Spinal arteriovenous malformation (AVM) is a broad term that constitutes diverse vascular pathologies. To date, various classification schemes for spinal AVM have been proposed in literature, which helped neurosurgeons understand the pathophysiology of the disease and determine an optimal treatment strategy. To discuss indications and results of surgical and endovascular interventions for spinal AVM, this article refers to the following classification proposed by Anson and Spetzler in 1992: type I, dural arteriovenous fistula (AVF); type II, glomus intramedullary AVM; type III, juvenile malformations; and type IV, perimedullary AVF. In general, complete obliteration of the fistula is a key for better outcome in type I dural and type IV perimedullary AVFs. On the other hand, in type II glomus and type III juvenile malformations, functional preservation, instead of pursuing angiographical cure, is the main goal of the treatment. In such cases, reduction of the shunt flow can alleviate clinical symptoms. Proper management of spinal AVM should start with neurological examination and understanding of angioarchitectures, which provide critical information that guides the indication and modality of intervention. Finally, close collaboration of the microsurgical and endovascular teams are mandatory for successful treatment.

Object: Spinal intradural arachnoid cysts are a rare cause of spinal cord compression. Since 2000, the authors have treated patients using 2- or 3-level hemilaminectomy or laminectomy followed by partial cyst wall resection as well as endoscopic inspection and fenestration of the cyst wall. They evaluated the usefulness and reliability of endoscopic treatment for this clinical entity based on long-term follow-up results. Methods: Between 1997 and 2003, 11 patients (3 males and 8 females) with spinal intradural arachnoid cysts were treated, and the authors conducted a retrospective review of these cases. Before 2000, 5 patients were surgically treated without the use of endoscopic techniques. During that time, more than 4 levels of hemilaminectomy were performed to expose and remove cyst walls that extended longitudinally over the spinal axis. Beginning in 2000, endoscopy was used in all 6 cases. Up to 3 levels of hemilaminectomy or 2 levels of laminectomy were performed, and the cyst wall was resected through the bone window. An endoscope was inserted into the cyst cavity and moved in the cranial and caudal direction to fenestrate the cyst wall, resulting in communication of the cyst cavity with the subarachnoid space. Results: Postoperatively, the neurological symptoms of all patients improved. During long-term follow-up (mean 114.8 months), none of the patients treated with or without endoscopy experienced recurrent cyst formation. Conclusions: Endoscopic techniques allow neurosurgeons to treat spinal intradural arachnoid cysts less invasively than with standard surgical approaches. Although the number of cases reviewed in this report is small, the data suggest that the use of endoscopy can be an important option in the surgical treatment of spinal arachnoid cysts.

Objective: We performed a retrospective observational study to demonstrate the surgical risks and long-term prognoses of intramedullary tumors in Japan using a multicenter registry authorized by the Neurospinal Society of Japan.Methods: Data from 1,033 consecutive patients with intramedullary tumors, treated between 2009 and 2020, were collected from 58 centers. Patients with spinal lipomas or myxopapillary ependymomas were excluded. Patient characteristics, clinical presentations, imaging characteristics, treatments, and outcomes were analyzed. The modified McCormick scale was used to classify functional status. Survival was described using Kaplan-Meier curves, and multivariable logistic regression analyses were performed.Results: The mean age of the patients was 48.4 years. Data of 361 ependymomas, 196 hemangioblastomas, 168 astrocytic tumors, 160 cavernous malformations, and the remaining 126 cases including subependymomas, metastases, schwannomas, capillary hemangiomas, and intravascular B-cell lymphomas were analyzed. Twenty-two patients were undiagnosed. The mean follow-up duration was 46.1 ± 38.5 months. Gross total tumor removal was achieved in 672 tumors (65.1%). On the modified McCormick scale, 234 patients (22.7%) had worse postoperative grades at the time of discharge. However, neurological status gradually improved. At 6 months postoperatively, 251 (27.5%), 500 (54.9%), and 160 patients (17.6%) had improved, unchanged, and worsened grades, respectively. Preoperative functional status, gross total tumor removal, and histopathological type were significantly associated with mortality and functional outcomes.Conclusion: Our findings demonstrate better postoperative functional outcomes in patients with fewer preoperative neurological deficits. Degree of resection, postoperative treatments, and prognoses are closely related to the histology of intramedullary tumors.

BACKGROUND:. Reports of cervical perimedullary arteriovenous shunt (PMAVS) are limited, and treatment strategies have not been established.OBJECTIVE:. T