Cryopreserved Allograft Repair of Aortic Hypoplasia and Interrupted Aortic Arch John A. St. Cyr, MD, PhD, David N. Campbell, MD, David A. Fullerton, MD, Michael Grosso, MD, Deborah A. Bishop, BS, and David R. Clarke, MD Cardiothoracic Surgery, University of Colorado Health Sciences Center, The Children’s Hospital, Denver, Colorado
Mortality for interruption of the aortic arch approaches 100% within the first year of life if untreated. Prostaglandin Elcan stabilize the patient’s condition in anticipation of surgical palliation, but total repair is required for long-term survival. Successful complete repair of type B
I
Interruption of the aortic arch comprises 1.4% of all congenital cardiac lesions [l].If the anomaly is untreated, mortality approaches 100%within the first year of life [2, 31. Intravenous prostaglandin E, is crucial in maintaining ductal patency, thereby avoiding or reversing metabolic acidosis in the newborn period. To support extended survival, surgical intervention is required. Substantial operative mortality is associated with palliation and with complete repair in the neonate. If palliation is chosen, it usually consists of reconstruction of the interrupted aortic arch and pulmonary artery (PA) banding. Innovative surgical repair with a cryopreserved aortic valve allograft was accomplished in a child who had previously undergone an unusual method of palliation secondary to his small size and associated lesions. A 1,500-g premature male infant was born with hypoplasia of the aortic valve annulus, root, and ascending aorta; interrupted aortic arch; aberrant right subclavian artery; patent ductus arteriosus; and a large ventricular septal defect (VSD). Because of his small size, the neonate underwent placement of a synthetic graft conduit from the main PA to the descending thoracic aorta and banding of the distal main PA. At 2 years of age, total surgical repair was attempted. Intraoperatively, conventional complete repair was impossible due to extreme hypoplasia of the left ventricular outflow tract. Because cardiac transplantation was deemed the only other alternative, the child was referred for placement of an aortic valve allograft to establish adequate left ventricular outflow and aortic arch continuity. Preoperatively, the child was mildly cyanotic with minimal clubbing and normal vital signs. Auscultation revealed a systolic murmur along the left sternal border. Laboratory values and further physical examination were within normal limits. Accepted for publication Oct 10, 1991. Address reprint requests to Dr Clarke, Cardiothoracic Surgery, 8200, The Children‘s Hospital, 1056 E 19th Ave, Denver, CO 80218.
0 1992 by The Society of Thoracic Surgeons
interrupted aortic arch, hypoplasia of the left ventricular outflow tract, and ventricular septal defect was possible using a cryopreserved allograft in a child who previously had undergone unusual palliation. (Ann Thorac Surg 1992;53:1110-3)
In the operating room, the chest was reopened and dense adhesions were dissected. After systemic heparinization, bicaval and dual arterial cannulation was accomplished and cardiopulmonary bypass with immediate cooling was instituted. An apical left ventricular vent was inserted and a cardioplegia administration catheter was placed into the proximal aorta. The synthetic PA to descending aorta graft was ligated and divided proximal to the cannula (Fig 1A). The main PA was resected distal to the band and proximal to the synthetic graft anastomosis. The stenotic origin of the right PA was then incised longitudinally. The transected ends of the main PA were anastomosed, enlarging the right PA orifice (Fig 1B). A cryopreserved aortic valve allograft with 14 mm internal diameter was chosen to create a new left ventricular outflow tract. The allograft left carotid and subclavian arteries were trimmed flush with the conduit and sutured closed. End-to-end anastomosis was performed between the distal allograft conduit and native descending thoracic aorta. The aorta was cross-clamped, and cold sanguineous cardioplegia was administered. A right ventriculotomy was performed. The ascending aorta was carefully transected immediately above the valve proximal to the coronary ostia and closed as a blind pouch. The small bicuspid aortic valve and subvalvar aortic membrane were resected. The annulus and subvalvar area were opened into the VSD (Fig 1C). The interventricular septum was augmented with a polytetrafluoroethylene patch sutured anteriorly, inferiorly, and posteriorly. Running suture was used to anastomose the proximal aortic valve allograft to the patient’s aortic annular region posteriorly. The superior aspect of the VSD patch was sutured to the anterior muscular rim of the allograft (Fig 2A). The open brachiocephalic ostium remaining in the allograft conduit was extended proximally with a longitudinal incision. Tourniquets were tightened around the native arch vessels. A 15-mm longitudinal aortotomy was 0003-4975/92/$5.00
CASE REPORT ST. CYR ET AL ALLOGRAFT REPAIR OF AORTIC HYPOPLASIA
Ann Thorac Surg 1992;53:1110-3
A
1111
B
Fig 1 . The graft conduit is taken down, followed by resection and reanastomosis of the pulmonary artery band. The ascending aorta is detached and closed below the coronary arteries and the allograft is attached to the descending thoracic aorta. (Reprinted by permission of the publisher from: Clarke DR, Campbell DN, Bishop DA. Homografts for congenital heart disease. In. Cardiac surgery: state of the art reviews. Hanley b Belfus, 1989;3:363-79.)
