operative treatment atrial septal defect: clinical hamodynamic … · operative treatment ofatrial...

Brit. Heart ., 1967, 29, 725.

Operative Treatment of Atrial Septal Defect:Clinical and Hamodynamic Assessments

in 175 PatientsLAWRENCE H. COHN, ANDREW G. MORROW, AND EUGENE BRAUNWALD

From the Clinic of Surgery and the Cardiology Branch, National Heart Institute, Bethesda, Maryland, U.S.A.

Atrial septal defect is one of the most commoncongenital cardiovascular malformations, and as aresult cardiologists have become generally familiarwith its various clinical and hiemodynamic mani-festations, and surgeons with the methods of opera-tive treatment required. Relatively less informationis available, however, concerning the effectivenessof operation as measured by the results of detailedpre- and post-operative evaluations. The presentreport describes such evaluations, carried out in 175patients with atrial septal defect, who were studiedand operated upon at the National Heart Institute.

SELECTION OF PATIENTSThe 175 patients described were studied and operated

upon consecutively between February 1958 and July1965. Atrial septal defects of the septum secundumtype were proved to be present in 150 patients, and sinusvenosus defects, associated with partial anomalous pul-monary venous connexion, in the remaining 25.Patients with the incomplete form of persistent A-Vcanal, and those in whom atrial septal defect was asso-ciated with another congenital or acquired cardio-vascular malformation that required concomitanttreatment were excluded from the analysis.

CLINIcAL DESCRIPTIONSAge and Sex. The 175 patients, of whom 70 were

male and 105 female, ranged in age from 4 to 65 years;41 were less than 13 years, and 37 were more than 40years. The sex distribution was identical amongpatients with secundum and sinus venosus defects.

Symptoms and Historical Data. One-hundred andfifty patients were symptomatic before operation. Exer-tional dyspnoea and decreased exercise tolerance werethe most frequent symptoms, and were described by 97patients. Thirty-one patients had had frequent respira-tory infections, 28 palpitations, 10 retarded growth, 17

Received January 2, 1967.725

substernal chest pain, 13 recurrent tachycardia, and 4 hadexperienced syncope. Twenty-nine patients were undertreatnent for heart failure or much reduced cardiacreserve at the time of initial evaluation. Only 25patients were completely asymptomatic, as judged byboth prospective and retrospective analysis, and theywere initially referred solely because a heart murmur orcardiomegaly had been detected on a routine examina-tion.

PHYsICAL FINDINGSRight ventricular enlargement, indicated by a

palpable right ventricular lift, was evident in 144 ofthe 175 patients. A systolic thrill along the leftsternal border was palpable in 16 patients, only 7 ofwhom subsequently proved to have a systolic pressuregradient between the right ventricle and pulmonaryartery greater than 10 mm. Hg. Fixed splitting ofthe second heart sound throughout the respiratorycycle was present in 161 patients; 14 (8%) exhibitednormal splitting of the second sound during respira-tion, a finding verified in each instance by phono-cardiography. The pulmonary component of thesecond sound was increased in intensity in 133patients. An early systolic ejection sound was audibleat the pulmonary area in 24 of the 175 patients(13%), but was not consistently related to increasedpulmonary arterial pressure, as only 4 patients withthis finding had a systolic pulmonary arterial pres-sure greater than 50 mm. Hg. A systolic ejectionmurmur, best heard in the second and third leftintercostal spaces, was detected in 173 of the 175patients; the usual intensity was grade 2/6 or 3/6.In one patient only a diastolic murmur characteristicof pulmonary regurgitation was present, and in an-other only a tricuspid flow murmur was audible.Murmurs characteristic of pulmonary regurgitationwere noted in 14 patients, and only 7 of these hadsystolic pulmonary artery pressures greater than 30

Cohn, Morrow, and Braunwald

mm. Hg. A rumbling diastolic murmur, maximalat the left lower sternal border, and increasing withinspiration, was audible in 31 patients. Of these31 patients, 20 had a pulmonary to systemic flowratio (Qp/Qs) greater than 2 0/1 0. Cyanosis waspresent in 4 patients, left ventricular heaves in 9,and sustained systemic hypertension in 4.

