Stereoscopic Monitoring technique for motor area tumors.

BACKGROUND AND OBJECTIVES: The balance between a comprehensive intraoperative-neuromonitoring (IONM) for both upper and lower limb while ensuring the reliability of motor-evoked potentials (MEPs) is paramount in motor area surgery. It's commonly hard to obtain a good simultaneous stimulation of both upper/lower limb, a series of factors can bias MEP accuracy and inappropriate stimulation intensity can result in unreliable monitoring. The presented IONM technique is based on the concurrent use of both transcranial and strip electrodes to facilitate a simultaneous monitoring of both upper and lower limb at optimized stimulation intensities, increasing IONM accuracy, during motor-area surgery. METHODS: Ten nonconsecutive motor area tumors were studied. A good visualization of both limbs was observed in the series, at a low amperage (1.2mA from strip-electrode and 165,3mA from transcranial-electrode). RESULTS: Our analysis confirm concordance between IONM data and postoperative outcome: a MEP reduction >20% and >50% was coherent with postoperative mRS changes, without false negative IONM. CONCLUSION: The technique demonstrated to be accurate in providing a good simultaneous neurophysiological evaluation of both upper/lower limb with an optimized and stimulation amplitude; it warrants a low encumbrance of electrodes in the surgical field. Results confirm its feasibility and reliability. Considering the relatively small sample, this study represents a "proof of concept" rather than an applicability study.

Epithelial ovarian cancer and brain metastases: might the BRCA status, PARP inhibitor administration, and surgical treatment impact the survival?

OBJECTIVE: To evaluate disease characteristics and survival according to BRCA status, administration of poly-(ADP-ribose) polymerase inhibitors (PARPi), and surgery in patients with ovarian cancer and brain metastases. METHODS: This is a monocentric retrospective cohort of patients with ovarian cancer and brain metastases treated between 2000 and 2021. Data were collected by a retrospective review of medical records and analyzed according to: (1) BRCA mutation; (2) PARPi before and after brain metastases; (3) surgery for brain metastases. RESULTS: Eighty-five patients with ovarian cancer and brain metastasis and known BRCA status (31 BRCA mutated (BRCAm), 54 BRCA wild-type (BRCAwt)) were analyzed. Twenty-two patients had received PARPi before brain metastases diagnosis (11 BRCAm, 11 BRCAwt) and 12 after (8 BRCAm, 4 BRCAwt). Brain metastases occurred >1 year later in patients who had received previous PARPi. Survival was longer in the BRCAm group (median post-brain metastasis survival: BRCAm 23 months vs BRCAwt 8 months, p=0.0015). No differences were found based on BRCA status analyzing the population who did not receive PARPi after brain metastasis (median post-brain metastasis survival: BRCAm 8 months vs BRCAwt 8 months, p=0.31). In the BRCAm group, survival was worse in patients who had received previous PARPi (median post-brain metastasis survival: PARPi before, 7 months vs no-PARPi before, 24 months, p=0.003). If PARPi was administered after brain metastases, survival of the overall population improved (median post-brain metastasis survival: PARPi after, 46 months vs no-PARPi after, 8 months, p=0.00038).In cases of surgery for brain metastases, the prognosis seemed better (median post-brain metastasis survival: surgery 13 months vs no-surgery 8 months, p=0.036). Three variables were significantly associated with prolonged survival at multivariate analysis: BRCA mutation, multimodal treatment, and ≤1 previous chemotherapy line. CONCLUSIONS: BRCA mutations might impact brain metastasis occurrence and lead to better outcomes. In a multimodal treatment, surgery seems to affect survival even in cases of extracranial disease. PARPi use should be considered as it seems to prolong survival if administered after brain metastasis.

Bone health and skeletal fragility in second- and third-line medical therapies for acromegaly: preliminary results from a pilot single center experience.

