Complete atrioventricular septal defect with tetralogy

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1 Atrioventricular Septal Defect With Tetralogy of Fallot: Results of Surgical Correction Stacey B. O Blenes, MD, David B. Ross, MD, Maurice A. Nanton, MD, and David A. Murphy, MD Divisions of Cardiovascular Surgery and Cardiology, The IWK Grace Health Centre, Halifax, Nova Scotia, Canada Background. The outcome of surgical correction of complete atrioventricular septal defect with tetralogy of Fallot has improved in recent years. Controversy exists about the optimal approach to this complex lesion. Our experience over the past 8 years with a single technique is reviewed. The important anatomic features of this lesion are discussed in relation to our method of repair. Methods. Between 1988 and 1996, 11 consecutive patients underwent correction of complete atrioventricular septal defect with tetralogy of Fallot. Nine patients had undergone prior palliative shunts. The two-patch technique for atrioventricular septal defect was used. The ventricular septal defect was closed through a right ventriculotomy in each case. The commissure between the superior and inferior bridging leaflets of the left portion of the common atrioventricular valve was closed in each patient. Management of the right ventricular outflow tract was individualized. Results. There was one mortality in the early postoperative period. One patient required reoperation for closure of a dehiscent left atrioventricular valve cleft. All survivors are currently in New York Heart Association functional class I or II at follow-up ranging from 2 to 101 months. Conclusions. Atrioventricular septal defect with tetralogy of Fallot can be corrected with low mortality using the two-patch technique and closure of the ventricular septal defect through a combined approach using a right ventriculotomy and right atriotomy. Routine closure of the commissure of the left portion of the atrioventricular valve results in a low incidence of regurgitation. A good functional result can be achieved in most patients at intermediate-term follow-up. (Ann Thorac Surg 1998;66: ) 1998 by The Society of Thoracic Surgeons Complete atrioventricular septal defect with tetralogy of Fallot (AVSD-TOF) is a well-recognized congenital heart defect. Tetralogy of Fallot (TOF) is thought to occur simultaneously in 6% to 10% of hearts with complete atrioventricular septal defect (AVSD) [1 3]. Early attempts at surgical correction of this lesion were associated with high mortality rates [2, 4, 5]. Improvement in the results of surgical repair has been reported in recent years, suggesting that normal hemodynamics can be restored in these patients with a mortality rate of around 10% [6 8]. Controversy still exists about the optimal approach to surgical correction of this lesion. Variations in surgical technique are related to the number of patches used to close the AVSD, the use of a right ventriculotomy, and closure of the commissure (cleft) in the left-sided portion of the common atrioventricular (AV) valve. Over the past 10 years we have used a single technique for complete correction of AVSD-TOF. This report describes the relevant anatomic features of this lesion, the rationale of our approach, and our results. Accepted for publication June 15, Address reprint requests to Dr Ross, Cardiovascular Surgery, I.W.K. Grace Health Centre, P.O. Box 3070, Halifax, Nova Scotia, Canada B3J 3G9 ( dross@iwkgrace.ns.ca). Material and Methods Patients From 1988 to 1996, 11 patients underwent complete correction of AVSD-TOF and are summarized in Table 1. All patients were investigated using echocardiography and cardiac catheterization with cineangiography. Echocardiography and cineangiography revealed a common AV valve and an AV septal defect extending far into the outlet septum. Right ventricular outflow tract obstruction with pulmonary infundibular stenosis was present in all patients. Ten patients had Down s syndrome. Nine patients experienced cyanosis and underwent palliative procedures before surgical correction (Table 1). Two patients underwent complete correction as the initial procedure, one on an urgent basis for heart failure. Operative Technique Complete repair was performed with the aid of cardiopulmonary bypass, moderate hypothermia, and intermittent cold blood cardioplegia. Palliative shunts were divided, and cardioplegia was administered through the aortic root after application of the cross-clamp. The lesion was exposed through a right atriotomy, and the cardioplegia cannula was replaced with a 10F catheter passed through the aortic valve and into the left ventricle [9]. Cold crystalloid cardioplegia solution was infused through the catheter to distend the ventricles and com by The Society of Thoracic Surgeons /98/$19.00 Published by Elsevier Science Inc PII S (98)

