Objective To investigate the risk factors associated with post traumatic cerebral infarction (PTCI) after craniotomy hematoma evacuation for severe traumatic brain injury (sTBI) so as to provide clinical reference for the early prevention of postoperative PTCI.Methods A retrospective case control study was conducted to analyze the clinical data of 558 sTBI patients who received craniotomy hematoma evacuation admitted to Changsha Hospital of Traditional Chinese Medicine from October 2006 to June 2016.There were 340 males and 218 females,aged 15-71 years,with an average of 47.8 years.Among them,75 patients were at the age of less than 30 years,315 were at 30-50 years,and 168 were above 50 years.According to the Glasgow coma score (GCS),there were 127 patients with 3-4 points,124 with 5-6 points,and 307 with 7-8 points.The patients were divided into PTCI group (51 patients)and non-PTCI group (507 patients).The related indicators of the two groups of patients after admission were collected,including gender,age,injury cause,GCS,skull base fracture,traumatic subarachnoid hemorrhage (tSAH),cerebral hernia,hypotension,the time from injury to craniotomy,and whether decompressive craniectomy was performed.Univariate analysis was first performed for these factors,followed by multivariate logistic regression analysis.Results There were no significant differences in gender,age,injury cause,skull base fracture,and decompressive craniectomy between PTCI group and control group (P ＞ 0.05).In the PTCI group,there were 29 patients with GCS of 3-4 points,17 with 5-6 points,and five with 7-8 points;there were 48 patients with tSAH,37 patients with cerebral hernia,and 18 patients with hypotension.In terms of the time from injury to craniotomy,it took ＜ 3 hours in 30 patients,3-6 hours in 12,6-12 hours in five,and ＞ 12 hours in four.In the non-PTCI group,there were 98 patients with GCS of 3-4 points,107 with 5-6 points,and 302 with 7-8 points.There were 34 patients with tSAH,117 with cerebral hernia,and 35 with hypotension.In terms of the time from injury to craniotomy,it took ＜3 hours in 294 patients,3-6 hours in 130,6-12 hours in 68,and ＞ 12 hours in 15.The differences between the two groups were statistically significant (P ＜ 0.05).Multivariate logistic regression analysis indicated that GCS of 3-6 points,tSAH,cerebral hernia,time from injury to craniotomy,and hypotension were significantly associated with PTCI after operation for sTBI (P ＜ 0.01).Conclusions GCS of 3-6 points,tSAH,cerebral hernia,duration from injury to craniotomy,and hypotension time ＞ 3 hours are the high risk factors of PTCI in sTBI patients after craniotomy.For patients with these high risk factors,craniotomy should be performed in time,and the perioperative blood pressure and intracranial pressure stability should be maintained so as to relieve vasospasm.