Corrective Repair of Complete Atrioventricular

Transcription

1 Corrective Repair of Complete Atrioventricular Canal Defects and Major Associated Cardiac Anomalies A. D. Pacifico, M.D., A. Ricchi, M.D., L. M. Bargeron, Jr., M.D., E. C. Colvin, M.D., J. W. Kirklin, M.D., and J. K. Kirklin, M.D. ABSTRACT Twenty-nine patients with balanced forms of complete atrioventricular (AV) canal defects and tetralogy of Fallot in 12, double-outlet right ventricle (DORV) in 10, and additional anomalies associated with atrial isomerism in 7 underwent corrective repair. Age ranged from 39 days to 24 years (median, 3.7 years). Repair included reconstruction of the common AV valve in 25 patients and prosthetic valve replacement in 4. Construction of an intraventricular tunnel connecting the left ventricle with the aorta was accomplished in 23 of 25 patients with ventriculoarterial concordant or double-outlet connections. In 2 patients with situs inversus and associated DORV and in 4 patients in the isomerism group who had ventriculoarterial discordant connections, repair included intraatrial venous diversion by a modified Senning procedure in 2, a modified Mustard venous switch in 1, and a tailored atrial baffle in 3. A valved extracardiac conduit was required for repair in 4 patients. Partial anomalous systemic venous connection was repaired in 7 patients and total anomalous pulmonary venous connection, in 5. There was 1 hospital death (3%) and 3 late deaths (11%). There was 1 (3.6%) reoperation to replace an incompetent right (systemic) AV valve 17 months postoperatively, and each of the 25 surviving patients was in New York Heart Association Functional Class I (80%) or I1 (20%) at follow- UP. The results of repair of isolated complete atrioventricular (AV) canal defect have improved markedly in this era [I, 21. In 1984 and 1985, there was 1 hospital death (2%) among 41 patients who underwent repair of this isolated defect at the University of Alabama at Birmingham [2]. In earlier years, repair of this defect when accompanied by major associated cardiac anomalies was linked with high hospital mortality [l, 3, 41. This report describes our recent experience with repair of complex complete AV canal defects. From the Division of Cardiothoracic Surgery and the Alabama Congenital Heart Disease Diagnosis and Treatment Center, the University of Alabama at Birmingham, Birmingham, AL. Resented at the 60th Scientific Session of the American Heart Association, Anaheim, CA, Nov 16-19, Accepted for publication July 26, Address reprint requests to Dr. Pacifico, Division of Cardiothoracic Surgery, The University of Alabama at Birmingham, Birmingham, AL Material and Methods Twenty-nine consecutive patients underwent corrective repair of complete AV canal defect with major associated anomalies between July 1,1982, and December 31,1986. Earlier experience was included in previous publications [I, 41. Each patient had a common AV valve with an underlying interventricular communication. In addition, 12 patients had tetralogy of Fallot, 10 had double-outlet right ventricle (DORV), and 7 had various defects associated with atrial isomerism. Situs solitus was present in 20 patients, situs inversus in 2, and situs ambiguus in 7. A D-loop was present in 28 and L-loop, in 1. Age at operation ranged from 39 days to 24 years (median, 3.7 years). Thirteen patients had undergone previous palliative procedures. A Glenn shunt had been constructed in the oldest patient, a systemic-pulmonary artery shunt had been made in 11 patients (single in 9 and multiple in 2), and repair of coarctation with pulmonary artery banding had been accomplished in 1 patient. The pulmonary artery arose completely from the right ventricle in each patient with associated tetralogy of Fallot or DORV. Tetralogy of Fallot was diagnosed when there was severe infundibular or valvular pulmonary stenosis or both and an overriding aorta that arose partly from the right ventricle. DORV was diagnosed when the aorta arose more than 50% from the right ventricle in those without pulmonary stenosis and more than 90% in those with pulmonary stenosis. The ventricular septa1 defect (VSD) was related to the aorta in each patient with associated tetralogy of Fallot and in 8 of the 10 patients with associated DORV; in the remaining 2 it was noncommitted. Among the 8 patients with DORV and a subaortic VSD, pulmonary stenosis was present in 2, total anomalous pulmonary venous connection (TAPVC) to a left vertical vein was present