Doppler ultrasound surveillance of recently formed haemodialysis arteriovenous fistula: the SONAR observational cohort study.

Background: Arteriovenous fistulas are considered the best option for haemodialysis provision, but as many as 30% fail to mature or suffer early failure. Objective: To assess the feasibility of performing a randomised controlled trial that examines whether, by informing early and effective salvage intervention of fistulas that would otherwise fail, Doppler ultrasound surveillance of developing arteriovenous fistulas improves longer-term arteriovenous fistula patency. Design: A prospective multicentre observational cohort study (the 'SONAR' study). Setting: Seventeen haemodialysis centres in the UK. Participants: Consenting adults with end-stage renal disease who were scheduled to have an arteriovenous fistula created. Intervention: Participants underwent Doppler ultrasound surveillance of their arteriovenous fistulas at 2, 4, 6 and 10 weeks after creation, with clinical teams blinded to the ultrasound surveillance findings. Main outcome measures: Fistula maturation at week 10 defined according to ultrasound surveillance parameters of representative venous diameter and blood flow (wrist arteriovenous fistulas: ≥ 4 mm and > 400 ml/minute; elbow arteriovenous fistulas: ≥ 5 mm and > 500 ml/minute). Mixed multivariable logistic regression modelling of the early ultrasound scan data was used to predict arteriovenous fistula non-maturation by 10 weeks and fistula failure at 6 months. Results: A total of 333 arteriovenous fistulas were created during the study window (47.7% wrist, 52.3% elbow). By 2 weeks, 37 (11.1%) arteriovenous fistulas had failed (thrombosed), but by 10 weeks, 219 of 333 (65.8%) of created arteriovenous fistulas had reached maturity (60.4% wrist, 67.2% elbow). Persistently lower flow rates and venous diameters were observed in those fistulas that did not mature. Models for arteriovenous fistulas' non-maturation could be optimally constructed using the week 4 scan data, with fistula venous diameter and flow rate the most significant variables in explaining wrist fistula maturity failure (positive predictive value 60.6%, 95% confidence interval 43.9% to 77.3%), whereas resistance index and flow rate were most significant for elbow arteriovenous fistulas (positive predictive value 66.7%, 95% confidence interval 48.9% to 84.4%). In contrast to non-maturation, both models predicted fistula maturation much more reliably [negative predictive values of 95.4% (95% confidence interval 91.0% to 99.8%) and 95.6% (95% confidence interval 91.8% to 99.4%) for wrist and elbow, respectively]. Additional follow-up and modelling on a subset (n = 192) of the original SONAR cohort (the SONAR-12M study) revealed the rates of primary, assisted primary and secondary patency arteriovenous fistulas at 6 months were 76.5, 80.7 and 83.3, respectively. Fistula vein size, flow rate and resistance index could identify primary patency failure at 6 months, with similar predictive power as for 10-week arteriovenous fistula maturity failure, but with wide confidence intervals for wrist (positive predictive value 72.7%, 95% confidence interval 46.4% to 99.0%) and elbow (positive predictive value 57.1%, 95% confidence interval 20.5% to 93.8%). These models, moreover, performed poorly at identifying assisted primary and secondary patency failure, likely because a subset of those arteriovenous fistulas identified on ultrasound surveillance as at risk underwent subsequent successful salvage intervention without recourse to early ultrasound data. Conclusions: Although early ultrasound can predict fistula maturation and longer-term patency very effectively, it was only moderately good at identifying those fistulas likely to remain immature or to fail within 6 months. Allied to the better- than-expected fistula patency rates achieved (that are further improved by successful salvage), we estimate that a randomised controlled trial comparing early ultrasound-guided intervention against standard care would require at least 1300 fistulas and would achieve only minimal patient benefit. Trial Registration: This trial is registered as ISRCTN36033877 and ISRCTN17399438. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR135572) and is published in full in Health Technology Assessment; Vol. 28, No. 24. See the NIHR Funding and Awards website for further award information.

For people with advanced kidney disease, haemodialysis is best provided by an 'arteriovenous fistula', which is created surgically by joining a vein onto an artery at the wrist or elbow. However, these take about 2 months to develop fully ('mature'), and as many as 3 out of 10 fail to do so. We asked whether we could use early ultrasound scanning of the fistula to identify those that are unlikely to mature. This would allow us to decide whether it would be practical to run a large, randomised trial to find out if using early ultrasound allows us to 'rescue' fistulas that would otherwise fail. We invited adults to undergo serial ultrasound scanning of their fistula in the first few weeks after it was created. We then analysed whether we could use the data from the early scans to identify those fistulas that were not going to mature by week 10. Of the 333 fistulas that were created, about two-thirds reached maturity by week 10. We found that an ultrasound scan 4 weeks after fistula creation could reliably identify those fistulas that were going to mature. However, of those fistulas predicted to fail, about one-third did eventually mature without further intervention, and even without knowing what the early scans showed, another third were successfully rescued by surgery or X-ray-guided treatment at a later stage. Performing an early ultrasound scan on a fistula can provide reassurance that it will mature and deliver trouble-free dialysis. However, because scans are poor at identifying fistulas that are unlikely to mature, we would not recommend their use to justify early surgery or X-ray-guided treatment in the expectation that this will improve outcomes.