ELECTROCARDIOGRAPHIC FINDINGSSinus rhythm was present in 163, nodal rhythm

in one, and atrial fibrillation in 5 patients. Theremaining 6 patients had coronary sinus rhythm,and 5 of them had sinus venosus defects. An RSR'complex in right praecordial leads was evident in 111ofthe 175 patients,and complete right bundle-branchblock was present in 23 of them. Electrocardio-graphic evidence of right ventricular hypertrophywithout an' RSR' complex in right prxcordial leadswas found in 12 patients.

Ninety-nine patients presented with either rightor vertical axis. Ten patients exhibited left axisdeviation which, .though unusual in secundum typeatrial septal defect, is a finding that has been pre-viously documented (Harrison and Morrow, 1963).Right atrial enlargement was indicated in 31patients. In 6 other patients the P wave in lead IIwas broad and notched. Although this configura-tion is generally considered to represent left atrialenlargement, it has previously been observed inpatients with atrial septal defect and probablyresults from a disturbance of intra-atrial conduction(Sanchez-Cascos and Deuchar, 1963). The electro-cardiograms of 4 patients were entirely normal.

RADIOLOGICAL FINDINGSThe right ventricle and main pulmonary artery

were enlarged in 130 of the 175 patients. Increasedprominence of the pulmonary vasculature was evi-dent in 155 patients, and ranged in severity from amild increase to frank plethora. A radiologicaldiagnosis of pulmonary hypertension, indicated byincreased central vascularity and tapering of pul-monary arteries toward the periphery, was made in14 patients, all of whom were subsequently shownto have systolic pulmonary arterial pressures greaterthan 70 mm. Hg. The radiographic appearance ofthe heart and great vessels was normal in only 3 ofthe 175 patients.

H)MODYNAMIC FINDINGSAll patients were studied before operation by right

heart catheterization. The presence, site, and mag-nitude of the left-to-right shunt was established bythe results of inhaled 85Kr (Sanders and Morrow,1959) or N20 tests (Morrow, Sanders, and

Braunwald, 1958), and also by oximetry when abidirectional shunt was present. Arterial indicator-dilution curves were also recorded in all patientsafter injections into the right side of the heart, andusually after injections into the left atrium, left ven-tricle, and one or more pulmonary veins.The right ventricular systolic pressure was 30

mm. Hg or more in 101 of the 175 patients, and30 had a right ventricular systolic pressure of 50mm. Hg or more. In most of these patients thepulmonary arterial systolic pressure was equal tothat in the right ventricle, but in several youngerpatients significant flow gradients between the rightventricle and pulmonary artery were recorded. In-crease of the right ventricular end-diastolic pressureabove the normal level of 6 mm. Hg was notedbefore operation in 35 patients. The right ventri-cular end-diastolic pressure was 10 mm. Hg or morein 10 patients, 9 ofwhom had raised right ventricularsystolic pressures.The left ventricle was catheterized, via the inter-

atrial communication, in 126 patients, and in 5 theleft ventricular end-diastolic pressure was abnor-mally high (> 12 mm. Hg). Four of these patientshad Qp/Qs greater than 2 0/1 .0, and the fifth had asystolic pulmonary arterial pressure of 95 mm. Hg.All but one of the 5 patients with abnormal leftventricular end-diastolic pressures also had ab-normally raised right atrial mean pressures.

Systolic pressure gradients between the rightventricle and pulmonary artery were recorded in112 patients, ranging from 1 to 33 mm. Hg, andaveraging 6 mm. Hg. In atrial septal defect, suchpressure gradients have been attributed to increasedblood flow across a relatively rigid valve ring whichdoes not dilate to the same extent as the pulmonaryartery (Schrire and Vogelpoel, 1964). Among thepresent patients, however, there was no correlationbetween the magnitude of the "flow" gradient andthe magnitude of the pulmonary to systemic flowratio. Of the 112 patients with gradients, only 19had a Qp/Qs in excess of 2 5/1 0; 11 had a Qp/Qsgreater than 3 0/1 0. Of 19 patients with gradientsof 10 mm. Hg or more, only 10 had a Qp/Qs in ex-cess of 2 0/1 -0. Fifty-eight patients demonstratedpressure gradients in excess of 5 mm. Hg, and againno correlation with the Qp/Qs could be discerned.The mean pressure was recorded as the cardiac

catheter was withdrawn from the left atrium to theright, across the interatrial defect, in 159 patients;in 82 a small pressure differential from 1 to 5mm. Hg (average 1 8) was noted; the left atrialalways exceeded the right atrial pressure. Theaverage size of the defects in these 82 patients, asdetermined at operation, was approximately 3 cm.This 'finding contrasts with a popular conception

726

Operative Treatment of Atrial Septal Defect

that with defects greater than 2 cm. the two atriaare functionally a common chamber and that thepressures in them are identical (Nadas, 1963).

