Preoperative angiographic considerations and neurological outcome after surgical treatment of intradural spinal hemangioblastoma: a multicenter retrospective case series.

PURPOSE: Intradural spinal hemangioblastomas are rare highly hypervascularized benign neoplasms. Surgical resection remains the treatment of choice, with a significant risk of postoperative neurological deterioration. Due to the tumor infrequency, scientific evidence is scarce and limited to case reports and small case series. METHODS: We performed a retrospective multicenter study including five high-volume neurosurgical centers analyzing patients surgically treated for spinal hemangioblastomas between 2006 and 2021. We assessed clinical status, surgical data, preoperative angiograms, and embolization when available. Follow-up records were analyzed, and logistic regression performed to assess possible risk factors for neurological deterioration. RESULTS: We included 60 patients in Germany and Austria. Preoperative angiography was performed in 30% of the cases; 10% of the patients underwent preoperative embolization. Posterior tumor location and presence of a syrinx favored gross total tumor resection (93.8% vs. 83.3% and 97.1% vs. 84%). Preoperative embolization was not associated with postoperative worsening. The clinical outcome revealed a transient postoperative neurological deterioration in 38.3%, depending on symptom duration and preoperative modified McCormick grading, but patients recovered in most cases until follow-up. CONCLUSION: Spinal hemangioblastoma patients significantly benefit from early surgical treatment with only transient postoperative deterioration and complete recovery until follow-up. The performance of preoperative angiograms remains subject to center disparities.

Spinal cord compression in patients with mucopolysaccharidosis.

PURPOSE: Spinal abnormalities frequently occur in patients with mucopolysaccharidosis (MPS) types I, II, IV, and VI. The symptoms are manifold, which sometimes prolongs the diagnostic process and delays therapy. Spinal stenosis (SS) with spinal cord compression due to bone malformations and an accumulation of storage material in soft tissue are serious complications of MPS disease. Data on optimal perioperative therapeutic care of SS is limited. METHODS: A retrospective chart analysis of patients with MPS and SS for the time period 01/1998 to 03/2021 was performed. Demographics, clinical data, neurological status, diagnostic evaluations (radiography, MRI, electrophysiology), and treatment modalities were documented. The extent of the SS and spinal canal diameter were analyzed. A Cox regression analysis was performed to identify prognostic factors for neurological outcomes. RESULTS: Out of 209 MPS patients, 15 were included in this study. The most dominant type of MPS was I (-H) (n = 7; 46.7%). Preoperative neurological deterioration was the most frequent indication for further diagnostics (n = 12; 80%). The surgical procedure of choice was dorsal instrumentation with microsurgical decompression (n = 14; 93.3%). A univariate Cox regression analysis showed MPS type I (-H) to be associated with favorable neurological outcomes. CONCLUSION: Early detection of spinal stenosis is highly relevant in patients with MPS. Detailed neurological assessment during follow-up is crucial for timeous detection of patients at risk. The surgical intervention of choice is dorsal instrumentation with microsurgical decompression and resection of thickened intraspinal tissue. Patients with MPS type I (-H) demonstrated the best neurological course.

Refining the treatment of spinal cord lesions: experience from 500 cases.

