Microwave Ablation as a Treatment for Spinal Metastatic Tumors: A Systematic Review.

BACKGROUND: Microwave ablation (MWA) is a novel technique that offers several potential advantages over existing ablation systems, which include production of larger ablation zones, shorter procedural times, and more effective heating through high impedance tissues such as bone. METHODS: A systematic review was performed using inclusion criteria defined as follows: 1) metastatic spinal tumors treated with open or percutaneous MWA alone or in combination with other treatments, 2) available data on pain palliation and/or local tumor control, and 3) retrospective or prospective studies with at least 1 patient. RESULTS: A total of 156 patients harboring 196 spinal lesions underwent MWA in the 8 included studies. Most studies employed the use of additional interventions, which included minimally invasive open surgery with pedicle screw fixation, traditional open surgical intervention, and cement augmentation. Despite the variability in time intervals for pain assessment, postoperative pain scores decreased considerably in both percutaneous and open MWA studies. No evidence of tumor progression was additionally seen in >80% of patients at the last follow-up across 5 studies. Complications were reported in 6.5% of all patients who underwent percutaneous MWA and in 12.2% of patients who underwent open MWA. CONCLUSIONS: This review showed that MWA can be effective in achieving analgesia for up to 6 months in select cases, although most procedures were performed in combination with augmentation and/or open surgery. Local tumor control was additionally successful in most patients, suggestive of a potential curative role for MWA.

Embolization of brain arteriovenous malformations with intent to cure: a systematic review.

OBJECTIVE: Endovascular embolization has been established as an adjuvant treatment strategy for brain arteriovenous malformations (AVMs). A growing body of literature has discussed curative embolization for select lesions. The transition of endovascular embolization from an adjunctive to a definitive treatment modality remains controversial. Here, the authors reviewed the literature to assess the lesional characteristics, technical factors, and angiographic and clinical outcomes of endovascular embolization of AVMs with intent to cure. METHODS: Electronic databases-Ovid MEDLINE, Ovid Embase, and PubMed-were searched for studies in which there was evidence of AVMs treated using endovascular embolization with intent to cure. The primary outcomes of interest were angiographic obliteration immediately postembolization and at follow-up. The secondary outcomes of interest were complication rates. Descriptive statistics were used to calculate rates and means. RESULTS: Fifteen studies with 597 patients and 598 AVMs treated with intent-to-cure embolization were included in this analysis. Thirty-four percent of AVMs were Spetzler-Martin grade III. Complete obliteration immediately postembolization was reported in 58.3% of AVMs that had complete treatment and in 45.8% of AVMs in the entire patient cohort. The overall clinical complication rate was 24.1%. The most common complication was hemorrhage, occurring in 9.7% of patients. Procedure-related mortality was 1.5%. CONCLUSIONS: While endovascular embolization with intent to cure can be an option for select AVMs, the reported complication rates appear to be increased compared with those in studies in which adjunctive embolization was the goal. Given the high complication rate related to a primary embolization approach, the risks and benefits of such a treatment strategy should be discussed among a multidisciplinary team. Curative embolization of AVMs should be considered an unanticipated benefit of such therapy rather than a goal.

Hypoglossal schwannomas: A systematic review of the literature.

BACKGROUND: Schwannomas of the hypoglossal nerve are rare and account for a very small percentage of non-vestibular schwannomas. OBJECTIVES: In this systematic review of the literature, we examined the epidemiology, symptomatology, management, and outcomes of patients with hypoglossal schwannomas. METHODS: The electronic database Pubmed was searched for all reports of hypoglossal schwannomas with descriptions of symptoms, management, and outcome characteristics. Data was extracted from each study and compiled in a spreadsheet. Continuous variables were reported as means and medians. Categorical variables were reported as proportions. Additional analysis was not done due to inconsistent reporting of outcomes and small sample sizes. RESULTS: A total of 59 studies (94 total individual cases) were included. 64% of patients were female with mean age of 44.6 years. The majority were intracranial/extracranial (50%). The most common symptoms were tongue deviation or speech disturbance (38%) and headaches (33%). Hypoglossal nerve dysfunction was present in 80% of patients. Surgical excision was performed in 93%, with a 15% complication rate. Evidence of residual mass after surgery was noted in 29%. Permanent hypoglossal nerve deficits occurred in 67%. Recurrence of tumor burden was reported in 6 studies, with median time to recurrence of 16.5 months. CONCLUSION: Current evidence suggests overall favorable outcomes with surgical resection of hypoglossal schwannomas, with a large percentage of patients experiencing mild and usually well-tolerated neurologic deficit. Limitations of this study include the use of retrospective data taken from case reports/series with highly selected patients, selective reporting, and absence of control groups.

Encephalopathy following melphalan administration.

OBJECTIVE: To describe a rare case of encephalopathy following melphalan administration. Presentation and intervention:: A 59-year-old female with multiple myeloma developed encephalopathy following administration of melphalan. After ruling out other aetiologies, we hypothesized elevated cytokines from systemic inflammatory response to melphalan as the likely aetiology. The TNF-alpha level was found to be significantly elevated. Plasmapharesis was performed which reduced the level of cytokines, and also improved the patient's neurological status. CONCLUSION: Melphalan administration, especially in renally impaired patients, may lead to development of encephalopathy. Based on our case report, we suggest that elevated levels of cytokines could be the underlying mechanism of worsening mental status.