Absent Pulmonary Valve Syndrome: Operation in Infants With Airway Obstruction Kevin G. Watterson, FRACS, Torsten K. Malm, MD, PhD, Tom R. Karl, MD, and Roger B. B. Mee, FRACS Royal Children’s Hospital, Melbourne, Victoria, Australia
From 1979 through 1991, 19 infants with absent pulmonary valve syndrome and airway obstruction were seen for surgical treatment. All patients underwent extensive pulmonary artery aneurysmorrhaphy using cardiopulmonary bypass. Fourteen patients had simultaneous transatrial ventricular septal defect (VSD) closure, infundibular resection, and placement of a short transannular patch; 2 had transventricular VSD closure and infundibular resection without a transannular patch; 1 underwent transventricular VSD closure and transannular patching; and 2 underwent pulmonary artery aneurysmorrhaphy alone with the VSD left open. All 19 infants had good hemodynamics when taken from the operating theater, but 3 died postoperatively of severe airway obstruction, despite further tracheobronchopexy
procedures in 2 (hospital mortality rate, 16%; confidence limits, 7% to 29%). Among the 16 patients discharged from the hospital, there was one late death. Five other patients have required reoperation for branch pulmonary artery stenosis (n = 21, residual airway obstruction resulting from persistent pulmonary artery dilatation (n = 11, closure of VSD (n = 11, and homograft valve insertion for pulmonary incompetence and right ventricular dysfunction (n = 1). There are 15 long-term survivors. Eight of them have episodic bronchospasm of mild to moderate severity, and all are responsive to sympathomimetic bronchodilator aerosols. The remaining 7 are asymptomatic.
A
syndrome and airway obstruction (8 were ventilator dependent). Older children without airway obstruction were not included in this series. Mean age and weight at operation were 5.2 months (range, 4 days to 14 months) and 5.1 kg (range, 1.7 to 10.2 kg), respectively. All 19 patients had a ventricular septal defect (VSD). Additional associated congenital cardiac abnormalities occurred in 4 patients: double aortic arch (n = l), anomalous left PA arising from the aorta (n = l), right lower lobe sequestration (n = l), and a left superior vena cava draining to the coronary sinus (n = 1).In 15 patients, the diagnosis was made using a combination of echocardiography and cardiac catheterization, whereas echocardiography alone was used in the remaining 4 patients. Preoperative PA pressures were measured in 10 patients, and mean PA pressure ranged from 9 to 35 mm Hg (mean pressure, 19 mm Hg). Preoperative cinetracheobronchograms were obtained in 17 of the 19 patients. All showed anteroposterior compression of the lower trachea and right and left main bronchi, best seen in the lateral view.
bsent pulmonary valve syndrome is a rare congenital cardiac lesion, the components of which include dysplasia and severe incompetence of the pulmonary valve, annular stenosis (usually not severe), and dilatation of the pulmonary artery (PA) system leading to tracheobronchial compression of varying degree [l, 21. Presentation is often in infancy, with severe progressive airway obstruction. Management of this form of the condition has proved difficult because of an inability to consistently obtain relief of airway obstruction. Consequently, patient survival has been poor, and debate has continued regarding the most appropriate form of surgical management [3, 41. Medical management with long-term ventilation has had a very high mortality [5, 61. Recently reported series have focused on the role of pulmonary incompetence in this condition, and it has been suggested that optimum results are obtained when a pulmonary valve is inserted [7, 81. This prompted a review of our surgical strategy, which emphasizes the technique of pulmonary aneurysmorrhaphy rather than valve insertion [91.
Material and Methods Patient Population During the period 1979 through 1991, 19 infants, 9 female and 10 male, were seen with absent pulmonary valve Accepted for publication March 20, 1992. Address reprint requests to Dr Karl, Victorian Paediatric Cardiac Surgical Unit, Royal Children’s Hospital, Flemington Rd, Parkville, Victoria, 3052, Australia.
