Abstract 026: Initial Experience with the Walrus BGC results from 300 cases

Background Until recently only the Flowgate2 (Stryker Neurovascular) was available clinically despite multiple advances in aspiration catheter and stent‐retriever technology. The Walrus BGC (Q'Apel Medical Inc, Fremont, California, USA) is a next generation BGC with improved flexibility and compatibility with large bore aspiration catheters. We report our experience with the Walrus BGC in anterior circulation LVO MT with a focus on procedural aspects related to the vascular anatomy, recanalization efficacy and complications. Materials and Methods A retrospective review at two high volume MT centres in the United Kingdom (>300 cases annually) was performed to identify all patients where the Walrus BGC was used between July 2023 and January 2024. The inclusion criteria included: •Age ≥18• NIHSS score ≥6•ASPECT score ≥3•mRS 0‐2•Life expectancy of >6months•The Walrus BGC was used 1 st line during the MT. All patients underwent plain CT + CTA prior to the MT procedure. Patients received IV tPA if they met the appropriate criteria. The anatomical configuration was recorded as per the ASMET score (Assessment for Mechanical Thrombectomy Score) which assesses and scores the:•Presence of a Bovine arch (0‐1)•The aortic arch confirguration (0‐2)•The degree of dolichoarteriopathy affecting the supra‐aortic vessels (0‐2)•Presence of ICA dolichoarteriopathy (0‐1)The ASMET score gives a range of 0‐6 and higher scores have been previously been shown to be associated with longer procedural times. Positioning of the BGC was divided into either proximal ICA and distal ICA and standard times such as puncture time, time to first angiogram, first pass effect and final eTICI score were recorded. Results 300 patients that met the inclusion criteria with average age 69.5±15yrs, and 168 (56%) male. The average NIHSS score was 15.8±6.5 and average ASPECT score 7.6±1.9. 51.5% of patients received IV tPA. The vast majority of LVo were located in M1 (60%), ICA 21.5% and M2 17.8%. Tandem lesions were present in 18.1%. Arch configuration was as follows: I.34.7%II.21.7%III.43.6% The average ASMET score was 2.6±1.6. Kinked or coiled ICA was seen in 18.1%, tortuous in 53.8% and straight in 28.1%. A distal location of the BGC was achieved in 77.9% and proximal location in 22.1%. FPE was seen in 49% with mFPE in 65.9%. Final eTICI≥2c was 75.9% and ≥2b 92.7%. There was one major complication – a CCF caused by the BGC. Minor non‐flow limiting dissections were seen in 4.3% of cases. With regards to arch configuration and ASMET score there was no statistical significant difference between the puncture to first run time, first pass time, or final angiogram between different arch types. Conclusion The Walrus BGC is highly navigable and there is no statistically significant difference between the time taken to navigate the Walrus in patients with minimal tortuosity compared to very tortuous anatomy. The use of Walrus is associated with a high degree of first pass success and low complication rates.