The slope of the learning curve in 600 consecutive endoscopic transsphenoidal pituitary surgeries

Neurocognitive Safety of Endoscopic Colloid Cyst Resection: Paired Pre- and Post-Operative Cognitive Function from an Exploratory Cohort

OBJECTIVE

Resection of colloid cysts, a rare third ventricle pathology, is accepted clinical practice. Owing to their location proximal to deep gray nuclei and forniceal columns, colloid cysts have been theorized to contribute to cognitive decline. Comprehensive pre- and post-operative cognitive testing, however, has rarely been implemented.

METHODS

We analyzed formal neuropsychological testing performed in 20 patients undergoing endoscopic cyst resection. Pre- and post-operative performance was compared either for each individual patient or according to aggregated neuropsychological factor scores grouped via expert census. A change in performance was deemed significant if (i) it reached statistical significance and (ii) was greater than 1.5 pre-operative standard deviations.

RESULTS

Twenty patients with colloid cysts (average diameter 13.3 ± 1.3 mm) underwent matched pre- and post-operative testing. No patient had a significant change in cognitive performance. Neurocognitive metrics assessing cognitive functions typically subsumed by the temporal (p = 0.35), extratemporal (p = 0.20), occipitoparietal (p = 0.31), or frontal lobes (p = 0.11) did not change post-operatively. Similarly, no differences emerged when factor scores were generated according to composite scores of different neurocognitive domains: attention (p = 0.32), executive function (p = 0.14), language (p = 0.98), and visuospatial function (p = 0.42).

CONCLUSIONS

Neuropsychological testing allows for the careful monitoring of cognitive status before and after surgery and for the identification of patients who may benefit from pre- and post-operative cognitive rehabilitation. It should also be used as a valuable surgical psychometric marker and adjuvant. No significant cognitive decline was observed in this cohort.

Single Center Neurosurgical Outcomes and Trends in Endoscopic Endonasal Resection of 297 Sellar/Suprasellar Tumors Stratified by Duration of Neurosurgical Career

BACKGROUND/OBJECTIVE

Endoscopic endonasal transsphenoidal surgery (EETS) is a common treatment for sellar and suprasellar tumors. While endoscopic training has improved over the years and formal fellowship training is now broadly available, the operative nuances of EETS conjectures the existence a learning curve as a neurosurgeon matures with experience. We aim to evaluate operative outcomes of 3 different experience levels of neurosurgeons over time at a single institution.

METHODS

We reviewed all adult patients who underwent EETS at Loyola University Medical Center by 3 early career, 1 midcareer, and 2 late career neurosurgeons from 2007 to 2023. A comparative assessment of patient demographics, tumor features, and surgical outcomes was done using metrics such as length of surgery, rates of gross total resection (GTR) and symptomatic improvement, new postoperative steroid dependence, and development of diabetes insipidus (DI). T-tests and χ2 were used to statistically evaluate the study cohorts.

RESULTS

A total of 297 patients underwent EETS. One hundred three (35%) were operated on by an early career, 122 (41%) by a mid-career, and 72 (24%) by a late career neurosurgeon. Late-career surgeons had shorter operation times (144 vs. 180 minutes with early and mid-career, P = 0.029) and increased GTR rates (P = 0.008). There were no significant differences between the symptomatic improvement rates amongst various surgeon experience levels. Although not statistically significant, early-career neurosurgeons had lower rates of new postoperative steroid dependence. Patients of early career surgeons experienced significantly less DI (15% vs. 40%, P = 0.004).

CONCLUSIONS

Late-career neurosurgeons had shorter operation lengths, achieved higher rates of GTR, and their patients experienced significantly higher rates of DI. Overall outcomes remained stable throughout the course of 16 years between different surgeon experience levels.

3 Tesla intra-operative MRI as an adjunct to endoscopic pituitary surgery: an early assessment of clinical utility

BACKGROUND

Extent of resection is a major determinant of outcomes following pituitary surgery. Intra-operative magnetic resonance imaging (iMRI), provides an immediate assessment of the extent of resection, allowing further tumour resection during the same procedure. However, such systems are expensive and significantly increase operative time, prompting some authors to question the additional benefit conferred by iMRI when combined with endoscopy. Our aim was to assess the impact of combining 3 T iMRI with endoscopy in patients with pituitary tumours.

METHODS

We retrospectively reviewed a prospectively maintained database to identify patients who underwent iMRI guided endoscopic resection of pituitary tumours between May 2017 and November 2018 (iMRI cohort). This cohort was compared with a pre-iMRI cohort of patients who underwent endoscopic resection of pituitary adenomas. Operative time, extent of resection, control of endocrine disease and post-operative complications were recorded and analysed.

RESULTS

Thirty-seven patients were included in each cohort. iMRI facilitated additional tumour resection in 6/37 (16%) of cases. In 4/37 cases (11%), iMRI prompted a return to theatre but no further tumour could be identified. The overall GTR rate, following iMRI was 24/37 (65%) as compared to 21/37 (57%) in the pre-iMRI cohort. Cure of endocrine disease associated with hormonally active tumours was achieved in 9/11 (82%) of cases in the iMRI cohort. The mean operative time in the iMRI cohort was 327 minutes (five hours 27 minutes).