0 1992 by The Society of Thoracic Surgeons
(Ann Tkorac Surg 1992;54:1116-9)
Operative Technique All patients underwent attempted relief of airway obstruction, mainly by extensive PA aneurysmorrhaphy. Pulmonary artery banding was not employed. In the earlier phase of the series, profound hypothermia and circulatory arrest using a single venous cannula was used. More recently, cardiopulmonary bypass with moderate hypothermia and two venous cannulas has been employed in 8 patients weighing more than 3 kg. 0003-4975/92/$5.00
WATTERSON ET AL ABSENT PULMONARY VALVE SYNDROME
Ann Thorac Surg 1992;54:111&9
1117
Table 1. Summaru of Patient Data ~
Patient
No. 1
2 3 4
5 6 7 8 9 10
11 12 13 14 15
16 17 18 19
Age (mo) 7 5 5 7
11 3 0.25 2.5 8 3 6 4 0.25 0.5 14 6 0.75 3 12
Operation
Year of
Type of Operation”
1979 1980 1983 1983 1983 1983 1984 1984 1984 1985 1985 1986 1986 1987 1987 1988 1989 1990 1991
2 2 1 4 4 4 1 4 4 4 4 4 3 4 4 4 4 4 4
Reoperation (interval) 6 mo
No reop 3.5 y 3 mo
No reop No reop 4 mo 6.5 y 5.5 y No reop No reop No reop No reop 2Y No reop No reop No reop 2 mo No reop
Status Died (at reop) Well Well Died (airway problems) Well
Well Died (airway problems) Asthma Asthma Well Well
Well Died (pneumonia, renal failure) Well Well Weli Well Well Well
a The types of operation were as follows: 1 = pulmonary aneurysmorrhaphy only; 2 = pulmonary aneurysmorrhaphy and transventricular ventricular septa1 defect (VSD); 3 = pulmonary aneurysmorrhaphy, transventricular VSD closure, and transannular patch; and 4 = pulmonary aneurysmorrhaphy, transatrial VSD closure, and transannular patch.
The various operative strategies are shown in Table 1. Pulmonary artery aneurysmorrhaphy has been described previously [ 9 ] . The essential features are as follows: (1) shortening of the main PA by posterior plication to lift the bifurcation area away from the trachea and draw the orifice of the right PA inferiorly, (2) posterior wall plication of the right and left PAS, and (3) anterior wall resection of the main and branch PAS. Currently, posterior wall plication of the main PA has been superseded by transection of that artery with excision of PA wall to achieve shortening of the main PA. In those patients undergoing VSD closure and infundibular resection, the approach evolved during the course of this series from transventricular (n = 3) to transatrial (n = 14). Fifteen patients had an associated transannular incision and homograft monocusp patch (n = 2), autologous pericardial monocusp patch (n = 3), or autologous main PA wall patch (n = 10). Two who underwent transventricular VSD closure and infundibular resection did not have a transannular patch, and 2 patients with a balanced pulmonary to systemic flow ratio underwent pulmonary aneurysmorrhaphy only. Associated cardiac lesions requiring treatment were anomalous left PA (detached from the upper descending aorta and reimplanted into the PA) and right lower lobe sequestration (aortopulmonary collateral ligation). The double aortic arch was left undisturbed because preoperative airway studies had not identified it as the offending lesion, although currently we would advise division of the minor arch in such a case.
Results Initial Procedure All 19 infants left the operating theater with good hemodynamics, and 16 were discharged from the hospital. The operative mortality rate was 16% (70% confidence limits, 7% to 29%). Three patients, all ventilated preoperatively, could not be weaned postoperatively because of persisting severe airway obstruction, confirmed by cinetracheobronchography. Two of these children were premature (1.7 kg and 2.3 kg) and were seen in the first days of life with severe airway obstruction requiring assisted ventilation and operation in the first week of life. The smallest (patient 13) of these 2 infants had severe persistent tracheobronchomalacia,finally complicated by sepsis and renal failure, and died 12 days postoperatively. The second premature infant (patient 7) underwent reoperation 10 weeks after the first procedure. The main and branch PAS were excised and replaced with 10-mm Gore-Tex conduits from the right and left PA stumps to the right ventricular outflow tract on each side of the aorta. This was unsuccessful in relieving airway obstruction, and an anterior tracheobronchopexy was performed the following week. Some transient improvement was noted after this procedure, but repeat bronchography revealed persistent tracheobronchomalacia. A further bronchopexy was performed, but distal airway obstruction persisted, and the patient died 5 months after the initial procedure. The third patient who could not be weaned postoperatively (patient 4)underwent repeat sternotomy and ante-
1118
WATTERSON ET AL ABSENT PULMONARY VALVE SYNDROME
rior bifurcation tracheopexy 3 months after the initial operation. Obstruction persisted, and the patient eventually died. Postmortem examination revealed a diffusely hypoplastic bronchial tree with almost complete absence of cartilage. In retrospect, this patient had a pathological condition that was not amenable to intracardiac repair and PA aneurysmorrhaphy. Overall, 5 of the 8 patients who were ventilator dependent preoperatively survived (mortality rate, 38%; 70% confidence limits, 18%to 61%).
