Microsurgical removal of supratentorial and cerebellar cavernous malformations: what has changed? A single institution experience.

BACKGROUND: Features associated with a safe surgical resection of cerebral cavernous malformations (CMs) are still not clear and what is needed to achieve this target has not been defined yet. METHODS: Clinical presentation, radiological features and anatomical locations were assessed for patients operated on from January 2008 to January 2018 for supratentorial and cerebellar cavernomas. Supratentorial CMs were divided into 3 subgroups (non-critical vs. superficial critical vs. deep critical). The clinical outcome was assessed through modified Rankin Scale (mRS) and was divided into favorable (mRS 0-1) and unfavorable (mRS ≥ 2). Post-operative epilepsy was classified according to the Maraire Scale. RESULTS: A total of 144 were considered eligible for the current study. At 6 months follow-up the clinical outcome was excellent for patients with cerebellar or lobar CMs in non-critical areas (mRS ≤ 1: 91.1 %) and for patients with superficial CMs in critical areas (mRS ≤ 1: 92.3 %). Patients with deep-seated suprantentorial CMs showed a favorable outcome in 76.9 %. As for epilepsy 58.5 % of patients presenting with a history of epilepsy were free from seizures and without therapy (Maraire grade I) at last follow-up (mean 3.9 years) and an additional 41.5 % had complete control of seizures with therapy (Maraire grade II). CONCLUSIONS: Surgery is safe in the management of CMs in non-critical but also in critical supratentorial locations, with a caveat for deep structures such as the insula, the basal ganglia and the thalamus/hypothalamus.

Recurrent oligodendroglioma with changed 1p/19q status.

We report a case of oligodendroglioma that had consistent histopathological features as well as a distinct change in 1p/19q status in the second recurrence, after temozolomide chemotherapy and radiotherapy. The first tumor recurrence had oligodendroglial morphology, IDH1 R132H and TERT promoter mutations, and 1p/19q codeletion detected by fluorescent in situ hybridization (FISH). Copy number analysis, assessed by next-generation sequencing, confirmed 1p/19q codeletion, and disclosed loss of heterozygosity (LOH) of chromosomes 4 and 9 and chromosome 11 gain. The second recurrence featured not only oligodendroglial morphology but also the appearance of admixed multinucleated giant cells or neoplastic cells having oval nuclei and mitoses and showing microvascular proliferation; it maintained IDH1 R132H and TERT promoter mutations, acquired TP53 mutation, and showed 19q LOH, but disomic 1p, detected by FISH. Copy number analysis depicted LOH of chromosomes 3p, 13, and 19q, 1p partial deletion (1p chr1p34.2-p11), and gain of chromosomes 2p25.3-p24.1, 8q12.2-q24.3, and 11q13.3-q25. B-allele frequency analysis of polymorphic sites disclosed copy-neutral LOH at 1p36.33-p34.2, supporting the initial deletion of 1p, followed by reduplication of 1p36.33-p34.2 alone. These findings suggest that the two tumor recurrences might have originated from an initial neoplastic clone, featuring 1p/19q codeletion and IDH1 and TERT promoter mutations, and have independently acquired other copy number alterations. The reduplication of chromosome 1p might be the result of temozolomide treatment, and gave rise to false negative 1p deletion detected by FISH. The possibility of 1p copy-neutral LOH should be considered in recurrent oligodendrogliomas with altered 1p/19q status detected by FISH.

Endoscopic Endonasal Surgery of Clival Chordomas: Preliminary Results.

Chordomas are rare malignant tumors, often affecting the clival region. Traditionally, they are removed via craniotomic approach but the introduction of the endoscopic endonasal technique (EEA) allowed to control this area. This article shows a series of patients affected by clival chordomas treated with endoscopic approach. Patients who underwent EEA or transoral approach (TO) for clival chordomas at our Skull Base Referral Center, have been retrospectively examined. Clinical symptoms, preoperative neuroradiological evaluation, surgical approach, complications and postoperative results were evaluated. Nine patients (4 females and 5 males; age range 45-82 years, mean 61 years) were included. Chordomas involved upper clivus in 4/9 cases, with (2) or without (2) extension to the middle clivus, middle clivus alone in 2/9, lower clivus in 2/9, and the whole clivus in 1/9. Tumors were totally (4/9) or subtotally (5/9) removed. Skull base reconstruction was performed with a multilayer technique (6/9) or a gasket-seal closure (1/9), using pedicled nasoseptal flaps, middle turbinate and mucoperichondrial grafts, fascia lata and synthetic fascia. No reconstruction was performed in 2 cases. Recurrence occurred in 4 cases, who underwent a new operation. All the other patients underwent proton-beam radiotherapy with no documented tumor growth at the last follow-up (median: 24.9 months; range: 7-36 months). EEA and TO resulted to be safe procedures for treatment of clival chordomas. These approaches may be used as an alternative to the traditional approaches, according to the extension of the pathology.

Expanded Endoscopic Approach for Anterior Skull Base Tumors: Experience of a Multidisciplinary Skull Base Team.