OBJECTIVE: Tumorous lesions of the spinal cord, as well as some vascular lesions like cavernous hemangiomas, demand careful consideration as to the indication and approach for surgery. As these lesions are rare in any departmental series, refinement of treatment strategies evolves over long periods. In this context, the authors evaluated a series of 500 intramedullary lesions for approach, technique, outcome, complications, and follow-up. METHODS: Five hundred intramedullary lesions in 460 patients were treated with a continuously evolving departmental strategy between 1985 and 2020. No lesions of the cauda equina or filum terminale were included. The focus of the evaluation was on the adaptation of exposure, resective methodology, sequelae, imaging, and rate of recurrence. Thirty-seven patients were children at the time of diagnosis. RESULTS: Among the 348 neoplastic lesions, the largest subtype was ependymoma (n = 192, 55.2%), followed by astrocytoma (n = 89, 25.6%). As a trend, metastases (n = 21) have become more frequent and more apparent only in the past 15 years. Reoperations for recurrent or progressive cases or referrals after incomplete resection were performed in 56 cases, mostly for progressive diffuse or pilocytic astrocytomas. Among the vascular lesions, 68 (54.8%) were hemangioblastomas, followed by 56 (45.2%) cavernous hemangiomas. All intramedullary tumors were approached through a midline myelotomy, refining an en bloc resection technique for endophytic tumors to increase the rate of radical resection. Cavernous hemangiomas reaching the surface and hemangioblastomas were approached directly. Complete removal was possible in 77.2% of endophytic tumors but in only 41.7% of diffuse tumors. All WHO grade II diffuse astrocytomas, WHO grade III tumors, and glioblastoma progressed despite treatment according to standard regimens. Vascular lesions were regularly removed completely, with only 1 recurrence of a large hemorrhagic thoracic cavernous hemangioma. The major sequelae were sensory deficits and neuropathic pain. Stabilizing instrumentation was placed in 5 cases of spinal deformity, mostly when more than 4 levels were affected, and in the pediatric population. CONCLUSIONS: In a large series of intramedullary surgeries, refinement of treatment strategies related to exposure, implementation of intraoperative adjuncts such as ultrasound, intraoperative neuromonitoring, resective strategies, and reconstruction were evaluated. The authors found that for almost any defined, endophytic medullary lesion, a safe and complete removal can be offered.

Surgical management of spinal metastases involving the cervicothoracic junction: results of a multicenter, European observational study.

OBJECTIVE: Surgical management of spinal metastases at the cervicothoracic junction (CTJ) is highly complex and relies on case-based decision-making. The aim of this multicentric study was to describe surgical procedures for metastases at the CTJ and provide guidance for clinical and surgical management. METHODS: Patients eligible for this study were those with metastases at the CTJ (C7-T2) who had been consecutively treated in 2005-2019 at 7 academic institutions across Europe. The Spine Instability Neoplastic Score, neurological function, clinical status, medical history, and surgical data for each patient were retrospectively assessed. Patients were divided into four surgical groups: 1) posterior decompression only, 2) posterior decompression and fusion, 3) anterior corpectomy and fusion, and 4) anterior corpectomy and 360° fusion. Endpoints were complications, surgical revision rate, and survival. RESULTS: Among the 238 patients eligible for inclusion this study, 37 were included in group 1 (15%), 127 in group 2 (53%), 18 in group 3 (8%), and 56 in group 4 (24%). Mechanical pain was the predominant symptom (79%, 189 patients). Surgical complications occurred in 16% (group 1), 20% (group 2), 11% (group 3), and 18% (group 4). Of these, hardware failure (HwF) occurred in 18% and led to surgical revision in 7 of 8 cases. The overall complication rate was 34%. In-hospital mortality was 5%. CONCLUSIONS: Posterior fusion and decompression was the most frequently used technique. Care should be taken to choose instrumentation techniques that offer the highest possible biomechanical load-bearing capacity to avoid HwF. Since the overall complication rate is high, the prevention of in-hospital complications seems crucial to reduce in-hospital mortality.

Spine surgery in pregnant women: a multicenter case series and proposition of treatment algorithm.

PURPOSE: Spinal diseases requiring urgent surgical treatment are rare during pregnancy. Evidence is sparse and data are only available in the form of case reports. Our aim is to provide a comprehensive guide for spinal surgery on pregnant patients and highlight diagnostic and therapeutic aspects. METHODS: The study included a cohort of consecutive pregnant patients who underwent spinal surgery at five high-volume neurosurgical centers between 2010 and 2017. Perioperative and perinatal clinical data were derived from medical records. RESULTS: Twenty-four pregnant patients were included. Three underwent a preoperative cesarean section. Twenty-one patients underwent surgery during pregnancy. Median maternal age was 33 years, and median gestational age was 13 completed weeks. Indications were: lumbar disk prolapse (n = 14; including cauda equina, severe motor deficits or acute pain), unstable spine injuries (n = 4); intramedullary tumor with paraparesis (n = 1), infection (n = 1) and Schwann cell nerve root tumor presenting with high-grade paresis (n = 1). Two patients suffered transient gestational diabetes and 1 patient presented with vaginal bleeding without any signs of fetal complications. No miscarriages, stillbirths, or severe obstetric complications occurred until delivery. All patients improved neurologically after the surgery. CONCLUSION: Spinal surgical procedures during pregnancy seem to be safe. The indication for surgery has to be very strict and surgical procedures during pregnancy should be reserved for emergency cases. For pregnant patients, the surgical strategy should be individually tailored to the mother and the fetus.

