Category: Surgical technique

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Relationships Between Surgical Approach, Tumor Classification Scheme, and Early Neurocognitive Outcome After Awake Craniotomy for Resection of Insular Glioma

Operative Neurosurgery 30:880–889, 2026

This study evaluates early postoperative neurocognitive outcomes after awake craniotomy for insular glioma resection, comparing transcortical and transsylvian approaches and examining tumor classification schemes. It reports frequent, domain-specific declines—most notably in memory and verbal fluency—and analyzes relationships with tumor hemisphere, insular zone, and extension.

The authors found similar overall neurocognitive change across surgical corridors but identified higher verbal fluency decline with transcortical approaches and greater domain-specific risk linked to left-sided tumors, extra-insular extension, and anterior or inferior insular involvement.

Study aim: Assessed how surgical approach (transsylvian vs transcortical) and tumor classification/location relate to early postoperative neurocognitive function (NCF) after awake resection of insular glioma.

Cohort & design: Retrospective series of 53 newly diagnosed insular glioma patients (47% high-grade; 75% left hemisphere) treated with awake craniotomy, with neuropsychological testing pre-op and within 60 days post-op.

Classification schemes: Tumors were categorized by Berger–Sanai zones (collapsed to anterior/posterior/superior/inferior) and Pitskhelauri extension groups (insula only; insula + extension; predominantly extra-insular).

Overall NCF change: Postoperative decline occurred across multiple domains, with the largest effects most often in memory and verbal fluency (executive function).

Frequency of clinically meaningful decline: 85% declined on ≥1 test (Δz ≤ −1.0), 52% on ≥2 tests, and 22% on ≥5 tests; decline was most frequent/severe in memory and also common in executive function, attention, and processing speed.

Surgical approach comparison: Mean NCF change generally did not differ by approach, but the transcortical approach showed a higher rate of verbal fluency decline than transsylvian (61% vs 26%).

Tumor hemisphere & localization effects: Left-hemisphere tumors were linked to poorer outcomes on multiple tests (notably memory, verbal fluency, naming, and token comprehension), while anterior tumors had worse executive function (mental flexibility) than posterior, and inferior lesions had worse recognition memory than superior.

Tumor extent/size associations: Predominantly extra-insular tumors had greater fluency reduction than insula-only; more Berger–Sanai quadrants involved correlated with worse executive function change; larger tumor volume and higher postoperative FLAIR volume related to worse processing speed and comprehension outcomes.

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The posterior approach for removal of all thoracic disc herniations

J Neurosurg Spine 44:876–883, 2026

his single-surgeon series evaluates a posterior partial transpedicular approach for symptomatic thoracic disc herniation augmented by intraoperative ultrasound (IOUS) and ultrasonic aspiration (UA). Over 108 patients (137 discs) treated from 2012–2024, the technique produced significant neurological improvement with an acceptable complication and reoperation profile.

The report details patient selection, operative steps, radiographic grading, neuromonitoring use, outcomes (Frankel grade improvements), and multivariate predictors, highlighting the method’s versatility for giant and calcified herniations and its accessibility to general spine surgeons.

Clinical problem Thoracic disc herniation is surgically challenging due to ventral location, frequent calcification, and risk of severe neurologic compromise; anterior/lateral approaches can be effective but carry substantial morbidity and technical demands.

Study aim Evaluated safety, efficacy, and versatility of a posterior partial transpedicular discectomy augmented with intraoperative ultrasound (IOUS) and ultrasonic aspiration (UA) for symptomatic TDH.

Cohort & design Retrospective single-surgeon series of 108 consecutive patients (137 TDHs) treated from 2012–2024; outcomes tracked with Frankel grades preop, 3–6 months, and final follow-up; multivariate regression used to identify predictors of improvement.

Key technique Posterior midline exposure with laminectomy, <50% medial facetectomy, and superomedial caudal pedicle removal using UA to create a corridor; IOUS used after laminectomy, during ventral work, and after resection to confirm decompression and detect residual/migrated fragments; IONM used in all cases.

Case mix severity Most patients presented with myelopathy (86.1%); many discs were giant (>40% stenosis, 68.6%) and frequently calcified (complete 38.7%, incomplete 21.2%).

Neurologic outcomes Mean Frankel grade improved from 3.77 preop to 4.54 at last follow-up (p < 0.001); 61.1% improved by ≥1 Frankel grade; follow-up for the primary outcome was 100%.

Safety & complications IOUS and UA enabled safe decompression in all cases; reoperation-requiring complications occurred in 9.3% (most commonly reherniation 4.6%); no postoperative CSF leaks through the wound were reported.

Predictors & conclusion Less neurologic improvement was associated with diabetes and obesity (and heart disease); overall conclusion: posterior partial transpedicular approach with IOUS and UA is safe, effective, and broadly applicable for TDH (including large/calcified lesions) and can be adopted by general spine surgeons.

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History and evolution of the far‑lateral approach in neurosurgery

Acta Neurochirurgica (2026) 168:122

This review chronicles the development and technical refinement of the far‑lateral approach (FLA) for accessing the foramen magnum, lower clivus, and craniovertebral junction, tracing its origins from lateral suboccipital exposures to contemporary transcondylar, supracondylar, paracondylar, and extreme lateral transodontoid variants. It summarizes modifications in skin incisions, bony resection strategies, VA management, positioning, and closure techniques that improved exposure while minimizing brain retraction and craniovertebral morbidity.

