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Surgical Treatment of Patent Ductus Arteriosus In Childhood
Surgical Treatment of Patent Ductus Arteriosus In Childhood H. WILLIAM SCOTT, JR., M.D., F.A.C.S. *
AT THE present time patent ductus arteriosus is largely a pediatric surgical problem and there is good reason to believe that in future years the surgical treatment of this malformation will be effected almost exclusively in childhood. In Gross and Longino's recent report of 412 patients with patent ductus operated on at the Children's Hospital and the Peter Bent Brigham Hospital of Boston 314 were children under 15 years of age. l Essentially the same proportion between children and adults has obtained in patients with patent ductus treated surgically at The Johns Hopkins Hospital. 2 A large amount of information concerning patent ductus arteriosus has been accumulated in the last decade, stimulated in the main by Gross' demonstration of the feasibility and therapeutic value of surgical closure.a, 4 No attempt will be made to review this data in detail. The purpose of this report is to summarize briefly the experience at The Johns Hopkins Hospital with some of the clinical manifestations, technics of surgical correction and results of treatment in infants and children with patent ductus arteriosus. ANATOMIC AND PHYSIOPATHOLOGIC ASPECTS
The ductus arteriosus is an important fetal vascular pathway whereby blood is shunted in intra-uterine life from the pulmonary artery into the aorta. With the expansion of the lungs at birth there is believed to be a reduction in the pulmonary vascular resistance, a fall in pulmonary pressure and a reversal of the direction of flow of blood through the ductus. 6 Supposedly, the pressures in the systemic and pulmonary arterial circuFrom the Department of Surgery of The Johns Hopkins University and the Surgical Service of The Johns Hopkins Hospital, Baltimore, Maryland.
* Professor of Surgery, Vanderbilt University School of Medicine; Surgeon-inChief, Vanderbilt University Hospital, Nashville, Tennessee. 1299
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H. William Scott, Jr.
lations quickly become equalized in the normal newborn infant and flow through the ductus ceases. Certainly the ductus is anatomically patent at birth but whether it remains functionally patent in the normal infant, and for how long, is actually not known. Barclay and his associates have shown that functional closure of the ductus in the sheep takes place in the first few minutes of extra-uterine life. 6 The mechanism of obliteration of the ductus arteriosus in man and specific data as to the pressures in aorta and pulmonary artery with relation to flow of blood through the anatomically patent ductus in the neonatal period are large gaps in present knowledge. When the ductus arteriosus remains patent after the neonatal period it usually exists as an isolated defect which increases the work of the heart and is ultimately detrimental to the continued health of the individual,7, 8 Occasionally, however, persistent patency of the ductus when associated with certain other malformations of the cardiovascular system serves as a means of maintaining life. For example, in patients with tetralogy of Fallot and extreme stenosis or atresia of the pulmonary orifice the ductus arteriosus may serve as the main route of blood flow to the lungs. In some cases of transposition of the great arterial trunks the ductus arteriosus may be an important means of interchange between the systemic and the pulmonary circulations. Aside from its infrequent association with these and a few other more uncommon cardiac malformations accompanied by cyanosis, persistent patency of the ductus arteriosus serves no useful function in extra-uterine life. An extensive study of the effects of the isolated patent ductus on the circulation has been made by Eppinger, Burwell and Gross8 who showed that the direction of the blood flow through the ductus in extra-uterine life is from aorta to pulmonary artery. These studies and subsequent work have indicated that there is essentially a direct relationship between the size of the ductus, the volume of the left to right shunt and the magnitude of the left ventricular output. 9 , 10 The physiologic observations support the clinical view that a small ductus is usually very well tolerated in childhood, whereas a large ductus may impose a considerable handicap. If a great proportion of the aortic blood flow leaks through the ductus there may be retardation of growth and development; increased ventricular work may lead to early cardiac failure. Damman and Sellu and others have suggested that pulmonary hypertension and irreversible pulmonary vascular changes may develop at an early age with a large shunt of this type. Children with either a small or a large ductus face equally the hazard of subacute bacterial endarteritis. Aneurysmal change in the ductus with the attendant danger of rupture may occur infrequently in adult life but is excessively rare in childhood.
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CLINICAL ASPECTS
Patent ductus arteriosus is two or three times more common in females than in males. In the majority of children the size of the shunt is such that there are no symptoms whatsoever. Activities and behavior are usually those of the normal child unless restrictions have been imposed by the parents or attending physician after the discovery of the presence of a "murmur" on routine examination. The characteristic machinery murmur is the most typical finding in the classical syndrome of patent ductus arteriosus. It is a harsh, continuous murmur with systolic accentuation and is of maximal intensity in the second left intercostal space close to the sternum. A thrill, similar to the murmur, is usually present. These findings are virtually pathognomonic of the continuous flow of blood from the high-pressured aorta through the open ductus into the pulmonary artery. Since there is no escape of venous blood into the systemic circulation and an adequate (actually excessive) flow of blood to the lungs, there is no cyanosis, clubbing, polycythemia or reduction in peripheral arterial oxygen saturation. The electrocardiogram usually shows no abnormalities; there is no axis deviation. Fluoroscopy ordinarily shows the sizeof the heart to be within normal limits and the cardiac contour is not distorted except for a variable degree of prominence of the pulmonary conus. The pulmonary vascular markings may be normal or somewhat accentuated. Approximately 80 per cent of children with patent ductus arteriosus who have been observed at The Johns Hopkins Hospital have presented this classical syndrome. In children who have an unusually large ductus, retardation of growth is occasionally quite striking. Dyspnea, palpitation and limited exercise tolerance in such patients are associated with cardiac enlargement. The systemic diastolic pressure may be quite low and the peripheral signs of aortic insufficiency may be present. Hilar dance may be a prominent fluoroscopic finding. This minority group of children with incapacitating symptoms includes in addition to individuals with excessively large shunts those .patients who have patent ductus associated with other cardiac defects and with superimposed subacute bacterial endarteritis or rheumatic heart disease. Damman and Sell have recently described a small but important group of infants and children observed in "this clinic with patent ductus and absence of the classical continuous murmur.n The ductus was unusually large in each of these young patients and the incidenceof associated cardiac enlargement and pulmonary hypertension was striking. Cardiac catheterization is of considerable diagnostic value in these "atypical ductus" cases and in the evaluation of children with the clas-
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sical syndrome when it is associated with severe symptoms and when an additional anomaly is suspected. However, as Gross,! Taussig 5 and others have frequently emphasized, in the majority of children with persistent patency of the ductus arteriosus the diagnosis can be made on clinical grounds alone. SURGICAL TREATMENT
Indications
The indications for surgical closure of the patent ductus arteriosus have been clearly stated recently by Gross and Longino. 1 Their policies are in close agreement with those which have been established by Dr. Helen Tauiilsig and Dr. Alfred Blalock in this clinic. Operation has been recommended strongly for children with patent ductus who have retardation of growth and development and is considered a life-saving necessity in those with cardiac enlargement and other manifestations of decompensation. As first demonstrated by Touroff and Vesell, closure of the open ductus may result in cure of a complicating bacterial endarteritis. 12 Certainly operation is urgently demanded in children with an infected ductus but it is desirable to bring the infection under control with antibiotics, if possible, before attempting definitive surgery. In the "atypical ductus" group with systolic murmurs and pulmonary hypertension early closure of the ductus may prevent irreversible vascular changes in the lungs. Closure of the ductus is usually indicated and may offer considerable benefit in instances in which patent ductus is associated with defects of the auricular or ventricular septum or with rheumatic heart disease. In summary, when the patent ductus has imposed a serious handicap, pfC)mpt operative closure has been strongly advised for infants and children at any age in this clinic. More of a problem is presented by the much larger group of children with persistent patency of the ductus who are essentially asymptomatic. In these patients surgical closure must be considered as a preventive rather than a therapeutic measure. Keys and Shapiro have demonstrated that the life expectancy of patients with patent ductus who are alive at age 17 averages only half that of the general population.13 The incidence of Streptococcus viridans infection and cardiac decompensation is greater in young adults than in children with patent ductus. 1 As operative experience with closure of the ductus has grown, it has become increasingly apparent that the risk to the patient imposed by the untreated patent ductus is considerably greater than the negligible risk of surgical closure. In consequence, closure of the ductus in symptomless children with the classical syndrome is advised as a prophylactic procedure. The elective operation, however, is not recommended for asymptomatic infants and
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very young children in whom diagnostic difficulties are frequently encountered. It is technically easiest and probably least hazardous in children of 4 to 12 years of age. Con traindica tions
The cardinal contraindication to surgical closure of the patent ductus is the coexistence of other cardiae malformations, such as the tetralo!!;y of Fallot, for which the ductus may serve in lit compensatory capacity. In those rare instances in which patent ductus is associated with vascular disease of the lung, severe pulmonary hypertension and reversal of the ductal shunt, the ductus apparently acts as an escape valve; closure of the ductus in these circumstances would precipitate acute cor pulmonale. Fortunately, the various combinations of defects in which closure of the ductus might prove disastrous are not common. They are usually associated with some degree of peripheral arterial oxygen unsaturation which is an aid in their clinical recognition. Procedure
The surgical procedure followed in closure of the patent ductus arteriosus in this clinic has become well standardized. Intratracheal anesthesia is used with nitrous oxide-oxygen-ether and, less frequently, cyclopropane as the anesthetic agents. A left anterolateral thoracotomy approach is used routinely and the chest is usually entered in the third intercostal space. The mediastinal pleura is incised between the phrenic and vagus nerves over the ductal area. Dissection of the ductus is carried out as described by Gross.4 This consists essentially of clearing the ductus and the adjacent aorta and pulmonary artery of the investing areolar tissue and elements of the fibrous pericardium. A reHection of the serous pericardium which usually overlies the pulmonary end of the ductus must be freed from the ductus and the adjacent pulmonary artery. Sharp dissection under direct vision is used as much as possible and no attempt is made to close the ductus until the vascular structures concerned in the dissection have been mobilized widely. Great care is taken not to injure the left recurrent laryngeal nerve. In by far the great majority of children with patent ductus treated in this clinic the suture-ligation method of closure described by Blalock has been used. 14 This technic provides a means of obliteration of the ductus in continuity without dividing the vessel. Purse-string sutures of medium silk on French or atraumatic needles are placed at either end of the ductus, catching the adventitia in several places. Usually 2-0 silk is used with an atraumatic needle. These sutures are not tied tightly but with enough tension to stop the How of blood through the ductus. Two trans-
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fixion sutures of the same material are then placed through the ductus between the purse-string sutures and tied tightly around the vessel.. All of the sutures are spaced as far apart as possible. This simple and effective method of closure of the ductus is illustrated in Figure 410. If the ductus is unusually large in diameter, for instance 10 to 12 mm. or more, closure by a method of division is probably preferable to the
Fig. 410. Closure of the patent ductus by suture-ligation technic.
use of the suture-ligation technic. There are several methods of division of the ductus, most of which are essentially modifications of the procedure originally described by Gross.4. 15. 16 The clamps devised by Potts are particularly well adapted to division of a short, broad ductus and have been used in most of the cases in this clinic recently when a method of division has been employed. 15 The Potts clamps are applied to the ductus as far apart as possible prior to division of the vessel. It is wise to have a third clamp of the same type available to permit readjustment if necessary after the ductus has been divided. In order to curtail any possibility of the clamps being opened inadvertently after the ductus is
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divided a lock is placed on the catch of each clamp after it is applied to the vessel. After the ductus is divided between Potts ductus clamps, each end is closed with a running mattress suture which is returned as a continuous hemostatic over-and-over suture (Fig. 411). The suture material is 4-0 or 5-0 silk on an atraumatic needle. Conklin and Watkins have described the use of the Potts-Smith-Gibson aortic partial occlusion clamp as a means of control of the aortic end
Fig. 411. Closure of the patent ductus by division and suture using Potts ductus clamps.
of theductus during its division and suture.17 Figure 412 demonstrates a modification of this technic as it has been used in a few cases in this clinic in division and suture of the exceptionally large ductus. The application of the partial occlusion clamp to the aorta is awkward with the usual anterolateral exposure. In consequence, this technic, which probably has . its greatest usefulness in the closure of a huge ductus or an aneurysm of the ductus, is reserved for the rare individual (usually an adult) in whom the suspected very large caliber of the ductus prompts the use of the more extensive exposure afforded by the posterolateral approach. A somewhat similar procedure has been used in this clinic in the technical management of patent ductus associated with coarctation of the
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aorta (Fig. 413). After completing the dissection and mobilization of the coarctate zone and the ductus, clamps are applied to the aorta proximal and distal to the site of coarctation and the pulmonary end of the ductus is occluded with a Potts ductus clamp. The ductus is divided and its aortic end is excised with the zone of aortic stenosis. The pulmonary end of the ductus is closed with a running suture of silk as previously de-
Fig. 412. Closure of unusually large patent ductus by modification of the method of division and suture described by Conklin and Watkins.17
scribed and the continuity of the aorta is restored by end-to-end anastomosis. The postoperative care of children following surgical closure of the patent ductus requires no elaborate measures in most cases. In this clinic it is routine to give oxygen and supplemental parenteral fluids for the first twelve to eighteen hours after operation. Penicillin is used in full doses for the first week. Unless coexistent cardiac defects or other complications prevent, the patients are permitted to sit up on the second or third postoperative day and are usually ambulatory by the fifth day.
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The majority of patients have been able to leave the hospital by the eighth to tenth day after operation. RESULTS
Three hundred and sixty-four patients with patent ductus arteriosus were operated on at The Johns Hopkins Hospital during the period Octo-
Fig. 413. Technical management of patent ductus associated with coarctation of the aorta.
ber 1, 1942 to December 1, 1951. Of this group 273 were infants and children whose ages ranged from 3 months to 12 years. The great majority of these patients have been studied preoperatively, referred for operation and followed postoperatively by Dr. Helen B. Taussig and her associates in the Cardiac Clinic of the Harriet Lane He>me. In Table 1 the operative experience with the patent ductus arteriosus in this group of children is summarized. Approximately 80 per cent of the operations were essentially prophy-
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lactic procedures in children who were either totally asymptomatic or had minimal incapacity. Except for a single operative fatality the results in this large group have been excellent. As indicated in Table 1 and elaborated in Table 2, 6 other deaths occurred, all of which were in the smaller group of children who had incapacitating symptoms. Included Table 1 OPERATIVE EXPERIENCE WITH PATENT DUCTUS ARTERIOSUS IN CHILDREN AT THE JOHNS HOPKINS HOSPITAL
Procedure
No. of Patients
Attempted closure ............. Ligation only .................. Division ....................... Suture-ligation ................. TotaL .......................
Deaths
R&canalization
5 15 251
2 0 1 4
0 0 0 1
273
7
1
2
Table 2 CAUSES OF DEATH IN 7 CHILDREN WITH PATENT DUCTUS ARTERIOSUS TREATED SURGICALLY AT THE JOHNS HOPKINS HOSPITAL PATIENT
AGE
CAUSE OF DEATH
R. S.
3 yr.
C.D.
5 yr.
W.G.
3 yr.
Convulsions and hyperpyrexia after operation Laceration of pulmonary artery at operation Convulsions and hyperpyrexia after operation Ventricular fibrillation on opening chest Bled from aortic end of ductus after division Convulsions and hyperpyrexia after operation Laceration of aorta during repair of recurrent aneurysm of ductus
If:
J. F.C.
5 yr. 5 yr.
E.W.
2 yr.
A.E.
5 yr.
,p
with older children in the latter group there were 9 infants ranging from 3 to 11 months of age and 27 babies aged 1 to 2 years in whom the ductus " was closed successfully. In the early days of this series simple ligation of the ductus with one or two ligatures of heavy silk or linen tape was used in a few cases. Although no difficulties were encountered in children, one instance of recanalization occurred in an older patient with subacute bacterial endocarditis. This method has now been entirely abandoned. Division of the ductus was carried out in 15 children. In a few of these
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patients the method of division described by Gross4 was used; in a few others the ductus was divided between suture ligatures after purse-string sutures had been placed at the ends of the vessel. One death occurred from postoperative hemorrhage subsequent to division of the ductus between suture ligatures. At autopsy the aortic stump of the ductus was found to be open, the suture ligature having slipped off. This is an illadvised method for closure of the patent ductus and is no longer used. No difficulties have been encountered in division and suture of the ductus using the Potts ductus clamps as shown in Figure 411. Successful division of the open ductus has been accomplished in several children with coarctation by the method shown in Figure 413. These cases are not included in the present data. In 2 instances attempts to close the patent ductus in children were unsuccessful because of accidents at the time of operation. In one case fatal ventricular fibrillation occurred as the chest was opened; cyclopropane was the anesthetic agent. In the other case there was uncontrollable hemorrhage from a laceration of the pulmonary artery during the dissection of the ductus. The suture-ligation technic of closure of the ductus was used in 251 children. Three deaths have occurred in the immediate postoperative period after closure of the ductus by this method. In each instance hyperpyrexia, convulsions, failure to regain consciousness and peripheral vascular collapse led to death within twelve to twenty-four hours. Proven recanalization of the ductus has occurred in one child in this series. This was a 5 year old girl without a continuous murmur who was one of the "atypical" ductus group. At operation a large ductus measuring 16 mm. in diameter was found and was closed by the suture-ligation method. During the first four or five months after operation the child had intermittent febrile episodes. Six months after operation she was readmitted with evidence of subacute bacterial endarteritis, recanalization of the ductus and formation of an aneurysm of the ductus. After prolonged antibiotic therapy, operation was carried out and an effort was made to repair the aneurysmal recanalization of the ductus. However, laceration of the aorta proximal to the aneurysm resulted in uncontrollable hemorrhage. Autopsy showed that the silk sutures used in the original closure of the ductus had cut through the wall and lay within the aneurysmal sac. In the majority of the children in this series the postoperative course following closure of the patent ductus has been uneventful. Pulmonary complications have been rare and no cases of wound infection or empyema have occurred. With the single exception of the child described above whose ductus recanalized there have been no instances of subacute bacterial endocarditis after operation in these children. Persistence of or
