Right Ventricular Outflow Tract Stenting Research Articles

Palliative Right Ventricular Outflow Tract Stenting in Tetralogy of Fallot with Severe Cyanosis: Experience from a Single Center in Southern India

Background: This study conducted at an Indian tertiary care hospital aimed to characterize the clinical profile of tetralogy of Fallot (ToF) patients undergoing right ventricular outflow tract (RVOT) stenting and assess their immediate postprocedural outcomes until discharge. Methods: In this retrospective analysis, the clinical and procedural outcomes were analyzed for 20 patients who underwent palliative stenting in the RVOT for severe cyanosis associated with ToF during 2021–2023. Results: The median age for the patients was 2.3 years (range 3 months–21 years), two being adults (>18 years). Fourteen (70%) patients underwent elective RVOT stent and 30% underwent emergency stenting. The most common indication of RVOT stenting was hypoplastic branch pulmonary arteries (PAs) (n = 11, 78.6%) and cyanotic spell (n = 4, 66.7%) for elective and emergency surgeries, respectively. The average improvement in SpO2 was 27.2% (95% confidence interval 23.4–31.0, P < 0.001). Six (30%) patients had complications including reperfusion injury of lungs (n = 2, 33.4%) sepsis (n = 1, 16.7%), stent embolization (n = 1, 16.7%), re-stenting (n = 1, 16.7%), transient complete heart block (n = 1, 16.7%) during the procedure, and. One child went through RVOT stent postoperative due to severe residual stenosis and child developed severe tricuspid regurgitation and succumbed to death due to culture positive sepsis with multi-organ dysfunction. Rest (n = 19, 95%) were discharged with an average 6.7 days of hospital stay. Conclusion: ROVT stenting is a safe and effective palliative management in ToF enhancing oxygen saturation prior to definitive surgical repair.

The Current Strategy in Managing Congenital and Structural Heart Disease: Find and Treat Them Appropriately

Significant progress has been made in diagnosing and treating congenital heart defects (CHDs) over the past five decades. Notable advancements include pulse oximetry screening for critical CHDs in newborns and percutaneous, catheter-based procedures, improving outcomes even in developing nations. Recent studies demonstrate favorable outcomes with device closure of acyanotic CHDs, with non-fluoroscopy techniques adopted to minimize radiation risks. Positive results are observed with right ventricular outflow tract (RVOT) stent palliation for late-presenting cyanotic congenital heart diseases such as tetralogy of Fallot (TOF). Novel interventions like reverse Potts shunt anastomosis show promise in managing pediatric pulmonary arterial hypertension (PAH), while prophylactic treatments effectively reduce postoperative arrhythmias. Fontan procedure significantly enhances survival rates for individuals with single functional ventricles, although challenges arise with aging populations. In developed countries, fetal cardiac interventions utilizing advanced imaging techniques allow for early detection and preventive interventions, reducing secondary complications. Keyword: Fetal Intervention, Fontan, Non-Fluoroscopy, Percutaneous, Reverse Potts, Rheumatic Heart Disease, RVOT Stenting.

Right ventricular outflow tract stenting for late presenter unrepaired Fallot physiology: a single-center experience.

The purpose of this study was to assess the clinical outcome after right ventricular outflow tract (RVOT) stenting in late presenter patient with unrepaired Fallot physiology. In younger patients, RVOT stenting is an alternative to mBTT shunt; however, there have been few reports of this palliative technique in late presenter population, including adults. This was a single-center, retrospective study of nonrandomized, palliated Fallot patients. Clinical outcomes such as left ventricular ejection fraction and saturation were measured in 32 individuals following RVOT stenting in adults (n = 10) and children (n = 22). The Statistical Package for Social Science (SPSS) 26.0 software was used to analyze the statistical data. During the procedure, the average stent diameter and length were 8.84 ± 1.64 mm and 35.46 ± 11.23 mm, respectively. Adult patients received slightly longer stents than pediatric patients (43.60 ± 11.64 mm vs. 31.77 ± 9.07 mm). Overall, patients' saturation increased from 58.56 ± 19.03% to 91.03 ± 8.98% (p < 0.001), as did their left ventricular ejection fraction (LVEF) from 64.00 ± 18.21% to 75.09 ± 12.98% (p = 0.001). Three patients improved their LVEF from 31 to 55%, 31 to 67%, and 26 to 50%. The median length of stay was 8 (2-35) days, with an ICU stay of 2 (0-30) days. The median time from RVOT stent palliation to total repair was 3 months (range: 1 month-12 months). RVOT stenting is a safe and effective method for increasing saturation and ejection fraction not only in newborn infants but also in late presenters, including adults with unrepaired Fallot physiology.

