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Palliative arterial repair for transposition, ventricular septal defect, and pulmonary vascular disease
Palliative Arterial Repair for Transposition, Ventricular Septa1 Defect, and Pulmonary Vascular Disease Ara K. Pridjian, MD, Theresa A. Tacy, MD, Douglas Teske, MD, and Edward L. Bove, MD Section of Thoracic Surgery, Department of Surgery, and Division of Pediatric Cardiology, Department of Pediatrics, C. S. Mott Children‘s Hospital, The University of Michigan Medical Center, Ann Arbor, Michigan; and Division of Pediatric Cardiology, Department of Pediatrics, Columbus Children’s Hospital, Ohio State University Medical School, Columbus, Ohio
Failure to repair transposition of the great arteries and ventricular septal defect in the young infant results in the early development of pulmonary vascular occlusive disease. Complete repair, preferably by an arterial switch procedure and ventricular septal defect closure, may then not be possible. We report a palliative arterial switch procedure in a 5%-year-old patient with transposition, ventricular septal defect, and severe pulmonary vascular obstructive disease in whom progressive hypoxemia and
exercise intolerance developed. An arterial repair without ventricular septal defect closure was performed. After the operation, the child’s systemic arterial oxygen saturation and exercise tolerance have substantially improved. Although the progression of pulmonary vascular disease may not be altered, arterial repair can provide effective palliation in this subset of patients.
D
The findings at operation demonstrated the typical arrangement of the great vessels with the aorta anterior and slightly rightward of the pulmonary artery. The band was situated distally with mild deformity of the right and left branch pulmonary arteries. The coronary arrangement was unusual with the right coronary artery and the left anterior descending coronary artery originating from a common orifice in sinus 1 and the circumflex coronary artery originating from sinus 2 (lL,R; 2C). Arterial repair was performed in the standard fashion as previously described [l].The atrial septal defect was closed with a patch, and the VSD was not repaired. The patient was easily weaned from cardiopulmonary bypass. The postoperative hemodynamic course was unremarkable. The patient was extubated on the second postoperative day and was discharged from the hospital on the seventh postoperative day. At the 4-month follow-up visit, the patient demonstrated improved exercise tolerance. Oxygen saturation measured transcutaneously was 93%.
irect arterial repair in the neonatal period is the preferred method of correction for most patients with simple and complex forms of d-transposition of the great arteries (TGA). Delayed diagnosis or concurrent illness, however, may preclude early repair. In patients with transposition and ventricular septal defect (VSD) this delay can result in pulmonary vascular obstructive disease (PVOD), making total correction impossible. In the past, palliation for patients with TGA and VSD who have PVOD has been achieved with atrial repair by the Mustard or Senning procedure, leaving the VSD open. We report herein application of the arterial switch operation without VSD closure as effective palliation for a patient with TGA and VSD with advanced PVOD. A 5Yz-year-old girl was seen with progressive cyanosis, dyspnea, and congestive heart failure. She was first seen at 6 months of age and was found to have TGA, VSD, and atrial septal defect. Because the right ventricle appeared slightly hypoplastic on her initial echocardiogram she underwent pulmonary artery banding instead of arterial repair. Repeat cardiac catheterization at 5 years of age demonstrated that the band was ineffective as pulmonary artery pressure distal to the band was nearly systemic. Calculated pulmonary vascular resistance was 22 Wood units in room air and 19 Wood units in 100% inspired oxygen. Systemic arterial oxygen saturation in room air was 71%, and the pulmonary artery saturation was 83%. Accepted for publication Nov 14, 1991 Address reprint requests to Dr Bove, Section of Thoracic Surgery, The University of Michigan, 1500 E Medical Center Dr, Box 0344, 2120 Taubman Center, Ann Arbor, MI 48109.
