Month: November 2024

Posted on

Anterior selective targeting for radiosurgical treatment of trigeminal neuralgia: a cohort study

Acta Neurochirurgica (2024) 166:482

Before commonly used targets such as the Retrogasserian Zone (RGZ) and the Root Entry Zone (REZ) were adopted for the radiosurgical treatment of trigeminal neuralgia (TN), a more anterior target involving the Gasserian ganglion was used. Thanks to advancements in imaging technology, it is now possible to identify and target separate nerve divisions in Meckel’s Cave as desired. Although this approach has been mentioned previously, no clinical study has investigated it until now. This study aims to fill this gap in the literature.

Methods Trigeminal neuralgia patients who received radiosurgical treatment between February 2019 and June 2022 in a single centre were included in the study. Pain relief, medication dependency and side effect profiles of the investigated anterior selective target (AST) were compared to those of the classical targets at 1 week, 1–3-6 months, and 1 year.

Results A total of 66 patients were included in the study. Effectiveness, safety and application convenience parameters were compared between; the REZ (n = 21), RGZ (n = 20) and AST (n = 25) groups. All groups showed significant improvement in pain with similar results to each other. AST treatments were performed in significantly shorter beam-on-times and with significantly lower brainstem doses.

Conclusions The investigated AST showed comparable results to the classical targets without any indication of superiority or inferiority in terms of efficacy and safety in this preliminary investigation. As no blocks were needed to protect the brainstem with this method, it can be used for select patients as needed and could even be investigated in larger studies as an alternative approach.

Posted on

Preoperative stereotactic radiosurgery for cerebral metastases: safe, effective, and decreases steroid dependency

J Neurosurg 141:1332–1342, 2024

Preoperative stereotactic radiosurgery (SRS) is emerging as a viable alternative to standard postoperative SRS. Studies have suggested that preoperative SRS provides comparable tumor control and overall survival (OS) and may reduce the incidence of leptomeningeal disease (LMD) and adverse radiation effects (AREs). It is unknown, however, if preoperative SRS remains effective in cohorts including large brain metastases (> 14 cm 3 ) or if preoperative SRS affects steroid taper/immunotherapy. Here, the authors report the results of a phase 2 single-arm trial assessing a prospectively acquired series of 26 patients who underwent preoperative SRS, without a volumetric cutoff, compared with a propensity score–matched concurrent cohort of 30 patients who underwent postoperative SRS to address these salient questions.

METHODS Demographics, oncological history, surgical details, and outcomes were collected from the medical records. Coprimary endpoints were local tumor control (LTC) and a composite outcome of LTC, ARE, and LMD. Additional outcomes were OS, steroid taper details, and immunotherapy resumption. For survival analyses, cohorts were propensity score matched.

RESULTS Preoperative and postoperative SRS patients were comparable in terms of age, sex, Karnofsky Performance Status score, oncological history, and operative details. Gross tumor volume (GTV) was significantly higher in the preoperative group (median 12.2 vs 5.3 cm 3 , p < 0.001). One-year LTC (preoperative SRS: 77.2% vs postoperative SRS: 82.5%, p = 0.61) and composite outcome (68.3% vs 72.7%, p = 0.38) were not significantly different between the groups. In multivariable analysis, preoperative SRS did not have a significant effect on LTC (HR 1.57 [95% CI 0.38–6.49], p = 0.536) or the composite outcome (HR 1.18 [95% CI 0.38–3.72], p = 0.771), although the confidence intervals were large. The median OS (preoperative SRS: 17.0 vs postoperative SRS: 14.0 months, p = 0.61) was not significantly different. Rates of LMD were nonsignificantly lower in the preoperative SRS group (3.8% vs 16.7%, p = 0.200). Greater GTV volume was associated with prolonged (> 10 days) steroid taper (OR 1.24 [95% CI 1.04–1.55], p = 0.032). However, in multivariable analysis, preoperative SRS markedly reduced the steroid taper length (OR 0.13 [95% CI 0.02–0.61], p = 0.016). Time to immunotherapy was shorter in the preoperative SRS group (36 [IQR 26, 76] vs OR 228 [IQR 129, 436] days, p = 0.02).

CONCLUSIONS Compared with postoperative SRS, preoperative SRS is a safe and effective strategy in the management of cerebral metastases of all sizes and provides comparable tumor control without increased adverse effects. Notably, preoperative SRS enabled rapid steroid taper, even in larger tumors. Future studies should specifically examine the interaction of preoperative SRS with steroid usage and resumption of systemic therapies and the subsequent effects on systemic progression and OS.

Clinical trial registration no.: NCT02514915 (ClinicalTrials.gov)

Posted on

Effect of cranial entry site on the rate of proximal catheter misplacement in ventriculoperitoneal shunt insertion

J Neurosurg 141:1418–1426, 2024

The insertion of a ventriculoperitoneal shunt (VPS) is a common neurosurgical procedure, but the optimal entry site of the ventricular catheter is still under debate. In this study, the authors compare the parietal (Keen’s) and frontal (Kocher’s) entry sites in terms of the rate of revision surgery due to ventricular catheter misplacement, VPS dysfunction, and VPS infection.

