A Double Blind,single Center Clinical Trial Of The Correlation Of Cranioplasty And The Improvement Of Cerebral Blood Flow And The Recovery Of Neurological Function

Objective:Cranioplasty is considered to be a common surgical procedure for the protection of brain tissue after decompressive craniectomy.After consulting a number of literatures,we found that more and more researches have showed that cranioplasty can improve the cerebrospinal fluid and brain blood flow and increase cerebral metabolic rate so as to promote the recovery of neurological functions and the improvement of clinical symptoms.The study on the relationship between the recovery of nerve function after cranioplasty and the operation time of skull defect repairment surgery is limited.The purpose of this study is to explore whether cerebral blood flow is improved after the cranioplasty and declare the relationship between timing of cranioplasty and neurological function restoration.Methods:We collected the data from all patients who want to have a cranioplasty at the First Affiliated Hospital of Nanchang University in Jiangxi province between Sep.2014 and Sep.2016.All subjects were required to record the Barthel index(BI)score and the mini mental state examination(MMSE)score and perform brain CT perfusion(CTP)and Transcranial Doppler(TCD)examination one week before and after the cranioplasty.In CTP,we adopted four parameters,cerebral blood flow(CBF),cerebral blood volume(CBV),time to peak(TTP),and the mean transit time(MTT)to evaluate the bilateral cerebral blood supply.For TCD,we adopted the systolic blood flow velocity(Vp),the average blood flow velocity(Vm),pulsatility index(PI)and resistance index(RI)to assess the blood supply and vascular condition of bilateral anterior cerebral artery(ACA),middle cerebral artery(MCA),posterior cerebral artery(PCA),internal carotid artery(ICA).△ represented thechange before and after cranioplasty.Finally,we used a variety of statistical methods to analyze preoperative and postoperative data.Results:We collected a total of 26 samples,23 males and 3 females,4 were automatically withdrawn from the study.22 patients completed the trail and average age was 43.3 years old.The average interval between DC and cranioplasty was 186 days.The average area of skull defect was 71.9cm2.21 patients performed both CTP examination and TCD examination one week before and after the cranioplasty.Bilateral skull defects were repaired in 2 samples.All patients had no operation-related complications such as postoperative infection,new onset epilepsy or hydrocephalus after cranioplasty.Decreased BI scores and increased MMSE scores after operation were observed,but there was no statistically significant differences.In defective side,CBF and CBV were improved according to CTP examination and TTP decreased after surgery,but both were not statistically significant.In contralateral side,CBF and CBV were significantly increased(P=0.0456,P=0.0479),TTP and MTT decreased after cranioplasty,but no statistically significant differences was found.In TCD,Vp and Vm in bilateral ICA,MCA,PCA,VA were increased,but only the increase of VP in defective side was statistically significant(p=0.044).In the analysis of 2 patients with bilateral cranioplasty,we found that the bilateral decreased CBV and increased TTP after cranioplasty in 1 case,both had statistically significant differences(P<0.05).The other patient had higher CBF,CBV and lower MTT compared with preoperation,both had statistically significant differences(P<0.05).When 6 months was defined as the time point,the patients were divided into two groups,4-6 months group and more than 6 months group,we found that the change of BI and MMSE between two groups has no significant difference(P>0.05),bilateral △CBF and△CBV,△Vp and △Vm of ACA,ICA,MCA between two groups had no statisticallysignificant differences(P>0.05).Conclusions:Cranioplasty after DC can improve the cerebral blood flow of both defective side and contralateral side,but the improvement of contralateral side was significant.We haven’t found the correlation between the timing of cranioplasty and recovery ofcerebral function or cerebral blood flow when 6 months was defined as the time point,.