Evaluation of Tissue Apposition and Seroma Prevention in an Ovine Model of Surgical Dead Space Using a Novel Air-Purged Vacuum Closure System.

Background: Postoperative complications associated with seroma formation resulting from surgical dead space continue to present a challenge in modern surgery. There is an unmet need for new technologies that address surgical dead space as well as prevent seroma formation and associated downstream postoperative complications. Methods: The novel implantable tissue apposition and drainage system ENIVO was developed and tested in a bilateral ovine external abdominal oblique (EAO) resection model of surgical dead space. The ENIVO system is a portable powered pump and wound interface featuring air-purged vacuum closure (APVC) that delivers a sustained level of vacuum pressure (80 and 100 mmHg) to the treatment site with an intermittent burst of sterile filtered air through the implanted wound interface. Seroma area, seroma volume, and drain migration were assessed at postoperative days 7 and 14, and all animals were euthanized at day 28 with gross assessment of treatment efficacy including the presence of residual seroma and tissue apposition. Results: The bilateral model created relatively uniform defects of ~120 cm2 following excision of ~30 to 50 g of EAO muscle. Median seroma area of ENIVO-treated defects was statistically smaller than standard of care (SoC)-treated defects at days 7 and 14. Median seroma volume at 14 days was significantly reduced in ENIVO-treated defects relative to SoC-treated defects [1.3 (IQR 0.0-79.5) mL and 188.5 (IQR 27.6-342.9) mL, respectively]. At postoperative day 28, 40% (n = 4/10) of SoC defects showed a residual seroma, whereas in contrast, none of the ENIVO-treated defects showed signs of a residual seroma. Median tissue apposition scoring was higher in the ENIVO treatment group [3 (IQR 3-3)] compared with the SoC group [3 (IQR 0-3)]. Conclusions: The ENIVO system represents a new approach to dead space management and seroma prevention and was shown to outperform a SoC surgical drain in a challenging large defect model of surgical dead space management and seroma prevention.

Biopsy of parotid masses: Review of current techniques.

Definitive diagnosis of parotid gland masses is required optimal management planning and for prognosis. There is controversy over whether fine needle aspiration cytology (FNAC) or ultrasound guided core biopsy (USCB) should be the standard for obtaining a biopsy. The aim of this review is to assess the current evidence available to assess the benefits of each technique and also to assess the use of intra-operative frozen section (IOFS). Literature searches were performed using pubmed and google scholar. The literature has been reviewed and the evidence is presented. FNAC is an accepted and widely used technique. It has been shown to have variable diagnostic capabilities depending on centres and experience of staff. USCB has a highly consistent diagnostic accuracy and can help with tumour grading and staging. However, the technique is more invasive and there is a question regarding potential for seeding. Furthermore, USCB is less likely to be offered as part of a one-stop clinic. IOFS has no role as a first line diagnostic technique but may be reserved as an adjunct or for lesions not amenable to percutaneous biopsy. On balance, USCB seems to be the method of choice. The current evidence suggests it has superior diagnostic potential and is safe. With time, USCB is likely to supplant FNAC as the biopsy technique of choice, replicating that which has occurred already in other areas of medicine such a breast practice.

Chronic kidney disease and dipstick proteinuria are risk factors for stent thrombosis in patients with myocardial infarction.

BACKGROUND: Kidney failure (stage 5 chronic kidney disease [CKD]) is an independent risk factor for stent thrombosis (ST). Moderate (stage 3-4) CKD and proteinuria are both associated with adverse cardiovascular events, including worse outcomes after myocardial infarction (MI). Whether moderate CKD and proteinuria increase the risk of ST after MI is not known. This study evaluated the risk of ST associated with moderate CKD and dipstick proteinuria. METHODS: We retrospectively analyzed clinical and laboratory data from 956 non-stage 5 CKD patients who were admitted with MI and received intracoronary stenting. Clinical follow-up was collected at 1 year for definite or probable ST, as well as for all-cause mortality, nonfatal MI or death, and target vessel revascularization or coronary artery bypass graft surgery. RESULTS: After adjustment for multiple clinical and biochemical covariates, patients with both estimated glomerular filtration rate (GFR) of 15 to 59 mL min(-1) 1.73 m(-2) and > or =30 mg/dL dipstick proteinuria had increased cumulative incidence of ST (hazard rate [HR] 3.69, 95% CI 1.54-8.89), all-cause mortality (HR 2.68, 95% CI 1.34-5.37), and nonfatal MI or death (HR 3.20, 95% CI 1.77-5.81) at 1 year. In addition, estimated GFR of 15 to 59 mL min(-1) 1.73 m(-2) was a significant independent predictor of ST (HR 2.61, 95% CI 1.33-5.10). Dipstick proteinuria > or =30 mg/dL was associated with a trend toward increased risk for all outcomes. CONCLUSIONS: In an acute MI population, moderate CKD was identified as a novel prognostic marker for ST. In addition, patients with both decreased GFR and proteinuria had higher incidences of all-cause mortality and nonfatal MI or death than patients with either condition alone.