Outcomes of Right Ventricular Outflow Tract Stenting as a Palliative Procedure in Tetralogy of Fallot Patients

Background: Certain groups of tetralogy of Fallot (TOF) patients require a palliative procedure until factors permit a full surgical repair. An aorto-pulmonary shunt is the gold standard palliative procedure but requires a cardiothoracic surgeon in a well-equipped facility. In the government sector in a developing country this limited resource has an overwhelming caseload. Right ventricular outflow tract (RVOT) stenting via cardiac catheterization by a trained paediatric cardiologist is a possible alternative. Objectives: To demonstrate that RVOT stenting is a safe and effective palliative procedure in TOF patients in a resource limited setting. Method: A retrospective, cohort observational study at Steve Biko Academic Hospital from January 2014 to March 2021. Results: 37 patients required RVOT stent placement. Mean oxygen saturation increased from 65% to 95% post-stent insertion. Mean pulmonary artery (PA) growth, measured by McGoon ratio, increased from 1.36 to 2.05. Average Intensive Care Unit stay was 2 days with a zero 30-day mortality. Three stents fractured requiring replacement. Conclusion: Stenting the RVOT in TOF patients who present at an older age, with multiple comorbidities and often in extremis, has yielded good results. Significant improvement in oxygen saturations and PA growth permits majority of our patients to a full TOF surgical repair.

Hybrid Stent Implantation Into Right Ventricular Outflow Tract in a Newborn With Tetralogy of Fallot

A case is presented of a newborn with tetralogy of Fallot and aortic coarctation. Progressive right ventricular outflow tract (RVOT) obstruction required urgent surgical therapy. Coronary artery crossing the outflow tract made ventriculotomy impossible. Hybrid RVOT stent implantation was performed, providing effective pulmonary flow and enabling postponing of corrective jumping graft implantation.

Right Ventricular Outflow Tract Stenting is a Safe and Effective Bridge to Definitive Repair in Symptomatic Infants With Tetralogy of Fallot1.

Right ventricular outflow tract (RVOT) stent angioplasty is a palliative procedure for neonates and infants with symptomatic tetralogy of Fallot prior to surgical repair. We review our institutional outcomes of RVOT stenting. Retrospective review of all infants with tetralogy of Fallot under 3 months of age who underwent primary native RVOT stent angioplasty at The Children's Hospital at Westmead, Sydney, Australia between January 2010 and December 2020. Demographics and echocardiographic pulmonary artery dimensions were collected pre-stent angioplasty and prior to surgical repair. Twenty (20) infants underwent primary RVOT stenting. Median age at stent was 14 days (interquartile range [IQR] 7-32) and median weight 2.7 kg (IQR 2.1-3.4). Three patients underwent hybrid per-ventricular procedures. Indication for RVOT stenting was recurrent hyper-cyanotic spells in 12 (60%) and duct-dependent pulmonary blood flow in 8 (40%). Saturations increased from a median of 80% (IQR 75-85) to 91% (IQR 90-95) post procedure (P<0.001). A single major complication occurred: transient complete atrioventricular dissociation requiring isoprenaline infusion for <24 hours. Twelve (12, 60%) required catheter re-intervention prior to definitive repair for further augmentation of pulmonary blood flow. There were two non-cardiac deaths distant from the stent procedure, but prior to surgical repair. Median right and left pulmonary artery Z-scores increased respectively from -2.06 (IQR -2.99 to -0.17) and -1.2 (IQR -2.59 to -0.14) prior to RVOT stent, to -0.74 (IQR [-1.21 to 0.26], P=0.01) and 0.06 (IQR [-1.87 to 1.15], P=0.006) by the time of definitive repair. Eighteen (18) patients achieved definitive repair at a median age of 6.1 months (IQR 4.7-7.3). Palliation with more than one RVOT stent was associated with an increased duration of cardiac bypass (P=0.035) and cross-clamp (P=0.044) time at definitive repair. In symptomatic neonates and infants with tetralogy of Fallot at high-risk of peri-operative complications, RVOT stent angioplasty can safely and effectively augment pulmonary blood flow prior to definitive repair.

