The Study On Facial Nerve Reconstruction With Vestibular Schwannomas By Diffusion Tensor Imaging

Objective:To investigate the clinical application research of guiding intraoperative the tumor resection and facial nerve preservation based on facial nerves reconstruction with DTI before the vestibular schwannoma surgery.Methods:We retrospectively collected 38 cases of patients with acoustic neuroma surgery excluding the previous intracranial surgery,radiotherapy history and postoperative pathology for non schwannoma patients.in Tianjin Medical University General Hospital from September 2013 to September 2015.We collected the image information of 38 acoustic neuroma patients with American GE(General Electric)company for HDX 3.0 T MR.The images of each patient were performed by the same technician including three sequences:(1)3D fast spoiled gradient-echo sequence,3D-FSPGR;(2)fast imaging empolying steady state acquisition,FIESTA;(3)diffusion tensor imaging,DTI.Using 3D-Slicer software to complete the facial nerve fiber bundle tracking imaging and 3D imaging reconstruction of tumor,all operations were completed by me,exclude the subjective effects of different operators,and the reconstruction of the fiber bundle were not modified.According to the experience of the operator,the facial nerve image we finally selected was the long continuous fiber bundle Through the internal brainstem,brainstem and the internal auditory canal.The construction of 3D anatomical image tumor mainly based on enhanced T1 WI sequence with the Editor module in application software,and constructed the images of the tumor anatomy and the results of fiber bundle tracking in order to visually and clearly show the walking of the facial nerve and the relationship between the facial nerve and the tumor.During the operation,we used the facial nerve active electrical stimulation to reconstruct the facial nerve and the three-dimensional spatial relation of the tumor carefully.We checked whether the nerve was preserved by electrical stimulation.We collected surgical videos,validated the results of anterior nerve reconstruction,and evaluated the surgical resection and facial nerve injuries after surgery.Results: The results of facial nerve reconstruction with DTI and surgery:In 38 cases,32 cases(84.2%)of facial nerve can be reconstructed by DTI technology,including facial nerve in the anterior ventral inferior in the case of the abdomen,in the middle of the abdomen in 16 cases,in front of the abdomen in the case of the upper and lower,in the lower level of 1 cases in the case of 10 cases.During the operation,the facial nerve was used to detect the actual position of the facial nerve.The results of reconstruction were consistent with the actual operation of the facial nerve and the location of the tumor.The coincidence rate was 100%.6 cases(15.8%)of facial nerve failed to pass the DTI reconstruction technique,including 3 cases of patients with preoperative facial paralysis,2 cases of tumor diameter,5 cm,1 cases of internal auditory meatus enlarged by 2.6 cm.Postoperative and facial nerve function preservation: 38 cases,total resection of the tumor in all patients(89.5%),subtotal resection in 4 cases(10.5%).Intraoperative facial nerve anatomic preservation in 36 cases(94.7%),2 cases(5.3%)of facial nerve surgery because of severe adhesion,fracture of tumor,with 0 suture ends.36 cases of patients,postoperative 7d facial nerve function House-Brackmann grade I in 10 cases,grade II in 20 cases,grade III in 3 cases,IV ~ V level in patients with facial nerve function in more than 5 of all patients accounted for more than 78.9%.Follow up results: all patients were followed up for 6 to 24 months,and 1 patients were lost to follow-up.All the 37 patients were able to take care of themselves,and there was no sign of tumor recurrence.Conclusions: On the basis of modern imaging and computer science,we reconstructed the facial nerve in patients with vestibular schwannoma by 3D-slicer software and applied it to the clinical treatment.We show the position between facial nerve and tumor by this method,according to the position of facial nerve,surgery can make a detailed plan before operation,this helps careful observation,in the process of tumor resection in looking carefully,combined with intraoperative electrophysiological monitoring,early detection of facial nerve,so as to improve the facial nerve the retention rate of anatomy.In the interaction of facial nerve imaging and electrophysiological monitoring,neurosurgeons can complete resection of the tumor,shorten the operation time and improve the quality of life of patients.