- Email: [email protected]
CLOSURE OF PATENT DUCTUS DURING OPEN-HEART SURGERY
CLOSURE OF P A T E N T D U C T U S D U R I N G OPEN-HEART SURGERY Dwight C. McGoon, M.D.*
Rochester,
Minn.
T
HE proper time to close a patent ductus arteriosus that is associated with some other significant intracardiac anomaly is at the open-heart procedure. This policy is in direct variance to the contention supported in other publica tions on this subject, 1 ' 2 which state that the ductus should be closed several months or years preliminary to the intracardiac repair. Presentation of the rationale for concurrent repair of this combination of defects is the purpose of this communication. RATIONALE FOR ONE-STAGE PROCEDURE
Simplicity.—It is generally agreed that, all other factors being equal, a single procedure is preferable to one that is staged. Ductus Should Not Be Closed Preliminarily in Some Conditions.—In a few instances, the patent ductus arteriosus must be closed at the time of the intra cardiac repair. This is true of the tetralogy of Fallot, which has been fortui tously palliated by a natural patent ductus arteriosus. Obviously, in this in stance prior closure of the ductus is contraindicated for it would result in diminution of pulmonary blood flow, perhaps to a lethal degree. No Significant Benefit From Prior Closure of Small Ductus.—In many in stances, the anomaly that contributes more significantly to the hemodynamic burden is the intracardiac one, whereas the lumen of the ductus is narrow and the flow through it of little significance. Preliminary closure of the ductus in this instance could contribute nothing in a physiologic sense to the safety of the later open-heart procedure, so that staging the operation would represent the payment of ransom to a technical threat that seemed great in the early ex perience with open-heart surgery but one that is believed now not to exist. No Significant Benefit From Prior Closure of Ductus Associated With Large Ventricular Septal Defect.—Even when a patent ductus is large, it does not necessarily follow that its closure, in the presence of an associated large ven tricular septal defect, will materially reduce pulmonary blood flow or pulmonary From the Mayo Clinic and Mayo Foundation, Rochester, Minn. Received for publication March 20, 1964. •Section of Surgery. 456
Vol. 48, No. 3
September, 1964
CLOSURE OF P A T E N T DUCTUS ARTERIOSUS
457
^° '
hypertension. Indeed, ample experience shows no significant change in these parameters after closure of the ductus alone.1"3 This is because the principal resistance to pulmonary blood flow in this circumstance is at the pulmonary arteriole and not at the ductus or the ventricular septal defect. Thus, closure of either the ductus alone or the ventricular septal defect alone does not ma terially alter the hemodynamic abnormalities existing when both are present. It is known that any operation, even closure of a ductus, carries a higher risk in the presence of persisting pulmonary hypertension and increased pulmonary flow.3 Of course, if the associated intracardiac lesion was insignificant, such as a very small ventricular septal defect, which itself would not require open-heart surgery, closure of the ductus alone by the conventional approach is all that need be advised. No Need to Establish Presence of Patent Ductus Prior to Surgery.—After initial clinical and laboratory examination of a patient, including cardiac catheterization, it is often true that a diagnosis can be made with certainty of the presence of a certain intracardiac anomaly which requires correction, but the presence or absence of an associated patent ductus would not be clearly established. To define this point would require additional study, usually an aortogram. But if its presence or absence would not influence in any way the necessity of operation, nor the type of incision the surgeon would prefer, and if the surgeon could determine accurately and safely the presence or absence of a patent ductus at the time of operation, then certain identification of a patent ductus before the operation would not be necessary. At operation, the presence of a patent ductus can be detected by palpation of the typical continuous thrill at the superior end of the main pulmonary artery only in those patients without significant pulmonary hypertension. If the pulmonary artery is soft and if no continuous thrill is detected, the absence of a patent ductus can be confirmed after instituting extracorporeal circula tion by the collapse of the pulmonary artery, which then occurs. However, if pulmonary hypertension exists, and if there is any question as to the presence of a patent ductus, it is necessary to settle the doubt by isolating the ligamentum or ductus, using the technique of dissection of Kirklin and Silver,* to be re viewed later. This dissection should be accomplished prior to the institution of extracorporeal circulation. Technical Feasibility.—Most important, it must be technically feasible and safe to close a patent ductus through the median sternotomy incision if a singlestage procedure is to be acceptable. A modification of the conventional method of dividing the ductus has allowed closure of the ductus at the time of openheart surgery to be convenient and safe. The procedure consists of two steps: (1) isolation of the ductus with pas sage of a heavy ligature around it, and (2) closure of the ductus. Although no technical difficulty has been encountered with either of these steps, it would seem that any hazard associated with the procedure occurs during the isolation
458
McGOON
J . Thoracic and Cardiovas. Surg.
