Neurosurgery

ObjectivesAcademic medical institutions are the gatekeepers of the physician workforce and shape the future of medicine by regulating medical school admissions as well as residency training. Although broadly the field of medicine is seeing more representation from traditionally underrepresented groups, the critical decision-making platform of academic medicine continues to be uncharacteristically homogeneous, represented mainly by white males. This is even more pronounced in surgical subspecialties, such as academic neurosurgery. This study aims to quantify this phenomenon, uncover its driving factors, and define opportunities for improvement. MethodsUsing a mixed research methodology, academic neurosurgical faculty in the U.S were identified, and their demographic data was collected. An internet search using Google Scholar and Scopus was conducted to determine scholarly activity using number of publications and h-index. ResultsWe found a significant increase in female faculty in academic neurosurgery within the last decade. Comparing the faculty rank amongst male and female faculty, we found that the majority of female faculty are at the assistant professor level (n=36/79; 45.6%) while male faculty are more at the full professor rank (n=265/582; 45.5%). A similar trend was seen for under-represented minority neurosurgery faculty. Strong scholarly activity corelated with a departmental chair position for male faculty, however, this trend was not true for female faculty. There was a significant difference in the number of publications and h-index in female vs male faculty, but only when including male faculty outliers at the full professor level. ConclusionSlowly but steadily, academic neurosurgery is making progress towards a more diverse and representative workforce in the U.S that better reflects the patient population. Facilitating timely progression of females and URM neurosurgeons into senior professorship and academic leadership roles will further advance this essential progress.

This research demonstrates that the trans-aqueduct approach is a feasible, minimally invasive access pathway to the third ventricle, offering a potential route to the deep brain for therapeutic technologies. Further pre-clinical investigation is required to thoroughly evaluate physiological tolerance, trauma risk, and the long-term implications of intraventricular implantation. The third ventricle is a high-value site for neuromodulation due to its proximity to deep-brain targets, including the subthalamic nucleus (STN) and globus pallidus internus (GPi). This study defined the anatomical pathway; and evaluated the technical feasibility of retrograde access to the third ventricle via the cerebral aqueduct using minimally invasive interventional techniques. Evaluation was conducted in three phases using human MRI datasets (n=16; mean age 48.4 years) and cadaveric specimens (n=6; mean age 88.2 years). Phase 1 involved morphometric MRI analysis of the aqueduct and ventricles. Phase 2 tested trans-aqueduct access on cadaver specimens via fluoroscopically guided guidewires and catheters. Phase 3 utilized direct anatomical dissections on cadaver specimens (n=3) to morphometrically measure the third ventricular cavity and its relationship to deep-brain nuclei. Measurements across the sample groups showed a mean aqueduct diameter of 1.6 mm (SD=0.14). Third ventricle dimensions averaged 27.6 mm (ventral-dorsal), 19.9 mm (caudal-cranial), and 5.7 mm (lateral). Successful access to the third ventricle was achieved in 83% (5/6) of cadaveric specimens. The optimal technical configuration utilized a 0.018'' angled-tip guidewire and 5-6 Fr catheters; the aqueduct accommodated diameters up to 2.0 mm with minimal resistance. The STN and GPi were localized within 5-20 mm of the ventricular volumetric centroid. The trans-aqueduct approach is a technically feasible, minimally invasive pathway for accessing the third ventricle. This route offers a potential alternative for the delivery of therapeutic neurotechnologies. Further research is required to assess physiological tolerance, trauma risk, and the long-term safety of intraventricular implantation.

