Occlusion assessment of intracranial aneurysms treated with the WEB device

Neuroradiology. 2016 Sep;58(9):887-91. doi: 10.1007/s00234-016-1715-9. Epub 2016 Jun 16.


Introduction: The Woven EndoBridge (WEB) system is an innovative device under evaluation for its capacity to treat wide-neck bifurcation intracranial aneurysms. The purpose of this study is to evaluate the use of the different occlusion scales available in clinical practice.

Methods: Seven WEB-experienced neurointerventionalists were provided with 30 angiographic follow-up data sets and asked to grade each evaluation point according to the Bicêtre Occlusion Scale Score (BOSS), firstly based on DSA images only then using additional C-Arm VasoCT analysis. This BOSS evaluation was then converted into the WEB Occlusion Scale (WOS) and into a dichotomized scale (complete occlusion or not). To estimate the inter-rater agreement among the seven raters, an overall kappa coefficient [1] and its standard error (SE) were computed.

Results: Using the five-grade BOSS, raters showed "moderate" agreement (kappa = 0.56). Using the three-grade WOS, agreement appeared slightly better (kappa = 0.59). Strongest inter-rater agreement was observed with a dichotomized version of the scale (complete occlusion or not), which enabled an "almost perfect" agreement (kappa = 0.88). VasoCT consistently enhanced the agreement particularly with regards depicting intra-WEB residual filling.

Conclusion: The WOS is a consistent means to angiographically evaluate the WEB device efficiency. But the five-grade BOSS scale allows to identify aneurysm subgroups with differing risks of recurrence and/or rehemorrhage, which needs to be separated especially at the initial phase of evaluation of this innovative device. The additional use of VasoCT allows better inter-rater agreement in evaluating occlusion and specially in depicting intra-WEB persistent filling.

Keywords: Endovascular treatment; Flow disruption; Intracranial aneurysms; WEB; Woven EndoBridge device.

Publication types

  • Clinical Trial

MeSH terms

  • Blood Vessel Prosthesis*
  • Cerebral Angiography / methods*
  • Computed Tomography Angiography / methods*
  • Endovascular Procedures / instrumentation*
  • Equipment Failure Analysis
  • Humans
  • Intracranial Aneurysm / diagnostic imaging*
  • Intracranial Aneurysm / therapy*
  • Prosthesis Design
  • Stents*
  • Treatment Outcome