The supraorbital approach for recurrent or residual suprasellar tumors.

BACKGROUND: Suprasellar tumors can be removed through a variety of approaches including conventional frontotemporal craniotomies, the transsphenoidal route, or the supraorbital (SO) eyebrow craniotomy. Herein we assess the utility of the SO route for recurrent or residual suprasellar tumors previously treated by an alternative route. MATERIAL AND METHODS: A retrospective analysis of all consecutive patients who underwent an SO approach for removal of a recurrent/residual tumor was undertaken. RESULTS: Between December 2007 and February 2010, 11 patients underwent an SO craniotomy for a recurrent or growing residual tuberculum sellae meningioma (n=7) or craniopharyngioma (n=4). All 11 patients had prior craniotomies, 5 had transsphenoidal surgery, 6 had radiation treatment, and 1 had chemotherapy. In the last 5 cases, the endoscope was used in addition to the microscope for intraoperative visualization. 3 patients underwent decompression of multicystic craniopharyngiomas and the remaining 8 patients had tumor debulking, all achieving 70% or more tumor removal. Of 9 patients with preoperative visual deterioration, 6 (67%) had improvement and no patient had visual worsening. No new adenohypophysis or neurohypophysis dysfunction was noted. One patient had a postoperative CSF leak requiring reoperation. CONCLUSION: The SO approach should be considered as a safe and effective alternative route for recurrent or residual suprasellar tumors previously treated by conventional craniotomy or TS surgery. It typically offers a simplified trajectory that minimizes scar tissue from prior approaches and provides excellent access for optic apparatus decompression. Endoscopy is helpful to visualize hidden tumor remnants and maximize safe tumor removal.

Vidian nerve neurofibroma removed via a transpterygoid approach.

BACKGROUND: Lesions originating in the vidian canal are extremely rare. Most frequently, they are extensions from contiguous carcinomas. We present a rare case of a vidian nerve neurofibroma and discuss its surgical management. CASE REPORT: A 62-year-old woman with a history of a basal cell skin cancer was evaluated for bilateral tinnitus. Imaging revealed a left-sided lesion at the medial aspect of the pterygoid process base, over the vidian canal. Under image-guidance, an endonasal endoscopic transpterygoid approach was performed. The histopathological examination supported the diagnosis of neurofibroma. CONCLUSION: Benign nerve sheath tumors of the vidian nerve should be considered in the differential diagnosis of a vidian canal lesion. Given the propensity of more aggressive tumors, a tissue diagnosis should be warranted in order to coordinate appropriate subsequent treatment. The expanded endonasal transpterygoid approach offers a safe, less invasive, and effective route to perform the excisional biopsy of such a lesion.

Animal model for endoscopic neurosurgical training: technical note.

OBJECTIVE: The learning curve for endonasal endoscopic and neuroendoscopic port surgery is long and often associated with an increase in complication rates as surgeons gain experience. We present an animal model for laboratory training aiming to encourage the young generation of neurosurgeons to pursue proficiency in endoscopic neurosurgical techniques. METHODS: 20 Wistar rats were used as models. The animals were introduced into a physical trainer with multiple ports to carry out fully endoscopic microsurgical procedures. The vertical and horizontal dimensions of the paired ports (simulated nostrils) were: 35×20 mm, 35×15 mm, 25×15 mm, and 25×10 mm. 2 additional single 11.5 mm endoscopic ports were added. Surgical depth varied as desired between 8 and 15 cm. The cervical and abdominal regions were the focus of the endoscopic microsurgical exercises. RESULTS: The different endoscopic neurosurgical techniques were effectively trained at the millimetric dimension. Levels of progressive surgical difficulty depending upon the endoneurosurgical skills set needed for a particular surgical exercise were distinguished. LEVEL 1 is soft-tissue microdissection (exposure of cervical muscular plane and retroperitoneal space); LEVEL 2 is soft-tissue-vascular and vascular-capsule microdissection (aorto-cava exposure, carotid sheath opening, external jugular vein isolation); LEVEL 3 is artery-nerve microdissection (carotid-vagal separation); LEVEL 4 is artery-vein microdissection (aorto-cava separation); LEVEL 5 is vascular repair and microsuturing (aortic rupture), which verified the lack of current proper instrumentation. CONCLUSION: The animal training model presented here has the potential to shorten the length of the learning curve in endonasal endoscopic and neuroendoscopic port surgery and reduce the incidence of training-related surgical complications.

The antero-medial triangle: the risk for cranial nerves ischemia at the cavernous sinus lateral wall. Anatomic cadaveric study.

