-graphic features include a “3” sign on a highly penetratedchest radiograph (frontal view) or inverted “3” sign of thebarium-filled esophagus.

ElectrocardiogramThe electrocardiogram may be normal or it may show LVH.Sometimes the LVH may be manifested by increased Swaves in leads V5 and V6, the so-called posterobasal LVH.

Echocardiography-Doppler studiesEchocardiographic imaging usually reveals the coarctationin suprasternal notch, two-dimensional echocardiographicviews. Increased Doppler flow velocity in the descendingaorta by continuous wave Doppler and a demonstrablejump in velocity at the coarcted segment by pulsed-Dop-pler technique are usually present. Instantaneous peakpressure gradients across the AC can be calculated byemploying a modified Bernoulli equation [6]:

where � P is peak instantaneous gradient and V2 and V1are peak flow velocities in the descending aorta distal tocoarctation (continuous-wave Doppler) and proximal tothe coarctation (pulsed Doppler), respectively.

MRI/MR angiographyThese studies are useful in demonstrating the anatomyclearly. If the clinical and noninvasive evaluation outlinedabove indicates the need for intervention, I usually go ahead

P∆ 4 V22

V12

–( )=

Coarctation of the Aorta • Rao 427

with catheterization and angiography, and perform interven-tional procedures. If the data are not clear, then MRI or MRangiography are performed to define the problem further.

Cardiac catheterization and selective cineangiographyAlthough not required for diagnosis, cardiac catheteriza-tion is helpful in demonstrating the anatomic nature of theaortic obstruction (discrete vs long segment), assessing theextent of collateral circulation, determining the presenceand severity of associated lesions (especially in the neo-nates and infants), and more recently as a prerequisite tothe consideration of transcatheter intervention.

Elevation of LV and ascending aortic peak systolicpressures with a peak to peak systolic pressure gradientacross the coarcted segment are usually found. A peak topeak gradient in excess of 20 mm Hg is generally consid-ered indicative of significant obstruction. However, themagnitude of the gradient is not necessarily indicative ofthe degree of narrowing because the gradient is depen-dent not only upon the extent of aortic narrowing butalso on the size and number of collateral vessels. In addi-tion, cardiac output and the state of ductus arteriosus,particularly in the neonate and young infant, also deter-mine the pressure gradient.

Selective aortic root or aortic arch angiography is nec-essary to clearly demonstrate the aortic narrowing. Aor-tography is useful in demonstrating the type of AC(diffuse, long segment, or aortic kinking [pseudocoarcta-tion]), extent of collateral circulation, the size of ductusarteriosus, if patent, and presence and degree of hypopla-sia of transverse aortic arch and aortic isthmus. If thoraciccoarctation is not demonstrated despite clinical featuresof coarctation or if neurofibromatosis is suspected,abdominal aortography may be needed to demonstrate(or exclude) abdominal coarctation.

TreatmentSignificant hypertension or congestive heart failure are indi-cations of intervention. Surgical relief of the aortic obstruc-tion and catheter interventional techniques (balloonangioplasty and stents) are available alternatives. Asymp-tomatic patients should undergo the procedure electively. Ifneither hypertension nor heart failure are present, electivesurgical or balloon therapy between the ages of 2 and 5years is suggested. Waiting beyond 5 years of age is notadvisable because of evidence for residual hypertension ifthe aortic obstruction is relieved after 5 years of age [7].

Medical management at initial presentationIn patients with congestive heart failure, initial treatment,consisting of anticongestive measures including digitalispreparations and diuretics should be promptly instituted[3]. If hypertension (rather than heart failure) is the clini-cal problem, it is better to relieve the aortic obstruction

promptly rather than attempting to treat hypertensionwith antihypertensive medications, although some clini-cians use such an approach.

Surgical therapySince the introduction of surgical correction by Crafoordand Nylin, and Gross and Hufnagel in the mid-1940s, sur-gical therapy has become the treatment of choice for aorticcoarctation. A variety of techniques have been used inrepairing AC and these include resection and end to endanastomosis, subclavian flap angioplasty, prosthetic patchaortoplasty, and tubular bypass grafts. Several other modifi-cations of the initially described techniques have been uti-lized to improve the results of the operation. The type ofsurgical procedure used depends upon the age of thepatient, aortic arch anatomy, and preference of the surgeon.Although surgical correction has improved the prognosis ofpatients with coarctation, there still remain problems asso-ciated with surgical correction, which include operativemortality and morbidity, recoarctation, aneurysms in alltypes of coarctation repair [8], particularly well-docu-mented following prosthetic patch angioplasty [9], devel-opment of paraplegia, paradoxical hypertension, andvascular complications related to subclavian flap repair.

Despite these problems surgical repair is considered bymany as a therapeutic option of choice in the treatment ofaortic coarctation. Some groups, including ours, considerballoon angioplasty as initial therapy of choice and reservesurgical intervention for those coarctations that 1) involvethe long segment of the aorta, 2) are completely or almostcompletely occluded such that no catheter or guide wire canbe passed across the coarcted segment, and 3) are associatedwith a large patent ductus arteriosus and ventricular septaldefect, which requires prompt surgical intervention for theprimary cardiac problem. There is no consensus with regardto whether surgical or balloon therapy is the preferred treat-ment for AC. The issues related to balloon angioplasty andstenting coarctation segment are addressed below.

Balloon angioplastySince the initial descriptions of balloon angioplasty ofneonatal postmortem native aortic coarctation, postsurgi-cal AC, and native coarctation, a large number of investiga-tors reported their experiences with balloon angioplasty ofnative aortic coarctation. The technique of balloon angio-plasty is described elsewhere [9–11].

Immediate resultsDespite an initial report of poor results [12], subsequentexperience with balloon angioplasty appears encouragingand has been detailed elsewhere [9,13,14]. Reduction ofpressure gradient across the coarctation and increase in thesize of the coarctation segment are observed in all agegroups. An example of improvement in angiographicappearance is shown in Figure 1. The femoral pulses,which had been either absent or markedly reduced and

428 Hypertension

delayed (when compared with brachial pulse) become pal-pable with increased pulse volume after balloon angio-plasty. The patients who were in heart failure improved asdid their hypertension. None of our patients requiredimmediate surgical intervention.

Intermediate-term follow-upSeveral investigators have reported 1- to 2-year follow-upresults, reviewed previously [9,13,14,15•]; these studiessuggest continued improvement. From our own study[15•], 60 patients were followed; the residual peak gradi-ents 14 ± 11 (mean ± SD) months following angioplastyremained low at 16 ± 15 mm Hg. These gradients continueto be lower (P < 0.001) than those prior to angioplasty (46± 17 mm Hg) and are slightly higher (P < 0.05) than thegradients (11 ± 9 mm Hg) immediately following angio-plasty (Fig. 2). Angiographically measured coarctation seg-ment remained wide. There is only a modest increase (11 ±9 vs 16 ± 15 mm Hg; P < 0.05) in peak gradients for thegroup as a whole, but when individual patient values areexamined 15 (25%) of the 60 patients had evidence forrecoarctation, defined as a peak to peak systolic pressuregradient in excess of 20 mm Hg. The incidence of recoarcta-tion is higher in neonates (five [83%] of six; P < 0.01) andinfants (seven [39%] of 18; P = 0.011) than children (three[8%] of 36); 10 of these children underwent repeat balloonangioplasty and two patients underwent surgical resection,all with good result. Aneurysms developed in three (5%) of58 who underwent follow-up catheterization and angio-plasty; one of these patients required surgical excision ofthe aneurysm and the other two are followed clinically.

Long-term follow-upThere are scant data on long-term follow-up after balloonangioplasty of native coarctation [15•,16–18], reviewedelsewhere [19•]. Despite the problems of recoarctationand aneurysms, some requiring repeat intervention atintermediate-term follow-up, the long-term follow-upresults (5–9 years) appear encouraging, in that there wasminimal incidence of late recoarctation and no late aneu-rysm formation. Near-normal blood pressure and low

gradient between arms and legs (Fig. 2) were found in themajority of patients.

Results in adult patientsAlthough balloon angioplasty of AC has most frequentlybeen used in infants and children, it has been used in adultpatients as well. Lababidi et al. [20] were the first to applythis technique in an adult patient (27-year-old man), whichresulted in reduction of peak systolic pressure gradientacross the coarctation from 70 to 15 mm Hg, angiographicimprovement, and reduced hypertension (190/124 mm Hgvs 130/80 mm Hg). They subsequently reported theirexperience with balloon dilatation of native coarctation ineight consecutive adults, aged 19 to 30 years (25 ± 5 years)[21]. The systolic pressure gradient across the coarctationwas reduced from 48 ± 19 mm Hg to 7 ± 5 mm Hg. The sizeof the coarcted segment increased from 6.8 ± to 2.2 mm to15.2 ± 5.0 mm. No complications were encountered. Clini-cal and echocardiographic-Doppler follow-up 1 year afterthe procedure revealed good result with no more than 15mm Hg peak systolic blood pressure difference, measured bycuff, between arms and legs. They concluded that results inyoung adults are similar to those observed in children; bal-loon angioplasty should be considered as an option tosurgical intervention; and follow-up studies (longer than 1year) are required. Other reports followed [22–33], whichare tabulated in Table 1. Based on the review of these publi-cations, the conclusion drawn by Attia and Lababidi [21] areappropriate but, aortic perforation and dissection during theprocedure and aneurismal formation at follow-up are alsoseen in adults. Therefore, it is prudent to 1) avoid manipula-tion to tips of the catheters and guide wires in the region offreshly dilated coarctation, 2) chose an appropriate-sizedballoon (no larger than the diameter of the descending aortaat the level of the diaphragm), and 3) monitor fordevelopment of aneurysms, which, if found, should beclosely followed by repeated angiography or MRI.

RecoarctationResidual and recurrent obstructions cannot be easily dis-tinguished from each other and the term recoarctation may

Figure 1. Selected cine frame from a posteroan-terior view of left ventricular (LV) cineangiogram (A) showing discrete aortic coarctation (white arrow) in a 6-year-old child. Following balloon angioplasty (B), aortogram revealed no evidence for significant residual coarctation (black arrow). Ao—aorta; DAo—descending aorta.(From Rao [9]; with permission.)

