Resection Of Hemangioblastoma Research Articles

Preoperative embolization and microsurgical resection of a cerebellar hemangioblastoma: embolization goals and technical nuances of the approaches. Illustrative case.

Resection remains the optimal treatment for hemangioblastomas, highly vascular tumors commonly located in the cerebellum or spinal cord. Preoperative embolization can be used with caution to reduce intraoperative blood loss and promote gross-total resection while reducing neurological morbidity. The authors report a case of a 44-year-old male who presented with worsening dizziness, gait imbalance, and diplopia. Imaging revealed a large vascular cerebellar mass with brainstem compression and hydrocephalus, concerning for hemangioblastoma. The patient underwent preoperative embolization of the main arterial supply from the right superior cerebellar artery, which devascularized the tumor and reduced the early venous shunting, followed by gross-total resection of the tumor. Preoperative embolization helped to facilitate safe microsurgical resection because this main arterial supply was deep to the planned surgical approach, and the Onyx cast served as a landmark of the dorsal midbrain and remaining arterial supply. This resulted in minimal intraoperative blood loss. At 2-year follow-up, the patient's diplopia and vertigo had resolved, and his gait continues to improve. Despite controversy regarding the use of preoperative embolization for hemangioblastoma resection, the authors emphasize its safety and utility during resection of a large cerebellar hemangioblastoma. Onyx embolization provided benefit in both reducing the tumor blood supply and serving as intraoperative visual guidance.

Preoperative Embolization as a Strategy to Mitigate Hemorrhage Risk in Surgical Resection of Spinal Hemangioblastomas

Objectives: This study aims to explore the interest and indications of preoperative embolization as an adjunctive technique to mitigate hemorrhage risk during surgical resection of spinal hemangioblastomas. Background: Spinal hemangioblastomas are benign vascular tumors that pose a surgical challenge due to the risk of intraoperative hemorrhage. The standard treatment for these tumors is surgical resection, but the potential for significant bleeding necessitates additional strategies to enhance safety.

How I do it: cervical hemangioblastoma resection. Surgical technique and complication avoidance.

Spinal cord hemangioblastomas are benign, highly vascular neoplasms that affect the brain and, rarely, the spinal cord. They can be solitary or as part of von Hippel-Lindau syndrome. Radiosurgery is not a suitable treatment option. Endovascular embolization can only be adjunct to surgery. We present a detailed approach to resection of a spinal cord hemangioblastoma. A video demonstrates the microsurgical technique and discusses complication avoidance. The pitfalls to consider are preservation of normal spinal cord vessels, protection of the pia-arachnoid cleavage plane, and avoidance of tumor piecemeal removal. Careful microsurgical resection and detailed preoperative planning are key.

375 Vorinostat for Missense Mutated Von Hippel Lindau Disease Associated Hemangioblastomas: A Pilot Study

INTRODUCTION: Missense mutated VHL protein (pVHL) maintains intrinsic function but undergoes proteasomal degradation, loss of function and tumor initiation/progression of VHL-associated tumors. Histone deacetylase inhibitors (HDACi) can rescue missense mutated pVHL and arrest tumor growth in pre-clinical models. METHODS: Seven subjects with missense VHL received 400mg/day of vorinostat (7-days) and surgical resection of hemangioblastomas. We analyzed vorinostat-treated HBs (and paired untreated HBs from the same patients) for gene and protein expression in the pVHL-HIF-VEGF pathway, and protein-protein interactions. We explored the transcriptional landscape of these tumors with single nucleus gene expression analysis. We recapitulated patient specific missense mutations and validated the clinical findings using lentiviral expression recombinant constructs in VHL-/- 786-O cells. RESULTS: Short-term oral vorinostat was well tolerated by all patients (age 46.0 ± 14.5 years; 25-61 years). In the 6 evaluable tumors, pVHL expression in neoplastic stromal cells of vorinostat treated tumors was significantly elevated compared to untreated tumors (p = 0.01). We found transcriptional suppression of downstream effectors including VEGF-A and GLUT1 in human tumor samples and validated the effects in patient-specific missense mutations expressed in VHL 786-O cells. Mechanistically, we found that vorinostat prevented Hsp90 recruitment to missense mutated pVHL. The vorinostat effects on pVHL rescue, transcriptional repression and Hsp90-pVHL interaction was independent of the location of the mutation on VHL. Lastly, we found a HB stromal cell specific effect in suppression of pro-tumorigenic pathways with single nucleus gene expression analysis. CONCLUSIONS: Short-term treatment with vorinostat increased pVHL levels and suppressed tumor progression signaling in VHL-associated hemangioblastomas. These results indicate that proteostasis modulation can rescue tumor pVHL in germline missense mutated VHL patients and such treatment could arrest tumor growth.