Carbon fiber-reinforced PEEK versus titanium implants: an in vitro comparison of susceptibility artifacts in CT and MR imaging.

Artifacts in computed tomography (CT) and magnetic resonance imaging (MRI) due to titanium implants in spine surgery are known to cause difficulties in follow-up imaging, radiation planning, and precise dose delivery in patients with spinal tumors. Carbon fiber-reinforced polyetheretherketon (CFRP) implants aim to reduce these artifacts. Our aim was to analyze susceptibility artifacts of these implants using a standardized in vitro model. Titanium and CFRP screw-rod phantoms were embedded in 3% agarose gel. Phantoms were scanned with Siemens Somatom AS Open and 3.0-T Siemens Skyra scanners. Regions of interest (ROIs) were plotted and analyzed for CT and MRI at clinically relevant localizations. CT voxel-based imaging analysis showed a significant difference of artifact intensity and central overlay between titanium and CFRP phantoms. For the virtual regions of the spinal canal, titanium implants (ti) presented - 30.7 HU vs. 33.4 HU mean for CFRP (p < 0.001), at the posterior margin of the vertebral body 68.9 HU (ti) vs. 59.8 HU (CFRP) (p < 0.001) and at the anterior part of the vertebral body 201.2 HU (ti) vs. 70.4 HU (CFRP) (p < 0.001), respectively. MRI data was only visually interpreted due to the low sample size and lack of an objective measuring system as Hounsfield units in CT. CT imaging of the phantom with typical implant configuration for thoracic stabilization could demonstrate a significant artifact reduction in CFRP implants compared with titanium implants for evaluation of index structures. Radiolucency with less artifacts provides a better interpretation of follow-up imaging, radiation planning, and more precise dose delivery.

Surgical treatment and neurological outcome of infiltrating intramedullary astrocytoma WHO II-IV: a multicenter retrospective case series.

INTRODUCTION: Primary malignant spinal astrocytomas present rare oncological entities with limited median survival and rapid neurological deterioration. Evidence on surgical therapy, adjuvant treatment, and neurological outcome is sparse. We aim to describe the treatment algorithm and clinical features on patients with infiltrating intramedullary astrocytomas graded WHO II-IV. METHODS: The following is a multicentered retrospective study of patients treated for spinal malignant glioma WHO II-IV in five high-volume neurosurgical departments from 2008 to 2019. Pilocytic astrocytomas were excluded. We assessed data on surgical technique, perioperative neurological status, adjuvant oncological therapy, and clinical outcome. RESULTS: 40 patients were included (diffuse astrocytoma WHO II n = 11, anaplastic astrocytoma WHO III n = 12, WHO IV n = 17). Only 40% were functionally independent before surgery, most patients presented with moderate disability (47.5%). Most patients underwent a biopsy (n = 18, 45%) or subtotal tumor resection (n = 15, 37.5%), and 49% of the patients deteriorated after surgery. Patients with WHO III and IV tumors were treated with combined radiochemotherapy. Median overall survival (OS) was 46.5 months in WHO II, 25.7 months in WHO III, and 7.4 months in WHO IV astrocytomas. Preoperative clinical status and WHO significantly influenced the OS, and the extent of resection did not. CONCLUSION: Infiltrating intramedullary astrocytomas WHO II-IV present rare entities with dismal prognosis. Due to the high incidence of surgery-related neurological impairment, the aim of the surgical approach should be limited to obtaining the histological tissue via a biopsy or, tumor debulking in cases with rapidly progressive severe preoperative deficits.

