Hybrid Stenting of Pulmonary Venous Baffle Stenosis: Subxiphoid Approach in Transposition of the Great Arteries.

A 31-year-old woman with transposition of the great arteries status post-Senning operation presents with severe pulmonary venous baffle obstruction. Both standards of care (percutaneous stenting or open repair) were deemed suboptimal and/or high risk. A multidisciplinary, hybrid approach via subxiphoid incision, guided by 3-dimensional modeling, provided a lower risk and minimally invasive intervention.

Safety and Short-Term Outcomes for Infants < 2.5 kg Undergoing PDA Device Closure: A C3PO Registry Study.

To evaluate short-term procedural outcomes and safety for infants < 2.5 kg who underwent catheterization with intended patent ductus arteriosus (PDA) device closure in a multi-center registry, as performance of this procedure becomes widespread. A multi-center retrospective review was performed using data from the Congenital Cardiac Catheterization Project on Outcomes (C3PO) registry. Data were collected for all intended cases of PDA closure in infants < 2.5 kg from April 2019 to December 2020 at 13 participating sites. Successful device closure was defined as device placement at the conclusion of the catheterization. Procedural outcomes and adverse events (AE) were described, and associations between patient characteristics, procedural outcomes and AEs were analyzed. During the study period, 300 cases were performed with a median weight of 1.0 kg (range 0.7-2.4). Successful device closure was achieved in 98.7% of cases with a 1.7% incidence of level 4/5 AEs, including one periprocedural mortality. Neither failed device placement nor adverse events were significantly associated with patient age, weight or institutional volume. Higher incidence of adverse events associated with patients who had non-cardiac problems (p = 0.017) and cases with multiple devices attempted (p = 0.064). Transcatheter PDA closure in small infants can be performed with excellent short-term outcomes and safety across institutions with variable case volume.

Procedural Risk in Congenital Cardiac Catheterization (PREDIC3T).

Background Advancements in the field, including novel procedures and multiple interventions, require an updated approach to accurately assess patient risk. This study aims to modernize patient hemodynamic and procedural risk classification through the creation of risk assessment tools to be used in congenital cardiac catheterization. Methods and Results Data were collected for all cases performed at sites participating in the C3PO (Congenital Cardiac Catheterization Project on Outcomes) multicenter registry. Between January 2014 and December 2017, 23 119 cases were recorded in 13 participating institutions, of which 88% of patients were <18 years of age and 25% <1 year of age; a high-severity adverse event occurred in 1193 (5.2%). Case types were defined by procedure(s) performed and grouped on the basis of association with the outcome, high-severity adverse event. Thirty-four unique case types were determined and stratified into 6 risk categories. Six hemodynamic indicator variables were empirically assessed, and a novel hemodynamic vulnerability score was determined by the frequency of high-severity adverse events. In a multivariable model, case-type risk category (odds ratios for category: 0=0.46, 1=1.00, 2=1.40, 3=2.68, 4=3.64, and 5=5.25; all P≤0.005) and hemodynamic vulnerability score (odds ratio for score: 0=1.00, 1=1.27, 2=1.89, and ≥3=2.03; all P≤0.006) remained independent predictors of patient risk. Conclusions These case-type risk categories and the weighted hemodynamic vulnerability score both serve as independent predictors of patient risk for high-severity adverse events. This contemporary procedure-type risk metric and weighted hemodynamic vulnerability score will improve our understanding of patient and procedural outcomes.

Percutaneous Hydrogel Coil Embolization of Aneurysms and Coronary Artery Fistulae in Congenital Heart Disease.

Patients with congenital heart disease frequently have aneurysms or coronary artery fistulae that necessitate treatment. Metal vascular coils have been a mainstay of treatment for these lesions. In 2002, coils coated or filled with expandable hydrogel were introduced to treat cerebral aneurysms; however, the literature on their use in patients with congenital heart disease is limited. We present 5 cases in which large vascular lesions in children or adolescents with congenital heart disease were successfully occluded with hydrogel coils.

Longitudinal Improvements in Radiation Exposure in Cardiac Catheterization for Congenital Heart Disease: A Prospective Multicenter C3PO-QI Study.

