Neuroendoscopic and microscopic transsphenoidal approach for resection of nonfunctional pituitary adenomas

BACKGROUND Nonfunctional pituitary adenoma is a common type of pituitary adenoma, which can lead to headache, visual field disturbance, and cranial nerve damage due to increased tumor volume. Neuroendoscopic and microscopic transsphenoidal approaches have been widely used in the resection of nonfunctional pituitary adenomas. However, the clinical efficacy in neuroendoscopic and microscopic surgery is still controversial. AIM To explore the clinical efficacy of neuroendoscopic and microscopic transsphenoidal approach for resection of nonfunctional pituitary adenomas. METHODS We retrospectively analyzed 251 patients with nonfunctional pituitary adenomas;138 underwent neuroendoscopic surgery via transsphenoidal approach, and 113 underwent microscopic surgery via transsphenoidal approach between July 2010 and September 2015. All patients were followed up for > 6 mo. Gender, age, course of disease, tumor diameter, tumor location, and percentage of patients with headache, visual impairment, sexual dysfunction, and menstrual disorders were contrasted between the two groups to compare the difference of preoperative data. Cure rate, symptom improvement rate, recurrence rate, the postoperative hospital stay, operating time, intraoperative blood loss, and the incidence of postoperative complications were compared in order to evaluate the advantages and disadvantages of neuroendoscopic and microscopic surgery.RESULTS There was no significant difference in cure rate, symptom improvement rate, and recurrence rate between neuroendoscopy group and microscopy group (82.6% vs 85.8%, P > 0.05;90.6% vs 93.8%, P > 0.05;5.1% vs 9.7%, P > 0.05). In the neuroendoscopy group, the postoperative hospital stay was 8.4 ± 0.6 d;operating time was 167.2 ± 9.6 min;intraoperative blood loss was 83.4 ± 9.3 mL, and the rates of diabetes insipidus and electrolyte imbalance were 4.3% and 8.0%, respectively. The corresponding results in the microscopic group were 11.2 ± 0.6 d, 199.7 ± 9.3 min, 138.8 ± 13.6 mL, and 32.7% and 20.4%, respectively. There were significant differences in postoperative hospital stay, operating time, intraoperative blood loss, and the rates of diabetes insipidus and electrolyte imbalance between the two groups (P < 0.05). CONCLUSION Neuroendoscopic and microscopic transsphenoidal approaches have similar clinical efficacy for the resection of nonfunctional pituitary adenomas. Neuroendoscopic surgery reduces operating time, intraoperative bleeding, postoperative recovery, and complications.

Degrees of Diaphragma Sellae Descent during Transsphenoidal Pituitary Adenoma Resection:Predictive Factors and Effect on Outcome

This study is aimed to classify degrees of diaphragma sellae (DS) descent into sella turcica according to the surgical field block caused by the descent and to construct predictive imaging criteria for the degree of descent,and in addition,to determine whether there is any correlation between the degree of DS descent and the operative outcome (in the form of cerebrospinal fluid leak and/or presence of residual tumor).Totally,72 patients were enrolled in our study.Their clinical and radiological data as well as the high definition videos of operations were retrospectively reviewed.The degree of DS descent during the operation was classified into five degrees according to surgical field block caused by the descent.We investigated the correlation between these five degrees and the clinical findings,radiological findings as well as the surgical outcomes.We found that the most important determining factors of DS descent degree were the volume and the height of the tumor portion above diaphragma opening.On the other hand,the total tumor volume,the maximum tumor height and the morphological pattern according to Wilson's system (modified from Hardy) had no statistically significant correlation with DS degree of descent.Presence of residual tumor on postoperative magnetic resonance images was significantly correlated with Wilson's classification and with supradiaphragmatic tumor height.On the other hand,cerebrospinal fluid leak showed no statistically significant difference between variable degrees of DS descent.Volumetric data of the tumor portion above the diaphragma opening are more important than morphological data for prediction of surgical field block caused by descended DS.While DS prolapse significantly increases the difficulty of the operative procedure,residual tumor presence is mainly dependent on morphological classification,especially cavernous sinus invasion.