OBJECTIVE: Vascular damage in the cavernous sinus can cause ischemic injury to the cranial nerves. An appropriate anatomical knowledge of the blood supply to the cranial nerves can help to reduce the morbidity associated with cavernous sinus surgery. MATERIAL AND METHODS: Three formalin-fixed and six adult cadaveric fresh heads, with common carotid arteries injected, were used for anatomical dissection in this study. A fronto-temporal craniotomy was performed and the cavernous sinus was explored according to the Dolenc technique. With microsurgical dissection and photographic documentation, we demonstrate the anatomy of the superior orbital fissure artery in the antero-medial triangle. RESULTS: The 12 explored cavernous sinuses demonstrated the presence of two principal branches directly from the intracavernous internal carotid artery that supply the cranial nerves: the infero-lateral trunk and the meningohypophyseal trunk. The artery of the Superior Orbital Fissure (SOF), originated more often from the infero-lateral trunk, and vascularized the III, IV, VI, and VI, and ophtalmic division of the trigeminal nerve (TGN VI) at their entry in the fissure. CONCLUSION: In this study we demonstrate that the superior orbital fissure artery is a branch from the infero-lateral trunk which runs immediately under the reticularis layer at the level of the anteromedial triangle in the lateral wall of the cavernous sinus. The blood supply to all cranial nerves in the SOF is at risk to injury when the lateral wall of the cavernous sinus is transgressed at the anteromedial triangle since the SOF-artery runs superficially at this level.

Stenting and angioplasty of the symptomatic chronically occluded carotid artery.

Patients with hemodynamic impairment ipsilateral to a carotid occlusion are at a high risk of subsequent stroke, and currently 2 surgical options have been studied: extracranial-to-intracranial bypass and direct thromboendarterectomy. We report the successful revascularization of 2 symptomatic chronically occluded carotid arteries with stenting and angioplasty.

Comprehensive transcript analysis in small quantities of mRNA by SAGE-lite.

Serial analysis of gene expression (SAGE) is a powerful technique that can be used for global analysis of gene expression. Its chief advantage over other methods is that SAGE does not require prior knowledge of the genes of interest and provides quantitative and qualitative data of potentially every transcribed sequence in a particular tissue or cell type. Furthermore, SAGE can quantify low-abundance transcripts and reliably detect relatively small differences in transcript abundance between cell populations. However, SAGE demands high input levels of mRNA which are often unavailable, particularly when studying human disease. To overcome this limitation, we have developed a modification of SAGE that allows detailed global analysis of gene expression in extremely small quantities of tissue or cultured cells. We have called this approach 'SAGE-Lite'. This technique was used for the global analysis of transcription in samples of normal and pathological human cerebrovasculature to study the molecular pathology of intracranial aneurysms. These samples, which are obtained during operative surgical repair, are typically no bigger than 1 or 2 mm and yield <100 ng of total RNA. In addition, we show that SAGE-Lite allows simple and rapid isolation of long cDNAs from short (15 bp) SAGE sequence tags.

Molecular anatomy of an intracranial aneurysm: coordinated expression of genes involved in wound healing and tissue remodeling.

BACKGROUND AND PURPOSE: Approximately 6% of human beings harbor an unruptured intracranial aneurysm. Each year in the United States, >30 000 people suffer a ruptured intracranial aneurysm, resulting in subarachnoid hemorrhage. Despite the high incidence and catastrophic consequences of a ruptured intracranial aneurysm and the fact that there is considerable evidence that predisposition to intracranial aneurysm has a strong genetic component, very little is understood with regard to the pathology and pathogenesis of this disease. METHODS: To begin characterizing the molecular pathology of intracranial aneurysm, we used a global gene expression analysis approach (SAGE-Lite) in combination with a novel data-mining approach to perform a high-resolution transcript analysis of a single intracranial aneurysm, obtained from a 3-year-old girl. RESULTS: SAGE-Lite provides a detailed molecular snapshot of a single intracranial aneurysm. These data suggest that, at least in this specific case, aneurysmal dilation results in a highly dynamic cellular environment in which extensive wound healing and tissue/extracellular matrix remodeling are taking place. Specifically, we observed significant overexpression of genes encoding extracellular matrix components (eg, COL3A1, COL1A1, COL1A2, COL6A1, COL6A2, elastin) and genes involved in extracellular matrix turnover (TIMP-3, OSF-2), cell adhesion and antiadhesion (SPARC, hevin), cytokinesis (PNUTL2), and cell migration (tetraspanin-5). CONCLUSIONS: Although these are preliminary data, representing analysis of only one individual, we present a unique first insight into the molecular basis of aneurysmal disease and define numerous candidate markers for future biochemical, physiological, and genetic studies of intracranial aneurysm. Products of these genes will be the focus of future studies in wider sample sets.