in 1, and subaortic stenosis was present in another. The 2 patients with DORV and a noncommitted VSD each had situs inversus with dextrocardia and TAPVC to the superior vena cava. Pulmonary stenosis was present in each, and 1 had partial anomalous systemic venous connection with the inferior vena cava connected to the left atrium and with the hepatic veins and left superior vena cava connected to the right atrium. The aorta arose 100% from the right ventricle in each of the 5 patients with a muscular conus separating the aortic and AV valve annuli. In the remaining 5 without a subaortic conus, it arose 100% from the right ventricle in 2, 90% in 1 with associated pulmonary stenosis, and 70% in 2 without pulmonary stenosis. A common atrium was present in 1 patient, a left 645 Ann Thorac Surg , Dec Copyright by The Society of Thoracic Surgeons

2 646 The Annals of Thoracic Surgery Vol46 No 6 December 1988 Table 1. Complete Atrioventricular Canal with Atrial Isomerisma Ventriculoarterial No. of Pulmonary Connection Patients Stenosis TAPVC PASVC Concordant Discordant 4 4b 1' 2 DORV 'There was left isomerism in 4 and right isomerism in 3 patients. bthere was acquired pulmonary atresia in 1, and discontinuity of the left and right pulmonary arteries in 1. 'This patient had L-loop. TAPVC = total anomalous pulmonary venous connection; PASVC = partial anomalous systemic venous connection; DORV = double-outlet right ventricle. superior vena cava connected to the coronary sinus in another, and the inferior vena cava connected to the left atrium in a third. The anatomical details in the 7 patients in the isomerism group are shown in Table 1. In addition, 1 patient had subaortic stenosis from a narrow muscular conus. Partial anomalous systemic venous connection was present in 5 patients, and included connection of a left superior vena cava directly to the left-sided atrium in 4 and to the coronary sinus in 1. The inferior vena cava connected to the left-sided atrium in 1, to a left superior vena cava (and then to the left-sided atrium) in another, and to a right superior vena cava in a third. Hepatic veins connected to the left-sided atrium in 2 patients. Four patients had a common atrium. The magnitude of AV valve incompetence as judged from preoperative cineangiograms combined with intraoperative assessment is shown in Table 2. The family or physician or both of each hospital survivor was contacted in June, 1987, to obtain follow-up information. Surgical Repair The goal of corrective repair included reconstruction of the common AV valve without leaflet division by previously described methods [3, 51. Prosthetic valve replacement was employed only when adequate competence could not be achieved by repair. Whenever possible, an intraventricular tunnel was constructed using a commashaped Dacron patch to connect the left ventricle through the interventricular communication with the aorta (Figure) [3]. When the interventricular defect was unrelated (noncommitted) to the aorta, it was closed with a Dacron patch. The left superior and inferior leaflets of the common AV valve were attached to the crest of the Dacron patch, and the left side of the common AV valve remained a trileaflet structure. When residual incompetence was present through the resultant septal commissure, a few interrupted sutures were placed to approximate the left superior and inferior leaflets, thereby partially closing this commissure to improve valve competence. When residual incompetence was present at the left superolateral or inferolateral com- Table 2. Preoperative Atrioventricular Valve Incompetence Magnitude of Valvular Incompetence Category None Mild Moderate Severe Tetralogy of Fallot " Double-outlet right b ventricle Atrial isomerism ' Total athis patient had left atrioventricular valve replacement at the age of 4 ';:patient aged 8 years had replacement of a left atrioventricular valve that was necrotic as a result of previous endocarditis. 