Cerebral venous sinus thrombosis following transsphenoidal surgery for craniopharyngioma:A case report

BACKGROUND Cerebral venous sinus thrombosis(CVST)is a rare condition in patients with craniopharyngioma following transsphenoidal surgery.CASE SUMMARY A 56-year-old man who underwent transsphenoidal surgery for craniopharyngioma 26 d ago presented gradual headache and cerebrospinal fluid leakage while vomiting 5 d post-discharge and required readmission to our department of neurosurgery.After admission,head imaging examination showed a hyperdense shadow in the superior sagittal sinus and right transverse sinus,edema at the bilateral parietal lobe,and hemorrhage at the left parietal lobe and right occipital lobe;the venous phase of cerebral angiography revealed CVST.The patient was treated immediately by intravenous thrombolysis,endovascular thrombolysis,and mechanical thrombectomy after the definite diagnosis.However,the neurological status of the patient continued to deteriorate and he died on the fourth day after readmission.CONCLUSION For craniopharyngioma undergoing transsphenoidal surgery,it is vital to take an effective strategy to manage the postoperative complications,such as diabetes insipidus,severe electrolyte imbalance,and cerebrospinal fluid leakage.Additionally,the early differential diagnosis of CVST is essential when it develops clinical symptoms,especially in patients following transsphenoidal surgery with a high risk of CVST.Subsequently,the timely and effective treatment of the CVST is critical for preventing neurological deterioration.

Surgical Technique and Efficacy Analysis of Extra-pseudocapsular Transnasal Transsphenoidal Surgery for Pituitary Microprolactinoma

Objective To elucidate the role of transsphenoidal surgery in the treatment of pituitary microprolactinoma.Methods The clinical data of 107 prolactinoma cases treated by extra-pseudocapsular transnasal transsphenoidal surgery(ETTS)for different indications in our department since 2011 was retrospectively analyzed.Results The most common indication was the ineffectiveness of oral medication(41.1%),followed by the personal willingness of the patient(35.5%),and 20.6%of the patients were young women with clear tumor boundaries.The pseudocapsule was not observed in 63 cases(58.9%),incomplete pseudocapsule was observed in 26 cases(24.3%),and complete pseudocapsule in 18 cases(16.8%).A total of 97 patients(90.7%)obtained 1-year post-operation remission.According to the relative location of the adenoma and pituitary gland on the MRI scan,46 patients were classified into a central type,59 a lateral type,and 2 a supra-pituitary type.Two patients developed hypogonadism,one patient developed hypocortisolism,and one patient developed post-operative hypothyroidism.Two patients were administrated with hormone replacement treatment,and the treatment was stopped within one week.There was no permanent hypopituitarism.Further investigation demonstrated that the adenoma types could affect the remission rates of hyperprolactinemia and gross total resection rate in microprolactinoma.Conclusion ETTS was an effective treatment for pituitary microprolactinomas.This could be the first choice for patients who presented enclosed adenoma on the MRI and were potentially curable in a preoperative evaluation.Maximal safe removal of the adenoma by ETTS with the aim to increase the sensitivity of the drugs was also recommended for patients with invasive dopamine agonist resistant prolactinomas and patients with difficulty in childbirth.

Extra-pseudocapsular Transnasal Transsphenoidal Resection of Pituitary Macroadenoma:Technique Note and Evaluation of Endocrine Function

Objective In this study,we investigated the surgical technique and endocrine assessment of pituitary function of patients with macroadenoma treated by extra-pseudocapsular transnasal transsphenoidal surgery(ETTS).Methods Clinical data of 144 patients with pituitary macroadenomas in the same surgical group at the Department of Neurosurgery,Tongji Hospital,Tongji Medical College,Huazhong University of Science and Technology were retrospectively analyzed from January 2019 to June 2021.Based on the results of the endocrinological evaluation and MRI examinations before and after surgery,the fluctuation of pituitary function and the extent of resection were analyzed.Multiple Logistic regression analysis was used to determine the predictors affecting postoperative tumor residual.Results Among the 144 patients with pituitary macroadenomas,72(50.0%)were female and 72(50.0%)were male,the median age was 50 years,26(18.1%)had invasiveness grade 0,46(31.9%)had grade I,57(39.6%)had grade II,and 15(10.4%)had grade III according to Lu’s classification method.Based on observation during surgery,37 cases(25.7%)had no pseudocapsule,54 cases(37.5%)had incomplete pseudocapsule,and 53 cases(36.8%)had intact pseudocapsule.In addition,91(63.2%)patients had total resection,39(27.1%)had subtotal resection,and 14(9.7%)had partial resection.As for anterior pituitary function,13 of 19 hypothyroid patients had recovery after surgery,with a remission rate of 68.4%.Eighteen of the 26 decreased cortisol patients got back to normal,with a remission rate of 69.2%.A total of 27 of 51 patients with hypogonadism improved,with a remission rate of 52.9%.Univariate and multivariate analyses indicated that gender,tumor size,and invasiveness were predictors of postoperative residual in patients(P<0.05).Conclusion The results showed that ETTS is an effective treatment modality for restoring the function of pituitary gland of the patients with macroadenomas.Tumor size and invasiveness are predictors of the extent of surgical resection and postoperative residual of macroadenomas.