The aim of this study is to describe the experience of a multidisciplinary skull base team with transnasal endoscopic surgery for anterior cranial base tumors.A retrospective chart review was conducted on patients who underwent an exclusive expanded transnasal approach to the anterior skull base in the period from December 2014 to November 2015. Data on patient demographics, tumor characteristics, surgical information, imaging, and postoperative complications were collected and analyzed.From a total of 120 patients with skull base diseases managed by the skull base team, 36 were admitted to this study. The overall complication rate in this series was 16.7%, gross total resection was achieved in 32 cases (88.9%) and postoperative CSF leakage occurred in 5 cases (13.9%).Our preliminary results confirm that an exclusive endoscopic transnasal approach to the anterior cranial base is a reliable technique with acceptable perioperative morbidity.

Intraoperative Measurement of Arterial Blood Flow in Aneurysm Surgery.

Intraoperative flowmetry (IF) has been recently introduced during cerebral aneurysm surgery in order to obtain a safer surgical exclusion of the aneurysm. This study evaluates the usefulness of IF during surgery for cerebral aneurysms and compares the results obtained in the joined surgical series of Verona and Padua to the more recent results obtained at the neurosurgical department of Verona.In the first surgical series, between 2001 and 2010, a total of 312 patients were submitted to IF during surgery for cerebral aneurysm at the neurosurgical departments of Verona and Padua: 162 patients presented with subarachnoid hemorrhage (SAH) whereas 150 patients harbored unruptured aneurysms. In the second series, between 2011 and 2016, 112 patients were submitted to IF during surgery for cerebral aneurysm at the neurosurgical department of Verona; 24 patients were admitted for SAH, whereas 88 patients were operated on for unruptured aneurysms.Comparison of the baseline values in the two surgical series and the baseline values between unruptured and ruptured aneurysms showed no statistical differences between the two clinical series. Analysis of flowmetry measurements showed three types of loco-regional flow derangements: hyperemia after temporary arterial occlusion, redistribution of flow in efferent vessels after clipping, and low flow in patients with SAH-related vasospasm.IF provides real-time data about flow derangements caused by surgical clipping of cerebral aneurysm, thus enabling the surgeon to obtain a safer exclusion; furthermore, it permits the evaluation of other effects of clipping on the loco-regional blood flow. It is suggested that-in contribution with intraoperative neurophysiological monitoring-IF may now constitute the most reliable tool for increasing safety in aneurysm surgery.

Endoscopic transnasal surgery of clival lesions: our experience.

BACKGROUND: The clivus is a region characterized by complex anatomy, with vascular and neural structures that are located in close proximity. Different pathologies can affect this area, and traditional surgical approaches were open approaches. Recently, the endoscopic transnasal technique has been introduced, and currently represents a good alternative for the surgical management of these lesions. This is a preliminary report on patients treated endoscopically for clival lesions by the authors' Skull Base Team. PATIENTS AND METHODS: This was a retrospective chart review of patients who underwent an endoscopic exclusive transnasal approach (EEA) or a transoral one (TO) for clival lesions between June 2015 and November 2017 at our Skull Base Referral Center. Patient characteristics and symptoms, preoperative neuroradiological evaluation, surgical approach, complications, and postoperative results were evaluated. RESULTS: Nine patients (6 females and 3 males; age range 6-82 years, mean 50.8 years) underwent EEA or TO. From histological analysis, we found chordomas (6/9 subjects), chondrosarcoma (1/9), craniopharyngioma (1/9), and eosinophilic granuloma (1/9). Three patients had previously been operated for a parasellar chondrosarcoma (1/9), a pituitary macroadenoma (1/9), or a chondroid chordoma (1/9). The lesions were totally (2/9) or sub-totally (5/9) resected, debulked (1/9), or analyzed with a biopsy (1/9). Reconstruction was accomplished with a multilayer technique (7/9), or with a gasket-seal (1/9), using a mucoperichondrial graft, a single/double nasoseptal flap, a middle turbinate flap, a fascia lata, or a synthetic fascia. One patient (11.1%) was re-operated on due to cerebrospinal leakage, without further complications. Two patients (22.2%) were re-operated on due to chordoma regrowth. Adjuvant chemotherapy was administered to 1/9 patient with progressive healing. All of the other patients underwent proton-beam radiotherapy with no documented tumor growth (median follow-up: 20 months; range 5.1-29.9 months). CONCLUSIONS: Clival lesions represent a heterogeneous group of lesions located in a very complex and difficult area. EEA and TO approaches are safe and mini-invasive, with lower morbidity and with postoperative complications when compared to the traditional open approaches, according to the extent and type of pathology.

Late deterioration of neurologic function in patients surgically treated for spinal dural arteriovenous fistulas.