Long-Term Follow-up Sixteen patients survived the initial hospitalization, and there has been only one late death (see Table 1).The first patient in the series died at reoperation 6 months after the initial procedure. Postoperative catheterization had revealed a small residual VSD and high left PA pressures. The patient could not be weaned from cardiopulmonary bypass. Postmortem examination revealed a previously undetected obstruction of the right PA caused by acute angulation at its takeoff from the main PA, which in this case had not been shortened. All 15 long-term survivors have had regular follow-up examinations using echocardiography, with additional cardiac catheterization in 12 patients. Range of follow-up is 3 months to 11 years. Five of these patients have undergone reoperation (see Table 1).Patient 3 underwent reoperation 3% years after the original procedure to close a previously unrepaired VSD. Patient 8 had residual left PA stenosis with major pulmonary incompetence and right ventricular dilatation. He had a reoperation at 6% years for pulmonary homograft conduit insertion and relief of the stenoses. Patients 9 and 18 required reoperation at 5.5 years and 2 months, respectively, for relief of residual airway compression from large branch left PAS. Patient 14 had a left PA arising from the aorta and was reoperated on after 2 years for a dilated right PA beyond a proximal right PA stenosis with associated mild compression of the right main bronchus. In the 15 survivors pulmonary incompetence is present but currently well tolerated. In 2 patients the right ventricle is dilated but contracting well. In 7 the right ventricular size is within normal limits. In 5 of these 7 there is additional mild right ventricular outflow tract obstruction. Eight patients have episodic bronchospasm of mild to moderate severity, both isolated and in association with respiratory tract infections. All apparently obtain symptomatic relief with bronchodilators. These episodes have tended to lessen with time. The remaining 7 survivors are asymptomatic.
Comment Absent pulmonary valve syndrome has two basic modes of presentation [3, 8, 101. In the older, minimally symptomatic group, elective operation carries a risk similar to that of tetralogy of Fallot. In the infant group, usually symptomatic because of progressive severe airway obstruction, operation carries a higher risk. This review has focused on the latter group.
Ann Thorac Surg 1992;54:111fG9
The hospital mortality of 16% (70% confidence limits, 7% to 29%) represents 3 patients, 2 of whom were premature. Both survived initial operation with good hemodynamics but died of airway complications. This has led us to question the value of our current surgical strategy in very small infants who appear to have "softer" than normal airways and are seen with life-threatening airway obstruction at birth. Palliative procedures such as PA banding or PA ligation with shunt insertion may be worth considering, although they have had variable results [ll-131. Intrapulmonary abnormalities other than direct airway compression by primary PA branches have previously been reported. In a pathological study [14], dilatation of peripheral PA vasculature and compression of intrapulmonary bronchi with consequent distal bronchomalacia was noted. Patients needing ventilatory support soon after birth may represent the severe end of this spectrum with marked peripheral bronchomalacia. At present, a direct surgical attack at this level is not possible. Consequently, many patients will be left with residual compression of small airways despite palliation at the main bronchial level (as is likely to occur after aneurysmorrhaphy). The majority of infants in this series have not fallen into this category and have exhibited a curious period of 1 month to 6 months during which airway obstruction is not immediately life threatening. Perhaps because of the rarity of this lesion, debate has continued regarding both the etiology in and the appropriate surgical strategy for the infant group. It has been postulated that in utero closure of the ductus in absent pulmonary valve syndrome leads to increased pulmonary flow through an immature PA [15, 161. The role of pulmonary incompetence has also been emphasized, and some published series [7, 8, 17, 181 of absent pulmonary valve syndrome have suggested that the interposition of a pulmonary valve is important to achieve early survival and relief of airway compression. This recommendation is not supported by our series, in which none of the infants had insertion of a pulmonary valve during the initial operation (although monocusp onlay patches were placed in some). The essential component of our surgical strategy to relieve airway obstruction has been extensive PA aneurysmorrhaphy, as has been suggested by others 19, 191. We believe this to be more important than establishing pulmonary valvar competence, at least in the short term. The aneurysmorrhaphy must incorporate shortening of the main PA to lift the PA bifurcation and proximal right PA away from the lower trachea and upper main bronchi. The reduction in diameter of the central PA system will, for a given intraluminal pressure, reduce the PA wall tension. The "hardness" of the PA (as "felt" by the main bronchi) is the PA wall tension. In the majority of infants treated on these principles, there was substantial relief of airway obstruction. The method was unsuccessful in 2 premature neonates with severe airway obstruction soon after birth and in a 7-month-old infant with distal hypoplasia of the bronchial tree, which also was largely unsupported by cartilage.
