The management of aortopulmonary window

The management of aortopulmonary window Advantages of transaortic closure with a Dacron patch Since 1970, 7 patients varying in age between I month and 3 years have had successful correction of an aortopulmonary septal defect. Three of these patients had associated cardiac lesions which were repaired at the same time. Extracorporeal circulation was used in 3 patients and profound hypothermia with limited extracorporeal circulation in 4. In 5 patients the defect was closed with a Dacron patch through a transaortic approach. The advantages of this method are discussed.

C. P. Clarke, F.R.A.C.S., and J. P. Richardson, F.R.C.S., F.R.A.C.S., F.A.C.S., Melbourne, Australia

A< .ortopulmonary window is a relatively rare congenital cardiac lesion in which there is a localized absence

of the truncoconal septum.12 The defect usually lies just above the origin of the left coronary artery, and its size can be quite variable. It is embryologically related to truncus arteriosus, but there are separate aortic and pulmonary valves, and the hemodynamic effects are more similar to those of patent ductus arteriosus. The lesion was first described in an autopsy study by Elliotson8 in 1830, and its successful closure was initially reported by Gross10 in 1952. The advantages of extracorporeal circulation as an adjunct were described by Cooley and associates4 in 1957, and the transaortic approach as the method of choice by Wright and colleagues15 in 1968. Clinical material The patients were between the ages of 1 month and 3Vi years at the time of operation (Table I). Four were boys and 3 girls. Five first presented in infancy with tachypnea and failure to thrive. In 2 patients who had the clinical features of a patent ductus arteriosus, this anomaly was initially diagnosed. The electrocardiograms showed biventricular hypertrophy in 5, right ventricular hypertrophy in 1, and left ventricular hypertrophy in 1. The chest roentgenograms showed cardiomegaly and pulmonary plethora in all the From The Division of Cardiac Surgery, Royal Children's Hospital, Melbourne, Australia. Received for publication Dec. 29, 1975. Accepted for publication March 16, 1976.

48

patients. This had been decreasing in one patient who was initially considered to have a ventricular septal defect. Although he responded well to medical therapy, he appeared to be developing signs of increasing pulmonary vascular resistance, and a catheter study showed the true diagnosis. Data from cardiac investigations are shown in Table II. In 3 patients an incorrect diagnosis was made before operation. Two of them had had exploratory operations for a suspected patent ductus arteriosus, and when this was not found, the true diagnosis was shown at a subsequent aortogram. One infant who was failing to thrive was considered to have a large ventricular septal defect, despite an apparently adequate catheter study which, however, did not include an aortogram. Fortunately, primary repair of the defect was planned. At operation, a large aortopulmonary septal defect, which also involved an unroofing of the right pulmonary artery, was demonstrated. Three patients had associated defects. Two had a right-sided aortic arch associated with the intraventricular anatomy of tetralogy of Fallot, and one of them also had congenital cysts of the upper lobe of the right lung. The patient who had an unroofed right pulmonary artery also had a small ventricular septal defect. Although most of the patients had some increase in pulmonary vascular resistance, only one had evidence of significant disease. A lung biopsy was performed to help resolve the debate as to whether an operation was indicated or not. However, the study did not really prove helpful, as there was a wide spectrum of changes in the small vessels of the parenchyma. Because the

Volume 72 Number 1 July, 1976

Aortopulmonary window

49

Table I. Associated defects and type of operative repair Patient

Sex

Age at operation

P. T. D. Y.

F M

1 mo. 2 yr., 3 mo.

V. K. L. H.

F F

7 mo. 2 mo.

T. H. T. R. E. L.

M M F

5 mo. 2V4 yr. 3'/2 yr.

Associate defects

Operation

_

Division and suture Dacron patch, repair of Fallot Dacron patch Dacron patch

Right-sided aortic arch, tetralogy of Fallot

-

Unroofed right pulmonary artery, small VSD

-

Dacron patch Suture, secondary ligation Dacron patch, repair of Fallot

Right-sided aortic arch, tetralogy of Fallot, cysts of RUL

Circulatory support PH + ECC ECC PH + ECC PH + ECC PH + ECC ECC ECC

Legend: VSD, Ventricular septal defect. RUL, Right upper lobe. PH + Ecc, Profound hypothermia with circulatory arrest. ECC, Extracorporeal bypass with moderate hypothermia.

