Double switch operation in cardiac anomalies with atrioventricular and ventriculoarterial discordance

Transcription

1 Double switch operation in cardiac anomalies with atrioventricular and ventriculoarterial discordance Since June 1987, 10 of 19 consecutive patients with atrioventricular and ventriculoarterial discordance (average age 4 ± 2 years) had undergone a double switch operation with the morphologically left ventricle used as a systemic ventricle. There were two combinations of procedures. Atrial switch combined with arterial switch was used in two patients who had a normal pulmonary valve. Atrial switch combined with ventriculoarterial switch by Rastelli's procedure was used in eight patients with pulmonary stenosis or atresia and a large ventricular septal defect. One early death and two late deaths have occurred in a postoperative follow-up period of up to 4 years. Subsequent problems were mainly related to the results of atrial switch procedures in patients who had a small atrium because of low pulmonary flow, especially in patients with apicocaval juxtaposition. Our experience suggested that the double switch operation would open a new era of definitive surgical treatment in half of the patients with atrioventricular and ventriculoarterial discordance. (J THORAC CARDIOVASC SURG 1994;107:351-8) Toshikatsu Yagihara, MD, Hidefumi Kishimoto, MD, Fumitaka Isobe, MD, Fumio Yamamoto, MD, Kyouich Nishigaki, MD, Osamu Matsuki, MD, Hideki Uemura, MD, Tetsuro Kamiya, MD, and Yasunaru Kawashima, MD, Osaka, Japan For the surgical correction of cardiac anomalies associated with atrioventricular discordance, the anatomically right ventricle has commonly been used as a systemic ventricle. The long-term prognosis of this procedure remains open to question, however, mainly because of the deterioration of right ventricular function with tricuspid regurgitation. To overcome this problem, we have applied another technique to use the anatomically left ventricle as a systemic ventricle in this anomaly since June Patients From June 1987 to July 1990, 10 of 19 consecutive patients who underwent definitive repair for cardiac anomalies with atrioventricular and ventriculoarterial discordance at the National Cardiovascular Center received complete anatomical repair-the double switch operation-in which the morphologically left ventricle was used as a systemic ventricle. From the Departments of and Pediatric Cardiology, National Cardiovascular Center, Suita, Osaka, Japan. Received for publication Sept. 5,1991. Accepted for publication June 16,1993. Address for reprints: Toshikatsu Yagihara, MD, Department of Cardiovascular Surgery, National Cardiovascular Center, 5-7-1, Fujishirodai, Suita, Osaka, 565, Japan. Copyright 1994 by Mosby-Year Book, Inc /94 $ /1/49797 The diagnoses in these 10 patients are presented in Table I. There were eight male patients and two female patients. Ages at operation ranged from 3 to 6 years with an average of 4 ± 1 years. Four of the patients had atrioventricular and ventriculoarterial discordance with a normal pulmonary valve (patients 4 and 6) or pulmonary stenosis (patients 1 and 5) and six patients had cardiac anomalies accompanied by atrioventricular discordance, an aorta originating from the right ventricle, and pulmonary atresia (absence of communication between the pulmonary trunk and either of the ventricles). All patients had a ventricular septal defect and three of them had an atrial septal defect as well. In one patient with a normal pulmonary valve (patient 4), coarctation of the aorta and mild subaortic stenosis were present, and reconstruction of the aorta and pulmonary arterial banding had been undertaken as the previous operation in early infancy. In another patient with a normal pulmonary valve (patient 6), the pulmonary/systemic pressure and flow ratios were 1.0 and 2.2, respectively, and the pulmonary vascular resistance was 7.8 U. m 2, therefore; the pulmonary vascular bed was considered to be protected within a reversible range. Moderate tricuspid valve incompetence was noted in two patients (patients 5 and 6). Seven patients had cardiac situs solitus and one patient (patient 2) had situs inversus. Two patients with left isomerism of the atrial appendages were included in this series. Their intracardiac anatomies were similar to those of patients with atrioventricular and ventriculoarterial discordance with pulmonary atresia (patients 3 and 10). In six patients (patients 2, 3, 5, 7, 8, and 10), the cardiac apex and venae cavae were located on the same side (apicocaval juxtaposition). One patient had bilateral superior venae cavae (patient 10). Bilateral or unilateral Blalock-Taussig shunts had been constructed in four patients and two patients, respectively. 35 1

