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How safe and effective are existing treatments for wide-necked bifurcation aneurysms? Literature-based objective performance criteria for safety and effectiveness
  1. David Fiorella1,
  2. Adam S Arthur2,
  3. Richard Chiacchierini3,
  4. Evelyne Emery4,
  5. Andy Molyneux5,
  6. Laurent Pierot6
  1. 1 Department of Neurosurgery, State University of New York at Stony Brook, Stony Brook, New York, USA
  2. 2 Department of Neurosurgery, Semmes-Murphey Neurologic and Spine Institute, University of Tennessee, Memphis, Tennessee, USA
  3. 3 Chiacchierini Consulting, Gaithersburg, Maryland, USA
  4. 4 Department of Neurosurgery, Centre Hospitalier Universitaire de Caen, Caen, France
  5. 5 Oxford Neurovascular and Neuroradiology Research Unit, Oxford Radcliffe Hospital, Oxford, UK
  6. 6 Department of Radiology, CHU Maison Blanche, Reims, France
  1. Correspondence to Dr Adam S Arthur, Department of Neurosurgery, Semmes-Murphey Neurologic and Spine Institute, University of Tennessee, 6325 Humphreys Blvd, Memphis, Memphis, Tennessee, USA; aarthur{at}


Introduction Wide-necked bifurcation aneurysms (WNBAs) present unique technical challenges for both endovascular and surgical treatments which aim to achieve complete occlusion of the aneurysm without compromising the patency of the incorporated regional parent vessels. We present a meta-analysis of traditional therapies for WNBAs to provide critical benchmarks for safety and effectiveness.

Methods Following a systematic search of the literature and the application of pre-specified appropriateness criteria, 43 (including 2794 aneurysms treated) and 65 (including 5366 patients treated) references with sufficient detail were identified to include in a meta-analysis of efficacy and safety, respectively. Effectiveness endpoints of both complete and adequate occlusion were assessed. A composite safety endpoint was based upon commonly applied metrics for major adverse events. Fleiss analyses were performed for both effectiveness and safety endpoints for the entire group, and then parsed separately by treatment modality (surgical clipping (SC) or endovascular therapy (EVT)) and location (anterior or posterior circulation).

Results Using the above methods, the core laboratory adjusted rate of complete occlusion was 46.3% (standard error 3.6%), 39.8% (3.7%), and 52.5% (9.6%) for all therapies, EVT, and SC, respectively. The rate of adequate occlusion was 59.4% (12.2%), 43.8% (5.3%), and 69.7% (14.3%) for all therapies, EVT, and SC, respectively. The rates of occurrence for pre-specified safety endpoints were 18.7% (2.9%), 21.1% (2.8%), and 24.3% (4.9%) for all therapies, EVT, and SC, respectively.

Conclusions Conventional therapies for WNBAs are associated with relatively low rates of complete occlusion and peri-procedural complications are not uncommon. As new treatment technologies are investigated, it is important that the available data regarding predicate treatments is understood.

  • Aneurysm
  • Hemorrhage
  • Intervention

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  • Contributors All named authors contributed substantially to the work described by actively participating in the study and the generation of the data and providing editorial evaluation of the manuscript.

  • Funding Statistical support for this study was provided by Microvention Inc.

  • Competing interests The primary investigators received institutional salary support for the WEB-IT study, proctoring, consulting and study-related activities from Microvention Inc.

  • Provenance and peer review Not commissioned; externally peer reviewed.