Hypoxemia after thrombectomy deteriorating functional prognosis and aggravates inflammatory response in acute ischemic stroke.

Background: Following endovascular therapy (EVT) in acute ischemic stroke (AIS), there is a discrepancy between vessel reperfusion and favorable prognosis. Hypoxemia commonly occurs during the acute phase of AIS and may exacerbate damage to the ischemic penumbra. This study aims to investigate the correlation between hypoxemia and functional prognosis after EVT, and its influence on inflammatory response.

Method: A retrospective study was conducted involving patients who underwent EVT for anterior circulation AIS. Hypoxemia was defined as arterial blood oxygen pressure <80 mmHg. The propensity score matching (PSM) method was performed to match the Hypoxemia and non-Hypoxemia groups at 1:1 ratio. The primary outcome was the difference in the mRS score at 90 days. Secondary outcomes included functional independence, NIHSS, infarct volume, mortality, symptomatic intracranial hemorrhage (sICH), pneumonia, urinary infection, and seizures. Inflammatory cytokines and cell data were also collected and analyzed.

Results: A total of 116 patients were analyzed. Patients with hypoxemia had worse outcomes at 90 days, evidenced by higher modified Rankin Scale (mRS) scores (3 vs. 2), lower rates of functional independence (43.1 vs. 63.7%), and larger infarct volumes. Additionally, the hypoxemia group had lower lymphocyte but higher neutrophil and monocyte counts. Inflammatory cytokine levels were significantly elevated in the hypoxemia group, includingIL22, IL-1β, IL-6, and IL-8. Logistic regression analysis identified six factors associated with functional prognosis, including ASPECTS score, age, hypoxemia, neutrophil count, lymphocyte count, and IL-1β level.

Conclusion: Hypoxemia during early phases may worsen functional prognosis of AIS patients after EVT and exacerbate inflammatory response.