Selective intra-arterial hypothermia combined with endovascular thrombectomy for large vessel occlusion: A systematic review and meta-analysis

Background Systemic therapeutic hypothermia may improve outcomes after acute ischemic stroke but increases complications. Selective intra-arterial hypothermia at the ischemic site during endovascular thrombectomy (EVT) theoretically offers benefits with fewer risks. However, there is little clinical evidence to support this approach. Methods We searched Medline/PubMed, Embase and Cochrane electronic databases for studies evaluating the safety and feasibility of selective intra-arterial hypothermia as an adjunct to EVT for large vessel occlusion (LVO). Effect sizes with 95% confidence intervals (CIs) were pooled using the fixed-effect model. Odds ratios (ORs) were computed for binary variables, while the mean differences (MDs) were pooled for continuous data. Results Of identified records, five clinical studies involving 463 LVO patients (62.9% male) were included. Of those, 224 (48.4%) patients received adjuvant selective intra-arterial hypothermia, while 239 (51.6%) received EVT alone. Selective intra-arterial hypothermia resulted in higher rates of good functional outcome (modified Rankin scale [mRS] 0–2 at 90-days) (OR 2.07, [95% CI, 1.36 to 3.16]), and lower final infarct volume (MD, −20.96 ml [95% CI, −26.17 to −15.75]) and lower rates of severe disability (mRS 3–5 at 90 days) (OR 0.44 [95% CI, 0.26 to 0.75]). Safety parameters including rates of symptomatic intracerebral hemorrhage, mortality, pneumonia, coagulation abnormalities, and arterial spasm were comparable between groups. Conclusions The initial evidence supports the safety and feasibility of selective intra-arterial hypothermia when combined with EVT for LVO. This approach shows promise for advancing research on neuroprotective strategies for ischemic stroke.