INTRODUCTION
Acute ischemic stroke (AIS) is the second most common cause of death on a global scale, posing a significant public health issue. Recent research has revealed that, in addition to the critical time window for intervention, another key factor for achieving a favorable stroke outcome is the cerebral collateral circulation (CC) – a factor that has remained clinically and radiologically underappreciated until recently. This CC maintains ischemic tissue viability and significantly prolongs the time before irreversible brain tissue damage occurs. Closely related to CC are perfusion parameters, as they are a good indicator of ischemic brain tissue damage. The aim of this study was to investigate whether CC and perfusion parameters influence the neurological and functional outcomes of endovascular thrombectomy (EVT) in patients with AIS. We also examined how the etiology of AIS affects the extent of CC and the resulting neurological and functional outcomes of EVT.
METHODS
A retrospective and prospective study included 208 consecutive patients with AIS in the anterior cerebral circulation, all of whom underwent EVT. For each patient, we performed two head CT scans: the first immediately after the patient examination and the second 24 hours post-EVT. The modified Rankin Scale (mRS) was used to assess the neurological and functional status of patients at admission and 90 days after hospital discharge. Imaging data obtained from the CT scans were processed using the e-STROKE SUITE and syngo.CT Neuro Perfusion software packages. For statistical analyses, we utilized SPSS software (v.29) and the Python extension libraries, Pandas and Matplotlib. Patients were divided into four groups based on the degree of CC, as indicated by the CTA-CS (Computed tomography angiography collateral score) score (0–3), and a bivariate analysis was conducted for these groups. To assess the final outcome at 90 days, patients were dichotomized into two groups: favorable outcome (mRS 0–2) and poor outcome (mRS 3–6), and a bivariate analysis was conducted on these groups. Variables with p-values less than 0.1 (p < 0.1) were then used for logistic regression, and multiple models were created to predict the final outcome at 90 days.
RESULTS
Of the 208 included patients, 114 were women (55 %), and the average age was 71.4 ± 13.3 years. The mortality rate in our population was 13 % (n = 27). Patients with better CC had significantly lower mRS scores at 90 days (p = 0.008). A favorable outcome at 90 days (mRS 0–2) was achieved by 103 patients (49.5 %), while 105 patients (50.5 %) had a poor outcome (mRS 3–6). Patients with a favorable outcome at 90 days (mRS 0–2) exhibited significantly better CC (p = 0.019), and the mean volumes of hypoperfused tissue (p < 0.001), infarct core (p = 0.003), and penumbra (p = 0.008) were significantly smaller, while the mismatch ratio was significantly higher (p = 0.024). The logistic regression models confirmed the predictive value of CC (OR 1.81 [95% CI, 1.08–3.04], p = 0.025) and infarct core (OR 0.95 [95% CI, 0.91–0.99], p = 0.013) for a favorable outcome at 90 days (mRS 0–2). Carotid atherosclerosis was more common in patients with better CC (p = 0.014), whereas atrial fibrillation (AF) was not statistically significant. Neither variable demonstrated statistical significance as prognostic factors for the final outcome at 90 days.
CONCLUSIONS
Our study demonstrated that CC and perfusion parameters are significantly associated with the neurological and functional outcomes of EVT in patients with AIS. We found that better CC, along with smaller volumes of hypoperfused tissue, infarct core, and penumbra, as well as a higher mismatch ratio, correlated with a favorable outcome at 90 days (mRS 0–2). Both the infarct core and CC were identified as predictive factors for achieving a favorable outcome at 90 days (mRS 0–2). Additionally, we showed that carotid atherosclerosis was more common in patients with better CC, while no association was found between poor CC and AF. Our study did not demonstrate any association between the etiology of AIS and the final outcome.
|