CONCLUSIONS

3 T iMRI provides immediate identification of residual tumour following endoscopic pituitary surgery. This allows for resection of surgically accessible residual disease during the same procedure and is likely to reduce the requirement for later re-intervention. However, the use of iMRI in this setting is associated with significant resource allocation issues which must be considered prior to the widespread adoption of this technique.

Central diabetes insipidus (vasopressin deficiency) after surgery for pituitary tumours: a systematic review and meta-analysis

OBJECTIVE

Central diabetes insipidus or vasopressin deficiency (AVP-D) is the most frequent water balance disorder after transsphenoidal surgery (TSS) with variable prevalence amongst studies. We aimed to determine rates of newly developed transient or permanent AVP-D in patients with pituitary tumours treated with TSS.

DESIGN AND METHODS

We performed systematic review of Medline, Embase, and Cochrane Library between January 1, 2000 and January 31, 2021 for studies reporting on outcomes for pituitary adenoma, craniopharyngioma, and Rathke's cleft cyst (RCC) after TSS and providing definition of post-operative AVP-D. We pooled the results as proportions with 95% confidence intervals (CIs) using Freeman-Tukey transformation random effects meta-analysis.

RESULTS

From 11 694 studies, 51 were included. Rates of transient or permanent AVP-D were: 17% (95% CI, 13-21) and 3% (95% CI, 2-5) in total group, 16% (95% CI, 12-21) and 2% (95% CI, 2-3) in pituitary adenomas, 31% (95% CI, 24-39) and 30% (95% CI, 22-39) in craniopharyngiomas, and 35% (95% CI, 16-57) and 14% (95% CI, 6-23) in RCCs, respectively. Based on diagnostic criteria, rates of transient or permanent AVP-D were: For hypotonic polyuria, 14% (95% CI, 8-22) and 3% (95% CI, 1-4), for hypotonic polyuria and hypernatraemia, 21% (95% CI, 13-29) and 5% (95% CI, 2-11), and for desmopressin administration, 22% (95% CI, 15-29) and 9% (95% CI, 0-30), respectively.

CONCLUSIONS

Following TSS, a small proportion of patients with pituitary adenoma have permanent AVP-D (2%), but prevalence reaches 30% in ones with craniopharyngioma and 14% in those with RCC. Diagnostic criteria for post-operative AVP-D remain variable affecting reported rates of this condition.

Endonasal endoscopic surgery for pituitary adenomas

Pituitary adenomas are slow-growing, benign intracranial tumors that can be characterized as functional (hormone-producing) or non-functional (non-hormone producing). Symptoms therefore arise from either endocrinologic abnormalities or mass effect on surrounding structures resulting in symptoms such as visual impairment and headache. In the last two decades, technical innovations have shifted surgical resection of such adenomas to endoscopic endonasal approaches. In this review, we describe the evolving approach to pituitary adenomas in the modern endoscopic era, including preoperative multidisciplinary review, relevant surgical anatomy, and a description of the technical nuances of standard and expanded approaches to the anterior skull base.

The Learning Curve for Endoscopic Endonasal Transsphenoidal Pituitary Surgery: Evaluating Endocrine Outcomes

OBJECTIVE

In South Australia endoscopic endonasal approach (EEA) pituitary surgery has been practiced since 2006, largely by two neurosurgeons with a small fellowship-trained otolaryngology team. The aim of this cohort study was to determine if a "learning curve" can be established over this time period, as represented by structural and endocrine patient outcomes.

METHOD

Retrospective cohort study of patients undergoing EEA surgery between 2006 and 2021 in Adelaide, South Australia at three tertiary teaching hospitals.. Cases were divided by each surgeon and split into groups of sequential 40 cases. Endocrine assessment pre- and post-operatively involved static pituitary and end-organ hormones, with dynamic tests as required, assessed by an pituitary endocrinologist. Each hormonal axis (gonadal, cortisol, thyroid, prolactin and growth hormone) was documented preoperatively and at an early and long term follow up at 1-2 and 12 months, respectively.

RESULTS

The study included a cohort of 443 pituitary adenomas managed with endoscopic endonasal transsphenoidal surgery in a consecutive fashion between two neurosurgeons over 16-years. Gross tumour resection but not visual visual outcomes improved with surgical experience but this outcome may be neurosurgeon dependent. Endocrine outcomes were not consistently improved with experience, but lower rates of hypopituitarism were seen with experience with one neurosurgeon. Average follow up was approximately 5 years, and a minimum follow up of 12 months for all patients.

CONCLUSIONS

We present long term endocrine follow up for patients with functional and non-functional adenomas. Improved rates of gross tumour resection were evident with with surgical experience. However, there was no apparent change in post-operative endocrine outcomes.

Exposure of the Cavernous Sinus via the Endoscopic Transorbital and Endoscopic Endonasal Approaches: A Comparative Study

OBJECTIVE

To compare the endoscopic transorbital approach (ETOA) and endoscopic endonasal approach (EEA) in terms of cavernous sinus (CS) exposure.

METHODS

Four cadaveric heads (8 sides) were dissected. The CS was accessed using the EEA and ETOA. Stereotactic measurements of the length of the main structures exposed, angles of attack, depths of surgical corridor, and areas of exposure were obtained and compared between the approaches. An illustrative case is also presented.