Ann Thorac Surg 1992;54:1116-9
The insertion of a pulmonary valve may not be necessary for a successful outcome, although valve insertion may be required at a later date because of long-term effects of free pulmonary incompetence on the right ventricle. This has been the case in only 1 of our patients to date, although at least 2 others with free pulmonary incompetence and mild right ventricular dilatation are expected to require pulmonary valve insertion at a later date. The reoperation rate in this series has been rather high, although the condition of most patients was improved afterward. Some of these patients would currently be candidates for balloon catheter interventions, and we now would close all VSDs at the time of PA repair. Whether or not valve insertion at the time of primary operation can further reduce this incidence is unclear. Certainly a small conduit will need to be replaced at least once in long term survivors, generating further reoperations. A selective approach to primary valve insertion is probably justified at this time, with aneurysmorrhaphy as the primary treatment.
References 1. Macarh-tey F, Miller G. Congenital absence of the pulmonary valve. Br Heart J 1970;32:483-90. 2. Lakier J, Stanger P, Heymann M, Hoffman J, Rudolph A. Tetralogy of Fallot with absent pulmonary valve: natural history and hemodynamic considerations. Circulation 1974; 50:167-75. 3. Fischer D, Neches W, Beerman L, et al. Tetralogy of Fallot with absent pulmonic valve: analysis of 17 patients. Am J Cardiol 1984;531433-7. 4. McCaughan 8, Danielson G, Driscoll D, McGoon D. Tetralogy of Fallot with absent pulmonary valve. Early and late results of surgical treatment. J Thorac Cardiovasc Surg 1985; 89:280-7. 5. Venables AW. Absence of the pulmonary valve with ventricular septa1 defect. Br Heart J 1962;24:293-6. 6. DCruz I, Arcilla R, Agustsson M. Dilatation of the pulmonary trunk in stenosis of the pulmonary valve and of the pulmonary arteries in children. Am Heart J 1964;68:72&u).
WATTERSON ET AL ABSENT PULMONARY VALVE SYNDROME
1119
7. Karl T, Musumeci F, de Leval M, Pincott M, Taylor JFN, Stark J. Surgical treatment of absent pulmonary valve syndrome. J Thorac Cardiovasc Surg 1986;91:590-7. 8. Ilbawi M, Idriss F, Muster A, Wessel H, Paul M, DeLeon S. Tetralogy of Fallot with absent pulmonary valve. J Thorac Cardiovasc Surg 1981;81:906-15. 9. Stellin G, JOMS RA, Goh TH, Brawn WJ, Venables AW, Mee RBB. Surgical treatment of absent pulmonary valve syndrome in infants: relief of bronchial obstruction. Ann Thorac Surg 1983;36:468-75. 10. Mavroudis C, Turley K, Stanger P,Ebert P. Surgical management of tetralogy of Fallot with absent pulmonary valve. J Cardiovasc Surg (Torino) 1983;24:604-9. 11. Byrne JP, Hawkins JA, Battiste CE, Khoury GH. Palliative procedures in tetralogy of Fallot with absent pulmonary valve: a new approach. Ann Thorac Surg 1982;33:499-502. 12. Ilbawi M, Fedorchik J, Muster A, et al. Surgical approach to severely symptomatic newborn infants with tetralogy of Fallot and absent pulmonary valve. J Thorac Cardiovasc Surg 1986;91:584-9. 13. Mocellin R, Henglein D, Beitzke A, Ahmedi A, Suppan C, Rigler B. Successful treatment of the absent pulmonary valve syndrome by banding of the pulmonary trunk. Int J Cardiol 1989;22:241-7. 14. Rabinovitch M, Grady S, David I, et al. Compression of intrapulmonary bronchi by abnormally branching pulmonary arteries associated with absent pulmonary valves. Am J Cardiol 1982;50:804-13. 15. Emmanouilides GC, Thonopoulos B, Siassi 8, Fishbein M. Agenesis of ductus arteriosus associated with the syndrome of tetralogy of Fallot and absent pulmonary valve. Am J Cardiol 1976;37403-7. 16. Callan NA, Kan JS. Prenatal diagnosis of tetralogy of Fallot with absent pulmonary valve. Am J Perinatol 1991;8:15-7. 17. Layton CA, McDonald A, McDonald L, et al. The syndrome of absent pulmonary valve. Total correction with aortic valvular homografts. J Thorac Cardiovasc Surg 1972;63: 800-8. 18. Snir E, de Leval MR, Elliott MJ, Stark J. Current surgical technique to repair Fallot's tetralogy with absent pulmonary valve syndrome. Ann Thorac Surg 1991;51:979-82. 19. Dunnigan A, Oldham HN, Benson DW Jr. Absent pulmonary valve syndrome in infancy: surgery reconsidered. Am J Cardiol1981;48:117-22.