Recovery of hand and arm function is critical for improving quality of life in individuals with tetraplegia due to spinal cord injury (SCI). Nerve transfer procedures can restore meaningful hand and arm function in chronic SCI, yet postoperative outcomes vary widely. We conducted a prospective, single-arm, open-label trial to assess the impact of intensive, robot-assisted rehabilitation training on functional recovery and cortical reorganization following nerve transfer. The primary endpoint was assessment of hand and arm function measured by the Box and Blocks Test. We report the results from three participants, AIS A at enrollment, who completed six weeks of intensive robotic training at least 1 year after nerve transfer surgery (NCT04041063). All participants demonstrated minimally important difference improvements in at least one secondary clinical outcome. These improvements were accompanied by cortical reorganization measured by transcranial magnetic stimulation motor mapping, indicating integration of the newly established peripheral motor pathways. No serious adverse events related to surgery or rehabilitation occurred. Although recruitment was limited by the COVID-19 pandemic and precludes definitive conclusions regarding efficacy, these findings suggest that standardized, intensive robotic rehabilitation may enhance functional outcomes after nerve transfer surgery for chronic tetraplegia.

Patients with brain tumors involving language-critical regions face surgical limitations when balancing resection with preservation of function. Non-invasive neuromodulation-induced prehabilitation (NIP) aims to guide preoperative neuroplastic reorganization, potentially facilitating larger resections while preserving function. We investigated whether NIP selectively modulates the targeted language network compared with control networks, and whether such modulation is behaviorally safe. We enrolled 26 patients (mean age = 55.9 {+/-} 11.8 years) from the Prehabilita project (Clinical Trial: NCT05844605) with operable brain tumors affecting language or motor regions. Eleven received language-targeted NIP, combining transcranial magnetic stimulation and/or transcranial direct current stimulation with intensive language training. Fourteen patients with NIP targeting non-language networks, primarily motor networks, served controls. Assessments included task-based functional magnetic resonance imaging (tb-fMRI) and a neuropsychological battery assessing language and cognitive domains before and after prehabilitation. Results indicated a group-specific NIP effect on the language network. In the language-targeted group, tb-fMRI revealed reduced overlap between a region of interest centered on the stimulation target and fMRI-derived language activation maps, whereas no comparable changes were observed in controls. No significant modulation effects were detected in the motor network in either group. These findings indicate that NIP can selectively reorganize the language network, with modulation patterns differing in sensorimotor networks. Importantly, language network modulation occurred while preserving language and cognitive performance. These results support NIP targeting higher-order functions such as language as a safe preoperative strategy that may reduce functional constraints on surgery and enable larger and safer resections in patients with tumors involving language-critical regions.

IntroductionDelivering large-bore aspiration catheters through tortuous anatomy remains challenging during mechanical thrombectomy (MT). The Carrier delivery-assist catheter (DAC) was designed to facilitate aspiration catheter navigation, but multicenter data remain limited. We evaluated the efficiency and safety of the Carrier DAC. MethodsWe performed a multicenter retrospective study of prospectively collected data from patients undergoing MT at 15 U.S. Comprehensive Stroke Centers (September 2024-September 2025). Co-primary endpoints were puncture-to-clot engagement time and first-pass effect (FPE; eTICI 2c-3). A pre-specified single-center analysis compared upfront contact aspiration using the Carrier DAC versus standard 0.021'' microcatheter techniques with identical aspiration catheter sizes. ResultsThe multicenter cohort included 211 Carrier-assisted MTs. Median aspiration catheter inner diameter was 0.071'', with super-bore catheters used in 5.7%. Median puncture-to-clot time was 12 minutes, and FPE was achieved in 50.7%. Median puncture-to-reperfusion time was 20 minutes, and mFPE occurred in 74.4%. Parenchymal hematoma and subarachnoid hemorrhage occurred in 11.8% and 6.6%, respectively. Cavernous tortuosity did not affect primary endpoints. The single-center analysis included 242 patients. Carrier use was associated with shorter puncture-to-clot times and numerically higher FPE rates without increased hemorrhagic complications. ConclusionsThe Carrier DAC enables efficient navigation of large-bore aspiration catheters and may reduce procedural time while maintaining procedural safety. Prospective studies are warranted.