RESULTS

The endoscopic transorbital approach (ETOA) exposed the lateral and superior compartments of the CS without obstruction by the internal carotid artery (ICA). The EEA exposed all compartments after mobilizing the ICA. Both approaches enabled similar exposure of the cranial nerves. The depth of surgical corridor was significantly shorter with the ETOA (P < 0.01). The areas of lateral compartment exposure were similar. As the number of instruments placed into the surgical channel increased, the available angles of attack with the ETOA became smaller and were smaller than those of the EEA. In the clinical case presented, the tumor was successfully removed without complications.

CONCLUSIONS

The ETOA has the advantages of a sterile surgical channel, short operation time, little patient trauma, short surgical corridor, large exposure area, and interdural pathway; moreover, it allows dissection through the interdural space without entering the neurovascular compartment of the CS. Although the space for manipulation of instruments is limited, the ETOA is suitable for treating selected tumors in the superior and lateral compartments of the CS.

Learning Curve for Endoscopic Transsphenoidal Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Endoscopic transsphenoidal surgery (ETSS) is emerging as an effective, minimally invasive surgery technique for brain tumors of the pituitary fossa. Using a surgical endoscope, surgeons can obtain a broader, nearer, and more apparent visual field with minimal keyhole entrance. However, ETSS may require a steep learning curve to achieve technical competence and relevant outcomes. Moreover, there is no consensus on the learning process of ETSS. We aimed to review and determine the technical proficiency points of ETSS and discuss how to accelerate the learning curve.

METHODS

Core databases, including PubMed, Embase, and the Cochrane Library, were systematically searched for learning curve studies that demonstrated the clinical outcomes and learning status of ETSS for pituitary adenomas using numerical data. Quality assessments of the included articles were performed using the Newcastle-Ottawa scale. The cutoff points were evaluated based on various outcome measures.

RESULTS

Eleven full-text articles, representing 2780 cases, were selected from 317 screened studies. The outcome measures were operative time, tumor removal, endocrinological results, visual field, and surgical complications. The plateaus or cutoff points in the learning curve varied with a mean of 103 ± 139.43 (range, 9-500) cases.

CONCLUSIONS

ETSS is an efficient and minimally invasive alternative surgical option for pituitary tumors. Plateau points may differ according to outcome measures, patient selection, training status, and surgical conditions. Therefore, great care should be taken when interpreting the learning curve. A systematic training program is essential to improve the learning process of endoscopic neurosurgical procedures.

Application of binasal speculum in endoscopic endonasal surgery for lesions in sellar region

Objective

This study aims to access the efficacy of the binasal speculum in endoscopic endonasal surgery by evaluating clinical outcomes and examining its utility through process-based performance measures in both surgeons and assistants.

Methods

A total of 59 patients with lesions in sellar region who underwent endoscopic endonasal surgery with the binasal speculum between September 2020 and March 2023 were included in this study. We assessed the extent of resection and documented postoperative nasal condition. Both surgeons and assistants completed post-use surveys to exam the utility of the binasal speculum and provide an overall grading.

Results

Gross total resection (GTR) was successfully achieved in 94.9% (56/59) of patients, with subtotal resection (STR) observed in 5.1% (4/59) of patients. Intraoperative cerebrospinal fluid (CSF) leakage occurred in 23.7% (14/59) of cases, and nasoseptal flap (NSF) reconstruction was required in 55.9% (33/59) of cases. The nasal airway patency rapidly recovered within 14 days in a significant majority of patients (94.9%, 56/59). Moreover, olfactory function was regained within three months postoperatively by 91.5% (54/59) of patients. The overall post-use survey mean score was 26.4. Specifically, surgeons had a mean score of 26.5, while assistants had a slightly lower mean score of 26.2. The mean overall grading for the binasal speculum was 3. Both surgeons and assistants provided a mean overall grading of 3.

Conclusion

The binasal speculum provides nasal mucosa protection and reduces the risk of an endoscopic lens clouded by mucosa or blood. It plays a crucial role in accurate guidance and facilitates the swift delivery of surgical instruments, particularly in left-blinded nasal cavities. The binasal speculum reduces the learning curve, especially for endoscopic surgeons with limited experience, while enhancing collaboration and coordination between surgeons and assistants during surgery. Both surgeons and assistants rated the overall utility of the binasal speculum as "excellent."

Anterior-posterior diameter is a key driver of resectability and complications for pituitary adenomas with suprasellar extension in endoscopic transsphenoidal surgery

BACKGROUND

As endoscopic transsphenoidal approaches are more routinely selected for progressively larger pituitary adenomas with parasellar extension, understanding potential anatomical factors that limit resection and contribute to complications is becoming increasingly important for tailoring a surgical approach. This study aimed to reevaluate existing predictive tools for resectability in pituitary adenomas specifically with suprasellar extension, and furthermore identify any additional measurable features that may be more useful in preoperative planning.

METHODS

A single-center retrospective chart review of adult patients who underwent endoscopic transsphenoidal surgery for pituitary adenomas with suprasellar extension from 2015 to 2020 was performed. Preoperative MRIs were systematically assessed to assign a Knosp classification, a Zurich Pituitary Score (ZPS), and for dimensional measurements of the suprasellar aspect of the lesions. Univariate comparisons and multivariate regression models were employed to assess the influence of these factors on extent of resection and postoperative complications.

