DIRECT CARDIAC SURGERY IN THE TREATMENT OF CONGENITALPULMONARY STENOSIS

R. C. BROCK, M.S., F.R.C.S., F.A.C.S.LONDON, ENGLAND

THE LOT OF THE STTFFERER from cyanoticcongenital heart disease was indeed harduntil the brilliant pioneer work of Blalockand Taussig at last provided a remedy. Thestory is now too well known to need tellingagain; it is a part of surgical history. Thebasis of their contribution lay in recognitionthat the cyanosis and disability are caused inmany cases by the passage of far too littleblood to the lungs; associated with this isvenous-arterial mixing of the blood enteringthe aorta. Their remedy was a systemic-pul-monary anastomosis which, by conductinginadequately oxygenated blood back to thelungs, lessens the cyanosis and disability.The operation gained instant approval andhas given and continues to give excellentresults in the hands of surgeons the worldover. It is now well tried, well proved andwithout great risk. Nevertheless it is a pro-cedure to which there are a number of pos-sible objections. These may be consideredas follows.

1. It is an indirect operation which doesnot improve the primary or underlyingcardiac abnormality; the obstruction withinthe heart remains.

2. To the already abnormal circulation itadds yet another abnormality, an artificialductus arteriosus; this is a condition which,when it occurs naturally, is usually cor-rected by an operation. The analogy is per-haps not entirely satisfactory, because, in anaturally occurring patent ductus arteriosus(one that is not compensatory) there is anincreased pulmonary blood-flow and theheart is called upon to do an unnecessaryamount of extra work. In congenital pul-

monary stenosis the pulmonary blood-flowis diminished and the effect of the artificialductus is to correct this diminution-to bringthe pulmonary blood-flow nearer normal.

3. With the ordinary daily wear and tearcaused by the circulation forcing its way andswirling past the pulmonary obstructionmonth in and month out, year in and yearout, progressive increase of the pulmonarystenosis occurs. This is caused by the depo-sition of fibrin platelets from the blood-stream upon the obstructed region, leadingto fibrosis and contracture and the deposi-tion of a firm hyaline layer, often sur-mounted by warty vegetations and ulti-mately by calcification. The pulmonarystenosis becomes increasingly severe untileventually a condition of virtual pulmonaryatresia is reached. This can be observed inalmost all late cases dying from the disease.The presence of a systemic-pulmonaryanastomosis will enable many sufferers tolive in comfort for many years but it is in-evitable that this progressive increase of thepulmonary stenosis will still continue and,indeed, progress even further as life is fur-ther prolonged. Ultimately a condition ofpulmonary atresia is reached in which all,or virtually all, the blood from the rightventricle leaves the heart via the aorta andcan reach the lungs only through the arti-ficial ductus or other anastomotic channels;arteriovenous mixing is complete. In otherwords the condition resembles that of atruncus arteriosus, scarcely a condition thatis compatible with a long and trouble-free life.These potential drawbacks to the indirect

63

R. C. BROCK Annals of SurgeryJ u l y , 1 9 5 2

or anastomotic operations for the relief ofpulmonary stenosis inevitably raise thequestion whether, in spite of the immediateexcellent results, the long term results willbe found disappointing.

This in no way detracts from the meritsof the contributions of Blalock and Taussig,and of Potts and his colleagues, for theiroperations provide life and hope wherenone existed before. Certainly no one candeny the great benefits conferred upon aninfant or young child in such a desperatestate that its parents can look forward onlyto death to deliver it from its life of frus-tration and torment. The improvement thatfollows a successful anastomosis is pricelessin conferring relief to the sufferer and joy tothe parents. Whatever the later prognosismay be, the immediate saving of life andrelief of cyanosis and disability are para-mount.With older patients, however, the situa-

tion is not necessarily so immediately grave.The boy or girl in the early, middle, or lateteens who is reasonably well developed phy-sically and who is perhaps doing well atschool in so far as the disability and cya-nosis allow, demands more critical thought.The same immediate benefit can be con-ferred by a successful anastomosis; theparents attain the same joy. But we our-selves should be less content if we con-sider that the later prognosis is far fromcertain.The obvious alternative is an attempt to