Spinal cord injury (SCI) is a devastating neurological injury that results in the profound loss of voluntary motor function and marked reduction in quality of life. Rehabilitation remains as the standard of care for recovery after SCI; however, it often falls short in recovering meaningful motor function. Spinal cord stimulation (SCS) has emerged as a promising neurostimulation approach to fill this gap and recover lost voluntary motor function. Two main approaches of SCS have been designed and implemented for human use: epidural and transcutaneous SCS. Over the last two decades, several clinical studies have shown convincing evidence that both epidural and transcutaneous SCS can be used in conjunction with rehabilitation to improve motor function of individuals after SCI. Yet fundamental clinical questions remain unanswered: when should clinicians choose epidural or transcutaneous SCS, which technique provides the most durable outcomes, and for whom is each therapy best? Without these answers, widespread and meaningful adoption of either approach into clinical practice will remain limited. To address these questions, in this Review, we define the distinct therapeutic goals, intended use cases, clinical parameters, and responder profiles for both epidural and transcutaneous SCS to guide their eventual adoption into clinical practice. We found that indeed epidural and transcutaneous SCS serve distinct therapeutic roles. Epidural SCS is designed as an assistive therapy that can restore muscle activity and single joint movements immediately within one week of implantation, while transcutaneous SCS is designed as a long-term therapeutic device with cumulative functional gains observed over treatment periods of up to 18 weeks. Lastly, epidural SCS produced benefits for all participants (AIS A-D) despite the extent of their injury, while transcutaneous SCS only consistently benefits individuals with incomplete motor injuries (AIS C-D).

High-density electrophysiological recording using Neuropixels probes enables single-unit resolution of human neural activity. However, integrating these systems into clinical environments remains challenging. Reported human recordings have been limited to a few centres in the United States utilising variable regulatory, sterilisation and operative techniques. Here, we present human Neuropixels recordings under a nationally managed ethical and regulatory framework in the United Kingdom. We provide a reproducible roadmap to overcome regulatory and equipment constraints. Guided by the IDEAL Stage 2a (Development) framework, we established a frameless intraoperative workflow utilising manufacturer-sterilised probes and a commercially available, clinical-grade setup for Neuropixels insertion including micromanipulator and endoscope holder. We prospectively evaluated this workflow across six participants (mean age 62.5 years) undergoing elective ventriculoperitoneal shunt surgery. Iterative failure-mitigation cycles successfully resolved key technical barriers, including neuronavigation interference and hardware instability. Assessed across three predefined endpoints (clinical safety, procedural timing, and neural data yield), the workflow achieved zero research-related adverse events and maintained a strict 30-minute procedural extension. Progressive technical refinements increased single-unit yield from 25 units during early development to 146 manually curated units. This approach provides a scalable, clinically integrated workflow to safely perform high-density electrophysiology in routine neurosurgical environments.

Background: Poor-grade aneurysmal subarachnoid hemorrhage (aSAH) remains associated with high mortality and severe disability, yet contemporary outcomes may differ substantially from historical estimates. We performed a systematic review and meta-analysis to evaluate long-term outcomes after poor-grade aSAH and assess temporal, geographic, and treatment-related factors associated with prognosis. Methods: PubMed/MEDLINE, Embase, Cochrane Central, Scopus, and Google Scholar were searched from inception through March 2026. Studies enrolling consecutive adults with poor-grade aSAH (World Federation of Neurosurgical Societies grades IV-V, Hunt-Hess grades IV-V, or equivalent) reporting mortality and/or functional outcomes at 3 months were included. To minimize survivorship bias, studies excluding untreated patients or patients dying before aneurysm treatment were excluded. Random-effects meta-analyses of proportions were performed using generalized linear mixed models. Prespecified subgroup analyses and exploratory meta-regression analyses evaluated temporal, geographic, and treatment-related factors associated with outcomes. Results: Forty-two studies including 7,726 patients from 16 countries across 4 continents were included. The pooled favorable functional outcome rate was 27.2% (95% CI, 23.9%-30.8%), whereas pooled overall mortality was 53.3% (95% CI, 49.0%-57.5%). Pre- and post-treatment mortality were 25.9% and 33.9%, respectively. Aneurysm treatment rate was 72.0% (95% CI, 65.6%-77.7%). Favorable outcomes improved over time from 13.5% (95% CI, 7.0%-24.3%) in the 1980s to 33.7% in the 1990s but plateaued thereafter. In exploratory meta-regression analyses, higher aneurysm treatment rates were independently associated with improved favorable functional outcome (0.134 log-odds increase per 10% increase in treatment rate; p = 0.01) and lower mortality (-0.224 log-odds per 10% increase in treatment rate; p < .001). Publication year was associated with lower mortality (p = 0.03) but not favorable outcome. Geographic region, country income group, and the proportion of grade V patients were not independently associated with outcomes. Conclusions: Mortality after poor-grade aSAH remains high, but approximately one-third of patients achieved favorable outcome. Higher aneurysm treatment rates were independently associated with improved functional outcomes and lower mortality.

