Introduction
Stenting the arterial duct emerged as an alternative to a variety of surgical interventions like systemic to pulmonary shunts (like Blalock-Taussig shunt) in the early 1990s. Reference Gibbs, Rothman, Rees, Parsons, Blackburn and Ruiz1–Reference Boshoff, Michel-Behnke, Schranz and Gewillig3 Although early reports were not encouraging, the results of ductal stenting have improved significantly over the years with experienced hands, better patient selection, and by applying new procedural technique and more recent hardware devices. Reference Gibbs, Wren, Watterson, Hunter and Hamilton2,Reference Gibbs, Uzun, Blackburn, Wren, Hamilton and Watterson4–Reference Simsic, Phelps and Kirchner9
The first successful delivery of a balloon-dilatable stent in the closing patent ductus arteriosus was successfully performed in an experimental bovine model in 1991. Reference Coe and Olley10 Subsequently, the technique was translated to neonates. Reference Gibbs, Rothman, Rees, Parsons, Blackburn and Ruiz1 The mortality rate associated with Blalock-Taussig shunt, ranges between 7.2% and 13.9%. Reference Dorobantu, Pandey and Sharabiani11 However, current data on mortality rates following ductal stenting are scarce and highly variable (ranging between 3.6 and 31%). Reference Simsic, Phelps and Kirchner9,Reference Alwi, Choo, Latiff, Kandavello, Samion and Mulyadi12,Reference Gewillig, Boshoff, Dens, Mertens and Benson13 In certain cases, ductal stenting could replace Blalock-Taussig shunt, having the potential advantages of being less invasive, avoiding neonatal surgery and cardiopulmonary bypass, and providing effective and more symmetrical pulmonary artery growth. Reference Santoro, Capozzi and Caianiello14,Reference Santoro, Gaio and Capozzi15 In addition, ductal stenting seems to be superior to Blalock-Taussig shunt in terms of early postprocedural haemodynamic stability, duration of intensive care and hospital stays, and noninferior to Blalock-Taussig shunt regarding survival rates for next-stage surgery. Reference Bentham, Zava and Harrison6,Reference Glatz, Petit and Goldstein7,Reference Amoozgar, Cheriki and Borzoee16–Reference McMullan, Permut, Jones, Johnston and Rubio18
Previous experiences showed that the results of Blalock-Taussig shunt were poor in our limited resource set up with almost 25% mortality rate because of the lack of experienced neonatal cardiac surgeons, trained intensivists, and nursing personnel. The poor socio-economic condition of the patients in our catchment area also provides a negative impact on ideal and timely management as per the protocol. They cannot even afford to reach medical centres with properly equipped neonatal cardiac surgery setups located in metro cities. Most of them are late presenters in our centre, where we lack neonatal surgical backup. In this scenario with limited resources, ductal stenting as an alternative to Blalock-Taussig shunt improved the survival of duct-dependent pulmonary circulation patients and helped them reach the final stage of palliative surgery.
Objective
In this retrospective study, we tried to assess our overall institutional experience, including short-term and midterm follow-up of ductal stenting with limited resources in duct dependent pulmonary circulation and other cardiac lesions where we were able to stent the duct as an alternative to surgical Blalock-Taussig shunt.
Materials and methods
This is a retrospective review from a single centre with a developing paediatric cardiology unit and limited paediatric cardiac surgical scope. Eighty-nine symptomatic patients, who underwent the ductal stenting procedure to establish adequate pulmonary blood flow through the patent ductus arteriosus were included in this study from October 2018 to December 2022. The medical records—included demography, echocardiographic findings, transcatheter procedure records, complications (immediate and delayed), poststent management, and follow-up details (weight gain, oxygen saturation, stent flow, branch pulmonary artery growth and Z score, preparedness for the next step of treatment for either the single ventricle or the biventricular pathway), were systematically studied and analysed.
Pre-procedure assessment
Detailed echocardiography was performed with special emphasis on the origin, morphology, and size of the duct. Although most of our patients were neonates with a single source of pulmonary blood flow through the patent duct, intravenous prostaglandin administration was given in minimum number of patients at the lowest possible dose needed to maintain oxygen saturation at approximately 65%. For those patients who started prostaglandin infusions, we stopped 12 hours before the procedure. We offered ductal stenting to all 89 patients, as there was a poor facility for Blalock-Taussig shunts in our institute. No patients underwent preprocedural diagnostic CT angiography to delineate the duct because of economic constraints and the unavailability of CT scans.
