The Significance Of Interbed In Invasive Pituitary Tumors

Objective:Based on the evidence of pathology of dura which was suspicious of interbed,we confirm the existence of interbed.To explore the significance of interbed in the occurrence of the invasive pituitary adenomas,clinical data of 47 patients with pituitary tumor which discovered with interbed during operation were analyzed retrospectively.This study will provide certain theoretical basis in clinical diagnosis,preoperative predictions and approach selections.Methods:In this study,the dura(if the interbed was discovered during operation)specimen was obtained by the transsphenoidal approach,under the microscope,the relationship between the tumor and dura should be carefully observed and recorded.129 patients with pituitary tumors who underwent endoscopic endonasal surgery in the neurosurgery department of our hospital from January 2017 to December 2017 were included in this study.Data were collected in detail on age,sex,residence,work environment,education background,history of nasal disease and nasal medication.All patients available should be conducted the MRI head scans,CT examination,including the scails to the nasal cavity and the axial and coronal positions of paranasal sinuses,to understand the structure of the nasal cavity,the extent of sphenoid gasification and the situation of separation and its ymmetry,MRI scan was used to observe the shape size and the expansion direction of tumors.SPSS(version 21.0)was used for statistical analyses.Results:1.Of the 129 cases,46 cases can be defined invasive pituitary tumors before surgery and 47 cases were discovered interbed during surgery.2.47 cases discovered with interbed,32 cases with interbed appeared in the position of the anterior sella floor,while preoperative MRI imaging showed 18 casesof invasive pituitary tumors.12 cases with interbed appeared in the position of the inferior sella floor,5 cases with interbed appeared in the position of dorsum sellae.3cases with interbed appeared in the position of diaphragm sellar,while 2 cases with interbed appeared in the position of intercavernous sinus.On the basis of tatistics;the anterior sella floor has the most common rates,followed bythe inferior sella floor.The pituitary tumors can invade sphenoid sinus,clivus,cavernous sinus,intracranial lesions staged by interbed.3.the stages of interbed can be divided into 4 levels: 0 level: original tumor:tumor located in the sellar without invasion of dura and other lesions;grade 1: tumor breaks through the inner layer(meningeal dura).No invasion of outer layer(periosteal dura)layer,for the tumor grows between the meningeal dura and periosteal dura;grade 2: tumor breaks through the inner layer(meningeal dura),push the periosteal layer of dura and not to break the periosteum layer of dura,yet,tumor may invade the periosteum layer mater but didn’t break through the not to break the periosteum layer of dura,it may push the sellar bone or suprasellar without invasion,in that case,it may appear with daughter tumors;grade 3: tumor break the periosteal meningeal layer into other potential spaces or intracranial lesions,such as sphenoid sinus,clivus,cavernous sinus,intracranial lesions.4.Among the 47 cases of interbed,37 cases discovered residual pituitary during operation,and the interbed was located on the opposite or lower part of the residual pituitary.Conclusions:1.Interbed is the mechanism of invasive pituitary tumors invade other lesions.2.The existence of interbed can be diagnosed as Invasive pituitary adenomas.3.Where there is residual pituitary,there will be no interbed,the interbed is located on the opposite side or below of the residual pituitary.