INTRODUCTION: Skeletal fragility is a clinically relevant and not-reversible complication of acromegaly, involving around 30-40% of patients since the disease diagnosis. Few studies have investigated the effects on skeletal health of medical therapies for acromegaly. In this retrospective longitudinal monocentre study, we investigated the outcome of skeletal fragility in patients treated with Pasireotide Lar in combination with Pegvisomant (Pasi-Lar + Peg-V), also comparing those observed in patients treated with conventional therapies. RESULTS: We included 6 patients treated with Pasi-Lar + Peg-V, 5 patients treated with Peg-V in monotherapy (m-Peg-V), 16 patients treated with Peg-V plus first-generation somatostatin receptor ligands (fg-SRLs + Peg-V), 9 patients treated with Pasi-Lar. None of the patients treated with Pasi-Lar + Peg-V experienced worsening of spine and femoral bone mineral density (BMD) and incident vertebral fractures (i-VFs). Eight patients experienced i-VFs. The frequency of i-VFs was significantly lower in patients treated with the Pasi-Lar + Peg-V (0/8; 0%), as compared to those observed in m-Peg-V treated patients (4/8; 50%, p = 0.02). The frequency of i-VFs was slightly but not significantly higher in Pasi-Lar treated patients (1/8; 12.5% p = 0.6) and in fg-SRLs + Peg-V treated patients (3/8; 37.5% p = 0.364), concerning those treated with Pasi-Lar + Peg-V (0/8; 0%). I-VFs occurred more frequently in patients with higher GH levels at acromegaly diagnosis (p < 0.001), and in patients who experienced a BMD worsening (p = 0.005). CONCLUSION: Our preliminary data suggested that in conventional and multi-drug resistant acromegaly, the combination therapy Pasi-Lar + Peg-V may prevent the worsening of BMD and the occurrence of i-VFs. Prospective and translational studies should further validate these results and ascertain underlying physiopathology mechanisms.

Posterior cranial fossa surgery with a 3D Exoscope: a single-center survey-based analysis and a literature review.

BACKGROUND: The potential advantages of exoscopy have been discussed theoretically for a long time. Such a concept holds significance, especially in the specific setting of the posterior cranial fossa (PCF), characterized by complex anatomy and long and narrow surgical corridors with relatively extreme working angles. AIM: We aimed to: 1) analyze the institutional preliminary case-based data on the use of the Robotic 3D Exoscope AEOS Aesculap in three different PCF approaches: retrosigmoid (RSA), midline suboccipital (MSA), and supra cerebellar infratentorial (SIA) via feedbacks was collected using a 20-point questionnaire. 2) perform a comprehensive review of the literature concerning the use of EX in PCF surgery RESULTS: A total of 38 patients with neurosurgical pathologies underwent a neurosurgical procedure using the EX (Robotic 3D exoscope AEOS Aesculap) at our institution between January and March 2022. 21 surgeons were involved in the abovementioned PCF surgeries and answered the questionnaire. The main perceived advantages were in terms of ergonomics (67%) and magnification (52%) and visualization of extreme angles. The main reported disadvantage was color vision (16, 76%), followed by manual mobility (24%). Concerning the review, the search of the literature yielded a total of 177 results. Upon full-text review, 17 articles were included, including 153 patients. CONCLUSIONS: In conclusion, our study provides a comprehensive evaluation of the advantages and challenges associated with using the exoscope in posterior fossa surgery, setting a precedent as the first to report on a questionnaire-based analysis of exoscope utilization in this specific domain.

Trouillas's Grading and Post-Surgical Tumor Residue Assessment in Pituitary Adenomas: The Importance of the Multidisciplinary Approach.

BACKGROUND: We aim to assess the role of a multidisciplinary approach in pituitary adenomas (PitNETs) classification, evaluate criteria concordance, and compare intraoperative assessments with post-operative MRIs for tumor remnants. METHODS: Clinical, radiological, histological, and intra- and post-operative data of the treated PitNETs were extracted from prospectively created records. PitNETs were graded according to Trouillas, and the evaluation of the tumor remnants was recorded. RESULTS: Of 362 PitNETs, 306 underwent surgery, with Trouillas grading assigned to 296. Eight-nine radiologically non-invasive PitNETs progressed to grades 1b (27), 2a (42), or 2b (20) due to proliferative or surgical invasiveness criteria. Twenty-six radiologically invasive tumors were graded 2b due to proliferative criteria. Surgical resection details and post-surgical MRI findings revealed that residual tumors were more common in grades 2a and 2b. During surgery, small tumor remnants were documented in 14 patients which were not visible on post-surgical MRI. Post-surgical MRIs identified remnants in 19 PitNETs not seen during surgery, located in lateral recesses of the sella (4), retrosellar (2), or suprasellar regions (7), along the medial wall of the cavernous sinus (6). CONCLUSIONS: The Pituitary Board allows for the correct grading of PitNETs to be obtained and an accurate identification of high-risk patients who should undergo closer surveillance due to tumor remnants.

