- Email: [email protected]
Open-heart surgery in the first year of life
Open-heart surgery in the first year of life lain M. Breckenridge, Ch.M., F.R.C.S. (by invitation), Hellmut Oelert, M.D. (by invitation), Gerald R. Graham, M.D. (by invitation), Jaroslav Stark, M.D. (by invitation), David J. Waterston, F.R.C.S. (by invitation), and Richard E. Bonham-Carter, F.R.C.P. (by invitation), London, England Sponsored by John W. Kirklin, M.D., Birmingham, Ala.
Open intracardiac surgery very early in life may be required in two main groups of cases. In the first, or "emergency" group, corrective surgery is undertaken as a lifesaving measure because of severe hypoxia, intractable cardiac failure, or a combination of the two. Medical treatment has failed, and no palliative procedure exists. Typical of this emergency group are patients with total anomalous pulmonary venous drainage (TAPVD), for whom the mortality rate without treatment is at least 75 per cent in the first year of lite." In the second, or "elective" group, operation is performed early in life because the prognosis without treatment, or even after palliative treatment, is unfavorable. The best examples of this group are patients with transposition of the great arteries (TGA). Without treatment, 85 per cent of these infants die before 12 months of age," and even after adequate balloon atrial septostomy the mortality rate at 1 year is still 35 per cent, mainly from thromboembolism and pulmonary vascular disease." In this paper we present our experience From the Thoracic Unit, Hospital for Sick Children, Great Ormond Street, London, W.e. I, England. Read at the Fifty-second Annual Meeting of The American Association for Thoracic Surgery, Los Angeles, Calif.,
May 1,2, and 3, 1972.
58
at the Hospital for Sick Children, Great Ormond Street, London, with open-heart surgery in the first year of life, In the 9 year period from 1963 to the end of 1971, 124 infants underwent correction of congenital cardiac malformations with the aid of cardiopulmonary bypass, Clinical material
The number of patients operated upon each year, together with the mortality rates after operation, are shown in Fig. 1. Increasing use of the Mustard operation'> for correction of TGA in infancy was mainly responsible for the greater number of infants operated upon in the last 3 years and for the reduction in mortality rate. Obviously this elective procedure carried a lower risk than did emergency correction of TAPVD, which had formed the bulk of the series before 1969. There were 63 operations in 1970 and 1971 combined, while in the preceding 7 years there were 61. This division into groups of similar size made it possible to compare early and more recent experience. In the whole series, ages ranged from 4 days to 2 days short of 12 months, with a mean of 5.6 months, and weights ranged from 2.5 to 10 kilograms, with a mean of 5.5 kilograms. Principal diagnostic groups are listed in
Volume 65
59
Open-heart surgery in first year of life
Number 1 January, 1973
40
40
Doeaths
30 No.of
cases
23 20
15 10
1963
11
11
64
65
11
66
67
68
69
70
71
Fig. 1. Annual distribution of 124 cases with postoperative mortality rate (1963 to 1971).
Table I. Patients with TAPVD accounted for 44 per cent of the total, with a mean age of 3,8 months and a mean weight of 4.6 kilograms. The second largest group comprised those with TGA (32 per cent of the total); in this predominantly elective category, the mean age was 8.9 months and the mean weight 6.8 kilograms. The miscellaneous group of 13 patients included 3 with secundum atrial septal defect (ASD), 2 with pulmonary valve stenosis, and single cases of mitral incompetence, cor tria triatum, truncus arteriosus, aorto-pulmonary window, aorto-Ieft ventricular tunnel, and anomalous origin of the left coronary artery.
Table I. Open-heart surgery in the first year of life (1963 to 1971) Per cent
Diagnosis
TAPVD TGA Aortic stenosis VSD Tumors Miscellaneous Totals
55 40 9 4 3 13
36 5 0 2 10
65 20 56 0 67 77
124
61
49
8
Legend: TAPVD. Total anomalous pulmonary venous drainage. TGA, Transposition of the great arteries. VSD, Ventricular septal defect.
Perfusion technique
Operative methods
Bypass methods remained fairly standard throughout the series. A rotating disc oxygenator that was primed mainly with blood and had a wire mesh filter on the arterial line was used. In most cases, a right-angled metal cannula was placed in the ascending aorta for perfusion return, although in some it was positioned in the femoral or external iliac arteries. Moderate cooling to 30° C. was the rule; however, in the first 2 and the last 5 patients with T APVD, circulatory arrest at 15 to 20° C. for 20 to 60 minutes was employed. In the early cases cooling was achieved entirely by perfusion, while in the recent 5 it was by the combination of surface and perfusion cooling described by Barratt-Boyes and his colleagues."
TAPVD. The frequency with which the various types of TAPVD were encountered is shown in Table II. In the supracardiac and infracardiac types, operation involved anastomosis of the common pulmonary venous trunk to the left atrium with ligation of the connecting vein. In all but the last 4 cases, the anastomosis was made over clamps and the ASD was not closed. In these 4 infants, circulatory arrest at 20° C. was used to permit an "open" anastomosis with closure of the ASD.7 For TAPVD to the coronary sinus or right atrium, a Dacron patch was used to redirect pulmonary venous blood to the left atrium. TGA. Mustard's" operation was performed in 40 infants, who thus represented
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Thoracic and Cardiovascular Surgery
Table II. Results of correction of T APVD in 55 infants (1963 to 1971) No.
Deaths
of
I
Per cent
cases
No.
34 2
18 2
53 100
11 2
10 2
91 100
Infracardiac
3
3
100
Mixed
3
Type of TAPVD
Supracardiac Left innominate vein Right superior vena cava
Postoperative care
Cardiac Coronary sinus Right atrium
55
Totals Legend: TAPVD. drainage.
Total
anomalous
33 65
36
pulmonary
venous
Table III. Mortality rate according to age ARe (mo.)
0-3 3-6 6-12 Totals
patient with truncus arteriosus, who presented in 1966, was of interest. An unsuccessful attempt was made to connect the right ventricle to the right and left pulmonary arteries by means of two pericardial tubes containing no valves. The patients with cardiac tumor have been reported upon previously. 11
Per cent
39 24 61
32 15 14
82 63 23
124
61
49
20 per cent of our total experience with this procedure.' All had previously undergone balloon atrial septostomy." Between 1967 and 1970, pericardium was used for the intra-atrial baffle in 23 cases, while in 1971 Dacron was used in 17 cases. The baffle suture line was kept posterior to the coronary sinus orifice, thus permitting a small right-to-left shunt (because the coronary sinus drained with the pulmonary veins) but minimizing the risk of arrhythmias from damage to the atrioventricular node and bundle of His.' Associated ventricular septal defects (VSD) in 9 patients were closed by suture or Dacron patch through the right atrium whenever possible. In 1971 median sternotomy gave way to right thoracotomy, transecting the sternum, as the preferred approach. Other lesions. In 4 infants with a single high VSD, closure was effected by a Dacron patch placed through the right atrium. The
Important features included the use of indwelling arterial and left atrial lines, ventilatory support, and the use of appropriate intravenous fluids. Optimal systemic ventricular stroke volume was best achieved by using mean left (or pulmonary venous) atrial pressure as a guide to infusion of blood or plasma. In the last year, routine elective tracheostomy at the end of operation was discarded in favor of nasotracheal ventilation, with tracheostomy reserved for those cases in which ventilation was required for more than 7 days or in which aspiration of secretions was a problem. Arterial bloodgas measurements were used to control ventilation. Experience with continuous positive airway pressure respiration- dates only from the completion of this series of patients. Intravenous sodium-free fluids with potassium supplements were given according to standard formulas based on surface area,> pending a reassessment of the postoperative metabolic requirements of infants. Results The over-all mortality rate after operation in 124 infants was 49 per cent (Table I). Age at operation was clearly a factor in postoperative deaths, irrespective of the cardiac lesion (Table III). Of the 39 patients under 3 months of age, 82 per cent died, of the 24 between 3 and 6 months, 63 per cent died, and of the 61 between 6 and 12 months of age, 23 per cent died. Infants requiring operation in the first 3 months of life are generally more seriously ill than those who have survived a reasonable "trial of living." Table IV divides the series into its early and more recent parts and shows postopera-
Volume 65 Number 1 Jonuory, 1973
tive mortality rates in relation to the same three age groups, again regardless of the cardiac lesion. Improvements in the last 2 years, particularly in the group under 3 months of age, were due as much to better postoperative care as to modifications in operative technique. The recent increase in cases of TGA principally involved the 6 to 12 month group and was a factor in the improved results. TAPVD. Mortality rates in the various types of TAPVD are shown in Table II. Thirty-six of 55 infants died (65 per cent). Of the 34 patients with the commonest variety, supracardiac drainage into the left innominate vein, 18 (53 per cent) died. Particularly unsatisfactory results followed correction of the cardiac type, despite the relative simplicity of operation in this group. None of 3 infants with infracardiac drainage survived operation. Factors influencing the results of correction of TAPVD in our series were similar to those reported by others"the type of drainage, age at operation, degree of arterial desaturation, and the interrelated effects of obstruction to the connecting vein and pulmonary vascular disease. Before 1970 there were no long-term survivors under 3 months of age, while more recently 3 out of 9 in this age group survived. The reason for this improvement was twofold: (1) Circulatory arrest at 20° C. was used in 5 of the 9 patients and (2) the open method of anastomosis described by Gersony and his associates' was used in 4 patients with supracardiac TAPVD, 3 of whom survived. TGA. Thirty-two of 40 infants survived the Mustard operation. Of 31 patients with TGA and ASD (simple transposition), 3 died (l0 per cent), 2 in the hospital from low cardiac output and pulmonary edema and the third 5 months after operation from pulmonary venous obstruction due to contraction of the pericardial baffle. Five of 9 infants with TGA and VSD died (56 per cent), mainly from inadequate cardiac output. Table V compares the results of operation in 23 infants between 1967 and 1970 with the results in 17 infants during 1971.
61
Open-heart surgery in first year of life
Table IV. Mortality rate according to year of operation 1963 to 1969 Age (mo.) 0-3 3-6
6-12 Totals
1970 to 1971
Mortality Mortality No. of rate No. of rate cases (per cent) cases (per cent)
22 12
59
27
100 67 30
34
58 18
61
62
63
37
17
12
Table V. Mustard's operation in 40 infants (1967 to 1971) Pericardium baffle (1967 to 1970)
Diagnosis
Dacron baffle (1971)
No. Mortality No. Mortality of rate of rate cases (per cent) cases (per cent)
TGA and
19
16
12
o
VSD
4
100
5
20
Totals
23
30
17
6
ASD TGA and
Legend: TGA, Transposition of the great arteries. ASD. Atrial septal defect. VSD. Ventricular septal defect.
