[Application of microchannel technique in minimally invasive resection of cervical intraspinal tumors].

OBJECTIVE: To explore the application and key points of microchannel approaches in resection of cervical intraspinal tumors. METHODS: A retrospective analysis was performed on 51 cases of cervical spinal canal tumors from February 2017 to March 2020. Among them, 5 cases were located epidural space, 6 cases were located epidural and subdural space, and 40 cases were located under the subdural extramedullary space(6 cases were located on the ventral side of the spinal cord). The maximum diameter ranged from 0.5 to 3.0 cm. The clinical manifestations included neck, shoulder or upper limb pain 43 cases, sensory disturbance (numbness) in 22 cases, and limb weakness in 8 cases. The microchannel keyhole technique was used to expose the tumor, and the tumor was resected microscopically. RESULTS: In this study, 35 patients underwent hemilaminectomy, 12 patients underwent interlaminar fenestration, 2 patients underwent medial 1/4 facetectomy on the basis of hemilaminectomy or interlaminar fenestration. Two tumors were resected through anatomy space (no bone was resected). The degree of tumor resection included total resection in 50 cases and subtotal resection in 1 case. The type of the tumor included 36 schwannomas, 12 meningiomas, 2 enterogenic cysts and 1 dermoid cyst. There was no infection and cerebrospinal fluid leakage postoperatively. Limb numbness occurred in 7 patients. The average follow-up time was 15 months (3 to 36 months). No deformity such as cervical instability or kyphosis was found. The tumor had no recurrence. CONCLUSION: The cervical spinal canal is relatively wide, cervical tumors with no more than three segments can be fully exposed by means of microchannel technology. Besides intramedullary or malignant tumors, they can be microsurgically removed. Preservation of the skeletal muscle structure of cervical spine is beneficial to recover the anatomy and function of cervical spine. The electrophysiological monitoring helps to avoid spinal cord or nerve root injury.

[Minimally invasive surgical treatment of extramedullary tumors at the level of craniovertebral junction: experience of the Burdenko Neurosurgical Center]. / Minimal'no invazivnoe khirurgicheskoe lechenie patsientov s ekstramedullyarnymi opukholyami na urovne kraniovertebral'nogo perekhoda: opyt NMITs neirokhirurgii im. akad. N.N. Burdenko.

OBJECTIVE: To describe own experience of treating patients with extramedullary tumors at the level of craniovertebral junction using minimally invasive surgical approaches. MATERIAL AND METHODS: The study included 29 patients who underwent minimally invasive microsurgical resection of extramedullary tumors at the level of craniovertebral junction. We analyzed the main clinical and surgical parameters. RESULTS: Gross total resection was achieved in most patients with high degree of safety. Two patients required redo surgery due to CSF leakage and soft tissue cyst. Mean length of hospital-stay was 7 days. VAS score of pain syndrome at discharge was 2 points and 0 points after 3 months. No significant differences in neurophysiological monitoring indicators were observed (p=0.76). CONCLUSION: Minimally invasive posterior approaches to extramedullary tumors at the level of craniovertebral junction can significantly reduce surgical trauma with equal extent of resection.

Intramedullary spinal cord tumors in pediatric patients presenting later with brain lesions: case series and systematic review of the literature.

