Fifteen years of experience in repair of aortopulmonary window in children

Introduction: Aorto-pulmonary window is a very rare Malformation which accounts for about 0.15% of all cardiac anomalies. There is no tendency for AP windows to close spontaneously. The natural history of infants with large AP windows is as unfavorable rarely they survive to childhood and those who survive beyond early life have important pulmonary vascular disease (1). The Richardson classification system for aorto-pulmonary window includes simple defects between the ascending aorta and pulmonary trunk (type I), defects extending distally to include the origin of the right main pulmonary artery (type II), and anomalous origin of the right main pulmonary artery from the ascending aorta with no other aorto-pulmonary communication (type III). Material and Methods: We reviewed our cases of aorto-pulmonary window who underwent surgical repair From 1992 to 2007 at Sahid Rajee Heat center, Tehran, Iran. There were 30 children with male to female ratio of 2:1 .We evaluated demographic information of the patients.We used different operative techniques . The approach for AP Window repair was ligation without CPB in two cases, division and suturing using CPB in one patient, trans-window in 17 (PTFE patch in16; Dacron in 1), trans-aortic in 9 (in 8 PTFE patch, in one simple suturing) and trans-pulmonary in 2 (both with PTFE) Among 15 patients with associated cardiac anomalies, 13 (87%) underwent single stage repair with the IAA repair was the most common (2 cases) .Factors such as cross-clamp and bypass time, mortality, early and late morbidity, ICU stay, hospital stay, duration of ventilator support were compared between groups with various methods of repair using “SPSS 16”. Resullts: In among 30 patients male to female ratio was 2:1 .Mean age of the opatients was 28± 9 months ;range 2-90 months,weight 8.6±4.6;range 2-17 kg . Most patients (73%) had sub-systemic or systemic pulmonary hypertension (23% and 50% respectively) .Morphology of Ap windows was type I (87%, n=26), type II (10%, n=3) distal and one type III (3%), This agree with other reportsres. 63% of patients were symptomatic, most commonly dyspnea and 43% were in heart failure on admission. Preoperative EF was 0.66 ± 0.07 which increased to 0.75 ± 0.07 post-operatively apparently duo to elimination of shunt and resultant increase in forward flow of aorta. Preoperative pulmonary artery pressure was 63 ± 13 mm Hg. 19 (63%) of patients had associated cardiac anomalies most frequently various forms of Aortic stenosis (23%) fallowed by interrupted aortic arch (IAA), coronary anomalies and VSD (each about 7%). In most other series IAAhas been most common associated anomaly (6), (7). The overall in-hospital mortality was 10% (3 patients), two of whom had associated anomaly, one had undergone arterial switch operation for TGA who couldn’t be separated from CPB, and the other one had simultaneous repair for interrupted aortic arch. The mortality was no different among patients with or without associated anomaly (10% each). Among the 27 survivors, the mean ICU stay was 4.4 days (range 3 -12 days) and the mean post-operative hospital stay was 10.7 days (range 7 -16 days). Early complications were bleeding (two cases), pneumonia (one) and CVA (one). Mean follow-up was 49 months (range 2 – 280 months) and there was no re-operation or late death. There were 4 cases of residual AP Window detected by echocardiography; none of them required re-intervention. Among patients with residual AP Window two cases were seen with banding technique (100%) one with trans-aortic patch repair (11%) and one case with trans-window patch repair (5%). Discussion: An aorto-pulmonary window is a communication between the pulmonary artery (PA) and the ascending aorta in the presence of two separate semilunar valves. There is no tendency for AP Windows to close spontaneously [8] Since the early 1990s, diagnosis has relied exclusively on two-dimensional echocardiography [9] but type II and III lesions are difficult to differentiate from PDA [10]. Cardiac catheterization and cineangiography with retrograde aortography is done in infants 6 months of age for evaluating the presence of irreversible pulmonary vascular disease and in case of complex APW for delineating the exact morphology. In our series in 27% (8) of patients the diagnosis was made only through echocardiography, remainder of the cases was diagnosed via both echocardiography and angiography.Using multivariate analysis, we assessed the effects of (1) patient related factors (age, sex, weight and type of aorto-pulmonary window) and (2) procedural factors (type of approach) on post-operative course (ICU stay, Post-operative hospital stay, duration of ventilator support and post-operative EF). Age ,sex and weight had no clear impact on post operative course. As mentioned earlier the overall in-hospital mortality was 10% (3 patients). The reported mortality among other series ranged from 7.6% to 27%).The mortality was no different among patients with or without associated anomaly (3% each). Also there was no difference among various methods of repair in respect of morbidity, ICU stay; ventilator support and post operative EF . Conclusion: In our view Trans aortic or transwindow repair is the procedure of choice for APW repair and, simple ligation without CPB should be avoided due to the possibility of residual APW and distortion of pulmonary artery.