RESULTS

Of the 96 patients with suprasellar pituitary adenomas who underwent endoscopic transsphenoidal surgery, 74 patients (77%) had a gross total resection (GTR). Neither Knosp grade nor ZPS score, even when dichotomized, demonstrated an association with GTR (Knosp 3A-4 versus Knosp 0-2, p = 0.069; ZPS III-IV versus ZPS I-II, p = 0.079). Multivariate regression analysis identified suprasellar anterior-posterior tumor diameter (SSAP) as the only significant predictor of extent of resection in this cohort (OR 0.951, 95% CI 0.905-1.000, p = 0.048*). A higher SSAP also had the strongest association with intraoperative CSF leaks (p = 0.0012*) and an increased overall rate of postoperative complications (p = 0.002*). Further analysis of the regression model for GTR suggested an optimal cut point value for SSAP of 23.7 mm, above which predictability for failing to achieve GTR carried a sensitivity of 89% and a specificity of 41%.

CONCLUSIONS

This study is unique in its examination of endoscopic transsphenoidal surgical outcomes for pituitary adenomas with suprasellar extension. Our findings suggest that previously established grading systems based on lateral extension into the cavernous sinus lose their predictive value in lesions with suprasellar extension and, more specifically, with increasing suprasellar anterior-posterior diameter.

Neuroendoscopy: The State of the Art

Over the past century, neuroendoscopy developed into a mainstay of neurosurgical practice, allowing for minimally invasive approaches to the ventricles, skull base, and spine. Its development, however, is far from over. Current challenges are inherent in the very feature that renders neuroendoscopy appealing-the small channels of the modern endoscope allow surgery to be performed with minimal tissue retraction, but they also make hemostasis and resection of large masses difficult. New optics allow for significantly improved image quality; yet open craniotomy often allows for 3-dimensional visualization and bimanual dissection and is part of everyday neurosurgical training. Finally, the utilization of neuroendoscopy remains limited, presenting ongoing challenges for neurosurgical teaching and achievement of technical mastery.

The learning curve for endoscopic endonasal pituitary surgery: a systematic review

Recent literature demonstrates that a learning curve exists for endoscopic pituitary surgery. However, there is significant variability in the way these studies report their outcomes. This study aims to systematically review the literature regarding outcomes for endoscopic pituitary surgery and how this may be related to a surgical learning curve. An electronic search of the databases Medline, Scopus, Embase, Web of Science and Cochrane Library databases was performed and data extracted according 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. Ten articles were included in the review as they examined the following: rates of gross total resection, average operative time, CSF leak rate, visual outcomes, endocrine outcomes and how these results were influenced by surgical experience. We have demonstrated that a learning curve exists for some outcome variables for endoscopic pituitary surgery. However, there is significant heterogeneity in the current body of literature which makes clear comparisons difficult.

Efficacy of hydroxyapatite-based skull base reconstruction for intraoperative high-flow cerebrospinal fluid leakage performed by less-experienced surgeons

Cerebrospinal fluid (CSF) leakage after endoscopic skull base surgery remains a challenge despite multilayer reconstruction including nasoseptal flap (NSF) has become a standard technique. Injectable hydroxyapatite (HXA) has shown promising results to prevent CSF leakage. This study aimed to validate the efficacy of HXA-based skull base reconstruction performed by less-experienced neurosurgeons who had short-term clinical experiences as independent surgeons. Between March 2018 and November 2022, 41 patients who experienced intraoperative high-flow CSF leakage following endoscopic endonasal surgery at two independent tertiary institutions were enrolled. Skull base reconstruction was performed using conventional multilayer techniques combined with or without HXA. The primary outcome was postoperative CSF leakage. The surgical steps and nuances were described in detail. The most common pathology was craniopharyngioma. Injectable HXA was used in 22 patients (HXA group) and conventional techniques were performed in 19 patients (control group). The HXA group achieved a significantly lower incidence of postoperative CSF leakage than the control group (0% vs. 26.3%, p = 0.016). No HXA-related complications were observed. The use of injectable HXA in skull base reconstruction was highly effective and safe. This technique and its favorable results might be readily reproduced by less-experienced neurosurgeons.

Navigating the learning curve with large and giant tumors: Initial experience with endoscopic endonasal transphenoidal resection of PitNETs

BACKGROUND

The endoscopic endonasal approach (EEA) has progressively become the preferred choice of surgical intervention for PitNETs. However, the adoption in Sub-Saharan Africa has been low. We report our initial experience with the utility of the EEA in PitNETs particularly in large and giant tumors despite limited resources.

METHODS

The study was over a 73-month period at the University College Hospital, Ibadan, Nigeria. Pre and post-operative clinical, imaging and neuro-ophthalmological findings were documented. Perioperative and postoperative outcomes were recorded. We compared the outcomes between the early 23 and later 22 patients. Data were analyzed using descriptive statistics, student's t test, Mann-Whitney U test and Chi square test at α = 0.05.

RESULTS

There were 45 patients; 25(55.6%) were males. Mean age was 49.9 ± 13.4 years. Visual symptoms predominated with 12(26%) blind in at least one eye. Median tumor volume was 20.9 cm³ and mean tumor diameter was 4.09 ± 0.89 cm. 31(68.9%) had gross or near total excision. Vision improved in 31(68.9%). There were 2 procedure related mortality from CSF leak/meningitis. The mean of the tumor diameter of the earlier patients was less than that of the latter (3.84 vs 4.40 cm, p = 0.04,). The latter group also had more gross or near total resections (26.8% versus 41.5%) but this was not statistically significant. There was no difference in postoperative complications.

