Right Subclavian Artery · The famous “blue baby operation,” or Blalock-Taussig shunt, was the first surgical procedure developed to treat a congenital heart defect. In this operation,

96

Drs. Alfred Blalock(left) and HelenTaussig (right).

Fig. 7.1: The famous “blue babyoperation,” or Blalock-Taussig shunt, was thefirst surgical procedure

developed to treat acongenital heart defect.

In this operation, anartery from the arm isconnected to the pul-monary artery to help

supplement blood flowto the lungs and thus

provide more oxygenat-ed blood to the body.

Right Subclavian Artery

Right Carotid Artery

Innominate Artery

Left Carotid Artery

Aorta

Shunt (LeftSubclavian

Artery)

PulmonaryArtery

Fig. 7.1

ACONGENITAL HEART DEFECTmeans an abnormality that ispresent at birth. Congenital heart

surgery started before the heart-lung ma-chine was developed as surgeons startedto work on abnormalities of the arteriesthat came out of the heart. Dr. JohnStreider at the Massachusetts GeneralHospital in Boston tied off a patent ductusarteriosus (an abnormal pathway betweenthe aorta and the pulmonary artery) ina child on March 6, 1937. Unfortunately,the patient was quite sick at the time anddied four days after the surgery. A yearand a half later, in the same city, onAugust 16, 1938, Dr. Robert Gross at theBoston Children’s Hospital operated on agirl seven and a half years old who wasshort of breath because of the same con-genital defect. The patient made a success-ful recovery. Soon surgeons all over theworld were performing this operation.

The next major congenital cardiovas-cular defect to be overcome was called“coarctation of the aorta.” This is a defectin which the aorta narrows and, in somecases, becomes totally blocked, resultingin decreased blood flow to the lower half ofthe body. Historically, most patients withthis defect eventually died of complicationsby the age of twenty years. In 1944, Dr.

Clarence Crafoord in Stockholm, Sweden,successfully removed this narrow area ofthe aorta in a twelve-year-old boy.

Only a year later, Gross suc-cessfully treated a condition known asvascular ring, which occurs when the aortaand its major arterial branches wraparound the esophagus and trachea in anabnormal manner and compress them.Before this landmark surgical procedure,many infants and children with the condi-tion died of suffocation and/or starvation.

During that same period, doctorsannounced the famous “blue baby opera-tion” at Johns Hopkins University Hospitalin Baltimore. This operation treats congen-ital heart defects in which the unoxygenat-ed blood returning from the body is shunt-ed through a hole in the heart instead ofgoing through the lungs and is pumpedout through the aorta, which causes thechild to have a bluish color.

The first patient was a fifteen-month-old girl who had suffered her first cyanot-ic spell (turning blue) at age eightmonths. Dr. Helen Taussig, a pediatriccardiologist at Johns Hopkins UniversityHospital, took her as a patient and con-sulted with other doctors about trying anew operation. Over the next severalmonths, the baby girl refused most of her

C H A P T E R S E V E N

HEART PROBLEMS OFINFANTS AND CHILDREN

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Dr. Robert Gross performed the world’sfirst successful surgicalclosure of a patentductus arteriosus, anabnormal pathway between the aorta and pulmonary arteryin newborns.

S T A T E O F T H E H E A R T

feedings and lost weight. She weighedonly 8.3 pounds at the time the operationwas performed by Dr. Alfred Blalockat Johns Hopkins University Hospitalon November 29, 1944. During the oper-ation, Blalock sewed an artery that nor-mally supplies blood to the arm to the leftpulmonary artery so more blood could getto the lungs and be oxygenated (Fig. 7.1).The successful operation required slight-ly less than an hour and a half. Althoughthis was not a cure for her heart condi-tion, it improved the patient’s symptomsand quality of life substantially.

Thus, within a seven year period, threecongenital cardiovascular defects — patentductus arteriosus, coarctation of the aorta,and vascular ring — were all attacked sur-gically and treated successfully. However,the introduction of the Blalock-Taussigshunt was probably a much more powerfulstimulus to the development of open heartsurgery because the operation palliated acomplex intracardiac defect and focusedattention on the abnormal physiology ofcardiac disease.

