Recent Evolution of Endoscopic Endonasal Surgery for Treatment of Pituitary Adenomas

Headache in patients with non-functioning pituitary adenoma before and after transsphenoidal surgery - a prospective study

PURPOSE

To study the long-term effect of transsphenoidal surgery (TSS) on headache in patients with non-functioning pituitary adenoma (NFPA) and identify factors predicting headache relief following TSS.

METHODS

We evaluated headache in 101 consecutive patients with NFPA who underwent TSS from September 2015 to December 2021, preoperatively and 12-months post-surgery, by using the Migraine Disability Assessment (MIDAS) questionnaire. Health-related quality of life (QoL) was assessed using the EQ-5D visual analogue scale (EQ-VAS).

RESULTS

Of 101 patients, 27 (27%) experienced disabling preoperative headache. Among these, the median total MIDAS score improved from 60 (interquartile range (IQR): 19-140) to 10 (IQR: 0-49) (P = 0.004). Additionally, headache frequency over a 90-day period decreased from 45 (IQR: 25-83) to 6 (IQR: 3-36) days (P = 0.002), and headache intensity decreased from 5 (IQR: 4-7) to 4 (IQR: 2-7) (P = 0.016) at 12-months post-surgery. At 12 months post-surgery, 18 (67%) of 27 patients with preoperatively disabling headache showed clinically relevant improvement of their headache, 4 (15%) showed deterioration, and 5 (19%) remained unchanged. In patients with clinically relevant improvement of their headache, the EQ-VAS score improved from 50 (IQR: 30 - 7) to 80 (IQR: 65-86) (P < 0.001). Of the 74 patients with no preoperative headache, 11 (15%) developed postoperative headache. We identified no clinical factors predicting postoperative headache relief.

CONCLUSION

The study supports that clinically significant and long-lasting improvements of disabling headache and QoL can be achieved with TSS in a substantial number of patients with NFPA.

Predicting the Consistency of Pituitary Macroadenomas: The Utility of Diffusion-Weighted Imaging and Apparent Diffusion Coefficient Measurements for Surgical Planning

Understanding the consistency of pituitary macroadenomas is crucial for neurosurgeons planning surgery. This retrospective study aimed to evaluate the utility of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) as non-invasive imaging modalities for predicting the consistency of pituitary macroadenomas. This could contribute to appropriate surgical planning and therefore reduce the likelihood of incomplete resections. The study included 45 patients with pathologically confirmed pituitary macroadenomas. Conventional MRI sequences, DWIs, ADC maps, and pre- and post-contrast MRIs were performed. Two neuroradiologists assessed all of the images. Neurosurgeons assessed the consistency of the tumor macroscopically, and histopathologists examined it microscopically. The MRI findings were compared with postoperative data. According to the operative data, macroadenomas were divided into the two following categories based on their consistency: aspirable (n = 27) and non-aspirable tumors (n = 18). A statistically significant difference in DWI findings was found when comparing macroadenomas of different consistencies (p < 0.001). Most aspirable macroadenomas (66.7%) were hyperintense according to DWI and hypointense on ADC maps, whereas most non-aspirable macroadenomas (83.3%) were hypointense for DWI and hyperintense on ADC maps. At a cut-off value of 0.63 × 10-3 mm2/s, the ADC showed a sensitivity of 85.7% and a specificity of 75% for the detection of non-aspirable macroadenomas (AUC, 0.946). The study concluded that DWI should be routinely performed in conjunction with ADC measurements in the preoperative evaluation of pituitary macroadenomas. This approach may aid in surgical planning, ensure that appropriate techniques are utilized, and reduce the risk of incomplete resection.

Treatment outcomes of neuroendoscopic and microscopic trans-sphenoidal pituitary adenomectomies and the effects on hormone levels

BACKGROUND

We aimed to compare the treatment outcomes of neuroendoscopic and microscopic trans-sphenoidal pituitary adenomectomies, as well as the effects on hormone levels and clinical symptoms.

