Automated online safety margin (GLIOVIS) for glioma surgery model.

Purpose: Glioblastoma is the most common type of primary brain malignancy and has a poor prognosis. The standard treatment strategy is based on maximal safe surgical resection followed by radiotherapy and chemotherapy. Surgical resection can be optimized by using 5-delta-aminolevulinic acid (5-ALA)-induced fluorescence, which is the current mainstay. Although 5-ALA-induced fluorescence has gained general acceptance, it is also limited by inter-observer variability and non-standardized fluorescence parameters. We present a new software for processing images analysis to better recognize the tumor infiltration margins using an intraoperative immediate safety map of 5-ALA-induced fluorescence. We tested this in a brain model using a commercial surgical exoscope. Methods: A dedicated software GLIOVIS (ACQuF-II, Advanced Colorimetry-based Quantification of Fluorescence) was designed for processing analysis of images taken on the Intraoperative Orbital Camera Olympus Orbeye (IOC) to determine the relative quantification of Protoporphyrin IX (5-ALA metabolite) fluorescence. The software allows to superpose the new fluorescence intensity map and the safety margins over the original images. The software was tested on gel-based brain models. Results: Two surrogate models were developed: PpIX agarose gel-integrated in gelatin-based brain model at different scales (1:25 and 1:1). The images taken with the IOC were then processed using GLIOVIS. The intensity map and safety margins could be obtained for all available models. Conclusions: GLIOVIS for 5-ALA-guided surgery image processing was validated on various gelatin-based brain models. Different levels of fluorescence could be qualitatively digitalized using this technique. These results need to be further confirmed and corroborated in vivo and validated clinically in order to define a new standard of care for glioblastoma resection.

Clinical Relevance and Interplay between miRNAs in Influencing Glioblastoma Multiforme Prognosis.

Glioblastoma multiforme (GBM) is usually treated with surgery followed by adjuvant partial radiotherapy combined with temozolomide (TMZ) chemotherapy. Recent studies demonstrated a better survival and good response to TMZ in methylguanine-DNA methyltransferase (MGMT)-methylated GBM cases. However, approximately 20% of patients with MGMT-unmethylated GBM display an unexpectedly favorable outcome. Therefore, additional mechanisms related to the TMZ response need to be investigated. As such, we decided to investigate the clinical relevance of six miRNAs involved in brain tumorigenesis (miR-181c, miR-181d, miR-21, miR-195, miR-196b, miR-648) as additional markers of response and survival in patients receiving TMZ for GBM. We evaluated miRNA expression and the interplay between miRNAs in 112 IDH wt GBMs by applying commercial assays. Then, we correlated the miRNA expression with patients' clinical outcomes. Upon bivariate analyses, we found a significant association between the expression levels of the miRNAs analyzed, but, more interestingly, the OS curves show that the combination of low miR-648 and miR-181c or miR-181d expressions is associated with a worse prognosis than cases with other low-expression miRNA pairs. To conclude, we found how specific miRNA pairs can influence survival in GBM cases treated with TMZ.

'Armed kyphoplasty' with posterior stabilization avoids corpectomy in complex thoracolumbar spine fractures: a case series.

BACKGROUND: Complex thoracolumbar fractures require reduction and stabilization. Posterior instrumentation alone and standard cement augmentation may represent undertreatment, while corpectomy has significant morbidity. In a series of unstable thoracolumbar fractures, we assessed the feasibility, safety, and results of 'armed kyphoplasty' (AKP) and surgical posterior stabilization (PS). METHODS: A total of 24 consecutive patients were treated with combined AKP and PS. Minimally invasive and open surgery techniques were used for PS. AKP was performed with C-arm or biplane fluoroscopic guidance, and screws were placed under navigation or fluoroscopic guidance. A postoperative CT scan and standing plain films were obtained. Patients were followed up according to clinical standards. Kyphosis correction (measured with regional Cobb angle), pain (measured with the Numeric Rating Scale), neurological status (measured with Frankel grade) were assessed. RESULTS: A total of 25 fractures of neoplastic (40%), traumatic (32%), and osteoporotic (28%) nature were treated. Open surgery and minimally invasive techniques were applied in 16/24 and 8/24 patients, respectively. Decompressive laminectomy was performed in 13 cases. No intraprocedural complications occurred. Two patients (8%) died due to underlying disease complications and three complications (12%) required re-intervention (one surgical site infection, one adjacent fracture, and one screw pull-out) in the first month. The mean Cobb angle was 20.14±6.19° before treatment and 11.66±5.24° after treatment (P<0.0001). No re-fractures occurred at the treated levels. CONCLUSIONS: Combined AKP and PS is feasible and effective in the treatment of complex thoracolumbar fractures of all etiologies. AKP avoided highly invasive corpectomy. Anterior and posterior support ensured stability, preventing implant failure and re-fracture. The complication rate was low compared with more invasive traditional 360° open surgical approaches.

