Pulsed doppler echocardiographic evaluation of the cyanotic newborn: Identification of the pulmonary artery in transposition of the great arteries

During M mode echocardiographic evaluation of cyanotic newborn infants, one may find two ventricles and two great vessels, but not have proof of their identity. Identification of the great vessels is important in evaluation of possible transposition of the great arteries. In a series of 68 cyanotic neonates pulsed Doppler echocardtography was applied to test the hypotheses that (1) a patent ductus arterlosus in present in most cyanotic neonates, (2) the great vessel that receives diastolic ductal flow is the pulmonary artery, and (3) specific noninvasive identification of pulmonary artery will allow diagnosis or exclusion of transposition of the great arteries. On M mode examination, the relations of the great vessels were normal in 43 infants; in all, pulsed Doppler echocardiography detected a patent ductus arteriosus flowing into a normally positioned pulmonary artery. The cyanosis in these 43 patients was later proved to be of pulmonary origin. In eight infants, the relation of the great vessels suggested transposition, and in all eight, Doppler echocardiography detected a patent ductus flowing into the posterior great vessel, proved at angiocardiography to be the transposed pulmonary artery. In 17 patients, the relation of the great vessels was front to back, neither “normal” nor suggestive of classic d transposition. A patent ductus arterlosus, detected with pulsed Doppler echocardiography in all 17, flowed into the anterior great vessel in the 14 normal infants, and flowed into the transposed pulmonary artery in the 3 with proved transposition. It is concluded that ductal patency is prevalent in cyanotic neonates, and that pulsed Doppler echocardiographic detection of ductal flow can define the pulmonary artery; such definition is most helpful in resolving the question of transposition in infants with a relation of the great vessels that is neither normal nor suggestive of transposition.     

Doppler echocardiographic flow characteristics of isolated patent ductus arteriosus: better delineation by Doppler color flow mapping

Eighteen infants and children with isolated ductus arteriosus and various hemodynamic states were examined with the Doppler color flow mapping technique to study the flow patterns of the patent ductus and its adjacent structures. Direct visualization of the ductus was achieved in all patients. All ductal flow was shunting left to right from the descending aorta to the pulmonary artery even in the presence of significant elevation of pulmonary artery pressure. However, transient bidirectional shunting was observed in two patients on serial studies. Disturbed systolic and diastolic flows were demonstrated within the ductus in each case. The blood flows in the main pulmonary artery consisted of three distinguishable areas: 1) a characteristic high velocity turbulent retrograde ductal jet throughout the entire cardiac cycle, located in the anterolateral aspect of the main pulmonary artery; 2) nonspecific low velocity retrograde late systolic and early diastolic flow, located in the posteromedial aspect of the main pulmonary artery; and 3) low velocity forward systolic and diastolic flow, occupying the remaining area of the pulmonary artery. The blood flows in the descending aorta near the ductal orifice consisted of disturbed systolic and diastolic flows in a reversed direction. By providing detailed real time blood flow information with simultaneous imaging of the ductus, Doppler color flow mapping greatly facilitates the detection of a small ductal shunt. This technique also allows detection of a bidirectional or right to left ductal shunt.     

The ductus arteriosus in healthy newborn infants studied by continuous Doppler guided by two-dimensional Doppler color echocardiography

To characterize the ductus arteriosus shunt after birth, 53 normal newborn infants (36-41 weeks gestation), appropriate in size for gestational age, were examined using two dimensional Doppler echocardiography directed continuous Doppler for evidence of patent ductus arteriosus. The infants were examined within six hours of birth, and every six-eight hours thereafter until ductus arteriosus shunt could no longer be detected. In 51/53 infants, an adequate examination was possible and ductus arteriosus was detected in every infant using the standard precordial approach. Using two dimensional Doppler echocardiography a yellow-orange-red jet, sometimes blue in the central area, directed at the lateral wall of the pulmonary artery was recorded; using continuous Doppler a diastolic or continuous spectral flow into the main pulmonary artery was recorded. Ductus arteriosus shunt could no longer be detected in 7 infants 12 hours after birth, in 26 infants 12-24 hours after birth, in 11 infants 24-36 hours after birth, in 5 infants 36-48 hours after birth and in 2 infants 48-60 hours after birth. A diastolic spectral Doppler flow was present in 38 infants and became continuous before duct closure in 27 infants. In 13 infants it was continuous at first examination and until the ductus arteriosus closure. Both diastolic or continuous spectral Doppler flow could present a flat waveform profile, or a protodiastolic or protosystolic peak velocity. The shunt peak velocity increased significantly with the age i.e. (1.5 +/- 0.7 m/sec mean and SD-), at first examination, vs 2.3 +/- 0.6 m/sec at last examination before ductus arteriosus closure (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Noninvasive Doppler echocardiographic evaluation of shunt flow dynamics of the ductus arteriosus