2 Ann Thorac Surg O BLENES ET AL 1998;66: ATRIOVENTRICULAR SEPTAL DEFECT WITH TETRALOGY OF FALLOT 2079 Table 1. Patient Data Patient No. Presentation Palliation Palliative Procedure Repair Repair Procedure Follow-up Findings 1 Cyanosis 48 RMBT 84 Infundibulectomy alone 101 mod. MR, FC II 2 Asymptomatic 12 Infundibulectomy alone 91 FC II 3 Cyanosis 2 RMBT 95 RV patch, PA patch 62 FC I 59 LMBT 4 Cyanosis 3 RMBT 39 Transannular patch died 5 Cyanosis 1 LMBT 30 Transannular patch 43 FC I 6 Cyanosis 5 LMBT 30 Transannular patch 60 mild MR, FC I 7 CHF 7 RV patch 12 mild MR, FC I 8 Cyanosis 6 Central 24 Transannular patch 23 FC I 9 Cyanosis 6 RMBT 33 Homograft 20 FC I 10 Cyanosis 20 LMBT 51 Transannular patch 12 VSD, FC I 11 Cyanosis 5 RMBT 55 Homograft 2 FC I 36 P Valv CHF congestive heart failure; FC NYHA functional class; LMBT left modified Blalock-Taussig shunt; mod. moderate; MR mitral regurgitation; PA pulmonary artery; P Valv Pulmonary Valvotomy; RMBT right modified Blalock-Taussig shunt; RV right ventricle; VSD ventricular septal defect. mon AV valve apparatus (Fig 1A). The anatomy of the AV valve was clearly demonstrated in the functional position allowing identification of the ideal site for coaptation of the superior and inferior bridging leaflets. The coaptation site on each leaflet was marked with a suture. A longitudinal right ventriculotomy was created in each patient. The ventriculotomy allowed a precise infundibulectomy and visualization of the anterior aspect of the ventricular septal defect (VSD) (Fig 1B). A commashaped prosthetic patch (USCI Dacron Velour Fabric ; USCI, Billerica, MA) was tailored to the dimensions of the defect with redundancy anteriorly. The patch was sewn along the ridge of the muscular septum with a running mattress suture starting at the base of the posterior bridging leaflet. The suture was buttressed with a strip of pericardium on the right ventricular side of the septum. The suture was withdrawn through the ventriculotomy and the patch was sewn around the aortic root (Fig 1C). Autologous pericardium was sutured to the top of the VSD patch with a running suture incorporating the bridging leaflets (Fig 2). The suture line was carried through the previously marked coaptation point on each bridging leaflet. On reaching the annulus of the AV valve posteriorly, the suture line was carried toward the left ventricle for a few bites to avoid injuring the AV node. The atrial component of the defect was then closed using the pericardial patch, placing the coronary sinus on the right side. The commissure between the superior and inferior bridging on the left-sided portion of the common AV valve was closed with interrupted sutures in all cases. The bridging leaflets were never divided. Each patient underwent an extensive infundibulectomy performed through the right ventriculotomy. Various additional procedures were used to relieve residual right ventricular outflow tract obstruction (Table 1). Results Patient 4 died 10 days postoperatively from low cardiac output, sepsis, and multisystem organ failure. The intraoperative course was complicated by unbalanced AV valve anatomy resulting in a small right AV valve. Postmortem examination revealed an intact repair, but the sinus portion of the right ventricle was very small and likely contributed to the poor outcome in this case. There have been no late mortalities. Patient 6 required reoperation 39 months after repair of worsening heart failure. Investigation revealed a residual atrial septal defect, aneurysmal dilatation of the transannular patch with free pulmonary insufficiency, branch pulmonary artery stenosis, and left AV valve regurgitation. The left AV valve cleft that had been closed at the original operation was found to have become dehiscent. The cleft was closed at reoperation, thereby eliminating regurgitation. The atrial septal defect was repaired and the right ventricular outflow tract was reconstructed using a pulmonary homograft. All patients are in New York Heart Association class I or II with a