Assessment of long-term results of intracranial aneurysm clipping by means of computed tomography angiography

Treatment strategies for saccular anterior inferior cerebellar artery aneurysms: a systematic review

INTRODUCTION

The anterior inferior cerebellar artery (AICA) plays a crucial role in cerebellar blood supply, and AICA aneurysms are relatively rare, comprising less than 1-1.5% of all brain aneurysms. Understanding their clinical scenarios, management approaches, and outcomes is essential. This systematic review analyzes data from 86 studies to comprehensively explore AICA aneurysms.

MATERIALS AND METHODS

The process of obtaining relevant research, which includes patients with AICA aneurysms, was carried out using the PubMed, Web of Science, and Scopus databases. This review exclusively included extensive papers written in English. The search included the MeSH phrases "Anterior inferior cerebellar artery aneurysm" and "AICA aneurysm." Microsurgical and endovascular treatments were compared using statistical analysis, exploring demographics, risk factors, treatment modalities, and clinical outcomes.

RESULTS

The review includes 85 case reports and one retrospective study, totaling 140 patients. The study reveals a diverse patient profile with a slight female predominance (65%), a mean age of 50.7 years, and an 82.86% prevalence of no identified risk factors. Ruptured aneurysms accounted for 55%, with microsurgery and endovascular procedures accounting for 70.71% and 27.86%, respectively. The mortality rate was 2.86%, and no significant differences were found in rebleed, recurrence, or mortality rates between treatment groups.

CONCLUSION

Microsurgical and endovascular interventions demonstrate comparable effectiveness, with microsurgery showing superiority in specific situations. Therefore, tailoring treatment is crucial to individual patient needs. Subgroup analyses highlight demographic-specific trends, guiding clinicians in managing this rare pathology.

Incidence of Postoperative Cerebral Aneurysm Clip Slippage: Review of a Consecutive Case Series of 115 Clipped Aneurysms

OBJECTIVE

Although delayed postoperative clip slippage has been reported in previous case reports and case series, its true incidence with high rate of follow-up imaging has not been reported. We attempted to determine the incidence of clip slippage in a cohort of consecutive aneurysm clippings.

METHODS

We performed a retrospective review of a prospectively maintained database of 115 consecutive saccular aneurysm clippings at a single institution. Postoperative imaging was reviewed for clip slippage within 24 hours and at 3-12 months. Eighty-six aneurysms (75.8%) were exclusively clipped with Sugitaclip (Mizuho Medical, Tokyo, Japan) Titanium II clips, 16 aneurysms were exclusively clipped with Yaşargil (Aesculap, Center Valley, PA) titanium clips (13.9%), 5 aneurysms were only clipped with Sugita aneurysm clips (4.3%), and 3 aneurysms were only clipped with Peter Lazic (Peter Lazic Microsurgical Innovations, Tuttlingen, Germany) clips (2.6%).

RESULTS

In this cohort, 94.7% of clipped aneurysms had follow-up imaging within 24 hours, and 51.3% had delayed follow-up imaging within 3-12 months. We identified 3 cases of clip slippage in 115 consecutive aneurysm clippings, resulting in an incidence of 2.6%. The average cumulative closing force of clips per aneurysm across the study was 2.32 N, and the median number of clips placed was 1. Two of the 3 cases of clip slippage had a closing force <2.32 N and only placement of a single clip.

CONCLUSIONS

Because our series showed a 2.6% incidence of clip slippage, clipped aneurysms should be monitored with early and delayed vascular follow-up imaging. Lower cumulative clip closing force, single clip placement, and oversized clip blade length may be risk factors for postoperative aneurysmal clip slippage.

Pathogenic Factors and Prognosis of De Novo Aneurysms vAfter Aneurysm Clipping

OBJECTIVE

To confirm this hypothesis, this study aimed to explore the pathogenic factors, prognosis, and their relationship in de novo aneurysms and to reach a consensus on their management.

METHODS

First, the clinical data of 5 patients with de novo aneurysms from April 1998 to October 2021 were analyzed retrospectively. Then, the English literature on de novo aneurysms reported in Pubmed from 1985 to 2021 was systematically reviewed, and 18 case reports from 17 articles and 16 case series were identified. Univariate and multivariate analyses and modified Fisher test were used to analyze the relationship between pathogenic factors and prognosis.

