Outcomes in 45 Children With Ductal Origin of the Distal Pulmonary Artery

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1 CARDIOVASCULAR PEDIATRIC CARDIAC SURGERY: To participate in The Annals of Thoracic Surgery CME Program, please visit Outcomes in 45 Children With Ductal Origin of the Distal Pulmonary Artery Kalyani R. Trivedi, MBBS, MD, Tara Karamlou, MD, Shi-Joon Yoo, MD, William G. Williams, MD, Robert M. Freedom, MD,* and Brian W. McCrindle, MD, MPH Division of Cardiology, Department of Pediatrics, and Departments of Diagnostic Imaging and Cardiovascular Surgery, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada Background. There are no large series describing the morphologic spectrum and the clinical outcomes of children with ductal origin of the distal pulmonary artery (PA). Methods. Medical records were reviewed for all children presenting between 970 and 200. Angiograms were reviewed at presentation and at last available follow-up. Results. Forty-five patients were identified with median presenting age of 4 days (range, birth to 6.5 years). Ductal origin of the distal PA occurred as an isolated finding in 6 patients (36%), with tetralogy of Fallot in 2 (27%), with pulmonary atresia ventricular septal defect in 3 (29%), and with heterotaxy in 4 (9%). Diagnostic pulmonary venous wedge angiography was performed in 2 patients (47%). Surgical procedures were undertaken in 3 patients, and were initial systemic-ductal PA shunt in 3 patients, interposition graft in 6, direct anastomosis to the main PA in 2, ductal PA banding in 2, unifocalization of the ductal PA with complete or staged pulmonary atresia-ventricular septal defect repair in 7, and heart transplantation in patient. Surgical revision was required in 3 patients and catheter interventions in 2 patients. Overall 20-year survival was 70% and was improved among patients without congestive heart failure at presentation (p 0.08, hazard ratio: 2.8). Reconstruction of the ductal PA decreased the prevalence of pulmonary parenchymal hypoplasia (p < 0.00) and scoliosis at last available follow-up. Conclusions. Ductal origin of the distal PA is associated with important multisystem morbidity and mortality. Early diagnosis and repair of the ductal PA, especially in children presenting with pulmonary overcirculation, may improve outcomes. (Ann Thorac Surg 2006;8:950 7) 2006 by The Society of Thoracic Surgeons Accepted for publication Aug 29, *Dr Freedom died on May 7, Address correspondence to Dr McCrindle, The Hospital for Sick Children, 555 University Ave, Toronto, ON M5G X8, Canada; brian.mccrindle@sickkids.ca. Ductal origin of the distal pulmonary artery (PA) is a congenital condition in which the right or left PA supplying all the bronchopulmonary segments of the lung is in continuity with the distal end of the arterial duct (AD), without continuity to the main PA []. Closure of the AD results in progressive loss of blood flow to the dependent PA with perfusion of the affected lung dependent on either the bronchial or anomalous systemic collateral arteries, and is associated with multisystem morbidity. Pulmonary hypertension, lung and hemithorax hypoplasia, hemoptysis, scoliosis, high altitude pulmonary edema, and respiratory failure can occur [ ]. Appreciation of the pathophysiology, improved diagnostic imaging, and early intervention may prevent these sequelae [6, 7, 2 20]. That such a PA is not absent but undergoes progressive diminution upon closure of AD has been recognized [, 7, 8, 2 7]. We sought to determine the morphologic spectrum, impact of interventions, residual disease burden, and survival of patients with ductal origin of the distal PA. Patients and Methods Patients The databases of the Divisions of Cardiology and Pathology at the Hospital for Sick Children, Toronto, were reviewed to identify patients younger than 0 years presenting between January 970 and April 200. Imaging Data Angiograms were reviewed. A PA was deemed to have ductal origin when not confluent to the main PA with evidence of an ipsilateral AD. A ligamental AD was identified from a remnant diverticulum at typical sites on the aortic arch (Fig ). Bilateral ductal origin of the distal PAs was identified by the presence of bilateral ADs with absence of continuity between one of the distal PAs and the main PA. Patients with pulmonary atresia were excluded from the study if aortopulmonary collateral 2006 by The Society of Thoracic Surgeons /06/$32.00 Published by Elsevier Inc doi:0.06/j.athoracsur

