The Influence Of Compensatory Flow Pattern Of Acute Internal Carotid Artery Occlusion On The Prognosis Of Mechanical Thrombectomy

Background and purpose: Endovascular mechanical thrombectomy has become an important treatment for acute ischemic stroke(AIS).Acute internal carotid artery occlusion is a relatively serious and common type of AIS.Even if the embolus is removed within the time window and the blood vessels are opened,the prognosis is uncertain.Several studies have shown that the level of intracranial collateral circulation is associated with the prognosis of AIS patients undergoing endovascular mechanical thrombectomy.In this study,we compared the imaging and clinical data of patients with acute internal carotid artery terminal occlusion with different blood flow compensation patterns to investigate the relationship between blood flow compensation patterns and embolectomy prognosis in patients with acute internal carotid artery terminal occlusion,providing a further theoretical basis for the selection of cases of mechanical embolectomy in patients with acute internal carotid artery terminal occlusion.Methods: The imaging and clinical data of patients with acute terminal internal carotid artery occlusion who underwent emergency thrombectomy and were successfully opened in our hospital from September 2015 to September 2020 were retrospectively studied.The patients were divided into groups according to the integrity of circle of Willis: group A(unilateral internal carotid artery occlusion,anterior communicating artery not open,typical "T" occlusion);group B(unilateral internal carotid artery occlusion,anterior communicating artery open,"L" occlusion);group C(unilateral internal carotid artery occlusion,anterior cerebral artery A1 segment absent or not shown);group D(unilateral internal carotid artery occlusion,anterior cerebral artery A1 segment absent or not shown,combined with embryonic posterior cerebral artery).We compared the baseline data,NIHSS score at 24 hours after surgery,at discharge,and 90 days after surgery,m RS score at 90 days after surgery,good prognosis rate at 90 days after surgery,postoperative symptomatic intracranial hemorrhage rate,and mortality rate in each group,respectively.Results: A total of 67 patients,43 males(64.18%)and 24 females(35.82%),aged between33 and 85 years,were included in this study.Among them,34 cases rushed to the hospital within 3 hours of onset,32 cases rushed to the hospital within 3 – 6 hours,and 1 case more than6 hours.The preoperative ASPECTS score was 6 – 8 in 19 patients and less than 6 in 48 patients;among the 34 patients who rushed to the hospital within 3 hours,the ASPECTS score was 6 –8 in 13 patients(38.24%)and less than 6 in 21 patients(61.76%).During postoperative follow-up,34 patients(50.75%)had symptomatic intracranial hemorrhage,13 patients(19.40%)died,and 11 patients(16.42%)had good postoperative prognosis.They were divided into groups according to the integrity(or opening)of the circle of Willis:19 patients in group A,26 patients in group B,15 patients in group C,and 7 patients in group D.The preoperative NIHSS score in group B was significantly lower than that in the other three groups,and the preoperative ASPECTS score was higher than that in the other three groups,and the difference was statistically significant(P<0.05).After mechanical thrombectomy,the incidence rate of postoperative symptomatic intracranial hemorrhage and mortality in group B were significantly lower than those in the other three groups;the incidence rate of symptomatic intracranial hemorrhage in group C and D was higher than that in group A,and the differences had statistical significance(P<0.05);the good prognosis rate at 90 days after operation in group B was significantly higher than that in the other three groups,and the differences had statistical significance(P<0.05).Through the observation and analysis of the imaging data of patients with symptomatic intracranial hemorrhage and death caused by"L"occlusion,it is found that it has the following characteristics:slender or hypoplastic development of A1 segment of anterior cerebral artery;or slender development of anterior communicating artery.Conclusions: The occlusion of the end of internal carotid artery in acute ischemic stroke is dangerous.The complete circle of Willis determines the prognosis of mechanical thrombectomy to a certain extent.The patients with open anterior communicating artery have a good prognosis after thrombectomy.The patients with unopen anterior communicating artery and absence of A1 segment are difficult to obtain a good prognosis even if they are successfully opened within the traditional time window.The level of collateral compensation also affects the prognosis of patients.For the "L" occlusion mode,the A1 segment of anterior cerebral artery or the development of anterior communicating artery is slender,which may be an important factor for the poor prognosis of patients.