Closed-cell stent for coil embolization of intracranial aneurysms: clinical and angiographic results

BACKGROUND AND PURPOSE: Recanalization is observed in 20-40% of endovascularly treated intracranial aneurysms. To further reduce the recanalization and expand endovascular treatment, we evaluated the safety and efficacy of closed-cell SACE. MATERIALS AND METHODS: Between 2007 and 2010, 147 consecutive patients (110 women; mean age, 54 years) presenting at 2 centers with 161 wide-neck ruptured and unruptured aneurysms were treated by using SACE. Inclusion criteria were wide-neck aneurysms ( \u3e 4 mm or a dome/neck ratio RESULTS: Eighteen aneurysms (11%) were treated following rupture. Procedure-related mortality and permanent neurologic deficits occurred in 2 (1.4%) and 5 patients (3.4%), respectively. In total, 7 patients (4.8%) died, including 2 with reruptures. Of the 140 surviving patients, 113 (80.7%) patients with 120 aneurysms were available for follow-up neurologic examination at a mean of 11.8 months. An increase in mRS score from admission to follow-up by 1, 2, or 3 points was seen in 7 (6.9%), 1 (1%), and 2 (2%) patients, respectively. Follow-up angiography was performed in 120 aneurysms at a mean of 11.9 months. Recanalization occurred in 12 aneurysms (10%), requiring retreatment in 7 (5.8%). Moderate in-stent stenosis was seen in 1 (0.8%), which remained asymptomatic. CONCLUSIONS: This series adds to the evidence demonstrating the safety and effectiveness of SACE in the treatment of intracranial aneurysms. However, SACE of ruptured aneurysms and premature termination of antiplatelet treatment are associated with increased morbidity and mortality

Conscious sedation and analgesia in colonoscopy: Ketamine/propofol combination has superior patient satisfaction versus fentanyl/propofol

Background: Colonoscopy is performed without preparing sedation in many countries. However, according to the current literature patients are more satisfied when appropriate sedation is prepared for them. Objectives: We hypothesize that propofol-ketamine may prepare more patient satisfaction compared to propofol-fentanyl combination. Patients and Methods: Sixty adult patients older than 18 with ASA physical status of I, II or III were enrolled in the present study after providing the informed consent. They were prospectively randomized into two equal groups: 1- Group PF: was scheduled to receive IV bolus dose of fentanyl 1μg/kg and propofol 0.5mg/kg. 2- Group PK: was scheduled to receive IV bolus dose of ketamine 0.5mg/kg and propofol 0.5mg/kg. As a primary goal, patient's satisfaction was assessed by the use a Likert five-item scoring system in the recovery. Comparisons of hemodynamic parameters (mean heart rate, mean systolic blood pressure, mean diastolic blood pressure), mean Spo2 values during the procedure and side effects such as nausea, vomiting, and psychological reactions during the recovery period were our secondary goals. Level of sedation during the colonoscopy was assessed with the Observer's Assessment of Alertness/Sedation score (OAA/S). Results: Mean satisfaction scores in the group PK were significantly higher than the group PF (P = 0.005) while the level of sedation during the procedure was similar (P = 0.17). Hemodynamic parameters and SpO2 values were not significantly different (P > 0.05). Incidence of nausea and vomiting was the same in both groups. Conclusions: IV bolus injection of propofol-ketamine can lead to more patients' satisfaction than the other protocols during colonoscopy. © 2013 Iranian Society of Regional Anesthesia and Pain Medicine

The incidence of transient neurologic syndrome after spinal anesthesia with lidocaine or bupivacaine: The effects of needle type and surgical position: brief report

"nBurning Transient Neurologic Syndrome (TNS) which was first described by Schneider et al in 1993, is defined as a transient pain and dysesthesia in waist, buttocks and the lower limbs after spinal anesthesia.1,2 The incidence of TNS after spinal anesthesia with lidocaine is reported to be as high as 10-40%.3,4 This prospective study was designed to determine the incidence of TNS with two different types of drugs, lidocaine and bupivacaine, in lithotomy or supine positions as the primary outcomes and to determine the association between two different types of needles and surgical positions with the occurrence of TNS as the secondary outcome."nThe present study was conducted on 250 patients (ASA I-II), aged 18-60 years old, who were candidates for surgery in supine or lithotomy positions. According to the needle type (Sprotte or Quincke) and the local anesthetic (lidocaine or bupivacaine) all patients were randomly divided into four groups. After establishing standard monitoring, spinal anesthesia was performed in all sitting patients by attending anesthesiologists at L2-L3 or L3-L4 levels. The patients were placed in supine or lithotomy position, in regards to the surgical procedure. During the first three postoperative days, patients were observed for post spinal anesthesia complications, especially TNS. Any sensation of pain, dysesthesia, paresthesia or hyperalgesia in the low back area, buttocks, the anterior or posterior thigh, knees, either foot or both feet were recorded. Moreover, duration of pain, its radiation and its relation to sleep and the patients' position were all carefully considered. Ultimately, the patients' response to opioid (pethidine) for analgesia was determined."nThe incidence of TNS was higher when spinal anesthesia was induced with lidocaine (68% vs. 22%, P=0.003). TNS developed in 85% of the patients in lidocaine group and 58% in bupivacaine group after surgery in lithotomy position (P=0.002). In 77 patients pain was in lumbosacral area that radiated to lower limbs and was aggravated in sitting position but in 22 patients pain was in thighs with no radiation. The mean visual analogue scale (VAS) for the determination of pain severity was six in all patients. Pain was alleviated by the administration of pethidine. With regard to the needle type, there were no significant differences between the two types of needles (P=0.7)."nAccording to the results of this prospective study, it seems that induction of spinal anesthesia by lidocaine combined with surgical lithotomy position increases the risk of TNS. Our study is in concordance with Keld's study.5 Higher neurotoxicity of lidocaine in comparison with bopivacaine may justify the higher incidence of TNS in the lidocaine group. Moreover, natural lumbar lordosis is maintained better in supine position while it is lost in lithothomy position which may lay traction forces on cauda equina or other nerve roots in the lumbar area leading to neuropraxia

