Towards a common language in neurosurgical outcome evaluation: the NEON (NEurosurgical Outcome Network) proposal.

BACKGROUND: The aim of this study was to achieve a consensus on the minimum set of outcome measures and predictors to be used in the neurosurgical practice and on the timing of outcome assessment. METHODS: A consensus building approach was employed. All neurosurgical departments in Lombardy (Italy) were invited to participate by the Carlo Besta Neurologic Institute IRCCS Foundation. Three workshops were organized during which a multidisciplinary group called Neurosurgical Outcome Network (NEON) was created and the methodology to select outcome measures, predictors, and timing of outcome assessment was established. Eight working groups were created for the different neurosurgical diseases (neuro-oncological, skull base, vascular, traumatic, spinal, peripheral nervous system, malformation, functional) and 8 workshops were organized to identify the outcome measures and predictors specific for each of the neurosurgical diseases based on the experts' clinical practice and the existing literature. RESULTS: A total of 20 neurosurgical departments participated in this study. Specific outcome measures, predictors and the timing of outcome assessment were identified for each of the 8 neurosurgical diseases. Moreover, a list of variables common to all pathologies were identified by the NEON group as further data to be collected. CONCLUSIONS: A consensus on the minimum set of outcome measures and predictors and the timing of outcome assessments for 8 neurosurgical diseases was achieved by a group of neurosurgeons of the Lombardy region, called NEON. These sets could be used in future studies for a more homogeneous data collection and as a starting point to reach further agreement also at national and international level.

Critical Evaluation of the Scientific Literature Concerning Bone Graft Alternatives in Spinal Surgery and Focus on Bioceramics.

To improve solid spinal fusion while avoiding the morbidity associated with autograft harvesting procedures, numerous alternatives have been investigated, including allograft, demineralized bone matrix (DBM), cell-based therapies and growth factors (i.e., bone morphogenetic proteins, platelet concentrates), and ceramic-based biomaterials. Even though all of these approaches have the potential to improve the outcome of spinal fusion procedures, most of them have not yet been validated by evidence-based clinical results, and thus they are not strongly advisable for clinical use, in addition to being particularly expensive. Here, we give an overview of the current clinical evidence for bone graft alternatives for spine surgery procedures. We will also evaluate the pros and cons of their use and briefly review the more relevant literature.

Internal carotid artery dissection related to abnormalities of styloid process: is it only a matter of length?

INTRODUCTION: Vascular Eagle syndrome, due to impingement of the extracranial internal carotid artery (ICA) by the styloid process (SP), is an uncommon and not yet widely recognized cause of ICA dissection. Up to now, this diagnosis is still presumptive, based mainly on the length of the SP. However, given the discrepancy between the much higher prevalence of an elongated SP in the population compared to the reported rate of Eagle syndrome, other anatomical factors beyond the length itself of this bony structure seem to be involved. MATERIAL AND METHODS: We performed a retrospective single center case-control study of ICA dissection related to abnormalities of styloid process and age- and sex-matched controls affected by ICA dissection not related to abnormal relationship with the styloid process. In our work instead of considering SP length as the main criteria to differentiate the two groups, we decided to consider styloid process-internal carotid artery distance (at the dissection point) as the main factor to define a styloid process related dissection (SPRD). In fact in some patients, the distance between the dissected artery and the bony prominence was virtual. RESULTS: Our study showed that in patients with SPRD the styloid process angulation on the coronal plane tends to be more acute and that styloid process-C1 distance is significantly shorter at the side of the dissection. This data reinforces the idea that ICA dissection risk in the vascular Eagle syndrome has probably a multifactorial pathogenesis.

Acute neurologic decline in a patient with spinal stenosis: blame it on the epidural fat.