The Multibiomarker Acro-TIME Score Predicts fg-SRLs Response: Preliminary Results of a Retrospective Acromegaly Cohort.

CONTEXT: The prompt control of acromegaly is a primary treatment aim for reducing related disease morbidity and mortality. First-generation somatostatin receptor ligands (fg-SRLs) are the cornerstone of medical therapies. A non-negligible number of patients do not respond to this treatment. Several predictors of fg-SRL response were identified, but a comprehensive prognostic model is lacking. OBJECTIVE: We aimed to design a prognostic model based on clinical and biochemical parameters, and pathological features, including data on immune tumor microenvironment. METHODS: A retrospective, monocenter, cohort study was performed on 67 medically naïve patients with acromegaly. Fifteen clinical, pathological, and radiological features were collected and analyzed as independent risk factors of fg-SRLs response, using univariable and multivariable logistic regression analyses. A stepwise selection method was applied to identify the final regression model. A nomogram was then obtained. RESULTS: Thirty-seven patients were fg-SRLs responders. An increased risk to poor response to fg-SRLs were observed in somatotropinomas with absent/cytoplasmatic SSTR2 expression (OR 5.493 95% CI 1.19-25.16, P = .028), with low CD68+/CD8+ ratio (OR 1.162, 95% CI 1.01-1.33, P = .032). Radical surgical resection was associated with a low risk of poor fg-SRLs response (OR 0.106, 95% CI 0.025-0.447 P = .002). The nomogram obtained from the stepwise regression model was based on the CD68+/CD8+ ratio, SSTR2 score, and the persistence of postsurgery residual tumor and was able to predict the response to fg-SRLs with good accuracy (area under the curve 0.85). CONCLUSION: Although our predictive model should be validated in prospective studies, our data suggest that this nomogram may represent an easy to use tool for predicting the fg-SRL outcome early.

Aggressive PitNETs and Potential Target Therapies: A Systematic Review of Molecular and Genetic Pathways.

Recently, advances in molecular biology and bioinformatics have allowed a more thorough understanding of tumorigenesis in aggressive PitNETs (pituitary neuroendocrine tumors) through the identification of specific essential genes, crucial molecular pathways, regulators, and effects of the tumoral microenvironment. Target therapies have been developed to cure oncology patients refractory to traditional treatments, introducing the concept of precision medicine. Preliminary data on PitNETs are derived from preclinical studies conducted on cell cultures, animal models, and a few case reports or small case series. This study comprehensively reviews the principal pathways involved in aggressive PitNETs, describing the potential target therapies. A search was conducted on Pubmed, Scopus, and Web of Science for English papers published between 1 January 2004, and 15 June 2023. 254 were selected, and the topics related to aggressive PitNETs were recorded and discussed in detail: epigenetic aspects, membrane proteins and receptors, metalloprotease, molecular pathways, PPRK, and the immune microenvironment. A comprehensive comprehension of the molecular mechanisms linked to PitNETs' aggressiveness and invasiveness is crucial. Despite promising preliminary findings, additional research and clinical trials are necessary to confirm the indications and effectiveness of target therapies for PitNETs.

Colon Cancer Presenting as Pituitary Mass and Hypopituitarism: Recognition and Multidisciplinary Approach of a Rare Case.