relieve the obstruction within the heart bysome form of direct operation; this shouldhave numerous advantages. The relief ofthe pulmonary obstruction would permit anincreased blood-flow to the lungs and sorelieve the cyanosis and disability; the factthat more blood can leave the right ventriclevia the normal route means that less leavesvia the aorta and there is less venous-arterialmixing (Fig. 1). The abnormal heart con-dition is rendered less complex instead ofmore complex. Provided the operation is

successful in relieving the pulmonary ste-nosis, the daily wear and tear on any re-maining obstruction will doubtless not besignificant over many years. A good long-term prognosis therefore appears possible.We do not yet know whether these ob-

jections and advantages suggested for thetwo methods, indirect or direct, are corrector not. Time alone can tell. It may be thatwhen sufficient time has elapsed, the resultsof the indirect procedures will be shown tobe fully satisfactory and superior to thoseof the direct operations, which may provedisappointing. It is even now argued thatit is not justifiable to reject well-tried andsuccessful procedures, such as the Blalockand Potts operations, for something that isuntried. Surgery is not static, it mustdevelop and evolve, and for this reasonalone it is essential to test out the directoperations for the relief of pulmonary ste-nosis whatever the ultimate results may be.It is no disparagement of the indirect meth-ods to try and develop the direct ones; itwill be no shame to the direct procedures ifthey ultimately prove disappointing. Aproblem in surgery will have been facedand the answer found. 'We must await thisfinal answer; in the meantime it is clearlyjustifiable to evolve and apply bothmethods.

THE DIRECT RELIEF OF PULMONARY STENOSIS

The principle of a short-circuiting oper-ation to by-pass an obstruction is an excel-lent one in surgery and its application invarious parts of the body has led to the in-troduction of operations that have conferredgreat benefit upon mankind. In general,these anastomotic procedures are preferredbecause the direct removal of the obstruc-tion is either impossible or more dangerous,or more difficult. Before deciding whetherdirect operations for the relief of pulmonarystenosis are desirable we have, therefore, toconsider whether they are possible andwhether they can be carried out with no

64

CARDIAC SURGERY IN CONGENITAL PULMONARY STENOSIS

significantly greater morbidity or mortality.It can be said at once that they are indeedpossible, that the mortality and morbidityare no greater than with the indirect pro-cedures, and that the immediate results are

just as good.There are two conditions in which the

nature of the obstruction is generally suchas to make a direct operation impossible

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 4

FIG. 1.-Diagram to illustrate the impc

in determining the amount of right-to-lelan over-riding aorta. In pulmonary atresia high degree of pulmonary stenosis ( B)enters the aorta. In (C), in which the steoperation, more blood enters the puliescapes into the aorta.

and in which an anastomotic operation mustbe used. These are tricuspid atresia and thesevere forms of pulmonary atresia.

In tricuspid atresia the obstruction to theinflow portion of the right ventricle is suchthat the outflow portion is rendered largelyfunctionless, and in any case there is com-

plete venous-arterial mixing in the leftatrium and left ventricle; a systemic-pul-monary anastomosis is, therefore, the onlypracticable procedure and, as all the bloodmust leave the left ventricle, it matters littlewhether it reaches the lungs via the inter-ventricular septal defect and the pulmonaryarteries, or. via the aorta and an artificialductus.

In pulmonary atresia the obliteration ofthe pulmonary artery may be so long and so

severe that nothing but an anastomoticoperation can be done, and often not even

that. In two cases, however, I have found itpossible to perform a direct relief of theobstruction when it has been a pulmonaryvalvular atresia; the results have beenexcellent.

Apart from these two conditions, directrelief of the pulmonary stenosis is a feasibleand practical procedure in almost all cases.

