Microscopic And Endoscopic Anatomy Study Of Extended Transsphenoidal Approach And Clinical Application

ObjectivesThe goles in this study were to investigate the characteristics of extended transsphenoidal approach through the anatomic study. The characteristics include the anatomic parameter and characteristics under microscopic and ensoscopic.To make clear of microscopic structure and the relationship between sella region and parasella region. To establish an anatomic basis for clinical application of this anatomy study.Materials and MethodsTwelve(twenty-four sides) human cadaver heads, in which the common carotid artery and the vertebral artery were injected with red latex ,the internal jugular vein was injected with blue latex.Two injected adult cadaveric heads were sectioned longitudinally and coronally respectively, taken photograph and studied by microscope, ten specimens were resected with endoscopy thropugh simulated classic transsphenoidal approach. The extention of the surgical exposure in version of endoscopy to the anterior skull base, the cavernous sinus(CS) and clivus.The anatomic observation and measurements were abtained. To observe the endoscopic characteristics of the sella region and parasellar region and their relationships.Results1. Sphenoethmoid recess and posterior nasal aperture were the landmarks to determine sphenoidal ostium. The sphenoidal ostium was determined by the spinous shape of anterior sphenoidal wall under microscopy.2. Anterior ethmoidal artery was a landmark to identify ethmoid roof and frontal recess. Posterior ethmoidal artery was a landmark to determine optic prominence.3. The distance between superior margin of sphenopalatine foramen and lower border of sphenoidal ostium is 11.81mm±2.61mm(8.23-16.86mm).There is a sharp protuberant microsclere whose size is about 3.0mm×4.0mm.It is an anatomic landmarks to determine sphenopalatine foramen.4. Sphenoidal sinus was the most important structure in this transnasal-sphenoidal approach. The most common and certain anatomic landmarks in the posterior bony wall of sellar-type sphenoidal sinus was clival indentation, which is the certain landmark to identify the sellar floor.5. The cavernous internal carotid artery can be divided into five segments and three vessal branchs. The optico-carotid recess is the landmark for the midline definition during operation through endoscopy. The optico-carotid recess is located between carotid prominence which is formed on the lateral wall of sphenoidal sinus and optic prominence.6. The cavernous sinus could be exposed clearly through transnasal-sphenoidal approach. The medial wall of the cavernous sinus lateral to the pituitary gland is only a thin dura. The cavernous internal carotid artery is the most important structure in the cavernous sinus of extended transsphenoidal approach. The distance between the media edge of the anterior bend of cavernous internal carotid artery and the midline of pituitary gland is 11.94mm±1.90mm(9.02mm-14.86mm), the distance between the media edge of the posterior bend and the midline of pituitary gland is 7.96mm±2.07mm(5.64mm-11.58mm).Conclusion1. Sellar and parasellar region are a complicated anatomic structure. Overall prehension and be familiar with the anatomic study of the sellar and parasellar region can provide the operation basis of the extended transsphenoidal approach.2. The posterior nasal septal artery and the nasal cavity haemorrhage have the most intimate relationships. The posterior nasal septal artery was injured easily during the sphenoidal ostium enlargement.3. To determine the location of the sphenoidal ostium by anatomic landmark during operation is the first mission and abide by median line approach strictly.The bilateral carotid prominences and optic-carotid recesses are the landmark to determine median line under endoscopy during operation.4. The important anatomic landmark of transnasal-sphenoidal approach can be determined through endoscopic prominence and recess which were formed in the basilar region,which can also guide the correct direction of operation.Such as the common and certain anatomic landmarks in the posterior bony wall of sellar-type sphenoidal sinus is clival indentation, which is the certain landmark to identify the sellar floor.5. The hemorrhage of anterior intercarvenous sinus can be decreased greatly if the discission place of the sellar floor dura below the sellar floor slightly. The style of dura discussion and haemostasis should be choiced rationally.6. There have no bone protection on the surface of internal carotid artery in less cases, so internal carotid artery can be damaged and caused hemorrhage when treatment inappropriately. ObjectivesThe purpose of this article is to summarize the clinical experience of 117 patients with invasive pituitary adenoma underwent surgery via extended transsphenoidal approach at the Neurosurgical Department of Peking Union Medical College Hospital in Beijing. To study the feasibility and value of the extended transsphenoidal approach to invasive pituitary adenoma and make the technique into a clinical method of pituitary adenoma.MethodsBetween September 1999 and March 2007, 117 patients with invasive pituitary adenoma underwent surgery via extended transsphenoidal approach at the Neurosurgical Department of Peking Union Medical College Hospital in Beijing. The clinical data and follow-up of this series were retrospectively analyzed.The skills of tumors resection during operation were investigated and the therapeutic effects were analyzed.ResultsThere were 49 male and 68 female.The patients ranged in age from 12 to 75 years (mean age is 43.9 years).The disease course ranged from three days to twenty-five years.The average is 42.3 monthes.The clinical manifestations includes 60 cases of visual descend, 96 cases of field of vision disorder,39 cases of menstruation confusion or amenorrhea,13 cases of lactation. 10 cases has hypopituitarism before operation. Somatostatin was applicated in 3 cases before operation. Bromocriptine was applicated in 11 cases,while cabergoline was applicated in 1 case.This series included 77 macroadenomas (diameter of neoplasm is 1 - 4cm) and 40 giant adenomas (diameter of neoplasm is greater than 4cm).Among them, 14 adenomas extended anteriorly to the anterior cranial base, 103 laterally to the cavernous sinus,27 posteriorly to the clivus, and 45 inferiorly to the sphenoidal sinus.57 adenomas involved multiple direction structures. Total tumor removal was achieved in 73 cases, subtotal removal in 40, and partial removal in 4 cases. There was no perioperative mortality. Transient postoperative complications included 7 cases of CSF fistulae, 5 cases of partial cranial nerve palsy. 5 cases developed acute panhypopituitarism,in which lcase needed hormone replaced all his life. Permanent neurological complications included 2 cases of carotid artery injury, 2 cases of monocular blindness, one case of permanent diabetes insipidus.None of patient dead. 19 patients were treated with postoperative common radiotherapy. 15 patients underwent gamma knife treatment. 25 patients received medicine treatment. The follow-up period ranged from 3 months to 8 years. The tumor recurred in two patients and then was treated with gamma knife. No patient needed re-operation.Conclusion1. The extended transsphenoidal approach has been proved to be the first choice to remove the invasive pituitary adenomas, which has less trauma and the coincidence time of patients is shorter than transcranial approach.2. The application of neuroendoscopy during operation can decrease the "dead area" which cannot be seen under microscopy. Expecially, the using of angled endoscopy can decrease the residual of neoplasm and decrease recurrence rate.3. The application of neuro-navigation during operation can decrease the operation complications,especially for those that the development of sphenoid sinus was unsuitable or patients who experienced twice operations.4. The endocrinology healing of functioning pituitary adenoma remained a tough problem.5. Take important in dealing with water ,electrolyte and hormone balance or disturbance during operation.6. The treatment of invasive pituitary adenoma is a multiple-department cooperation task and required close follow-up. Medicine treatment and radiotherapy are comprehensive treatments for invasive pituitary adenomas to decrease neoplasm recurrence.