Interventional Closure of Secundum Type Atrial Septal Defects in Infants Less Than 10 Kilograms: Indications and Procedural Outcome.

AIMS: This study set out to assess indications, feasibility, complications, and clinical outcome of percutaneous transcatheter device closure of atrial septal defects (ASDs) in infants with a bodyweight below 10 kg. METHODS AND RESULTS: Retrospective single center chart and echocardiography review study from 8/2005-12/2013. Twenty-eight children with ASD (13 female) with a median age of 1.15 years (0.2-2.8) and a median weight of 7.2 kg (4.5-9.9) were analyzed. Indications for early ASD closure were failure to thrive (n = 15, 54%), bronchopulmonary dysplasia (BPD) with supplemental oxygen dependency (n = 7, 25%), and genetic syndromes with suspected pulmonary hypertension (n = 12, 43%). Device implantation was successful in all patients without any periprocedural mortality or major complication. Clinical outcome after a median follow-up period of 2.1 years (0.25-7.3) revealed no residual shunt and a significant decrease of right ventricular volume load. Patients with pulmonary hypertension experienced a significant reduction of pulmonary artery/RV pressure. Patients also showed decreased supplemental oxygen dependency and less cardiac medications, but no significant "catch-up growth" in those with failure to thrive. CONCLUSION: Interventional ASD closure in children weighing less than 10 kg can be performed without any additional major risks and shows a favorable outcome, especially in selected patients with significant non cardiac co-morbidities.

Living-engineered valves for transcatheter venous valve repair.

BACKGROUND: Chronic venous insufficiency (CVI) represents a major global health problem with increasing prevalence and morbidity. CVI is due to an incompetence of the venous valves, which causes venous reflux and distal venous hypertension. Several studies have focused on the replacement of diseased venous valves using xeno- and allogenic transplants, so far with moderate success due to immunologic and thromboembolic complications. Autologous cell-derived tissue-engineered venous valves (TEVVs) based on fully biodegradable scaffolds could overcome these limitations by providing non-immunogenic, non-thrombogenic constructs with remodeling and growth potential. METHODS: Tri- and bicuspid venous valves (n=27) based on polyglycolic acid-poly-4-hydroxybutyrate composite scaffolds, integrated into self-expandable nitinol stents, were engineered from autologous ovine bone-marrow-derived mesenchymal stem cells (BM-MSCs) and endothelialized. After in vitro conditioning in a (flow) pulse duplicator system, the TEVVs were crimped (n=18) and experimentally delivered (n=7). The effects of crimping on the tissue-engineered constructs were investigated using histology, immunohistochemistry, scanning electron microscopy, grating interferometry (GI), and planar fluorescence reflectance imaging. RESULTS: The generated TEVVs showed layered tissue formation with increasing collagen and glycosaminoglycan levels dependent on the duration of in vitro conditioning. After crimping no effects were found on the MSC level in scanning electron microscopy analysis, GI, histology, and extracellular matrix analysis. However, substantial endothelial cell loss was detected after the crimping procedure, which could be reduced by increasing the static conditioning phase. CONCLUSIONS: Autologous living small-diameter TEVVs can be successfully fabricated from ovine BM-MSCs using a (flow) pulse duplicator conditioning approach. These constructs hold the potential to overcome the limitations of currently used non-autologous replacement materials and may open new therapeutic concepts for the treatment of CVI in the future.