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development of congestive heart failure after operation has been uncommon. Follow-up studies in this group of children have been made by Dr. Taussig and her associates and their findings in a part of this series have been reported previously by Lynxwiler and Wells. 18 In general, the long range results in these children after closure of the patent ductus with few exceptions have been excellent. In those instances in which retardation of growth and development existed prior to operation there has been striking improvement after closure of the ductus. The majority of children with large shunts and incapacitating symptoms have shown a return to normality in heart size and in exercise tolerance within a few months after operation. In some of the more complicated cases in which a small ductus was associated with a large defect of the interauricular or interventricular septum there has been little or no apparent improvement after closure of the ductus. However, closure of a large ductus has proved to be quite beneficial to many of the patients with coexisting septal defects. In addition to the child who developed definite aneurysmal recanalization of the ductus following surgical closure there are two other children who were recently operated on in whom the possibility of recanalization must be entertained. Both of these children had a large ductus and were in the group of "atypical" ductus cases described by Damman and Sell. 11 Surgical closure by the suture-ligation technic was followed almost immediately by the" development of a soft continuous murmur in the pulmonic area. Both children, however, have been improved functionally by operation and have had a rise to normal in systemic diastolic pressure. They are being followed carefully and will return shortly for re-evaluation. It is possible that another anomaly such as an aortic septal defect accounts for the continuous murmur. COMMENT
Surgical closure of the patent ductus arteriosus at an early age, even in asymptomatic pat~ents, is preferable to a watch-and-wait policy of deferring operation until difficulties develop in later life. The studies of Keys and Shapiro, the experience of Gross and his associates and that of this clinic indicate that the incidence of the dangerous complications of the untreated ductus is greater in the second, third and fourth decades than in the first. 13 • 1. 6, 18 An additional advantage for the patient afforded by early surgical closure of the ductus is the curtailment of the psychological handicap and invalidism which may be imposed by overprotective parents. From the surgeon's viewpoint the technical problem of dealing with patent ductus in children with elastic, resilient vessels is considerably
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easier and less hazardous than in the closure of the more rigid and sclerotic ductus of the older patient. In the large group of asymptomatic children in this series in which closure of the ductus was done essentially as a preventive measure the mortality rate was under 0.5 per cent. The over-all operative mortality rate in the 273 infants and children was 2.5 per cent. This mortality rate can and should be lowered in the future, as many of the 7 deaths were preventable (Table 2). The suture-ligation technic of closure of the patent ductus is a safe and effective method, particularly in children with readily compressible and resilient vessels of the usual (5 to 8 mm.) diameter and length. The technic has proved to be satisfactory as a means of producing permanent obliteration of the open ductus of both large and average caliber in over 300 children and adults in this clinic. However, recanalization has definitely occurred following its use in one case and may have occurred in two others. In each of these cases the ductus was unusually large in caliber (16, 12 and 10 mm. respectively) and short in length. In consequence it seems logical to use a method of division of the ductus when the vessel is over 10 mm. in diameter and is short in length and to employ the suture-ligation procedure in the closure of the ductus of average dimensions. SUMMARY
Since patent ductus arteriosus is largely a pediatric surgical problem, this report has attempted to summarize the experience at The Johns Hopkins Hospital with some of the clinical manifestations, technics of surgical correction and results of treatment in 273 infants and children with patency of the ductus. This experience emphasizes the desirability of surgical closure of the patent ductus in childhood as a preventive measure. REFERENCES 1. Gross, R. E. and Longino, L. A.: The Patent Ductus Arteriosus. Observations from 412 Surgically Treated Cases. Circulation 3: 125, 1951. 2. Scott, H. W., Jr.: Closure of the Patent Ductus by Suture-Ligation Technique. Surg., Gynec. & Obst. 90: 91, 1950. 3. Gross, R. E. and Hubbard, J. P.: Surgical Ligation of a Patent Ductus; Report of First Successful Case. J.A.M.A. 112: 729, 1939. 4. Gross, R. E.: Complete Division for the Patent Ductus Arteriosus. J. Thoracic Surg. 16: 314, 1947. 5. Taussig, H. B.: Congenital Malformations of the Heart. The Commonwealth Fund, New York, 1947. 6. Barclay, A. E., Barcroft, J., Barron, D. H. and Franklin, K. J.: A Radiographic Demonstration of the Circulation through the Heart in the Adult and in the Foetus, and the Identification of the Ductus Arteriosus. Brit. J. Radiol. 12: 505, 1939. 7. Burwell, C. S., Eppinger, E. C. and Gross, R. E.: The Effects of Patency of
1312 8. 9. 10.
11. 12. 13. 14. 15. 16. 17. 18.
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the Ductus Arteriosus on the Circulation. J. Clin. Investigation 19: 774, 1940. Eppinger, E. C., Burwell, C. S. and Gross, R. E.: Effects of Patent Ductus Arteriosus on Circulation. J. Clin. Investigation 20: 127, 1941. Bing, R. J.: The Physiology of Congenital Heart Disease. Nelson's Loose Leaf Medicine 4: 423, Spring, 1950. Nelson, New York. Dexter, L. and others: Studies in Congenital Heart Disease; Venous Catheterization as Diagnostic Aid in Patent Ductus Arteriosus, Tetralogy of Fallot, Ventricular Septal Defect and Auricular Septal Defect. J. Clin. Investigation 26: 561, 1947. Damman, J. F., Jr. and Sell, C. G. R.: Patent Ductus Arteriosus in the Absence of a Continuous Murmur. Circulation. In press. Touroff, A. S. W. and Vesell, H.: Subacute Streptococcus Viridans Endarteritis Complicating Patent Ductus Arteriosus. J.A.M.A. 115: 1270, 1940. Keys, A. and Shapiro, M. J.: Patency of the Ductus Arteriosus in Adults. Am. Heart J. 25: 158, 1943. Blalock, A.: Operative Closure of the Patent Ductus Arteriosus. Surg., Gynec. & Obst. 82: 113, 1946. Potts, W. J., Gibson, S., Smith, S. and Riker, W. L.: Diagnosis and Surgical Treatment of Patent Ductus Arteriosus. Arch. Surg. 58: 612, 1949. Wangensteen, 0., Varco, R. L. and Baronofsky, I. D.: The Technique of Surgical Division of Patent Ductus Arteriosus. Surg., Gynec. & Obst. 88: 62, 1949. Conklin, W. S. and Watkins, E., Jr.: Use of the Potts-Smith-Gibson Clamp for Division of Patent Ductus Arteriosus. J. ThoracicSurg. 19: 361, 1950. Lynxwiler, C. P. and Wells, C. R. E.: Patent Ductus Arteriosus. South Med. J. 43: 61, 1950.