METHODS

A total of 82 patients with pituitary adenomas that were surgically resected from June 2018 to March 2021 were selected and divided into a group receiving neuroendoscopic trans-sphenoidal pituitary adenomectomy (group A, N.=40), and the other group receiving microscopic surgery (group B, N.=42). Surgery-related indices, hormone levels before discharge and alleviation of symptoms 24 weeks after surgery were compared.

RESULTS

Both groups had significantly different degrees of tumor resection (P<0.05). The proportion of cases receiving total adenomectomy in group A significantly exceeded that of group B (P<0.05). The surgical time of group A was significantly longer than that of group B (P<0.05). Group A had significantly shorter mean hospitalization stay than that of group B (P<0.05). The postoperative hormone levels of both groups decreased significantly differently (P<0.05). Before discharge, the hormone recovery rate of group A significantly surpassed that of group B (P<0.05). The hormone levels of cases with prolactinoma, adrenocorticotropic hormone adenoma and growth hormone adenoma in group A dropped more significantly than those of group B did (P<0.05).

CONCLUSIONS

Compared with microscopic surgery, neuroendoscopic trans-sphenoidal pituitary adenomectomy worked more effectively, induced fewer postoperative complications and better promoted the postoperative recovery of hormone levels.

Endoscopic endonasal approach for acromegaly: surgical outcomes using 2018 consensus criteria for remission

Objective

The primary aim is to analyze the endoscopic endonasal surgical results in short-term and two-year follow-ups according to the 11th Acromegaly Consensus statement (2018). Indeed, prognostic factors and complications were analyzed.

Subjects and methods

40 patients who underwent endoscopic endonasal surgery by acromegaly between 2013 to 2020 was analyzed. Patients were considered in remission if an upper limit of normal (ULN) IGF-1 was less than 1.0 at the six-month and two-year follow-ups. Moreover, we assessed the Knosp grade, tumor volumetry, ULN, T2 signal in MRI, reoperation, and complications.

Results

The mean age of admission was 46.7 years. Thirty-two patients were in remission after six months of surgery (80%), decreasing to 76.32% at the two-year follow-up. All microadenomas presented remission (n = 6). Regarding the complications, three patients had permanent panhypopituitarism (7.5%); postoperative cerebrospinal fluid (CSF) leaks did not occur in this series. The hyperintense signal on the T2 MRI and a higher tumor volumetry were the single predictor's factors of non-emission in a multivariate regression logistic analysis (p < 0.05). Preoperative hormone levels (GH and IGF-1) were not a prognostic factor for remission. The re-operated patients who presented hypersignal already had a high predictor of clinical-operative failure.

Conclusion

The endoscopic endonasal surgery promotes high short-term and two-year remission rates in acromegaly; the tumor's volumetry and the T2 hypersignal were statistically significant prognostic factors in non-remission - the complications presented at similar rates in comparison to the literature. In invasive GH-secreting tumors, we should offer these patients a multi-disciplinary approach to improve acromegalic patients' remission rates.

Sinonasal Outcome After Endoscopic Transnasal Surgery-A Prospective Rhinological Study

BACKGROUND

The sinonasal outcome after transnasal skull base surgery has often been neglected aside from major outcome criteria as extent of tumor resection, ophthalmological, and endocrinological parameters.

OBJECTIVE

To analyze rhinological outcome after endoscopic transnasal neurosurgery.

METHODS

Patients were treated using a middle turbinate-preserving transnasal endoscopic approach for sellar/parasellar lesions. As major variables, olfactory function and nose breathing ability were assessed. The study participants were investigated by odor testing ("Sniffin' sticks"), rhinomanometry, and endoscopic inspection of the nasal cavity before and 6 months after surgery. Furthermore, sinonasal-associated quality of life was measured before, immediately and 6 months after surgery with a standardized questionnaire (SNOT-20-GAV).

RESULTS

Eighty-two patients (47 male, 35 female, median age 55 years) matched the inclusion criteria. Before surgery, the average odor was found to be 30.75 (≥31 = normosmia); in the postinterventional examination at 6 months, the average increased to 33.08 (n.s.). Rhinomanometric examination of binostril nasal airflow showed an average of 590.42 mL/s on inspiration before and an increase to 729.78 mL/s at 6 months after surgery. SNOT-20 symptom scores had a maximum score right after and no difference at 6 months after surgery (scores 23.76 and 14.91 vs 15.53 before surgery).