Procedure
Informed written consent was obtained at the time of admission, mentioning complications, the possibility of surgical intervention, and poor outcomes. Mostly, the procedure was performed under general anaesthesia, and the primary target was to extubate the baby on the table if possible. After obtaining vascular access, the duct was approached mainly through the arterial side, either axillary or femoral. For a classical ductus arising from the descending thoracic aorta, it was approached from the femoral artery. In cases of vertical ductus arising from the under surface of the arch or any of the arch branches, axillary access was preferred. In a few instances, the duct was stented ante grade way through the venous side crossing the ventricular septal defect.
Aortic arch angiogram was taken through arterial access at different angles in a mono plane catheterisation lab to profile the ductus-origin, length, tortuosity, narrowest point, branch pulmonary artery anatomy, and branch origin stenosis. Considering the findings, the stent diameter and length were selected. The length of the stent was chosen according to the angiographic morphology of the duct. The ductal tortuosity index or ductal curvature index is often used to assess the risk of ductal stenting. Reference Mini, Schneider and Zartner19 However, in our study, we did not calculate the ductal curvature index. In a very tortuous duct, we used to pass buddy wire in it and made the duct straight to delineate the actual length of the duct to choose the appropriate stent length. The stent diameter was chosen based on the weight of the baby and diameter of the ductus.
Anticoagulation
After successful stent implantation, anticoagulation was started with low molecular weight heparin at 20 IU per kg body weight per hour for the first 24–36 hours, which was overlapped by an oral antiplatelet agent and gradually stopped. Oral antiplatelet drugs were continued till the next stage of surgery as per our institutional protocol. Everyday transthoracic echocardiography was performed to check the patency of the stent, stent flow and any complications, such as pleural effusion. In cases of stent overflow or the appearance of pleural effusion, low-dose diuretics with either intermittent or slow infusion started.
Discharge and follow-up
Once the caring of the babies was acceptable to the parents, they were discharged. Families were taught regarding the danger signs of possible stent block and regular follow-up at certain intervals. The parameters were documented including weight gain, oxygen saturation, stent flow, branch pulmonary artery growth and Z score, and preparedness for the next step of treatment either for a single ventricle or biventricular pathway.
After achieving adequate branch pulmonary artery size, patients were referred to higher centres with good paediatric cardiac surgical and intensive care facilities, which are linked with our centre for the next stage of correction as per the case.
Statistical analysis
Data were analysed using Statistical Program for Social Science (SPSS) version 18.0. Quantitative data were expressed as the median and mean with standard deviation. Qualitative data are expressed as frequencies and percentages.
Results
Ductal stenting was attempted in 89 cases and successfully performed in 88 cases; the remaining case could not be performed because the closed duct was not opened even after repeated attempts, and the patient was referred to the surgical unit for a Blalock Tausig shunt. In all the other calculations, the denominator has been taken as 88 excluding the one-off unsuccessful procedure.
Demographic data
Among all patients, 64% (56 out of 88) were girls, and the rest were boys. Among 88 cases, 42 were under one month of age, and 26 were between 1 and 6 months. Almost twenty-three percent of patients (20 out of 88) were more than 6 months of age, and they were naturally selected for duct-dependent pulmonary circulation from a wide underserved area of the remote part of eastern India. Comparatively older patients (> 6 months) with duct-dependent pulmonary circulation referred to our centre for evaluation, all had small branch pulmonary arteries that were not suitable for single-ventricle palliation or biventricular repair. The median body weight was 4.30 kg (range from 1.2 kg to 12 kg). The older patients were underweight due to chronic malnutrition and the systemic effect of cyanotic heart disease. Pre-procedure saturation was < 30% in 3 patients, between 30 and 60% in 31 patients, and > 60% in the remaining cases.
Echocardiography findings
Among 88 patients, 12 had tricuspid atresia with pulmonary atresia or critical pulmonary stenosis, 43 had tetralogy of Fallot with pulmonary atresia or critical stenosis, 15 had pulmonary atresia with intact ventricular septum, and18 had other complex lesions, such as atrioventricular septal defect with pulmonary atresia or critical stenosis or single ventricle with pulmonary atresia or critical stenosis. Among 88 patients, 73 had a vertical tortuous ductus (among them, 39 arose from the arch, 26 from the ascending aorta, 4 from the descending aorta, and 4 from the left subclavian artery), and a classical ductus was found in 15 patients.