Comparison between the modified Blalock-Taussig shunt and right ventricular outflow tract stent in the palliative treatment for tetralogy of Fallot.

For patients with tetralogy of Fallot (TOF) who are not suitable candidates for primary corrective surgery or have a high surgical risk, transcatheter right ventricular outflow tract (RVOT) stent implantation is considered a safe and effective palliative intervention. This study aims to investigate the therapeutic outcomes of RVOT stent implantation in neonates and infants with TOF in comparison with the modified Blalock-Taussig shunt (mBTS) and to compare the impact of the 2 palliative interventions on arterial oxygen saturation and pulmonary artery development in pediatric patients. Clinical data of 32 patients with TOF admitted to the Second Xiangya Hospital of Central South University from March 2011 to March 2021 were retrospectively collected. The patients were divided into an mBTS group (undergoing mBTS, n=15) and a stent implantation group (undergoing RVOT stenting, n=17) according to the surgical procedures. The 2 groups were assessed and compared in the surgical-related arterial oxygen saturation, postoperative complication rate, mortality rate, and re-intervention rate. The development of the patients' main pulmonary artery, right pulmonary artery, and left pulmonary artery was assessed by z-scores according to echocardiographic results. The children in the stent implantation group were younger and less weighed compared with the mBTS group (both P<0.05). Compared with the preoperative period, children in the stent implantation group had significantly higher arterial oxygen saturation [(75±17)% vs (96±3)%, P=0.026]; z-scores of pulmonary trunk [(-2.82±1.27) points vs (0.86±0.77) points, P=0.014], right pulmonary artery [(-1.88±0.59) points vs (-0.28±0.71) points, P=0.011], and left pulmonary artery [(-2.34±0.36) points vs (-1.67±0.36) points, P=0.036] were significantly increased. However, there were no significant differences in arterial oxygen saturation and pulmonary artery z-scores between pre- and post-mBTS procedures (all P>0.05). RVOT stent would have good surgical outcomes used in TOF patients with low weight and severe comorbidities. It also leads to an higher postoperative oxygen saturation and better promotion of pulmonary artery growth with RVOT stent compared to mBTS.

Rescue right ventricular outflow tract stenting for refractory hypoxic spells.

While right ventricular outflow tract stenting (RVOTS) has become an acceptable alternative to palliative surgery in Tetralogy of Fallot (TOF) and similar physiologies, its utility for relief of refractory hypoxic spells is unclear. Patients who underwent RVOTS for emergency relief of refractory hypoxic spells were identified. Specific modifications to enable expeditious RVOTS included use of stent delivery systems (guiding catheter or long sheath) upfront to minimize catheter exchanges; using coronary wires to cross RVOT initially; stabilizing the catheter with a wire in the aorta while crossing RVOT with a second wire. From 2015 to 2022, 11 patients underwent RVOTS for hypoxic spells refractory to medical management. Their median age was 27 days (IQR 8.5-442.5); weight 3.27 kg (2.7-8.96); 9 males. Median pulmonary annulus Z score was -4.13 (IQR-4.85 to-0.86). Thirteenstents with median diameter 5 (4-6.5) mm and length 19 (16-19.75) mm were implanted, fluoroscopy time:13.6 (11-26.3) min; procedure time (60, 30-70 min). All were ventilated. Oxygen saturations improved from 45% (40-60) to 90% (84-92); (p < 0.0001) with no major complications. Postprocedure ventilation was needed for 21 (20-49) hours and 4 required diuretic infusion for pulmonary over-circulation. Four needed re-stenting 13 days to 5 months later. At median follow-up of 7 (4-17) months; 2 died from unrelated causes, 3 underwent surgery (two correction and one aorto-pulmonary shunt) and 6 await surgery. RVOTS enables safe, expeditious and effective short-term palliation for refractory hypoxic spells. Specific technical modifications facilitate safety, ease and swiftness.

