机械取栓术中平板CT高密度征出血转化及预后的影响因素分析

Flat-panel CT high-density sign and hemorrhagic transformation and prognosis in mechanical thrombectomy: an analysis of influencing factors

目的分析大血管闭塞的急性缺血性卒中机械取栓术中局部脑组织平板CT高密度征的特点以及影响其出血转化及患者预后的因素。方法回顾性连续纳入2013年9月至2018年3月海军军医大学第一附属医院脑血管病中心收治的大血管闭塞急性缺血性卒中行机械取栓治疗且术中行平板CT检查的患者244例(后循环病变64例),其中桥接治疗85例。根据平板CT结果是否存在局部高密度征,分为高密度征组(71例)和非高密度征组(173例)。记录并分析两组患者基线资料[性别、年龄、术前美国国立卫生研究院卒中量表(NIHSS)评分]、临床资料[桥接治疗、闭塞部位、血管再通达改良脑梗死溶栓(mTICI) 2b～3级、术后90 d预后良好、出血转化、病死率]的组间差异。对术中平板CT高密度征的分布特点进行分析。评价高密度征组患者出血转化及预后良好的单因素分析及多因素Logistic回归分析。结果 (1)高密度征组术前NIHSS评分高于非高密度征组,组间差异有统计学意义[20(15,23)分比17(10,22)分,Z=5. 454,P=0. 028],余基线资料的组间差异均无统计学意义(均P>0. 05)。(2)高密度征组颈内动脉末端T形或L形、大脑中动脉M1段的闭塞比例均高于非高密度征组[36. 6%(26/71)比22. 5%(39/173),50. 7%(36/71)比35. 3%(61/173)],椎-基底动脉的闭塞比例低于非高密度征组[5. 6%(4/71)比31. 2%(54/173)],组间差异均有统计学意义(均P <0. 05);高密度征组预后良好率低于非高密度征组[39. 4%(28/71)比61. 3%(106/173)],出血转化率及病死率均高于非高密度征组[33. 8%(24/71)比11. 0%(19/173),16. 9%(12/71)比6. 9%(12/173)],组间差异均有统计学意义(均P <0. 05)。(3)前循环大血管闭塞机械取栓术后高密度征发生率为29. 1%(71/244),高密度征病灶可见于1个或多个部位(共计87个),常见部位分别为尾状核头40. 2%(35个)、外囊23. 0%(20个)、内囊11. 5%(10个)、皮质及皮质下白质17. 2%(15个)、脑干2. 3%(2个)及距状沟5. 7%(5个),尾状核头和外囊的出血转化率分别为25. 7%(9/35)、40. 0%(8/20),内囊、皮质及皮质下、距状沟及脑干发生出血转化占比分别为3/10、2/15、5/5和1/2。(4)高密度征组出血转化发生率为33. 8%(24/71),发生出血转化者中,术前NIHSS评分≤22分的比例高于未发生出血转化者,二者差异有统计学意义[87. 5%(21/24)比61. 7%(29/47),P <0. 05]。高密度征组预后良好者中,桥接治疗的比例高于预后不良者,二者差异有统计学意义[53. 6%(15/28)比27. 9%(12/43),P <0. 05]。(5)分别以发生出血转化及预后良好为因变量,将单因素结果中P≤0. 15的自变量进一步行多因素Logistic回归分析,结果显示,桥接治疗(OR=0. 310,95%CI:0. 107～0. 893)及无出血转化(OR=0. 249,95%CI:0. 075～0. 828)均为90 d预后良好的保护因素(均P <0. 05)。结论伴有大血管闭塞的急性缺血性卒中机械取栓术中平板CT特征性高密度征可能提示高出血转化风险,且高密度征患者桥接治疗及无出血转化是90 d预后良好的保护因素。

