Posttraumatic Progressive Vertebral Hemangioma Induced by a Fracture.

The authors present an extremely rare case of an aggressive and progressive vertebral capillary hemangioma of the lumbar spine secondary to a trauma. A 40-year-old man who complained of back and leg pain due to a hemangioma of L1 that had begun a year after the fracture of the same vertebra was subsequently operated on. Due to the profuse bleeding, only a subtotal removal was possible. Histopathological diagnosis of the lesion revealed a capillary hemangioma. Postoperative control MRI taken at eight months showed that the lesion and destruction of the L1 vertebra were progressive. A second embolization procedure was performed and this time the hemangioma was totally removed via an anterior approach and corpectomy. Fusion was achieved by Th12-L2 graft and plaque. In the fourteenth year of follow-up, he was symptom-free and radiologically clear of this lesion. We propose that progressive hemangioma is extremely rare and that its cure is possible by total surgical removal of the lesion. This case is the second extradural capillary hemangioma secondary to spinal trauma ever to have been documented in English literature. The emergence of a hemangioma in a fractured vertebra suggests that its pathogenesis can be related to the deviation of the angiogenetic pathways from the normal healing process.

Superior medullary velum: anatomical-histological study in the sheep brain and a preliminary tractographic study in the human brain.

AIM: To study the anatomy, histology and fiber relations of the superior medullary velum. MATERIAL AND METHODS: Ten previously frozen and formalin-fixed sheep brains were used. The fiber dissection was done using the operating microscope at the Rhoton Anatomy Laboratory of Marmara Faculty of Medicine. A tractographic study was conducted on five volunteer patients to see the fiber anatomy of the superior medullary velum. RESULTS: The average thickness and length was found to be 0.296 mm (range 0.09-1 mm) and 4.25 mm (range 3.25-4.5 mm) respectively. Histologically, the superior medullary velum consisted of cuboidal layer of ependymal cells on the anterior surface related to fourth ventricle. The subependymal layer contained hypocellular fibrillary zone with few glial cells, and the outer layer consisted of thin layer of fibroblasts. Under the hypocellular fibrillary zone, abundant axons and organized structures were observed. Tractographically, only a few fibers were identified on diffusion-tensor imaging (DTI). CONCLUSION: We could not identify a distinct tract anatomically and neuron cells histologically. Neuron-like cells and organized structures were observed on immunohistochemical analysis. Also a few tracts were observed on DTI study as an ascending pathway from spinal tracts to the superior medullary velum. Further studies including human cadaveric, histologic and fiber tractographic investigations are needed to say that it is harmless to divide this anatomical structure.

An unexpected complication of occipitocervical stabilization surgery: retropharyngeal hematoma.

BACKGROUND CONTEXT: To report a unique case of an unexpected complication of occipitocervical stabilization surgery that is retropharyngeal hematoma (RH). PURPOSE: Postoperative RH is a very rare complication and has never been reported after posterior occipitocervical surgery. STUDY DESIGN: Case report. METHODS: A 44-year-old woman being treated for rheumatoid arthritis for 20 years was admitted to our hospital in a wheelchair with the complaints of neck pain and weakness in both upper and lower extremities. She was diagnosed with basilar invagination, and occipitocervical (C0-C5) transpedicular fixation with osteosynthesis using iliac autograft was performed. The airway was seen as obstructed after extubation. The airway was maintained with laryngeal mask, and computed tomography revealed an RH. Emergent tracheotomy was performed. The patient was decannulated because of the resorption of RH after 10 days and was discharged. CONCLUSION: This patient is the first patient, to our knowledge, to be reported for unexplained RH after cervical posterior spinal surgery.

Gamma knife radiosurgery inhibits angiogenesis of meningiomas: in vivo rat corneal assay.

OBJECTIVE: The aim of this study is to reveal inhibitory effect of gamma knife irradiation on angiogenesis of meningiomas using rat corneal angiogenesis assay. METHODS: A total of 72 rats were divided into three preliminary groups. Each group, consisting of 24 rats, was implanted to World Health Organization (WHO) grade I (typical), grade II (atypical), and grade III (malignant) meningioma. Each of these three preliminary groups of 24 rats, were then divided into four subgroups, each consisting of 6 rats and subsequently irradiated by gamma knife with dose prescriptions of 0, 14, 18, and 22 Gy. The numbers of vessels that developed around the micropockets of the corneas were counted and photographed on days 5, 10, 15, and 20. RESULTS: For WHO grade I meningiomas, 18 and 22 Gy doses (P < 0.001), and for grade II meningiomas, the 22-Gy (P = 0.021) dose were found to inhibit tumor-induced angiogenesis compared with the radiation-free control group. For grade III meningiomas, there was no statistical difference with the control group in any of the doses applied. Our findings demonstrate that gamma knife irradiation may suppress the angiogenic activity of WHO grades I and II meningiomas but not of the grade III meningiomas. CONCLUSIONS: For the first time, this study provides an experimental data to show the antiangiogenic effect of gamma knife irradiation on meningiomas.

Inhibition of angiogenesis induced by cerebral arteriovenous malformations using gamma knife irradiation.