CONCLUSION

Based on the study, the endoscopic transnasal technique preserving the middle turbinate has no significant negative effects on the rhinological outcome.

Effects of Staged Nursing Care on Neuroendoscopic Transsphenoidal Pituitary Adenoma Resection and Postoperative Complications

Objective

The purpose of this study was to determine whether staged nursing had an impact on the outcome of neuroendoscopic transsphenoidal pituitary tumor resection and postoperative complications.

Methods

As research participants, we chose 88 individuals with pituitary adenomas who were treated at our institution between February 2020 and November 2021; all patients received endoscopic transsphenoidal pituitary adenoma excision. The patients were randomly divided into two groups: the routine group (n = 44) and the stage group (n = 44). Patients in the routine group received care according to the routine nursing mode, and patients in the stage group received care according to the stage nursing mode. The staged nursing interventions included preoperative, intraoperative, and postoperative nursing. Postoperative recovery-related indicators such as the self-rating anxiety scale (SAS) and a self-rating depression scale (SDS), contentment, comfort, and postoperative complications were compared between the two groups.

Results

The postoperative recovery-related indexes of patients in the stage group were significantly lower than those in the routine group (P < 0.05); the SAS and SDS scores in the stage group after treatment were significantly lower than those in the routine group (P < 0.05); patients in the stage group were significantly more satisfied with their treatment after treatment than those in the routine group (P < 0.05); patients in the stage group were significantly more comfortable after treatment than those in the routine group (P < 0.05); a significantly lower incidence of postoperative complications was observed in the stage group compared to the routine group (P < 0.05).

Conclusion

Patients with neuroendoscopic transsphenoidal pituitary tumor excision benefit greatly from staged nursing. The nursing approach may successfully assure the procedure's smooth completion, boost patients' postoperative recovery, and reduce patients' worry, despair, and other unpleasant feelings. The nursing approach may successfully increase clinical satisfaction and comfort of patients by minimizing the likelihood of postoperative problems, and it is well-suited for practical use.

Endoscopic transsphenoidal surgery for resection of pituitary macroadenoma: A retrospective study

BACKGROUND

The endoscopic transsphenoidal approach is an efficient minimally invasive procedure for removal of pituitary tumors that can be accomplished through a one-hand or two-hand approach. The one-hand procedure through one nostril is more intuitive for surgeons, but maneuvering the instruments can be restrictive. The two-hand procedure using a one-and-half nostril approach provides more precise manipulation. This study aimed to compare the surgical outcomes of one-hand/mono-nostril and two-hand/one-and-half nostril surgeries for resection of large pituitary tumors by a single neurosurgeon.

MATERIALS AND METHODS

The surgical data of 78 consecutive cases with pituitary macroadenoma (diameter >1 cm) were reviewed retrospectively. Altogether, 30 cases received one-hand/mono-nostril surgery, while 48 cases received two-hand/one-and-half nostril surgery. Postoperative outcomes of the two operations were compared.

RESULTS

The operative time, hospital stay, residual rate of pituitary macroadenoma, visual field, surgical complications, and re-operative rates were slightly improved in the two-hand/one-and-half nostril surgery group compared with that in the one-hand/mono-nostril surgery group (all p>0.05). However, postoperative hypopituitarism was less frequent (1/48; 2.0%) with the two-hand/one-and-half nostril approach than with the mono-nostril approach (p = 0.004). Similar surgical outcomes were found in all patients with either small or large pituitary tumors, except that the difference in postoperative improvement in visual field change reached statistical significance (p = 0.044).

CONCLUSION

A single-surgeon endoscopic endonasal transsphenoidal surgery with two-hand/one-and-half nostril approach is an effective and safe procedure for removal of large pituitary tumors.

Endoscopic Endonasal Approach for Giant Pituitary Adenoma Occupying the Entire Third Ventricle: Surgical Results and a Review of the Literature

BACKGROUND

Pituitary macroadenomas occasionally disrupt the sellae diaphragma and extend directly to the third ventricle causing hydrocephalus. We present the results of a single-stage extended endoscopic approach for managing giant pituitary adenomas (GPAs) occupying the entire third ventricle.

