surgical repair of congenital heart defects has undergone a remarkable evolution in a developing country like india . a significant proportion of major defects are now often completely corrected in early infancy with improving rates of survival . residual cardiovascular lesions , anatomical or functional are a major cause of morbidity and mortality after surgical repair . the increasing availability and use of epicardial echocardiography have made the pediatric cardiac surgeons aware that intraoperative epicardial echocardiography can provide valuable information during all types of procedures . epicardial echocardiography was introduced 3 decades ago and resulted in prompt recognition of significant residual defects . later , transesophageal echocardiography ( tee ) was introduced and largely replaced it in adults undergoing cardiac surgery . in our center , transesophageal echocardiography is not performed in neonates , infants , and small children undergoing cardiac surgery for congenital heart defects . in the above mentioned pediatric population epicardial echocardiography was introduced since 2010 . hence , a prospective study was designed to determine the accuracy of epicardial echocardiography to detect residual lesions and its impact on surgical outcome . to determine this , intraoperative epicardial echocardiography was compared with surgical findings and immediate postoperative transthoracic echocardiography done in intensive therapy unit . pediatric and adult patients with congenital heart disease undergoing cardiac surgery involving cardiopulmonary bypass between january 2012 and december 2012 were studied . data collection included cardiac diagnosis , surgical procedure , epicardial echocardiography findings , surgical revision , surgical outcome , and postoperative transthoracic echocardiography findings . all the cases of epicardial echocardiography were done using sonos 7500 echo machine with s12 probe in infants , s8 probe in children , and s3 probe in adults . a small quantity of ultrasound gel was put in gloves in addition to applying on the probe head . parasternal long axis view was useful for assessment of ventricular septal defect ( vsd ) , left ventricular outflow tract , aortic valve , mitral valve , and pulmonary venous return to left atrium . with modification of long axis view it was possible to visualize the right ventricular inflow and outflow . short axis view of great vessels was useful to assess flow across the pulmonary valve annulus , branch pulmonary artery , and residual patent ductus arteriosus . short axis view at the level of ventricle was used to assess the muscular vsd , shape of the ventricle and systolic ventricular function . in those patients with residual lesions detected by epicardial echocardiography it was performed as a routine in all patients within 24 h of surgery , usually before extubation in the intensive therapy unit . subsequent echo studies were done according to the need of the patient . as a routine pre discharge echo pediatric and adult patients with congenital heart disease undergoing cardiac surgery involving cardiopulmonary bypass between january 2012 and december 2012 were studied . data collection included cardiac diagnosis , surgical procedure , epicardial echocardiography findings , surgical revision , surgical outcome , and postoperative transthoracic echocardiography findings . all the cases of epicardial echocardiography were done using sonos 7500 echo machine with s12 probe in infants , s8 probe in children , and s3 probe in adults . a small quantity of ultrasound gel was put in gloves in addition to applying on the probe head . parasternal long axis view was useful for assessment of ventricular septal defect ( vsd ) , left ventricular outflow tract , aortic valve , mitral valve , and pulmonary venous return to left atrium . with modification of long axis view it was possible to visualize the right ventricular inflow and outflow . short axis view of great vessels was useful to assess flow across the pulmonary valve annulus , branch pulmonary artery , and residual patent ductus arteriosus . short axis view at the level of ventricle was used to assess the muscular vsd , shape of the ventricle and systolic ventricular function . in those patients with residual lesions detected by epicardial echocardiography it was performed as a routine in all patients within 24 h of surgery , usually before extubation in the intensive therapy unit . subsequent echo studies were done according to the need of the patient . as a routine pre discharge echo a total of 290 pediatric and adult patients with congenital heart disease were operated between january 2012 and december 2012 . in 224 of them the primary diagnosis of patients in whom epicardial echo was done is given in table 1 . distribution of various surgical cases for whom epicardial echocardiography was done asd = atrial septal defect ; vsd = ventricular septal defect ; av = arterioventricular ; alcapa = anomalous origin of left coronary artery from pulmonary artery ; lmca = left main coronary artery based on the epicardial echo findings , a total of 38 out of 158 cases were having residual lesions . significant residual lesions were found in 28 cases . in 24 out of these 28 cases , table 2 describes these 24 cases . in remaining four cases who had significant residual lesion , residual postoperative lesions requiring immediate reoperation ( n = 24 ) rvot = right ventricular outflow tract ; vsd = ventricular septal defect ; icr = intracardiac repair ; lpa = left pulmonary artery ; ivc = inferior vena cava ; asd = atrial septal defect out of 53 cases of vsd closure , there were significant residual vsd seen in 10 cases . in