Substantial improvements occurred in both the ASD and VSD groups in 1971, with no deaths in 12 cases of simple transposition and only one death (in a 7-month-old boy with multiple VSD's) among 5 cases of TGA and VSD. We do not claim that the transition from pericardium to Dacron for the intra-atrial baffle was the only factor responsible for the improved results in 1971. Operation was facilitated by the use of a right thoracotomy, and average bypass time was reduced to around 60 minutes by intermittent aortic cross-clamping. Other lesions. Patients with aortic stenosis presented for emergency relief very early in life. The youngest patient in the entire series died after aortic valvotomy at 4 days of age, and the youngest survivor had the same operation at 10 days of age. Five of 9 infants died after aortic valvotomy, with left ventricular hypoplasia and endocardial fibro-
62
The Journal of Thoracic and Cardiovascular Surgery
Breckenridge et al.
elastosis as important causes of death. Transatrial patch closure of single, high VSD's was successful in all of 4 infants requiring surgical treatment because of intractable cardiac failure. Discussion
New standards in cardiac surgery for infants are being set by those groups who have revived profound hypothermia with circulatory arrest." By adopting this method we have begun to improve our results in the emergency correction of TAPVD in patients under 3 months of age, having had no longterm survivors in this age group while using conventional bypass techniques. However, these techniques have proved satisfactory in the correction of TGA by the Mustard operation. In 1971, the results in infants compared very favorably with those in children over 1 year of age. For TGA with ASD, there were no deaths among 12 infants but five deaths among 27 older children. For TGA with VSD, corresponding figures were one death in 5 and one in 9. These results justify our policy of elective correction of most forms of TGA in infancy and have encouraged us to use the Mustard operation instead of the Blalock-Hanlon procedure" in cases in which balloon atrial septostomy has failed. For the minority of infants with VSD who require some form of surgical treatment, primary closure is replacing pulmonary artery banding as the procedure of choice," and our 4 cases represent an acceptance of this trend. The possibility of multiple VSD's in infants presenting with intractable cardiac failure must be borne in mind at investigation and operation. fi Comparison of the results of open-heart surgery in infancy from various reported series is made difficult by variable and imprecise definitions of "infancy?" 15 and by differences in the composition of each series. For example, the Mayo Clinic reported upon 275 patients under 2 years of age, of whom 149 complied with our criterion of infancy by being under 12 months of age." The
mortality rate for those patients was 48 per cent, remarkably similar to our 49 per cent in 124 patients, although the Mayo series contained more patients with VSD and fewer with TAPVD than did our own. Conspicuously absent from our series is tetralogy of Fallot, for which we continue to rely on anastomotic procedures as palliation before correction when the child is around 5 years of age. Modification of this satisfactory policy will depend on long-term results from those currently enthusiastic about early correction of most congenital cardiac malformations.
Summary Between 1963 and the end of 1971, 124 infants under 12 months of age underwent correction of congenital cardiac malformations with the aid of cardiopulmonary bypass. Principal diagnostic groups were TAPVD (55 cases) and TGA (40 cases). The over-all mortality rate was 49 per cent (62 per cent in the first 61 patients and 37 per cent in the last 63) and was highest in those under 3 months of age. The mortality rate after emergency correction of TAPVD (65 per cent) was higher than that after elective Mustard operation for TGA (20 per cent). The use of circulatory arrest at 20° C. has produced a recent improvement in the results of TAPVD correction in infants under 3 months of age. However, conventional bypass has proved satisfactory in the TGA group, for there have been no deaths in the last 12 infants with TGA and ASD. REFERENCES Aberdeen, E.: Correction of Uncomplicated Cases of Transposition of the Great Arteries, Br. Heart J. 33: 66, 1971 (Supp!.). 2 Barratt-Boyes, B. G., Simpson, M., and Neutze, J. M.: Intracardiac Surgery in Neonates and Infants Using Deep Hypothermia With Surface Cooling and Limited Cardiopulmonary Bypass, Circulation 43: 25, 1971 (Supp!. I). 3 Blalock, A., and Hanlon, C. R.: The Surgical Treatment of Complete Transposition of the
Volume 65 Number 1
Open-heart surgery in first year of life
63
January, 1973
Aorta and the Pulmonary Artery, Surg. Gynecol. Obstet. 90: 1, 1950. 4 Breckenridge, I. M., Oelert, H., Stark, J., Graham, G. R., Bonham-Carter, R. E., and Waterston, D. J.: Mustard's Operation for Transposition of the Great Arteries: A Review of 200 Cases, Lancet 1: 1140, 1972. 5 Breckenridge, I. M., Stark, J., Waterston, D. J., and Bonham-Carter, R. E.: Multiple Ventricular Septal Defects, Ann. Thorac. Surg. 13: 128, 1972. 6 Ching, E., DuShane, 1. W., McGoon, D. C., and Danielson, G. K.: Total Correction of Cardiac Anomalies in Infancy Using Extracorporeal Circulation, 1. THORAC. CARDIOVASC. SURG.62: 117, 1971. 7 Gersony, W. M., Bowman, F. 0., Steeg, C. N., Hayes, C. J., Jesse, M. J., and Malm, J. R.: Management of Total Anomalous Pulmonary Venous Drainage in Early Infancy, Circulation 43: 19, 1971 (Suppl, I). 8 Gomes, M. M. R., Feldt, R. H., McGoon, D. C., and Danielson, G. K.: Total Anomalous Pulmonary Venous Connection, 1. THORAC. CARDIOVASC. SURG. 60: 116, 1970. 9 Gregory, G. A., Kitterman, 1. A., Phibbs, R. H., Tooley, W. H., and Hamilton, W. K.: Treatment of the Idiopathic Respiratory-Distress Syndrome With Continuous Positive Airway Pressure, N. Engl. J. Med. 284: 1333, 1971. 10 Keith, J. D., Rowe, R. D., and Vlad, P.: Heart Disease in Infancy and Childhood, ed. 2, New York, 1967, The Macmillan Company, p. 525. 11 Kirklin, J. W.: Pulmonary Arterial Banding in Babies With Large Ventricular Septal Defects, Circulation 43: 321, 1971. 12 Liebman, J., Cullum, L., and Belloc, N. B.: Natural History of Transposition of the Great Arteries, Circulation 40: 237, 1969. 13 Mustard, W. T., Keith, J. D., Trusler, G. A., Fowler, R., and Kidd, L.: The Surgical Management of Transposition of the Great Vessels, J. THORAC. CARDIOVASC. SURG. 48: 953, 1964. 14 Pacifico, A. D., Digerness, S., and Kirklin, J. W.: Acute Alterations of Body Composition After Open Intracardiac Operations, Circulation 41: 331, 1970. 15 Pierce, W. S., Raphaely, R. C., Downes, J. J., and Waldhausen, J. A.: Cardiopulmonary Bypass in Infants: Indications, Methods, and Results in 32 Patients, Surgery 70: 839, 1971. 16 Rashkind, W. J., and Miller, W. W.: Creation of an Atrial Septal Defect Without Thoracotomy: A PalIiative Approach to Complete Transposition of the Great Arteries, J. A. M. A. 196: 991, 1966. 17 Simcha, A., Wells, B. G., Tynan, M. J., and Waterston, D. J.: Primary Cardiac Tumours in Childhood, Dis. Child. 46: 508, 1971.
