Endovascular treatment of very small (3 mm or smaller) intracranial aneurysms: Report of a consecutive series and a meta-analysis

Waleed Brinjikji, Giuseppe Lanzino, Harry J. Cloft, Alejandro Rabinstein, David F. Kallmes

Research output: Contribution to journalArticlepeer-review

117 Scopus citations


BACKGROUND AND PURPOSE-: We performed a meta-analysis of published studies on the endovascular treatment of very small intracranial aneurysms, including 71 patients treated at our institution. METHODS-: We conducted a computerized MEDLINE search of the literature for reports on the treatment of intracranial aneurysms with a maximum dimension of ≤3 mm by using the search terms "small," "tiny," "intracranial aneurysm," "endovascular," and "coil." A total of 7 studies, including our institution's consecutive case series of 71 intracranial aneurysms, were included in this study. We extracted information regarding intraoperative complications, procedural mortality and morbidity, immediate-and long-term angiographic outcomes, and retreatment rate. The meta-analysis was performed with the statistical package Comprehensive Meta-Analysis. RESULTS-: Approximately 61% of the aneurysms in this meta-analysis presented as ruptured, whereas 39% of the aneurysms were unruptured. Procedural rupture rates for very small aneurysms was 8.3% (95% CI, 6.0% to 11.4%). The mortality rate due to procedural rupture was 2.4% (95% CI, 1.2% to 4.7%). The morbidity rate due to thromboembolic complications was 1.9% (95% CI, 0.9% to 3.9%). Subarachnoid hemorrhage within 1 month of treatment occurred in 1.6% (95% CI, 0.6% to 3.7%) of cases. There was no statistically significant difference between unruptured and ruptured aneurysms for any of these outcomes. CONCLUSION-: Our meta-analysis suggests that treatment of very small aneurysms is feasible and effective in >90% of treated aneurysms. However, the risk of periprocedural rupture is higher than that reported for larger aneurysms. Similarly, the combined rate of periprocedural mortality and morbidity is not negligible (7.3%) and should be considered when considering the best therapeutic option for these aneurysms.

Original languageEnglish (US)
Pages (from-to)116-121
Number of pages6
Issue number1
StatePublished - Jan 2010


  • Aneurysm
  • Coils
  • Neuroradiology
  • Neurosurgery
  • Subarachnoid hemorrhage

ASJC Scopus subject areas

  • Clinical Neurology
  • Cardiology and Cardiovascular Medicine
  • Advanced and Specialized Nursing


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