BACKGROUND: The C3PO-QI (Congenital Cardiac Catheterization Project on Outcomes - Quality Improvement), a multicenter registry launched in 2015, instituted quality improvement (QI) initiatives to reduce patient radiation exposure. Through regular collaboration, this initiative would allow for harmony among active participants, maximizing efforts and efficiency at achieving radiation best practices. This study sought to report these efforts with a detailed methodology for which institutions can target initiatives, reducing radiation exposure, and increasing patient safety. METHODS: Data were collected prospectively by 8 C3PO-QI institutions between January 1, 2015 and December 31, 2017. Radiation exposure was measured in dose area product per body weight (dose area product/kg; µGy*m2/kg) and reported by expected radiation exposure categories (REC) and institution for 40 published unique procedure types. Targeted interventions addressing selected strategic domains for radiation reduction were implemented in the pediatric catheterization labs of the C3PO-QI institutions. RESULTS: The study consisted of 15 257 unique cases. Median exposure (dose area product/kg) was decreased by 30% for all procedures. Dose area product/kg was reduced in all 3 REC, with the greatest improvement observed in REC I (REC I, -37%; REC II, -23%; REC III, -27%). Although the baseline radiation exposures and exact percent decrease varied across all C3PO-QI sites, each institution demonstrated improvements in radiation dose over time. These improvements occurred with the implementation of institution-specific QI interventions accelerated by participation in the C3PO-QI multicenter collaborative. CONCLUSIONS: Substantial radiation dose reductions can be achieved using targeted QI methodology and interventions. Participation in a multicenter QI collaborative may accelerate improvement across all centers due to enhanced engagement and shared learning between sites.

Variability in radiation dose and image quality: A comparison across fluoroscopy-system vendors, generations of equipment and institutions.

OBJECTIVES: To evaluate differences in radiation dose and image quality across institutions, fluoroscope vendors and generations of fluoroscopes for pediatric cardiac catheterization. BACKGROUND: Increased recognition of the potentially harmful effects of ionizing radiation has spurred technological advances in fluoroscopes, as well as increased focus on optimizing fluoroscope performance. There is currently little understanding of variability in the dose-image quality relationship across institutions, fluoroscope vendor and/or generation of equipment. METHODS: We evaluated latest generation fluoroscopes from Phillips, Siemens, GE, and Toshiba, and an older generation Phillips fluoroscope (release date 2003) at three different institutions. Radiation dose was measured using an anthropomorphic dose-assessment phantom with effective dose in mSv estimated from Monte Carlo simulations. Image quality phantom images were scored on a 12-point scale by three blinded reviewers. RESULTS: Fluoroscope effective doses ranged from 0.04 to 0.14 mSv/1,000 pulses for fluoroscopy with associated composite image quality scores ranging from 8.0 ± 0.6 to 10.4 ± 1.3. For cineangiography, effective doses ranged from 0.17 to 0.57 mSv/1,000 frames with image quality scores ranging from 10.1 ± 0.3 to 11.1 ± 0.3. There was modest correlation between effective dose and image quality (r = 0.67, P = 0.006). The older generation fluoroscope delivered consistently higher doses than the newer generation systems (2.3- to 3.5-fold higher for fluoroscopy; 1.1- to 3.4-fold higher for cineangiography) without appreciable differences in image quality. CONCLUSION: Technological advances have markedly improved fluoroscope performance. Comparing latest generation systems across vendors and institutions, we found variability in the dose-IQ relationship and speculate that this reflects both equipment and institutional optimization practices.

Left main coronary artery stent placement in a 7.0 kg infant with Williams Syndrome.

We report the case of a 9-month-old male with Williams syndrome who underwent patch augmentation of supravalvar aortic stenosis and pulmonary artery stenosis, and required emergent drug-eluting left coronary artery stenting on post-operative day 1 for severe left ventricular dysfunction related to myocardial ischemia.

Abstract 12670: Variability in Radiation Dose and Image Quality: A Comparison Across Fluoroscopy-system Vendors and Generations of Equipment.

INTRODUCTION: Increased recognition of the potentially harmful effects of ionizing radiation has spurred technological advances to reduce exposure during fluoroscopy. However there is currently little understanding of the dose-image quality (IQ) relationship between fluoroscopy vendors and across generations of equipment used for imaging during pediatric catheterization. METHODS: We evaluated latest generation fluoroscopy systems from Phillips, Siemens, GE and Toshiba, and an older generation Phillips system (2004 release). Fluoroscopy and cineangiography were performed on a tissue simulation anthropomorphic phantom using a standardized imaging approach. Phantom surface exposures were used for Monte Carlo simulations to calculate radiation effective dose, accounting for differences in beam parameters. We also imaged a fluoroscopy IQ phantom to assess contrast-detail and line-per-inch visualization. IQ images were scored by 3 blinded reviewers with scores averaged to produce a composite rating (scale 0-18). To assess the impact of imaging approach we then simulated a neonatal cardiac catheterization incorporating "typical" imaging protocols provided by institutions using the various systems. RESULTS: Effective doses and IQ scores are summarized in the table. Effective doses varied by >400% with the older generation system consistently delivering markedly higher doses. The associated figure summarizes dose and IQ for a simulated neonatal cardiac catheterization which accounts for measured doses as well as the reported institutional imaging parameters summarized in the figure legend. CONCLUSION: These data demonstrate substantial technological improvements in fluoroscopy equipment and may be useful to justify institutional "upgrades". Comparing latest generation systems across vendors and institutions, we found variability in the dose-IQ relationship that reflects both equipment and imaging approach.

