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Intracardiac repair of single ventricle with pulmonary stenosis
Intracardiac repair of single ventricle with pulmonary stenosis Marian I. Ionescu, M.D., Fergus J. Macartney, M.D., and Geoffrey H. Wooler, M.D., Leeds, England
Isome t has long been realized that, in theory, forms of single ventricle should be correctable. A review of the literature has revealed no reported success with intracardiac repair of such an anomaly. We wish to report surgical correction in a patient with single ventricle, transposition of the great arteries, and pulmonary stenosis. Case report The patient was a 23-year-old white man who had been cyanotic from birth and did not walk until he was 2 years old. Thereafter, he suffered moderate exertional dyspnea and squatted frequently. Cardiac catheterization in 1954, at 4Y2 years of age, demonstrated that both great arteries originated from a ventricle whose systolic pressure was at systemic level; the examination further revealed pulmonary valve stenosis (systolic gradient of 76 mm. Hg ), aortic desaturation (oxygen saturation 70 per cent), and, interestingly, no apparent intracardiac left-to-right shunt as assessed by oxygen saturations. The pulmonary-systemic flow ratio was 0.32: 1. Because of increasing cyanosis, a right subclavian-pulmonary artery anastomosis was created on June 14, 1955. Following this, a loud continuous murmur developed beneath the right clavicle. The cyanosis lessened but the patient remained somewhat dyspneic on exertion. In October, 1971, he developed subacute bacterial endocarditis which responded well to medical treatment. From the Departments of Cardiothoracic Surgery and Cardiology, The General Infirmary at Leeds, Killingbeck Hospital, and Leeds University, Leeds, England. Supported by the British Heart Foundation. Received for publication Oct. 2, 1972. Address for reprints: Dr. M. I. Ionescu, Department of Cardiothoracic Surgery, The General Infirmary, Leeds, England.
602
When admitted for corrective surgery the patient was dyspneic on moderate exertion. Physical examination revealed mild cyanosis at rest and a weak but regular right radial pulse. There was no elevation of the jugular venous pressure. A systolic thrill was palpable at the upper left sternal border and in the suprasternal notch, and there was a mild left parasternal lift. The first and second heart sounds were single, and there was a loud continuous murmur maximal under the right clavicle. The electrocardiogram showed sinus rhythm with a P-R interval of 0.21 second. The mean frontal QRS axis was + 90 degrees, inscribed in a clockwise direction, and the precordial leads indicated biventricular hypertrophy. There was a 3 mm. Q wave in Lead V" but not in Leads V., III, or aV F. This was interpreted as consistent with severe right ventricular hypertrophy. The chest x-ray film showed a cardiothoracic ratio of 0.51 with a hollow pulmonary arc and a left aortic arch. The vascular pedicle was narrow and the cardiac apex was not tilted upward. Pulmonary vascularity was normal on the right and slightly diminished on the left. A preoperative angiocardiogram (Fig. 1) demonstrated that contrast medium, injected via a catheter that had been placed through the tricuspid valve, opacified a somewhat trabeculated ventricular chamber from which both great arteries originated. The aortic valve lay anterior to and to the right of the pulmonary valve, but at about the same horizontal level. The cusps of the pulmonary valve were thickened and domed. There was also mild stenosis of the main pulmonary artery, the main right pulmonary artery, and the right upper lobe pulmonary artery. Operation was performed on July 4, 1972, through a median sternotomy. The heart was found to be moderately enlarged. The atria were in situs solitus, of normal size, and had a normally connected venous return. The aorta was anterior
Volume 65 Number 4 April, 1973
Fig. 1. Preoperative angiocardiogram. Contrast medium, injected via a catheter placed through the tricuspid valve, opacified a ventricular chamber from which both great arteries originate. The aortic valve (open arrow) lay anterior and to the right of the pulmonary valve (colored arrow), but at about the same horizontal level. Asterisk (*), Ascending aorta. PS, Stenosis of the main pulmonary artery. and to the right of the pulmonary artery, which was considerably smaller than the aorta (Fig. 2). Behind the aorta an accessory left auricular appendage was found. A coronary artery, similar in position to the anterior descending branch, was seen on the anterolateral aspect of the ventricle. No vessel corresponding to the posterior descending branch could be found, instead, several medium-sized branches spread irregularly over the entire posterior surface of the ventricle. No major coronary branches crossed the anterior aspect of the ventricle below the origin of the pulmonary artery. The right subclavian artery was dissected free near its anastomosis to the pulmonary artery and was later ligated after heart-lung bypass had been started. Total euthermic cardiopulmonary bypass at 2.5 L. per square meter per minute was instituted and maintained for 115 minutes with the use of a Travenol bag and nonhemic prime. Two cannulas through the venae cavae and one through the ascending aorta were used for perfusion. A vent tube was introduced into the ventricle through the left atrium and across the mitral valve. The right atrial cavity was inspected through a small incision parallel to the atrioventricular groove. The atrial septum was intact. The tri-
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Fig. 2. Operative view of the heart. The aorta is anterior and to the right of the pulmonary artery. cuspid valve was competent, but its anterior cusp ballooned into the atrium during systole. The ventricle was opened through a vertical incision which was extended downward halfway to the apex and upward across the pulmonary annulus into the main pulmonary trunk and the origin of its left main branch. The main pulmonary trunk measured 10 mrn., and the pulmonary annulus was 15 mm. in diameter. The pulmonary valve had a central orifice of 6 mm. with three thickened and fused cusps. There was a localized stenosis at the origin of the right pulmonary artery. Two atrioventricular valves, in fibrous continuity, entered a finely trabeculated common ventricle. The valve that entered from the right atrium was tricuspid, whereas the valve from the left atrium bicuspid. The aorta arose from a subaortic chamber lying anterior to, above, and to the right of the common ventricle. There was an additional shallow, fibrous recess about 10 mm. in diameter between the mitral and the aortic valves. The aortic valve was anterior, slightly to the right of, and at about the same horizontal level as the pulmonary valve. The communication between the single ventricle and the rudimentary chamber was about the size of the aortic annulus. There was no continuity between the atrioventricular valves on the one hand and
