Anatomy Study Of Extended Transsphenoidal Operation Approach

ObjectivesThis experiment mainly through anatomic study to explore the characteristics ofexpanded transsphenoidal operation approach. Mainly includes the characteristicsunder microscope anatomic of extended transsphenoidal operation approach. To makeclear of microscopic structure and the relationship between sella region andparasellaregion. To establish an anatomic basis for clinical application of this anatomystudy.Materials and MethodsEight(sixteen sides) human cadaver heads, in which the common carotid arteryand the vertebral artery were injected with red latex,the internal jugular vein wasinjected with blue latex.Two injected adult cadaveric heads were sectionedlongitudinally and coronally respectively, taken photograph and studied by microscope,six specimens were resected with microscope through simulated classic transsphenoidalapproach. The extention of the surgical exposure in version of microscope to theanterior skull base, the cavernous sinus(CS) and clivus.The anatomic observation andmeasurements were abtained. To observe the microscope characteristics of the sellaregion and parasellar region and their relationships.Results1. The sphenoidal ostium was determined by the spinous shape of anteriorsphenoidal wall under microscopy.2. Sphenoidal sinus was the most important structure in this transnasal-sphenoidalapproach. The most common and certain anatomic landmarks in the posterior bony wallof sellar-type sphenoidal sinus was clival indentation, which is the certain landmark toidentify the sellar floor.3. Anterior ethmoidal artery was a landmark to identify ethmoid roof and frontalrecess. Posterior ethmoidal artery was a landmark to determine optic prominence. 4. The distance between superior margin of sphenopalatine foramen and lowerborder of sphenoidal ostiumis11.55mm±2.41mm (9.14-13.94mm). There is a sharpprotuberant microsclere whose size is about3.5mm×4.1mm.It is an anatomic landmarksto determine sphenopalatine foramen.5. The cavernous internal carotid artery can be divided into five segments. Theoptico-carotid recess is the landmark for the midline definition during operation throughmicroscopy. The optico-carotid recess is located between carotid prominence which isformed on the lateral wall of sphenoidal sinus and optic prominence. According to needof intraoperative to increases operative field exposure of lateral or inferior lateralexpansion.Conclusion1. Sellar and parasellar region are a complicated anatomic structure. Overallprehension and be familiar with the anatomic study of the sellar and parasellar regioncan provide the operation basis of the extended transsphenoidal approach.2. The posterior nasal septal artery and the nasal cavity haemorrhage have themost intimate relationships. The posterior nasal septal artery was injured easily duringthe sphenoidal ostium enlargement.3. The hemorrhage of anterior intercarvenous sinus can be decreased greatly if thediscission place of the sellar floor dura below the sellar floor slightly. The style of duradiscussion and haemostasis should be choiced rationally.4. There have no bone protection on the surface of internal carotid artery in lesscases, so internal carotid artery can be damaged and caused hemorrhage when treatmentinappropriately.5. Sphenoid sinus anterior region has a direct effect on field exposure of extendedtranssphenoidal operative approach. The window range of Sphenoid sinus anteriorarea is the key to exposure the superior wall、 inferior wall、 lateral wall of sphenoidsinus.6. Extended transsphenoidal approach extending the direction to both sides of thecavernous sinus,Open medial wall of cavernous sinus can reveal cavernous segment ofinternal carotid artery and its branches and the cranial nerves,In the region ofintraoperative prone to injury the internal carotid artery and the abducens nerve,Posterior ethmoid sinus has a direct effect on the exposure field extendedtranssphenoidal operative approach. Resection of ethmoid sphenoid sinus on the rear,can increase the lateral region of the operative field exposure, Can be used for the treatment of cavernous sinus invasion.7. Extended transsphenoidal approach extending in the direction of the saddle toskull base, can reveal optic nerve and optic chiasma, supraclinoidal segment of internalcarotid artery and the anterior communicating artery. Tuberculum sellae and sieve thetrailing edge of the effective safety operation range should be not more than1.5cm. Canbe used for the treatment of localized to the saddle, the anterior skull base growthlesions.8. Extended transsphenoidal approach can extended into the direction of the slope,pons, medulla oblongata, revealed basilar artery and its branches. The slope of grindingwidth less than20mm can effectively protect the nerve vascular structure. Can be usedfor the treatment of invasive, the slope of the lesions.