Surgical management of spinal cord hemangioblastoma

Background. Hemangioblastomas are considered rare tumours that are located, in most cases, in the posterior cranial fossa. In most of cases, spinal hemangioblastomas are identified on the thoracic and cervical levels and can be associated in one-third of cases with von Hippel Lindau Syndrome.
 Material and methods. In this paper, we are presenting our clinic`s experience with spinal hemangioblastomas and the follow-up of the patients in the last 10 years.
 Results. In our study, we included six men and three women with a mean age of 45 years, ranging between 36 to 61 years. The mean hospitalization days was 17 days. Among nine patients, there were identified 12 tumors. Six patients presented cervical spine hemangioblastomas, two of them had thoracic spine lesions and in one case, the tumour was identified at the lumbar level. Furthermore, two patients presented multiple lesions. Two patients had been associated with von Hippel Lindau Syndrome. In all cases, surgery was the therapeutic approach.
 Discussions. Despite the rapid advance of technology and the new alternatives for the treatment of these lesions, surgical resection of hemangioblastomas remains the gold standard treatment.
 Conclusions. Hemangiolbastomas are benign tumours that can be associated with von Hippel Lindau. A whole-body scan is required to confirm or exclude this syndrome. Even though the surgical treatment for asymptomatic patients remains debatable, surgical intervention is the only treatment that can lead to the total removal of the tumour.

Endoscope-Assisted Resection for Cystic Cerebellar Hemangioblastomas

Hemangioblastomas are benign, often cystic tumors occurring most commonly in the cerebellum. We describe resection of cystic cerebellar hemangioblastomas using an endoscope-assisted technique. We present a series of 9 cases and discuss the endoscopic technique for resection of cystic hemangioblastoma. Frameless neuronavigation was used in all cases. A small 1- to 1.5-cm corticotomy lined with Surgicel and patties allows access to the peritumoral cyst. Using bimanual microsurgical techniques and the 30-degree rigid endoscope to provide visualization, the mural nodule can be resected and the cyst cavity inspected. Complete resection of the mural nodule was achieved in all cases. One patient had a postsurgery pseudomeningocele requiring ventriculoperitoneal shunt. Hospital length of stay was short for all the patients. Endoscope-assisted resection is a safe and effective technique for surgical resection of cystic hemangioblastoma.

Tool-Tissue Forces in Hemangioblastoma Surgery

Surgical resection of intracranial hemangioblastoma poses technical challenges that may be difficult to impart to trainees. Here, we introduce knowledge of tool-tissue forces in Newton (N), observed during hemangioblastoma surgery. Seven surgeons (2 groups: trainees and mentor), with mentor (n= 1) and trainees (n= 6, PGY 1-6 including clinical fellowship), participated in 6 intracranial hemangioblastoma surgeries. Using sensorized bipolar forceps, we evaluated tool-tissue force profiles of 5 predetermined surgical tasks: 1) dissection, 2) coagulation, 3) retracting, 4) pulling, and 5) manipulating. Force profile for each trial included force duration, average, maximum, minimum, range, standard deviation (SD), and correlation coefficient. Force errors including unsuccessful trial bleeding or incomplete were compared between surgeons and with successful trials. Force data from 718 trials were collected. The mean (standard deviation) of force used in all surgical tasks and across all surgical levels was 0.20 ± 0.17 N. The forces exerted by trainee surgeons were significantly lower than those of the mentor (0.15 vs. 0.24; P < 0.0001). A total of 18 (4.5%) trials were unsuccessful, 4 of them being unsuccessful trial-bleeding and the rest, unsuccessful trial-incomplete. The force in unsuccessful trial-bleeding was higher than successful trials (0.3 [0.09] vs. 0.17 [0.11]; P= 0.0401). Toward the end of surgery, higher force was observed (0.17 vs. 0.20; P < 0.0001). The quantification of tool-tissue forces during hemangioblastoma surgery with feedback to the surgeon, could well enhance surgical training and allow avoidance of bleeding associated with high force error.

Imaging Diagnosis of Von Hippel-Lindau Syndrome

Von Hippel-Lindau (VHL) syndrome is a group of rare autosomal dominant hereditary diseases that involve multiple organs. Due to its high recurrence rate and complex and diverse clinical manifestations, VHL is prone to being either misdiagnosed or missed entirely. Therefore, patients with VHL syndrome have a poor prognosis. This study reports the details of 2 patients, a 55-year-old male and a 37-year-old female, who were diagnosed as having VHL syndrome with a positive family history. The male patient presented with upper abdominal discomfort 2 years prior to the current study, and was diagnosed in another hospital as having a space-occupying lesion at the head of the pancreas. After undergoing hemangioblastoma resection of the right cerebellar hemisphere 1 month ago, he was admitted to the hospital for recent aggravation of upper abdominal discomfort to receive further diagnosis and treatment. The female patient previously underwent right ovarian cystectomy and T5-T6 intramedullary hemangioblastoma resection. She was diagnosed at another hospital as having pancreatic cancer, and was admitted to the hospital for recent aggravation of upper abdominal discomfort to receive further diagnosis and treatment. The diagnosis and treatment of VHL syndrome is currently relatively difficult. It poses a substantial threat to patients and their families. The early and timely diagnosis and treatment of VHL syndrome can improve patients' prognosis and rates of survival.

Minimally invasive resection of spinal hemangioblastoma: feasibility and clinical results in a series of 18 patients.

Hemangioblastomas are benign, highly vascularized tumors that can occur sporadically or as part of von Hippel-Lindau (VHL) disease. Traditionally, spinal hemangioblastomas have been surgically treated via an open approach. In recent years, however, minimally invasive techniques using tubular retractors have been increasingly applied in spine surgery. Such procedures involve less tissue trauma but are also particularly demanding for the surgeon, especially in cases of highly vascular tumors such as hemangioblastomas. The object of this study was to evaluate the safety and efficacy of minimally invasive resection of selected spinal hemangioblastomas. The authors conducted a retrospective single-center study of all patients who, between January 2010 and January 2018, had been operated on for spinal hemangioblastoma via a minimally invasive approach performed at the surgeon's discretion. The surgical technique is described and the pre- and postoperative neurological and imaging results were analyzed descriptively. The primary outcome was the postoperative compared to preoperative neurological condition (McCormick grade). The secondary outcomes were the extent of tumor resection and postoperative complications. Eighteen patients, 12 female and 6 male, harboring a total of 19 spinal hemangioblastomas underwent surgery in the study period. Seventeen patients had stable neurological findings with stable or improved McCormick grades (94.5%) at a mean of 4.3 months after surgery. One (5.5%) of the 18 patients developed progressive neurological symptoms with a worsened McCormick grade that did not improve in the long-term follow-up. Sixteen of the 18 patients had VHL disease, whereas 2 patients had sporadic spinal hemangioblastomas. In all patients, postoperative MRI showed complete resection of the tumors. No other surgery-related perioperative or postoperative complications were recorded. A minimally invasive approach for the resection of selected spinal hemangioblastomas is safe and allows complete tumor resection with good clinical results in experienced hands.

Microsurgical Resection of Medulla Oblongata Hemangioblastoma: 2-Dimensional Operative Video.

This video demonstrates the microsurgical resection of brainstem hemangioblastoma. The patient is a 32-yr-old woman with Von Hippel Lindau syndrome who presented with quadriparesis and inability to swallow. Magnetic resonance imaging (MRI) of the neuroaxis revealed a brainstem cystic lesion with contrast-enhancing tumor nodule right along the posterior aspect of the lower part of medulla oblongata. The surgery was performed in the prone position with suboccipital craniectomy and partial C1 posterior arch removal. The aim of the surgery was to remove the tumor nodule.1-12The tumor was separated from the right dorsal nerve roots, and then progressively dissected with coagulation of arterial feeders and draining vein and division of the pia circumferentially. Postoperative MRI revealed complete resection. The patient completely recovered from her quadriparesis and difficulty swallowing.

A Rare Complication of Endovascular Embolization: Extruded Onyx on Trigeminal Nerve.

Objectives To demonstrate a rare complication of endovascular tumor embolization with onyx. Design Operative video. Setting Department of neurological surgery in a university hospital. Participants A 39-year-old male who was diagnosed with a right sided hemangioblastoma. Main Outcome Measures Surgical resection of the tumor, preservation of the cranial nerves and extruded embolization material on trigeminal nerve. Results The tumor was embolized with onyx the day before surgery. Patient woke up with no sensation in the right side of his face. Diffusion magnetic resonance imaging (MRI) showed a small restricted diffusion area within the right superior cerebellar vermis. Microsurgical resection of the tumor was uneventful and complete resection was achieved (Fig. 1). After the resection was completed, the trigeminal nerve was identified. Some of the capillaries overlying the nerve as well as the cerebellum and brain stem had extruded onyx-embolic material (Fig. 2). Some of the onyx over the cerebellum was removed; however, the ones on the trigeminal nerve and brain stem were not removed due to the risk of injury to the nerve. Postoperative MRI confirmed total resection. Patient made excellent recovery except he continued to have no sensation in the right side of his face. Conclusion Preoperative embolization is an important adjunct to resection of large hemangioblastomas in selected cases because it may facilitate circumferential dissection and debulking of the tumor. Although extrusion of the embolization material is relatively common, immediate extrusion of onyx and its transfixion on a cranial nerve has not been reported before. Judicial selection of preoperative embolization is required in hemangioblastomas. The link to the Video can be found at: https://youtu.be/s0DjD26Xkas .

Long-term outcome and prognostic factors of intramedullary spinal hemangioblastomas

Spinal hemangioblastomas constitute 1.6-5.8% of all spinal cord tumors. Microsurgical excision of these tumors is challenging. The purpose of this study is to analyze the neurological improvement and long-term functional outcome of spinal hemangioblastomas. This retrospective study included 15 patients who underwent surgery for intramedullary spinal hemangioblastoma at the Department of Neurosurgery of Sri Chitra Tirunal Institute for Medical Sciences and Technology from January 2001 to June 2014. Eight patients (53%) were diagnosed to have von Hippel-Lindau (vHL) disease. Eight (53%) of them were females, and seven were males (47%). Mean age was 33.8years (16-55years). Duration of illness ranged from 2weeks to 4years, and average duration was 10.5months. Most common symptom was motor weakness followed by sensory disturbances, pain, and bladder incontinence. Six (85.7%) sporadic spinal hemangioblastomas were in McCormick grade I; whereas, 7 (87.5%) of vHL spinal hemangioblastomas were in grade II or above. In the immediate postoperative period, three patients noticed improvement in their motor weakness. Six patients (40%) experienced deterioration of preoperative neurological status in the immediate postoperative period. Three of them were sporadic tumors, and others had vHL syndrome. Favorable long-term outcome was achieved in 80% of cases. Though neurological deterioration is common after surgical resection of spinal hemangioblastomas, majority of them are reversible. Long-term functional outcome is favorable with minimal postoperative morbidities. Both sporadic- and vHL-associated tumors share common clinical and radiological features, and neurological outcome is equally good in both.

Surgical Treatment of Vascular Intramedullary Spinal Cord Lesions.

BackgroundVascular lesions represent a rare subset of intramedullary spinal cord pathology and consist of cavernous malformations (CM), hemangioblastomas, and arteriovenous malformations (AVM). These lesions are each unique and the literature pertaining to their surgical management is largely limited to retrospective case series and case reports.ObjectivesTo evaluate the surgical management of each of these lesions with special attention to postoperative functional status.MethodsA single-institution case series of intramedullary vascular lesions treated with surgery was retrospectively evaluated. The primary variables of interest included preoperative and postoperative McCormick grades. Other variables of interest included frequency and indication for conventional spinal angiography, rates of preoperative embolization, postprocedural complications, operative time, intraoperative blood loss, and length of hospital stay.ResultsThirty-six patients were identified over the 17-year study period, including 20 with hemangioblastomas, 13 with CMs, and three with AVMs. The median preoperative McCormick grades were 2, 2, and 3 for hemangioblastomas, CMs, and AVMs, respectively. The median postoperative McCormick grades were 2, 2, and 2 for hemangioblastomas, CMs, and AVMs, respectively at the most recent follow-up. Preoperative angiography was performed in all AVM cases and 29% of hemangioblastomas. Preoperative embolization was performed in 40% of hemangioblastoma cases undergoing preoperative angiography. Operative times were similar between the three lesion groups. In three cases of hemangioblastoma resection and one case of CM resection, McCormick grade improved by one point following surgery. At a mean follow-up of 30.9 months for hemangioblastomas, 7.95 months for CMs, and 24 months for AVMs, all patients were at least at their discharge baseline, with no new neurologic complaints.ConclusionIntramedullary vascular lesions are rare and represent a complex surgical patient population. Surgical resection with or without preoperative angiography and embolization appears to be safe and to halt neurologic decline.

Severe paralysis after spinal hemangioblastoma resection: A case report

Severe paralysis after spinal hemangioblastoma resection: A case report

VITREORETINAL SURGERY FOR PATIENTS WITH SEVERE EXUDATIVE AND PROLIFERATIVE MANIFESTATIONS OF RETINAL CAPILLARY HEMANGIOBLASTOMA BECAUSE OF VON HIPPEL-LINDAU DISEASE.

The evaluation of long-term results of vitreoretinal surgery and retinal capillary hemangioblastoma (RCH) resection in patients with complicated retinal detachment (RD) secondary to RCHs. Twelve eyes of 12 patients were operated on with vitreoretinal surgery, including occlusion of afferent and efferent feeder vessels with endodiathermy and endolaser photocoagulation, and subsequent resection of RCHs. The long-term anatomical and visual outcomes were retrospectively evaluated. Total exudative RD was detected in six eyes and subtotal exudative RD was found in the remaining six eyes. A tractional component was present in eight eyes, and four eyes had pure exudative RD. Laser treatment had been previously applied to four eyes but vitreoretinal surgery was the primary treatment in eight eyes. A total of 19 RCHs were resected. The quadrant location of RCHs was superior temporal in six, superior nasal in five, inferior nasal in five, and inferior temporal in three. The dimensions of the RCHs ranged between 1 and 4 disk diameters (DD) (1-DD in 1 eye, 1.5-DD in 3, 2-DD in 10, 2.5-DD in 3, 3-DD in 1, and 4-DD in 1). Preoperative mean logarithm of the minimum angle of resolution visual acuity was 1.9 ± 1.0 (3.0-0.7) (20/1,588 ± 20/200 [20/20,000-20/100]). Silicone oil and C3F8 was applied to four and eight eyes, respectively. The median postoperative follow-up was 30.5 (18-48) months. Single operation and final anatomical success was obtained in 9 and 11 eyes, respectively. Mean logarithm of the minimum angle of resolution visual acuity in the postoperative 18th month and at the final visit were 1.05 ± 0.8 (3.0-0.2) (20/224 ± 20/125 [20/20,000-20/32]) and 0.96 ± 0.8 (3.0-0.2) (20/182 ± 20/125 [20/20,000-20/32]), respectively. New RCHs occurred in eight eyes. Rubeosis iridis was not present in any of the eyes. Promising anatomical and visual outcomes were obtained after vitreoretinal surgery and resection of RCHs in eyes with complicated RD secondary to RCH. However, life-long follow-up is needed to recognize recurrent RD seen even in the early period or recurrences of RCHs seen in the long-term period.

Intraoperative fluorescein staining for benign brain tumors

ObjectiveSuccessful use of high-dose fluorescein-sodium (20mg/kg) with a standard light microscope for resection of high-grade gliomas, meningiomas, hemangioblastoma and metastases was reported. The principle of brain tumor staining by fluorescein-sodium (Fl-Na) consists in the accumulation of fluorescein in brain tumors with impaired blood-brain barrier. The aim of our study was to investigate for the first time the usefulness of high-dose fluorescein in patients operated on for benign neuroepithelial brain tumors (grade I WHO tumors) with contrast enhancement on magnetic resonance imaging. MethodsOur study included 11 patients operated on for benign neuroepithelial primary brain tumors with contrast enhancement on magnetic resonance imaging (MRI): pilocytic astrocytomas (5 patients), dysembrioplastic neuroepithelial tumors (4) and gangliogliomas grade I (2). In all cases, Fl-Na was injected intravenously (20mg/kg) just after the craniotomy using a peripheral venous line. The dural opening was performed 10min later. Microsurgical tumor resection using conventional neurosurgical microscope guided by the fluorescein staining was performed. ResultsComplete resection of the yellow-green stained tissue was achieved in 10 patients confirmed by postoperative control MRI study. Subtotal resection of the colored tissue was achieved in one case with fourth ventricle pilocytic astrocytoma because of the involvement of the medial eminence and functional constraints discovered during intraoperative neuromonitoring. Three patients have had a postoperative volume of resection greater than the tumor volume because of the planed perilesionectomy by our epilepsy surgery team. Surrounding tissue not stained by Fl-Na was obtained in these 3 cases. The histopathological examination did not find tumor tissue in the perilesional Fl-Na negative tissue. On the other hand, all 11 Fl-Na positive specimens presented signs of tumor involvement. We did not observe complications related to the use of high dose Fl-Na. ConclusionsHigh doses intravenous Fl-Na seems to be a useful intraoperative technique for delineation of benign neuroepithelial brain tumors with contrast enhancement. Further larger studies may reveal the real value of high doses Fl-Na as intraoperative method for increasing the extent of resection in these particular indications.

Personalized Medicine for Nervous System Manifestations of von Hippel-Lindau Disease.

von Hippel–Lindau disease (VHL) is a familial neoplasia syndrome associated with multisystem tumor development. Depending on tumor type and location, current treatments for VHL-associated tumors can include a combination of chemotherapy, radiation therapy, and/or surgery. Central nervous system (CNS) manifestations of VHL include craniospinal hemangioblastomas and endolymphatic sac tumors (ELSTs). While the first-line treatment for both types of VHL-associated CNS tumors is surgery, the indications for treatment are patient specific and different for each tumor type. Although early sign/symptom formation is the primary indication for resection of craniospinal hemangioblastomas, radiographic discovery (asymptomatic and symptomatic) of ELSTs can be an indication for resection of ELSTs in VHL patients. Recently, research has revealed that specific VHL germline mutations may permit targeted medical treatments of not only CNS manifestations of VHL-associated tumors but also visceral tumors. Specifically, missense mutations can result in the translation of functional VHL protein (pVHL) that is rapidly degraded resulting in functional loss of the pVHL, and inhibitors of pVHL degradation may slow protein degradation and restore pVHL function. Emerging research will investigate the safety and practicality of using potential targeted therapies.

Surgical resection of cerebellar hemangioblastoma with enhanced wall thickness: A report of two cases.

Hemangioblastomas are tumors of the central nervous system, and the cerebellum is the most common site of occurrence. Cerebellar hemangioblastoma with enhanced wall thickness is rare and often misdiagnosed preoperatively. At present, no unified radiological classification system based on magnetic resonance imaging (MRI) findings exists for cerebellar hemangioblastoma, and this tumor type can be solid or cystic mass, according to the MRI findings. The most common presentation of cerebellar hemangioblastoma observed radiologically is a large sac with small nodules, where the wall of the large cyst is not enhanced. A tumor with enhanced large cysts and tumor nodules is extremely rare. The most effective treatment is complete resection of the cyst and the solid growth. The present case reports the successful treatment of two cases of cerebellar hemangioblastoma with enhanced wall thickness, including the MRI findings for the differential diagnoses and the surgical experiences.

P12.02 * BRAINSTEM HEMANGIOBLASTOMAS IN PATIENTS WITH VON HIPPEL-LINDAU DISEASE - SURGICAL CONSIDERATIONS

BACKGROUND: Von Hippel-Lindau disease (VHL) predisposes to the development of CNS hemangioblastomas. Brainstem hemangioblastomas present in 15 to 30% of VHL patients, particularly in the medulla. Hemangioblastomas at this location are characteristic and almost exclusive for VHL. There is scarce information about the most adequate management of these particular tumors. The objective of this work is to analyze the results of treatment at a VHL dedicated unit and following personal surgical criteria. MATERIAL AND METHODS: Since 2001 we have studied and treated 105 patients with VHL disease. Thirty three have presented brainstem hemangioblastomas. A microsurgical resection was performed of tumors when symptomatic and/or growing to a diameter of 1.5 cm. In all cases, neuronavigation and neurophysiology intraoperative monitorization (NIM) were used. All patients have a postoperative clinical and imaging follow up of at least 12 months (mean 47.37 m). Clinical evaluation has been monitored with McCormick and Karnofsky scales before surgery, at immediate postoperative, and 1, 6 and 12 months later. RESULTS: Twenty one surgical procedures were performed in sixteen patients, 9 males and 7 women, with mean age of 40.6 y (range 15-49 y), for resection of 26 brainstem hemangioblastomas. Mean tumor maximal diameter was 17.9 mm. Most frequent symptoms were sensory and motor disturbances, dizziness, and unsteadiness. Some cases presented very particular symptoms, as recurrent hiccup, persistent nausea, and dysphagia. Three patients were asymptomatic, and surgery was proposed because of rapid tumor growth up to more than 15 mm. All patients did well, improving their symptoms and maintaining or improving their functional level. CONCLUSIONS: The resection of brainstem hemangioblastomas in VHL patients can be followed by very good results, when indicated with specific criteria and performed in expert units. Neuronavigation and NIM are recommended tools for accurate and safe procedures. We recommend brainstem hemangioblastoma surgery just at the beginning of symptoms, and/or when tumor diameter grows equal to or exceeds 15 mm, in order to maximize the preservation of brainstem tissue and nearby vasculature shared by the tumor, providing the best functional recovery.

O5.10 * 5-ALA FLUORESCENCE GUIDED RESECTION OF HEMANGIOBLASTOMAS - IS IT USEFUL WITH CONVENTIONAL SURGICAL TOOLS?

BACKGROUND: The use of 5-aminolevulinic acid (5-ALA) for fluorescent guided malignant glioma surgery has proved to be useful to ensure a complete resection and thus, a best survival result. One report has described its usefulness for the detection of hemangioblastoma fragments at the cyst wall after apparently complete tumor resection. Von Hippel-Lindau disease patients suffer from many CNS hemangioblastomas, requiring multiple surgical procedures for resection of tumors, many times obscured because distorted structures and dense gliotic scars. MATERIAL AND METHODS: In order to test the eventual utility of 5-ALA fluorescent guided surgery in multiple hemangioblastomas, we have performed surgical procedures in two VHL patients for resection of multiple hemangioblastomas. After patient consent and approval by the Ethical Committee, 5-ALA was administered as oral dose 20 mg/kg 3 hours before anesthesia induction. A surgical microscope modified for Protoporphyrin IX (PpIX)fluorescence guidance, and frameless neuronavigation were used for the surgical procedure. After neuronavigated location and microsurgical dissection of tumors, some involved in dense scars, surgical field visualization was performed alternating standard light illumination and violet-blue light mode, to excite PpIX and collect fluorescence by visualization in surgical oculars and registration on a color camera. RESULTS: Both VHL patients had been previously subjected to surgical procedures for resection of previous posterior fossa tumors. In one case, resection of 7 cerebellar and brainstem tumors was planned on neuronavegator after MRI images, and performed; postsurgical MRI showed a one residual tumor, unnoticed during the surgical procedure because dense scarring tissue. In the second patient, 4 tumors were planned for resection, 3 in cerebellum and 1 in brainstem, and all of them were found and resected. In no case red remitted fluorescence was observed during the location, dissection or resection of tumors. Histopathology analysis proved that all 11 tumors were typical hemangioblastomas. One small area with pink remitted fluorescence in the surgical bed of a tumor proved to be just gliosis without tumor cells. CONCLUSIONS: In the present cases, 5-ALA fluorescent guided surgery for multiple hemangioblastoma resections has not been of utility with the regular surgical armamentarium, instead of the above mentioned experience from one author. The different system for fluorescence evaluation (adapted surgical microscope visualization versus spectroscopy adapted probe system and digitized evaluation) could explain the different results. Other studies are necessary to confirm the results with regular surgical armamentarium, and to explore ancillary tools for detection of localization and extension of CNS tumors under fluorescent conditions during surgical procedures.