METHODS

A retrospective study of all GPAs occupying the entire third ventricle operated on via the endoscopic endonasal approach between January 2016 and December 2020 was performed.

RESULTS

The study included 8 cases of GPA occupying the entire third ventricle, of which 2 (25%) were functioning adenomas. Of 8 patients, 4 (50%) presented with hydrocephalus, 2 underwent preoperative ventriculoperitoneal shunt, and 2 had an intraoperative external ventricular drain. No patients had postoperative cerebrospinal fluid rhinorrhea. Complete resection of the third ventricular component could be achieved in all cases radiologically; minimal residual tumor was present either in the lateral compartment of the cavernous sinus or over the anterior cerebral artery complex in 5 of 8 (62.5%) patients. Complete resolution of temporal hemianopia was seen in 8 of the 12 eyes (66.67%), and partial resolution was seen in 4 of 12 (33.3%) eyes. At a mean follow-up of 24.62 ± 10.01 months, none of the patients needed another surgical procedure.

CONCLUSIONS

The extended endonasal endoscopic approach can be safely and efficiently used for single-stage excision of GPAs that disrupt the diaphragm and occupy the third ventricle. Preoperative cerebrospinal fluid diversion may be used to manage associated acute hydrocephalus in these cases.

The Challenges in Neurosurgery Training in a Third World Country

BACKGROUND

Neurosurgery in Pakistan is an advanced field with significant challenges. The training program tests one's endurance, knowledge, empathy, and dedication. The training structure in Pakistan consists of 5 years, of which 2 years are spent in general surgery followed by 3 years of dedicated neurosurgery. This study aimed to conduct a survey to address the quality of neurosurgery training in Pakistan so that its strengths and deficiencies could be identified, recommendations could be made, and actions could be taken toward improvement.

METHODS

A nationwide survey was conducted of neurosurgery residents from all over Pakistan. An e-mail invitation was sent to 177 neurosurgery residents certified by the College of Physicians and Surgeons Pakistan from 22 institutes in all provinces of Pakistan. The questionnaire was divided into the following sections: sociodemographics of participants, infrastructure of training site, clinical skills training and exposure, and knowledge-based education. Data were collected through Google Forms and analyzed using statistical software.

RESULTS

A total of 151 residents responded to the survey. More than half of the institutes had >10 neurosurgery residents in their department (59.6%). More than half of the residents did not attend any international conference during their residency (51%). More than one fourth of the residents did not participate in any hands-on workshop during their residency tenure.

CONCLUSIONS

The neurosurgical training program in Pakistan requires updating of the curriculum with better implementation. These data will help the College of Physicians and Surgeons Pakistan in standardizing neurosurgical training across Pakistan to improve competence among trainees.

Crisis Management Simulation: Review of Current Experience

Crisis management simulation is important in training the next generation of surgeons. In this review, we highlight our experiences with the cavernous carotid injury model. We then delve into other crisis simulation models available for the neurosurgical specialty. The discussion focuses upon how these trainings can continue to evolve. Much work is yet to be done in this exciting arena and we present several avenues for future discovery. Simulation continues to be an important training tool for the surgical learner.

Trends in endoscopic and microscopic transsphenoidal surgery: a survey of the international society of pituitary surgeons between 2010 and 2020

PURPOSE

This comparative survey of surgical practice patterns between 2010 and 2020 aims to elicit trends in practice patterns for transsphenoidal surgery and to identify areas for improvement.

METHODS

Web-based surveys were sent to the International Society of Pituitary Surgeons via a membership listserv in 2010 and 2020. These 33-item surveys collected information on demographics, surgical approach, perceived advantages and disadvantages, and recommendations for improvements. Statistical analyses were conducted using the Mann-Whitney U test for continuous variables and Fisher's exact test for categorical variables.