Spinal epidural lipomatosis [SEL] is defined as an excessive accumulation of extradural normal adipose tissue. This condition may be idiopathic or acquired. Surgical decompression is considered the gold standard treatment in patients presenting with progressive neurologic deficit. We report a case of a 69-year-old male patient presented with neurogenic claudication and lower left limb radiculopathy. The magnetic resonance imaging (MRI) revealed a L5-S1 epidural compression sustained by a large epidural plaque whose signal was consistent with adipose tissue. A conservative approach, including weight loss attempt, revealed unsuccessful and the patient presented some months after the diagnosis at the emergency department with acute onset bilateral drop foot, more severe on the right side and urinary disturbances. Microsurgical decompression via L5 laminectomy and partial L4 laminectomy and fatty plaque debulking was performed. The post operative course was uneventful and at the two months post operative follow up the patient reported a significative improvement of the pre operative neurological signs and symptoms and of pain control. SEL deserves attention as an identifiable cause of radiculopathies, typically attributed to spinal stenosis, with a higher incidence than previously reported. Moreover cases of acute onset of cauda equina like syndrome were reported in patent affected by SEL, probably related to a local venous engorgement with stasis and edema. Therefore it should be considered as a possible diagnosis not only in patients complaining of stenosis-type symptoms but also in cases of acute neurological decline with cauda equina like syndrome, especially when provided with a "benign" imaging reading.

Giant tuberculoma of the corpus callosum, the unforeseen diagnosis.

OBJECTIVE: Isolated intracranial tuberculomas are rare, especially in adults and it is not uncommon that they are easily confused with other diseases. To address this issue, we reported a case of a tuberculoma of the corpus callosum focusing on clinical characteristics, diagnostic clues, and outcome. CONCLUSIONS: Intracranial masses are frequently targeted as neoplastic pathology with surgical treatment in most cases. It is important to distinguish between neuro tuberculoma and brain tumors because of their different management and prognosis. Therefore even in absence of a known history of primary TB and in immunocompetent patients, tuberculoma must be in the differential diagnosis of solitary intracranial lesions also in countries where TB is not endemic.

Aldosterone Secretion in Patients With Primary Hyperparathyroidism Without Arterial Hypertension.

OBJECTIVE: There is a direct bidirectional link between parathyroid hormone (PTH) and the renin-angiotensin-aldosterone system (RAAS), but few studies evaluated the RAAS in patients with primary hyperparathyroidism (PHPT), mainly biased from concomitant antihypertensive treatment. METHODS: We retrospectively evaluated a consecutive series of 130 normotensive patients with PHPT comparing aldosterone (ALD) levels and plasma renin activity (PRA) with the demographic, biochemical, or clinical features of PHPT. RESULTS: No correlation was found between ALD and PRA, and the demographic, biochemical, and bone densitometry parameters in patients with PHPT without hypertension, with the exception of a negative correlation between age and serum PRA. Moreover, there was no significant correlation between PTH and ALD levels even in patients whose PTH level was >100 ng/L (P = .088). CONCLUSION: In our normotensive patients with PHPT, the ALD, PRA, and aldosterone/renin ratio were not correlated to PTH and calcium levels. In addition, they were neither related to PHPT clinical presentation nor renal function, vitamin D status, bone mass loss, or the presence of comorbidities such as diabetes and obesity. Further studies are needed to clarify the complex interplay between PTH and the RAAS in the modern PHPT presentation.

Endoscope-assisted far-lateral transcondylar approach for craniocervical junction chordomas: a retrospective case series and cadaveric dissection.