PURPOSE: Intramedullary spinal cord tumors are an uncommon pathology in adults and children. Most descriptive studies of intramedullary spinal cord tumors have not focused on a possible association with future brain lesions. To the best of our knowledge, few reports describe this potential relationship. This is one of the most extensive case series of secondary brain lesions of intramedullary spinal cord tumors in the pediatric population. METHODS: Retrospective chart review was performed on pediatric patients (21 years old and younger) who underwent resection of an intramedullary spinal cord tumor at two tertiary care hospitals from 2001 to 2020. Patients previously treated or diagnosed with spinal cord tumor, and subsequent development of intracranial manifestation of the same or different tumor, were included. Data regarding epidemiology, surgical intervention, and clinical and follow-up course were gathered. Data analysis was performed according to a standardized clinical protocol with a literature review. RESULT: More than 500 patients underwent intradural spinal tumor resection surgeries at participating hospitals from 2001 to 2020. After excluding adult patients (older than 21 years old) and those with extramedullary lesions, 103 pediatric patients were identified who underwent resection of an intramedullary spinal cord tumor. Four underwent resection of an intermedullary tumor and later in their follow-up course developed a secondary intracranial neoplasm. In every case, the secondary neoplasm had the same pathology as the intramedullary tumor. Three of the patients had tumors at the cervico-thoracic junction, and one patient had a high cervical tumor. These patients had a negative primary workup for any metastatic disease at the time of the presentation or diagnosis. Complete and near complete resection was performed in three patients and subtotal in one patient. CONCLUSION: Secondary brain tumors disseminated after initial spinal cord tumor are extremely rare. This study aims to allow specialists to better understand these pathologies and treat these rare tumors with more certainty and better expectations of unusual associated lesions and conditions.

Survival and neurological outcomes following management of intramedullary spinal metastasis patients: a case series with comprehensive review of the literature.

Intramedullary spinal cord metastasis (ISCM), though rare, represents a potentially debilitating manifestation of systemic cancer. With emerging advances in cancer care, ISCMs are increasingly being encountered in clinical practice. Herein, we describe one of the larger retrospective single institutional case series on ISCMs, analyze survival and treatment outcomes, and review the literature. All surgically evaluated ISCMs at our institution between 2005 and 2023 were retrospectively reviewed. Demographics, tumor features, treatment, and clinical outcome characteristics were collected. Neurological function was quantified via the Frankel grade and the McCormick score (MCS). The pre- and post-operative Karnofsky performance scores (KPS) were used to assess functional status. Descriptive statistics, univariate analysis, log-rank test, and the Kaplan-Meier survival analysis were performed. A total of 9 patients were included (median age 67 years (range, 26-71); 6 were male). Thoracic and cervical spinal segments were most affected (4 patients each). Six patients (75%) underwent surgical management (1 biopsy and 5 resections), and 3 cases underwent chemoradiation only. Post-operatively, 2 patients had an improvement in their neurological exam with one patient becoming ambulatory after surgery; three patients maintained their neurological exam, and 1 had a decline. There was no statistically significant difference in the pre- and post-operative MCS and median KPS scores in surgically treated patients. Median OS after ISCM diagnosis was 7 months. Absence of brain metastasis, tumor histology (renal and melanoma), cervical/thoracic location, and post-op KPS ≥ 70 showed a trend toward improved overall survival. The incidence of ISCM is increasing, and earlier diagnosis and treatment are considered key for the preservation of neurological function. When patient characteristics are favorable, surgical resection of ISCM can be considered in patients with rapidly progressive neurological deficits. Surgical treatment was not associated with an improvement in overall survival in patients with ISCMs.

Intraoperative Neurophysiologic Monitoring and Mapping During Surgery on Intramedullary Spinal Cord Tumors in Children and Adolescents.

SUMMARY: Surgical resection of intramedullary spinal cord tumors carries significant risks of neurologic deficits, especially in cases of infiltrative tumors. In pediatric patients, this type of surgery may be associated with a high risk of poor neurologic outcome. Intraoperative neurophysiologic monitoring has been adopted as part of the clinical routine by many centers as a useful adjunct for intraoperative assessment of neurologic integrity. To what extent intraoperative neurophysiologic mapping strategies may further support intraoperative decision-making is still a matter of debate. Here, we report on a small cohort of five pediatric patients in whom mapping with the double-train paradigm was used to identify the dorsal column and corticospinal tract and to guide the surgical resection. We also discuss the possible benefits and challenges regarding the available literature.

Complex lumbosacral spinal cord lipomas: A longitudinal study on outcomes from a Singapore children's hospital.

