Dural arteriovenous fistulas are not observed to convert to a higher grade after partial embolization.

OBJECTIVE: Borden-Shucart type I dural arteriovenous fistulas (dAVFs) lack cortical venous drainage and occasionally necessitate intervention depending on patient symptoms. Conversion is the rare transformation of a low-grade dAVF to a higher grade. Factors associated with increased risk of dAVF conversion to a higher grade are poorly understood. The authors hypothesized that partial treatment of type I dAVFs is an independent risk factor for conversion. METHODS: The multicenter Consortium for Dural Arteriovenous Fistula Outcomes Research database was used to perform a retrospective analysis of all patients with type I dAVFs. RESULTS: Three hundred fifty-eight (33.2%) of 1077 patients had type I dAVFs. Of those 358 patients, 206 received endovascular treatment and 131 were not treated. Two (2.2%) of 91 patients receiving partial endovascular treatment for a low-grade dAVF experienced conversion to a higher grade, 2 (1.5%) of 131 who were not treated experienced conversion, and none (0%) of 115 patients who received complete endovascular treatment experienced dAVF conversion. The majority of converted dAVFs localized to the transverse-sigmoid sinus and all received embolization as part of their treatment. CONCLUSIONS: Partial treatment of type I dAVFs does not appear to be significantly associated with conversion to a higher grade.

Direct Versus Indirect Revascularization for Moyamoya: a Large Multicenter Study.

BACKGROUND: Moyamoya is a chronic occlusive cerebrovascular disease of unknown etiology causing neovascularization of the lenticulostriate collaterals at the base of the brain. Although revascularization surgery is the most effective treatment for moyamoya, there is still no consensus on the best surgical treatment modality as different studies provide different outcomes. OBJECTIVE: In this large case series, we compare the outcomes of direct (DR) and indirect revascularisation (IR) and compare our results to the literature in order to reflect on the best revascularization modality for moyamoya. METHODS: We conducted a multicenter retrospective study in accordance with the Strengthening the Reporting of Observational studies in Epidemiology guidelines of moyamoya affected hemispheres treated with DR and IR surgeries across 13 academic institutions predominantly in North America. All patients who underwent surgical revascularization of their moyamoya-affected hemispheres were included in the study. The primary outcome of the study was the rate of symptomatic strokes. RESULTS: The rates of symptomatic strokes across 515 disease-affected hemispheres were comparable between the two cohorts (11.6% in the DR cohort vs 9.6% in the IR cohort, OR 1.238 (95% CI 0.651 to 2.354), p=0.514). The rate of total perioperative strokes was slightly higher in the DR cohort (6.1% for DR vs 2.0% for IR, OR 3.129 (95% CI 0.991 to 9.875), p=0.052). The rate of total follow-up strokes was slightly higher in the IR cohort (8.1% vs 6.6%, OR 0.799 (95% CI 0.374 to 1.709) p=0.563). CONCLUSION: Since both modalities showed comparable rates of overall total strokes, both modalities of revascularization can be performed depending on the patient's risk assessment.

Risk of Early Versus Later Rebleeding From Dural Arteriovenous Fistulas With Cortical Venous Drainage.

BACKGROUND: Cranial dural arteriovenous fistulas with cortical venous drainage are rare lesions that can present with hemorrhage. A high rate of rebleeding in the early period following hemorrhage has been reported, but published long-term rates are much lower. No study has examined how risk of rebleeding changes over time. Our objective was to quantify the relative incidence of rebleeding in the early and later periods following hemorrhage. METHODS: Patients with dural arteriovenous fistula and cortical venous drainage presenting with hemorrhage were identified from the multinational CONDOR (Consortium for Dural Fistula Outcomes Research) database. Natural history follow-up was defined as time from hemorrhage to first treatment, rebleed, or last follow-up. Rebleeding in the first 2 weeks and first year were compared using incidence rate ratio and difference. RESULTS: Of 1077 patients, 250 met the inclusion criteria and had 95 cumulative person-years natural history follow-up. The overall annualized rebleed rate was 7.3% (95% CI, 3.2-14.5). The incidence rate of rebleeding in the first 2 weeks was 0.0011 per person-day; an early rebleed risk of 1.6% in the first 14 days (95% CI, 0.3-5.1). For the remainder of the first year, the incidence rate was 0.00015 per person-day; a rebleed rate of 5.3% (CI, 1.7-12.4) over 1 year. The incidence rate ratio was 7.3 (95% CI, 1.4-37.7; P, 0.026). CONCLUSIONS: The risk of rebleeding of a dural arteriovenous fistula with cortical venous drainage presenting with hemorrhage is increased in the first 2 weeks justifying early treatment. However, the magnitude of this increase may be considerably lower than previously thought. Treatment within 5 days was associated with a low rate of rebleeding and appears an appropriate timeframe.