Coarctation of the Aorta • Rao 429

Tab

le 1

.R

esul

ts o

f bal

loo

n a

ngi

opl

asty

of a

ort

ic c

oar

ctat

ion

in a

dult

pat

ien

ts

Age

, y G

radi

ent

acro

ss c

oar

ctat

ion

(mea

n ±

SD

) m

m H

g*

Stu

dy

NM

ean

± S

D

Ran

ge P

re P

ost

FU

Fo

llow

-up:

n/m

ean

dura

tio

n, m

oC

om

men

ts

Att

ia a

nd L

abab

idi [

21]

825

± 5

19

–30

48 ±

19

7 ±

5<

15†

8/12

No

com

plic

atio

nsSu

arez

de

Lezo

et a

l. [2

2]9

22 ±

5

18–3

1‡

11

± 9

13 ±

10

‡/‡

Pre-

BA g

radi

ent

for

the

grou

p co

mbi

ned

with

19

child

ren

was

49

± 1

6 m

m H

gEr

bel e

t al.

[23]

729

± 1

4 14

–49

59

± 2

213

± 7

6 ±

9

7/6

Intim

al d

isse

ctio

n in

one

pat

ient

at

6-m

o fo

llow

-up

Tya

gi e

t al.

[24]

3523

± 7

14

–37

81 ±

23

15 ±

13

16 ±

13

26/1

3T

hree

ane

urys

ms

Faw

zy e

t al.

[25]

2323

± 9

15

–55

66 ±

19

8 ±

8

8 ±

922

/15

One

aor

tic p

erfo

ratio

n, t

wo

deve

lope

d re

sten

osis

req

uiri

ng r

epea

t ba

lloon

, tw

o de

velo

ped

a sm

all a

neur

ysm

Kal

e et

al.

[26]

828

± 1

2 18

–56

71 ±

12

14 ±

9

20 ±

9

4/6

No

aneu

rysm

s, o

ne r

este

nosi

sPh

adke

et a

l. [2

7]

1330

± 1

416

–61

69 ±

30

8 ±

10

‡9/

20T

wo

aneu

rysm

s re

quir

ing

surg

ery

Schr

ader

et a

l. [2

8]

2925

14–5

4 62

± 1

8 21

± 1

3 14

± 1

329

/48

One

dea

th a

nd o

ne s

urge

ry fo

r an

eury

smde

Gio

vann

i et a

l. [2

9]

2333

15–5

846

±14

10 ±

10

10 ±

7

22/3

3R

ecoa

rcta

tion

in th

ree

and

aneu

rysm

in o

neK

oers

elm

an e

t al.

[30]

19

2914

–67

49 ±

21

5 ±

8

‡19

/20

One

pat

ient

had

sub

optim

al r

esul

tPa

ddon

et a

l. [3

1]

1628

15–6

051

1818

16/8

8 O

ne p

atie

nt r

equi

red

surg

ery

Wal

hout

et a

l. [3

2]

17

3616

–67

50 ±

22

5 ±

9‡

‡/59

U

nsuc

cess

ful i

n al

l thr

ee p

osto

pera

tive

reco

arct

atio

nsFa

wzy

et a

l. [3

3]§

4920

± 7

‡

66 ±

23

11 ±

7

6 ±

6

49/1

22

Rep

eat

ballo

on in

four

& a

neur

ysm

s in

four

*Pea

k to

pea

k sy

stol

ic p

ress

ure

grad

ient

mea

sure

d at

car

diac

cat

hete

riza

tion

exce

pt fo

r †.

† Syst

olic

pre

ssur

e di

ffere

nce

betw

een

arm

s an

d le

gs.

‡ Dat

a no

t gi

ven.

§ Incl

udes

pat

ient

s pr

evio

usly

rep

orte

d in

199

2.BA

—ba

lloon

ang

iopl

asty

; FU

—fo

llow

-up;

Pre

—pr

ior

to a

ngio

plas

ty; P

ost—

imm

edia

tely

aft

er a

ngio

plas

ty.

430 Hypertension

be used to describe both these entities and is defined aspeak to peak systolic pressure gradient in excess to 20 mmHg with or without angiographically demonstrable nar-rowing [34]. Recoarctation may take place both followingsurgical correction and balloon angioplasty.

Development of recoarctation following surgery isindependent of the type of surgical repair [35]; it has beenobserved following resection with end to end anastomosis,subclavian flap angioplasty, prosthetic patch repair, subcla-vian artery turn-down procedure, and interposition tubegrafts. The reported incidence of recoarctation has varied,depending on the study. In the article by Pinzon et al. [8],reporting on a large number of patients, recoarctationoccurred in 23% of patients studied. The younger the childat surgery, the higher is the probability for recoarctation.There is general agreement among cardiologists that bal-loon angioplasty is the treatment of choice for postsurgicalaortic coarctation. The immediate and follow-up results ofballoon angioplasty for postsurgical recoarctation areessentially similar to those of native coarctation and havebeen reviewed in detail elsewhere [19•,35,36].

Restenosis following balloon angioplasty also appearsto be aged-dependent; the younger the child, the greateris the probability for recoarctation [15•,34]. We[15•,19•,37] and others [16] recommend repeat balloondilatations in such cases, whereas still others [38] prefersurgical intervention.