BACKGROUND: Total/near-total resection (TR/NTR) of complex lumbosacral lipomas (CSL) is reported to be associated with better long-term functional outcomes and lower symptomatic re-tethering rates. We report our institutional experience for CSL resection in affected children. METHODS: This is a single-institution, retrospective study. Inclusion criteria consist of patients with CSL with dorsal, transitional and chaotic lipomas based on Pang et al's classification. The study population is divided into 2 groups: asymptomatic patients with a normal preoperative workup referred to as 'prophylactic intent' and 'therapeutic intent' for those with pre-existing neuro-urological symptoms. Primary aims are to review factors that affect post-operative clean intermittent catheterization (CIC), functional outcomes based on Necker functional score (NFS), and re-tethering rates. RESULTS: 122 patients were included from 2000 to 2021. There were 32 dorsal lipomas (26.2 %), 74 transitional lipomas (60.7 %), and 16 chaotic lipomas (13.1 %). 82 % patients achieved TR/NTR. Favourable NFS at 1-year was 48.2 %. The re-tethering rate was 6.6 %. After multivariable analysis, post-operative CIC was associated with median age at surgery (p = 0.026), lipoma type (p = 0.029), conus height (p = 0.048) and prophylactic intent (p < 0.001). Next, extent of lipoma resection (p = 0.012) and the post-operative CSF leak (p = 0.004) were associated with re-tethering. Favourable NFS was associated with lipoma type (p = 0.047) and prophylactic intent surgery (p < 0.001). CONCLUSIONS: Our experience shows that TR/NTR for CSL is a feasible option to prevent functional deterioration and re-tethering. Efforts are needed to work on factors associated with post-operative CIC.

Spinal intramedullary uterine carcinosarcoma metastasis.

Intramedullary spinal cord metastases (ISCM) are a rare and challenging manifestation of metastatic cancer that have devastating impacts on the individual's neurological function, survival expectancy and overall quality of life. Given the rarity and poor prognosis, there is a lack of consensus in management. Uterine carcinosarcoma itself is a rare cancer, accounting for less than 3% of all uterine cancers. It carries a poor prognosis, with only one-third of patients surviving beyond 5 years. There are no previous reports of uterine carcinosarcoma metastases to the spinal cord. Here, we present the case of a woman in her late 70s with a uterine carcinosarcoma intramedullary metastasis that was refractory to radiotherapy treatment and responded favourably to surgical debulking.

Far lateral approach for dumbbell-shaped C1 schwannomas: how I do it.

BACKGROUND: Dumbbell-shaped C1 schwannomas are rare lesions that involve both intra- and extradural compartments. Because of the intimate relationships these lesions develop with the third and fourth segments of the vertebral artery, surgical removal of these lesions remains a challenge. METHOD: We describe the key steps of the far lateral approach for dumbbell-shaped C1 schwannomas with a video illustration. The surgical anatomy is described along with the techniques for protecting the vertebral artery. CONCLUSION: Dumbbell-shaped C1 schwannomas can be safely removed by using the far lateral approach, surgical anatomy expertise, and intraoperative microvascular Doppler.

[Laser fluorescence spectroscopy and navigation in surgical treatment of spinal tumors: a systematic review]. / Primenenie lazernoi flyuorestsentnoi spektroskopii i navigatsii pri khirurgicheskom lechenii opukholei spinnogo mozga i pozvonochnika: sistematicheskii obzor literatury.

The main problem in microsurgical resection of spinal cord tumors is excessive surgical aggression. The last one often leads to unsatisfactory clinical and neurological outcomes. Laser fluorescence spectroscopy is a modern neurosurgical approach to distinguish tumor boundaries even if standard visible fluorescence techniques are ineffective. OBJECTIVE: To evaluate the effectiveness of laser fluorescence spectroscopy alone or in combination with visual 5-ALA fluorescence for improvement of safety and quality of resection, as well as intraoperative diagnosis. MATERIAL AND METHODS: Searching for literature data was carried out in accordance with the PRISMA recommendations. The authors reviewed articles independently of each other. These data were systematized. RESULTS: Laser fluorescence spectroscopy is valuable to identify fragments of intramedullary ependyomas in 86% of cases, while visual fluorescence only in 81% of cases. Advisability of this technique for low-grade astrocytomas is still unclear and requires further study. Its effectiveness is 87.5% for extramedullary meningiomas. Neuromas do not accumulate 5-ALA. In addition, this method can be used to determine the boundaries of intradural metastatic lesions. CONCLUSION: 5-ALA fluorescence is a safe and useful intraoperative method for identifying tumor tissue and resection margins in patients with intramedullary or infiltrative extramedullary spinal cord tumors. Visual fluorescence combined with laser spectroscopy is a perspective method for intraoperative visualization of tumor remnants. This approach can improve safety and postoperative outcomes while maintaining resection quality.