2 Ann Thorac Surg TRIVEDI ET AL 2006;8:950 7 DUCTAL ORIGIN OF DISTAL PULMONARY ARTERY 95 Fig. (A) Selective angiogram showing arterial duct from the base of innominate artery with right pulmonary artery at its distal end. The triad of imaging findings with ligamental origin of the pulmonary artery is as follows: (B) diverticulum on the aortic arch on the same side as (C) nonopacification of the pulmonary artery and (D) demonstration of its presence by a pulmonary venous wedge angiogram. CARDIOVASCULAR arteries were a sole supply to bronchopulmonary segments of the lung without branches from the vessel at the distal end of AD. Pulmonary artery dimension was estimated by measuring the PA proximal to the upper lobe branch on the initial and the most recent angiogram with correction for magnification. The estimated dimension was indexed to the body surface area to normalize for age. The AD was described as follows: patent with opacification of the pulmonary artery, nonpatent diverticular, and nonpatent in the absence of angiographic findings of patency or diverticulum when there were operative findings of an AD. Plain radiographic films of the chest were reviewed for lung hypoplasia, which was classified as grade, 25%; grade 2, 25% to 50%; grade 3, more than 50%; and grade 0, no reduction of lung volume as compared with the contralateral lung. Outcome Data Evidence of right ventricular and pulmonary hypertension, pulmonary vascular disease, lung hypoplasia, bronchiectasis, hemoptysis, respiratory failure, congestive heart failure, and scoliosis was sought at latest follow-up. Exercise tolerance and medication histories were likewise determined at last available follow-up. Data Analysis Results are presented as number (percent) of patients, median with range or mean SD as appropriate. Where there are missing data, the number of nonmissing values is given. Time-related survival was determined by Kaplan-Meier estimates. The independent effect of the following variables on time-related survival was sought using Cox s proportionate hazard modeling: age at presentation, age at diagnosis, presenting features, associated cardiac and non-cardiac lesions, medical interventions, surgical interventions, transcatheter interventions, size of the ductal PA and the contralateral PA at diagnosis and at the latest angiographic follow-up, and the patency of AD at presentation. Changes in the PA dimensions from presentation to latest follow-up were compared using paired t tests. All analyses were performed using SAS statistical software Version 8 (SAS Institute, Cary, North Carolina) using default settings. Results Demographics and Presentation Forty-five eligible patients were identified. Mean birth weight (n 27) was 3.7 kg ( 0.57 kg). Median age at

3 CARDIOVASCULAR 952 TRIVEDI ET AL Ann Thorac Surg DUCTAL ORIGIN OF DISTAL PULMONARY ARTERY 2006;8:950 7 Table. Associated Cardiac Lesions Number Isolated Secundum atrial septal defect 2 Aberrant left subclavian artery Ventricular septal defect (restrictive) 2 With right ventricular muscle bundles Partial anomalous pulmonary venous return Interrupted inferior vena cava with hemiazygous continuation Tetralogy of Fallot Secundum atrial septal defect 4 Aberrant right subclavian artery Left superior vena cava to coronary sinus Absent pulmonary valve syndrome 2 Double-outlet right ventricle and left heart hypoplasia Coronary artery anomaly Aorto pulmonary window Partial anomalous pulmonary venous return Pulmonary atresia ventricular septal defect Secundum atrial septal defect 2 Pulmonary vein stenosis Left superior vena cava to coronary 2 sinus Retroaortic innominate vein Coronary artery anomaly Coronary artery fistula to main pulmonary artery Aberrant right subclavian artery 2 Aberrant left subclavian artery Heterotaxia Complex atrioventricular defect 3 With transposition of great arteries 2 Pulmonary atresia 4 presentation was 4 days (range, birth to 6.5 years). Patients with an isolated ductal PA without associated cardiac lesions presented significantly later (median, 3 months; range, birth to 8 years) than patients with associated complex cardiac lesions (median, day; range, birth to 4 days; p 0.002). Presenting features were cyanosis (n 30), heart murmur (n 23), congestive heart failure (n 2), frequent pulmonary infections (n 9), pulmonary hypertension (n 7), failure to thrive (n 6), dextrocardia on chest