METHODS The authors retrospectively analyzed the data on consecutive adults (age ≥ 18 years) who had undergone primary VPS insertion between 2010 and 2020 at two neurosurgical centers. One center regularly inserts the ventricular catheter frontally (frontal group); the other center, parietally (parietal group). The primary outcome of interest was the rate of ventricular catheter misplacement necessitating revision surgery. Secondary outcomes were functional outcome as measured by the modified Rankin Scale (mRS), rate of revision surgery for VPS dysfunction and infection, as well as early (≤ 30 days) and late (> 30 days) mortality rates. Propensity score matching was performed based on baseline variables, such as normal pressure hydrocephalus, postinfectious hydrocephalus, and idiopathic intracranial hypertension, which were identified as predictors of ventricular catheter misplacement using logistic regression analysis.

RESULTS Among 539 consecutive patients, 301 (55.8%) were in the frontal group and 238 (44.2%) in the parietal group. Postoperative rates of revision surgery due to misplacement were comparable in the two catheter entry site groups (frontal 14 [4.7%] vs parietal 11 [4.6%], p = 0.987). Rates of revision surgery for VPS dysfunction (14 [4.7%] vs 10 [4.2%], respectively, p = 0.802) and infection (22 [7.3%] vs 10 [4.2%], p = 0.13) exhibited no significant differences. Favorable functional outcomes (mRS score ≤ 2; 164 [76.3%] vs 174 [79.5%], respectively, p = 0.058) and early mortality rates (5 [1.7%] vs 6 [2.5%], p = 0.483) were similar between the groups. After propensity score matching, the primary and secondary outcome measures remained comparable between the groups.

CONCLUSIONS The entry site of the ventricular catheter in VPS surgery does not seem to affect proximal revision rates. Further, revision rates due to VPS dysfunction, VPS infection, and morbidity were comparable as well.

Posted on

Subtemporal Approach for the Treatment of Ruptured and Unruptured Distal Basilar Artery Aneurysms: Is There a Contemporary Use?

Operative Neurosurgery 27:581–596, 2024

Distal basilar artery aneurysms (DBAs) are high-risk lesions for which endovascular treatment is preferred because of their deep location, yet indications for open clipping nonetheless remain. The subtemporal approach allows for early proximal control and direct visualization of critical posterior perforating arteries, especially for posterior-projecting aneurysms. Our objective was to describe our clinical experience with the subtemporal approach for clipping DBAs in the evolving endovascular era.

METHODS: This was a retrospective, single-institution case series of patients with DBAs treated with microsurgery over a 21-year period (2002-2023). Demographic, clinical, and surgical data were collected for analysis.

RESULTS: Twenty-seven patients underwent clipping of 11 ruptured and 16 unruptured DBAs with a subtemporal approach (24 female; mean age 53 years). Ten patients had expanded craniotomies for treatment of additional aneurysms. The aneurysm occlusion rate was 100%. Good neurological outcomes as defined by the modified Rankin Scale score ≤2 and Glasgow Outcome Scale score ≥4 were achieved in 21/27 patients (78%). Two patients died before hospital discharge, one from vasospasm-induced strokes and another from an intraoperative myocardial infarction.

CONCLUSION: These results demonstrate that microsurgical clip ligation of DBAs using the subtemporal approach remains a viable option for complex lesions not amenable to endovascular management.

Posted on

Segmental Sagittal Alignment in Lumbar Spinal Fusion: A Review of Evidence-Based Evaluation of Preoperative Measurement, Surgical Planning, Intraoperative Execution, and Postoperative Evaluation

Operative Neurosurgery 27:533–548, 2024

Maintaining and restoring global and regional sagittal alignment is a well-established priority that improves patient outcomes in patients with adult spinal deformity. However, the benefit of restoring segmental (level-by-level) alignment in lumbar fusion for degenerative conditions is not widely agreed on. The purpose of this review was to summarize intraoperative techniques to achieve segmental fixation and the impact of segmental lordosis on patient-reported and surgical outcomes.

METHODS: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, PubMed, Embase, Cochrane, and Web of Science databases were queried for the literature reporting lumbar alignment for degenerative lumbar spinal pathology. Reports were assessed for data regarding the impact of intraoperative surgical factors on postoperative segmental sagittal alignment and patient-reported outcome measures. Included studies were further categorized into groups related to patient positioning, fusion and fixation, and interbody device (technique, material, angle, and augmentation).

RESULTS: A total of 885 studies were screened, of which 43 met inclusion criteria examining segmental rather than regional or global alignment. Of these, 3 examined patient positioning, 8 examined fusion and fixation, 3 examined case parameters, 26 examined or compared different interbody fusion techniques, 5 examined postoperative patient-reported outcomes, and 3 examined the occurrence of adjacent segment disease. The data support a link between segmental alignment and patient positioning, surgical technique, and adjacent segment disease but have insufficient evidence to support a relationship with patient-reported outcomes, cage subsidence, or pseudoarthrosis.

CONCLUSION: This review explores segmental correction’s impact on short-segment lumbar fusion outcomes, finding the extent of correction to depend on patient positioning and choice of interbody cage. Notably, inadequate restoration of lumbar lordosis is associated with adjacent segment degeneration. Nevertheless, conclusive evidence linking segmental alignment to patient-reported outcomes, cage subsidence, or pseudoarthrosis remains limited, underscoring the need for future research.