Intravascular stentsVascular stenotic lesions can be opened up by balloonangioplasty, but because of elastic recoil of the vessel wall,the vessel lumen may return to the predilatation size follow-ing withdrawal of the balloon catheter. Such recoil and vas-cular dissection, if any, following balloon dilatation can becircumvented by implantation of endovascular stents.Initially, stents were used in the treatment of peripheral arte-rial disease and coronary artery stenotic lesions in adults[39]. The technique was then extended to the treatment ofother stenotic vessels including aortic coarctation [40,41•].

Despite reasonably good short- and long-term results ofballoon angioplasty, some problems remain, including rest-enosis, probability of aortic rupture, formation of aneurysms,and inability to effectively treat long-segment tubularnarrowing. Because of these and other reasons, endovascularstenting of AC has gained acceptance over the past decade[42–48,49••,50–57,58••]. The perceived advantages ofstents over balloon angioplasty are 1) the ability to expandtubular long-segment coarctation and hypoplastic isthmusand distal transverse aortic arch, 2) ability to increasecoarcted segment diameter independent of the intimal tear,3) ability to decrease the probability of restenosis, 4) preven-tion of dissection of a torn intimal flap by facilitating apposi-tion of the intima against the media, and 5) prevention ofaneurysms because of support of a weakened aortic wall withthe stent and neointima.

To my knowledge, O’Laughlin et al. [42] were the firstto report use of a stent for treatment of aortic coarctation,although the results in a 12-year-old child were marginal.Subsequent ly, a number of other workers [42–48,49••,50–57,58••] reported use of stent in AC withencouraging results.

The indication for employing stents are 1) long-seg-ment coarctation, 2) associated hypoplasia of the isthmusor aortic arch, 3) tortuous coarctation with malalignmentof proximal with distal aortic segment, and 4) recurrentAC or an aneurysm following prior surgical or balloontherapy. Because of issues related to growth and the needfor large sheaths for implantation, most cardiologists limitstent usage to adolescents and adults.

Immediate resultsReduction of peak systolic pressure gradients and increasein the diameter of the coarcted segment (Table 2) havebeen demonstrated following stent implantation. Stentingwas found effective in postsurgical and postballoon reco-arctations as well as in native coarctations. Improvement inthe size of hypoplastic isthmus or transverse aortic archand exclusion of the aneurysm, if such is present, alsooccurred after stent placement.

In the first series of 10 patients published by Suarez deLezo et al. [44] in 1995, the peak systolic pressure gradientacross the coarctation decreased from 43 ± 12 to 2 ± 3 mmHg (P < 0.001). The ratio of isthmus/descending aortaincreased from 0.65 ± 0.14 to 1 ± 0.08 following the proce-

Figure 2. Bar graph demonstrating immediate and follow-up results after balloon angioplasty of aortic coarctation. Peak to peak systolic pressure gradients across the coarctation in mm Hg (mean + SEM) are shown. Note significant (P < 0.001) drop in the gradient following angioplasty (Pre, prior to vs post, immediately following). The gradient increases (P < 0.05) slightly at a mean follow-up to 15 mo (range, 4–56 mo). However, these values are lower (P < 0001) than prior to angioplasty. At late follow-up (LFU), 6 months to 9 years (median 5 y) following balloon angioplasty, blood pressure-measured arm-leg peak pressure difference is lower than catheterization measured peak gradi-ents prior to (P < 0.001) balloon angioplasty and those obtained at intermediate-term follow-up (P < 0.01). FU—follow-up; Pre—pre-angioplasty; Post—post-angioplasty. (From Rao [3]; with permission.)

Coarctation of the Aorta • Rao 431

Tab

le 2

.R

esul

ts o

f ste

nt

trea

tmen

t o

f ao

rtic

co

arct

atio

n fr

om

sel

ecte

d p

ublic

atio

ns

Stu

dy

Pat

ient

s un

derg

oin

g st

ent

impl

anta

tion

, n

Typ

e o

f co

arct

atio

n M

ean

grad

ient

± S

D, m

m H

g C

oar

ctat

ion

segm

ent

Mea

n ag

e ±

SD

, y

(ran

ge)

Nat

ive

Po

stP

ost-

ballo

onP

re

Po

stP

re

Po

st

Suar

ez d

e Le

zo e

t al.

[44]

105

± 4

(0.

1–43

)6

22

43 ±

12

2

± 3

*

12

± 4

Bulb

ul e

t al.

[46]

620

± 5

(13

–34)

24

037

± 1

7

13 ±

23

9 ±

2

16

± 3

Ebei

d et

al.

[48]

930

± 1

8 (1

4–63

)2

70

37 ±

20

4

± 4

9 ±

3

15

± 3

Suar

ez d

e Le

zo e

t al.

[49•

•]†

4814

± 1

2 (0

.1–4

5)31

611

42 ±

12

3

± 4

4 ±

2

12 ±

2M

agee

et a

l. [5

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432 Hypertension

dure. Similar results have been reported subsequently byother investigators which are listed in Table 2.