The next major step forward in heartsurgery needed to wait for the develop-ment of the heart-lung machine, whichoccurred in the middle 1950s. With theadvent of techniques to support the cir-culation and oxygenate the blood, usingeither the cross circulation technique ofDr. C. Walton Lillehei or the modifiedGibbon-IBM heart-lung machine of Dr.John Kirklin, the cardiac teams of theUniversity of Minnesota and the MayoClinic led the way and did many of thefirst intracardiac repairs for a number ofcommonly occurring congenital heartdefects. Palliative operations, however, con-tinued to be used and developed to improvecirculatory physiology without directlyaddressing the anatomic pathology. Thepalliative operations somewhat improvedthe patients’ conditions but did not curethem. As the safety of the heart-lungmachine steadily improved, surgeonsaddressed more and more complex con-genital abnormalities of the heart inyounger and younger patients. Some ofthe milestones in the development of op-

98

Table 7-1:Within a few years in

the mid- to late 1950s,surgeons corrected

thirteen types of con-genital heart defects.

Congenital heart surgerylater evolved into its

own subspecialty.

Palliative:A treatment that im-

proves a condition butdoes not cure it.

Table 7-1: First intracardiac repairs using heart-lung machine or cross circulation

Congenital Heart Defect Year Surgeon CommentAtrial septal defect 1953 Gibbon Heart-lung machine (HLM)Ventricular septal defect 1954 Lillehei Cross circulationComplete atrioventricular canal 1954 Lillehei Cross circulationTetralogy of Fallot 1954 Lillehei Cross circulationTetralogy of Fallot 1955 Kirklin HLMTotal anomalous pulmonary veins 1956 KirklinCongenital aneurysm, sinus of Valsalva 1956 KirklinCongenital aortic stenosis 1956 Kirklin First directly viewed correctionAortopulmonary window 1957 Cooley First closure using HLMDouble outlet right ventricle 1957 Kirklin Extemporarily devised correctionCorrected transposition of great arteries 1957 LilleheiTransposition of great arteries: atrial switch 1959 Senning Physiologic total correctionCoronary arterial-venous fistula 1959 SwanEbstein’s anomaly 1964 Hardy Repair of atrialized tricuspid valveTetralogy with pulmonary atresia 1966 Ross Aortic allograftTruncus arteriosus 1967 McGoon Aortic allograftTricuspid atresia 1968 Fontan Physiologic correctionSingle ventricle 1970 HoriuchiSubaortic tunnel stenosis 1975 KonnoTransposition of great arteries: atrial switch 1975 Jatene Anatomic correctionHypoplastic left heart syndrome 1983 Norwood Two-stage operationPediatric heart transplantation 1985 Bailey

C H A P T E R S E V E N : H E A RT P R O B L E M S O F I N FA N T S A N D C H I L D R E N

erations to correct congenital defectsusing cardiopulmonary bypass appear inTable 7-1.

Diagnosing a Congenital Heart Defect

The human heart begins to developat the end of the first month of fetal lifeand takes about another eight weeksbefore it resembles an adult heart. Duringthis period, about eight out of every onethousand newborns develop some form ofcongenital heart defect ranging from verymild to quite severe. The exact cause ofcongenital heart defects is unknown, butrecent information suggests there may begenetic influences. In some cases, theyare associated with other medical condi-tions, such as the mother contractingGerman measles (rubella) while pregnant.At this point, most doctors don’t thinkcongenital heart defects are hereditary inthe strict sense of being passed from par-ent to offspring, but children of parentswho were born with such a defect will besomewhat more likely to have a congeni-tal heart defect.

Some congenital heart defects arediagnosed shortly after birth or evenwhile the baby is in the uterus by usingultrasound or echocardiography. They

may be diagnosed later when the child isof school age, or in rare circumstances,the congenital cardiac defect remainshidden until adulthood. One indicator ofsome types of congenital heart defect ina newborn is a faint bluish color in theskin. Some children with heart defectsmay not thrive, and many suffer fromcongested lungs, which may be relatedto heart failure. Heart murmurs can alsoindicate congenital heart defects, al-though not necessarily.

If a defect in a newborn is suspected,your child’s pediatrician will recommendan electrocardiogram and probably anechocardiogram, which do not requireany needle sticks. Other tests used to diag-nose congenital heart defects include car-diac catheterization and magnetic reso-nance imaging. After the heart defect isdiagnosed and analyzed, your pediatri-cian and pediatric cardiologist will developa treatment plan. This may require noth-ing more than yearly checkups or per-haps medications. Occasionally, a cathetercan be used to dilate a heart valve or toinsert a plug to close a hole. Heartsurgery may be recommended and, inrare cases, heart transplantation is thebest option.