MRI‐Related Heating of Implants and Devices: A Review

During an MRI scan, the radiofrequency field from the scanner's transmit coil, but also the switched gradient fields, induce currents in any conductive object in the bore. This makes any metallic medical implant an additional risk for an MRI patient, because those currents can heat up the surrounding tissues to dangerous levels. This is one of the reasons why implants are, until today, considered a contraindication for MRI; for example, by scanner manufacturers. Due to the increasing prevalence of medical implants in our aging societies, such general exclusion is no longer acceptable. Also, it should be no longer needed, because of a much-improved safety-assessment methodology, in particular in the field of numerical simulations. The present article reviews existing literature on implant-related heating effects in MRI. Concepts for risk assessment and quantification are presented and also some first attempts towards an active safety management and risk mitigation.Level of Evidence 5Technical Efficacy Stage

Hybrid Metal-Dielectric Metasurfaces for Refractive Index Sensing

Hybrid metal-dielectric nanostructures have recently gained prominence because they combine strong field enhancement of plasmonic metals and the several low-loss radiation channels of dielectric resonators, which are qualities pertaining to the best of both worlds. In this work, an array of such hybrid nanoantennas is successfully fabricated over a large area and utilized for bulk refractive index sensing with a sensitivity of 208 nm/RIU. Each nanoantenna combines a Si cylinder with an Al disk, separated by a SiO2 spacer. Its optical response is analyzed in detail using the multipoles supported by its subparts and their mutual coupling. The nanoantenna is further modified experimentally with an undercut in the SiO2 region to increase the interaction of the electric field with the background medium, which augments the sensitivity to 245 nm/RIU. A detailed multipole analysis of the hybrid nanoantenna supports our experimental findings

Chemical-specific biosensing through mid-infrared graphene plasmons

Infrared spectroscopy provides chemical information of biomolecules by detecting their vibrational fingerprints. Here, we use graphene plasmons to enhance infrared absorption and to demonstrate a tunable biosensor with high sensitivity for label-free and chemically-specific detection of protein monolayers. We show that the tunability and extreme light confinement of graphene offer great possibilities for biosensing

Endovascular treatment of popliteal artery aneurysms: a single-center experience

PURPOSE: To evaluate the use of covered stent-grafts in the endovascular treatment (ET) of popliteal artery aneurysms (PAAs). MATERIALS AND METHODS: A retrospective analysis was conducted over a period of 52 months in 18 consecutive patients (17 men; mean age +/- SD, 70 years +/- 11) undergoing ET of PAAs with the Viabahn endograft in a single center. Patient symptoms, aneurysm characteristics, technical outcomes, complications, and follow-up were assessed. RESULTS: Aneurysm diameters ranged from 12 to 51 mm with a mean of 30 mm (+/-11). Thirteen aneurysms (72.2%) were partially thrombosed and 12 patients (66.6%) had symptoms of lower limb ischemia at presentation (11 chronic and one acute). The technical success rate was 94%. Intraprocedural emboli and endoleak occurred in one and two patients, respectively. Fourteen patients were available for follow-up after successful treatment, with a mean follow-up time of 15 months (range, 7-37 months). All stent-grafts were patent after 1 month, with no mortality or limb loss. The primary patency rate with complete exclusion of the aneurysm at 6 months was 86%. Pre- and postprocedural noninvasive arterial studies were available in 10 patients, demonstrating improvement of the ankle-brachial index from 0.96 +/- 0.41 to 1.17 +/- 0.18, respectively (P = .06). CONCLUSIONS: Endovascular stent-graft repair of PAAs is a feasible treatment option. However, further follow-up studies regarding the durability of results are required