three of them had residual shunt across swiss cheese vsds , four were newly diagnosed additional vsd , and three had significant shunting through the edge of the patch . in four cases of vsd patch closure , there was tiny residual leak detected in the postoperative period which were not mentioned in the epicardial echocardiography report [ figures 1 and 2 ] . however , the shunt was nonsignificant and postoperative course was uneventful . there were two cases with significant residual vsd shunt detected by postoperative echocardiography . in both these cases epicardial echo epicardial echocardiography showing ventricular septal defect ( vsd ) patch with no residual shunt epicardial echocardiography showing vsd patch with residual vsd it was seen in eight cases . in five out of these eight cases the chordae of septal leaflet of the tricuspid valve had got trapped in vsd patch closure , resulting in non - coaptation between anterior and septal leaflet of tricuspid valve . tricuspid valve repair to correct tr was done in four out of these eight cases . in remaining cases of new onset severe tr however , in none of these cases the epicardial echo showed left ventricular dysfunction . in 10 out of 14 patients there it was an observation seen in adolescent and adults with large vsd who had undergone surgical patch closure . left ventricular systolic dysfunction was noticed in 1 postoperative day which subsequently worsened . in an infant with large vsd who had undergone patch closure developed new onset severe ventricular dysfunction with mitral regurgitation which was not seen in the epicardial echo . on a detailed echocardiography evaluation it was diagnosed as a case of anomalous origin of left coronary artery from pulmonary artery ( alcapa ) , which was not reported in preoperative and epicardial echocardiography . preoperatively the child had normal left ventricle systolic function , large vsd with severe pulmonary arterial hypertension ( pah ) . after surgical patch closure of the vsd , the pulmonary arterial pressures significantly dropped resulting in coronary steal phenomena and new onset left ventricle dysfunction . in four cases , two had undergone repair for tetralogy of fallot , one each for rastelli and truncus repair . a total of 38 cases of the icr for tetralogy of fallot were done . in four patients , , the pulmonary artery annulus was causing significant turbulence and there was significant gradient across the pulmonary valve . in remaining one case , there was left pulmonary artery origin stenosis which had persisted even after left pulmonary artery plasty . there was a significant right ventricular outflow tract obstruction noted in one case in postoperative echocardiography , which was not mentioned in the epicardial echo . doppler echocardiography was not able to detect significant gradient . however , direct measurement of pressure in operation theatre showed near systemic right ventricular pressure . it was discovered that child had borderline sized pulmonary artery resulting in increased main pulmonary artery pressure and hence significant gradient was not detected in the right ventricular outflow tract . in a total of eight cases of asd ( four ostium primum + four sinus venous defects ) epicardial echo was done . there was no significant residual mitral regurgitation seen . however , one case of inferior vena cava ( ivc ) type of sinus venosus asd had postoperative desaturation . epicardial echo confirmed direction of ivc flow to left atrium which was corrected . in two out of five cases of aso , there was severe stenosis of both branch pulmonary arteries . in one case , it was due to kinking of pulmonary artery anastamosis and in another there was narrowing of anastamosis site . in both these cases , the diagnosis was done by epicardial echocardiography and immediate repair was done . out of 10 cases of tapvc for whom epicardial echo was done , one case of infracardiac type of tapvc had significant stenosis at the anastamosis site . repair of stenosis was done immediately . in all the remaining cases the repair was adequate . in one case of senning , there was stenosis of systemic venous baffle that caused superior vena caval obstruction as detected by turbulent flow and mean gradient of 5 mmhg . in three out of seven cases reported to have mild mitral regurgitation after mitral valve repair by epicardial echocardiography , the severity increased to moderate . two cases of vsd patch closure had significant residual vsd shunt . one case of patent ductus arteriosus ( pda ) ligation had residual pda flow seen in postoperative echocardiography . out of 53 cases of vsd closure , there were significant residual vsd seen in 10 cases . in three of them had residual shunt across swiss cheese vsds , four were newly diagnosed additional vsd , and three had significant shunting through the edge of the patch . in four cases of vsd patch closure , there was tiny residual leak detected in the postoperative period which were not mentioned in the epicardial echocardiography report [ figures 1 and 2 ] . there were two cases with significant residual vsd shunt detected by postoperative echocardiography . in both epicardial echocardiography showing ventricular septal defect ( vsd ) patch with no residual shunt epicardial echocardiography showing vsd patch with residual vsd the chordae of septal leaflet of the tricuspid valve had got trapped in vsd patch closure , resulting in non - coaptation between anterior and septal leaflet of tricuspid valve . tricuspid valve repair to correct tr was done in four out of these eight cases . in remaining cases of new onset severe tr however , in none of these cases the epicardial echo showed left ventricular dysfunction . in 10 out of 14 patients there it was an observation seen in adolescent and adults with large vsd who had undergone surgical patch closure . left ventricular systolic dysfunction was noticed in 1 postoperative day which subsequently worsened . in an infant with large vsd who had undergone patch closure developed new onset severe ventricular dysfunction with mitral regurgitation which was not seen in the epicardial echo . on a detailed echocardiography evaluation it was diagnosed as a case of anomalous origin of left coronary artery from pulmonary artery ( alcapa ) , which was not reported in preoperative and epicardial echocardiography . preoperatively the child had normal left ventricle systolic function , large vsd with severe pulmonary arterial hypertension ( pah ) . after surgical patch closure of the vsd , the pulmonary arterial pressures significantly dropped resulting in coronary steal phenomena and new onset left ventricle dysfunction . in four cases , two had undergone repair for tetralogy of fallot , one each for rastelli and truncus repair . a total of 38 cases of the icr for tetralogy of fallot were done . in four patients , there was a small residual shunt which was not considered significant . in eight cases , the pulmonary artery annulus was causing significant turbulence and there was significant gradient across the pulmonary valve . in remaining one case , there was left pulmonary artery origin stenosis which had persisted even after left pulmonary artery plasty . there was a significant right ventricular outflow tract obstruction noted in one case in postoperative echocardiography , which was not mentioned in the epicardial echo . doppler echocardiography was not able to detect significant gradient . however , direct measurement of pressure in operation theatre showed near systemic right ventricular pressure . it was discovered that child had borderline sized pulmonary artery resulting in increased main pulmonary artery pressure and hence significant gradient was not detected in the right ventricular outflow tract . in a total of eight cases of asd ( four ostium primum + four sinus venous defects ) epicardial echo was done . . however , one case of inferior vena cava ( ivc ) type of sinus venosus asd had postoperative desaturation . in two out of five cases of aso , there was severe stenosis of both branch pulmonary arteries . in one case , it was due to kinking of pulmonary artery anastamosis and in another there was narrowing of anastamosis site . in both these cases , out of 10 cases of tapvc for whom epicardial echo was done , one case of infracardiac type of tapvc had significant stenosis at the anastamosis site . repair of stenosis was done immediately . in all the remaining cases the repair was adequate . in one case of senning , there was stenosis of systemic venous baffle that caused superior vena caval obstruction as detected by turbulent flow and mean gradient of 5 mmhg . in three out of seven cases reported to have mild mitral regurgitation after mitral valve repair by epicardial echocardiography , the severity increased to moderate . one case of patent ductus arteriosus ( pda ) ligation had residual pda flow seen in postoperative echocardiography . overall , out of 158 cases for which epicardial echo was done , there was a significant residual lesion seen in 28 cases . in 24 out of these 28 cases , the lesions were operated upon . in the remaining four cases reported to have new onset severe tr in whom the residual lesion was not corrected , had poor outcome . in 10 cases in whom the residual lesions were reported to be nonsignificant and repair was not advised , all patients did well in postoperative period . in four out of 130 cases reported to have normal epicardial echo without residual shunt needed reoperation [ table 3 ] . in one case there was alcapa , detected in postoperative period . third was a case of mitral regurgitation which was reported as moderate , but progressed to severe mitral regurgitation . fourth was a case of branch pulmonary artery stenosis in transposition of the great arteries ( tga ) following aso . new findings in postoperative ( icu ) echocardiography which were not mentioned in epicardial echocardiography * epicaridal echocardiography was not done ; icu = intensive care unit ; vsd = ventricular septal defect ; icr = intracardiac repair ; rvot = right ventricular outflow tract ; alcapa = anomalous origin of left coronary artery from pulmonary artery ; pda = patent ductus arteriosus in eight out of 58 ( 14% ) cases of vsd closure had either significant residual vsd or additional vsd diagnosed by epicardial echocardiography . in all these cases the diagnosis was confirmed and repair of residual lesion was done . in seven cases there was tiny to small residual shunt for which repair was not advised . in none of these cases similarly , for icr in tetralogy of fallot , eight out of 38 cases had significant right ventricular outflow tract obstruction diagnosed by epicardial echocardiography . in all these cases the diagnosis was confirmed intraoperatively and operated upon . in four out of 38 cases hence , the overall sensitivity and specificity of epicardial echocardiography in detecting significant residual lesions is 86 and 100% , respectively . the positive predictive value and negative predictive value of epicardial echocardiography to detect significant residual lesion in immediate post cardiopulmonary bypass period was 100 and 97% , respectively . the percentage of false negative and false positive of epicardial echocardiography was 14 and 0% , respectively . intraoperative epicardial echocardiography is a well - established diagnostic