Specific Defects

There are many types of congenitalheart defects. Of the following eleven con-genital heart defects, the first nine arerelatively common. The last two are muchmore rare and included for a sense of per-spective on the challenges facing a con-genital heart surgeon. I also have purelypersonal reasons for mentioning them.In the 1970s and early 1980s, I was fortu-nate enough to work with Dr. C. EverettKoop at the Children’s Hospital ofPhiladelphia. It was my privilege to havebeen involved with the care and surgery ofsome of these patients. Koop, later to be-come surgeon general of the United States,was then chief of pediatric surgery and

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Table 7-2:This table shows the most common congenital heart andmajor vessel defects.The ventricular septaldefect, comprising almost 30 percent of congenital heart defects, is by far themost common.

Table 7-2: Relative frequency of occurrence of cardiac malformations at birth

Disease PercentageVentricular septal defect . . . . . . . . . . . 30.5Atrial septal defect . . . . . . . . . . . . . . . . 9.8Patent ductus arteriosus. . . . . . . . . . . . 9.7Pulmonary stenosis . . . . . . . . . . . . . . . 6.9Coarctation of the aorta . . . . . . . . . . . . 6.8Aortic stenosis . . . . . . . . . . . . . . . . . . . 6.1Tetralogy of Fallot. . . . . . . . . . . . . . . . . 5.8Complete transposition

of great arteries . . . . . . . . . . . . . . 4.2Truncus arteriosus . . . . . . . . . . . . . . . . 2.2Tricuspid atresia. . . . . . . . . . . . . . . . . . 1.3All others . . . . . . . . . . . . . . . . . . . . . . 16.5

Source: Heart Disease: A Textbook of Cardiovascular Medicine.


had cared for patients with both types ofthese very rare and difficult defects.

Ventricular Septal Defect

In this most common congenital defectthere is a hole in the septum that sepa-rates the right and left ventricles (Fig.7.2). As a result, blood is short-circuitedback into the lungs, putting a burden onboth heart and lungs. About 30 percent to50 percent of these holes, especially thesmaller ones, close over time. Patientswith large- or moderate-size defects thatdo not close spontaneously, however,eventually need an operation to closethem. Larger defects may have to beclosed in the first year of life because theycan cause shortness of breath and othersymptoms of heart failure. If the defect isnot closed, the patient can also developpulmonary vascular disease, which dam-ages blood vessels in the lungs and caneventually be fatal.

Ventricular septal defects vary in sizeand location, so naturally some of themare more easily closed surgically than oth-ers. While in surgery, the patient’s heartand lung function are provided by a heart-lung machine, and the actual hole is closed

with a patch. The chances of surviving thesurgery in childhood and subsequently liv-ing a normal life are superb.

Patent Ductus Arteriosus

While the fetal heart is developing,a tube develops between the aorta andthe pulmonary artery. This tube, calledthe ductus arteriosus, is responsible forbypassing the lungs, moving blood fromthe pulmonary artery to the aorta. Becausethe fetus receives oxygenated blood from itsmother through the placenta, it has noneed for functioning lungs. After the child isborn, however, the lungs begin to function,and the ductus arteriosus is no longerneeded. It normally closes from a coupleof hours to a couple of days after birth.However, if it remains open, or patent, it isconsidered a congenital defect and usuallyneeds treatment (Fig. 7.3).

In some cases, the patent ductus ar-teriosus is so large that enough blood isshunted back from the aorta into the low-pressure pulmonary artery to actuallyflood the lungs. Heart failure can developbecause the heart is working so hard topump blood, and much of it is just beingshort-circuited back to the lungs. In othercases, infections develop in the tube, orover time high blood pressure in the pul-monary arteries can result in what’s calledpulmonary vascular disease. This diseasedamages the blood vessels in the lungswhere resistance to blood flow increasesand, at some point, the blood flow can ac-tually reverse. If this happens, the rightventricle, which should be pumping un-oxygenated blood into the lungs, isactually pumping unoxygenated bloodthrough the ductus directly into the aorta.This condition causes blueness, orcyanosis, and is very serious. Fortunately,the open ductus is usually diagnosed wellbefore this condition develops, and the de-fect can be corrected.

There are three ways to close a patentductus. In newborn babies, especially

100

Ductus Arteriosus:A tube connecting the

pulmonary artery tothe aorta. After birth,

when the lungs beginto function, this tube

normally closes.

Fig. 7.2: Ventricular Septal Defect:

In this defect there is a hole in the wall ofmuscle, or septum,

that separates the leftand right ventricles.

It is usually correctedwith a patch.