Spinal ependymoma in adults: a multicenter investigation of surgical outcome and progression-free survival.

OBJECTIVE Spinal ependymomas are rare glial neoplasms. Because their incidence is low, only a few larger studies have investigated this condition. There are no clear data concerning prognosis and therapy. The aim of the study was to describe the natural history, perioperative clinical course, and local tumor control of adult patients with spinal ependymomas who were surgically treated under modern treatment standards. METHODS The authors performed a multicenter retrospective study. They identified 158 adult patients with spinal ependymomas who had received surgical treatment between January 2006 and June 2013. The authors analyzed the clinical and histological aspects of these cases to identify the predictive factors for postoperative morbidity, tumor resectability, and recurrence. RESULTS Gross-total resection (GTR) was achieved in 80% of cases. At discharge, 37% of the patients showed a neurological decline. During follow-up the majority recovered, whereas 76% showed at least preoperative status. Permanent functional deterioration remained in 2% of the patients. Transient deficits were more frequent in patients with cervically located ependymomas (p = 0.004) and in older patients (p = 0.002). Permanent deficits were independently predicted only by older age (p = 0.026). Tumor progression was observed in 15 cases. The 5-year progression-free survival (PFS) rate was 80%, and GTR (p = 0.037), WHO grade II (p = 0.009), and low Ki-67 index (p = 0.005) were independent prognostic factors for PFS. Adjuvant radiation therapy was performed in 15 cases. No statistically relevant effects of radiation therapy were observed among patients with incompletely resected ependymomas (p = 0.079). CONCLUSIONS Due to its beneficial value for PFS, GTR is important in the treatment of spinal ependymoma. Gross-total resection is feasible in the majority of cases, with acceptable rates of permanent deficits. Also, Ki-67 appears to be an important prognostic factor and should be included in a grading scheme for spinal ependymomas.

Impact of the surgical strategy on the incidence of C5 nerve root palsy in decompressive cervical surgery.

OBJECTIVE: Our aim was to identify the impact of different surgical strategies on the incidence of C5 palsy. BACKGROUND: Degenerative cervical spinal stenosis is a steadily increasing morbidity in the ageing population. Postoperative C5 nerve root palsy is a common complication with severe impact on the patients´ quality of life. METHODS: We identified 1708 consecutive patients who underwent cervical decompression surgery due to degenerative changes. The incidence of C5 palsy and surgical parameters including type and level of surgery were recorded to identify predictors for C5 nerve palsy. RESULTS: The overall C5 palsy rate was 4.8%, with 18.3% of cases being bilateral. For ACDF alone the palsy rate was low (1.13%), compared to 14.0% of C5 palsy rate after corpectomy. The risk increased with extension of the procedures. Hybrid constructs with corpectomy plus ACDF at C3-6 showed significantly lower rates of C5 palsy (10.7%) than corpectomy of two vertebrae (p = 0.005). Multiple regression analysis identified corpectomy of C4 or C5 as a significant predictor. We observed a lower overall incidence for ventral (4.3%) compared to dorsal (10.9%) approaches (p<0.001). When imaging detected a postoperative shift of the spinal cord at index segment C4/5, palsy rate increased significantly (33.3% vs. 12.5%, p = 0.034). CONCLUSIONS: Extended surgical strategies, such as dorsal laminectomies, multilevel corpectomies and procedures with extensive spinal cord shift were shown to display a high risk of C5 palsy. The use of extended procedures should therefore be employed cautiously. Switching to combined surgical methods like ACDF plus corpectomy can reduce the rate of C5 palsy.

Circulating Tumour Cell Release after Cement Augmentation of Vertebral Metastases.