Digital 3D Exoscope is Safe and Effective in Surgery for Intradural Extramedullary Tumors: A Comparative Series.

BACKGROUND: Digital 3D exoscopes have been shown to be comparably safe and effective as surgical microscopes in complex microneurosurgical procedures. However, the results of exoscopic spinal tumor surgeries are scarce. The purpose of this study is to compare results of a transition from microscope to exoscope in surgeries for spinal intradural extramedullary tumors. METHODS: We included all consecutive patients with intradural extramedullary spinal tumors operated on by the senior author during January 2016 to October 2023. The 3D exoscope was used in the latter half of the series from November 2020. We evaluated pre- and postoperative clinical findings, imaging studies, intra- and postoperative events, and analyzed surgical videos from the operations retrospectively. RESULTS: We operated 35 patients (exoscope n = 19, microscope n = 16) for intradural extramedullary tumors (meningioma n = 18, schwannoma n = 12, other n = 5). Tumors in the cervical and thoracic spine were more common than in the lumbar region. The duration of surgery was slightly longer (median 220 vs. 185 minutes) in the exoscope group. However, the rate of gross total resection of the tumor was higher (81% vs. 67%) and the tumors more often located anteriorly to the spinal cord (42% vs. 13%) in the exoscope group. No major complications (i.e., permanent motor deficit or postoperative hematoma) occurred in either group. We saw postoperative gait improvement in 81% and 85% of the patients with preoperative deterioration of gait after exoscopic and microscopic surgeries, respectively. CONCLUSIONS: This study demonstrates that exoscope-assisted surgery for spinal intradural extramedullary tumors is comparable in safety and effectiveness to traditional microscopic surgery.

Intraoperative High-Resolution Color-Coded Ultrasound to Identify the Posterior Median Sulcus for Midline Myelotomy in Intramedullary Spinal Cord Surgery.

A 14-year-old boy presented with a 2-year history of slowly increasing weakness and atrophy in the right forearm and leg. Magnetic resonance imaging (MRI) revealed an intramedullary diffusely infiltrating lateralized tumor at C3-7. An extended biopsy was planned. After laminotomy and durotomy, the swollen spinal cord was noted to be rotated by 45° with the right dorsal root entry zone being in the midline. A 15 MHz linear ultrasound probe was used to identify the midline by visualizing the dorsal median sulcal vein within the midline raphe. A myelotomy was made in that zone without deterioration of somatosensory evoked potentials (SEPs) and an extended biopsy was performed. Histological examination revealed a pilocytic astrocytoma. Modern intraoperative high-resolution color-coded ultrasound enables the identification of the midline in intramedullary spinal cord lesions even when the spinal cord anatomy is distorted.

Intramedullary spinal capillary hemangioma with secondary neurulation defect in children.

Intramedullary spinal capillary hemangioma is a rare occurrence in pediatric patients, and only limited cases have been reported. This study presents the first two cases of spinal capillary hemangioma co-present with retained medullary cord and one case of spinal capillary hemangioma with lumbosacral lipomatous malformation. Previous literature on ten patients with this pathology was reviewed. We speculated pathogenesis, imaging features, and histopathologic findings of the disease.

Resection of an Intradural Intramedullary C7-T1 Tumor: Technical Nuances and Complication Management.