Preprocedural left pulmonary artery diameter Z score values ranged from −5.6 to + 0.9 with a mean of −2.68 [Standard deviation: 1.16], whereas right pulmonary artery diameter Z score values ranged from −6.1 to + 0.1 with a mean of −2.87 (standard deviation: 1.45). Branch pulmonary artery stenosis was seen in 21 cases (16 cases had left pulmonary artery and 5 cases had right pulmonary artery stenosis), and a non-confluent branch pulmonary artery was seen in 5 cases.
Procedural details
Among 88 cases, 69 cases were performed under general anaesthesia, and 19 cases were performed under local anaesthesia. Trans-axillary stent placement was performed in 51 cases (right axillary artery in 2 cases, left axillary artery in 49 cases); trans-femoral artery placement was performed in 29 cases. An ante grade approach via the femoral vein and crossing the ventricular septal defect was performed in 8 cases (Figure 1).
PDA access through different route, 1( a ) right axillary artery. 1( b ) Left axillary artery; 1( c ) right femoral artery; 1( d ) right femoral venous.
In this series, we used stent diameter sizes varying from 2.5 mm to 5 mm (depending on body weight and ductus size). The sizes of the stents used in the maximum number were 4 and 4.5 mm (31 in each size, 70% of total stents). A three and half millimetre (3.5 mm) diameter stent was used in 17 (20%) cases. In the remaining 10% of cases, we used 2.5 mm (2 cases), 3 mm (4 cases) or 5 mm (3 cases) diameter stents. The length of the stent was determined by the angiographic length of the ductus, which varied from 15 mm to 30 mm. In the maximum number of cases, the stent length was 25 mm. In two tiny babies having weight less than 1.5 kg, we used 2.5 mm stent. One of them with weight 1.2 kg did not survive and died due to overflow situation in NICU, other baby was weighting 1.4 kg and had 2.5 mm stent, survived the procedure but lost to follow-up.
In our series, twenty-one patients had branch pulmonary origin stenosis (LPA: 16, RPA:5). In these cases, the stent was directed towards the normal branch pulmonary artery. The wire was directed through the stent and placed in the stenosed branch pulmonary artery after crossing the stent strut. After that, a 2 mm coronary balloon was taken over the wire and placed across the strut and pushed sideways to create a large enough hole to augment blood flow towards the stenosed branch PA in all 21 cases. (Figure 2)
2( a ) Right pulmonary artery (RPA) origin stenosis; 2( b ) stent placed across the RPA to augment flow in RPA; 2( c ) wire and balloon passed through the stent strut and placed in the left pulmonary artery (LPA); 2( d ) post balloon strut enlargement shows good flow across the LPA.
Procedural complications
Failed axillary artery access was observed in 2 cases, and inadvertent puncture of axillary veins was performed in 2 cases. Pneumothorax and pericardial effusion were observed in one case each. One patient had extremely difficult intubation. Ductus perforation and stent migration were observed in one patient each. In the case where ductal perforation occurred, we abandoned the procedure and stabilised the patient in the intensive care unit with optimum support and sent the patient to the nearest higher centre with good paediatric cardiac surgical care for further management. In the patient who had stent migration, the stent migrated and stuck in the distal branch pulmonary artery. As the stent was long, the other end of the stent was stuck by the narrowest segment of the duct, so the flow through the duct and branch pulmonary artery were both unhampered. That is why we kept the stent in that position. Both of these patients were lost to follow-up. We did have one case of loss of femoral pulse, and severe right lower limb venous congestion in three newborn babies, which resolved medically.
Cath lab data and immediate post-procedure management and outcome
In this series, the fluoroscopy time ranged from 3.15 min to 55 min (mean: 22.37 min with SD: 10), the procedure time ranged from 24 min to 200 min (mean: 74 min with SD:28) and the dose-area product ranged from 0.25 to 15 Gy.cm2 (mean: 3.43 Gy.cm2 with SD: 2).
