Atrioventricular Valve Repair or Replacement in Atriopulmonary Anastomosis: Surgical Considerations Florentino J. Vargas, M.D., John E. Mayer, Jr., M.D., Richard A. Jonas, M.D., and Aldo R. Castaneda, M.D. ABSTRACT Three patients who underwent a modified Fontan-Kreutzer (F-K) operation required additional procedures to correct left atrioventricular valve regurgitation. Valve replacement was performed in two additional procedures, and initial annuloplasty with a Carpentier ring was carried out in the third. All 3 survived the combined procedures and are doing well after a follow-up period ranging from five months to three years. More frequent presentation of these types of patients can be expected with broadening indications for F-K procedure to more complex lesions. Elevated pulmonary venous pressures can produce disastrous results after an atriopulmonary connection procedure (Fontan-Kreutzer, or F-K), and normal left atrioventricular valve (LAVV) function has been considered a prerequisite to this procedure [l].As the F-K approach has been applied to a number of more complex anatomic defects [2-41, which may include atrioventricular (AV) valve abnormalities, the problem of regurgitant AV valves in patients who otherwise would be good candidates for an F-K type of repair has become apparent. The purpose of this report is to describe the diagnostic and surgical features of 3 patients in whom LAVV repair or replacement was subsequently or simultaneously undertaken in conjunction with an F-K procedure. Case Reports Patient 2 S.M., an 18-year-old man, had a single ventricle, Ltransposition of the great arteries (S,L,L), pulmonary stenosis, and probable regurgitation of both L A W and right atrioventricular valve (RAVV). Several cardiac catheterization studies had failed to quantitate the degree of insufficiency of each atrioventricular valve ( A W ) . On this admission the patient was cyanotic and moderately incapacitated (New York Heart Association [NYHA] Functional Class 11). Chest roentgenogram showed moderate cardiac enlargement with reduced pulmonary artery markings. A harsh holosystolic murmur was heard over the pericardium. Cardiac catheteriFrom the Department of Cardiovascular Surgery, The Children’s Hospital, and the Department of Surgery, Harvard Medical School, Boston, MA. Accepted for publication June 27, 1986. Address reprint requests to h.Castaneda, Department of Cardiovascular Surgery, The Children’s Hospital, 300 Longwood Ave, Boston, MA 02115. 403 Ann Thorac Surg 43:403-405, Apr 1987 zation and two-dimensional echocardiography confirmed the anatomic diagnosis and also identified severe RAW and mild L A W regurgitation. At catheterization, left atrial pressure was 14 mm Hg, left ventricular end-diastolic pressure (VEDP) was 12 mm Hg, mean pulmonary artery pressure was 15 mm Hg, and calculated pulmonary arteriolar vascular resistance (indexed) was 2 Wood units/m2. operative repair included patch obliteration of a hypoplastic, regurgitant RAW, patch closure of an atrial septal defect, suture closure of the pulmonary valve, and direct atriopulmonary anastomosis between the cavoatrial junction and the right pulmonary artery. Because of inability to wean the patient from bypass, and the presence of a mean left atrial pressure of 20 mm Hg with prominent V waves, severe residual L A W regurgitation was diagnosed. Through a left atriotomy a prolapsed Ebstein-like deformed LAVV was resected and replaced with a no. 27 St. Jude Medical prosthesis. A residual leak in the atrial baffle suture line resulted in postoperative cyanosis and was repaired 1 day later. Because of persistent recurrent pericardial effusions, a pericardial-pleural window was created 30 days later. He was discharged 45 days after admission in good condition. A repeat catheterization and echocardiogram prior to discharge showed good ventricular function and absence of gradients across the AV valve prosthesis or across the atriopulmonary anastomosis. Normal function of the prothesis was demonstrated from the left ventriculogram (Figure). Two years later this patient is clinically well (NYHA Functional Class I) on diuretics and anticoagulants. Patient 2 C.L., an 8-year-old boy who had previously undergone a Blalock-Taussig shunt procedure, was admitted with tricuspid atresia, normally related great arteries, and pulmonary stenosis as diagnosed by catheterization and echocardiography. The calculated pulmonary vascular resistance (indexed) was 0.2 Wood units/m2. Pulmonary pressure was 20 mm Hg (mean) and VEDP was 7 mm Hg.The