CT-based assessment of acute stroke: CT, CT angiography, and xenon-enhanced CT cerebral blood flow.

BACKGROUND AND PURPOSE: Only a small percentage of acute-stroke patients receive thrombolytic therapy because of time constraints and the risks associated with thrombolytic therapy. We sought to determine whether xenon-enhanced CT (XeCT) cerebral blood flow (CBF) and/or CT angiography (CTA) in conjunction with CT can distinguish subgroups of acute ischemic stroke victims and thereby better predict the subgroups most likely to benefit and not to benefit from thrombolytic therapy. METHODS: An analysis of 51 patients who had a CT, CTA, and stable XeCT CBF examination within 24 hours of stroke symptom onset was conducted. These initial radiographic studies and National Institutes of Health Stroke Scale score on admission were assessed to determine whether they could predict new infarction on follow-up CT or discharge disposition by use of the Fisher exact test to determine statistical significance. RESULTS: Patients with no infarction on initial CT and normal XeCT CBF had significantly fewer new infarctions and were discharged home more often than those with compromised CBF. The same held true for patients with an open internal carotid artery and middle cerebral artery by CTA and normal CT compared with those with an occluded internal carotid artery and/or middle cerebral artery by CTA. Either was superior to CT and the National Institutes of Health Stroke Scale in prediction of outcome. Both enable the selection of a group of patients not identifiable by CT alone that would do well without being exposed to the risks of thrombolytic therapy. This study included too few patients to statistically assess the role of combining CTA and XeCT CBF information. CONCLUSIONS: The combination of CT, CTA, and Xe/CT CBF does define potentially significant subgroups of patients. The utility of this classification is supported by the observation that CTA and XeCT CBF are superior to CT alone in predicting infarction on follow-up CT and clinical outcome. This information may be useful in selecting patients for acute-stroke treatment.

Endoscopic and endoscopic-assisted surgery for juvenile angiofibroma.

OBJECTIVES/HYPOTHESIS: The mainstay treatment for juvenile angiofibromas is surgery. Endoscopic techniques have been applied to the resection of juvenile angiofibromas. The aim of the study is to establish the efficacy of endoscopic and endoscopic-assisted techniques for the removal of juvenile angiofibromas. STUDY DESIGN: Retrospective review. METHODS: Retrospective review was made of all patients with juvenile angiofibromas who were treated with endoscopic and endoscopic-assisted surgery from January 1994 to July 1999. RESULTS: Fifteen tumors in 13 patients were removed using endoscopic or endoscopic-assisted surgeries. In 11 patients, endoscopic surgery or endoscopic-assisted surgery (or both) was successful and the patients remained without evidence of disease at a median follow-up of 34 months. In two patients tumor persisted, which was detected during routine follow-up less than 6 months after the initial surgery. These tumors were managed with a second endoscopic or endoscopic-assisted surgery, and patients remained without evidence of disease. We encountered one postoperative complication, a progressive optic neuropathy that was successfully managed with endoscopic decompression. CONCLUSIONS: Endoscopic and endoscopic-assisted surgery is a feasible alternative or adjunct to traditional techniques.

Pituitary surgery.

This article focuses on surgical indications, perioperative management, and endoscopic approaches for pituitary surgery. Also discussed are sinonasal, neurologic, and endocrine complications, which may include bleeding, sinusitis, and synechiae; cerebrospinal fluid leaks and bleeding; and diabetes insipidus and panhypopituitarism, respectively.

Endoscopic endonasal approach for the treatment of schwannomas of the pterygopalatine fossa: case report and review of the literature.

INTRODUCTION: Pterygopalatine fossa (PPF) schwannomas are rare lesions most often arising from branches of the trigeminal nerve. Symptomatic lesions have been traditionally treated by conventional external approaches. However, the development of an expanded endonasal approach (EEA) enables skull base surgeons to reach these deeply seated lesions via a different route with its own advantages and drawbacks. METHODS: Case report and review of the literature. CASE DESCRIPTION: A 41-year-old woman presented with a 6-year history of right facial pain and numbness. Her symptoms had increased progressively over a year, and she recently had developed right-sided otalgia. MRI revealed a right PPF mass, hypointense on T1 and T2 sequences with homogeneous enhancement following the use of gadolinium. A biopsy, attempted at another institution, was considered non-diagnostic. We totally removed the lesion through an endoscopic endonasal transmaxillary approach. Final pathology confirmed the diagnosis of schwannoma. Post-operatively, the patient noted a significant improvement of her facial pain (V2 territory). CONCLUSION: The endonasal endoscopic transmaxillary approach provides adequate access to the PPF, thus enabling safe tumor removal with less morbidity than conventional routes.