radiography (n 4), electrocardiographic right ventricular hypertrophy (n 3), chest pain (n 2), small hemithorax on chest radiography (n 2), and feeding difficulties (n ). Of patients with cyanosis, 3 had duct-dependent pulmonary circulation. Diagnosis Median age at diagnosis was 69 days (range, birth to 7.9 years). Patients with isolated ductal PA were diagnosed later (median, 98 days; range, 9 days to 6.8 years) than those with complex cardiac lesions (median, 6 days; range, birth to 7.9 years; p 0.0). Pulmonary venous wedge angiograms (n 27) were performed in 2 patients (47%) to demonstrate the presence of, or further evaluate a known ductal PA (n 22), identify the pulmonary veins (n ), estimate PA pressure (n ), and estimate PA size (n ). Morphologic Spectrum Ductal PA occurred in isolation (ie, without a major intracardiac malformation) in 6 patients (36%), with tetralogy of Fallot in 2 (27%), with pulmonary atresia ventricular septal defect in 3 (29%), and with heterotaxy in 4 (9%). Six of the 4 patients (3%) with bilateral AD had bilateral ductal PAs. The AD giving origin to the ductal PA was patent in 2 patients and nonpatent diverticular in 8 patients. In those with unilateral ductal PA, the ductal PA was contralateral to the aortic arch in all patients without a major intracardiac malformation, in 5 (42%) with tetralogy of Fallot, and in 2 (5%) with pulmonary atresia ventricular septal defect. Cardiac lesions grouped according to diagnostic type are listed in Table. Surgical Strategies Sixty-three surgical procedures were undertaken in 3 patients addressing intracardiac, ductal, and nonductal PA. Repair was either by single stage (n 4) or multistage repair (n 7). Surgical procedures included initial systemic-ductal PA shunt to rehabilitate a hypoplastic ductal PA in 3 patients (3 modified Blalock Taussig, 2 central). Subsequent complete reconstruction with an interposition graft from the ductal PA to the main PA was performed in 4 of these 3 patients. Initial placement of an interposition graft was undertaken in 6 patients; of these patients was subsequently revised to a systemicductal PA shunt. Interposition graft material consisted of Gore-Tex (W. L. Gore & Associates, Flagstaff, Arizona) in 6 patients and homograft in 2; pericardium and Dacron (C. R. Bard, Haverhill, Pennsylvania) were used in patient each. Direct end-to-end anastamosis to the main PA was performed in 2 patients as an initial surgical procedure and in 2 after initial systemic-ductal PA shunt operation. Reoperation (n 7) defined as surgical intervention after achievement of complete repair was undertaken in 6 patients. After direct anastamosis of the ductal PA to the main PA, anastomotic revision was required in 3 patients. Of the 3 patients with pulmonary atresia ventricular septal defect, 6 underwent unifocalization procedure of the ductal PA as a single-stage repair and had unifocalization as part of a staged repair. Initial banding of the ductal PA was performed in 2 patients to control heart failure. Cardiopulmonary bypass time was significantly shorter (mean, minutes) in patients with isolated ductal PA than it was in patients with complex cardiac lesions (mean, minutes; p 0.06). Aortic cross-clamping, performed in 8 procedures (median

4 Ann Thorac Surg TRIVEDI ET AL 2006;8:950 7 DUCTAL ORIGIN OF DISTAL PULMONARY ARTERY time, 43 minutes; range, 23 to 37) was not required in patients undergoing repair for isolated ductal PA. Transcatheter Strategies Catheter interventions (34 procedures), undertaken in 6 patients (35%), included procedures after surgical intervention in 2 (26%) and presurgical intervention in 7, including stent placement (n 3) and balloon angioplasty (n ) of the AD, balloon atrial septostomy (n ), and transeptal puncture (n 2). Median time to postsurgical catheter intervention was 6 months (range, 0 to 3.6 years). Procedures on the ductal PA were performed in 7 patients; these were balloon angioplasty (n ), stent implantation (n 6), and stent dilation (n 2). Procedures on the nonductal PA included angioplasty (n 4), stent implantation (n 2), and stent dilation (n ). Transcatheter reintervention (2 procedures) for augmentation of PA dimension was undertaken in 5 patients. Stent implantation in Blalock-Taussig shunt (n ), conduit dilation (n ), stent implantation in right ventricular outflow tract (n 2), balloon dilation of right ventricular outflow tract (n ), intraoperative balloon