OBJECTIVE: Craniocervical junction (CCJ) chordomas are a neurosurgical challenge because of their deep localization, lateral extension, bone destruction, and tight relationship with the vertebral artery and lower cranial nerves. In this study, the authors present their surgical experience with the endoscope-assisted far-lateral transcondylar approach (EA-FLTA) for the treatment of CCJ chordomas, highlighting the advantages of this corridor and the integration of the endoscope to reach the anterior aspect and contralateral side of the CCJ and the possibility of performing occipitocervical fusion (OCF) during the same stage of surgery. METHODS: Nine consecutive cases of CCJ chordomas treated with the EA-FLTA between 2013 and 2020 were retrospectively reviewed. Preoperative characteristics, surgical technique, postoperative results, and clinical outcome were analyzed. A cadaveric dissection was also performed to clarify the anatomical landmarks. RESULTS: The male/female ratio was 1.25, and the median age was 36 years (range 14-53 years). In 6 patients (66.7%), the lesion showed a bilateral extension, and 7 patients (77.8%) had an intradural extension. The vertebral artery was encased in 5 patients. Gross-total resection was achieved in 5 patients (55.6%), near-total resection in 3 (33.3%), and subtotal resection 1 (11.1%). In 5 cases, the OCF was performed in the same stage after tumor removal. Neither approach-related complications nor complications related to tumor resection occurred. During follow-up (median 18 months, range 5-48 months), 1 patient, who had already undergone treatment and radiotherapy at another institution and had an aggressive tumor (Ki-67 index of 20%), showed tumor recurrence at 12 months. CONCLUSIONS: The EA-FLTA provides a safe and effective corridor to resect extensive and complex CCJ chordomas, allowing the surgeon to reach the anterior, lateral, and posterior portions of the tumor, and to treat CCJ instability in a single stage.

Double cystic brain metastasis in a patient with stable pancreatic intraductal papillary mucinous neoplasm.

BACKGROUND: Brain metastases in pancreatic cancer are a rare condition and are usually seen in case of pancreatic adenocarcinoma. Only few cases of brain metastasis in patients affected by Intraductal papillary mucinous neoplasm (IPMN) are actually reported. CASE DESCRIPTION: We report a patient diagnosed with double cystic brain lesions that the histological examination reveal to be consistent, with pancreatic metastasis. Our patient had an history shown of stable pancreatic IPMN which has never made the oncologist suspicious about neoplastic progression or degeneration into pancreatic carcinoma. Considering the rarity of these metastasis we did a literature review on the topic. CONCLUSIONS: Despite rare, pancreatic origin of a cystic brain metastasis should considered in differential diagnosis in both patient with IPMN or patient with unknown primitive tumor.

TRANS-FRONTAL SINUS APPROACH FOR OLFACTORY GROOVE MENINGIOMAS: A 19 YEAR EXPERIENCE.

INTRODUCTION: Olfactory groove meningiomas (OGMs) account for 8-13 % of all intracranial meningiomas. The gold standard of treatment is generally surgery, however various approaches have been used and the literature is still uncertain about the superiority of one treatment over the others. The most debated techniques are traditional microscopic open approaches versus the endoscopic endonasal ones. The aim of this paper is to prove a valid surgical route that gathers the benefits of both endoscopic and transcranial routes. METHODS: Fifty consecutive patients underwent trans-frontal sinus surgical removal of an OGM between January 2000 and January 2019 at the Neurosurgical Departments in Torino, Brescia and Legnano (Italy). The clinical features were collected in a database and compared with neuroimaging and outcomes. All patients were investigated with neuroimaging techniques. Clinical evaluations were performed 3-4 months and 1 year after surgery, together with neuroradiological follow-up. RESULTS: All patients with OGM underwent Simpson grade I resection. The most common neurological symptom leading to neuroradiological evaluations were headaches (36 %), followed by behavioural changes (30 %), hyposmia/anosmia (12 %), visual impairments (6%) and focal deficits (6%). At 3-4 months follow-up 48 patients underwent a brain MRI (2 patients underwent a brain CT), and a complete resection was confirmed in 45 patients (94 %). CONCLUSIONS: Despite different techniques and studies supported by good evidence, there is no consensus on the best surgical approach for OGMs. The data shown in this article suggests that the trans-frontal sinus approach is a valid alternative to an endoscopic approach and the classical transcranial routes, collecting benefits from both approaches.

Surgical management of pituitary adenomas: does age matter?