Blalock-Taussig shunt appeared to be large angiographically. Although a murmur of mitral regurgitation was present, the degree of valve insufficiency was considered mild and was thought to have been accentuated by LAVV distortion by the angiography catheter. Repair included shunt ligation, suture closure of the pulmonary valve and atrial septal defect, and direct right atrial appendage-to-right pulmonary artery anastomosis, which was augmented with an autologous pericardial patch. After an uncomplicated postoperative 404 The Annals of Thoracic Surgery Vol 43 No 4 April 1987 Postoperative study after Fontan-Kreutzer procedure with LAVV replacement (Patient 2 ) : ( A ) Right atrial injecton shows simultaneous filling of both right atrium (RA) and pulmonary artery (PA) which have been connected with an atriopulmonary anastomosis. There is no evidence of restriction at the anastomotic orifice. The LAVV has been replaced with a no. 29 St. 1ude prosthesis (arrow). (B) Ventriculogram displayed good ventricular contraction and normal prosthetic function (arrow). Both prosthetic regurgitation and peri-prosthetic leaks are absent. (SV = single ventricle). course, the patient was discharged in good condition, on diuretics and digoxin. Although asymptomatic, a murmur suggestive of mitral regurgitation was still present at the time of discharge. The murmur gradually became more intense, cardiomegaly increased, and cardiac failure developed. Cardiac catheterization and echocardiography disclosed severe mitral valve regurgitation. Reoperation was undertaken two years after the initial procedure, and a prolapsed mitral valve (with elongated chordae of both leaflets) was replaced with a no. 29 St. Jude Medical prosthesis. The patient was weaned from bypass uneventfully. A right atrial pressure of 12 mm Hg and a left atrial pressure of 7 mm Hg were recorded two days postoperatively. The patient was discharged on diuretics and anticoagulants and has remained asymptomatic (NYHA Functional Class I) for three years after the reoperation. Patient 3 J.M., a 10-year-old boy, was admitted with the diagnosis of tricuspid atresia, D-transposition of the great vessels, severe pulmonary stenosis, and moderate mitral regurgitation, confirmed by both catheterization and twodimensional echocardiographic evaluation. Although VEDP was 7 mm Hg, a mild degree of left ventricular dysfunction was suggested by the echocardiogram (shortening fraction = 27%;ejection fraction = 52%).At operation, the mitral valve regurgitation was considered significant as assessed by passively filling the left ventri- cle with saline (after excision of the atrial septum). The regurgitation seemed to result primarily from a massively dilated annulus. Both the leaflet tissue and its subvalvular apparatus seemed normal. A mitral annuloplasty with a no. 34 Carpentier ring was performed. Retesting of valve function showed considerable improvement. The atrial septa1 defect and the pulmonary valve annulus was closed, and a direct right atriopulmonary anastomosis was performed. The patient’s postoperative course was uneventful. Left atrial pressure was below 5 mm Hg, and the right atrial pressure was 13 mm Hg. He was discharged in good hemodynamic condition and has remained well for five months since the operation. Comment Normal AV valve function has been considered to be an indispensable requirement for an F-K procedure [l, 21. To our knowledge there are no reports in the medical literature of patients who had AV valve replacement or repair as an adjunct to a F-K operation. Because the indications for F-K procedure now include a more complex spectrum of lesions (3, 41, the need for AV valve repair or replacement has become apparent in some patients. These 3 patients illustrate the diagnostic and intraoperative management problems that can arise in this setting. Mitral regurgitation with tricuspid atresia was recognized clinically and was associated with pathologic abnormalities of the mitral valve in an unpublished necropsy series (S. Van Praagh, personal correspondence, May, 1981).Abnormal right or left AV valves have been also reported either in D- or L-loop types of single ventricle [ 5 ] .The need for AV valve repair may be more likely to occur in those patients with abnormal leaflet anatomy (common AVV) or in those in whom a morphologic tricuspid valve has to be used as the sole systemic A W for a F-K procedure (such as in certain L-loop single ventricles or in mitral atresia and hypoplastic left ventricular syndrome). In the latter cases, there is both