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A2, M2, P2 aneurysms and beyond: results of treatment with pipeline embolization device in 65 patients
  1. Christopher T Primiani1,
  2. Zeguang Ren1,
  3. Peter Kan2,
  4. Ricardo Hanel3,
  5. Vitor Mendes Pereira4,
  6. Wai Man Lui5,
  7. Nitin Goyal6,
  8. Lucas Elijovich6,
  9. Adam S Arthur6,
  10. David M Hasan7,
  11. Santiago Ortega-Gutierrez8,
  12. Edgar A Samaniego8,
  13. Ajit S Puri9,
  14. Anna L Kuhn10,
  15. Kirill Orlov10,
  16. Dmitry Kislitsin10,
  17. Anton Gorbatykh10,
  18. Muhammad Waqas11,
  19. Elad I Levy11,
  20. Adnan H Siddiqui11,
  21. Maxim Mokin1
  1. 1 Department of Neurosurgery, University of South Florida, Tampa, Florida, USA
  2. 2 Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA
  3. 3 Department of Lyerly Neurosurgery, Baptist Neurological Institute, Jacksonville, Florida, USA
  4. 4 Division of Neuroradiology, University Health Network - Toronto Western Hospital, Toronto, Ontario, Canada
  5. 5 Division of Neurosurgery, Department of Surgery, The University of Hong Kong, Hong Kong, Hong Kong
  6. 6 Semmes-Murphey Neurologic and Spine Institute, Memphis, Tennessee, USA
  7. 7 Department of Neurosurgery, University of Iowa, Iowa City, Iowa, USA
  8. 8 Department of Neurology, University of Iowa, Iowa City, Iowa, USA
  9. 9 Department of Radiology, University of Massachusetts, Worcester, Massachusetts, USA
  10. 10 Department of Neurosurgery, Meshalkin National Medical Research Center, Novosibirsk, Russia
  11. 11 Department of Neurosurgery, University at Buffalo, Buffalo, New York, USA
  1. Correspondence to Dr Maxim Mokin, Department of Neurosurgery, University of South Florida, Tampa, Florida, USA ; mokin{at}


Background Intracranial aneurysms located in the distal vessels are rare and remain a challenge to treat through surgical or endovascular interventions.

Objective To describe a multicenter approach with flow diversion using the pipeline embolization device (PED) for treatment of distal intracranial aneurysms.

Methods Cases of distal intracranial aneurysms defined as starting on or beyond the A2 anterior cerebral artery, M2 middle cerebral artery, and P2 posterior cerebral artery segments were included in the final analysis.

Results 65 patients with distal aneurysms treated with the PED were analyzed. Median aneurysm size at the largest diameter was 7.0 mm, 60% were of a saccular morphology, and 9/65 (13.8%) patients presented in the setting of acute rupture. Angiographic follow-up data were available for 53 patients, with a median follow-up time of 6 months: 44/53 (83%) aneurysms showed complete obliteration, 7/53 (13.2%) showed reduced filling, and 2/53 (3%) showed persistent filling. There was no association between patient characteristics, including aneurysm size (P=0.36), parent vessel diameter (P=0.27), location (P=0.81), morphology (P=0.63), ruptured status on admission (P=0.57), or evidence of angiographic occlusion at the end of the embolization procedure (P=0.49). Clinical outcome data were available for 60/65 patients: 95% (57/60) had good clinical outcome (modified Rankin Scale score of 0–2) at 3 months.

Conclusions This large multicenter study of patients with A2, M2, and P2 distal aneurysms treated with the PED showed that flow diversion may be an effective treatment approach for this rare type of vascular pathology. The procedural compilation rate of 7.7% indicates the need for further studies as the flow diversion technology constantly evolves.

  • aneurysm
  • angiography
  • artery
  • blood flow
  • device

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  • Contributors MM: study concept and design. MM and CTP wrote the manuscript. MM and CTP performed the statistical analysis. All authors participated in data collection, edited the manuscript, and approved the final version.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial, or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent Not required.

  • Ethics approval The study was approved by the local institutional review board at each participating center for retrospective data collection and review.

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

  • Data sharing statement All data was presented in this paper.