aortopulmonary window ( apw ) is a rare entity in congenital heart disease with a prevalence of 0.2%0.4% of all the cardiac lesions .
we present an infant with a distal apw who underwent surgical repair of the same and stressed the importance of intraoperative transesophageal echocardiography ( tee ) as an invaluable tool that aids in confirming and assessing the adequacy of surgical repair .
a 4-month - old boy , 4.5 kg , presented to our hospital with a history of recurrent upper and lower respiratory infections , feeding difficulties and excessive forehead sweating , progressive tachypnea , and obvious chest retraction at rest and a soft systolic heart murmur .
his cardiothoracic ratio was near 65% in chest x - ray [ figure 1 ] .
chest x - ray revealing cardiomegaly with dilated pulmonary artery and congested lung fields transthoracic echocardiography showed increased the pulmonary venous return to the left atrium , dilated all four chambers , large distal apw ( 15 mm  11 mm ) , intact interventricular septum .
cardiac catheterization was deferred as the defect was quite evident on two - dimensional echo with an increased pulmonary venous return to the left atrium and the infant being 4 months in age with chest x - ray showing plethoric lung fields and cardiomegaly , surgical repair was planned .
mid - esophageal view at 86 with probe turned to the right revealing a patent foramen ovale shunting left to right upper esophageal view at 0 revealing the aortopulmonary window extending till the bifurcation of the pulmonary artery upper esophageal view with a transesophageal echocardiography demonstrating the aortopulmonary window measuring 11.2 mm color doppler ( left ) showing turbulent flow in pulmonary artery across the aortopulmonary window the child was subjected to a surgical repair .
intraoperative snapshot of the aortopulmonary window from head end cardiopulmonary bypass ( cpb ) was instituted after occluding pulmonary arteries with moderate hypothermia using two venous cannulas and a single arterial cannula positioned in the aorta distal to the defect .
upper esophageal view at 24 postrepair showing the gore - tex patch closure of the defect the child had an uneventful postoperative course in the hospital with regression of pulmonary hypertension .
an apw is a communication between the pulmonary artery ( pa ) and the ascending aorta in the presence of two separate semilunar valves .
mori et al . classified the apw as proximal , distal , and total depending on the extent of the lesion .
richardson classified apw as simple defects between the ascending aorta and pulmonary trunk ( type i ) , defects extending distally till the bifurcation of pa ( type ii ) , and anomalous origin of the right main pa from the ascending aorta with no other aortopulmonary communication ( type iii ) .
complex apw is associated with ventricular septal defect ( vsd ) , interrupted aortic arch , transposition of the great artery , tetralogy of fallot , or coronary artery anomalies .
there can be artifactual dropouts with transthoracic echo in the lateral wall of the aorta with normal or aberrant coronaries in the aortic root area which does not happen with a transesophageal echo that can be superior in imaging the defect .
there have been reports regarding the role of intraoperative transesophageal echo in complex apw . cardiac catheterization and cineangiography with retrograde aortography are 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 .
closure of apw is indicated in all patients , and it should be performed as soon as possible after diagnosis .
successful repair of an apw was reported from several years ago , and many authors have reported their results . the spectrum of the surgical techniques which evolved with time include simple ligation , division and suturing without cpb , division and suturing with cpb , trans - pa closure using cpb , trans - window closure ( anterior sandwich patch closure ) , transaortic direct closure ; to transaortic patch closure of the defect ; using cpb and arresting the heart .
transaortic direct closure of an apw was first reported by wright et al . in 1968 . in the year 1969 , deverall et al .
we had used a gore - tex patch to close the defect in our patient by transaortic route , and the pfo was closed .
as the transaortic repair using cpb allows accurate visualization of coronaries arteries and right pa reconstruction using a dacron patch without distorting either the aorta or the pa , it is the recommended approach for most patients with an apw .
the possible occurrence of pulmonary hypertensive crisis should be kept in mind while managing these children in the postoperative period .
intraoperative tee aids in confirming the diagnosis and is an invaluable tool in detecting additional intracardiac defects which may have been missed by a transthoracic echocardiography .
the severe pulmonary hypertension usually associated with apw may mask underlying small shunts in the heart which become evident once we close the apw .
tee is more sensitive in picking up the defects in the prebypass period , as well as postbypass , when it mandates addressing the additional shunts immediately .
in addition , tee in postbypass period confirms the adequacy of repair and detects any residual shunt across the window , direction of pfo shunting indicates the severity of pulmonary arterial hypertension , valvular competence of the semilunar valves , the left ventricular function which can have an afterload mismatch when shunt across into the low resistance pulmonary circulation is suddenly removed , and the delineation of coronaries postrepair in type 1 proximal apw .
tee guides us in the postoperative plan of an apw repair patient , be it simple or complex , the pulmonary hypertension management and left ventricular afterload reduction strategies .
postoperative mortality depends on the age of the patient at operation , status of preoperative pulmonary vascular disease , and presence of associated intracardiac defects .
as the natural history of apw is similar to that of a large vsd or pda , early recognition is necessary for a successful surgical result before the onset of irreversible pulmonary vascular disease in both simple and complex apw .
 aortopulmonary window ( apw ) is a relatively rare cardiac lesion representing approximately 0.2%0.4% of all cardiac malformation . 
 it is a cardiac abnormality that results from abnormal communication between the proximal aorta and the main pulmonary artery in the presence of two normally separated aortic and pulmonary valves . in the past , the diagnostic and surgical approach to apw was almost always preceded by cardiac catheterization . with recent advances in noninvasive approach and techniques of two - dimensional echocardiography diagnosis of the defect and associated anomalies 
 are facilitated without a cath study . 
 we report a 4-month - old infant with a distal apw who was referred to our center for surgical repair . 
 we emphasize the usage of transesophageal echocardiography as a valuable intraoperative tool which not only confirms the preoperative diagnosis but also helps in assessing the surgical repair of an apw . 
INTRODUCTION
CASE REPORT
DISCUSSION
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