In every patient a left-to-right shunt was shownto enter the right atrium. The Qp/Qs ranged from1-2/1 0 to 6-0/1 0, and averaged 21/1 0. Right-to-left shunts at the atrial level were demonstrated in40 patients by arterial indicator-dilution curvesrecorded after injections into the venm cave or rightatrium.

Attempts were made to define the drainage path-ways of the pulmonary veins in all patients, by com-parison of the appearance times and contours ofarterial indicator-dilution curves recorded after in-jections into the pulmonary veins, right atrium, andvene cave (Braunwald, Lombardo, and Morrow,1960). In 25 patients such pre-operative assess-ments indicated partial anomalous pulmonaryvenous connexions, and in 19 of these patients sinusvenosus defects and anomalous right pulmonaryvenous connexions were found at operation; in theother 6, large defects of the secundum type werepresent. In the other 6 patients who proved to havesinus venosus defects, the correct diagnosis was notestablished before operation, usually because indi-cator-dilution curves from appropriate sites ofinjection could not be obtained. Indicator-dilutioncurves were recorded after left atrial injections in 17patients with sinus venosus defects; in 10 of the 17patients no left-to-right shunt was apparent, indi-cating that in them the shunt originated almostentirely from the anomalous pulmonary veins.

OPERATIVE METHODSAU patients were operated upon with the use of

cardiopulmonary bypass. The early and generallyunsatisfactory experience in this clinic with theoperative treatment of atrial septal defect duringinflow occlusion and general hypothermia has pre-viously been reported (Morrow et al., 1960). Acomplete median sternotomy was almost universallyemployed, though right thoracotomies were used insome patients. The heart-lung machine consistedof a disc oxygenator and roller pumps, and in mostinstances was primed with heparinized whole bloodwhich had been drawn from donors 48 hours pre-viously. Bypass was conducted at 37°C., and flowrates of 2-0-2-2 l./min./m.2 were provided.The septum secundum defects were of the recog-

nized anatomical types, i.e. foramen ovale, inferiorvena cava, and posterior; they ranged in diameterfrom 1 to 6 cm. In some instances two defectsseparated by strands of fibrous tissue were present,and were converted to a single defect by excision ofthe intervening tissue. In 129 patients with septumsecundum defects the interatrial septum was re-

constituted with a patch of knitted teflon fabric,and the specific operative methods are illustrated inFig. 1 and 2. Only 21 secundum defects wereclosed by direct suture. The sinus venosus defectswere all repaired by the insertion of a teflon fabricpatch which partitioned the superior vena cava andright atrium in such a manner as to direct the flowfrom the upper and middle lobe pulmonary veinsinto the left atrium (Fig. 3-5).

Interatrial communications were closed with per-forated prostheses in 6 adult patients, 5 of whomhad severe pulmonary hypertension and bidirec-tional shunts. The sixth patient had systemichypertension and had had pulmonary cedema andleft ventricular failure; in him the perforated patchwas employed to permit decompression of the leftrather than the right ventricle in the early post-operative period. Four of these patients hadsecundum defects, and 2 had sinus venosus defects.All of these 6 patients survived operation.

RESULTS OF OPERATIONSix of the 175 patients (3 4%) died at or following

operation. All 6 patients had septum secundumdefects, and the principal causes of death in eachpatient are summarized in Table I. Post-operativecomplications of greater or lesser significanceoccurred in 88 of the 175 patients, and these aresummarized in Table II. Arrhythmias representedmore than half of all complications, and atrial flutter,atrial fibrillation, and rapid nodal rhythm were mostfrequently observed. In only 3 patients did a post-operative arrhythmia (atrial fibrillation) persist untildischarge. The methods in this clinic for themanagement of post-operative arrhythmias, and theother frequent complications of cardiac operations,have been presented elsewhere in detail (Williams,Morrow, and Braunwald, 1965).