AT THE present time patent ductus arteriosus is largely a pediatric surgical problem and there is good reason to believe that in future years the surgical treatment of this malformation will be effected almost exclusively in childhood. In Gross and Longino's recent report of 412 patients with patent ductus operated on at the Children's Hospital and the Peter Bent Brigham Hospital of Boston 314 were children under 15 years of age. l Essentially the same proportion between children and adults has obtained in patients with patent ductus treated surgically at The Johns Hopkins Hospital. 2 A large amount of information concerning patent ductus arteriosus has been accumulated in the last decade, stimulated in the main by Gross' demonstration of the feasibility and therapeutic value of surgical closure.a, 4 No attempt will be made to review this data in detail. The purpose of this report is to summarize briefly the experience at The Johns Hopkins Hospital with some of the clinical manifestations, technics of surgical correction and results of treatment in infants and children with patent ductus arteriosus. ANATOMIC AND PHYSIOPATHOLOGIC ASPECTS
The ductus arteriosus is an important fetal vascular pathway whereby blood is shunted in intra-uterine life from the pulmonary artery into the aorta. With the expansion of the lungs at birth there is believed to be a reduction in the pulmonary vascular resistance, a fall in pulmonary pressure and a reversal of the direction of flow of blood through the ductus. 6 Supposedly, the pressures in the systemic and pulmonary arterial circuFrom the Department of Surgery of The Johns Hopkins University and the Surgical Service of The Johns Hopkins Hospital, Baltimore, Maryland.
* Professor of Surgery, Vanderbilt University School of Medicine; Surgeon-inChief, Vanderbilt University Hospital, Nashville, Tennessee. 1299
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H. William Scott, Jr.
lations quickly become equalized in the normal newborn infant and flow through the ductus ceases. Certainly the ductus is anatomically patent at birth but whether it remains functionally patent in the normal infant, and for how long, is actually not known. Barclay and his associates have shown that functional closure of the ductus in the sheep takes place in the first few minutes of extra-uterine life. 6 The mechanism of obliteration of the ductus arteriosus in man and specific data as to the pressures in aorta and pulmonary artery with relation to flow of blood through the anatomically patent ductus in the neonatal period are large gaps in present knowledge. When the ductus arteriosus remains patent after the neonatal period it usually exists as an isolated defect which increases the work of the heart and is ultimately detrimental to the continued health of the individual,7, 8 Occasionally, however, persistent patency of the ductus when associated with certain other malformations of the cardiovascular system serves as a means of maintaining life. For example, in patients with tetralogy of Fallot and extreme stenosis or atresia of the pulmonary orifice the ductus arteriosus may serve as the main route of blood flow to the lungs. In some cases of transposition of the great arterial trunks the ductus arteriosus may be an important means of interchange between the systemic and the pulmonary circulations. Aside from its infrequent association with these and a few other more uncommon cardiac malformations accompanied by cyanosis, persistent patency of the ductus arteriosus serves no useful function in extra-uterine life. An extensive study of the effects of the isolated patent ductus on the circulation has been made by Eppinger, Burwell and Gross8 who showed that the direction of the blood flow through the ductus in extra-uterine life is from aorta to pulmonary artery. These studies and subsequent work have indicated that there is essentially a direct relationship between the size of the ductus, the volume of the left to right shunt and the magnitude of the left ventricular output. 9 , 10 The physiologic observations support the clinical view that a small ductus is usually very well tolerated in childhood, whereas a large ductus may impose a considerable handicap. If a great proportion of the aortic blood flow leaks through the ductus there may be retardation of growth and development; increased ventricular work may lead to early cardiac failure. Damman and Sellu and others have suggested that pulmonary hypertension and irreversible pulmonary vascular changes may develop at an early age with a large shunt of this type. Children with either a small or a large ductus face equally the hazard of subacute bacterial endarteritis. Aneurysmal change in the ductus with the attendant danger of rupture may occur infrequently in adult life but is excessively rare in childhood.
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CLINICAL ASPECTS
Patent ductus arteriosus is two or three times more common in females than in males. In the majority of children the size of the shunt is such that there are no symptoms whatsoever. Activities and behavior are usually those of the normal child unless restrictions have been imposed by the parents or attending physician after the discovery of the presence of a "murmur" on routine examination. The characteristic machinery murmur is the most typical finding in the classical syndrome of patent ductus arteriosus. It is a harsh, continuous murmur with systolic accentuation and is of maximal intensity in the second left intercostal space close to the sternum. A thrill, similar to the murmur, is usually present. These findings are virtually pathognomonic of the continuous flow of blood from the high-pressured aorta through the open ductus into the pulmonary artery. Since there is no escape of venous blood into the systemic circulation and an adequate (actually excessive) flow of blood to the lungs, there is no cyanosis, clubbing, polycythemia or reduction in peripheral arterial oxygen saturation. The electrocardiogram usually shows no abnormalities; there is no axis deviation. Fluoroscopy ordinarily shows the sizeof the heart to be within normal limits and the cardiac contour is not distorted except for a variable degree of prominence of the pulmonary conus. The pulmonary vascular markings may be normal or somewhat accentuated. Approximately 80 per cent of children with patent ductus arteriosus who have been observed at The Johns Hopkins Hospital have presented this classical syndrome. In children who have an unusually large ductus, retardation of growth is occasionally quite striking. Dyspnea, palpitation and limited exercise tolerance in such patients are associated with cardiac enlargement. The systemic diastolic pressure may be quite low and the peripheral signs of aortic insufficiency may be present. Hilar dance may be a prominent fluoroscopic finding. This minority group of children with incapacitating symptoms includes in addition to individuals with excessively large shunts those .patients who have patent ductus associated with other cardiac defects and with superimposed subacute bacterial endarteritis or rheumatic heart disease. Damman and Sell have recently described a small but important group of infants and children observed in "this clinic with patent ductus and absence of the classical continuous murmur.n The ductus was unusually large in each of these young patients and the incidenceof associated cardiac enlargement and pulmonary hypertension was striking. Cardiac catheterization is of considerable diagnostic value in these "atypical ductus" cases and in the evaluation of children with the clas-
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sical syndrome when it is associated with severe symptoms and when an additional anomaly is suspected. However, as Gross,! Taussig 5 and others have frequently emphasized, in the majority of children with persistent patency of the ductus arteriosus the diagnosis can be made on clinical grounds alone. SURGICAL TREATMENT
Indications
The indications for surgical closure of the patent ductus arteriosus have been clearly stated recently by Gross and Longino. 1 Their policies are in close agreement with those which have been established by Dr. Helen Tauiilsig and Dr. Alfred Blalock in this clinic. Operation has been recommended strongly for children with patent ductus who have retardation of growth and development and is considered a life-saving necessity in those with cardiac enlargement and other manifestations of decompensation. As first demonstrated by Touroff and Vesell, closure of the open ductus may result in cure of a complicating bacterial endarteritis. 12 Certainly operation is urgently demanded in children with an infected ductus but it is desirable to bring the infection under control with antibiotics, if possible, before attempting definitive surgery. In the "atypical ductus" group with systolic murmurs and pulmonary hypertension early closure of the ductus may prevent irreversible vascular changes in the lungs. Closure of the ductus is usually indicated and may offer considerable benefit in instances in which patent ductus is associated with defects of the auricular or ventricular septum or with rheumatic heart disease. In summary, when the patent ductus has imposed a serious handicap, pfC)mpt operative closure has been strongly advised for infants and children at any age in this clinic. More of a problem is presented by the much larger group of children with persistent patency of the ductus who are essentially asymptomatic. In these patients surgical closure must be considered as a preventive rather than a therapeutic measure. Keys and Shapiro have demonstrated that the life expectancy of patients with patent ductus who are alive at age 17 averages only half that of the general population.13 The incidence of Streptococcus viridans infection and cardiac decompensation is greater in young adults than in children with patent ductus. 1 As operative experience with closure of the ductus has grown, it has become increasingly apparent that the risk to the patient imposed by the untreated patent ductus is considerably greater than the negligible risk of surgical closure. In consequence, closure of the ductus in symptomless children with the classical syndrome is advised as a prophylactic procedure. The elective operation, however, is not recommended for asymptomatic infants and
Patent Ductus Arteriosus in Childhood
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very young children in whom diagnostic difficulties are frequently encountered. It is technically easiest and probably least hazardous in children of 4 to 12 years of age. Con traindica tions
The cardinal contraindication to surgical closure of the patent ductus is the coexistence of other cardiae malformations, such as the tetralo!!;y of Fallot, for which the ductus may serve in lit compensatory capacity. In those rare instances in which patent ductus is associated with vascular disease of the lung, severe pulmonary hypertension and reversal of the ductal shunt, the ductus apparently acts as an escape valve; closure of the ductus in these circumstances would precipitate acute cor pulmonale. Fortunately, the various combinations of defects in which closure of the ductus might prove disastrous are not common. They are usually associated with some degree of peripheral arterial oxygen unsaturation which is an aid in their clinical recognition. Procedure
The surgical procedure followed in closure of the patent ductus arteriosus in this clinic has become well standardized. Intratracheal anesthesia is used with nitrous oxide-oxygen-ether and, less frequently, cyclopropane as the anesthetic agents. A left anterolateral thoracotomy approach is used routinely and the chest is usually entered in the third intercostal space. The mediastinal pleura is incised between the phrenic and vagus nerves over the ductal area. Dissection of the ductus is carried out as described by Gross.4 This consists essentially of clearing the ductus and the adjacent aorta and pulmonary artery of the investing areolar tissue and elements of the fibrous pericardium. A reHection of the serous pericardium which usually overlies the pulmonary end of the ductus must be freed from the ductus and the adjacent pulmonary artery. Sharp dissection under direct vision is used as much as possible and no attempt is made to close the ductus until the vascular structures concerned in the dissection have been mobilized widely. Great care is taken not to injure the left recurrent laryngeal nerve. In by far the great majority of children with patent ductus treated in this clinic the suture-ligation method of closure described by Blalock has been used. 14 This technic provides a means of obliteration of the ductus in continuity without dividing the vessel. Purse-string sutures of medium silk on French or atraumatic needles are placed at either end of the ductus, catching the adventitia in several places. Usually 2-0 silk is used with an atraumatic needle. These sutures are not tied tightly but with enough tension to stop the How of blood through the ductus. Two trans-
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H. William Scott, Jr.
fixion sutures of the same material are then placed through the ductus between the purse-string sutures and tied tightly around the vessel.. All of the sutures are spaced as far apart as possible. This simple and effective method of closure of the ductus is illustrated in Figure 410. If the ductus is unusually large in diameter, for instance 10 to 12 mm. or more, closure by a method of division is probably preferable to the
Fig. 410. Closure of the patent ductus by suture-ligation technic.
use of the suture-ligation technic. There are several methods of division of the ductus, most of which are essentially modifications of the procedure originally described by Gross.4. 15. 16 The clamps devised by Potts are particularly well adapted to division of a short, broad ductus and have been used in most of the cases in this clinic recently when a method of division has been employed. 15 The Potts clamps are applied to the ductus as far apart as possible prior to division of the vessel. It is wise to have a third clamp of the same type available to permit readjustment if necessary after the ductus has been divided. In order to curtail any possibility of the clamps being opened inadvertently after the ductus is
Patent Ductus Arteriosus in Childhood
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divided a lock is placed on the catch of each clamp after it is applied to the vessel. After the ductus is divided between Potts ductus clamps, each end is closed with a running mattress suture which is returned as a continuous hemostatic over-and-over suture (Fig. 411). The suture material is 4-0 or 5-0 silk on an atraumatic needle. Conklin and Watkins have described the use of the Potts-Smith-Gibson aortic partial occlusion clamp as a means of control of the aortic end
Fig. 411. Closure of the patent ductus by division and suture using Potts ductus clamps.
of theductus during its division and suture.17 Figure 412 demonstrates a modification of this technic as it has been used in a few cases in this clinic in division and suture of the exceptionally large ductus. The application of the partial occlusion clamp to the aorta is awkward with the usual anterolateral exposure. In consequence, this technic, which probably has . its greatest usefulness in the closure of a huge ductus or an aneurysm of the ductus, is reserved for the rare individual (usually an adult) in whom the suspected very large caliber of the ductus prompts the use of the more extensive exposure afforded by the posterolateral approach. A somewhat similar procedure has been used in this clinic in the technical management of patent ductus associated with coarctation of the
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aorta (Fig. 413). After completing the dissection and mobilization of the coarctate zone and the ductus, clamps are applied to the aorta proximal and distal to the site of coarctation and the pulmonary end of the ductus is occluded with a Potts ductus clamp. The ductus is divided and its aortic end is excised with the zone of aortic stenosis. The pulmonary end of the ductus is closed with a running suture of silk as previously de-
Fig. 412. Closure of unusually large patent ductus by modification of the method of division and suture described by Conklin and Watkins.17
scribed and the continuity of the aorta is restored by end-to-end anastomosis. The postoperative care of children following surgical closure of the patent ductus requires no elaborate measures in most cases. In this clinic it is routine to give oxygen and supplemental parenteral fluids for the first twelve to eighteen hours after operation. Penicillin is used in full doses for the first week. Unless coexistent cardiac defects or other complications prevent, the patients are permitted to sit up on the second or third postoperative day and are usually ambulatory by the fifth day.
Patent Ductus Arteriosus in Childhood
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The majority of patients have been able to leave the hospital by the eighth to tenth day after operation. RESULTS
Three hundred and sixty-four patients with patent ductus arteriosus were operated on at The Johns Hopkins Hospital during the period Octo-
Fig. 413. Technical management of patent ductus associated with coarctation of the aorta.
ber 1, 1942 to December 1, 1951. Of this group 273 were infants and children whose ages ranged from 3 months to 12 years. The great majority of these patients have been studied preoperatively, referred for operation and followed postoperatively by Dr. Helen B. Taussig and her associates in the Cardiac Clinic of the Harriet Lane He>me. In Table 1 the operative experience with the patent ductus arteriosus in this group of children is summarized. Approximately 80 per cent of the operations were essentially prophy-
H. William Scott, Jr.
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lactic procedures in children who were either totally asymptomatic or had minimal incapacity. Except for a single operative fatality the results in this large group have been excellent. As indicated in Table 1 and elaborated in Table 2, 6 other deaths occurred, all of which were in the smaller group of children who had incapacitating symptoms. Included Table 1 OPERATIVE EXPERIENCE WITH PATENT DUCTUS ARTERIOSUS IN CHILDREN AT THE JOHNS HOPKINS HOSPITAL
Procedure
No. of Patients
Attempted closure ............. Ligation only .................. Division ....................... Suture-ligation ................. TotaL .......................
Deaths
R&canalization
5 15 251
2 0 1 4
0 0 0 1
273
7
1
2
Table 2 CAUSES OF DEATH IN 7 CHILDREN WITH PATENT DUCTUS ARTERIOSUS TREATED SURGICALLY AT THE JOHNS HOPKINS HOSPITAL PATIENT
AGE
CAUSE OF DEATH
R. S.
3 yr.
C.D.
5 yr.
W.G.
3 yr.
Convulsions and hyperpyrexia after operation Laceration of pulmonary artery at operation Convulsions and hyperpyrexia after operation Ventricular fibrillation on opening chest Bled from aortic end of ductus after division Convulsions and hyperpyrexia after operation Laceration of aorta during repair of recurrent aneurysm of ductus
If:
J. F.C.
5 yr. 5 yr.
E.W.
2 yr.
A.E.
5 yr.
,p
with older children in the latter group there were 9 infants ranging from 3 to 11 months of age and 27 babies aged 1 to 2 years in whom the ductus " was closed successfully. In the early days of this series simple ligation of the ductus with one or two ligatures of heavy silk or linen tape was used in a few cases. Although no difficulties were encountered in children, one instance of recanalization occurred in an older patient with subacute bacterial endocarditis. This method has now been entirely abandoned. Division of the ductus was carried out in 15 children. In a few of these
Patent Ductus Arteriosus in Childhood
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patients the method of division described by Gross4 was used; in a few others the ductus was divided between suture ligatures after purse-string sutures had been placed at the ends of the vessel. One death occurred from postoperative hemorrhage subsequent to division of the ductus between suture ligatures. At autopsy the aortic stump of the ductus was found to be open, the suture ligature having slipped off. This is an illadvised method for closure of the patent ductus and is no longer used. No difficulties have been encountered in division and suture of the ductus using the Potts ductus clamps as shown in Figure 411. Successful division of the open ductus has been accomplished in several children with coarctation by the method shown in Figure 413. These cases are not included in the present data. In 2 instances attempts to close the patent ductus in children were unsuccessful because of accidents at the time of operation. In one case fatal ventricular fibrillation occurred as the chest was opened; cyclopropane was the anesthetic agent. In the other case there was uncontrollable hemorrhage from a laceration of the pulmonary artery during the dissection of the ductus. The suture-ligation technic of closure of the ductus was used in 251 children. Three deaths have occurred in the immediate postoperative period after closure of the ductus by this method. In each instance hyperpyrexia, convulsions, failure to regain consciousness and peripheral vascular collapse led to death within twelve to twenty-four hours. Proven recanalization of the ductus has occurred in one child in this series. This was a 5 year old girl without a continuous murmur who was one of the "atypical" ductus group. At operation a large ductus measuring 16 mm. in diameter was found and was closed by the suture-ligation method. During the first four or five months after operation the child had intermittent febrile episodes. Six months after operation she was readmitted with evidence of subacute bacterial endarteritis, recanalization of the ductus and formation of an aneurysm of the ductus. After prolonged antibiotic therapy, operation was carried out and an effort was made to repair the aneurysmal recanalization of the ductus. However, laceration of the aorta proximal to the aneurysm resulted in uncontrollable hemorrhage. Autopsy showed that the silk sutures used in the original closure of the ductus had cut through the wall and lay within the aneurysmal sac. In the majority of the children in this series the postoperative course following closure of the patent ductus has been uneventful. Pulmonary complications have been rare and no cases of wound infection or empyema have occurred. With the single exception of the child described above whose ductus recanalized there have been no instances of subacute bacterial endocarditis after operation in these children. Persistence of or
H . William Scott, Jr.