Left Ventricle

VentricularSeptal DefectRight Ventricle

Fig. 7.2


101

Homograft: A donor graft, or piece of tissue, takenfrom a donor andplaced into a recipientof the same species.

Endocarditis: An infection involvingthe heart, caused by bacteria or virus.

WHILE TRAINING TO BECOMEa heart surgeon, native NewZealander Sir Brian Barratt-

Boyes had the opportunity to spendtwo years working at the Mayo Clinic.

“I was assigned to various surgeons,”he said. “Dr. John Kirklin was one. Hehad recently begun there,but he was making aname for himself, and in1955, began doing openheart surgery with theGibbon-IBM heart-lungmachine. It was a stag-gering responsibility.

”We went through avery rapid learning curve,”Barratt-Boyes said. “Someof it was pretty traumat-ic, but the results wereexceptional. I used to besent as a spy to Minne-apolis to see what Dr.C. Walton Lillehei wasdoing. I reported what was happening soI saw the cross circulation operationsas well, which were very fascinating.”

In 1956, he returned to his nativeNew Zealand and entered a kind ofcreative vacuum. New Zealand wasisolated from the medical community.Later, in fact, Barratt-Boyes would becredited with founding modern openheart surgery in the Pacific Rim area.

“If you are working independentlyand follow your own star and yourown ideas, you can sometimes comeup with something that wouldn’t be

the case if you worked in a group,where everybody has their own ideas,”Barratt-Boyes said.

It was there that Barratt-Boyesmade two contributions to cardiacsurgery. In 1962, only a month afterDr. Donald Ross in England, Barratt-

Boyes performed theworld’s second success-ful aortic valve homo-graft implantation. “Itworked extremely well,even in the first patient,who was a young girl ofabout fifteen with endo-carditis,” Barratt-Boyessaid. “She had a suc-cessful operation and re-covered from her endo-carditis. She’s now hadseveral children andworks outside the home.She is a remarkable per-son.”

After this, Barratt-Boyes, workingwith surgeons from Japan, helped in-troduce and popularize open heartsurgery in infants by using hypother-mia, or lowering the body temperatureto protect the brain.

His results with infants, often des-perately ill and with complex forms ofcongenital heart disease, set new worldstandards. This method was an impor-tant stepping stone, and even todaymost centers use variations of hypother-mia techniques in some infants andadult patients.

SIR BARRATT-BOYES:OPENING HEART SURGERY

“DOWN UNDER”

Brian B. Barratt-Boyes


premature newborns, it can frequentlybe closed by giving a medicine called in-domethacin, which causes the ductus toconstrict and close. This treatment doesnot always work, however.

The conventional treatment is surgi-cal closure. This is done by opening thechest on the left side and dividing theductus and oversewing its ends, or clos-ing it with a tie or a metal clip.

There are also catheters that can bethreaded through blood vessels to deliv-er devices that actually plug the ductus.This avoids a surgical incision in thechest. This procedure has advantagesand disadvantages that should be dis-cussed with the pediatrician and the pe-diatric cardiologist. Trial tests of thesedevices are being evaluated by the U.S.Food and Drug Administration (FDA).

With all methods, the chances of sur-viving the closure procedure are betterthan 99 percent, and in most cases thepatient is cured.

Atrial Septal Defect

An atrial septal defect (ASD) is a hole inthe common wall separating the two atria(Fig. 7.4). There are different types of atri-al septal defects. In most cases, they are

well tolerated by children and may not bediagnosed until the child is older — andsometimes not even until adulthood.

Once diagnosed, however, most ofthese should be closed. Depending on thesize, the hole can be sewn up. Larger holesmay require a patch of pericardial tissueor an artificial material such as Dacron.

If the hole is not repaired, heart fail-ure can develop because much of theblood pumped by the heart is being short-circuited through the lungs instead ofbeing pumped out to the body, meaningthe heart has to work harder to pumpmore blood. Occasionally, pulmonary vas-cular disease may develop, or blood clotsdislodged from veins in the legs may trav-el through the ASD and lodge in the brain,causing a stroke. In most cases, the riskof the surgery to repair the defect in chil-dren is low, and the survival rate is greaterthan 99 percent. Devices to close ASDswith a catheter are under developmentand are being tested at some centers.

There is another, more complex atri-al septal defect that may occur with aventricular septal defect called atrioven-tricular canal defect. The risks associat-ed with the surgical repair of this defect

102

Fig. 7.3: Patent DuctusArteriosus:

An abnormality inwhich a tube connects

the pulmonary arteryto the aorta, mixing

unoxygenated and oxy-genated blood. Thistube is open during

fetal development whenthe lungs are not

needed but is supposed to close

after birth.