From 1979 through 1991, 19 infants with absent pulmonary valve syndrome and airway obstruction were seen for surgical treatment. All patients underwent extensive pulmonary artery aneurysmorrhaphy using cardiopulmonary bypass. Fourteen patients had simultaneous transatrial ventricular septal defect (VSD) closure, infundibular resection, and placement of a short transannular patch; 2 had transventricular VSD closure and infundibular resection without a transannular patch; 1 underwent transventricular VSD closure and transannular patching; and 2 underwent pulmonary artery aneurysmorrhaphy alone with the VSD left open. All 19 infants had good hemodynamics when taken from the operating theater, but 3 died postoperatively of severe airway obstruction, despite further tracheobronchopexy
procedures in 2 (hospital mortality rate, 16%; confidence limits, 7% to 29%). Among the 16 patients discharged from the hospital, there was one late death. Five other patients have required reoperation for branch pulmonary artery stenosis (n = 21, residual airway obstruction resulting from persistent pulmonary artery dilatation (n = 11, closure of VSD (n = 11, and homograft valve insertion for pulmonary incompetence and right ventricular dysfunction (n = 1). There are 15 long-term survivors. Eight of them have episodic bronchospasm of mild to moderate severity, and all are responsive to sympathomimetic bronchodilator aerosols. The remaining 7 are asymptomatic.
A
syndrome and airway obstruction (8 were ventilator dependent). Older children without airway obstruction were not included in this series. Mean age and weight at operation were 5.2 months (range, 4 days to 14 months) and 5.1 kg (range, 1.7 to 10.2 kg), respectively. All 19 patients had a ventricular septal defect (VSD). Additional associated congenital cardiac abnormalities occurred in 4 patients: double aortic arch (n = l), anomalous left PA arising from the aorta (n = l), right lower lobe sequestration (n = l), and a left superior vena cava draining to the coronary sinus (n = 1).In 15 patients, the diagnosis was made using a combination of echocardiography and cardiac catheterization, whereas echocardiography alone was used in the remaining 4 patients. Preoperative PA pressures were measured in 10 patients, and mean PA pressure ranged from 9 to 35 mm Hg (mean pressure, 19 mm Hg). Preoperative cinetracheobronchograms were obtained in 17 of the 19 patients. All showed anteroposterior compression of the lower trachea and right and left main bronchi, best seen in the lateral view.
bsent pulmonary valve syndrome is a rare congenital cardiac lesion, the components of which include dysplasia and severe incompetence of the pulmonary valve, annular stenosis (usually not severe), and dilatation of the pulmonary artery (PA) system leading to tracheobronchial compression of varying degree [l, 21. Presentation is often in infancy, with severe progressive airway obstruction. Management of this form of the condition has proved difficult because of an inability to consistently obtain relief of airway obstruction. Consequently, patient survival has been poor, and debate has continued regarding the most appropriate form of surgical management [3, 41. Medical management with long-term ventilation has had a very high mortality [5, 61. Recently reported series have focused on the role of pulmonary incompetence in this condition, and it has been suggested that optimum results are obtained when a pulmonary valve is inserted [7, 81. This prompted a review of our surgical strategy, which emphasizes the technique of pulmonary aneurysmorrhaphy rather than valve insertion [91.
Material and Methods Patient Population During the period 1979 through 1991, 19 infants, 9 female and 10 male, were seen with absent pulmonary valve Accepted for publication March 20, 1992. Address reprint requests to Dr Karl, Victorian Paediatric Cardiac Surgical Unit, Royal Children’s Hospital, Flemington Rd, Parkville, Victoria, 3052, Australia.