18 Tynan, M.: Survival of Infants With Transposition of the Great Arteries After Balloon Atrial Septostomy, Lancet 1: 621, 1971.
Discussion DR. LAWRENCE I. BONCHEK Portland, Ore.
Dr. Breckenridge and his colleagues are certainly to be commended for outstanding results in their series of small infants with various congenital lesions who were operated upon in the first year of life. As you have just heard from Dr. Starr, we have had an interest in the correction of congenital lesions in infancy at the University of Oregon, but our experience has been overwhelmingly with cardiopulmonary bypass. That technique was used in all of the infants with tetralogy who were operated upon. Because of the increasing use of profound hypothermia with circulatory arrest in some centers, we would like to bring to your attention our experience with cardiopulmonary bypass in the correction of transposition of the great arteries. These patients were somewhat younger than those with tetralogy, which emphasizes the feasibility of total cardiopulmonary bypass not only in infants who are extraordinarily young but in those who must undergo an emergency procedure to survive. [Slide] Our complete experience with transposition in infants was reported in San Francisco last January, but this slide depicts only the group under 6 months of age who had simple or complicated transposition. The first 5 in that age group had a mean age of about 2Y2 months with a range in days from 12 days to 5 months. The mean weight was 4.2 kilograms with a range from 3.4 to 5.7 kilograms. One of these infants had a large ventricular septal defect, pulmonary artery pressure of 100 mm. Hg, and pulmonary vascular resistance of 15 Wood units. Only 1 patient in this group died-not the patient with the ventricular septal defect. The death was caused by a large patent ductus that bled during ligation through a median sternotomy. We recently carried out a Mustard procedure in a 12-day-old infant using profound hypothermia and circulatory arrest and were disturbed by the occurrence of seizures during the first postoperative day. The infant had depressed cerebral function postoperatively and died subsequently. We would like to emphasize that cardiopulmonary bypass was utilized successfully in 4 out of 5 infants with transposition, either simple or complicated, who were under 6 months of age (mean age 2Y2 months). The next few years should provide an informative period during which
64
Breckenridge et al.
0'
The Journol Thoracic and Cardiovascular
Surgery
the relative merits of cardiopulmonary bypass and profound hypothermia with circulatory arrest should become clear. DR. JAMES R. MALM New York, N. Y.
Dr. Breckenridge and his group are to be congratulated on reviewing this exciting experience at Great Ormond Street. Certainly, open-heart surgery in infants still is a frontier in cardiac surgery. We have recently reviewed our own experience with open-heart surgery in infants at Columbia Presbyterian Hospital. This group of patients was operated upon by Dr. Bowman and me, and all required emergency surgery. [Slide] Forty-nine infants younger than 1 year of age were operated upon, with an over-all survival rate of 70 per cent. We divided these infants into categories according to age: those less than 6 months of age, less than 3 months of age, and less than 6 weeks of age. In our hands, there was little over-all difference in the survival rates among these groups. However, from a technical point of view, it is the patient under 3 months of age who presents the real problem. Certainly, no one would argue that a patient I year of age could undergo safe bypass. [Slide] The technique is very important. We have used high-flow normothermia or moderate hypothermia in all patients. We have used a disposable small prime oxygenator. Several points are important. One is that the stroke output of the pump used must be of small volume so that a continuous small amount of blood is pumped into the aorta. Of course, the aortic cannulation is essential for good input so that the mean blood pressure remains high throughout bypass. The infant requires a very high regional blood flow and, hence, we believe
that the high flow throughout bypass is critical. [Slide] This slide shows those patients who were under 3 months of age. The bulk of these patients had total anomalous venous drainage. Our most difficult group was those infants who had drainage below the diaphragm or who had mixed lesions with veins draining into the coronary sinus and into the right atrium and pericoronary region. These patients are really difficult to evaluate in the operating room, particularly in the presence of high bronchial flow and venous return to the field. In this group of patients, some form of circulatory arrest during the period of repair probably would facilitate intra-cardiac reconstruction. However, in our experience, simple cardiopulmonary bypass has been effective with the majority of patients. DR. lAIN M. BRECKENRIDGE (Closing) I am grateful to Dr. Bonchek and Dr. Maim for their comments. We are, of course, familiar with Dr. Maim's excellent work, which has given us a standard to aim at in the correction of TAPVD. We now use the open method of anastomosis described by his group. You will note, perhaps, from our series that we had only 4 infants in whom ventricular septal defects were closed primarily. This represents the beginning of our adoption of a policy of primary closure in preference to banding followed by debanding. You will notice, also, the total absence from our series of correction of Fallot's tetralogy. We have not yet begun to correct Fallot's tetralogy in infancy, but, after hearing Dr. Starr's excellent presentation today, we no doubt shall. I think that in Britain we tend to be rather slow to climb onto American band wagons; we like to join them. However, I think in this case we will see which direction they are taking before we soon be up there with you.