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Table I. Hemodynamic and oxygen saturation data Pressures (mm. Hg) At operation Before correction Vessel
Right atrium Left atrium Pulmonary wedge "Right" ventricle Pulmonary artery "Left" ventricle Common ventricle Systemic artery
Dynamic
I
Mean
I After correction
I
Dynamic
10/0 12/0
15/6 12/2
10/-5 92/0 102/70
either the aortic or the pulmonary valve on the other. Therefore, the anatomy of the heart was typical of a single ventricle with a non inverted infundibulum, transposition of the great arteries, a bilateral conus (double-outlet right ventricle morphology"), and pulmonary stenosis. Muscle was resected from the right aspect of the ventriculotomy, thereby enlarging the communication between the common and the rudimentary ventricle. A Dacron felt patch, 3 mm. thick and 90 by 60 mm. in size, was tailored and sutured inside the single ventricle in order to create two separate cavities. The patch was attached to the fibrous tissue in between the atrioventricular valves and halfway down to the apex by multiple" interrupted sutures. Along the remaining posterior wall of the ventricle, toward the apex and on the lower half of the anterior aspect, a continuous suture was used, with deep bites taken longitudinally in the trabeculae. At the upper part, the Dacron patch was attached to the ventricular muscle with interrupted sutures that were reinforced with Dacron pledgets. The line of sutures was placed in such a way as to form a tunnel from the "left" ventricle to the aorta. The distal portion of the tunnel was somewhat narrow due to the small space available between the tricuspid and pulmonary valves, but the bulging of the patch into the "right" ventricular outlet was considered sufficient for unobstructed "left" ventricular emptying. During this part of the procedure, the aorta was cross-clamped intermittently (for a total of 42 minutes) and the heart continued to contract in sinus rhythm. Three times complete heart block occurred, and the responsible sutures were removed and repositioned. Sinus rhythm was present after the ventricle had been partitioned. Four additional Dacron-reinforced, interrupted sutures had to be inserted in order to obliterate residual leaks at the margins of the septum. A prefabricated graft measuring 100 by 45 mm. was used for reconstruction of the "right"
I
Mean
10 8
Six weeks after operation Dynamic I Mean
17/6
13
20/6 60/12 42/10 106/13
13
36/8 22/8 110/2 112170
104/62
Oxygen saturation (per cent)
68
21
82 77 92
76
92
ventricular outflow. This consisted of a valve-bearing, diamond-shaped piece of preserved heterologous pericardium." The posterior cusp of the hypoplastic pulmonary valve was retained, while the fibrosed anterior cusps were removed. The graft was attached to the margins of the incision in the pulmonary artery and ventricle via continuous sutures. The repair was thus completed, and perfusion was discontinued without incident. Pressures were recorded from the heart and great vessels under stable hemodynamic conditions and were considered satisfactory (Table I). Hemostasis was secured, and the chest wall was closed with drainage tubes, left and right atrial catheters, and four temporary epicardial pacemaker leads still in place. The postoperative period was unremarkable except for slight peripheral edema which responded to administration of digitalis and diuretics. Six weeks postoperatively, a further cardiac catheterization was carried out with the patient's informed consent. At this time he was still in the stage of postoperative fluid retention, receiving digoxin tablets, 0.25 mg. twice a day, and Lasix tablets, 40 mg. every other day. He was acyanotic. There was no peripheral edema or hepatic enlargement, but the jugular venous pressure was elevated 4 cm. above the suprasternal notch when the patient was sitting upright, and the V wave was dominant. The cardiac impulse was double, and there was a marked left parasternal lift. There was a systolic thrill at the left sternal edge, and on auscultation a pansystolic murmur was heard in the same site. The second heart sound was widely split and did not vary with respiration. There was a short diastolic murmur originating at the second pulmonic sound. No added sounds were present in the lungs. The electrocardiogram showed complete right bundle branch block, and the chest x-ray film revealed a cardiothoracic ratio of 59 per cent with increased pulmonary vascularity. Cardiac catheterization (Table I) demonstrated
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Fig. 3. Postoperative angiocardiograms. Contrast medium was injected retrogradely into the "left" ventricle. A, Lateral view. The prosthetic septum (open arrows) is concave toward the "left" ventricle. There is a well defined subaortic outflow chamber (star) anterior to the original single ventricular chamber. AO, Aorta. R, Recess between the mitral and aortic valves. B, Posteroanterior view. PA, The reconstructed pulmonary artery. a 9 mm. Hg systolic gradient between the distal and proximal right pulmonary arteries, with an 18 mm. Hg systolic gradient across the pericardial monocusp pulmonary valve. The "right" ventricular systolic pressure was 46 mm. Hg lower than a simultaneous "left" ventricular systolic pressure. There was no significant systolic gradient between the "left" ventricle and the aorta. There was a 14 per cent step-up in oxygen saturations at high "right" ventricular level. Pulmonary blood flow (direct Fick ) was 7.4 and systemic blood flow 2.9 L. per minute per square meter at rest. Both "right" and "left" ventricular end-diastolic pressures were mildly elevated at 13 mm. Hg, with consequent elevation of the right and indirect left atrial pressures. Selective angiocardiograms of both "ventricles" were obtained (Fig. 3, A and B). These demonstrated mild nonsustained regurgitation into the left atrium, probably the result of ectopic beats during injection. The mitral valve orifice was well distant from either semilunar valve, as was the tricuspid valve. The two "ventricles" were trabeculated to the same extent, slightly more than is a normal left ventricle. The interventricular patch was clearly visible; it was concave toward the "left" ventricle, and a jet of contrast medium passed anteriorly alongside and about halfway up the patch, into the anterior "right" ventricle. There was a well-defined subaortic outflow chamber anterior to the original