ComplicationsVes s e l d i s r u p t io n [ 4 4 ] , d i s p l a c e me n t o f s t e n t[44,49••,51,56], and aneurysms [49••,50] may occur,but infrequent. Balloon rupture [43,56] resulting ininadequate stent expansion and stent migration hasbeen reported but may be prevented by avoiding curva-ture of the balloon/stent assembly, use of newer stentswith less injurious ends [59–61] and by the use of bal-loon in balloon catheters. Because of large size sheathrequired, loss of pulse [44,49••,52] and bleeding frompuncture site [46,51] may occur. Use of vascular closuredevices may help circumvent this problem. Rare compli-cations included myocardial infarctation [52], andretroperitoneal hemorrhage [56].

Follow-up resultsIn most studies, there was only a short-term and incom-plete follow-up in a limited number of patients. However,a few studies [49••,52,55,56] examined results of morethan 20 patients at a mean follow-up of 2 years or longer.The pressure gradients across the coarctation site (bloodpressure, Doppler, or catheterization) remained low andsystemic hypertension decreased both in degree and fre-quency with consequent decrease in the need for antihy-pertensive medications. No evidence for recoarctation,aneurismal formation, or stent fracture/displacement wasobserved, although no systematic or complete follow-upwas achieved in the majority of studies. Residual or recur-rent obstruction was present in a few patients and in thesesuccessful redilatation with larger balloons was accom-plished. Detailed angiographic studies by Suarez de Lezo etal. [49••] revealed no detectable neointimal proliferationin 75% patients; in the remaining patients focal neointi-mal ridge formation was observed at ends of the stent caus-ing minimal restenosis. Segmental analysis of the aortarevealed increase in nonstented segments of the aorta, con-sistent with normal growth. Two (7%) young patientsdeveloped small new aneurysms, which were obliteratedby coil placement following angiographic detection. Theoverall follow-up results were encouraging, however.

CommentsStent therapy appears to be an attractive method for treat-ment of recurrent coarctation or aneurysm formationfollowing prior surgical or balloon intervention and forlong-segment hypoplasia. Most cardiologists use stents inadolescents and adults, although a few have advocatedtheir use in younger children. The selection of the type ofstent and the type of balloon catheter used for stentdeployment appears to be evolving [40,62]. Balloon-expandable instead of self-expandable stents are pre-ferred. Use of balloon in balloon catheters for stent deliv-ery appears to be gaining momentum in an attempt to

prevent balloon ruptures and perforation of other cardio-vascular structures. Positioning the guidewire into theright or left subclavian artery may avoid excessive curva-ture, thus may prevent balloon rupture. Flexible [59–61]instead of rigid Palmaz (Cordis, Miami Lakes, FL) stentsare being utilized, and rightly so. Selected stent diameterat implantation should be at least twice the diameter ofnarrowest aortic segment to prevent stent displacementduring implantation.

Relief of obstruction both acutely and at follow-upwith a low incidence of major complications is well dem-onstrated in several studies. Meticulous attention to thetechnique and adoption of new technology may furtherreduce the incidence of complications. Recoarctation rateat follow-up appears to be low. Re-expansion of the stent[63] to treat residual or recoarctation and growth relatednarrowing appears feasible, safe and effective, althoughsuch is based on limited experience. Comparison ofstents with balloon angioplasty was undertaken in a fewstudies [58••,64,65]; these studies suggest that stents maybe more effective than balloon angioplasty. Based on theavailable data, stenting AC appears to be preferred alter-native to surgical or balloon therapy in the adolescentand young adult.

Covered stentsThere is extremely limited experience in the use of coveredstents in the management of aortic coarctation [66–70].Different types of stents were used and include Jostentgrafts (Jomed International, Helsingborg, Sweden), C-Pstents (NuMed, Hopkinton, NY), and AneuRx (Medtronic,Minneapolis, MN) to treat aortic coarctation. The indica-tions for intervention are similar to those used for balloonangioplasty and deployment of standard stent. The indica-tions for use of covered stents are postangioplasty aneu-rysm, tortuous aortic arch, and isthmus, associated patentductus arteriosus, prior surgical conduit, Takayasu’s arteri-tis and extremely narrow (subatretic) coarcted segment.When the assessed risk for development of aneurysm ordissection is high, covered stent should be utilized. Theresults of the limited use of covered stent appear to begood [66–70]. Some of the stents can only be expanded to18 mm in diameter. Also, the stent shortens whenexpanded to larger diameters. Use of covered stents hasalso another disadvantage in that the vessels arising fromthe aorta are blocked. Based on the currently availabledata, the covered stents may be useful in highly selectedpatients with aortic coarctation.

Conclusions and PrognosisThe immediate prognosis is good for isolated aortic coarc-tation. The majority of mortality is related to severity ofassociated defects. Once aortic obstruction is relieved bysurgical or balloon therapy, the significance of associateddefects should be evaluated and treatment instituted based

Coarctation of the Aorta • Rao 433

on their physiologic and clinical impact on the patient.Sometimes, the initially mild aortic stenosis may increasein severity during follow-up requiring balloon or surgicalaortic valvotomy. Subvalvar membranous aortic stenosismay develop years after coarctation therapy; this can occurboth in isolated AC and AC with ventricular septal defect.Relief of the subaortic obstruction may be necessary, whenit becomes severe or progressive. As mentioned in the pre-vious section, recoarctation may develop requiring repeatintervention. Reappearance of hypertension during adoles-cence or adulthood has been noted [7,71]. Appropriatetherapy with antihypertensive medication or relief of aorticobstruction if present, is a warranted in such cases. Becauseof these and other problems that might be present, peri-odic follow-up of patients after relief of aortic obstructionis highly recommended.