RESULTS

There were 51 respondents in 2010 and 82 respondents in 2020. The majority were full-time academic surgeons from the United States or Europe. Preference for a purely endoscopic technique increased from 43% in 2010 to 87% in 2020. Preference for routinely working with an otolaryngologist or second neurosurgeon increased from 35 to 51%. Most surgeons (74%) reported that they were more likely to achieve a greater extent of resection with the endoscope, though 51% noted increased operating time. The most commonly rated advantage (34%) of endoscopic TSS was fewer postoperative nasoseptal perforations; the most commonly (34%) rated disadvantage was more postoperative complications, including cerebrospinal fluid leak. Respondents were divided on whether microscopic TSS should continue to be taught in residency. Many (32%) advocated for improved endoscopic instrumentation and team training.

CONCLUSION

Endoscopic TSS is now the clearly preferred method for surgery amongst a cohort of higher-volume academic neurosurgeons. This trend is likely to continue, and this provides guidelines for future training.

Challenges, Learning Curve, and Safety of Endoscopic Endonasal Surgery of Sellar-Suprasellar Lesions in a Community Hospital

BACKGROUND AND OBJECTIVE

Endoscopic endonasal surgery (EES) for the management of sellar, suprasellar, and anterior skull base lesions is gaining popularity. Our aim was to analyze and present the clinical outcomes of EES for the management of these lesions in a community hospital setting.

METHODS

We retrospectively reviewed the charts of 56 patients with sellar, suprasellar, and anterior skull base lesions who underwent EES between 2010 and 2018.

RESULTS

There was male predominance (53.6%) with a mean age of 54.9 ± 13.7 years. Lesions were 45 pituitary adenomas, 5 meningiomas, 3 metastatic, 1 craniopharyngioma, 1 Rathke cyst, and 1 mucocele. Gross total excision was achieved in 57.1%, subtotal excision occurred in 37.5%, and decompression and biopsy were achieved in 5.4% patients. Postoperative vision normalized or improved in 27 patients (86.1%) and was stable in 4 patients (13.9%). Recovery of a preexisting hormonal deficit occurred in 13 (23.2%) patients, and a new hormonal deficit occurred in 9 patients (16.1%). The mean hospital stay was 6.1 ± 4.9 days. Postoperative complications included cerebrospinal fluid leak in 8 patients (14.3%). Four patients (7.1%) had meningitis. Diabetes insipidus was present in 19 patients (33.9%), and postoperative intracranial hematoma requiring evacuation was necessary in 2 patients (3.6%). The mean follow-up duration was 47.5 ± 25.8 months. Lesion progression or recurrence requiring redo surgery occurred in 5 patients (8.9%). Regarding the learning curve, the postoperative cerebrospinal fluid leak, meningitis, new hormonal deficits, and diabetes insipidus decreased in the second half of the patients.

CONCLUSIONS

EES provides an effective and safe surgical option with low morbidity and mortality for the treatment of sellar, suprasellar, and anterior skull base lesions in a community hospital setting.

Transnasal Transsphenoidal Approach for Pituitary Tumors: An ENT Perspective

Endoscopic transnasal transsphenoidal (ETNTS) approach was first described in 1992 and is standard approach for the resection of benign pituitary adenomas. This prospective study aims in incidence and preoperative assessment of extent of the pituitary adenoma, peroperative findings of transnasal transsphenoidal excision, techniques of skull base repair, complications and its management in a tertiary centre. A prospective analysis from Jan 2017 to May 2019, of patients undergoing ETNTS approach of pituitary adenomas was made in terms of incidence in various age-groups, type of adenoma, operative findings including CSF leak, repair of the skull base defect, complications encountered and its management was done in a tertiary care centre and compared with the present literature. A total of 141 patients underwent ETNTS, with highest number of cases found in 41-50 years age-group with mean age of 42.6 years. Male: Female ratio was 1.6. Macroadenoma was in 123 patients while 18 had microadenoma, of these 63.74% were functional adenoma, highest of GH secreting, while 36.26% were non-functional. Mean surgical time was 98.4 min ± 21.2 min. Peroperative CSF leak was in 30.5% cases in various grades. Closure techniques included use of fat, multilayer techniques, Hadad's flap and gasket technique as per the type of CSF leak. Neurological and rhinological complications were 6.38% each. This study is focused on the ENT perspective of the endoscopic transnasal trans-sphenoidal approach for pituitary adenomas. The reduced rate of morbidity and complications is encouraging. The endoscopic skull base defect closure is challenging and requires skill, meticulous approach and synchronised team work in order to achieve a favourable outcome. The incidence of CSF leak can be minimised and if encountered has to be dealt in an organised manner, thus contributing to a reduced rate of complications. The complications encountered must be foreseen and managed with a proficient approach.