single ventricular chamber, and a small recess could be seen immediately anterior to and above the mitral valve annulus. The reconstructed pulmonary artery was comparable in size to the aorta. The monocusp valve was not well visualized. The appearance of the pulmonary arteries has already been described. On pulmonary venous return to the left atrium, the accessory left atrial appendage was identified lying to the right of the aortic root.
Discussion
Single ventricle is one of the few congenital heart anomalies which has not benefited from definitive surgical repair. Intracardiac correction of absent septum, on the other hand, was recently achieved in 4 cases." By all definitions and in all classifications," 4, 13 single or common ventricle is a complex malformation characterized by the presence of one main ventricle which receives two atrioventricular valves and empties directly or indirectly into both the aorta and pulmonary artery. In the majority of these cases, transposition of the great arteries is present, and obstruction to outflow tracts is also common. Various other
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anomalies may be associated with this malformation. The complexity of the cardiac defect alone explains the technical difficulties involved in its complete surgical correction. Definitive repair can be achieved by partitioning the ventricle in order to separate and direct appropriately the venous return without compromising the conduction system or the function of the atrioventricular valves. Experimental work from the Mayo Clinic-'- 12 has demonstrated the feasibility of replacing the ventricular septum with a prosthesis in dogs, thereby maintaining near normal cardiac function postoperatively. Furthermore, these studies have shown that the main function of the ventricular septum, and hence of a prosthetic septum, is to separate the two ventricles and to maintain their normal relative volumes. In the case reported here, it was possible to insert the prosthetic septum without permanently damaging the conduction system. The use of an instrument to detect the location of the system should be of great help in such cases. In order to avoid injury to coronary artery branches, none of the sutures used for the insertion of the septum were passed through the whole thickness of the ventricular wall. All were tied inside the "right" ventricular cavity. Although at the end of the surgical procedure there was no apparent leak around the prosthetic septum, the recurrent interventricular communication might have been caused by this suturing technique. The optimal size and positioning of the patch were determined by careful examination of the anatomy of the ventricle and the orientation of the valve orifices while the heart was contracting. The second part of the surgical repair consists in relieving the "right" ventricular outflow obstruction when present. Depending on the position of major coronary arteries and the access to the pulmonary annulus, one of two techniques can be used: patch reconstruction of the outflow tract, as in the case described here, or bypass of the pulmonary stenosis with a valve-bearing
conduit.s- 9, 10 The necessity of placing a valve in the newly fashioned right ventricular outflow tract is not clearly established.' It seems that the absence of such a valve, when associated with other structural and functional abnormalities, would impose a significant additional burden on the "right" ventricle. Because it is difficult to elucidate during the operation if the partition of the ventricle is functionally correct, we have used a cusp-bearing pericardial patch in order to obviate any additional strain imposed on the "right" ventricle. The question as to which type of outflow tract substitute is the best will be answered only after a long period of time. The preserved homograft of ascending aorta with an integral valve has proved to function satisfactorily over a period of up to 5 years." Our early results with glutaraldehydetreated heterologous pericardium for the replacement of all heart valves have been encouraging. Definitive criteria for the selection of patients with single ventricle to undergo surgery will only emerge as experience with this lesion increases. The presence of severe pulmonary vascular disease contraindicates surgery, and at present it would seem logical to use the same criteria for selection that have been used in patients with ventricular septal defect"; namely, the ratio of pulmonary to systemic resistance should be less than about 0.75. Two separate atrioventricular valves should be demonstrated on preoperative angiocardiography. Since the prosthetic septum is not expected to grow, definitive repair should be undertaken in later childhood. Because many patients with single ventricle present with serious symptoms in infancy, it follows that palliative surgery will be necessary at that stage to provide optimal pulmonary blood flow and to prevent, if possible, the onset of pulmonary vascular obstructive disease. Thus, in patients with marked cyanosis due to diminished pulmonary blood flow and pulmonary stenosis, systemic-pulmonary artery anastomoses
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should be created. In those patients with increased pulmonary blood flow and pulmonary hypertension, banding of the pulmonary artery should be considered. Successful repair in the case reported here may be attributed to the favorable anatomy ("normally" positioned and functionally competent atrioventricular valves), to the adequate partitioning of the ventricle, and to the use of a valve-bearing patch for reconstruction of the "right" ventricular outlet. However, there are cases in which the complex anatomy of the cardiac malformation precludes definitive surgery, at least in the present state of our knowledge.