Cement augmentation via percutaneous vertebroplasty or kyphoplasty for treatment of spinal metastasis is a well-established treatment option. We assessed whether elevated intrametastatic pressure during cement augmentation results in an increased dissemination of tumour cells into the vascular circulation. We prospectively collected blood from patients with osteolytic spinal column metastases and analysed the prevalence of circulating tumour cells (CTCs) at three time-points: preoperatively, 20 minutes after cement augmentation, and 3-5 days postoperatively. Enrolling 21 patients, including 13 breast- (61.9%), 5 lung- (23.8%), and one (4.8%) colorectal-, renal-, and prostate-carcinoma patient each, we demonstrate a significant 1.8-fold increase of EpCAM+/K+ CTCs in samples taken 20 minutes post-cement augmentation (P < 0.0001). Despite increased mechanical CTC dissemination due to cement augmentation, follow-up blood draws demonstrated that no long-term increase of CTCs was present. Array-CGH analysis revealed a specific profile of the CTC collected 20 minutes after cement augmentation. This is the first study to report that peripheral CTCs are temporarily increased due to vertebral cement augmentation procedures. Our findings provide a rationale for the development of new prophylactic strategies to reduce the increased release of CTC after cement augmentation of osteolytic spinal metastases.

Cervical vertebroplasty for osteolytic metastases as a minimally invasive therapeutic option in oncological surgery: outcome in 14 cases.

OBJECTIVE The treatment of cervical spinal metastases represents a controversial issue regarding the type, extent, and invasiveness of interventions. In the lumbar and thoracic spine, kypho- and vertebroplasties have been established as minimally invasive procedures for patients with metastases to the vertebral bodies and without neurological deficit. These procedures show good results with respect to pain reduction and low complication rates. However, limited data are available for kypho- and vertebroplasties for cervical spinal metastases. In an effort to add to existing data, the authors here present a case series of 14 patients who were treated for osteolytic metastases of the cervical spine using vertebroplasty alone or in addition to another surgical procedure involving the cervical spine in a palliative setting to reduce pain and restore stability. METHODS Fourteen patients consisting of 8 males and 6 females, with a mean age of 64.7 years (range 44-85 years), were treated with vertebroplasty at the authors' clinic between January 2015 and November 2016. In total, 25 vertebrae were treated with vertebroplasty: 10 C-2, 5 C-3, 2 C-4, 2 C-5, 3 C-6, and 3 C-7. Two patients had an additional posterior stabilization and 5 patients an additional anterior stabilization. In 13 cases, the surgical approach was a modified Smith-Robinson approach; in 1 case, the cement was injected into the corpus axis from posteriorly. Patients with osteolytic defects of the posterior wall of the vertebral body did not undergo surgery, nor did patients with neurological deficits. Preoperatively, on the 2nd day after surgery, and at the follow-up, neck pain was rated using the visual analog scale (VAS). RESULTS Twelve patients were examined at follow-up (mean 9 months). Neck pain was rated as a mean of 6.0 (range 3-8) preoperatively, 2.9 on Day 2 after surgery (range 0-5), and 0.5 at the follow-up (range 0-4), according to the VAS. The mean Neck Disability Index at follow-up was 3.6% (range 0%-18%). CONCLUSIONS Anterior vertebroplasty of the cervical spine via an anterolateral approach represents a safe and minimally invasive procedure with a low complication rate and appears suitable for reducing pain and restoring stability in cases of cervical spinal metastases. Vertebroplasties can be combined with other anterior and posterior operations of the cervical spine and, in the axis vertebra, can be performed transpedicularly from posteriorly. Thus, in cases in which the posterior wall of the vertebral body is intact, vertebroplasty represents a less invasive alternative to vertebral replacement in oncological surgery. Prospective randomized trials with a longer follow-up period and a larger patient cohort are needed to confirm the encouraging results of this case series.

Keyhole approaches to intradural pathologies.

OBJECTIVE Spinal tumors account for 2%-4% of all tumors of the central nervous system and can be intramedullary, intradural extramedullary, or extradural. In the past, wide approaches were used to obtain safe access to these tumors, as complete resection is the goal in treating most tumor entities. To reduce surgical complications due to large skin incisions and destabilizing laminectomies, minimally invasive approaches were established. In this study, the authors share their experience with mini-open approaches to intradural tumor pathologies. METHODS The authors retrospectively reviewed cases involving patients with intramedullary and intradural extramedullary lesions treated between 2009 and 2016. They present their surgical mini-open approach to the spinal cord as well as unique characteristics, key steps, and postsurgical complications for specific tumor subgroups (meningioma, neuroma, and intramedullary tumors). RESULTS A total of 245 intradural tumors were surgically treated during the study period. Of these lesions, 151 were intradural extramedullary meningiomas (n = 79) or neuromas (n = 72). Nine (12.5%) of the neuromas were dumbbell neuromas. Ninety-four tumors were intramedullary. The mean age of the patients was 51.4 years, and 53.9% were female. The mean duration of follow-up was 46.0 months. All meningiomas and neuromas could be resected using a mini-open keyhole approach, but only 5.3% of the intramedullary lesions could be accessed using this technique. Of the 94 patients with intramedullary tumors, 76.6% required a laminotomy, 7.4% required a hemilaminectomy, and 10.6% required a 2-level laminectomy. Only 2 of the patients with intramedullary tumors needed stabilization for progressive cervical kyphosis during follow-up. None of the other patients developed spinal instability after undergoing surgery via the mini-open (keyhole/interlaminar) approach. There were significantly more surgery-associated complications in the large exposure group than in the patients treated with the mini-open approach (19.1% vs 9.6%, p < 0.01). CONCLUSIONS Intradural extramedullary and in selected cases intramedullary pathologies may safely be resected using a mini-open interlaminar approach. Avoiding laminectomy, laminotomy, and even hemilaminectomy preserves spinal stability and significantly reduces comorbidities, while still allowing for complete resection of these tumors.

Impact of spinal cord compression from intradural and epidural spinal tumors on perioperative symptoms-implications for surgical decision making.

Spinal cord or cauda equina compression (SCC) is an increasing challenge in clinical oncology due to a higher prevalence of long-term cancer survivors. Our aim was to determine the clinical relevance of SCC regarding patient outcome depending on different tumor entities and their anatomical localization (extradural/intradural/intramedullary). We retrospectively analyzed 230 patients surgically treated for SCC. Preoperative status for pain and neurological impairment were correlated to the degree of compression, tumor location, and early as well as short-term follow-up outcome parameters. Interestingly, we did not observe any differences between intradural-extramedullary compared to extradural tumors. Unilaterally localized tumors were likely to present with pain (72.9 %, p < 0.01), whereas concentric growth was associated with motor deficits (41.0 %, p < 0.01, as primary symptom, 49.3 % on admission, p < 0.05). In concentric tumors, the pain pattern was diffuse (40.5 % vs. 17.5 in unilateral disease, p < 0.01), whereas unilateral tumors resulted in localized pain (61.4 % local axial or radicular, p < 0.01). Diffuse pain, patients without a sensory or motor deficit, progressive disease, cervical localization, and a higher degree of stenosis were identified as beneficial for an early improvement in pain (p < 0.05). Notably, 29 % of patients with unchanged pain and 30.8 % with unchanged neurologic function at day 7 postoperative improved during follow-up (p < 0.001). Our data demonstrate that the preoperative tumor anatomy in patients with SCC was closely related to their presenting symptoms and early clinical outcome. The detailed analysis elucidates the biology of SCC and might thereby aid in determining which patients will benefit from surgery.

Value of 18 F-FDG PET/MRI for the outcome of CT-guided facet block therapy in cervical facet syndrome: initial results.