angioplasty of the PA (n ), and coil embolization of major aortopulmonary collateral artery (n ) were other catheter interventions. Results of Intervention Figure 2 is a flow diagram outlining events after presentation in all 45 patients. Interventions were performed more often (p 0.005) in patients with complex defects (86%) versus isolated ductal PA (44%). Intracardiac repair with confluent PAs was achieved in 8 patients (67%) with tetralogy of Fallot and in 0 (77%) with pulmonary atresia ventricular septal defect. Cardiac transplantation resulted in full repair with confluent PAs in patient with heterotaxy. Complete repair of the ductal PA was achieved in 22 patients, of whom 7 survived. Complete repair was attempted but not achieved in 0, and was not attempted in 3 patients. Of these 23 patients, 6 survived. Complete repair of the ductal PA was more likely (p 0.005) in patients with complex lesions (66%) than in patients without such lesions (9%). Late presenting patients with diminutive ductal PA occurring in isolation Fig 2. Flow chart showing outcomes in 45 patients with a ductal pulmonary artery after presentation to the Hospital for Sick Children. 953 were more likely to be routed to nonintervention. Causes of death are listed in Table 2. Important cardiac morbidity occurred in 6 patients (3%) and included infective endocarditis (n 2), inferior vena cava thrombus (n ), femoral vein stenosis (n ), chronic atrial flutter with venous thrombosis (n ), and reentrant tachycardia (n ). Outcomes Overall survival was 82% at 6 months, 76% at 2 years, and 70% at 20 years (Fig 3). By multivariable analysis, the presence of congestive heart failure at presentation was associated with decreased survival (p 0.08, hazard ratio [HR] 2.8). Patency of the AD showed a trend toward decreased survival (p 0.2, HR 3.40) as did higher indexed ductal PA diameter at presentation (p 0.7, HR.04 per mm/m 2 increment). Angiographic Results of PA Dimensions and Growth The mean indexed dimension of the ductal PA (right or left) was 9.6 mm/m 2 (range, 3.3 to 44. mm/m 2,n 36) at diagnosis and 6.9 mm/m 2 (range, 3.4 to 39.9 mm/m 2,n 2) at the most recent angiographic follow-up. The mean indexed dimension of the nonductal PA (right or left) was 28.8 mm/m 2 (range, 7.6 to 68.5 mm/m 2,n 35) at diagnosis and 2.6 mm/m 2 (range,.0 to 45.0 mm/m 2,n 24) at latest available follow-up. There was a small but significant decrease in the dimension of both the ductal (p 0.005) and the nonductal PA (p 0.02), with the ductal PA having a smaller dimension both at presentation (p 0.002) and at follow-up (p 0.2; Fig 4). The McGoon ratio did not change significantly (mean change, , p 0.3) from presentation (mean, , n 32) to follow-up (mean, , n 6), nor did the Nakata index (mean change, , p 0.0) from presentation (mean, , n 30) to follow-up (mean, , n 2). Clinical Follow-Up Mean follow-up for the 33 survivors was 7.7 years (range, days to 20 years). At latest follow-up of survivors, right ventricular hypertension (more than 30% of systemic pressure) and pulmonary hypertension (mean PA pressure more than 25 mm Hg) by catheterization data were present in 57% (n 28) and 30% (n 30), respectively, in the absence of significant intracardiac shunts. Angiographic pulmonary vascular disease was present in 3.5% (n 28), congestive heart failure in 3% (n 32), radiographic ipsilateral lung hypoplasia in 52% (n 2), and scoliosis in 44% (n 2). Somatic growth impairment (weight less than the third percentile) occurred in 64% (n 34). Cardiac medications were required in 7% (n 35). Exercise tolerance was New York Heart Association class I in 20, II in 4, and III and IV in patient each. Important additional outcomes included 3 patients with repair to a single lung, and patient each with cardiac transplantation, pneumonectomy, severe impairment of right ventricular function, and an atrial septal defect. Among survivors, lung hypoplasia was more prevalent among patients without complete repair of the ductal PA CARDIOVASCULAR

