International Stroke Conference
February 6–8, 2019

Deepak Gulati, MD

There is uncertainty about factors affecting collaterals, natural course of collaterals and the type of anesthesia during thrombectomy. The session started with the detailed analysis of the GOLIATH trial to identify predictors of collateral circulation grade, infarct growth at 24hrs and the effect of collaterals on clinical outcome. The GOLIATH trial was a single center RCT comparing GA vs CS in acute patients with ELVO within 6 hours. Successful reperfusion was better in GA vs CS (76.9% vs 60.3, p=0.04). This study categorized Grade 2 ASTIN Collateral grading into 2- and 2+ based on <50% or >50% defect in ischemic territory, respectively. The anesthesia protocol included MAP>70 but could not be achieved in 26% of the entire population (35.4% in GA vs 15.9% in CS). Patient were also found to be hypocarbic with median ET CO2 of 33mmHg. There is no effect of collaterals noticed on clinical outcomes. Infarct growth is found to be associated with the use of pressor use (phenylephrine). This study concluded that sedation induced intraprocedural BP drop has a deleterious effect on collateral circulation and may not be reversed by IV pressor administration.

It has always been the source of controversy if general anesthesia has a beneficial or deleterious effect on outcome in spite of results from recent randomized trials. A post-hoc analysis of the DEFUSE 3 trial was presented next to study the effect of general anesthesia vs conscious sedation during thrombectomy on functional outcome in extended time window (>6 hours). 92 patients were randomized to intervention in DEFUSE 3 (28% GA vs 72% CS). Functional independence at 90 days is found to be significantly better in CS group (53% for CS vs 23% GA and 17% for medical management). Adjusted-odds ratio of functional independence with CS compared to GA is found to be 3.67 (1.08-12.43, p=0.037). The main limitation of this study is selection bias.

The next presentation was focused on to study the effect of blood pressure after thrombectomy on functional outcome and to predict the blood pressure cutoff. This study is retrospective from 9 comprehensive stroke centers (total of 1077 patients). Patients with higher mean SBP and maximum SBP are found to have poor functional outcome. Patients with higher maximum SBP and maximum mean BP are found to have a higher rate of symptomatic hemorrhage. The BP cutoff suggested as per this study is 160mmHg after thrombectomy.

Another retrospective study evaluated the outcomes of patients undergoing EVT in the late-time window comparing patients with CTP or non-contrast CT (CTP -ve). No significant difference in functional outcome, revascularization, symptomatic ICH is found between two groups. This study raised a point that late presenting patients who do not have access to CTP should not be excluded from EVT. CTP might play a crucial role in the hyperacute window when there are no obvious changes expected on NCCT.

Recent advances in endovascular treatment are beneficial to patients, but there are still many unanswered questions, as raised during this session, which likely need a randomized controlled trial for further clarification.