Noncurative microsurgery for cerebral aneurysms: a systematic review and meta-analysis of wrapping, residual, and recurrence rates

Abstract

OBJECTIVE Microsurgery for cerebral aneurysms is called definitive, yet some patients undergo a craniotomy that results in noncurative treatment. Furthermore, the overall rate of noncurative microsurgery for cerebral aneurysms is unclear. The objective of this study was to complete a systematic review and meta-analysis to quantify three scenarios of noncurative treatment: aneurysm wrapping, postclipping remnants, and late regrowth of completely obliterated aneurysms. METHODS A PRISMA-guided systematic literature review of the MEDLINE and Cochrane Library databases and meta-analysis was completed. Studies were included that detailed rates of aneurysm wrapping, residua confirmed with imaging, and regrowth after confirmed total occlusion. Pooled rates were subsequently calculated using a random-effects model. An assessment of statistical heterogeneity and publication bias among the included studies was also completed for each analysis, with resultant I2 values and p values determined with Egger’s test. RESULTS Sixty-four studies met the inclusion criteria for final analysis. In 41 studies, 573/15,715 aneurysms were wrapped, for a rate of 3.5% (95% CI 2.7%–4.2%, I2 = 88%). In 43 studies, 906/13,902 aneurysms had residual neck or dome filling, for a rate of 6.4% (95% CI 5.2%–7.6%, I2 = 93%). In 15 studies, 71/2568 originally fully occluded aneurysms showed regrowth, for a rate of 2.1% (95% CI 1.2%–3.1%, I2 = 58%). Together, there was a total rate of noncurative surgery of 12.0% (95% CI 11.5%–12.5%). Egger’s test suggested no significant publication bias among the studies. Meta-regression analysis revealed that the reported rate of aneurysm wrapping has significantly declined over time, whereas the rates of aneurysm residua and recurrence have not significantly changed. CONCLUSIONS Open microsurgery for cerebral aneurysm results in noncurative treatment approximately 12% of the time. This metric may be used to counsel patients and as a benchmark for other treatment modalities. This investigation is limited by the high degree of heterogeneity among the included studies.