The article evaluates clinical outcomes, biomechanical data, and technological integrations—endoscopic assistance, neuronavigation, and neuromonitoring—emphasizing a tailored, pathology-driven philosophy: remove only the bone necessary, mobilize the vertebral artery judiciously, and consider occipitocervical fusion when stability thresholds are exceeded to balance maximal resection with minimal long‑term instability and CSF complications.

Purpose: Provides a more anterior, tangential corridor to the foramen magnum/lower clivus/CVJ for ventrolateral or anterior brainstem pathology, reducing the need for brainstem/cerebellar retraction compared with older midline posterior and transoral routes.

Origins: Evolved from posterolateral aneurysm surgery—early unilateral suboccipital routes in the 1970s, with the first detailed “lateral suboccipital” (far-lateral) description by Heros in 1986 to reach distal vertebral and basilar trunk aneurysms by extending bone removal to the lateral foramen magnum rim.

Key bone-work concept: The major exposure-expanding step is selective occipital condyle drilling (transcondylar variant), typically about one-third to one-half to improve the angle of attack while aiming to preserve craniocervical stability; complete condyle removal is rare and generally prompts fusion.

Modular variants: The approach is used as adjustable “modules,” most notably transcondylar, supracondylar (jugular tubercle drilling), and paracondylar extensions, chosen based on lesion location and direction of extension.

Soft-tissue refinements: Incisions shifted from simple linear cuts to more tailored curvilinear/hockey-stick/C-shaped designs with larger musculocutaneous flaps to improve exposure, enable layered closure, and reduce wound/CSF-leak complications.

Positioning evolution: Use moved away from sitting (air embolism risk) toward lateral/modified park-bench positioning to leverage gravity-assisted relaxation and minimize fixed retraction.

Neurovascular strategy: Standardization of extradural vertebral artery (V3/V4) exposure and mobilization (when needed) improved proximal control and widened the corridor, turning the artery from an obstacle into a structure that can be safely managed to expand working space.

Modern extensions & technology: Continued refinement includes endoscope-assisted visualization, neuronavigation, and neuromonitoring; an extreme extension (ELTO) adds aggressive bony removal (including odontoid/C1 elements) for midline-crossing lesions but carries high instability risk, so occipitocervical fusion is typically performed.

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The utility of partial sensory rhizotomy and adjunct procedures in the surgical management of trigeminal neuralgia secondary to multiple sclerosis

J Neurosurg 144:1145–1153, 2026

This clinical study evaluates long-term outcomes of partial sensory rhizotomy (PSR) for trigeminal neuralgia (TN) secondary to multiple sclerosis (MS), comparing PSR alone, redo PSR, and PSR combined with microvascular decompression (MVD) or internal neurolysis (IN). Retrospective analysis of 37 procedures in 30 patients shows high immediate pain relief (89.2%), mean recurrence at 1.64 years, and variable durability across groups.

At final follow-up, combination therapy (PSR+MVD or PSR+IN) trended toward superior sustained pain freedom without increased complications, while first PSR commonly required additional interventions. The authors conclude PSR is an effective salvage option and suggest adjunctive MVD or IN may improve long-term outcomes, recommending prospective validation.

Objective Evaluate long-term outcomes of partial sensory rhizotomy (PSR) alone versus PSR combined with microvascular decompression (MVD) or internal neurolysis (IN) for trigeminal neuralgia secondary to multiple sclerosis.

Methods Retrospective review of PSR cases (2012–2023) grouped as first PSR, redo PSR, PSR+MVD, and PSR+IN; assessed pain outcomes, recurrence, and complications.

Cohort 30 patients underwent 37 procedures; 89.2% of procedures followed at least one prior ipsilateral TN procedure.

Immediate outcomes 89.2% achieved immediate postoperative pain relief (pain free with or without medication), with no significant differences between procedure groups.

Durability Pain recurred on average at 1.64 ± 1.71 years after the procedure, with no significant differences among groups.

Final follow-up pain freedom At mean 3.14 ± 2.58 years follow-up, 75% of PSR+MVD and 100% of PSR+IN cases were pain free; 52.3% of first PSR cases required additional procedures.

Complications Overall complication rate was 29.7% with no significant differences between groups; ipsilateral facial numbness was common (59.5%) and treated as an expected outcome rather than a complication.

Conclusion PSR functions effectively as a salvage option for MS-related TN, and adding MVD or IN may improve long-term pain relief without increasing complication rates.

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Addressing Temporal Muscle Atrophy and Enhancing Cranioplasty Outcome

Operative Neurosurgery 30:588–594, 2026

This multicenter prospective study evaluates a dual-layer dural substitute technique during decompressive craniectomy to prevent adhesions between the temporalis muscle and dura, thereby improving subsequent cranioplasty outcomes. Across 59 patients, the method reduced adhesions, preserved temporalis muscle thickness, shortened cranioplasty operative time, minimized blood loss, and eliminated postoperative cranioplasty-related seizures.

The paper details surgical steps, material selection (Neuro-Patch), intraoperative placement of two dural layers, and cranioplasty retrieval of the superficial patch to restore muscle function. Results show improved wound healing metrics, shorter hospital stays, and a low complication profile, while noting limitations including lack of a control group and nonstandardized long-term follow-up.

Problem: After decompressive craniectomy (DC), adhesions commonly form between the temporalis muscle (TM), dura, and brain surface, making later cranioplasty (CP) dissection difficult and increasing risks such as TM injury/atrophy and poor cosmetic outcome.

Technique: During DC, place a dual-layer dural substitute—a large patch for duraplasty plus a second patch beneath the TM (and sometimes an additional patch between TM and subcutaneous tissue)—to preserve a separable plane for future CP.

CP approach: During CP, reopen the prior incision and elevate the musculocutaneous flap between the two Neuro-Patch layers, then remove the patch under the TM and reposition the TM anatomically over the implant.

Study design: Three-year prospective multicenter series of 59 patients undergoing DC then CP; outcomes included adhesion formation, ease of dissection, TM thickness (CT-based), operative time, blood loss, and postoperative events.

Adhesion/TM preservation results: TM elevation during CP was consistently facilitated with nearly absent fibrotic adhesion, and TM thickness remained essentially unchanged pre- vs postoperatively (median 5.6 mm vs 5.5 mm).

Operative metrics: Median CP operative time was 66 minutes vs a previously estimated 105 minutes in centers not using the technique; mean blood loss was 24 mL.

Safety/complications: No reported infections, wound dehiscence, or CSF leak after DC and CP; 0% post-CP new-onset seizures in this cohort.

Conclusion: Dual-layer dural substitute placement during DC can prevent adhesions and improve subsequent CP by facilitating TM elevation, reducing operative time and blood loss, preserving TM integrity, and potentially lowering post-CP epilepsy rates.

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Simple Microvascular Decompression for Hemifacial Spasm Caused by Dolichoectatic Vertebral Artery

Operative Neurosurgery 30:606–609, 2026

This operative case report describes a straightforward microvascular decompression (MVD) technique for hemifacial spasm (HFS) caused by a dolichoectatic vertebral artery (VA), emphasizing translocation and padding of the root entry zone (REZ) with Teflon pledgets. The 67-year-old patient underwent retrosigmoid craniotomy with safe mobilization of the VA, achieving immediate and sustained symptom resolution despite residual distal contact.

The authors compare REZ-focused decompression to more complex options such as sling transposition and binder-ring bypass, arguing that limited REZ decompression offers a simpler, lower-risk solution when complete arterial mobilization is unfeasible. Operative nuances, monitoring, outcomes, and literature context are provided to support this effective, pragmatic approach.

Condition Hemifacial spasm can be caused by neurovascular compression of the facial nerve at the root entry zone (REZ), and a tortuous/dolichoectatic vertebral artery (VA) is a rare culprit that makes complete decompression challenging.

Standard MVD outcomes Typical microvascular decompression for HFS (usually targeting AICA/PICA) provides >90% symptomatic relief at 1-year follow-up with notable complications including hearing loss (2.3%) and facial palsy (0.9%).

Limitations of sling transposition Macrovascular decompression with a Teflon/Gore-Tex sling can be effective but may be infeasible when anchoring is poor or when artery manipulation risks kinking/disrupted blood flow or distal nerve stretching.

Higher-complexity alternative The “binder ring” approach (VA transection, relocation, and reanastomosis) is described but is lengthy, requires temporary occlusion, and carries elevated risk (e.g., brainstem/cerebellar infarct).

Case presentation A 67-year-old woman with debilitating left HFS had a large tortuous VA abutting the facial nerve REZ; after retrosigmoid craniotomy, mobilization relieved REZ compression but residual distal cisternal contact persisted.

Key technique Simple REZ-focused decompression was achieved by mobilizing the VA as safely feasible and placing Teflon pledgets to pad the vessel away from the REZ; complete distal nerve decompression was not feasible and further manipulation was avoided due to risk to perforators/7th–8th nerve complex.

Outcome Despite residual cisternal segment contact, symptoms resolved immediately post-op and remained absent at 12-month follow-up after REZ decompression alone.

Core conclusion Targeting decompression of the REZ alone can be a simple, effective strategy for HFS due to dolichoectatic VA, potentially avoiding more complex and riskier techniques when full nerve-complex decompression is not achievable.

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Historical evolution of microvascular decompression after Jannetta’s establishment: Anatomical maps and physiological compasses—a narrative review

Acta Neurochirurgica (2026) 168:74

This narrative review chronicles five decades of refinement in microvascular decompression (MVD) for trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia, tracing developments from Jannetta’s microsurgical breakthrough to contemporary practice. It emphasizes evolving microsurgical anatomy, tailored craniotomies, endoscopic/exoscopic visualization, and nuanced decompression techniques such as noncompressive transposition versus prosthetic interposition.

The article also highlights operative support advances—high-resolution MRI/MRA, virtual simulation, and intraoperative neuromonitoring (BAEP, LSR)—as physiological “compasses” that improve safety and outcome durability. Together, anatomical “maps” and physiological feedback frame current standards and ongoing challenges in achieving long-term, biologically harmonious decompression.

Microvascular Decompression (MVD) Evolution: MVD has developed from Jannetta’s original microsurgical demonstration of vascular compression into a safe, durable, and standardized surgical treatment for neurovascular compression syndromes, especially trigeminal neuralgia (TN), hemifacial spasm (HFS), and glossopharyngeal neuralgia (GPN).

Anatomical Foundations: Detailed microsurgical anatomy, including the “Rule of Three” for the cerebellopontine angle (CPA), enables tailored, minimally invasive approaches and underpins the understanding of neurovascular conflicts and surgical route selection.

Tailored Surgical Approaches: Three individualized approaches—lateral supracerebellar-infratentorial for TN, infrafloccular for HFS, and transcondylar fossa for GPN—minimize cerebellar retraction and optimize decompression, improving safety and efficacy.

Decompression Strategies: Techniques have shifted from prosthetic interposition (placing a material between vessel and nerve) to noncompressive transposition (mobilizing and securing the vessel away from the nerve), with evidence supporting better long-term outcomes for transposition.

Visualization and Simulation Advances: The integration of endoscopic/exoscopic systems, neuronavigation, and virtual simulation has enhanced visualization, surgical precision, and education, extending the original ethos of microscopic surgery.

Intraoperative Monitoring: Real-time monitoring using brainstem auditory evoked potentials (BAEPs) and lateral spread response (LSR) on facial EMG helps avoid complications and assess decompression adequacy, significantly reducing postoperative morbidity.

Role of Imaging: High-resolution MRI and MRA now routinely identify neurovascular compression preoperatively, though imaging findings are considered supportive rather than diagnostic due to limited specificity in low-grade conflicts.

Sustained First-Line Role: Despite advances in radiosurgery and pharmacotherapy, MVD remains the first-line surgical option for appropriately selected patients, due to its proven long-term efficacy and safety.

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Three-dimensional microsurgical anatomy of the basal aspect of the cerebrum: a fiber dissection study

J Neurosurg 144:690–702, 2026

This study presents a three-dimensional microsurgical fiber-dissection analysis of the basal aspect of the human cerebrum, detailing the spatial organization of commissural, projection, and association fibers and their relationships with subcortical nuclei, ventricles, and cortical landmarks. Using 10 formalin-fixed brains with layer-by-layer dissection and stereoscopic photography, the authors map tracts such as the ILF, UF, SS, cingulum, fornix, and connections around the amygdala and nucleus accumbens.

The findings emphasize surgical implications by clarifying trajectories and landmarks relevant to approaches like STIO and SCTT, illustrating a clinical case of hippocampal glioma resection with optic-radiation preservation, and proposing that 3D anatomical insight enhances safe, precise planning for medial temporal and basal lesions.

Objective Limited surgical exposure of the cerebral base makes basal fiber-tract injury a key risk; detailed 3D tract anatomy is needed to plan safer resections and support brain-function research.

Aim Mapped the topography of basal white-matter tracts and subcortical gray matter (including hippocampus, amygdala, and nucleus accumbens) and their relationships to cortex, ventricles, and nuclei.

Methods Performed Klingler-style layer-by-layer fiber dissection on 10 formalin-fixed human brains under ×6–×40 magnification, documenting each stage with stereoscopic 3D photography.

Key anatomy (basal tracts) Sequential basal dissection exposed U fibers, inferior cingulum (lower part), Li-Am fasciculus, SRF, and ILF; removing Li-Am/ILF revealed the temporal horn with the hippocampus medially.

Sagittal stratum layering The lateral wall of the atrium is layered (medial→lateral): ependyma, tapetum, IC-SL, optic radiations, posterior AC extension, IFOF, MdLF, posterior SLF/AF, U fibers, cortex—together forming the sagittal stratum.

ILF clarification The ILF was identified as a long association tract connecting the base of the temporal pole to the occipital base, located above the fusiform gyrus and beneath the sagittal stratum; “merging fibers” in lateral occipital base were distinguished from the temporal portion of the AF.

Amygdala connectivity The amygdala links to septal nuclei/hypothalamus/thalamus via the stria terminalis, projects to cortical regions via the uncinate fasciculus, and connects via additional pathways including amygdalofugal routes and the anterior commissure.

Surgical application (STIO case) A right hippocampal WHO grade 2 glioma was resected via a supratentorial-infraoccipital (STIO) approach; the fusiform gyrus was incised anterior to the basal turning point of the optic radiation to reach the lateral ventricle, and postoperative DTI confirmed optic-radiation preservation.

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A Validation of the Tarlov Cyst Quality-of-Life Survey in Men Surgically Treated for Symptomatic Spinal Tarlov Cysts

Operative Neurosurgery 30:379–384, 2026

This article validates the 11-item Tarlov Cyst Quality-of-Life (TCQoL) scale for male patients undergoing surgical treatment of sacral Tarlov cysts, demonstrating good internal consistency (Cronbach α = 0.85), significant postoperative improvement on nine items, and strong concurrent validity with ODI and SF-36 physical function and pain subscales. The TCQoL showed large responsiveness (SRM = 0.81) and correlated with VAS pain measures.

Methods include prospective preoperative and 3-month postoperative administration of TCQoL, ODI, SF-36, and VAS in 46 male patients treated surgically between 2016–2023, with detailed psychometric analyses assessing discriminative validity, construct validity, and responsiveness; limitations noted include small sample size, single-surgeon single-center design, and 20% attrition.

TCQoL Validation in Men: The Tarlov Cyst Quality-of-Life (TCQoL) scale, previously validated in women, was successfully validated for male patients undergoing surgical treatment for symptomatic sacral Tarlov cysts, demonstrating good internal consistency (Cronbach α = 0.85) and discriminative validity.

Study Population: The study included 46 male patients (final sample) with an average age of 48.4 years, mostly presenting with multiple sacral cysts and a median symptom duration of nearly 35 months.

Surgical Technique: Surgery involved a posterior approach with laminectomy, cyst drainage, and wrapping of the nerve root with a bovine pericardium sleeve to prevent refilling, followed by closure with a resorbable plate.

Symptom Improvement: Significant improvement was observed in 9 of 11 TCQoL items postoperatively, especially for discomfort while sitting, sacral pain, lower extremity pain, and weakness; sexual function items showed no significant change.

Correlation with Established Measures: The TCQoL showed strong positive correlation with the Oswestry Disability Index (ODI) (r = 0.63, P < .001) and moderate to strong negative correlations with key SF-36 subscales (physical function, bodily pain, vitality, and social functioning), indicating good concurrent validity.

Scale Responsiveness: The standardized response mean (SRM) for TCQoL was 0.81, indicating a large effect size and sensitivity to clinical change after surgery.

Limitations: The study is limited by a small sample size (reflecting the rarity of Tarlov cysts in men), single-center and single-surgeon design, and a 20% attrition rate; findings may not generalize to non-sacral or non-Tarlov cysts.

Clinical Utility: The TCQoL can now be used as a disease-specific HRQoL tool for both male and female patients with symptomatic sacral Tarlov cysts, supporting standardized outcome measurement in future research and clinical practice.

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Partial sensory rhizotomy in therapy‑refractory and recurrent trigeminal neuralgia

Acta Neurochirurgica (2026) 168:42

This single-center retrospective analysis reports outcomes of partial sensory rhizotomy (PSR) for therapy-refractory or recurrent trigeminal neuralgia (TN) in 48 patients treated between 2004 and 2023. The study details patient selection, surgical technique, and perioperative findings, noting immediate pain relief in most patients, variable hypesthesia, and acceptable complication rates without permanent deficits.

Long-term follow-up (mean 38 months) found 65% pain-free without medication and 95% overall satisfaction (BNI 1–3), including a substantive subset with multiple sclerosis; recurrence occurred in 27% with some successfully re-operated. The authors conclude PSR is a viable option for selected refractory or recurrent TN patients, emphasizing informed consent about unpredictable sensory deficits

Partial Sensory Rhizotomy (PSR) Role: PSR is a surgical option for therapy-refractory or recurrent trigeminal neuralgia (TN), especially in patients without neurovascular conflict or those who failed previous microvascular decompression (MVD) or other interventions.

Efficacy: PSR provided immediate total pain relief in 87.5% (42/48) of patients; long-term, 72.1% (31/43) had complete or partial pain relief without medication, and 23.3% were satisfied with ongoing medication.

Indications: PSR is particularly relevant for patients with multiple sclerosis (MS)-related TN and those without a clear neurovascular conflict, as well as for those not responding to or preferring to avoid repeated percutaneous or radiosurgical procedures.

Complications: Postoperative hypesthesia is expected and occurred in 77.1% of patients, but was generally well tolerated; no cases of anesthesia dolorosa or corneal anesthesia were observed. Other complications (e.g., CSF fistula, transient hearing impairment) were rare and resolved with treatment.

Recurrence: The observed recurrence rate after PSR was 27.1%, consistent with previously reported rates (10–49% over five years), and repeat PSR was effective in patients with recurrent pain.

Comparison with Other Treatments: While MVD is preferred when neurovascular conflict is present, PSR offers comparable long-term pain relief in selected patients, but with a higher risk of sensory deficits. Combined MVD+PSR does not improve long-term outcomes if no vascular conflict exists.

Patient Satisfaction: Overall, 95% of patients reported meaningful improvement and satisfaction with PSR, despite sensory deficits, when adequately counseled preoperatively.

Recommendation: PSR should be considered and discussed as a viable surgical alternative for therapy-refractory or recurrent TN, particularly in MS patients and those not suitable for or preferring to avoid other invasive procedures.

 

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Postoperative loss in segmental lumbar lordosis following L5–S1 anterior lumbar interbody fusion

J Neurosurg Spine 44:420–425, 2026

This clinical study evaluates predictors and thresholds for postoperative loss of L5–S1 segmental lordosis following anterior lumbar interbody fusion (ALIF) in 94 adults treated for degenerative disc disease. Multivariate analyses identified baseline obesity, absence of posterior fixation, and larger immediate lordotic correction as independent predictors of 6-week to 1-year segmental lordosis loss, which related to higher rates of cage subsidence and revision.

The authors derived 6-week postoperative L5–S1 lordosis thresholds (overall range 21.6°–26.8°, PI-specific: low 19.0°–24.8°, average 21.0°–26.4°, high 24.1°–28.7°) that minimized subsequent loss and need for revision. Findings support targeted preoperative planning to achieve sustainable correction while balancing risks of overcorrection and subsidence.

Segmental Lordosis Restoration: L5–S1 anterior lumbar interbody fusion (ALIF) provides strong and durable correction of segmental lumbar lordosis and disc height, with most correction maintained at 1 year postoperatively.

Predictors of Lordosis Loss: Baseline obesity, lack of posterior fixation, and larger initial correction in L5–S1 lordosis are independent predictors of postoperative segmental lordosis loss within 1 year.

Complications: Loss of segmental lordosis increases the risk of cage subsidence and revision surgery, particularly due to pseudarthrosis.

Optimal Correction Thresholds: Achieving 6-week postoperative L5–S1 segmental lordosis between 21.6° and 26.8° minimizes the risk of lordotic loss and need for revision; PI-specific thresholds are 19.0°–24.8° (low PI), 21.0°–26.4° (average PI), and 24.1°–28.7° (high PI).

Risks of Overcorrection/Undercorrection: Overcorrection (>26.8°) increases risk of cage subsidence and mechanical complications, while undercorrection (<21.6°) may predispose to implant failure and adjacent segment disease.

Surgical Planning Importance: Preoperative planning should target lordosis correction within these thresholds and consider modifiable risk factors to optimize outcomes and reduce complications.

Comparison to Other Techniques: ALIF offers greater segmental correction than other lumbar interbody fusion techniques such as TLIF or XLIF.

Clinical Implications: Nearly half of patients experience some degree of lordosis loss post-ALIF, highlighting the need for careful patient selection, surgical technique, and postoperative monitoring.

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Hurting More Than Helping? Decompressive Craniectomy in Patients With Symptomatic Intracerebral Hemorrhage After Mechanical Thrombectomy in Acute Ischemic Stroke

Neurosurgery 98:345–357, 2026

This multicentre registry study evaluates whether decompressive craniectomy (DC) improves 90-day functional outcomes in patients who developed symptomatic intracerebral haemorrhage (sICH) following mechanical thrombectomy for anterior-circulation acute ischaemic stroke. Using multivariable regression and propensity-score matching from 464 STAR registry patients, the authors compare clinical characteristics, procedural variables and mRS outcomes between DC and non-DC groups.

Findings indicate poor overall recovery (14% mRS 0–3; 56% mortality). After adjustment and matching, DC was associated with a lower odds of acceptable functional outcome and no consistent mortality benefit with similar results in low-ASPECTS subgroups. This suggests limited functional gains from DC in this population.

Decompressive craniectomy (DC) after symptomatic intracerebral hemorrhage (sICH) following mechanical thrombectomy (MT) for acute ischemic stroke (AIS) is not associated with improved functional outcomes at 90 days; only 11% of DC patients achieved a modified Rankin Scale (mRS) of 0-3, compared to 15% without DC (adjusted odds ratio [OR] 0.2, 95% CI 0.02-0.9, P = .045).

Mortality rates at 90 days were similar between DC and non-DC groups after multivariable adjustment and propensity score matching, despite a lower crude mortality in the DC group in univariable analysis (DC: 43%, non-DC: 59%; adjusted P = .5).

Propensity score–matched analysis confirmed that patients undergoing DC had significantly lower odds of achieving an acceptable functional outcome (8% vs 24%, P = .045), with no significant mortality difference (P = .10).

Patients selected for DC were generally younger, more likely to be female, and had higher-grade hemorrhages (parenchymal hematoma type 2) compared to those not undergoing DC.

Subgroup analysis of patients with large infarct cores (ASPECTS <6) showed that DC was not associated with improved functional outcome or mortality, suggesting limited benefit in this population.

Overall prognosis for sICH after AIS treated with MT is poor, with only 14% of all patients achieving mRS 0-3 at 90 days and 56% mortality, regardless of DC.

Findings challenge previous smaller studies and recent guidelines suggesting benefit of DC in malignant MCA infarction or spontaneous sICH, highlighting the unique poor prognosis in post-MT sICH.

Study limitations include retrospective design, lack of standardization in DC decision-making, missing imaging data, and potential selection bias, which could influence the observed associations.

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Resectability of spheno-orbital meningiomas: surgical outcome in 93 cases and a proposed clinically relevant anatomical classification

J Neurosurg 144:336–345, 2026

This clinical study evaluates surgical outcomes for 93 patients with spheno-orbital meningiomas (SOMs) treated over two decades, proposing a four-grade anatomical classification based on orbital involvement. The paper reports presentation patterns, operative techniques, extent of resection, proptosis quantification with an exophthalmos index, and postoperative visual and surgical morbidity rates.

Using retrospective imaging and clinical data, the authors validate the grading system’s predictive value for resectability, proptosis improvement, and visual risk, showing higher gross-total resection rates in lower-grade tumors and substantial vision stabilization or improvement across grades. The work offers practical guidance for surgical planning and patient counseling in complex skull-base and orbital tumor management.

Anatomical Grading System: SOMs are classified into four grades based on orbital involvement: grade 1 (orbital hyperostosis), grade 2 (periorbital involvement), grade 3a/b (intraorbital involvement without/with rectus muscle invasion), and grade 4 (involvement of the orbital apex or optic nerve).

Surgical Resectability: Gross-total resection (GTR) is most achievable in grade 1 (88.5%) and decreases with higher grades (grade 2: 50.0%, grade 3: 16.7%, grade 4: 24.1%), primarily limited by critical neurovascular structures and functional vision considerations.

Presenting Symptoms: Proptosis (74.2%) and visual decline (57.0%) are the most common symptoms, with higher-grade tumors more likely to present with proptosis, vision loss, and cranial neuropathies.

Visual Outcomes: Surgery led to stable or improved vision in nearly 95% of patients across all grades, with no significant difference in visual morbidity between low- and high-grade tumors.

Proptosis Improvement: Correction of proptosis was most significant in grades 2 and 4, with overall exophthalmos index (EI) significantly decreasing after surgery; clinically significant enophthalmos was rare.

Surgical Morbidity: Overall morbidity increased with higher tumor grade but was not statistically significant; new ophthalmological cranial nerve neuropathies occurred in 11.8% of patients.

Surgical Approach: Aggressive removal of tumor and hyperostotic bone, with selective intraorbital dissection, optimizes functional outcomes and proptosis reduction; rigid orbital reconstruction is generally not required.

Clinical Utility: The grading system aids in predicting surgical risks, visual outcomes, and in guiding patient counseling and surgical planning for SOMs.

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Customized Titanium Implants for Cranial Fibrous Dysplasia: A Personalized Surgical Approach and Single-Center Experience

Operative Neurosurgery 30:100–108, 2026

This single-center clinical series reports on 33 patients with monostotic cranial fibrous dysplasia treated with computer-assisted resection and reconstruction using patient-specific, 3D‑printed titanium cranioplasty implants. Methods detail high-resolution CT planning, surgeon‑engineer collaboration for CAD/CAM templates, intraoperative guidance, standardized perioperative care, and long-term radiological and FACE-Q patient‑reported outcome follow-up.

Results show complete tumor resections, favorable cosmetic outcomes, no postoperative complications or recurrences across extended follow-up, and high patient satisfaction; discussion addresses material selection, cost (≈$3000 per implant), production time, accessibility in low-resource settings, and the need for comparative studies.

Patient-Specific Titanium Implants: Customized, computer-aided design (CAD) and manufacturing (CAM) titanium implants enable precise resection and effective reconstruction for cranial fibrous dysplasia (CFD), resulting in excellent cosmetic outcomes and no postoperative complications or recurrences in a 33-patient series.

Surgical Process: Preoperative high-resolution CT scans and 3D modeling are used for surgical planning, including mirrored contralateral anatomy for symmetry; intraoperative templates guide tumor resection, and implants are secured with miniscrews.

Clinical Outcomes: All patients achieved complete tumor removal, satisfactory cosmetic results confirmed by postoperative CT, and no surgical site infections or cerebrospinal fluid leaks during a mean follow-up of 76–108 months.

Patient Satisfaction: High patient-reported satisfaction was observed, with FACE-Q scores indicating 84.8% of patients highly satisfied (score ≥85) and no patients dissatisfied with surgical outcomes.

Material Advantages: Titanium implants are favored for their biocompatibility, mechanical strength, and low infection rates compared to other materials like PEEK and PMMA, making them especially suitable for CFD reconstruction.

Cost and Accessibility: Average total cost per implant was $3000, with a 4-week production time; while feasible in middle-income settings, access remains limited in low-resource environments due to financial and infrastructural barriers.

Limitations: The study’s retrospective, single-center design, absence of a comparative cohort, and variable follow-up duration limit generalizability and long-term conclusions.

Future Directions: Broader adoption of CAD/CAM and patient-specific implants in craniofacial surgery may improve outcomes, but further comparative and cost-effectiveness studies are needed, especially in resource-constrained settings.

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Fully automated image updating for brain shift compensation after dural opening

J Neurosurg 144:206–216, 2026

This study presents a fully automated intraoperative image-updating system that compensates for brain shift after dural opening by assimilating intraoperative stereovision (iSV) data into a biomechanical finite element model to deform preoperative MR (pMR) images into updated MR (uMR) images. The pipeline integrates FastSAM segmentation, vessel/sulcus feature registration, and FEM-based whole-brain deformation to produce clinically usable uMRs.

In fifteen open cranial cases, automated updates reduced mean target registration error from 6.2 mm (pMR) to 1.9 mm (uMR) and completed without user intervention in 3.9 ± 0.6 minutes. Results demonstrate robust segmentation (DSC 0.93), submillimeter iSV reconstruction accuracy, and potential for broader adoption, while noting limitations in small or featureless openings and need for deeper-structure validation.

Fully automated image updating: Developed and validated a fully automated system to update preoperative MRI images for brain shift compensation after dural opening in open cranial surgery, eliminating user intervention and expertise requirements.

Intraoperative stereovision (iSV) integration: Utilized iSV images to capture high-resolution surface deformation data, which was processed by deep learning-based segmentation (FastSAM) and registered with preoperative MRI using vessel and sulcus features.

Two-step registration process: Employed translation-only cross-correlation for global alignment and Demons deformable registration for local nonrigid deformation between iSV and preoperative MRI surfaces.

Biomechanical modeling: Assimilated extracted nonrigid cortical displacements into a finite element model to estimate whole-brain deformation and generate updated MR images (uMR).

Accuracy improvement: Achieved significant reduction in target registration error (TRE) from 6.2 ± 1.2 mm (pMR) to 1.9 ± 1.0 mm (uMR), with overall mean computational time of 3.9 ± 0.6 minutes and no user intervention.

Robustness and efficiency: System was robust across a range of surgical conditions (lesion type, craniotomy size, brain shift magnitude), and performance was not significantly affected by these variables.

Limitations: Current system requires clear iSV images (free of instruments/blood), is limited to initial post-dural opening updates, and surface accuracy was primarily evaluated; further development is needed for autonomous updates during resection and deeper structure validation.

Potential for broad adoption: Elimination of user dependency and minimal workflow interruption suggest strong potential for integration into routine open cranial 

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Surgery of peritorcular meningiomas: the structural basis for preservation of torcular venous flow

J Neurosurg 143:1449–1457, 2025

This clinical and anatomical study defines the structural composition of the torcular Herophili and its implications for resection of peritorcular meningiomas, presenting histological evidence of a delaminable collagenous plane between venous endothelium and dural fibrous layers. The authors propose a four-type classification of tumor invasion based on endothelial integrity to guide operative strategy and preserve venous flow.

Clinical outcomes from 14 patients treated between 1997 and 2018 are reported, demonstrating feasibility of gross-total resection for type I–II tumors via layer-by-layer dissection with venous wall reinforcement, while types III–IV require preservation of collateral drainage and tailored reconstructive or adjunctive approaches.

• Torcular Anatomy: The torcular wall consists of two main compartments—an inner venous structure lined by endothelium and supported by elastic and smooth muscle fibers, and an outer fibrous dural layer, separated by a collagenous cleavage plane that enables surgical delamination.

• Meningioma Classification: Peritorcular meningiomas are classified into four types based on anatomical invasion: Type I (dural involvement only), Type II (dural involvement with sinus compression/displacement), Type III (endothelial layer disrupted, tumor penetrates lumen), and Type IV (complete sinus occlusion).

• Surgical Technique: For Type I and II tumors, gross-total resection is feasible by dissecting the tumor away from the inner venous wall at the cleavage plane, preserving venous integrity and flow; in Types III and IV, focus shifts to preserving venous collaterals due to disrupted or occluded flow.

• Preoperative Planning: Detailed imaging and identification of venous collaterals are critical for operative planning, especially when sinus flow is compromised or occluded.

• Outcomes: Gross-total resection was achieved in all patients with Type I and II tumors, with lower recurrence rates; subtotal resection and higher recurrence were associated with Types III and IV and higher-grade meningiomas.

• Complications and Mortality: No surgical mortality was reported; complications included wound infections and, rarely, recurrence or death related to aggressive tumor biology rather than surgery itself.

• Role of Radiotherapy: Radiation therapy was reserved for high-grade, residual, or recurrent tumors, particularly when total resection was not possible or in cases of sinus wall involvement.

• Clinical Significance: Preservation of the torcular venous wall and flow is paramount for favorable outcomes; anatomical understanding of the torcula enables safer, more effective resections and reduces recurrence in benign cases.

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The Far-Lateral Approach and Its Variants

Operative Neurosurgery 29:740–745, 2025

This technical report details the far‑lateral craniotomy and its variants for accessing ventral and ventrolateral craniovertebral pathologies, emphasizing indications, anatomical considerations, and operative steps. It outlines positioning, incision choices, bone work including condylar modifications, dural handling, and strategies to protect the vertebral artery and lower cranial nerves.

The article highlights advantages, limitations, and common pitfalls—such as occipitocervical instability with extensive condylectomy, hypoglossal canal risk, and CSF leak prevention—and supplements the text with high‑quality dissections and a 4K instructional video aimed at trainees and early‑career neurosurgeons.

 

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Avoidance of Major Vascular Injury in Transcranial Brain Tumor Surgery Using Real-Time Doppler Navigation

Operative Neurosurgery 29:633–638, 2025

This clinical technical note and case series evaluates real-time Doppler probe navigation during transcranial craniotomy for brain tumor resection, describing technique, operative workflow, and outcomes from 501 operations where the Doppler was used. The authors report a low rate of major vessel injury (<1%) and discuss how Doppler guidance complements neuronavigation and ultrasound as tumor resection progresses and brain shift reduces image accuracy.

The paper details patient selection, surgical approaches, probe specifications and intraoperative use, illustrates three case examples with video, and analyzes stroke and infarction rates attributable to vasospasm or small-vessel injury. Limitations include retrospective design and variable probe penetrance; the authors recommend routine Doppler adjunctive use for tumors encasing or adherent to major arteries.

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The Case Series of Contralateral Interhemispheric Transfalcine Approach to Medial Parietooccipital Pathologies: Surgical Technique and Results

Operative Neurosurgery 29:495–504, 2025

This retrospective case series evaluates the contralateral interhemispheric transfalcine approach (PITTA) for medial parietooccipital and peritrigonal brain lesions. The technique offers improved visualization and minimized brain manipulation, with acceptable complication rates, but requires careful venous management and is best suited for experienced neurosurgeons.

The contralateral interhemispheric transfalcine (PITTA) approach is used for challenging medial parietooccipital and peritrigonal brain lesions.

• A retrospective study of 19 cases showed PITTA was applied to vascular lesions (AVMs) and tumors (glioblastomas, meningiomas, metastases, pilocytic astrocytoma).

• The approach improves visualization and reduces manipulation of eloquent cortex and white matter compared to traditional ipsilateral approaches.

• Mean surgery time was about 4 hours 15 minutes, and most patients had temporary neurological deficits that resolved within days.

• Superior sagittal sinus injury and small vein sacrifice occurred in a few cases but were managed without lasting complications.

• No new visual deficits or permanent ipsilateral parietal lobe injuries were observed; most complications were minor and transient.

• PITTA is technically demanding and best suited for experienced neurosurgeons; careful preoperative planning and venous anatomy assessment are critical.

• The study concludes PITTA is a valuable option for selected cases, but larger prospective studies are needed to compare it with standard approaches.

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Surgery for mesial temporal pathology: a 26-year experience

J Neurosurg 143:738–747, 2025

Over 26 years, keyhole craniotomy via the inferior temporal gyrus for mesial temporal lobe surgery showed a low complication rate (5.3%), with only 0.3% permanent neurological deficits. Technique refinement and perioperative strategies minimized risks, supporting this approach as safe and effective for temporal lobe pathology.

A 26-year, single-surgeon study reviewed 717 mesial temporal lobe (MTL) surgeries using a keyhole inferior temporal gyrus (ITG) approach for epilepsy and other pathologies.

• Overall complication rate was low (5.3%), with only 0.3% of patients experiencing permanent neurological deficits and no perioperative deaths.

• Most common complications were hemorrhage (1.5%), postoperative seizure (1.3%), and cosmetic defects (0.6%).

• Neurological complications included transient cranial nerve deficits, visual field deficits, and speech difficulty, all rare.

• No significant correlation found between complications and age, sex, pathology type, operative time, or blood loss.

• Technical strategies such as meticulous closure, careful muscle reapproximation, and limiting brain retraction reduced complications over time.

• The ITG keyhole approach provided safe, effective, and cosmetically favorable access to the MTL, with complication rates improving as technique and teaching matured.

• Long-term follow-up (97% at 36 months) confirmed sustained safety and efficacy of this approach.

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