Factors impacting on technical success in stroke thrombectomy: experience of a UK neuro-interventional unit.

AIM: To investigate factors that could impact on recanalisation and reperfusion in patients undergoing mechanical thrombectomy and to assess the technical success over time.

MATERIALS AND METHODS: Two hundred consecutive patients who underwent thrombectomy for a proximal anterior circulation occlusion were dichotomised into equal groups (groups 1 and 2) based on the date that immediate access to emergency general anaesthesia (GA) commenced.

RESULTS: Recanalisation success using thrombolysis in cerebral infarction (TICI) 2b/3 or TICI 2c/3 significantly improved in group 2 (67% versus 93%, p<0.0001; 52% versus 78%, p=0.0002). Symptomatic haemorrhage also reduced from 9% to 4%. Despite similar presentation Alberta Stroke Program Early (computed tomography) CT Scores (ASPECTS), post-procedural ASPECTS was significantly increased in group 2 (7; [interquartile range {IQR} 4-9] versus 8 [IQR 7-9]; p=0.0034). The number of patients with a post procedural ASPECTS of 8-10 increased (46% versus 64%, p=0.0155) and the difference in ASPECTS between pre- and post-thrombectomy CT was significantly lower (2 [IQR 1-4] versus 1 [IQR 0-2], p<0.0001). GA use increased from 8% to 56% (p=0.0001) as did use of distal aspiration (59% versus 87%, p=0.0001) mostly in combination with a stent-retriever. Failed access fell from 8% to 3%. When GA was used, successful recanalisation (TICI 2b/3) was achieved more frequently (90.5% versus 76.7%; OR 3.04, 1.2-7.69, p=0.0187).

CONCLUSION: Technical results for thrombectomy are improving over time. Technique modification, operator experience, and judicious use of GA may be contributing.