C
made directly opposite the allograft conduit incision. The allograft and native ascending aorta were anastomosed side to side. The cannula was removed from the distal synthetic graft; which was amputated and oversewn (Fig 2B). The ascending aortic cannula was used to reestablish circulation, and rewarming was begun. Tourniquets were removed and warm blood cardioplegia was administerhd. The aortic cross-clamp was removed and cardiac rhythm returned spontaneously. A triangular patch of polytetrafluoroethylene was used to close the right ventriculotomy (Fig 2C). The child was weaned from cardiopulmonary bypass and decannulated in standard manner. Chest tubes were placed and the sternotomy was closed. The patient's postoperative course was complicated.
Multiple arrhythmias were treated unsuccessfully with digoxin, procainamide, and intermittent pacing. Control of arrhythmias was obtained with hypothermia and, later, flecainide acetate. Ventilation was problematic. Right PA stenosis had created a chronic discrepancy in right and left lung vascular resistance, and the physiologic shunt resulted in decreased oxygenation. A ventilationperfusion study confirmed a substantial mismatch; the right lung received a majority of blood flow whereas the left lung was better ventilated. Serial chest roentgenograms revealed an elevated left hemidiaphragm that required surgical plication. Vigorous pulmonary care and nutritional support ultimately enabled the patient to be weaned from the ventilator and extubated. One year postoperatively, cardiac catheterization revealed a func-
1112
CASE REPORT ST. CYR ET AL ALLOGRAFT REPAIR OF AORTIC HYPOPLASIA
Ann Thorac Surg 1992;s:11103
A B
Fig 2. The ascending aorta and aortic allograft are anastomosed side to side. The allograft is used to create a new left ventricular outflow tract. (Reprinted by permission of the publisher from: Clarke DR, Campbell ON,Bishop DA. Homografts for congenital heart disease. In: Cardiac surgery: state of the art reuims. Hanley b Belfus, 1989; 3:363-79.)
C
tional repair. The child remains asymptomatic 34 months after operation.
Comment Interrupted aortic arch is associated with other cardiac anomalies. Concurrent lesions include VSD most commonly, pulmonary stenosis, truncus arteriosus, or aortopulmonary window [l, 21. A bicuspid aortic valve is present in one third of the patients (41. The most prevalent anomaly combination consists of type B interruption of the aortic arch, VSD, patent ductus arteriosus, and left ventricular outflow hypoplasia and is considered a lethal lesion if the obstruction is severe. These children commonly are seen as neonates with severe congestive heart failure. The bleak prognosis has lead to controversy over
the optimal course of medical or surgical management, both immediate and long-term. Initial stabilization can be accomplished with prostaglandin El but operation provides the only chance for long-term survival. Palliative operation generally consists of arch repair with concomitant patent ductus arteriosus ligation and banding of the PA, which provides the opportunity for subsequent growth of the ieft ventricular outflow tract and ascending aorta. When this does not occur, the left ventricular outflow tract remains small and requires extensive reconstruction or replacement. Banding the main PA may distort the vessel and increase the risk of subsequent surgical procedures [5] or can aggravate existing subvalvar aortic stenosis [l].The case herein illustrates migration of the PA band producing
Ann Thorac Surg 1992;53:111m
unilateral right PA stenosis [6]. Pulmonary arterioplasty reestablished blood flow to a low-resistance lung and resulted in unilateral pulmonary edema, ventilationperfusion mismatch, a n d severe hypoxia. Stringent pulmonary care with modified postural drainage maneuvers are imperative for facilitation of ventilator management. Complete repair in a 2-year-old child with aortic hypoplasia, VSD, and a type B interrupted aortic arch was performed using a cryopreserved aortic allograft valve conduit. Allografts have been used in the repair of cardiac anomalies since 1956 [7]. Herein their use has been extended to successfully repair a potentially lethal congenital heart lesion.
