Right ventricular dysfunction after atrial repair for

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1 CURRENT REVIEW Arterial Switch Operation After Left Ventricular Retraining in the Adult Massimo A. Padalino, MD, Giovanni Stellin, MD, William J. Brawn, FRCS, Giuseppe Fasoli, MD, Luciano Daliento, MD, Ornella Milanesi, MD, and Dino Casarotto, MD Department of Cardiovascular Surgery, Cardiology, and Pediatrics, University of Padova Medical School, Padova, Italy, and Department of Cardiac Surgery, Birmingham Children s Hospital, Birmingham, United Kingdom Retraining the morphological left ventricle in transposition of the great arteries has been successfully reported in infancy, while older age seems to be a contraindication. A 23-year-old woman with {S,D,D} transposition of the great arteries and ventricular septal defect developed severe right systemic ventricular dysfunction 22 years after Mustard procedure and ventricular septal defect closure. Hemodynamic investigation revealed moderate pulmonary hypertension and preserved left ventricular function. A pulmonary artery band was applied to obtain a left right ventricular pressure ratio of Her postoperative course was characterized by biventricular failure, treated effectively with inotropic support. Six months later, she underwent a Mustard baffle takedown and arterial switch procedure. Her postoperative course was uneventful. She was discharged home on postoperative day 15. At 24-months follow-up, she is in excellent clinical condition; echocardiographic evaluation shows good left ventricular function (ejection fraction: 0.69) with left ventricular volume within normal limits (70 ml/m 2 ). Our experience demonstrates that, despite adult age, a staged arterial switch operation can be performed successfully in selected patients when left ventricular function is preserved. (Ann Thorac Surg 2000;70:1753 7) 2000 by The Society of Thoracic Surgeons Right ventricular dysfunction after atrial repair for transposition of the great arteries (TGA) is an increasingly frequent problem [1 4]. Attempts to retrain the morphological left ventricle (LV) have been successfully reported in infants and children [1 4], while the possibility for LV retraining in adults is still not defined [4, 5]. We report our experience with a 23-year-old woman (38 kg, 161 cm) with {S,D,D} transposition of the great arteries (TGA) and ventricular septal defect (VSD), in whom, 22 years after a Mustard procedure and VSD patch closure, we performed an arterial switch operation (ASO) after LV retraining. Case Report Diagnosis of {S,D,D,} TGA and VSD was made soon after birth. At the age of 11 months, a Mustard procedure was performed and a 5 mm VSD was patch closed through the tricuspid valve (TV). The postoperative course was uneventful. She was discharged home on postoperative day 12 in good condition, on sinus rhythm. Two years later, because of reduction of exercise tolerance, she underwent cardiac catheterization, showing a moderate systemic tricuspid valve regurgitation (TR) and a mild dysfunction of the morphological right ventricle (RV). She was discharged home on oral therapy with digoxin and diuretic with significant improvement in her Address reprint requests to Dr Stellin, Department of Cardiovascular Surgery, University of Padova Medical School, Via Giustiniani 2, Padova, Italy; stelgiov@ux1.unipd.it. clinical status. At 