2 3 5 2 Yagihara et al. svc I Fig. 1. Schema of the double switch operation combined with an atrial and an arterial switches for patients with atrioventricular and ventriculoarterial discordance, ventricular septal defect, situs solitus, and levocardia (patients 4 and 6). Patient 4 included postoperative status of coarctation of the aorta and right ventricular outflow tract reconstruction by a transannular patch in addition to the schema. sve, Superior vena cava; IVe, inferior vena cava; RV, anatomically right ventricle; LV, anatomically left ventricle. Method of operation The double switch operation includes two types of procedures as follows: In patients with a normal pulmonary valve, the combined operation with atrial and arterial switch was applied (Fig. 1). In patients who had pulmonary stenosis or atresia accompanied by a large ventricular septal defect, the combination of atrial switch and ventriculoarterial switch was selected, similar to a Rastelli procedure, which includes an internal conduit repair from the left ventricle to the aorta and an external conduit repair from the right ventricle to the pulmonary artery (Figs. 2 and 3, Table 11). Operations were performed with the aid of extracorporeal circulation, moderate hypothermia, and cold chemical cardioplegic arrest; a crystalloid cardioplegic solution was given in an initial dose of 10 mljkg and then 5 ml/kg every 30 minutes. All surgical shunts were ligated at the beginning of bypass. Extracorporeal circulation time ranged from 286 to 412 minutes with an average of 336 ± 41 minutes, and aorticcrossclamping time ranged from 127 to 225 minutes with an average of 174 ± 32 minutes, including repeated aortic crossclamping The Journal of Thoracic and February 1994 time for relief of the resultant caval obstruction in one patient. In the most recent operations, aortic crossclampling time was approximately 150 minutes. All patients underwent an atrial switch procedure as the initial operation. Early in this series, a Senning operation was performed for the atrial switch in two patients (patients 1 and 2). In the other eight patients, a Mustard operation was applied; equine pericardium was used for a pantaloon-shaped intraatrial baffle and for an atriotomy patch to increase the volume of the newly constructed left atrium. Coronary sinus blood was drained into the functional right atrium in all patients. After the a trial switch procedure, arterial or ventriculoarterial procedures were undertaken. Two patients (patients 4 and 6) underwent the arterial switch procedure by Lecompte's maneuver as shown in Fig. 1. In these patients, the right-sided coronary artery, arising from the right posterior aortic sinus, was a morphologically left coronary artery, and the artery that arose from the left posterior aortic sinus was a morphologically right coronary artery. In a patient with coarctation of the aorta and mild subaortic stenosis (narrowing of the anatomically right ventricular outflow tract), right ventricular outflow tract obstruction was relieved by insertion of a transannular patch with amonocusp (patient 4). Eight patients underwent the ventriculoarterial switch operation. An oblique right ventriculotomy was made in the outflow tract of the anatomically right ventricle. The internal conduit of duplicated equine pericardium was patched from the right ventriculotomy with interrupted mattress suture to allow drainage of blood from the left ventricle through the ventricular septal defect into the aorta. Sutures were started from the anulus ofthe anterior leaflet of the tricuspid valve through the inferior edge of the ventricular septal defect toward the anterior anulus of the aortic valve. In all patients, the ventricular septal defect was located in the perimembranous portion with extension toward the aortic orifice, and no major anomalies of the tricuspid