Observation Versus Intervention for Low-Grade Intracranial Dural Arteriovenous Fistulas.

BACKGROUND: Low-grade intracranial dural arteriovenous fistulas (dAVF) have a benign natural history in the majority of cases. The benefit from treatment of these lesions is controversial. OBJECTIVE: To compare the outcomes of observation versus intervention for low-grade dAVFs. METHODS: We retrospectively reviewed dAVF patients from institutions participating in the CONsortium for Dural arteriovenous fistula Outcomes Research (CONDOR). Patients with low-grade (Borden type I) dAVFs were included and categorized into intervention or observation cohorts. The intervention and observation cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was modified Rankin Scale (mRS) at final follow-up. Secondary outcomes were excellent (mRS 0-1) and good (mRS 0-2) outcomes, symptomatic improvement, mortality, and obliteration at final follow-up. RESULTS: The intervention and observation cohorts comprised 230 and 125 patients, respectively. We found no differences in primary or secondary outcomes between the 2 unmatched cohorts at last follow-up (mean duration 36 mo), except obliteration rate was higher in the intervention cohort (78.5% vs 24.1%, P < .001). The matched intervention and observation cohorts each comprised 78 patients. We also found no differences in primary or secondary outcomes between the matched cohorts except obliteration was also more likely in the matched intervention cohort (P < .001). Procedural complication rates in the unmatched and matched intervention cohorts were 15.4% and 19.2%, respectively. CONCLUSION: Intervention for low-grade intracranial dAVFs achieves superior obliteration rates compared to conservative management, but it fails to improve neurological or functional outcomes. Our findings do not support the routine treatment of low-grade dAVFs.

Endovascular treatment of a ruptured posterior fossa pure arterial malformation: illustrative case.

BACKGROUND: Pure arterial malformations (PAMs) are rare vascular anomalies that are commonly mistaken for other vascular malformations. Because of their purported benign natural history, PAMs are often conservatively managed. The authors report the case of a ruptured PAM leading to subarachnoid hemorrhage (SAH) with intraventricular extension that was treated endovascularly. OBSERVATIONS: A 38-year-old man presented with a 1-day history of headaches and nausea. A computed tomography scan demonstrated diffuse SAH with intraventricular extension, and angiography revealed a right posterior inferior cerebellar artery-associated PAM. The PAM was treated with endovascular Onyx embolization. LESSONS: To the authors' knowledge, only 2 other cases of SAH associated with PAM have been reported. In those 2 cases, surgical clipping was pursued for definitive treatment. Here, the authors report the first case of a ruptured PAM treated using an endovascular approach, showing its feasibility as a treatment option particularly in patients in whom open surgery is too high a risk.

Searching CINAHL did not add value to clinical questions posed in NICE guidelines.

OBJECTIVES: This study aims to quantify the unique useful yield from the Cumulative Index to Nursing and Allied Health Literature (CINAHL) database to National Institute for Health and Clinical Excellence (NICE) clinical guidelines. A secondary objective is to investigate the relationship between this yield and different clinical question types. It is hypothesized that the unique useful yield from CINAHL is low, and this database can therefore be relegated to selective rather than routine searching. STUDY DESIGN AND SETTING: A retrospective sample of 15 NICE guidelines published between 2005 and 2009 was taken. Information on clinical review question type, number of references, and reference source was extracted. RESULTS: Only 0.33% (95% confidence interval: 0.01-0.64%) of references per guideline were unique to CINAHL. Nursing- or allied health (AH)-related questions were nearly three times as likely to have references unique to CINAHL as non-nursing- or AH-related questions (14.89% vs. 5.11%), and this relationship was found to be significant (P<0.05). No significant relationship was found between question type and unique CINAHL yield for drug-related questions. CONCLUSIONS: The very low proportion of references unique to CINAHL strongly suggests that this database can be safely relegated to selective rather than routine searching. Nursing- and AH-related questions would benefit from selective searching of CINAHL.

Clofibrate in combination with phototherapy for unconjugated neonatal hyperbilirubinaemia.

