the patient had a birth weight of 1,360 g , which was categorized as very low birth weight ( vlbw < 1,500 g ) .
the patient was referred to chungnam national university hospital and transferred to the neonatal intensive care unit at arrival .
the patient s vital signs included a systolic blood pressure of 40 mmhg , a heart rate of 150 beats / min , and an oxygen saturation level of 80%90% with bag valve mask to maintain oxygen saturation under 100% o2 . an initial arterial blood gas analysis showed a ph of 7.21 , po2 of 37 mmhg , and pco2 of 59 mmhg .
chest radiography demonstrated diffuse pulmonary infiltration of the bilateral lung fields without cardiomegaly ( fig .
initial echocardiography showed that the size of the atrial septal defect was 2.89 mm and that patent ductus arteriosus was present .
the infant was diagnosed with respiratory distress syndrome ( rds ) , was intubated with mechanical ventilation , and surfactant was administered for the rds . after showing improvement , the endotracheal tube was removed from the patient 7 days after hospital admission . on the 15th day after admission , the patient s oxygen saturation level started to decrease gradually while pulmonary infiltration increased on chest radiography .
follow - up echocardiography showed that all pulmonary veins drained to the intrahepatic vein and the right atrium , indicating an infracardiac type of total anomalous pulmonary venous return ( tapvr ) .
the maximum velocity of tricuspid regurgitation was 4.7 m / sec , suggesting obstruction of the pulmonary vein .
therefore , emergency repair of tapvr was performed 21 days after birth . the patient s weight was 1,360 g at the time of surgery , with no weight gain since birth
cardiopulmonary bypass ( cpb ) was implemented with ascending aorta cannulation ( 8-fr medtronic dlp cannula ; medtronic inc . ,
minneapolis , mn , usa ) and bicaval venous cannulation ( 10-fr right - angled cannulae ; edwards lifesciences , irvine , ca , usa ) .
rerouting of the tapvr to the left atrium and ligation of the vertical vein to the patent ductus arteriosus were performed under moderate hypothermia .
therefore , we placed extracorporeal membranous oxygenation ( ecmo ) using an 8-fr aortic cannula and a 12-fr medtronic dlp
venous cannula on the right atrial appendage with a membrane oxygenator ( dideco 901 ; dideco , mirandola , italy ) and centrifugal pump ( stockert instrumente , munich , germany ) ( fig .
on the day of the operation , ecmo flow was maintained at 120150 ml / min with a fraction of inspired oxygen of 0.3 supported by inotropics .
iu / hr ) was used with activated clotting times ( acts ) of 180200 seconds .
we attempted to wean the infant off ecmo after 44 hours of good left ventricular function on follow - up echocardiography .
however , it was impossible to wean the patient from ecmo due to his decreased mean blood pressure . therefore , we restarted ecmo with a 5-fr central venous catheter , as the previous 8-fr dlp cannula was considered too large when compared to the ascending aortic size ( fig .
however , the 5-fr central venous catheter failed to maintain the flow of ecmo . the patient s cardiac function slowly recovered , and
the infant underwent approximation of the sternum 7 days postoperatively , and was extubated on day 16 postoperatively .
follow - up echocardiography showed normal left ventricular function without pulmonary venous obstruction on day 18 postoperatively .
brain sonography performed during the ecmo procedure did not display any sign of intracranial hemorrhage ( ich ) .
we deduced that the periventricular hyperechogenicity revealed by the brain sonography on the 13th day after birth might have developed during the course of recovery .
the patient was discharged on the 64th day postoperatively with a weight of 2,600 g ( fig .
therefore , we performed another operation when the patient was 14 months old ( weight , 6.6 kg ) .
currently , the patient shows no sign of pulmonary venous obstruction and is undergoing rehabilitation therapy .
as complex repairs for neonates with complicated manifestations of congenital heart disease ( chd ) become more common , ecmo support is more often used . according to the extracorporeal life support organization ( elso ) international registry , more than 5,000 cases of neonatal cardiac ecmo have been reported .
the application of neonatal cardiac ecmo has steadily risen in frequency to encompass 30% of all non - early cardiopulmonary resuscitation procedures in neonates .
approximately 8% to 18% of patients with chd have low birth weight ( lbw < 2,500 g ) or vlbw ( < 1,500 g ) due to prematurity or preterm birth .
