Results of total correction of tetralogy of Fallot with complete atrioventricular canal

J

THORAC CARDIOVASC SURG

81:768-773, 1981

Results of total correction of tetralogy of Fallot with complete atrioventricular canal Four patients with tetralogy of Fallot (TF) and complete atrioventricular canal (CAVC) underwent successful intracardiac repair. All patients had undergone preliminary palliative shunts. Associated cardiovascular lesions included muscular ventricular septal defect (VSD) and left superior vena cava (one patient), bilateral main pulmonary artery stenosis (one patient), and right aortic arch (two patients). The diagnosis was suspected clinically by electrocardiographic evidence of right ventricular hypertrophy and left anterior hemiblock, by echocardiographic findings suggestive of CAVC with aortic dextroposition, and by the association with trisomy 21. The diagnosis was confirmed by cardiac catheterization and cineangiography. Total correction consisted of closure of the VSD and atrial septal defect (ASD), reconstruction of the atrioventricular valves, and relief of the right ventricular outflow tract obstruction (RVOTO). There were no early or late postoperative deaths. Surgically induced complete heart block did not occur. One patient underwent successful reoperation for residual VSD and right ventricular outflow aneurysm. Late hemodynamic evaluation revealed good results in all patients. We recommend a staged treatment plan consisting of preliminary systemic-pulmonary artery shunting for symptomatic children under 4 to 5 years of age and total correction for older children. With proper preoperative diagnosis and accurate intracardiac repair, good results may be obtained after total correction ofTF with CAVC.

Eduardo Arciniegas, M.D., Mehdi Hakimi, M.D., Zia Q. Farooki, M.D., and Edward W. Green, M.D., Detroit, Mich.

Although recent reports'<" reveal improved results following total intracardiac repair of tetralogy of Fallot (TF) with complete atrioventricular canal (CA VC), the risk of surgical management of this complex cardiac defect remains high.v 5 In this communication we present our experience with complete correction of this infrequent combination of lesions and review the diagnostic and surgical details which are important for its adequate correction, improved postoperative survival rate, and good long-term anatomic and hemodynamic results.

Patients and methods From 1971 to 1979, four patients with TF and CA VC underwent total correction at Children's Hospital of Michigan. All patients had trisomy 21. Their ages From the Department of Cardiovascular Surgery and the Division of Cardiology, Children's Hospital of Michigan, Detroit, Mich. 48201. Received for publication Oct. 3, 1980. Accepted for publication Nov. 4,1980. Address for reprints: Eduardo Arciniegas, M.D., Department of Cardiovascular Surgery, Children's Hospital of Michigan, 3901 Beaubien, Detroit, Mich. 48201.

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at the time of repair ranged from 5.8 to 16.5 years (mean age 9.7 years). There were three boys and one girl. Each patient had undergone one or more preliminary systemic-pulmonary artery shunts (Table I). The mean preoperative hemoglobin concentration was 17.5 gmt 1()() ml. Physical examination in every patient revealed moderate cyanosis, a loud systolic ejection murmur in the mid-left sternal border, and continuous murmurs of pre-existing palliative shunts. One patient (Case 1) exhibited severe ischemic contracture of the right hand which developed after a preliminary Blalock-Taussig shunt. 6 The electrocardiogram showed right ventricular hypertrophy and left anterior hemiblock in all patients. Complete right bundle branch block was also present in one patient. Two-dimensional echocardiography demonstrated atrial and ventricular communications, common atrioventricular valves, and aortic dextroposition in each patient. Chest roentgenogram before palliative shunting revealed normal heart size, right ventricular enlargement, decreased main pulmonary artery segment, and diminished pulmonary vasculature in each instance. Mild cardiomegaly was present at the time of total correction in two patients with pre-existing

0022-5223/81/050768+06$00.60/0 © 1981 The C. V. Mosby Co.

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Fig. 1. Left ventriculogram showing gooseneck deformity of the left ventricular outflow tract. The pulmonary arteries till through a left Blalock-Taussig shunt.

Fig. 2. Right ventriculogram reveals severe infundibular obstruction. There is also stenosis at the origin of both pulmonary arteries (Case 3).

Table I. Clinical data in/our patients with trisomy 21 Case No. I 2

3 4

Age (yr) Sex

Previous shunt

At shunting

M M F M

BT WT BT BT and WT

2.3 4.0 6.9 1.8 and 3.8

I

At repair

5.8 16.5 9.7 6.9

Outcome Alive and Alive and Alive and Alive and

well well well well

Legend: BT, Blalock-Taussig. WT, Walerslon.