'One 24-year-old patient underwent left and right atrioventricular valve replacement, and a 5-year-old patient had right atrioventricular valve replacement. missures, localized commissuroplasties were employed [5]. The interatrial defect was closed with a separate pericardial patch. Pulmonary stenosis was relieved by valvotomy and mobilization and partial resection of infundibular stenosis. This and the decision to enlarge a small pulmonary valve annulus were accomplished according to previously described methods [6, 71. The TAPVC was repaired, and when necessary, a modified Senning or Mustard atrial baffle was constructed using standard methods ( An anomalous left superior vena cava connecting to the upper comer of the left atrium or left-sided atrium was repaired as previously described [ll]. Standard cardiopulmonary bypass methods were employed using direct caval cannulation, hypothermia, and low flow as previously described [12]. The time of cardiopulmonary bypass ranged from 50 to 183 minutes (mean, 89.1 minutes). Cold cardioplegic myocardial protection was employed in each patient; a sanguineous solution was used in 26 patients and a crystalloid solution in 3. Time of myocardial ischemia ranged from 37 to 129 minutes (mean, 64.4 minutes). Double-outlet right ventricle with subaortic ventricular septal defect. (A) The anatomy is shown as viewed through a right ventriculotomy (above) and a right atriotomy (below). The left superior leaflet is free floating, and is designated Ant. bridging leaflet. (B) The bridging leaflets have been retracted to show the crest of the ventricular septum and the deep interventricular communication, which extends to the subaortic area. (C) lnterrupted sutures are shown closing the septal commissure of the leftward portion of the atrioventricular valve. Currently, only the suture nearest the septum would be placed unless residual incompetence was present throughout the septal commissure. (D) A comma-shaped Dacron patch has been sutured to create a tunnel connecting the interventricular communication with the aorta. The broad, contoured nature of the tunnel in the immediate subaortic area is shown (#1 Patch). (E) A second patch (#2 Patch) has been used to close the interatrial communication and sandwich the atrioventricular valve leaflets to the crest of the Dacron patch. (P.A. = pulmonay artery; Ao = aorta; S.V.C. = superior vena cava; Lat. = lateral; Post. = posterior.) (From f31.)

3 647 Pacific0 et al: Repair of Complete AV Canal Defects and Associated Cardiac Anomalies

4 648 The Annals of Thoracic Surgery Vol46 No 6 December 1988 Associated Tetralogy of Fallot Each of the 12 patients with tetralogy of Fallot had transatrial repair of the AV canal defect with construction of a right ventricular tunnel connecting the left ventricle through the VSD to the aorta. AV valve reconstruction was accomplished in 11, and left AV valve replacement was necessary in 1 with severe AV valve incompetence. Infundibular and valvular pulmonary stenoses were relieved solely through a right atrial-pulmonary artery approach in 6 patients who did not have a right ventriculotomy [7]. In 1, it was relieved by a vertical right ventriculotomy, which was subsequently enlarged by patching. Five patients required a right ventricularpulmonary artery transannular patch, which was limited in 3 and classic in 2, because of a severely hypoplastic pulmonary valve annulus [7]. Associated DORV Eight of the 10 patients with DORV and situs solitus had a VSD that was more or less committed to the aorta. In each of them, the AV canal defect repair included construction of a tunnel connecting the left ventricle to the aorta. This was accomplished solely through a right atrial approach in 7 and a combined right atrial-right ventricular approach in 1. Cephalic enlargement of the VSD was necessary in 3 patients, and resection of muscular subaortic stenosis was accomplished in 1. Two of these 8 patients had pulmonary stenosis, which was relieved transatrially in each. TAPVC to a left vertical vein was repaired in 1 by anastomosis of the common venous sinus with the left atrium and vertical vein closure. The site of previous pulmonary artery banding was enlarged by patching in another. The leftward portion of the common AV valve was necrotic from previous bacterial endocarditis in 1 patient who required prosthetic valve replacement. Another required prosthetic valve replacement of a severely incompetent right AV valve. In the 2 patients with situs inversus and dextrocardia, a noncommitted VSD was present and it was not possible to construct an internal tunnel connecting the left ventricle to the aorta. The AV canal defect was transatrially repaired with VSD closure and AV valve reconstruction, the main pulmonary artery closed, and a homograft valved extracardiac conduit placed from the left ventricle to the main pulmonary artery. A venous switch at the atrial level was also constructed, and included diversion of the TAPVC to the superior vena cava in both and diversion of the