The majority of the cases (46 cases) who received general anaesthesia were extubated immediately after the procedure on the table. Three newborn babies and one infant with a poor pulmonary vascular pattern needed ventilation for more than 48 hours followed by nasal CPAP support. The remaining 19 patients were extubated in the NICU/PICU within 48 hours of the procedure. Apart from regular maintenance intravenous fluid DNS, an additional 50% extra fluid (150% of maintenance fluid) was given both pre-procedure (overnight) and post-procedure until full oral feeding was established in 78 cases to combat severe cyanosis and polycythaemia-related complications, resulting in better outcomes with respect to stent patency, duration of hospital stays and intensive care unit events. Four patients received low-dose infusion or oral furosemide during the intensive care stay for facial puffiness and basal crepitation. One patient had pulmonary haemorrhage and was managed medically successfully. No patient needed any form of ionotropic support. Three patients received intravenous antibiotics, one patient had possible sepsis, one had a high leukocyte count, and one had prolonged ventilation of more than 48 hours.
After successful stent implantation, anticoagulation was started with low molecular weight heparin at 20 IU per kg body weight per hour for the first 24–36 hours, which was overlapped by an oral antiplatelet agent and gradually stopped. All were discharged with oral antiplatelets, either single agent acetylsalicylic acid or combination acetylsalicylic acid plus clopidogrel, which were chosen randomly. The average post-procedure saturation ranged from 85 to 95%. Despite a well-functioning ductal stent in 5 newborn babies, the saturation was less than 70% on air. They were started on oral pulmonary vasodilator-phosphodiesterase inhibitors to improve persistent pulmonary hypertension in newborns and responded well with improved saturation. The average length of hospital stay was 72 hours post-procedure.
6-month follow-up
The dropout rate at 6-month follow-up was 20%. At the six-month post-procedure, the growth of branch pulmonary arteries was adequate in all cases (LPA Z score ranged from + 0.9 to −1.63 with a mean value of −0.78 (SD:0.78), and the RPA Z score ranged from + 1.39 to −2.6 with a mean value of −0.87 (SD:1.0)), where we performed strut dilation to augment blood flow through the stenosed branch pulmonary artery.(p value of Z scores of LPA and RPA was 0.0047 and 0.0045 respectively, which was statistically significant). At the six-month follow-up, all the patients showed increased oxygen saturation (80–85%), except for one baby who needed a second intervention and perforation of the atretic pulmonary valve at 7 months of age. Long-term follow-up reports were not available, as most of them underwent surgical repair, and some of them were lost to follow-up.
Overall outcome
Eighty-nine patients were attempted for patent ductus arteriosus stenting, successful stenting was performed in 88 cases (success rate 98.8%), and mortality was reported in 6 cases. Out of 88 patients initially we planned for single-ventricle palliation in 46 cases and biventricular repair in 37 patients. Five patients had non-confluent branch pulmonary arteries with complex cardiac anatomy, and stenting was performed as final palliation.
However, a total of 65 patients are now undergoing follow-up; among them, twenty-two patients had already undergone a single-ventricle palliative procedure, and eight patients underwent biventricular repair successfully. Among 17 lost to follow up patients we could reach only in 6 cases telephonically, although all of 6 patients were still alive but they refused further follow up or any further surgery due to economic and social constraints.
Patients with pulmonary atresia and intact ventricular septum
Among the 15 patients with pulmonary atresia with an intact ventricular septum, balloon dilation of the pulmonary valve along with ductal stenting was performed in three cases. There was no procedural mortality in any case of PA/IVS. Among them, six had already undergone surgical repair, and the rest are currently in follow-up and planned for surgical repair in the near future.
Mortality
In-hospital mortality was observed in three cases. The first was diagnosed as tetralogy of Fallot with pulmonary atresia having refractory cyanotic spell before taking the case for the procedure, and medical stabilisation was performed in the catheterisation laboratory recovery room. Although the stent was placed quickly through the ante grade route, the baby already had severe neurological damage and could not survive. The other one (tetralogy of Fallot with pulmonary atresia) was a preterm infant, with a body weight of 1.2 kg. This patient died due to overflow after the procedure in the NICU. The third baby was diagnosed with tricuspid atresia with pulmonary atresia with almost closed ductus. After multiple attempts, the ductus was crossed and stent was placed but the baby could not tolerate the long procedure time, and the baby succumbed on the table. Three patients died during follow-up. The mortality was due to pulmonary infection in two cases and severe dehydration and stent block following acute gastroenteritis in one case. In our study, we observed that very low body weight, long procedure time, pulmonary overflow situation, and dehydration following stent block were the main causes of mortality.