Introduction: Early exposure to otolaryngology (ENT) procedural skills in undergraduate medical education is limited by patient safety concerns, restricted clinical opportunities, and the cost of commercial simulators. As a result, essential ENT skills are often underrepresented in structured, hands-on curricula for medical students. Methods: We developed a low-cost, multistation ENT simulation curriculum consisting of five reproducible task trainers: ear examination and otologic procedures, mirror laryngoscopy, rigid and flexible endoscopic navigation, introductory mastoid drilling, and emergency cricothyrotomy. The curriculum was delivered as a 2-hour, faculty-led workshop during a third-year medical student otolaryngology rotation. Learners rotated through stations in small groups. Pre- and post-workshop surveys assessed self-reported anatomical familiarity, procedural confidence, and educational value using a 5-point Likert scale, with additional qualitative feedback collected. Results: All participants completed pre- and post-workshop evaluations. Learners demonstrated increased confidence across all assessed anatomical and procedural domains, including otoscopy, endoscopy, mirror laryngoscopy, mastoid drilling orientation, and cricothyroid membrane identification. Educational value ratings were high across all stations, with mean scores ranging from 4.33 to 5.00. Qualitative feedback emphasized the realism, accessibility, and benefit of hands-on practice in a low-stakes learning environment. Conclusion: This low-cost, multistation ENT simulation curriculum provides a feasible and reproducible approach for introducing foundational otolaryngology skills to medical students. The structured format and affordable models support early procedural exposure and may enhance learner preparedness prior to supervised clinical encounters, particularly in settings with limited simulation resources.

Effective modulation of cortical-subcortical motor circuits is essential for post-stroke recovery, yet progress has been constrained by the absence of non-invasive tools capable of precisely targeting deep brain structures. In this pilot proof of concept study, we explored the feasibility and preliminary neuromodulatory effects of a 12-minute transcranial focused ultrasound (tFUS) protocol targeting the ipsilesional ventral lateral posterior (VLp) thalamus in ischemic stroke patients. Six individuals with upper-limb hemiparesis received individualized, neuronavigation-guided tFUS. Sensorimotor tracking performance improved signiffcantly after a single session. Concurrent EEG revealed reversible beta-power suppression over the ipsilesional motor cortex and enhanced theta-phase synchronization in frontoparietal networks, both of which were associated with behavioral gains. Resting-state fMRI indicated rebalancing of inter-hemispheric motor networks. These preliminary ffndings suggest that thalamic tFUS can modulate both local and networklevel neural activity and is associated with immediate functional improvement, highlighting its potential as a feasible neuromodulation approach for deep motor circuit engagement in post-stroke rehabilitation.