Post-craniotomy coronal suture diastases in a transformed lower grade glioma.

Cranial suture diastases are an uncommon clinical entity, with post craniotomy diastases being a previously undescribed finding in literature to our best knowledge. Herein, we report a case of a 28-year-old adult who underwent a second-stage low-grade glioma surgery 7 months after initial surgery. This study presents coronal suture diastases adjacent to the previously performed craniotomy. After literature and pathophysiology review, we found it to be unique and that the craniotomy can resemble the mechanical stress of trauma.

Defining the Learning Curve of the Exoscope in Spine Surgery.

INTRODUCTION: In recent years, introduction of the exoscope system has been responsible for a new era of optics in surgery. Such a system has started to be widely used in neurosurgery. More recently, the exoscope has also been increasingly used for spinal procedures. Thus, we aimed to explore the potential for exoscope-assisted spinal procedures and define the advantages and drawbacks of implementing the system into our daily routine. METHODS: To achieve the aim of the study, we retrospectively reviewed the case series of patients treated by a senior surgeon and analyzed the results, complications, and operative time. The operating times were compared between the exoscope-assisted procedures and microscope-assisted procedures. RESULTS: A total of 24 spinal procedure were performed with the exoscope in a 2-month period. In this first patient series performed by a single surgeon without experience with the exoscope, the learning curve seemed to be relatively low, with mastery of the instrument achieved after the performance of only a few cases. Comparing the cases after the plateau of the learning curve had been reached with those performed during the still active phase of the learning curve, a significant difference was found in the operative times. No statistically significant difference was detected in terms of blood loss or intraoperative complications. CONCLUSIONS: Based on our first experience, use of the exoscope shows promising potential for opening up new frontiers in spinal microsurgery. In addition, it has a low learning curve for experienced surgeons.

Role of Enhanced Recovery after Surgery (ERAS) Protocol in the Management of Elderly Patients with Glioblastoma.

OBJECTIVE: Among the already difficult management of neuro-oncological patients, the elderly population remains vulnerable. Because of the pathology and the comorbidities, they present a significantly higher rate of medical issues related to surgical management. Despite this, the surgical option, if feasible, remains the gold standard in these patients, and an Enhanced Recovery After Surgery (ERAS) protocol could improve the postoperative safety of the patients. With this purpose, we prepared this study with the aim of defining the postoperative hospital length of stay (LOS), but also of evaluating the postoperative morbidity, perioperative complications, and postoperative pain scores. METHODS: This was a retrospective, single-cohort study performed at an academic hospital (Department of Neurosurgery, Neurocenter of South Switzerland, Switzerland) on elderly patients who underwent craniotomy for glioblastoma. Patients were enrolled in a novel ERAS protocol from January 2022 to December 2022. Since this is a feasibility study and a direct comparison was not possible, we used a historical cohort of elderly patients who had undergone elective craniotomy surgery for glioblastoma as a control group. RESULTS: A total of 19 patients treated in our center for glioblastoma multiforme (GBM) who were aged over 75 years were included in this study. Among those, seven were newly recruited patients included in the ERAS protocol, while the remaining twelve were part of a historical cohort of previously treated patients. From a statistical point of view, the two cohorts were comparable in terms of baseline demographics. In the follow-up, it was shown that in the ERAS group, there was a reduction in the use of opioids after the surgical procedures that could be seen at 30 days (36.2% vs. 71.7%, p < 0.001), but also at 3 months, after surgery (33.0% vs. 80.0%, p < 0.001). A significant difference has also been documented in terms of mobilization and ambulation: compared to the historical cohort, in the ERAS group, there was a higher rate of mobilization (60.0% vs. 10.0%, p < 0.001), but also of ambulation (36.1% vs. 10.0%, p < 0.001). CONCLUSIONS: The ERAS protocol for the management of glioblastoma in elderly patients seems to be an effective option for reducing LOS in the hospital, as well as for reducing the number of days spent in the ICU, improving the general recovery of the patient, and reducing the costs associated with hospitalization.