BACKGROUND: A limited number of reports on the long-term neurologic outcome of patients with SDAVFs treated by surgery and/or embolization are available in the literature. The aim of our study is to neurologically evaluate these patients at 2 different follow-up stages, after surgery, to demonstrate a possible late neurologic deterioration after an initial improvement. METHODS: Between January 1987 and May 2002, 29 patients with SDAVFs were operated on at the Verona Department of Neurosurgery. In this group we retrospectively identified 16 patients who had 2 different clinical follow-ups, at a mean of 4.5 and 9.2 years, respectively. We compared their neurologic status using the ALS. All these data were obtained from clinical charts and phone interviews. RESULTS: The epidemiologic, clinical, and radiologic features of our group of patients are very similar to those previously described in the literature. Comparing the global clinical status between the 2 different follow-up stages, we observed a late deterioration in 8 cases (50%). A worsening of the mean G and M values of the ALS was also noted. Spinal angiography and contrast-enhanced MRI did not show any signs of recurrence of the fistula. CONCLUSIONS: Our study confirms the possible occurrence of a late clinical deterioration in as many as 50% of patients surgically treated for a SDAVF. We deem that the main pathophysiologic mechanism underlining this phenomenon is a gradual and irreversible decline in spinal function related to those hemodynamic modifications induced by the fistula and to the persistence of a state of anatomofunctional deficiency of the spinal venous drainage.

Conservative treatment of an atlantoaxial degenerative articular cyst: case report.

BACKGROUND: Atlantoaxial degenerative articular cysts are rare lesions that can cause extradural compression of the cervicomedullary junction. When symptomatic, they usually require surgical treatment. We report an unusual case of spontaneous regression of an atlantoaxial degenerative articular cyst after conservative treatment with an external cervical brace along with a systemic therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) and steroids. We also discuss the potential pathogenetic mechanisms involved. PURPOSE: To describe a case of significant volume reduction of an atlantoaxial articular degenerative cyst in a patient treated with a Philadelphia collar and anti-inflammatory drugs. STUDY DESIGN: Case report with analysis of the literature. METHODS: A 80-year-old patient was admitted to our institution with a history of progressive tetraparesis, ataxic gait, and cervical pain. A cervical spine magnetic resonance imaging (MRI) scan showed an extradural mass lesion behind the dens of C2 causing significant compression of the cervicomedullary junction, suggesting the diagnosis of atlantoaxial degenerative articular cyst. The patient refused surgery in favour of a conservative treatment with a Philadelphia collar and a short-term course of NSAIDs and corticosteroids. RESULTS: After 6 weeks, the patient's neurological condition improved, and a 6-month follow-up cervical spine MRI scan revealed an almost complete regression of the atlantoaxial cystic lesion. At a 1-year follow-up, his clinical condition was further improved. CONCLUSIONS: Atlantoaxial articular degenerative cysts are rare lesions that should be included in the differential diagnosis of those extradural lesions that can cause a ventral or ventrolateral compression of the cervicomedullary junction. They most commonly occur in elderly female patients affected by diffuse arthrosic degeneration of the cervical spine, with or without clear radiological signs of atlantoaxial instability, and have a typical appearance on MRI imaging. Surgery, with direct excision of the cyst and/or a C1-C2 fusion, is the first treatment of choice. Nevertheless, our report points out the possibility of a significant spontaneous regression of these lesions following a simple conservative strategy based on the use of an external cervical brace together with a systemic anti-inflammatory therapy.

Comparison of different infratentorial-supracerebellar approaches to the posterior and middle incisural space: a cadaveric study.

OBJECT: The purpose of this investigation was to describe and compare through cadaveric dissection the microsurgical exposure afforded by the median, paramedian, and extreme-lateral infratentorial-supracerebellar approaches to the posterior and middle incisural space. METHODS: The median, paramedian, and extreme-lateral infratentorial-supracerebellar approaches were performed in 10 embalmed cadaveric heads by using standard microneurosurgical methods; each approach was executed a minimum of five times. The dissections were performed in a stepwise fashion, comparing the exposure afforded by each surgical route and highlighting the relationships among the targeted neurovascular structures. Exposure of the dural sinuses and transection of the tentorium were also evaluated in relation to the degree of exposure achieved. The median infratentorial-supracerebellar route provides direct exposure of the posterior incisural space, although the culmen represents a relative obstacle to exposure of the lower quadrigeminal plate. The paramedian variant allows a more lateral perspective on the posterolateral brainstem surface at the level of the middle incisural space, in addition to exposing the homolateral collicular plate. The extreme-lateral corridor widens the exposure of the paramedian approach to include the anterolateral brainstem surface, offering a complete view of the cisternal space surrounding the middle incisural space. Complete, constant exposure and retraction of the dural sinuses facilitated the surgical exposure. CONCLUSIONS: The infratentorial-supracerebellar approaches allow safe circumferential exposure of the posterior and middle incisural space. Choosing among different variants allows the surgeon to reach selected areas, with the midline variant being best for exposure of the posterior incisural space, and the paramedian and extreme-lateral variants being best for reaching the posterior and the anterior part of the middle incisural space, respectively. The more lateral the approach, the more anterior and multiangled the exposure gained. Complete, constant exposure and retraction of the dural sinuses improves the exposure. Accurate knowledge of the regional anatomy is mandatory.