Tissue plasminogen activator treatment of bilateral pulmonary emboli in a pediatric patient supported with a ventricular assist device.

Bleeding and thrombosis are well-known potential complications of VAD support. We present a pediatric patient who developed massive bilateral pulmonary emboli while on BiVAD support that was successfully treated with intravenous tPA and bridged to heart transplant.

Angiojet rheolytic thrombectomy in infants following cardiac surgery.

OBJECTIVES: To present our experience with the Angiojet thrombectomy system for percutaneous thrombectomy in infants following cardiac surgery. BACKGROUND: Arterial and venous thrombosis after pediatric cardiac surgery is life threatening, particularly in infants. The best method for treating these patients has not been determined. Angiojet rheolytic thrombectomy (Possis Medical, Minneapolis, MN) is a percutaneous method of thrombus removal with proven safety and efficacy in adults. METHODS: We reviewed the medical records and angiograms of all procedures in which Angiojet thrombectomy was used in infants following cardiac surgery at our institution during the years 2005 through 2007. RESULTS: Ten procedures were performed in eight infants. The procedure was performed a mean of 23 days from surgery. The mean age was 74 days with a mean weight of 4.3 kg. All patients had life or limb threatening thrombosis. Indications for thrombectomy included severe cyanosis, chronic pleural effusions secondary to extensive venous thrombosis, and acute iliac artery thrombosis. Thrombus was evacuated from pulmonary arteries in four patients, systemic veins in two patients, a surgical aorto-pulmonary shunt in two patients, and an iliac artery in one patient. Balloon angioplasty following thrombectomy was performed in eight procedures (80%), and stents were placed in addition to angioplasty in two procedures. All patients had significant improvement in flow across the affected area. There was one major complication and three minor complications with no procedural-related deaths. Survival to discharge from the hospital was 62.5%. CONCLUSION: Angiojet thrombectomy is an effective treatment for life-threatening postoperative thrombosis in infants following cardiac surgery.

Congenital pulmonary artery stenoses masquerading as chronic thromboembolic disease.

Stenotic pulmonary vascular lesions, often amenable to balloon angioplasty, can erroneously appear to suggest chronic thromboembolic disease on ventilation/perfusion (V/Q) scan. We report a case of multiple peripheral pulmonary artery stenoses and describe radiologic findings and treatment options.

Pulmonary venous wedge pressure provides a safe and accurate estimate of pulmonary arterial pressure in children with shunt-dependent pulmonary blood flow.

OBJECTIVES: To compare two methods of pulmonary arterial pressure measurement in children with shunt-dependent pulmonary blood flow. BACKGROUND: In children with shunt-dependent pulmonary blood flow, direct assessment of pulmonary arterial pressure requires passage of a catheter across the shunt. This can be technically difficult and dangerous. Use of the pulmonary venous wedge pressure offers an alternative but has not been validated in this patient population. METHODS: We prospectively studied 18 children with shunt-dependent pulmonary blood flow. Pulmonary venous wedge pressure and directly measured pulmonary arterial pressures were independently assessed by two blinded cardiologists. RESULTS: Directly measured mean pulmonary arterial pressure and pulmonary venous wedge pressure are closely correlated (R2 = 0.80, P < 0.01). Agreement between the two measures is improved at lower mean pressures with greater differences at higher pressures. For 20 of 24 ipsilateral measurements, pulmonary venous wedge pressure was > or = directly measured pulmonary arterial pressure. Pulmonary venous wedge pressure never underestimated pulmonary arterial pressure by more than 3 mm Hg. CONCLUSIONS: Pulmonary venous wedge pressure provides a safe and accurate means of estimating pulmonary arterial pressure in children with shunt-dependent pulmonary blood flow. The slightly lower pressures seen on direct measurement compared with the reverse pulmonary vein may reflect impairment of flow across the shunt by the catheter.

Thromboses in the native aorta in patients with hypoplastic left heart syndrome.

We present four children with hypoplastic left heart syndrome (HLHS) and development of thrombus in the native aortic root. There are only two previously reported cases in the literature. In all four of our patients, thrombus was noted on transthoracic echocardiography. In one patient, surgical thrombectomy was performed, with subsequent deterioration and death. Thrombolysis was used in one patient, with suspected embolic events following his treatment. In the remaining two patients, medical management with chronic anticoagulation was successful in reducing the size of the thrombus.

Occlusion of the coronary sinus ostium: a danger for cavopulmonary anastomosis.

Coronary sinus (CS) ostial obstruction decompressing through a left superior vena cava is a rare finding and presents unique risks to patients requiring a Glenn anastomosis for single-ventricle palliation. Preoperative diagnosis is imperative in order to avoid inadvertent ligation or coil occlusion. We report three cases with single-ventricle physiology and CS obstruction identified at cardiac catheterization. Balloon occlusion angiography proved valuable in making the diagnosis.