A qPCR technology for direct quantification of methylation in untreated DNA.

DNA methylation is important for gene expression and alterations in DNA methylation are involved in the development and progression of cancer and other major diseases. Analysis of DNA methylation patterns has until now been dependent on either a chemical or an enzymatic pre-treatment, which are both time consuming procedures and potentially biased due to incomplete treatment. We present a qPCR technology, EpiDirect®, that allows for direct PCR quantification of DNA methylations using untreated DNA. EpiDirect® is based on the ability of Intercalating Nucleic Acids (INA®) to differentiate between methylated and unmethylated cytosines in a special primer design. With this technology, we develop an assay to analyze the methylation status of a region of the MGMT promoter used in treatment selection and prognosis of glioblastoma patients. We compare the assay to two bisulfite-relying, methyl-specific PCR assays in a study involving 42 brain tumor FFPE samples, revealing high sensitivity, specificity, and the clinical utility of the method.

Prevalence of amyloid in ligamentum flavum of patients with lumbar spinal stenosis.

BACKGROUND: Transthyretin (ATTR) amyloidosis is often diagnosed in an advanced stage, when irreversible cardiac damage has occurred. Lumbar spinal stenosis (LSS) may precede cardiac ATTR amyloidosis by many years, offering the opportunity to detect ATTR already at the time of LSS surgery. We prospectively assessed the prevalence of ATTR in the ligamentum flavum by tissue biopsy in patients aged >50 years undergoing surgery for LSS. METHODS: Ligamentum flavum thickness was assessed pre-operatively on axial T2 magnetic resonance imaging (MRI) slices. Tissue samples from ligamentum flavum were screened centrally by Congo red staining and immunohistochemistry (IHC). RESULTS: Amyloid in the ligamentum flavum was detected in 74/94 patients (78.7%). IHC revealed ATTR in 61 (64.9%), whereas amyloid subtyping was inconclusive in 13 (13.8%). Mean thickness of ligamentum flavum was significantly higher at all levels in patients with amyloid (p < .05). Patients with amyloid deposits were older (73.1 ± 9.2 vs. 64.6 ± 10.1 years, p = .01). No differences in sex, comorbidities, previous surgery for carpal tunnel syndrome or LSS were observed. CONCLUSIONS: Amyloid, mostly of the ATTR subtype, was found in four out of five patients with LSS and is associated with age and ligamentum flavum thickness. Histopathological work-up of ligamentum flavum might inform future decision making.

Identification of MGMT Downregulation Induced by miRNA in Glioblastoma and Possible Effect on Temozolomide Sensitivity.

Glioblastoma multiforme (GBM) remains one of the tumors with the worst prognosis. In recent years, a better overall survival (OS) has been described in cases subjected to Gross Total Resection (GTR) that were presenting hypermethylation of Methylguanine-DNA methyltransferase (MGMT) promoter. Recently, also the expression of specific miRNAs involved in MGMT silencing has been related to survival. In this study, we evaluate MGMT expression by immunohistochemistry (IHC), MGMT promoter methylation and miRNA expression in 112 GBMs and correlate the data to patients' clinical outcomes. Statistical analyses demonstrate a significant association between positive MGMT IHC and the expression of miR-181c, miR-195, miR-648 and miR-767.3p between unmethylated cases and the low expression of miR-181d and miR-648 and between methylated cases and the low expression of miR-196b. Addressing the concerns of clinical associations, a better OS has been described in presence of negative MGMT IHC, in methylated patients and in the cases with miR-21, miR-196b overexpression or miR-767.3 downregulation. In addition, a better progression-free survival (PFS) is associated with MGMT methylation and GTR but not with MGMT IHC and miRNA expression. In conclusion, our data reinforce the clinical relevance of miRNA expression as an additional marker to predict efficacy of chemoradiation in GBM.

