The Clinical Anatomy Of Trigeminal Nerve Intracranial Segment And Its Clinical Significance

Objective: To investigate the applied anatomic relationship of the basicranial vessels and the intracranial segment of the trigeminal nerve,and to analyze the therapeutic effect of endoscopic assisted vascular decompression,so as to improve the development and popularization of new clinical techniques,reduce the injury of vessels and nerves,shorten the hospital stays and decrease complications.Methods: Part I: 6 adult cadaveric heads with Faure Marin fixed were included.Simulating the method of retrosigmoid keyhole approach,we exposed the trigeminal nerve and its surrounding blood vessels with microscopic technique.During the procedure,it should be taken more attention to protect the nerves and vessels to keep the original position of the anatomical structures.And we observed the structural relationship of trigeminal nerve,trigeminal ganglion and its surrounding tissues.SPSS 18.0 was used to describe the statistical analysis of the measured data.P < 0.05 stood for the difference significant limit and P < 0.01 was the difference extremely significant limit.The experimental data are expressed by mean ± standard deviation(`X±s).Part II: We retrospectively studied medical records of 29 patients with primary trigeminal neuralgia who had undergone endoscopic vascular decompression in PKU Care Luzhong Hospital.We systemically analyzed the operation findings,operation time,inpatient days,complications and therapeutic effects and discussed the induced factors for primary trigeminal neuralgia and the advantages of endoscopic surgery,so as to provide reference and gist for the surgical therapy.Results(1)The trigeminal nerve originates from the ventrolateral pontine and passes through the inferior part of the superior petrosal sinus.It becomes the semilunar ganglion of the trigeminal nerve in front of the petrous part of temporal bone.The cistern segment of the trigeminal nerve is accompanied by arachnoid membrane,which extends and enters into Meckel’s cavity.The main vascular structures near the trigeminal nerve root include superior cerebellar artery,anterior inferior cerebellar artery,pontine branch of basilar artery and petrosal vein.Intracranial segment of the trigeminal nerve is closed with facial nerve and vestibulocochlear nerve,which needs to be protected during the operation.(2)28 cases in 29 cases(96.55%)had responsible vascular compression,1 case had compression of the trigeminal nerve by hickened arachnoid.The compressing sites include: the root of the trigeminal nerve 24 cases(82.76%)at the root of the trigeminal nerve,2 cases(6.90%)in the middle,1 case(3.45%)in the distal,and 2 cases(6.90%)in the root and middle.After the operation,2 cases(6.90%)had facial numbness,2 cases(6.90%)had headache for more than one week,and 1 case(3.45%)had vertigo.The length of stay were 5~14(7.1±1.9)days.23 cases were cured,3 cases were markedly effective,2 cases were effective,1 cases were ineffective,the total effective rate was 96.55%(28/29).Conclution: The anatomical characteristics of the trigeminal nerve shows that the relationship between its root and many other blood vessels is very closed.According to the theory of vascular compression,it is one of the most important reasons for rigeminal neuralgia.It should be examine carefully to avoid missing responsible vessels.Endoscopic vascular decompression is a minimally invasive,low recurrence rate,less adverse reactions treatment technology.It is safe and efficient to treat primary trigeminal neuralgia.