12 years of age, because of the onset of paroxysmal supraventricular tachycardia and atrial fibrillation, she was started on oral treatment with calcium antagonists (diltiazem, 60 mg Q.I.D), with partial remission of the arrhythmic episodes. At the age of 21 years, because of increasing severity of symptoms (New York Heart Association functional class IV), angiotensin converting enzyme inhibitor (enalapril, 5 mg daily) was added to the previous oral therapy. She was admitted to the hospital for further investigation. On physical examination a loud systolic (4 to 5/6) heart murmur was audible over the whole heart auscultation area. Chest x-ray demonstrated cardiomegaly (cardiothoracic ratio of 0.70) and pulmonary vein congestion; electrocardiogram showed supraventricular tachycardia with a 2:1 atrioventricular (AV) block and RV hypertrophy. Twodimensional demonstrated systolic dysfunction of the morphological RV (ejection fraction [EF] of 0.27), with a significant dilatation (end-diastolic volume [EDV] of 152 ml/m 2 ); RV volumes were calculated from two intersecting crosssectional echocardiographic views (the apical fourchamber and the subcostal RV outflow tract views), according to Levine and colleagues [6]. There was a severe TR (3 /4). Interventricular septum and posterior LV free wall thickness were measured by 2D-echo being 12 mm and 8.4 mm, respectively (normal range is 6 to 11 mm [7]). Cardiac catheterization confirmed the echocardiographic data, revealing moderate pulmonary hyperten by The Society of Thoracic Surgeons /00/$20.00 Published by Elsevier Science Inc PII S (00)

2 1754 REVIEW PADALINO ET AL Ann Thorac Surg ARTERIAL SWITCH OPERATION IN THE ADULT 2000;70: Table 1. Review of Literature Concerning Ventricular Retraining After Atrial Switch Procedure Authors [Ref.] No. patients Mean Age at PAB (range) % Survival at PAB % Conversion to ASO s/p PAB Mean Age at ASO s/p PAB (range) % Survival at ASO s/p PAB Surviving Patient at Older Age Mee, 1986 [2] y ( y) 5/5 (100%) (One unsuccessful attempt b ) Mee, 1989 [1] b y (13 mo 17 y) 8/10 (80%) (17-yold patient died after 2 unsuccessful attempts of PAB) Chang et al, 1992 [11] 4 (1 additional patient had direct ASO) Cochrane et al, 24 (4 patients had direct 1993 [3] c ASO, without PAB) van Son et al, 1996 [12] Helvind et al, 1998 [4] 2/5 (40%) 3.5 y and 14.5 y 2/2 (100%) 14.5 y 5/8 (62%) (3 waiting b ) 7.0 y ( y) 4/4 (100%) 4/4 (100%) After a mean interval of 4.15 mo from PAB (8 days 12 mo) 8.6 y (13 mo 17 y) 17/20 (85%) 12/17 (70%) (3 waiting b ) 7.7 y ( y) 3/5 (60%) 14.5 y 9.6 y ( y; no. included 4 direct ASO) y (5 24 y) 5/5 (100%) 4/5% (80%) After a median 29 (1) ctga:14; 2) s/p asp:12; 3) d-tga:3) 1) 2.6 y (3 mo 8.5 y); 2) 10.1 y (16 mo 25.4 y); 3) 5.3 y (16 mo 8.5 y) 1) 4/4 (100%); 2) 9/11 (81%); 3) 2/2 (100%) 1) 4/4 (100%); 2) 8/11 (72%); 3) 2/2 (100%) interval of 6.2 mo from PAB After a mean interval of 11.2 mo from PAB (24 days 19 mo) 4/5 (80%) a 13.5 y 10/12 (83%) 16.5 y 4/4 (100%) 12 y (One 24-yold patient was not suitable for ASO) 1) 14/14 (100%); 2) 7/9 (63%) a ; 3) 3/3 (100%) 15 y a Includes 1 direct ASO. b Included are 5 patients reported on in 1986 [2]. c Included are 10 patients reported on in 1989 [1]. ASO arterial switch operation; asp atrial switch Procedure; PAB pulmonary artery banding; ctga corrected transposition of the great arteries; dtga D-transposition of the great arteries.