The pulsed Doppler technique was used to record the flow velocity patterns in the ductus arteriosus and the pulmonary artery in 26 patients with either isolated or complicated patent ductus arteriosus (PDA). In all patients, abnormal Doppler signals indicating left-to-right (L-R) or right-to-left shunt flow or both could be obtained at the site of the ductus arteriosus. These Doppler flow patterns determined within the ductus coincided with the direction of ductal flow seen on the contrast two-dimensional echocardiogram. No Doppler signals of shunt flow were demonstrated in any of 42 control subjects. The peak, mean, and diastolic velocities of the L-R shunt flow within the ductus were measured from the ductal flow velocity profiles. With the Doppler-derived measurements of the mean and diastolic velocities, patients with normal pulmonary arterial pressure and those with evidence of pulmonary hypertension could be correctly identified. In addition, the mean velocity of the diastolic antegrade flow portion obtained from the proximal left pulmonary artery, which was related to ductal L-R shunting, was measured in 16 patients with isolated PDA. This Doppler flow determinant showed a good linear correlation with the L-R shunt ratio determined by Fick's method (r = .88, p less than .01). Our technique permits the noninvasive evaluation of shunt flow dynamics in patients with PDA.     

Percutaneous catheter closure of the ductus arteriosus in children and young adults

The double-disk occluding device suitable for use in infants and children with patent ductus arteriosus, developed by Rashkind and Mullins, has been available to this institution since December 1987 on an investigational basis. Results of 43 nonsurgical ductal closure attempts using this device in children and young adults between December 1987 and October 1988 are presented. Successful implantation was achieved in 42 patients (98%). In 25 patients a residual shunt was seen on angiography immediately after implantation. In 12 patients a residual ductal shunt was detected by Doppler 24 hours after implantation; 6-week follow-up studies showed a small residual shunt in only 3 patients. After a second occluder device was implanted in 2 of these patients, complete closure of the patient ductus arteriosus was achieved. In 1 patient, early in the series, the occluder device embolized to the left pulmonary artery, necessitating surgical removal at the time of ductus division. This event was the only serious complication; there were no deaths.     

New serial contrast technique for assessment of left to right shunting patent ductus arteriosus in the neonate

A new serial echocardiographic contrast technique for detection of patent ductus arteriosus has been developed and validated by clinical course (33 infants), surgical observations (13 infants) and autopsy observations (4 infants). A left to right shunting patent ductus arteriosus was demonstrated in 30 of 33 prospectively studied premature infants (mean weight 1,371 g) using this new contrast method. The demonstration of left to right ductal shunting was accomplished by hand injection of a nonviscous material (saline solution, 5 percent dextrose in water or the patient's own blood) through an umbilical arterial catheter placed with its tip located above the diaphragm during recording of a suprasternal notch echocardiogram. In positive studies, both the transverse aortic arch and right pulmonary artery were opacified. If no left to right shunt existed, only the transverse aortic arch was opacified.This serial study helped elucidate the natural history of patent ductus arteriosus. Twenty-four of the 30 patients with a positive study initially had a left to right shunting patent ductus arteriosus without an audible murmur. Three of these patients with silent patent ductus arteriosus later had congestive heart failure and two required operative ligation of the patent ductus. The high rate of detection of silent patent ductus arteriosus and its bedside confirmation when suspected are important in the serial management of critically ill newborns with this condition. The test is safe and sensitive and it is useful for early demonstration of silent patent ductus arteriosus, for clarifying the origin of murmurs and for confirming spontaneous, operative or pharmacologie closure of a patent ductus arteriosus.     