POST-OPERATIVE CLINICAL AND HrMODYNAMICCORRELATIONS

Of the 169 patients who survived operation, 154returned to the Institute for detailed clinical andheemodynamic assessments at an average interval of7 months after operation. For various reasonscardiac catheterization was not carried out afteroperation in the remaining 15 patients and, thoughtheir clinical examinations indicate a satisfactoryoperative result, they have been excluded fromfurther analysis.

Complete abolition of the circulatory shunt, and aright ventricular systolic pressure less than 40mm. Hg were demonstrated after operation in 133patients. The absence of a shunt was proved in all

727


m I

FIG. 1.-Operative exposure and methods in the repair of a large atrial septal defect ofthe septum secundum(foramen ovale) type. After caval cannulation and the institution of cardiopulmonary bypass a right atriotomyis made. The margins of the defect are defined, and mattress sutures placed at the upper and lower poles.A series of interrupted sutures is placed when the intracardiac portion of the aortic root comprises a marginof the defect, or when no septal remnant remains posteriorly or inferiorly. The sutures are placed through

the margin of a teflon prosthesis cut to appropriate shape.

patients by the results of the inhaled foreign gastests, and by the appearance times and contours ofindicator-dilution curves recorded after injectionsin the right heart and/or pulmonary artery. Of

these 133 patients without significant residualhwmodynamic abnormalities, 125 were asympto-

matic; all of the remaining 8 patients describedsymptomatic improvement, but some limitation of

TABLE IPRINCIPAL AND CONTRIBUTORY CAUSES OF DEATH IN 6 PATIENTS WHO DIED AFTER OPERATIONS

FOR ATRIAL SEPTAL DEFECT

Prior treatment PulmonaryPatient, age, and sex for congestive artery pressure Circumstances of death

failure (mm. Hg)

1 8 F Yes 47/34 Tracheobronchitis, severe respiratory insufficiency, hypoxia leadingto cardiac arrest; no tracheostomy

2 5 M No 30/8 Tracheobronchitis, respiratory insufficiency, tracheostomy; acuteupper gastro-intestinal bleeding, perforated gastric ulcer, deathduring laparotomy

3 65 F Yes 33/5 Obliterative pleuritis, right lung lacerated when drainage tube(R.V.) placed; massive bleeding post-operatively necessitating lobec-

tomy; death during second operation4 51 F Yes 95/30 Staphylococcal infection of mediastinum and pericardium; prophy-

lactic antibiotics not given during this period (1960)5 43 F No 33/12 Inferior cava partially directed to left atrium at previous operation;

death from air embolism at second operation6 59 F Yes 68/36 Acute myocardial infarction on day of hospital discharge; necropsy

performed

728

,e-. -7 ----awQwa

elI

I O"

Operative Treatment of Atrial Septal Defect 729

Fig. 2.-The prosthesis is drawn into place, and the interrupted sutures tied. The repair is completedwith continuous sutures which approximate the prosthesis to the septum. The anterior-superior margin is

closed last, and as these sutures are drawn tight air is carefully evacuated from the left atrium.

TABLE II

SIGNIFICANT NON-FATAL POST-OPERATIVE COMPLI-<4. CATIONS AMONG 175 PATIENTS OPERATED UPON FOR

.f. ATRIAL SEPTAL DEFECT.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

FIG. 3.-Operative exposure in the repair of a sinus venosus

type of atrial septal defect with associated anomalous pul-monary venous connexion to the superior vena cava and rightatrium. The occluding tape around the superior vena cavamust be placed well above the entrance of the highest pul-monary vein, and ligation of the azygos vein is often necessary.A vertical incision in the right atrium is extended into the

superior vena cava as shown.