Posted on

The dural attachment length predict prognosis in patients with recurrent meningiomas

Neurosurgical Review (2024) 47:843

To investigate the prognostic factors of recurrent meningioma patients who underwent reoperation, so as to make relevant recommendations for the treatment.

A retrospective analysis was performed on 73 patients with recurrent meningioma. Patients’ clinical data were obtained from their medical records. Progression-free Survival (PFS) was defined as the interval from the date of surgery to the date of tumor recurrence, or to the date of the last imaging review. Overall survival (OS) was defined as the time from the date of surgery to death from any cause, or to the date of the last follow-up.

The multivariate COX regression showed that dural attachment length (HR = 1.238, 95%CI1.011–1.516, P = 0.039) and WHO grade (HR = 2.184, 95%CI1.135–4.203, P = 0.019) were independent risk factors for tumor progression. The factors associated with survival in multivariate regression analysis were preoperative Karnofsky Performance Scale (KPS) (HR = 0.951, 95%CI0.923–0.979, P = 0.001), dural attachment length (HR = 1.520, 95%CI1.124–2.057, P = 0.007) and WHO grade (HR = 4.829, 95%CI1.89112.331, P = 0.001). The dural attachment length (OR = 1.843, 95%CI1.236–2.748, P = 0.003) was the only risk factor associated with postoperative pulmonary infection. No correlation was observed between Simpson’s grade and either PFS or OS.

The dural attachment length is closely related to the prognosis of recurrent meningioma, which should be given importance during the perioperative assessment.

Posted on

Staged Versus Same-Day Surgery in Circumferential Minimally Invasive Deformity Correction

Neurosurgery 95:1040–1045, 2024

We sought to compare long-term clinical and radiographic outcomes in patients who underwent staged vs same-day circumferential minimally invasive surgery (cMIS) for adult spinal deformity (ASD).

METHODS: We reviewed staged and same-day cMIS ASD cases in a prospective multi-institution database to compare preoperative and 2-year clinical and radiographic parameters between cohorts.

RESULTS: A total of 85 patients with a 2-year follow-up were identified (27 staged, 58 same-day). Staged patients had more extensive surgeries and greater hospital length of stay (all P < .001). There were no significant differences in preoperative or 2-year postoperative clinical metrics between cohorts. Patients in the staged cohort also had greater preoperative coronal deformity and thus experienced greater reduction in coronal deformity at 2 years (all P < .01).

CONCLUSION: Patients undergoing staged or same-day cMIS correction had similar outcomes at 2 years postoperatively. Staged cMIS ASD correction may be more appropriate in patients with greater deformity, higher frailty, and who require longer, more extensive surgeries.

Posted on

Microscope-integrated optical coherence tomography for in vivo human brain tumor detection with artificial intelligence

J Neurosurg 141:1343–1351, 2024

It has been shown that optical coherence tomography (OCT) can identify brain tumor tissue and potentially be used for intraoperative margin diagnostics. However, there is limited evidence on its use in human in vivo settings, particularly in terms of its applicability and accuracy of residual brain tumor detection (RTD). For this reason, a microscope-integrated OCT system was examined to determine in vivo feasibility of RTD after resection with automated scan analysis.

METHODS Healthy and diseased brain was 3D scanned at the resection edge in 18 brain tumor patients and investigated for its informative value in regard to intraoperative tissue classification. Biopsies were taken at these locations and labeled by a neuropathologist for further analysis as ground truth. Optical OCT properties were obtained, compared, and used for separation with machine learning. In addition, two artificial intelligence–assisted methods were utilized for scan classification, and all approaches were examined for RTD accuracy and compared to standard techniques.

RESULTS In vivo OCT tissue scanning was feasible and easily integrable into the surgical workflow. Measured backscattered light signal intensity, signal attenuation, and signal homogeneity were significantly distinctive in the comparison of scanned white matter to increasing levels of scanned tumor infiltration (p < 0.001) and achieved high values of accuracy (85%) for the detection of diseased brain in the tumor margin with support vector machine separation. A neuronal network approach achieved 82% accuracy and an autoencoder approach 85% accuracy in the detection of diseased brain in the tumor margin. Differentiating cortical gray matter from tumor tissue was not technically feasible in vivo.

CONCLUSIONS In vivo OCT scanning of the human brain has been shown to contain significant value for intraoperative RTD, supporting what has previously been discussed for ex vivo OCT brain tumor scanning, with the perspective of complementing current intraoperative methods for this purpose, especially when deciding to withdraw from further resection toward the end of the surgery.

Posted on

Deep learning algorithm for fully automated measurement of sagittal balance in adult spinal deformity

European Spine Journal (2024) 33:4119–4124

Deep learning (DL) algorithms can be used for automated analysis of medical imaging. The aim of this study was to assess the accuracy of an innovative, fully automated DL algorithm for analysis of sagittal balance in adult spinal deformity (ASD).

Material and methods Sagittal balance (sacral slope, pelvic tilt, pelvic incidence, lumbar lordosis and sagittal vertical axis) was evaluated in 141 preoperative and postoperative radiographs of patients with ASD. The DL, landmark-based measurements, were compared with the ground truth values from validated manual measurements.