Primary spinal cord tumors are relatively rare, comprising approximately 4%-16% of all tumors originating from the central nervous system. These tumors are anatomically separable into 2 broad categories: intradural intramedullary and intradural extramedullary. Intramedullary tumors are composed predominantly of gliomas (infiltrative astrocytoma) and ependymomas.1-4 The primary treatment approach for these tumors is surgical resection, aiming to preserve neurologic function.5-9 In Video 1, the authors showcase a step-by-step approach for microsurgical resection of a primary spinal ependymoma, with emphasis on microsurgical technique and utility of adjunct equipment, such as intraoperative ultrasound and neuromonitoring.10,11 The patient consented to the procedure.

Does Preoperative Bilsky Score Predict Outcome Following Surgical Resection of Primary Tumors of the Spine?

OBJECTIVE: In patients undergoing surgery for primary bone tumors of the spine, we sought to compare Bilsky score 0-1 versus 2-3 in: 1) preoperative presentation, 2) perioperative variables, and 3) long-term outcomes. METHODS: A single-center, retrospective cohort study was undertaken of patients undergoing surgery for extradural, primary bone tumors of the spine between January 2010 and January 2021. The primary exposure variable was Bilsky score, dichotomized as 0-1 versus 2-3. Survival analysis was performed to assess local recurrence (LR) and overall survival (OS). RESULTS: Of 38 patients undergoing resection of primary spinal tumors, 19 (50.0%) patients presented with Bilsky 0-1 and 19 (50.0%) Bilsky 2-3 grades. The most common diagnosis was chondrosarcoma (33.3%), followed by chordoma (16.7%). There were 15 (62.5%) malignant tumors. Preoperatively, there was no significant difference in demographics, Karnofsky Performance Scale (KPS) (P > 0.999), or motor deficit (P > 0.999). Perioperatively, no difference was found in operative time (P = 0.954), blood loss (P = 0.416), length of stay (P = 0.641), neurologic deficit (P > 0.999), or discharge disposition (P = 0.256). No difference was found in Enneking resection status (69.2% vs. 54.5%, P = 0.675). Long-term, no differences were found regarding reoperation (P = 0.327), neurologic deficit (P > 0.999), postoperative KPS (P = 0.605) and modified McCormick Scale (MMS) (P = 0.870). No difference was observed in KPS (P = 0.418) and MMS (P = 0.870) at last follow-up. However, patients with Bilsky 2-3 had shorter time to LR (1715.0 vs. 513.0 ± 633.4 days, log-rank; P = 0.002) and shorter OS (2025.0 ± 1165.3 vs. 794.0 ± 952.6 days, log-rank; P = 0.002). CONCLUSIONS: Bilsky 2-3 lesions were associated with shorter time to LR and shorter OS. Patients harboring primary spinal tumors with higher grade Bilsky score appear to be at a higher risk for worse outcomes.

Upstream Effects: Intraoperative Migration of Intradural Extramedullary Tumor After Non-Adjacent Level Stenosis Decompression.

A 74-year-old man with back pain, foot numbness, and hip/thigh radiculopathy was found to have an L1-L2 intradural extramedullary neoplasm and severe L4-L5 stenosis. L4-L5 minimally invasive laminectomy for decompression and concomitant L1-L2 minimally invasive laminectomy for tumor resection were planned. L4-L5 laminectomy was completed first followed by the L1-L2 laminectomy. On extensive intradural exploration at L1-L2, no neoplasm was found. Immediate postoperative imaging showed that the intradural extramedullary tumor had migrated caudally by nearly a complete spinal level, presumably due to changes in cerebrospinal fluid pressure and resultant shift in intradural contents after the L4-L5 laminectomy. Successful resection of the intradural extramedullary tumor was performed, with improvement in the patient's symptoms.

Intraoperative mixed-reality spinal neuronavigation system: a novel navigation technique for spinal intradural pathologies.