I. CardiopulmonaryHamothorax requiring evacuationAtelectasisPneumonitisRespiratory distressPneumothoraxPost-pericardiotomy syndromeAcute congestive heart failure

II. Cardiac ArrhythnmiaAtrial flutterAtrial fibrillationNodal rhythmSinus arrestTransient complete heart blockSecond degree heart blockEctopic atrial pacemakerParoxysmal atrial tachycardiaInterference dissociation

III. Gastro-intestinalUpper gastro-intestinal bleedingJaundice, idiopathic

IV. NeurologicalCerebral embolus, no residual

V. HFematologicalAcute thrombocytopeniaTransfusion reactionHxmolytic anamiaParoxysmal myoglobinuria

VI. InfectionsInguinal incisionPhlebitis

(35) (33%)

(5E111114

) (55%)

(2) (1-9%)

(3) (2 7%)3(4) (3-7%)

1

1

(4) (3*7%)1

3

Total 106 complicationsin 88 patients


FIG. 4.-The high-lying interatrial defect and the orifices of the pulmonary veins are exposed by retractionof the cannula, and a patch of teflon is cut to such a size and shape as to cover both, and partition the cavaand right atrium. The prosthesis is anchored with interrupted sutures and the repair completed with

continuous sutures.

exercise activity or mild dyspncea on exertion per-sisted (Functional Class II). Sixteen of the 133patients had been in congestive heart failure beforeoperation; of this number, 13 were asymptomaticand 3 were improved.The second heart sound varied normally with

respiration in 125 patients, but in 8 persistent fixedsplitting of the second heart sound was present. Asystolic murmur was no longer audible in 76 patients.Electrocardiographic evidences of some degree ofright ventricular hypertrophy were still present in76 patients, 18 of whom had had severe pulmonaryhypertension (24%). The changes in rate ofgrowthwhich occurred after operation were determined inthe 36 children (less than 12 years of age) in thisgroup, and many evidenced a spurt in growth.Within 6 to 12 months the weight of 30 of the 36patients increased from an average percentile of 25to one of 51. Nineteen patients increased theirheight percentiles, from an average of 40 to anaverage of 63.

Systolic pressure gradients between the rightventricle and pulmonary artery in excess of 5mm. Hg disappeared after operation in 23 of the 53patients in this group in whom such gradients hadbeen demonstrated before operation. In those inwhom gradients persisted, they ranged from 1 to10 mm. Hg, and averaged 4 mm. Hg. Normalright ventricular end-diastolic pressures weredemonstrated in 28 of the 31 patients in whom thispressure was abnormally raised before operation.

Twenty-three patients who had severe pulmonaryhypertension before operation (right ventricularsystolic pressure 50 mm. Hg or greater) were studiedafter surgery. In 14 the systolic right ventricularpressure was less than 40 mm. Hg, and in 7 it was30 mm. Hg or less (Fig. 6). Of these 14 patients,also considered in the foregoing analysis, 2 (ages 44and 56) had been in congestive heart failure. Oneof them was asymptomatic after operation.

In the 9 remaining patients the right ventricular

730


)ulm.vernr1.at'viuh

FIG. 5.-Final appearance of the repair. The blood returned from the pulmonary veins is diverted beneaththe prosthesis, through the defect, and into the left atrium. The incision in the atrium and cava is closedwith an everting suture to assure approximation of the intima, and care is taken that the caval lumen is not

narrowed. In this patient the foramen ovale was patent and was closed by a single suture.

systolic pressure was reduced in comparison to thepre-pperative level, but was still 40 mm. Hg or

more. These 9 patients ranged in age from 12 to44 years at operation, and 4 of them had been incongestive heart failure. After operation, 8 of thepatients with residual right ventricular hyper-tension were asymptomatic, and one was improved.All had electrocardiographic evidence of rightventricular hypertrophy before operation, and thisfinding persists in 8. The right ventricular end-

diastolic pressure was raised before operation in 3of these 9 patients, and after operation in 2. Threepatients had systolic pressure gradients between theright ventricle and pulmonary artery before opera-tion, and in each no gradient was evident at post-operative study.The interatrial defect was closed with a perforated

prosthesis in 5 of the 30 patients who had severe

pulmonary hypertension before operation, and havebeen included in that analysis. The detailedhaemodynamic findings in 4 of these patients havebeen presented previously (Braunwald and Morrow,1963), and the pre- and post-operative right ventri-cular pressures in all 5 are included in Fig. 6. Theright ventricular pressure in one patient fell from100 to 35 mm. Hg, but in the others the systolicpressure remains at or near pre-operative levels. In4 patients determinations of the pulmonary to

systemic resistance ratio were made both before andafter operation. All were raised before (0-29 to0 55, average 0 44), and no significant changesoccurred after operation, the ratios ranging from0 36 to 9 55. One patient has no residual shuntthrough the prosthesis (36 months); 2 have negative85KKr inhalation tests, but small left-to-right shuntsare evident on indicator-dilution curves (8 and 12months); the remaining 2 patients have residualleft-to-right shunts resulting in Qp/Qs of 1.1 and1 2: 1, respectively. No patient has a right-to-leftshunt.