Results The DL algorithm showed an excellent consistency with the ground truth measurements. The intra-class correlation coefficient between the DL and ground truth measurements was 0.71–0.99 for preoperative and 0.72–0.96 for postoperative measurements. The DL detection rate was 91.5% and 84% for preoperative and postoperative images, respectively.

Conclusion This is the first study evaluating a complete automated DL algorithm for analysis of sagittal balance with high accuracy for all evaluated parameters. The excellent accuracy in the challenging pathology of ASD with long construct instrumentation demonstrates the eligibility and possibility for implementation in clinical routine.

Posted on

Cost-effectiveness of posterior lumbar interbody fusion and/or transforaminal lumbar interbody fusion for grade 1 lumbar spondylolisthesis: a 5-year Quality Outcomes Database study

J Neurosurg Spine 41:596–603, 2024

Posterior lumbar interbody fusion (PLIF) and/or transforaminal lumbar interbody fusion (TLIF), referred to as “PLIF/TLIF,” is a commonly performed operation for lumbar spondylolisthesis. Its long-term cost-effectiveness has not been well described. The aim of this study was to determine the 5-year cost-effectiveness of PLIF/TLIF for grade 1 degenerative lumbar spondylolisthesis using prospective data collected from the multicenter Quality Outcomes Database (QOD).

METHODS Patients enrolled in the prospective, multicenter QOD grade 1 lumbar spondylolisthesis module were included if they underwent single-stage PLIF/TLIF. EQ-5D scores at baseline, 3 months, 12 months, 24 months, 36 months, and 60 months were used to calculate gains in quality-adjusted life years (QALYs) associated with surgery relative to preoperative baseline. Healthcare-related costs associated with the index surgery and related reoperations were calculated using Medicare reimbursement–based cost estimates and validated using price transparency diagnosis-related group (DRG) charges and Medicare charge-to-cost ratios (CCRs). Cost per QALY gained over 60 months postoperatively was assessed.

RESULTS Across 12 surgical centers, 385 patients were identified. The mean patient age was 60.2 (95% CI 59.1–61.3) years, and 38% of patients were male. The reoperation rate was 5.7%. DRG 460 cost estimates were stable between our Medicare reimbursement–based models and the CCR-based model, validating the focus on Medicare reimbursement. Across the entire cohort, the mean QALY gain at 60 months postoperatively was 1.07 (95% CI 0.97–1.18), and the mean cost of PLIF/TLIF was $31,634. PLIF/TLIF was associated with a mean 60-month cost per QALY gained of $29,511. Among patients who did not undergo reoperation (n = 363), the mean 60-month QALY gain was 1.10 (95% CI 0.99–1.20), and cost per QALY gained was $27,591. Among those who underwent reoperation (n = 22), the mean 60-month QALY gain was 0.68 (95% CI 0.21–1.15), and the cost per QALY gained was $80,580.

CONCLUSIONS PLIF/TLIF for degenerative grade 1 lumbar spondylolisthesis was associated with a mean 60-month cost per QALY gained of $29,511 with Medicare fees. This is far below the well-established societal willingness-to-pay threshold of $100,000, suggesting long-term cost-effectiveness. PLIF/TLIF remains cost-effective for patients who undergo reoperation.

 

Posted on

Revisiting the microsurgical anatomy of the sagittal stratum and surgical implications: fiber microdissection and tractography study

J Neurosurg 141:1433–1446, 2024

The term “sagittal stratum” was coined by Heinrich Sachs in 1892 to define a parasagittally oriented white matter layer at the temporo-occipital cortex. Although this term has been widely used for more than 100 years, the description, classification, borders, and involved fibers of the structure vary among authors and remain imprecise. Through fiber microdissection and tractography, the authors aimed to define the sagittal stratum and resolve the uncertainty by revealing the relationship of this structure to other cerebral white matter pathways and the orientation of fibers in it.

METHODS Twenty postmortem human cerebral hemispheres were prepared according to Klingler’s method. Fiber dissections were performed under a surgical microscope and with microsurgical techniques. The results of dissection at each step were photographed with 2D and 3D imaging techniques, and 3D photogrammetry techniques were used to create a 360° model. Diffusion tensor imaging and 7T high-resolution MRI were used to confirm the findings.

RESULTS This study revisited the 3D organization of white matter tracts in the sagittal stratum through fiber microdissection and tractography. The microneuroanatomical structure of the sagittal stratum and its special organization with fibers from all three fiber systems are demonstrated. The authors’ findings revealed that the sagittal stratum has two layers consisting of four different fiber tracts. Its external layer consists of a long association fiber and a commissural fiber, while its internal layer consists of intertwined projection fibers, including temporo-parieto-occipitopontine fibers and the posterior thalamic peduncle. Detailed microdissection also showed the location of the posterior thalamic peduncle in the most medial site of all posterior hemispheric projection fibers.

CONCLUSIONS The structure of the sagittal stratum is distinctive in that it contains all three main fiber systems: association, commissural, and projection. Because of its expansive location in the temporal and occipital lobes, it can be damaged by most neurosurgical pathologies and procedures. The authors emphasize the significance of preserving the sagittal stratum during surgical interventions while also challenging the notion of a “silent” brain, suggesting that the current inability to fully comprehend cerebral function contributes to this misconception. Detailed knowledge of the complex white matter anatomy of the sagittal stratum can guide neurosurgeons in surgical planning and the selection of appropriate surgical approaches with intraoperative orientation for safe surgery and less comorbidity.