Open intracardiac surgery very early in life may be required in two main groups of cases. In the first, or "emergency" group, corrective surgery is undertaken as a lifesaving measure because of severe hypoxia, intractable cardiac failure, or a combination of the two. Medical treatment has failed, and no palliative procedure exists. Typical of this emergency group are patients with total anomalous pulmonary venous drainage (TAPVD), for whom the mortality rate without treatment is at least 75 per cent in the first year of lite." In the second, or "elective" group, operation is performed early in life because the prognosis without treatment, or even after palliative treatment, is unfavorable. The best examples of this group are patients with transposition of the great arteries (TGA). Without treatment, 85 per cent of these infants die before 12 months of age," and even after adequate balloon atrial septostomy the mortality rate at 1 year is still 35 per cent, mainly from thromboembolism and pulmonary vascular disease." In this paper we present our experience From the Thoracic Unit, Hospital for Sick Children, Great Ormond Street, London, W.e. I, England. Read at the Fifty-second Annual Meeting of The American Association for Thoracic Surgery, Los Angeles, Calif.,
May 1,2, and 3, 1972.
58
at the Hospital for Sick Children, Great Ormond Street, London, with open-heart surgery in the first year of life, In the 9 year period from 1963 to the end of 1971, 124 infants underwent correction of congenital cardiac malformations with the aid of cardiopulmonary bypass, Clinical material
The number of patients operated upon each year, together with the mortality rates after operation, are shown in Fig. 1. Increasing use of the Mustard operation'> for correction of TGA in infancy was mainly responsible for the greater number of infants operated upon in the last 3 years and for the reduction in mortality rate. Obviously this elective procedure carried a lower risk than did emergency correction of TAPVD, which had formed the bulk of the series before 1969. There were 63 operations in 1970 and 1971 combined, while in the preceding 7 years there were 61. This division into groups of similar size made it possible to compare early and more recent experience. In the whole series, ages ranged from 4 days to 2 days short of 12 months, with a mean of 5.6 months, and weights ranged from 2.5 to 10 kilograms, with a mean of 5.5 kilograms. Principal diagnostic groups are listed in
Volume 65
59
Open-heart surgery in first year of life
Number 1 January, 1973
40
40
Doeaths
30 No.of
cases
23 20
15 10
1963
11
11
64
65
11
66
67
68
69
70
71
Fig. 1. Annual distribution of 124 cases with postoperative mortality rate (1963 to 1971).
Table I. Patients with TAPVD accounted for 44 per cent of the total, with a mean age of 3,8 months and a mean weight of 4.6 kilograms. The second largest group comprised those with TGA (32 per cent of the total); in this predominantly elective category, the mean age was 8.9 months and the mean weight 6.8 kilograms. The miscellaneous group of 13 patients included 3 with secundum atrial septal defect (ASD), 2 with pulmonary valve stenosis, and single cases of mitral incompetence, cor tria triatum, truncus arteriosus, aorto-pulmonary window, aorto-Ieft ventricular tunnel, and anomalous origin of the left coronary artery.
Table I. Open-heart surgery in the first year of life (1963 to 1971) Per cent
Diagnosis
TAPVD TGA Aortic stenosis VSD Tumors Miscellaneous Totals
55 40 9 4 3 13
36 5 0 2 10
65 20 56 0 67 77
124
61
49
8
Legend: TAPVD. Total anomalous pulmonary venous drainage. TGA, Transposition of the great arteries. VSD, Ventricular septal defect.
Perfusion technique
Operative methods
Bypass methods remained fairly standard throughout the series. A rotating disc oxygenator that was primed mainly with blood and had a wire mesh filter on the arterial line was used. In most cases, a right-angled metal cannula was placed in the ascending aorta for perfusion return, although in some it was positioned in the femoral or external iliac arteries. Moderate cooling to 30° C. was the rule; however, in the first 2 and the last 5 patients with T APVD, circulatory arrest at 15 to 20° C. for 20 to 60 minutes was employed. In the early cases cooling was achieved entirely by perfusion, while in the recent 5 it was by the combination of surface and perfusion cooling described by Barratt-Boyes and his colleagues."
TAPVD. The frequency with which the various types of TAPVD were encountered is shown in Table II. In the supracardiac and infracardiac types, operation involved anastomosis of the common pulmonary venous trunk to the left atrium with ligation of the connecting vein. In all but the last 4 cases, the anastomosis was made over clamps and the ASD was not closed. In these 4 infants, circulatory arrest at 20° C. was used to permit an "open" anastomosis with closure of the ASD.7 For TAPVD to the coronary sinus or right atrium, a Dacron patch was used to redirect pulmonary venous blood to the left atrium. TGA. Mustard's" operation was performed in 40 infants, who thus represented
60
The Journal of
Breckenridge et al.
Thoracic and Cardiovascular Surgery
Table II. Results of correction of T APVD in 55 infants (1963 to 1971) No.
Deaths
of
I
Per cent
cases
No.
34 2
18 2
53 100
11 2
10 2
91 100
Infracardiac
3
3
100
Mixed
3
Type of TAPVD
Supracardiac Left innominate vein Right superior vena cava
Postoperative care
Cardiac Coronary sinus Right atrium
55
Totals Legend: TAPVD. drainage.
Total
anomalous
33 65
36
pulmonary
venous
Table III. Mortality rate according to age ARe (mo.)
0-3 3-6 6-12 Totals
patient with truncus arteriosus, who presented in 1966, was of interest. An unsuccessful attempt was made to connect the right ventricle to the right and left pulmonary arteries by means of two pericardial tubes containing no valves. The patients with cardiac tumor have been reported upon previously. 11
Per cent
39 24 61
32 15 14
82 63 23
124
61
49
20 per cent of our total experience with this procedure.' All had previously undergone balloon atrial septostomy." Between 1967 and 1970, pericardium was used for the intra-atrial baffle in 23 cases, while in 1971 Dacron was used in 17 cases. The baffle suture line was kept posterior to the coronary sinus orifice, thus permitting a small right-to-left shunt (because the coronary sinus drained with the pulmonary veins) but minimizing the risk of arrhythmias from damage to the atrioventricular node and bundle of His.' Associated ventricular septal defects (VSD) in 9 patients were closed by suture or Dacron patch through the right atrium whenever possible. In 1971 median sternotomy gave way to right thoracotomy, transecting the sternum, as the preferred approach. Other lesions. In 4 infants with a single high VSD, closure was effected by a Dacron patch placed through the right atrium. The
Important features included the use of indwelling arterial and left atrial lines, ventilatory support, and the use of appropriate intravenous fluids. Optimal systemic ventricular stroke volume was best achieved by using mean left (or pulmonary venous) atrial pressure as a guide to infusion of blood or plasma. In the last year, routine elective tracheostomy at the end of operation was discarded in favor of nasotracheal ventilation, with tracheostomy reserved for those cases in which ventilation was required for more than 7 days or in which aspiration of secretions was a problem. Arterial bloodgas measurements were used to control ventilation. Experience with continuous positive airway pressure respiration- dates only from the completion of this series of patients. Intravenous sodium-free fluids with potassium supplements were given according to standard formulas based on surface area,> pending a reassessment of the postoperative metabolic requirements of infants. Results The over-all mortality rate after operation in 124 infants was 49 per cent (Table I). Age at operation was clearly a factor in postoperative deaths, irrespective of the cardiac lesion (Table III). Of the 39 patients under 3 months of age, 82 per cent died, of the 24 between 3 and 6 months, 63 per cent died, and of the 61 between 6 and 12 months of age, 23 per cent died. Infants requiring operation in the first 3 months of life are generally more seriously ill than those who have survived a reasonable "trial of living." Table IV divides the series into its early and more recent parts and shows postopera-
Volume 65 Number 1 Jonuory, 1973
tive mortality rates in relation to the same three age groups, again regardless of the cardiac lesion. Improvements in the last 2 years, particularly in the group under 3 months of age, were due as much to better postoperative care as to modifications in operative technique. The recent increase in cases of TGA principally involved the 6 to 12 month group and was a factor in the improved results. TAPVD. Mortality rates in the various types of TAPVD are shown in Table II. Thirty-six of 55 infants died (65 per cent). Of the 34 patients with the commonest variety, supracardiac drainage into the left innominate vein, 18 (53 per cent) died. Particularly unsatisfactory results followed correction of the cardiac type, despite the relative simplicity of operation in this group. None of 3 infants with infracardiac drainage survived operation. Factors influencing the results of correction of TAPVD in our series were similar to those reported by others"the type of drainage, age at operation, degree of arterial desaturation, and the interrelated effects of obstruction to the connecting vein and pulmonary vascular disease. Before 1970 there were no long-term survivors under 3 months of age, while more recently 3 out of 9 in this age group survived. The reason for this improvement was twofold: (1) Circulatory arrest at 20° C. was used in 5 of the 9 patients and (2) the open method of anastomosis described by Gersony and his associates' was used in 4 patients with supracardiac TAPVD, 3 of whom survived. TGA. Thirty-two of 40 infants survived the Mustard operation. Of 31 patients with TGA and ASD (simple transposition), 3 died (l0 per cent), 2 in the hospital from low cardiac output and pulmonary edema and the third 5 months after operation from pulmonary venous obstruction due to contraction of the pericardial baffle. Five of 9 infants with TGA and VSD died (56 per cent), mainly from inadequate cardiac output. Table V compares the results of operation in 23 infants between 1967 and 1970 with the results in 17 infants during 1971.
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Open-heart surgery in first year of life
Table IV. Mortality rate according to year of operation 1963 to 1969 Age (mo.) 0-3 3-6
6-12 Totals
1970 to 1971
Mortality Mortality No. of rate No. of rate cases (per cent) cases (per cent)
22 12
59
27
100 67 30
34
58 18
61
62
63
37
17
12
Table V. Mustard's operation in 40 infants (1967 to 1971) Pericardium baffle (1967 to 1970)
Diagnosis
Dacron baffle (1971)
No. Mortality No. Mortality of rate of rate cases (per cent) cases (per cent)
TGA and
19
16
12
o
VSD
4
100
5
20
Totals
23
30
17
6
ASD TGA and
Legend: TGA, Transposition of the great arteries. ASD. Atrial septal defect. VSD. Ventricular septal defect.