Summary A case of single ventricle with a noninverted infundibulum, transposition of the great arteries, bilateral conus, and pulmonary stenosis is described. Successful intracardiac repair was achieved by partitioning the ventricle and relieving the pulmonary stenosis. A Dacron felt prosthesis was used for the construction of the septum, while the "right" ventricular outflow was reconstructed with a monocusp pericardial patch. The preoperative diagnosis and the results of early postoperative investigations are discussed along with details of the surgical technique. The indications for surgical treatment of single ventricle are broadly outlined. REFERENCES Bartek, I. T., Holden, M. P., and Ionescu, M. I.: Techniques for the Construction of Tissue Heart Valves, Thorax. In press. 2 Cartmil\, T. B., Du Shane, 1. W., McGoon, D. C., and Kirklin, J. W.: Results of Repair of Ventricular Septal Defect, J. THORAc. CAROIOVAse. SURG. 52: 486, 1966. 3 Elliott, L. P., Anderson, R. C., and Edwards,
J. E.: The Common Cardiac Ventricle With Transposition of the Great Vessels, Br. Heart J. 26: 289, 1964. 4 Hallerman, F. J., Davis, E. D., Ritter, D. G., and Kincaid, O. W.: Roentgenographic Features of Common Ventricle, Radiology 87: 409, 1966. 5 Hallerman, F. J., Kincaid, O. W., Ritter, D. G., Ongley, P. A., and Titus, J. L.: Angiecardiographic and Anatomic Findings in Origin of Both Great Arteries From the Right Ventricle, Am. J. Roentgeno!. Radium Ther. Nuc!. Med. 109: 51, 1970. 6 Ionescu, M. I., and Deac, R. C.: Fascia Lata Composite Graft For Right Ventricular Outflow Tract and Pulmonary Artery Reconstruction, Thorax 25: 427, 1970. 7 Ionescu, M. I., Deac, R. C., Ionescu, C. M., and Wooler, G. H.: Reconstruction of the Right Ventricular Outlet With Fascia Lata Composite Graft, in Ionescu, M. I., Ross, D. N., and Wooler, G. H., editors: Biological Tissue in Heart Valve Replacement, chap. 35, London, 1971, Butterworth & Co., Ltd., p. 743. 8 Maim, J. R.: Personal communication. 9 McGoon, D. C, Wallace, R. B., and Danielson, G. K.: Homografts in Reconstruction of Congenital Cardiac Anomalies, Mayo Clin. Proc. 47: 101, 1972. 10 Rastelli, G. C, Wallace, R. B., and Ongley, P. A.: Complete Repair of Transposition of the Great Arteries With Pulmonary Stenosis: A Review and Report of a Case Corrected by Using a New Surgical Technique, Circulation 39: 83, 1969. 11 Seki, S., and McGoon, D. C.: Surgical Techniques for Replacement of the Interventricular Septum, 1. THoRAc. CAROIOVASC. SURG. 62: 919, 1971. 12 Seki, S., Tsakiris, A. G., Dandade, P. B., Rastelli, G. C., and McGoon, D. c.: Replacement of the Ventricular Septum as a Potential Correction for Single Ventricle, Circulation 42: 197, 1970 (Suppl, 3). 13 Van Praagh, R., Ongley, P. A., and Swan, H. J. C.: Anatomic Types of Single or Common Ventricle in Man: Morphologic and Geometric Aspects in 60 Necropsied Cases, Am. J. Cardiol. 13: 367, 1964.