Pituitary surgery's epidemiology using a national inpatient database in Japan

BACKGROUND

Between 2010 and 2014, microscopic transsphenoidal surgery (mTSS) was performed more frequently than endoscopic TSS (eTSS) in the USA. However, few epidemiological studies on pituitary surgery are currently available.

METHODS

We performed a retrospective study on patients who had undergone pituitary surgery between July 2010 and March 2016. To this end, a nationwide inpatient database in Japan was used. Patients' characteristics, diagnoses, types of surgery, complications, and discharge status were examined.

RESULTS

A total of 16,253 inpatients who received pituitary surgery were identified. Patients were diagnosed with diseases for insurance claims described below: pituitary adenoma, hyperprolactinemia, other pituitary disorders (e.g., Rathke's cleft cyst), hyperpituitarism, craniopharyngioma, acromegaly, Cushing's disease, and pituitary cancer. Among them, pituitary adenomas, primarily the non-functioning ones, were the most frequent (66.9%). A total of 14,285 (88%) patients underwent TSS, while 1968 (12%) patients were treated using transcranial surgery. The number of patients undergoing TSS increased each year. The number of eTSS operations was 8140 (77%) and that of mTSS operations was 2419 (23%). Of note, eTSS increased each year. We found that high-volume hospitals more frequently selected eTSS. Compared with mTSS, eTSS was associated with a reduction of hyponatremia incidence (odds ratio, 0.69; p = 0.019). Additionally, it was not associated with other major complications.

CONCLUSION

The present study showed that both TSS and eTSS increased on a yearly basis. We believe that the present study will be the basis of future epidemiological investigations of pituitary surgery.

The role of multimodal navigation in endoscopic endonasal surgery for giant pituitary adenomas

Background

Giant pituitary adenoma (GPA) (diameter >40 mm) remains challenging to treat, and the radical resection rate is low. The intraoperative multimodal navigation is sometimes used in endoscopic endonasal surgery (EES). However, the effect of this technique on GPA surgical outcomes is not clear. This study aims to explore the surgical and clinical outcomes of the navigation used in EES for GPA.

Methods

A retrospective review of 60 consecutive patients with GPA who underwent EES was performed. The total resection rate, residual volume, clinical outcomes, and complications were compared. Factors associated with tumor gross total resection (GTR) were analyzed by multinomial logistic regression analysis.

Results

There were 31 patients in the standard group in which intraoperative multimodal navigation was not used, with a mean maximum tumor diameter of 5.21±1.24 cm; meanwhile, there were 29 patients in the navigation group, in which navigation was used, with a mean maximum tumor diameter of 5.32±1.18 cm. GTR was achieved in 10 patients (32.26%) in the standard group, which was significantly lower than that in the navigation group (18/29=62.07%). The residual volume was 7.93±10.78 cm³ in the standard group which was significantly greater than that in the navigation group (2.44±1.26 cm³, P=0.046). There was no significant difference between the two groups in terms of cerebrospinal fluid (CSF) leak, new pituitary deficit, and postoperative diabetes insipidus (DI). The higher Knosp grade of tumor, lobulated configuration and lack of intraoperative multimodal navigation use were relative risk factors associated with the GTR.

Conclusions

The intraoperative multimode navigation appeared to be safe and effective when used in EES for GPA with higher GTR and lower residual tumor volume.

Use of Artemis Neuro Evacuation Device in Resection of Pituitary Adenoma: Initial Technical Note

BACKGROUND

Endoscopic transsphenoidal resection has become the primary approach for resection of pituitary macroadenomas. However, challenges such as narrow sinuses, dense tumor consistency, and invasion of surrounding structures exist.

METHODS

We report a case in which the Artemis Neuro Evacuation device was used to endonasally remove a pituitary macroadenoma with suprasellar and parasellar extensions. The methodology and technical aspects of this device's novel use are illustrated.