Right Ventricular Outflow Tract Stenting as the First Option for Palliation of Neonates with Severe Tetralogy of Fallot

Background: Neonates with Tetralogy of Fallot (TOF) might be prostaglandin dependent and cannot be discharged from the hospital except after complete correction or palliation. Palliation could be achieved by modified Blalock-Taussig Shunt (BTS), ductal stenting, or right ventricular outflow tract (RVOT) stenting. Objective: The objective of this study was to present our experience of palliating neonates with severe TOF who require augmentation of the pulmonary blood flow by RVOT stenting. Methods: This study was conducted on a series of patients who had RVOT stenting in PSCC-Qassim, Saudi Arabia, from August 2016 till December 2019. Cases that had RVOT stenting are included. The patient's clinical data, echocardiography, cardiac catheterization, and follow-up data were recorded. Data were analyzed using The Microsoft Excel data analysis tool. Results: During the study period, four consecutive patients with a diagnosis of TOF with significant cyanosis underwent RVOT stenting. The mean age and weight were 2.8±1.7 days and 2.9±0.1 kg respectively. All were on prostaglandin infusion before the intervention. The mean saturation before and after RVOT stenting was 63% (±11%) and 82% (±4%) respectively (p = 0.018). One patient required RVOT stent dilatation after 4 months. All patients are alive and had complete TOF repair at a median age of 6.5 months (range 6 to 12 months). The median follow-up period is 13 months. The median branch PAs diameter and Z-score before RVOT stenting and immediately before complete TOF repair were 2.8 mm (Z score: -2.5) and 5.5 mm (Z score: -0.5 to -1.16) respectively (p = 0.001). Conclusion: RVOT stenting is a reasonable alternative palliation for patients with severe TOF. The technique of stent deployment in the RVOT is challenging and requires pre-intervention planning and discussion. Using soft catheters, coronary wires, and the premounted coronary stents facilitate crossing of the RVOT and pulmonary valve and then stent deploymen

Role of Echocardiography in Catheter Interventions for the Right Ventricular Outflow Tract

The treatment strategies and timing of corrective or palliative procedures for patients with right ventricular outflow tract (RVOT) obstruction vary depending on the lesion and also on the severity of the patient's symptoms. A wide variety of right heart obstructive lesions ranging from severe valvar pulmonary stenosis, pulmonary atresia with intact ventricular septum, and tetralogy of Fallot can be treated effectively with corrective or palliative interventions in the catheterization laboratory. Interventional procedures to relieve right ventricular outflow obstruction and/or to augment antegrade pulmonary blood flow include balloon pulmonary valvotomy, pulmonary valve perforation, and RVOT stenting. In all these interventions, echocardiography plays an essential role, not only in the preprocedural assessment and case selection but also during the actual procedure in the catheter laboratory. With proper use, a transthoracic echocardiogram can minimize radiation exposure, help in stent positioning in the RVOT, and even detect complications instantaneously. This manuscript reviews the role of echocardiography in transcatheter interventions of the RVOT.

Transcatheter Approaches to Palliation for Tetralogy of Fallot.

To this day, controversy still exists regarding the optimal method to treat symptomatic neonates and infants with Tetralogy of Fallot (TOF). Symptomatic (severely cyanotic or ductal dependent) infants with TOF can undergo either a staged repair approach (consisting of initial palliation followed by complete repair) or primary repair. Traditionally, initial palliative procedures have been surgical, for example placement of a Blalock-Taussig-Thomas (BTT) shunt. Recent advances in technology have facilitated the introduction of catheter-based procedures as palliative techniques, for example, patent ductus arteriosus (PDA) stenting and right ventricular outflow tract (RVOT) stenting as more durable solutions than balloon pulmonary valvuloplasty (BPV). In this article, we discuss the rationale for these procedures, technical aspects of these procedures and outcomes data compared to traditional surgical procedures. Recent data have suggested that RVOT and PDA stenting procedures offer many advantages over traditional surgical palliative procedures as palliative methods in this patient population. This comes at a cost of increased reintervention burden, which may be considered part of the overall treatment strategy in smaller neonates and can be minimized with a focus on technical aspects and overall treatment strategies. Advanced surgical techniques are required at the eventual complete repair to negotiate removal of stent material and pulmonary artery reconstruction in some instances. Further adoption of catheter based palliative procedures for infants with symptomatic TOF has the potential to tip the outcomes towards favoring a staged approach, particularly in high-risk infants.

Is there a role for endovascular stent implantation in the management of postoperative right ventricular outflow tract obstruction in the era of transcatheter valve implantation?