Endoscopic, endonasal decompression of spinal stenosis with myelopathy secondary to cranio-vertebral tuberculosis: two cases.

BACKGROUND: Tuberculosis can cause extensive osseo-ligamentous destruction at the cranio-vertebral junction, leading to atlanto-axial instability and compression of vital cervico-medullary centres. This may manifest as quadriparesis, bulbar dysfunction and respiratory insufficiency. AIM: We report two patients presenting with spinal stenosis and cord compression secondary to cranio-vertebral tuberculosis, who were successfully decompressed via an endoscopic, endonasal approach. STUDY DESIGN: Two case reports. METHODS AND RESULTS: Both patients were successfully decompressed via an endoscopic, endonasal approach which provided access to the cranio-vertebral junction and upper cervical spine. CONCLUSION: An endoscopic, endonasal approach is feasible for the surgical management of cranio-vertebral junction stenosis; such an approach minimises surgical trauma to critical structures, reducing post-operative morbidity and the duration of hospital stay.

The MR imaging appearance of the vascular pedicle nasoseptal flap.

BACKGROUND AND PURPOSE: Recently, surgeons have used an expanded endonasal surgical approach (EENS) to access skull base lesions not previously accessible by minimally invasive techniques. Reconstruction of the large skull base defects created during EENS is necessary to prevent postoperative CSF leaks. A vascular pedicle nasoseptal mucoperiosteal flap based on the nasoseptal artery, (Hadad-Bassagasteguy flap) is becoming a common reconstructive technique. The purpose of this study was to review the expected MR imaging appearance of these flaps and to discuss variations in the appearance that may suggest potential flap failure. MATERIALS AND METHODS: We retrospectively reviewed 10 patients who underwent EENS for resection of sellar lesions with skull base reconstruction by multilayered reconstruction including the Hadad-Bassagasteguy flap. All patients had preoperative, immediate, and delayed postoperative MR imaging scans. Flap features that were evaluated included flap configuration, signal intensity characteristics on T1-weighted and T2-weighted images, enhancement patterns, location, and flap thickness. RESULTS: All patients had detectable postoperative skull base defects. All patients had C-shaped configuration flaps within the operative defect, which were isointense on T1-weighted and T2-weighted images on both immediate and delayed postoperative MR imaging scans. On the immediate scans, 8 of 10 patients had enhancing flaps and 2 of 10 had minimal to no enhancement. There were 9 of 10 patients who had enhancing flaps on delayed scans, and 2 of 10 patients had flaps that increased in enhancing coverage on the delayed scans. CONCLUSIONS: Vascular pedicle nasoseptal flaps have a characteristic MR imaging appearance. It is important for the radiologist to recognize this appearance and to evaluate for variations that may suggest potential flap failure.

Hypoxia promotes expansion of the CD133-positive glioma stem cells through activation of HIF-1alpha.

Hypoxia contributes to the progression of a variety of cancers by activating adaptive transcriptional programs that promote cell survival, motility and tumor angiogenesis. Although the importance of hypoxia and subsequent hypoxia-inducible factor-1alpha (HIF-1alpha) activation in tumor angiogenesis is well known, their role in the regulation of glioma-derived stem cells is unclear. In this study, we show that hypoxia (1% oxygen) promotes the self-renewal capacity of CD133-positive human glioma-derived cancer stem cells (CSCs). Propagation of the glioma-derived CSCs in a hypoxic environment also led to the expansion of cells bearing CXCR4 (CD184), CD44(low) and A2B5 surface markers. The enhanced self-renewal activity of the CD133-positive CSCs in hypoxia was preceded by upregulation of HIF-1alpha. Knockdown of HIF-1alpha abrogated the hypoxia-mediated CD133-positive CSC expansion. Inhibition of the phosphatidylinositol 3-kinase(PI3K)-Akt or ERK1/2 pathway reduced the hypoxia-driven CD133 expansion, suggesting that these signaling cascades may modulate the hypoxic response. Finally, CSCs propagated at hypoxia robustly retained the undifferentiated phenotype, whereas CSCs cultured at normoxia did not. These results suggest that response to hypoxia by CSCs involves the activation of HIF-1alpha to enhance the self-renewal activity of CD133-positive cells and to inhibit the induction of CSC differentiation. This study illustrates the importance of the tumor microenvironment in determining cellular behavior.

