Thromboprophylaxis strategies for children with single-ventricle circulations (superior or total cavo-pulmonary connections) after stent implantation.

OBJECTIVE: To define optimal thromboprophylaxis strategy after stent implantation in superior or total cavopulmonary connections. BACKGROUND: Stent thrombosis is a rare complication of intravascular stenting, with a perceived higher risk in single-ventricle patients. METHODS: All patients who underwent stent implantation within superior or total cavopulmonary connections (caval vein, innominate vein, Fontan, or branch pulmonary arteries) were included. Cohort was divided into aspirin therapy alone versus advanced anticoagulation, including warfarin, enoxaparin, heparin, or clopidogrel. Primary endpoint was in-stent or downstream thrombus, and secondary endpoints included bleeding complications. RESULTS: A total of 58 patients with single-ventricle circulation underwent 72 stent implantations. Of them 14 stents (19%) were implanted post-superior cavopulmonary connection and 58 (81%) post-total cavopulmonary connection. Indications for stenting included vessel/conduit stenosis (67%), external compression (18%), and thrombotic occlusion (15%). Advanced anticoagulation was prescribed for 32 (44%) patients and aspirin for 40 (56%) patients. Median follow up was 1.1 (25th-75th percentile, 0.5-2.6) years. Echocardiograms were available in 71 patients (99%), and advanced imaging in 44 patients (61%). Thrombosis was present in two patients on advanced anticoagulation (6.3%) and none noted in patients on aspirin (p = 0.187). Both patients with in-stent thrombus underwent initial stenting due to occlusive left pulmonary artery thrombus acutely post-superior cavopulmonary connection. There were seven (22%) significant bleeding complications for advanced anticoagulation and none for aspirin (p < 0.001). CONCLUSIONS: Antithrombotic strategy does not appear to affect rates of in-stent thrombus in single-ventricle circulations. Aspirin alone may be sufficient for most patients undergoing stent implantation, while pre-existing thrombus may warrant advanced anticoagulation.

Angiographic follow-up of infants and children undergoing percutaneous carotid artery interventions.

OBJECTIVE: The purpose of this study was to review the outcomes following the percutaneous carotid arterial (PCA) approach in infants and children with congenital heart disease. BACKGROUND: PCA access is becoming more commonly adopted following reports demonstrating it is a safe alternative to surgical carotid cutdown and even the femoral arterial route. However, follow-up outcomes after PCA remain unreported. METHODS: We reviewed all cases with PCA access and follow-up catheterizations which included carotid artery (CA) angiography between May 2012 until December 2016. We examined for evidence of CA stenosis at follow-up angiography and assessed any other CA complications associated with vascular access. RESULTS: There were 61 PCA catheterizations performed in 55 unique patients. Follow-up CA imaging with angiography was available in 43 patients (78%, 43/55). There was no vessel stenosis nor lumen irregularity in 28 (65%) patients. In 15 cases (35%), there was a mild degree of irregularity or narrowing by angiography (median 4.1%, range 2.3%-12.5%). Nine patients underwent repeat PCA catheterizations. Seven of these had no visible vascular stenosis on follow-up angiographic imaging, including a patient who was accessed three separate times from the CA. No statistically significant risk factors for developing mild CA stenosis were identified. CONCLUSIONS: PCA access for pediatric interventional catheterization appears to be safe with a very low rate of mild stenosis, and very few complications. Follow-up outcomes in our series are excellent, with a CA patency rate of 100%, even after multiple procedures. Mild CA stenosis was not associated with patient size or sheath introducer caliber. While the acute results from percutaneous CA catheterization have proven safe in recent literature, longer-term outcomes remain unreported. At our institution, the outcomes following percutaneous carotid access are associated with an excellent patency rate of 100%, even after multiple procedures on the same vessel. A low incidence of mild vessel stenosis can be appreciated on follow-up angiography.

High-risk single ventricle palliation in children with Down syndrome: single institution experience.

