Intramedullary Spinal Tumors Research Articles

Spinal perimedullary vein enlargement sign: an added value for the differentiation between intradural-extramedullary and intramedullary tumors on magnetic resonance imaging

The purpose of this study was to determine the added value of the perimedullary spinal vein enlargement sign on magnetic resonance imaging (MRI) in distinguishing intradural-extramedullary tumors (IDEMTs) from intramedullary spinal tumors (IMTs). Two hundred and eight consecutive spinal intradural tumors with histopathologic confirmation (21 IMTs, 187 IDEMTs) were enrolled. Two readers blinded to the final pathological diagnosis and clinical data independently assessed the venous enlargement sign to determine the agreement between them and jointly distinguished IDEMTs from IMTs according to the common MRI findings. Sensitivity, specificity, and accuracy for the diagnosis of IDEMTs were calculated for the common MRI findings, vein enlargement sign, and a combination of both. Intraobserver agreement and interobserver agreement for both readers was excellent. The sensitivity, specificity, and accuracy of common MRI findings for differentiating IDEMTs from IMTs were 83.4, 95.2, and 89.3%, respectively. Thirty-one IDEMTs were mistakenly diagnosed as IMTs, in which seven were cases with vein enlargement signs. By applying the vein enlargement sign to the common MRI findings, the specificity remained at 95.2%, while the sensitivity improved to 89.3% and the accuracy increased to 92.3%. The spinal perimedullary vein enlargement sign is useful in assessing intradural tumors and to differentiate IDEMTs from IMTs.

Gender-specific growth dynamics of neurofibromatosis type-2-related tumors of the central nervous system.

To date, few studies have been published about the growth dynamics of tumors associated with neurofibromatosis type-2 (NF2), none of which evaluated gender-specific differences. Our aim was to compare radiographic data of female and male patients with NF2. MR images of 40 patients (20 female, 20 male) from the regional NF2 referral center were included in this analysis. Tumor sizes were determined by semi-automated volumetric measurement. Intracranial tumors were measured on post-contrast T1-weighted MRI datasets and volumes of intramedullary spinal tumors were determined from sagittal T2-weighted MRI datasets. The median follow-up time was 91months (range, 16-199months) per patient. Intracranial tumors: On average, female patients had 13.4 neoplasms, while male patients had 6.75 (p = 0.042). The overall median time to tumor progression of ≥20% was 20months for females and 18months for males. Tumors of the cerebellopontine angle (CPA) that had undergone previous surgery had shorter progression-free intervals in females than in males (16 and 24months, respectively; p = 0.012). The median 1-year growth rate was 17.5 ± 44.6% in females compared to 12.5 ± 44.9% in males (p = 0.625). Intramedullary spinal tumors: On average, females had 2.05 tumors and males had 1.75 tumors (p = 0.721). Median time to tumor progression was 21months in females and 44months in males (p = 0.204). After 2years, the median growth rate was 24.4 ± 56.8% in female and 13.5 ± 40.4% in male patients (p = 0.813). The radiographic data in this study suggest that female patients are affected by a greater number of tumors than male patients and that post-surgery tumors of the CPA grow faster in females than in males.

Growth dynamics of intramedullary spinal tumors in patients with neurofibromatosis type 2

ObjectivesVolumetric data on the natural growth of intramedullary tumors in patients with neurofibromatosis type 2 (NF2) are rare, but crucial for long-term disease monitoring. Our aim was to evaluate the growth rates and growth patterns of these tumors. Patients and methodsPatient records from the regional neurofibromatosis referral center were evaluated for inclusion in this analysis. Magnetic resonance images of the spine were collected and digitized as necessary. Tumor volumes were determined by volumetric extrapolation after segmentation in datasets (iPlan Net software, BrainLAB, Munich) if the tumors met the following inclusion criteria: sagittal T2-weighted MRI scans had to be available from at least two investigations and tumors had to be visible on at least two slices. All tumors that had undergone previous therapy, such as surgery, radiation or bevacizumab treatment were excluded from this study. ResultsSuitable MR images of the spine were available from 51 patients (20 males, 31 females) with NF2. The median follow-up time per patient was 54 months (range 0–190 months). 23 patients (15 females, 11 males) of the 51 patients with spinal imaging harbored intramedullary tumors. Across this cohort, there was an aggregate of 68 tumors at baseline. Over the course of follow-up, the patients developed 19 additional tumors, resulting in a total of 87 tumors. A final set of 42 tumors from 19 patients met the inclusion criteria and was included in the growth analysis. The median follow-up time per tumor was 44 months (range 9–122 months). 23 of the tumors were located in the cervical spine; 19 of them were located in the thoracic spine. The median tumor size±standard deviation (SD) after 5 years was 136±71.0% compared to baseline. The median time to ≥20% tumor growth was 24 months. Overall, 30 tumors (71.4%) grew, 8 (19.1%) remained stable and 4 (9.52%) decreased in size. The most common growth pattern was saltatory growth. ConclusionIntramedullary spinal cord tumors are present in about half of patients with NF2. The majority of these tumors grow over time, albeit slowly. Given the confines of the spinal medulla and the limited scope for functional recovery after symptomatic tumor expansion, NF2 patients should be under continual surveillance in order to rapidly identify intramedullary spinal tumors that may require microsurgical resection.

Intramedullary ependymoma: Microsurgical resection technique

Spinal ependymomas are predominantly slow-growing lesions constituting approximately 30–88% of primary spinal intramedullary tumors. They usually present as circumscribed lesions, with regular margins and a clear surgical plane. Gross-total resection is often feasible and potentially curative but neurosurgeons should keep in mind that the ultimate goal of surgery is the preservation of spinal cord function. We present the surgical technique to safely resect an intramedullary ependymoma using a posterior median sulcus approach. A brief description of current management of this pathology is also presented.

Intramedullary hemangioblastoma: Microsurgical resection technique

Spinal hemangioblastomas are benign and highly vascular tumors accounting for 1–5% of intramedullary spinal tumors in surgical series. Surgery is curative in sporadic cases. We present the description of a surgical technique to safely resect an intramedullary hemangioblastoma. A dorsal midline myelotomy provides an excellent exposure of the tumor and identification of the feeding arteries. Interruption of these arteries and precise dissection of the tumor from the cord tissue followed by division of the venous drainage allow the in toto excision of the tumor. Closure of the dorsal myelotomy may be achieved with sequential fusion of the pial and arachnoid edges using a “welding” technique.

Findings from frozen sections of spinal subependymomas: Is it possible to differentiate this diagnosis from other common spinal tumors?

Subependymomas are slow-growing, benign neoplasms that are rarely found in the spinal cord. Because of the differences in the treatment plans, it might be very helpful for neurosurgeons to intraoperatively establish a diagnosis of spinal subependymoma, differentiated from other spinal intramedullary tumors. In this study, we analyzed frozen sections of spinal subependymomas to identify potential histological clues of spinal subependymomas to differentiate them from tumors that mimic spinal subependymoma. We reviewed the frozen sections and the corresponding permanent slides for 7 cases of spinal subependymoma. The spinal subependymomas showed several characteristic patterns, including, most importantly, an eccentric or both central and eccentric location in the axial plane. Histologically, they showed a (1) well-demarcated and multinodular mass with (2) low or moderate cellularity, (3) a microlobular pattern, and (4) small clusters of neoplastic cells. These features appear to be very specific to spinal subependymomas and could help differentiate them from ependymomas or astrocytomas. Although we might not be able to provide an exact diagnosis of all spinal subependymomas using these histological features, we hope that they help neuropathologists and neurosurgeons to adequately diagnose and treat spinal subependymomas.

Microsurgical resection of intramedullary spinal cord tumors: clinical efficacy and the medium- and long-term follow-up outcomes