Purpose DICER1-mutant primary intracranial sarcoma (PIS-DICER1) is a rare, recently defined high-grade intracranial tumor. This systematic review and meta-analysis aimed to comprehensively investigate its imaging characteristics to improve preoperative diagnostic accuracy and facilitate differential diagnosis. Methods A systematic literature search was conducted in PubMed and Web of Science for studies published up to December 31, 2025. Original studies with pathologically and molecularly confirmed PIS-DICER1 and detailed imaging data were included. Imaging features, including tumor location, margin definition, meningeal contact, intratumoral hemorrhage, enhancement pattern, cystic components, peritumoral edema, and advanced imaging findings (SWI, DWI, MRS, PWI), were extracted and analyzed. Pooled proportions with 95% confidence intervals (CIs) were calculated using a random-effects model. Results Twenty-four studies comprising 110 patients with detailed imaging data were included. The pooled mean age was 18.6 years (95% CI: 15.2-22.0), with a slight female predominance (53.3%, 96/180). Tumors were predominantly supratentorial (87%, 95% CI: 80%-93%). Substantial heterogeneity was observed across studies for location (I2 = 78%). Intratumoral hemorrhage was observed in 85% (95% CI: 78%-91%). Contrast-enhanced MRI demonstrated heterogeneous enhancement in all cases (100%, 95% CI: 96%-100%). Due to sparse data, advanced MRI features could not be quantitatively synthesized, underscoring a critical knowledge gap. Conclusion PIS-DICER1 exhibits imaging features including supratentorial location, intratumoral hemorrhage, heterogeneous enhancement, well-defined margins, and meningeal involvement. These features, particularly in children and young adults with hemorrhagic supratentorial masses, should prompt differential diagnosis. Definitive diagnosis requires molecular confirmation, but recognition of these characteristics facilitates diagnosis and preoperative planning.

BackgroundManual video-based evaluation of surgical skills can be time-consuming and delays trainee feedback. Artificial intelligence (AI) offers opportunities to automate aspects of assessment while maintaining clinician oversight. We developed an interpretable spatiotemporal model that classifies surgical expertise directly from endoscopic video in standardized training tasks and generates saliency-based "highlights reels" showing the most influential frames. MethodsAn RGB pipeline combining InceptionV3 for spatial feature extraction and a gated recurrent unit (GRU) for temporal modeling was trained on the JIGSAWS dataset. The model outputs novice, intermediate, or expert labels. A rolling-window, low-latency evaluation at 30 fps with a stride of 10 frames was used. A motion-augmented variant fused RGB with optical-flow features. Spatial and temporal saliency maps highlighted key decision-making regions. ResultsThe RGB model achieved 95% accuracy (F1: 92% expert, 86% intermediate, 99% novice). Performance was strongest for novice and expert trials, while intermediate trials showed the lowest recall, consistent with greater ambiguity around the intermediate skill level. Saliency maps consistently emphasized tool-tissue interactions and peaked during technically demanding phases. The optical-flow variant underperformed, approximately 38% accuracy, which may reflect sensitivity to global camera motion and other non-informative motion patterns. ConclusionsThis interpretable AI pipeline accurately classifies surgical skill while producing intuitive visual highlights. Future work will refine highlight thresholds and validate on laparoscopic inguinal hernia repair for realworld deployment.

Background: Deep brain stimulation (DBS) is a widely used therapy for neurologic and psychiatric disorders. Conventional DBS delivers highly regular stimulation patterns that suppress pathological activity but can induce stimulation-related side effects, limiting the therapeutic window. Introducing controlled temporal variability through stochastic pulse timing may represent an alternative programming dimension to improve tolerability while preserving clinical benefit. Methods: An adult in their 60's with bilateral Vim DBS underwent evaluation of tonic, pink-noise, and white-noise stimulation patterns delivered through his chronically implanted Boston Scientific Genus system using the Chronos research platform. We assessed tremor and stimulation-induced side effects using accelerometry, spiral drawing tasks, standardized speech recordings, and patient-reported paresthesias. Results: Pink noise stimulation preserved meaningful tremor suppression while improving tolerability compared with conventional tonic 130 Hz stimulation. Under tonic stimulation, dysarthria and paresthesias were prominent at 2.0 mA, narrowing the usable therapeutic window. In contrast, pink noise maintained tremor control across the same amplitude range with reduced side-effect burden. White noise stimulation demonstrated intermediate effects, providing improved tolerability relative to tonic stimulation but less tremor suppression than pink noise. Findings were consistent across accelerometry and functional drawing tasks. Conclusion: This study provides first-in-human evidence that temporally structured stochastic pulse timing can preserve therapeutic benefit while expanding the tolerable stimulation range relative to tonic DBS. These findings suggest that temporal structure represents a clinically meaningful programming dimension that may broaden the DBS therapeutic window using software based updates to existing hardware. Further evaluation in larger cohorts is warranted