OBJECTIVE: The objective of this study was to assess the intraoperative accuracy and feasibility of 3D-printed marker-based mixed-reality neurosurgical navigation for spinal intradural pathologies. METHODS: The authors produced 3D segmentations of spinal intradural tumors with neighboring structures by using combined CT and MRI, and preoperative registration of pathology and markers was successfully performed. A patient-specific, surgeon-facilitated application for mobile devices was built, and a mixed-reality light detection and ranging (LIDAR) camera on a mobile device was employed for cost-effective, high-accuracy spinal neuronavigation. RESULTS: Mobile device LIDAR cameras can successfully overlay images of virtual tumor segmentations according to the position of a 3D-printed marker. The surgeon can visualize and manipulate 3D segmentations of the pathology intraoperatively in 3D. CONCLUSIONS: A 3D-printed marker-based mixed-reality spinal neuronavigation technique was performed in spinal intradural pathology procedures and has potential to be clinically feasible and easy to use for surgeons, as well as being time saving, cost-effective, and highly precise for spinal surgical procedures.

Giant Myxopapillary Ependymoma with Multi-Site Neural Axis Metastases: A Rare Case with Suboptimal Outcome.

BACKGROUND Myxopapillary ependymoma is a rare type of slow-growing tumor that mainly occurs in the spinal cord, particularly in the region of the conus medullaris and the cauda equina. It originates from the ependymal glial cells found in the filum terminale. CASE REPORT We present a clinical case of a 44-year-old male patient who presented with symptoms of non-specific pain in the lower back persisting for the past 2 years. He did not report any specific neurological deficits or radicular symptoms. Unenhanced MRI of the lumbar spine showed a giant intradural, extramedullary, heterogenous, expansive tumor at the level L1-S4 with erosion of the sacral bone and invasion of presacral tissue. Based on its characteristic localization and growth pattern, suspicion arose for myxopapillary ependymoma. Biopsy confirmed the initial diagnosis. Partial resection of the tumor with laminectomy and laminoplasty was deemed necessary. Preoperative neural axis MRI showed contrast-enhancing lesions in the cerebellum and the cervical and thoracic spine; therefore, adjuvant radiation therapy was administered. Following the surgery, the patient experienced intermittent episodes of neurological deficits and required physiotherapy. Control MRI a year after the operation showed tumor growth and more metastases along the neural axis. CONCLUSIONS Complete surgical excision of the tumor is the preferred treatment approach, but there is a risk of recurrence even after total excision, so radiotherapy is recommended to minimize the risk of recurrence. Prior to surgery, it is essential to conduct MRI/PET/CT of the head and spine to assess the possibility of metastases.

Development of a novel prediction model for differential diagnosis between spinal myxopapillary ependymoma and schwannoma.

Spinal myxopapillary ependymoma (MPE) and schwannoma represent clinically distinct intradural extramedullary tumors, albeit with shared and overlapping magnetic resonance imaging (MRI) characteristics. We aimed to identify significant MRI features that can differentiate between MPE and schwannoma and develop a novel prediction model using these features. In this study, 77 patients with MPE (n = 24) or schwannoma (n = 53) who underwent preoperative MRI and surgical removal between January 2012 and December 2022 were included. MRI features, including intratumoral T2 dark signals, subarachnoid hemorrhage (SAH), leptomeningeal seeding, and enhancement patterns, were analyzed. Logistic regression analysis was conducted to distinguish between MPE and schwannomas based on MRI parameters, and a prediction model was developed using significant MRI parameters. The model was validated internally using a stratified tenfold cross-validation. The area under the curve (AUC) was calculated based on the receiver operating characteristic curve analysis. MPEs had a significantly larger mean size (p = 0.0035), higher frequency of intratumoral T2 dark signals (p = 0.0021), associated SAH (p = 0.0377), and leptomeningeal seeding (p = 0.0377). Focal and diffuse heterogeneous enhancement patterns were significantly more common in MPEs (p = 0.0049 and 0.0038, respectively). Multivariable analyses showed that intratumoral T2 dark signal (p = 0.0439) and focal (p = 0.0029) and diffuse enhancement patterns (p = 0.0398) were independent factors. The prediction model showed an AUC of 0.9204 (95% CI 0.8532-0.9876) and the average AUC for internal validation was 0.9210 (95% CI 0.9160-0.9270). MRI provides useful data for differentiating spinal MPEs from schwannomas. The prediction model developed based on the MRI features demonstrated excellent discriminatory performance.

