The Anatomical Study And Clinical Application Of Neuro-endoscope

Part 1 The Study of Neuroendoscopic Applied Anatomy1. endoscopic Anatomical study of the sella regionObjective To study the endoscopic anatomical characteristics of the sella region and to evaluate its clinical application value. Methods two fresh cadaver heads and six cadaver heads fixed by formalin were studied via pterion or enlarged pterion approach. Sylvian fissures were dissected under microscope and the sella region was observed and measured under endoscope and microscope. Results Through different anatomical fissures, with the help of endoscope we could observe all the cisterns around sella region and important anatomical structures in it without any destroy to normal tissues. 1.1 Carotid cistern: in it we could find supraclinoid portion of ICA, PCA, AchoA and uncus artery. 1.2 Optic chiasma cistern: It surrounds optic nerve and optic chiasma. Infundibulum, stalk hypophysial and diaphragma sellae were connected with its floor. Carotid cistern located on its lateral. Bottom of Cisterna lamina terminalis located on its posterior side. And it was separated from interpeduncular cistern by Liliquist membrane on the basalar portion. 1.3 Cisterna lamina terminalis: It seated anterior to the terminal lamina and was separated from the third ventricle by a layer of ependyma and a thin terminal lamina. 1.4 Interpeduncular cistern: It seats inferior to diencephalon and looks like a cop, and also it is close to the medial surface of temporal lobe and hippocampus, and usually entends to clivus at anterior-inferior side, and at posterior-inferior side it entends to superior side of the pons, and it is connected to ambient cistern on the posterior-lateral side. 2.1 The first interspace: The distance between tuberculum sellae and Optic chiasma is 5.5±1.1mm, and the biggest distance between the medial surface of two optic nerve is 10.5±1.3mm. 2.2 The second interspace: The length of three sides are 6.5±0.6mm,6.8±0.8mm,4.1±0.3mm. 2.3 The third interspace: The length of three sides are 8.7±0.7mm,6.7±0.6mm,4.4±1.0mm. 2.4 The fourth interspace: That is the terminal lamina fissure. 3.1 ICA: The closest site of bilateralis usually located at supraclinoid (75%), carvernous sinus (12.5%), and sphenoid sinus (12.5%). 3.2 MCA: The superior trunk and the inferior trunk are not always of the same size. Usually the superior trunk of 25% persons'are bigger, and at 31.25% persons the inferior trunk is bigger, and at 18.75% persons trunks of both side are of the same diameter. 3.3 The complex of AcoA: We observed that in about 43.75% persons calibers of the left side are equal to that of the right side, and in about 37.5% persons calibers of the left side artery are bigger than right side, and in the rest calibers of the left side are smaller than the right side. ACA of both sides are connected together by the AcoA. It has a lot of variation and aneurysms usually locate at this site. 3.4 PcoA: We found that in 31.25% persons calibers of PcoA and PCA are of the same size, and in these cases there must be some maldevelopment on PCA of the same side. Conclusions Neuroendoscope can be used to observe the hidden but important anatomic structures. Endoscope-assisted micro-neurosurgery may provide maximal removal of the lesions, maximal safety of patients, and minimal destruction to normal structures.2. applied anatomical study of endoscopic operation via trans-sphenoid sinus approachObjective To study the endoscopic characteristics of anatomic structures on trans-sphenoid sinus approach, and explore the potential values of endoscope in resection of masses on sella area via trans-sphenoid sinus approach.Methods :The anatomical structures and landmarks of 10 formalin-fixed cadaveric heads, were studied and measured under endoscope via trans-sphenoid sinus approach.Results :The distance from base of columella nasi to ostia of sphenoidal sinus was (64.3±3.2) mm, distance from radix nasi to ostia of sphenoidal sinus was (44.8±2.4) mm, distance from ostia of sphenoidal sinus to sphenoethmoidal recess was (7.3±3.4) mm,distance from root of sella downward to line through base of columella nasi and middle turbinate was (12.5±2.3) mm. The sagittal diameter of ostia of sphenoidal sinus was (3.5±1.5) mm,The transverse diameter was (1.2±0.5) mm. The distance from the anterio-superior and inferio-exterior end of ostia of sphenoidal sinus to the midline were (3.0±1.0) mm and (3.9±1.2) mm. The distance from the ostia of sphenoidal sinus to tuberculu sellae, internal carotid artery, optic nerve