A Novel Marking Technique for Accurate Minimal Invasive Approaches in Spine Tumor Surgeries With Activated Carbon Marking

Operative Neurosurgery 28:255–261, 2025

To describe a novel, practical, reproducible, and effective preoperative marking technique for accurate localization of the spinal level in a series of patients with tumor lesions.

METHODS: We retrospectively analyzed patients undergoing minimally invasive (MIS) surgery for spine tumors from 2016 to 2021, in which this marking technique was used. Twenty-one patients, with tumor lesions involving difficult radioscopic visualization (cervicothoracic junction or upper dorsal spine, C6-T8), were included. Tumor lesion level was previously determined with enhanced MRI in all cases. Twenty-four to forty-eight hours before surgery, computed tomography image–guided carbon marking was performed by administration of aqueous suspension of carbon with a 21-gauge needle placed resembling the MIS approach planned trajectory. During surgery, activated carbon marking was followed until reaching the final target on the bone. Next, sequential dilators and an MIS retractor were placed. Then, bone resection and tumor exeresis were performed according to the case.

RESULTS: Average age was 60.6 years (26-76 years). Fifteen (71%) patients were women. In most cases (76%), tumor pathology involved intradural lesions (meningiomas and schwannomas). In all cases, the marking described allowed to accurately guide the MIS approach to tumor site. Neither intraoperative fluoroscopy nor approach enlargement was required in any procedure. Postoperative complications were reported in only 4 patients, none related with the marking.

CONCLUSION: Computed tomography image–guided activated carbon marking allows to accurately lead MIS approaches in a practical, reproducible, and effective way in cases of tumors localized in regions of the spine of difficult radioscopic visualization.

A Speech Neuroprosthesis in the Frontal Lobe and Hippocampus: Decoding High-Frequency Activity into Phonemes

Neurosurgery 96:356–364, 2025

Loss of speech due to injury or disease is devastating. Here, we report a novel speech neuroprosthesis that artificially articulates building blocks of speech based on high-frequency activity in brain areas never harnessed for a neuroprosthesis before: anterior cingulate and orbitofrontal cortices, and hippocampus.

METHODS: A 37-year-old male neurosurgical epilepsy patient with intact speech, implanted with depth electrodes for clinical reasons only, silently controlled the neuroprosthesis almost immediately and in a natural way to voluntarily produce 2 vowel sounds.

RESULTS: During the first set of trials, the participant made the neuroprosthesis produce the different vowel sounds artificially with 85% accuracy. In the following trials, performance improved consistently, which may be attributed to neuroplasticity. We show that a neuroprosthesis trained on overt speech data may be controlled silently.

CONCLUSION: This may open the way for a novel strategy of neuroprosthesis implantation at earlier disease stages (eg, amyotrophic lateral sclerosis), while speech is intact, for improved training that still allows silent control at later stages. The results demonstrate clinical feasibility of direct decoding of high-frequency activity that includes spiking activity in the aforementioned areas for silent production of phonemes that may serve as a part of a neuroprosthesis for replacing lost speech control pathways.

Dural and cranial reconstruction techniques in retrosigmoid craniotomy: key factors associated with CSF leaks in 225 patients

Neurosurg Focus 58(2):E8, 2025

This study evaluated the effectiveness of various dural closure and bone reconstruction techniques in preventing CSF leakage following retrosigmoid craniotomy for cerebellopontine angle (CPA) tumors. The goal was to identify whether newer combinations of reconstructive materials offer any advantage in reducing CSF leaks and improving surgical outcomes.

METHODS The authors conducted a retrospective review of 225 patients who underwent a retrosigmoid craniotomy for CPA neoplasms between January 2018 and August 2024. Patient demographics, intraoperative reports, and postoperative complications were analyzed. Various reconstructive methods, including the use of TachoSil, HydroSet, autologous or heterologous dural patches, and bone flap repositioning, were compared. CSF-related complications such as CSF leakage, infections, and postoperative hydrocephalus were systematically evaluated.

RESULTS CSF leakage occurred in 31% of cases (n = 69), while CSF infections and postoperative hydrocephalus were noted in 6% and 7% of patients, respectively. HydroSet combined with bone flap repositioning significantly reduced CSF leakage (p = 0.008), as did the combination of HydroSet and heterologous dural patches (p = 0.007). TachoSil did not show a significant reduction in CSF leakage. Craniectomy with titanium mesh or heterologous cranioplasty was not associated with any CSF leaks. No other single or combined techniques showed significant associations with CSF leakage.

CONCLUSIONS HydroSet in combination with bone reconstruction and heterologous patches demonstrated superior outcomes in reducing CSF leaks. TachoSil did not significantly affect leakage rates, with less definite results. Refining surgical techniques and selecting appropriate materials for dural and bone reconstruction may help reduce complications and improve patient outcomes in CPA tumor surgeries using the retrosigmoid approach.

Outpatient lateral lumbar interbody fusion: single-institution consecutive case series

J Neurosurg Spine 42:140–146, 2025

Outpatient spine surgery could reduce hospital costs and improve patient outcomes. Outpatient lateral lumbar interbody fusion (LLIF) can be performed for select patients. This study identified and compared the demographic, clinical, and surgical characteristics of patients who underwent outpatient versus inpatient single-level LLIF.

METHODS A retrospective review was conducted of a prospectively collected database of patients who underwent first-time single-level LLIF at a single institution performed by the same surgeon from January 1, 2017, through December 31, 2022. Demographic characteristics, including age, sex, BMI, and medical comorbidities, were collected. Surgical factors, such as level of surgery, operative duration, and estimated blood loss, were also collected. Length of stay and 30-day readmission were the primary outcomes of interest. Patients discharged on the day of surgery or the following day were considered to be in the outpatient group. ANOVA and chi-square tests were performed to compare continuous and categorical variables, respectively. Univariate logistic regression was used to examine the correlation between baseline demographic and surgical variables and outpatient surgery. If a variable significantly correlated with outpatient surgery on univariate analysis, it was subsequently used in multivariate logistic regression.

RESULTS A total of 107 patients underwent first-time single-level LLIF, and 48 (44.9%) did not have posterior instrumentation. Fifty-three (49.5%) patients were women. The median age and BMI were 66.3 years and 28.9, respectively. The mean length of stay was 1 day (range 0–4 days), with 71 (66.4%) of 107 single-level LLIFs managed on an outpatient basis. There were no readmissions within 30 days. Patients in the outpatient group were more likely than patients in the inpatient group to be male (59% [42/71] vs 25% [9/36], p = 0.002), have a low LACE (risk criteria based on length of stay, acuity of the admission, comorbidity of the patient, and emergency department use within 6 months before admission) readmission index (63% [45/71] vs 28% [10/36], p < 0.001), and have a stand-alone construct (62% [44/71] vs 11% [4/36], p < 0.001). The outpatient cohort also had a shorter mean operative duration (104.4 vs 175.5 minutes, p < 0.001) and lower mean estimated blood loss (20 vs 100 mL, p < 0.001). There was no difference in age between the groups. Factors that remained significant on multivariate logistic regression were male sex (OR 0.14, 95% CI 0.04–0.53; p = 0.004), lower LACE readmission index (OR 0.06, 95% CI 0.02–0.25; p < 0.001), and stand-alone construct (OR 8.17, 95% CI 1.49–44.74; p = 0.02).

CONCLUSIONS Multiple baseline and surgical characteristics were more common in the outpatient setting. With appropriate patient selection, single-level LLIF can be achieved on an outpatient basis.

When and how are complications suspected after shunt surgery in patients with normal pressure hydrocephalus?

Acta Neurochirurgica (2025) 167:6

The follow-up routine for patients with idiopathic normal pressure hydrocephalus (iNPH) after shunt surgery differs across medical centers. Shunt surgery is not without risks, with complications emerging at various times after the procedure. The aim was to explore the timing and methods of detecting complications following ventriculoperitoneal shunt surgery for iNPH.

Methods This retrospective study examined patients who underwent shunt surgery for iNPH at Uppsala University Hospital between 2011 and 2018. The cohort comprised 491 patients. Postoperative complications within the first 12 months were recorded from medical records. Complications were classified by type, and the method or event that first indicated the complication was documented.

Results Of the 491 patients, 102 (20.8%) experienced complications during the one-year follow-up period, with a shunt revision rate of 15.5% (76 patients requiring reoperation). Subdural hematomas/hygromas were the most common complications, with 27 cases; only three required surgical intervention. Most complications were identified through additional appointments triggered by patient-reported symptoms (31.4%), while the planned follow-up routine with CT scans and planned follow-up visits together accounted for 56% of the detections. The 3-month and 12-month follow-up visits detected similar proportions of complications (12.7% and 11.8%, respectively).

Conclusion The majority of the complications were detected at a planned visit or investigation. Given the cognitive impairments in iNPH patients and that signs of shunt dysfunction can be subtle, a structured follow-up routine is important for timely detection of complications. The findings suggest that both CT scans and planned follow-up visits are critical components of effective postoperative monitoring.

The correlation study between posterior fossa crowding and classical trigeminal neuralgia

Acta Neurochirurgica (2025) 167:14

Objective To explore the correlation between posterior fossa crowding and the occurrence of classical trigeminal neuralgia (TN).

Methods A total of 60 patients diagnosed with classical TN and 60 age- and sex-matched healthy volunteers were included as a control group for a case-control study. All subjects underwent high-resolution 3D magnetic resonance imaging (MRI) examinations (including 3D-FIESTA and 3D-TOF MRA sequences). The original data were subjected to 3D reconstruction and measurement of posterior fossa volume (PFV) and hindbrain volume (HBV) using 3D-slicer software. The posterior fossa crowding index (PFCI) was calculated as HBV/PFV × 100%. Finally, data were analyzed using SPSS 22.0 statistical software.

Results The average PFCI in patients with TN was 85.0% ± 3.9%, compared to 82.7% ± 3.9% in the control group, with a significant statistical difference (P = 0.025). Female patients with TN had a more crowded posterior fossa than male patients (86.4% ± 3.8% vs. 83.4% ± 3.4%, P = 0.033). Multiple linear regression analysis showed that a higher PFCI was associated with being female (P = 0.022), younger age (P = − 0.003), and being a patient with TN (P = − 0.023).

Conclusion Patients with PTN have a more crowded posterior fossa compared to the healthy control group. A higher PFCI is associated with being female, younger age, and being a patient with TN. Posterior fossa crowding may be a risk factor for neurovascular conflict (NVC), making it more likely to lead to the occurrence of TN.

Does Baseline Facet Arthropathy Influence Early Clinical and Radiographic Outcomes After Cervical Disc Replacement?

Neurosurgery 96:87–95, 2025

Severe facet arthropathy is generally a contraindication to undergoing cervical disc replacement (CDR) due to associated instability and potentially limited improvement in neck pain caused by arthropathy. This study evaluates the influence of facet arthropathy on radiographic/early clinical outcomes after CDR.

METHODS: One/two-level CDR patients from a single surgeon’s prospectively maintained database created 2 cohorts based on facet arthropathy: grade 0-1 or 2-3 (milder/moderate arthropathy). Patient-reported outcome measures for neck disability, neck/arm pain, depressive burden, mental/physical health/function were obtained preoperatively and through final follow-up (average follow-up: 8.5 ± 6.5 months). Preoperative/postoperative radiographs measured segmental lordosis and C2-C7/segmental range of motion (ROM) and determined facet grade for each operative level. Demographic differences, perioperative variables, baseline patient-reported outcomes, and intercohort differences/ changes for postoperative patient-reported/radiographic outcomes were determined.

RESULTS: Of 161 patients, 100 were in the milder arthropathy group. There were no differences in baseline patientreported outcomes. Patients with moderate arthropathy reported superior 6-week 12-Item Veterans Rand Mental/ Physical Composite Scores (P ≤ .047, all). By final follow-up, moderate patients reported better 12-Item Veterans Rand Mental/Physical Composite Scores/Patient-Reported Outcome Measurement Information System-Physical Function/Patient-Health Questionnaire-9 (P ≤ .049, all). Cohorts reported similar improvements in all patientreported outcomes by 6 weeks/final follow-up. Those with more severe facet arthropathy had significantly shorter preoperative disc heights (P < .001). Accounting for baseline disc height differences, by final follow-up, moderate patients had lower segmental ROM (P = .036). There were no significant differences in radiographic measurement changes (P ≥ .264, all).

CONCLUSION: Postoperatively, patients with moderate facet arthropathy reported lower depressive burden, better mental health/physical function, and lower segmental ROM. However, this did not translate to inferior short-term clinical outcomes. Further study should be conducted on the relationship between clinical/radiographic outcomes in CDR patients with facet arthropathy.

Radiological and anatomical evaluation of the internal venous system in the context of access to the third ventricle ‑ proposal of a new classification

Acta Neurochirurgica (2025) 167:23

The internal venous system of the brain is a crucial anatomical landmark during accesses to the third ventricle through the foramen of Monro. Many classifications based on radiological assessment of the system have been developed, but they tend to be descriptive and do not highlight favorable anatomical variants. The aim of our study was to create a system based on morphometric measurements to facilitate preoperative decision-making regarding access to third ventricle tumors.

Methods We conducted an analysis of 119 MRI scans with SWI sequence using BrainLab software to create a model of the ventricular system, which allowed us to perform radiological measurements. We then validated these findings anatomically using 32 human brain specimens. The analyzed structures included the foramen of Monro (FM), the anterior septal vein (ASV), the thalamostriate vein (TSV), the venous angle (VA), the internal cerebral vein (ICV), and the distance between the FM and VA.

Results Based on the radiological analysis, we identified 9 internal venous systems, accounting for variations in each analyzed structure. The statistical analysis revealed no differences in the frequency of subtypes between radiological and anatomical studies (p = 0.097), nor in the occurrence of false venous angles (p = 0.520). We identified venous configurations that, in our assessment, are unfavorable in the context of accessing the third ventricle.

Conclusion The resulting classification accounts for significant clinical anatomical variations and, for the first time, provides specific morphometric values for each anatomical subtype. Consequently, it serves as a reproducible reference framework for preoperative planning of access to the third ventricle.

Outcome prediction following lumbar disc surgery: a longitudinal study of outcome trajectories, prognostic factors, and risk models

J Neurosurg Spine 42:33–42, 2025

This study aimed to 1) describe the 2-year postoperative trajectories of leg pain and overall clinical outcome after surgery for radiculopathy, 2) identify the preoperative prognostic factors that predict trajectories representing poor clinical outcomes, and 3) develop and internally validate multivariable prognostic models to assist with clinical decision-making.

METHODS This retrospective cohort study included patients enrolled in the Canadian Spine Outcomes and Research Network who were diagnosed with lumbar disc pathology and radiculopathy and had undergone lumbar discectomy at one of 18 spine centers. Potential outcome predictors included preoperative demographic, health-related, and clinical prognostic factors. Clinical outcomes were 1) 2-year univariable latent trajectories of leg pain intensity (numeric pain rating scale) and 2) overall outcomes comprising multivariable trajectories showing the combined postoperative courses of leg and back pain intensity (numeric pain rating scale) together with pain-related disability (Oswestry Disability Index). Each outcome model identified a subgroup of patients classified as experiencing a poor outcome based on minimal change in their clinical status after surgery. Multivariable risk model performance and internal validity were evaluated with discrimination and calibration statistics based on bootstrap shrinkage with 500 resamplings.

RESULTS The authors included data from 1142 patients (47.6% female). The trajectory models identified 3 subgroups based on the patients’ postoperative courses of pain or disability: 88.6% of patients in the leg pain model and 71.9% in the overall outcome model experienced a good-to-excellent outcome. The models classified 11.4% (leg pain outcome) and 28.2% (overall outcome) of patients as experiencing a poor clinical outcome, which was defined as minimal improvement in pain or disability after surgery. Eleven individual demographic, health, and clinical factors predicted patients’ poor leg pain and overall outcomes. The performance of the multivariable risk model for leg pain was inadequate, while the overall outcome model had acceptable discrimination, calibration, and internal validity for predicting a poor surgical outcome.

CONCLUSIONS Patients with lumbar radiculopathy experience heterogeneous postoperative trajectories of pain and disability after lumbar discectomy. Individual preoperative factors are associated with postoperative outcomes and can be combined within a multivariable risk model to predict overall patient outcome. These results may inform clinical practice but require external validation before confident clinical implementation.

Multistaged Stereotactic Radiosurgery for Complex Large Lobar Arteriovenous Malformations

Neurosurgery 96:223–232, 2025

Although stereotactic radiosurgery (SRS) has well defined outcomes in the management of smaller-volume arteriovenous malformations (AVM), this report evaluates the outcomes when SRS is used for large-volume (≥10 cc) lobar AVMs.

METHODS: Between 1990 and 2022, a cohort of 1325 patients underwent Leksell Gamma Knife SRS for brain AVMs. Among these, 40 patients (25 women; median age: 37 years) with large lobar AVMs underwent volume-staged SRS followed by additional SRS procedures if needed (2-5 procedures). The patients presented with diverse AVM locations and Spetzler-Martin Grades. Before SRS, 16 patients underwent a total of 43 embolization procedures.

RESULTS: Over a median follow-up of 73 months, 20 patients achieved AVM obliteration. The 3, 5, and 10-year obliteration rates were 9.3%, 15.3%, and 53.3%, respectively. During the latency interval between the first SRS procedure and the last follow-up, 11 patients had intracerebral hemorrhages (ICH) and 6 developed new neurological deficits unrelated to ICH. The postoperative hemorrhage risk after the first SRS was 13.8% at 3 years, 16.6% at 5 years, and 36.2% at 10 years. No hemorrhagic event was documented after confirmed obliteration. Compared with the modified Rankin Scale (mRS) scores before SRS, the mRS improved or remained stable in 28 patients. Nine patients died during the observation interval. Five were related to ICH.

CONCLUSION: These outcomes underscore both the potential effectiveness and the limitations of multistage SRS procedures for complex high-risk large volume AVMs in critical brain lobar locations. Most patients retained either stable or improved long-term mRS scores. During the latency interval from the first SRS until obliteration, achieved after two or more procedures, the risk of hemorrhage and treatment-related complications persists.

In vivo 9.4 Tesla MRI of a patient with drug‑resistant epilepsy

Acta Neurochirurgica (2025) 167:18

In resective epilepsy surgery for drug-resistant focal epilepsy (DRE), good seizure outcome is strongly associated with visualization of an epileptogenic lesion on MRI. Standard clinical MRI (≤ 3 Tesla (T)) may fail to detect subtle lesions. 7T MRI enhances detection and delineation, the potential benefits of increasing field strength to 9.4T are explored.

Methods A 36 years old male patient with DRE evaluated for resective surgery, in which 3T and 7T MRI failed to detect any epileptogenic lesions, was submitted to a dedicated epilepsy scan protocol using T1 and T2* weighted imaging at 9.4T. Images were evaluated independently by two neuroradiologists and one neurosurgeon.

Results 9.4T MRI offered increased spatial resolution and enhanced depiction of anatomical structures vital for epilepsy imaging, exemplified by regions mesio-temporal (hippocampus, amygdala), latero-temporal, insula, frontal and temporal operculum, and gray-white matter junction (precentral gyrus/frontal lobe) compared to 3T and 7T, albeit with challenges in mesial-temporal and antero-inferior temporal lobe imaging. No epileptogenic lesion was identified.

Conclusion 9.4T demonstrates promise in the identification and delineation of anatomical structures and small epileptogenic lesions in patients with DRE eligible for resective surgery. Whether clinical 9.4T MRI in DRE has clinical advantages over 7T or leads to a more complete resection of the epileptogenic zone and improved seizure outcome after epilepsy surgery needs to be established.

Patients May Return to Work Sooner After Laminoplasty: Occupational Outcomes of the Cervical Spondylotic Myelopathy Surgical Trial

Neurosurgery 96:131–141, 2025

Return-to-work (RTW) is an important outcome for employed patients considering surgery for cervical spondylotic myelopathy (CSM). We conducted a post hoc analysis of patients as-treated in the Cervical Spondylotic Myelopathy Surgical Trial, a prospective, randomized trial comparing surgical approaches for CSM to evaluate factors associated with RTW.

METHODS: In the trial, patients were randomized (2:3) to either anterior surgery (anterior cervical decompression/fusion [ACDF]) or posterior surgery (laminoplasty [LP], or posterior cervical decompression/fusion [PCDF], at surgeon’s discretion). Work status was recorded at 1, 3, 6, and 12 months postoperatively. For patients working full-time or part-time on enrollment, time to RTW was compared across as-treated surgical groups using discrete-time survival analysis. Multivariate logistic regression was used to assess predictors of RTW. Clinical outcomes were compared using a linear mixed-effects model. RESULTS: A total of 68 (42%) of 163 patients were working preoperatively and were analyzed. In total, 27 patients underwent ACDF, 29 underwent PCDF, and 12 underwent LP. 45 (66%) of 68 patients returned to work by 12 months. Median time to RTW differed by surgical approach (LP = 1 month, ACDF = 3 months, PCDF = 6 months; P = .02). Patients with longer length-of-stay were less likely to be working at 1 month (odds ratio 0.51; 95% CI, 0.29-0.91; P = .022) and 3 months (odds ratio 0.39; 95% CI, 0.16-0.96; P = .04). At 3 months, PCDF was associated with lower Short-Form 36 physical component summary scores than ACDF (estimated mean difference [EMD]: 6.42; 95% CI, 1.4-11.4; P = .007) and LP (EMD: 7.98; 95% CI, 2.7-13.3; P = .003), and higher Neck Disability Index scores than ACDF (EMD: 12.48; 95% CI, 2.3-22.7; P = .01) and LP (EMD: 15.22; 95% CI, 2.3-28.1; P = .014), indicating worse perceived physical functioning and greater disability, respectively.

CONCLUSION: Most employed patients returned to work within 1 year. LP patients resumed employment earliest, while PCDF patients returned to work latest, with greater disability at follow-up, suggesting that choice of surgical intervention may influence occupational outcomes.

Could indirect decompression occur for cord compression by the ligamentum flavum with anterior cervical discectomy and fusion?

J Neurosurg Spine 42:100–109, 2025

Cord compression by the ligamentum flavum (CCLF) has been reported to adversely affect the clinical outcomes of anterior cervical discectomy and fusion (ACDF). While indirect decompression does occur for foraminal stenosis with ACDF, whether ACDF could improve CCLF with the distraction of disc space remains unclear. This study aimed to identify 1) whether indirect decompression occurs for CCLF with ACDF, and 2) risk factors that hinder the improvement of CCLF.

METHODS This retrospective cohort study included 119 patients who underwent ACDF for the treatment of cervical myelopathy and CCLF was detected on preoperative MRI. Patients who demonstrated improvement in CCLF grade after ACDF were included in the improved group, while those who did not show improvement were classified as the unimproved group. Patient characteristics, cervical sagittal parameters, neck and arm pain visual analog scale score, and Japanese Orthopaedic Association (JOA) score were assessed. A comparison between the improved and unimproved groups was performed. Regression analyses were performed to identify factors associated with CCLF grade improvement.

RESULTS Overall, 58.0% (69/119) of patients showed improvement in CCLF grade after ACDF. CCLF grade did not improve in the remaining 42.0% (50/119) of patients, and 3.4% (4/119) of patients experienced aggravation of CCLF after ACDF. Preoperative spondylolisthesis (OR 0.252, 95% CI 0.090–0.711; p = 0.009) and greater segmental lordosis 3 months postoperatively (OR 0.835, 95% CI 0.731–0.953; p = 0.008) were the factors that hindered the improvement of CCLF after ACDF. Furthermore, patients with higher pre- or postoperative CCLF grades showed significantly less improvement in JOA score 2 years postoperatively.

CONCLUSIONS Indirect decompression for CCLF with ACDF is not reliable because 42.0% of patients did not demonstrate improvement in CCLF grade after the operation. Preoperative spondylolisthesis and postoperative increased segmental lordosis were risk factors for failure of CCLF improvement. Both pre- and postoperative higher CCLF grades were associated with poor neurological recovery 2 years postoperatively.

 

Use of Patient-Specific Interbody Cages Through a Minimally Invasive Lateral Approach for Unstable Lumbar Spondylodiskitis

Operative Neurosurgery 28:59–68, 2025

Patients with diskitis/osteomyelitis who do not respond to medical treatment or develop spinal instability/deformity may warrant surgical intervention. Irregular bony destruction due to the infection can pose a challenge for spinal reconstruction. The authors report a lateral approach using patient-specific interbody cages combined with posterior or lateral instrumentation to achieve spinal reconstruction for spinal instability/deformity from spondylodiskitis.

METHODS: This is a retrospective review of 4 cases undergoing debridement, lateral lumbar interbody fusion using patient-specific interbody cages, and supplemental lateral or posterior instrumentation for spinal instability/deformity after spondylodiskitis. The surgical technique is reported, as are the clinical and imaging outcomes.

RESULTS: Four male patients with a mean age of 69 years comprised this study. One had lateral lumbar interbody fusion at L2/3 and 3 at L4/5. The mean hospital stay was 5.8 days. The mean follow-up was 8.5 months (range 6-12 months). There were no approach-related neurological injuries or complications. The mean visual analog scale back pain scores improved from 9.5 to 1.5, and the mean Oswestry disability index improved from 68.5 to 23 at the end of the follow-up. The mean lumbar lordosis increased from 18°to 51°. The segmental angle increased from 6.5°to 18°. The coronal shift was 2.8 cm preoperatively and 0.9 cm postoperatively. The coronal Cobb angle reduced from 8.8°preoperatively to 2.8°postoperatively. On postoperative computed tomography, all patients had interval development of bridging bone across the surgical level through or around the cage. None of them developed cage migration or subsidence.

CONCLUSION: Patients with irregular bony destruction due to diskitis/osteomyelitis may benefit from patient-specific cages for spinal reconstruction to address spinal instability and deformity.

Microvascular Decompression Using the Gelatin Sponge Insertion Technique for Trigeminal Neuralgia

Operative Neurosurgery 28:52–58, 2025

Microvascular decompression (MVD) is the primary surgical intervention for trigeminal neuralgia (TN), with Teflon being the most conventional decompressing material. However, Teflon has been associated with adhesion and granulomas after MVD, which closely correlated with the recurrence of TN. Therefore, we developed a new technique to prevent direct contact between Teflon and nerve. The purpose of this study is to compare the efficacy of MVD using the gelatin sponge (GS) insertion technique with that of Teflon inserted alone in treating primary TN.

METHODS: We retrospectively analyzed the medical records and the follow-up data of 734 patients with unilateral primary TN who underwent MVD at our center from January 2014 to December 2019. After exclusions, we identified 313 cases of GS-inserted MVD and 347 cases of traditional MVD. The follow-up exceeded 3 years.

RESULTS: The operating time of the GS-inserted group was longer than that of the Teflon group (109.38 ± 14.77 vs 103.53 ± 16.02 minutes, P < .001). There was no difference between 2 groups in immediate surgical outcomes and postoperative complications. The yearly recurrence rate for GS-inserted MVD was lower at first (1.0%), second (1.2%), and third (1.2%) years after surgery, compared with its counterpart of Teflon group (3.7%, 2.9%, and 1.7% respectively). The first-year recurrence rate (P = .031) and total recurrence rate in 3 years (P = .013) was significantly lower in the GS-inserted group than Teflon group. Kaplan–Meier survival analysis demonstrated better outcomes in GS-inserted Microdescompresión vascular groups (P = .020).

CONCLUSION: The application of the GS insertion technique in MVD reduced first-year postoperative recurrence of TN, with similar complications rates compared with traditional MVD.

Anterior choroidal artery aneurysms: a systematic review and meta-analysis of outcomes and ischemic complications following surgical and endovascular treatment

J Neurosurg 142:127–137, 2025

Anterior choroidal artery (AChA) aneurysms account for 2%–5% of all intracranial aneurysms. Treatment considerations include microsurgical clipping, flow diversion, or coiling with or without adjunctive devices. AChA aneurysms pose challenges in treatment due to the origination of the aneurysm from the origin or proximal segment of the AChA. The AChA is particularly susceptible to vasospasm and occlusion during treatment with devastating neurological deficits, including hemiparesis, hemianesthesia, lethargy, neglect, and hemianopia. In this study, the authors performed a meta-analysis to quantify the outcomes and complication rates across treatment modalities for AChA aneurysms and to identify risk factors reported in the literature.

METHODS The authors performed a systematic review of AChA aneurysms treated with surgical clipping, endovascular coiling, or flow diversion and reported in the PubMed, Embase, Scopus, and Cochrane search databases. Single-arm meta-analyses of the selected outcomes were performed in RStudio.

RESULTS Literature review yielded 25 studies that met the inclusion criteria. In total, 1627 patients were included in the analysis, with 554 males, 1009 females, and 64 unspecified. The rate of any complication in the full cohort was 11.6%, with a rate of ischemic complications of 5.5% and a favorable recovery rate of 90.3% of all patients treated. In total, 1064 patients underwent surgical clipping, 443 were treated with coiling, and 120 patients with flow diversion. In clipped patients, the rate of total surgical complications was 17.6%, with an ischemic complication rate of 9.4%. The rate of good functional recovery, defined on the basis of a Glasgow Outcome Scale score of 4–5 or modified Rankin Scale score of 0–2, was 88.0%, and complete obliteration was achieved in 84.5% of surgically clipped aneurysms. The complication rate in coiled patients was 10.3%, with an ischemic complication rate of 3.0%. Good functional recovery was achieved in 88.6% of coiled patients and complete aneurysm obliteration in 74.1%. Flow diversion resulted in a complication rate of 1.3%, with 0.7% rate of ischemic complications. Good functional recovery was achieved in 98.4% of patients and complete aneurysm obliteration in 79.0% in the flow diversion group. Aneurysm morphological features that impacted the complication rate were also identified to augment quantitative data and to help guide treatment selection for AChA aneurysms.

CONCLUSIONS Flow diversion showed significantly lower total and ischemic complications and improved outcomes compared to clipping and coiling. There may be differences in outcomes between treatment types, especially when considering the varied patient presentations that guide treatment selection.

Presentation, surgical outcome, and supplementary motor area syndrome risk of posterior superior frontal gyrus tumors

J Neurosurg 142:162–173, 2025

Following resection of posterior superior frontal gyrus (PSFG) tumors, patients can experience supplementary motor area (SMA) syndrome consisting of contralateral hemiapraxia and/or speech apraxia. Given the heterogeneity of PSFG tumors, the authors sought to determine the risk of postoperative deficits and assess predictors of outcomes for all intraparenchymal PSFG tumors undergoing surgery (biopsy or resection), regardless of histology.

METHODS This was a retrospective single-center cohort study of adult PSFG-region tumors undergoing biopsy or resection by a single surgeon.

RESULTS A total of 106 consecutive patients undergoing 123 procedures (21 biopsies, 102 resections) fulfilled inclusion and exclusion criteria. Anaplastic astrocytomas were the most frequent among resected tumors (39% vs 29%), while glioblastomas were most common among biopsies (38% vs 27%) (p < 0.0001). The biopsy cohort was more likely to have tumor involvement outside the PSFG (90% vs 62%) (p = 0.011), most commonly in the motor cortex (67% vs 31%) (p = 0.005). Seizures were the most common presenting symptom in the resection cohort (p = 0.017), while motor deficits were more common in the biopsy cohort (58% vs 29%) (p < 0.001). Immediate postoperative neurological deficits occurred in 71 cases (58%), but only 3 of the deficits were permanent at 6 months of follow-up (2%). Postoperative SMA syndrome occurred in 48 cases (47%) and was significantly associated with involvement of the motor cortex (p = 0.018) or cingulate gyrus (p = 0.023), which were also significant in multivariate analysis as risk factors for SMA syndrome. However, postoperative SMA syndrome was not significantly associated with overall survival (p = 0.51). There were no perioperative deaths, but corpus callosum involvement (p < 0.001), contrast enhancement (p = 0.003), and glioblastoma pathology (p = 0.038) predicted worse overall survival in patients undergoing resection.

CONCLUSIONS Nearly half of all patients undergoing resection of PSFG-region tumors experience a postoperative SMA syndrome. Individuals with corpus callosum and/or motor cortex involvement may be at an increased risk of experiencing SMA syndrome. However, these deficits are usually transient, and the risk of permanent new deficits is very low (3%). Preoperative characteristics including corpus callosum involvement and tumor enhancement—in addition to pathology—might serve as predictors of overall survival within this patient population.

Microsurgical preservation of lenticulostriate artery perforators in insular glioma: the two point antegrade skeletonization technique

Acta Neurochirurgica (2025) 167:11

Reaching parenchymal segments of the lateral lenticulostriate artery (LSA) perforators, which represent the medial resection limit in insular gliomas (IG), remains a challenge. The currently described methods are indirect and sometimes, imprecise.