of the ductus. Once isolation has been accomplished, the surgeon has at his command the ability to control nearly any technical complication that might develop in this region. It is significant that the reported instances of technical mishap 1-3 while dealing with the ductus during open-heart surgery have oc curred in those instances when the patent ductus was discovered only after the institution of extracorporeal circulation. Isolation of the Ductus by Technique of Kirklin and Silver.4 (Fig. 1).— Just prior to the institution of heart-lung bypass and after cannulations have been completed, rather firm, downward traction is made on the main pulmonary artery. Finger pressure applied to dry gauze allows controlled traction on the main pulmonary artery in a caudal and dorsal direction. This maneuver pulls the bifurcation of the pulmonary artery downward from the arch of the aorta,
Fig. 1.—The technique of isolation of the patent ductus through an anterior approach. (From Kirklin and Silver.4)
stretching the tissue planes in the region and drawing the ductus taut. Usually by this traction alone, the ductus may be identified beneath the uppermost portion of the epicardium where it folds anteriorly onto the parietal peri cardium. This is the same lappet of pericardium that must be elevated from the ductus during the conventional approach. It is the presence of this pericardial extension over the ductus which greatly facilitates its dissection from within the pericardium. With traction thus applied, the closed scissors' points can be gently pressed alongside the margin of the ductus. By gently separating the scissors' points repeatedly, they advance into a free areolar cleavage plane that continues about the dorsal aspect of the ductus. The pericardial attachments to the ductus lie outside this plane and do not obstruct the dissection. A blunt-nosed right angle clamp may be used to complete the separation of the areolar tissue be hind the ductus and a heavy ligature is then passed around it. As pointed out
Vol. 48, No. 3
September, 1964
CLOSURE OF P A T E N T DUCTUS AETERIOSUS
459
by Kirklin and Silver,4 the recurrent nerve is not apparently jeopardized dur ing this dissection. Seldom does the pressure of traction on the main pulmonary artery cause a drop in systemic pressure. In fact, the constriction of the pulmonary artery by the retracting fingers may improve hemodynamics by creating temporarily a functional banding of the artery with a decrease in the left-to-right shunt, if one is present. However, should this traction embarrass cardiac function, intermittent release of the pressure on the pulmonary artery may be necessary. Closure of the Ductus.—If the ductus is small, long, and elastic and, par ticularly, if it is present in a small child, it is believed sufficient to tie a simple ligature of No. 2-0 silk at each end of the ductus. This is accomplished just prior to the beginning of perfusion. The possibility of recanalization of a ductus of this type is negligible. In 5 of the 10 patients in the series presented here (Table I ) , multiple ligation of the ductus was considered sufficient. If there is any doubt whether multiple ligation is adequate, the ductus should be divided, for this can be accomplished with ease and control. As total perfusion is begun, a vascular clamp is closed about the exposed segment of the ductus. A left ventricular vent is then placed through the apex of the left ventricle. A right ventriculotomy is now made, if it is to be required later for the intracardiac procedure, through which a sump-type sucker tip attached to a flexible intracardiac suction tube is advanced into the left main pulmonary artery (Pig. 2, a). If no ventriculotomy will be required and, particularly, if the pulmonary artery is well decompressed, suction directly through the transected pulmonary end of the ductus will suffice. The principal innovation of the method being described involves the con cept that division of the ductus itself, between clamps, with poor exposure and in friable tissues, is not required. Rather, the ductus is simply discon nected from, or cut out of, the pulmonary artery, thus leaving a very adequate stump of ductus on the aortic side for suturing and leaving a hole in the pul monary artery where the ductus once was that can be simply closed as would any arteriotomy (Fig. 2, b). A ligature may be tied gently about the stump of the ductus when the vascular clamp is released if oozing of heparinized arterial blood through the suture holes is annoying. Attention can next be given to repair of the intracardiac lesion (Fig. 2, c). The aortic stump of the ductus is longer after division of the ductus by this method than after the standard division at mid-ductus level. I t does not seem likely that the resulting cul-de-sac would enlarge through the years to form an aneurysm. Nothing suggestive of such a complication has been ob served in our cases thus far. Practicality.—Finally, the single-stage method is meritorious only if it can be shown to be practical in application. Our Series.—The above-described method of dealing with the ductus has been employed in all patients in the author's experience since its first use on
McGOON
460
J. Thoracic and Cardiovas. Surg.
Fig. 2.—The technique of division of the patent ductus employing extracorporeal circula tion, in conjunction with open repair of an associated intracardiac lesion, a, Isolation of the ductus and insertion of a flexible intracardiac sucker into the left pulmonary artery. 6, Transection of the ductus at its pulmonary end. c, Closure of the aortic end of ductus and of the pulmonary artery defect.