Objective To investigate the operation strategies and clinical prognosis of the different pathological types of intramedullary tumors. Methods The clinical data of 178 patients with intramedullary tumor whose tumors were resected by microsurgery under the neural electrophysiological assistance at the Department of Neurosurgery, Tianjin Medical University General Hospital from June 2000 to August 2013 were analyzed retrospectively. Klekamp-Samii (KS) score was used to evaluate the spinal cord function before and after procedure. The follow-up time ≥18 months and surgical resection and recurrence in the patients with different pathological types were evaluated. Results In 178 patients, the symptoms of 142 were improved at 6 months after procedure, 28 did not have any change, and 8 aggravated. In addition astrocytoma, the KS scores of spinal cord function of other types of tumors at six months after surgery were improved significantly compared with before surgery. There was significant difference (P<0.05). The follow-up time of 157 patients were ≥18 months (18 to 78 months, mean 46.6±5.4 months). In 157 patients, 95 were resected totally, 1 (1.1%) had recurrence, 44 were nearly resected totally, and 5 (11.4%) had recurrence; 18 were resected partially and 17 (94.4%) had recurrence. Sixty-eight of them had ependymoma and 68 were resected totally, and none of them had recurrence. Nineteen patients had astrocytoma, 5 were resected totally, and one had recurrence; 14 were resected partially and all had recurrence; 19 had lipoma, 17 were nearly resected totally, and none of them had recurrence; 2 were resected partially and all had recurrence. A total of 22 patients had hemangioblastoma, cavernous hemangioma, hemangioma, hemangiopericytoma, and intestinal cyst, all were resected totally, none of them had recurrence; 15 had epidermoid cyst, all were nearly resected totally, and 3 had recurrence; 14 had dermoid cyst, 12 were nearly resected totally, and 2 had recurrence; 2 were resected partially and one had recurrence. Conclusions Micrographic surgery is safe and effective for the treatment of intramedullary spinal cord tumors. The histological types of the tumors and the range of tumor resection are the important reasons for the decision of the medium- and long-term efficacy. Key words: Spinal cord neoplasms; Microsurgery; Pathology, surgical; Follow-up studies

Recurrence rates and functional outcome after resection of intrinsic intramedullary tumors

IntroductionIntramedullary tumors account for 2–4% of all CNS neoplasms. Surgical resection is challenging because of aggravated neurological impairment in up to 64% of patients. We analyzed a consecutive series of patients with intramedullary tumors and focused on the extent of resection, functional outcome, and tumor recurrence. Methods53 patients (23 women and 30 men; mean age 46.3 years) were included who had undergone microsurgical resection for intramedullary spinal tumors. We reviewed the patient records for tumor size, edema, intratumoral hemorrhage, consistency, midline detection, resection method, extent of resection, histopathology, and recurrence. Outcome was measured by the Karnofsky Score (KPI), the McCormick score (MCS), and the Medical Research Council Neurological Performance Score (MRC-NPS). ResultsThe most frequent diagnosis was ependymoma (37.7%), lymphoma (13.2%) and astrocytoma (11.3%). The majority of tumors were located in the thoracic spine (62.2%). Gross total resection was achieved in 73.6% and most successful in patients with ependymal histology (p<0.01). Tumor recurrence – observed in 11.3% – was significantly associated with age >65 years, astrocytic histology, higher tumor grades, and higher Ki-67 labeling. At follow-up, MCS and MRC-NPS showed significantly better results than prior to resection (p<0.001), and pain and sensory deficits had improved in 67.9% and 64.2% of patients, respectively. Microsurgical resection improved the neurological status significantly. Pain and sensory deficits showed higher improvement rates than paresis and vegetative dysfunction. ConclusionOur data help identify patients at risk of tumor recurrence and classify the course of postoperative neurological performance.

Surgical management of spinal intramedullary tumors: radical and safe strategy for benign tumors.

Surgery for spinal intramedullary tumors remains one of the major challenges for neurosurgeons, due to their relative infrequency, unknown natural history, and surgical difficulty. We are sure that safe and precise resection of spinal intramedullary tumors, particularly encapsulated benign tumors, can result in acceptable or satisfactory postoperative outcomes. General surgical concepts and strategies, technical consideration, and functional outcomes after surgery are discussed with illustrative cases of spinal intramedullary benign tumors such as ependymoma, cavernous malformation, and hemangioblastoma. Selection of a posterior median sulcus, posterolateral sulcus, or direct transpial approach was determined based on the preoperative imaging diagnosis and careful inspection of the spinal cord surface. Tumor-cord interface was meticulously delineated in cases of benign encapsulated tumors. Our retrospective functional analysis of 24 consecutive cases of spinal intramedullary ependymoma followed for at least 6 months postoperatively demonstrated a mean grade on the modified McCormick functional schema of 1.8 before surgery, deteriorating significantly to 2.6 early after surgery (< 1 month after surgery), and finally returning to 1.7 in the late postoperative period (> 6 months after surgery). The risk of functional deterioration after surgery should be taken into serious consideration. Functional deterioration after surgery, including neuropathic pain even long after surgery, significantly affects patient quality of life. Better balance between tumor control and functional preservation can be achieved not only by the surgical technique or expertise, but also by intraoperative neurophysiological monitoring, vascular image guidance, and postoperative supportive care. Quality of life after surgery should inarguably be given top priority.