Pituitary metastases are rare. Until now, few cases have been reported; about 50% of pituitary metastases originate from breast or lung cancers. We describe the clinical case of a primary colon carcinoma first presenting with a pituitary metastasis. A 76-year-old woman, with no history of malignancy, presented with headache, dizziness, and diplopia, at the Emergency Department. The neurologic examination was remarkable for complete left ophthalmoplegia with sensitivity deficit on the left side of the face. Radiologic investigations documented a voluminous sellar and suprasellar lesion, with extension in the left cavernous sinus and temporal lobe. Pituitary hormone levels were suggestive of anterior hypopituitarism and mild hyperprolactinemia. Subtotal surgical removal of the lesion was achieved through a trans-sphenoidal endoscopic endonasal approach. The histological examination disclosed a metastasis of gastrointestinal adenocarcinoma. A subsequent colonoscopy identified right colon cancer. A contrasted total-body computerized tomography ruled out other metastases. Postsurgical MRI showed a stable parasellar residual tumor. Conventional radiotherapy was scheduled. This case underlines the importance of considering pituitary metastases in the differential diagnosis of aggressive pituitary lesions, which should be managed in a pituitary tumor center of excellence through a multidisciplinary approach, for the complexity in diagnosis and therapeutic management of this rare condition.

Ultra-Early Treatment of Neurosurgical Emergencies with Endoscopic Endonasal Approach: Experience from Three Italian Referral Centers.

PURPOSE: the aim of this multicenter study is to preliminarily assess the role of the Endoscopic Endonasal Approach (EEA) in ultra-early (i.e., within 12 h) management of selected neurosurgical emergencies in terms of clinical and radiological outcomes. METHODS: 26 patients affected by sellar/parasellar pathologies with rapid progression of symptoms were managed with EEA within 12 h from diagnosis in three Italian tertiary referral Centers from January 2016 to December 2019. Both clinical and radiological data have been collected preoperatively as well as post-operatively in order to perform retrospective analysis. RESULTS: The average time from admission to the operating room was 5.5 h (±2.3). The extent of resection was gross-total in 20 (76.9%), subtotal in 6 (23.1%) patients. One patient experienced re-bleeding after a subtotal removal of a hemorrhagic lesion. Patients with a longer time from admission (>4 h) to the operatory room (OR) experienced stable impairment of the visual acuity (p = 0.033) and visual field (p = 0.029) in the post-operative setting. CONCLUSIONS: The Endoscopic Endonasal Approach represents a safe, effective technique that can be efficiently used with good results in the management of selected neurosurgical emergencies in centers with adequate experience.

Reliability of intraoperative visual evoked potentials (iVEPs) in monitoring visual function during endoscopic transsphenoidal surgery.

OBJECTIVE: To refine a reliable and reproducible intraoperative visual evoked potentials (iVEPs) monitoring protocol during endoscopic transsphenoidal surgery. To assess the reliability of baseline iVEPs in predicting preoperative visual status and perioperative iVEP variation in predicting postoperative visual outcome. METHODS: Sixty-four patients harboring tumors of the pituitary region were included. All patients underwent endoscopic endonasal approach (EEA) with iVEPs monitoring, using a totally intravenous anesthetic protocol. Ophthalmological evaluation included visual acuity and visual field studies. RESULTS: Preoperatively, visual acuity was reduced in 86% and visual field in 76.5% of cases. Baseline iVEPs amplitude was significantly correlated with preoperative visual acuity and visual field (p = 0.001 and p = 0.0004, respectively), confirming the reliability of the neurophysiological/anesthetic protocol implemented. Importantly, perioperatively the variation in iVEPs amplitude was significantly correlated with the changes in visual acuity (p < 0.0001) and visual field (p = 0.0013). ROC analysis confirmed that iVEPs are an accurate predictor of perioperiative visual acuity improvement, with a 100% positive predictive value in patients with preoperative vision loss. CONCLUSIONS: iVEPs during EEA is highly reliable in describing preoperative visual function and can accurately predict postoperative vision improvement. SIGNIFICANCE: iVEPs represent a promising resource for carrying out a more effective and safe endoscopic transsphenoidal surgery.

Treatment of Clival Chordomas: A 20-Year Experience and Systematic Literature Review.