June 7, 1961. A summary of the 10 cases involved is presented in Table I. A patent ductus was not diagnosed before operation in Cases 3, 5, 6, and 7. The ages of the patients ranged from 6 months to 14 years. The associated anomaly that required intracardiac surgery was a ventricular septal defect in four instances, both ventricular and atrial septal defects in four, atrial septal defect in one, and pulmonary stenosis with atrial septal defect in one. No com plications or technical problems relating to the presence of the ductus were encountered. There were no surgical deaths. One late death occurred (Case 4) suddenly 2 months after operation in the only patient suffering from com plete heart block; in this patient, a "Swiss-cheese" ventricular septum had been encountered. All other patients had obtained excellent results at the time of follow-up, which extended to 2 years. No eatheterizations have been performed postoperatively. LITERATURE
It is not proposed to review here the details of the clinical, hemodynamic, and diagnostic features of the patent ductus arteriosus when associated with
Vol. 48, No. 3
September, 1964
CLOSUEE O F P A T E N T DUCTUS ARTEBIOSUS
461
intracardiac anomalies. This information is available in texts and in the re views now to be discussed.1"3 Tsuji and associates2 recently have recommended that the patient with a high-pressure patent ductus arteriosus and a predominant left-to-right shunt have a two-stage operation, the first stage being for division of the ductus with the intracardiac repair following by 1 or 2 years. They surmised that if the intracardiac procedure were performed at the same time as the division of the ductus, the operative mortality rate would be significantly increased, but they reported no experiences leading to this assumption. In 2 of the 3 cases listed in their experience, there was no significant amelioration of pulmonary hypertension after division of the ductus alone. Elliott and co-workers1 have given a detailed account of the clinical, hemodynamic, diagnostic, and surgical observations in 40 patients with a patent ductus in association with a ventricular septal defect. These authors also favored the two-stage approach. They encountered fatalities in 6 of 19 patients under going repair of both lesions at one operation, and in 2 of 10 patients in whom the ductus was closed first and open-heart surgery was performed later. How ever, the three deaths in the first group that were clearly attributable to com plications arising from the presence of patent ductus occurred among the five operations in which the presence of a ductus had not been suspected prior to the institution of extracorporeal circulation. It seems probable that this cir cumstance can now be avoided by either preoperative diagnostic studies or by brief preliminary dissection, as described in this paper. Thus, if these five operations were excluded, the results of the study by Elliott and associates1 do not show a difference in surgical risk between the staged or the non-staged repair. Furthermore, it is of interest that of their 6 patients, for whom data were available, the total pulmonary vascular resistance remained unchanged or elevated in each after closure of the patent ductus and before closure of the ventricular septal defect, and the ratio of pulmonary flow to systemic flow remained the same or increased in 5, and decreased in only 1. The findings of an earlier study by Sasahara and co-workers3 were similar to those of Elliott and associates,1 but their conclusions were different. Sasahara and his colleagues3 had experience with 13 patients having the combined de fects. In 3, correction of both lesions at one operation was undertaken, and 2 patients died as the result of hemorrhage occurring through a previously un suspected ductus during the time of cardiac bypass. The surviving patient showed marked improvement, as did a fourth patient who had closure of both defects by staged operation. Closure of the ductus alone was performed in 9 patients, with the deaths of 2 of these, and only 2 of the 7 survivors were significantly improved. These authors concluded that surgical correction of the ductus alone is hazardous and not likely to result in significant improve ment. Therefore, they concluded that closure of both ductus and ventricular septal defect at one operation is preferable if technically feasible, except in the absence of pulmonary hypertension, in which case the ventricular septal defect would be small and relatively insignificant, and closure of the ductus alone would then be sufficient.
McGOON
462
J. Thoracic and Cardiovas. Surg.
TABLE I. P A T I E N T S UNDERGOING CLOSURE OF P A T E N T DUCTUS
CASE
SEX AND AGE (YR.)
DATE OF OPERA TION
OPERATIVE DIAGNOSIS*
T E C H N I Q U E OF REPAIR*
1
M, 14
6 / 7/61
Large V S D ; large PDA
2
M, 8
9/20/61
2 Small VSD; moderate size P D A ; mild in fundibular stenosis
3
F, 3
10/18/61
Small A S D ; large PDA
Direct suture, A S D ; division, PDA
Excellent
4
M, 3
1 1 / 5/62
Very large A S D ; swisscheese vent, septum; large PDA
Patch closure, A S D ; suture, V S D ; division, PDA
Heart block; sud den death (2 mo.)
F, 8
1/23/63
Severe pulmonary steno sis; large A S D ; mod erate size PDA
Pulmonary eommissurotomy; direct su ture, ASD; ligation, PDA
Excellent
F,2
5/29/63
Large V S D ; 1 cm. A S D ; moderate size PDA (previous band ing of pulmonary artery)
Direct suture, V S D ; direct suture, A S D ; ligation, P D A ; recon struction of pulmonary artery
Excellent; systolic murmur (Grade 3)
F,3
9 / 5/63
Large V S D ; large A S D ; small P D A ; left superior vena cava
Direct suture, V S D ; direct suture, A S D ; ligation, PDA
Excellent
F, 2
9/18/63
Large V S D ; 1 cm. A S D ; large P D A ; tricuspid insufficiency
Patch closure, V S D ; direct suture, A S D ; division, PDA
Excellent
F, 3
10/26/63
Large V S D ; moderate
Patch closure, V S D ; ligation, P D A
Excellent
F , 6 mo.
