Surpass Flow Diverter for Treatment of Posterior Circulation Aneurysms

BACKGROUND AND PURPOSE:Flow diverters for the treatment of posterior circulation aneurysms remain controversial. We aimed to identify factors contributing to outcome measures in patients treated with the Surpass flow diverter for aneurysms in this location.MATERIALS AND METHODS:We conducted an observational study of 53 patients who underwent flow-diverter treatment for posterior circulation aneurysms at 15 centers. Key outcome measures were mortality, complete aneurysm occlusion, and modified Rankin Scale score at follow-up.RESULTS:At follow-up (median, 11.3 months; interquartile range, 5.9–12.7 months), 9 patients had died, resulting in an all-cause mortality rate of 17.3% (95% CI, 7%–27.6%); 7 deaths (14%) were directly related to the procedure and none occurred in patients with a baseline mRS score of zero. After adjusting for covariates, a baseline mRS of 3–5 was more significantly (P = .003) associated with a higher hazard ratio for death than a baseline mRS of 0–2 (hazard ratio, 17.11; 95% CI, 2.69–109.02). After adjusting for follow-up duration, a 1-point increase in the baseline mRS was significantly (P < .001) associated with higher values of mRS at follow-up (odds ratio, 2.93; 95% CI, 1.79–4.79). Follow-up angiography in 44 patients (median, 11.3 months; interquartile range, 5.9–12.7 months) showed complete aneurysm occlusion in 29 (66%; 95% CI, 50.1%–79.5%).CONCLUSIONS:Clinical results of flow-diverter treatment of posterior circulation aneurysms depend very much on patient selection. In this study, poorer outcomes were related to the treatment of aneurysms in patients with higher baseline mRS scores. Angiographic results showed a high occlusion rate for this subset of complex aneurysms.

Flow diverters (FDs) have proved to be reliable tools for the treatment of complex aneurysms,¹ but their use for aneurysms in the posterior circulation remains controversial.^2–4 The large number of perforating and branching arteries of the posterior circulation potentially increases the risk in flow diversion, exposing patients to thromboembolic complications and brain stem stroke. FD treatment of giant, fusiform aneurysms of the vertebrobasilar (VB) junction or basilar trunk (BT) has been associated with high morbidity and mortality of up to 71%.^2–4A recent meta-analysis identified 14 studies, which reported on 225 posterior circulation aneurysms treated with FDs in 220 patients.⁵ The procedure-related good outcome rate was 79% (95% confidence interval, 72%–84%), and the procedure-related mortality rate was 15% (95% CI, 10%–21%). Most studies included only a small number of patients (median, 9.5; range, 5–55), and most of these patients (155/220) were treated with the Pipeline Embolization Device (Covidien, Irvine, California).The Surpass FD (Stryker Neurovascular, Fremont, California) has various features that seem to predetermine its use in the posterior circulation: 1) The maximum length of 50 mm allows aneurysm treatment with a single device, thus avoiding telescoping; 2) due to the rhomboid shape of the FD cells, the flow-diverting effect remains constant in tapered vessels. The rhomboid shape allows a consistent cell shape across a wide range of vessel diameters. Specifically, this feature enables consistent porosity and pore density along the length of the implant in a tapering vessel. These are known variables that contribute to flow diversion and thrombosis of the aneurysm.On the other hand, the Surpass FD has a particularly high mesh density compared with the Pipeline Embolization Device, potentially increasing the risk of perforator strokes.⁶ The purpose of this study was to identify factors contributing to outcome measures in patients treated with the Surpass FD for aneurysms located in the posterior circulation.     

Can Cerebrospinal Fluid Pressure Detect Catheter Complications in Patients Who Experience Loss of Effectiveness With Intrathecal Baclofen Therapy?

ObjectiveThe catheter status of patients who presented with loss of intrathecal baclofen (ITB) therapy effectiveness was investigated using measurements of cerebrospinal fluid (CSF) pressure transmitted through the catheter fluid path to the pump. The aim of the study was to estimate the appropriate threshold separating catheter complications from “normal” catheter function, and to compare catheter status based on CSF pressure with the clinical diagnosis.MethodsThis was a prospective, masked nonsignificant risk, research study. Patients (N = 47) received ITB for the treatment of severe spasticity and presented with symptoms of catheter malfunction. CSF pressure data were recorded using an external sensor connected to a needle inserted into the catheter access port. An algorithm calculated the energy of the variations in CSF pressure caused by respiration and heartbeat within the intrathecal space. These data were evaluated against a threshold that separated normal from abnormal catheter function. Catheter status based on the algorithm was compared with the clinical diagnosis.ResultsComplete data were available for 37 patients. Mean CSF pressure energy was significantly higher (p = 0.025; student t-test) for patients diagnosed with normal catheter function vs. catheters with complications. The CSF pressure algorithm matched the clinical diagnosis in 16 of 18 patients with catheter complications (sensitivity = 89%), and 13 of 19 patients with normal catheter function (specificity = 68%).ConclusionIn-clinic CSF pressure data acquisition is technically feasible. Overall, catheter status based on the algorithm demonstrated concordance with the clinical diagnosis in 29 of 37 patients (78.4%).     