CONCLUSIONS

EEA remains a veritable option for PitNETs, including for large and huge tumors, even within resource challenged environments, with acceptable limits of complications.

The learning curve of endoscopic endonasal transsphenoidal surgery for pituitary adenomas with different surgical complexity

Objective

To investigate the learning curve under different surgical complexity in endoscopic transsphenoidal approach for pituitary adenoma.

Methods

273 patients undergoing endoscopic transsphenoidal surgery for pituitary adenoma were collected retrospectively and divided into three groups chronologically (early, middle, and late periods). Surgical complexity was differentiated based on Knosp classification (Knsop grade 0-2 vs. Knosp grade 3-4), tumor maximum diameter (MD) (macroadenomas vs. giant adenomas), and history of previous surgery for pituitary adenoma (first operation vs. reoperation). Then the temporal trends in operative time, surgical outcomes, and postoperative complications were evaluated from early to late.

Results

The median operative time decrease from 169 to 147 min across the three periods (P = 0.001). A significant decrease in operative time was seen in the simple groups [Knosp grade 0-2 adenoma (169 to 137 min, P < 0.001), macroadenoma (166 to 140 min, P < 0.001), and first operation (170.5 to 134 min, P < 0.001)] but not in their complex counterparts (P > 0.05). The GTR rate increased from 51.6% to 69.2% (P = 0.04). The surgical period was an independent factor for GTR in the simple groups [Knosp grade 0-2 adenoma: OR 2.076 (95%CI 1.118-3.858, P = 0.021); macroadenoma: OR = 2.090 (95%CI 1.287-3.393, P = 0.003); first operation: OR = 1.809 (95%CI 1.104-2.966, P = 0.019)] but not in the complex groups. The biochemical cure rate increased over periods without statistical significance (from 37.5% to 56.3%, P = 0.181). Although intraoperative CSF leakage rose (from 20.9% to 35.2%) and postoperative CSF leakage reduced (from 12.1% to 5.5%), there was no statistically significant trend across the three time periods (P > 0.05).

Conclusion

This study showed that complex operations might have a prolonged learning curve. Differentiating surgical difficulty and using multivariate combined analysis may be more helpful in clinical practice.

Endoscopic endonasal odontoidectomy: a long-term follow-up results for a cohort of 21 patients

BACKGROUND

Endoscopic endonasal odontoidectomy (EEO) has been described as a potential approach for craniovertebral junction (CVJ) disease which could cause anterior bulbomedullary compression and encroaching. Due to the atlantoaxial junction's uniqueness and complex biomechanics, treating CVJ pathologies uncovers the challenge of preventing C1-C2 instability. A large series of patients treated with endonasal odontoidectomy is reported, analyzing the feasibility and necessity of whether or not to perform posterior stabilization. Furthermore, the focus is on the long-term follow-up, especially those whom only underwent partial C1 arch preservation without posterior fixation.

METHODS

This study is a retrospective analysis of patients with ventral spinal cord compression for non-reducible CVJ malformation, consecutively treated with EEO from July 2011 to March 2019. Postoperative dynamic X-ray and CT scans were obtained in each case in order to document CVJ decompression as well as to exclude instability. The anterior atlas-dens interval, posterior atlas-dens interval and C1-C2 total lateral overhang were measured as a morphological criteria to determine upper cervical spine stability.

RESULTS

Twenty-one patients (11:10 F:M) with a mean age of 60.6 years old at the time of surgery (range 34-84 years) encountered the inclusion criteria. For all 21 patients, a successful decompression was achieved at the first surgery. In 11 patients, the partial C1 arch integrity did not require a posterior cervical instrumentation on the bases of postoperative and constant follow-up radiological examination. In 13 cases, an improvement of motor function was recorded at the time of discharge. Only one patient had further motor function improvement at follow-up. Among the patients that did not show any significant motor change at discharge, 4 patients showed an improvement at the last follow-up.

CONCLUSIONS

The outcomes, even in C1 arch preservation without posterior fixation, are promising, and it could be said that the endonasal route potentially represents a valid option to treat lesions above the nasopalatine line.

Endoscopic transsphenoidal surgery for non-functioning pituitary adenoma: Learning curve and surgical results in a prospective series during initial experience

Background

To report the initial experience of surgery for non-functioning pituitary adenoma (NFPA) from a neurosurgeon in a dedicated residency training endoscopic transsphenoidal (ETS) program, and detail the surgical and clinical outcomes during this period.

Methods

A prospective series of all patients operated for NFPA, using an ETS approach, during the three first years of experience of a newly board-certified neurosurgeon was analysed. Clinical, radiological and peri-operative data were collected. Extent of resection (EOR) was determined by formal volumetric analysis. Impact of the learning curve and predictive factors of gross total resection (GTR) were determined.