There are scant data on long-term follow-up. The avail-able studies [7,72] indicated that there is a significant mor-tality at long-term follow-up of AC. The survival curve,although not approaching normal population, is signifi-cantly improved [72] compared with Campbell’s naturalhistory data [73]. The causes of death appear to be related torecoarctation repair, aneurysms at the site of coarctationrepair or at a remote site, congestive heart failure, bacterialendocarditis, and hypertension. Attempts to define factorsaffecting long-term survival have been made, and age atoperation, and degree and duration of hypertension prior tosurgery/intervention appear to affect the long-term survival.

References and Recommended ReadingPapers of particular interest, published recently, have been highlighted as:• Of importance•• Of major importance

1. Nadas AS, Fyler DC: Pediatric Cardiology, edn 3. Philadelphia: WB Saunders, 1972:683.

2. Keith JD, Rowe RD, Vlad P: Heart Disease in Infancy and Child-hood, edn 3. New York: Macmillan; 1978:4–6.

3. Rao PS: Coarctation of the aorta. Semin Nephrol 15:87–105.4. Stafford MA, Griffiths SP, Gersony WM: Coarctation of the

aorta: a study in delayed detection. Pediatrics 1982, 69:159–163.

5. Thoele DG, Muster AJ, Paul MH: Recognition of coarctation of the aorta: a continuing challenge for the primary care physi-cian. Am J Dis Child 1987, 141:1201–1204.

6. Rao PS, Carey P: Doppler ultrasound in the prediction of pressure gradients across aortic coarctation. Am Heart J 1989, 118:229–307.

7. Liberthson RR, Pennington DG, Jacobs ML, et al.: Coarctation of the aorta: review of 243 patients and clarification of man-agement problems. Am J Cardiol 1979, 43:835–845.

8. Pinzon JL, Burrows PE, Benson LN, et al.: Repair of coarctation of the aorta in children: postoperative morphology. Radiology 1991, 180:199–203.

9. Rao PS: Balloon angioplasty of native aortic coarctation. In Transcatheter Therapy in Pediatric Cardiology. Edited by Rao PS. New York: Wiley-Liss; 1993:153–196.

10. Rao PS: Technique of balloon valvuloplasty/angioplasty. In Transcatheter Therapy in Pediatric Cardiology. Edited by Rao PS. New York: Wiley-Liss; 1993:29–44.

11. Rao PS: Balloon angioplasty of native aortic coarctation [let-ter]. J Am Coll Cardiol 1992, 20:756–757.

12. Lock JE, Bass JL, Amplatz K, et al.: Balloon dilation angioplasty of aortic coarctation in infants and children. Circulation 1983, 68:109–116.

13. Rao PS: Balloon angioplasty of aortic coarctation: a review. Clin Cardiol 1989, 12:618–628.

14. Rao PS, Chopra PS: Role of balloon angioplasty in the treat-ment of aortic coarctation. Ann Thorac Surg 1991, 52:621–631.

15.• Rao PS, Galal O, Smith PA, Wilson AD: Five-to-nine-year follow-up results of balloon angioplasty of native aortic coarctation in infants and children. J Am Coll Cardiol 1996, 27:462–470.

Describes long-term results of balloon angioplasty of AC.16. Lababidi Z: Percutaneous balloon coarctation angioplasty:

long-term results. J Intervent Cardiol 1992, 5:57–62.17. Mendelsohn AM, Lloyd TR, Crowley DC, et al.: Late follow-up

of balloon angioplasty in children with a native coarctation of the aorta. Am J Cardiol 1994, 74:696–700.

18. Fletcher SE, Nihill MR, Grifka RG, et al.: Balloon angioplasty of native coarctation of the aorta: mid-term follow-up and prog-nostic factors. J Am Coll Cardiol 1995, 25:730–734.

19.• Rao PS: Long-term follow-up results after balloon dilatation of pulmonic stenosis, aortic stenosis and coarctation of the aorta: a review. Progr Cardiovasc Dis 1999, 42:59–74.

An excellent review of long-term results of balloon dilatation of con-genital stenotic lesions of the heart.20. Lababidi Z, Madigan N, Wu J, et al.: Balloon coarctation angio-

plasty in an adult. Am J Cardiol 1982, 53:350–351.21. Attia JM, Lababidi ZA: Early results of balloon angioplasty of

native coarctations in young adults. Am J Cardiol 1988, 61:930–931.

22. Suarez de Lezo J, Sancho M, Pan M, et al.: Angiographic follow-up after balloon angioplasty for coarctation of the aorta. J Am Coll Cardiol 1989, 13:689–695.

23. Erbel R, Bednarezyk I, Pop T, et al.: Detection of dissection of the aortic intima and media after angioplasty of coarctation on the aorta. Circulation 1990, 81:805–814.