Table II. Presentation and cardiac investigation data Pressures (nm.Hg) Patient

Presentation

P. T. D. Y. V. K. L. H. T. H. T. R.

Failure to thrive Exploration for PDA; known VSD Failure to thrive Failure to thrive Exploration for PDA VSD responded to medication; signs of PVD Failure to thrive; responded to medication

E. L.

Aorta

PA

Balanced Balanced Balanced Balanced Not done Balanced 97/35

80/30

PIS flow

Angiographic studies

2.2/1 2/1 Large 4/1 1.3/1

RV and aortogram RV and aortogram RV and aortogram LV* Aortogram RV and aortogram

2.5/1

RV and aortogram

—

Legend: PA, Pulmonary artery. P/S, Pulmonary/systemic. PDA, Patent ductus arteriosus. VSD, Ventricular septal defect. PVD, Pulmonary vascular disease. RV, Right ventriculogram. LV, Left ventriculogram. * Diagnosis of VSD made.

patient still had an over-all left-to-right shunt, the defect was closed. Surgical management All the defects were closed with the use of extracorporeal circulation. Standard perfusion with moderate hypothermia was used in the 3 larger patients, and profound hypotermia with circulatory arrest and extracorporeal assistance during the rewarming phase3 was used in the 4 smaller patients. In one patient the fistula was divided and oversewn, after having been torn posteriorly during an attempt to dissect it. One was closed by direct suture through the aorta but had to be secondarily ligated as well, because at the end of the operation there was an obvious persistent leak. Five fistulas were closed by placing a knitted Dacron patch over the defect from the aortic side. In one of these patients the patch was shaped like a comma (Fig. 1), the body of the comma being placed over the window and the tail being used to reconstitute

Fig. 1. Diagram of placement of patch in patient with aortopulmonary window and unroofing of the right pulmonary artery.

5 0 Clarke and Richardson

the roof of the right pulmonary artery as it lay behind the aorta. There were no operative deaths. One patient required a second operation 6 hours after the first for persistent bleeding, but then made an uneventful recovery. One had an unexplained melena which necessitated transfusion one week postoperatively. The others had uncomplicated postoperative courses. To date the follow-up in all patients has been satisfactory, with particularly marked improvement in the infants. One patient who also had repair of tetralogy of Fallot has been restudied and shown to have virtually normal hemodynamics. Discussion Although aortopulmonary window defects may vary greatly in size, they are generally quite large. Pulmonary artery hypertension with an increasing tendency for pulmonary vascular resistance to develop with time is the rule. Neufeld and associates,12 reviewing a series of 66 patients, noted that 80 per cent did not have a continuous murmur. They reported that the clinical picture commonly mimics a large patent duct or ventricular septal defect with pulmonary hypertension. The smaller defects may cause signs and symptoms very similar to those of an uncomplicated patent ductus arteriosus, and the true diagnosis may not be apparent until the operation. There have however been reports of an aortopulmonary window defect and a patent ductus arteriosus coexisting in the same patient.2' 12 If the diagnosis is suspected, the best method of confirming it is selective angiograms.9 When there is a coexisting ventricular septal defect there may be no further step-up in oxygen saturation levels at the great arteries, and the diagnosis of the aortopulmonary window will be missed unless an aortogram is performed.14 There are 5 reported cases of an aortopulmonary septal defect coexisting with interrupted aortic arch,7 which is a particularly difficult diagnostic challenge. Even when a ventricular septal defect has been demonstrated, the existence of the aortopulmonary window may obscure the fact that the intracardiac anatomy is tetralogy of Fallot.14 It is noteworthy that both of our patients with this anomaly had a right-sided aortic arch. An autopsy specimen similar to the anatomy in our patient with an unroofed right pulmonary artery has previously been reported.8 Initial attempts at correction of these defects were of necessity closed heart procedures, and they included ligation and division.10, 13 These procedures were