RESULTS

The long and narrow wand of the Artemis system allowed the operators to navigate through patient's narrow sinuses. Despite a dense tumor that did not come easily into a suction, the entire tumor debulking procedure lasted <10 minutes with the preservation of an intact arachnoid membrane using the Artemis. No perioperative complication was encountered, and the patient's neurologic deficits resolved.

CONCLUSIONS

To the authors' knowledge, this represents the first reported case of the Artemis system's utility in the treatment of pituitary tumor beyond cranial hematoma and hemorrhage.

The Predictive Role of Intraoperative Visual Evoked Potentials in Visual Improvement After Endoscopic Pituitary Tumor Resection in Large and Complex Tumors: Description and Validation of a Method

BACKGROUND

With the advent of extensive endoscopic approaches for pituitary tumors, there has also been an increase in surgery for larger and more complex tumors. Intraoperative manipulation during endoscopic resection of sellar tumors poses potential risk in postoperative visual function in this tumor population. This study proposes a method of accurate intraoperative monitoring of visual evoked potentials (VEPs) and its role in predicting visual function outcomes.

METHODS

Intraoperative VEPs were monitored for 42 resections from a single surgical team, with average tumor size of 2.84 cm. Changes in VEP amplitude and latency in excess of 50% were considered significant. Preoperative and postoperative visual information was obtained from ophthalmology and hospital records, along with patient demographics, comorbidities, and tumor characteristics.

RESULTS

Patients were stratified as experiencing deteriorations in VEPs that did not restore to baseline (n = 4), deteriorations in VEPs that did restore to baseline (n = 6), no change in VEPs (n = 31), and improvement in VEPs (n = 1). Correlation between VEP changes and postoperative visual fields was measured through univariate ordered logistic regression. Improved intraoperative VEP measurements were associated with odds ratio (OR) of visual field improvement of 3.15 (95% confidence interval, 1.15-8.59). Specifically, changes in VEP amplitude were positively associated with visual field improvement with OR of 4.35 (OR, 1.29-14.7). No association was observed between VEPs and other patient or tumor characteristics.

CONCLUSION

Changes in VEP amplitude during endoscopic sellar tumor resection correlate with postoperative visual function. Intraoperative VEP monitoring can serve an important role in preventing postoperative visual field loss.

Nonfunctioning Pituitary Adenoma Recurrence and Its Relationship with Sex, Size, and Hormonal Immunohistochemical Profile

BACKGROUND

Tumor recurrence or incomplete resection in nonfunctioning pituitary adenomas (NFPAs) is relatively common. However, predictive factors of tumor recurrence in NFPAs are not well established. We evaluated possible factors related to tumor recurrence in a large cohort of NFPAs at a single pituitary neurosurgery center.

METHODS

A retrospective analysis was conducted of 410 medical records of patients with NFPAs treated by transsphenoidal surgery between 2000 and 2014.

RESULTS

Among the participants, 210 were female (51.0%). A total of 14.1% had giant adenomas. Null-cell pituitary adenomas (n = 239; 58.9%) were the most frequent, followed by silent gonadotroph adenomas (n = 112; 27.3%). Null-cell adenomas were more frequent in women (P = 0.008) and silent gonadotroph adenomas were more frequent in men (P = 0.004). Recurrence was not related to sex or age. Tumor recurrence occurred more often among silent corticotropic adenomas and giant adenomas (hazard ratio 2.45; P < 0.0001 and hazard ratio 2.35; P = 0.001, respectively). Silent thyrotrophic adenoma presented a comparable frequency of recurrence of silent corticotropic adenomas, despite having borderline significance (P = 0.07).

CONCLUSIONS

NFPA tumors have a high heterogeneous hormonal profile and may have prognostic importance. Silent corticotropic adenomas and giant adenomas present a high rate of recurrence.