Objective To analyze the characteristics of local brain tissue flat-panel CT high-density sign in mechanical thrombectomy for acute ischemic stroke with large vessel occlusion and the effect on the hemorrhagic transformation and prognosis of patients.Methods From September 2013 to March 2018,a total of 244 consecutive patients(64 posterior circulation lesions)with acute ischemic stroke of large vessel occlusion treated with mechanical thrombectomy,checked by intraoperative flat-panel CT and admitted to the Department of Cerebrovascular Disease Center,First Hospital Affiliated to Naval Military Medical University were enrolled retrospectively.Eighty-five of them were treated with bridging treatment.According to whether the findings of flat-panel CT having local high-density sign or not,they were divided into either a high-density sign group(n=71)or a non-high-density sign group(n=173).The inter-group differences of the baseline data of both groups(sex,age,preoperative National Institutes of Health Stroke Scale[NIHSS]score),clinical data(bridge treatment,occlusion site,revascularization reaching the modified treatment in cerebral infarction[mTICI]grade 2b-3,good prognosis at 90 d after procedure,hemorrhagic transformation,and mortality)were documented and analyzed.The distribution characteristics of high-density signs of intraoperative flat CT were analyzed.Univariate and multivariate logistic regression analyses of the hemorrhagic transformation and good prognosis in the high-density group were evaluated.Results(1)The preoperative NIHSS score of the high density sign group was higher than that of the non-high density sign group.There was significant difference between the two groups(20[15,23]vs.17[10,22],Z=5.454,P=0.028).There were no significant differences in other baseline data between the two groups(all P >0.05).(2)The occlusion ratio of T-shaped and L-shaped internal carotid artery and M1 segment of middle cerebral artery in the high-density sign group were higher than those in the non-high-density sign group(36.6%[26/71]vs.22.5%[39/173],50.7%[36/71]vs.35.3%[61/173]),and the occlusion ratio of vertebrobasilar artery was lower than that in the non-high-density sign group(5.6%[4/71]vs.31.2%[54/173]).There was significant difference between the two groups(all P<0.05).The good prognosis rate of the high-density sign group was lower than that of non-high-density sign group(39.4%[28/71]vs.61.3%[106/173]),and the hemorrhagic transformation rate and mortality were higher than those of in the non-high-density sign group(33.8%[24/71]vs.11.0%[19/173],16.9%[12/71]vs.6.9%[12/173]).There was significant difference between the two groups(all P<0.05).(3)The incidence of high-density sign was 29.1%(71/244)after mechanical thrombectomy for anterior circulation large-vessel occlusion.The high-density sign lesions were found in one or more sites(a total of 87).The common sites were the head of caudate nucleus 40.2%(n=3 5),outer capsule 23.0%(n=20),inner capsule 11.5%(n=10),the cortex and subcortical white matter 17.2%(n=15),brain stem 2.3%(n=2),and fissura calcarina 5.7%(n=5),respectively.The hemorrhagic transformation rates of the head of caudate nucleus and outer capsule were 25.7%(9/35)and 40.0%(8/20)respectively.The proportion of hemorrhagic transformation in inner capsule,cortex and subcortex,fissura calcarina or brain stem was 3/10,2/15,5/5 and 1/2,respectively.(4)The incidence of hemorrhagic transformation in the high-density group was 33.8%(24/71).Among the patients with hemorrhagic transformation,the proportion of preoperative NIHSS score≤22 was higher than that of the non-hemorrhagic transformation.The difference was statistically significant(87.5%[21/24]vs.61.7%[29/47],P<0.05).Among the patients with good prognosis in the high-density sign group,the proportion of bridging treatment was higher than that of the patients with poor prognosis.The difference was statistically significant(53.6%[15/28]vs.27.9%[12/43],P<0.05).(5)Regarding hemorrhagic transformation and good prognosis as dependent variables,the independent variables of P≤0.15 in univariate results were further analyzed by multivariate logistic regression.The results showed that bridging treatment(OR,0.310,95%CI 0.107-0.893)and non-hemorrhagic transformation(OR,0.249,95%CI 0.075-0.828)were all the protective factors of the good prognosis at 90 d(all P<0.05).Conclusion The characteristic high-density sign of the flat-panel CT in mechanical thrombectomy for acute ischemic stroke with large vascular occlusion might indicate that the risk of high hemorrhagic transformation,and the bridging treatment and no hemorrhagic transformation in patients with high-density sign were the protective factors of good prognosis at 90 d.