Advanced Imaging Guidance for Ductus Venosus Stenting in Obstructed Total Anomalous Pulmonary Venous Return.

Obstructed infracardiac total anomalous pulmonary venous return is nearly always a surgical emergency in which infants present in severe cardiopulmonary distress. Ductal venosus stenting can provide a temporizing option for premature, low birth weight infants with high risk for surgical complications. In challenging anatomic cases, virtual reality, 3D-printed models, and fusion image guidance can aid in procedural planning and provide support for successful intervention.

Computational Fluid Dynamic Assessment of Patients with Congenital Heart Disease from 3D Rotational Angiography.

For congenital heart disease patients, multiple imaging modalities are needed to discern anatomy and functional information such as differential blood flow. During cardiac catheterization, 3D rotational angiography (3DRA) can provide CTA-like images, enabling anatomical information and intraprocedural guidance. We seek to establish whether unique aspects of this technique can also generate quantitative functional blood flow information. We propose that systematic integration of 3DRA imaging, catheter hemodynamic information, and computational fluid dynamics (CFD), can provide quantitative information regarding blood flow dynamics and energetics, without additional imaging or procedures. We report a single center retrospective feasibility study comprising four patients with 3DRA imaging and a complete set of hemodynamic data. 3DRA was processed and segmented to reconstruct vascular regions of interest (ROI), and a computational grid for CFD modeling of blood flow through the ROI was generated. Blood flow was simulated by integrating catheter hemodynamic data to devise boundary conditions at vascular ROI inlets and outlets. The 3DRA-based workflow successfully generated key computational outputs commonly used for cardiovascular applications, including flow patterns, distribution fractions, wall shear stress. Computational outputs obtained were as detailed and resolved as those obtained from more commonly used CT or MR angiography. Accuracy was confirmed by comparing computed flow distributions with measurements for 2 cases, showing less than 2.0% error from the measured data. Systematic integration of catheter hemodynamic information, 3DRA imaging, and CFD modeling, provides an effective and feasible alternative to obtain important quantitative blood flow information and visualization, without additional imaging.

Management of Complex Pulmonary Vein Stenosis at Altitude Combining Comprehensive Percutaneous Interventional Treatment with Sirolimus, Pulmonary Hypertension Medications and Intraluminal Imaging with Optical Coherence Tomography.

BACKGROUND: Pulmonary vein stenosis (PVS) is a growing problem for the pediatric congenital heart population. Sirolimus has previously been shown to improve survival and slow down the progression of in-stent stenosis in patients with PVS. We evaluated patients before and after initiation of sirolimus to evaluate its effects on re-intervention and vessel patency utilizing Optical Coherence Tomography (OCT). METHODS: We performed a retrospective study, reviewing the charts of patients with PVS, who had been prescribed sirolimus between October 2020 and December 2021. OCT was performed in the pulmonary vein of interest as per our published protocol. Angiographic and OCT imaging was retrospectively reviewed. Statistical analysis was performed using Chi square and Wilcoxon signed-rank test to compare pre-and post-sirolimus data. RESULTS: Ten patients had been started and followed on sirolimus. Median age at sirolimus initiation was 25 months with median weight of 10.6 kg and average follow-up of 1 year. Median total catheterizations were 7 for patients prior to starting sirolimus and 2 after starting treatment (p = 0.014). Comparing pre- and post-sirolimus, patients were catheterized every 3 months vs every 11 months (p = 0.011), median procedure time was 203 min vs 145 min (p = 0.036) and fluoroscopy time, 80 min vs 57.2 min (p = 0.036). 23 veins had severe in-stent tissue ingrowth prior to SST (luminal diameter < 30% of stent diameter). Post-sirolimus, 23 pulmonary veins had moderate to severe in-stent tissue ingrowth that responded to non-compliant balloon inflation only with stent luminal improvement of > 75%. CONCLUSION: Our study suggests that the addition of sirolimus in patients with moderate-severe PVS helps to decrease disease progression with decrease frequency of interventions. Reaching therapeutic levels for sirolimus is critical and medication interactions and side-effects need careful consideration. OCT continues to be important for evaluation and treatment guidance in this patient population.

Catheter-based Interventions in Tetralogy of Fallot Across the Lifespan.