chd is a major cause of death for lbw and vlbw neonates , with prematurity accounting for a quarter of all neonate deaths .
early corrective repair is often the preferred strategy for chd , requiring surgery in lbw or vlbw infants rather than delay or palliative operations [ 35 ] .
the increasing number of in high - risk infant operations implies a potential increase in the frequency of cardiac ecmo in premature lbw or vlbw .
the primary indications of neonatal cardiac ecmo include preoperative stabilization of uncorrected chd , postcardiotomy low cardiac output state , and failure to wean from cpb .
other indications of emco are pulmonary hypertension , intractable arrhythmias , cardiac arrest , myocarditis , cardiomyopathy , bridge to transplantation , hemodynamic stabilization for procedures , and respiratory failure or sepsis .
when infants demonstrate cardiopulmonary failure , especially when weaning from cpb , using ecmo in neonates requires recognition that it is a viable option and astute decision - making on the part of the pediatric cardiac surgeons .
the use of ecmo in such a high - risk population is associated with significant morbidity and mortality , with an overall survival rate of approximately 40% .
it is difficult to come to a consensus regarding absolute contraindications for neonatal ecmo , although is generally agreed that ecmo should not be used in patients with a lethal congenital malformation or severe irreversible brain injury .
a number of previously recognized absolute contraindications are now reconsidered to be relative contraindications , such as gestational age < 34 weeks , weight < 2.5 kg , end - organ damage , and intracranial or solid - organ hemorrhage . according to the elso registry data , the overall survival rate for premature infants under 37 weeks of gestational age is 31% , whereas it is 41% for term infants , and only 19% for those under 33 weeks of gestation .
reported a 10% survival rate in hypoplastic left heart syndrome neonates ( weight < 2.5 kg ) who were treated using ecmo .
reported an overall 30-day survival rate of 33% in infants ( weight <3 kg ) who required postcardiotomy ecmo support after decannulation .
their report listed single - ventricle anatomy , low birth weight ( especially < 2.5 kg ) , longer duration of ecmo , and renal replacement therapy as some of the factors associated with poor outcomes .
problems with cannulation are the most common mechanical complication related to cardiac ecmo in neonates .
clinical seizures , ich , cannulae site bleeding , and surgical site bleeding are some of the other frequent complications .
seizures , ich , and cannula problems develop with high frequency in neonates , particularly in patients with lbw or vlbw . in general
however , it is important to note that serious intracranial injuries , which are a major complication of ecmo , are one of the main causes of fatalities in neonates who undergo ecmo . in this case ,
a neonate patient with a weight of 1,360 g at 30 weeks of gestation was initially diagnosed with rds . after treating the patient for 21 days , no improvement was noted .
after reevaluation , the infant was diagnosed with obstructed infracardiac tapvr . during an emergency operation under cpb ,
we maintained low acts ( 180200 seconds ) while running ecmo given the patient s tendency to bleed .
an aortic cannula measuring 8 fr was too large for the aorta , which could lead to failure in weaning from cpb due to an increased afterload and subsequent obstruction of the outflow from the aorta , potentially compromising left ventricle function . after changing the aortic cannula to a 5-fr central venous catheter , thrombosis occurred within the small lumen .
an appropriately sized cannula is critical to maintain the flow in ecmo , but choosing an appropriate cannula for neonates with vlbw or elow is very difficult .
although brain sonography performed during the ecmo run did not display signs of ich , brain sonography after recovery from the operation revealed pvl .
we deduced that the periventricular hyperechogenicity revealed by the brain sonography on the 13th day after birth might have developed during the course of recovery .
based on this case , the decision to perform ecmo in patients with preoperative abnormal neurologic findings should be made prudently , with consideration of both the potential benefit in terms of survival and the possibility of neurologic injury .
 with advancements in complex repairs in neonates with complicated congenital heart diseases , extracorporeal membrane oxygenation ( ecmo ) has been increasingly used as cardiac support . 
 ecmo has also been increasingly used for low birth weight ( lbw ) or very low birth weight ( vlbw ) neonates . however , since prematurity and lbw are risk factors for ecmo , the appropriate indications for neonates with lbw , especially vlbw , are under dispute . 
 we report a case of ecmo performed in a 1,360-g premature infant with vlbw due to cardiopulmonary bypass weaning failure after repairing infracardiac total anomalous pulmonary venous return . 
Case report
Discussion