Waterston shunts. The diagnosis was confirmed by cardiac catheterization and biplane cineangiography, which was done before preliminary shunting and prior to total repair. Cineangiography revealed atrial (ASD) and ventricular septal defects (VSD), gooseneck deformity of the left ventricular outflow tract (Fig. 1), severe right ventricular outflow tract obstruction (R VOTO) (Fig. 2), and significant aortic dextroposition (Fig. 3) in all patients. The hemodynamic and angiographic findings are summarized in Table II. Asssociated cardiovascular lesions included apical muscular VSD and persistent left superior vena cava in one patient, bilateral main pulmonary artery stenosis in one patient, and right aortic arch in two patients. Operative management. Pre-existing palliative shunts were closed immediately after inception of extracorporeal circulation. Intracardiac repair was done with cardiopulmonary bypass and moderate systemic hypothermia (250 to 280 C). Total circulatory arrest under deep hypothermia (180 C) facilitated extensive

bilateral pulmonary artery angioplasty in one patient with associated stenosis of both main pulmonary arteries. Intracardiac exposure was improved by intermittent aortic cross-clamping in the first patient and, in the other three patients, by a single period of aortic clamping, ranging from 129 minutes to 180 minutes (mean 157 minutes). In the latter patients, ischemic myocardial injury was minimized by multidose asanguineous cold cardioplegia and topical myocardial hypothermia. The anatomic details of the CA VC were carefully assessed through a right atriotomy. The common anterior atrioventricular valve leaflet was undivided and unattached to the ventricular septum (Rastelli type C) 7 in each instance. The posterior common leaflet was also undivided but was attached to the edge of the ventricular septum by several short chordae tendineae. The ostium primum was large in all patients. The VSD was also large and its anteriormost portion, located under the dextroposed aorta, was inaccessible from the atrium. The common anterior and posterior leaflets were

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770 Arciniegas et al.

Fig. 4. The common anterior and posterior atrioventricular valveleaflets are cutevenly.The cleft in theanterior leaflet of the mitral valve is repaired. Fig. 3. Postoperative left ventriculogram (Case I). Marked aortic dextroposition is evident. There is no residual interventricular communication. evenly incised to their attachment in the atrioventricular ring (Fig. 4). The portion of the VSD accessible through the right atrium was closed with a circular Dacron patch that was sutured in place with interrupted horizontal mattress sutures, buttressed with small Dacron pledgets. These sutures were placed below and to the right of the edge of the defect to avoid injury to the conduction system (Fig. 5). The mitral and tricuspid valve leaflets were then attached to the newly constructed prosthetic septum with interrupted pledgetsupported sutures (Fig. 6). The cleft in the anterior leaflet of the mitral valve was repaired with interrupted sutures. A well-defined cleft in the septal leaflet of the tricuspid valve was not observed in any patient. The ostium primum was closed with the upper portion of the prosthetic patch (Fig. 7) by means of running sutures, except in the area between the coronary sinus and the tricuspid valve, where the stitches were interrupted and placed superficially to avoid damage to the atrioventricular node. The subaortic portion of the VSD was exposed through a vertical right ventriculotomy and closed with a separate Dacron patch, which was fashioned large enough to avoid subaortic obstruction (Fig. 8). The competence of both atrioventricular valves was tested by saline injection into each ventricle prior to completing the closure of the ostium primum. The RVOTO was relieved by infundibulectomy alone in one patient

and by infundibulectomy and pulmonary valvulotomy in two patients. In one of the latter patients a pericardial patch on the right ventricular outflow was inserted so that it extended to but not through the pulmonary valve anulus. The remaining patient had marked hypoplasia of the pulmonary valve ring and required insertion of a transannular pericardial patch; this patient also underwent extensive reconstruction of the stenotic origin of both main pulmonary arteries and replacement of the pulmonary valve with a 23 mm porcine valve. Normal sinus rhythm resumed spontaneously in all patients after release of the aortic cross-clamp. Intracardiac pressures were measured in each patient after termination of cardiopulmonary bypass and hemodynamic stabilization. Postoperative care included continuous monitoring of leaft atrial, right atrial, and systemic arterial pressures, careful maintenance of blood volume, replacement of blood losses, and overnight ventilatory assistance with a volume-controlled respirator. Systematic postoperative measurements of cardiac output were made by thermodilution in the last three patients.

Results There were no early or late postoperative deaths, and the postoperative course was relatively uncomplicated. Mild low cardiac output in two patients necessitated inotropic support for 12 and 24 hours, respectively. Wound infection and staphylococcal bacteremia occurred in one patient and were controlled with appropriate antibiotic therapy. Surgically induced heart block

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Tetralogy with complete AV canal

Fig. S. The portion of the ventricular septaldefect accessible through the right ventricle is closed with a Dacron patch by means of interrupted, pledget-supported sutures.