Methods We report an antegrade direct skeletonization technique to identify these tiny arteries at the medial end of IGs with an illustrative case of grade 2 astrocytoma. The patient recovered uneventfully following a near total tumor resection without any postoperative radiological ischemia in the LSA territory.

Conclusions Our microsurgical technique of antegrade LSA skeletonization may be useful in insular gliomas with a sharp medial border.

Endoscopic Versus Traditional Thoracic Discectomy: A Multicenter Retrospective Case Series and Meta-Analysis

Neurosurgery 96:152–171, 2025

Surgical treatment for symptomatic thoracic disc herniations (TDH) involves invasive open surgical approaches with relatively high complication rates and prolonged hospital stays. Although advantages of full endoscopic spine surgery (FESS) are well-established in lumbar disc herniations, data are limited for the endoscopic treatment of TDH despite potential benefits regarding surgical invasiveness. The aim of this study was to provide a comprehensive evaluation of potential benefits of FESS for the treatment of TDH.

METHODS: PubMed, MEDLINE, EMBASE, and Scopus were systematically searched for the term “thoracic disc herniation” up to March 2023 and study quality appraised with a subsequent meta-analysis. Primary outcomes were perioperative complications, need for instrumentation, and reoperations. Simultaneously, we performed a multicenter retrospective evaluation of outcomes in patients undergoing full endoscopic thoracic discectomy.

RESULTS: We identified 3190 patients from 108 studies for the traditional thoracic discectomy meta-analysis. Pooled incidence rates of complications were 25% (95% CI 0.22-0.29) for perioperative complications and 7% (95% CI 0.05-0.09) for reoperation. In this cohort, 37% (95% CI 0.26-0.49) of patients underwent instrumentation. The pooled mean for estimated blood loss for traditional approaches was 570 mL (95% CI 477.3-664.1) and 7.0 days (95% CI 5.91-8.14) for length of stay. For FESS, 41 patients from multiple institutions were retrospectively reviewed, perioperative complications were reported in 4 patients (9.7%), 4 (9.7%) required revision surgery, and 6 (14.6%) required instrumentation. Median blood loss was 5 mL (IQR 5-10), and length of stay was 0.43 days (IQR 0-1.23).

CONCLUSION: The results suggest that full endoscopic thoracic discectomy is a safe and effective treatment option for patients with symptomatic TDH. When compared with open surgical approaches, FESS dramatically diminishes invasiveness, the rate of complications, and need for prolonged hospitalizations. Full endoscopic spine surgery has the capacity to alter the standard of care for TDH treatment toward an elective outpatient surgery.

Long-term survivors in 976 supratentorial glioblastoma, IDH-wildtype patients

J Neurosurg 142:174–186, 2025

Glioblastoma, isocitrate dehydrogenase (IDH)–wildtype is the most aggressive glioma with poor outcomes. The authors explored survival rates and factors associated with long-term survival in patients harboring a glioblastoma, IDH-wildtype.

METHODS In an observational, retrospective, single-center study, the authors examined the medical records of 976 adults newly diagnosed with supratentorial glioblastomas, IDH-wildtype between January 2000 and January 2021. They analyzed clinical-, imaging-, and treatment-related factors associated with 2-year and 5-year survival.

RESULTS The median overall survival was 11.2 months (12.2 months for patients included after 2005 and the introduction of standard combined chemoradiotherapy). The median progression-free survival was 9.4 months (10.0 months for patients included after 2005). Overall, 17.6% of patients reached a 2-year overall survival, while 2.2% of patients reached a 5-year overall survival. Furthermore, 6.6% of patients survived 2 years without progression, while 1.1% of patients survived 5 years without progression. Two factors that were consistently associated with 2-year and 5-year survival were first-line oncological treatment with standard combined chemoradiotherapy and methylated O 6 -methylguanineDNA methyltransferase promoter. Other factors that were significantly associated with 2-year or 5-year survival were age at diagnosis ≤ 60 years, headaches or signs of raised intracranial pressure at diagnosis, cortical contact of contrast enhancement, no contrast enhancement crossing the midline on initial imaging, total or subtotal tumor resection, and a second line of oncological treatment at recurrence. Within 21 cases of 5-year survival, 18 were confirmed to be glioblastomas, IDH-wildtype, and 7 of the 5-year survivors (38.9%) had additional genetic alterations: 3 cases had an FGFR mutation or fusion, 3 cases had a PIK3CA mutation, 1 case had a PTPN11 mutation, and 1 case had a PMS2 mutation in the context of constitutional mismatch repair deficiency syndrome.

CONCLUSIONS Five-year overall survival in patients with glioblastoma, IDH-wildtype is extremely low. Predictors of a longer survival are mostly treatment factors, emphasizing the importance of a complete oncological treatment plan, when achievable. Glioblastoma, IDH-wildtype 5-year survivors could be screened for actionable targets in case of recurrence.