valve or the subvalvular attachment were present. The subaortic conus was attenuated and the ventricular septal defect was large and in close proximity to the aortic valve in seven patients. In the remaining patient (patient 5), who had mild pulmonary stenosis, the ventricular septal defect was relatively small, and an additional aortopulmonary anastomosis l was created to secure the optimal size of the left ventricular outflow tract to the aorta, as shown in Fig. 3, II-c. The pulmonary trunk was ligated in patient 1 (Fig. 2, I-a). After the aortic crossclamp was released, a handmade equine pericardial roll bearing three leaflets was interposed between the right ventricle and the pulmonary artery. The external conduit was placed in the left side of the aorta in six patients who had a right-sided inferior vena cava, as shown in Fig. 2, II-a (patients 1 and 9), II-b (patients 3, 7, and 8), and Fig. 3, II-c (patient 5), or on the opposite side in patients who had a left-sided inferior vena cava, as shown in Fig. 3, II-d (patients 2 and 10). We chose the position of the external conduit to avoid conduit compression beneath the sternum, independent of the position of the cardiac apex and the pulmonary trunk. Figs. 4 and 5 show preoperative and postoperative left and right ventriculograms of patient 8, who underwent the operation shown in Fig. 2, II-b. Results In the first patient, caval obstruction produced low cardiac output syndrome, and she died 22 days after the

3 The Journal of Thoracic and Volume 107, Number 2 Yagihara et al svc svc II -a IVC II-b Fig. 2. II-a, Schema of the double switch operation combined with atrial switch and ventriculoarterial switch for patients with atrioventricular and ventriculoarterial discordance, ventricular septal defect, pulmonary stenosis, situs solitus, and levocardia (patient I). Patient 9 received the same operation except that the pulmonary trunk was absent. An external conduit was placed in the left side of the aorta. II-b, Schema of the double switch operation combined with atrial switch and ventriculoarterial switch for patients with atrioventricular and ventriculoarterial discordance, ventricular septal defect, pulmonary atresia, situs solitus, and dextrocardia (patients 7 and 8). Patient 3 with left isomerism of the heart, had the same situation. An external conduit was placed in the left side of the aorta. For abbreviations see Fig. I. Table I. Diagnosis in 10 patients with atrioventricular and ventriculoarterial discordance Patient Age VA Associated Previous No. (yr) Sex connection PSjPA defect operation Situs IVC SVC 3 F VAD PS VSD Solitus R R 2 4 M VAD PA VSD,ASD Bilateral BT Inversus L L 3 3 M VAD PA VSD Bilateral BT Left isomerism R R 4 3 M VAD VSD, ASD, CoA, PDA, CoA repair, P AB Solitus R R subaortic stenosis 5 5 F VAD PS VSD Solitus R R 6 4 M VAD VSD Solitus R R 7 4 M VAD PA VSD Bilateral BT Solitus R R 8 4 M VAD PA VSD Bilateral BT Solitus R R 9 6 M VAD PA VSD Left BT Solitus R R 10 3 M VAD PA VSD,ASD Right BT Left isomerism L B Apex L L* R* L R* L R* R* L L* VA, Ventriculoarterial; PS, pulmonary stenosis; P A, pulmonary atresia; IVC, inferior vena cava; SVC, superior vena cava; VAD, ventriculoarterial discordance; VSD, ventricular septal defect; ASD, atrial septal defect; CoA, coarctation of the aorta; PDA, patent ductus arteriosus; DT, Blalock-Taussig shunt; PAD, pulmonary arterial banding; R, right; L, left, D, bilateral. * Apicocaval juxtaposition. operation. The other patients survived the operations. Three patients with apicocavaljuxtaposition (patient 2,3, and 5), who underwent the atrial and ventriculoarterial switch operation, exhibited low cardiac output syndrome in the early postoperative phase and required delayed sternal closure. However, in recent patients of this series (patients 6 to 10), including the patients with apicocaval juxtaposition (patients 7, 8, and 10), primary sternal closure was possible and the postoperative course was uncomplicated, without low cardiac output syndrome. In a patient (patient 4) who received the atrial and arterial switch procedure, the early postoperative course was uneventful, but an obstruction of the right-sided coronary artery developed and resulted in advanced atrioventricu-