In the first type that is to be presented, pul-monary valvular stenosis, not only is a directoperation eminently satisfactory but it is theonly one that should be done. It is now

generally accepted that a systemic-pulmo-nary anastomosis should be avoided, as the

Irtance of the degree of pulmonary stenosist shunting that ocurs in the presence ofl ( A) all the blood enters the aorta. Withmost of the blood from the right ventriclenosis is less or lias been relieved by directnonary artery and correspondinlgly less

results are inevitably bad. Hence, pulmo-nary valvulotomy for pulmonary, valvularstenosis with a closed interventricular sep-tum(ao-called "pure" lmonary valvularlsteneosis) is inevitably the operation to beselected to introduce the direct procedures.

PULMONARY VALVU'LOTOMY FOR "PVALVULAR STENOSIS

This condition was,r until recently,thought to be so rare as to be of little prac-tical significance. In the early days of theBlalock and Potts operations, a number ofcases were submitted to an anastomoticoperation, either due to an error of diagnosisor without realization of the ill-effects thatfollow. The cndition is now recognized tobe fairly common; certainly commonenough to make it imperative to recognizeBit so as to perform the correct operationupon it, avoiding an anastomosis.

Cases vary considerably in their clinicalpresentation, and this is no place to elab-orate upon them; it must suffice to mention

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that the interventricular septum is closed inall, but in a number the foramen ovale re-mains patent and allows venous-arterialmixing between the right and left atrium.The patients are either cyanosed from birthor become cyanosed later in life. Whenboth septa are closed central cyanosis is notseen, but the severe back-pressure effectsbehind the obstruction are transmitted, un-relieved, to the systemic venous system.

If a systemic-pulmonary anastomosis ismade, cyanosis is usually relieved and dis-

A.B. 7YEARA51m.J1

lessened in this way as well. The systemicvenous congestion is also lessened, espe-cially in those cases in which the foramenovale is closed.

If an anastomosis is done unwittingly ormistakenly in such a case, the only remedyis to perform a pulmonary valvulotomy andto close the anastomosis. In this way, theprimary disorder is corrected and the sec-ondary cardiac failure is relieved. I havehad to do this somewhat more complicatedoperation a number of times.

op/FA0LOT

'jeso100 ~~~~~~~~~R.V.V.A.

SLCS. PA. RM.BEfoRE %ALWL otff IS/A 72/APlER VALYULTOTY 30/xs 63/C9

FIG. 2.-Intracardiac pressure tracings taken at operation in a case of valvular stenosisin tetralogy of Fallot, before and after valvulotomy. It will be observed that althoughthe pulmonary artery pressure is raised and pulsations are now evident, the pressure in theartery is still less than that in the right ventricle.

ability is lessened. Sooner or later, however,right-sided failure develops; often sooner

than later. This is because no relief isafforded to the obstructed right ventricle;instead an extra strain is thrown on the leftventricle. The already overloaded circula-tion in the right heart finds an added burdenfrom the increased flow of systemic bloodinto the lungs.The correct treatment is relief of the

valvular obstruction by pulmonary valvu-lotomy, which allows more blood to enterthe lungs, thus allowing greater oxygena-

tion and reducing cyanosis and disability.The high pressure in the right ventricle andright atrium is relieved; the back-flow intothe left atrium is also relieved and cyanosis

The Results of Pulnmonary ValvulotomyFor "Pure" Valvular Stenosis. The technicaldetails of pulmonary valvulotomy have beendescribed elsewhere (Brock,4 Brock andCampbell5). I have operated upon 43 pa-

tients with "pure" pulmonary valvular ste-nosis; nine of these died as a result of theoperation, but in four of these, death oc-

curred before valvulotomy could be done;in one case during induction of anesthesia.These were all severe, late cases with gross

cardiac enlargement and a hopeless prog-

nosis. They died, not because of a directoperation upon the heart, but because theywere bad cases. If we exclude these, therewere five deaths among 39 patients on

whom a valvulotomy was done; two of these66

opERATn tECOb

BIEfORE VALVULOTOmY

CARDIAC SURGERY IN CONGENITAL PULMONARY STENOSIS

had previously had a Blalock's operationperformed and both were in heart failure.