anomalous inferior vena cava in 1. Associated Atrial Isomerism The AV canal defect was transatrially repaired in each of the 7 patients. AV valve reconstruction was accomplished in 6, and 1 patient aged 24 years required prosthetic valve replacement of severely incompetent left and right AV valves. In each of the 3 patients with ventriculoarterial concordant or DORV connections, an intraventricular tunnel was constructed to connect the left ventricle to the aorta. This was not possible in the 4 Table 3. Hospital and Late Deaths Hospital Late Age at Operation No. of Deaths Deaths (mo) Patients No. % No. % > loo 0 0 > > > Total patients with ventriculoarterial discordant connections. In each of them, the AV canal defect repair included VSD closure with AV valve reconstruction, a modified Senning procedure in 2 patients, a modified Mustard venous switch in 1, and an atrial baffle in 1 with ventricular inversion and TAPVC to the right-sided atrium. Two patients also required a left ventricular-pulmonary arterial homograft valved extracardiac conduit, in 1 because of valvular pulmonary atresia and in the other because of severe subvalvular pulmonary stenosis and discontinuity of the right pulmonary artery from the main and left pulmonary arteries. Transatrial relief of pulmonary stenosis was accomplished in 4 patients and repair of TAPVC to the right-sided atrium in 1 (mentioned already) and to a posterior confluence from which arose a connection to the junction between the left-sided atrium and the left superior vena cava in another. Muscular subaortic stenosis was resected through the rightsided atrium in 1 patient, and partial anomalous systemic venous connection was repaired by atrial rerouting in 5 patients. Results Hospital and late mortality according to age at operation is shown in Table 3. The single hospital death occurred in a 7-month-old child with associated DORV, absent pulmonary stenosis, and a subaortic VSD who could not be weaned from cardiopulmonary bypass. Postmortem examination confirmed the accuracy of the repair and the presence of an unobstructed tunnel connecting the left ventricle through the VSD with the aorta. Complete heart block occurred intraoperatively in 2 patients (6.9%), both of whom were in the isomerism group. One had L-IOOP, and the other with D-loop (age, 24 years) had undergone replacement of severely incompetent left and right AV valves. Each received a permanent pacemaker. Follow-up information was obtained for each of the 28 hospital survivors in June, There were 3 late deaths (11%) and 1 reoperation (3.6%). Twenty (80%) of the late survivors were in New York Heart Association Functional Class I and 5 (20%), in Class 11. One late death occurred suddenly 1 month after repair of complete AV septa1 defect with moderate AV valve 0

5 649 Pacific0 et al: Repair of Complete AV Canal Defects and Associated Cardiac Anomalies incompetence and associated tetralogy of Fallot. The patient was a 5-year-old child who had been convalescing normally. The repair included placement of a limited transannular patch, and the peak right to left ventricular pressure ratio was 0.7 after repair. The 2 other late deaths were in the isomerism group. One patient with a ventriculoarterial discordant connection and moderate AV valve incompetence preoperatively, later had severe right (systemic) ventricular dysfunction and severe right AV valve incompetence, and died 29 months postoperatively following right (systemic) AV valve replacement at 17 months postoperatively. This was the only reoperation among hospital survivors. The other death in this subset occurred 24 months postoperatively and was due to chronic heart failure. The patient was the 24-year-old woman whose repair included replacement of severely incompetent right and left AV valves. Comment Just as the results of repair of isolated complete AV canal defects have markedly improved in this era [I, 21, so have the results of repair of these defects associated with additional major cardiac anomalies. At the University of Alabama at Birmingham between 1967 and 1982, 29 patients with complete AV canal defects and associated tetralogy of Fallot or DORV underwent corrective repair with 11 hospital deaths (37.9%)(70% confidence limits [CL] = 27.6 to 49.3%) [4]. This was significantly higher than the rate in the current series-1 hospital death (3.4%) (CL 0.4 to 11%) among 29 patients with similar complex defects (p < 0.05). Similar improvement in hospital mortality has been