4 354 Yagihara et al. The Journal of Thoracic and February 1994 sve sve Ive -c II -d Ive Fig. 3. I1-c, Schema of the double switch operation combined with atrial switch and ventriculoarterial switch for patients with atrioventricular and ventriculoarterial discordance, relatively small ventricular septal defect, mild pulmonary stenosis, situs solitus, and dextrocardia (patient 5). External conduit was placed in the left side of the aorta. I1-d,Schema of the double switch operation combined with atrial switch and ventriculoarterial switch for patients with atrioventricular and ventriculoarterial discordance, ventricular septal defect, pulmonary atresia, situs inversus, and levocardia (patient 2). Patient 10, with left isomerism of the heart, had the same situation. An external conduit was placed in the right side of the aorta. For abbreviations see Fig. 1. lar block. This patient required the implantation of a pacemaker 3 months after the operation. However, the deterioration ofleft ventricular function caused late death at 17 months after the operation. Postoperative catheterizations were performed at 1 to 16 months (average 11 ± 4 months after operation) in nine operative survivors. Hemodynamics and ventricular performance are summarized in Table III. Left ventricular ejection fraction ranged from 0.31 to 0.62 with an average of 0.52 ± In patient 4, coronary obstruction caused low cardiac output and low left ventricular ejection fraction. In the other eight patients, satisfactory values were maintained. An electrocardiogram showed normal sinus rhythm in all patients but patient 4. Patient 2 had episodes of supraventricular tachyarrhythmia in the late postoperative period, followed by late death 3 years after the operation, probably because of arrhythmogenic shock. The other seven long-term survivors remain well with good development and improved exercise tolerance in a follow-up period of 13 to 39 months (average 21 ± 9 months). Discussion Late results with the use of the morphologically right ventricle as a systemic ventricle are controversial. Some studies revealed deterioration of the morphologically right ventricle in patients with atrioventricular discordance who underwent conventional surgical treatment for associated lesions 2-8 and in patients with surgically created atrioventricular discordance who underwent the venous switch operation for complete transposition of the great arteries. 8,9 These studies suggested that the main disadvantages of these anomalies were complete heart block and right ventricular deterioration with tricuspid incompetence. McGrath and colleagues 2 reported that the 10-year actuarial survival after operation among 99 consecutive patients with atrioventricular discordance was only 68%. A few trials of anatomic repair with the morphologically left ventricle used as a systemic ventricle for rare cardiac anomalies with atrioventricular discordance were reported previously. In a patient with isolated atrioventricular discordance, Clarkson and colleagues,1o in 1972, had performed balloon atrial septostomy in infants followed by a successful atrial switch operation. Furthermore, Subirana, de Leval, and Somerville ll reported in 1984 that a patient with atrioventricular discordance and double-outlet left ventricle underwent an atrial switch, closure of the ventricular septal defect, and an external conduit repair between the morphologically right ventricle and the pulmonary artery; however, the patient died. More recently, regarding the double switch operation performed by atrial and ventriculoarterial switches, Ilbawi and colleagues 12 reported successful surgical experience in two patients with atrioventricular and ventricu-

5 The Journal of Thoracic and Volume 107, Number 2 Yagihara et at, Fig. 4. Preoperative ventriculograms of a patient with pulmonary atresia, ventricular septal defect, and atrioventricular and ventriculoarterial discordance (patient 8). The aorta is supported by an anatomically right ventricle (1 and 2) and is also opacified through a ventricular septal defect after injection into the anatomically left ventricular (3 and 4). Ao, Aorta; RV, anatomically right ventricle; LV, anatomically left ventricle. Table II. Operative procedures of double switch operation Patient Intraatrial Intraventricular Ventriculoarterial Early No. procedure procedure procedure Additional procedures