Discussion
Patent ductus arteriosus stenting is a well-established procedure in duct-dependent pulmonary circulation. This has been practised since the1990s as an alternative to surgical aortopulmonary shunt wherever possible. Reference Gibbs, Rothman, Rees, Parsons, Blackburn and Ruiz1–Reference Boshoff, Michel-Behnke, Schranz and Gewillig3
Preprocedural ductal evaluation is crucial for successful stent implantation. The difficulties in crossing the duct are mainly because of the complex morphology of the duct and its tortuous course. The duct morphology varies from case to case in regard to its origin—from the aorta or any of the neck vessels, shape, length, tortuosity, insertion site at the pulmonary end, and presence or absence of stenosis. Apart from routine transthoracic echocardiogram, additional imaging, such as CT pulmonary angiogram, provides better quality information before attempting stenting. This helps in case selection and in choosing the vascular access, stent diameter and length. Reference Alwi, Choo, Latiff, Kandavello, Samion and Mulyadi12,Reference Mini, Schneider and Zartner19–Reference Alwi and Mood22 In our study, the ductus could not be crossed in a single case out of 89 cases, whereas Alwi et al. faced unsuccessful stenting in 8.9% of cases. This significant difference might be due to the smaller study population and more complex case selection in their study. Reference Alwi21,Reference Alwi and Mood22
The early published data were very encouraging, with a high success rate of ductal stenting over a time period of 10 years. Alwi et al. documented 91% successful ductal stenting in their study population. Reference Alwi, Choo, Latiff, Kandavello, Samion and Mulyadi12 In comparison to Santoro et al. and Alwi et al., we had better procedural success rate (98.87%) and a better successful post-procedure discharge rate (96.6%). Reference Santoro, Gaio and Giugno8,Reference Alwi, Choo, Latiff, Kandavello, Samion and Mulyadi12
We did not require any early reintervention for stent thrombosis, but we had one case of stent migration. Over a period of 10 years of experience, Schranz et al. reported 3.7% stent migration, and Vida et al. mentioned in their report that 13% of patients needed emergency stent retrieval and surgical aortopulmonary shunt because of stent displacement towards the left pulmonary artery. Reference Schranz, Michel-Behnke and Heyer23,Reference Vida, Speggiorin and Maschietto24 Glatz et al. showed a high rate (almost 50%) of surgical revision of ductal stents. Reference Glatz, Petit and Goldstein7
Even in properly equipped and practising surgical units, mortality related to BT shunt is not uncommon. The poor surgical outcomes depicted by Glatz et al., Santoro et al., and Nasser et al. vary from 10.4%, 3.6%, and 1%, respectively. Reference Glatz, Petit and Goldstein7,Reference Santoro, Capozzi and Caianiello14,Reference Naser, Abdulrahaman, Qwaee, Alakfash, Mohamad and Kabbani25 As per recent western data, despite vast experience in neonatal shunt surgeries during the last two decades, Promphan W et al. showed that the mortality of BT shunt remains significant, at 5–9%. Reference Promphan and Qureshi26 Petrucciet et al. also showed 7.2% mortality in their surgical data analysis, with a morbidity rate of 13.1%. Reference Petrucci, O’Brien and Jacobs27
Santoro et al. Glatz et al. and Nasser et al. showed that the mortality following ductal stent placement was 17.6%, 6.6%, and 7.1%, respectively, whereas we had an in-house mortality rate of 3.4% (3 out of 88), who were among the sickest groups and 6-month survival rate of 93%. Reference Glatz, Petit and Goldstein7,Reference Santoro, Gaio and Giugno8,Reference Naser, Abdulrahaman, Qwaee, Alakfash, Mohamad and Kabbani25
In spite of resource limitations, we had better outcomes after ductal stenting probably because of the inclusion of not only duct-dependent circulation but also patients with cardiac anatomy who needed shunts for palliation (critical or severe pulmonary stenosis group) beyond the neonatal age group to augment pulmonary blood flow (35% cases).
Although both the shunt and stent work in a similar way, intensive care management is also on the same line, but the course is different with respect to the duration of ventilation, hospital stay, associated morbidities, and cost. Similar to the multicentre comparative study by Glatz et al., our observation with ductal stenting correlates with their findings: less intensive care stay, early discharge, minimal or no ionotropic drug use, and very limited use of antibiotics. Reference Glatz, Petit and Goldstein7 These are important and determining factors in a resource-limited set up and building a new paediatric cardiac care unit in a developing country.