Fig. 7.4:Atrial Septal Defect: An abnormal opening

in the wall of muscle, orseptum, that divides the

two filling chambers,or atria, of the heart.

Patent DuctusArteriosus

PulmonaryArtery

Aorta

AtrialSeptalDefect

Right Atrium

SuperiorVena Cava

Fig. 7.3

Inferior Vena Cava

Fig. 7.4


are somewhat higher. Children with Down’ssyndrome have a higher chance of hav-ing atrioventricular canal defect.

Any surgical repair of atrial septal de-fect requires a heart-lung machine, andafterwards most patients can look forwardto a normal life expectancy.

Coarctation of the Aorta

In coarctation of the aorta, there is anabnormal narrowing of a short segmentof the aorta, usually less than an inchlong (Fig. 7.5). The aorta can be narrowedup to 90 percent in this area. Over time,it can become totally occluded. If theaorta is narrowed, blood to the lower bodybypasses the narrowing by using collat-erals, or tiny channels. In a healthy per-son, these collaterals are barely func-tioning, but in patients with coarctationthey can become very large.

This defect can be diagnosed at birthor shortly afterwards. Typical signs in-clude high blood pressure in the armsand abnormally low blood pressure inthe legs, and strong pulses in the armsand minimal or absent pulses in the legs.Some infants may develop severe heartfailure, and an emergency operation maybe required. In less severe cases, coarc-tation of the aorta is not diagnosed untila child is older and sometimes not untilhe or she is a teenager or an adult.

The life span of people with coarcta-tion of the aorta can be severely short-ened if they do not have surgical correc-tion. This is partially because of the highblood pressure in the upper body, whichcan result in strokes or heart failure.Also, infection is prone to occur at thepoint of the coarctation, or the aorta canrupture near the coarctation.

In surgery, doctors can remove thenarrowed area and suture the normalends of the aorta back together. Or theycan widen the narrowed area with apatch, or replace the narrowed area witha tube made of Dacron. This is a curative

operation. The chance of surviving repairof isolated coarctation of the aorta isgreater than 99 percent. The arteries thatsupply blood to the spinal cord sometimesoriginate from the aorta in the area of thecoarctation. Because of this, about one intwo hundred patients undergoing surgicalrepair develops some degree of paralysis ofthe lower half of the body. Occasionallythe defect can recur and has to be reoper-ated on. If it does recur, the narrowed seg-ment can sometimes be dilated with a bal-loon catheter.

Transposition of the Great Arteries

In transposition of the great arter-ies, the two main arteries coming out ofthe heart, the aorta and the pulmonaryartery, are switched (Fig. 7.6). As a re-sult, when the unoxygenated blood re-turns from the veins into the heart, it ispumped directly back into the aorta,making the infant very cyanotic. Theoxygenated blood that returns fromthe lungs is pumped back into the lungsthrough the pulmonary artery, whichbranches off the left ventricle. Whenchildren have any congenital heart de-fect in which the child is cyanotic or the

103

Fig. 7.5: Coarctation of the Aorta: An abnormal narrowingof the aorta after itleaves the heart.

Coarctationof the Aorta

AorticArch

Fig. 7.5


skin is a bluish color, they are sometimesreferred to as “blue babies.” In some casesof transposition of the great arteries, therealso may be other heart defects, such asventricular septal defect.

Infants suffering from transpositionare usually quite cyanotic, and if it is notcorrected, they will probably not survivetheir first year of life. Before the advent ofthe heart-lung machine, there were somepalliative operations developed, but theseprocedures were not cures. In fact, eventoday many infants with transposition un-dergo a procedure to make or enlarge ahole in the atrial septum shortly afterbirth. This procedure is done in the car-diac catheterization laboratory with a spe-cial catheter threaded up through a bloodvessel in the groin. The hole in the atrialseptum allows mixing of blood and tem-porarily improves the infant’s conditionuntil a surgical repair can be made.

Currently there are a number of waysthis defect can be repaired surgically. Onetechnique involves switching the pul-monary artery back to the right ventricleand the aorta back to the left ventricle.This procedure is technically challengingbecause the coronary arteries that come

off the aorta are quite small, particularlyin infants. These tiny coronary arterieshave to be moved and reconnected to theaorta in its new location.