Background: Endoscopic endonasal transsphenoidal surgery (EETS) requires navigation around neurocritical anatomy. Today, artificial intelligence clinical decision support systems (AI-CDSSs) can orientate surgeons, but clinician trust in AI remains unclear, limiting safe deployment. This study evaluates how modifiable design affects trust and performance in a real-world pituitary surgery AI-CDSS. Method: Online, 70 clinicians with pituitary surgery experience were randomised evenly to a Basic or Enhanced AI-CDSS which outline the sella on EETS operative video. The Enhanced group additionally received explanation of the model and previous publications, alongside confidence labels depicting outline reliability. Both groups annotated the sella on six video clips, first alone then with the optional AI-CDSS. Clips were ordered by declining AI performance, except for the final clip. Self-reported trust was measured using a 1-7 scale after each annotation, and performance was the DICE overlap between user annotations and the ground truth. Comparisons used Mann-Whitney U and permutation analysis. Results: Sixty-four participants (91%) finished the exercise (31 Basic, 33 Enhanced). When AI performed best, median trust was 5.00 in both arms (U=559, p=.521). However, when AI performed worst, trust was significantly lower for the Enhanced group (3.00 vs 3.67, U=668, p=.035), sustained in the final clip (3.67 vs 4.33 U=687, p=.019). User performance improved with the AI-CDSS, but with no significant difference between the groups on the best or worst AI performing clips. Nevertheless, for the best AI, senior clinicians had higher median performance in the Enhanced group (0.95 vs 0.90, U=75, p=.066). There was also less dispersion in the Enhanced group when AI was inaccurate (IQR: 0.07 vs 0.21, p=.004). Conclusion: Interface design can improve trust calibration in a surgical AI-CDSS and may increment performance in seniors when AI is accurate, and consistency when AI is inaccurate. In future, these features may form important safety checks during translation to the operating room.

Artificial intelligence (AI) decision support systems for surgery hold promise but face barriers to adoption, particularly around the interpretability of their outputs. We conducted an international cross-sectional survey of 47 neurosurgeons to evaluate perspectives on literature-derived explanation techniques for AI-generated anatomical segmentations, using endoscopic pituitary surgery as a high-risk exemplar. Participants ranked certainty scores, certainty maps, saliency maps, scene similarity scores, and nearest-neighbour illustrations, and rated them using a modified Explanation Satisfaction Scale alongside free-text feedback. Certainty-based techniques were consistently ranked and rated highest for interpretability - valued for aligning with surgical decision-making by conveying confidence (via scores) and anatomical boundaries (via maps). Saliency- and similarity-based methods were judged less clinically relevant and better suited to educational settings. Certainty-based explanations, therefore, appear most acceptable to surgeons for clinical integration of decision support systems, though their impact on AI acceptability, trust calibration, and performance requires prospective evaluation across surgical domains.

