Clinical outcomes after endovascular thrombectomy in different triage methods

Abstract

Abstract Objective: We compare three treatment strategies for acute ischemic stroke (AIS) for effectiveness and safety: 1) patients seen at a primary stroke center (PSC), started on emergency intravenous thrombolysis (IVT) and then transported to a comprehensive stroke center (CSC) [“drip and ship” (DS)]; 2) patients immediately transferred to CSC without starting IVT, for mechanical thrombectomy (MT) [“non-drip and ship” (non-DS)]; and 3) patients admitted directly to the CSC for assessment and subsequent bridging thrombolysis (BT) [“mothership” (MS)].Methods: We retrospectively reviewed the data of patients that underwent MT for AIS from November 2020 to November 2021 at our institution. Patients were divided into three groups: DS, non-DS, and MS, as defined above. Time course, multimodal CT features and clinical results were compared among the three groups, including onset-to-needle time (OTN), onset-to-groin time (OGT), onset-to-PSC time (OTP), PSC-to-groin-puncture time (PTG), door to needle time (DNT), door to puncture time (DPT), intravenous thrombolysis to puncture time (IVT-P), volumes of ischemic core and ischemic penumbra, postoperative modified thrombolysis in cerebral infarction (mTICI) score, postoperative hemorrhagic transformation and malignant edema, 90-day modified Rankin scale (mRS) score and mortality.Results: The study included 41 patients, with 12, 12, and 17 patients in DS, non-DS, and MS groups, respectively. Baseline characteristics, such as age, gender, past history, and National Institutes of Health Stroke Scale (NIHSS) score, did not differ among the three groups. OGT differed among the three groups (P <0.001). The DS group had a significantly longer OGT than the MS group (DS median, 390 minutes; interquartile range [IQR], 326-500 minutes versus MS median, 235 minutes; IQR, 159-270 minutes; P <0.001), a significantly shorter OTP than the non-DS group (DS median, 94 minutes; IQR, 82-116 minutes versus non-DS median, 463 minutes; IQR, 335-787 minutes; P <0.001), and a longer PTG than the non-DS group (DS median, 271 minutes; IQR, 204-364 minutes versus non-DS median, 162 minutes; IQR, 111-240 minutes; P =0.002). OTN was longer in the MS group than the DS group (MS, 150.9 ± 48.8 minutes versus DS, 111.7 ± 47.7 minutes; P = 0.041). IVT-P was shorter in the MS group compared with DS (MS median, 56 minutes; IQR, 39.5-102 min versus DS median, 275 minutes; IQR, 186-390.75 min, P <0.001). No significant differences were present among groups in volume of the ischemic core, ischemic penumbra, rate of recanalization, malignant edema, hemorrhage transformation, number with mRS ≤2 at 3 months, or mortality at 3 months.Conclusions: DS is a safe and effective method, with no increased risk of postoperative hemorrhage transformation, malignant edema or death compared to non-DS and MS methods.