The optimal management pathway for the dysfunctional right ventricular outflow tract (RVOT) is uncertain. We evaluated the long-term outcomes and clinical impact of stent implantation for obstructed RVOTs in an era of rapidly progressing transcatheter pulmonary valve technology. Retrospective review of 151 children with a biventricular repair who underwent stenting of obstructed RVOT between 1991 and 2017. RVOT stenting resulted in significant changes in peak right ventricle (RV)-to-pulmonary artery (PA) gradient (39.4 ± 17.1-14.9 ± 8.3; p < 0.001) and RV-to-aortic pressure ratio (0.78 ± 0.22-0.49 ± 0.13; p < 0.001). Subsequent percutaneous reinterventions in 51 children to palliate recurrent stenosis were similarly effective. Ninety-nine (66%) children reached the primary outcome of subsequent pulmonary valve replacement (PVR). Freedom from PVR from the time of stent implantation was 91%, 51%, and 23% at 1, 5, and 10 years, respectively. Small balloon diameters for stent deployment were associated with shorter freedom from PVR. When additional children without stent palliation (with RV-to-PA conduits) were added to the stent cohort (total 506 children), the multistate analysis showed the longest freedom from PVR in those with stent palliation and subsequent catheter reintervention. Pulmonary regurgitation was well-tolerated clinically. Indexed RV dimensions and function estimated by echocardiography remained stable at last follow up or before primary outcome. Prolongation of conduit longevity with stent implant remains an important strategy to allow for somatic growth to optimize the risk-benefit profile for subsequent surgical or transcatheter pulmonary valve replacement performed at an older age.

Evaluation of Right Ventricular Outflow Tract Stenting as Palliative Treatment in Severely Cyanotic Tetralogy of Fallot: A Systematic Review and Meta-Analysis of Observational Studies.

Background: Tetralogy of Fallot (ToF) is a cardiac malformation that accounts for up to 1/10 of all congenital diseases. Although surgical repair serves as a treatment of choice, it cannot be performed unless weight and anatomical key factors are favorable. The stenting of the right ventricular outflow tract (RVOT) has become an alternative palliative procedure for ToF as an option to alleviate infundibular obstruction with minimal invasion. Methods: A literature search was conducted through 7 databases, followed by the screening and independent assessment of 6 final studies, using the Newcastle-Ottawa Quality Assessment Scale (NOS). Analysis was then conducted using inverse variance analysis, and cumulative data were presented with forest and funnel plots. Results: Studied patients were referred for RVOT stenting due to the marked obstruction of the pulmonary blood flow, a low birth weight, or a small pulmonary artery size. The analysis revealed a significant increase in O2 saturation (mean difference [MD=18%; 13–23.78). The same trend was observed concerning an increase in the Nakata index (MD=54.59; 10.05–99.14), the right pulmonary artery diameter (MD=2.28; 1.20–3.36), and the left pulmonary artery diameter (MD=1.77; 0.22–3.32). Several complications were found, including tricuspid regurgitation and frequent premature beats. Conclusion: RVOT stenting is considered a feasible palliative treatment for ToF, with its high effectiveness in improving patients’ condition, especially their pulmonary flow. While complications are scarce, several conditions should be noted, particularly for fatal complications. Finally, this study has limitations as catheterization details in studies and diverse infants’ conditions may have caused potential bias

The features of step-by-step surgical approach for correction of tetralogy fallot using modern palliative methods

Aim. To evaluate the hospital results of one-stage radical correction (RC) of Fallot's tetrad (TF) and stage-by-stage correction of the defect using stenting of the right ventricular outflow tract (RVOT).Methods. The group of step-by-step correction included 24 patients with the classic cyanotic form of TF: 1st stage – stenting of the RVOT (Me age 73.5 days, weight 3.8 kg), 2nd stage – RC of TF Me age 187 days. The group of one-stage RC TF included 30 newborns with Me aged 121.5 days and weight 5.5 kg.Results. After performing stenting of RVOT, there was a significant increase in SpO2 from 80 to 94%, end diastolic volume of left ventricle index from 24 to 33.3 ml/m2 , a decrease in the severity of hypoplasia of the pulmonary artery trunk (PA) compared with the stage before stenting of RVOT (p˂ 0.05). Patients of the two groups had equal values of weight, SpO2, the severity of PA hypoplasia, and a gradient in the RVOT at the time of RC. After the RC in stenting group there was an increase in SpO2 up to 98%, a decrease in the RVOT gradient from 75 to 16.5 mm Hg, an increase in the end diastolic volume left ventricle index to 56.5 ml/m2 (p˂ 0.05). The dynamics of the status of patients in Group 1 with the use of palliative intervention did not significantly differ from the dynamics in Group 2 (one-stage RC TF).Conclusion. Application of the approach of step-by-step correction of TF with stenting of RVOT in low weight infants with severe hypoxemia demonstrated an equal effect on the dynamics of SpO2, reverse cardiac remodeling compared with patients who underwent simultaneous RC of classical TF.

