What are some of the factors that we, as clinicians, take into account when deciding whether a patient is an endovascular candidate? Certainly last known well time is one, and often times, lesion size is another. Previous studies have reported poorer outcomes in patient with large lesion size, and therefore, patients with large DWI lesions pre-treatment have traditionally been excluded from clinical practice as well as research studies. This patient population is very poorly characterized in the endovascular therapy group. Here, the authors try to fill in this gap with an analysis of patients with either ICA or MCA lesions who underwent thrombectomy, specifically evaluating outcomes in patients with large DWI lesions.
Not unexpectedly, when compared to patients with a DWI lesion volume < 70 mL (n=292), patients with DWI lesions > 70 mL (n=66) had lower rates of favorable outcomes, lower survival, and more symptomatic ICH (sICH), especially in patients who received thrombolysis preceding thrombectomy. However, in patients who achieved good reperfusion (as determined as a TICI 2b-3 score), 11/31 patients, or nearly 1/3rd of patients, had a good outcome compared to 3/35 patients with a TICI 0-2a. In the overall group of patients with lesion size > 70 mL, independent predictors of favorable outcomes were smaller DWI size, younger age, and reperfusion success. Younger patients had better outcomes compared to older patients, with no patients older than 75 years of age having a favorable outcome. The authors also evaluated patients when stratified by lesion size < 100 mL vs > 100 mL, with similarly poor outcomes and less survival in patients with larger lesions, but again, better outcomes when patients achieved better reperfusion.
This study confirmed that indeed, patients with large DWI lesions do have poorer outcomes; however, this is qualified by the finding that even in this population, a favorable outcome was seen in every third patient when endovascular reperfusion was successful. No size cut off was identified, but the treatment effect was better in younger patients. Although there may have been a selection bias, in that large lesions in younger patients may have been more likely to be selected for endovascular therapy, this study suggests that contrary to current practice, large DWI lesions may not be a contraindication to thrombectomy.