PURPOSE: Along with increased life expectancy and improvements in the diagnostic tools and techniques, the number of elderly patients with symptomatic pituitary tumors being evaluated for surgery is increasing. To date, contrasting results of the safety and effectiveness of transsphenoidal surgery in patients over 65 years old were published in the medical literature. An investigation concerning the extension of resection, post operative complications and, recovery rate from endocrinological and visual symptoms in elderly patients who underwent transsphenoidal surgery for pituitary adenoma was conducted. METHODS: A retrospective review, which included a series of 81 patients 65 years old or older who underwent endoscopic endonasal surgery for pituitary adenomas was analyzed. Pre operative and post operative data were collected and patients were then compared among four age groups: 65-69 years old, 70-74 years old, 75-79 years old and 80 years and over. The results were then compared with the findings from the medical literature review. RESULTS: The statistical analysis failed to highlight any difference in terms of clinical presentation or complications among the four age groups, however there seems to be a slightly higher risk of post operative hypopituitarism in patients over 74 years old. CONCLUSION: The results of the study seem to confirm that transsphenoidal surgery for PA is safe and effective among patients that are 65 and over. Moreover, a partial resection is preferred over a gross total one in order to reduce the surgical risk.

From the Occipital Condyle to the Sphenoid Sinus: Extradural Extension of the Far Lateral Transcondylar Approach with Endoscopic Assistance.

BACKGROUND: Surgical management of extensive skull base tumors, such as chordoma and chondrosarcoma, remains very challenging. The need for gross total removal to improve survival must be weighed against the risk of injury to neurovascular structures and the loss of stability at the craniovertebral junction. In cases of tumors that are already compromising craniovertebral junction stability, the occipital condyle can be exploited as a deep keyhole to reach the clivus, petrous apex, and sphenoid sinus. METHODS: We performed an anatomic study on 7 cadaveric specimens to describe the main landmarks and boundaries of the corridor. We also provide a clinical case to demonstrate the feasibility of the approach. RESULTS: In all specimens, using the space provided by the condyle, it was possible to drill the petrous bone up to the posterior wall of the sphenoid sinus following the direction of the inferior petrosal sinus. To successfully complete the approach, after the hypoglossal canal was exposed, endoscopic assistance was needed to overcome the narrowing of the visual field provided by the microscope. CONCLUSIONS: In cases of invasive skull base tumor involving the craniovertebral junction and affecting its stability, the occipital condyle can be exploited as a deep keyhole to the homolateral and contralateral petrous apex, clivus, and sphenoid sinus.

Supratotal Resection of Glioblastoma: Is Less More?

BACKGROUND: A relationship between the extent of resection (EOR) and survival has been demonstrated in patients with glioblastomas (GBMs). However, despite gross total resection (GTR) of the enhancing nodule (EN), GBMs usually relapse, generally near the surgical cavity. OBJECTIVE: The aim of this study was to determine the prognostic role of FLAIR resection of GBMs by analyzing pre- and post-operative MRIs to estimate the EOR of EN, FLAIR-hyperintense regions and total tumor volume (TTV). METHODS: Radiologic and clinical outcomes were analyzed retrospectively. Pre- and post-operative EN volume, pre- and postoperative FLAIR volume (POFV), and pre- and postoperative TTV were analyzed. EOR was then calculated for each component. Time-dependent ROC curves and cut-off values for pre- and post-operative volumes and EOR were calculated. A Kaplan-Meier analysis with the log-rank test and Cox regression analysis were then used to analyze progression-free survival (PFS) and overall survival (OS). RESULTS: We did not find any correlation between EOR of FLAIR-altered regions and patient survival. On the other hand, there were statistically significant relationships between the prognosis and both a preoperative EN volume less than 31.35 cm3 (p=0.032) and a postoperative EN volume less than 0.57 cm3 (p=0.015). Moreover, an EOR of EN greater than 96% was significantly associated with the prognosis (p=0.0051 for OS and p=0.022 for PFS). CONCLUSION: Our retrospective, multi-center study suggests that survival in patients with GBM is not affected by the extent of resection of FLAIR-hyperintense areas.

Prognostic Characterization of Higher-Grade Meningiomas: A Histopathological Score to Predict Progression and Outcome.