BACKGROUND: There are many pathological conditions leading to an elevated unconjugated bilirubin level (hyperbilirubinaemia) in neonates. Currently the standard therapies for unconjugated hyperbilirubinaemia include phototherapy and exchange transfusion. In addition to phototherapy, clofibrate has been studied as a treatment for hyperbilirubinaemia in several countries. OBJECTIVES: To determine the efficacy and safety of clofibrate in combination with phototherapy versus phototherapy alone in unconjugated neonatal hyperbilirubinaemia. SEARCH METHODS: Randomised controlled trials were identified by searching MEDLINE (1950 to April 2012) before being translated for use in The Cochrane Library, EMBASE 1980 to April 2012 and CINAHL databases. All searches were re-run on 2 April 2012. SELECTION CRITERIA: We included trials where neonates with hyperbilirubinaemia received either clofibrate in combination with phototherapy or phototherapy alone or placebo in combination with phototherapy. DATA COLLECTION AND ANALYSIS: Data were extracted and analysed independently by two review authors (MG and HM). Treatment effects on the following outcomes were determined: mean change in bilirubin levels, mean duration of treatment with phototherapy, number of exchange transfusions needed, adverse effects of clofibrate, bilirubin encephalopathy and neonatal mortality. Study authors were contacted for additional information. Studies were analysed for methodological quality in a 'Risk of bias' table. MAIN RESULTS: Fifteen studies (two including preterm neonates and 13 including term neonates) were included in this review. All but one of the included studies were conducted in Iran. For preterm neonates, there was a significantly lower bilirubin level in the 100 mg/kg clofibrate group compared to the control group with a mean difference of -1.37 mg/dL (95% CI -2.19 mg/dL to -0.55 mg/dL) (-23 µmol/L; 95% CI -36 µmol/L to -9 µmol/L) after 48 hours. For the term neonates, there were significantly lower bilirubin levels in the clofibrate group compared to the control group after both 24 and 48 hours of treatment with a weighted mean difference of -2.14 mg/dL (95% CI -2.53 mg/dL to -1.75 mg/dL) (-37 µmol/L; 95% CI -43 µmol/L to -30 µmol/L] and -1.82 mg/dL (95% CI -2.25 mg/dL to -1.38 mg/dL) (-31 µmol/L; 95% CI -38 µmol/L to -24 µmol/L), respectively.There was a significantly lower duration of phototherapy in the clofibrate group compared to the control group for both preterm and term neonates with a weighted mean difference of -23.82 hours (95% CI -30.46 hours to -17.18 hours) and -25.40 hours (95% CI -28.94 hours to -21.86 hours), respectively.None of the studies reported on bilirubin encephalopathy rates, neonatal mortality rates, or the levels of parental or staff satisfactions with the interventions. AUTHORS' CONCLUSIONS: There are insufficient data from different countries on the use of clofibrate in combination with phototherapy for hyperbilirubinaemia to make recommendations for practice. There is a need for larger trials to determine how effective clofibrate is in reducing the need for, and duration of, phototherapy in term and preterm infants with hyperbilirubinaemia.

The ORION statement: guidelines for transparent reporting of outbreak reports and intervention studies of nosocomial infection.

The quality of research in hospital epidemiology (infection control) must be improved to be robust enough to influence policy and practice. In order to raise the standards of research and publication, a CONSORT equivalent for these largely quasi-experimental studies has been prepared by the authors of two relevant systematic reviews, following consultation with learned societies, editors of journals, and researchers. The ORION (Outbreak Reports and Intervention Studies Of Nosocomial infection) statement consists of a 22 item checklist, and a summary table. The emphasis is on transparency to improve the quality of reporting and on the use of appropriate statistical techniques. The statement has been endorsed by a number of professional special interest groups and societies. Like CONSORT, ORION should be considered a "work in progress", which requires ongoing dialogue for successful promotion and dissemination. The statement is therefore offered for further public discussion. Journals and research councils are strongly recommended to incorporate it into their submission and reviewing processes. Feedback to the authors is encouraged and the statement will be revised in 2 years.

The incidence of delirium associated with orthopedic surgery: a meta-analytic review.

