Application Of Three-dimensional Virtual Reconstruction In The Disease Of Cranial Nerve

Objective:To explore how vascular compression cause TN,we used the technique of three dimension volume rendering reconstruction(3D-VRR)according to TN patient's MRI images to study the spatial structure of the offending vessels and their relations to the intracisternal part of trigeminal nerve.Materials and methodsCollecting clinical characters,MR images,reconstructed 3D 3D-VRR images by 3D-slicer software and intraoperative findings of 48 patients who received MVD due to idiopathic TN and VRR documents of another 18 patients with 16 hemifacial spasm(HFS)and 2 glossopharyngeal neuralgia(GN)in our department from 2015 to 2017.Difference and correlation were analyzed between the group of painful side and the healthy control of the unaffected side on the site of compression,bending degree of the arterial loop and the angle between the nerve and the arterial loop.Other characters including the classification of the offending vessels,difference between classical TN(TTN)and atypical trigeminal neuralgia(ATN),relevance and difference between MR findings and 3D-VRR findings were also analyzed respectively.ResultsIn 48 patients with TN and 18 patients without TN,the consistancy between the offending vessels of MRI and intraoperative findings is 54.8%,which is inferior to the 79.2%of VRR.The correlation of offending vessels on MRI to them in operation is not significant,where as it is significent between VRR and MVD.In group of painful side,not only the bending degree of the arterial loop(76.85±12.16° vs.99.34±20.48°)and the angle between the arterial loop and the trigeminal nerve(39.90±15.92 vs.27.81±12.97)have significant difference with them in the healthy side(P<0.05),but the vascular compression site is more frequent on the REZ than it in the control group(89.6%vs.35.7%,P<0.05).More than that,TN has certain correlations with the site of compression,the degree of bending of artery and the angle between the arterial loop and the nerve.Among the TN patients,except case history,there are no difference of age,gender,affected side,classification of the offending vessels,the compression site,the bending degree of the offending artery and the angle between the arterial loop and the nerve between the TTN and the ATN groups.Among the patients without TN,the compression site,arterial bending degree and angle between the artery and nerve have no difference between the left and Right side.ConclusionAn artery contacting with the intracisternal part of the trigeminal nerve is an offending artery of the idiopathic trigeminal neuralgia on the condition that it has a larger bending degree and compresses the root of trigeminal nerve with a large degree of intersection angle.3D-VRR has more accuracy in finding out offending vessels than the traditional MRI before operation.