Higher-grade meningiomas (WHO grade II and III) represent a diagnostic and prognostic challenge. We assessed the pathological and molecular characteristics of 94 higher-grade meningiomas (85 grade II, 9 grade III) to identify novel prognostic parameters. Higher mitotic count (p = 0.018), diffuse (≥50%) prominent nucleoli (p < 0.001), and sheeting (p < 0.001) were associated with recurrence. Lower SSTR2a-positive cells median rate (p = 0.048) and TERT promoter mutations (p = 0.014) were associated with recurrence and patient death, respectively; further analyses did not identify other outcome associations. Presence of Ki67 hot spots was associated with a shorter progression-free survival (PFS), independently of WHO grade at multivariate analysis (HR = 3.35, p = 0.008). Necrosis was related to a poorer overall survival (OS) at univariate (focal: HR = 4.55, p = 0.041 and diffuse: HR = 7.38, p = 0.020) and Kaplan-Meier analyses. A prognostic score was designed based on previous results: Presence of diffuse (≥50%) prominent nucleoli (0/1 point), diffuse (≥50%) sheeting (0/1 point), focal (<50%) or diffuse (≥50%) necrosis (0/1/2 points), and Ki67 hot spots (0/1 point). A total score ≥4 predicted poorer PFS and OS by Kaplan-Meier (PFS: 1.7 vs 6.4 years, p < 0.001 and OS: 5.2 vs 10.8 years, p = 0.001) and multivariate (PFS: HR = 5.98, p < 0.001 and OS: HR = 2.99, p = 0.048) analyses. These results were confirmed in an independent series of 58 grade II meningiomas (PFS: HR = 7.22, p = 0.002 and OS: HR = 9.69, p = 0.003). These associations and the integrated score could complement WHO grading.

The Endoscopic Endonasal Approach to Craniovertebral Junction Pathologies: Surgical Skills and Anatomical Study.

INTRODUCTION: Surgical anterior decompression is the treatment of choice for symptomatic irreducible ventral craniovertebral junction (CVJ) compression. Along with the classic transoral approach, the endoscopic endonasal approach has evolved and is gaining growing success. MATERIALS AND METHODS: In this work we discuss the surgical technique, give a complete step-by-step description of dissection of the craniovertebral junction and report a specific case of endoscopic endonasal odontoidectomy with use of a high-definition (HD) three-dimensional (3D) endoscope. DISCUSSION: The extended endonasal approach exploits an anatomical corridor to the odontoid process, involving only a small incision in the nasopharynx and sparing palate integrity. The most important limitation of the technique is 2D visualization, which hinders correct recognition of anatomical structures. CONCLUSION: The endoscopic endonasal route to the odontoid process has proven to be a feasible, safe and well-tolerated procedure. Anatomical study is very important for better understanding of the 3D anatomy of the CVJ and relation of critical neurovascular structures to specific bony and muscular landmarks.

Intraoperative ultrasound and 5-ALA: the two faces of the same medal?

BACKGROUND: High Grade Gliomas (HGG) still remain the most demanding neuro-oncological challenge. Several studies have confirmed that the extent of resection (EOR) correlates with increased survival in patients with HGGs. The Gross Total Resection (GTR) of HGGs can be difficult and challenging. For this reason, technologies to improve EOR have been of interest. The aim of this paper is to analyze advantages and limitations of both intra-operative fluorescence and intra-operative ultrasound (IOUS) resection techniques. METHODS: Our work deals with the comparison of one group of 15 patients treated with both tools (study group) with a control group of 15 patients in where only fluorescence was used. Post operative outcome are valued using Karnofsky Performance Status scale (KPS) while EOR are valued with MRI within 24 h after surgery. RESULTS: The difference between the postoperative KPS and between EOR in the 2 groups resulted not statistically significant considering p<0.05. In our experience 5-ALA has a limited sensitivity before starting resection while shows it's central role in identifying the tumor remnants after its removal. Conversely, IOUS is very useful in identifying the tumor before starting resection. After the tumor removal, the sensitivity of the ultrasound in identifying tumor remnants in the margins of the cavity decreased significantly. However, in one case, at the end of resection, we have not visualized any fluorescent tissue but we detect a residual of tumor using the IOUS. CONCLUSIONS: In our preliminary experience we observe that there are no significative advantages using IOUS plus 5-ALA. However we feel that IOUS is useful in first step of resection and fluorescence in the latest steps of operation. Therefore these two technologies could be considered the two faces of the same medal because they can help the surgeon to detect the tumor in all step of tumor removal.