With current surgical techniques, thechances of surviving the surgical proce-dure, depending on the complexity of thetransposition malformation, are between90 and 95 percent. The long-term survivalis good for most patients.

Tetralogy of Fallot

This complicated condition is actual-ly four different congenital defects occur-ring simultaneously in the same heart.Tetralogy, in fact, means “set of four,” andFallot was a French physician who wasone of the first to describe the condition.

In this defect (Fig. 7.7), 1) there is aventricular septal defect; 2) blood flowfrom the right ventricle to the pulmonaryarteries is obstructed (the obstruction canbe at the pulmonary valve or in the rightventricular outflow tract leading to thevalve and/or in the pulmonary arteriesthemselves); 3) the aortic valve overridesthe ventricular septal defect; and 4) theright ventricle is abnormally thickened.

104

Fig. 7.6: Transpositionof the Great Arteries:

When the two main ar-teries arising from theheart, the pulmonaryartery and the aorta,

are switched, causingunoxygenated blood to

be pumped back outthrough the aorta

into the circulation. Thenormal heart at far

right is shown here forcomparison.

Aorta

PulmonaryVein

InferiorVena Cava

SuperiorVena Cava

RightVentricle

LeftVentricle

PulmonaryArtery

Normal HeartFig. 7.6


Because of the location of the ven-tricular septal defect in relation to theaortic valve and the obstruction of bloodflow through the pulmonary arteries tothe lungs, unoxygenated blood return-ing from the body is shunted from theright ventricle to the left ventricle. It mixeswith the oxygenated blood returning fromthe lungs, which results in blueness orcyanosis. In some forms of tetralogy ofFallot, the defects are more severe, par-ticularly in terms of the amount of un-oxygenated blood flowing from the rightventricle across to the left ventricle. Themore severe the obstruction, the morecyanotic the patient. In some cases, new-borns will suffer from severe cyanosis andmay have to undergo urgent surgery.

In most cases, doctors recommendthat the defect be corrected sooner ratherthan later, usually within the first sixmonths of life. The surgical repair in-cludes closing the ventricular septal defectand relieving the obstruction of bloodflow to the pulmonary arteries. In somespecial circumstances, however, palliativeshunting procedures are recommendedbefore a complete repair is made.

Because of the cyanosis associatedwith this defect, patients used to be called

“blue babies,” and the early surgical shunts,like the Blalock-Taussig shunt, that wereperformed were known as “blue baby oper-ations.” These operations would alleviatea good deal of the cyanosis and restorethe children to a more normal color.

The chance of surviving a primarysurgical repair is greater than 90 percent.Long-term survival in most of the patientswhose defect is repaired is good.

If the defect is not repaired, seriouscomplications can develop, including pro-gressive cyanosis, strokes and infectionsof the brain, pulmonary hemorrhage, andsevere hypoxic spells related to a lack ofoxygen. Without surgical intervention, mostpatients with tetralogy of Fallot will notsurvive until their twentieth birthday.

Pulmonary Valve Stenosis

Pulmonary valve stenosis is a narrow-ing of the heart valve located between theright ventricle and the pulmonary artery(Fig. 7.8). When the valve is very narrow,the patient may have substantial symp-toms while still an infant, including abluish tinge to the skin. This defect can belife threatening. In older children, symp-

105

Fig. 7.7:Tetralogy of Fallot:

A set of four individualdefects, including: 1) a ventricular septaldefect; 2) an obstructionof blood flow from theright ventricle to thepulmonary arteries; 3) overriding of the aor-tic valve above the ven-tricular septal defect;and 4) an abnormallythickened right ventricle.

Fig. 7.8: Pulmonary Valve Stenosis: An abnormally narrowed pulmonaryvalve, which is locatedbetween the right ventricle and the pulmonary artery.

Aortic ValveOverriding Defect

VentricularSeptal Defect

NarrowedPulmonary Valve

Thickened RightVentricular Wall

NarrowedPulmonary Valve

Fig. 7.7

Fig. 7.8


toms include fatigue or a reduced ability toexercise. The child may stand out becausehe or she cannot keep up with the otherchildren physically.

The diagnosis is often suspected afterhearing a heart murmur and obtaining anelectrocardiogram. An echocardiogramwill likely identify the defect and allow adefinitive diagnosis to be made. For sim-ple pulmonary valve stenosis, a ballooncatheter is used to dilate the valve, usual-ly with good results. Sometimes surgeryusing the heart-lung machine is neces-sary. In some cases, there is also muscu-lar obstruction within the right ventricle,and this tissue needs to be removed. Theresults, after balloon dilatation or surgery,are usually excellent. The chance of sur-viving these procedures is greater than 99percent. The long-term results are usual-ly excellent.