Posted on

Predictors of patient satisfaction in the surgical treatment of cervical spondylotic myelopathy

J Neurosurg Spine 41:611–618, 2024

Patients with cervical spondylotic myelopathy (CSM) experience progressive neurological impairment. Surgical intervention is often pursued to halt neurological symptom progression and allow for recovery of function. In this paper, the authors explore predictors of patient satisfaction following surgical intervention for CSM.

METHODS This is a retrospective review of prospectively collected data from the multicenter Quality Outcomes Database. Patients who underwent surgical intervention for CSM with a minimum follow-up of 2 years were included. Patient-reported satisfaction was defined as a North American Spine Society (NASS) satisfaction score of 1 or 2. Patient demographics, surgical parameters, and outcomes were assessed as related to patient satisfaction. Patient quality of life scores were measured at baseline and 24-month time points. Univariate regression analyses were performed using the chi-square test or Student t-test to assess patient satisfaction measures. Multivariate logistic regression analysis was conducted to assess for factors predictive of postoperative satisfaction at 24 months.

RESULTS A total of 1140 patients at 14 institutions with CSM who underwent surgical intervention were included, and 944 completed a patient satisfaction survey at 24 months postoperatively. The baseline modified Japanese Orthopaedic Association (mJOA) score was 12.0 ± 2.8. A total of 793 (84.0%) patients reported satisfaction (NASS score 1 or 2) after 2 years. Male and female patients reported similar satisfaction rates (female sex: 47.0% not satisfied vs 48.5% satisfied, p = 0.73). Black race was associated with less satisfaction (26.5% not satisfied vs 13.2% satisfied, p < 0.01). Baseline psychiatric comorbidities, obesity, and length of stay did not correlate with 24-month satisfaction. Crossing the cervicothoracic junction did not affect satisfactory scores (p = 0.19), and minimally invasive approaches were not associated with increased patient satisfaction (p = 0.14). Lower baseline numeric rating scale neck pain scores (5.03 vs 5.61, p = 0.04) and higher baseline mJOA scores (12.28 vs 11.66, p = 0.01) were associated with higher satisfaction rates.

CONCLUSIONS Surgical treatment of CSM results in a high rate of patient satisfaction (84.0%) at the 2-year follow-up. Patients with milder myelopathy report higher satisfaction rates, suggesting that intervention earlier in the disease process may result in greater long-term satisfaction.

Posted on

Arteriovenous malformations in the cerebellopontine angle: assessment of the “backdoor resection” technique and microsurgical results in 38 patients

J Neurosurg 141:1198–1211, 2024

Posterior fossa arteriovenous malformations (AVMs) represent 7% to 15% of all intracranial AVMs and are associated with an increased risk of hemorrhage, morbidity, and mortality compared with supratentorial AVMs, thus prompting urgent and definitive treatment. Cerebellopontine angle (CPA) AVMs are a unique group of posterior fossa AVMs incorporating characteristics of brainstem and cerebellar lesions, which are particularly amenable to microsurgical resection. This study reports the clinical, radiological, operative, and outcome features of patients with CPA AVMs in a large cohort.

METHODS The authors conducted a single-surgeon, 2-institution retrospective cohort study of all consecutive patients with CPA AVMs treated with microsurgical resection during a 25-year period.

RESULTS CPA AVMs represented 22% (38 of 176) of all infratentorial AVMs resected by the senior author. Overall, 38 patients (22 [58%] male and 16 [42%] female) met the study inclusion criteria and were analyzed. Most patients presented with hemorrhage (n = 29, 76%). The median age at surgery was 56 (range 6–82) years. Subtypes included 22 (58%) petrosal cerebellar AVMs, 11 (29%) lateral pontine AVMs, and 5 (13%) AVMs involving both the brainstem and cerebellum. Most AVM niduses were small (< 3 cm; n = 35, 92%) and compact (n = 31, 82%). Fourteen (37%) patients harbored flow-related aneurysms. Twenty (53%) patients underwent preoperative embolization. Complete angiographic obliteration was achieved with microsurgery in 35 (92%) patients. Five (13%) patients with poor neurological conditions at presentation died before hospital discharge. Of the 7 (18%) patients with new postoperative neurological deficits, 5 had transient deficits. The median (interquartile range) follow-up was 1.7 (0.5–3.2) years; 32 (84%) patients were alive at last follow-up, and 30 (79%) had achieved a favorable neurological outcome (modified Rankin Scale [mRS] score 0–2). The only independent predictor of unfavorable postoperative outcome (mRS score 3–6) was the preoperative mRS score (p = 0.002).

CONCLUSIONS CPA AVMs are unique posterior fossa lesions, including petrosal cerebellar and lateral pontine AVMs. The “backdoor resection” technique provides a safe and efficient strategy with high obliteration rates and a low risk of treatment-related morbidity. Microsurgical resection should be considered the frontline treatment for most CPA AVMs, except for those with a significant diffuse brainstem component.

