Packing density and the angiographic results of coil embolization of intracranial aneurysms: A systematic review and meta-analysis

Abstract

Background: Endovascular coil embolization (ECE) for intracranial aneurysms has been proven as an effective minimally invasive treatment. However, the aneurysm recanalization after coiling is a serious complication of this technique. Among all the proposed factors associated with recanalization, the impact of packing density (PD) is still controversial.

Objective: To clarify the role of PD in the aneurysm recanalization following ECE, via conducting a systematic review and meta-analysis.

Methods: A systematic literature search was conducted using PubMed, Scopus, Embase, and Web of Science databases, until November 28, 2022, by adhering to the Preferred Reporting Items for Systematic Review and Meta-Analyses statement guidelines. Considering the eligibility criteria, all the studies reporting the outcomes of interest were included. Data elements of interest were extracted and analyzed using R software version 4.2.1.

Results: The pooled analysis of the 17 eligible papers revealed a 29% higher PD of the nonrecanalized aneurysms (ROM = 1.29, 95% confidence interval [CI] = 1.18-1.40, p < 0.001), even after removing outlier studies to reduce heterogeneity. However, the pooled estimates from multivariable regression models within nine included studies showed no significant effect of PD on recanalization odds when incorporated into a multivariable model with other predictors (odds ratio [OR] = 0.93, 95% CI = 0.84-1.02, p = 0.126), even after removing outlier studies.

Conclusion: The current literature does not support PD as a significant predictor of aneurysm treatment outcomes, especially with adjusting for other variables. This finding necessitates further prospective multicenter studies with a larger sample size to overcome the current methodological shortcomings.

Keywords: Aneurysm; angiography; coil.