12/4/63
8
10
size PDA
Direct suture, V S D ; division, PDA Direct suture, V S D ; division, P D A ; ex cision, infundibular stenosis
Excellent Excellent
Moderate size V S D ; Direct suture, V S D ; Excellent large PDA ligation, PDA •VSD = ventricular septal defect; PDA — patent ductus arteriosus; ASD = atrial septal defect. tSystolic pressure. $XJP = pulmonary blood flow; QS = systemic blood flow.
EXCEPTIONS TO ONE-STAGE PROCEDURE
Recommendation for a single-stage repair of the patent ductus and as sociated intracardiae lesions is the thesis of the present paper. However, a few exceptions to this policy are evident. One has already been mentioned, namely, the presence of an intracardiae anomaly that is itself too small and insignificant to require repair, in which case closure of the ductus by the con ventional approach is all that is required. Another exception might be the case of a baby who has intractable cardiac failure with pneumonia, a large ventricular septal defect, and a patent ductus arteriosus. In such an instance, closure of the ductus by the conventional ap proach and banding of the pulmonary artery at the same procedure might be
Vol. 48, No. 3 September, 1964
CLOSURE O F P A T E N T DUCTUS ARTERIOSUS
463
AND INTRACARDIAC ANOMALY IN O N E OPERATION PRESSURE
(MM. H g )
L E F T VENTRICULAR
RIGHT VENTRICULAR
SYSTEMIC ARTERY ( P R E OPERATIVE)
PREREPAIRt
POSTREPAIRt
PREOPERATIVE
125/72
100
115
112/12
140
POSTREPAIR t
QP/QSt
74
52
1.75
105
60
40
115
110
70
55
86/35
95
85
86/5
85
48
135/62
90
105
89/0
96/40
110
90
86/8
110
45
1.6
120
95
108/70
105
42
2.3
94/45
110
95
81/2
95
50
1.6
90/40
100
105
84/8
100
75
1.2
63/22
85
75
57/6
55
30
5.5
PREREPAIRt
3.5
65
preferable. As in our Case 10 (Table I ) , however, if the failure can be im proved by intensive medical measures, the complete one-stage repair is pre ferred. When a coarctation of the aorta is associated with a patent ductus arteriosus and an intracardiac anomaly, an altogether different problem exists. Not only does repair of the coarctation from an anterior approach seem to be a forbidding technical challenge but, in this situation, prior repair of the coarcta tion and ductus would be expected to improve the hemodynamic load of the heart, in contrast to the same situation where the coarctation was not present. Thus, when coarctation, patent ductus arteriosus, and an intracardiac anomaly coexist, prior repair of the coarctation and ductus is advisable. Finally, it is dubious whether either the staged or the single repair would be preferable in the case of an older patient with an associated intracardiac anomaly whose ductus is large, calcified, and perhaps aneurysmal, and is as-
McGOON
464
J. Thoracic and Cardiovas. Surg.
sociated with severe pulmonary hypertension. Risks by either approach in this instance would be great. SUMMARY
The rationale for the preference of a one-stage procedure over a staged procedure for closure of a patent duetus during open-heart surgery is pre sented. Dissection and isolation of the patent duetus arteriosus through a median sternotomy incision just prior to beginning extracorporeal circulation by the technique of Kirklin and Silver has not proved to be hazardous. By clamping the duetus at its center and by dividing it at the point of its at tachment to the pulmonary artery, the duetus can be divided safely during the course of open-heart surgery. It is therefore often unnecessary and unwise to perform preliminary closure of a patent duetus when it is associated with an intracardiac anomaly that requires repair. In 10 consecutive cases, a single operation for repair of a patent duetus arteriosus and associated intracardiac anomalies was accomplished successfully by the methods described. REFERENCES
1. Elliott, L. P., Ernst, R. W., Anderson, R. C , Lillehei, C. W., and Adams, P., J r . : Silent Patent Duetus Arteriosus in Association With Ventricular Septal Defect: Clinical, Hemodynamic, Pathological and Surgical Observations in 40 Patients, Am. J . Cardiol. 10: 475, 1962. 2. Tsuji, H., Shapiro, M., Magidson, O., Dunne, E., Dykstra, P., and Kay, J . H . : Surgical Treatment of High Pressure Patent Duetus Arteriosus, Circulation 27: 652, 1963. 3. Sasahara, A. A., Nadas, A. S., Rudolph, A. M., Wittenborg, M. H., and Gross, R. E . : Ven tricular Septal Defect With Patent Duetus Arteriosus: A Clinical and Hemodynamic Study, Circulation 22: 254, 1960. 4. Kirklin, J . W., and Silver, A. W . : Technie of Exposing the Duetus Arteriosus Prior to Establishing Extracorporeal Circulation, Proc. Staff Meet., Mayo Clin. 33: 423, 1958.