It will thus be seen that the mortality ofthe operation need not be high. The initialhigh mortality was due to selection ofsevere, advanced cases because of ignoranceof the dangers of the operation and the wishto avoid high risk in a comparatively wellpatient. We now know that if pulmonaryvalvulotomy is done early enough in thedisease, before severe secondary changeshave occurred, the mortality is low and the

nosis is so low as to make pulmonary valvu-lotomy of little practical importance intetralogy of Fallot; that if one is to relyupon valvulotomy as a treatment, few pa-tients would benefit.

This is not so. If a proper search is made,a valvular stenosis will be found in between40 and 50 per cent of all cases. Apart frommy own experiences, Keith8 found a val-vular stenosis in 25/63 (40 per cent) ofcases of tetralogy of Fallot; Brown7 statesthat it is present in "about half," and Sellors

eoo emw.Iig

R.V. esA.?.A.tIRCHHIEJ lf.CMaSltRi t R.V.R.. P.A

so ___I_-_I

aa A t.a .k .. .. .lttitltiiLLti.,,LLLILII[Iid lI I

I -0 I

I ? A . w~P .V

FIG. 3.-Pressure tracings taken at operation to show a combined valvular and infundib-ular stenosis in tetralogy of Fallot. The lower tracing is after pulmonary valvulotomy andinfundibular resection. The improved pressure and pulsation in the pulmonary arterycan be seen; note the right ventricular pressure is still at a higher level.

results excellent. This has now beenabundantly proved bv a number of surgeons

(Blalock,1 Potts,9 and various personal com-

munications) in addition to my own ex-

periences.

PULMONARY VALVULOTOMY IN TETRALOGY OF

FALLOT

The same absolute need for a directoperation on the valvular stenosis does notexist in tetralogy of Fallot because thepresence of an interventricular septal defectand an overriding aorta spares the right sideof the heart. The arguments in favor of a

valvulotomy in place of an anastomosishave been detailed; it remains to considerhow often this is a feasible procedure intetralogy of Fallot. It has been stated thatthe incidence of pulmonary valvular ste-

and Belcher10 found it in 20 out of 65 cases(30 per cent).

I have performed pulmonary valvulotomyin tetralogy of Fallot 39 times; in the last 50cases a valvular stenosis was found in 24.In seven of these it was combined with an

infundibular stenosis; in -17, the valvularobstruction was solitary. The incidence was,

therefore, 34 per cent, or 48 per cent ifcombined with infundibular stenosis. Anisolated infundibular stenosis was presentin 21 (42 per cent); in four cases pulmon-ary atresia, and in one, tricuspid atresia waspresent. There is, therefore, no doubt thatthe presence of a valvular stenosis is an

important practical feature and pulmonaryvalvulotomy at once assumes great practicalimportance in the treatment of the con-

dition.67

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ILL11hillillfill.lLill ill

LLL PAVEhImit- - - IIW-rt- . __3IL:-I i I ,

R. C. BROCK Annals of SurgeryJuly, 1 9 5 2

The mortality in the 39 cases was three;two of the deaths occurred in adults. Theresult has been fair in seven; good or excel-lent in the remaining 29.Combined Figures for Pulmonary Valvu-

lotomy. If the cases of valvular stenosisoperated upon directly are combined, thetotal is 82: 39 of Fallot type and 43 withpure pulmonary valvular stenosis.Deaths total 12, an overall mortality of

some 15 per cent. Nine deaths occurred inthe first 21 cases, only three in the last 61(5 per cent).

PURE INFUNDIBULAR STENOSIS

Just as valvular stenosis occurs withclosed septa and demands a direct oper-ation for its relief, an indirect operationgiving a poor result, so may an infundibular

ISO."

valvular. It can be stated at once that it ispossible.