Derived fibrinogen compared with C-reactive protein and brain natriuretic peptide for predicting events after myocardial infarction and coronary stenting.

BACKGROUND: After myocardial infarction (MI), biomarkers can be helpful to identify patients who might benefit from more intensive therapies. The prothrombin time-derived fibrinogen (PTDF) assay is widely available and relatively inexpensive. We determined whether PTDF predicts events in patients with MI and compared this assay with brain natriuretic peptide (BNP) and C-reactive protein (CRP). METHODS: We retrospectively analyzed data from 915 patients admitted with MI. Follow-up was collected at 1 year for major adverse cardiac events (MACE) defined as death from any cause, nonfatal MI or death, target vessel revascularization, or coronary artery bypass grafting. RESULTS: Patients in the fourth quartile of PTDF were older and had more risk factors but fewer ST-elevation MI and lower peak troponin values. The fourth quartiles of PTDF, CRP, and BNP were associated with increased MACE compared with the first quartiles with hazard ratios of 2.08 (1.30-3.33), 1.94 (1.22-3.07), and 2.56 (1.57-4.18), respectively, findings that remained significant after adjustment. When outcomes by strata of PTDF were examined, CRP failed to add additional prognostic value. Higher BNP levels predicted MACE in the upper but not lower stratum of PTDF. CONCLUSION: In patients with MI, PTDF is a predictor of MACE at 1 year, with equivalent value compared to BNP and CRP. With low PTDF levels, neither BNP nor CRP adds prognostic value. At elevated PTDF values, higher BNP, but not CRP, identifies a higher-risk population. Therefore, PTDF can be substituted for CRP, with BNP being useful in the presence of elevated PTDF.

Development of an abbreviated Social Phobia and Anxiety Inventory (SPAI) using item response theory: the SPAI-23.

An abbreviated version of the Social Phobia and Anxiety Inventory (SPAI) was developed using methods based in nonparametric item response theory. Participants included a nonclinical sample of 1,482 undergraduates (52% female, mean age = 19.4 years) as well as a clinical sample of 105 individuals (56% female, mean age = 36.4 years) diagnosed with either generalized (73%) or specific social phobia (27%). Twenty-three of the 45 SPAI items demonstrated good discrimination along the social anxiety continuum. In addition, option characteristic curves (OCCs) indicated that the SPAI's 7-point scale may generate errors in ranking individuals. Thus, options were collapsed to improve item performance. No gender differences emerged between any of the items' OCCs, suggesting that items function similarly among men and women. The abbreviated version also correlated highly with the original 45-item SPAI and exhibited similar patterns of correlations with measures of social anxiety. The SPAI-23 has considerable practical benefits, including a screening of both social and agoraphobic anxiety as well as decreased assessment and scoring time.

Reliability of the Social Phobia and Anxiety Inventory (SPAI) Portuguese version in a heterogeneous sample of Brazilian university students

OBJETIVO: Avaliar consistência interna e estabilidade temporal, através de fidedignidade teste-reteste, da versão em português do Inventário de Ansiedade e Fobia Social (SPAI), em uma amostra brasileira heterogênea. MÉTODOS: Após consentimento informado, a versão traduzida e adaptada para o português do SPAI foi testada e re-testada, com 14 dias de intervalo, em uma amostra de 225 estudantes universitários de ambos os gêneros, de quatro cursos de graduação. Após dupla entrada de dados, a análise estatística incluiu Alfa de Cronbach e os coeficientes de correlação de Pearson e Intra-classe. RESULTADOS: A amostra estudada consistiu de 213 estudantes de quatro sub-amostras: 95 estudantes de Direito, 31 de Comunicação Social, 54 de Engenharia Civil e 33 de Odontologia. A média de idade foi de 23 anos (± 6) e 110 (51,6%) eram do gênero feminino. O Alpha de Cronbach foi de 0,96, sem diferenças entre os gêneros. O escore diferencial (total) do SPAI português apresentou coeficiente de Pearson de 0,83 (IC95% 0,78-0,87) e coeficiente Intra-classe de 0,83 (IC95% 0,78-0,86). Não houve diferença estatística nos coeficientes de Pearson entre os gêneros (p = 0,121) ou entre as quatro sub-amostras (p = 0,258). CONCLUSAO: Os resultados não asseguram validade; a versão do SPAI português apresentou boa homogeneidade de conteúdo com nível satisfatório consistência interna. A estabilidade temporal avaliada foi consistente. Os dados demonstram que o SPAI português apresenta fidedignidade perfeitamente aceitável para ambos os gêneros e sugerem sua utilização na população brasileira.