Results

Fifty-three patients with NFPA were included in this prospective cohort which was divided in two periods of time (“First period”: 30 first cases, and “second period”: 23 following cases). Baseline characteristics of the patients in the two periods were similar. Overall occurrence of complication was 22% and was not significantly different in the two periods of time. No patient had severe neurological complication. Gross total resection was achieved in 70% of patients. Mean Extent of resection was 96%. In a multiple linear regression model, a higher EOR was positively correlated with experience (p = 0.018) and negatively correlated with Knosp Score equal to 4 (p < 0.001). Predictive factors for GTR were Higher Knosp grade (p = 0,01), higher pre-operative volume (p = 0.03), and second period of time (p = 0.01).

Conclusion

NFPA surgery can be safe and efficient during the learning period. Dedicated intensive learning, careful patient selection and multidisciplinary work are key to shorten the learning curve and achieve satisfactory results.

Reevaluating Innovations in Medical Student Neurosurgery Education: Lessons Learned Today from Data Collected Before COVID-19

OBJECTIVE

Virtual learning has made neurosurgery education more available to medical students (MSs) of all stages than ever before. We aimed to evaluate the impact of on-site learning in order to assess whether a return to this method of teaching, when safe, is warranted for MSs of all years.

METHODS

Registrants of the 2019 MS Neurosurgery Training Camps were sent precourse and postcourse surveys to assess changes in self-assessed confidence in concrete neurosurgical skills. Data were analyzed using a 2-tailed paired Student's t-test for continuous variables. A P value <0.05 was considered significant.

RESULTS

The 2019 Training Camp had 105 attendees, of whom 94 (89.5%) completed both surveys. Students reported statistically significant improvements in every surveyed skill area, except for understanding what is and is not sterile in an operating room. The cohort of MS 3/4 students indicated a postcourse decrease in confidence in their ability to understand what is and is not sterile in an operating room (93.69 ± 16.41 vs. 86.20 ± 21.18; P < 0.05). MS 3/4 students did not benefit in their ability to perform a neurologic examination or tie knots using a 1-handed technique.

CONCLUSIONS

Neurosurgical education initiatives for MSs should continue to be developed. Hands-on neurosurgical training experiences for MSs serve as a valuable educational experience. Improvement in training models will lead to capitalizing on MS education to better improve readiness for neurosurgical residency without concern for patient safety.

Effects of a transsphenoidal surgery quality improvement program on patient outcomes and hospital financial performance

OBJECTIVE

A comprehensive quality improvement (QI) program aimed at all aspects of patient care after pituitary surgery was initiated at a single center. This initiative was guided by standard quality principles to improve patient outcomes and optimize healthcare value. The programmatic goal was to discharge most elective patients within 1 day after surgery, improve patient safety, and limit unplanned readmissions. The program is described, and its effect on patient outcomes and hospital financial performance over a 5-year period are investigated.

METHODS

Details of the patient care pathway are presented. Foundational elements of the QI program include evidence-based care pathways (e.g., for hyponatremia and pain), an in-house research program designed to fortify care pathways, patient education, expectation setting, multidisciplinary team care, standard order sets, high-touch postdischarge care, outcomes auditing, and a patient navigator, among other elements. Length of stay (LOS), outcome variability, 30-day unplanned readmissions, and hospital financial performance were identified as surrogate endpoints for healthcare value for the surgical epoch. To assess the effect of these protocols, all patients undergoing elective transsphenoidal surgery for pituitary tumors and Rathke's cleft cysts between January 2015 and December 2019 were reviewed.

RESULTS

A total of 609 adult patients who underwent elective surgery by experienced pituitary surgeons were identified. Patient demographics, comorbidities, and payer mix did not change significantly over the study period (p ≥ 0.10). The mean LOS was significantly shorter in 2019 versus 2015 (1.6 ± 1.0 vs 2.9 ± 2.2 midnights, p < 0.001). The percentage of patients discharged after 1 midnight was significantly higher in 2019 versus 2015 (75.4% vs 15.6%, p < 0.001). The 30-day unplanned hospital readmission rate decreased to 2.8% in 2019 from 8.3% in 2015. Per-patient hospital profit increased 71.3% ($10,613 ± $19,321 in 2015; $18,180 ± $21,930 in 2019), and the contribution margin increased 42.3% ($18,925 ± $19,236 in 2015; $26,939 ± $22,057 in 2019), while costs increased by only 3.4% ($18,829 ± $6611 in 2015; $19,469 ± $4291 in 2019).

CONCLUSIONS

After implementation of a comprehensive pituitary surgery QI program, patient outcomes significantly improved, outcome variability decreased, and hospital financial performance was enhanced. Future studies designed to evaluate disease remission, patient satisfaction, and how the surgeon learning curve may synergize with other quality efforts may provide additional context.

Pediatric pituitary adenomas are more aggressive, more likely to be hormone producing and are more difficult to cure than adult pituitary adenomas: case series and systematic literature review

PURPOSE

Pediatric pituitary adenomas (pPAs) are uncommon. Thus, their presentation and outcomes after treatment are less well-understood than those of pituitary adenomas in adulthood (aPAs).

METHODS

A retrospective chart review was conducted for all patients who underwent endoscopic endonasal transsphenoidal surgery (EETS) for pPA at NewYork-Presbyterian Hospital/Weill Cornell Medicine (NYP/WCM) from 2005-2020. Eleven patients were identified, and information pertaining to age, sex, adenoma characteristics, procedural details, and outcomes was reviewed. A systematic review of the literature was also performed to compare outcomes of EETS versus microscopic endonasal transsphenoidal surgery (METS) for pPA.