0 1992 by The Society of Thoracic Surgeons
(Ann Tkorac Surg 1992;54:355-6)
Comment Atrial repair by the method of Mustard or Senning is a well-established means of palliation for the infant with d-TGA, VSD, and PVOD [2, 31. Palliation has also been accomplished with atrial septectomy and by relocation of the atrial septum to the opposite side of the right pulmonary veins [3, 41. The mortality for arterial switch in selected centers is less than 5% to lo%, comparable with that of atrial switch procedures [5]. Low mortality has also been achieved for TGA with VSD [6]. Because of fewer late arrhythmias, 0003-4975/92/$5.00
356
CASE REPORT PRIDJIAN ET AL PALLIATIVE ARTERIAL SWITCH OPERATION
better long-term preservation of systemic ventricular function, and avoidance of the complication of systemic venous obstruction from an intraatrial baffle, arterial switch is a more durable option than atrial switch, and is now the procedure of choice for neonates with transposition [5, 71. For these reasons, we believed that arterial repair would provide better long-term palliation than atrial repair for this patient. The feasibility of the arterial switch operation performed at any age is predicated on preservation of left ventricular mass and chamber volume and prevention of PVOD. The former conditions are satisfied when concomitant defects result in left ventricular volume or pressure loading, whereas the latter depends on obstruction to left ventricular outflow. Because a nonrestrictive VSD maintains left ventricular volume and pressure, primary arterial repair may be performed beyond the neonatal period when diagnosis is delayed or when other congenital anomalies or illness preclude early repair. However, the period of temporizing is limited as PVOD develops in as many as 25% of children by 3 months of age [8]. For this reason we and others have previously recommended definitive arterial repair with VSD closure by 1 month of age [61. As in patients who have received the palliative Mustard operation, our patient demonstrated a gain in systemic oxygen saturation greater than would be expected by simple reversal of pulmonary and systemic saturations [2]. With TGA and VSD, blood in the left ventricular outflow tract is made up of fully saturated pulmonary venous blood and desaturated systemic venous blood shunted across the VSD. The relative amounts of saturated and desaturated blood determine oxygen saturation in the left ventricular outflow tract. Before repair, systemic venous blood recirculating directly to the aorta becomes thoroughly deoxygenated by the time it returns to the right atrium. After repair, the saturation of systemic venous blood increases because there is less recirculating desaturated blood in the systemic vascular bed. There is no appreciable change in the saturation of pulmonary venous blood or the proportion of saturated to desaturated blood in the left ventricular outflow tract. Thus, the saturation of the systemic venous blood that crosses the VSD is higher than before repair, resulting in higher left ventricular outflow tract (systemic) oxygen saturation. The pulmonary vascular resistance is a crucial parameter in deciding whether palliation or total correction is appropriate when treatment is delayed beyond the neo-
Ann Thorac Surg 1992;54:3554
natal period. When the resistance is 5 Wood units or less, we perform total correction with arterial switch and VSD closure. When the resistance is 10 units or more, we perform palliative arterial switch, leaving the VSD open. When resistance is between 5 and 10 units, ”reversibility” of elevated pulmonary vascular resistance, determined by response to 100% oxygen, is assessed. If there is a substantial reduction in pulmonary vascular resistance, total repair is attempted. The ventricular septal patch can be perforated or removed if the patient demonstrates hemodynamic compromise after repair. The net hemodynamic effect of the palliative arterial switch operation is to increase systemic oxygen saturation. The Eisenmenger’s physiology is not changed and the progression of pulmonary vascular disease is probably not altered. Obviously total correction in the neonate is preferred, given the demonstrated safety and durability of the arterial switch operation and the mounting experience with complex forms of transposition. However, when the opportunity for early repair is missed and pulmonary vascular disease develops, the arterial switch operation can provide effective palliation.
References 1. Bove E. Current technique of the arterial switch procedure for transposition of the great arteries. J Cardiac Surg 1989;4:19>9. 2. Bernhard WF, Dick M, Sloss LJ, Castaneda AR, Nadas AS. The palliative Mustard operation for double outlet right ventricle or transposition of the great arteries associated with ventricular septal defect, pulmonary arterial hypertension, and pulmonary vascular obstructive disease. Circulation 1976;
54:81&7. 3. Lindesmith GG, Stiles QR, Tucker BL, Gallaher ME, Stanton RE, Meyer BW. The Mustard operation as a palliative procedure. J Thorac Cardiovasc Surg 1972;63:75-80. 4. Rosenthal A, Freed MD, Litwin SB, Bernhard WF. Atrial septectomy in patients with d-transposition of the great arteries, ventricular septal defect, and severe pulmonary vascular obstructive disease. Circulation 1974;49,5O(Suppl2):35-8. 5. Backer CL, Ilbawi MN, Ohtake S, et al. Transposition of the great arteries: a comparison of results of the Mustard procedure versus the arterial switch. Ann Thorac Surg 1989;48:10-4. 6. Bove EL, Beekman RH, Snider RA, et al. Arterial repair for transposition of the great arteries and large ventricular septal defect in early infancy. Circulation 1988;78(Suppl3):26-31. 7. Hayes CJ, Gersony WM. Arrhythmias after the Mustard operation for transposition of the great arteries: a long term study. J Am Coll Cardiol 1986;7:13>7. 8. Clarkson PM, Neutze JM, Wardhill JC, Barratt-Boyes BG. The pulmonary vascular bed in patients with complete transposition of the great arteries. Circulation 1976;53:539-43.