3D HD Endoscopy in Skull Base Surgery: From Darkness to Light.

The introduction of modern endoscopy in neurosurgery brought light to one of the darkest areas: the skull base. In particular, the trans-nasal route allowed skull base surgeons to visualize and dominate the entire midline skull base. We analyzed our surgical series of 199 patients that were affected by several pathologies (pituitary adenomas, clivalchordomas, craniopharyngioma, Rathke's cleft cysts, tuberculum sellaemeningiomas, and craniovertebral junction pathologies with bulbar compression) and treated each by using a 3D-HD endoscope between December 2012 and December 2015 and reviewed the literature. We present our results in terms of tumor resections and decompression inpatients affected by craniovertebral junction pathologies. Analyzing our direct experience, as well as the literature, we can assert that the amount and accuracy of necessary movements in order to achieve a determined target are affected by the screen clarity and image resolution of the device. Additionally, the experience of the surgeon has an important role in the surgical outcome. Moreover, depth perception is critical in order to obtain precise and accurate movements. Our observations and the experts' opinion indicate that this modality provides improved surgical dexterity by affording the surgeon with depth perception while manipulating tissue and maneuvering the endoscope in the endonasal corridor, which is especially crucial in reducing the learning curve of young neurosurgeons.

Nanofibrous Synthetic Dural Patch for Skull Base Defects: Preliminary Experience for Reconstruction after Extended Endonasal Approaches.

Setting One of the consequences of the widespread use of endoscopic endonasal approaches (EEA) to skull base pathologies is the management of complex skull base defects. Nowadays, the gold standard is a multilayer closure that reproduces the physiological tissue barriers. Several techniques have been described in the literature; however, skull base reconstruction after EEA still represents a matter of debate, especially after extended EEA. A watertight closure is paramount to prevent cerebrospinal fluid leak and meningitis. Design Regarding this issue, we present our experience with a new synthetic dural patch, ReDura (Medprin Biotech, La Mirada, California, United States), as a subdural inlay in three patients who underwent endoscopic endonasal removal of sellar and suprasellar lesions. Conclusions ReDura patch showed the same versatility of autologous iliotibial tract. A dural patch that easily adapts to all defects, revealed to be a useful tool for performing watertight closure, possibly in a short operative time, after endoscopic approaches.

Endoscopic Endonasal Approach to the Odontoid Pathologies.

BACKGROUND: Surgical anterior decompression represents the treatment of choice for symptomatic irreducible ventral craniovertebral junction (CVJ) compression. With the refinement of the endoscopic techniques, the endonasal route has been proposed as alternative to the classic transoral approach to CVJ. Some reports assess the effectiveness and safety of endoscopic endonasal approaches to CVJ pathologies. MATERIALS AND METHODS: From July 2011 to February 2014, 12 patients with symptomatic nonreducible ventral spinal cord compression underwent purely 3-dimensional endoscopic endonasal odontoidectomy in our department. The surgical technique is described. RESULTS: A good brainstem-medullary decompression was achieved in all patients. In 10 of 12 patients the endotracheal tube was removed just after the procedure with good recovery of the respiratory function. We report no cases of velopharyngeal insufficiency. In 5 of 12 patients the preservation of C1 anterior was achieved, without the need for posterior cervical fixation. DISCUSSION AND CONCLUSIONS: Endoscopic endonasal odontoidectomy has proven to be safe and effective in selected patients. Soft and hard palate preservation dramatically reduces the risk of postoperative velopharyngeal insufficiency. Moreover, the endonasal endoscopic approach provides a direct access to the dens. Three-dimensional high-definition endoscope, laser, and ultrasound bony curettes revealed to be useful tools for this approach that, however, remains a demanding one.