Rochester,
Minn.
T
HE proper time to close a patent ductus arteriosus that is associated with some other significant intracardiac anomaly is at the open-heart procedure. This policy is in direct variance to the contention supported in other publica tions on this subject, 1 ' 2 which state that the ductus should be closed several months or years preliminary to the intracardiac repair. Presentation of the rationale for concurrent repair of this combination of defects is the purpose of this communication. RATIONALE FOR ONE-STAGE PROCEDURE
Simplicity.—It is generally agreed that, all other factors being equal, a single procedure is preferable to one that is staged. Ductus Should Not Be Closed Preliminarily in Some Conditions.—In a few instances, the patent ductus arteriosus must be closed at the time of the intra cardiac repair. This is true of the tetralogy of Fallot, which has been fortui tously palliated by a natural patent ductus arteriosus. Obviously, in this in stance prior closure of the ductus is contraindicated for it would result in diminution of pulmonary blood flow, perhaps to a lethal degree. No Significant Benefit From Prior Closure of Small Ductus.—In many in stances, the anomaly that contributes more significantly to the hemodynamic burden is the intracardiac one, whereas the lumen of the ductus is narrow and the flow through it of little significance. Preliminary closure of the ductus in this instance could contribute nothing in a physiologic sense to the safety of the later open-heart procedure, so that staging the operation would represent the payment of ransom to a technical threat that seemed great in the early ex perience with open-heart surgery but one that is believed now not to exist. No Significant Benefit From Prior Closure of Ductus Associated With Large Ventricular Septal Defect.—Even when a patent ductus is large, it does not necessarily follow that its closure, in the presence of an associated large ven tricular septal defect, will materially reduce pulmonary blood flow or pulmonary From the Mayo Clinic and Mayo Foundation, Rochester, Minn. Received for publication March 20, 1964. •Section of Surgery. 456
Vol. 48, No. 3
September, 1964
CLOSURE OF P A T E N T DUCTUS ARTERIOSUS
457
^° '
hypertension. Indeed, ample experience shows no significant change in these parameters after closure of the ductus alone.1"3 This is because the principal resistance to pulmonary blood flow in this circumstance is at the pulmonary arteriole and not at the ductus or the ventricular septal defect. Thus, closure of either the ductus alone or the ventricular septal defect alone does not ma terially alter the hemodynamic abnormalities existing when both are present. It is known that any operation, even closure of a ductus, carries a higher risk in the presence of persisting pulmonary hypertension and increased pulmonary flow.3 Of course, if the associated intracardiac lesion was insignificant, such as a very small ventricular septal defect, which itself would not require open-heart surgery, closure of the ductus alone by the conventional approach is all that need be advised. No Need to Establish Presence of Patent Ductus Prior to Surgery.—After initial clinical and laboratory examination of a patient, including cardiac catheterization, it is often true that a diagnosis can be made with certainty of the presence of a certain intracardiac anomaly which requires correction, but the presence or absence of an associated patent ductus would not be clearly established. To define this point would require additional study, usually an aortogram. But if its presence or absence would not influence in any way the necessity of operation, nor the type of incision the surgeon would prefer, and if the surgeon could determine accurately and safely the presence or absence of a patent ductus at the time of operation, then certain identification of a patent ductus before the operation would not be necessary. At operation, the presence of a patent ductus can be detected by palpation of the typical continuous thrill at the superior end of the main pulmonary artery only in those patients without significant pulmonary hypertension. If the pulmonary artery is soft and if no continuous thrill is detected, the absence of a patent ductus can be confirmed after instituting extracorporeal circula tion by the collapse of the pulmonary artery, which then occurs. However, if pulmonary hypertension exists, and if there is any question as to the presence of a patent ductus, it is necessary to settle the doubt by isolating the ligamentum or ductus, using the technique of dissection of Kirklin and Silver,* to be re viewed later. This dissection should be accomplished prior to the institution of extracorporeal circulation. Technical Feasibility.—Most important, it must be technically feasible and safe to close a patent ductus through the median sternotomy incision if a singlestage procedure is to be acceptable. A modification of the conventional method of dividing the ductus has allowed closure of the ductus at the time of openheart surgery to be convenient and safe. The procedure consists of two steps: (1) isolation of the ductus with pas sage of a heavy ligature around it, and (2) closure of the ductus. Although no technical difficulty has been encountered with either of these steps, it would seem that any hazard associated with the procedure occurs during the isolation
458
McGOON
J . Thoracic and Cardiovas. Surg.
