An Anatomic Research Of Thalamic Region Under Microscope And Endoscope And A Research Of Clinical Treatment Of Thalamic Glioma

Object:By means of simulating operations on latex injected cadaver head specimen through transcorpus callosal ventricle approach, combine microscope with endoscope to observe the whole thalamic region’s anatomy. To find out and record the major anatomical signs during the entire operation process, to explore the complement between microscope and endoscope on the aspect of exposition, and finally provide an anatomic foundation for clinical application.Methods:6(12sides) formalin-fixed adult cadaver head specimens was selected, immersed in75%alcohol for two weeks, perfused carotid and vertebral artery with red latex, and internal jugular vein with blue latex. Then simulated transcorpus callosal ventricle approach to expose thalamus, utilized microscope and endoscope alternately to observe the anatomic structure of four different stages:interhemispheric, septum pellucidum cavity, lateral ventricle and third ventricle. Finally, observed the thalamus and its neighboring structure elaborately and measured relevant anatomic date during the process.Results:1. Interhemispheric fissure stage:Draining vein located4cm behind the coronal suture was found in4sides, excepted1draining vein’s diameter was relatively thick, another3ones were thin. Separated the interhemispheric fissure and made a15.73±0.9mm width, which can sequently expose falx, medial frontal lobe, cingulate sulcus, callosal margin artery, cingulate gyrus, corpus callosum sulcus, pericallosal artery and corpus callosum. Both microscope and endoscope can well show the entire anatomic structures of interhemispheric fissure. When used microscope, the visual field was wider than endoscope’s and it was easier to control. While used endoscope, such deep structures as cingulate sulcus, callosal margin artery, pericallosal artery and corpus callosum could be exposed more clearly, it was favorable to recognition and separation of these structures. Combination of both could accurately expose interhemispheric fissure’s anatomy from macroscopic and microcosmic level.2. Septum pellucidum cavity stage:Retracted the bilateral pericallosal arteries about7.44±0.4mm, longitudinally cut the corpus callosum and restrained the incision in2-2.5cm, then separated downward about9.08±0.7mm would find the cavity of septum pellucidum. In this group,5cases existed an evident cavity while1case was lack of it. The wall of the cavity was extremely thin, approximately0.72±0.1mm, and the height was8.38±1.0mm. The difference of visual field between microscope and endoscope was not significant. However, the endoscope which took advantage of30°lens can expose the entire cavity and bilateral septum pellucidum easily, it was favorable toward ensuring the incised location of septum pellucidum. But used microscope to make an exposition of the cavity which needed to adjust projection angle repeatedly,it not only influenced operation, but also cannot expose the septum pellucidum perfectly due to the restraint of the width of interhemispheric fissure.3. Lateral ventricle stage:The lateral ventricle was situated in the front of foramen of monro, the visual field of frontal horn under the microscope was limited to14.24±1.2mm, but when put the30°lens in the ventricle which can effectively widen the inner visual field of frontal horn (25.67±1.7mm) and definitely showed every wall of it. The foramen of monro was4.51±0.6mm long and2.65±0.4mm broad, behind which was the body of ventricle. The body of choroid plexus extended forward, and intersected with septum vein, thalamus striatum vein in front of monro as "Y" shape. Beneath the choroid plexus was the body of choroid fissure, it was23.22±0.9mm long. Microscope can relatively well expose thalamus’s neighboring structure and3/5(18.65±1.4mm) of its front part as well as2/3(6.98±0.9mm) of its medial part. Meanwhile, because of microscope’s wide visual field, eloquent structures can be safely protected. But2/5of posterior part and1/3lateral part of thalamus where existed visual dead angles duo to the restriction of interhemispheric width and corpus callosum’s incision length and width. Nevertheless, through using the endoscope, both the two dead angles can be eliminated, even the posterior thalamic pulvinar and the lateral caudate nucleus can be exposed.4. Third ventricle stage:Opened the tenia of fornix and retracted the body of fornix medially about4.77±0.4mm. Then the velum interpositum where contained internal cerebral vein and medial posterior choroid artery can be exposed. In the third ventricle, all6cases possessed massa intermedia which was9.02±2.4mm long and2.21±0.5mm broad. The up side of the lateral wall of third ventricle was the medial side of thalamus which was limited to be exposed by microscope. Even though using endoscope can effectively expose the entire medial side of thalamus and bottom wall of third ventricle, which need to retract internal cerebral vein laterally about3.71±0.2mm, the vein was strained