Failure to repair transposition of the great arteries and ventricular septal defect in the young infant results in the early development of pulmonary vascular occlusive disease. Complete repair, preferably by an arterial switch procedure and ventricular septal defect closure, may then not be possible. We report a palliative arterial switch procedure in a 5%-year-old patient with transposition, ventricular septal defect, and severe pulmonary vascular obstructive disease in whom progressive hypoxemia and
exercise intolerance developed. An arterial repair without ventricular septal defect closure was performed. After the operation, the child’s systemic arterial oxygen saturation and exercise tolerance have substantially improved. Although the progression of pulmonary vascular disease may not be altered, arterial repair can provide effective palliation in this subset of patients.
D
The findings at operation demonstrated the typical arrangement of the great vessels with the aorta anterior and slightly rightward of the pulmonary artery. The band was situated distally with mild deformity of the right and left branch pulmonary arteries. The coronary arrangement was unusual with the right coronary artery and the left anterior descending coronary artery originating from a common orifice in sinus 1 and the circumflex coronary artery originating from sinus 2 (lL,R; 2C). Arterial repair was performed in the standard fashion as previously described [l].The atrial septal defect was closed with a patch, and the VSD was not repaired. The patient was easily weaned from cardiopulmonary bypass. The postoperative hemodynamic course was unremarkable. The patient was extubated on the second postoperative day and was discharged from the hospital on the seventh postoperative day. At the 4-month follow-up visit, the patient demonstrated improved exercise tolerance. Oxygen saturation measured transcutaneously was 93%.
irect arterial repair in the neonatal period is the preferred method of correction for most patients with simple and complex forms of d-transposition of the great arteries (TGA). Delayed diagnosis or concurrent illness, however, may preclude early repair. In patients with transposition and ventricular septal defect (VSD) this delay can result in pulmonary vascular obstructive disease (PVOD), making total correction impossible. In the past, palliation for patients with TGA and VSD who have PVOD has been achieved with atrial repair by the Mustard or Senning procedure, leaving the VSD open. We report herein application of the arterial switch operation without VSD closure as effective palliation for a patient with TGA and VSD with advanced PVOD. A 5Yz-year-old girl was seen with progressive cyanosis, dyspnea, and congestive heart failure. She was first seen at 6 months of age and was found to have TGA, VSD, and atrial septal defect. Because the right ventricle appeared slightly hypoplastic on her initial echocardiogram she underwent pulmonary artery banding instead of arterial repair. Repeat cardiac catheterization at 5 years of age demonstrated that the band was ineffective as pulmonary artery pressure distal to the band was nearly systemic. Calculated pulmonary vascular resistance was 22 Wood units in room air and 19 Wood units in 100% inspired oxygen. Systemic arterial oxygen saturation in room air was 71%, and the pulmonary artery saturation was 83%. Accepted for publication Nov 14, 1991 Address reprint requests to Dr Bove, Section of Thoracic Surgery, The University of Michigan, 1500 E Medical Center Dr, Box 0344, 2120 Taubman Center, Ann Arbor, MI 48109.