0 1992 by The Society of Thoracic Surgeons
(Ann Tkorac Surg 1992;54:1116-9)
Operative Technique All patients underwent attempted relief of airway obstruction, mainly by extensive PA aneurysmorrhaphy. Pulmonary artery banding was not employed. In the earlier phase of the series, profound hypothermia and circulatory arrest using a single venous cannula was used. More recently, cardiopulmonary bypass with moderate hypothermia and two venous cannulas has been employed in 8 patients weighing more than 3 kg. 0003-4975/92/$5.00
WATTERSON ET AL ABSENT PULMONARY VALVE SYNDROME
Ann Thorac Surg 1992;54:111&9
1117
Table 1. Summaru of Patient Data ~
Patient
No. 1
2 3 4
5 6 7 8 9 10
11 12 13 14 15
16 17 18 19
Age (mo) 7 5 5 7
11 3 0.25 2.5 8 3 6 4 0.25 0.5 14 6 0.75 3 12
Operation
Year of
Type of Operation”
1979 1980 1983 1983 1983 1983 1984 1984 1984 1985 1985 1986 1986 1987 1987 1988 1989 1990 1991
2 2 1 4 4 4 1 4 4 4 4 4 3 4 4 4 4 4 4
Reoperation (interval) 6 mo
No reop 3.5 y 3 mo
No reop No reop 4 mo 6.5 y 5.5 y No reop No reop No reop No reop 2Y No reop No reop No reop 2 mo No reop
Status Died (at reop) Well Well Died (airway problems) Well
Well Died (airway problems) Asthma Asthma Well Well
Well Died (pneumonia, renal failure) Well Well Weli Well Well Well
a The types of operation were as follows: 1 = pulmonary aneurysmorrhaphy only; 2 = pulmonary aneurysmorrhaphy and transventricular ventricular septa1 defect (VSD); 3 = pulmonary aneurysmorrhaphy, transventricular VSD closure, and transannular patch; and 4 = pulmonary aneurysmorrhaphy, transatrial VSD closure, and transannular patch.
The various operative strategies are shown in Table 1. Pulmonary artery aneurysmorrhaphy has been described previously [ 9 ] . The essential features are as follows: (1) shortening of the main PA by posterior plication to lift the bifurcation area away from the trachea and draw the orifice of the right PA inferiorly, (2) posterior wall plication of the right and left PAS, and (3) anterior wall resection of the main and branch PAS. Currently, posterior wall plication of the main PA has been superseded by transection of that artery with excision of PA wall to achieve shortening of the main PA. In those patients undergoing VSD closure and infundibular resection, the approach evolved during the course of this series from transventricular (n = 3) to transatrial (n = 14). Fifteen patients had an associated transannular incision and homograft monocusp patch (n = 2), autologous pericardial monocusp patch (n = 3), or autologous main PA wall patch (n = 10). Two who underwent transventricular VSD closure and infundibular resection did not have a transannular patch, and 2 patients with a balanced pulmonary to systemic flow ratio underwent pulmonary aneurysmorrhaphy only. Associated cardiac lesions requiring treatment were anomalous left PA (detached from the upper descending aorta and reimplanted into the PA) and right lower lobe sequestration (aortopulmonary collateral ligation). The double aortic arch was left undisturbed because preoperative airway studies had not identified it as the offending lesion, although currently we would advise division of the minor arch in such a case.
Results Initial Procedure All 19 infants left the operating theater with good hemodynamics, and 16 were discharged from the hospital. The operative mortality rate was 16% (70% confidence limits, 7% to 29%). Three patients, all ventilated preoperatively, could not be weaned postoperatively because of persisting severe airway obstruction, confirmed by cinetracheobronchography. Two of these children were premature (1.7 kg and 2.3 kg) and were seen in the first days of life with severe airway obstruction requiring assisted ventilation and operation in the first week of life. The smallest (patient 13) of these 2 infants had severe persistent tracheobronchomalacia,finally complicated by sepsis and renal failure, and died 12 days postoperatively. The second premature infant (patient 7) underwent reoperation 10 weeks after the first procedure. The main and branch PAS were excised and replaced with 10-mm Gore-Tex conduits from the right and left PA stumps to the right ventricular outflow tract on each side of the aorta. This was unsuccessful in relieving airway obstruction, and an anterior tracheobronchopexy was performed the following week. Some transient improvement was noted after this procedure, but repeat bronchography revealed persistent tracheobronchomalacia. A further bronchopexy was performed, but distal airway obstruction persisted, and the patient died 5 months after the initial procedure. The third patient who could not be weaned postoperatively (patient 4)underwent repeat sternotomy and ante-
1118
WATTERSON ET AL ABSENT PULMONARY VALVE SYNDROME
rior bifurcation tracheopexy 3 months after the initial operation. Obstruction persisted, and the patient eventually died. Postmortem examination revealed a diffusely hypoplastic bronchial tree with almost complete absence of cartilage. In retrospect, this patient had a pathological condition that was not amenable to intracardiac repair and PA aneurysmorrhaphy. Overall, 5 of the 8 patients who were ventilator dependent preoperatively survived (mortality rate, 38%; 70% confidence limits, 18%to 61%).