Transsphenoidal Surgery for Secreting Pituitary Microadenomas: Results with Intraoperative Application of Absolute Alcohol

Background: Pituitary adenomas represent a quite frequent neurosurgical disease. Secreting pituitary adenomas are represented by PRL, GH, ACTH and TSH tumours;the rate of postoperative hormonal recurrence is not ineligible. Methods: We present 106 patients affected by secreting pituitary microadenomas operated through transsphenoidal approach from 1998 through to 2008;in 54 (group 1) patients, intraoperative absolute alcohol was applied, while in the other 52 (group 2) it was not employed. The indications and the intraoperative technique of absolute alcohol application are presented. Hormonal recurrence was treated by hypofractionated stereotactic radiotherapy and/or medical therapy. Results: Postoperative hormonal and clinical remission was achieved in 50 and 47 patients respectively of group one and group two. At the first follow-up control, after 3 months from surgery, no patient of both groups presented hormonal/clinical recurrence. Six months after surgery, no patient of group one presented hormonal recurrence, while two patients of group 2 presented hormonal recurrence. After 2 years from surgery, two patients of group 1 and 4 patients of group 2 presented hormonal recurrence. Three years after operation, hormonal hypersecretion recurred in three patients of group one and in six patients of group 2. At 5 years follow-up, six patients of group one and 8 of group two presented hormonal recurrence. Conclusions: Intraoperative application of absolute alcohol, in selected cases, resulted useful to achieve better results in secreting pituitary microadenomas concerning both postoperative hormonal recurrence and hormonal persistence.

Acute Obstructive Hydrocephalus Caused by <i>Pseudomonas</i><i>aeruginosa</i>Ventriculitis after Transsphenoidal Surgery: Case Report

Pseudomonas aeruginosa (P. aeruginosa) frequently causes various infections, some of which are serious and require prompt medical detection and appropriate antibiotic selection. Although P. aeruginosa commonly exists within the nasal cavity, meningitis or ventriculitis following transsphenoidal surgery to relieve P. aeruginosa has been reported only occasionally. However, as the endoscopic transnasal approach is more widely utilized for the suprasellar lesions, nosocomical P. aeruginosa infection associated with cerebrospinal fluid (CSF) leakage becomes more common in patients with panhypopituitarism who undergo transsphenoidal surgery. We report a case of a 36-year-old man with an intrasellar craniopharyngioma presenting with an acute obstructive hydrocephalus caused by P. aeruginosa ventriculitis following transsphenoidal surgery. Treatment with optimal antibiotics was initiated immediately after P. aeruginosa was recognized as the pathogen, and was continued for 3 months. After removal of the infected fascia and fat graft used for the closure of CSF leakage and sellar floor reconstruction, endoscopic third ventriculostomy was successfully performed to treat the obstructive hydrocephalus induced by the occlusion of the fourth ventricle outlet, resulting in a positive outcome. Although the obstructive hydrocephalus caused by P. aeruginosa is extremely rare, prompt detection and appropriate treatment should be required once P. aeruginosa ventriculitis happens.

Endoscopic Transsphenoidal Surgery for Pituitary Adenoma. Early Experience in Sohag University Hospitals

Objective: To report the results of our first series of patients undergoing a purely endoscopic endonasal approach for pituitary surgery in Sohag University Hospitals. Patients and Methods: We reviewed 20 consecutive patients during the period from January 2017 to January 2020 with pituitary adenoma who underwent purely endoscopic transsphenoidal resection of their lesions. The patients’ clinical outcomes, degrees of tumor removal, and complications were reported. Results: There were 18 primary and 2 recurrent adenomas (19 nonfunctioning and 1 functioning GH secreting adenoma). The average degree of gross total removal for tumors was 70%, C.S.F leak occurred in 20%, diabetes insipidus in 10% and sellar hemorrhage in 5%. There was no post-operative mortality, vascular injury, sphenoiditis, septal perforation, epistaxis or general complication. Conclusion: A purely endoscopic approach for pituitary adenoma treatment is a safe and effective alternative to the traditional microscopic procedure.