recorded by others [ Precise reasons for improved surgical results with repair of these defects were not established in this study. However, important factors almost certainly include improved knowledge of the anatomy of these defects, more efficient and complete repair, and reduced level of preoperative disability through improved timing of operation. These factors undoubtedly contributed to the fact that earlier date of operation was a highly significant (p < ) incremental risk factor for hospital mortality in our overall experience with all types of AV canal defects between 1967 and 1982 [l]. The precise surgical technique employed is an important factor in achieving success in the repair of these defects. We continue to believe the use of a separate patch to close the interventricular defect in repair of isolated complete AV canal defects permits AV valve reconstruction with less alteration of the AV valve leaflet architecture and supporting structures [5]. This is especially important in these complex defects where the patch employed to close the interventricular communication usually must also form a tunnel to connect the dextraposed aorta with the left ventricle [3]. The configuration of this patch is usually that of the shape of a comma (see Figure), and the depth of its cephalic protrusion should be about two-thirds the circumference of the aortic annulus when the aorta arises completely or nearly completely from the right ventricle. The patch must be precisely sutured to create an unobstructed tunnel from the left ventricle to the aorta and yet not compromise the quality of the AV valve repair. Tunnel repair was possible in 23 of 25 patients with ventriculoarterial concordant or double-outlet connections. In each, the interventricular communication extended cephalad so that it was "committed" to the aorta, although cephalic enlargement of the VSD was used in 3 with DORV to permit tunnel reconstruction. In the 2 patients with situs inversus and associated DORV, the interventricular communication did not extend cephalad and was in a "noncommitted' position. It could not have been converted to a subaortic defect by septa1 excision. Repair was accomplished by closure of the interventricular communication, AV valve reconstruction, closure of the main pulmonary artery, placement of a valved extracardiac conduit from the left ventricle to the main pulmonary artery, and venous switching. Although the modified Fontan operation might be considered an alternative surgical option for these 2 patients, since each had severe pulmonary stenosis [4], it would have been complicated by the presence of AV valve incompetence, which was moderate in 1 and mild in the other. It would have been further complicated by the presence of TAPVC to the superior vena cava in each and an anomalous inferior vena cava connected to the left atrium in 1. In the isomerism group, a tunnel repair connecting the left ventricle with the aorta was accomplished in 3 patients, 2 with the concordant and 1 with the DORV type of ventriculoarterial connection. The remaining 4 patients had a discordant ventriculoarterial connection, 1 with ventricular inversion; 3 had pulmonary stenosis, and 1 had acquired pulmonary atresia. The 3 patients without ventricular inversion had a venous switch as part of their repair. Potential alternative surgical methods include an arterial switch operation or a Fontan repair. The former would not have application because of the presence of valvular pulmonary stenosis in 2 and atresia in 1. A Fontan repair would have been complicated by the presence of systemic venous anomalies and AV valve incompetence in each. Anomalies of systemic and pulmonary venous return, as expected, were common in the 7 patients with atrial isomerism. Partial anomalous systemic venous connection was present in 5 and TAPVC, in 2. Of interest was the presence of TAPVC in 3 patients in the DORV group. It occurred in 1 of 8 with situs solitus and in each of the 2 with situs inversus. Partial anomalous systemic venous connection was present in 1 patient in each subset. These anomalies complicate surgical repair and although it is useful for the surgeon to have preoperative knowledge of them, he must search for them at the time of repair. The precise details of repair must be formulated at the time of operation in accordance with the specific anatomical relationships encountered, but general guidelines used to repair each anomaly in its isolated form remain useful [4, 11, 161.