脊髄腫瘍・脊髄血管障害に対する手術治療

脊髄腫瘍・脊髄血管障害に対する手術治療

42. Multimodality intraoperative neurophysiologic monitoring in spondilotic myelopathy

Cervico/dorsal spondilotyc myelopathy (CDSM) is the most frequent spinal disorder encountered in people aged >55 years. Although CDSM is frequently scheduled for multimodal intraoperative monitoring (MIOM), it is not completely clarified the rate of monitorability and intraoperative modification. We retrospectively reviewed the data from 361 consecutive spinal surgeries (213 CDSM, 35 intramedullary spinal cort tumors – IMSCT – and 113 extranedullary spinal cord tumors – EMSCT) in whom 4 lower limbs Motor Evoked Potentials (ll-MEPs) and posterior tibial nerve somatosensory evoked potential (ptn-SEPs) were studied. Patients were clinically classified according the MacKormick scale. The overall monitorability was 96.4% (IMSCT = 97.1%, EMSCT = 99.1%, CDSM = 94.8%). ptn-SEPs were absent or unilaterally present in 16.9% of the whole casistic (20% of IMSCT, 9.7% of EMSCT and 20.2% of CDSM); globally, ll-MEPs were absent or unilaterally recordable in 15.2% (11.4% of IMSCT, 4.4% of EMSCT and 21.6% of CDSM). The rate of postoperative worsening was higher in patients with T2 signal abnormality on preoperative MR images. Spondilotic myelopathy is the worst “scenario” for the intraoperative neurophysiologist.

Pediatric intramedullary spinal cord tumors: A single center experience

AimTo evaluate clinical and radiological findings, pathological features and treatment modalities in pediatric patients with intramedullary spinal cord tumors. Patients and methodsThe medical records of 36 patients with intramedullary spinal tumors were reviewed for clinical, radiological and histopathological data, chemotherapy, radiotherapy, surgical resection, treatment responses, events, and final outcome. Survival analyses were performed. ResultsThe median age was 7.9 years (range: 1–16 years; male/female ratio:1.4). Majority of the tumors were histopathologically diagnosed as astrocytomas (n = 16, 44.4%) and ependymomas (n = 19, 52.8%); whereas one was unclassified glioma. Overall, 94% of the astrocytomas and 84% of the ependymomas were low-grade, only three tumors were high-grade. In one patient with ependymoma, histopathological grade was undetermined. The primary tumor was commonly located in thoracic (47%) and cervical segments (28%). All patients had undergone surgery (gross-total resection, 33%; subtotal resection, 45%; biopsy, 22%). Radiotherapy was administered to 26 patients (72%) and chemotherapy to 15 patients (42%). The 3-, 5- and 10-year overall survival rates were 72%, 63% and 56%, respectively; and event-free survival rates were 43%, 40% and 40%. Survival did not significantly differ with gender, age groups, lag-time, neurologic status, histopathological tumor type, tumor location, extent of resection, treatment, or treatment responses in univariate survival analyses. Survival rates were significantly higher in patients with low-grade tumors and in ependymoma patients with resected tumors. ConclusionsPatients with low-grade tumors and those who underwent gross-total tumor resection had better prognosis. Surgery remains the main treatment in intramedullary spinal tumors. The role of radiotherapy and chemotherapy is limited and even controversial in low-grade tumors.

Progressive Quadriplegia from Kyposis in Pediatric Patient after Laminectomy for Cervical Intramedullary Tumor Excision: Case Report and Literature Review in Short

Cervical spinal deformities with progressive neurological deficit after laminectomy is relatively uncommon. But, it can happen more commonly after resection of intramedullary spinal cord lesions than other spinal lesion. Postlaminectomy cervical spinal deformity is most common in children with an immature skeletal system. Many factors such as the extent of laminectomy and facetectomy, number of laminae removed, location of laminectomy, preoperative loss of lordosis, postoperative radiation therapy, etc. can precipitate such deformities. We report a pediatric patient with who underwent successful complete removal of long segment cervical intramedullary spinal tumor. Postoperatively he developed progressive kyphosis in cervical spine with progressive neurological deficit. We went for second operation (anterior cervical spinal cord decompression by two segments corpectomy followed by iliac crest strut graft fusion and stabilization). Postoperatively patient recovered well. He had loss of cervical spinal lordosis with mild kyphosis before first operation. Such a case report in the literature is relatively uncommon. Here, we also go for short review of literature on this topic.

An uncommon intramedullary tumor: primary spinal cord melanoma.