result Senning LV-Ao IC RV-PAEC Died 2 Senning LV-Ao IC RV-PAEC 3 Mustard LV-Ao IC RV-PAEC 4 Mustard VSD closure Arterial switch RVOTR with transannular patch 5 Mustard LV-Ao IC RV-PAEC Additional aortopulmonary anastomosis 6 Mustard VSD closure Arterial switch 7 Mustard LV-AoIC RV-PAEC 8 Mustard LV-Ao IC RV-PA EC 9 Mustard LV-Ao IC RV-PAEC 10 Mustard LV-Ao IC RV-PA EC LV, Left ventricle; Ao, aorta; IC, internal conduit; VSD, ventricular septal defect; RV, right ventricle; PA, pulmonary artery; EC, external conduit; RVOTR, right ventricular outflow tract reconstruction. loarterial discordance associated with ventricular septal defect and pulmonary stenosis or atresia in They claimed that the main advantages of this operation were the use of the left ventricle as the systemic pumping chamber and the use of a right ventriculotomy, which provides excellent exposure to the right ventricular side of the septum with minimal chance of injury to the conduction bundle. We have introduced two types of double switch operations and attempted to use these procedures preferen-

6 356 Yagihara et al. The Journal of Thoracic and February 1994 Fig. 5. Postoperative ventriculograms of the same patient as in Fig. 4, who received the double switch operation (atrial and ventriculoarterial switches). The anatomically left ventricle is connected to the aorta and the anatomically right ventricle to the pulmonary artery (PA) by an external conduit (Ee). Views and abbreviations are as in Fig. 4. Table III. Postoperative cardiac catheterization data Patient Pas top. period RAP Cardiac index RVEDV LVEDV Late No. (rna) (mm Hg) ( L/min/m2) (%) RVEF (%) LVEF Rhythm result 2 I SSS+AF LD (3 yr) SR Excellent CAVB LD (17mo) SR Excellent SR Excellent SR Excellent SR Excellent SR Excellent SR Excellent Average II ± 4 5 ± ± ± ± ± ± 0.12 RAP, Right atrial pressure; RVEDV, right ventricular end-diastolic volume; RVEF, right ventricular ejection fraction; LVEDV, left ventricular end-diastolic volume; LVEF, left ventricular ejection fraction; SSS, sick sinus syndrome; AF, atriaillutter; SR, sinus rhythm ; CAVB, complete atrioventricular block; LD, late death. tially as the definitive operations for patients with atrioventricular and ventriculoarterial discordance. Among 19 consecutive patients with these anomalies who underwent definitive repair in the recent 4 years since 1987, 10 patients (53%) received the double switch operation. Our initial policy in the remaining nine patients was to use the conventional repair, in which the right ventricle was used as a systemic ventricle, for several reasons: a ventricular septal defect that was too small to be used as an outlet orifice of the left ventricle (two patients with pulmonary

7 The Journal of Thoracic and Volume 107, Number 2 Yagihara et al. 357 stenosis), mitral incompetence (one patient), straddling tricuspid valve with a remote ventricular septal defect (one patient), older age (three adult patients), and uncontrollable congestive heart failure resulting from severe tricuspid regurgitation and low left ventricular systolic pressure (two patients early in this series). Currently, patients in the latter two categories would be considered candidates for the double switch operations. For patients with atrioventricular and ventriculoarterial discordance with a normal pulmonary valve, the arterial switch procedure together with an atrial switch might provide more complete physiologic and anatomic repair l3 than another type of double switch operation and should be indicated in patients in whom the condition of the left ventricle was favorable. This technique is considered to be particularly suitable for patients who have coarctation of the aorta and subaortic stenosis (obstruction of the morphologically right ventricular outflow tract), because this procedure possesses several advantages to avoid left ventricular outflow obstruction by the arterial switch, as well as right ventricular outflow obstruction by patch enlargement. It might be possible to extend the indications for this operation to patients with severe tricuspid regurgitation, even if left ventricular pressure is low, after preparation by pulmonary arterial banding, as was proved by Mee. 14 The indications for the double switch operation combined with atrial and ventriculoarterial switches is still unclear. A large ventricular septal defect located near the aortic orifice might be desirable because extensive enlargement of the ventricular septal defect is sometimes difficult in these anomalies. 