Middle column Stent-screw Assisted Internal Fixation (SAIF): a modified minimally-invasive approach to rescue vertebral middle column re-fractures.

BACKGROUND: There is limited literature regarding the re-fracture of a previously augmented vertebral compression fracture (VCF). These re-fractures may present as an asymptomatic remodeling of the vertebral body around the cement cast while in other cases they involve the middle column, at the transition zone between the cement-augmented and non-augmented vertebral body. In the latter, a posterior wall retropulsion is possible and, if left untreated, might progress to vertebral body splitting, central canal stenosis, and kyphotic deformity. There is no consensus regarding the best treatment for these re-fractures. There are cases in which a repeated augmentation relieves the pain, but this is considered an undertreatment in cases with middle column involvement, posterior wall retropulsion, and kyphosis. METHODS: We report four cases of re-fracture with middle column collapse of a previously augmented VCF, treated with the stent-screw assisted internal fixation (SAIF) technique. A modified more postero-medial deployment of the anterior metallic implants was applied, to target the middle column fracture. This modified SAIF allowed the reduction and stabilization of the middle column collapse as well as the partial correction of the posterior wall retropulsion and kyphosis. RESULTS: Complete relief of back pain with stable clinical and radiographic findings at follow-up was obtained in all cases. CONCLUSIONS: In selected cases, the middle column SAIF technique is safe and effective for the treatment of the re-fracture with middle column collapse of a previously cement-augmented VCF. This technique requires precision in trocar placement and could represent a useful addition to the technical armamentarium for VCF treatment.

Tau protein quantification in skin biopsies differentiates tauopathies from alpha-synucleinopathies.

Abnormal accumulation of microtubule-associated protein tau (τ) is a characteristic feature of atypical parkinsonisms with tauopathies, such as progressive supranuclear palsy and corticobasal degeneration. However, pathological τ has also been observed in α-synucleinopathies like Parkinson's disease and multiple system atrophy. Based on the involvement of the peripheral nervous system in several neurodegenerative diseases, we characterized and compared τ expression in skin biopsies of patients clinically diagnosed with Parkinson's disease, multiple system atrophy, progressive supranuclear palsy and corticobasal degeneration and in healthy control subjects. In all groups, τ protein was detected along both somatosensory and autonomic nerve fibres in the epidermis and dermis by immunofluorescence. We found by western blot the presence of mainly two different bands at 55 and 70 kDa, co-migrating with 0N4R/1N3R and 2N4R isoforms, respectively. At the RNA level, the main transcript variants were 2N and 4R, and both were more expressed in progressive supranuclear palsy/corticobasal degeneration by real-time PCR. Enzyme-linked immunosorbent assay demonstrated significantly higher levels of total τ protein in skin lysates of progressive supranuclear palsy/corticobasal degeneration compared to the other groups. Multivariate regression analysis and receiver operating characteristics curve analysis of τ amount at both sites showed a clinical association with tauopathies diagnosis and high diagnostic value for progressive supranuclear palsy/corticobasal degeneration versus Parkinson's disease (sensitivity 90%, specificity 69%) and progressive supranuclear palsy/corticobasal degeneration versus multiple system atrophy (sensitivity 90%, specificity 86%). τ protein increase correlated with cognitive impairment in progressive supranuclear palsy/corticobasal degeneration. This study is a comprehensive characterization of τ in the human cutaneous peripheral nervous system in physiological and pathological conditions. The differential expression of τ, both at transcript and protein levels, suggests that skin biopsy, an easily accessible and minimally invasive exam, can help in discriminating among different neurodegenerative diseases.

Longer survival of glioblastoma complicated by bacterial infections after surgery: what is known today.