and dorsum sellae were (15.6±3.0) mm,(13.7±2.2) mm,(11.6±1.8) mm,and (22.6±3.2) mm. With the help of endoscope, we could see anatomical landmarks such as knob of ICA, optic canal, and lacune on break-over part of sella base, where is the center to open the sella base. We can not get sufficient exposure of structures in sella or upon sella under zero degree endoscope, but under 30 degree endoscope we can observe structures easily such as stalk hypophysial, medial wall of cavernous, sellae diaphragma, etc. conclusions under the direct visual angle of endoscope, with the specified equipment, anatomical landmarks on trans-sphenoid sinus approach could be exposed sufficiently. The surgeons should be familiar with the endoscopic characteristics of anatomical malformations and landmarks, then normal tissues can be avoided of destruction and masses can be resected safely and totally.3. endoscopic anatomical study of lateral cerebral ventricleObjective To study and measure the intra-ventricle structures under different view angles of endoscope, and collect effective reference for safe operation in ventricles. Methods : The anatomical structures and landmarks of 10 formalin-fixed cadaveric heads, were studied and measured under endoscope via different approach to frontal and occipital ventricle horn. Results The distance from frontal horn to interventricular foreman(monro) were (30.3±2.2) mm. The roof width, height of medial and lateral wall of frontal horn were (16.7±2.1)mm, (16.1±3.0)mm, (23.0±3.6)mm, and that at middle body of lateral ventricle and point of Monro's foramen were (13.1±1.7)mm,(8.6±1.3)mm,(15.5±1.4)mm and (18.0±1.6)mm, (17.0±1.9)mm, (24.1±2.5)mm. The distance from occipital horn to frontal horn, temporal horn and Monro's foreman were (86.5±6.3)mm, (59.5±6.4)mm and ( 56.3±5.2)mm. The height of arcuate bulge of lateral ventricular bottom between globe of choroids plexus and Monro's foreman was (9.9±1.6)mm. The utmost width in trigone of ventricle was ( 9.3±2.1)mm. The width of lateral ventricle superior to trigone was (8.3±2.0)mm, and (9.4±1.8)mm at the inferior side. The distances from cortex-punctured point to lateral ventricle and Monro's foreman in supra-eyebrow approach were (29.6±2.5) mm and (55.6±2.4) mm, and in fore-coronale approach were (29.4±2.8) mm and (55.4±3.0) mm. We observed the body of lateral cerebral ventricle occipital horn, bottom and posterior part of the third ventricle via frontal horn approach; and choroids plexus which extends from temporal horn to frontal horn via occipital horn approach. The most important landmark in ventricle was the"Y"shaped structure nearside Monro's foramen. Conclusion there are obvious dominance in exposing and operating on the masses located around Monro's foramen via fore-coronale approach and longitudinal split approach, and the working distance is not very long, and endoscope could be impelled into anterior part of third ventricle through Monro's foramen easily. Supra-eyebrow approach is suitable for exposing and operating on masses located around frontal horn and body of lateral ventricle, and in this approach there is little destruction to normal neurofunction. Occipital horn approach is suitable for dealing with the masses located around triangular part and posterior part of lateral ventricular body.4. endoscopic anatomical study of the third ventricleObjective To study and measure the structures and landmarks in third ventricle under different view angles of endoscope via different operational approach. Methods :The anatomical structures and landmarks of 6 formalin-fixed and 2 fresh cadaveric heads, were studied and measured under endoscope via frontal ventricle horn, occipital ventricle horn and endoscopic Monro's foramen approach. Results massa intermedia appeared in 75 % specimens. The sagittal and transverse diameter of interthalamic adhesion were (5.4±1.2)mm and (2.7±0.9)mm. We found Monro's foramen, choroids plexus in lateral ventricle via frontal horn approach, and in third ventricle we found anterior border of massa intermedia, choroids plexus suspending on the roof of third ventricle, terminal plate, recessus infundibuli, rescessus pinealis, upper entrance of aqueduct, etc. Conclusions we can get into third ventricle through cutting off fornix collumn of the same side or choroids fissure when Monro's foramen is not large enough. Working-scope can expose structures locating inferior to third ventricle and posterior to massa intermedia when massa intermedia is absent or not very large. Because masses locating at anterior third ventricle and