INTRODUCTION: The aim of this study was to evaluate the ability of 18 F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (18 F-FDG PET/MRI) to detect PET-positive cervical facet arthropathy and identify patients who benefit from facet block therapy. METHODS: Ten patients with cervical facet syndrome (mean age: 65 ± 12 years) underwent 18 F-FDG PET/MRI of the neck. Focal 18 F-FDG uptake in PET-positive facet joints served as target for computed tomography (CT)-guided facet blocks. In PET-negative patients, the target joint for facet block therapy was selected by current clinical standards considering the level of maximum facet arthrosis and pain. Neck pain was measured on visual analogue scale (VAS) before and after therapy. Bone marrow signal intensity (SI) ratio on turbo inversion recovery magnitude (TIRM) images and maximum standard uptake values (SUVmax) was calculated for each facet joint. Pearson's correlation coefficient (r) was calculated between bone marrow SI ratios on TIRM and SUVmax. RESULTS: 18 F-FDG PET/MRI detected PET-positive facet arthropathy in six patients. Patients with PET-positive facet arthropathy had significantly less pain compared with the pretreatment pain 3 h (P = 0.002), 4 weeks (P = 0.002) and 3 months (P = 0.026) after facet block therapy. Pain did not change significantly in patients with PET-negative facet arthropathy. TIRM SI ratio was higher in PET-positive facet arthropathy than in PET-negative facet arthropathy (P < 0.001). Correlation was strong between bone marrow SI ratio on TIRM images and SUVmax (r = 0.7; P < 0.001). CONCLUSIONS: 18 F-FDG PET/MRI can detect PET-positive cervical facet arthropathy and help to identify patients benefitting from facet block therapy. Bone marrow TIRM SI ratio might be a surrogate for PET-positive facet arthropathy.

Surgery for adult spondylolisthesis: a systematic review of the evidence.

Surgery for isthmic and degenerative spondylolisthesis (SL) in adults is carried out very frequently in everyday practice. However, it is still unclear whether the results of surgery are better than those of conservative treatment and whether decompression alone or instrumented fusion with decompression should be recommended. In addition, the role of reduction is unclear. Four clinically relevant key questions were addressed in this study: (1) Is surgery more successful than conservative treatment in relation to pain and function in adult patients with isthmic SL? (2) Is surgery more successful than conservative treatment in relation to pain and function in adult patients with degenerative SL? (3) Is instrumented fusion with decompression more successful in relation to pain and function than decompression alone in adult patients with degenerative SL and spinal canal stenosis? (4) Is instrumented fusion with reduction more successful in relation to pain and function than instrumented fusion without reduction in adult patients with isthmic or degenerative SL? A systematic PubMed search was carried out to identify randomized and nonrandomized controlled trials on these topics. Papers were analyzed systematically in a search for the best evidence. A total of 18 studies was identified and analyzed: two for question 1, eight for question 2, four for question 3, and four for question 4. Surgery appears to be better than conservative treatment in adults with isthmic SL (poor evidence) and also in adults with degenerative SL (good evidence). Instrumented fusion with decompression appears to be more successful than decompression alone in adults with degenerative SL and spinal stenosis (poor evidence). Reduction and instrumented fusion does not appear to be more successful than instrumented fusion without reduction in adults with isthmic or degenerative SL (moderate evidence).

Intramedullary spinal cord metastases: an increasingly common diagnosis.

OBJECT Intramedullary spinal cord metastases (ISCM) represent a small proportion of intramedullary tumors. However, with the lifespans of patients with malignant tumors increasing, incidents of ISCM are on the rise. Due to threateningly severe disabilities in patients, accompanied by limited life expectancy, every attempt should be made to treat these tumors the same way as metastases elsewhere in the CNS, with the goal of complete removal of the ISCM and preservation of neurological functions. The object of this study is to retrospectively analyze the experiences of 22 patients who were surgically treated for ISCM over a 22-year period. METHODS Hospital charts of 22 patients, who were surgically treated for ISCM between 1992 and 2014, were reviewed retrospectively. Demographic data, histopathological diagnoses of primary cancer, chronological sequence of the disease, and neurological status using the simplified McCormick functional classification were collected and reanalyzed. RESULTS The most frequent histology was metastasis of lung cancer, followed by brain and breast cancers. The time span from primary cancer diagnosis to the development of symptomatic spinal metastases ranged from 0 to 285 months, with a mean interval of 38 months. The leading presenting sign was dysesthesia (77% of the population), followed by paresis (68%). Only 5 patients (23%) showed urinary retention. Initial performance status represented by the McCormick Scale was on average 2.47. Total or near-total removal was achieved in 87% of cases. Compared with the clinical status 1-2 days after surgery, there was an improvement in the McCormick Scale grade at the last follow-up from 2.47 to 2.12 (p = 0.009). Likewise, an improvement was detected when comparing the preoperative status with the last follow-up (from 2.45 to 2.12; p = 0.029). The mean survival time after surgery was 11.6 months. CONCLUSIONS These results suggest that surgery for intramedullary metastases-with all of the challenges of a rare and potentially risky procedure-can be beneficial to patients with advanced stages of cancer. Surgery can be performed with minimal new morbidity and results in maintaining neurological performance status.