The value of Doppler color flow mapping in determining pulmonary blood supply in infants with pulmonary atresia with ventricular septal defect

Thirty-two neonates and infants with pulmonary atresia with ventricular septal defect were initially investigated with cross-sectional and spectral Doppler echocardiography and Doppler color flow mapping. All 32 had subsequent correlative angiography. This demonstrated that 24 infants had adequate-sized right and left pulmonary arteries (19 confluent, 5 nonconfluent). Of the five infants with nonconfluent pulmonary arteries, four had bilateral ductus arteriosus and one had a single left-sided ductus with anomalous origin of the right pulmonary artery from the ascending aorta. Nineteen infants had confluent pulmonary arteries, all of which were supplied by a single ductus. Eight infants had complete absence of or inadequate pulmonary arteries; all had multiple aortopulmonary collateral vessels arising from the descending aorta. The presence of adequate-sized right and left pulmonary arteries was correctly predicted in 21 of 24 infants by cross-sectional echocardiography alone and in all 24 by Doppler color flow mapping. Confluence of the right and left pulmonary arteries was predicted by cross-sectional imaging in 14 of the 19 infants in whom it occurred, and by Doppler color flow mapping in all 19 infants. The precise definition of the pulmonary blood supply was correctly predicted by Doppler color flow mapping in 16 of the 19 infants with confluent pulmonary arteries and a single ductus. However, in three infants in this group, Doppler color flow mapping made a false diagnosis of multiple aortopulmonary collateral vessels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pulsed Doppler flow characteristics of ductus arteriosus in infants with associated congenital anomalies of the heart or great arteries

Pulsed Doppler echocardiography (PDE) from the suprasternal approach was used to assess flow characteristics of ductus arteriosus (DA) in 145 infants (aged 1 day to 6 months) with major congenital heart disease. Direct ductal Doppler interrogation was possible in 138 patients and serial studies before and after medical treatment were performed in 28 infants. According to pulmonary artery pressure and associated heart lesions, 3 ductal shunting patterns were identified. An isolated left-to-right shunt, observed in isolated DA or in right ventricular outflow tract obstruction, was characterized by a continuous flow with a peak velocity in late systole. An isolated right-to-left shunt, observed in persistent fetal circulation and aortic arch abnormalities, was characterized by a continuous flow with a peak velocity in early systole. In patients with a bidirectional ductal shunt, the right-to-left shunt always occurred in systole and the left-to-right shunt began in late systole and extended into diastole. A systolic right-to-left shunt always corresponded to the presence of significant pulmonary hypertension. Ductal flow changes could be documented after prostaglandin E1 therapy in patients with ductus-dependent heart disease or after tolazoline therapy in patients with persistent fetal circulation. Thus, PDE with direct ductal Doppler interrogation is an important complement to the echocardiographic evaluation of DA. It is a safe noninvasive approach to ductal shunt and permits convenient evaluation of the effects of drugs on pulmonary artery resistance (tolazoline) and ductal patency (prostaglandin E1).     

Transcatheter treatment of "pulmonary artery hypertension" due to patent ductus arteriosus and pulmonary artery stenosis

The association between large, left-sided patent ductus arteriosus and severe, peripheral, right pulmonary artery stenosis with no other cardiac malformation is an unreported condition that might be misdiagnosed as pulmonary hypertension due to long-standing ductal shunt. A 57-year-old man with supposed hypertensive patent ductus arteriosus underwent confirmatory cardiac catheterization. At angiography, a severe pre-hilar right pulmonary artery stenosis (peak pressure gradient, 65 mmHg) was found to complicate the hemodynamic picture of a moderate-to-large patent ductus arteriosus (QP/QS, 1.7:1), by causing pulmonary hypertension (mean pressure, 65 mmHg) and left-to-right pulmonary flow imbalance. Both lesions were treated in a single procedure of right pulmonary artery stenting and patent ductus arteriosus closure, after which the pulmonary artery pressure significantly decreased (mean, 35 mmHg). In our opinion, a thorough hemodynamic evaluation followed by pulmonary angiography should be mandatory before proceeding to patent ductus arteriosus closure in the adult patient who has "hypertensive" ductus, in whom possible associated malformations can be missed due to a poor echocardiographic window.     