Isome t has long been realized that, in theory, forms of single ventricle should be correctable. A review of the literature has revealed no reported success with intracardiac repair of such an anomaly. We wish to report surgical correction in a patient with single ventricle, transposition of the great arteries, and pulmonary stenosis. Case report The patient was a 23-year-old white man who had been cyanotic from birth and did not walk until he was 2 years old. Thereafter, he suffered moderate exertional dyspnea and squatted frequently. Cardiac catheterization in 1954, at 4Y2 years of age, demonstrated that both great arteries originated from a ventricle whose systolic pressure was at systemic level; the examination further revealed pulmonary valve stenosis (systolic gradient of 76 mm. Hg ), aortic desaturation (oxygen saturation 70 per cent), and, interestingly, no apparent intracardiac left-to-right shunt as assessed by oxygen saturations. The pulmonary-systemic flow ratio was 0.32: 1. Because of increasing cyanosis, a right subclavian-pulmonary artery anastomosis was created on June 14, 1955. Following this, a loud continuous murmur developed beneath the right clavicle. The cyanosis lessened but the patient remained somewhat dyspneic on exertion. In October, 1971, he developed subacute bacterial endocarditis which responded well to medical treatment. From the Departments of Cardiothoracic Surgery and Cardiology, The General Infirmary at Leeds, Killingbeck Hospital, and Leeds University, Leeds, England. Supported by the British Heart Foundation. Received for publication Oct. 2, 1972. Address for reprints: Dr. M. I. Ionescu, Department of Cardiothoracic Surgery, The General Infirmary, Leeds, England.
602
When admitted for corrective surgery the patient was dyspneic on moderate exertion. Physical examination revealed mild cyanosis at rest and a weak but regular right radial pulse. There was no elevation of the jugular venous pressure. A systolic thrill was palpable at the upper left sternal border and in the suprasternal notch, and there was a mild left parasternal lift. The first and second heart sounds were single, and there was a loud continuous murmur maximal under the right clavicle. The electrocardiogram showed sinus rhythm with a P-R interval of 0.21 second. The mean frontal QRS axis was + 90 degrees, inscribed in a clockwise direction, and the precordial leads indicated biventricular hypertrophy. There was a 3 mm. Q wave in Lead V" but not in Leads V., III, or aV F. This was interpreted as consistent with severe right ventricular hypertrophy. The chest x-ray film showed a cardiothoracic ratio of 0.51 with a hollow pulmonary arc and a left aortic arch. The vascular pedicle was narrow and the cardiac apex was not tilted upward. Pulmonary vascularity was normal on the right and slightly diminished on the left. A preoperative angiocardiogram (Fig. 1) demonstrated that contrast medium, injected via a catheter that had been placed through the tricuspid valve, opacified a somewhat trabeculated ventricular chamber from which both great arteries originated. The aortic valve lay anterior to and to the right of the pulmonary valve, but at about the same horizontal level. The cusps of the pulmonary valve were thickened and domed. There was also mild stenosis of the main pulmonary artery, the main right pulmonary artery, and the right upper lobe pulmonary artery. Operation was performed on July 4, 1972, through a median sternotomy. The heart was found to be moderately enlarged. The atria were in situs solitus, of normal size, and had a normally connected venous return. The aorta was anterior
Volume 65 Number 4 April, 1973
Fig. 1. Preoperative angiocardiogram. Contrast medium, injected via a catheter placed through the tricuspid valve, opacified a ventricular chamber from which both great arteries originate. The aortic valve (open arrow) lay anterior and to the right of the pulmonary valve (colored arrow), but at about the same horizontal level. Asterisk (*), Ascending aorta. PS, Stenosis of the main pulmonary artery. and to the right of the pulmonary artery, which was considerably smaller than the aorta (Fig. 2). Behind the aorta an accessory left auricular appendage was found. A coronary artery, similar in position to the anterior descending branch, was seen on the anterolateral aspect of the ventricle. No vessel corresponding to the posterior descending branch could be found, instead, several medium-sized branches spread irregularly over the entire posterior surface of the ventricle. No major coronary branches crossed the anterior aspect of the ventricle below the origin of the pulmonary artery. The right subclavian artery was dissected free near its anastomosis to the pulmonary artery and was later ligated after heart-lung bypass had been started. Total euthermic cardiopulmonary bypass at 2.5 L. per square meter per minute was instituted and maintained for 115 minutes with the use of a Travenol bag and nonhemic prime. Two cannulas through the venae cavae and one through the ascending aorta were used for perfusion. A vent tube was introduced into the ventricle through the left atrium and across the mitral valve. The right atrial cavity was inspected through a small incision parallel to the atrioventricular groove. The atrial septum was intact. The tri-