Substantial improvements occurred in both the ASD and VSD groups in 1971, with no deaths in 12 cases of simple transposition and only one death (in a 7-month-old boy with multiple VSD's) among 5 cases of TGA and VSD. We do not claim that the transition from pericardium to Dacron for the intra-atrial baffle was the only factor responsible for the improved results in 1971. Operation was facilitated by the use of a right thoracotomy, and average bypass time was reduced to around 60 minutes by intermittent aortic cross-clamping. Other lesions. Patients with aortic stenosis presented for emergency relief very early in life. The youngest patient in the entire series died after aortic valvotomy at 4 days of age, and the youngest survivor had the same operation at 10 days of age. Five of 9 infants died after aortic valvotomy, with left ventricular hypoplasia and endocardial fibro-
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The Journal of Thoracic and Cardiovascular Surgery
Breckenridge et al.
elastosis as important causes of death. Transatrial patch closure of single, high VSD's was successful in all of 4 infants requiring surgical treatment because of intractable cardiac failure. Discussion
New standards in cardiac surgery for infants are being set by those groups who have revived profound hypothermia with circulatory arrest." By adopting this method we have begun to improve our results in the emergency correction of TAPVD in patients under 3 months of age, having had no longterm survivors in this age group while using conventional bypass techniques. However, these techniques have proved satisfactory in the correction of TGA by the Mustard operation. In 1971, the results in infants compared very favorably with those in children over 1 year of age. For TGA with ASD, there were no deaths among 12 infants but five deaths among 27 older children. For TGA with VSD, corresponding figures were one death in 5 and one in 9. These results justify our policy of elective correction of most forms of TGA in infancy and have encouraged us to use the Mustard operation instead of the Blalock-Hanlon procedure" in cases in which balloon atrial septostomy has failed. For the minority of infants with VSD who require some form of surgical treatment, primary closure is replacing pulmonary artery banding as the procedure of choice," and our 4 cases represent an acceptance of this trend. The possibility of multiple VSD's in infants presenting with intractable cardiac failure must be borne in mind at investigation and operation. fi Comparison of the results of open-heart surgery in infancy from various reported series is made difficult by variable and imprecise definitions of "infancy?" 15 and by differences in the composition of each series. For example, the Mayo Clinic reported upon 275 patients under 2 years of age, of whom 149 complied with our criterion of infancy by being under 12 months of age." The
mortality rate for those patients was 48 per cent, remarkably similar to our 49 per cent in 124 patients, although the Mayo series contained more patients with VSD and fewer with TAPVD than did our own. Conspicuously absent from our series is tetralogy of Fallot, for which we continue to rely on anastomotic procedures as palliation before correction when the child is around 5 years of age. Modification of this satisfactory policy will depend on long-term results from those currently enthusiastic about early correction of most congenital cardiac malformations.
Summary Between 1963 and the end of 1971, 124 infants under 12 months of age underwent correction of congenital cardiac malformations with the aid of cardiopulmonary bypass. Principal diagnostic groups were TAPVD (55 cases) and TGA (40 cases). The over-all mortality rate was 49 per cent (62 per cent in the first 61 patients and 37 per cent in the last 63) and was highest in those under 3 months of age. The mortality rate after emergency correction of TAPVD (65 per cent) was higher than that after elective Mustard operation for TGA (20 per cent). The use of circulatory arrest at 20° C. has produced a recent improvement in the results of TAPVD correction in infants under 3 months of age. However, conventional bypass has proved satisfactory in the TGA group, for there have been no deaths in the last 12 infants with TGA and ASD. REFERENCES Aberdeen, E.: Correction of Uncomplicated Cases of Transposition of the Great Arteries, Br. Heart J. 33: 66, 1971 (Supp!.). 2 Barratt-Boyes, B. G., Simpson, M., and Neutze, J. M.: Intracardiac Surgery in Neonates and Infants Using Deep Hypothermia With Surface Cooling and Limited Cardiopulmonary Bypass, Circulation 43: 25, 1971 (Supp!. I). 3 Blalock, A., and Hanlon, C. R.: The Surgical Treatment of Complete Transposition of the
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January, 1973
Aorta and the Pulmonary Artery, Surg. Gynecol. Obstet. 90: 1, 1950. 4 Breckenridge, I. M., Oelert, H., Stark, J., Graham, G. R., Bonham-Carter, R. E., and Waterston, D. J.: Mustard's Operation for Transposition of the Great Arteries: A Review of 200 Cases, Lancet 1: 1140, 1972. 5 Breckenridge, I. M., Stark, J., Waterston, D. J., and Bonham-Carter, R. E.: Multiple Ventricular Septal Defects, Ann. Thorac. Surg. 13: 128, 1972. 6 Ching, E., DuShane, 1. W., McGoon, D. C., and Danielson, G. K.: Total Correction of Cardiac Anomalies in Infancy Using Extracorporeal Circulation, 1. THORAC. CARDIOVASC. SURG.62: 117, 1971. 7 Gersony, W. M., Bowman, F. 0., Steeg, C. N., Hayes, C. J., Jesse, M. J., and Malm, J. R.: Management of Total Anomalous Pulmonary Venous Drainage in Early Infancy, Circulation 43: 19, 1971 (Suppl, I). 8 Gomes, M. M. R., Feldt, R. H., McGoon, D. C., and Danielson, G. K.: Total Anomalous Pulmonary Venous Connection, 1. THORAC. CARDIOVASC. SURG. 60: 116, 1970. 9 Gregory, G. A., Kitterman, 1. A., Phibbs, R. H., Tooley, W. H., and Hamilton, W. K.: Treatment of the Idiopathic Respiratory-Distress Syndrome With Continuous Positive Airway Pressure, N. Engl. J. Med. 284: 1333, 1971. 10 Keith, J. D., Rowe, R. D., and Vlad, P.: Heart Disease in Infancy and Childhood, ed. 2, New York, 1967, The Macmillan Company, p. 525. 11 Kirklin, J. W.: Pulmonary Arterial Banding in Babies With Large Ventricular Septal Defects, Circulation 43: 321, 1971. 12 Liebman, J., Cullum, L., and Belloc, N. B.: Natural History of Transposition of the Great Arteries, Circulation 40: 237, 1969. 13 Mustard, W. T., Keith, J. D., Trusler, G. A., Fowler, R., and Kidd, L.: The Surgical Management of Transposition of the Great Vessels, J. THORAC. CARDIOVASC. SURG. 48: 953, 1964. 14 Pacifico, A. D., Digerness, S., and Kirklin, J. W.: Acute Alterations of Body Composition After Open Intracardiac Operations, Circulation 41: 331, 1970. 15 Pierce, W. S., Raphaely, R. C., Downes, J. J., and Waldhausen, J. A.: Cardiopulmonary Bypass in Infants: Indications, Methods, and Results in 32 Patients, Surgery 70: 839, 1971. 16 Rashkind, W. J., and Miller, W. W.: Creation of an Atrial Septal Defect Without Thoracotomy: A PalIiative Approach to Complete Transposition of the Great Arteries, J. A. M. A. 196: 991, 1966. 17 Simcha, A., Wells, B. G., Tynan, M. J., and Waterston, D. J.: Primary Cardiac Tumours in Childhood, Dis. Child. 46: 508, 1971.