Background: Meningiomas are the most common primary intracranial tumors in adults, and volumetric assessment increasingly guides surveillance and treatment decisions. Automated segmentation could enable standardized volumetry but requires robust validation. Purpose: To develop a fully automated three-dimensional deep learning model for meningioma segmentation on multiparametric MRI, and to evaluate segmentation accuracy, external generalizability, failure modes, radiologist-rated clinical plausibility, and workflow feasibility. Methods: From 2024 to 2026, this retrospective study trained a custom 3D nnU-Net residual encoder model. Expert segmentations covered enhancing tumor (ET), tumor core (TC), and whole tumor (WT). Dice similarity coefficient (DSC) was the primary metric. External validation used an independent single-institution dataset (n = 310 intracranial cases) with incomplete MRI protocols. Failure modes, model equity, and inference time were assessed. A blinded multi-rater study (10 radiologists; 510 cases) rated TC segmentations using a 0-10 Likert scale, analyzed with linear mixed-effects models. Results: Model training used the BraTS Meningioma 2023 dataset (n = 1000; mean age 60.2 {+/-} 14.5; 705 female). In cross-validation, mean DSC was 0.939 for ET, 0.937 for TC, and 0.921 for WT. In external validation, mean DSC was 0.872 for TC and 0.842 for WT, despite heterogeneous protocols and incomplete sequences. Predicted TC volumes correlated strongly with reference volumes in cross-validation (r = 0.995) and external validation (r = 0.971). Most common failure modes were skull base and intraosseous tumors with performance equitable across demographic subgroups. Mean inference time was 1.2 seconds. In blinded evaluation (1120 ratings), model segmentations received higher scores than reference annotations (+0.32 BraTS; +1.38 external validation). Conclusion: A fully automated deep-learning model achieved high meningioma segmentation accuracy across multi-institutional training data and external clinical imaging. In a blinded study, model segmentation quality exceeded reference annotations, and 1.2-second inference supported workflow integration. Prospective evaluation is warranted before routine deployment.

Background Endoscopic pituitary surgery involves navigating high-stakes anatomy where complications, such as carotid artery injury, cause devastating morbidity. While computer vision AI offers potential for real-time anatomical recognition to mitigate these risks, successful translation requires rigorous human-factors and performance evaluation. We present the iterative development and preclinical evaluation of a surgeon-controlled, real-time AI-assisted navigation system. Methods Guided by IDEAL Stage 0 and DECIDE-AI frameworks, the study was conducted in two phases. Phase 1 was an exploratory study where surgeons used the system during high-fidelity simulated surgery and provided feedback via "Think Aloud" protocols and surveys. Following prototype iteration, a Phase 2 randomized crossover comparative trial was conducted with 19 neurosurgeons (15 trainees, 4 experts) performing high-fidelity simulated tumour resections with and without AI assistance, separated by a minimum 2-week washout. The primary outcome was surgical technical performance (OSATS). Workload, educational value, usability, trust, and implementation outcomes were also assessed. Results Phase 1 informed hardware, model, and interface refinements, including optimized pedal-controlled overlays and prediction confidence metrics. In the comparative trial, AI assistance significantly improved overall technical performance (OSATS 19.79+/-4.06 vs. 17.32+/-4.11; p=0.027). This gain was experience-dependent; AI significantly augmented trainee performance (19.20+/-3.76 vs. 16.60+/-3.78), narrowing the proficiency gap, while expert performance remained high and stable. 100% of participants identified the system as a useful training tool. However, subjective workload was significantly higher in the AI arm (SURG-TLX 26.42+/-9.56 vs. 22.26+/-7.81; p=0.014). Despite this, usability (SUS 75.13+/-14.31) and implementation feasibility, acceptability, and appropriateness scores were consistently high (means >4.4/5). Conclusions This study provides a stepwise process for real-time AI development using pituitary surgery as a high-stakes exemplar. The refined surgeon-centric AI system improves training and technical performance, particularly for trainees. Next steps involve first-in-human studies and further exploration of longer-term human factors such as over-reliance, cognitive overload mitigation and trust calibration.