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Fig. 2. Operative view of the heart. The aorta is anterior and to the right of the pulmonary artery. cuspid valve was competent, but its anterior cusp ballooned into the atrium during systole. The ventricle was opened through a vertical incision which was extended downward halfway to the apex and upward across the pulmonary annulus into the main pulmonary trunk and the origin of its left main branch. The main pulmonary trunk measured 10 mrn., and the pulmonary annulus was 15 mm. in diameter. The pulmonary valve had a central orifice of 6 mm. with three thickened and fused cusps. There was a localized stenosis at the origin of the right pulmonary artery. Two atrioventricular valves, in fibrous continuity, entered a finely trabeculated common ventricle. The valve that entered from the right atrium was tricuspid, whereas the valve from the left atrium bicuspid. The aorta arose from a subaortic chamber lying anterior to, above, and to the right of the common ventricle. There was an additional shallow, fibrous recess about 10 mm. in diameter between the mitral and the aortic valves. The aortic valve was anterior, slightly to the right of, and at about the same horizontal level as the pulmonary valve. The communication between the single ventricle and the rudimentary chamber was about the size of the aortic annulus. There was no continuity between the atrioventricular valves on the one hand and
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The Journal of Thoracic and Cardiovascular Surgery
Ionescu, Macartney, Wooler
Table I. Hemodynamic and oxygen saturation data Pressures (mm. Hg) At operation Before correction Vessel
Right atrium Left atrium Pulmonary wedge "Right" ventricle Pulmonary artery "Left" ventricle Common ventricle Systemic artery
Dynamic
I
Mean
I After correction
I
Dynamic
10/0 12/0
15/6 12/2
10/-5 92/0 102/70
either the aortic or the pulmonary valve on the other. Therefore, the anatomy of the heart was typical of a single ventricle with a non inverted infundibulum, transposition of the great arteries, a bilateral conus (double-outlet right ventricle morphology"), and pulmonary stenosis. Muscle was resected from the right aspect of the ventriculotomy, thereby enlarging the communication between the common and the rudimentary ventricle. A Dacron felt patch, 3 mm. thick and 90 by 60 mm. in size, was tailored and sutured inside the single ventricle in order to create two separate cavities. The patch was attached to the fibrous tissue in between the atrioventricular valves and halfway down to the apex by multiple" interrupted sutures. Along the remaining posterior wall of the ventricle, toward the apex and on the lower half of the anterior aspect, a continuous suture was used, with deep bites taken longitudinally in the trabeculae. At the upper part, the Dacron patch was attached to the ventricular muscle with interrupted sutures that were reinforced with Dacron pledgets. The line of sutures was placed in such a way as to form a tunnel from the "left" ventricle to the aorta. The distal portion of the tunnel was somewhat narrow due to the small space available between the tricuspid and pulmonary valves, but the bulging of the patch into the "right" ventricular outlet was considered sufficient for unobstructed "left" ventricular emptying. During this part of the procedure, the aorta was cross-clamped intermittently (for a total of 42 minutes) and the heart continued to contract in sinus rhythm. Three times complete heart block occurred, and the responsible sutures were removed and repositioned. Sinus rhythm was present after the ventricle had been partitioned. Four additional Dacron-reinforced, interrupted sutures had to be inserted in order to obliterate residual leaks at the margins of the septum. A prefabricated graft measuring 100 by 45 mm. was used for reconstruction of the "right"
I
Mean
10 8
Six weeks after operation Dynamic I Mean
17/6
13
20/6 60/12 42/10 106/13
13
36/8 22/8 110/2 112170
104/62
Oxygen saturation (per cent)
68
21
82 77 92
76
92
ventricular outflow. This consisted of a valve-bearing, diamond-shaped piece of preserved heterologous pericardium." The posterior cusp of the hypoplastic pulmonary valve was retained, while the fibrosed anterior cusps were removed. The graft was attached to the margins of the incision in the pulmonary artery and ventricle via continuous sutures. The repair was thus completed, and perfusion was discontinued without incident. Pressures were recorded from the heart and great vessels under stable hemodynamic conditions and were considered satisfactory (Table I). Hemostasis was secured, and the chest wall was closed with drainage tubes, left and right atrial catheters, and four temporary epicardial pacemaker leads still in place. The postoperative period was unremarkable except for slight peripheral edema which responded to administration of digitalis and diuretics. Six weeks postoperatively, a further cardiac catheterization was carried out with the patient's informed consent. At this time he was still in the stage of postoperative fluid retention, receiving digoxin tablets, 0.25 mg. twice a day, and Lasix tablets, 40 mg. every other day. He was acyanotic. There was no peripheral edema or hepatic enlargement, but the jugular venous pressure was elevated 4 cm. above the suprasternal notch when the patient was sitting upright, and the V wave was dominant. The cardiac impulse was double, and there was a marked left parasternal lift. There was a systolic thrill at the left sternal edge, and on auscultation a pansystolic murmur was heard in the same site. The second heart sound was widely split and did not vary with respiration. There was a short diastolic murmur originating at the second pulmonic sound. No added sounds were present in the lungs. The electrocardiogram showed complete right bundle branch block, and the chest x-ray film revealed a cardiothoracic ratio of 59 per cent with increased pulmonary vascularity. Cardiac catheterization (Table I) demonstrated
