title: Evaluation of the Angiographic Grading Scale in Aneurysms Treated with the WEB Device in 80 Rabbits: Correlation with Histologic Evaluation.
abstract: OBJECTIVE
  The WEB Occlusion Score has been proposed to assess angiographic outcomes for intracranial aneurysms treated with the Woven EndoBridge (WEB) device. Using a large series of experimental aneurysms treated with the WEB, we had the following objectives: 1) to compare angiographic outcomes as measured by the WEB Occlusion Scale with histologic results, and 2) to assess interobserver and intraobserver agreement of the WEB Occlusion Scale.
  
  
  METHODS
  Intracranial aneurysms were created in 80 rabbits and treated with WEB devices. Animals were sacrificed at last follow-up for histologic evaluation. DSA was performed just after the deployment of the device and at follow-up. Four investigators independently and retrospectively graded the DSA twice according to the WEB Occlusion Scale. One histopathologist blinded to the angiographic results graded the occlusion according to a 4-point scale patterned on the WEB Occlusion Scale. Intra- and interobserver agreement were evaluated for DSA. Follow-up angiographic grading and histologic reference were compared to determine the WEB Occlusion Scale accuracy for complete (with or without recess filling) versus incomplete occlusion and adequate (complete occlusion or neck remnant) versus inadequate occlusion.
  
  
  RESULTS
  Inter- and intraobserver weighted κ for the angiographic WEB Occlusion Scale were, respectively, 0.76 and 0.76, indicating substantial agreement. The sensitivity and specificity of the WEB Occlusion Scale for complete occlusion at follow-up compared with the histologic reference standard were, respectively, 75% and 83.3%, with an overall accuracy of 80%. Similarly, for adequate occlusion at follow-up, sensitivity was 97.7%, specificity was 64.9%, and overall accuracy was 82.5%.
  
  
  CONCLUSIONS
  The WEB Occlusion Scale appears to be consistent, reliable, and accurate compared with a histologic reference standard.
authors.affiliation: From the Neuroradiology Research Laboratory (A.R., Y.-H.D., D.D., Y.Q.Z., D.F.K., R.K.), Mayo Clinic College of Medicine, Rochester, Minnesota the Department of Radiology (A.R., W.B., H.J.C., D.F.K.), Mayo Clinic, Rochester, Minnesota. Rouchaud.Aymeric@mayo.edu aymeric.rouchaud@gmail.com.
authors.forename: A
authors.identifier: http://orcid.org/0000-0003-0902-3375
authors.initials: A
authors.lastname: Rouchaud
authors.affiliation: the Department of Radiology (A.R., W.B., H.J.C., D.F.K.), Mayo Clinic, Rochester, Minnesota.
authors.forename: W
authors.identifier: http://orcid.org/0000-0001-5271-5524
authors.initials: W
authors.lastname: Brinjikji
authors.affiliation: From the Neuroradiology Research Laboratory (A.R., Y.-H.D., D.D., Y.Q.Z., D.F.K., R.K.), Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: Y-H
authors.identifier: http://orcid.org/0000-0003-4329-3192
authors.initials: YH
authors.lastname: Ding
authors.affiliation: From the Neuroradiology Research Laboratory (A.R., Y.-H.D., D.D., Y.Q.Z., D.F.K., R.K.), Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: D
authors.identifier: http://orcid.org/0000-0003-4051-6450
authors.initials: D
authors.lastname: Dai
authors.affiliation: From the Neuroradiology Research Laboratory (A.R., Y.-H.D., D.D., Y.Q.Z., D.F.K., R.K.), Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: Y Q
authors.identifier: http://orcid.org/0000-0001-5476-9075
authors.initials: YQ
authors.lastname: Zhu
authors.affiliation: the Department of Radiology (A.R., W.B., H.J.C., D.F.K.), Mayo Clinic, Rochester, Minnesota.
authors.forename: H J
authors.identifier: http://orcid.org/0000-0003-2590-3815
authors.initials: HJ
authors.lastname: Cloft
authors.affiliation: From the Neuroradiology Research Laboratory (A.R., Y.-H.D., D.D., Y.Q.Z., D.F.K., R.K.), Mayo Clinic College of Medicine, Rochester, Minnesota the Department of Radiology (A.R., W.B., H.J.C., D.F.K.), Mayo Clinic, Rochester, Minnesota.
authors.forename: D F
authors.identifier: http://orcid.org/0000-0002-8495-0040
authors.initials: DF
authors.lastname: Kallmes
authors.affiliation: From the Neuroradiology Research Laboratory (A.R., Y.-H.D., D.D., Y.Q.Z., D.F.K., R.K.), Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: R
authors.identifier: http://orcid.org/0000-0002-6786-9953
authors.initials: R
authors.lastname: Kadirvel
mesh_terms: D000818:Animals; D002533:Cerebral Angiography / Q000379:methods; D004195:Disease Models, Animal; D004621:Embolization, Therapeutic / Q000295:instrumentation*; D057510:Endovascular Procedures / Q000295:instrumentation; D005260:Female; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000628:therapy; D015588:Observer Variation; D011817:Rabbits; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome