The Era of Onyx Embolization: A Systematic and Literature Review of Preoperative Embolization Before Stereotactic Radiosurgery for the Management of Cerebral Arteriovenous Malformations.

INTRODUCTION: The current treatment paradigm for intracranial arteriovenous malformations (AVMs) focuses on reducing the risk of intracranial hemorrhage using various therapeutic means including embolization, stereotactic radiosurgery (SRS), and microsurgical resection. To improve AVM obliteration rates with SRS, pre-radiosurgical embolization has been trialed in a number of studies to reduce the volume of the AVM nidus prior to radiosurgery. This study aimed to review the efficacy of pre-radiosurgical embolization in the pre-Onyx era compared to the current Onyx era. METHODS: A systematic review was performed using PubMed to identify studies with 20 or more AVM patients, embolization material, and obliteration rates for both embolization + stereotactic radiosurgery (E+SRS) and SRS-only groups. RESULTS: Seventeen articles consisting of 1133 eligible patients were included in this study. A total of 914 (80.7%) patients underwent embolization prior to SRS. Onyx was used as the embolysate in 340 (37.2%) patients in the E+SRS cohorts. Mean obliteration rate for the embolized cohort was 46.9% versus 46.5% in the SRS-only cohort. When comparing obliteration rates based on embolysate material, obliteration rate was 42.1% with Onyx+SRS and 50.0% in the non-Onyx embolysate + SRS cohort. CONCLUSIONS: Onyx (ethylene vinyl-alcohol copolymer dissolved in dimethyl sulfoxide and suspended in micronized tantalum powder) has been increasingly used for the embolization of intracranial AVMs with increased success regarding its ease of use from a technical standpoint and performs similarly to other embolysate materials.

Reducing CXCR4-mediated nociceptor hyperexcitability reverses painful diabetic neuropathy.

Painful diabetic neuropathy (PDN) is an intractable complication of diabetes that affects 25% of patients. PDN is characterized by neuropathic pain and small-fiber degeneration, accompanied by dorsal root ganglion (DRG) nociceptor hyperexcitability and loss of their axons within the skin. The molecular mechanisms underlying DRG nociceptor hyperexcitability and small-fiber degeneration in PDN are unknown. We hypothesize that chemokine CXCL12/CXCR4 signaling is central to this mechanism, as we have shown that CXCL12/CXCR4 signaling is necessary for the development of mechanical allodynia, a pain hypersensitivity behavior common in PDN. Focusing on DRG neurons expressing the sodium channel Nav1.8, we applied transgenic, electrophysiological, imaging, and chemogenetic techniques to test this hypothesis. In the high-fat diet mouse model of PDN, we were able to prevent and reverse mechanical allodynia and small-fiber degeneration by limiting CXCR4 signaling or neuronal excitability. This study reveals that excitatory CXCR4/CXCL12 signaling in Nav1.8-positive DRG neurons plays a critical role in the pathogenesis of mechanical allodynia and small-fiber degeneration in a mouse model of PDN. Hence, we propose that targeting CXCR4-mediated DRG nociceptor hyperexcitability is a promising therapeutic approach for disease-modifying treatments for this currently intractable and widespread affliction.

Visual-palpatory versus fluoroscopic intraoperative determination of the femoral entry point in medial patellofemoral ligament reconstruction.

PURPOSE: Malpositioning of the femoral entry point in reconstruction of the medial patellofemoral ligament (MPFL) can lead to abnormal and painful patellar kinematics and loss of flexion. Determination of this point is usually performed by palpation of anatomic landmarks. Accuracy of this method has not yet been investigated. The hypotheses were: 1. palpatory method is not as accurate as fluoroscopically guided method using established radiological criteria; 2. accuracy correlates with surgical experience. METHODS: Three surgeons of varying experience defined the femoral entry point for the MPFL by palpation in ten cadaveric legs. The blinded procedures were repeated three times, and subjective difficulty of the determination was recorded. Results were documented by fluoroscopy on a true lateral radiograph. The accuracy was assessed using established radiological criteria. Surgical experience was correlated with the results, and confounding or interacting variables were assessed. RESULTS: Mean deviation from the correct zone for the femoral entry point was 3.5 mm (range 0-18 mm). Twenty-nine percent of all palpatory determinations were inside the correct zone, 47 % were within 5 mm distance from the correct zone, and 23 % were further than 5 mm apart from the correct zone ("outliers"). No significant difference was found between surgeons of varying experience. No correlation was observed between subjective difficulty of the procedure and accuracy of determination. CONCLUSIONS: The validity of the isolated palpatory determination of the femoral entry point in MPFL reconstruction seems to be insufficient, regardless of surgical experience. Derived from this study, fluoroscopic guidance is used in our clinic by default.

AAP principles concerning retail-based clinics.