Residual left-to-right shunts were found at post-operative cardiac catheterization in 11 of the 148patients in whom immediate and complete correc-tion of the malformation had been attempted, i.e.patients in whom a perforated prosthesis was notinserted. Eight of the patients had secundunm de-fects, and 3 had venosus defects. In 4 patients withresidual shunts secundum defects had been closedby direct suture, a method no longer employed inthis clinic. Seven of the 11 patients were asympto-matic after operation, and 6 of them had smallshunts, Qp/Qs being 1 3/1-0 or less. The 3patients who improved (Class II) have largershunts (Qp/Qs 1 -3-1 5/1 -0), but a further operationwas not recommended. The remaining patient

731


I lOr

I*F~90

EELi'= 80-n

(.

-J

t> 6C

cn

cc 5

C-)

Ir-

z 4C

= 3Cc-

Hk

20f

1o0

PRE-OP POST- OP

FIG. 6.-Graphic representation of the right ventri-cular systolic pressures recorded before and afteroperation in 23 patients with atrial septal defect, andin whom the pre-operative pressure was 50 mm. Hg orgreater. Points designated P.P. indicate thosepatients in whom the defect was closed with a per-

forated prosthesis.

is the only one in the entire group of operativesurvivors whose symptoms became worse afteroperation. Before operation, he had only slightexertional dyspncea, and Qp/Qs was 2 0/1 -0. Threemonths after operation he became distinctly moresymptomatic, and developed left and right heartfailure; only a small residual shunt was demon-strated at catheterization, but the right atrial andright ventricular end-diastolic pressures were

strikingly raised. He was considered to havedeveloped a cardiomyopathy of unknown type. In9 of the 11 patients who later proved to have residualshunts, appropriate arterial indicator-dilution curveswere recorded at the conclusion of the operativeprocedure (Morrow et al., 1966). In 3 patients thecontours of the curves were normal, indicating thata complete repair was achieved, but was followed byrecurrence of the defect; in 6 patients the intra-operative curves were abnormal, indicating that theinitial repair was incomplete.

One additional patient, not previously described,was found to have a small (Qp/Qs= 1 2/1 0) residualshunt after repair of a secundum defect. Post-operative hemodynamic and angiographic studiesdemonstrated that the defect was closed, and thatthe shunt resulted from a previously unrecognizedconnexion ofa left pulmonary vein to a left vena cava.He was asymptomatic.

COMMENTIn this clinic a decision concerning the advisa-

bility of operative treatment in a patient with atrialseptal defect is arrived at only after both clinical andhmmodynamic assessments. Operation has usuallybeen recommended to any patient, symptomatic ornot, when a pulmonary to systemic flow ratio1.5/1.0 or greater is demonstrated at cardiaccatheterization. Infants, unless in severe cardiacdecompensation, or patients with serious inter-current disease constitute infrequent exceptions tothis general policy. When severe pulmonary hyper-tension and a bidirectional shunt are demonstratedat pre-operative study, operation has been advisedwhenever the net flow through the defect has beenshown to be left to right; in such patients gradualclosure of the communication with a perforatedprosthesis has generally been employed. The re-sults of operative treatment in the 175 patientsdescribed indicate that these criteria are generallyvalid ones in the management of patients with atrialseptal defect.