Bibliometric Analysis of Journals in the Field of Endoscopic Endonasal Surgery for Pituitary Adenomas

Endoscopic endonasal surgery for pituitary adenomas is being performed more frequently worldwide in the recent years. This first bibliometric analysis was conducted aiming to have a microscopic view of research activities about endoscopic endonasal surgery for pituitary adenomas. The original articles about endoscopic endonasal surgery for pituitary adenomas were extracted from the Web of Science (WoS) and analyzed concerning their distributions. We also explored the potential correlations between publications of different countries and their gross domestic product (GDP) via Pearson correlation test. The total number of original articles retrieved from WoS was 307 from 1997 to 2017. The number of original articles published in the last decade has increased by 530.95% compared with that published in the former decade. The United States has published 124 articles (40.391%), followed by Italy with 40 (13.029%) and Japan with 27 articles (8.795%). The journal that published the highest number of original articles was Journal of Neurosurgery with 31 (10.098%), followed by Neurosurgery (n = 23, 7.492%), World Neurosurgery (n = 23, 7.492%), and Neurosurgical Focus (n = 15, 4.886%). There was a strong correlation between publication numbers and GDP of different countries (r = 0.889, P < 0.001). There is a skyrocket trend of endoscopic endonasal surgery for pituitary adenomas during the last 2 decades, and countries with high GDP tend to make more contributions to this field.

Anesthesia for minimally invasive neurosurgery

PURPOSE OF REVIEW

With an ultimate aim of improving patients overall outcome and satisfaction, minimally invasive surgical approach is becoming more of a norm. The related anesthetic evidence has not expanded at the same rate as surgical and technological advancement. This article reviews the recent evidence on anesthesia and perioperative concerns for patients undergoing minimally invasive neurosurgery.

RECENT FINDINGS

Minimally invasive cranial and spinal surgeries have been made possible only by vast technological development. Points of surgical interest can be precisely located with the help of stereotaxy and neuronavigation and special endoscopes which decrease the tissue trauma. The principles of neuroanethesia remain the same, but few concerns are specific for each technique. Dexmedetomidine has a favorable profile for procedures carried out under sedation technique. As the new surgical techniques are coming up, lesser known anesthetic concerns may also come into light.

SUMMARY

Over the last year, little new information has been added to existing literature regarding anesthesia for minimally invasive neurosurgeries. Neuroanesthesia goals remain the same and less invasive surgical techniques do not translate into safe anesthesia. Specific concerns for each procedure should be taken into consideration.

The learning curve for endoscopic trans-sphenoidal resection of pituitary macroadenomas. A single institution experience, Leeds, UK

BACKGROUND

The object of this study was to assess whether increasing operative experience results in greater endoscopic trans-sphenoidal resection of pituitary macroadenomas and lower complications.

METHODS

A retrospective single institution cohort study was performed. Subjects underwent endoscopic trans-sphenoidal resection of pituitary macroadenoma between July 2009 and July 2016 by three neurosurgeons. Following data collection, statistical analysis compared percentage of tumor resection and length of hospital stay (LOS) with experience. Complications including CSF leak are reported.

RESULTS

In total, 142 patients (87 male, 55 female) mean age 55.1 were included. Surgeon 1 performed 106 cases; surgeon 2 performed 23 cases; and surgeon 3 performed 13 cases. Mean pre-operative tumor volumes were 8.18 cm³, 6.52 cm³, and 3.47 cm³ and post-operative volumes were 2.21, 1.74, and 1.93 cm³ for surgeons 1, 2, and 3, respectively. Respective percentage resections were 74.3, 77.2, and 52.1%. Analysis demonstrated no difference in tumor resection with increasing experience for all three surgeons (p = 0.11, p = 0.17, and p = 0.26). Tumor consistency and cavernous sinus involvement did not appear to affect tumor resection. Mean LOS was 5 days, 4 days, and 3 days, respectively, with no significant correlation with experience for all three surgeons. Intraoperative CSF leak incidence was 19/106 (18%) for surgeon 1, 6/23(26%) for surgeon 2, and 2/13(15%) for surgeon 3. Primary closure rate was 96.3% and only three other complications occurred.

CONCLUSIONS

This study demonstrates that in our institution there is no statistically significant learning curve for the endoscopic resection of pituitary macroadenoma. However, there is a trend of improvement in tumor resection with experience for one surgeon. These findings suggest that the surgeons in our institution were capable of performing this procedure effectively with a low complication rate since adoption of the endoscopic technique in 2009.