The Application Of Magnetic Resonance Angiography For Anterolateral Thigh Perforator Flap Vessel Locating

Objective:To investigate and present the application of the magnetic resonance angiography?MRA?technique in the anterolateral thigh flap?ALT?perforator vessel locating.Methods:The preoperative aspects:Between April 2015 and November 2016,23MRA-mapped anterolateral thigh flaps undergoing traumatic extremities defect reconstructions were studied.Standard scanning was deployed in all cases to inspect the perforator features including amount,location,course.All these perforator data were testified and documented within the surgical area intraoperatively,calculating the MRA predicting sensitivity,specificity and its standard error,confidence interaval.For the perforators both found preoperatively and postoperatively,kappa value,the 95%confidence intervel?CI?and the?² test was conducted by SPSS 23.H₀ means the results of the MRA equal to the results of the intraperative findings,H₁ means the results of the MRA do not equal to the results of the intraperative findings.Comparing the?² value and the?²_0.05,1 value,for the?²<?²_0.05,1,H₀ was accepted,otherwise,H₁ was accepted.Caculating the discrepancy between the predicting and the verification of the presence of the perforator,for those discrepancy was less than 1cm,the predicting value means accurate,for those discrepancy was more than 1cm,kappa value was caculated to assess the coherance.The dornor site morbidity and follow-up status were observed.Results:Of the 23 patients,preoperatively,50 anterolateral thigh perforators were located within the surgical area,40 belonged to musculocutaneous perforator,10 belonged to septocutaneous perforator,42 belonged to descending perforator,6 from the oblique branch,2 from the transverse branch.Intraoperatively,52 perforators were found,41branches were the musculocutaneous perforator,11 musclocutaneous perforator;44 from the descending branch,6 from the oblique branch,2 from the transverse branch.MRA has a perforator amount predicting sensitivity of 96.15%and a specificity of 100%for the ALT,and the confidence interaval is 0.584-1.000.The kappa coherence test was performed for the 50 perforators both found preoperatively and postoperatively.The kappa values of the origin and course was 1.?²=0.5<?²_0.05,1=3.84,P>0.05,H₀ was accepted.Caculating the discrepancy between the predicting and the verification of the presence of the perforator,for those discrepancy was less than 1cm,the predicting value means accurate.All patients were followed up for 8 weeks and all flaps survived..Conclusion:With no radiation exposure,contrast-enhanced Magnetic Resonance angiography is a reliable modality for anterolateral thigh flap perforators locating and predicting in perforator course,origin,position,thus greatly facilitate the perforator dissection during the surgery.