Six of the 175 patients (3 4%) died at or followingoperation, and the principal contributory factorsare worthy of comment. Four of the patients wereadults, all over 40 years of age; 3 of them had beentreated for congestive heart failure, and 2 hadsevere pulmonary hypertension. These factors,prior congestive heart failure, advanced age, andpulmonary hypertension, have been designated inother reports as contributing to an increased opera-tive risk in atrial septal defect (McGoon et al., 1959;Gross, 1962; Sellers et al., 1966). In 3 of thesepatients, however, these factors were not directlyresponsible for the deaths which resulted fromtechnical errors (air embolism, lung laceration, in-fection). The deaths of the two children wereprobably the result of the inadequate methodsutilized in managing post-operative respiratorycomplications at the time they were operated upon(1958). With the exception of the patient who diedof myocardial infarction, it is likely that none of thepatients would have died if present methods ofoperative and post-operative management had beenavailable, a conjecture attested by the fact that nopatient has died following operation for atrial septaldefect within the past four years.

732

DF

Dk

0e

0F


The post-operative hmmodynamic studies re-vealed that complete abolitionm of the circulatoryshunt was achieved in 137 of 148 patients (93%) inwhom immediate complete closure of the defect wasattempted, an incidence of complete repair similarto that reported by Sellers and associates (Sellerset al., 1966). Fortunately, the residual shunts havegenerally been small, and no patient has required asecond operation. Incomplete repairs may belargely obviated by more precise operative methods.Direct suture of secundum defects is inadvisable,since dehiscence of the suture line may result whenthe heart fills with blood (Morrow et al., 1960);among the 21 patients in whom secundum defectswere sutured, residual shunts were demonstratedin 4 (19%). When a prosthesis is utilized in eithera secundum or sinus venosus defect, it must beaccurately and securely fixed, preferably with syn-thetic non-absorbable sutures. With a sinusvenosus defect, it is also necessary that all the rightpulmonary veins be identified before the prosthesisis placed, since a residual shunt may result from anunrecognized segmental pulmonary vein enteringthe vena cava at or even above the level of theazygos vein. Finally, the adequacy of the repairmay be immediately assessed by appropriate intra-operative indicator-dilution curves, and if a residualshunt is demonstrated a further attempt at correc-tion may be indicated (Morrow et al., 1966).

Severe pulmonary hypertension did not prove tobe a significant direct cause of increased mortalityand morbidity in the group of patients described.Twelve patients had right ventricular systolic pres-sures of 70 mm. Hg or greater; one died, of a media-stinal infection. Among surviving patients whohad right ventricular hypertension before operation,however, 16 of 23 still had an abnormally raisedpressure ( > 30 mm. Hg) after operation. In asimilar group of 11 patients reported by Beck andassociates (Beck et al., 1960), the pulmonary arterialsystolic pressure remained greater than 40 mm. Hgin 6 patients after operation; in patients with normalpressures at rest, increases to abnormal levels wereobserved with muscular exercise. Unlike patientswith large ventricular septal defects, where pul-monary vascular changes may begin in infancy(Shepherd, 1959), pulmonary vascular disease israrely seen before the third decade of life in patientswith atrial septal defect (Dexter, 1956), a findingsubstantiated by this study. It has been postulatedthat the hamodynamic sequelse of an atrial septaldefect, high pulmonary flow at a low pulmonaryarterial pressure, require 20 or more years to producepulmonary vascular disease. Thus, despite com-plete repair of the defect, varying degrees of in-creased pulmonary vascular resistance persist in

many older patients following operation. The im-portant question as to whether the pulmonaryvascular resistance may ultimately fall can beanswered only by the results of hemodynamicstudies performed at much later post-operativeintervals.

SUMMARYThe results of operative treatment were assessed

in 175 patients with atrial septal defects; 150 haddefects of the septum secundum type, and 25 hadsinus venosus defects with partial anomalous pul-monary venous connexion. Forty-one patientswere younger than 13 years, 37 older than 40; 150patients were symptomatic, and 29 were undertreatment for heart failure. Cardiac catheterizationwas performed in every patient before operation,and left-to-right shunts resulting in pulmonary tosystemic flow ratios of 1 '2/1 -0 to 6 0/1 0were demon-strated. Right-to-left shunts were present in 40patients. The right ventricular systolic pressurewas abnormally high (> 30 mm. Hg) in 101 patients,and it was 50 mm. Hg or greater in 30.During cardiopulmonary bypass, 129 secundum

defects were closed with prostheses, 21 by directsuture; prostheses which partitioned the atrium andcava and diverted the return from the anomalouspulmonary veins were utilized in all sinus venosusdefects. Perforated intracardiac prostheses wereemployed in 5 patients with extreme pulmonaryhypertension and bidirectional shunts; all survived.Six of the 175 patients (3 4%) died at or followingoperation, and significant but not fatal complica-tions occurred in 88 patients.