5 CARDIOVASCULAR 954 TRIVEDI ET AL Ann Thorac Surg DUCTAL ORIGIN OF DISTAL PULMONARY ARTERY 2006;8:950 7 Table 2. Cause of Death in Patients With Ductal Pulmonary Artery Lesion Cause (Year). Isolated Pneumohemothorax (984) Interval (Intervention to Death) Confluence Autopsy 3 days No Right heart dilation, pulmonary congestion, and hemorrhage 2. Isolated PHT (989).5 months No Not available 3. Isolated Bronchiolitis, PHT, 2 cardiac output (989) 4. Isolated Failure to wean off bypass (995) 5. TOF/DORV Not known (992) 6. PA-VSD Not known (98).5 months No Right ventricular dilation, hypertrophy, pulmonary congestion 0 days Yes Myocardial necrosis a a No No Not available Bronchopneumonia, thrombus- PA, pulmonary congestion, myocardial infarction 7. PA-VSD Sepsis (998) 9 days Yes Lung abscesses, occlusive PA thrombus 8. PA-VSD Cardiorespiratory 3 months Yes Not available arrest (999) 9. PA-VSD Not known (2000) 2 months Yes Rupture of right ventricular pseudoaneurysm 0. PA-VSD Not known (985) 2.5 months Yes Not available. PA-VSD Aortic dissection 0 days No Not available NEC (998) b 2. Heterotaxia NEC sepsis (98) No Not available a No intervention. b Postembolization of ductal stent. DORV double-outlet right ventricle; NEC necrotizing enterocolitis; PA pulmonary artery; PHT pulmonary hypertension; TOF tetralogy of fallot; VSD ventricular septal defect. (p 0.00). The prevalence of scoliosis was also higher among patients without complete repair of the ductal PA (67%) compared with patients with repair (22%), although statistical significance was not reached. Comment Ductal origin of the PA occurs in.5% of patients with discontinuous PAs [22]. The terms previously used to describe this condition, unilateral absent pulmonary artery and isolated unilateral pulmonary artery agenesis, are misleading because an intrapulmonary vessel Fig 3. Kaplan-Meier survival curve after presentation for the entire group with ductal pulmonary artery. Dotted lines represent the 95th percentile. with relatively normal distribution is present in these patients [4]. More recently, the term isolated unilateral absence of the proximal pulmonary artery has been applied [2]. The term ductal origin of the distal PA is preferable because it gives insight into the embryology of this rare lesion and most correctly captures those anatomic features with important pathophysiologic impact [6, 4, 7, 9 22]. The principal embryologic explanation for ductal origin of the PA is involution of the proximal sixth aortic arch, which results in absence of the proximal pulmonary artery and the persistent connection of the hilar pulmonary artery to the distal sixth aortic arch (destined to become the ductus arteriosus) [2, 4]. All patients in our study had a ductus arteriousus or ligamentum ipsilateral to the absent proximal PA, and complete literature review revealed only case [20] in which an ipsilateral ductus arteriosus was not identified [, 8, 2, 4, 9, 22 26]. Presentation and Diagnosis Cyanosis is a common presenting feature in those with associated cardiac lesions. When ductal origin of the distal PA is in isolation, persistent pulmonary hypertension is common, occurring in 9% to 88% of infants [7, 0, 25]. Frequent respiratory infections, an abnormal chest radiogram, or hemoptysis are later presenting features [2, 0,, 27, 28]. Accurate diagnosis requires several modalities [2, 4]. Echocardiography is a useful screening modality, but is insufficient to make a definitive diagnosis

6 Ann Thorac Surg TRIVEDI ET AL 2006;8:950 7 DUCTAL ORIGIN OF DISTAL PULMONARY ARTERY Fig 4. Initial and latest angiographic dimension of (top) the ductal pulmonary artery (PA) and (bottom) the nonductal pulmonary artery. (DDO ductal origin of the distal pulmonary artery; non- DDO non-ductal origin of the distal pulmonary artery.) [2, 4, 8, 20]. One study found that echocardiography depicted the absent PA in older patients, but findings were inconclusive in infants [4]. Demonstration of the hilar blind end of the PA with branches to all the bronchopulmonary segments of the lung by pulmonary venous wedge angiography is diagnostic [2, 29]. Angiography is particularly helpful in planning surgical intervention as it can provide hemodynamic data and depict hypoplastic intrapulmonary vessels that may require rehabilitation with a systemic-ductal PA shunt before single-stage repair [4]. Noninvasive techniques such as contrast-enhanced arterial and venous phase computed tomography and magnetic resonance imaging are potential alternatives to angiography [2, 4, 30]. These modalities have consistently produced quality anatomic definition of the pulmonary arteries in previous studies [2 4, 20] and can demonstrate the presence of additional pathology, such as aortopulmonary collaterals. Ventilation-perfusion scans are useful to follow PA perfusion equivalence after surgical repair [2, 4]. 