The Use of Neuronavigation with Vasular Microdoppler in Transsphenoidal Pituitary Surgery

Object: To evaluate the use of neuronavigation with vascular micro-doppler in transsphenoidal pituitary surgery. Methods: 141 cases having done transsphenoidal pituitary surgery are evaluated from 2005 to 2014. Fluoroscopy was used in 69 cases and vascular micro-doppler with neuronavigation were used in 72 cases. Results: Transsphenoidal surgery has a lot of risks due to sella’s deep location, and position of the carotid artery and the optic nerve. Clasically the fluoroscopy and microscopic anatomical markers were used in order to minimize the risk of carotid artery and optic nerve damage. Additional devices such as neuronavigation and vascular micro-doppler are needed to decrease the morbidity and mortality arising from these injuries. Conclusion: Neurovascular complications such as carotid artery and optic nerve injuries owing to disorientation in transsphenoidal surgery will reduce the use of neuronavigation with vascular micro-doppler.

Transsphenoidal pituitary surgery with one endonasal incision and modified repairation of sella floor

Objective To study the advantage of modified methods involving incision,repairation of the sella floor etc.in transsphenoidal approach for pituitury tumor removal.Methods The transsphenoidal approach with one endonasal incision of mucosa was performed for resecting pituitary tumor in 86 patients,of which total resection of the tumor in 67 cases and subtotal in 19 cases.Results There was no case with postoperative meningitis and rhinoseptal perforation.Tachocombs were used for repairation of the tumor resection cavection cavity and the sella floor,of which there was no case with postoperative CSF leakage happened.Conclusion These modified methods simplified operative procedurej Areduced damage and prevented postoperative complications of CSF leakage and rhinoseptal perforation etc.

Effect of Single Nostril Transsphenoidal Resection of Pituitary Adenoma under Neuroendoscope on Hospitalization Time and Bleeding Volume in Patients with Pituitary Adenoma

Objective:This study mainly discusses the clinical effect of treating pituitary adenoma by using single nostril transsphenoidal resection of pituitary adenoma under neuro-endoscope,and analyzes the influence on hospitalization time and bleeding volume.Methods:A total of 335 patients with pituitary adenoma treated in our hospital from January 2017 to January 2019 were randomly selected for study.The patients were divided into two groups by number table method.167 patients in the reference group underwent single nostril transsphenoidal resection of pituitary adenoma under microscope.Also,168 patients in the study group underwent single nostril transsphenoidal resection of pituitary adenoma under neuroendoscope.The hospitalization time and bleeding volume and other surgical treatment effects were observed and compared.Results:There was no significant difference in the levels of prolactin(PRL),adrenocorticotropic hormone(ACTH)and thyroid stimulating hormone(TSH)between the two groups before operation(P>0.05);After surgical treatment,the levels of PRL,ACTH and TSH in the study group were lower than those in the control group(P<0.05);In terms of surgical indexes,the operation time and hospital stay in the study group were shorter than those in the reference group,and the amount of surgical bleeding was less than that in the reference group(P<0.05);The total tumor resection rate in the study group was higher than that in the reference group,and the incidence of complications such as nasal septal defect,cerebrospinal fluid leakage and diabetes insipidus in the study group was lower than that in the reference group(P<0.05).Conclusion:For pituitary adenoma diseases,using single nostril transsphenoidal resection of pituitary adenoma under neuroendoscope can improve the tumor resection rate,reduce the bleeding volume and shorten postoperative hospitalization time.

The causes and prevention and treatment of cerebrospinal fluid leak during transsphenoidal pituitary adenomas surgery

Objective To analyze the causes and prevention and treatment of cerebrospinal fluid leak during transsphenoidal pituitary adenoma surgery. Methods Retrospective study of 260 cases of microscopic transsphenoidal surgery and 274 cases of endoscopic surgery for resection of the pituitary adenomas was performed. CSF leak occurred

Analysis of complications of transsphenoidal surgery for pituitary adenomas

Objective To analyze the complications of transsphenoidal operation for pituitary adenomas. Methods Postoperative complications of 323 patients underwent transphenoidal surgery for pituitary adenoma between January 2001 and December 2009 in our department were retrospectively reviewed. Results Insipidus was the most common complication after

Complications's prophylaxis in neuroendoscopic endonasal transsphenoidal surgery for pituitary adenomas