OBJECT: The authors studied the effect of Gamma Knife irradiation on angiogenesis induced by cerebral arteriovenous malformation (AVM) tissues implanted in the corneas of rats. METHODS: Ten AVM specimens obtained from tissue resections performed at Marmara University between 1998 and 2004 were used. A uniform amount of tissue was implanted into the micropocket between the two epithelial layers of the cornea. Gamma Knife irradiation was applied with dose prescriptions of 15 or 30 Gy to one cornea at 100% isodose. Dosing was adjusted so that the implanted cornea of one eye received 1.5 Gy when 15 Gy was applied to the other cornea. Similarly, one cornea received 3 Gy when 30 Gy was applied to the other cornea. Angiogenic activity was graded daily by biomicroscopic observations. Forty-eight other rats were used for microvessel counting and vascularendothelial growth factor (VEGF) staining portions of the experiment. Micropieces of the specimens were again used for corneal implantation. Rats from each group were killed on Days 5, 10, 15, and 20, and four corneas from each group were examined. Gamma Knife irradiation dose dependently decreased AVM-induced neovascularization in the rat cornea as determined by biomicroscopic grading of angiogenesis, microvessel count, and VEGF expression. CONCLUSIONS: The results suggest that Gamma Knife irradiation inhibits angiogenesis induced by AVM tissue in the cornea angiogenesis model. The data are not directly related to understanding how Gamma Knife irradiation occludes existing AVM vasculature, but to understanding why properly treated AVMs do not recur and do not show neovascularization after Gamma Knife irradiation.

Bilateral internal carotid to anterior cerebral artery anastomosis with anterior communicating artery aneurysm: technical case report.

OBJECTIVE AND IMPORTANCE: The present case report is the first one to report a bilateral anastomotic artery between the internal carotid artery and the anterior communicating artery in the presence of a bilateral A1 segment, fenestrated anterior communicating artery (AComA), and associated aneurysm of the AComA, which was discovered by magnetic resonance angiography and treated surgically. CLINICAL PRESENTATION: A 38-year-old man who was previously in good health experienced a sudden onset of nuchal headache, vomiting, and confusion. Computed tomography revealed a subarachnoid hemorrhage. Magnetic resonance angiography and four-vessel angiography documented an aneurysm of the AComA and two anastomotic vessels of common origin with the ophthalmic artery, between the internal carotid artery and AComA. INTERVENTION: A fenestrated clip, introduced by a left pterional craniotomy, leaving in its loop the left A1 segment, sparing the perforating and hypothalamic arteries, excluded the aneurysm. CONCLUSION: The postoperative course was uneventful, with complete recovery. Follow-up angiograms documented the successful exclusion of the aneurysm. Defining this particular internal carotid-anterior cerebral artery anastomosis as an infraoptic anterior cerebral artery is not appropriate because there is already an A1 segment in its habitual localization. Therefore, it is also thought that, embryologically, this anomaly is not a misplaced A1 segment but the persistence of an embryological vessel such as the variation of the primitive prechiasmatic arterial anastomosis. The favorable outcome for our patient suggests that surgical treatment may be appropriate for many patients with this anomaly because it provides a complete and definitive occlusion of the aneurysm.

Testing the angiogenic potential of cerebrovascular malformations by use of a rat cornea model: usefulness and novel assessment of changes over time.

OBJECTIVE: This experimental study assessed the usefulness of a rat model of corneal angiogenesis for assessing the angiogenic activity of cerebrovascular malformations (CVMs) over time. It is the first investigation to have focused on dynamic quantification of angiogenesis related to CVMs (i.e., assessing changes over time as opposed to one point in time) and the first to have compared different CVMs and other tissues in this way. METHODS: The CVM specimens were from 15 randomly selected arteriovenous malformation (AVM) cases, 15 randomly selected cavernous malformation cases, and 2 venous angioma cases. All the samples came from surgical resections performed in the Marmara University Department of Neurosurgery and the Marmara University Institute of Neurological Sciences between January 1998 and January 2003. Glioblastoma multiforme tissues, normal adult brain tissues, and normal brain artery tissues were used as controls. Tissue from each specimen was implanted in one corneal micropocket in each cornea of a single rat, and the level of angiogenic activity in the cornea was graded (low, moderate, or high) at Days 1 through 9 after tissue implantation. Another set of rats was subjected to the same corneal implantation procedure, and two widely accepted indicators of neovascularization, microvessel counts and vascular endothelial growth factor expression, were assessed at Days 3, 5, 7, and 9 after surgery. The tissue-group results for grade of angiogenic activity, microvessel count, and grade of vascular endothelial growth factor expression were compared. RESULTS: Of the three CVM types, the AVMs showed the highest angiogenic activity, cavernous malformations exhibited some degree of angiogenic activity (less than AVMs but more than normal brain artery tissue), and angiogenesis induction by venous angiomas was comparable to that of normal brain artery tissue. Corneas implanted with the AVM samples showed Grade 1 angiogenesis on Day 2, Grade 2 angiogenesis on Day 4, and Grade 2.5 angiogenesis on Day 8. Cavernous malformation samples caused Grade 1 angiogenesis after Day 5, and grading remained less than 1.5. Venous angioma samples resulted in angiogenesis graded less than 1. CONCLUSION: The results showed that this rat model of corneal angiogenesis is of value for assessing the angiogenic potential of CVMs and for evaluating details of the neovascularization process over time. Further investigation of CVMs with this model might yield information about how angiogenesis can be modulated, and this could lead to development of biological treatments that inhibit this process.

Primary spinal extradural hydatid cyst in a child: case report and review of the literature.

Spinal hydatid cyst is a rare but serious condition. An 8-year-old boy presented with back pain, progressive weakness and numbness in both legs. Magnetic resonance imaging (MRI) of the lumbar region showed a cystic lesion with regular contour located in extradural space. There was cerebrospinal fluid- (CSF-) like signal intensity on T1- and T2-weighted images. The lesion had excessively compressed the dural sac and caudal roots, and expanded to the L3 and L4 neural foramina. The case was explored with L2, L3, L4 laminectomy and the hydatid cyst was removed totally. The clinical presentation, diagnosis and surgical treatment of this rare case of spinal hydatid disease is discussed, and all available cases of primary extradural hydatid cyst reported in the literature are presented.