References 1. Van Praagh R, Bernhard WF, Rosenthal A, Parisi LF, Fyler
DC. Interrupted aortic arch: surgical treatment. Am J Cardiol 1971;27:200-11.
CASE REPORT ST. CYR ET AL ALLOGRAFT REPAIR OF AORTIC HYPOPLASIA
1113
2. Moller JH, Edwards JE. Interruption of aortic arch; anatomic
patterns and associated cardiac malformations. Am J Roentgenol Radium Ther Nucl Med 1965;95:557-72. 3. Roberts WC, Morrow AG, Braunwald E. Complete interruption of the aortic arch. Circulation 1962;26:39-59. 4. Moulton AL, Bowman FO Jr. Primary definitive repair of type B interrupted aortic arch, ventricular septa1 defect, and patent ductus arteriosus. Early and late results. J Thorac Cardiovasc Surg 1981;82:501-10. 5. Turley K, Yee ES, Ebert PA. The total repair of interrupted arch complex in infants: the anterior approach. Circulation 1984;70(Suppl 1):16-20. 6. Durmowicz AG, St.Cyr JA, Clarke DR, Stenmark KR. Unilateral pulmonary hypertension as a result of chronic high flow to one lung. Am Rev Respir Dis 1990;142:2303. 7. Murray G. Homologous aortic-valve-segment transplants as surgical treatment for aortic and mitral insufficiency. Angiology 1956;746671.
Mortality for interruption of the aortic arch approaches 100% within the first year of life if untreated. Prostaglandin Elcan stabilize the patient’s condition in anticipation of surgical palliation, but total repair is required for long-term survival. Successful complete repair of type B
I
Interruption of the aortic arch comprises 1.4% of all congenital cardiac lesions [l].If the anomaly is untreated, mortality approaches 100%within the first year of life [2, 31. Intravenous prostaglandin E, is crucial in maintaining ductal patency, thereby avoiding or reversing metabolic acidosis in the newborn period. To support extended survival, surgical intervention is required. Substantial operative mortality is associated with palliation and with complete repair in the neonate. If palliation is chosen, it usually consists of reconstruction of the interrupted aortic arch and pulmonary artery (PA) banding. Innovative surgical repair with a cryopreserved aortic valve allograft was accomplished in a child who had previously undergone an unusual method of palliation secondary to his small size and associated lesions. A 1,500-g premature male infant was born with hypoplasia of the aortic valve annulus, root, and ascending aorta; interrupted aortic arch; aberrant right subclavian artery; patent ductus arteriosus; and a large ventricular septal defect (VSD). Because of his small size, the neonate underwent placement of a synthetic graft conduit from the main PA to the descending thoracic aorta and banding of the distal main PA. At 2 years of age, total surgical repair was attempted. Intraoperatively, conventional complete repair was impossible due to extreme hypoplasia of the left ventricular outflow tract. Because cardiac transplantation was deemed the only other alternative, the child was referred for placement of an aortic valve allograft to establish adequate left ventricular outflow and aortic arch continuity. Preoperatively, the child was mildly cyanotic with minimal clubbing and normal vital signs. Auscultation revealed a systolic murmur along the left sternal border. Laboratory values and further physical examination were within normal limits. Accepted for publication Oct 10, 1991. Address reprint requests to Dr Clarke, Cardiothoracic Surgery, 8200, The Children‘s Hospital, 1056 E 19th Ave, Denver, CO 80218.