Clival chordomas are rare but aggressive skull base tumors that pose significant treatment challenges and portend dismal prognosis. The aim of this study was to highlight the advantages and limitations of available treatments, to furnish prognostic indicators, and to shed light on novel therapeutic strategies. We conducted a retrospective study of clival chordomas that were surgically treated at our institution from 2003 to 2022; for comparison purposes, we provided a systematic review of published surgical series and, finally, we reviewed the most recent advancements in molecular research. A total of 42 patients underwent 85 surgeries; median follow-up was 15.8 years, overall survival rate was 49.9% at 10 years; meanwhile, progression-free survival was 26.6% at 10 years. A significantly improved survival was observed in younger patients (<50 years), in tumors with Ki67 ≤ 5% and when adjuvant radiotherapy was performed. To conclude, clival chordomas are aggressive tumors in which surgery and radiotherapy play a fundamental role while molecular targeted drugs still have an ancillary position. Recognizing risk factors for recurrence and performing a molecular characterization of more aggressive lesions may be the key to future effective treatment.

Quantitative Anatomical Studies in Neurosurgery: A Systematic and Critical Review of Research Methods.

BACKGROUND: The anatomy laboratory can provide the ideal setting for the preclinical phase of neurosurgical research. Our purpose is to comprehensively and critically review the preclinical anatomical quantification methods used in cranial neurosurgery. METHODS: A systematic review was conducted following the PRISMA guidelines. The PubMed, Ovid MEDLINE, and Ovid EMBASE databases were searched, yielding 1667 papers. A statistical analysis was performed using R. RESULTS: The included studies were published from 1996 to 2023. The risk of bias assessment indicated high-quality studies. Target exposure was the most studied feature (81.7%), mainly with area quantification (64.9%). The surgical corridor was quantified in 60.9% of studies, more commonly with the quantification of the angle of view (60%). Neuronavigation-based methods benefit from quantifying the surgical pyramid features that define a cranial neurosurgical approach and allowing post-dissection data analyses. Direct measurements might diminish the error that is inherent to navigation methods and are useful to collect a small amount of data. CONCLUSION: Quantifying neurosurgical approaches in the anatomy laboratory provides an objective assessment of the surgical corridor and target exposure. There is currently limited comparability among quantitative neurosurgical anatomy studies; sharing common research methods will provide comparable data that might also be investigated with artificial intelligence methods.

Integrated Neurosurgical Management of Retroperitoneal Benign Nerve Sheath Tumors.

Peripheral nerve sheath tumors (PNST) of the retroperitoneum are rare and are often treated by general surgeons dealing with retroperitoneal cancers. However, resection without the correct microsurgical technique can cause permanent neurological deficits and pain. Here, we discuss our interdisciplinary approach based on the integration of expertise from neurosurgery and abdominal surgery, allowing for both safe exposure and nerve-sparing microsurgical resection of these lesions. We present a series of 15 patients who underwent resection of benign retroperitoneal or pelvic PNST at our institution. The mean age of patients was 48.4 years; 67% were female. Tumors were 14 schwannomas and 1 neurofibroma. Eight patients (53%) reported neurologic symptoms preoperatively. The rate of complete resection was 87% (n = 13); all symptomatic patients showed improvement of their preoperative symptoms. There were no postoperative motor deficits; one patient (7%) developed a permanent sensory deficit. At a mean postoperative follow-up of 31 months, we observed no recurrences. To our best knowledge, this is the second-largest series of benign retroperitoneal PNST consistently managed with microsurgical techniques. Our experience confirms that interdisciplinary management allows for safe treatment of these tumors with good neurological and oncological outcomes.

CD68+ and CD8+ immune cells are associated with the growth pattern of somatotroph tumors and response to first generation somatostatin analogs.