Right Ventricular Outflow Tract Stenting as Palliation of Critical Tetralogy of Fallot: Techniques and Results

Background. Despite current trends toward early primary repair, the surgical systemic-to-pulmonary shunt is still considered the first-choice palliation in patients with critical tetralogy of Fallot (TOF) and duct-dependent pulmonary circulation unsuitable for primary repair. However, stenting of the right ventricular outflow tract (RVOT) is nowadays emerging as an effective alternative to surgical palliation in selected patients. Methods and results. RVOT stenting is usually performed from a venous route, either femoral or, in selected cases, the right internal jugular vein. Less frequently, mostly in pulmonary infundibular/valvar atresia, this procedure can be performed using a hybrid surgical/interventional approach by surgical exposure of the RVOT, puncture of the atretic valve, and stent deployment under direct vision. The size and type of the most appropriate stent may be chosen, based on ultrasound measurements of the RVOT, to cover the right ventricular infundibulum completely and, at the same time, sparing the pulmonary valve, unless significant pulmonary valve annulus hypoplasia and/or supra-valvular stenosis is a significant component of the obstruction. In the large series so far published, early mortality of RVOT stenting is less than 2%, comparing favourably with either Blalock-Thomas-Taussig shunt or early primary repair. In addition, morbidity and clinical sequelae of this approach do not significantly differ from surgical palliation, even if RVOT stenting shows lesser durability and a higher rate of trans-catheter re-interventions over a mid-term follow-up. Finally, similar but more balanced pulmonary artery growth than surgical palliation following RVOT stenting is reported over a mid-term follow-up. Conclusions. RVOT stenting is a technically feasible, well-tolerated, and effective palliation in critical TOF. This approach is cost-effective with respect to surgical palliation either in high-risk neonates or whenever a short-term pulmonary blood flow source is anticipated due to the early surgical repair. It effectively increases pulmonary blood flow, improves arterial saturation, and promotes balanced pulmonary artery growth over a mid-term follow-up.

Use of the ductal curvature index to assess the risk of ductal stenting in patients with duct-dependent pulmonary circulation

BackgroundTo evaluate whether a quantitative curvature threshold can contribute to risk stratification of ductal stenting in patients with a duct-dependent pulmonary circulation (DDPC).MethodsA single-center retrospective analysis was performed. The ductal curvature index (DCI) was calculated in 71 patients with DDPC. The ducts were divided into four classes based on quartile thresholds of DCI: class I (≤0.12), class II (0.13–0.33), class III (0.34–0.44), and class IV (≥0.45). The primary outcome of this study was defined as free from all of the following: (I) intervention related death, (II) need of unplanned surgery (III) need of unplanned pulmonary valve (PV) perforation with stent in right ventricular outflow tract (RVOT), and (IV) intervention related permanent complications.ResultsEighty percent of patients in class IV (DCI ≥0.45) failed to achieve the primary outcome; odds ratio (OR) 9 and 95% confidence interval (CI): 3.7–21.4 compared to 26.6% in all classes with DCI <0.45. 66.7% of these patients needed unplanned surgery or PVP with RVOT stent; OR 12.4 (95% CI: 4–39). 80% of major complications were observed in class IV (P<0.01). Need of pulmonary arterioplasty was in class IV 53.3%; OR 3.3 (95% CI: 1.5–7.1).ConclusionsDCI can be useful to guide the clinical decision-making in patients with torqued ducts. Patients with a DCI ≥0.45 belong to a high-risk group, in which ductal stenting is associated with an elevated risk for early surgery or unplanned re-intervention.

Palliative Balloon Pulmonary Valvotomy in Tetralogy of Fallot: Is There a Role in 2021?