0 1992 by The Society of Thoracic Surgeons
interrupted aortic arch, hypoplasia of the left ventricular outflow tract, and ventricular septal defect was possible using a cryopreserved allograft in a child who previously had undergone unusual palliation. (Ann Thorac Surg 1992;53:1110-3)
In the operating room, the chest was reopened and dense adhesions were dissected. After systemic heparinization, bicaval and dual arterial cannulation was accomplished and cardiopulmonary bypass with immediate cooling was instituted. An apical left ventricular vent was inserted and a cardioplegia administration catheter was placed into the proximal aorta. The synthetic PA to descending aorta graft was ligated and divided proximal to the cannula (Fig 1A). The main PA was resected distal to the band and proximal to the synthetic graft anastomosis. The stenotic origin of the right PA was then incised longitudinally. The transected ends of the main PA were anastomosed, enlarging the right PA orifice (Fig 1B). A cryopreserved aortic valve allograft with 14 mm internal diameter was chosen to create a new left ventricular outflow tract. The allograft left carotid and subclavian arteries were trimmed flush with the conduit and sutured closed. End-to-end anastomosis was performed between the distal allograft conduit and native descending thoracic aorta. The aorta was cross-clamped, and cold sanguineous cardioplegia was administered. A right ventriculotomy was performed. The ascending aorta was carefully transected immediately above the valve proximal to the coronary ostia and closed as a blind pouch. The small bicuspid aortic valve and subvalvar aortic membrane were resected. The annulus and subvalvar area were opened into the VSD (Fig 1C). The interventricular septum was augmented with a polytetrafluoroethylene patch sutured anteriorly, inferiorly, and posteriorly. Running suture was used to anastomose the proximal aortic valve allograft to the patient’s aortic annular region posteriorly. The superior aspect of the VSD patch was sutured to the anterior muscular rim of the allograft (Fig 2A). The open brachiocephalic ostium remaining in the allograft conduit was extended proximally with a longitudinal incision. Tourniquets were tightened around the native arch vessels. A 15-mm longitudinal aortotomy was 0003-4975/92/$5.00
CASE REPORT ST. CYR ET AL ALLOGRAFT REPAIR OF AORTIC HYPOPLASIA
Ann Thorac Surg 1992;53:1110-3
A
1111
B
Fig 1 . The graft conduit is taken down, followed by resection and reanastomosis of the pulmonary artery band. The ascending aorta is detached and closed below the coronary arteries and the allograft is attached to the descending thoracic aorta. (Reprinted by permission of the publisher from: Clarke DR, Campbell DN, Bishop DA. Homografts for congenital heart disease. In. Cardiac surgery: state of the art reviews. Hanley b Belfus, 1989;3:363-79.)
C
made directly opposite the allograft conduit incision. The allograft and native ascending aorta were anastomosed side to side. The cannula was removed from the distal synthetic graft; which was amputated and oversewn (Fig 2B). The ascending aortic cannula was used to reestablish circulation, and rewarming was begun. Tourniquets were removed and warm blood cardioplegia was administerhd. The aortic cross-clamp was removed and cardiac rhythm returned spontaneously. A triangular patch of polytetrafluoroethylene was used to close the right ventriculotomy (Fig 2C). The child was weaned from cardiopulmonary bypass and decannulated in standard manner. Chest tubes were placed and the sternotomy was closed. The patient's postoperative course was complicated.