Somatotropinomas are pituitary tumors with a heterogenous clinical behavior. The tumor microenvironment regulates the interaction between tumor cells and the host immune system, potentially modulating tumor behavior. Here, we aimed to investigate the tumor immune infiltration in a cohort of medically naïve acromegaly patients. A retrospective, monocenter study was designed to analyze the presence of CD3+, CD20+, CD138+, CD4+, CD8+, CD68+ immune cells in samples of somatotropinomas and their prognostic significance on tumor behavior and response to first generation somatostatin analogs (fg-SSA). Thirty-six patients (23 females) were included in the study. Macroadenomas were identified in 23 cases: 12 with cavernous sinus invasion. The number of CD8+ lymphocytes positively correlated with CD4+ lymphocytes (p = .05, r:0.245) and with CD68+ macrophages (p = .01, r = 0.291). The CD8+/CD4+ ratio inversely correlated with CD68+/CD8+ ratio (p < .001, r = -0.626). CD68+ macrophages positively correlated with tumor size (maximum diameter p = .003, r = 0.574; volume p = .009, r = 0.566) and were more numerous in somatotropinomas with Ki-67 > 3% (median 65/HPF, IQR:15), compared to cases with Ki67 < 3% (median 50/HPF, IQR:22, p < .001). CD8+ and CD138+ lymphocytes were more numerous in cases responsive to fg-SSA (respectively median 18/HPF IQR:18 and median 8/HPF IQR: 6.5) as compared to fg-SSA nonresponsive cases (median 14.5/HPF IQR:40 p = .03; median 3.5/HPF IQR: 14 p = .03). CD8+ lymphocytes act as single predictor of response to fg-SSA, independently from age, GH and IGF-I levels, tumor dimension and invasion. Our results support that lymphocytes and macrophages generate an immune network in somatotropinomas and the characteristic of the immune infiltrate may predict treatment outcome.

CT-Based Intraoperative Navigation for Quick Identification of the Stylomastoid Foramen During Hypoglossal-Facial Nerve Anastomosis.

AIM: To present the ability of standard intraoperative neuronavigation to reliably identify the stylomastoid foramen, thus providing a quick and effective recognition of the facial nerve at its exit from the skull base. MATERIAL AND METHODS: We describe the technical nuances of this procedure by presenting two surgical cases who underwent hypoglossal-facial nerve anastomosis for complete facial nerve palsy occurring post removal of a giant vestibular schwannoma 6 months earlier. RESULTS: CT-based neuronavigation allowed a quick and reliable identification of the stylomastoid foramen and of the facial nerve at its exit from the skull. The entire procedure lasted for 3 hours. Three months after the anastomosis, the first signs of facial muscle reinnervation were visible. CONCLUSION: The use of neuronavigation during hypoglossal-facial nerve anastomosis is a simple and cost-effective strategy to decrease operative duration and increase surgical effectiveness.

Comparison of Effectiveness, Feasibility, Indications, and Limitations of Different Intraoperative Dyes in Spinal Neuro-Oncologic Surgery. A Systematic Review.

BACKGROUND: Intramedullary spinal cord tumors (IMSCTs) are rare neoplasms and their management involves tumors resection in most cases. Regarding the surgical procedure, adequate identification of tumor boundaries is paramount to achieve an extensive tumor resection. Fluorescence image-guided surgery (FIGS) has become an increasing popular intraoperative technique used in spine neuro-oncology surgery. However, evidence is lacking of their usefulness and their safety in spinal tumors. Therefore, the aim of the present study is to give an update of the existing literature and systematically review all studies that focus on the most-used fluorophores (5 aminolevulinic acid [5-ALA], sodium fluorescein, and indocyanine green [ICG]) in IMSCTs. METHODS: Using PubMed and Scopus, we performed a systematic review in accordance with the PRISMA protocol and screened all original studies involving humans treated for neurosurgical conditions and studies evaluating FIGS application in IMSCTs. RESULTS: After the screening phase, 27 articles were found to be relevant. The literature results were grouped according to the used fluorophores, resulting in 3 groups: 5-ALA (10 studies); fluorescein (5 studies), and ICG (12 studies). CONCLUSIONS: In intramedullary tumor surgery, 5-ALA has shown its usefulness in identifying the tumor margins and in searching for residues because of its properties as a tumor-specific metabolic marker. Sodium fluorescein and ICG video angiography have shown promising application in ependymoma and hemangioblastomas surgery, respectively. However, the evolving role of fluorescent dyes in guiding surgical strategies in intramedullary spinal tumor has yet to be shown by randomized clinical trials.

Neurosurgical Defeats: Critically Ill Patients and the Role of Palliative Care Service.