The current treatment practice for Tetralogy of Fallot (TOF) is to undertake complete surgical repair between 6–9 months of age with excellent immediate and long-term results. In patients with increased cyanosis or frequent cyanotic spells, younger age of complete repair as early as 3 months is usually acceptable. Although neonatal TOF repair is reported with good immediate survival from a few centres, post-operative morbidity is significant, and the hospital stay is prolonged. Hence, in neonates and small term and preterm infants with severe cyanosis, palliative procedures such as modified Blalock-Taussig (BT) shunt, ductal stenting, right ventricular outflow tract (RVOT) stenting and balloon pulmonary valvotomy (BPV) have been reported. With the development of low-profile stents, an increasing clinician experience and more predictable outcome with both duct and RVOT stenting, these procedures have gained popularity as the preferred palliations for TOF at most centres. We reviewed the literature to analyse whether BPV for TOF palliation, a technique first reported three decades ago, still has a role in the present era of paediatric cardiac care. In this review, we have concluded that BPV has very specific indications in patients with TOF, with predominantly valvar pulmonary stenosis, and may be a preferred option over other palliative strategies in hypoxemic preterm or low-birth weight infants.

Right ventricular outflow tract stenting in symptomatic infants without the use of a long delivery sheath.

Right ventricular outflow tract (RVOT) stenting improves systemic oxygenation and facilitates pulmonary arterial growth in symptomatic infants prior to repair of tetralogy of Fallot. The aim of this study was to evaluate the safety and efficacy of RVOT stenting without the use of a long delivery sheath. Retrospective data analysis of patients under 1 year of age undergoing RVOT stenting from January 2010 to January 2020 at a single tertiary pediatric cardiology center. Sixty-three RVOT stents were deployed during 53 procedures into 44 patients. The median age and weight at insertion were 41 days (range 2-204) and 3.6kg (range 1.59-7) respectively. Thirty-one procedures were semi-elective and 22 were emergencies. Stent positioning was guided by transthoracic echocardiogram and/or RV angiography from a pigtail micro-catheter placed via the aorta. The median total procedure and fluoroscopy times were 67.5 (range 15-145) and 19 min (1-107), respectively. The median length of hospital stay was 7 days (range 1-258). Twenty-one patients were admitted to ICU post-procedure with a median ICU length of stay of 3 days (range 3-11). There were three major complications including two deaths within 30 days of the procedure. A patient with Cornelia de Lange Syndrome (1.8 kg) died following stent migration and inability to wean from emergency cardiopulmonary bypass and the second infant had an unexplained asystolic arrest post-procedure while awaiting transfer to ICU. RVOT stenting is technically possible with minimal complications without the need for a long delivery sheath. Additional imaging with transthoracic echocardiography can facilitate the safe deployment of the stent.

Right Ventricular Outflow Tract Stenting in Infants Less Than 3.5kg to Augment Pulmonary Blood Flow Prior to Surgical Repair of Tetralogy of Fallot

Right ventricular outflow tract (RVOT) Stent angioplasty is a well described staging palliation for young infants with Tetralogy of Fallot (and morphological variants). We review our institutional outcomes of RVOT Stenting.

Short to medium term outcomes of right ventricular outflow tract stenting as initial palliation for symptomatic infants with complete atrioventricular septal defect with associated tetralogy of Fallot.

To assess the impact of right ventricular outflow tract (RVOT) stenting as the primary palliation in infants with complete atrioventricular septal defect with associated tetralogy of Fallot (cAVSD/TOF). Historically, palliation of symptomatic patients with cAVSD/TOF has been achieved through surgical systemic to pulmonary artery shunting. More recently RVOT stenting has evolved as an acceptable alternative in patients with tetralogy of Fallot. Retrospective review of all patients with cAVSD/TOF who underwent RVOT stenting as palliation over a 13-year period from two large tertiary referral centers. Twenty-six patients underwent RVOT stenting at a median age of 57 days (interquartile range [IQR] 25.5-106.5). Median weight for stent deployment was 3.7 kg (IQR 2.91-5.5 kg). RVOT stenting improved oxygen saturations from a median of 72% (IQR 70-76%) to 90% (IQR 84-92%), p < .001. There was a significant increase in the median Z-score for both branch pulmonary arteries at median follow-up of 255 days (IQR 60-455). Eight patients required RVOT stent balloon dilatations and 8 patients required re-stenting for progressive desaturation. The median duration between reinterventions was 122 days (IQR 53-294 days). Four patients died during the follow-up period. No deaths resulted from the initial intervention. To date, definitive surgical intervention was achieved in 19 patients (biventricular repair n = 15) at a median age of 369 days (IQR 223-546 days). RVOT stenting in cAVSD/TOF is a safe and effective palliative procedure in symptomatic infants, promoting pulmonary artery growth and improving oxygen saturations.