RESULTS

Hypertension was noted in 60% of our clinical cases, 50% of the case series identified in the literature review, and 66.7% of the case reports in the literature review. In the case reports identified from our literature review, the proportion of original aneurysms in the anterior circulation was 96.3%. Moreover, in our 5 cases, all original aneurysms occurred in the anterior circulation. The rupture rate of original aneurysms in our 5 cases was 100%, and that of the cases reported in the literature review was 88.9%. Univariate logistic analysis showed that the time interval was related to the prognosis of de novo aneurysms with a P value of 0.048 and an odds ratio of 0.968 (95% confidence interval 0.938-1.000). Modified Fisher exact tests showed that patient age at the occurrence of de novo aneurysm P = 0.029) was related to the prognosis of de novo aneurysms.

CONCLUSIONS

Hypertension, an original aneurysms located in the anterior circulation and rupture represent the pathogenic factors associated with de novo aneurysms. The time interval to de novo aneurysm and patient age at the occurrence of de novo aneurysm are predictive of prognosis. Based on the above information, we can prevent and improve the prognosis of de novo aneurysms.

Frequency and risk factors for postoperative aneurysm residual after microsurgical clipping

OBJECTIVE

Aneurysm residuals after clipping are a well-known problem, but the course of aneurysm remnants in follow-up is not well studied. No standards or follow-up guidelines exist for treatment of aneurysm remnants. The aim of this study was to evaluate the risk factors for postoperative aneurysm remnants and their changes during follow-up.

METHODS

We performed a retrospective analysis of 666 aneurysms treated via clipping in our hospital from 2006 to 2016. Postoperative and follow-up angiographic data were analyzed for aneurysm remnants and regrowth. Clinical parameters and aneurysm-specific characteristics were correlated with radiological results.

RESULTS

The frequency of aneurysm residuals was 12% (78/666). Aneurysms located in the middle cerebral artery (p = 0.02) showed a significantly lower risk for incomplete aneurysm occlusion. Larger aneurysms with a diameter of 11-25 mm (p = 0.005) showed a significantly higher risk for incomplete aneurysm occlusion. Five patients underwent re-clipping during the same hospital stay. Remnants were stratified based on morphological characteristics into "dog ears" (n = 60) and "broad based" (n = 13). The majority of the "dog ears" stayed stable, decreased in size, or vanished during follow-up. Broad-based remnants showed a higher risk of regrowth.

CONCLUSIONS

A middle cerebral artery location seems to lower the risk for the incomplete clip occlusion of an aneurysm. Greater aneurysm size (11-25 mm) is associated with a postoperative aneurysm remnant. The majority of "dog-ear" remnants appear to remain stable during follow-up. In these cases, unnecessarily frequent angiographic checks could be avoided. By contrast, broad-based residuals show a higher risk of regrowth that requires close imaging controls if retreatment cannot be performed immediately.

Gemstone spectral imaging reduced artefacts from metal coils or clips after treatment of cerebral aneurysms: a retrospective study of 35 patients

OBJECTIVE

This study aimed to evaluate the effect of gemstone spectral imaging (GSI) for metal artefact reduction in cerebral artery CT angiography (CTA) after metal coils or clips treatment.

METHODS

35 patients with cerebral aneurysms were treated with metal coils or clips and underwent CTA using gemstone spectral CT between February and December 2013. The data were reconstructed into three image groups including Group A (quality check images with 140 kVp), Group B (monochromatic image sets in the range of 40-140 keV) and Group C [monochromatic image sets with metal artefacts reduction software (MARS GE Medical Systems, Waukesha, WI)]. CT attenuation value of cerebral artery, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and the subjective score of all images were measured and compared statistically.

RESULTS

CT attenuation value of cerebral artery decreased in Groups B and C as the photon energy increased. The average energy levels of 60.05 ± 5.37 and 59.93 ± 5.57 keV presented the best CNR in Groups B and C, respectively. CNR values, SNR values and the subjective scores of the image quality of the two sets were higher than those of Group A.

CONCLUSION

GSI reduced metal artefact and improved the image quality of CTA after metal coils or clips treatment in patients with cerebral aneurysm. The monochromatic images at the average energy level of 60.05 ± 5.37 keV with MARS and 59.93 ± 5.57 keV without MARS were suggested to be the optimal parameters.

ADVANCES IN KNOWLEDGE

GSI could reduce metal artefact after metal coils or clips treatment in patients with cerebral aneurysm.