The onco-functional balance in neuro-oncology requires maximizing tumor removal while rigorously preserving patients' neurological status. When postoperative worsening prevents the implementation of oncologic treatments, palliative care service offers an individualized path for symptom and psychosocial distress relief. Here, we report on a series of 25 patients operated on for malignant brain tumor who did not undergo adjuvant treatments after neurosurgery; they represented 3.9% of the whole institutional surgical series. These patients were significantly older and had a lower preoperative Karnofsky performance status than the whole cohort. Importantly, in 22 out of 25 (88%) cases, a surgical complication occurred, leading to clinical worsening in 21 patients. For the end of life, the majority of patients chose a hospice care facility (72%). While a careful selection of brain tumor patients candidate to neurosurgery is required, palliative care service provided invaluable help in coping with patients' and caregivers' needs.

Interpretable Machine Learning-Based Prediction of Intraoperative Cerebrospinal Fluid Leakage in Endoscopic Transsphenoidal Pituitary Surgery: A Pilot Study.

Purpose Transsphenoidal surgery (TSS) for pituitary adenomas can be complicated by the occurrence of intraoperative cerebrospinal fluid (CSF) leakage (IOL). IOL significantly affects the course of surgery predisposing to the development of postoperative CSF leakage, a major source of morbidity and mortality in the postoperative period. The authors trained and internally validated the Random Forest (RF) prediction model to preoperatively identify patients at high risk for IOL. A locally interpretable model-agnostic explanations (LIME) algorithm is employed to elucidate the main drivers behind each machine learning (ML) model prediction. Methods The data of 210 patients who underwent TSS were collected; first, risk factors for IOL were identified via conventional statistical methods (multivariable logistic regression). Then, the authors trained, optimized, and audited a RF prediction model. Results IOL reported in 45 patients (21.5%). The recursive feature selection algorithm identified the following variables as the most significant determinants of IOL: Knosp's grade, sellar Hardy's grade, suprasellar Hardy's grade, tumor diameter (on X, Y, and Z axes), intercarotid distance, and secreting status (nonfunctioning and growth hormone [GH] secreting). Leveraging the predictive values of these variables, the RF prediction model achieved an area under the curve (AUC) of 0.83 (95% confidence interval [CI]: 0.78; 0.86), significantly outperforming the multivariable logistic regression model (AUC = 0.63). Conclusion A RF model that reliably identifies patients at risk for IOL was successfully trained and internally validated. ML-based prediction models can predict events that were previously judged nearly unpredictable; their deployment in clinical practice may result in improved patient care and reduced postoperative morbidity and healthcare costs.

Ergonomics in Endoscopic Transsphenoidal Surgery: A Survey of the North American Skull Base Society.

Objective Different surgical set-ups for endoscopic transsphenoidal surgery (ETS) have been described, but studies on their ergonomics are limited. The aim of this article is to describe present trends in the ergonomics of ETS. Design and Participants A 33-question, web-based survey was sent to North American Skull Base Society members in 2018 and 116 responded to it (16% of all members). Most respondents were from North America (76%), in academic practice (87%), and neurosurgeons (65%); they had more than 5 years of experience in ETS (73%), had received specific training (66%), and performed at least 5 procedures/mo (55%). Results Mean reported time for standard and complex procedures were 3.7 and 6.3 hours, respectively. The patient's body is usually positioned in a straight, supine position (84%); the head is in a neutral position (46%) or rotated to the side (38%). Most surgeons perform a binostril technique, work with a partner (95%), and operate standing (94%), holding suction (89%) and dissector (83%); sometimes the endoscope is held by the primary surgeon (22-24%). The second surgeon usually holds the endoscope (72%) and irrigation (42%). During tumor removal most surgeons stand on the same side (65-66%). Many respondents report strain at the dorsolumbar (50%) or cervical (26%) level. Almost one-third of surgeons incorporate a pause during surgery to stretch, and approximately half exercise to be fit for surgery; 16% had sought medical attention for ergonomic-related symptoms. Conclusion Most respondents value ergonomics in ETS. The variability in surgical set-ups and the relatively high report of complaints underline the need for further studies to optimize ergonomics in ETS.