Comparative efficacy and safety of N-butyl cyanoacrylate vs. Onyx in the treatment of arteriovenous malformations: a systematic review and meta-analysis.

Since the first use of embolization for cerebral arteriovenous malformations (AVMs) by Luessenhop and Spence in 1960, this procedure has become a cornerstone in the multimodal treatment approach for brain AVMs. Currently, in the United States, the main embolic agents employed are n-butyl cyanoacrylate (NBCA) and Onyx (Medtronic, Minneapolis, MN). This systematic review and meta-analysis aim to compare these two agents in terms of efficacy and safety. An updated guideline for Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was followed. The search strategy involved retrieving articles from PubMed, Scopus, and Web of Science from inception of these databases until June 27th, 2024, using specific search terms. Inclusion criteria were comparative studies of Onyx (Medtronic, Minneapolis, MN) and NBCA, peer-reviewed original studies published in full-text, and studies reporting at least one of the outcomes of interest. Statistical analysis was performed using R software version 4.3.1. After screening 3177 articles, 33 articles were assessed in full-text, and 4 studies were included in the final analysis. These studies included 374 patients, 170 (45.4%) females. There was no significant difference in complication rates between Onyx (Medtronic, Minneapolis, MN) and NBCA (risk ratio [RR]: 0.91; CI: 0.31 to 2.67, p = 0.86) with significant heterogeneity (I²=68%, p = 0.02). Technical success did not differ significantly (RR: 1.38; CI: 0.72 to 2.62, p = 0.33) with significant heterogeneity (I²=73%, p = 0.02). Mortality (RR: 1.5; CI: 0.28 to 8.08, p = 0.64; I²=16%, p = 0.31), morbidity (RR: 1.39; CI: 0.16 to 12.08, p = 0.76; I²=53%, p = 0.14), and blood loss (MD: -0.1; CI: -0.8 to 0.5, p = 0.72; I²=53%, p = 0.15) also showed no significant differences. Both NBCA and Onyx are effective and safe for embolization of cerebral AVMs, with no significant differences in complications, technical success, mortality, morbidity, and blood loss. Further research, particularly randomized controlled trials, is needed to better understand their comparative efficacy and safety.