RT Journal Article SR Electronic T1 Concomitant coiling reduces metalloproteinase levels in flow diverter-treated aneurysms but anti-inflammatory treatment has no effect JF Journal of NeuroInterventional Surgery JO J NeuroIntervent Surg FD BMJ Publishing Group Ltd. SP 307 OP 310 DO 10.1136/neurintsurg-2015-012207 VO 9 IS 3 A1 Evan Thielen A1 Megan McClure A1 Aymeric Rouchaud A1 Yong-Hong Ding A1 Daying Dai A1 Dana Schroeder A1 Juan Cebral A1 David F Kallmes A1 Ramanathan Kadirvel YR 2017 UL http://jnis.bmj.com/content/9/3/307.abstract AB Background and purpose Flow diverters (FD) can cause rare but devastating delayed aneurysm ruptures in which matrix metalloproteinases (MMPs) have been potentially implicated. Concomitant coiling or anti-inflammatory medications have been proposed to prevent the risk of delayed ruptures. The aim of this study was to evaluate concomitant coiling and ciclosporin in regulating the expression of MMPs in FD-treated aneurysms.Materials and methods Elastase-induced aneurysms were created in 20 rabbits. Aneurysms were treated with (1) FD alone; (2) FD with concomitant coiling; (3) FD+ ciclosporin; or (4) left untreated as controls. At sacrifice, MMP levels were analyzed by zymography. Kruskal–Wallis one-way non-parametric ANOVA was performed for each enzyme. If significant results were observed for the Kruskal–Wallis test, pairwise group comparisons were performed using Dunn's test with Bonferroni multiple-testing correction.Results Significant differences were observed among groups for pro-MMP9 (p=0.0337). Pairwise comparison demonstrated higher levels of pro-MMP9 with concomitant coiling compared with untreated aneurysms (p=0.012), with higher though not significantly different levels of pro-MMP9 in FD with concomitant coiling versus FD alone. While not statistically significant, trends were noted regarding differences in active-MMP9 across groups, with a lower level of active-MMP9 with concomitant coiling compared with the other FD groups. No significant differences were observed for pro- or active-MMP2 across groups, or for FD + ciclosporin compared with FD alone.Conclusions FD implantation increases the level of pro-MMP9 expression in aneurysms. Provocative trends regarding modulation of active-MMP9 expression with concomitant coiling suggest the need for larger confirmatory preclinical studies. Anti-inflammatory treatment with ciclosporin appears to have a minimal biological effect.Trial registration number R01NS076491