Detailed post-operative clinical and heemo-dynamic evaluations were performed in 154 sur-viving patients; 135 are asymptomatic, 18 improved,and one patient worse as the result of cardiomyo-pathy. Complete abolition of circulatory shuntswas proved at post-operative cardiac catheterizationin 93 per cent (137/148) of patients in whom com-plete closure was attempted. In no patient has aresidual shunt necessitated further operation. Of30 patients with right ventricular systolic pressuregreater than 50 mm. Hg before operation, 23 wererecatheterized; 7 have normal pressures, while in 16the right ventricular pressure was found to be re-duced but still abnormal.

REFERENCESBeck, W., Swan, H. J. C., Burchell, H. B., and Kirklin, J. W.

(1960). Pulmonary vascular resistance after repair ofatrial septal defects in patients with pulmonary hyper-tension. Circulation, 22, 938.

Braunwald, E., Lombardo, C. R., and Morrow, A. G. (1960).Drainage pathways of pulmonary veins in atrial septaldefect. Brit. Heart-J., 22, 385.

733


Braunwald, N. S., and Morrow, A. G. (1963). The delayedclosure of atrial septal defects with perforated pros-

theses. Surg. Gynec. Obstet., 116, 579.Dexter, L. (1956). Atrial septal defect. Brit. Heart .,

18, 209.Gross, R. E. (1962). Atrial septal defects of the secundum

type. Progr. cardiovasc. Dis., 4, 301.Harrison, D. C., and Morrow, A. G. (1963). Electrocardio-

graphic evidence of left-axis deviation in patients withdefects of the atrial septum of the secundum type.New Engl. J7. Med., 269, 743.

McGoon, D. C., Swan, H. J. C., Brandenberg, R. O.,Connolly, D. C., and Kirklin, J. W. (1959). Atrialseptal defect: factors affecting the surgical mortalityrate. Circulation, 19, 195.

Morrow, A. G., Gilbert, J. W., Baker, R. R., and Collins, N. P.(1960). The closure of atrial septal defects utilizinggeneral hypothermia. J. thorac. cardiovasc. Surg., 40,776.

, Oldham, H. N., Callard, G. M., and Braunwald, E.(1966). The assessment of operative results in con-genital heart disease by intraoperative indicator-dilutioncurves. Circulation, 33, 263.

, Sanders, R. J., and Braunwald, E. (1958). The nitrousoxide test. An improved method for the detection ofleft-to-right shunts. Circulation, 17, 284.

Nadas, A. S. (1963). Pediatric Cardiology, 2nd ed., p. 366.Saunders, Philadelphia.

Sinchez-Cascos, A., and Deuchar, D. (1963). The P wave

in atrial septal defect. Brit. Heart_J., 25, 202.Sanders, R. J., and Morrow, A. G. (1959). The identifica-

tion and quantification ofleft-to-right circulatory shunts:a new diagnostic method utilizing the inhalation of a

radioactive gas, Kr06. Amer. J3. Med., 26, 508.Schrire, V., and Vogelpoel, L. (1964). Atrial septal defect.

Amer. Heart J., 68, 263.Sellers, R. D., Ferlic, R. M., Stems, L. P., and Lillehei, C. W.

(1966). Secundum type atrial septal defects: early andlate results of surgical repair using extracorporeal circu-lation in 275 patients. Surgery, 59, 155.

Shepherd, J. T. (1959). The pulmonary circulation in thepresence of interatrial, interventricular and inter-arterial communications. In Pulmonary Circulation-An International Symposium, 1958, ed. W. R. Adamsand I. Veith, pp. 204-215. Grune and Stratton, NewYork.

Williams, J. F., Jr., Morrow, A. G., and Braunwald, E. (1965).The incidence and management of "medical" com-

plications following cardiac operations. Circulation, 32,608.

734

operative treatment atrial septal defect: clinical hamodynamic … · operative treatment ofatrial...

Documents