Objective To discuss the complicatiaons’s prophylaxis of removing pituitary adenomas by neuroendoscopy in tranasphenoidal surgery. Methods Clinical data of 253 cases treated by endoscopic endanasal transsphenoidal surgery were analysed. Results The total tumor removal was done in 216 (85.38%) cases,subtotal in

Transsphenoidal microsurgical operation for pituitary adenomas with suprasellar extensions

Objective: To evaluate the feasibility and therapeutic effectiveness of the transsphenoidal microsurgical removal of pituitary adenomas with suprasellar extensions. MethodS: We reviewed the diagnosticmodes, surgical technique, and outcomes of 152 patients suffering from pituitary adenomas with suprasellarextensions who were treated by transsphenoidal microsurgery in our department. Diagnosis was confirmed byCT or MRI scanning. All tumours with diameter >10 mm were characterized by suprasellar extensions. Op.erations were performed via either sublabio-septo-sphenoidal approach or naso-vestibulo-sphenoidal approachunder microscope. A subarachnoid catheter was preoperatively inserted in the lumbar cistern, through whichsaline was slowly injected during operation to increase the intracranial pressure (ICP) so as to deliver thesuprasellar tumour into the operative field to aid the removal. Result: Of the 152 cases, the gross total removal of adenoma in 106 cases (69. 7% ) and subtotal removal in 37 cases (24. 4% ) were achieved, and partial removal was carried out in the remaining 9 cases (5. 9 % ) of fibrous or dumbbell-shaped adenomas. Therewere no deaths after operation in this group. Follow-up review (median 3. 5 years) in 137 patients revealedgood recovery in 97 patients (70. 8% ), and late recurrence in 40 patients (29. 2% ) who need reoperativemanagement, drug therapy, radiotherapy, or radiosurgery used either alone or combined. Conclusion: Microsurgical technique via transsphenoidal approach is a safe and effective way to remove the pitoitary adenomas with suprasellar extensions but not for fibrous or dumbbell-shaped ones.

Transsphenoidal surgery for prolactinomas in male patients:a retrospective study

Male patients with prolactinomas usually present with typical hyperprolactinemia symptoms,including sexual dysfunction and infertility.However,clinical factors related to sexual dysfunction and surgical outcomes in these patients remain unclear.This study aimed to investigate the outcomes of male patients with prolactinomas after transsphenoidal surgery and the risk factors affecting sexual dysfunction.This study was conducted on 58 male patients who underwent transsphenoidal surgery for prolactinomas between May 2014 and December 2020 at the First Affiliated Hospital of Sun Yat-sen University,Guangzhou,China.We evaluated the sexual function of patients before and after surgery through International Index of Erectile Function-5 scores,libido,and frequency of morning erection.Of the 58 patients,48(82.8%)patients had sexual intercourse preoperatively.Among those 48 patients,41(85.4%)patients presented with erectile dysfunction.The preoperative International Index of Erectile Function-5 scores in patients with macroprolactinomas were significantly higher than those in patients with giant prolactinomas(17.63±0.91 vs 13.28±1.43;P=0.01).Postoperatively,the incidence of erectile dysfunction was 47.9%,which was significantly lower than that preoperatively(85.4%;P=0.01).Twenty-eight(68.3%)patients demonstrated an improvement in erectile dysfunction.Tumor size and invasiveness were significantly correlated with the improvement of erectile dysfunction.Preoperative testosterone<2.3 ng ml^(-1)was an independent predictor of improvement in erectile dysfunction.In conclusion,our results indicated that tumor size and invasiveness were important factors affecting the improvement of sexual dysfunction in male patients with prolactinoma.The preoperative testosterone level was an independent predictor related to the improvement of erectile dysfunction.

Predictors and dynamic online nomogram for postoperative delayed hyponatremia after endoscopic transsphenoidal surgery for pituitary adenomas:a single-center,retrospective,observational cohort study with external validation