this moment and maybe impaired.Conclusion:The main anatomical sings of transcorpus callosal ventricle approach to thalamus were that Interhemispheric fissure stage-falx, callosal margin artery, cingulate gyrus, pericallosal artery and corpus callosum. Septum pellucidum cavity stage-septum pellucidum and the body of fornix. Lateral ventricle stage-foramen of monro, septum vein, thalamus striatum vein, choroid plexus, choroid fissure, the body of fornix and caudate nucleus. Third ventricle stage-internal cerebral vein and medial posterior choroid artery, choroid plexus, massa intermedia and hypothalamic sulcus. The anatomical structures of interhemispheric fissure and Septum pellucidum cavity, both the microscope and endoscope can expose clearly, and they complemented each other in aspect of visual field. In the lateral ventricle, endoscope can compensate for some visual dead angles under microscope, such as the anterior of front horn,2/5of posterior part and1/3lateral part of thalamus. However, in the third ventricle, neither microscope nor endoscope was far from enough to expose the medial side of thalamus perfectly, due to the restriction of fornix and internal cerebral vein. Object:To explore the treatment effect of thalamic glioma by using conservation and microsurgery respectively. To summary the characteristics of different surgery approaches and analyze the prognosis of thalamic glioma patients.Methods:Collect clinical data of thalamic glioma patients those experienced therapies in our group from2005.1-2012.12, include sexy, age, course of disease, clinical manifestation, radiological image, treatment ways, pathology etc. Make a comparison of the characteristics between two different therapies and implement a long follow-up to every patients. To calculate the overall survival rate(OS) and progression free survival rate(PFS).Results:1. In the group of conservative treatment:25patients adopted such ways as radiotherapy, chemotherapy, biopsy and V-P shunt.15cases experienced radio-chemotherapy after biopsy,10cases adopted radio-chemotherapy directly,2cases adopted radio-chemotherapy and shunt and1cases experienced all these treatments. The main acute treatment reaction of our patients was grade Ⅰ-Ⅱ, there was no grade III. The median KPS had risen20after the radio-chemotherapy. All patients were followed up by4-52months, the average was14.7months. Kaplan-Meier showed that the OS of6month,1year and2year were84.0%,48.0%and8.0%respectively, the median survival time was12months. The the PFS of6month,1year and2year were56.0%,28.0%and4.0%respectively, the median progression free survival time was8months.2. In the group of microsurgery treatment:37patients adopted microsurgery which was aimed to reduce the pressure of tumor.10cases were used transcallosal ventricular approach,14cases were trans-superior parietal ventricle approach,8cases were trans-frontal gyral approach and5cases were translateral fissure insular approach.21cases received greatly partial tumor resection(more than80%),16cases partial(less than80%). All patients were pathologically diagnosed,3cases were glioma Ⅰ,8cases were glioma Ⅱ,13cases were glioma Ⅲ,13cases were glioma IV.3months after operation, the symptoms of6cases significantly improved,20cases improved,5cases unchanged,1cases worsen and5cases died. The followed-up time was1-25months, the average was8.2months. The KPS of patients at the last follow-up was that3cases was90-100,17cases was60-80,5cases was40-50, none case was10-30and12cases was0. The OS and PFS of6month was83.4%and59.1%respectively, and1year was65.0%and43.1%respectively.Conclusion:1. We used such conservative ways as radiotherapy, chemotherapy, biopsy and shunt to treat25thalamic glioma patients and got a comparatively well short effect. The OS and PFS of6month reached84.0%and56.0%respectively. The acute treatment reaction was moderate. But, the long effect was still unsatisfactory, the2year’s OS was only8.0%. So, on the premise that the patients’survival quality was well, how to combine with surgery, radiotherapy, chemotherapy and other treatments to promote thalamic glioma patients’curative effect will be the research direction in the near future.2. We used4different approaches to resect thalamic gliomas of37patients. The transcallosal ventricular approach was mainly adapted to those tumors were located on antero-middle, middle and bilateral of thalamus.Trans-superior parietal ventricle approach applied to tumors situated in mid-posterior, posterior of thalamus. Trans-frontal gyral approach applied to tumors lied in anterior, antero-middle of thalamus and translateral fissure insular approach applied to lateral thalamic tumors.3. We try our best to promote the resection rate(≥80%) on the premise that the normal neurological function was protected and received a comparatively ideal short effect. However, because of our cases were still increasing continuously, and the follow-up time of most patients will be gradually prolonged, the long effect of the surgery treatment of thalamic glioma needed a deeper research.