Surgical treatment of tetralogy of Fallot (TOF) involves surgical relief of right ventricular outflow tract (RVOT) obstruction and closure of ventricular septal defect. However, some patients may require staged palliation before surgical repair. This traditionally was achieved only with surgery but recently evolved to include catheter-based techniques. RVOT dysfunction occurs inevitably after the surgical repair of TOF and, depending on the surgical approach, manifests as either progressive stenosis, regurgitation, or a combination of both. This predisposes the individual to repeated RVOT interventions with the attendant risks of multiple open-heart surgeries. The advent of transcatheter pulmonary valve replacement has reduced the operative burden, and the expansion of transcatheter pulmonary valve replacement device platforms has widened the type and size of RVOT anatomies that can be treated. This review will discuss the transcatheter therapies available throughout the lifespan of the patient with TOF.

Les traitements chirurgicaux de la tétralogie de Fallot (TF) comprennent la correction de l'obstruction de la voie de chasse du ventricule droit (VCVD) et la fermeture de la malformation du septum interventriculaire. Toutefois, chez certains patients, une palliation par étapes doit être entreprise avant la correction chirurgicale. Cette palliation était autrefois réalisée par des interventions chirurgicales, mais des techniques de cathétérisme interventionnel sont récemment apparues. La dysfonction de la VCVD survient inévitablement après une correction chirurgicale de la TF et peut se manifester par une sténose progressive, une régurgitation ou les deux, selon l'approche chirurgicale utilisée. Les personnes qui vivent avec la TF sont ainsi susceptibles de subir plusieurs interventions à cœur ouvert et d'être exposées aux risques que cela comporte. L'arrivée de la valvulation pulmonaire percutanée (VPP) a permis de réduire le fardeau chirurgical, et la multiplication des plateformes pour les appareils de VPP rend possible le traitement d'une plus grande diversité d'anomalies de la VCVD. Notre article de synthèse présente les traitements par cathétérisme interventionnel qui peuvent être offerts aux patients atteints de TF au fil de leur vie.

Simultaneous deployment of a covered stent and a Sapien S3 as a bridge to surgical valve replacement in acute infective endocarditis.

A 25-year-old male presented to our institution with acute right ventricular (RV) failure secondary to an infected pulmonary prosthetic valve (Melody® Valve, Medtronic Inc., Minneapolis, MN, USA), 3 months after percutaneous placement. Due to his decompensated state, his surgical risk was determined to be very high during his acute illness. As a bridge to surgical valve replacement, we elected to percutaneously implant a Sapien S3 valve (Edwards Lifesciences, Irvine, CA, USA), mounted within a covered stent and deployed simultaneously to exclude the mass of infected tissue within the RV outflow tract, and improve his hemodynamics. Our patient tolerated the procedure well; recovered fully and returned 2 months later for planned surgical valve replacement. .

Standard volume infusion unmasked diastolic dysfunction in pediatric heart transplant recipients during surveillance cardiac catheterization, but without echocardiographic correlates.

BACKGROUND: Adult experience evaluating left ventricular diastolic function (LVDFx) includes volume administration during catheterization while obtaining pulmonary capillary wedge pressures (PCWP) or left ventricular end diastolic pressures (LVEDP). Catheterization is inherently challenging in pediatric patients, making echocardiographic assessment ideal. Pediatric echocardiographic studies predicting LVDFx have variable hemodynamic and hydration conditions and have produced inconsistent results. We evaluated the association between simultaneous echocardiographic and catheterization assessment of LVDFx, using a fluid bolus for optimal loading conditions. METHODS: Prospective cohort study of pediatric heart transplant recipients receiving echocardiogram simultaneous with routine cardiac catheterization. Mitral valve inflow velocities, septal and lateral wall tissue Doppler indices, and PCWP and/or LVEDP were obtained and repeated following a 10 ml/kg bolus. Echocardiographic parameters were evaluated for an association with changes in PCWP or LVEDP following the bolus. Abnormal LVDFx was defined as PCWP or LVEDP ≥12 mm Hg. RESULTS: Twenty-nine patients underwent catheterization. Median pre-bolus PCWP and LVEDP were 11.0 mm Hg and 10.0 mm Hg, respectively. After bolus, median PCWP and LVEDP increased to 14.0 mm Hg (p < .001) and 13 mm Hg (p < .001), respectively. Of 21 patients with normal pre-bolus catheterization hemodynamics, 14 (66.7%) increased to abnormal following fluid bolus. Using area under an ROC, no echocardiographic parameter of LVDFx, or their ratios, were associated with predetermined abnormal LVEDP and/or PCWP. CONCLUSION: After bolus, our cohort demonstrated significant increases in LVEDP and/or PCWP, unmasking diastolic dysfunction. Fluid challenges should be considered in pediatric patients undergoing cardiac catheterization with suspected diastolic dysfunction. Echocardiographic measurements were unable to discriminate between normal and abnormal LVEDP and/or PCWP.