Multiple arrhythmias were treated unsuccessfully with digoxin, procainamide, and intermittent pacing. Control of arrhythmias was obtained with hypothermia and, later, flecainide acetate. Ventilation was problematic. Right PA stenosis had created a chronic discrepancy in right and left lung vascular resistance, and the physiologic shunt resulted in decreased oxygenation. A ventilationperfusion study confirmed a substantial mismatch; the right lung received a majority of blood flow whereas the left lung was better ventilated. Serial chest roentgenograms revealed an elevated left hemidiaphragm that required surgical plication. Vigorous pulmonary care and nutritional support ultimately enabled the patient to be weaned from the ventilator and extubated. One year postoperatively, cardiac catheterization revealed a func-
1112
CASE REPORT ST. CYR ET AL ALLOGRAFT REPAIR OF AORTIC HYPOPLASIA
Ann Thorac Surg 1992;s:11103
A B
Fig 2. The ascending aorta and aortic allograft are anastomosed side to side. The allograft is used to create a new left ventricular outflow tract. (Reprinted by permission of the publisher from: Clarke DR, Campbell ON,Bishop DA. Homografts for congenital heart disease. In: Cardiac surgery: state of the art reuims. Hanley b Belfus, 1989; 3:363-79.)
C
tional repair. The child remains asymptomatic 34 months after operation.
Comment Interrupted aortic arch is associated with other cardiac anomalies. Concurrent lesions include VSD most commonly, pulmonary stenosis, truncus arteriosus, or aortopulmonary window [l, 21. A bicuspid aortic valve is present in one third of the patients (41. The most prevalent anomaly combination consists of type B interruption of the aortic arch, VSD, patent ductus arteriosus, and left ventricular outflow hypoplasia and is considered a lethal lesion if the obstruction is severe. These children commonly are seen as neonates with severe congestive heart failure. The bleak prognosis has lead to controversy over
the optimal course of medical or surgical management, both immediate and long-term. Initial stabilization can be accomplished with prostaglandin El but operation provides the only chance for long-term survival. Palliative operation generally consists of arch repair with concomitant patent ductus arteriosus ligation and banding of the PA, which provides the opportunity for subsequent growth of the ieft ventricular outflow tract and ascending aorta. When this does not occur, the left ventricular outflow tract remains small and requires extensive reconstruction or replacement. Banding the main PA may distort the vessel and increase the risk of subsequent surgical procedures [5] or can aggravate existing subvalvar aortic stenosis [l].The case herein illustrates migration of the PA band producing
Ann Thorac Surg 1992;53:111m
unilateral right PA stenosis [6]. Pulmonary arterioplasty reestablished blood flow to a low-resistance lung and resulted in unilateral pulmonary edema, ventilationperfusion mismatch, a n d severe hypoxia. Stringent pulmonary care with modified postural drainage maneuvers are imperative for facilitation of ventilator management. Complete repair in a 2-year-old child with aortic hypoplasia, VSD, and a type B interrupted aortic arch was performed using a cryopreserved aortic allograft valve conduit. Allografts have been used in the repair of cardiac anomalies since 1956 [7]. Herein their use has been extended to successfully repair a potentially lethal congenital heart lesion.
References 1. Van Praagh R, Bernhard WF, Rosenthal A, Parisi LF, Fyler
DC. Interrupted aortic arch: surgical treatment. Am J Cardiol 1971;27:200-11.
CASE REPORT ST. CYR ET AL ALLOGRAFT REPAIR OF AORTIC HYPOPLASIA
1113
2. Moller JH, Edwards JE. Interruption of aortic arch; anatomic
patterns and associated cardiac malformations. Am J Roentgenol Radium Ther Nucl Med 1965;95:557-72. 3. Roberts WC, Morrow AG, Braunwald E. Complete interruption of the aortic arch. Circulation 1962;26:39-59. 4. Moulton AL, Bowman FO Jr. Primary definitive repair of type B interrupted aortic arch, ventricular septa1 defect, and patent ductus arteriosus. Early and late results. J Thorac Cardiovasc Surg 1981;82:501-10. 5. Turley K, Yee ES, Ebert PA. The total repair of interrupted arch complex in infants: the anterior approach. Circulation 1984;70(Suppl 1):16-20. 6. Durmowicz AG, St.Cyr JA, Clarke DR, Stenmark KR. Unilateral pulmonary hypertension as a result of chronic high flow to one lung. Am Rev Respir Dis 1990;142:2303. 7. Murray G. Homologous aortic-valve-segment transplants as surgical treatment for aortic and mitral insufficiency. Angiology 1956;746671.