It has been assumed in the past, and isstill assumed by many, that in infundibularstenosis the obstruction is a long tubularfibrous or muscular narrowing quite unsuit-able for relief by resection. This error hasarisen from faulty observation on the deadheart in a oontracted state of rigor mortis,or worse still, when fixed hard in formalin.If specimens are examined carefully, andespecially if the heart is examined in thenatural living state at operation, it will befound that although in most, or all cases, theoutflow portion, or infundibulum, of theright ventricle shows a varying degree ofarrested development, the effective lumen isadequate except at one level, where thesignificant obstruction is linear or diaphrag-

AoMTICc MU.

0o - f t

GMONOFFFIG. 4.-Aortic blood-pressure tracing in a case of tetralogy of Fallot after infundib-

ular resection. When the pulmonary outflow tract is compressed the aortic pressure rises10 mm.Hg and falls again when the pressure is released, thus demonstrating variation inthe right-to-left shunt.

stenosis be met with as an isolated lesionwith the septa closed. Clearly, an anasto-motic operation should not be done for thesame reasons as in "pure" valvular stenosis.These cases are rare, but I have operatedupon two with success.

INFUNDIBULAR RESECIION IN TETRALOGY OF

FALLOT

The incidence of infundibular stenosisin tetralogy of Fallot, is seen to be rathermore than that of valvular stenosis;in a small proportion the two conditionsco-exist. If direct operation to relieve theobstruction within the heart is to be feas-ible in all cases of pulmonary stenosis, it isnecessary to consider whether it is possiblewhen the stenosis is infundibular and not

matic. This obstruction may be high (justbelow the valves); it may be low (at thejunction of the infundibulum and the inflowportion of the ventricle); or it may be inter-mediate (Brock,3 Brock and Campbell6).Reference should be made to these earlierarticles for a fuller account. It is also hopedto publish in the near future a monographon this important matter of the surgicalanatomy of pulmonary stenosis.

In pulmonary valvular stenosis an impor-tant diagnostic feature is post-stenotic dila-tation of the pulmonary artery. In infundib-ular stenosis, a condition of post-stenoticdilatation is also present and this forms whatmay be called an "infundibular chamber"whose dilated walls throw into greater con-trast the precise linear or diaphragmatic ob-struction proximal to the chamber.

68

CARDIAC SURGERY IN CONGENITAL PULMONARY STENOSIS

By incising the wall of the right ventriclebelow the obstruction, a cutting punch canbe inserted and the obstructing ring or dia-phragm resected. In some cases in whichthe obstruction is low, the approach may bemore conveniently made from above,through the anterior wall of the infundibularchamber.

160

J140Qilso

912011010090

130120

t_s 110-100o 90

< 80C] 60

THE POLICY OF DIRECr EXPLORATION ANDDIRECT OPERATION ON PULMONARY

STENOSIS

If the policy of an indirect operation forpulmonary stenosis is followed, especially ifthe anastomosis is done through the rightside of the chest, in most cases no attemptis made to confirm or complete the diag-

570

ISO-140-130-120110.10090

-1201101oo19070

3 4 S ~~~~~~~~60Ai .~~~~~~~~~50so( . -

a .

__' 24 ' 2S 26 21z asJULY 1951 JULY

FIG. 5.-Blood-pressure chart after a direct operation on tetralogy oftemporary rise in blood pressure often observed.

If a valvular stenosis co-exists, pulmonaryvalvulotomy may be performed at the same

time.I have performed a direct operation on

the infundibular stenosis in 39 cases, withseven deaths; there have been no deaths inthe last 26 cases. In ten cases, infundibularresection has been combined with pulmon-ary valvulotomy with no deaths. In fourcases, the result has been fair or poor; in theremaining 28 it has been good or excellent.

COMBINED RESULTS FOR PULMONARY VALVU-

LOTOMY AND INFUNDIBULAR RESECTION

IN TETRALOGY OF FALLOT

Direct operations have been performedin 68 cases of tetralogy of Fallot (39 valvu-lotomy, 39 infundibular resection, ten com-

bined). Ten patients have died (14 per

cent); the result has been fair or poor ineight, good or excellent in 50. It will beseen that these results compare favorablywith those obtained after an indirect pro-cedure.