of the ductus. Once isolation has been accomplished, the surgeon has at his command the ability to control nearly any technical complication that might develop in this region. It is significant that the reported instances of technical mishap 1-3 while dealing with the ductus during open-heart surgery have oc curred in those instances when the patent ductus was discovered only after the institution of extracorporeal circulation. Isolation of the Ductus by Technique of Kirklin and Silver.4 (Fig. 1).— Just prior to the institution of heart-lung bypass and after cannulations have been completed, rather firm, downward traction is made on the main pulmonary artery. Finger pressure applied to dry gauze allows controlled traction on the main pulmonary artery in a caudal and dorsal direction. This maneuver pulls the bifurcation of the pulmonary artery downward from the arch of the aorta,
Fig. 1.—The technique of isolation of the patent ductus through an anterior approach. (From Kirklin and Silver.4)
stretching the tissue planes in the region and drawing the ductus taut. Usually by this traction alone, the ductus may be identified beneath the uppermost portion of the epicardium where it folds anteriorly onto the parietal peri cardium. This is the same lappet of pericardium that must be elevated from the ductus during the conventional approach. It is the presence of this pericardial extension over the ductus which greatly facilitates its dissection from within the pericardium. With traction thus applied, the closed scissors' points can be gently pressed alongside the margin of the ductus. By gently separating the scissors' points repeatedly, they advance into a free areolar cleavage plane that continues about the dorsal aspect of the ductus. The pericardial attachments to the ductus lie outside this plane and do not obstruct the dissection. A blunt-nosed right angle clamp may be used to complete the separation of the areolar tissue be hind the ductus and a heavy ligature is then passed around it. As pointed out
Vol. 48, No. 3
September, 1964
CLOSURE OF P A T E N T DUCTUS AETERIOSUS
459
by Kirklin and Silver,4 the recurrent nerve is not apparently jeopardized dur ing this dissection. Seldom does the pressure of traction on the main pulmonary artery cause a drop in systemic pressure. In fact, the constriction of the pulmonary artery by the retracting fingers may improve hemodynamics by creating temporarily a functional banding of the artery with a decrease in the left-to-right shunt, if one is present. However, should this traction embarrass cardiac function, intermittent release of the pressure on the pulmonary artery may be necessary. Closure of the Ductus.—If the ductus is small, long, and elastic and, par ticularly, if it is present in a small child, it is believed sufficient to tie a simple ligature of No. 2-0 silk at each end of the ductus. This is accomplished just prior to the beginning of perfusion. The possibility of recanalization of a ductus of this type is negligible. In 5 of the 10 patients in the series presented here (Table I ) , multiple ligation of the ductus was considered sufficient. If there is any doubt whether multiple ligation is adequate, the ductus should be divided, for this can be accomplished with ease and control. As total perfusion is begun, a vascular clamp is closed about the exposed segment of the ductus. A left ventricular vent is then placed through the apex of the left ventricle. A right ventriculotomy is now made, if it is to be required later for the intracardiac procedure, through which a sump-type sucker tip attached to a flexible intracardiac suction tube is advanced into the left main pulmonary artery (Pig. 2, a). If no ventriculotomy will be required and, particularly, if the pulmonary artery is well decompressed, suction directly through the transected pulmonary end of the ductus will suffice. The principal innovation of the method being described involves the con cept that division of the ductus itself, between clamps, with poor exposure and in friable tissues, is not required. Rather, the ductus is simply discon nected from, or cut out of, the pulmonary artery, thus leaving a very adequate stump of ductus on the aortic side for suturing and leaving a hole in the pul monary artery where the ductus once was that can be simply closed as would any arteriotomy (Fig. 2, b). A ligature may be tied gently about the stump of the ductus when the vascular clamp is released if oozing of heparinized arterial blood through the suture holes is annoying. Attention can next be given to repair of the intracardiac lesion (Fig. 2, c). The aortic stump of the ductus is longer after division of the ductus by this method than after the standard division at mid-ductus level. I t does not seem likely that the resulting cul-de-sac would enlarge through the years to form an aneurysm. Nothing suggestive of such a complication has been ob served in our cases thus far. Practicality.—Finally, the single-stage method is meritorious only if it can be shown to be practical in application. Our Series.—The above-described method of dealing with the ductus has been employed in all patients in the author's experience since its first use on
McGOON
460
J. Thoracic and Cardiovas. Surg.
Fig. 2.—The technique of division of the patent ductus employing extracorporeal circula tion, in conjunction with open repair of an associated intracardiac lesion, a, Isolation of the ductus and insertion of a flexible intracardiac sucker into the left pulmonary artery. 6, Transection of the ductus at its pulmonary end. c, Closure of the aortic end of ductus and of the pulmonary artery defect.