Long-Term Follow-up Sixteen patients survived the initial hospitalization, and there has been only one late death (see Table 1).The first patient in the series died at reoperation 6 months after the initial procedure. Postoperative catheterization had revealed a small residual VSD and high left PA pressures. The patient could not be weaned from cardiopulmonary bypass. Postmortem examination revealed a previously undetected obstruction of the right PA caused by acute angulation at its takeoff from the main PA, which in this case had not been shortened. All 15 long-term survivors have had regular follow-up examinations using echocardiography, with additional cardiac catheterization in 12 patients. Range of follow-up is 3 months to 11 years. Five of these patients have undergone reoperation (see Table 1).Patient 3 underwent reoperation 3% years after the original procedure to close a previously unrepaired VSD. Patient 8 had residual left PA stenosis with major pulmonary incompetence and right ventricular dilatation. He had a reoperation at 6% years for pulmonary homograft conduit insertion and relief of the stenoses. Patients 9 and 18 required reoperation at 5.5 years and 2 months, respectively, for relief of residual airway compression from large branch left PAS. Patient 14 had a left PA arising from the aorta and was reoperated on after 2 years for a dilated right PA beyond a proximal right PA stenosis with associated mild compression of the right main bronchus. In the 15 survivors pulmonary incompetence is present but currently well tolerated. In 2 patients the right ventricle is dilated but contracting well. In 7 the right ventricular size is within normal limits. In 5 of these 7 there is additional mild right ventricular outflow tract obstruction. Eight patients have episodic bronchospasm of mild to moderate severity, both isolated and in association with respiratory tract infections. All apparently obtain symptomatic relief with bronchodilators. These episodes have tended to lessen with time. The remaining 7 survivors are asymptomatic.
Comment Absent pulmonary valve syndrome has two basic modes of presentation [3, 8, 101. In the older, minimally symptomatic group, elective operation carries a risk similar to that of tetralogy of Fallot. In the infant group, usually symptomatic because of progressive severe airway obstruction, operation carries a higher risk. This review has focused on the latter group.
Ann Thorac Surg 1992;54:111fG9
The hospital mortality of 16% (70% confidence limits, 7% to 29%) represents 3 patients, 2 of whom were premature. Both survived initial operation with good hemodynamics but died of airway complications. This has led us to question the value of our current surgical strategy in very small infants who appear to have "softer" than normal airways and are seen with life-threatening airway obstruction at birth. Palliative procedures such as PA banding or PA ligation with shunt insertion may be worth considering, although they have had variable results [ll-131. Intrapulmonary abnormalities other than direct airway compression by primary PA branches have previously been reported. In a pathological study [14], dilatation of peripheral PA vasculature and compression of intrapulmonary bronchi with consequent distal bronchomalacia was noted. Patients needing ventilatory support soon after birth may represent the severe end of this spectrum with marked peripheral bronchomalacia. At present, a direct surgical attack at this level is not possible. Consequently, many patients will be left with residual compression of small airways despite palliation at the main bronchial level (as is likely to occur after aneurysmorrhaphy). The majority of infants in this series have not fallen into this category and have exhibited a curious period of 1 month to 6 months during which airway obstruction is not immediately life threatening. Perhaps because of the rarity of this lesion, debate has continued regarding both the etiology in and the appropriate surgical strategy for the infant group. It has been postulated that in utero closure of the ductus in absent pulmonary valve syndrome leads to increased pulmonary flow through an immature PA [15, 161. The role of pulmonary incompetence has also been emphasized, and some published series [7, 8, 17, 181 of absent pulmonary valve syndrome have suggested that the interposition of a pulmonary valve is important to achieve early survival and relief of airway compression. This recommendation is not supported by our series, in which none of the infants had insertion of a pulmonary valve during the initial operation (although monocusp onlay patches were placed in some). The essential component of our surgical strategy to relieve airway obstruction has been extensive PA aneurysmorrhaphy, as has been suggested by others 19, 191. We believe this to be more important than establishing pulmonary valvar competence, at least in the short term. The aneurysmorrhaphy must incorporate shortening of the main PA to lift the PA bifurcation and proximal right PA away from the lower trachea and upper main bronchi. The reduction in diameter of the central PA system will, for a given intraluminal pressure, reduce the PA wall tension. The "hardness" of the PA (as "felt" by the main bronchi) is the PA wall tension. In the majority of infants treated on these principles, there was substantial relief of airway obstruction. The method was unsuccessful in 2 premature neonates with severe airway obstruction soon after birth and in a 7-month-old infant with distal hypoplasia of the bronchial tree, which also was largely unsupported by cartilage.