The Journal of Thoracic and Cardiovascular Surgery

troublesome because of the awkward lie and the lack of length of the defect. With the advent of open-heart surgery it soon became apparent that extracorporeal circulation was preferable, for it allowed division and suture in an unhurried fashion.4 Putnam and Gross13 suggested a transpulmonary approach to the defect in 1966, but this has not been found satisfactory by others.5' 15 The transaortic approach was described by Wright's group15 in 1968, who sutured the defect directly. Deverall and associates5 demonstrated that placement of a Dacron patch over the defect was a preferable method of management; they reported that suture may narrow one or another of the great arteries. Recent developments in techniques of circulatory support and postoperative care in infants3 make it realistic to manage these defects at an early age before significant pulmonary vascular disease supervenes. The transaortic approach is easier to close, allows the origin of the coronary arteries to be accurately visualized and, as in one of our cases, the right pulmonary artery to be reconstituted if necessary. There have been reports of the coronary arteries originating from the pulmonary artery1' 5 and the area of the window itself.11 The patch placed from the aortic side does not distort either main vessel and is naturally self-sealing. REFERENCES 1 Burroughs, J. T., Schmutzer, K. J., Luder, F., and Neuhas, G.: Anomalous Origin of the Right Coronary Artery With Aorticopulmonary Window and Ventricular Septal Defect, J. Cardiovasc. Surg. 3: 142, 1962. 2 Coleman, E. N., Barclay, R. S., Reid, J. M., and Stevenson, J. G.: Congenital Aorto-pulmonary Fistula Combined With Persistent Ductus Arteriosus, Br. Heart J. 29: 571, 1967. 3 Clarke, C. P., Brown, T. C. K., McKie, B. D., Jones, P. G. and Venables, A. W.: Open Heart Surgery in Infants Using Deep Hypothermia and Partial Heart-Lung Bypass, Med. J. Aust. 2: 710, 1971. 4 Cooley, D. A., McNamara, D. G., and Latson, J. R.: Aorticopulmonary Septal Defect: Diagnosis and Surgical Treatment, Surgery 42: 101, 1957. 5 Deverall, P. B., Lincoln, J. C. R., Aberdeen, E., Bonham-Carter, R. E., and Waterston, D. J.: Aortopulmonary Window, J. THORAC. CARDIOVASC. SURG. 57: 479, 1969. 6 Elliotson, J.: Case of Malformation of the Pulmonary Artery and Aorta, Lancet 1: 247, 1830. 7 Fisher, E. A., Dubrow, I. W., Eckner, F. A. O., and Hastreiler, A. R.: Aorticopulmonary Septal Defect and Interrupted Aortic Arch: A Diagnostic Challenge, Am. J. Cardiol. 34: 356, 1974.

Volume 72 Number 1 July, 1976

8 Fraentzel, O.: Ein Fall von abnormer Kommunication der Aorta mit der Arteria pulmonalis, Virchows Arch. Pathol. Anat. 43: 420, 1868. 9 Gasul, B. M., Fell, E. H., and Casas, R.: Diagnosis of Aortic Septal Defect by Retrograde Aortography, Circulation 4: 251, 1951. 10 Gross, R. E.: Surgical Closure of an Aortic Septal Defect, Circulation 5: 858, 1952. 11 Morrow, A. G., Greenfield, L. J., and Braunwald, E.: Congenital Aorto-pulmonary Septal Defect, Circulation 25: 463, 1962. 12 Neufeld, H. N., Lester, R. G., Adams, P. J., Anderson,

Aortopulmonary

window

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R. C , Lillehei, C. W., and Edwards, J. E.: Aorticopulmonary Septal Defect, Am. J. Cardiol. 9: 12, 1962. 13 Putnam, T. C , and Gross, R. E.: Surgical Management of Aortopulmonary Fenestration, Surgery 59: 727, 1966. 14 Tandon, R., DaSilva, C. L., Moller, J. H., and Edwards, J. E.: Aorto-pulmonary Septal Defect Co-existing With Ventricular Septal Defect, Circulation 50: 188, 1974. 15 Wright, J. S., Freeman, R., and Johnston, J. B.: Aorto-pulmonary Fenestration: A Technique of Surgical Management, J. THORAC. CARDIOVASC. SURG. 55: 280,

1968.