A 47-year-old woman was admitted with complaints of progressive weakness in the lower extremities and pain in the back and left leg. Thoracic magnetic resonance imaging (MRI) revealed a spinal intramedullary tumor between the T9 and L1 levels, which were iso- to hypointense on T2 and slightly hyperintense on T1-weighted images. The tumor was resected as total, and the diagnosis was malignant melanoma confirmed with histopathology. Neurological findings improved at the postoperative period and no residual or recurrence was noted on postoperative MRI at the 9-month follow-up. Primary melanoma of the spinal cord, particularly intramedullar localization, is seldomly reported in the literature. We report a primary malignant melanoma of the spinal cord and emphasize the diagnostic and prognostic challenges.

Primary Spinal Neurocytoma Involving the Medulla Oblongata: Two Case Reports and a Literature Review

Central neurocytoma is a rare neuroectodermal tumor found in young adults. These tumors are generally located in the lateral or third ventricles. Extraventricular neurocytoma in the spinal cord is extremely rare. We report on two patients with primary spinal neurocytomas who presented with progressive numbness and weakness in the limbs. Both patients had intramedullary masses between the medulla and the upper thoracic levels. The clinical, radiological, surgical, and pathological features of this abnormality are discussed, and all 20 reported cases were reviewed. In conclusion, neurocytoma should be included in the differential diagnosis of a spinal intramedullary tumor, and subtotal resection is acceptable for a relatively favorable prognosis if gross total removal is unachievable. The efficacy of adjuvant radiochemotherapy to control tumor recurrence is unknown.

Intramedullary Spinal Cord Neoplasia in 53 Dogs (1990–2010): Distribution, Clinicopathologic Characteristics, and Clinical Behavior

Intramedullary neoplasms of the canine spinal cord are infrequently reported. To describe distribution, clinicopathologic characteristics, radiographic findings, and clinical features of canine intramedullary spinal tumors. Retrospective series of histologically confirmed canine intramedullary spinal tumors. Contingency tables were generated for categorical variables (breed, sex, treatment, pain, chief complaint, localization, histology, imaging, and site). Associations were assessed by Fisher's exact, Wilcoxon rank sum test, t-test, and one-way ANOVA. Intramedullary spinal cord tumors comprised 16% (53/331) of all tumors of the spinal cord. Primary tumors were diagnosed in 66% (35/53) of cases, with neuroepithelial-origin tumors comprising 51% (18/35) of all primary neoplasms. Intraparenchymal metastases of transitional cell carcinoma and hemangiosarcoma accounted for 66% (6/18 each) of all secondary tumors. Primary tumors were more likely to affect younger dogs. Dogs with intramedullary metastases were most commonly presented for primary myelopathic signs (8/18, 44%). The majority of all tumors (52.8%) occurred in the T3-L3 spinal cord segments. All dogs with cervical neurolocalization had primary tumors. Dogs with metastatic lesions had a shorter duration of clinical signs before presentation, but there was no difference in survival time between dogs with primary as compared with secondary tumors. Intramedullary spinal cord tumors are uncommon. Primary intramedullary spinal cord tumors are more common than secondary intramedullary spinal cord tumors and tend to occur in the cervical spinal cord of younger dogs. Intramedullary metastases occur in older dogs, are rarely asymptomatic, and neurologic dysfunction is a common clinical presentation. Dogs with primary tumors may have a protracted clinical course compared with those with intramedullary metastases.

Osteotomy for Laminoplasty without Soft Tissue Penetration, Performed Using a Harmonic Bone Scalpel: Instrumentation and Technique

Laminoplasty in the case of intramedullary spinal tumor requires care to avoid neurologic injury. The harmonic bone scalpel provides a method of laminoplasty that can be done safely and quickly for this and other indications. Five cases are presented, each of which required operative intervention, namely laminoplasty. The pathologies presented are one cervical intramedullary tumor, one thoracic intramedullary spinal mass, one lumbar extramedullary intradural tumor, and two cases of multiple lower brachial plexus nerve root avulsions requiring dorsal root entry zone (DREZ) lesion. These five patients underwent laminoplasty for either tumor resection or DREZ lesion. The laminotomies were performed using the BoneScalpel™ (Misonix Inc., Farmingdale, NY, USA), which is a harmonic bone scalpel instrument. This obviated the need to place any instrument under the intact lamina. Kerrison punches and various instruments were still used, but for purposes other than the bony removal of the laminoplasty. These cases demonstrate that the BoneScalpel™ can be used to facilitate the laminar cuts while still allowing a safe and effective operation, even in cases as delicate as an intramedullary thoracic spinal cord tumor. The mechanism of action of the harmonic bone scalpel allows osteotomies without cutting or penetrating soft tissue and also leaves minimal bony defect.