Congenital Aortic Stenosis

In this defect’s simplest form, the aor-tic valve is abnormally narrowed (Fig. 7.9).Other variations of this defect include nar-rowing of the aorta immediately above theheart valve or a membrane obstructingblood flow below the aortic valve. In some

cases, an abnormality of the muscle im-mediately below the heart valve causesobstruction. Children with severe forms ofaortic stenosis are likely to have symp-toms of heart failure and shortness ofbreath. This defect may be suspected be-cause of a heart murmur or because of anabnormal ECG. Confirmation of the diag-nosis would be made with an echocardio-gram. In some instances a cardiaccatheterization may be necessary to makethe diagnosis.

With the most severe forms, an infantmay require emergency heart surgery toopen the valve. Some pediatric heart cen-ters use a balloon catheter to open thenarrowed heart valve, thus postponingvalve surgery until the child is older.

The decision to recommend heartvalve surgery depends on how serious theobstruction is. This defect may be so mildthat surgical intervention is unnecessary.If surgery is necessary in straightforwardand uncomplicated forms of the disease,the chance of surviving the procedure isgreater than 98 percent. The chance ofsurviving the surgery is somewhat lowerin more complex forms of the disease, andsurgery is higher risk in critically illneonates. With a successful procedure,long-term results are often very good, al-though in many instances, a second heartvalve operation may be needed later.

Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS)is one of the most severe and life-threat-ening malformations of the human heart.“Hypoplastic” means “underdeveloped,”left heart refers to the structures thatmake up the left side of the heart, andsyndrome means a group of things thatappear together.

The job of the left heart is to receiveoxygenated blood from the lungs anddistribute it to the body. The left heartincludes the left atrium (left filling cham-ber), the left ventricle (main pumping

106

Heart Murmur:A noise produced fromblood flowing through

the heart or otherblood vessels or

through the lungs.

Neonate:A newborn, or a childwithin the first several

weeks after birth.

Fig. 7.9: Congenital Aortic Stenosis:

This defect is usually anabnormal narrowing ofthe aortic valve, whichis located between the

aorta and the left ventri-cle. There are, however,several different forms

of this defect.

NarrowedAorticValveFig. 7.9


chamber), the mitral valve (valve betweenthe left atrium and the left ventricle), theaortic valve (valve between the left ventri-cle and the aorta), and the aorta. HLHSconsists of a wide spectrum of malfor-mations in which one or more of thesestructures are critically small (Fig. 7.10).Despite the variation that can exist incases of HLHS, the net result is the same:The left side of the heart cannot do itsjob properly.

Unfortunately, this is not a rarecondition. Data from the New EnglandRegional Infant Cardiac Program foundHLHS to be present at a rate of 0.163 perone thousand live births.

Without surgery, 99 percent ofpatients with HLHS will die shortly afterbirth. In 1983, Dr. William Norwood atBoston Children’s Hospital reported thathe had successfully operated on an infantin two separate stages about a year anda half apart. That two-stage operationhas greatly improved the chance of sur-vival for infants born with HLHS. Today,Norwood’s two-stage repair has evolvedinto a three-stage repair performed overthe first few years of the patient’s life.

The goal of these three operations isto bypass the small left side of the heartby making the right ventricle the heart’smain pumping chamber. Since the rightventricle will, therefore, no longer be avail-able to perform its usual job of pump-ing blood to the lungs, the vessels thatnormally carry the unoxygenated blood(superior and inferior vena cavae) are con-nected directly to the lung arteries. Theflow of unoxygenated blood to the lungsoccurs passively without the benefit of anintervening pumping chamber. This typeof passive pulmonary blood flow in aheart with only one good pumping cham-ber is called a Fontan operation — anoth-er variation is the Glenn operation. Theyare applicable not only in HLHS but alsoin other types of abnormal hearts with asingle pumping chamber.

The advantage of the three-stageNorwood procedure is that these opera-tions can almost always be performed;the disadvantage is that it requires threeoperations and still results in a heart withonly one pumping chamber. Furthermore,the long-term results of using the rightventricle (instead of the left ventricle) topump oxygenated blood to the body arenot known.

