Endoscopic Anatomy And Clinical Application Of Superior And Inferior Transtentorial Approach To The Posterior Third Ventricle

Part ? Endoscopic anatomy of superior and inferior transtentorial approach to the posterior third ventricleObjective:To do anatomic study of structures and exposure of the posterior third ventricle by stimulating superior and inferior transtentorial approach with endoscope and to provide anatomical basis for treatment of this area with endoscope.Methods:Five formalin-fixed cadaver heads were dissected bilaterally(ten sides).To observe and measure anatomical structures and surgical freedom of the posterior third ventricle by endoscopic infratentorial-supracerebellar(midline or paramedian)approach and occipital-tentorial approach with comparison of exposure in different surgical approaches.And then,endoscopic entered the third ventricle,and analysis of safety and feasibility.Results:(1)Measurement of anatomical structures: Average bridging veins of the cerebellum are 3.6±0.5,the diameter of the vein of Galen,internal cerebral vein,internal occipital vein,basal vein is 5.6±0.5mm,3.2±0.4mm,2.4±0.5mm,2.6±0.55 mm The distance from Habenular commissure to confluence of sinuses is 74.4±6.7 mm.The distance of habenular commissure to torcular is 74.4±6.7mm,and anterior commissure to torcular is 107.2±7.3mm.(2)Comparison of different surgical approaches: The exposed area of pineal glands is 19.6±2.8 mm2,which is almost the same in infratentorial-supracerebellar(midline or paramedian)approach and occipital-tentorial approach.The average of exposed area in splenium of corpus callosum are 55.2±7.9 mm2,34.7±7.9 mm2 and 44.9±5.9 mm2(P=0.01),respectively and in ipsilateral superior colliculus are 153.8±13.4 mm2,177.5±24.0 mm2 and 197.6±19.8 mm2(P=0.014),respectively Both have statistical significance.Conclusion: Endoscopic superior and inferior transtentorial approach is feasible and safe for removal of tumors in the posterior third ventricle.The selection of surgical approaches should be based on tumor type,size,location and the relationship with the surrounding structures.Part ? Clinical application of endoscopic supracerebellar infratentorial approach for resecting the posterior third ventricle lesionsObjective: To explore the surgery treatment strategies for endoscopic supracerebellar infratentorial approach for resecting the posterior third ventricle lesions,and analysis of safety and effectivess.Methods: A retrospective analysis of the clinical data of 9 patients with the posterior third ventricle adenomas treated by endoscopic supracerebellar infratentorial approaches at the Department of Neurosurgery,the First Affiliated Hospital of Shenzhen University combined with Zhongshan Hospital of Fudan University from August 2014 to April 2017.The data include clinical manifestation,surgical methods and resection rate,complications.Results:Nine posterior third ventricle tumors were removal by endoscopic supracerebellar infratentorial approach,include 8 males and 1 female,the average age was 42.0±18.2,5 cases of severe hydrocephalus,3 cases of slight hydrocephalus and 1 patient with no hydrocephalus,The gross total resection(GTR)was 8 patients and tumor residue was 1 patient.Pathological diagnoses were goniolma 3 cases,glioblastoma 2 cases(WHO grade IV),anaplastic astrocytoma 2 cases(WHO grade III),pilocytic astrocytoma 1 case(WHO grade I).The follow-up lasted 4-36 months,average 16.9±10.9 months.three patients accepted postoperative treatment of radiotherapy and chemotherapy and 1 patient accepted chemotherapy.1 patient with glioblastoma recurred one month after operation,1 patient died of tumor recurrence after 1 year postoperative.Conclusion: Endoscopic supracerebellar infratentorial approach is feasible and safe for removal of tumors in the posterior third ventricle.The result shows that it integrates the of the advantage microscopy and the minimal invasive of endoscopic.The use of multi angle endoscopy can increase the exposed area.Proper surgical approach can reduce operative risk and complications.