Background Postoperative delayed hyponatremia(PDH)is a major cause of readmission after endoscopic transsphenoidal surgery(eTSS)for pituitary adenomas(PAs).However,the risk factors associated with PDH have not been well established,and the development of a dynamic online nomogram for predicting PDH is yet to be realized.We aimed to investigate the predictive factors for PDH and construct a dynamic online nomogram to aid in its prediction.Methods We analyzed the data of 226 consecutive patients who underwent eTSS for PAs at the Department of Neurosurgery in Jinling Hospital between January 2018 and October 2020.An additional 97 external patients were included for external validation.PDH was defined as a serum sodium level below 137 mmol/L,occurring on the third postoperative day(POD)or later.Results Hyponatremia on POD 1-2(OR=2.64,P=0.033),prothrombin time(PT)(OR=1.78,P=0.008),and percentage of monocytes(OR=1.22,P=0.047)were identified as predictive factors for PDH via multivariable logistic regression analysis.Based on these predictors,a nomogram was constructed with great discrimination in internal validation(adjusted AUC:0.613-0.688)and external validation(AUC:0.594-0.617).Furthermore,the nomogram demonstrated good performance in calibration plot,Brier Score,and decision curve analysis.Subgroup analysis revealed robust predictive performance in patients with various clinical subtypes and mild to moderate PDH.Conclusions Preoperative PT and the percentage of monocytes were,for the first time,identified as predictive factors for PDH.The dynamic nomogram proved to be a valuable tool for predicting PDH after eTSS for PAs and demonstrated good generalizability.Patients could benefit from early identification of PDH and optimized treatment decisions.

Complications of transsphenoidal surgery for sellar region： intracranial vessel injury

Background Intracranial vessel injury is a severe complication of transsphenoidal surgery （TSS） for lesions of sellar region. The purpose of this study was to improve recognition of the complication. Methods The clinical data of 400 cases of TSS for sellar region from 1964 to 2004 were reviewed retrospectively. Ten patients with complications of intracranial vessel injury were included in this study, 7 underwent transsphenoidal microsurgery and 3 underwent endoscopic TSS. Subarachnoid hemorrhage （SAH） occurred in 8 cases, hemorrhage of cavernous sinus in one, and post-operative cerebral hemorrhagic infarction caused by thrombosis of injured right internal carotid artery in one. The clinical data of all the patients were analyzed. Results The SAH resulted from hemorrhage of residues of tumor in 2 patients and from damaged sellar and arachnoidea in 6 patients. The cause of hemorrhage of anterior intercavernous sinus was malformation of anterior intercavernous sinus. The reason of thrombus of internal carotid artery was manipulation of operation. Three patients died and six patients were cured. One patient lived with hemiplegia. Conclusions The cause of intracranial vessels injury of TSS is complicated. Detailed anatomic knowledge of seller and skilled operation is helpful to reduce the complication.

Prospective study of transsphenoidal pituitary surgery： is tumor volume a predictor for the residual tumor？

Background The presence of residual tumor after surgery for pituitary adenoma may necessitate further treatment. The suprasellar and parasellar extension of the tumor have been widely considered as the predictors for residual tumor. However there is scarcity of studies regarding the preoperative tumor volume and residual tumor. This study was conducted to evaluate if tumor volume could predict the outcome of transsphenoidal pituitary surgery. Methods A prospective study was designed and 48 patients who underwent transsphenoidal pituitary surgery within 1 year in the First Affiliated Hospital of Xi＇an Jiaotong University were included in this study. The preoperative tumor volume and immediate postoperative tumor volume （within 4-7 days） were calculated in the contrast magnetic resonance imaging by using the formula of ellipsoid. All these volumes were divided into three subgroups, i.e. group 1, group 2 and group 3 with preoperative volume of less than 4 cm3, 4-8 cm3, and more than 8 cm3 respectively. The parasellar and suprasellar extension of the tumor were also classified by Knosp and modified Hardy＇s classifications. Results Baseline characteristics were comparable. The preoperative tumor volume of more than 8 cm3 （group 3, （12.1±1.1） cm3） had increased risk on postoperative tumor residue （P 〈0.01） than the other two groups （（2.1±0.3） cm3 and （6.1±0.3） cm3 in groups 1 and 2）. The mean postoperative volume in group 3 patients （（2.2±0.1） cm3） was significantly higher than the other two groups （P 〈0.01）. Conclusion Preoperative volume of more than 8 cm3 can be considered as a predictor for postoperative residual volume.

Transsphenoidal approach to pituitary adenoma： surgical technique of the Peking Union Medical College Hospital

Although presented over one hundred years ago, the transsphenoidal approach to pituitary adenoma is still the most suitable and safe route to pituitary adenoma, with a series of significant evolutional steps. The transsphenoidal approach to pituitary adenoma is still a non-universal approach used in different centers of different areas in our country. The transsphenoidal approach has a number of variations, including the endonasal rhinoseptoplastic, transnasal displacement,