middle third ventricle are close to Monro's foramen, we may choose endoscopic Monro's foramen approach, but in that locating near posterior third ventricle may choose choroid fissure approach.5. study of endoscopic anatomy of the cerebello-pontine angle RegionObjective Tr study the anatomic characteristics of the cerebellopontine angle region under the neuroendoscope and its clinical values. Methods We observed the related microdissection of the cerebellopontine angle region of 8 cadavers through retrosigmoid approach by operative microscope and neuroendoscope, in which 2 cadavers were fresh. We also studied the microdissection of the cerebellopontine angle region by operative microscope and neuroendoscope in 15 cases of acoustic neurilemoma, 6 cases of cholesteatoma and 5 cases of trigeminal neuralgia. Results The anatomy of important cerebral cisterns and operative fissures and vessels in the cerebellopontine angle region were observed by various neuroendoscope through various anatomic fissures with minimal invasiveness. Endoscope-assisted microneurosurgery can improve the resection rate of the tumor. Conclusions neuroendoscope has different visual angle from operative microscope. Endoscope can be used to inspect hidden but important anatomic structures in the cerebellopontine angle zone. This study supply the anatomical basis for microneurosurgery, also demonstrate that a good understanding of pathological microanatomy of tumor, as well as its relationship with adjacent neurovascular structures. The neuroendoscope will make up for the deficiencies of the microscope and be of important assistance to the microsurgical operating. Endoscope-assisted microneurosurgery may provide maximum efficiency to remove the lesion, maximum safety for the patient, and minimum invasiveness.Part 2 The Clinical Application of Neuroendoscope1. values of endoscope in microneurosurgical resection for pituitary adenomas via sphenoidal sinus approach and comparison of different correlated approachobjective to explore the assisted effect of endoscope in micro-resection for pituitary adenomas via different approach and the merit and defect of each approach. Methods analysis the clinical data, operational process and curative effect of 500 cases who suffered of different kinds of pituitary adenomas and treated in our department via trans-sphenoidal sinus approach, retrospectively. 200 of them were operated via improved mouth-nasal-sphenoidal sinus approach, and 20 of them were operated with the help of endoscope. 250 of them were operated via vestibulum nasi-nasal septum-sphenoidal sinus approach and 20 of them operated with help of endoscope. 50 of them were operated via direct transsphenoidal approach and 10 of them with the help of endoscope. Results there is little complications of operations via transsphenoidal approach. No post-operational infection and death appeared in each group. Total resection rate was improved with the help of endoscope. Conclusion with the help of endoscope we could see structures and masses in blind area of the microscopic tubular visual field, and rate of total resection was improved. Endoscope could provide good lighting of deep part and imaging amplification, which help surgeon get distinct observation of anatomical structures intra-sphenoidal sinus, intra-sella, or supra-sella.2. Endoscope-assisted microsurgical treatment of intracranial Epidermoid cystObjective To study the value of Endoscope-assisted Neurosurgery technique performed in surgical treatment of intracranial epidermoid cyst. Methods Endoscope-assisted Neurosurgery were applied in 25 cases of intracranial epidermoid cysts, in which 17 were Cerebellopontine Angle epidermoids, other 8 cases extended to sellar, clival, third ventricle or opposite CPA region. Craniotomy and surgical approach included suboccipital retrosigmoid (in 17 cases), pterion (in 4 cases), subtemporal (in 3 cases) and transcorticle approach (in 1 cases). Most part of tumors were resected under microscope, then explored and resected the remained tumors under neuroendoscope. Results In these all 25 cases,remained tumors were found under neuroendoscope after routine microsurgery and resected. Total removement rate was 92%(23/25 cases). 21/25 cases (84%) obviously recovered from former symptoms postoperation, 4/25 partially remission. Conclusions Endoscope-assisted neurosugery treatment of intracranial epidermoid cyst can increase total-resection rates, reduce surgery-ralated trauma, improve safety of the operation, reduce occurrence of complications, reduce length of stay.