mean duration of follow-up of 43 months (Table 1). Patient 10 has a tiny and clinically insignificant residual VSD. No patients have shown evidence of subaortic stenosis and there have been no significant dysrhythmias. Comment Since 1975 there have been 22 separate reports of complete surgical repair of AVSD-TOF in 117 patients. The major series are listed in Table 2. The improvement in recent results can be attributed to several factors, including better diagnostic accuracy, perioperative care, and surgical approach. There are several factors that are thought to contribute to morbidity and mortality after repair of AVSD-TOF. These include AV valve insufficiency, residual shunts, right ventricular outflow tract

3 2080 O BLENES ET AL Ann Thorac Surg ATRIOVENTRICULAR SEPTAL DEFECT WITH TETRALOGY OF FALLOT 1998;66: Fig 2. Closure of the atrial portion of the defect. The commissure between the bridging leaflets is approximated before completion of the atrial closure. Fig 1. After atriotomy, (A) a 10F catheter is passed through the aortic valve and the ventricles are distended with cold cardioplegia solution. The coaptation site of the anterior and posterior bridging leaflets are marked with sutures. The extent of the ventricular septal defect (B) is exposed through a right ventriculotomy. The anterior aspect of the ventricular septal defect (C) is patched through the right ventriculotomy (atrioventricular valve removed for clarity). obstruction, and left ventricular outflow tract obstruction. The optimal surgical approach to this complex lesion should be designed to minimize the occurrence of these problems. The simultaneous occurrence of AVSD with TOF results in a unique anatomic situation that must be considered carefully when planning surgical correction. The morphology of the VSD typical of AVSD-TOF is similar to that of complete AVSD except that the anterior superior border extends far anteriorly. When the infundibulum of TOF occurs in a heart with complete AVSD, the VSD has a characteristically extensive subaortic extension (Fig 3). This is caused by the unwedging of the aorta seen in AVSD, a factor that is not often mentioned in the context of AVSD-TOF. The aortic valve sits anterior to and above the base of the anterior bridging leaflet [13], resulting in the long left ventricular outflow tract that gives the gooseneck appearance on cineangiography. The unwedging of the aorta exaggerates the anterior extension of the VSD in AVSD-TOF and is one of the reasons why the transatrial approach used to repair the VSD in isolated TOF may not be ideal for the combined lesion. In AVSD-TOF, the view of the anterior extension of the VSD under the unwedged aorta is obscured by the location of the superior bridging leaflet. If the one-patch technique for repair of AVSD is used, the anterior bridging leaflet is divided, affording an improved view of the margins of the defect. Nine cases have been reported in which the VSD was closed through the right atrium alone without division of the superior bridging leaflet, resulting in a 33% incidence of residual VSD [1, 7]. Unless the superior bridging leaflet is divided, the true extent of the VSD cannot easily be appreciated through the atrium. We use the two-patch technique for AVSD repair and do not divide the anterior bridging leaflet; therefore, a right ventriculotomy was performed in all cases for closure of the anterior extension of the VSD. We feel this approach prevents residual VSDs and subaortic obstruc-

4 Ann Thorac Surg O BLENES ET AL 1998;66: ATRIOVENTRICULAR SEPTAL DEFECT WITH TETRALOGY OF FALLOT 2081 Table 2. Summary of Published Series Study Date n Technique a Ventriculotomy b Cleft c Mortality Berger et al [4] one-patch 3? 3 (60%) Pacifico et al [5] both? 5 2 (40%) Arciniegas et al [3] one-patch Uretzky et al [2] one-patch (36%) Vargas et al [10] one-patch (23%) Pacifico et al [6] two-patch 0? 1 (8%) Alonso et al [11] two-patch Ilbawi et al [7] two-patch (11%) Gatzoulis et al [8] two-patch (10%) Bertolini et al [12] two-patch in (42%) a Method for closure of atrioventricular septal defect. b Number of patients receiving right ventriculotomy. c Number of patients with closure of left atrioventricular valve cleft. tion. Our group has enjoyed good results with the twopatch technique for isolated AVSD [9]. This technique preserves AV valve tissue and should theoretically result in better short- and long-term valve function as compared to the one-patch technique. Good results are reported using both techniques, but the literature suggests a higher incidence of significant mitral insufficiency and valve dehiscence with the one-patch technique [14, 15]. There have been reports of valve dehiscence after repair of AVSD-TOF using the one-patch technique [16]. However, the number of patients in this and other series are small and it is impossible to draw any definitive conclusion about the superiority of the one- or two-patch techniques. Opinions vary regarding the significance of the commissure of the left-sided portion of the common AV valve after repair of AVSD. Although the so-called cleft may be considered a functional commissure, the literature seems to support the idea that failure to close the cleft results in higher rates of left AV valve incompetence, requiring reoperation [17, 18]. In our experience, the only case of significant left AV valve regurgitation was related to dehiscence of a previously closed cleft and resolved with resuturing of the cleft at reoperation. Although not routinely done in our series, reinforcement of the cleft sutures might have helped prevent this complication. The transatrial transpulmonary approach allows closure of the VSD and relief of right ventricular outflow tract obstruction in isolated TOF without the need for a right ventriculotomy. The right ventricular outflow tract in the combined lesion of AVSD-TOF could also be managed in a similar fashion, but as mentioned previously, the unique VSD is out of easy reach from the right atrium, necessitating a combined right atrial and right ventricular approach. This technique also allows a precise infundibulectomy to be easily performed. The potential drawbacks of a right ventriculotomy include postoperative ventricular dysfunction and late dysrhythmias. Serious ventricular dysrhythmias are a recognized complication on long-term follow-up of repair of TOF. Retrospective reviews of dysrhythmia rates between transatrial transpulmonary and right ventricular approaches report an increased incidence of dysrhythmias associated with ventriculotomy. The major shortcoming of these studies is that follow-up in the ventriculotomy group is significantly longer, introducing selection bias [19]. The rate of dysrhythmias may relate primarily to right ven- Fig 3. (A) The rim of the ventricular septal defect (VSD) in isolated atrioventricular septal defect. The aorta is unwedged, but the infundibular septum (IS) is normally related to the septomarginal trabeculation (SMT). (B) In tetralogy of Fallot, the IS is malaligned resulting in a VSD extending from the membranous septum to the anterior limb of the SMT. (C) Atrioventricular septal defect with tetralogy of Fallot is characterized by a VSD extending from the posterior rim of the AV valve to the anterior limb of the SMT.

5 2082 O BLENES ET AL Ann Thorac Surg ATRIOVENTRICULAR SEPTAL DEFECT WITH TETRALOGY OF FALLOT 1998;66: tricular dysfunction and dilatation, which is progressive with time in the face of pulmonary insufficiency [20]. Right ventricular dysfunction in the early postoperative period may be secondary to suboptimal myocardial preservation or infundibulectomy as opposed to the ventriculotomy itself, but this question remains unanswered. Potential benefit from avoiding a ventriculotomy must be weighed against the risk of residual VSDs or subaortic stenosis. The only mortality in this series was from low cardiac output in the early postoperative period. Right ventricular failure likely contributed to the patient s demise, but postmortem examination suggested that this was related to a small ventricular cavity and not necessarily because of dysfunction from the ventriculotomy. In retrospect, this child should have been considered for a univentricular repair (Fontan procedure) or possibly a one and a half ventricular repair (AVSD-TOF repair plus bidirectional Glenn shunt). In this series, 9 of the 11 children were palliated before repair by shunts; 2 received an additional shunt at 36 and 59 months of age. In the present era, we as well as many others prefer early, primary, complete repair for most congenital lesions including, isolated TOF and complete AVSDs. We would prefer to perform the definitive repair of combined AVSD-TOF after 4 to 6 months of age as we find that the AV valve tissue is somewhat stronger than in the newborn period. We have successfully palliated one infant recently with transcatheter