955 Treatment Strategies Treatment varied extensively in our study population, reflecting the historical nature of this series. Initial palliation with a systemic-ductal PA shunt for those without pulmonary overcirculation was favored early in our experience. This strategy continues to be used in our center as a first-stage rehabilitative procedure for those with hypoplastic ductal PA followed by later complete reconstruction, similar to the management paradigm for patients with small PAs and a diagnosis of pulmonary atresia and ventricular septal defect. Although ductal PA banding was undertaken in 2 patients, we would not recommend this in the present era, as patients with overcirculation generally have adequate size pulmonary arteries, and the contemporary results with primary complete repair (ie, primary unifocalization of the ductal PA) at our institution have been favorable in this population. Furthermore, patients presenting with overcirculation in this series generally had the worst outcomes and may derive magnified benefit from early definitive correction. Direct end-to-end anastomosis without patch augmentation cannot be recommended, as all patients in our series managed with this approach required either surgical revision or catheter-based reintervention for stenosis. Newer strategies using autologous tissue reconstruction with anterior patch augmention may potentially obviate these problems and provide attractive alternatives to other repair methods [2, 3]. Welch and colleagues [2] described a technique incorporating a filleted ligamentum to bridge the gap between the ductal PA and the main PA with anterior pulmonary homograft patch augmentation. The 2 patients managed with this technique at 30 months of follow-up had equivalent blood-flow distribution to both lungs on ventilationperfusion scan, no evidence of pulmonary stenosis, and normal PA pressures. Kosaka and coworkers [3] similarly described a completely autologous tissue reconstruction in which a longitudinally incised ductal PA is anastomosed to a reverse U-shaped pedicled flap developed from the left PA. The anterior surface is then covered with an autologous pericardial patch. At 6 years postoperatively, angiography demonstrated normal PA pressures without evidence of PA stenoses. Interposition grafts were used in 0 patients in our series, either as a single-stage reconstruction or as the second stage in patients requiring initial rehabilitation with a systemic-ductal PA shunt. The small number of patients managed with a single strategy precluded definitive identification of either the optimal method of reconstruction of the ductal PA, or the optimum graft material. However, the important disadvantages of using an interposition graft, including somatic outgrowth and need for anticoagulation, make this a theoretically less attractive option for many children [2, 3], especially given the recent introduction of autologous tissue reconstruction. Transcatheter therapy has an important role in management of patients both preoperatively and during follow-up. In the short term, stent implantation in the AD CARDIOVASCULAR

7 CARDIOVASCULAR 956 TRIVEDI ET AL Ann Thorac Surg DUCTAL ORIGIN OF DISTAL PULMONARY ARTERY 2006;8:950 7 can maintain blood flow to the ductal PA. Balloon atrial septostomy supports cardiac output in those with severe pulmonary hypertension. Stenosis after surgical PA reconstitution can be managed by balloon angioplasty and stent implantation. Patients with recurrent hemoptysis benefit from coil embolization of collateral arteries []. Early diagnosis and intervention have been advocated in other case reports [2, 3, 8 20, 25, 28, 3, 32]. The benefit of early intervention may be magnified in patients with pulmonary overcirculation. In our study, the presence of congestive heart failure and larger ductal PA dimensions were associated with increased mortality. Delayed therapy may result in diminutive PA size or pulmonary hypertension, precluding later reconstruction [2 4, 3, 32]. Furthermore, the likelihood of lifethreatening hemorrhage from acquired indirect aortopulmonary collaterals may complicate later surgical repair [25, 28]. Such patients may require pneumonectomy for intractable infection or unremitting hemoptysis [25, 28]. Detection of a benefit to complete repair of the ductal PA is complicated by several factors: () those not undergoing repair had favorable morphology and no associated cardiac malformations; (2) the