Ann Thorac Surg 1992;54:1116-9
The insertion of a pulmonary valve may not be necessary for a successful outcome, although valve insertion may be required at a later date because of long-term effects of free pulmonary incompetence on the right ventricle. This has been the case in only 1 of our patients to date, although at least 2 others with free pulmonary incompetence and mild right ventricular dilatation are expected to require pulmonary valve insertion at a later date. The reoperation rate in this series has been rather high, although the condition of most patients was improved afterward. Some of these patients would currently be candidates for balloon catheter interventions, and we now would close all VSDs at the time of PA repair. Whether or not valve insertion at the time of primary operation can further reduce this incidence is unclear. Certainly a small conduit will need to be replaced at least once in long term survivors, generating further reoperations. A selective approach to primary valve insertion is probably justified at this time, with aneurysmorrhaphy as the primary treatment.
References 1. Macarh-tey F, Miller G. Congenital absence of the pulmonary valve. Br Heart J 1970;32:483-90. 2. Lakier J, Stanger P, Heymann M, Hoffman J, Rudolph A. Tetralogy of Fallot with absent pulmonary valve: natural history and hemodynamic considerations. Circulation 1974; 50:167-75. 3. Fischer D, Neches W, Beerman L, et al. Tetralogy of Fallot with absent pulmonic valve: analysis of 17 patients. Am J Cardiol 1984;531433-7. 4. McCaughan 8, Danielson G, Driscoll D, McGoon D. Tetralogy of Fallot with absent pulmonary valve. Early and late results of surgical treatment. J Thorac Cardiovasc Surg 1985; 89:280-7. 5. Venables AW. Absence of the pulmonary valve with ventricular septa1 defect. Br Heart J 1962;24:293-6. 6. DCruz I, Arcilla R, Agustsson M. Dilatation of the pulmonary trunk in stenosis of the pulmonary valve and of the pulmonary arteries in children. Am Heart J 1964;68:72&u).
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7. Karl T, Musumeci F, de Leval M, Pincott M, Taylor JFN, Stark J. Surgical treatment of absent pulmonary valve syndrome. J Thorac Cardiovasc Surg 1986;91:590-7. 8. Ilbawi M, Idriss F, Muster A, Wessel H, Paul M, DeLeon S. Tetralogy of Fallot with absent pulmonary valve. J Thorac Cardiovasc Surg 1981;81:906-15. 9. Stellin G, JOMS RA, Goh TH, Brawn WJ, Venables AW, Mee RBB. Surgical treatment of absent pulmonary valve syndrome in infants: relief of bronchial obstruction. Ann Thorac Surg 1983;36:468-75. 10. Mavroudis C, Turley K, Stanger P,Ebert P. Surgical management of tetralogy of Fallot with absent pulmonary valve. J Cardiovasc Surg (Torino) 1983;24:604-9. 11. Byrne JP, Hawkins JA, Battiste CE, Khoury GH. Palliative procedures in tetralogy of Fallot with absent pulmonary valve: a new approach. Ann Thorac Surg 1982;33:499-502. 12. Ilbawi M, Fedorchik J, Muster A, et al. Surgical approach to severely symptomatic newborn infants with tetralogy of Fallot and absent pulmonary valve. J Thorac Cardiovasc Surg 1986;91:584-9. 13. Mocellin R, Henglein D, Beitzke A, Ahmedi A, Suppan C, Rigler B. Successful treatment of the absent pulmonary valve syndrome by banding of the pulmonary trunk. Int J Cardiol 1989;22:241-7. 14. Rabinovitch M, Grady S, David I, et al. Compression of intrapulmonary bronchi by abnormally branching pulmonary arteries associated with absent pulmonary valves. Am J Cardiol 1982;50:804-13. 15. Emmanouilides GC, Thonopoulos B, Siassi 8, Fishbein M. Agenesis of ductus arteriosus associated with the syndrome of tetralogy of Fallot and absent pulmonary valve. Am J Cardiol 1976;37403-7. 16. Callan NA, Kan JS. Prenatal diagnosis of tetralogy of Fallot with absent pulmonary valve. Am J Perinatol 1991;8:15-7. 17. Layton CA, McDonald A, McDonald L, et al. The syndrome of absent pulmonary valve. Total correction with aortic valvular homografts. J Thorac Cardiovasc Surg 1972;63: 800-8. 18. Snir E, de Leval MR, Elliott MJ, Stark J. Current surgical technique to repair Fallot's tetralogy with absent pulmonary valve syndrome. Ann Thorac Surg 1991;51:979-82. 19. Dunnigan A, Oldham HN, Benson DW Jr. Absent pulmonary valve syndrome in infancy: surgery reconsidered. Am J Cardiol1981;48:117-22.
