title: Wall Apposition Is a Key Factor for Aneurysm Occlusion after Flow Diversion: A Histologic Evaluation in 41 Rabbits.
abstract: OBJECTIVE
  Robust wall apposition for flow-diverter stents may be important for endothelialization. Using a large series of experimental aneurysms treated with the Pipeline Embolization Device, the objectives of this study were to 1) assess interobserver agreement for the evaluation of wall apposition on posttreatment DSA and evaluate its association with aneurysm occlusion, and 2) measure the relationship between wall apposition assessed with histology and aneurysm occlusion rate after treatment.
  
  
  METHODS
  Saccular aneurysms were created in 41 rabbits and treated with the Pipeline Embolization Device. DSA was performed just after the deployment of the device and at follow-up. Three investigators independently graded wall apposition on posttreatment DSA as good or poor. A histopathologist blinded to the angiographic results graded the wall apposition on histologic samples. We examined the correlation between angiographic occlusion and wall apposition with histology and angiography.
  
  
  RESULTS
  Wall apposition evaluated on histology was strongly associated with saccular aneurysm occlusion. Sensitivity and specificity of wall apposition to predict complete occlusion at follow-up were 76.9% and 84.0%, respectively, with an overall accuracy of 81.6%. In this experimental study, DSA was suboptimal to assess flow-diverter apposition, with moderate interobserver agreement and low accuracy.
  
  
  CONCLUSIONS
  Good wall apposition is strongly associated with complete occlusion after flow-diverter therapy. In this study, DSA was suboptimal for assessing wall apposition of flow-diverter stents. These findings suggest that improved tools for assessing flow diverter-stent wall apposition are highly relevant.
authors.affiliation: From the Applied Neuroradiology Laboratory (A.R., C.R., W.B., Y.-H.D., D.D., D.F.K., R.K.) aymeric.rouchaud@gmail.com.|Interventional Neuroradiology NEURI Center (A.R.), Hôpital Bicêtre, Le Kremlin-Bicêtre, France.
authors.forename: A
authors.identifier: http://orcid.org/0000-0003-0902-3375
authors.initials: A
authors.lastname: Rouchaud
authors.affiliation: From the Applied Neuroradiology Laboratory (A.R., C.R., W.B., Y.-H.D., D.D., D.F.K., R.K.).
authors.forename: C
authors.identifier: http://orcid.org/0000-0002-7258-6456
authors.initials: C
authors.lastname: Ramana
authors.affiliation: From the Applied Neuroradiology Laboratory (A.R., C.R., W.B., Y.-H.D., D.D., D.F.K., R.K.).|Departments of Radiology (W.B., D.F.K.).
authors.forename: W
authors.identifier: http://orcid.org/0000-0001-5271-5524
authors.initials: W
authors.lastname: Brinjikji
authors.affiliation: From the Applied Neuroradiology Laboratory (A.R., C.R., W.B., Y.-H.D., D.D., D.F.K., R.K.).
authors.forename: Y-H
authors.identifier: http://orcid.org/0000-0003-4329-3192
authors.initials: YH
authors.lastname: Ding
authors.affiliation: From the Applied Neuroradiology Laboratory (A.R., C.R., W.B., Y.-H.D., D.D., D.F.K., R.K.).
authors.forename: D
authors.identifier: http://orcid.org/0000-0003-4051-6450
authors.initials: D
authors.lastname: Dai
authors.affiliation: Health Sciences Research, Division of Biomedical Statistics and Informatics (T.G.), Mayo Clinic, Rochester, Minnesota.
authors.forename: T
authors.identifier: http://orcid.org/0000-0002-1678-8774
authors.initials: T
authors.lastname: Gunderson
authors.affiliation: Department of Bioengineering (J.C.), George Mason University, Fairfax, Virginia.
authors.forename: J
authors.identifier: http://orcid.org/0000-0002-3216-0856
authors.initials: J
authors.lastname: Cebral
authors.affiliation: From the Applied Neuroradiology Laboratory (A.R., C.R., W.B., Y.-H.D., D.D., D.F.K., R.K.).|Departments of Radiology (W.B., D.F.K.).
authors.forename: D F
authors.identifier: http://orcid.org/0000-0002-8495-0040
authors.initials: DF
authors.lastname: Kallmes
authors.affiliation: From the Applied Neuroradiology Laboratory (A.R., C.R., W.B., Y.-H.D., D.D., D.F.K., R.K.).
authors.forename: R
authors.identifier: http://orcid.org/0000-0002-6786-9953
authors.initials: R
authors.lastname: Kadirvel