18 Tynan, M.: Survival of Infants With Transposition of the Great Arteries After Balloon Atrial Septostomy, Lancet 1: 621, 1971.
Discussion DR. LAWRENCE I. BONCHEK Portland, Ore.
Dr. Breckenridge and his colleagues are certainly to be commended for outstanding results in their series of small infants with various congenital lesions who were operated upon in the first year of life. As you have just heard from Dr. Starr, we have had an interest in the correction of congenital lesions in infancy at the University of Oregon, but our experience has been overwhelmingly with cardiopulmonary bypass. That technique was used in all of the infants with tetralogy who were operated upon. Because of the increasing use of profound hypothermia with circulatory arrest in some centers, we would like to bring to your attention our experience with cardiopulmonary bypass in the correction of transposition of the great arteries. These patients were somewhat younger than those with tetralogy, which emphasizes the feasibility of total cardiopulmonary bypass not only in infants who are extraordinarily young but in those who must undergo an emergency procedure to survive. [Slide] Our complete experience with transposition in infants was reported in San Francisco last January, but this slide depicts only the group under 6 months of age who had simple or complicated transposition. The first 5 in that age group had a mean age of about 2Y2 months with a range in days from 12 days to 5 months. The mean weight was 4.2 kilograms with a range from 3.4 to 5.7 kilograms. One of these infants had a large ventricular septal defect, pulmonary artery pressure of 100 mm. Hg, and pulmonary vascular resistance of 15 Wood units. Only 1 patient in this group died-not the patient with the ventricular septal defect. The death was caused by a large patent ductus that bled during ligation through a median sternotomy. We recently carried out a Mustard procedure in a 12-day-old infant using profound hypothermia and circulatory arrest and were disturbed by the occurrence of seizures during the first postoperative day. The infant had depressed cerebral function postoperatively and died subsequently. We would like to emphasize that cardiopulmonary bypass was utilized successfully in 4 out of 5 infants with transposition, either simple or complicated, who were under 6 months of age (mean age 2Y2 months). The next few years should provide an informative period during which
64
Breckenridge et al.
0'
The Journol Thoracic and Cardiovascular
Surgery
the relative merits of cardiopulmonary bypass and profound hypothermia with circulatory arrest should become clear. DR. JAMES R. MALM New York, N. Y.
Dr. Breckenridge and his group are to be congratulated on reviewing this exciting experience at Great Ormond Street. Certainly, open-heart surgery in infants still is a frontier in cardiac surgery. We have recently reviewed our own experience with open-heart surgery in infants at Columbia Presbyterian Hospital. This group of patients was operated upon by Dr. Bowman and me, and all required emergency surgery. [Slide] Forty-nine infants younger than 1 year of age were operated upon, with an over-all survival rate of 70 per cent. We divided these infants into categories according to age: those less than 6 months of age, less than 3 months of age, and less than 6 weeks of age. In our hands, there was little over-all difference in the survival rates among these groups. However, from a technical point of view, it is the patient under 3 months of age who presents the real problem. Certainly, no one would argue that a patient I year of age could undergo safe bypass. [Slide] The technique is very important. We have used high-flow normothermia or moderate hypothermia in all patients. We have used a disposable small prime oxygenator. Several points are important. One is that the stroke output of the pump used must be of small volume so that a continuous small amount of blood is pumped into the aorta. Of course, the aortic cannulation is essential for good input so that the mean blood pressure remains high throughout bypass. The infant requires a very high regional blood flow and, hence, we believe
that the high flow throughout bypass is critical. [Slide] This slide shows those patients who were under 3 months of age. The bulk of these patients had total anomalous venous drainage. Our most difficult group was those infants who had drainage below the diaphragm or who had mixed lesions with veins draining into the coronary sinus and into the right atrium and pericoronary region. These patients are really difficult to evaluate in the operating room, particularly in the presence of high bronchial flow and venous return to the field. In this group of patients, some form of circulatory arrest during the period of repair probably would facilitate intra-cardiac reconstruction. However, in our experience, simple cardiopulmonary bypass has been effective with the majority of patients. DR. lAIN M. BRECKENRIDGE (Closing) I am grateful to Dr. Bonchek and Dr. Maim for their comments. We are, of course, familiar with Dr. Maim's excellent work, which has given us a standard to aim at in the correction of TAPVD. We now use the open method of anastomosis described by his group. You will note, perhaps, from our series that we had only 4 infants in whom ventricular septal defects were closed primarily. This represents the beginning of our adoption of a policy of primary closure in preference to banding followed by debanding. You will notice, also, the total absence from our series of correction of Fallot's tetralogy. We have not yet begun to correct Fallot's tetralogy in infancy, but, after hearing Dr. Starr's excellent presentation today, we no doubt shall. I think that in Britain we tend to be rather slow to climb onto American band wagons; we like to join them. However, I think in this case we will see which direction they are taking before we soon be up there with you.