Vorhofohr-Verschlusssysteme entwickelt und implantiert. Studien belegen, dass diese einer medi-kamentösen oralen Antikoagulation in der Wirksamkeit nicht unterlegen, aber weniger sicher sind.
Durch die Weiterentwicklung der Okkluder und ihrer Implantationstechnik sollen operations-asso-ziierte Komplikationen reduziert und die Sicherheit für Patienten erhöht werden. Um eine optimale Passform zu gewährleisten, die Undichtigkeiten vermeidet, ist die Entwicklung individueller Okklu-dersysteme anzustreben.
Fig. 1:
LAA morphologies classified as described previously (from top to bottom): Chicken Wing, Cactus, Windsock and Cauliflower; (A) CT-Image, (B) MR-Imaging.
Peter Osypka Institute for Pacing and Ablation – POI
Methods
This work examines the current state of the closure of the left atrial appendage. In addition, findings on actual implantation procedures of occluder systems could be won at Heart-Center Lahr/Baden, Germany (Figure 2, 3, 4).
Results
Currently, in Europe there are 3 commerci-ally available systems for percutaneous atrial appendage closure, the Watchman® (Boston Scientific) (Figure 5), the AmplatzerTM (St. Jude Medical) and the Coherex WaveCrestTM (Coherex Medical). All are CE certified, the Watchman sys-tem since 2005, the Amplatzer Cardiac Plug since 2008 and the Wavecrest system since 2013 /2/.
Due to anatomical limitations, the success rate in the mentioned occluders is highly vari-able and depends on the individual characteri-stics of the patient. There is a large discrepancy between the geometric opening of the atrial appendage and the structural design of the oc-cluder. Since the opening of the atrial append-age usually is rather oval than round, a larger device has to be implanted than the one pri-marily intended. This can lead into leaking by gaps, which may play a clinical role. Drug the-rapy with oral anticoagulants or aggregation inhibitors should be continued in the case of a residual flux. Effectiveness of the atrial append-age closure was investigated in the randomized controlled PROTECT-AF study, only. However, this study has several limitations, e.g. with re-spect to the selection of the included patients, so that these population is not representative.
Therefore, results can not be applied to patients with contraindications for OAC /2/.
In 2012, recommendations concerning the implantation of atrial appendage closure sys-tems were implemented into the guidelines of the ESC (European Society of Cardiology).
Percutaneous atrial appendage closure is taken into account with level “B” of evidence as Class IIb recommendation. It can be considered for patients with high risk of stroke and contrain-dications for oral anticoagulants. However, gui-deline points out that no data from controlled studies are available so far for this patients /3/.
Fig. 2:
Radiological presentation of the pigtail catheter in the LAA (left to right pigtail catheter without contrast agent; inflow of contrast agent; representation of the LAA with contrast agent) (respectively on the left: TEE probe)
Referenzen/References:
[1] Romero J et al. (2014) Cardiac imaging for assessment of left atrial appendage stasis and thrombosis. Nat Rev Cardiol. 11(8) 470-480
[2] Reinsperger I and Nachtnebel A (2014) Perkutaner Verschluss des linken Vorhofohres zur Thrombembolieprophy-laxe bei PatientInnen mit Vorhofflimmern 1. (Update 2014). Decision Support Do-cument Nr. 44/Update 2014, Wien: Ludwig Boltzmann Institut für Health Technology Assessment.
[3] Camm AJ et al. (2012) 2012 focused update of the ESC Guidelines for the management of atrial fibrillation: an update of the 2010 ESC Guidelines for the management of atrial fibrillation.
Developed with the special contribution of the European Heart Rhythm Association. Eur Heart J.
33(21) 2719-47
[4] Alli O et al. (2013) Quality of life assessment in the randomized PROTECT AF (Percutaneous Closure of the Left Atrial Appendage Versus Warfarin Therapy for Prevention of Stroke in Patients With Atrial Fibrillation) trial of patients at risk for stroke with nonvalvular atrial fibrillation.