RESULTS

From 2005-2020, 11 patients underwent EETS for pPA at NYP/WCM. Mean age at operation was 14.9 ± 2.7 years, and 5 patients (45.5%) were male. 10 adenomas (90.9%) were hormone-producing. Of the functional adenomas, 8 (80.0%) were PRL-secreting and 2 (20.0%) were GH-secreting. Maximum adenoma diameter (MAD) ranged from 1.2-5.1 cm, with a median of 1.55 cm. Cavernous sinus invasion (CSI) occurred in 2 patients with macroprolactinoma. Gross total resection (GTR) was achieved in 10 (90.9%). Biochemical remission occurred in 5/10 (50.0%). Post-operative complications were documented in 8 cases (72.7%) and included diabetes insipidus, hypopituitarism, sinusitis, weight gain, cerebrospinal fluid leak, meningitis, and hydrocephalus. Systematic literature review of 105 microscopic and 175 endoscopic cases revealed high frequency of hormone-producing tumors (83.6%) and similar rates of GTR (82.4% vs 85.1%) and biochemical cure (75.8% vs 64.3%).

CONCLUSIONS

pPAs are more likely to be hormone producing and may be more aggressive and difficult to cure than aPAs. EETS is an effective treatment, although complication rates may be higher than in adult populations.

Complication avoidance protocols in endoscopic pituitary adenoma surgery: a retrospective cohort study in 514 patients

PURPOSE

To evaluate the impact of using consistent complication-avoidance protocols in patients undergoing endoscopic pituitary adenoma surgery including techniques for avoiding anosmia, epistaxis, carotid artery injury, hypopituitarism, cerebrospinal fluid leaks and meningitis.

METHODS

All patients undergoing endoscopic adenoma resection from 2010 to 2020 were included. Primary outcomes included 90-day complication rates, gland function outcomes, reoperations, readmissions and length of stay. Secondary outcomes were extent of resection, short-term endocrine remission, vision recovery.

RESULTS

Of 514 patients, (mean age 51 ± 16 years; 78% macroadenomas, 19% prior surgery) major complications occurred in 18(3.5%) patients, most commonly CSF leak (9, 1.7%) and meningitis (4, 0.8%). In 14 of 18 patients, complications were deemed preventable. Four (0.8%) had complications with permanent sequelae (3 before 2016): one unexplained mortality, one stroke, one oculomotor nerve palsy, one oculoparesis. There were no internal carotid artery injuries, permanent visual worsening or permanent anosmia. New hypopituitarism occurred in 23/485(4.7%). Partial or complete hypopituitarism resolution occurred in 102/193(52.8%) patients. Median LOS was 2 days; 98.3% of patients were discharged home. Comparing 18 patients with major complications versus 496 without, median LOS was 7 versus 2 days, respectively p < 0.001. Readmissions occurred in 6%(31/535), mostly for hyponatremia (18/31). Gross total resection was achieved in 214/312(69%) endocrine-inactive adenomas; biochemical remission was achieved in 148/209(71%) endocrine-active adenomas. Visual field or acuity defects improved in 126/138(91.3%) patients.

CONCLUSION

This study suggests that conformance to established protocols for endoscopic pituitary surgery may minimize complications, re-admissions and LOS while enhancing the likelihood of preserving gland function, although there remains opportunity for further improvements.

Evaluation of the Gross Total Resection Rate of Suprasellar Pituitary Macroadenomas with and without the Removal of the Tuberculum Sellae Bone

OBJECTIVE

Improving the gross total resection (GTR) rate of suprasellar pituitary macroadenomas (SPMAs) using the pure endoscopic endonasal transsphenoidal approach (EETA) has been a long-standing focus of neurosurgeons. This study was aimed at evaluating the influences of the removal of the tuberculum sellae bone (TSB) without opening the dura of the tuberculum sellae on the GTR rate of SPMAs via the EETA.

METHODS

We retrospectively analyzed medical reports of patients with SPMAs who underwent EETA between February 2015 and November 2020. Data on clinical manifestations, endocrinologic types, imaging features (Hardy classification, morphology, and texture), clinical outcomes, and TSB removal status were collected. All patients were followed up for 6 months postoperatively.

RESULTS

Seventy-eight patients were enrolled in our study. The GTR rates of the TSB removal group (45/78, 57.7%) and nonremoval group (33/78, 42.3%) were 80.0% (36/45) and 57.6% (19/33), respectively. Univariate logistic regression analysis found that the removal of TSB, rounded morphology, and low Hardy classification were correlated with higher GTR rates. Multiple logistic regression analysis indicated that even after adjusting for tumor types and imaging features, the removal of TSB had an independent effect on the GTR rate (odds ratio, 7.6; 95% confidence interval, 1.8-31.6; P = 0.005). The incidence rates of postoperative cerebrospinal fluid leakage and diabetes insipidus were not significantly different between the TSB removal group and TSB nonremoval group.

CONCLUSIONS

TSB removal using EETA without opening the tuberculum sellae dura improves the GTR rate of SPMAs without increasing the incidence of postoperative complications.