3 Ann Thorac Surg REVIEW PADALINO ET AL 2000;70: ARTERIAL SWITCH OPERATION IN THE ADULT 1755 sion (main pulmonary artery pressure 58/21, mean 40 mm Hg), with normal pulmonary arteriolar resistances (1.5 U/m 2 ). Wedge pulmonary capillary pressure was 30 mm Hg, with an end-diastolic RV pressure of 10 mm Hg, suggesting a possible obstruction at the pulmonary venous return level. The global function of the morphological LV was preserved (EF 0.53, EDV 44 ml/m 2 ) with a mass to volume ratio of 0.6. Because of increasing severity of her clinical status, in the presence of a satisfying LV function, at the age of 22 years and 11 months, through a redo midline sternotomy, a pulmonary artery banding (PAB) was applied. It was gradually tightened until LV systolic pressure reached about three-fourths of systemic systolic arterial pressure (60/10 mm Hg versus 80/40 mm Hg), and the systolic left to right ventricular pressure ratio (P LV/RV ) was equal to 0.75 (preoperative P LV/RV 0.63). The entire procedure was performed with monitoring of the arterial pressure by right radial arterial catheter, of the LV pressure by a Swan Ganz catheter, of the central venous pressure by a double lumen catheter, and of cardiac contractility with intraoperative transesophageal echocardiography. During the PAB, oxygen saturation remained normal (about 100%) and central venous pressure was about 9 mm Hg at the end of procedure. Twelve hours later, while on stable hemodynamic condition, supported with 6 mcg/kg/min infusion of dobutamine, because of a decreased P LV/RV (0.57), she was returned to the operating room and the PAB was tightened to obtain a nearly systemic pressure in the morphological LV (P LV/RV 0.91); the hemodynamic state remained unchanged during this procedure. She was extubated on postoperative day 1, without complications. A transthoracic two-dimensional echocardiographic and color flow Doppler study performed on postoperative day 2, showed a mild depression of morphological LV systolic function (EF 0.41, EDV 84 ml/m 2 ) with a trans-banding peak pressure gradient of 45 mm Hg (estimated P LV/RV 0.8). The postoperative clinical course in the wards was characterized by signs of biventricular failure, requiring prolonged infusion of dobutamine (5 mcg/kg/min) for a total period of 18 days, and subsequent vasodilator oral therapy (enalapril, 10 mg 2 daily); bilateral pleural effusions required multiple drainage. She had recurrent episodes of paroxysmal supraventricular tachycardia, treated with calcium antagonists (diltiazem, 60 mg Q.I.D.). Forty-eight days later, she was discharged home on stable hemodynamic condition, on oral treatment with digoxin (0.25 mg daily), diuretics, enalapril, and diltiazem. Predischarge twodimensional showed a flattened interventricular septum and improved competence of the tricuspid valve (TR of 2 /4), with moderate depression of the morphological LV systolic function (EF 0.43); LV posterior free wall thickness had already increased from 8.4 mm to 9.5 mm. Two months later, she underwent magnetic resonance imaging that demonstrated a morphological LV myocardium free wall thickness of 12 mm, with no evidence of myocardial edema. Cardiac catheterization performed 6 months after PAB demonstrated LVEF of 0.53, transbanding pressure gradient of 50 mm Hg, mild TR, LV pressure 110/0 7 mm Hg (P LV/RV 0.87). At the age of 23 years and 5 months, through a midline re-resternotomy, moderate hypothermic (25 C) cardiopulmonary bypass and aortic cross-clamping, a calcified pantaloon atrial patch was removed and a new anatomical interatrial septum was constructed with preserved bovine pericardium. The PAB was removed and the ascending aorta was sectioned 2 cm above the valvar plane. Left and right coronary ostia were harvested from sinus 1 and 2, respectively, and translocated utilizing the trap door technique [1]; RV-to-pulmonary artery continuity was reconstructed by means of a valved cryopreserved homograft pulmonary conduit (18 mm). The French maneuver was not performed because of the reduced elasticity of the tissues in adult age and for the fear of postoperative bleeding after extensive dissection of the pulmonary artery branches. The patient was easily weaned from cardiopulmonary bypass. Eight hours later, while in stable hemodynamic condition, she was extubated without complications and, the following morning, she was transferred to the wards. The remaining postoperative course remained uneventful. She was discharged home on postoperative day 15, in good condition, on sinus rhythm and on oral therapy with diuretics, digoxin, diltiazem, and warfarin medications. Predischarge twodimensional showed mild LV dilatation (68 ml/m 2 ), flat interventricular septum, and mild TR with an estimated peak RV pressure of 40 mm Hg. At 24 months follow-up, the patient is asymptomatic, in excellent general condition, on oral therapy with digoxin (0.25 mg daily) and enalapril (5 mg daily); she has gained 9 kg of weight since her discharge from the hospital, and her tolerance of physical effort has increased so that she has started mild gym under medical control (New York Heart Association functional class I). Cardiothoracic ratio is Two-dimensional echocardiography and color flow Doppler shows normal LV systolic function (EF 0.69), and a LV volume within normal limits (EDV 70 ml/m 2 ; Fig 2). In addition, there is a mild degree of aortic regurgitation, with a persistent mild TR (1 /3). Baseline electrocardiogram shows sinus rhythm; electrocardiogram Holter and exercise tolerance test are within normal limits. Occasional episodes of supraventricular tachycardia are treated periodically with diltiazem (60 mg T.I.D). Comment Right ventricular dysfunction after atrial TGA repair occurs in about 10% of patients within 10 years from operation [1 4]. Long-term survival after atrial switch procedure is acceptably good; however, in the majority of patients, RV function shows abnormal response to afterload stress as short as 1 year postoperatively [8]. Causes for RV failure after atrial inversion are poorly understood. Van Praagh [9] postulates that the embryological

