World Neurosurg
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Treatment of extremely large cerebral arteriovenous malformations (AVMs) is challenging. Although volume-staged stereotactic radiosurgery (SRS) is a possible multimodal treatment option for such lesions, reports of these procedures are scarce. We evaluated the efficacy and safety of volume-staged SRS in patients with AVMs >20 cm(3) with >3 years of follow-up. ⋯ In our series, volume-staged SRS for AVMs >20 cm(3) achieved a nidus obliteration rate of 35% at 5 years. There was still a high risk for hemorrhage (∼ 4% per year) after treatment, which seemed to be higher than the rate commonly observed in the posttreatment course of single-session SRS for average-size AVMs. Further cases will help determine whether volume-staged SRS could be routinely considered, based on its efficacy and risks, including comparison with the natural history of large AVMs.
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Case Reports
The valveless saphenous vein graft technique for EC-IC high flow bypass: Technical Note.
Extracranial to intracranial (EC-IC) high-flow bypass using radial artery or saphenous vein (SV) graft has remained vital for complex aneurysms. If an Allen test is positive, the radial artery cannot be harvested because of poor palmer collateral circulation. The valves are thought to be one of causes of SV graft failure. Herein we illustrate the "valveless SV graft technique" as bypass conduits. ⋯ The valveless SV graft technique is a useful technique in patients with complex ICA aneurysms who undergo EC-IC high-flow bypass with therapeutic ICA occlusion and whose Allen tests are positive.
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Rosai-Dorfman disease is a rare benign histiocytic proliferative disorder with a self-limiting clinical course. Skull base Rosai-Dorfman disease presents with intracranial lesions that often mimic meningiomas and other benign skull base tumors. The disease is difficult to diagnose radiographically, and tissue diagnosis exposes patients to significant perioperative risk. Surgical resection may require a large skull base exposure that risks significant surgical morbidity. Aggressive surgical resection, although often attempted, is of unproven efficacy. Our objective was to determine the optimal surgical management of skull base Rosai-Dorfman disease. ⋯ Tumors commonly occur in the sellar/parasellar region and result in loss of vision. Regardless of extent of resection, the majority of patients (>78%) have subsequent tumor regression or stable disease. Steroids and/or radiation are effective treatments for tumor recurrence. Tumor biopsy followed by observation, steroids, and/or radiation may be the most appropriate surgical management of skull base Rosai-Dorfman disease.
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Accurate frameless neuronavigation is highly important in cranial neurosurgery. The accuracy demonstrated in phantom models might not be representative for results in patients. Few studies describe the in vivo quantitative accuracy of neuronavigation in patients. The use of a frameless stereotactic drilling technique for stereoelectroencephalography depth electrode implantation in epilepsy patients, as well as diagnostic biopsies, provides a unique opportunity to assess the accuracy with postoperative imaging of preoperatively planned trajectories. ⋯ In this study, we showed that the in vivo accuracy of our frameless stereotactic drilling technique, suitable for stereoelectroencephalography depth electrode placement and diagnostic brain biopsies, was 3.5 mm.
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Recent reports have validated the use of retrosigmoid approach extensions to deal with posterior fossa lesions extending laterally extracranially or superiorly into the petroclival areas. The purpose of our research is to describe the topographic retrosigmoid anatomy of the petrous pyramid and provide guidelines for neurovascular sparing drilling (hence for a functional petrosectomy), via this surgical route. ⋯ Knowledge of the topographic anatomy of the labyrinthine structures examined may be useful (combined with careful assessment of the preoperative imaging and with the use of neuronavigation and endoscopy) to accomplish a retrosigmoid neurovascular sparing petrosectomy.