6 650 The Annals of Thoracic Surgery Vol46 No 6 December 1988 Construction of the intraventricular tunnel was completely accomplished through transatrial exposure in 22 of the 23 patients who underwent this type of repair. One patient with DORV had marked myocardial hypertrophy from previous pulmonary artery banding, and required transventricular exposure as well. Transatrial exposure is facilitated by the use of cardioplegic myocardial protection, which results in a softer, more malleable myocardium, fine traction sutures placed on the AV valve leaflets, and the use of separate direct caval cannulation [12]. These methods have allowed us in most patients to avoid the need for additional exposure of the cephalic margin of the suture line through a right ventriculotomy, which, although we have employed it previously, further complicates the repair [3]. Excluding the 4 patients whose repair included a valved extracardiac conduit, pulmonary stenosis was present in 18. Five patients required enlargement of a small pulmonary annulus by transannular patching, which was classic in 2 and limited in 3 [7]. In the remaining 13 patients, pulmonary stenosis was relieved by transatrial-transpulmonary exposure in 12, thereby completely avoiding a right ventriculotomy [7]. This exposure also simplified the overall repair and particularly when a competent pulmonary valve is left, may result in improved right ventricular function after repair [17]. Although the magnitude of AV valve incompetence was judged moderate or severe in 17 patients (59%) (see Table 2), valve reconstruction was accomplished in 13 of them and in 25 (86%) of the overall group. Although some surgeons 15, 151 prefer to divide bridging AV valve leaflets to aid in exposure, leaflet division was avoided in each patient who underwent AV valve reconstruction. This prevents the potential future development of severe AV valve incompetence from dehiscence of the leaflet from the patch used to close the interventricular communication. It also minimizes consumption of valuable leaflet tissue; this is especially prone to occur when pledgeted mattress sutures are used to reattach a divided leaflet to the patch. Valve replacement was required in 4 patients (14%), each of whom had severe AV valve incompetence preoperatively. In 1, the incompetent valve was related to tissue destruction from previous bacterial endocarditis and in another, aged 24 years, from long-standing heart disease with biventricular dilatation and dysfunction. Over the period of follow-up, valve repair failure occurred in 1 patient in the isomerism group who required right (systemic) AV valve replacement 17 months postoperatively. This patient had moderate AV valve incompetence preoperatively and a ventriculoarterial discordant connection. Therefore, as in isolated complete AV septal defects, valve reconstruction can be accomplished in most patients with these complex defects. Complete heart block occurred in 2 patients, both in the isomerism group. One had L-loop, and 1 with D-loop had undergone both left and right AV valve replacement. Normal sinus rhythm persisted postoperatively in each patient with D-loop who had AV valve reconstruc- tion. This is similar to our experience with repair of isolated complete AV canal defects [l]. The experience reported here supports the advisability of corrective repair for patients with these complex defects. The morphological left ventricle usually remains as the systemic ventricle after repair as in 23 of 25 patients in this experience with ventriculoarterial concordant or double-outlet connections. When pulmonary stenosis is present, repair is probably best advised between 1 year and 3 years of age. If earlier operation is necessary, a systemic-pulmonary artery shunt should be considered. When an extracardiac conduit is needed as part of the repair, it is prudent to defer operation to permit the use of a larger conduit, and to employ a systemic-pulmonary artery shunt for those with pulmonary stenosis as an interval measure. When pulmonary stenosis is absent, corrective repair is advised in the first year of life before the development of advanced pulmonary vascular disease. When a valved extracardiac conduit is necessary as part of the repair, early pulmonary artery banding to control congestive heart failure and protect the pulmonary vasculature is advised. References 1. 