modality to assess the adequacy of repair in surgery for congenital heart disease . hence , it is important to document both the advantages and limitation of the technique before using it on a routine basis . advantages were timely and accurate decision - making based on epicardial echocardiography in cases where there were significant residual lesions . as a result patient underwent reoperation in the same sitting and thus avoiding excessive complications and cost of surgery . , to evaluate visualization of branch pulmonary arteries , coronary arteries , blalock taussig shunt , glenn / fontan circuit , pulmonary veins / baffles , and residual vsds by epicardial echocardiography and tee . it was concluded that epicardial echocardiography detects residual intraoperative lesion not visualized by tee . in most of these cases the use of epicardial echocardiography may decrease the need for early reintervention . in a study done by narayanswami et al . , on comparative roles of intraoperative epicardial and early postoperative transthoracic echocardiography it was detected that epicardial echocardiogram correctly identified six out of seven patients with residual lesion that needed revision . however , they noted that in three patients there was underestimation of left atrioventricular valve regurgitation . ungerleider et al . , did a study to evaluate the exactness of surgical repair using epicardial echo in children with congenital heart disease it was found that the rate of reoperation and early death was significantly higher in those with unrepaired residual lesion detected by epicardial echo . accordingly in those subset of patients in whom the residual lesion was corrected based on epicardial echocardiography had no postoperative events with good long - term results . , it was found that in 18% of patients in whom pre - bypass epicardial echo was done , there were significant newly detected lesions . after bypass 7% of patients had unsuspected residual lesion in whom immediate revision was done . thus authors concluded that routine intraoperative epicardial echocardiography was useful in aiding , planning , conduct , and assessment of results in operations for congenital heart disease . in a study done by kaushal et al . , to evaluate the role of routine use of intraoperative echocardiography to assess surgical repair , it was found that intra operative echocardiography was inexpensive , accurate , valuable and safe . there were no comparative studies between epicardial echo and micro tee probe to assess the adequacy of surgical repair for congenital heart disease . zyblewski et al . , have reported that micro tee provides high quality images without hemodynamic or ventilation compromise in small infants undergoing cardiac operations . immediate surgical revision of such lesion results in excellent outcome , thus saving them from reoperation and postoperative complications . in our study we have demonstrated a very high sensitivity and specificity along with high positive and negative predictive value of epicardial echocardiography in detecting significant residual lesions . however , it is possible to miss out on certain unsuspected lesions such as alcapa . rarely the epicardial echocardiography may underestimate the mitral valve regurgitation in cases of mitral valve repair . similarly , residual gradient in right ventricular outflow tract ( rvot ) . in a significant number of cases of operated large vsd with pah , it was observed that on 1 postoperative day there was significant left ventricular dysfunction which was not observed at the time of epicardial echocardiography . in our experience and that of others this method has not resulted in complications such has infection or serious arrhythmias requiring cardioversion . we recommend that epicardial echocardiography is accurate , economical , and safe modality of investigation ; it should be used routinely in all patients undergoing corrective surgical procedure . thus , it possible to avoid complications and limitations in using tee in neonates and children . the following measures are used to evaluate a screening test : sensitivity = a/(a + c )  100 specificity = d/(b + d )  100 predictive value of a positive test = a/(a + b )  100 predictive value of a negative test = d ( c + d )  100 percentage of false of negatives = c/(a + c )  100 percentage of false positive = b/(b + d )  100
objective : to determine the accuracy of epicardial echocardiography in detecting residual lesions after surgical repair of congenital heart defects . to determine the sensitivity , specificity , positive predictive valve , negative predictive valve , and false negative and false positive percentage of the same.materials and methods : 
 one year hospital - based prospective study of epicardial echocardiography in patients undergoing cardiopulmonary bypass for surgical correction of congenital heart defects in children and adults.results:epicardial echocardiography was done in 158 patients . 
 residual lesions were detected in 38 patients by epicardial echocardiography . in 28 of these cases 
 the residual lesions were significant . in 24 of them 
 immediate reoperation was done with good outcome . 
 epicardial echo has high sensitivity , specificity , positive and negative predictive valve , in detecting residual lesion with congenital heart defects.conclusion:routine use of intraoperative epicardial echocardiography allows detection of majority of residual defects . 
 it has high accuracy . 
 there were no complications associated with use of epicardial echocardiography . 
 the use of transesophageal echocardiography ( tee ) can be avoided in small children and neonates undergoing cardiac surgery .