4 1756 REVIEW PADALINO ET AL Ann Thorac Surg ARTERIAL SWITCH OPERATION IN THE ADULT 2000;70: Fig 1. The 2D-echo studies performed before and after pulmonary artery banding, and after ASO demonstrate an immediate improvement of RV function immediately after banding, while LV function, which is acutely depressed soon after banding, gradually improves during retraining, and increases until reaching normal values after 24 months from ASO. (ASO arterial switch operation; EF ejection fraction; LV left ventricle; RV right ventricle.) origins of the morphological RV make it less efficient than the LV in supporting the systemic circulation. Conversion to anatomic repair after adequate LV retraining has been proven to be a successful alternative to cardiac transplantation [1 4]. A two-stage ASO for TGA was initially reported in 1977 by Yacoub and coworkers [10] as a treatment for those case with unprepared LV. However, there are several fundamental differences in the conduct of a two-stage anatomic correction between the unrepaired cyanotic infants with TGA and older children with prior atrial switch, which have been previously outlined [11]. In 1986, Mee reported the first 2 cases of successful conversion of atrial to arterial switch repair after LV retraining [2]. Guidelines for suitability for arterial switch conversion have been fully described by Cochrane and colleagues [3], who updated Mee s experience on 20 patients, the oldest of whom was 16.5 years. Subsequent experience in Mee s group updated to 1998 [4] did not report any survivor converted after the age of Fig 2. The 2D-echo studies performed before and after pulmonary artery banding, and after ASO demonstrate a reduction of RV size and an acute dilation of the LV after ASO, which returns to nearly normal value after 24 months. (ASO arterial switch operation; EDV end diastolic volume; LV left ventricle; RV right ventricle.) 15 years. Change and associates [11], in 1992, reported on indications to ASO or cardiac transplantation for RV failure after atrial switch procedure. In this group of 5 patients addressed to LV retraining, none of them was older than 12 years. In van Son s series of five patients [12], a 24-year-old male entered the program, but ASO could not be performed after the PAB (Table 1). From different groups experience with LV retraining [1 4, 11 13] and double-switch repair for corrected TGA [4, 11 16], it seems that better results are achieved in younger patients. Di Donato and colleagues [5] raise concern regarding the capacity of the mature myocardium to respond to pressure overload, and question the efficacy of ASO in older children and adults after PAB. Some authors consider the age of 11 years or older as an important risk factor [15]. Bearing this in mind, we can speculate that the longest the morphological LV works at low pulmonary pressure, the lower is the capability for inducing LV hypertrophy. However, there is little information as to just how late arterial switching can be successfully performed [5]. In our experience, a moderate degree of pulmonary hypertension might have played an important role in preserving some degree of LV hypertrophy. The importance of chronic pressure overload in stimulating adequate ventricular hypertrophy can possibly be supported by the previously reported experience of De Jong and coworkers [17], and by other reported clinical experiences of ASO in adult age [18, 19], in which a PAB was applied in infancy. Twenty-four months after ASO, two-dimensional echocardiographic monitoring has demonstrated that LV and RV still maintain a good ventricular function (LVEF: 0.69, RVEF: 0.65; Fig 1), and RVEDV is reduced (125 ml/m2 versus 152 ml/m 2 before banding; Fig 2). It is interesting to note that the moderate degree of LV dilatation, which we observed in the early period follow-up after ASO, is no longer present at 24 months follow-up (70 ml/m 2 ; Fig 2). We can explain this as an adaptive response of the LV geometry to systemic resistances, rather than due to aortic regurgitation, which has constantly remained mild. We do agree with Helvind and associates [4] in stating that probably not all ventricles are retrainable. However, a preliminary unpublished study at our Institution on hystologic sections obtained from heart specimens with TGA have showed that, despite age older than 18 at death, the morphological LV maintains a degree of hypertrophy which is comparable to normal LV. In conclusion, we think that the result of this case is important for selecting a subset of patients with systemic RV dysfunction after atrial switch procedure and with preserved LV contractility, who, despite their older age, can be addressed to LV retraining for ASO as an alternative choice to cardiac transplantation. Wider experience and further evaluation of mid-long-term performance of the retrained LV is necessary to verify the effectiveness of this approach.