4 a v .uAUGUST AUGUST

Fallot showing the

nosis. The chest is opened, two relevantvessels are dissected and anastomosed, andthe chest is closed.My policy in all cases is to explore the

heart as thoroughly as possible so as to ar-

rive at an exact diagnosis of the nature andsite of the pulmonary stenosis and then toselect the best operation for the particularcase. A great deal of information can beobtained before operation by means of theclinical and radiologic examination, includ-ing angiocardiography; cardiac catheteriza-tion is also helpful. The final and precisediagnosis can, however, be made only atoperation when the heart is actually ex-

posed after opening the pericardium. I usu-

ally employ a long left lateral incision thatcan be extended forwards or backwards atwill; this approach allows either a directoperation or an indirect anastomotic oper-

ation to be performed.External inspection and palpation of the

heart and pulmonary artery will usuallyallow a fairly precise diagnosis to be made

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wj iLeft thoracotomy .infundibular resection

- A P.M. AM.I 12 2 3 4 5 6 7 8 910 11 12 1 2. a . I a a a . I a I I.-I

R. C. BROCK Annals of SurgeryJuly, 1 9 5 2

when one is familiar with the relevant mor-bid anatomical features. The diagnosis can,however, be made exact by introducing acardiac catheter through a small incision inthe right ventricle and taking the pressureswithin the right ventricle and pulmonaryartery and observing the exact level of thepressure changes. In this way a valvularor an infundibular stenosis ean readily berecognized, or even a combined obstruction(Figs. 2 and 3).

I feel that it is quite wrong to operateupon a patient with congenital pulmonarystenosis without having catheters and anelectromanometer available so that theexact morbid anatomy can be elucidated inthis way and the proper operation planned.Secondary Effects of Direct Operation on

the Stenosis. The pressure tracings in Fig-ures 2 and 3 introduce another matter ofsome importance. One objection put for-ward to the direct operations for the reliefof pulmonary stenosis is that after the re-moval of the obstruction-the high ventric-ular pressure will be transmitted to thepulmonary circulation and a secondary pul-monary hypertension or an Eisenmengercomplex will be produced. It will be ob-served from Figures 2 and 3 that althoughthe pressure in the pulmonary artery doesrise, it is still well below the pressure in theright ventricle. This is a constant observa-tion and it seems that some, at least, of thepulmonary stenosis remains to protect thepulmonary circulation. In addition, it doesnot follow that because the pulmonaryblood flow is increased there is necessarilya marked rise in pressure; if the pulmonaryvessels are healthy they should be able tocompensate by relaxation for any reason-able rise in pressure.

Earlier in this paper it was argued that,in addition to increasing directly the blood-flow to the lungs, the effect of a successfulrelief of the pulmonary stenosis is to dimin-ish the right-to-left shunt because the in-creased flow to the lungs must be at theexpense of blood previously directed into

the aorta (Fig. 1). This is an importantmatter, since harmful venous-arterial mixingis thereby lessened.The action of this shunt can often be ob-

served at operation, chiefly as a result of achange in its proportions. The most com-mon observation is diminution of the flowin the pulmonary artery; this is noted by alessening or disappearance of the thrill andtension (it is imperative that the surgeonshould watch closely, all the time, the stateof the circulation in the pulmonary arteryso as to obtain prompt warning of anydeterioration). Such a diminution in thepulmonary circulation may be caused bygeneral failing of the heart's action and isobviously of serious import. However, Ihave observed cases in which the failure ofthe pulmonary circulation is not associatedwith evidence of failure of the systemiccirculation; the peripheral pulse and thesystemic blood pressure are well main-tained. This is due to great increase of theright-to-left shunt. It could obviously beproduced by directly compressing the pul-monary outflow tract.The reverse may, however, be seen. In a