June 7, 1961. A summary of the 10 cases involved is presented in Table I. A patent ductus was not diagnosed before operation in Cases 3, 5, 6, and 7. The ages of the patients ranged from 6 months to 14 years. The associated anomaly that required intracardiac surgery was a ventricular septal defect in four instances, both ventricular and atrial septal defects in four, atrial septal defect in one, and pulmonary stenosis with atrial septal defect in one. No com plications or technical problems relating to the presence of the ductus were encountered. There were no surgical deaths. One late death occurred (Case 4) suddenly 2 months after operation in the only patient suffering from com plete heart block; in this patient, a "Swiss-cheese" ventricular septum had been encountered. All other patients had obtained excellent results at the time of follow-up, which extended to 2 years. No eatheterizations have been performed postoperatively. LITERATURE
It is not proposed to review here the details of the clinical, hemodynamic, and diagnostic features of the patent ductus arteriosus when associated with
Vol. 48, No. 3
September, 1964
CLOSUEE O F P A T E N T DUCTUS ARTEBIOSUS
461
intracardiac anomalies. This information is available in texts and in the re views now to be discussed.1"3 Tsuji and associates2 recently have recommended that the patient with a high-pressure patent ductus arteriosus and a predominant left-to-right shunt have a two-stage operation, the first stage being for division of the ductus with the intracardiac repair following by 1 or 2 years. They surmised that if the intracardiac procedure were performed at the same time as the division of the ductus, the operative mortality rate would be significantly increased, but they reported no experiences leading to this assumption. In 2 of the 3 cases listed in their experience, there was no significant amelioration of pulmonary hypertension after division of the ductus alone. Elliott and co-workers1 have given a detailed account of the clinical, hemodynamic, diagnostic, and surgical observations in 40 patients with a patent ductus in association with a ventricular septal defect. These authors also favored the two-stage approach. They encountered fatalities in 6 of 19 patients under going repair of both lesions at one operation, and in 2 of 10 patients in whom the ductus was closed first and open-heart surgery was performed later. How ever, the three deaths in the first group that were clearly attributable to com plications arising from the presence of patent ductus occurred among the five operations in which the presence of a ductus had not been suspected prior to the institution of extracorporeal circulation. It seems probable that this cir cumstance can now be avoided by either preoperative diagnostic studies or by brief preliminary dissection, as described in this paper. Thus, if these five operations were excluded, the results of the study by Elliott and associates1 do not show a difference in surgical risk between the staged or the non-staged repair. Furthermore, it is of interest that of their 6 patients, for whom data were available, the total pulmonary vascular resistance remained unchanged or elevated in each after closure of the patent ductus and before closure of the ventricular septal defect, and the ratio of pulmonary flow to systemic flow remained the same or increased in 5, and decreased in only 1. The findings of an earlier study by Sasahara and co-workers3 were similar to those of Elliott and associates,1 but their conclusions were different. Sasahara and his colleagues3 had experience with 13 patients having the combined de fects. In 3, correction of both lesions at one operation was undertaken, and 2 patients died as the result of hemorrhage occurring through a previously un suspected ductus during the time of cardiac bypass. The surviving patient showed marked improvement, as did a fourth patient who had closure of both defects by staged operation. Closure of the ductus alone was performed in 9 patients, with the deaths of 2 of these, and only 2 of the 7 survivors were significantly improved. These authors concluded that surgical correction of the ductus alone is hazardous and not likely to result in significant improve ment. Therefore, they concluded that closure of both ductus and ventricular septal defect at one operation is preferable if technically feasible, except in the absence of pulmonary hypertension, in which case the ventricular septal defect would be small and relatively insignificant, and closure of the ductus alone would then be sufficient.
McGOON
462
J. Thoracic and Cardiovas. Surg.
TABLE I. P A T I E N T S UNDERGOING CLOSURE OF P A T E N T DUCTUS
CASE
SEX AND AGE (YR.)
DATE OF OPERA TION
OPERATIVE DIAGNOSIS*
T E C H N I Q U E OF REPAIR*
1
M, 14
6 / 7/61
Large V S D ; large PDA
2
M, 8
9/20/61
2 Small VSD; moderate size P D A ; mild in fundibular stenosis
3
F, 3
10/18/61
Small A S D ; large PDA
Direct suture, A S D ; division, PDA
Excellent
4
M, 3
1 1 / 5/62
Very large A S D ; swisscheese vent, septum; large PDA
Patch closure, A S D ; suture, V S D ; division, PDA
Heart block; sud den death (2 mo.)
F, 8
1/23/63
Severe pulmonary steno sis; large A S D ; mod erate size PDA
Pulmonary eommissurotomy; direct su ture, ASD; ligation, PDA
Excellent
F,2
5/29/63
Large V S D ; 1 cm. A S D ; moderate size PDA (previous band ing of pulmonary artery)
Direct suture, V S D ; direct suture, A S D ; ligation, P D A ; recon struction of pulmonary artery
Excellent; systolic murmur (Grade 3)
F,3
9 / 5/63
Large V S D ; large A S D ; small P D A ; left superior vena cava
Direct suture, V S D ; direct suture, A S D ; ligation, PDA
Excellent
F, 2
9/18/63
Large V S D ; 1 cm. A S D ; large P D A ; tricuspid insufficiency
Patch closure, V S D ; direct suture, A S D ; division, PDA
Excellent
F, 3
10/26/63
Large V S D ; moderate
Patch closure, V S D ; ligation, P D A
Excellent
F , 6 mo.