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 84:523, Kirklin JW, Blackstone EH, Bargeron LM Jr, et al: The repair of atrioventricular septal defects in infancy. Int J Cardiol 13:333, Paafico AD, Kirklin JW, Bargeron LM Jr: Repair of complete atrioventricular canal associated with tetralogy of Fallot or double-outlet right ventricle: report of 10 patients. Ann Thorac Surg 29:351, Kirklin JW, Barratt-Boyes BG: Cardiac Surgery. New York, Wiley, 1986, pp Pacifico AD: Atrioventricular septal defects. In Stark J, de Leval M (eds): Surgery for Congenital Heart Defects. London, Grune & Stratton, 1983, pp Blackstone EH, Kirklin JW, Pacifico AD Decision-making in repair of tetralogy of Fallot based on intraoperative measurements of pulmonary arterial outflow tract. J Thorac Cardiovasc Surg 77526, Pacifico AD, Sand ME, Bargeron LM Jr, Colvin EC: Transatrial-transpulmonary repair of tetralogy of Fallot. J Thorac Cardiovasc Surg 93:919, Senning A: Surgical correction of transposition of the great vessels. Surgery 45:966, Pacifico AD: Concordant transposition: Senning operation. In Stark J, de Leval M (eds): Surgery for Congenital Heart Defects. London, Grune & Stratton, 1983, pp Mustard WT, Keith JD, Trusler GA, et al: The surgical management of transposition of the great vessels. J Thorac Cardiovasc Surg 48:953, Sand ME, McGrath LB, Pacifico AD, Mandke NV: Repair of left superior vena cava entering the left atrium. Ann Thorac Surg 42:560, Pacifico AD: Cardiopulmonary bypass and hypothermic circulatory arrest in congenital heart surgery. In Grillo HC, Austen WG, Wilkins EW Jr, et a1 (eds): Current Therapy in Cardiothoracic Surgery. Toronto, Decker (in press) 13. Binet JP, Losay J, Hvass U: Tetralogy of Fallot with type C

7 651 Paafico et al: Repair of Complete AV Canal Defects and Associated Cardiac Anomalies complete atrioventricular canal. J Thorac Cardiovasc Surg 79:761, Uretzky G, Puga FJ, Danielson GK, et al: Complete atrioventricular canal associated with tetralogy of Fallot: morphologic and surgical considerations. J Thorac Cardiovasc Surg 87:756, Vargas FJ, Otero Cot0 E, Mayer JE Jr, et al: Complete atrioventricular canal and tetralogy of Fallot: surgical considerations. Ann Thorac Surg 42:258, Pacific0 AD, Fox LS, Kirklin JW, Bargeron LM Jr: Surgical repair of atrial isomerism. In Anderson RH, Shinebourne EA, Macartney FJ, Tynan MJ (eds): Paediatric Cardiology. New York, Churchill Livingstone, 1983, vol 5, pp 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 90:856, 1985 Notice from the American Board of Thoracic Surgery The American Board of Thoracic Surgery began its recertification process in Diplomates interested in participating in this examination should maintain a documented list of the cardiothoracic operations they performed during the year prior to application for recertification. They should also keep a record of their attendance at thoracic surgical meetings, and other continuing medical education activities, for the two years prior to application. A minimum of 100 hours of approved CME activity is required. In place of a cognitive examination, candidates for recertification will be required to complete both the general thoracic and cardiac portions of the SESATS I11 syllabus (Self-EducatiodSelf-Assessment in Thoracic Surgery). It is not necessary for candidates to purchase SESATS 111 booklets prior to applying for recertification. SESATS I11 booklets will be forwarded to candidates after their applications have been accepted. Diplomates whose 10-year certificates will expire in 1991 may begin the recertification process in This new certificate will be dated 10 years from the time of expiration of the original certificate. Recertification is also open to any Diplomate with an unlimited certificate and will in no way affect the validity of the original certificate. The deadline for submission of applications is July 1, A recertification brochure outlining the rules and requirements for recertification in thoracic surgery is available upon request from the American Board of Thoracic Surgery, One Rotary Center, Suite 803, Evanston, IL