0 1992 by The Society of Thoracic Surgeons
(Ann Tkorac Surg 1992;54:355-6)
Comment Atrial repair by the method of Mustard or Senning is a well-established means of palliation for the infant with d-TGA, VSD, and PVOD [2, 31. Palliation has also been accomplished with atrial septectomy and by relocation of the atrial septum to the opposite side of the right pulmonary veins [3, 41. The mortality for arterial switch in selected centers is less than 5% to lo%, comparable with that of atrial switch procedures [5]. Low mortality has also been achieved for TGA with VSD [6]. Because of fewer late arrhythmias, 0003-4975/92/$5.00
356
CASE REPORT PRIDJIAN ET AL PALLIATIVE ARTERIAL SWITCH OPERATION
better long-term preservation of systemic ventricular function, and avoidance of the complication of systemic venous obstruction from an intraatrial baffle, arterial switch is a more durable option than atrial switch, and is now the procedure of choice for neonates with transposition [5, 71. For these reasons, we believed that arterial repair would provide better long-term palliation than atrial repair for this patient. The feasibility of the arterial switch operation performed at any age is predicated on preservation of left ventricular mass and chamber volume and prevention of PVOD. The former conditions are satisfied when concomitant defects result in left ventricular volume or pressure loading, whereas the latter depends on obstruction to left ventricular outflow. Because a nonrestrictive VSD maintains left ventricular volume and pressure, primary arterial repair may be performed beyond the neonatal period when diagnosis is delayed or when other congenital anomalies or illness preclude early repair. However, the period of temporizing is limited as PVOD develops in as many as 25% of children by 3 months of age [8]. For this reason we and others have previously recommended definitive arterial repair with VSD closure by 1 month of age [61. As in patients who have received the palliative Mustard operation, our patient demonstrated a gain in systemic oxygen saturation greater than would be expected by simple reversal of pulmonary and systemic saturations [2]. With TGA and VSD, blood in the left ventricular outflow tract is made up of fully saturated pulmonary venous blood and desaturated systemic venous blood shunted across the VSD. The relative amounts of saturated and desaturated blood determine oxygen saturation in the left ventricular outflow tract. Before repair, systemic venous blood recirculating directly to the aorta becomes thoroughly deoxygenated by the time it returns to the right atrium. After repair, the saturation of systemic venous blood increases because there is less recirculating desaturated blood in the systemic vascular bed. There is no appreciable change in the saturation of pulmonary venous blood or the proportion of saturated to desaturated blood in the left ventricular outflow tract. Thus, the saturation of the systemic venous blood that crosses the VSD is higher than before repair, resulting in higher left ventricular outflow tract (systemic) oxygen saturation. The pulmonary vascular resistance is a crucial parameter in deciding whether palliation or total correction is appropriate when treatment is delayed beyond the neo-
Ann Thorac Surg 1992;54:3554
natal period. When the resistance is 5 Wood units or less, we perform total correction with arterial switch and VSD closure. When the resistance is 10 units or more, we perform palliative arterial switch, leaving the VSD open. When resistance is between 5 and 10 units, ”reversibility” of elevated pulmonary vascular resistance, determined by response to 100% oxygen, is assessed. If there is a substantial reduction in pulmonary vascular resistance, total repair is attempted. The ventricular septal patch can be perforated or removed if the patient demonstrates hemodynamic compromise after repair. The net hemodynamic effect of the palliative arterial switch operation is to increase systemic oxygen saturation. The Eisenmenger’s physiology is not changed and the progression of pulmonary vascular disease is probably not altered. Obviously total correction in the neonate is preferred, given the demonstrated safety and durability of the arterial switch operation and the mounting experience with complex forms of transposition. However, when the opportunity for early repair is missed and pulmonary vascular disease develops, the arterial switch operation can provide effective palliation.
References 1. Bove E. Current technique of the arterial switch procedure for transposition of the great arteries. J Cardiac Surg 1989;4:19>9. 2. Bernhard WF, Dick M, Sloss LJ, Castaneda AR, Nadas AS. The palliative Mustard operation for double outlet right ventricle or transposition of the great arteries associated with ventricular septal defect, pulmonary arterial hypertension, and pulmonary vascular obstructive disease. Circulation 1976;
54:81&7. 3. Lindesmith GG, Stiles QR, Tucker BL, Gallaher ME, Stanton RE, Meyer BW. The Mustard operation as a palliative procedure. J Thorac Cardiovasc Surg 1972;63:75-80. 4. Rosenthal A, Freed MD, Litwin SB, Bernhard WF. Atrial septectomy in patients with d-transposition of the great arteries, ventricular septal defect, and severe pulmonary vascular obstructive disease. Circulation 1974;49,5O(Suppl2):35-8. 5. Backer CL, Ilbawi MN, Ohtake S, et al. Transposition of the great arteries: a comparison of results of the Mustard procedure versus the arterial switch. Ann Thorac Surg 1989;48:10-4. 6. Bove EL, Beekman RH, Snider RA, et al. Arterial repair for transposition of the great arteries and large ventricular septal defect in early infancy. Circulation 1988;78(Suppl3):26-31. 7. Hayes CJ, Gersony WM. Arrhythmias after the Mustard operation for transposition of the great arteries: a long term study. J Am Coll Cardiol 1986;7:13>7. 8. Clarkson PM, Neutze JM, Wardhill JC, Barratt-Boyes BG. The pulmonary vascular bed in patients with complete transposition of the great arteries. Circulation 1976;53:539-43.