Posted on

Awake surgery with mapping-based resection to treat focal epilepsy in eloquent brain areas

Acta Neurochirurgica (2024) 166:430

Resective surgery is a potential therapeutic option for select patients with intractable focal epilepsy. However, the presence of ictal onset zones within or surrounding highly functional brain areas presents a surgical challenge, leading to poor seizure and functional outcomes. This report describes our experiences with awake mapping-tailored resection of epileptogenic areas involving eloquent cortices and evaluates their feasibility, tolerance, limitations, and significance.

Methods The study included patients who underwent surgery for drug-resistant focal epilepsy at our center under awake conditions. The surgical approach aimed to achieve maximum resection of preoperatively defined epileptogenic zones, considering the boundaries defined by surrounding functional areas. We collected data on preoperative evaluations, intraoperative tests and seizures, postoperative status epilepticus, and neurological functional outcomes.

Results We included 22 patients, 10 of whom had non-lesional epilepsy. Language, motor function, and sensory function were at risk in 19, 9, and 4 patients, respectively. Resection was performed as planned in 14 (63.6%) patients, while modifications were necessary in 8 (36.4%) patients due to functional constraints. The mean follow-up duration was 29.8 months. Sixteen (72.7%) patients achieved Engel class Ia outcomes, indicating seizure freedom, while none of the patients experienced clinically significant permanent postoperative neurological deficits.

Significance Resective surgery with intraoperative brain mapping under awake conditions was a valid treatment option for achieving a cure in cases of drug-resistant focal epilepsy, even in situations in which the condition is considered inoperable due to the risk of significant postoperative neurological deficits.

Posted on

Microsurgical management of recurrent intracranial aneurysm after endovascular treatment: a series of 60 consecutive patients

J Neurosurg 141:1235–1243, 2024

The aim of this study was to evaluate the morbidity associated with microsurgical treatment in patients with a recurrent aneurysm to improve their surgical management.

METHODS From 2012 to 2022, among the 3128 patients with ruptured or unruptured intracranial aneurysms managed at the authors’ institution, 954 patients were treated by a microsurgical procedure. Of these 3128 patients, 60 consecutive patients (6.3%) who had a recurrent microsurgically treated aneurysm after previous endovascular treatment were included in this study. Additional microsurgical treatment was considered in case of progressive remnant growth or significant aneurysm recurrence. Intraoperative and postoperative complications were noted. Early (< 7 days) and long-term clinical and radiological monitoring were performed. Good functional outcome was considered as a modified Rankin Scale score < 3.

RESULTS The mean age at initial treatment was 45 years (range 26–65 years). The mean delay between the first treatment and microsurgical treatment of the recurrence was 64 months (range 2 days–296 months). The mean size of the fundus recurrence was 5 mm, and the mean size of the neck recurrence was 4.6 mm. Five patients (8.3%) presented with subarachnoid hemorrhage associated with rupture of the recurrent aneurysm. Three patients died (6%) of aneurysm rupture and/or intensive care complications. The total morbidity rate associated with the microsurgical procedure was 14.5% (8/55) in patients with unruptured recurrent aneurysms. Among these patients, postoperative definitive complications (ischemic lesions) directly related to the microsurgical procedure were present in 3 patients (5.5%). Intraoperative rupture was recorded in these 3 patients. In the 54 surviving patients with unruptured recurrent aneurysms, good functional outcome was noted in 49 (91%). Poor functional outcome was significantly associated with intraoperative rupture.

CONCLUSIONS Microsurgery remains an effective therapeutic option for recurrent intracranial aneurysms. However, in the authors’ experience, postoperative morbidity is higher than in patients with nonrecurrent aneurysms. Therefore, a pretherapeutic multidisciplinary evaluation is mandatory to reduce the potential morbidity associated with the retreatment as much as possible. When endovascular occlusion of the aneurysm requires both stenting and coiling, alternative microsurgical treatment should be carefully evaluated, as microsurgical clipping will become much more challenging in cases of aneurysm recurrence.

Posted on

Contemporary cohort of cerebral cavernous malformations: natural history and utility of follow-up MRI

J Neurosurg 141:1159–1167, 2024

This study reports the natural history of cerebral cavernous malformations (CCMs) in a contemporary cohort with prospectively collected data from multiple sources, access to follow-up imaging, integrated electronic medical records, and detailed imaging review by study investigators. The authors aimed to define the first prospective symptomatic hemorrhage (SH) and severe SH rates, determine the risk of a second prospective SH, and identify risk factors for SH.

METHODS From a prospectively maintained database of adult patients with radiologically defined CCM, those with radiation-induced CCM, those who underwent surgery within 3 months postdiagnosis, and those with < 1 year of followup were excluded. The patients’ medical history and radiological features of the CCM were recorded at the time of diagnosis. Follow-up annual written surveys were completed for 5 years after the initial diagnosis and then semiannually thereafter in addition to medical record and follow-up imaging review. Outcomes of interest included SH and severe SH.