Volume 65 Number 4 April, 1973
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Fig. 3. Postoperative angiocardiograms. Contrast medium was injected retrogradely into the "left" ventricle. A, Lateral view. The prosthetic septum (open arrows) is concave toward the "left" ventricle. There is a well defined subaortic outflow chamber (star) anterior to the original single ventricular chamber. AO, Aorta. R, Recess between the mitral and aortic valves. B, Posteroanterior view. PA, The reconstructed pulmonary artery. a 9 mm. Hg systolic gradient between the distal and proximal right pulmonary arteries, with an 18 mm. Hg systolic gradient across the pericardial monocusp pulmonary valve. The "right" ventricular systolic pressure was 46 mm. Hg lower than a simultaneous "left" ventricular systolic pressure. There was no significant systolic gradient between the "left" ventricle and the aorta. There was a 14 per cent step-up in oxygen saturations at high "right" ventricular level. Pulmonary blood flow (direct Fick ) was 7.4 and systemic blood flow 2.9 L. per minute per square meter at rest. Both "right" and "left" ventricular end-diastolic pressures were mildly elevated at 13 mm. Hg, with consequent elevation of the right and indirect left atrial pressures. Selective angiocardiograms of both "ventricles" were obtained (Fig. 3, A and B). These demonstrated mild nonsustained regurgitation into the left atrium, probably the result of ectopic beats during injection. The mitral valve orifice was well distant from either semilunar valve, as was the tricuspid valve. The two "ventricles" were trabeculated to the same extent, slightly more than is a normal left ventricle. The interventricular patch was clearly visible; it was concave toward the "left" ventricle, and a jet of contrast medium passed anteriorly alongside and about halfway up the patch, into the anterior "right" ventricle. There was a well-defined subaortic outflow chamber anterior to the original
single ventricular chamber, and a small recess could be seen immediately anterior to and above the mitral valve annulus. The reconstructed pulmonary artery was comparable in size to the aorta. The monocusp valve was not well visualized. The appearance of the pulmonary arteries has already been described. On pulmonary venous return to the left atrium, the accessory left atrial appendage was identified lying to the right of the aortic root.
Discussion
Single ventricle is one of the few congenital heart anomalies which has not benefited from definitive surgical repair. Intracardiac correction of absent septum, on the other hand, was recently achieved in 4 cases." By all definitions and in all classifications," 4, 13 single or common ventricle is a complex malformation characterized by the presence of one main ventricle which receives two atrioventricular valves and empties directly or indirectly into both the aorta and pulmonary artery. In the majority of these cases, transposition of the great arteries is present, and obstruction to outflow tracts is also common. Various other
The Journal of
606
Ionescu, Macartney, Wooler
Thorccic and Cardiovascular Surgery
anomalies may be associated with this malformation. The complexity of the cardiac defect alone explains the technical difficulties involved in its complete surgical correction. Definitive repair can be achieved by partitioning the ventricle in order to separate and direct appropriately the venous return without compromising the conduction system or the function of the atrioventricular valves. Experimental work from the Mayo Clinic-'- 12 has demonstrated the feasibility of replacing the ventricular septum with a prosthesis in dogs, thereby maintaining near normal cardiac function postoperatively. Furthermore, these studies have shown that the main function of the ventricular septum, and hence of a prosthetic septum, is to separate the two ventricles and to maintain their normal relative volumes. In the case reported here, it was possible to insert the prosthetic septum without permanently damaging the conduction system. The use of an instrument to detect the location of the system should be of great help in such cases. In order to avoid injury to coronary artery branches, none of the sutures used for the insertion of the septum were passed through the whole thickness of the ventricular wall. All were tied inside the "right" ventricular cavity. Although at the end of the surgical procedure there was no apparent leak around the prosthetic septum, the recurrent interventricular communication might have been caused by this suturing technique. The optimal size and positioning of the patch were determined by careful examination of the anatomy of the ventricle and the orientation of the valve orifices while the heart was contracting. The second part of the surgical repair consists in relieving the "right" ventricular outflow obstruction when present. Depending on the position of major coronary arteries and the access to the pulmonary annulus, one of two techniques can be used: patch reconstruction of the outflow tract, as in the case described here, or bypass of the pulmonary stenosis with a valve-bearing