J Am Coll Cardiol. 61(17) 1790-8 [5] Holmes DR et al. (2009) Percutaneous closure of the left atrial appendage versus warfarin therapy for prevention of stroke in patients with atrial fibrillation: a ran-domised non-inferiority trial.
Lancet. 374(9689) 534-42 [6] Reddy VY et al. (2013) Left atrial appendage closure with the Watchman device in patients with a contraindication for oral anticoagulation: the ASAP study (ASA Plavix Feasibility Study With Watchman Left Atrial Appendage Closure Technology). J Am Coll Cardiol. 61(25) 2551-6
Fig. 4:
Radiological presentation of the leak test with contrast agent using implanted AMPLATZERTM AmuletTM occluder Fig. 3:
Measuring of the LAA Diameter in the radiological presenta-tion using contrast agents
108 I forschung im fokus 2017 I IAF Hochschule Offenburg
POI – Peter Osypka Institute for Pacing and Ablation
The proven correlation between success rate and the implanter`s experience is an deci-sive argument for the development of special training systems.
Considerable interindividual variations of the left atrial appendage require customized systems, possibly by magnetic resonance ima-ging and 3D printing technology, to ensure opti-mal individual fitting and to avoid leaking.
Fig. 5:
Closeup of 27 mm Watch-man® occluder, 10 Active fixation anchors around device perimeter engage LAA tissue for stability and retention
Conclusions
The present work considers recent occluder systems for closure of the left atrial appendage.
Studies /4-6/ have shown that the effectiveness of percutaneous atrial appendage closures is not inferior compared to oral anticoagulation, but less secure. However, in the follow-up, cur-rent occluder systems show significantly less side effects. Surgery-related complications could be lowered and safety for the patient could be raised by further development of the systems and their implantation technique.
Corinna Brenner M. Sc.
Akad. Mitarbeiterin am POI corinna.brenner@hs-offenburg.de
Markus Brudsche M. Sc., Akad. Mitarbeiter markus.brudsche@hs-offenburg.de Johannes Härtig, Ltd. Oberarzt Schrittmacher- / Defibrillatortherapie Herzzentrum Lahr/Baden johannes.haertig@mediclin.de
Prof. Dr. med. Juraj Melichercik, Leiter Abtlg.
Elektrophysiologie Herzzentrum Lahr/Baden juraj.melichercik@mediclin.de Prof. Dr. rer. nat. habil. Bruno Ismer Hochschule Offenburg, Leiter des Peter Osypka Institute for Pacing and Ablation bruno.ismer@hs-offenburg.de AUTOREN
INSTITUT
Am einfachsten beschreibt man Silikat-werkstoffe als polymeren Sand. Der Schlüs-sel zur vermehrten industriellen Nutzung von (Wüsten-)Sand ist die Geopolymerstruktur.
Diese wird aus Wasserglas gebildet, das schon heute kostengünstig aus Sand, Soda und Son-nenenergie (SSS-Ansatz) hergestellt werden kann.
Der Schwerpunkt der Institutsarbeit liegt auf der Erforschung der chemischen Bindun-gen, die eine Geopolymerstruktur ausmachen.
Hierzu werden als analytische Messmethoden die IR-Spektroskopie sowie in Zusammen-arbeit mit mehreren universitären Instituten
27Al-MAS NMR-, 29Si-MAS NMR- und 31
P-NM-Rspektroskopische Messungen an Festkörpern eingesetzt. Auch wird an der verfahrenstech-nischen Optimierung aller Prozesse geforscht, die der Bildung geopolymerer Strukturen zu-grunde liegen.
Konkret wird an der Herstellung neuartiger anorganischer Dämmstoffe mit einer Dichte von unter 0,09 g/cm3, an der Entwicklung von Dämmstoffen im Bereich bis 1.100 °C, an der Entwicklung eines Ziegelersatzes aus Wüs-tensand oder Betonabfällen sowie an der Verkieselung von Holz gearbeitet. Bei allen Forschungs- und Entwicklungsthemen stehen Ressourcenschonung, Umweltverträglichkeit und Langlebigkeit der Produkte im Mittelpunkt.
Institutsleitung
Prof. Dr. rer. nat. Bernd Spangenberg