Nevertheless, immediate- and short-term results should not be the only focus. Long-term results and successful next surgical steps after this palliative procedure should be considered. Compared to other studies, we have also noticed the descent growth of branch pulmonary arteries, as already documented by Santoro et al. Reference Santoro, Capozzi and Caianiello14
The accurate longevity of stent patency is not well known. The chance of stent endothelialisation can occur even in the first month of life, leading to stent block, as shown by Gibbs J L et al. Reference Gibbs, Uzun, Blackburn, Wren, Hamilton and Watterson4 In this study, one patient (1.2%) had possible stent restenosis within the first 3 months of the procedure, whereas in other studies, stent restenosis has been reported to have a variable rate ranging from no restenosis to 60% restenosis at 6 months. Reference Alwi, Choo, Latiff, Kandavello, Samion and Mulyadi12,Reference Amoozgar, Cheriki and Borzoee16,Reference Buys, Brown and Greig28–Reference Baho, Deraz, Abouzeid, Al-Ata and Kouatli30 This exceptionally high rate of restenosis has been attributed to small stent sizes (3 and 3.5 mm) and incomplete coverage of the ducts. Reference Curcio, Torella and Indolfi31 Alwi et al. had a restenosis rate of 16%. Reference Alwi, Choo, Latiff, Kandavello, Samion and Mulyadi12 Curcio A et al. showed that drug-eluting stents and double antiplatelet medication use in smaller diameter stents can delay the blockage, but the safety of these stents is not mentioned for small children. Reference Curcio, Torella and Indolfi31 Although the use and safety of double antiplatelets have yet to be studied in smaller babies, we did not observe any complications, such as bleeding, in our patients.
Sivakumar et al., in their study, showed that early surgical intervention was needed in univentricular anatomy after stent placement, 5–14 months, whereas 8–15 months was needed in biventricular anatomy after stent placement. Reference Sivakumar, Bhagyavathy, Coelho and Satish32 In our study, after 6 to 9 months of follow-up, the majority were ready for the next step of surgery and advised to attend the paediatric cardiac surgical unit after performing CT pulmonary angiography.
Vida V et al. and Nasser B et al. showed that surgical aortopulmonary shunt and ductal stenting are both associated with some degree of branch pulmonary artery distortion and require attention during the next step of surgery. Reference Vida, Speggiorin and Maschietto24,Reference Naser, Abdulrahaman, Qwaee, Alakfash, Mohamad and Kabbani25 We had limitations in our study in determining this complication because of the lack of surgical facilities to handle post stenting next surgery.
Patent ductus arteriosus stenting is now a well-described procedure but needs proper understanding related to ductal anatomy, stent selection and good post procedure care. In remote and underserved areas where timely diagnosis of CHD is a real challenge, most of the cases are diagnosed and referred to cardiac centres late. Most cardiac centres, especially outside metro cities, are not well equipped. As a result, the ideal treatment protocol or surgical protocol might not be followed up. In our centre, in the absence of a skilled surgical and cardiac intensivist team, we performed ductal stenting for branch pulmonary artery growth as an alternative to the Blalock-Taussig shunt. We even performed ductal stenting in comparatively older babies who had small branch pulmonary arteries that were not suitable for surgical correction (single ventricle palliation or biventricular repair) and referred them to cardiac centres with good surgical support subsequently. Our follow-up data showed appreciable growth of the branch pulmonary artery; moreover, a large number of patients underwent surgical correction.
Conclusions
In a resource-limited set up where surgical Blalock-Taussig shunt is a high-risk procedure; ductal stenting might be an alternative in duct-dependent pulmonary circulation to augment pulmonary blood flow and growth of branch pulmonary arteries for biventricular correction or single-ventricle palliation. Even older babies, diagnosed late in remote and underserved areas, benefitted from ductal stenting to augment branch pulmonary artery growth and for the final stage of surgical correction. Because of the wide age range of presentation (including > 6 months age) with relatively higher body weight in the study population, the procedural success rate was higher, and the complication rate was lower in our study than in other studies where neonates were the major population.
Limitation
Our study has the limitation of having a smaller population size. To strengthen our findings, we aim to include larger, more diverse populations and robust post procedure follow-up in the future that will help to refine treatment strategies for this kind of high-risk patient population.
Acknowledgements
Department of Paediatrics and Department of Cardiology, Health World Hospitals, Durgapur.
Financial support
This research received no specific grant from any funding agency or commercial or not-for-profit sectors.
Competing interests
The author(s) declare none.
Ethical standard
No ethical clearance was needed, as this was an observational retrospective study.