RESULTS Of 315 patients, 58.7% were female and 19.7% had familial CCMs. At diagnosis, 37.1% of patients had ruptured CCMs and 28.9% of the CCMs were located in the brainstem. The 5-year cumulative rates of prospective SH and severe SH in those with ruptured CCMs at diagnosis were 41.2% and 12.8%, respectively, compared with 6.1% and 2.5% in patients with unruptured CCMs at diagnosis (p < 0.0001). Risk factors for prospective SH included a ruptured CCM at diagnosis and persistent or new hyperintensity on T1-weighted MRI performed > 3 months after baseline MRI. For those with a ruptured CCM at diagnosis, the risk of developing a second prospective SH was similar to that of developing a first SH.

CONCLUSIONS In a contemporary cohort of adult patients with CCM, the authors report 5-year SH and severe SH rates, rates of second prospective hemorrhage, and predictors of SH. Persistent or new hyperintensity on T1-weighted MRI may be a useful marker of disease activity.

Posted on

Comparison of rostral facet joint violations in robotic- and navigation-assisted pedicle screw placement for adult lumbar spine instrumentation

The Spine Journal 24 (2024) 2102−2109

Facet joint violation by pedicle screws may lead to adjacent-segment disease and postoperative pain. Previous studies have reported the incidence of rostral facet joint violation using various pedicle screw insertion techniques. However, the incidence of facet joint violations with robotic guidance has not been determined.

PURPOSE: To investigate and compare the incidence of rostral facet joint violation by pedicle screws under robotic guidance and computerized tomography (CT) navigation guidance.

STUDY DESIGN/SETTING: Retrospective matched cohort.

PATIENT SAMPLE: All patients who underwent robotic-assisted lumbar fusion at a major spine center up until 2023 were retrospectively identified and matched 1:3 to patients undergoing CT navigation guidance based by on age, sex, rostral vertebral level, and length of construct. Inclusion criteria consisted of age greater than 18 years, bilateral pedicle screw fixation, and presence of a postoperative CT scan of the lumbar spine or abdomen/pelvis at any point in the postoperative period.

OUTCOME MEASURES: Rostral facet joint violations.

METHODS: Descriptive statistics were used to compare cohorts: frequencies, chi-squared analysis for categorical variables, and t-test for continuous variables.

RESULTS: A total of 408 rostral pedicle screws were implanted in 204 patients (Robot: 102; Navigation: 306). Overall, 13 (12.3%) rostral facet joint violations were observed in the robot cohort and 75 (24.5%) in the navigation cohort (p=.01). Specifically, fewer robotic violations were observed at the L2 (3.5% vs 32.1%, p=.003) and L3 levels (3.9% vs 18.1%, p=.08) compared to navigation. No difference was observed at L4 and L5. Bilateral violations are significantly reduced with robotic approaches (5.3% vs 14.4%, p=.03). Lastly, more facet joint violations were observed during open approaches (robot: 18.8%, navigation: 27.3%) than percutaneous approaches (robot: 11.6%, navigation: 7.1%) in both groups (p<.001). The rate of L4 facet violations was 18.8% in the robotic cohort and 27.3% in the navigation cohort. The rate of L5 facet violations was 31.3% in the robotic cohort and 29.2% in the navigation cohort.

CONCLUSIONS: Use of robotic assistance in lumbar pedicle screws significantly reduced the rate of rostral facet joint violations compared to navigation guidance at L2 and L3 levels, but not at L4 and L5, with facet violations approaching nearly one-third of the patients at L5 screws. Rostral facet violations can play a significant role in adjacent segment degeneration and disease. Technical factors and trajectory issues likely play a role and addressing these components should minimize unintended facet violation and proximal adding on.

Posted on

Technical report on intra-operative trigeminal root mapping in percutaneous lesioning for trigeminal neuralgias

Acta Neurochirurgica (2024) 166:434

Percutaneous lesioning-techniques for treating refractory Trigeminal Neuralgias not amenable to Micro-Vascular Decompression remain useful in neurosurgical practice. Success, avoidance of complications and reduction of side-effects depend on the accurate location of the lesion-maker especially for Radio-Frequency-Thermo-Rhizotomy (RF-Th-Rh). Added to X-ray-guidance, Intra-Operative Neurophysiology can be of significant help to achieve optimal accuracy of the surgery.

Based on previous research, this article aims to describe the simplest way to use direct electrical stimulation of the trigeminal root to evoke clinically observable muscle responses allowing to precisely position the tip of the needle for accurate lesioning. Technique to evoke specific localizing muscle responses Masticatory twitches can be easily produced by stimulating the motor root, through orthodromic conduction to the masticatory muscles.

Evoked Muscle Responses (EMRs) can be elicited in the facial nerve territory by stimulating the sensory rootlets, through Trigemino-Facial Reflexes’ pathways (TFRs). Responses in the Orbicularis Oculi is the well-known and readily used “Blink reflex”. On the contrary, TFRs in the lower territory of the facial nerve escaped clinical investigations not having been explored under direct stimulation of the trigeminal root. For both, stimulation at 5 c/s produces better observable twitches (because saccadic) than at 50 c/s which elicits tetanic contractions.

Conclusion The localizing-value of these facial EMRs (associated to evocation of paresthesias) and of the masticatory responses, justifies mapping the trigeminal root before lesioning. Their use could be extended to the other lesioning-techniques: not only Glycerol Neurolysis but also to Balloon Compression (to ascertain location of the trocar at the contact of the TGN inside the Meckel cave) and Open partial Rhizotomies (before deciding to cut the rootlets corresponding to the trigger-zone). This is of importance since lesioning-techniques are needed because not all trigeminal neuralgias are responsive to or even indications of Micro-Vascular Decompression.