A failure to communicate: patients with cerebral aneurysms and vascular neurosurgeons.

OBJECTIVE: To assess communication between vascular neurosurgeons and their patients with unruptured cerebral aneurysms about treatment options and expected outcomes. METHODS: Vascular neurosurgeons and their patients with cerebral aneurysms were surveyed immediately following outpatient appointments in a neurosurgery clinic. Data collected included how well the patient understood their aneurysm treatment options, the risks of a poor outcome from various treatments, and the consensus "best" treatment. Patient and neurosurgeon responses were measured using Likert scales, multiple choice questions, and visual analogue scales. Agreement between patient and neurosurgeon was assessed with kappa scores. The Wilcoxon sign rank test was used to compare visual analogue scale responses. RESULTS: Data for 44 patient-neurosurgeon pairs were collected. Only 61% of patient-neurosurgeon pairs agreed on the best treatment plan for the patient's aneurysm (kappa = 0.51, moderate agreement). Among the neurosurgeons, agreement with their patients ranged from 82% (kappa = 0.77, almost perfect agreement) to 52% (kappa = 0.37, fair agreement). Patients estimated much higher risks of stroke or death from surgical clipping, endovascular embolisation, or no intervention compared with the estimates offered by their neurosurgeons (surgical clipping: patient 36% v neurosurgeon 13%, p<0.001; endovascular embolisation: patient 35% v neurosurgeon 19%, p = 0.040; and no INTERVENTION: patient 63% v neurosurgeon 25%, p<0.001). CONCLUSIONS: Following consultation with a vascular neurosurgeon, many patients with cerebral aneurysms have an inaccurate understanding of their aneurysm treatment plan and an exaggerated sense of the risks of aneurysmal disease and treatment.

Aneurysm rupture during endovascular coiling: effects on cerebral transit time and neurophysiologic monitoring and the benefits of early ventriculostomy: case report.

OBJECTIVE AND IMPORTANCE: We report a case of intra-operative aneurysm rupture during endovascular therapy and document the effects of rupture on cerebral transit times and neurophysiologic monitoring. The effects of early ventriculostomy are clearly documented. CLINICAL PRESENTATION: A 42-year-old man with Hunt and Hess grade 1, Fisher grade 3 subarachnoid hemorrhage secondary to a 5 mm anterior communicating artery aneurysm underwent coil embolization. INTERVENTION: Endovascular therapy was complicated by intraprocedural aneurysm rupture. Changes in cerebral transit time and electroencephalography along with somatosensory evoked potentials were documented as were improvement in these parameters following aneurysm obliteration and ventriculostomy placement. The patient awoke without deficit and was discharged 2 weeks later with a grossly normal examination. CONCLUSION: Early recognition of aneurysm rupture during coil embolization and prompt aneurysm obliteration and reduction in intracranial hypertension can lead to acceptable patient outcomes. Use of neurophysiologic monitoring in the intubated patient can help the neurosurgeon determine the need for cerebrospinal fluid drainage in such situations.

Neurilemmomas of the paranasal sinuses.

Within the head and neck region, neurilemmomas are rarely found in the nasal cavity or paranasal sinuses. A 70-year-old man presented with complaints of left-sided epiphora, rhinorrhea, epistaxis, and transient diplopia. Nasal endoscopy showed a large necrotic mass filling the left middle meatus. A computed tomography scan showed a large left ethmoid mass, with erosion of the medial wall of the orbit and the anterior cranial base. Multiple biopsies were nondiagnostic. Complete excision of the tumor was performed with endoscopic techniques. Small dural defects were repaired with a middle turbinate mucosal flap. Postoperatively, the patient was treated with nasal packing and a lumbar spinal drain. Final pathology showed a benign neurilemmoma. There has been no evidence of recurrence or cerebrospinal fluid leakage in follow-up. A review of the literature shows a similar presentation of patients with neurilemmomas of the paranasal sinuses. Bony destruction and intracranial extension is viewed. Lack of encapsulation and locally destructive growth in an otherwise histologically typical neurilemmoma should not suggest malignant potential. Many benign tumors of the paranasal sinuses with bone destruction may be removed by using endoscopic techniques.