What is the current clinical practice in pituitary adenoma surgery in Europe? European Pituitary Adenoma Surgery Survey (EU-PASS) results-technical part

Pituitary adenoma surgery has evolved rapidly in recent decades, changing clinical practice markedly and raising new challenges. There is no current consensus or guidelines for perioperative care that includes possible complication management. This study aims to determine current practice across European neurosurgical centres. We created a list of eligible departments performing pituitary adenoma surgery based on cooperation with EANS, national neurosurgical societies, and personal communication with local neurosurgeons. We contacted the chairpersons from each department and asked them (or another responsible neurosurgeon) to fill out the survey. The survey consisted of 58 questions. For further analysis, departments were divided into subgroups: "academic"/ "non-academic centre", "high-volume"/"low-volume", "mainly endoscopic"/ "mainly microscopic"/ "mixed practise", and by geographical regions. Data from 254 departments from 34 countries were obtained. The average time to complete the survey was 18 min. Notably, the endoscopic approach is the predominant surgical approach in Europe, used in 56.8% of the centres. In routine cases without intraoperative cerebrospinal fluid leak, high-volume centres are less pedantic with sellar closure when compared with low-volume centres (p < 0.001). On the other hand, when a postoperative cerebrospinal fluid leak occurs, high-volume centres are more active and indicate early reoperation (p = 0.013). Less than 15% of the participating centres perform early postoperative MRI scans. Marked variation was noted among different groups of respondents and some contentious issues are discussed. Such information can encourage useful debate about the reasons for the variations seen and perhaps help develop standardised protocols to improve patient outcomes. A future research focus is to compare European results with other regions.

Learning curve and technical nuances of endoscopic skull base reconstruction with nasoseptal flap to control high-flow cerebrospinal fluid leakage: reconstruction after endoscopic skull base surgery other than pituitary surgery

PURPOSE

Although reconstruction techniques after endoscopic skull base surgery have been improved, there are difficulties in reconstructing the skull base with a nasoseptal flap (NSF), especially in the case of high-flow cerebrospinal fluid (CSF) leak. The aim of this study was to analyze risk factors for the development of postoperative CSF leaks in terms of less experienced surgeon practices.

METHODS

Retrospective review of medical records was performed for 125 patients who underwent endoscopic skull base surgery for intradural pathology with intraoperative high-flow CSF leakage between Oct 2012 and Apr 2017. Basic demographic data were collected, including body mass index (BMI), tumor pathology, comorbidities, and outcomes. To assess the learning curve effect, patients were divided into early cohort (n = 30) and late cohort (n = 95) groups.

RESULTS

Overall postoperative CSF leakage was 10.4% (13/125) in this series. There were no significant risk factors for postoperative CSF leakage among the demographic data including BMI, comorbidities, or radiation history. Postoperative CSF leakage was most prevalent in the transclival approach than in other approaches, but the difference was not statistically significant (20.8%, p = 0.351). When dividing the results by timetable, the patients who underwent skull base reconstruction in the early cohort experienced more postoperative CSF leakage (23.3%, 7 cases out of 30) than in the late cohort (6.3%, 6 cases out of 95, p = 0.014). The learning curve was steeper in the early cohort (30 early cases 23.3%, 31-60 10%, 61-90 6.7%, 91-125 2.9%).

CONCLUSIONS

To improve the success rate of endoscopic skull base reconstruction, surgeons have to keep the basic technical details in mind to reduce the learning curve.

Endoscopic, Endonasal Transsphenoidal Surgery for Tumors of the Sellar and Suprasellar Region: A Monocentric Historical Cohort Study of 369 Patients

BACKGROUND

The endoscopic endonasal transsphenoidal approach (EETA) is an established technique for the resection of a large variety of benign sellar and suprasellar lesions, mostly pituitary adenomas. It has clear advantages over the microscopic approach, like a superior close-up view of the relevant anatomy and the tumor-gland interface, an enlarged working angle, as well as an increased panoramic vision inside the surgical area. We have been performing the EETA for over a decade, and this study will focus on perioperative and postoperative outcomes and complications and their association with the learning curve.

MATERIAL AND METHODS

All patients in our tertiary referral center (n = 369) undergoing an EETA for a lesion of the sellar and suprasellar region between January 1st 2008 and December 31st 2018 were included, and data were retrospectively retrieved from the electronic patient records.

RESULTS

Median follow-up after surgery was 55 months. Pituitary adenomas (n = 322) were the most frequent pathology. Headache (43.4%) and loss of vision (29.3%) were the most common presenting symptoms. Median procedure duration was significantly longer during the initial 5 years (106 versus 79 minutes; p <0.0001), but incidence of peri- and postoperative CSF leaks in the early years was not significantly higher. Knosp grade >2 was associated with perioperative CSF leak (p =0.002), and perioperative CSF leak was associated with postoperative CSF leak (p <0.001). Almost all cases of meningitis were preceded by a postoperative CSF leak. In 22.4% of patients, tumor recurrence required additional therapy. Perioperative (iatrogenic) mortality was 0.8%. The overall hospital stay decreased over time from an average of 7 to 5 days, and the case load increased yearly (p =0.015).

CONCLUSION

The EETA is an excellent technique with complication rates comparable to or even lower than those in large microsurgical series in the literature. EETA has a significant learning curve affecting the procedure duration. Throughout the first 10 years following the transition from the microscopic approach to the EETA in our cohort, the caseload increased and hospital stay was reduced, while no increase in peri- and postoperative complications was observed.