LOVD v.2.0: the next generation in gene variant databases

Locus-Specific DataBases (LSDBs) store information on gene sequence variation associated with human phenotypes and are frequently used as a reference by researchers and clinicians. We developed the Leiden Open-source Variation Database (LOVD) as a platform-independent Web-based LSDB-in-a-Box package. LOVD was designed to be easy to set up and maintain and follows the Human Genome Variation Society (HGVS) recommendations. Here we describe LOVD v.2.0, which adds enhanced flexibility and functionality and has the capacity to store sequence variants in multiple genes per patient. To reduce redundancy, patient and sequence variant data are stored in separate tables. Tables are linked to generate connections between sequence variant data for each gene and every patient. The dynamic structure allows database managers to add custom columns. The database structure supports fast queries and allows storage of sequence variants from high-throughput sequence analysis, as demonstrated by the X-chromosomal Mental Retardation LOVD installation. LOVD contains measures to ensure database security from unauthorized access. Currently, the LOVD Website (http://www.LOVD.nl/) lists 71 public LOVD installations hosting 3,294 gene variant databases with 199,000 variants in 84,000 patients. To promote LSDB standardization and thereby database interoperability, we offer free server space and help to establish an LSDB on our Leiden server.     

Assessment of Patient Preference for Constant Voltage and Constant Current Spinal Cord Stimulation

Objectives: Spinal cord stimulation devices control energy by generating either constant voltage (CV) pulses or constant current (CC) pulses. This study aimed to investigate: 1) whether patients feel differences between CV and CC stimulation; 2) if patients prefer CV or CC stimulation. Methods: Fourteen patients blinded to the type of pulse generation received 20 randomized pairs of 15‐sec pulse trains (CC‐CV, CV‐CC, CV‐CV, or CC‐CC). Patients identified whether the pairs were the same or different, and if they preferred the first or second train. Results: There was no difference in charge‐per‐pulse input between CV and CC modes. Patients performed at chance level in identifying identical pairs (55.7 ± 24.1% correct, 10 trials), and slightly better in identifying different pairs (67.1 ± 25.2% correct, 10 trials). No patients correctly identified all pairs. Patients were categorized based on their performance in this task. Only three patients fell into a category where preference could be established with some confidence with respect to the group averages. Two of these patients preferred CV, while one patient preferred CC. Conclusion: The lack of patient ability to discriminate in this preliminary investigation suggests that patient preference for a stimulation type should not be the key determining factor in choosing a spinal cord stimulation system.     

Metal Carbonyls in the Petroleum Industry

Industrial conditions which utilize temperature, pressure, and carbon monoxide in the presence of metal catalysts are conducive to metal carbonyl formation. An evaluation of the thermodynamic equilibrium data associated with metal carbonyls shows a definite relationship between these parameters which allow us to construct nomographs concerning their equilibrium formation. Metal carbonyls represent a distinct medical hazard. Recommendations for safe exposure limits and safety devices for personnel protection are based on the toxicity associated with metal carbonyls. Analytical methods indicate that adequate monitoring of the carbonyls of nickel, cobalt, and iron can be obtained.     

牙科医生对口腔卫生服务体系的评价

目的 :分析牙科医生的日常工作量和牙医对口腔卫生服务的态度评价 ,有助于口腔卫生服务体系的制定和评价。方法 :根据武汉市卫生部门登记在册的牙科医生 ,采用整群抽样的方法随机选择 2 5 0名牙科医生进行开放式问卷调查。结果 :所调查的 2 5 0名样本中 ,5 2 %为女性 ,牙科医生平均工作年限为 11.6年 ,平均使用 0 .8台牙椅 ,每位牙医平均每天看 15个病人。主要工作时间用于充填治疗和拔牙。 93 %的牙医认为中国口腔卫生服务强调治疗而忽视预防保健。结论 :口腔卫生服务应重视口腔预防保健