5 Ann Thorac Surg REVIEW PADALINO ET AL 2000;70: ARTERIAL SWITCH OPERATION IN THE ADULT 1757 The authors gratefully acknowledge Roger B.B. Mee, MD, for his support during the patient s treatment, and Maurizio Rubino, MD, for his tireless help in postoperative care of the patient. References 1. Mee RBB. Arterial switch for right ventricular failure following Mustard or Senning operations. In: Stark J, Pacifico AD, eds. Reoperations in cardiac surgery. New York: Springer- Verlag, 1989: Mee RBB. Severe right ventricular failure after Mustard or Senning operation. Two-stage repair: pulmonary artery banding and switch. J Thorac Cardiovasc Surg 1986;92: Cochrane AD, Karl TR, Mee RBB. Staged conversion to arterial switch for late failure of the systemic right ventricle. Ann Thorac Surg 1993;56: Helvind MH, McCarthy JF, Imamura M, et al. Ventriculoarterial discordance: switching the morphologically left ventricle into the systemic circulation after 3 months of age. Eur J Cardiothorac Surg 1998;14: Di Donato RM, Fujii AM, Jonas RA, Castaneda AR. Age dependent ventricular response to pressure overload. Considerations for the arterial switch operation. J Thorac Cardiovasc Surg 1992;104: Levine RA, Gibson TC, Aretz T, et al. Echocardiographic measurement of right ventricular volume. Circulation 1984; 69: Feigenbaum H. Appendix. In: Feigenbaum H, ed. Echocardiography. Philadelphia: Lea & Febiger, 1994: Bender HW Jr, Stewart JR, Merrill WH, Hammon JW Jr, Graham TP Jr. Ten years experience with the Senning operation for transposition of the great arteries: physiological results and late follow-up. Ann Thorac Surg 1989;47: Van Praagh R. Transposition of the great arteries: history, pathologic anatomy, embriology, etiology, and surgical considerations. In: Mavroudis C, Backer CL, eds. The state of the art reviews in cardiac surgery: the arterial switch operation. Philadelphia: Hanley and Belfus, 1991: Yacoub MH, Radley-Smith R, Maclaurin R. Two stage operation for anatomical correction of transposition of the great arteries with intact ventricular septum. Lancet 1977;1: Chang AC, Wernovsky G, Wessel DL, et al. Surgical management of late right ventricular failure after Mustard or Senning repair. Circulation 1992;86: Van Son JAM, Reddy VM, Silvermann NH, Hanley FL. Regression of tricuspid regurgitation after two-stage arterial switch operation for failing systemic ventricle after atrial inversion operation. J Thorac Cardiovasc Surg 1996;111: Reddy VM, McElhinney DB, Silverman NH, Hanley F. The double switch procedure for anatomical repair of congenitally corrected transposition of the great arteries in infants and children. Eur Heart J 1997;18: Imai Y, Sawatari K, Hoshino S, Ishihara K, Nakazawa M, Momma K. Ventricular function after anatomic repair in patients with atrioventricular discordance. J Thorac Cardiovasc Surg 1994;107: Yamagishi M, Imai Y, Ishihara K, et al. Anatomic correction of atrioventricular discordance. J Thorac Cardiovasc Surg 1993;105: Stumper O, Wright JGC, De Giovanni JV, Silove ED, Sethia B, Brawn WJ. Combined atrial and arterial switch procedure for congenital corrected transposition with ventricular septal defect. Br Heart J 1995;73: De Jong PL, Bogers JJC, Witsenburg M, Bos E. Arterial switch for pulmonary venous obstruction complicating Mustard procedure. Ann Thorac Surg 1995;59: Trehan H, Ott DA. Arterial switch procedure in an adult. Ann Thorac Surg 1991;51: Alexi-Meskishvili V, Uhlemann F, Berger F, Lange PE, Hetzer R. Development of subneopulmonary obstruction early after arterial switch operation in an adult. Ann Thorac Surg 1996;61: