Resuscitative Endovascular Balloon Occlusion of the Aorta for Blood Control in Lumbar Spine Tumor Resection Surgery: A Technical Note.

OBJECTIVES: To describe the technique of the aorta balloon occlusion, and evaluate the blood loss in lumbar spine tumor surgery assisted by aortic balloon occlusion, and to observe the balloon-related complications. METHODS: Six patients with lumbar spine tumor underwent resuscitative endovascular balloon occlusion of the aorta prior to tumor resections in our institution between May 2018 to January 2021. Medical records including demographic, diagnosis, tumor location, surgical approach, intraoperative blood loss, surgical duration, and perioperative balloon-related complication were evaluated retrospectively. RESULTS: This series included four males and two females, with a median age of 50 years (range 22 to 69). Of these, three primary tumors were plasmacytoma, giant cell tumor of bone, and osteosarcoma, while recurrence of undifferentiated pleomorphic sarcoma (UPS), recurrence of giant cell tumor of bone (GCT), and metastatic thyroid cancer were diagnosed in cases 1, 6, and 2, respectively. L2 was involved in cases 1 and 5. L3 was involved in case 6. L4 was involved in case 2, 3, and 6. L5 was involved in case 4. One-stage total en bloc resection surgery (TES) was accomplished in all patients; of this series, signal anterior approach was conducted in case 1, signal posterior approach was utilized in cases 2, 3, and 6, while combined anterior and posterior approach was performed in cases 4 and 5. The median intraoperative blood loss was 1683 mL and ranged from 400 to 3200 mL with a median surgical duration of 442 min and a range from 210 to 810 min. During the perioperative period, no serious balloon-related complications occurred. CONCLUSIONS: Endovascular balloon occlusion of the aorta successfully controls intraoperative exsanguination, contributing to a more radical tumor resection and a low rate of tumor cell contamination in lumbar tumor surgery.

Intradural Hemangioendothelioma of Lumbar Spine: Dilemmas and Differentials in Diagnosis.

BACKGROUND: Vascular tumors of the spine range from benign hemangiomas to malignant angiosarcomas. Hemangioendotheliomas of spine are tumors of intermediate-grade malignancy with rare occurrence in the intradural location. The imaging and histopathologic features may mimic other common lesions occurring at this location. CASE DESCRIPTION: A 70-year-old woman presented with lower limb weakness and sensory impairment along the L5-S1 dermatome. A radiologic diagnosis of neurofibroma at the intradural location of the L4-L5 level was made, and total excision of the space-occupying lesion was done. Histopathologic examination, however, revealed a vascular tumor consistent with hemangioendothelioma, which was confirmed by immunohistochemical analysis. We present this case discussing the dilemmas and difficulties in arriving at the diagnosis, highlighting the role of immunohistochemical aid. CONCLUSION: Histomorphology, aided by ancillar tests like immunohistochemistry, remains the criterion for the definitive diagnosis of such rare lesions, and pathologists need to be aware of these lesions occurring in uncommon locations.

Assessing Vascularity of Osseous Spinal Metastases with Dual-Energy CT-DSA: A Pilot Study Compared with Catheter Angiography.

BACKGROUND AND PURPOSE: Spine debulking surgery in patients with hypervascular spinal metastasis is associated with massive intraoperative blood loss, but currently, the vascularity of tumor is determined by invasive conventional angiography or dynamic contrast MR imaging. We aimed to investigate the usefulness of noninvasive dual-energy CT-DSA, comparing it with conventional angiography in evaluating the vascularity of spinal metastasis. MATERIALS AND METHODS: We conducted a retrospective study from January to December 2018. A total of 15 patients with spinal metastasis undergoing dual-energy CT, conventional DSA, and subsequent debulking surgery were included. CT-DSA images were produced after rigid-body registration and subtraction between CT phases. Qualitative and quantitative assessments of tumor vascularity were conducted. Correlations between CT-DSA and conventional DSA results were evaluated using the Spearman coefficient. The mean enhancement in the estimated tumor volume and surgical blood loss was compared between hypervascular and nonhypervascular groups using the Wilcoxon rank sum test. RESULTS: The CT-DSA and DSA results were strongly correlated, with ρ = 0.87 (P < .001). The DSA and the quantitative enhancement index also showed a strong correlation with ρ = 0.83 (P < .001). Wilcoxon rank sum testing between hypervascular and nonhypervascular CT-DSA groups showed a difference in enhancement indices (P = .0003). The blood loss between the hypervascular and nonhypervascular groups was nonsignificant (P = .09). CONCLUSIONS: Dual-energy CT-DSA correlates well with conventional DSA in assessing the vascularity of spinal metastasis. It may serve as a noninvasive preoperative evaluation option before debulking surgery.

Clinical Monitoring of Sacrococcygeal Teratoma.

BACKGROUND: Sacrococcygeal teratomas (SCT) are often highly vascularized and may result in high-output cardiac failure, polyhydramnios, fetal hydrops, and demise. Delivery is guided by the SCT to fetus volume ratio (SCTratio), SCT growth rate, and cardiac output indexed for weight (CCOi). METHODS: We compared measurements and outcome in 12 consecutive fetuses referred with SCT. Adverse outcomes were: fetal surgery, delivery < 32 gestational weeks or neonatal demise. Only SCTratio and CCOi were used to manage the cases. SCT vascularization index (VI%) was derived from the 3D virtual organ computer-aided analysis (VOCAL) software. The SCTModel (modified from acardiac twins) calculated a hypothetical SCT draining vein size and derived a risk line, using diameters of the superior and inferior vena cava, the azygous and umbilical veins. VI% and a model of systemic and umbilical venous volumes (SCTModel) were tested as indicators for outcome in SCT. RESULTS: Fetuses were monitored from 20.1 to 36.4 gestational weeks and 5/12 had adverse outcomes: 1 had successful open fetal surgery at 23.8 weeks and delivered at term, 4 delivered at < 32 weeks with 3/4 having neonatal demise between 25 and 29 weeks. VI% was significantly higher in cases with adverse outcomes (mean 10.3 [8.9-11.6] vs. 4.4 [3.4-5.3], p < 0.0001). The additional fraction of the fetal cardiac output required to perfuse the SCT-draining vein (XSCO%) (p = 0.46), SCTratio (p = 0.08), and CCOi (p = 0.64) were not significant. All cases with adverse outcome had VI% > 8%. The SCTModel risk line predicted nonadverse outcomes well but lacked data in 2/5 cases with adverse outcomes. CONCLUSIONS: VI% is a significant indicator of SCT cases with adverse outcomes and combined with SCTratio may guide timing of delivery better than current measures.

Early Tissue Effects of Stereotactic Body Radiation Therapy for Spinal Metastases.

PURPOSE: Stereotactic body radiation therapy (SBRT) is a highly effective and potentially ablative treatment for complex spinal metastases. Recent data have suggested radiobiologic effects of SBRT that expand beyond the traditional concept of DNA damage. Antitumor immunity, vascular damage leading to tumor necrosis, and increased rates of tumor apoptosis have been implied; however, in-human evidence remains scarce. The present study reports unique pathologic confirmation of SBRT-induced biological effects within spinal metastases treated with preoperative SBRT. METHODS AND MATERIALS: Ten patients with spinal metastases secondary to various solid tumors were treated with preoperative single-fraction SBRT (18 Gy) to the magnetic resonance imaging-defined macroscopic metastasis, followed by spinal stabilization within 24 hours. Perioperative samples of spinal metastases were obtained, and 6 patients also had a pre-SBRT biopsy specimen available for a matched comparison. The samples were stained for tumor necrosis on routine hematoxylin-eosin-stained slices and, subsequently, immunohistochemical staining for T cells (CD3+, CD4+, CD8+), natural killer cells (CD56+), endothelium (CD31+), and apoptotic activity (caspase-3). RESULTS: Perioperative biopsy specimens were obtained ∼6 hours (range 4.5-7.5) or 21 hours (range 18.5-22.5) after SBRT. Necrosis was observed in 83% of the 21-hour post-SBRT samples (5 of 6) compared with 0% of pre-SBRT biopsies (0 of 6) and 6-hour post-SBRT biopsies (0 of 4). Tumor cell apoptosis had increased greatly in the 21-hour post-SBRT samples compared with before and 6 hours after SBRT. The CD31+ vessel counts decreased after SBRT, as did mitotic activity. Both of the renal cell metastases displayed major decreases in vessel density. Desmoplastic reaction was visible in 67% (4 of 6) of the pre-SBRT samples compared with 100% (10 of 10) the post-SBRT samples. The T-cell and natural killer cell counts were relatively unaffected. CONCLUSIONS: High-dose single-fraction SBRT induced tumor necrosis, desmoplasia, and tumor apoptosis and decreased tumor vessel density within 24 hours, even in renal cell metastases. The role of immune cells seems limited in this early phase. These first-in-human results imply direct vascular and DNA damage mechanisms important in the clinical efficacy specific to spinal SBRT.

Intraoperative Transpedicular Onyx Injection to Reduce Vascularity of a Thoracic Hemangiopericytoma After Unsuccessful Preoperative Endovascular Embolization: a Technical Report.

BACKGROUND AND IMPORTANCE: Hemangiopericytoma is a rare vascular tumor with central nervous system involvement representing only 1% of central nervous system tumors. They rarely affect the vertebral column. Complete surgical resection is the treatment of choice for hemangiopericytoma given their high rates of local recurrence. However, the high vascularity of such tumors with the risk of massive bleeding during surgery represents a significant challenge to surgeons. Therefore, preoperative endovascular embolization via the transarterial route has been advocated. CLINICAL PRESENTATION: In the current study, we present a case of a T12 hemangiopericytoma that was managed by a 2-stage surgical resection, with the use of intraoperative transpedicular onyx injection to reduce intraoperative blood loss following an unsuccessful trial of preoperative endovascular embolization. CONCLUSION: Preoperative endovascular embolization is not feasible in some cases due to the location of the segmental or radiculomedullary arteries in relation to tumor feeders and, rarely, small size of these arterial feeders. Percutaneous injection of onyx is an option. In this case report, we discuss direct intraoperative injection via a transpedicular route as a safe and effective method for decreasing the vascularity of some lesions and improving intraoperative blood loss.

Prevalence and characteristics of intravertebral enhancement on contrast-enhanced CT scans in cancer patients.

STUDY DESIGN: This was a single center, retrospective observational study. OBJECTIVE: to investigate-in a cancer population-the prevalence and hallmarks of intravertebral enhancement (IVE) detected on contrast-enhanced CT. SUMMARY OF BACKGROUND DATA: Intravertebral enhancements secondary to iodinated contrast stagnation have been described. Cancer patients have an increased risk of perivertebral venous thrombosis or stenosis secondary to several risk factors (cancer or drug induced hypercoagulability, deterioration of venous flow linked to catheter insertion, prolonged immobilization). In case of a high density lesion identified on CT, the diagnostic choice between metastasis and contrast media within bone marrow vessels may be an issue, especially as oncologic follow-up CT scans are usually performed with contrast medium injection. METHODS: 2572 contrast-enhanced body CT scans performed in cancer patients over 3 months in the medical imaging department of a university hospital were retrospectively reviewed. IVE was sought when paravertebral venous collateral circulation was detected and bone metastasis ruled out and classified as linear or nodular. Their locations within vertebra, their relation to the injection side and the predominant collateral venous network side were evaluated. RESULTS: Sixty-seven (2.8%) patients had a collateral paravertebral venous system and among them 21 had IVE (37%). There were 208 IVE locations involving 75 vertebrae. 199 IVE were linear-shaped (95.7%) and 9 nodular-shaped (4.3%). 80.8% were located between C6 and T4. 88.9% were localized in the vertebral body. 73.1% were located medially or ipsilateral to the injection side. CONCLUSION: Intravertebral enhancement is found in 37% of the patients with paraspinal collateral venous circulation when a CT scan is performed for cancer. The ipsilateral or medial position of the IVE relative to the injection side and the side of the dominant perivertebral venous system, and the possibility of connecting the IVE to a paravertebral vein may be in favor of vascular opacification.

Inter- and intra-rater agreement in the assessment of the vascularity of spinal metastases using digital subtraction angiography tumor blush.

Background Preoperative embolization is based on the preoperative digital subtraction angiography (DSA) tumor blush, and as such is considered the "gold standard" for determining tumor vascularity. However, to our knowledge reliability studies evaluating vascularity ratings of DSA tumor blush in spinal metastases have not been published previously. Purpose To evaluate inter- and intra-rater agreement in the assessment of the vascularity of spinal metastases using DSA tumor blush. Material and Methods This reliability study included 46 patients with symptomatic metastatic spinal cord compression requiring surgery. DSA data stored in the hospital picture archiving and communication system (PACS) from the participants of a randomized controlled trial were used. Inter- and intra-rater agreement on vascularity assessment using DSA tumor blush according to a three-step ordinal scale was evaluated: no hypervascularity; moderate hypervascularity; and pronounced hypervascularity. The statistical analysis was based on the linear weighted kappa's for multiple raters that extend Cohen's κ. Three raters and κ = 0.2 in the null hypothesis implied that the power of the study was 0.96. Results Inter- and intra-rater agreements were moderate in rating the vascularity of spinal metastases and the agreements were significantly higher than the κ = 0.20 in the null hypothesis ( P = 0.0002 and P = 0.0001). The κ value for inter-rater agreement was 0.57 (95% confidence interval [CI], 0.41-0.72) and for intra-rater agreement 0.55 (95% CI, 0.38-0.71). Conclusion There is moderate inter-rater and intra-rater agreement in classifying the vascularity of spinal metastases on a three-step ordinal scale for DSA tumor blush.

[Description of the Microsurgical Anatomy and Intramedullary Tumor Resection in the Anterior Part of the Spinal Cord].

During resection of an intramedullary spinal cord tumor, dissection of the ventro-central part of the tumor is most difficult because of the close anatomical relationship between the spinal branches of central vessels to be preserved and the tumor feeding arteries. The central vessels run anteroposteriorly through the anterior median septum(AMS), and a pair comprising a central artery and vein forms a vascular bundle that runs into the spinal cord from the tip of the AMS. These vascular bundles are covered with thin folds of the AMS, named septal sleeves, until they enter the spinal cords. Furthermore, the feeding arteries of the tumor arising from the spinal branches of the central arteries at the tip of the AMS are contained in thick septal sleeves; these thick sleeves indicate the position of the feeding arteries to be excised. To control brisk bleeding from the stump of the feeding artery at the top of the AMS, pinpoint coagulation of the arterial stump under direct vision after debulking the tumor is desirable. When pinpoint hemostasis cannot be achieved, coagulation of the AMS including the bleeding artery to a depth of 1-2 mm is advisable. As central arteries run tortuously in the AMS, the direction of the coagulation should be inclined craniocaudally, although this may increase the risk of damaging the adjacent central vessels. Surgeons should be aware of the anatomical relationship between the AMS, the central vessels, and the tumor feeding arteries to perform safe detachment of the tumors in the ventral region.

The efficacy and risks of preoperative embolization of spinal tumors.

BACKGROUND: The goal of preoperative embolization of spinal tumors is to improve surgical outcomes by diminishing the vascular supply to the tumor to reduce intraoperative blood loss and operative time. OBJECTIVE: To report our institutional experience with spinal tumor embolization and review the present literature. METHODS: Clinical records from January 1, 2001 to December 31, 2012 were reviewed and analyzed. Angiograms were used to calculate the percentage reduction in tumor vascularity, and relevant clinical and operative data were collected and analyzed. RESULTS: Thirty-seven patients underwent preoperative spinal tumor embolization (24 metastatic and 13 primary lesions) and were included in the study. One complication resulted in transient lower extremity weakness and was attributed to post-embolization swelling, which fully resolved after surgical resection. The transient neurological complication rate was 1/37 (3%) and the permanent rate was 0/37 (0%). The average surgical estimated blood loss (EBL) was 1946 mL (100-7000 mL) and the average operative time was 330 min (range 164-841 min). After embolization, tumor blush was reduced by 83% on average. Average pre- and postoperative modified Rankin Scale scores were 2.10 and 1.36, respectively (p=0.03). Cases in which tumor blush was decreased by ≥90% (classes 1 or 2) after embolization had significantly less operative blood loss than those cases in which <90% (classes 3 or 4) was achieved (mean EBL 1391 vs 2296 mL, respectively, p=0.05). CONCLUSIONS: Spinal tumor embolization is a safe procedure, is associated with few complications, and may improve surgical outcomes by limiting intraoperative blood loss and reducing operative time.

Risk factors for major complications in surgery for hypervascular spinal tumors: an analysis of 120 cases with adjuvant preoperative embolization.

PURPOSE: To determine the frequency of major complications and identify related risk factors in surgery for hypervascular spinal tumors after preoperative selective arterial embolization. METHODS: Patients with spinal tumors who underwent preoperative embolizations between January 2010 and March 2013 were retrospectively reviewed. Perioperative complications were classified as either major or minor. Preoperative and intraoperative factors were analyzed for any association with major complications using univariate and multivariate regression analysis. RESULTS: There were 120 embolizations with subsequent 120 spine operations that met the inclusion and exclusion criteria. Overall, 27.5% (33/120) experienced major complications and 11.7% (14/120) had at least two major complications. Respiratory complications were the most commonly seen with a rate of 10.8% (13/120). Multivariate regression analysis identified two risk factors for major complications: reoperation and higher score of surgical invasiveness index. Two risk factors were identified for two or more major complications: age≥65 years and higher score of surgical invasiveness index. Two risk factors were identified for major respiratory complications: thoracic surgery and higher score of surgical invasiveness index. However, embolization-related factors did not reach significance in the multiple regression model. CONCLUSION: Major complications in surgery for hypervascular spinal tumors after embolization are prevalent. Risk factors identified in this study are useful prognostic indicators when considering surgical treatment combined with embolization.

Hypervascular cervical spine metastases: embolization by direct injection of Onyx-18.

PURPOSE: Spinal metastases are common in patients with cancer. Following lung and liver, spine is the most common site for cancers to metastasize. Many of them are hypervascularized. These cases are a particular challenge for the surgeon and represent a significant danger of massive blood loss during surgery. Hypervascularized metastases of the cervical spine also include the risk of postoperative bleeding with severe neurological impairment. We report a case of a 67-year-old women with breast cancer (BC) metastasis within the vertebral bodies of C3 and C4 with nearly complete bony destruction of the ventral column and intraspinal tumor masses compressing the spinal cord at level C3 and C4. The hypervascularized tumor was supplied by multiple minor vessels from both vertebral arteries, too small to be coiled individually. Due to an allergy to aspirin, intravascular stenting of the vertebral arteries was not an option. We decided to perform a preoperative direct injection of onyx-18 for embolization of the tumor. CONCLUSION: Presurgical direct injection of Onyx-18 for treating hypervascular spinal metastases of breast cancer seems to be an effective and safe technique and reduces intraoperative bleeding to a minimum.

Hemorrhagic onset of spinal angiolipoma.

Spinal angiolipomas are rare benign tumors that generally induce slow progressive cord compression. Here, the authors describe a case of sudden-onset palsy of the lower extremities caused by hemorrhagic spinal angiolipoma. An emergent laminectomy was performed to achieve total lesion removal. Follow-up examinations indicated neurological improvement and the absence of recurrence.

Magnetic resonance perfusion characteristics of hypervascular renal and hypovascular prostate spinal metastases: clinical utilities and implications.

STUDY DESIGN: A total of 40 patients with spinal metastases from renal cell carcinomas (RCCs) or prostate carcinomas (PCs) were studied using DCE-MRI (dynamic contrast-enhanced magnetic resonance imaging). OBJECTIVE: To evaluate spinal metastases from RCC and PC to assess the sensitivity and specificity of perfusion parameters obtained by quantitative and semiquantitative methods, which would allow for noninvasive discrimination between hypovascular and hypervascular lesions. SUMMARY OF BACKGROUND DATA: Conventional MRI can be inconclusive in assessing diagnostically complex spinal lesions in patients with cancer in whom fibrosis, infarction, edema related to compression fractures, and infection may simulate malignant neoplasm. Conventional MRI is also of limited value in assessing tumor vascularity and identifying hypervascular tumors. DCE-MRI offers an advantage over conventional MRI in that it provides anatomical, physiological, and hemodynamic information about neoplastic lesions. METHODS: DCE perfusion parameters: vascular permeability, plasma volume (V(p)), wash-in slope, and peak-enhancement parameter were measured to assess their potential as discriminators of tumor vascularity. A Mann-Whitney U test (at P ≤ 0.01), was performed to quantify and compare significance of perfusion parameters between the 2 groups. RESULTS: Of the 4 perfusion parameters studied, V(p) was observed to have the largest difference in mean (µ) between PC (µ = 3.29/s) and RCC metastases (µ = 5.92/s). This was followed by the peak-enhancement, vascular permeability, and wash-in parameters. A Mann-Whitney U test showed a significant difference between V(p) values for PC and RCC lesions (P ≤ 0.001). Similarly, peak-enhancement parameter showed a significant difference between the 2 histologies (P ≤ 0.001), as did vascular permeability (P ≤ 0.01). The receiver operating characteristic curve showed that V(p) recorded the highest area under the curve (0.867). CONCLUSION: V(p) was shown to be the best discriminator between spinal metastases from PC and RCC with the mean V(p) of RCC metastasis being 1.8 times that of the PC lesions, thus discriminating between hyper- and hypovascular metastases, which has important clinical implications.

Dynamic contrast-enhanced magnetic resonance perfusion compared with digital subtraction angiography for the evaluation of extradural spinal metastases: a pilot study.

STUDY DESIGN: This was a retrospective study comparing dynamic contrast-enhanced magnetic resonance (DCE-MR) perfusion with digital subtraction angiography (DSA) in determining the vascularity of spinal tumors. OBJECTIVE: To report on the efficacy of DCE-MR perfusion as a potential noninvasive surrogate for measuring vascularity and thus determine the need for preoperative embolization. SUMMARY OF BACKGROUND DATA: Although primary spinal tumors are rare, spine metastases are relatively common and symptomatic in approximately 14% of patients. Symptomatic patients require palliation with radiotherapy and/or surgery, with possible preoperative endovascular embolization of the tumor. METHODS: A retrospective review revealed 10 patients with 11 diseased vertebral bodies who had received spine DCE-MR perfusion studies and subsequently underwent spinal DSA. Processed MR data were used to calculate a blood flow ratio comparing blood flow with a diseased and an adjacent normal vertebral body. Spinal tumor vascularity was graded on the basis of angiographic tumor blush from 0 (decreased enhancement compared with a normal vertebral body) to 4 (marked tumor blush with early arteriovenous shunting). RESULTS: Eight vertebral bodies demonstrated increased vascularity on DSA with blood flow ratios of greater than 1.8, 2 vertebral bodies demonstrated normal enhancement on DSA with cerebral blood flow (CBF) ratio of 0.55 to 1.14, and 1 vertebral body level had decreased enhancement on DSA, with a CBF ratio of 0.43. There was a strong correlation between CBF ratio and DSA score, with Spearman ρ = 0.87 (P = 0.00012). CONCLUSION: These data show a statistically significant correlation between CBF ratio and DSA and suggest that DCE-MR perfusion can serve as a surrogate to DSA for determining tumor vascularity in patients with extramedullary spinal metastases.

Preoperative embolization of hypervascular spinal tumors: current practice and center experience.

Preoperative transarterial embolization of hypervascular spinal tumors has been extensively used, and is considered to be a highly effective adjuvant technique in reducing intraoperative blood loss during surgery. Moreover, it has been reported to increase the feasibility and safety of the surgical procedure, leading to better surgical outcomes. We review the English literature in an attempt to identify indications, appropriate timing of embolization in relation to surgery, technical aspects of the procedure, complications, and the contribution of embolization to the surgical management of spinal tumors. In addition, we report our experience with embolization of hypervascular metastases.

Study of stem cell marker nestin and its correlation with vascular endothelial growth factor and microvascular density in ependymomas.

BACKGROUND: Ependymomas are relatively rare glial tumours, whose pathogenesis is not well elucidated. They are enigmatic tumours that show site-specific differences in their biological behaviour. Recent studies have hypothesized that ependymoma cancer stem cells (CSCs) are derived from radial glia and express stem cell markers such as nestin, which is associated with a poor prognosis. CSCs reside in 'vascular niches', where endothelial cells and molecular signals like vascular endothelial growth factor (VEGF) play an important role in their survival. Studies analysing VEGF expression in ependymomas showed that ependymal vascular proliferation is less sensitive to induction by VEGF, questioning the possible beneficial effect of anti-VEGF therapy in ependymomas. We aimed to study nestin and VEGF immunoexpression in ependymomas, correlate them with clinicopathological parameters and reveal a role for VEGF in ependymomas that extends beyond the context of tumour angiogenesis. METHODS: We analysed 126 cases of ependymomas of different grades and locations for nestin and VEGF immunoexpression. Endothelial cells were labelled with CD34. Vascular patterns and microvascular density was determined. RESULTS: Nestin and VEGF expression in tumour cells were more frequent in supratentorial tumours [89% (33/37) and 65% (24/37) respectively], and were associated with a significantly poor progression-free survival (PFS). VEGF expression did not reveal any correlation with necrosis or bizarre vascular patterns. CONCLUSIONS: Supratentorial location is an independent predictor of a poor PFS. Significant coexpression of nestin and VEGF suggests that latter possibly augments stem cell survival. Thus, anti-VEGF therapy may be a good option in future for nestin immunopositive ependymomas.

Usefulness of tumor blood flow imaging by intraoperative indocyanine green videoangiography in hemangioblastoma surgery.

OBJECTIVE: Hemangioblastomas remain a surgical challenge because of their arteriovenous malformation-like character. Recently, indocyanine green (ICG) videoangiography has been applied to neurosurgical vascular surgery. The aim of this study was to evaluate the usefulness of tumor blood flow imaging by intraoperative ICG videoangiography in surgery for hemangioblastomas. METHODS: Twenty intraoperative ICG videoangiography procedures were performed in 12 patients with hemangioblastomas. Seven lesions were located in the cerebellum, two lesions were in the medulla oblongata, and three lesions were in the spinal cord. RESULTS: Ten procedures were performed before or during dissection, and 10 procedures were performed after tumor resection. ICG videoangiography could provide dynamic images of blood flow in the tumor and its related vessels under surgical view. Interpretation of these dynamic images of tumor blood flow was useful for discrimination of transit feeders (feeders en passage) and also for estimation of unexposed feeders covered with brain parenchyma. Postresection ICG videoangiography could confirm complete tumor resection and normalized blood flow in surrounding vessels. CONCLUSIONS: In surgery for hemangioblastomas, careful interpretation of dynamic ICG images can provide useful information on transit feeders and unexposed hidden vessels that cannot be directly visualized by ICG.