Posted on

Can titanium surface technology reduce cost for biologics in anterior lumbar interbody fusion?

J Neurosurg Spine 41:589–595, 2024

Advances in surface architecture and technology have made interbody fusion devices more bioactive, with the hope of facilitating the fusion process more successfully. The advent of these increasingly bioactive implants may reduce reliance on more expensive biologics that have previously been used to achieve high fusion rates.

METHODS A retrospective review of prospectively collected data (August 2018–December 2019) was conducted of consecutively performed anterior lumbar interbody fusions in which an acid-etched, nanosurface-modulated, titanium interbody device packed only with corticocancellous allograft chips and local blood was used. Minimum follow-up was 1 year, and inclusion required available imaging and outcome metrics preoperatively and at 1 year. Fusion and subsidence were assessed via CT scans and/or dynamic radiographs. Health-related quality-of-life measures (Oswestry Disability Index [ODI], visual analog scale [VAS] back/leg) were collected pre- and postoperatively.

RESULTS In total, 55 patients met inclusion criteria (1 year of follow-up, available imaging, and outcome metrics). A total of 69 lumbar levels were treated in these 55 patients. The mean age was 67 ± 12.1 years, with 47% female patients. Roughly one-third (35%) had previous spine surgery, and approximately one-tenth (9.1%) had prior spinal fusion. A total of 20.6% were treated at multiple levels (mean levels per patient 1.2, minimum 1, maximum 3). The mean preoperative patient-reported outcomes were as follows: ODI 39.71 ± 18.15, VAS back 6.49 ± 2.19, and VAS leg 5.41 ± 2.71. One year after surgery, the mean improvements in patient-reported outcomes (vs preoperative scores) were as follows: ODI −22.9 ± 13.08 (p < 0.001), VAS back −3.75 ± 2.03 (p < 0.001), VAS leg −3.73 ± 2.32 (p < 0.001). All levels achieved fusion at 1 year postoperatively based on CT scans (65/69 levels) or dynamic radiographs (4/69 levels, change in score < 5% on flexion-extension radiographs). Four of the 65 levels were assigned to the grade 3 category according to a CT-based grading system, meaning cranial and caudal endplate bone apposition to the implant on both surfaces with no clear intervertebral bone connection through or around the implant. Sixty-one of 65 were found to have contiguous intervertebral bone bridging and thus were assigned to grade 1 (n = 54) or grade 2 (n = 7). Low-grade graft subsidence (Marchi grade 0 or I) occurred in 9 levels (13.0%) and high-grade subsidence (Marchi grade II or III) in 4 levels (5.8%). No patients required reoperation at the level of anterior lumbar interbody fusion and no radiographic or clinical evidence of pedicle screw loosening or failure was observed.

CONCLUSIONS The combination of advances in materials science and surface technology as demonstrated with a nanotechnology titanium cage resulted in the ability to obtain lumbar interbody fusion with allograft chips and local blood alone. Achieving high fusion rates with low-cost biologics/allograft provides for an attractive pathway toward reducing the cost of reconstructive spine care, and a potential incremental benefit for healthcare economics.

Posted on

Angiographic Features of Meningiomas Predicting Extent of Preoperative Embolization

Neurosurgery 95:1010–1025, 2024

Preoperative embolization is used as an endovascular adjunct to surgical resection of meningiomas. However, there is no standardized system to assess the efficacy or extent of embolization during the embolization procedure. We sought to establish a purely angiographic grading system to facilitate consistent reporting of the outcome of meningioma embolization and to characterize the anatomic and other features of meningiomas that predict the degree of devascularization achieved through preoperative embolization.

METHODS: We identified patients with meningiomas who underwent preoperative cerebral angiography and subsequent resection between 2015 and 2021. Demographic, clinical, and imaging data were collected in a research registry. We defined an angiographic devascularization grading scale as follows: grade 0 for no embolization, 1 for partial embolization, 2 for majority embolization, 3 for complete external carotid artery embolization, and 4 for complete embolization.

RESULTS: Eighty consecutive patients were included, 60 of whom underwent preoperative tumor embolization (20 underwent angiography with an intention to treat but ultimately not embolization). Embolized tumors were larger (59.0 vs 35.9 cc; P = .03). Gross total resection, length of stay, and complication rates did not differ among groups. The distribution of arterial feeders differed significantly across tumors in a location-specific manner. Both the tumor location and the identity of arterial feeders were predictive of the extent of embolization. Anterior midline meningiomas were associated with internal carotid (ophthalmic, ethmoidal) supply and lower devascularization grades (P = .03). Tumors fed by meningeal feeders (convexity, falcine, lateral sphenoid wing) were associated with higher devascularization grades (P < .01). The procedural complication rate for tumor embolization was 2.5%.

CONCLUSION: Angiographic outcomes can be graded to indicate the extent of tumor embolization. This system may facilitate consistency of reported angiographic results. In addition, arterial feeders vary in a manner predicted by tumor location, and these patterns correlate with typical degrees of devascularization achieved in those tumor locations.

Proudly powered by WordPress