12/4/63
8
10
size PDA
Direct suture, V S D ; division, PDA Direct suture, V S D ; division, P D A ; ex cision, infundibular stenosis
Excellent Excellent
Moderate size V S D ; Direct suture, V S D ; Excellent large PDA ligation, PDA •VSD = ventricular septal defect; PDA — patent ductus arteriosus; ASD = atrial septal defect. tSystolic pressure. $XJP = pulmonary blood flow; QS = systemic blood flow.
EXCEPTIONS TO ONE-STAGE PROCEDURE
Recommendation for a single-stage repair of the patent ductus and as sociated intracardiae lesions is the thesis of the present paper. However, a few exceptions to this policy are evident. One has already been mentioned, namely, the presence of an intracardiae anomaly that is itself too small and insignificant to require repair, in which case closure of the ductus by the con ventional approach is all that is required. Another exception might be the case of a baby who has intractable cardiac failure with pneumonia, a large ventricular septal defect, and a patent ductus arteriosus. In such an instance, closure of the ductus by the conventional ap proach and banding of the pulmonary artery at the same procedure might be
Vol. 48, No. 3 September, 1964
CLOSURE O F P A T E N T DUCTUS ARTERIOSUS
463
AND INTRACARDIAC ANOMALY IN O N E OPERATION PRESSURE
(MM. H g )
L E F T VENTRICULAR
RIGHT VENTRICULAR
SYSTEMIC ARTERY ( P R E OPERATIVE)
PREREPAIRt
POSTREPAIRt
PREOPERATIVE
125/72
100
115
112/12
140
POSTREPAIR t
QP/QSt
74
52
1.75
105
60
40
115
110
70
55
86/35
95
85
86/5
85
48
135/62
90
105
89/0
96/40
110
90
86/8
110
45
1.6
120
95
108/70
105
42
2.3
94/45
110
95
81/2
95
50
1.6
90/40
100
105
84/8
100
75
1.2
63/22
85
75
57/6
55
30
5.5
PREREPAIRt
3.5
65
preferable. As in our Case 10 (Table I ) , however, if the failure can be im proved by intensive medical measures, the complete one-stage repair is pre ferred. When a coarctation of the aorta is associated with a patent ductus arteriosus and an intracardiac anomaly, an altogether different problem exists. Not only does repair of the coarctation from an anterior approach seem to be a forbidding technical challenge but, in this situation, prior repair of the coarcta tion and ductus would be expected to improve the hemodynamic load of the heart, in contrast to the same situation where the coarctation was not present. Thus, when coarctation, patent ductus arteriosus, and an intracardiac anomaly coexist, prior repair of the coarctation and ductus is advisable. Finally, it is dubious whether either the staged or the single repair would be preferable in the case of an older patient with an associated intracardiac anomaly whose ductus is large, calcified, and perhaps aneurysmal, and is as-
McGOON
464
J. Thoracic and Cardiovas. Surg.
sociated with severe pulmonary hypertension. Risks by either approach in this instance would be great. SUMMARY
The rationale for the preference of a one-stage procedure over a staged procedure for closure of a patent duetus during open-heart surgery is pre sented. Dissection and isolation of the patent duetus arteriosus through a median sternotomy incision just prior to beginning extracorporeal circulation by the technique of Kirklin and Silver has not proved to be hazardous. By clamping the duetus at its center and by dividing it at the point of its at tachment to the pulmonary artery, the duetus can be divided safely during the course of open-heart surgery. It is therefore often unnecessary and unwise to perform preliminary closure of a patent duetus when it is associated with an intracardiac anomaly that requires repair. In 10 consecutive cases, a single operation for repair of a patent duetus arteriosus and associated intracardiac anomalies was accomplished successfully by the methods described. REFERENCES
1. Elliott, L. P., Ernst, R. W., Anderson, R. C , Lillehei, C. W., and Adams, P., J r . : Silent Patent Duetus Arteriosus in Association With Ventricular Septal Defect: Clinical, Hemodynamic, Pathological and Surgical Observations in 40 Patients, Am. J . Cardiol. 10: 475, 1962. 2. Tsuji, H., Shapiro, M., Magidson, O., Dunne, E., Dykstra, P., and Kay, J . H . : Surgical Treatment of High Pressure Patent Duetus Arteriosus, Circulation 27: 652, 1963. 3. Sasahara, A. A., Nadas, A. S., Rudolph, A. M., Wittenborg, M. H., and Gross, R. E . : Ven tricular Septal Defect With Patent Duetus Arteriosus: A Clinical and Hemodynamic Study, Circulation 22: 254, 1960. 4. Kirklin, J . W., and Silver, A. W . : Technie of Exposing the Duetus Arteriosus Prior to Establishing Extracorporeal Circulation, Proc. Staff Meet., Mayo Clin. 33: 423, 1958.