Minimally invasive approach for small ventrally located intradural lesions of the craniovertebral junction.

OBJECT: The surgical management of lesions ventral to the neuraxis at the level of the craniovertebral junction (CVJ) and upper cervical spine is challenging. Here, the authors describe a minimally invasive dorsal approach for small ventrally located intradural lesions at the CVJ as an alternative for the more extensive classic transoral approach or variants of suboccipital approaches. METHODS: Between 2012 and 2014, 6 symptomatic patients with a small lesion of the ventral aspect at the CVJ level were treated using a minimally invasive dorsal approach at the University Medical Center in Hamburg-Eppendorf, Germany. The anatomical distance between the posterior atlantooccipital membrane and the posterior atlantoaxial ligament, as determined by CT images, was assessed in the treated patients and in 100 untreated persons. RESULTS: The authors treated 6 patients (mean age 54.7 years) who had a clinical presentation of mild neurological symptoms that disappeared after resection. Minimally invasive surgical dorsal access was achieved by using tubular systems and using the natural space between the occiput (C-0) and C-1, and in 1 case between C-1 and C-2, without having to remove bony structures. The postoperative course in each of the 6 patients was uneventful. The neuropatho-logical findings confirmed a meningotheliomatous meningioma (WHO Grade I) in 5 cases and an extramedullary cavernous hemangioma in 1 case. MRI confirmed complete resection of all the lesions. The atlantooccipital distances ranged from 3 to 17 mm (mean 8.98 mm) in the supine neutral position, and the atlantoaxial distances ranged from 5 to 17 mm (mean 10.56 mm). There were no significant differences between women and men (atlantooccipital p = 0.14; atlantoaxial p = 0.72). CONCLUSIONS: The results of this study demonstrate that the minimally invasive dorsal approach using the space between C-0 and C-1 or C-1 and C-2 provides direct and sufficient exposure for the safe surgical resection of small ventrally located intradural lesions at the CVJ level while reducing the necessity for musculoskeletal preparation to a minimum.

Treatment of large thoracic and lumbar paraspinal schwannoma.

BACKGROUND: Paraspinal neurogenic tumors usually expand into the mediastinum and retroperitoneum and can reach a considerable size before they become symptomatic. Such large tumors are rare. We describe 14 cases of large schwannomas (>2.5 cm ø) with mild and late onset of symptoms, which were treated with total surgical resection through a single-approach surgery. METHODS: In 2013 14 patients with paraspinal large schwannomas were treated in our institutions. Data were analyzed retrospectively. Magnetic resonance imaging (MRI) showed lesions suspicious for a paraspinal schwannoma with partial intraforaminal growth. In case of ambiguity regarding tumor dignity, a needle biopsy was performed before final treatment. Three different approaches and their indications were discussed. RESULTS: Fourteen patients (7 female and 7 male, ages 18-58 years, mean: 39.8 years) requiring surgical exploration because of a thoracic (6) or lumbar/lumbosacral (8) lesion were treated in our institutions. Two patients received CT-guided needle biopsy preoperatively. Complete resection of the schwannoma was possible through a mini-thoracotomy in 1 case (7 %), a retroperitoneal approach in 2 cases (14 %), and dorsal interlaminar and intercostal fenestration in 11 cases (79 %). Histological examination revealed the diagnosis of schwannoma (WHO grade I) in all cases except one with neurofibroma (WHO grade I). There were no major complications in any case. CONCLUSION: Large benign schwannomas are rare. They need a tailored treatment, which in most cases works through one surgical approach. Usually it is possible to perform a complete resection with a good postoperative prognosis.