Annals of Biomedical Engineering

, Volume 46, Issue 9, pp 1337–1347 | Cite as

Mechanical Performance of Two Left Atrial Appendage Occlusion Systems: In Vitro Comparison of Tug Force, Radial Force, Sealing and Deformation

  • Matthias F. Menne
  • Jan W. Schrickel
  • Georg Nickenig
  • Baravan Al-Kassou
  • Dominik Nelles
  • Thomas Schmitz-Rode
  • Ulrich Steinseifer
  • Alexander SedaghatEmail author


The aim of this study was to establish in vitro bench-tests of left atrial appendage occlusion (LAAo) devices regarding tug force, radial force and sealing capacity. Two LAAo devices, namely the WATCHMAN™ and the Occlutech®, of three different sizes underwent testing in novel dedicated in vitro setups. Radial force was assessed in a commercial radial force tester. At baseline, tug force of the WATCHMAN™ was significantly higher when compared to Occlutech® for all devices. Repeated resheathing resulted in a reduction of device-diameter in the WATCHMAN™ devices of max. 7.9%, whereas diameters of Occlutech® occluders remained unchanged. Tug force was not significantly impacted by resheathing in both devices. At baseline, sealing capacity in a bench-test using silicone LAA-models did not differ between the devices. Resheathing lead to an in vitro loss of sealing capacity of the WATCHMAN™ devices, increasing with resheathing and resulting in a max. peridevice leak of 91.1 ± 7.9%. Radial force was higher for the Occlutech® devices and decreased for WATCHMAN™ occluders after resheathing. The WATCHMAN™ occluder series showed progressive deformation, increased peridevice leakage and decreased radial force after resheathing, presumably as a result of diameter reduction. Tug force of the WATCHMAN™ was not impaired by resheathing and was significantly higher than that of the Occlutech® device.


LAA occlusion Left atrial appendage In vitro testing Tug test Peridevice leak Radial force 



Chronic outward force


Instructions for use


Left atrial appendage


Left atrial appendage occlusion




Oral anticoagulation


Polyethylene terephthalate


Conflict of interest

A.S., J.W.S. and G.N. have participated in clinical trials conducted by both Occlutech as well as Boston Scientific. A.S. has received travel grants from Boston Scientific. The other authors have no conflicts of interest to declare.

Supplementary material

10439_2018_2057_MOESM1_ESM.tif (13.6 mb)
Online Fig. 1 Tug force results of the WATCHMAN™ and Occlutech® 27 and 33 devices at their intended deployment range (TIFF 13925 kb).
10439_2018_2057_MOESM2_ESM.tif (7.6 mb)
Online Fig. 2 Peridevice leakage of WATCHMAN™ 27/33 and Occlutech® 27/33 devices in different LAA models before and after repeated resheathing. W: WATCHMAN™, O: Occlutech® (TIFF 7752 kb).
10439_2018_2057_MOESM3_ESM.tif (13.7 mb)
Online Fig. 3 Radial force measurements of WATCHMAN™ 27/33 and Occlutech® 27/33 devices after repeated resheathing (TIFF 13999 kb).


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Copyright information

© Biomedical Engineering Society 2018

Authors and Affiliations

  1. 1.Institute of Applied Medical Engineering, Helmholtz InstituteRWTH Aachen UniversityAachenGermany
  2. 2.Medizinische Klinik und Poliklinik IIUniversitätsklinikum Bonn, Rheinische Friedrich-Wilhelms-Universität BonnBonnGermany
  3. 3.Monash Institute of Medical Engineering and Department of Mechanical and Aerospace EngineeringMonash UniversityMelbourneAustralia

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