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Fig. 6. The mitral and tricuspid valve leaflets are attached to the prosthetic patch. Sutures supported with Dacron pledgets are used.

Table II. Preoperative cardiac catheterization and angiographic data Case No. I

2 3 4

Systolic pressure (mm Hg) RV

102 90 120 110

I

PA 22 12 13

22

I

Aortic saturation (%)

Gooseneck LVOT

Aortic dextroposition

92

86 88

120 110

82 90

Yes Yes Yes Yes

Marked Marked Marked Marked

LV

108

Mitral insufficiency Slight Mild

Moderate None

Legend: RV, Right ventricle. PA, Pulmonary artery. LV, Left ventricle. LVOT, Left ventricular outflow tract.

or other arrhythmias were not observed in any patient. All patients are currently asymptomatic and acyanotic (Table I). Postoperative follow-up time ranged from 11 to 41 months (mean 20 months). Postoperative electrocardiographic tracings revealed normal sinus rhythm, left anterior hemiblock, and right bundle branch block in all patients. Cardiac catheterization and biplane cineangiography were done in each patient at a mean postoperative interval of 18 months. The pertinent hemodynamic information is summarized in Table III. In Case 1, initial studies 29 months after operation revealed residual shunting at the ventricular level (Qp/Qs 1.6), moderate pulmonary artery hypertension (systolic pressure 50 mm Hg), and aneurysm of the pericardial patch on the right ventricular outflow; successful correction of the residual defects at reoperation was confirmed by subsequent hemodynamic and angiographic evaluation. A minute residual apical ventricular shunt was demonstrated by angiography in one patient with an associated muscular VSD. Mitral in-

sufficiency was trivial in two patients and absent in the others.

Discussion The combination of TF and CA VC is uncommon. Berger," Kirklin," and their co-workers found it in four of 49 patients (8.1 %) who underwent intracardiac repair of CA VC and in five of 617 patients (0.8%) subjected to total correction of TF. 8 The four patients reported herein are among 64 patients with CA VC (6.2%) and 237 patients with TF (1.7%) who underwent intracardiac correction of their defects in our institution during the past 9 years. The diagnosis of TF and CA VC should be suspected clinically in any patient with TF and Down's syndrome, since endocardial cushion defects occur commonly in patients with trisomy 21. 9 , 10 The electrocardiogram usually reveals right ventricular hypertrophy and left anterior hemiblock. Two-dimensional echocardiography demonstrates the ASD and VSD, the ab-

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Fig. 7. The ostium primum defect is closed with the upper portion of the circular prosthetic patch.

Fig. 8. The subaortic portion of the ventricular septal defect is closed through a vertical right ventriculotomy. A separate, good-sized patch is used.

Table III. Postoperative cardiac catheterization and angiographic data Case No. I2 3 4

Interval after operation (mo)

Systolic pressure (mm Hg) RV

I

PA

I

LV

Aortic saturation (%)

Mitral insufficiency None

Slight None

39

24

22

92

14 10 9

32 50 30

10

110

36

104

93 95 95

24

95

96

Slight

Legend: RV, Right ventricle. PA. Pulmonary artery. LV. Left ventricle. 'Study done after successful reoperation for residual defects.

normal atrioventricular valves, and the dextroposition of the aorta and makes the diagnosis almost certain. Diagnostic confirmation is obtained by cardiac cineangiography, which demonstrates RVOTO, aortic dextroposition, ASD, VSD, gooseneck deformity of the left ventricular outflow tract, downward displacement of the insertion ofthe mitral valve, and varying degrees of mitral insufficiency. Axial views are particularly useful for the precise delineation of the anatomy and detection of associated defects. II Although recent reports reveal improved results of intracardiac correction of classical TP, 12. 13 and of CA VC7. 14. I~ in young children, the risk for total correction of these defects, when present in combination, remains high even in older patients. 4. 5 Consequently, we favor a staged-treatment plan and recommend a preliminary palliative systemic-pulmonary artery shunt, preferably a Blalock-Taussig anastomosis, for symptomatic children under 4 to 5 years of age. Intracardiac repair may be more safely performed after that age.