balloon pulmonary valvotomy and that child is presently awaiting repair. This may obviate the need for shunting and allow successful repair of these defects outside of the newborn period. Our method for repair of AVSD-TOF has so far been associated with an acceptable mortality rate and a good functional outcome in all survivors. Visualization of the entire VSD and accurate anatomic repair are essential to success and best achieved using the two-patch technique through a combined right atrial and right ventricular approach. The cleft in the left-sided AV valve should be closed, and the right ventricular outflow tract can be managed in the same fashion as for isolated TOF. We thank Mr Kevin Millar for the illustrations and Drs S. Litz, B. MacManus, and C. Soder for their help with these children. References 1. Guo-wei H, Mee RBB. Complete atrioventricular canal associated with tetralogy of Fallot or double-outlet right ventricle and right ventricular outflow tract obstruction: a report of successful surgical treatment. Ann Thorac Surg 1986;41: Uretzky G, Puga FJ, Danielson GK, et al. Complete atrioventricular canal associated with tetralogy of Fallot. J Thorac Cardiovasc Surg 1984;87: Arciniegas E, Hakimi M, Farooki ZQ, Green EW. Results of total correction of tetralogy of Fallot with complete atrioventricular canal. J Thorac Cardiovasc Surg 1981;81: 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 1978;41: 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 1980;29: Pacifico AD, Ricchi A, Bargeron LM, Colvin EC, Kirklin JW, Kirklin JK. Corrective repair of complete atrioventricular canal defects and major associated cardiac anomalies. Ann Thorac Surg 1988;46: Ilbawi M, Cua C, Deleon S, et al. Repair of complete atrioventricular septal defect with tetralogy of Fallot. Ann Thorac Surg 1990;50: Gatzoulis MA, Shore D, Yacoub M, Shinebourne EA. Complete atrioventricular septal defect with tetralogy of Fallot: diagnosis and management. Br Heart J 1994;71: Ross DA, Nanton M, Gillis DA, Murphy DA. Atrioventricular canal defects: results of repair in the current era. J Cardiac Surg 1991;16: Vargas FJ, Coto EO, Mayer JE, Jonas RA, Castaneda AR. Complete atrioventricular canal and tetralogy of Fallot: surgical considerations. Ann Thorac Surg 1986;42: Alonso J, Nunez P, Perez de Leon J, et al. Complete atrioventricular canal and tetralogy of Fallot: surgical management. Eur J Cardiothorac Surg 1990;4: Bertolini A, Dalmonte P, Bava GL, et al. Surgical management of complete atrioventricular canal associated with tetralogy of Fallot. Cardiovasc Surg 1996;4: Ebels T, Ho SY, Anderson RH, Meijboom EJ, Eijgelaar A. The surgical anatomy of the left ventricular outflow tract in atrioventricular septal defect. Ann Thorac Surg 1986;41: Studer M, Blackstone EH, Kirklin JW, et al. Determinants of early and late results of repair of atrioventricular septal (canal) defects. J Thorac Cardiovasc Surg 1982;84: Hanley FL, Fenton KN, Jonas RA, et al. Surgical repair of complete atrioventricular canal defects in infancy. J Thorac Cardiovasc Surg 1993;106: Leblanc JG, Williams WG, Freedom RM, Trusler GA. Results of total correction in complete atrioventricular septal defects with congenital or surgically induced right ventricular outflow tract obstruction. Ann Thorac Surg 1986;41: Capouya ER, Laks H, Drinkwater DC, Pearl JM, Milgalter E. Management of the left atrioventricular valve in the repair of complete atrioventricular septal defects. J Thorac Cardiovasc Surg 1992;104: Alexi-Meskishvili V, Ishno K, Dahnert I, et al. Correction of complete atrioventricular septal defects with the doublepatch technique and cleft closure. Ann Thorac Surg 1996;62: Kawashima Y, Matsuda H, Hirose H, et al. Ninety consecutive corrective operations for tetralogy of Fallot with or without minimal right ventriculotomy. J Thorac Cardiovasc Surg 1985;90: Gatzoulis MA, Till JA, Somerville J, Redington AN. Mechanoelectrical interaction in tetralogy of Fallot. Circulation 1995;92: INVITED COMMENTARY The paucity of articles on clinical results describing the repair of the combination of atrioventricular septal defects and tetralogy of Fallot is not in keeping with the reported incidence of this anomaly, said to be present in 5% to 10% of all patients with atrioventricular septal defect. The first article reporting successful corrective 1998 by The Society of Thoracic Surgeons /98/$19.00 Published by Elsevier Science Inc PII S (98)00976-X