Dr. Leonard Bailey at LomaLinda University has pioneered the useof newborn heart transplantation for thetreatment of HLHS. If a donor heart isavailable, cardiac transplantation requiresonly one operation and produces a struc-turally normal heart with two pumpingchambers. Unfortunately, about 25 per-cent of the newborns who would need acardiac transplantation die of complica-tions while waiting for a donor heart. Aftercardiac transplantation, the patient musttake antirejection medication for the restof his or her life. The side effects of thesemedicines can become serious over time,and rejection of the transplanted heartcan occur. Incidentally, Bailey createdquite an uproar in the news media in1984 when a human heart donor was not

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Fig. 7.10: Hypoplastic Left Heart Syndrome:This literally means underdeveloped leftheart. Some or all ofthe structures on theleft side of the heart,including the heart’smain pumping chamber, are undersized.It is a very seriouscongenital defect.

MitralValve

Aortic Arch

LeftVentricleFig. 7.10


available and he transplanted the heart ofa baboon into a desperately ill twelve-day-old premature girl known as “Baby Fay,”who was suffering from HLHS.

At this point it is not clear which sur-gical treatment is better for hypoplasticleft heart syndrome. Both, however, are animprovement on previously availabletreatments. HLHS used to be 100 percentfatal during the first year of life. Althoughpediatric heart surgeons tend to holdstrong opinions, neither the Norwood pro-cedure nor cardiac transplantation is aperfect treatment option for HLHS, andneither approach is clearly superior. In thebest centers, roughly 60 percent of pa-tients who undergo either surgery arealive ten years later.

Ectopia Cordis

This is a rare congenital heart de-fect. As of 1989, only 219 cases had everbeen reported in the medical literature.

Ectopia means displacement, and cordismeans heart.

There are four types of this defect: theheart may be located in the neck, eitherpartially or completely in the abdomen, or,almost unbelievably, outside of the bodyon the chest (Fig. 7.11). Many infants suf-fering from this defect have other abnor-malities inside the heart as well.

When the heart is outside of the body,it is recommended that the infant under-go immediate surgery to put the heartback into the chest. The first successfulsurgery of this type was performed by Dr.Narish Saxena at the Children’s Hospitalof Philadelphia in 1975. This case, inwhich I was involved, was that of a childwho had to undergo multiple innovativesurgeries and practically lived the first fewyears of his life in the hospital.

Thoracopagus Twins

Identical twins occur at an inci-dence of four per one thousand births.Conjoined twins are identical twins whoare joined to each other in some place ontheir bodies. This form of twin is muchrarer and has an incidence of one per fiftythousand to one hundred thousandbirths. In 1811, in the country of Siam(now Thailand), a Chinese mother gavebirth to identical twins joined at the hip.The boys were named Eng and Chang,and they lived unseparated until theirdeath at age sixty-three years. They be-came famous as a result of being promot-ed as “freaks” by P.T. Barnum, who calledthem the “Siamese Twins,” and the termhas been used since then for all twinswho are born attached to each other.

Most Siamese twins are born dead,but there are about four hundred setsknown to have lived, ranging in life spanfrom just a few hours to the sixty-threeyears of Eng and Chang. They can bejoined in various places on the body, in-cluding the lower back, the abdomen, thehip, the leg, and even the head. About 40

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Fig. 7.11: Ectopia Cordis:A rare condition

in which an infant isborn with its heart

mislocated. In somecases, the heart is even

located outside of thechest cavity. Fig. 7.11


percent of the surviving twins are joined atthe chest, face to face, looking each otherin the eye (Fig. 7.12). They are called “tho-

racopagus twins.” (Thoraco refers to thechest; pagus is a Greek word meaningfixed). Thoracopagus twins may also bejoined at the abdomen down to the pubis.They may share a common liver, intestinesor even a heart.

For pediatric heart and thoracic sur-geons, the division of thoracopagus chil-dren ranges from extremely challenging tooutright impossible with today’s knowl-edge. My experience in one case withKoop, the chief pediatric surgeon, and Dr.L. Henry Edmunds, Jr., the chief heartsurgeon at the University of Pennsylvania,involved a set of Siamese twins with onlyone heart between them. Before thesurgery could be done, the children had tobe taken to the operating room and theprocedure mapped out ahead of time, po-sition by position, turning them in differ-ent ways for each incision. The surgerywas considered a success even though wewere able to save only one child, but gen-erally success in this very complicatedfield has been limited. Twin separation re-mains a challenge for the pediatric surgi-cal community.

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Fig. 7.12: Conjoined Twins:Commonly referred to as “Siamese twins,”these are a set of twinswho are joined at someplace on their bodies,including at the chest.

Fig. 7.12

Documents

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