case in which infundibular resection hadbeen successfully performed, the pulmonaryartery was noted to be full, with markedpulsation and with obviously greatly in-creased flow; the color was also strikinglyimproved. In contrast, the peripheral pulsehad become poor and the systemic blood-pressure fell. Compression of the pulmon-ary out-flow tract to lessen the pulmonaryblood-flow resulted in an immediate im-provement in the superficial temporal pulseand the systemic blood pressure. A directpressure record was taken from the aortaand is shown in Figure 4; compression onthe right ventricular outflow tract causes arise of 10 mm.Hg in the intra-aortic pres-sure, which falls again when the compres-sion is released. Clearly, the right-to-leftshunt had been over-corrected. Aproper bal-ance was restored as soon as the pericar-dium was closed, the patient has done well.

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Volume 136 CARDIAC SURGERY IN CONGENITAL PULMONARY STENOSISNumber 1

The effect of the diminution of the right-to-left shunt is also demonstrated in manycases after operation by a study of the sys-temic blood-pressure. If this is taken at 15-minute intervals, it will be found that thepressure soon rises and may reach 160/120mm.Hg or even higher (Fig. 5); at the sametime the peripheral pulse is small and thelimbs pale and cool. This secondary or com-pensatory hypertension lasts for two to threedays, and in young children especially, pres-sures as high as 250,/170 mm.Hg may berecorded. We have learned to look for thissecondary rise in pressure and to be con-cerned if it is not present after a directoperation for pulmonary stenosis with apatent interventricular septum, especially ifthe patient's general condition is poor. In-deed, in these circumstances, steps are takento raise the blood-pressure by transfusionand vaso-pressor drugs. I suggest that thesecondary hypertension is caused by a fallin the systolic output into the aorta as aresult of the increased pulmonary blood-flow. Until the heart can compensate by in-creasing its stroke volume, the only way thedeficiency can be remedied would appearto be by peripheral vaso-constriction and asecondary rise in systemic pressure.

THE SELECTION OF A DIRECT OR AN INDIRECT

OPERATION

The policy of a direct attack on the pul-monary stenosis was not decided upon andfollowed at once in all cases. Before em-barking routinely upon such a radicalchange of procedure it is preferable to ex-pand slowly, feeling one's way, as it were, inthe new technic; selecting suitable casesand rejecting less certain ones until increas-ing experience, skill and knowledge enablethe direct operation to be used more often.For this reason, the proportion of direct toindirect operations has been steadily alter-ing from the initial routine anastomosis inthe early stages some four to five years agoto the present state, when an anastomosis isusually not performed unless there is no

alternative. Thus, I use an anastomosis inall cases of tricuspid atresia and in mostcases of pulmonary atresia. Valvulotomy isalways done if a valvular stenosis is diag-nosed; in general, today I do an infundib-ular resection when an infundibular stenosisis recognized, except in certain cases of highinfundibular stenosis. In adults (over 20years) with a high infundibular stenosis, ananastomosis is preferable. With patients inthe 'teens, or in children, I still sometimesprefer an anastomosis to resection if thestenosis is close to the valve, as I am cau-tious about possible damage to the valvecusps. Experience in the high operation is,however, increasing, and as more such casesare handled, doubtless the direct operationwill be used constantly in these cases, too.

Occasionally, the presence of large, tor-tuous coronary vessels, encroaching uponthe anterior surface of the right ventricleover the area needed for the cardiotomy,may compel abandonment of the directoperation and substitution of an anasto-mosis.

Comparative Figures of Direct and Indi-rect Operations. The progressive change inpolicy in regard to the performance of adirect or an indirect operation, influencedby increasing experience, is shown in ananalysis of the comparative figures of thetwo groups of operations now and two,three and four years ago.Thus I have operated on a total of 240

cases of congenital pulmonary stenosis. In17 of these, an exploratory thoraootomyonly was done, either due to an error indiagnosis or inability to perform any usefuloperation. The remaining 223 cases weredealt with as follows:

Anastomosis .......... 112Direct operation .......... 111

In eight cases an anastomosis was usedbecause of tricuspid atresia or pulmonaryatresia.The change of policy is clearly shown

from the following tables:-71

R. C. BROCK Annals of SurgeryR.G.BROCK ~~~~~~~July,19 52First 50 Cases (May, 1947-October, 1948)

Direct operation .............. 6Anastomosis .............. 44

Second 50 Cases (October, 1948-October, 1949)Direct operation ........... 18Anastomosis ......... .. 32

Last 50 Cases (February, 1951-January, 1952)Direct operation ........... 41Anastomosis ..... 9

These figures include cases of "pure" pul-monary valvular stenosis for which valvu-lotomy was always done.The following tables exclude cases of

pulmonary valvular stenosis with a closedinterventricular septum.

First 50 Cases (May, 1947-November, 1948)Direct operation ....... .... 2Anastomosis ..... ...... 48

Second 50 Cases (November, 1948--January, 1950)Direct operation ........... 14Anastomosis ..... ...... 36

Last 50 Cases (September, 1950-January, 1952)Direct operation ..... 36Anastomosis ..... ...... 14

Five of these 14 were examples of tricus-pid atresia or pulmonary atresia in which adirect operation was not possible. It will,therefore, be observed that in the last 50cases an anastomosis was done instead of adirect operation in only nine cases. Duringthe last six months no anastomosis has beenperformed when a direct operation was pos-sible. It will be seen that the transition fromuse of an anastomosis in almost all cases toits rejection in all but unavoidable caseshas taken about four years. In other words,the change in policy has not been made sud-denly or without the support of knowledgeand experience. To begin with, a directoperation was used in certain cases selectedas especially suitable, and in this way suffi-cient information was gained about thedirect and indirect procedures to make itjustifiable to change gradually from one tothe other without exposing the patients toundue or unjustifiable risk. It is felt thatthis method of progressive development waspreferable; it has at any rate permitted con-fidence to be engendered in the principles

and technic of the direct operations nowbeing almost exclusively practiced.The first result of this work which has

reached its summation during the last sixmonths, and after an experience with 111direct operations, has been to show conclu-sively that direct operations for the relief ofcongenital pulmonary stenosis are feasible,eminently practicable, have a low mortalityand morbidity, and the initial results at anyrate are as good as those obtained with asystemic-pulmonary anastomosis. A moredetailed survey of the clinical follow-up isbeing prepared; it is not possible to detailit here.

It now remains to continue to use thedirect operations and to observe the long-term results so that the late prognosis of thetwo methods can be assessed and compared.Only in this way can a final decision bemade on the comparative merits of thetwo procedures.

BIBLIOGRAPHY1 Blalock, A., and R. F. Kieffer: Valvulotomy for

the Relief of Congenital Pulmonic Stenosiswith Intact Ventricular Septum; Report of19 Operations by the Brock Method. Ann.Surg., 132: 496, 1950.

2 Brock, R. C.: Pulmonary Valvulotomy for theRelief of Congenital Pulmonary Stenosis; Re-port of Three Cases. Brit. M. J., I: 1121,1948.

3 ------: The Surgery of Pulmonary Stenosis.Brit. M. J., 2: 339, 1949.

4------: The Arterial Route to the Aortic andPulmonary Valves. The Mitral Route to theAortic Valves. Guy's Hosp. Rep., 99: 230,1950.

5 ------: Valvulotomy for Pulmonary Valvu-lar Stenosis. Brit. Heart J., 12: 377, 1950.

6------: Infundibular Resection or Dilatationfor Infundibular Stenosis. Brit. Heart J., 12:403, 1950.

7 Brown, J. W.: Congenital Heart Disease. Lon-don, 1939.

8 Keith, A.: Malformations of the Heart. Lancet,2: 359, 1909.

9 Potts, W. J., et al.: Congenital Pulmonary Ste-nosis with Intact Ventricular Septum. J. A.M. A., 144: 8, 1950.

10 Sellors, T. H., and J. R. Belcher: Surgical Reliefof Congenital Cyanotic Heart Disease. LateResults in 72 Cases. Lancet, 2: 88, 1950.

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