24. Tyagi S, Arora R, Kaul VA, et al.: Balloon angioplasty of native aortic coarctation of the aorta in adolescents and young adults. Am Heart J 1992, 123:167–171.

25. Fawzy ME, Dunn B, Galal O, et al.: Balloon coarctation angio-plasty in adolescents and adults: early and intermediate results. Am Heart J 1992, 124:167–171.

26. Kale P, Lokhandwala YY, Kulkarni HL, et al.: Balloon angioplasty for native aortic coarctation. Indian Heart J 1992, 44:207–211.

27. Phadke K, Dyet JF, Aber CP, et al.: Balloon angioplasty of adult aortic coarctation. Br Heart J 1993, 69:36–40.

28. Schrader R, Bussmann WD, Jacobi V, Kadel C: Long-term effects of balloon coarctation angioplasty on arterial blood pressure in adolescent and adult patients. Cathet Cardiovasc Diagn 1995, 36:220–225.

29. deGiovanni JV, Lip GY, Osman K, et al.: Percutaneous balloon dilatation of aortic coarctation in adults. Am J Cardiol 1966, 77:435–439.

30. Koerselman J, de Vries H, Jaarsma W, et al.: Balloon angio-plasty of coarctation of the aorta: a safe alternative for sur-gery in adults: immediate and mid-term results. Cathet Cardiovasc Intervent 2000, 50:28–33.

31. Paddon AJ, Nicholson AA, Ettles DF, et al.: Long-term follow-up of percutaneous balloon angioplasty in adult aortic coarc-tation. Cardiovasc Intervent Radiol 2000, 23:364–367.

32. Walhout RJ: Lekkerkerker JC, Ernst SM, et al.: Angioplasty of coarctation in different aged patients. Am Heart J 2002, 144:180–186.

33. Fawzy ME, Awad M, Hassan W, et al.: Long-term outcome (up to 15 years) of balloon angioplasty of discrete native coarcta-tion of the aorta in adolescents and adults. J Am Coll Cardiol 2004, 43:1062–1067.

34. Rao PS, Thapar MK, Kutayli F, et al.: Causes of recoarctation after balloon angioplasty of unoperated aortic coarctation. J Am Coll Cardiol 1989, 13:109–115.

434 Hypertension

35. Rao PS: Balloon angioplasty for aortic recoarctation follow-ing previous surgery. In Transcatheter Therapy in Pediatric Cardi-ology. Edited by Rao PS. New York: Wiley-Liss; 1993:197–212.

36. Siblini G, Rao PS, Nouri S, et al.: Long-term follow-up results of balloon angioplasty of postoperative aortic recoarctation. Am J Cardiol 1998, 81:61–67.

37. Rao PS, Galal O, Wilson AD: Feasibility and effectiveness of repeat balloon dilatation of restenosed obstructions follow-ing previous balloon valvuloplasty/angioplasty. Am Heart J 1996, 132:403–407.

38. Minich LL, Beekman RH, Rocchini AP, et al.: Surgical repair is safe and effective after unsuccessful balloon angioplasty of native coarctation of the aorta. J Am Coll Cardiol 1993, 19:389–383.

39. Zollikofer CL, Antonucci F, Stuckmann S: Historical overview on the development and characteristics of stents and future outlook. Cardiovasc Intervent Radiol 1992, 15:272–278.

40. Rao PS: Stents in the treatment of aortic coarctation [edito-rial]. J Am Coll Cardiol 1997, 30:1853–1855.

41.• Rao PS: Stents in the management of congenital heart disease in the pediatric and adult patients. Indian Heart J 2001, 53:714–730.

An extensive review of the role of stents in noncoronary vascular stenotic lesions, including AC.42. O'Laughlin MP, Perry SB, Lock JE, Mullins CE: Use of endovas-

cular stents in congenital heart disease. Circulation 1991, 83:1923–1939.

43. Reddington AN, Hayes AM, Ho SY: Transcatheter stent implan-tation to treat aortic coarctation in infancy. Br Heart J 1993, 69:80–82.

44. Suarez de Lezo J, Pan M, Romero M, et al.: Balloon expandable stent repair of severe coarctation of the aorta. Am Heart J 1995, 129:1002–1008.

45. Rosenthal E, Qureshi SA, Tynan M: Stent implantation for aor-tic recoarctation. Am Heart J 1995, 129:1220–1221.

46. Bulbul ZR, Bruckheimer E, Love JC, et al.: Implantation of bal-loon-expandable stents for coarctation of the aorta: implan-tation data and short-term results. Cathet Cardiovasc Diagn 1996, 39:36–42.

47. Thanopoulos B, Triposkiadis F, Margetakis A, Mullins CE: Long segment coarctation of the thoracic aorta: treatment with multiple balloon-expandable stent implantation. Am Heart J 1997, 133:470–473.

48. Ebeid MR, Preita LR, Latson LA: The use of balloon expand-able stents for coarctation of the aorta: initial results and intermediate-term follow-up. J Am Coll Cardiol 1997, 30:1847–1852.

