Progressive Occlusion and Recanalization After Endovascular Treatment for 287 Unruptured Small Aneurysms ( <5mm): A Single-Center 6-Year Experience

World Neurosurg. 2017 Jul;103:576-583. doi: 10.1016/j.wneu.2017.04.017. Epub 2017 Apr 14.


Objective: We aimed to investigate the effect of coiling for small unruptured intracranial aneurysms (UIAs) (<5 mm) on progressive occlusion and recanalization, and the dubious factors related to progressive occlusion and recanalization among UIAs without complete occlusion.

Methods: A total of 264 patients with 287 small UIAs were coiled in our institution between June 2009 and December 2014. All UIAs were divided into small (3-5 mm) and very small (<3 mm) groups, and UIAs without initial complete occlusion were divided into progressive, stable, and recanalization groups. Baseline characteristics, procedure-related complications, angiographic follow-up results, and clinical outcomes were statistically analyzed.

Results: Among 287 aneurysms, 211 aneurysms (73.5%) were completely coiled, 3 (1.2%) had intraoperative ruptures, and 12 (4.2%) had perioperative thromboembolic events. Angiographic follow-up was available for 174 patients (65.9%), and the incidence of recanalization was 5.7%. Among 56 aneurysms without complete occlusion, 43 (76.8%) had progressive occlusion and 6 (10.7%) had recanalization. Anatomic results of initial and follow-up between the small and very small groups were similar. On logistic regression analysis, smaller size (<3 mm) without complete occlusion related to recanalization (odds ratio, 8.0, 95% confidence interval 1.3-50.0; P = 0.026).

Conclusions: Our study suggested that coil embolization of small UIAs can achieve a high rate of progressive occlusion and a low rate of recanalization during follow-up. Anatomic results of initial and follow-up between small (3-5 mm) and very small (<3 mm) groups were similar. Smaller size (<3 mm), without complete occlusion, may relate to recanalization.

Keywords: Follow-up study; Recanalization; Small; Unruptured intracranial aneurysms.

MeSH terms

  • Adult
  • Aged
  • Aneurysm, Ruptured / epidemiology
  • Angiography, Digital Subtraction
  • Carotid Artery, Internal / diagnostic imaging
  • Carotid Artery, Internal / surgery*
  • Cerebral Angiography
  • Disease Progression
  • Endovascular Procedures*
  • Female
  • Follow-Up Studies
  • Humans
  • Imaging, Three-Dimensional
  • Intracranial Aneurysm / diagnostic imaging
  • Intracranial Aneurysm / surgery*
  • Intraoperative Complications / epidemiology
  • Logistic Models
  • Male
  • Middle Aged
  • Postoperative Complications / epidemiology
  • Recurrence
  • Retrospective Studies
  • Stents
  • Thromboembolism / epidemiology
  • Treatment Failure
  • Treatment Outcome
  • Young Adult