Transcatheter coil embolization for patent ductus arteriosus in the elderly: Report of a case and review of the published work

Patent ductus arteriosus is the third most common congenital cardiovascular anomaly, however, it is rarely found in the elderly. We describe a case of patent ductus arteriosus in a 72-year-old woman in whom patent ductus arteriosus was successfully managed by transcatheter coil embolization. The patient had been diagnosed with a heart murmur for the first time 1 year earlier at the age of 71. She was asymptomatic but a continuous murmur was heard. Cardiac catheterization revealed migration of a catheter from the main pulmonary artery into the descending aorta through a patent ductus arteriosus and a significant step-up of oxygen saturation in the main pulmonary artery with a pulmonary-to-systemic flow ratio of 1.68. Aortograms demonstrated a communication between the aorta and the pulmonary artery through a patent ductus arteriosus with a minimal diameter of 3.7 mm. Transcatheter coil embolization of the patent ductus arteriosus was successfully carried out with two 0.052-inch-diameter Gianturco coils. Doppler echocardiographic study confirmed no residual shunt in the main pulmonary artery after the procedure. Non-surgical transcatheter occlusion using coil embolization appears to be an effective and minimally invasive technique for treatment of patent ductus arteriosus in the elderly.     

Reversed shunting across the ductus arteriosus or atrial septum in utero heralds severe congenital heart disease

Objectives. This study was performed to define the significance of Doppler color flow mapping in demonstrating reversal of the direction of the normal physiologic flow across the atrial septum and ductus arteriosus in the human fetus.Background. Reversal of the physiologic shunting across the ductus arteriosus or atrial septum in utero (i.e., left to right) can be readily identified by Doppler color flow mapping, complemented by pulsed and continuous wave Doppler information.Methods. We reviewed echocardiograms recorded at our three institutions from 1988 to 1993, which displayed reversal of flow by Doppler color flow in 53 fetuses of gestational age 18 weeks to term. The diagnoses were confirmed by postnatal echocardiography, operation or autopsy. Reversal of shunting was consistently associated with severe heart disease.Results. Reversed atrial shunting was found with severe left heart obstructive lesions, including 19 with hypoplastic left heart syndrome, 3 with critical aortic stenosis, 2 with double-outlet right ventricle and 1 each with an interrupted aortic arch, atrioventricular septal defect and severe left ventricular dysfunction due to dilated cardiomyopathy. Reversed ductus arteriosus shunting was found with severe right heart obstructive lesions, including nine fetuses with pulmonary atresia, six with severe obstructive tricuspid valve abnormalities, five with severe tetralogy of Fallot, four with Ebstein's anomaly and two with single ventricle and pulmonary stenosis. Associated cardiac lesions were common in both groups. Only 3 of the 15 infants who were delivered alive from the reverse ductus arteriosus shunt group and 4 of 12 from the reverse atrial shunt group still survive.Conclusions. The finding of reversed flow by Doppler color flow mapping during fetal life provides a key to subsequent accurate diagnosis and denotes a spectrum of diseases with a very poor prognosis.     

The newborn transitional circulation: a two-dimensional Doppler echocardiographic study

To characterize changes in circulation after birth, 11 normal full-term infants were examined with two-dimensional and pulsed Doppler echocardiography. The initial examination was performed within 10 hours after delivery and serially for 3 days. Retrograde diastolic pulmonary artery velocities, which are evidence for a patent ductus arteriosus, were detected in 10 infants (91%) on day 1, in 2 (18%) on day 2 and in none on day 3. Retrograde systolic descending aortic velocities, which are evidence of flow from the aorta into the ductus arteriosus, were observed in 10 infants (91%) on day 1, 9 (81%) on day 2 and 7 (64%) on day 3. Persistence of the retrograde systolic velocity in the descending aorta in the absence of retrograde diastolic velocity in the pulmonary artery is consistent with physiologic ductal closure beginning near the pulmonary artery end of the ductus arteriosus. Localized turbulent retrograde systolic flow, proximal to the septal leaflet of the tricuspid valve and consistent with tricuspid insufficiency, was detected in six patients (55%) on day 1, in eight (73%) on day 2 and in seven (64%) on day 3. Thus, tricuspid insufficiency appears to be a frequent observation in healthy newborns. Normal Doppler velocities in the great arteries and across the tricuspid and mitral valves of newborns up to 3 days of age are presented. These normal measures of intracardiac flow velocities may be used for comparison to identify abnormal flow profiles in newborns with congenital heart defects.     