INTRODUCTION: Glioblastoma is the most common primary brain tumor in adults with the worst overall survival. Post-craniotomy intracranial infections are not infrequent after surgery; however, their impact on overall survival of glioblastoma patients remains unclear. Here we report the case of an unusual longer survival of a glioblastoma patient affected by multiple infections and the review of the literature on this topic. EVIDENCE ACQUISITION: PubMed, Embase and Cochrane search engines were reviewed for papers describing outcome of patients suffering from glioblastoma and associated cerebral infections. EVIDENCE SYNTHESIS: Four papers accounting a total of 29 patients met the eligibility criteria. Staphylococcus aureus and Staphylococcus epidermidis resulted the most common bacteria causing post-craniotomy intracranial infections in brain tumor patients. The overall median survival rate was 18±18.12 months when adding all 29 patients. Only one study described a significant higher survival rate for the infected group. CONCLUSIONS: Glioblastoma is the most frequent malignant brain tumor with a very poor outcome/survival. In the literature few cases described an exceptional longer survival often associated with a postoperative infection. To date, the pathophysiology behind this longer survival remains unclear, but it seems that Staphylococcus species could have an influence on the progression of this aggressive brain tumor.

ß-blockers and ACE inhibitors are not a risk factor for severe systemic sting reactions and adverse events during venom immunotherapy.

BACKGROUND: There is controversy whether taking ß-blockers or ACE inhibitors (ACEI) is a risk factor for more severe systemic insect sting reactions (SSR) and whether it increases the number or severity of adverse events (AE) during venom immunotherapy (VIT). METHODS: In this open, prospective, observational, multicenter trial, we recruited patients with a history of a SSR and indication for VIT. The primary objective of this study was to evaluate whether patients taking ß-blockers or ACEI show more systemic AE during VIT compared to patients without such treatment. RESULTS: In total, 1,425 patients were enrolled and VIT was performed in 1,342 patients. Of all patients included, 388 (27.2%) took antihypertensive (AHT) drugs (10.4% took ß-blockers, 11.9% ACEI, 5.0% ß-blockers and ACEI). Only 5.6% of patients under AHT treatment experienced systemic AE during VIT as compared with 7.4% of patients without these drugs (OR: 0.74, 95% CI: 0.43-1.22, p = 0.25). The severity of the initial sting reaction was not affected by the intake of ß-blockers or ACEI (OR: 1.14, 95% CI: 0.89-1.46, p = 0.29). In total, 210 (17.7%) patients were re-stung during VIT and 191 (91.0%) tolerated the sting without systemic symptoms. Of the 19 patients with VIT treatment failure, 4 took ß-blockers, none an ACEI. CONCLUSIONS: This trial provides robust evidence that taking ß-blockers or ACEI does neither increase the frequency of systemic AE during VIT nor aggravate SSR. Moreover, results suggest that these drugs do not impair effectiveness of VIT. (Funded by Medical University of Graz, Austria; Clinicaltrials.gov number, NCT04269629).

Clinical and radiological outcomes in relation with the anatomical orientation of clipped middle cerebral artery bifurcation aneurysms.

BACKGROUND: The middle cerebral artery (MCA) bifurcation represents the most frequent location for intracranial aneurysms. Often, the aneurysmal dome can hide the origin of perforating arteries from the M1 segment during the surgical clipping causing ischemic lesions and worse clinical outcome. The aim of this paper is to analyze the association between the orientation of the aneurysm sac and the clinical and radiological outcomes after surgical clipping. METHODS: Data from 50 MCA bifurcation clipped aneurysms in 47 patients were collected retrospectively. Three different groups were identified according to the aneurysmal sac orientation: anterior-inferior, posterior and superior. A possible association between the aneurysmal sac projection and the outcome was searched through a univariable logistic regression analysis. RESULTS: Statistical analysis showed significant correlation between the radiologic evidence of post-operative ischemia in the posterior group (p = 0.046, RR = 1.65) and an increased risk in the superior orientation group (p = 0.145, RR = 1.38). The anterior-inferior group was, instead, significantly associated with no evidence of radiologic ischemia (p = 0.0019, RR = 0.58). CONCLUSION: The orientation of the aneurysmal dome and sac represents a fundamental feature to be considered during the surgical clipping of the MCA aneurysms. Indeed, its posterior and superior projection is associated with a higher incidence of radiologic ischemic lesions due to the origin of perforating arteries from M1 segment behind the aneurysmal sac. The anterior-inferior orientation, on the contrary, is associated with a lower risk.