BACKGROUND: The aim of this study was to perform a systematic review and meta-analysis of the literature regarding the incidence of delirium following orthopedic surgery. METHODS: Relevant papers were sourced from online databases and gray literature. Included studies used a validated diagnostic method to measure the incidence of delirium in a prospective sample of adult/elderly orthopedic patients. Data were subject to meta-analysis after stratification by type of surgery (elective v. emergency) and inclusion/exclusion of pre-existing cognitive impairment. A funnel plot assessed for publication bias. RESULTS: 26 publications reported an incidence of postoperative delirium of 4-53.3% in hip fracture samples and 3.6-28.3% in elective samples. Significant heterogeneity was evident, and this persisted despite stratification. Hip fracture was associated with a higher risk of delirium than elective surgery both when the cognitively impaired were included in the sample (random effects pooled estimate = 21.7% [95% CI = 14.6-28.8] vs. 12.1% [95% CI = 9.6-14.6]), and when the cognitively impaired were excluded (random effects pooled estimate = 25% [95% CI = 15.7-34.7] vs. 8.8% [95% CI = 4.1-13.6]). The funnel plot showed a deficit of small studies showing low risk and large studies showing high risk. In eight hip fracture studies, the proportion of delirium cases with a preoperative onset ranged from 34 to 92%. CONCLUSIONS: Delirium occurs more commonly with hip fracture than elective surgery, and frequently has a preoperative onset when associated with trauma. Recommendations are made with the aim of standardizing future research in order to further explore and reduce the heterogeneity and possible publication bias observed.

Impact of participant and physician intervention preferences on randomized trials: a systematic review.

CONTEXT: Allocation on the basis of randomization rather than patient choice is the gold standard of unbiased estimates of efficacy in clinical medicine. However, randomly allocating patients to treatments that do not accord with their preferences may influence internal and external validity. OBJECTIVE: To determine whether preferences affect recruitment to trials (external validity) and outcomes in trials (internal validity). DATA SOURCES: We searched MEDLINE, EMBASE, PsycINFO, CINAHL, AMED, and the Cochrane Library for articles published between 1966 and September 2004. We also hand-searched several major medical journals, searched reference lists of relevant articles, and contacted authors of published preference designs. The 2 themes in the first filter of the search strategy were preferences and possible determinants of preferences. STUDY SELECTION: Comprehensive cohorts and 2-stage trials that measured or recorded patient or physician preference, included allocation of participants to random and preference cohorts, and followed up all participants. We excluded trials with no recording of preference; of decision aids; with measurements of preferences for economic analyses; in which patients who refused randomization were followed up without reference to preferences; and of nonclinical populations. DATA EXTRACTION: Up to 4 reviewers independently evaluated the articles, and disagreements were resolved at project steering group meetings. We extracted data on study design, measurement of preference, recruitment, attrition, and summary data on the primary outcome(s) at baseline and each follow-up point. DATA SYNTHESIS: Of 10,023 citations identified, 170 articles met screening criteria and 32 (27 comprehensive cohorts and 5 two-stage trials) were determined to be eligible and were used in the final review. Although treatment preferences led to a substantial proportion of people refusing randomization, there was less evidence of bias in the characteristics of individuals agreeing to be randomized. Differences in outcome across the trials between randomized and preference groups were generally small, particularly in large trials and after accounting for baseline measures of outcome. Therefore, there was little evidence that preferences substantially interfere with the internal validity of randomized trials. CONCLUSIONS: Preferences influence whether people participate in randomized trials, but there is little evidence that they significantly affect validity.

Metaanalysis of randomized trials of the efficacy and safety of donepezil, galantamine, and rivastigmine for the treatment of Alzheimer disease.

The authors estimated the effects of each of the three commonly used drugs for Alzheimer disease (donepezil, galantamine, and rivastigmine) in terms of predefined clinical outcomes and trial completion rates, by dosing level, and described differences among them. Using both electronic and manual search strategies (January 1992 to July 2002), a metaanalysis examined the effect of the drugs on clinical outcomes and completion rates. Regression analyses compared the effect of dose on clinical outcomes and completion rates, using 10 donepezil, 6 galantamine, and 5 rivastigmine articles. All three drugs showed beneficial effects on cognitive tests, as compared with placebo. For donepezil and rivastigmine, larger doses were associated with larger effect. This was not the case with galantamine. The odds of clinical global improvement demonstrated superiority over placebo for each drug, with no dose effects noted. Dropout rates were greater with galantamine and rivastigmine. There was little difference in dropout rate for each drug at each dose-level, except with high-dose donepezil. This was accounted for by the high dropout rate in two 52-week studies using larger doses. In summary, all three drugs had similar cognitive efficacy, with donepezil and rivastigmine showing a dose effect across the dosing levels studied. However, both galantamine and rivastigmine were associated with a greater risk of trial dropout than placebo, especially at higher dosing levels.