Radiographic characteristics of Cook detachable and Gianturco coils as well as clinical results of transcatheter closure of the patent ductus arteriosus

PURPOSE: To describe the radiographic appearance of the Gianturco and the Cook detachable coils and present the clinical results in patients who underwent transcatheter closure of patent ductus arteriosus. MATERIALS AND METHODS: Between January 1994 and June 1997, eighty-two patients underwent closure of patent ductus arteriosus (PDA) using either Gianturco or Cook detachable coils. The chest x-ray and echocardiography of all patients were reviewed and the following parameters were evaluated: 1) the size of the heart (cardiothoracic ratio), 2) the position and the type of the coils in the postero-anterior and the lateral projection, 3) the number of coils used, 4) the existence of residual ductal flow, 5) Doppler velocity in the left pulmonary artery. RESULTS: Complete occlusion was achieved in 94%, and cardio-thoracic ratio regressed from 0.57 to 0.53 (p < 0.01), after a mean follow-up of 1.2 years. The identification of the different coils on the chest radiograph was successful in only 47% of cases, difficulties arising especially, when multiple coils were used. In 55 patients (67%) the coil position was judged to be optimal, in 27 patients (33%) suboptimal. The latter correlates with the presence of residual shunt. Multiple coils correlated more with a left pulmonary artery flow velocity exceeding 1.5 m/s. CONCLUSION: Coil-occlusion of patent ductus arteriosus is effective and leads to reduced cardio-thoracic ratio. Radiographic coil identification is possible but may be difficult if multiple coils are deployed. Suboptimal coil position led more often to residual PDA shunt. Multiple coils are more commonly associated with increased LPA velocities, but hemodynamic significant obstruction to flow is rare.     

Real-time bidimensional-color Doppler evaluation of patent ductus arteriosus

In order to assess the presence and severity of left-to-right shunt at ductal level, eleven patients with proven ductus arteriosus (PDA), ages 1 day to 16 years, were examined by real-time two-dimensional Doppler echocardiography. Eighteen subjects with no signs of cardiovascular disease were selected as normal controls. Normal pulmonary flow pattern was clearly visualized in the healthy subjects examined. The jet stream through the ductus was well imaged in the main pulmonary artery in patients with PDA and disappeared in two infants after pharmacologic manipulation with indomethacin. The colour-coded shunt area was related to the left-to-right shunt calculated at cardiac catheterization. Moreover, the combined use of colour-flow Doppler and continuous-wave Doppler yielded a reliable noninvasive assessment of pulmonary artery pressure.     

Noninvasive detection of pulmonary hypertension in patent ductus arteriosus by pulsed Doppler echocardiography.

Twenty-five patients with proven patent ductus arteriosus were examined by pulsed Doppler echocardiography (PDE) before invasive assessment. Ten patients had normal pulmonary artery pressures, and by PDE, pandiastolic ductal flow. Fifteen patients had elevation of mean pulmonary artery pressure, and by PDE, all had abbreviations of diastolic ductal flow. PDE correctly distinguished between patients with normal pressure and those with evidence of pulmonary hypertension; the ECG did not allow such differentiation. Detection by PDE of pulmonary hypertension complicating patent ductus arteriosus appears to be clinically useful.     

Color Doppler and transesophageal echocardiography of vascular sling

Summary Three patients with vascular sling were studied by two-dimensional and color Doppler echocardiography and angiocardiography. One case was associated with atrial septal defect and another with tetralogy of Fallot and patent ductus arteriosus. The third case had no associated intracardiac anomalies. Color Doppler flow mapping was performed in all three patients, and transesophageal echocardiography was studied in two patients.Color Doppler echocardiography showed the characteristic features of this congenital anomaly in all three patients, especially in detecting the site of anomalous origin of the left pulmonary artery. A small patent ductus arteriosus was misinterpreted as the normal left pulmonary artery in one patient. Small pulmonary arteries in the patient with tetralogy of Fallot made the diagnosis difficult. Using transesophageal echocardiography, we clearly identified the trachea, esophagus, and abnormal left pulmonary artery.     

Responsiveness of the ductus arteriosus to prostaglandin E1 assessed by combined cross sectional and pulsed Doppler echocardiography.