conduit.s- 9, 10 The necessity of placing a valve in the newly fashioned right ventricular outflow tract is not clearly established.' It seems that the absence of such a valve, when associated with other structural and functional abnormalities, would impose a significant additional burden on the "right" ventricle. Because it is difficult to elucidate during the operation if the partition of the ventricle is functionally correct, we have used a cusp-bearing pericardial patch in order to obviate any additional strain imposed on the "right" ventricle. The question as to which type of outflow tract substitute is the best will be answered only after a long period of time. The preserved homograft of ascending aorta with an integral valve has proved to function satisfactorily over a period of up to 5 years." Our early results with glutaraldehydetreated heterologous pericardium for the replacement of all heart valves have been encouraging. Definitive criteria for the selection of patients with single ventricle to undergo surgery will only emerge as experience with this lesion increases. The presence of severe pulmonary vascular disease contraindicates surgery, and at present it would seem logical to use the same criteria for selection that have been used in patients with ventricular septal defect"; namely, the ratio of pulmonary to systemic resistance should be less than about 0.75. Two separate atrioventricular valves should be demonstrated on preoperative angiocardiography. Since the prosthetic septum is not expected to grow, definitive repair should be undertaken in later childhood. Because many patients with single ventricle present with serious symptoms in infancy, it follows that palliative surgery will be necessary at that stage to provide optimal pulmonary blood flow and to prevent, if possible, the onset of pulmonary vascular obstructive disease. Thus, in patients with marked cyanosis due to diminished pulmonary blood flow and pulmonary stenosis, systemic-pulmonary artery anastomoses
Volume 65 Number 4
Single ventricle with pulmonary stenosis
607
April, 1973
should be created. In those patients with increased pulmonary blood flow and pulmonary hypertension, banding of the pulmonary artery should be considered. Successful repair in the case reported here may be attributed to the favorable anatomy ("normally" positioned and functionally competent atrioventricular valves), to the adequate partitioning of the ventricle, and to the use of a valve-bearing patch for reconstruction of the "right" ventricular outlet. However, there are cases in which the complex anatomy of the cardiac malformation precludes definitive surgery, at least in the present state of our knowledge.
Summary A case of single ventricle with a noninverted infundibulum, transposition of the great arteries, bilateral conus, and pulmonary stenosis is described. Successful intracardiac repair was achieved by partitioning the ventricle and relieving the pulmonary stenosis. A Dacron felt prosthesis was used for the construction of the septum, while the "right" ventricular outflow was reconstructed with a monocusp pericardial patch. The preoperative diagnosis and the results of early postoperative investigations are discussed along with details of the surgical technique. The indications for surgical treatment of single ventricle are broadly outlined. REFERENCES Bartek, I. T., Holden, M. P., and Ionescu, M. I.: Techniques for the Construction of Tissue Heart Valves, Thorax. In press. 2 Cartmil\, T. B., Du Shane, 1. W., McGoon, D. C., and Kirklin, J. W.: Results of Repair of Ventricular Septal Defect, J. THORAc. CAROIOVAse. SURG. 52: 486, 1966. 3 Elliott, L. P., Anderson, R. C., and Edwards,
J. E.: The Common Cardiac Ventricle With Transposition of the Great Vessels, Br. Heart J. 26: 289, 1964. 4 Hallerman, F. J., Davis, E. D., Ritter, D. G., and Kincaid, O. W.: Roentgenographic Features of Common Ventricle, Radiology 87: 409, 1966. 5 Hallerman, F. J., Kincaid, O. W., Ritter, D. G., Ongley, P. A., and Titus, J. L.: Angiecardiographic and Anatomic Findings in Origin of Both Great Arteries From the Right Ventricle, Am. J. Roentgeno!. Radium Ther. Nuc!. Med. 109: 51, 1970. 6 Ionescu, M. I., and Deac, R. C.: Fascia Lata Composite Graft For Right Ventricular Outflow Tract and Pulmonary Artery Reconstruction, Thorax 25: 427, 1970. 7 Ionescu, M. I., Deac, R. C., Ionescu, C. M., and Wooler, G. H.: Reconstruction of the Right Ventricular Outlet With Fascia Lata Composite Graft, in Ionescu, M. I., Ross, D. N., and Wooler, G. H., editors: Biological Tissue in Heart Valve Replacement, chap. 35, London, 1971, Butterworth & Co., Ltd., p. 743. 8 Maim, J. R.: Personal communication. 9 McGoon, D. C, Wallace, R. B., and Danielson, G. K.: Homografts in Reconstruction of Congenital Cardiac Anomalies, Mayo Clin. Proc. 47: 101, 1972. 10 Rastelli, G. C, Wallace, R. B., and Ongley, P. A.: Complete Repair of Transposition of the Great Arteries With Pulmonary Stenosis: A Review and Report of a Case Corrected by Using a New Surgical Technique, Circulation 39: 83, 1969. 11 Seki, S., and McGoon, D. C.: Surgical Techniques for Replacement of the Interventricular Septum, 1. THoRAc. CAROIOVASC. SURG. 62: 919, 1971. 12 Seki, S., Tsakiris, A. G., Dandade, P. B., Rastelli, G. C., and McGoon, D. c.: Replacement of the Ventricular Septum as a Potential Correction for Single Ventricle, Circulation 42: 197, 1970 (Suppl, 3). 13 Van Praagh, R., Ongley, P. A., and Swan, H. J. C.: Anatomic Types of Single or Common Ventricle in Man: Morphologic and Geometric Aspects in 60 Necropsied Cases, Am. J. Cardiol. 13: 367, 1964.