Technical Feasibility on the Use of Optical Coherence Tomography in the Evaluation of Pediatric Pulmonary Venous Stenosis.

Pulmonary vein stenosis (PVS) in children is a morbid disease and limited progress has been made in improving outcomes for this heterogenous group of patients. Evaluation is currently limited to imaging techniques that fail to provide an adequate overview of the intraluminal and luminal pathology perpetuating our limited understanding of this condition. Optical coherence tomography (OCT) is an imaging modality which provides intraluminal profiling with microstructural detail through optical reflective technology. We sought to evaluate whether its use was technically feasible in pediatric PVS and whether the imaging data provided potentially useful outputs for clinical utility. Eleven patients were prospectively selected from our cardiac catheterization for OCT evaluation of their pulmonary veins (PV) during elective catheterization for PVS. Measurements were taken both pre and post intervention using both manual and automated tools. Stent morphology was characterized. Eleven patients had evaluation of 34 pulmonary veins, with 7 patients having more than one assessment, for a total of 25 overall catheterizations. Most patients were female (75%). Median age at cardiac catheterization was 35 months (range 5-45 months). Median weight of subjects was 10.6 kg (3.7-14.2) with a median BSA documented at 0.505 m2 (0.21-0.57). Median number of pulmonary veins involved was 3, (range 1-5 veins) and median contrast volume of 2.9 mL/kg (0.7-3.7) given. Median radiation dose (DAP) was 6095 µGy·cm2 (1670-12,400). Median number of previous cardiac catheterizations was 7 (range 1-11). All of the vessels with a diameter < 5 mm were adequately visualized. Of all the OCT images acquired, in 15 vessels (44%) contrast was used to clear the vessels from blood as an angiogram was required at the time, in the other 19 vessels (56%), saline was used with adequate imaging. There were no complications related to OCT. OCT is technically feasible to use in pediatric patients without any directly related complications. It provides intraluminal anatomy in children with both native and treated pulmonary venous stenosis when vessel size is less than 5 mm.

Contrast-free percutaneous pulmonary valve replacement: a safe approach for valve-in-valve procedures.

INTRODUCTION: Percutaneous pulmonary valve replacement (PPVI) continues to gather pace in pediatric and adult congenital practice. This is fueled by an expanding repertoire of devices, techniques and equipment to suit the heterogenous anatomical landscape of patients with lesions of the right ventricular outflow tract (RVOT). Contrast-induced nephropathy is a real risk for teenagers and adults with congenital heart disease (CHD). AIM: To present a series of patients who underwent PPVI without formal RVOT angiography and propose case selection criteria for patients who may safely benefit from this approach. MATERIAL AND METHODS: We retrospectively collected PPVI data from the preceding 2 years at our institution identifying patients who had been listed as suitable for consideration for contrast-free PPVI from our multidisciplinary team (MDT) meeting based on predefined criteria. Demographic, clinical, imaging and hemodynamic data were collected. Data were analyzed using SPSS. RESULTS: Twenty-one patients were identified. All patients had a technically successful implantation with improvements seen in invasive and echocardiographic hemodynamic measurements. 90% of patients had a bio-prosthetic valve (BPV) in situ prior to PPVI. One patient had a complication which may have been recognized earlier with post-intervention RVOT contrast injection. CONCLUSIONS: Zero-contrast PPVI is technically feasible and the suitability criteria for those who might benefit are potentially straightforward. The advent of fusion and 3D imaging in cardiac catheterization laboratories is likely to expand our capacity to perform more procedures with less contrast. Patients with bio-prosthetic valves in the pulmonary position may benefit from contrast-free percutaneous pulmonary valve implantation.

