Elsevier

World Neurosurgery

Volume 103, July 2017, Pages 576-583
World Neurosurgery

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

https://doi.org/10.1016/j.wneu.2017.04.017Get rights and content

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.

Introduction

Despite great technologic improvements and the published results of The International Study of Unruptured Intracranial Aneurysms (ISUIA), the endovascular treatment of small unruptured intracranial aneurysms (UIAs) has still been debated regarding the indication and use of endovascular treatment as a preventive treatment modality.1, 2, 3 There is no evidence confirming the long-term natural history of small UIAs in unselected populations or advantages to their conservative management versus endovascular coil embolization.3, 4 The challenges of coiling a small UIA are related to the inability to obtain a stable microcatheter position, initial selection, or reselection during coil packing, and risk of intraprocedural rupture due to perforation from packing coils into a shallow, confined sac.5, 6, 7

Studies comparing the outcomes and complication rates between the endovascular treatment of small and large intracranial aneurysms have found a nonsignificant increase in the frequency of intraprocedural rupture, thromboembolism, and recanalization on angiographic follow-up with coiling of small aneurysms compared with larger aneurysms.7, 8, 9 However, no studies on single or multiple aneurysms have evaluated the factors related to the progressive occlusion and recanalization of small UIAs.

In the present study, we performed a retrospective review of 287 UIAs coiled at our institution to investigate the effect of coiling for small UIAs (<5 mm) on progressive occlusion and recanalization, factors related to progressive occlusion and recanalization among UIAs without complete occlusion were also investigated.

Section snippets

Study Population

In total, 287 consecutive patients undergoing endovascular coil embolization for small aneurysms at our institution between June 2009 and December 2014 were enrolled. The indication for treatment and its modality depended on interdisciplinary consensus between a vascular neurosurgeon and a neurointerventional specialist based on amenability to embolization considering factors such as irregular or with daughter sac, wide-neck, and bifurcation location. All patients in this study chose

Results

Between June 2009 and December 2014, 264 patients with 287 small UIAs underwent endovascular treatment at our institution. The patient inclusion flow chart is shown in Figure 1. Basic characteristics of included patients are shown in Table 1. Of 264 patients, 201 (71.1%) were women and 83 (28.9%) were men. The mean age of patients was 54.0 ± 9.4 years (range, 22–77 years).

Discussion

Our study included a large series of consecutive endovascular treatments of unruptured small aneurysms. These findings suggest that coil embolization of small aneurysms can be performed with acceptable rates of progressive occlusion and recurrence. However, our study also revealed that smaller size (<3 mm) was associated with recanalization in aneurysms that did not have a complete occlusion initially.

Endovascular coil embolization has become a widely accepted procedure used in the treatment of

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. However, treatment options for small aneurysm may should be more strict and thoughtful, because a recurrence rate of 5.7% and an almost 4% rate of mRS 3–6 (including 2 deaths) does not seem to be a perfect result for a series aneurysms that may have a low rupture rate per year. Anatomic results of initial and follow-up between small (3–5

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  • Cited by (0)

    Conflict of interest statement: This research was supported by the Natural Science Foundation of Beijing, China (No.7142032), and Specific Research Projects for Capital Health Development (2014-3-2044).

    Xin Feng and Luyao Wang contributed equally.

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