Multimodal treatments of brain arteriovenous malformations: a comparison of microsurgical timings after endovascular embolization

Background: To compare the clinical outcomes of hybrid microsurgery and embolization with multi-staged procedure for patients harboring brain arteriovenous malformations (bAVMs). Methods: We retrospectively reviewed bAVM patients from a multicenter, prospectively collected database (NCT03774017) between June 2016 and June 2020. Patients were divided into single-staged hybrid operation (HO) group and multi-staged operation (MO) group according to the received treatment, in which microsurgeries were performed with embolization in a single setting or with multi-stage procedure, respectively. Cases were 1:1 matched between the two groups. Outcomes were compared between groups, which included neurological deficits (NDs), perioperative rupture, and proportion of complete resection. Variables associated with NDs were analyzed. Results: In total, 198 out of 544 cases were identified, including 120 in the HO group and 78 in the MO group. Sixty-six cases were matched in each group resulting in a total of 132 patients in this case-controlled study. Mean age was 29.2 years old, with 82 (62.1%) being male. No significant difference was observed in baseline demographics and clinical characteristics between the two groups. There were 7 ruptures occurred in the interval between embolization and microsurgery for MO group while none in the HO group (P=0.023). This yielded a rupture risk of 4.1% per year for the MO group. Duration of surgical resection was significantly reduced in HO group (P=0.001). Compared to MO, HO was more favorable to avoid short-term NDs (3.0% vs. 15.2%, P=0.021), but long-term outcomes were similar. The HO modality (OR, 0.110; 95% CI: 0.017-0.737; P=0.023) was confirmed as the protective factor for short-term NDs. Conclusions: HO is an effective setup to treat complex bAVMs with avoiding interval hemorrhage risk and reducing surgical risk. We also observed overall similar obliteration rate and resulting clinical outcomes between HO and MO.

Automated summary

In comparing the clinical outcomes of hybrid microsurgery and embolization with multi-staged procedure for patients harboring brain arteriovenous malformations, it was found that hybrid microsurgery is beneficial in avoiding the risk of interval hemorrhage and reducing surgical risk, while also reducing the rate of short-term neurological deficits. However, long-term outcomes were similar to those of the multi-staged procedure.