anatomic and clinical evidence of frequent tricuspid valve abnor- 405 Vargas, Mayer, Jonas, Castaneda: Atrioventricular Valve Repair or Replacement malities and dysfunction. Bharati and Lev [6] reported a high incidence of abnormal tricuspid valve in a necropsy series of hearts with hypoplastic left ventricular syndrome. Tricuspid valve abnormalities causing significant AV valve insufficiency occurred in 2 patients with hypoplastic left ventricular syndrome who subsequently required prosthetic valve replacement after an otherwise successful first-stage palliation for the syndrome [7]. In the presence of L A W regurgitation, hemodynamic evaluation of patients for a F-K operation can be difficult. First, the presence of a mean pulmonary artery pressure of 20 mm Hg or higher in these patients must be considered in a different light from that occurring in patients with normal AVV function, because the pulmonary artery pressure may be expected to fall after normal AVV function has been restored by AVV repair or replacement. Similar considerations apply to the evaluation of VEDP. In these cases, the additional ventricular volume overload produced by AVV incompetence makes the preoperative assessment of ventricular function difficult [ 8 ] . If a large systemic-to-pulmonary shunt is also present and contributing to the AV valve regurgitation by volume overload, the assessment of AV valve function is further confused. Under these circumstances it may be virtually impossible preoperatively to separate the individual effects of valvar regurgitation and systemic-to-pulmonary artery shunts on ventricular function. Although the degree of regurgitation of a single AV valve can be quite accurately evaluated preoperatively, this evaluation becomes more difficult if both AV valves are affected. This problem occurred in patient 1, in whom repeated contrast injections into a single ventricular chamber proved misleading because it suggested severe regurgitation of the RAVV alone. If the AV regurgitation is thought to be significant preoperatively, repair or replacement should be undertaken at the time of the atriopulmonary procedure. However, if the AV regurgitation is predicted to be mild postoperatively, AVV function can be assessed intraoperatively by inspecting the valve and testing its competence by passively filling the ventricle. If the function seems adequate, a conservative approach can be considered and an F-K procedure performed. However, after weaning from bypass, high mean left atrial pressure and tall V waves in the left atrial tracings indicate the need for AVV repair or replacement. The need for AV valve repair or replacement can only be made by hemodynamic evaluation after shunt ligation and Fontan anastomosis have reduced the effects of volume overload. AV valve repair and the F-K procedure should be considered early in patients with AVV regurgitation so that deterioration of ventricular function by volume overload can be prevented. Also, because even small elevations of left atrial pressure can be dangerous after an F-K procedure, the type and size of prosthesis should be chosen to provide a minimal gradient. Although the preoperative evaluation of these patients can be difficult, simultaneous F-K operation and AV valve repair or replacement is possible and has permitted a relatively normal life (NYHA Functional Class I) in 3 patients over a short follow-up period. References 1. Choussat A, Fontan F, Besse P, et al: Selection criteria for Fontan procedure. In Anderson RH, Shinebourne EA (eds): Pediatric Cardiology. Edinburgh, Churchill Livingstone, 1978, pp 559-566 2. Kreutzer G, Vargas FJ, Schlichter AJ, et al: Atriopulmonary anastomosis. J Thorac Cardiovasc Surg 83:427, 1982 3. Marcelletti C, Mazzera E, Olthof H, et al: Fontan’s operation: an expanded horizon. J Thorac Cardiovasc Surg 80:764, 1980 4. Di Carlo D, Marcelletti C, Nijved A, et al: The Fontan procedure in the absence of the interatrial septum: failure of its principle? J Thorac Cardiovasc Surg 85:923, 1983 5. Van Praagh R, Plat JA, Van Praagh S: Single ventricle, pathology, embriology, terminology and description. Herz 4:113, 1979 6. Bharati S, Lev M: The surgical anatomy of hypoplasia of the aortic tract complex. J Thorac Cardiovasc Surg 88:97, 1984 7. Lang P, Jonas RA, Norwood WI, et al: The surgical anatomy of hypoplasia of aortic tract complex. J Thorac Cardiovasc Surg 89:149, 1985 (Letter) 8. Mair DD, Rice MJ, Hagler DJ, et al: Outcome of the Fontan procedure in patients with tricuspid atresia. Circulation (Part 11) 7288, 1985