Impact of Pre-operative Embolization With Onyx for Brain Arteriovenous Malformation Surgery

Abstract

Objective: To clarify the safety and efficacy of pre-operative embolization using Onyx liquid embolic agent (Onyx; ev3) compared with N-butyl cyanoacrylate (NBCA; Cordis Neurovascular, Inc.) or coils in cerebral arteriovenous malformation (AVM) surgery.

Methods: This was a retrospective review of a prospectively collected clinical database of brain AVMs treated at our institute from January 2005 to March 2021. A total of 38 consecutive patients who underwent AVM resection after pre-operative embolization were included. Based on pre-operative embolization materials, the patients were divided into the pre-Onyx group (n = 16), in which NBCA or coils were used for embolization, and the Onyx group (n = 22). Patient characteristics and treatment results were compared between the two groups.

Results: Patient characteristics were comparable between the two groups in terms of age, sex, and rupture status. While the Spetzler-Martin grade was also similar between the two groups, the location of the AVM nidus in the eloquent area was slightly higher in patients in the Onyx group (72.7%) than in patients in the pre-Onyx group (43.8%) (P = 0.09). The embolization rate was higher in the pre-Onyx group (mean: 63.0%; range: 12.7-100%) than in the Onyx group (mean: 50.0%; range: 15.8-100%), but the difference was not statistically significant (P = 0.06). The time needed for surgical removal was shorter in the Onyx group (mean: 354.8 min; range: 144-884 min) than in the pre-Onyx group (mean: 457.9 min; range: 240-1,294 min); however, this difference was not statistically significant (P = 0.13). The amount of intraoperative bleeding was significantly lower in the Onyx group (mean: 129.8 ml; range: 20-540 mL) than in the pre-Onyx group (mean: 448.8 mL; range: 120-1,550 ml) (P = 0.0008). The surgical complication rates were comparable between the two groups (pre-Onyx group, 18.8%; Onyx group, 4.5%; P = 0.29).

Conclusions: Pre-operative embolization with Onyx can significantly reduce the amount of intraoperative bleeding in AVM resection and may contribute to safe AVM surgery.

Keywords: N-butyl cyanoacrylate; Onyx; cerebral arteriovenous malformation (cAVM); coils; neurosurgery.

Figure 1

(A,B) Lateral projection digital subtraction angiogram (DSA) showing Spetzler-Martin grade 1 AVM pre-embolization and post embolization using NBCA, respectively. The calculated embolization rate was 68.8%. (C) pathological findings of resected angiographically disappeared nidus showing remarkable red blood cells in the microvasculatures (Hematoxylin-Eosin staining, ×25). (D,E) Lateral projection DSA showing Spetzler-Martin grade 3 AVM pre-embolization and post embolization with Onyx, respectively. The calculated embolization rate was 52.1%. (F) Pathological findings of resected angiographically disappeared nidus showing the Onyx cast without red blood cells in the microvasculatures (Hematoxylin-Eosin staining, ×25). AVM, arteriovenous malformation; NBCA, N-butyl cyanoacrylate.