49.•• Suarez de Lezo J, Pan M, Romero M, et al.: Immediate and fol-low-up findings after stent treatment for severe coarctation of the aorta. Am J Cardiol 1999, 83:400–406.

An excellent original paper examining issues related to follow-up after AC stents.50. Thanopoulos BD, Hadjinikolaou L, Konstadopoulou GN, et al.:

Stent treatment for coarctation of the aorta: intermediate-term follow-up and technical considerations. Heart 2000, 84:65–70.

51. Magee AG, Brzezinsk-Rajszys G, Qureshi SA, et al.: Stent implan-tation for aortic coarctation and re-coarctation. Heart 1999, 82:600–606.

52. Marshall AE, Perry SB, Keane JF, et al.: Early results and medium-term follow-up of stent implantation for mild resid-ual or recurrent aortic coarctation. Am Heart J 2000, 139:1054–1060.

53. Harrison DA, McLaughlin PR, Lazzam C, et al.: Endovascular stents in the management of coarctation of the aorta in the adolescent and adult: 1-year follow-up. Heart 2001, 85:561–566.

54. Cheatham JP: Stenting of coarctation of the aorta. Cathet Car-diovascu Intervent 2001, 54:112–125.

55. Ledesma M, Alva C, Gomez FD, et al.: Results of stenting for aortic coarctation. Am J Cardiol 2001, 88:460–462.

56. Hamdan MA, Maheswari S, Fahey JT, et al.: Endovascular stents for coarctation of the aorta: initial results and intermediate-term follow-up. J Am Coll Cardiol 2001, 38:1518–1523.

57. Tyagi S, Singh S, Mukhopadhyay S, Kaul UA: Self- and balloon-expandable stent implantation for severe native coarctation of the aorta in adults. Am Heart J 2003, 146:920–928.

58.•• Pedra CAC, Fontes VF, Esteves CA, et al.: Stenting vs. balloon angioplasty for discrete unoperated coarctation of the aorta in adolescents and adults. Cathet Cardiovascu Intervent 2005, 64:495–506.

An original study comparing the results of stents vs balloon angio-plasty for coarctation of the aorta.59. Rao PS, Balfour IC, Singh GK, et al.: Bridge stents in the man-

agement of obstructive vascular lesions in children. Am J Car-diol 2001, 88:699–702.

60. Rao PS: Newer stents in the management of vascular stenosis in children. In Catheter Based Devices in the Treatment of Non-coronary Cardiovascular Disease in Adults and Children. Edited by Rao PS, Kern MJ. Philadelphia: Lippincott Williams & Wilkins; 2003:369–378.

61. Coulson JD, Everett AD, Owada CY: Recent technical develop-ments in implantation of stents for congenital and postsurgi-cal cardiovascular anomalies. In Catheter Based Devices in the Treatment of Non-coronary Cardiovascular Disease in Adults and Children. Edited by Rao PS, Kern MJ. Philadelphia: Lippincott William & Wilkins; 2003:285–296.

62. Kay JD, Al-Khatib Y, O’Laughlin MP, et al.: Congenital coarcta-tion and Takayasu’s arteritis: aortic stenting employing intra-vascular ultrasound. J Invasive Cardiol 2001, 13:705–707; discussion 707–709.

63. Duke C, Rosenthal E, Qureshi SA: The efficacy and safety of stent redilatation in congenital heart disease. Heart 2003, 89:905–912.

64. Zabal C, Attie F, Rosas F, et al.: The adult patient with native coarctation of the aorta: balloon angioplasty or stenting? Heart 2003, 89:3–5.

65. Macdonald S, Thomas SM, Cleveland TJ, Gaines PA: Angioplasty or stenting in adult coarctation of the aorta? A retrospective single center analysis over a decade. Cardiovasc Intervent Radiol 2003, 26:357–364.

66. Gunn J, Cleveland T, Gaines P: Covered stent to treat co-existent coarctation and aneurysm of the aorta in a young man. Heart 1999, 82:351–352.

67. De Giovanni JV: Covered stents in the treatment of aortic coarc-tation. J Intervent Cardiol 2001, 14:187–190.

68. Forbes T, Matisoff D, Dysart J, Aggarwal S: Treatment of coexist-ent coarctation and aneurysm of the aorta with covered stent in a pediatric patient. Pediatr Cardiol 2003, 24:289–291.

69. Qureshi SA, Zubrzycka M, Brzezinska-Rajszyz G, et al.: Use of cov-ered Cheatham-Platinum stents in aortic coarctation and reco-arctation. Cardiol Young 2004, 14:50–54.

70. Ewert P, Abdul-Khaliq H, Peters B, et al.: Transcatheter therapy of long extreme subatretic aortic coarctations with covered stents. Cathet Cardiovasc Intervent 2004, 63:236–239.

71. Maron BJ, Humphries JO, Rowe RD, et al.: Prognosis of surgi-cally corrected coarctation of the aorta: a 20-year post-opera-tive appraisal. Circulation 1973, 47:119–126.

72. Bobby JJ, Emanini JM, Farmer RDT, et al.: Operative survival and 40 year follow-up of surgical repair of aortic coarctation. Br Heart J 1991, 65:271–276.

73. Campbell M: Natural history or coarctation of the aorta. Br Heart J 1970, 32:633–640.