The American Academy of Pediatrics views retail-based clinics (RBCs) as an inappropriate source of primary care for pediatric patients, as they fragment medical care and are detrimental to the medical home concept of longitudinal and coordinated care. This statement updates the original 2006 American Academy of Pediatrics statement on RBCs, which flatly opposed these sites as appropriate for pediatric care, discussing the shift in RBC focus and comparing attributes of RBCs with those of the pediatric medical home.

Instrument-based pediatric vision screening policy statement.

A policy statement describing the use of automated vision screening technology (instrument-based vision screening) is presented. Screening for amblyogenic refractive error with instrument-based screening is not dependent on behavioral responses of children, as when visual acuity is measured. Instrument-based screening is quick, requires minimal cooperation of the child, and is especially useful in the preverbal, preliterate, or developmentally delayed child. Children younger than 4 years can benefit from instrument-based screening, and visual acuity testing can be used reliably in older children. Adoption of this new technology is highly dependent on third-party payment policies, which could present a significant barrier to adoption.

Immunizing parents and other close family contacts in the pediatric office setting.

Additional strategies are needed to protect children from vaccine-preventable diseases. In particular, very young infants, as well as children who are immunocompromised, are at especially high risk for developing the serious consequences of vaccine-preventable diseases and cannot be immunized completely. There is some evidence that children who become infected with these diseases are exposed to pathogens through household contacts, particularly from parents or other close family contacts. Such infections likely are attributable to adults who are not fully protected from these diseases, either because their immunity to vaccine-preventable diseases has waned over time or because they have not received a vaccine. There are many challenges that have added to low adult immunization rates in the United States. One option to increase immunization coverage for parents and close family contacts of infants and vulnerable children is to provide alternative locations for these adults to be immunized, such as the pediatric office setting. Ideally, adults should receive immunizations in their medical homes; however, to provide greater protection to these adults and reduce the exposure of children to pathogens, immunizing parents or other adult family contacts in the pediatric office setting could increase immunization coverage for this population to protect themselves as well as children to whom they provide care.

Increasing immunization coverage.

In 1977, the American Academy of Pediatrics issued a statement calling for universal immunization of all children for whom vaccines are not contraindicated. In 1995, the policy statement "Implementation of the Immunization Policy" was published by the American Academy of Pediatrics, followed in 2003 with publication of the first version of this statement, "Increasing Immunization Coverage." Since 2003, there have continued to be improvements in immunization coverage, with progress toward meeting the goals set forth in Healthy People 2010. Data from the 2007 National Immunization Survey showed that 90% of children 19 to 35 months of age have received recommended doses of each of the following vaccines: inactivated poliovirus (IPV), measles-mumps-rubella (MMR), varicella-zoster virus (VZB), hepatitis B virus (HBV), and Haemophilus influenzae type b (Hib). For diphtheria and tetanus and acellular pertussis (DTaP) vaccine, 84.5% have received the recommended 4 doses by 35 months of age. Nevertheless, the Healthy People 2010 goal of at least 80% coverage for the full series (at least 4 doses of DTaP, 3 doses of IPV, 1 dose of MMR, 3 doses of Hib, 3 doses of HBV, and 1 dose of varicella-zoster virus vaccine) has not yet been met, and immunization coverage of adolescents continues to lag behind the goals set forth in Healthy People 2010. Despite these encouraging data, a vast number of new challenges that threaten continued success toward the goal of universal immunization coverage have emerged. These challenges include an increase in new vaccines and new vaccine combinations as well as a significant number of vaccines currently under development; a dramatic increase in the acquisition cost of vaccines, coupled with a lack of adequate payment to practitioners to buy and administer vaccines; unanticipated manufacturing and delivery problems that have caused significant shortages of various vaccine products; and the rise of a public antivaccination movement that uses the Internet as well as standard media outlets to advance a position, wholly unsupported by any scientific evidence, linking vaccines with various childhood conditions, particularly autism. Much remains to be accomplished by physician organizations; vaccine manufacturers; third-party payers; the media; and local, state, and federal governments to ensure dependable vaccine supply and payments that are sufficient to continue to provide immunizations in public and private settings and to promote effective strategies to combat unjustified misstatements by the antivaccination movement. Pediatricians should work individually and collectively at the local, state, and national levels to ensure that all children without a valid contraindication receive all childhood immunizations on time. Pediatricians and pediatric organizations, in conjunction with government agencies such as the Centers for Disease Control and Prevention, must communicate effectively with parents to maximize their understanding of the overall safety and efficacy of vaccines. Most parents and children have not experienced many of the vaccine-preventable diseases, and the general public is not well informed about the risks and sequelae of these conditions. A number of recommendations are included for pediatricians, individually and collectively, to support further progress toward the goal of universal immunization coverage of all children for whom vaccines are not contraindicated.