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development of congestive heart failure after operation has been uncommon. Follow-up studies in this group of children have been made by Dr. Taussig and her associates and their findings in a part of this series have been reported previously by Lynxwiler and Wells. 18 In general, the long range results in these children after closure of the patent ductus with few exceptions have been excellent. In those instances in which retardation of growth and development existed prior to operation there has been striking improvement after closure of the ductus. The majority of children with large shunts and incapacitating symptoms have shown a return to normality in heart size and in exercise tolerance within a few months after operation. In some of the more complicated cases in which a small ductus was associated with a large defect of the interauricular or interventricular septum there has been little or no apparent improvement after closure of the ductus. However, closure of a large ductus has proved to be quite beneficial to many of the patients with coexisting septal defects. In addition to the child who developed definite aneurysmal recanalization of the ductus following surgical closure there are two other children who were recently operated on in whom the possibility of recanalization must be entertained. Both of these children had a large ductus and were in the group of "atypical" ductus cases described by Damman and Sell. 11 Surgical closure by the suture-ligation technic was followed almost immediately by the" development of a soft continuous murmur in the pulmonic area. Both children, however, have been improved functionally by operation and have had a rise to normal in systemic diastolic pressure. They are being followed carefully and will return shortly for re-evaluation. It is possible that another anomaly such as an aortic septal defect accounts for the continuous murmur. COMMENT
Surgical closure of the patent ductus arteriosus at an early age, even in asymptomatic pat~ents, is preferable to a watch-and-wait policy of deferring operation until difficulties develop in later life. The studies of Keys and Shapiro, the experience of Gross and his associates and that of this clinic indicate that the incidence of the dangerous complications of the untreated ductus is greater in the second, third and fourth decades than in the first. 13 • 1. 6, 18 An additional advantage for the patient afforded by early surgical closure of the ductus is the curtailment of the psychological handicap and invalidism which may be imposed by overprotective parents. From the surgeon's viewpoint the technical problem of dealing with patent ductus in children with elastic, resilient vessels is considerably
Patent Ductus Arteriosus in Childhood
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easier and less hazardous than in the closure of the more rigid and sclerotic ductus of the older patient. In the large group of asymptomatic children in this series in which closure of the ductus was done essentially as a preventive measure the mortality rate was under 0.5 per cent. The over-all operative mortality rate in the 273 infants and children was 2.5 per cent. This mortality rate can and should be lowered in the future, as many of the 7 deaths were preventable (Table 2). The suture-ligation technic of closure of the patent ductus is a safe and effective method, particularly in children with readily compressible and resilient vessels of the usual (5 to 8 mm.) diameter and length. The technic has proved to be satisfactory as a means of producing permanent obliteration of the open ductus of both large and average caliber in over 300 children and adults in this clinic. However, recanalization has definitely occurred following its use in one case and may have occurred in two others. In each of these cases the ductus was unusually large in caliber (16, 12 and 10 mm. respectively) and short in length. In consequence it seems logical to use a method of division of the ductus when the vessel is over 10 mm. in diameter and is short in length and to employ the suture-ligation procedure in the closure of the ductus of average dimensions. SUMMARY
Since patent ductus arteriosus is largely a pediatric surgical problem, this report has attempted to summarize the experience at The Johns Hopkins Hospital with some of the clinical manifestations, technics of surgical correction and results of treatment in 273 infants and children with patency of the ductus. This experience emphasizes the desirability of surgical closure of the patent ductus in childhood as a preventive measure. REFERENCES 1. Gross, R. E. and Longino, L. A.: The Patent Ductus Arteriosus. Observations from 412 Surgically Treated Cases. Circulation 3: 125, 1951. 2. Scott, H. W., Jr.: Closure of the Patent Ductus by Suture-Ligation Technique. Surg., Gynec. & Obst. 90: 91, 1950. 3. Gross, R. E. and Hubbard, J. P.: Surgical Ligation of a Patent Ductus; Report of First Successful Case. J.A.M.A. 112: 729, 1939. 4. Gross, R. E.: Complete Division for the Patent Ductus Arteriosus. J. Thoracic Surg. 16: 314, 1947. 5. Taussig, H. B.: Congenital Malformations of the Heart. The Commonwealth Fund, New York, 1947. 6. Barclay, A. E., Barcroft, J., Barron, D. H. and Franklin, K. J.: A Radiographic Demonstration of the Circulation through the Heart in the Adult and in the Foetus, and the Identification of the Ductus Arteriosus. Brit. J. Radiol. 12: 505, 1939. 7. Burwell, C. S., Eppinger, E. C. and Gross, R. E.: The Effects of Patency of
1312 8. 9. 10.
11. 12. 13. 14. 15. 16. 17. 18.
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the Ductus Arteriosus on the Circulation. J. Clin. Investigation 19: 774, 1940. Eppinger, E. C., Burwell, C. S. and Gross, R. E.: Effects of Patent Ductus Arteriosus on Circulation. J. Clin. Investigation 20: 127, 1941. Bing, R. J.: The Physiology of Congenital Heart Disease. Nelson's Loose Leaf Medicine 4: 423, Spring, 1950. Nelson, New York. Dexter, L. and others: Studies in Congenital Heart Disease; Venous Catheterization as Diagnostic Aid in Patent Ductus Arteriosus, Tetralogy of Fallot, Ventricular Septal Defect and Auricular Septal Defect. J. Clin. Investigation 26: 561, 1947. Damman, J. F., Jr. and Sell, C. G. R.: Patent Ductus Arteriosus in the Absence of a Continuous Murmur. Circulation. In press. Touroff, A. S. W. and Vesell, H.: Subacute Streptococcus Viridans Endarteritis Complicating Patent Ductus Arteriosus. J.A.M.A. 115: 1270, 1940. Keys, A. and Shapiro, M. J.: Patency of the Ductus Arteriosus in Adults. Am. Heart J. 25: 158, 1943. Blalock, A.: Operative Closure of the Patent Ductus Arteriosus. Surg., Gynec. & Obst. 82: 113, 1946. Potts, W. J., Gibson, S., Smith, S. and Riker, W. L.: Diagnosis and Surgical Treatment of Patent Ductus Arteriosus. Arch. Surg. 58: 612, 1949. Wangensteen, 0., Varco, R. L. and Baronofsky, I. D.: The Technique of Surgical Division of Patent Ductus Arteriosus. Surg., Gynec. & Obst. 88: 62, 1949. Conklin, W. S. and Watkins, E., Jr.: Use of the Potts-Smith-Gibson Clamp for Division of Patent Ductus Arteriosus. J. ThoracicSurg. 19: 361, 1950. Lynxwiler, C. P. and Wells, C. R. E.: Patent Ductus Arteriosus. South Med. J. 43: 61, 1950.