ST-Elevation Myocardial Infarction due to Acute Thrombosis in an Adolescent With COVID-19.

STEMI can be the presenting diagnosis in adults with COVID-19; presented is a case of a 15-year-old girl with coronary thrombosis-induced STEMI associated with COVID-19. ST-elevation myocardial infarction (MI) is an identified presentation of coronavirus disease 2019 in adults but has not been reported in children. We present a case of a 15-year-old girl with a coronary thrombosis-induced ST-elevation MI in the setting of acute severe acute respiratory syndrome coronavirus 2 infection, not associated with multisystem inflammatory syndrome in children. The patient presented with chest pain, ST elevation, and myocardial dysfunction. Coronary angiography identified thrombosis treated with anticoagulation and antiplatelet therapy. MI must be considered in children who present with coronavirus disease 2019-associated myocardial dysfunction.

Biomechanical Comparison of Cadaveric and Commercially Available Synthetic Osteoporotic Bone Analogues in a Locked Plate Fracture Model Under Torsional Loading.

OBJECTIVES: Biomechanical studies of osteoporotic bone have used synthetic models rather than cadaveric samples because of decreased variability, increased availability, and overall ease of the use of synthetic models. We compared the torsional mechanical properties of cadaveric osteoporotic bone with those of currently available synthetic osteoporotic bone analogues. METHODS: We tested 12 osteoporotic cadaveric humeri and 6 specimens each of 6 types of synthetic analogues. A 5-mm fracture gap model and posterior plating technique with 4.5-mm narrow 10-hole locking compression plate were used. Torque was applied to a peak of ±10 N·m for 1000 cycles at 0.3 Hz. Data were continuously collected during cyclical and ramped loading with a servohydraulic materials testing system. RESULTS: Cadaveric bone had a 17% failure rate before completing 1000 cycles. Three osteoporotic bone models had 100% failure (P < 0.05), 2 had 17% failure, and 1 had 0% failure before 1000 cycles. Significant differences in the stiffness of the 3 types of synthetic bone models that survived cyclic loading were noted compared with the cadaveric bone model (P < 0.05). Osteoporotic bone analogues had torsional mechanical properties different from those of osteoporotic cadaveric specimens. CONCLUSIONS: The differences between osteoporotic cadaveric humeri and synthetic osteoporotic bone analogues ranged from profound with complete catastrophic failure after a few cycles to subtler differences in stiffness and strain hardening. These findings suggest that different bone analogue models vary substantially in their torsional mechanical properties and might not be appropriate substitutes for cadaveric bone in biomechanical studies of osteoporotic bone.

Healing of rotator cuff tendons using botulinum toxin A and immobilization in a rat model.

BACKGROUND: We evaluated effects of botulinum toxin A (Botox) and cast immobilization on tendon healing in a rat model. Injection of Botox into rat supraspinatus was hypothesized to reduce muscle active force and improved healing. METHODS: Eighty-four supraspinatus tendons were surgically transected and repaired in 42 Sprague-Dawley rats (transosseous technique). After repair, supraspinatus muscle was injected with saline or Botox (3 or 6 U/kg). Half the shoulders were cast-immobilized for the entire postoperative period; half were allowed free cage activity. Histology was examined at 2, 4, 8, and 12 weeks. A healing zone cross-sectional area was measured, and biomechanical testing of repair strength and tendon viscoelastic properties was conducted at 4 and 12 weeks. RESULTS: Botox alone and cast immobilization alone exhibited increased ultimate load compared with controls (saline injection, no immobilization) at 4 weeks. No difference in ultimate load occurred between Botox-only and cast-only groups. At 12 weeks, the Botox (6 U/kg) plus cast immobilization group was significantly weakest (p < 0.05). A trend was shown toward decreased healing zone cross-sectional areas in casted groups. CONCLUSIONS: Supraspinatus Botox injection after rotator cuff repair might help protect the repair. However, cast immobilization plus Botox administration is harmful to rotator cuff healing in a rat tendon model.