Push-Through Filtration of Emulsified Adipose Tissue Over a 500-µm Mesh Significantly Reduces the Amount of Stromal Vascular Fraction and Mesenchymal Stem Cells.

BACKGROUND: Mechanical isolation of the stromal vascular fraction (SVF) separates the stromal component from the parenchymal cells. Emulsification is currently the most commonly used disaggregation method and is effective in disrupting adipocytes and fragmenting the extracellular matrix (ECM). Subsequent push-through filtration of emulsified adipose tissue removes parts of the ECM that are not sufficiently micronized, thereby further liquifying the tissue. OBJECTIVES: The aim of this study was to investigate whether filtration over a 500-µm mesh filter might affect the SVF and adipose-derived mesenchymal stem cell (MSC) quantity in emulsified lipoaspirate samples by removing ECM fragments. METHODS: Eleven lipoaspirate samples from healthy nonobese women were harvested and emulsified in 30 passes. One-half of the sample was filtered through a 500-µm mesh filter and the other half was left unfiltered. Paired samples were processed and analyzed by flow cytometry to identify cellular viability, and SVF and MSC yield. RESULTS: Push-through filtration reduced the number of SVF cells by a mean [standard deviation] of 39.65% [5.67%] (P < .01). It also significantly reduced MSC counts by 48.28% [6.72%] (P < .01). Filtration did not significantly affect viability (P = .118). CONCLUSIONS: Retention of fibrous remnants by push-through filters removed ECM containing the SVF and MSCs from emulsified lipoaspirates. Processing methods should aim either to further micronize the lipoaspirate before filtering or not to filter the samples at all, to preserve both the cellular component carried within the ECM and the inductive properties of the ECM itself.

Dual antiplatelet therapy after percutaneous left atrial appendage occlusion: single center experience with the Amplatzer Cardiac Plug.

BACKGROUND: Percutaneous left atrial appendage occlusion (LAAO) is an alternative to anticoagulation in atrial fibrillation patients at high bleeding risk. Dual antiplatelet therapy (DAPT) is generally recommended in the months following the procedure to prevent thrombotic complications. The aim of this study was to evaluate the safety and efficacy of DAPT after LAAO in a single-centre population of high bleeding risk patients. METHODS: All patients who received DAPT after LAAO using the Amplatzer Cardiac Plug at Jessa Hospital (Hasselt, BE) between February 2011 and October 2016 were included. Patient characteristics, procedural outcome and clinical events (bleeding, stroke and adverse events) were prospectively followed. Changes in antithrombotic and/or anticoagulant regimens were assessed. RESULTS: Thirty-nine patients (77 ± 7 years, 51% male, CHA2DS2-VASc 5(3-6), Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly (HAS-BLED) 3(3-4)) were included. An initial strategy of one month DAPT (n = 2) was changed to six months DAPT (n = 37) after one thrombotic complication (device thrombosis) at 4.5 months. Post-procedural DAPT duration was 6.1 ± 3.7 months, after which aspirin monotherapy (62%), no antiplatelet/anticoagulant therapy (15%) or a tailored antithrombotic regimen was maintained. At mean follow-up of 21 ± 13 months, seven patients had died (18%), no strokes had occurred (0%) and nine bleedings of which four were major (10%). All major bleedings occurred within the first six months after the procedure during DAPT. CONCLUSION: Antithrombotic therapy after percutaneous LAAO is needed to prevent thrombotic complications, yet these impose bleeding complications in this high-risk population. Further efforts are needed to define the optimal duration of DAPT, aimed at reducing bleeding complications while maintaining a low thrombosis rate.