Differentiation between Anterior and Posterior Roots Using Compound Muscle Action Potential in Intradural Extramedullary Spinal Tumor Surgery.

This study aims to determine the cutoff values for the compound muscle action potential (CMAP) stimulus in anatomically identified anterior (motor nerve) and posterior roots (sensory nerve) during cervical intradural extramedullary tumor surgery. The connection between CMAP data from nerve roots and postoperative neurological symptoms in thoracolumbar tumors was compared with data from cervical lesions. The participants of the study included 22 patients with intradural extramedullary spinal tumors (116 nerve roots). The lowest stimulation intensity to the nerve root at which muscle contraction occurs was defined as the minimal activation intensity (MAI) in the CMAP. In cervical tumors, the MAI was measured after differentiating between the anterior and posterior roots based on the anatomical placement of the dentate ligament and nerve roots. The MAIs for 20 anterior roots in eight cervical tumors were between 0.1 and 0.3 mA, whereas those for 19 posterior roots were between 0.4 and 2.0 mA. The cutoff was <0.4 mA for both the anterior and posterior roots, and sensitivity and specificity were both 100%. In thoracolumbar tumors, the nerve root was severed in 12 of 14 cases. All MAIs were determined to be at the dorsal roots as their scores were higher than the cutoff and did not indicate motor deficits. The MAIs of the anatomically identified anterior and posterior root CMAPs were found to have a cutoff value of <0.4 mA in the cervical lesions. Similar MAI cutoffs were also applicable to thoracolumbar lesions. Thus, CMAP may be useful in detecting anterior and posterior roots in spinal tumor surgery.

Treatment of intramedullary spinal cord tumors: a modified Delphi technique of the North American Spine Society Section of Spine Oncology.

OBJECTIVE: Intramedullary spinal cord tumors (IMSCTs) are rare tumors with heterogeneous presentations and natural histories that complicate their management. Standardized guidelines are lacking on when to surgically intervene and the appropriate aggressiveness of resection, especially given the risk of new neurological deficits following resection of infiltrative tumors. Here, the authors present the results of a modified Delphi method using input from surgeons experienced with IMSCT removal to construct a framework for the operative management of IMSCTs based on the clinical, radiographic, and tumor-specific characteristics. METHODS: A modified Delphi technique was conducted using a group of 14 neurosurgeons experienced in IMSCT resection. Three rounds of written correspondence, surveys, and videoconferencing were carried out. Participants were queried about clinical and radiographic criteria used to determine operative candidacy and guide decision-making. Members then completed a final survey indicating their choice of observation or surgery, choice of resection strategy, and decision to perform duraplasty, in response to a set of patient- and tumor-specific characteristics. Consensus was defined as ≥ 80% agreement, while responses with 70%-79% agreement were defined as agreement. RESULTS: Thirty-six total characteristics were assessed. There was consensus favoring surgical intervention for patients with new-onset myelopathy (86% agreement), chronic myelopathy (86%), or progression from mild to disabling numbness (86%), but disagreement for patients with mild numbness or chronic paraplegia. Age was not a determinant of operative candidacy except among frail patients, who were deemed more suitable for observation (93%). Well-circumscribed (93%) or posteriorly located tumors reaching the surface (86%) were consensus surgical lesions, and participants agreed that the presence of syringomyelia (71%) and peritumoral T2 signal change (79%) were favorable indications for surgery. There was consensus that complete loss of transcranial motor evoked potentials with a 50% decrease in the D-wave amplitude should halt further resection (93%). Preoperative symptoms seldom influenced choice of resection strategy, while a distinct cleavage plane (100%) or visible tumor-cord margins (100%) strongly favored gross-total resection. CONCLUSIONS: The authors present a modified Delphi technique highlighting areas of consensus and agreement regarding surgical management of IMSCTs. Although not intended as a substitute for individual clinical decision-making, the results can help guide care of these patients. Additionally, areas of controversy meriting further investigation are highlighted.