Cross sectional echocardiography combined with Doppler echocardiography was used to record either ductal morphology or the flow profile within the ductus arteriosus before and after infusion of prostaglandin E1 in 25 newborn infants with cyanotic and acyanotic congenital heart disease with ductus dependent blood flow. The ultrasound results were compared with changes in arterial oxygen tension and the overall clinical response to prostaglandin E1 seen during the same period in 24 of the 25 patients in whom the degree of ductal narrowing could be determined with the ultrasound method. At the time of the study, the ductus was widely patent or slightly narrowed in 12 patients and was closed in two patients. These patients did not respond to prostaglandin E1. There was prominent localised narrowing of the ductus in seven patients and generalised narrowing in three. After the infusion of prostaglandin E1 there was no ductal narrowing in these patients, except for one patient who had slight residual localised narrowing. There was also a considerable change in the ductal flow profiles in each patient. In these 10 patients infusion of prostaglandin E1 resulted in an increase in arterial oxygen tension, clinical improvement, or both. The present study indicates that prostaglandin E1 is effective in patients with prominent narrowing of the ductus but is not in patients in whom the ductus is widely patent or closed. Cross sectional echocardiography combined with Doppler echocardiography was useful for predicting the responsiveness of the ductus arteriosus to the infusion.     

Responsiveness of the ductus arteriosus to prostaglandin E1 assessed by combined cross sectional and pulsed Doppler echocardiography

Cross sectional echocardiography combined with Doppler echocardiography was used to record either ductal morphology or the flow profile within the ductus arteriosus before and after infusion of prostaglandin E1 in 25 newborn infants with cyanotic and acyanotic congenital heart disease with ductus dependent blood flow. The ultrasound results were compared with changes in arterial oxygen tension and the overall clinical response to prostaglandin E1 seen during the same period in 24 of the 25 patients in whom the degree of ductal narrowing could be determined with the ultrasound method. At the time of the study, the ductus was widely patent or slightly narrowed in 12 patients and was closed in two patients. These patients did not respond to prostaglandin E1. There was prominent localised narrowing of the ductus in seven patients and generalised narrowing in three. After the infusion of prostaglandin E1 there was no ductal narrowing in these patients, except for one patient who had slight residual localised narrowing. There was also a considerable change in the ductal flow profiles in each patient. In these 10 patients infusion of prostaglandin E1 resulted in an increase in arterial oxygen tension, clinical improvement, or both. The present study indicates that prostaglandin E1 is effective in patients with prominent narrowing of the ductus but is not in patients in whom the ductus is widely patent or closed. Cross sectional echocardiography combined with Doppler echocardiography was useful for predicting the responsiveness of the ductus arteriosus to the infusion.     

A pulsed Doppler echocardiographic study of the postnatal changes in pulmonary artery and ascending aortic flow in normal term newborn infants

Postnatal circulatory adaptations were studied with Doppler echocardiographic measures of flow velocity in the main pulmonary artery (PA) and ascending aorta (Ao) in 45 normal full-term neonates at 5 hours and at 27 hours after birth. PA flow velocity integral (FVI) was measured as the area under the systolic flow velocity curve and reflected total systemic flow in the presence of a left-to-right shunt through the ductus arteriosus. This index increased from 5 and 27 hours age, while Ao FVI, reflecting total pulmonary flow, remained unchanged. Evidence of a left-to-right ductal shunt demonstrated as diastolic retrograde flow in the main PA was detected in 42 neonates at 5 hours and in only four subjects after 27 hours of age, indicating a patent ductus arteriosus at 5 hours of age and its subsequent closure. In the PA, acceleration time (AT) increased while pre-ejection period to ejection time ratio (PEP/ET) decreased from 5 to 27 hours of age, reflecting the physiologic fall in PA pressure. In the Ao, FVI, AT, and PEP/ET remained unchanged, suggesting little change in left ventricular function.     

Variable approaches to arterial ductal stenting in infants with complex congenital heart disease

Stenting of the arterial duct to maintain postnatal communication between the pulmonary and systemic arterial circulations in infants with complex congenital heart disease is an acceptable alternative to a surgically created systemic to pulmonary artery shunt. The procedure, however, can be demanding given the variable anatomy of the patent ductus arteriosus. We report a series of cases of ductal stenting via a range of varying approaches in neonates with complex congenital heart disease, and display the variety of situations in which these approaches may be used.