ABSTRACT Background: Randomized trials have shown comparable reperfusion rates among stent-retriever, contact-aspiration, and combined thrombectomy techniques. We aim to evaluate the association between operator device-selection preference and procedural performance metrics. Methods: Retrospective analysis of prospective data from a comprehensive stroke center. Preferred technique was defined as a technique used in >50% of an operator's thrombectomies. Main exposure: proportion of usage of a given technique by operators in a certain period; primary endpoint: rate of first-pass effect(FPE). Results: 1405 patients fit inclusion criteria. The first time period(2019- mid 2022/n=839) included 4 operators(3 experienced/1 starting practice), with CoT being overall used in 58.9%, SR in 24.4%, and CA in 16.7%. The second( mid 2022-2024/n=566) included 4 total operators(2 experienced/2 starting), with CA reaching 48.2%, CoT 39.8% and SR 12.0%. The distribution of techniques varied between intra-/inter-operators and most(75.0%) had a preferred technique. The technique with the highest FPE rate was never the most used technique. The chances of operators achieving FPE were not dependent on the previous cumulative success for a given technique. Increasing case volume was associated with higher FPE on average, but the learning rate differed by technique and only contact aspiration had a significant learning curve. The parenchymal hemorrhage rates were comparable for individual operators regardless of technique. Conclusion: Neurointerventionists tended to rely on a preferred technique, which did not necessarily lead to superior reperfusion outcomes. The cumulative success with a given technique did not increase the likelihood of attaining FPE in subsequent cases. Among new operators, a learning curve for contact aspiration was observed.

BackgroundEven for experienced operators, endovascular treatment of unruptured intracranial aneurysms involves intraoperative uncertainty that may lead to adjustments in strategy, prolong the procedure, and potentially cause inefficiency and device waste. This study aimed to evaluate whether pre-procedural testing (PPT) of endovascular treatment using patient-specific models was associated with increased operator confidence and perceived clinical utility, including improvements in procedural efficiency and reduced resource waste. MethodsWe enrolled a cohort of patients who underwent PPT before endovascular treatment for complex unruptured intracranial aneurysms and compared their outcomes with a control group treated without PPT. The primary outcome was the Training Fidelity Score, a composite of three operator-reported Likert items defined a priori. Secondary outcomes included perceived clinical utility, intraoperative strategy changes, procedural time, radiation exposure, device waste and safety. ResultsA total of 85 patients met the inclusion criteria (PPT=40; control=45). The Training Fidelity Score was high across the PPT group (median, 4.33/5). Perceived clinical utility was high and further increased significantly after the procedure. A significant reduction was observed in intraoperative strategy changes, with no changes recorded in the PPT group, compared to 6/45 in the control group (RR 0.09; p=0.027). Reductions in treatment time, radiation exposure and device waste were also noted. ConclusionPPT using patient-specific models was associated with increased operator confidence, fewer intraoperative strategy changes, improved procedural efficiency, and reduced device waste without compromising safety. These findings support its use in pre-interventional preparation, but require prospective multicenter validation.

Parkinsons disease patients may experience a different therapeutic effect after replacement of the Medtronic Activa(R) deep brain stimulation neurostimulator with the newer Percept model, which features multiple independent current sources and constant-current control. We analyzed patient-reported therapeutic effect changes after Activa(R)-to-Percept replacements (AP, n=52) across six Dutch DBS-centers, comparing appropriate (AP+, n=36) and inappropriate/no (AP-, n=16) use of the manufacturers replacement workflow. Previous Activa(R)-to-Activa(R) replacements (AA, n=69) were used as reference. Worsened therapeutic effect was reported in 75.0% of AP-, 44.4% of AP+, and 21.7% of AA replacements (p<0.001). In the AP group, most patients with worsened effect were previously programmed with constant-voltage. Concluding, the risk of worsened therapeutic effect following AP replacements is higher compared to AA replacements, in particular when the replacement workflow is not properly used or in complex electrode configurations. We advise to use the workflow, inform the patient and plan closer follow-up appointments.