15 Creation of an additional aortopulmonary anastomosis I as a second outlet of the left ventricle to the aorta might be one modification for the patient with a relatively small ventricular septal defect and mild pulmonary stenosis to avoid left ventricular outflow obstruction. In patients in whom we have performed this type of anatomic correction, the ventricular septal defect was close to the aortic valve, which had an attenuated subaortic conus. Therefore, it was readily feasible to create an internal conduit in the right ventricle.l 2, 15 The main theoretic advantage of the double switch operation is that it preserves systemic ventricular function over the long term. In the present study, postoperative catheterization revealed that the left ventricular performance of some patients remained subnormal in the midterm period. However, despite the presence of these patients with poor ejection fraction caused by specific surgical complications such as coronary obstruction, the postoperative left ventricular ejection fraction is well preserved by comparison with previously reported right ventricular ejection fraction when the right ventricle was used as the systemic ventricle. 7-9 Longer follow-up is necessary to verify these controversial points. Concerning the disadvantage of the double switch operation, Ilbawi and colleagues l2 reported that the only potential drawback in this operation is the need for an atrial switch procedure with the inherent complications of obstruction of venous return and supraventricular arrhythmias. Our experience also indicated these problems relating to the atrial switch procedure. In our series, early death in one patient was due to caval obstruction followed by low output syndrome. In another patient, a junctional tachyarrhythmia was noted and resulted in late death. Three patients who required delayed sternal closure were those with pulmonary stenosis or atresia. In these patients with low pulmonary flow, the volume of the atrium could be smaller than that of complete transposition of the great arteries with high pulmonary flow. All three patients were also those with apicocaval juxtaposition; therefore, the atria located behind the two ventricles usually have a small lateral free wall. For these reasons the atrial switch procedure, especially a Senning procedure without the use of additional material, could offer a restrictive lesion in cavoatrial connection. Therefore, a Mustard procedure using some additional material for augmentation of the atrial volume was considered to be the procedure of choice and was successfully performed in the last eight patients of the present series. Most of the hearts with atrioventricular discordance had associated pulmonary stenosis (90%) and abnormal direction of the cardiac apex (85%) Therefore, preparation of the heart by a systemic-pulmonary shunt should be effective to develop the atrial cavity in patients with these conditions. Our recent experience based on these concepts improved these early postoperative results. In our experience, the double switch operation was possible in more than half of the patients with cardiac anomalies associated with atrioventricular and ventriculoarterial discordance. We now consider that this operation is particularly preferred for patients with these complex anomalies associated with right ventricular dysfunction. Because this operation has distinct advantages as well as disadvantages, longer follow-up study is mandatory for comparison with the conventional operations. REFERENCES 1. Kawashima Y, Matsuda H, Taniguchu K, Kobayashi J. Additional aortopulmonary anastomosis for subaortic obstruction in the Rastelli-type repair for the Taussig-Bing malformation. Ann Thorac Surg 1987;44: McGrath L, Kirklin JW, Blackstone EH, Pacifico L, Kirklin JK, Bargeron LM. Death and other events after cardiac repair in discordant atrioventricular connection. J THORAC CARDIOVASC SURG 1985;90: Williams WG, Suri R, Shindo G, Freedom R, March J, Trusler G. Repair of major intracardiac anomalies associ-

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