Paediatric spinal glioblastoma: case report and review of therapeutic strategies

Although uncommon, there is significant morbidity and mortality associated with paediatric spinal glioblastoma. The paucity of cases makes treatment options difficult. The current recommended standard of care is biopsy followed by adjuvant chemo-radiotherapy, with emerging data supporting the role of safe gross total resection. The purpose of this paper is to provide a single-institution case study and to discuss current and future therapeutic treatment strategies. A 14-year-old boy presented with a 2-year history of intermittent back pain with recent progressively worsening motor and sensory deficits of the right side. Pre-operative MRI revealed an enhancing intra-medullary tumour extending from C2 to C7. During the operative case, no tumour-cord margin could be identified, and the patient underwent a subtotal excision. Histopathology confirmed glioblastoma. In the subsequent weeks, the patient's clinical condition deteriorated. Adjuvant therapy was declined by the family, and the patient died 9weeks after initial presentation. Despite major advances in surgical techniques, peri-operative neuro-imaging as well as chemo-radiotherapy, the prognosis of a paediatric intra-medullary high-grade spinal tumour remains poor. Detailed analysis of our understanding of tumour dynamics in this patient group is important in establishing future therapeutic strategies.

Posterolateral Sulcus Approach for Spinal Intramedullary Tumor of Lateral Location: Technical Note

Posterolateral sulcus (PLS) approach of the spinal cord, being equivalent to the dorsal root entry zone myelotomy, may offer the satisfactory exposure of the spinal intramedullary tumor if applied appropriately. Eight consecutive patients with spinal intramedullary tumors of lateral location underwent the surgery of PLS approach in our institute. There were 6 male and 2 female patients, ranging in age from 34 to 72 years (mean, 57 years). PLS approach was indicated for the intramedullary tumor situated laterally in the spinal cord and that do not contact the posterior or lateral surfaces on magnetic resonance (MR) images before surgery. Total removal of the tumor was achieved in 6 cases except of 2 cases of anaplastic astrocytoma. All 6 patients with total removal of the tumor demonstrated the modest or mild deterioration of motor function on the approach side early after surgery, which resolved within 1 month after surgery. Average grade of the modified McCormick functional schema was 3.5 before surgery and improved to 3.0 at 3 months after surgery. These 6 patients demonstrated satisfactory pain relief early after surgery. Average grade of the sensory pain scale was 2.7 before surgery and improved to 1.7 at 3 months after surgery. PLS approach can be one of the surgical choices to the spinal intramedullary tumors, if applied appropriately. Better indication for PLS approach may be the tumors of the uneven location within the spinal cord associated with moderate or severe local pain.

Intraoperative assessment of spinal vascular flow in the surgery of spinal intramedullary tumors using indocyanine green videoangiography

Background:The authors demonstrate the utility of indocyanine green videoangiography (ICG-VA) for intraoperative vascular flow assessment in the surgery of a variety of spinal intramedullary tumors to achieve an additional level of safety as well as precision with the surgical procedure.Methods:Fourteen patients with spinal intramedullary tumors (nine cervical and five thoracic) operated on between August 2011 and April 2013 were included in the present study. A fluorescence surgical microscope was used to perform ICG-VA after standard exposure of the lesion to assess the dynamic flow of the spinal microvasculature.Results:Twenty-seven ICG-VA injections were performed in 14 cases. Pathological diagnosis of the tumors included ependymoa, astrocytoma, cavernous malformation, or hemagioblastoma. There were no complications or side-effects related to ICG-VA. Intraoperative ICG-VA provided dynamic flow images of the spinal microvasculature in accordance with the progress of surgical procedures. Angiographic images could be divided into arterial, capillary, and venous phases. All angiographic images were well integrated into the microscopic view. The utility of ICG-VA could be summarized into three categories: (1) Localization of normal spinal arteries and veins, (2) assessment of posterior spinal venous circulation, and (3) differentiation of feeding arteries, tumor, and draining veins.Conclusions:Intraoperative vascular flow assessment using ICG-VA was easy, repeatable, and practical without any significant procedure-related risks. ICG-VA can be used for careful analysis of spinal microvascular flow or anatomical orientation, which is necessary to ensure safe and precise resection of spinal intramedullary tumors.