BACKGROUND: Of the children with Down syndrome 40-50% have cardiac defects and the majority of these cardiac defects are amenable to biventricular repair. The outcome of single ventricle palliation is improving; nonetheless, there are limited data on Down syndrome patients with associated high-risk factors undergoing single ventricle palliation. Our aim was to study the outcomes of children with Down syndrome and high-risk factors on the single ventricle palliation pathway. METHODS: A retrospective study on all patients with Down syndrome on the single ventricle palliation pathway from 2005 until 2011 was conducted. Operative, clinical, echocardiographic, haemodynamic data, and follow-up data were reviewed. RESULTS: A total of 310 patients underwent at least one single ventricle surgical intervention. Of those, eight patients had Down syndrome, five of which had associated risk factors - low birth weight, high pulmonary vascular resistance, pulmonary vein stenosis, significant atrioventricular valve regurgitation, and extracardiac anomalies. Mortality in the high-risk group was 80% (4/5), compared with 33% (1/3) in the non-high-risk patients. Overall, after a median follow-up period of 138 days (8-576 days), only 37.5% (3/8) of patients were alive. CONCLUSION: Despite many improvements in the care of single ventricle patients, the fate of those with Down syndrome and associated high-risk factors remains poor. Further multicentre longer-term studies are needed to validate and quantify the cumulative effects of negative prognostic factors in this complex group of patients.

Intervention on Surgical Systemic-to-Pulmonary Artery Shunts: Carotid Versus Femoral Access.

OBJECTIVES: The purpose of this study was to compare results between the femoral arterial (FA) and carotid arterial (CA) approaches in catheter-based interventions on Blalock-Taussig shunts (BTS). BACKGROUND: Transcatheter intervention on BTS is often performed in shunt-dependent, hypoxemic infants. The approach to BTS intervention likely has an impact on timeliness and overall success. METHODS: The authors reviewed all cases of catheter intervention for BTS obstruction between 2012 and 2017 for their institution. They sought to compare procedural success rates and time, sheath time, time to arterial access, and time from access to stent implantation between FA and CA approaches. RESULTS: There were 42 BTS interventions between 34 patients. BTS intervention was more successful from the CA approach (p = 0.035). Among the FA cohort, BTS intervention was unsuccessful in 8 cases (25%), 5 of which were converted to CA with subsequent success. The CA cohort had lower procedure time (62 min vs. 104 min; p = 0.01) and anesthesia time (119 min vs. 151 min; p = 0.01). Additionally, CA access was associated with shorter time to arterial access (4.0 min vs. 9.3 min; p < 0.01), time to placement of the guidewire through the BTS (6.5 min vs. 13 min; p < 0.01), and time from the final sheath to BTS stent implantation (9 min vs. 20 min; p < 0.01). CONCLUSIONS: Operators should consider the route of access to the BTS deliberately. The authors' approach has been the carotid artery as an alternative access site-associated with greater procedural success, shorter procedural time, and shorter time to stent implantation.

Reintervention Is Associated With Improved Survival in Pediatric Patients With Pulmonary Vein Stenosis.

OBJECTIVES: The aim of this study was to evaluate survival following catheter intervention in pediatric patients with pulmonary vein stenosis (PVS). BACKGROUND: Despite aggressive surgical and catheter intervention on PVS in children, recurrence and progression of stenosis can lead to right heart failure and death. Clinicians continue to seek effective treatment options for PVS. METHODS: A single-center, retrospective study was performed including all patients <18 years of age who underwent catheter intervention (balloon angioplasty and bare-metal stent and drug-eluting stent insertion) on PVS. Endpoints included death, vein loss, and rate of reintervention. RESULTS: Thirty patients underwent intervention (balloon angioplasty, n = 9; bare-metal stent, n = 5; drug-eluting stent, n = 16) at a median age of 6.4 months (4.3 to 9.9 months). Median follow-up duration was 30.6 months (77 days to 10.5 years). Fourteen patients (47%) died at a median of 2.0 months (0.4 to 3.2 months) following intervention. There was no association between DES placement and survival (p = 0.067). Reintervention (catheter or surgical) was associated with improved survival (p = 0.001), with a 1-year survival rate of 84% compared with 25% for no reintervention. Vein loss occurred in 34 of 58 (59%) veins at a median of 3.3 months (1.0 to 5.0 months). One-year vein survival was higher with DES implantation (p = 0.031) and with reintervention (p < 0.001). CONCLUSIONS: DES implantation at first catheter intervention appears to be associated with improved vein survival but may not result in improved patient survival. However, reintervention appears to be associated with improved patient survival and vein patency, suggesting that despite mode of treatment, frequent surveillance is important in the care of these patients.