Corrigendum: Quantitative Modulation of PpIX Fluorescence and Improved Glioma Visualization.

[This corrects the article DOI: 10.3389/fsurg.2019.00041.].

Quantitative Modulation of PpIX Fluorescence and Improved Glioma Visualization.

5-Aminolevulinic acid (5-ALA) induced fluorescence to augment surgical resection for high grade glioma has become a standard of care. Protoporphyrin IX (PpIX) visibility is however subject to the variability of the single tumor expression and to the interobserver interpretation. We therefore hypothesized that in different glioma cell lines with variable 5-ALA induced fluorescence, the signal can be pharmacologically increased. We therefore analyzed in three different GBM cell lines, with different expression of epidermal growth factor receptor (EGFR), the variability of 5-ALA induced PpIX fluorescence after the pharmacological blockade at different steps of PpIX breakdown and influencing the outbound transport of PpIX. Using flow cytometry, fluorescence microplate reader, and confocal microscopy the PpIX fluorescence was analyzed after exposure to tin protoporphyrin IX (SnPP), deferoxamine (DFO), and genistein. We furthermore constructed a microscope (Qp9-microscope) being able to measure quantitatively the concentration of PpIX. These values were compared with the extraction of PpIX in tumor biopsy taken during the GBM surgery. Although all three cell lines showed an increase to 5-ALA induced fluorescence their baseline activity was different. Treatment with either SnPP, DFO and genistein was able to increase 5-ALA induced fluorescence. Qp9-microscopy of tumor sample produced a color coded PpIX concentration map which was overlaid on the tumor image. The PpIX extraction from tumor sample analyzed using the plate reader gave lower values of the concentration, as compared to the expected values of the Qp9-microscope, however still in the same decimal range of µg/mL. This may be due to homogenization of the values during extraction and cell disaggregation. In conclusion pharmacological augmentation in GBM cell lines of PpIX signal is possible. A quantitative PpIX map for surgery is feasible and may help refine surgical excision. Further correlations of tumor tissue samples and Qp9-microscopy is needed, prior to develop an intraoperative surgical adjunct to the already existing 5-ALA induced surgery.

The Impact of Surgery in IDH 1 Wild Type Glioblastoma in Relation With the MGMT Deregulation.

Object: The treatment of choice in glioblastoma (GBM) is the maximal surgical extent of resection (EOR) followed by adjuvant chemo-radiotherapy. Furthermore, methylguanine-DNA methyltransferase (MGMT) promoter methylation is associated with prolonged overall survival (OS) and progression free survival (PFS). The objective of the present study is correlate the biomolecular aspects in relation with EOR. Materials and methods: We analyzed a series of 116 patients with IDH-1 wild type GBM and different EOR (Gross Total Resection-GTR-, Partial Resection-PR- and Biopsy), treated with adjuvant chemo-radiotherapy. The MGMT status was analyzed in terms of promoter methylation and protein expression. Results: When GTR was possible, OS and PFS were significantly better compared to the other two groups (p = 0.001 and p = 0.035, respectively). MGMT methylation was significantly associated with better OS in the biopsy group (p = 0.022) and better OS and PFS in PR (p = 0.02 and p = 0.012, respectively), but not in the GTR group (p = 0.252 for OS, p = 0.256 for PFS) nor the PFS in the biopsy group (p = 0.259). MGMT protein expression levels do not show any association with OS and PFS, regardless of the type of surgery. Conclusions: Our study confirms the positive association of a safe maximal EOR with better OS and PFS, and indicates a positive prognostic value of MGMT methylation status only in case of the presence of residual tumor tissue. MGMT protein expression seems not to play a clinical role in relation with the type of surgery.