The previous contributions by Lev.!" Rastelli," and their associates added immensely to the understanding of the pathological anatomy of the defect. Such understanding is essential for accurate intraoperative delineation of the lesion, its proper surgical correction, and increased postoperative patient survival. As has been emphasized earlier by others,":" the subaortic portion of the VSD is not totally accessible from the right atrium; therefore, it is advisable to approach the defect through the right ventriculotomy. We prefer to repair it with a separate patch to ensure its complete closure and minimize the possibility of producing subaortic obstruction. The use of pledget-supported sutures for repair of the VSD and the atrioventricular valves also lessens the chances of late disruption. Although pulmonary valvular insufficiency after correction of TF is usually well tolerated, J8 we recommend insertion of a porcine valve in patients with associated CA VC who require transannular patching for adequate relief of the RVOTO. We recognize the potential long-

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tenn problems associated with the use of valvular bioprostheses in children. However, we base this policy on the adverse effect that pulmonary valvular regurgitation and elevation of the right ventricular end-diastolic pressure may have on immediate postoperative survival and on early and late function of the tricuspid valve in this subset of patients. The latter concern is supported by the high postoperative mortality recently reported by Pacifico, Kirklin, and Bargeron" in patients undergoing total repair of TF or double-outlet right ventricle with CA VC in whom relief of the R VOTO necessitated insertion of a transannular patch. Our experience confirms previous reports I-a suggesting that good early and late results can be obtained following total repair in patients with TF and CA VC if the lesion is accurately diagnosed preoperatively and properly corrected at operation. REFERENCES

2

3

4

5

6

Zavanella C, Matsuda H, Subramanian S: Successful correction of a complete form of atrioventricular canal associated with tetralogy of Fallot. Case report. J THORAC CARDIOVASC SURG 74:195-198, 1977 Sade RM, Riopel DA, Lorenzo R: Tetralogy of Fallot associated with complete atrioventricular canal. Ann Thorac Surg 30: 177-180, 1980 Binet J, Losay J, Hvass U: Tetralogy of Fallot with type C complete atrioventricular canal. Surgical repair in three cases. J THORAC CARDIOVASC SURG 79:761-764, 1980 Fisher RD, Bone DK, Rowe RD, Gott VL: Complete atrioventricular canal associated with tetraology of Fallot. Clinical experience and operative methods. J THORAC CARDIOVASC SURG 70:265-271, 1975 Pacifico AD, Kirklin JW, Bargeron LM: Repair of complete atrioventricular canal associated with tetralogy of Fallot or double outlet right ventricle. Report of 10 patients. Ann Thorac Surg 29:351-356, 1980 Arciniegas E, Blackstone EH, Pacifico AD, Kirklin JW: Classic shunting operations as part of two-stage repair for tetralogy of Fallot. Ann Thorac Surg 27:514-518, 1979

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7 Berger TJ, Kirklin JW, Blackstone EH, Pacifico AD, Kouchoukos NT: Primary repair of complete atrioventricular canal in patients less than 2 years old. Am J Cardiol 41:906-913, 1978 8 Kirklin JW, Blackstone EH, Pacifico AD, Brown RN, Bargeron LM: Routine primary repair vs two-stage repair of tetralogy of Fallot. Circulation 60:373-386, 1979 9 Park SC, Mathews RA, Zuberbuhler JR, Rowe RD, Neches WH, Lenox CC: Down's syndrome with congenital heart malformation. Am J Dis Child 131:29-33, 1977 10 Katlic MR, Black EB, Neill C, Haller JA: Surgical management of congenital heart disease in Down's syndrome. J THORAC CARDIOVASC SURG 74:204-209, 1977 11 Bargeron LM, Elliott LP, Soto B, Bream PR, Curry GC: Axial cineangiography in congenital heart disease. Circulation 56: 1075-1083, 1977 12 Castaneda AR, Freed MD, Williams RG, Norwood WI: Repair of tetralogy of Fallot in infancy. J THORAC CARDIOVASC SURG 74:372-381,1977 13 Barratt-Boyes BG, Neutze JM: Primary repair of tetralogy of Fallot in infancy using profound hypothermia with circulatory arrest and limited cardiopulmonary bypass. Ann Surg 178:406-411, 1973 14 McCabe JC, Engle MA, Gay WA, Ebert PA: Surgical treatment of endocardial cushion defects. Am J Cardiol 39:72-77, 1977 15 Midgley FM, Galioto FM, Shapiro SR, Perry LW, Scott LP: Experience with repair of complete atrioventricular canal. Ann Thorac Surg 30: 151-159, 1980 16 Lev M, Agustsson MH, Arcilla R: The pathologic anatomy of common atrioventricular orifice associated with tetralogy of Fallo!. Am J Clin Pathol 36:408-416, 1961 17 Rastelli G, Kirklin JW, Titus JL: Anatomic observations on complete form of persistent common atrioventricular canal with special reference to atrioventricular valves. Mayo Clin Proc 41:296-308, 1966 18 Poirier RA, McGoon DC, Danielson GK, Wallace RB, Ritter DG, Moodie DS, Wiltse CG: Late results after repair of tetralogy of Fallot. J THORAC CARDIOVASC SURG 73:900-908, 1977