morbidity in unrepaired patients occurs mainly late, and thus is likely underreported with only midterm follow-up data available in this series; and (3) incorporation of older repair methods may dilute potential benefits gained by more recent surgical and catheter-based techniques. Our data on PA dimensions suggest suboptimal growth of the ductal PA irrespective of the type of repair chosen. The evidence of considerable residual disease burden in our patients at last follow-up supports this contention. However, patients who underwent complete repair had less lung hypoplasia and scoliosis than did patients who remained unrepaired. Inferences and Recommendations Our experience suggests that the critical factor that determines treatment strategy is ductal PA size at diagnosis. For patients without pulmonary overcirculation, early staged repair with systemic-ductal PA shunt to rehabilitate the hypoplastic ductal PA followed by later autologous tissue reconstruction with patch augmentation is advisable. Similarly, early single-stage repair with autologous tissue reconstruction and patch augmentation for patients with adequately sized PAs or with pulmonary overcirculation is preferred. Close surveillance by noninvasive imaging with judicious reintervention is indicated to reduce residual disease. Patient education and surveillance is indicated for the late presenting patient who is deemed unsuitable for intervention. To conclude, we have described the largest series of patients with ductal origin of the distal PA and have shown that there is important multisystem morbidity and mortality associated with this condition. Early diagnosis and repair of the ductal PA, especially in patients presenting with congestive heart failure or a large ductal PA, may improve outcomes. References. Sotomora R, Edwards J. Anatomic identification of so-called absent pulmonary artery. Circulation 978;57: Byrne R, Bloom D. Absence of the right pulmonary artery as a cause of hemoptysis. J Thorac Cardiovasc Surg 970;59: Hackett PH, Creagh CE, Grover RF, et al. High-altitude pulmonary edema in persons without the right pulmonary artery. N Engl J Med 980;302: Rene M, Sans J, Dominguez J, et al. Unilateral pulmonary artery agenesis presenting with hemoptysis: treatment by embolization of systemic collaterals. Cardiovasc Intervent Radiol 995;8: Massumi R, Donohoe R. 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8 Ann Thorac Surg TRIVEDI ET AL 2006;8:950 7 DUCTAL ORIGIN OF DISTAL PULMONARY ARTERY 25. Canver C, Pigott J, Mentzer R Jr. Neonatal pneumonectomy for isolated unilateral pulmonary artery agenesis. Ann Thorac Surg 99;52: Ten Harkel A, Blom NA, Ottenkamp J. Isolated unilateral absence of a pulmonary artery: a case report and review of the literature. Chest 2002;224: Cogswell T, Singh S. Agenesis of the left pulmonary artery as a cause of hemoptysis. Angiology 986;37: Bekoe S, Pellegrini R, DiMarco R Jr, et al. Pneumonectomy for unremitting hemoptysis in unilateral absence of pulmonary artery. Ann Thorac Surg 993;55: Freedom R, Pongiglione G, Williams W, et al. Pulmonary vein wedge angiography: indications, results, and surgical correlates in 25 patients. Am J Cardiol 983;5: Lynch D, Higgins C. MR imaging of unilateral pulmonary artery anomalies. J Comput Assist Tomogr 990;4: Salaymeh K, Kimball T, Manning P. Anomalous pulmonary artery from the aorta via a patent ductus arteriosus: repair in a premature infant. Ann Thorac Surg 2000;69: Wang TD, Lin YM, Hwang JJ, Lee YT. Unilateral pulmonary artery agenesis in adulthood. Not always a benign disease. Chest 997;: CARDIOVASCULAR The Society of Thoracic Surgeons Policy Action Center The Society of Thoracic Surgeons (STS) is pleased to announce a new member benefit the STS Policy Action Center, a website that allows STS members to participate in change in Washington, DC. This easy, interactive, hassle-free site allows members to: Personally contact legislators with one s input on key issues relevant to cardiothoracic surgery Write and send an editorial opinion to one s local media senators and representatives about upcoming medical liability reform legislation Track congressional campaigns in one s district and become involved Research the proposed policies that help or hurt one s practice Take action on behalf of cardiothoracic surgery This website is now available at by The Society of Thoracic Surgeons Ann Thorac Surg 2006;8: /06/$32.00 Published by Elsevier Inc