UNASSIGNED: 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.
UNASSIGNED: A prospective multicentre observational cohort study (the \'SONAR\' study).
UNASSIGNED: Seventeen haemodialysis centres in the UK.
UNASSIGNED: Consenting adults with end-stage renal disease who were scheduled to have an arteriovenous fistula created.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: This trial is registered as ISRCTN36033877 and ISRCTN17399438.
UNASSIGNED: 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.
■为了评估进行随机对照试验的可行性,通过早期和有效的抢救干预瘘管,否则将失败,多普勒超声监测发展中的动静脉瘘可改善长期动静脉瘘的通畅性。
■一项前瞻性多中心观察性队列研究(“SONAR”研究)。
■英国有17个血液透析中心。
■同意患有终末期肾脏疾病的成年人计划进行动静脉瘘。
参与者在创建后2、4、6和10周接受了动静脉瘘的多普勒超声监测,临床团队对超声监测结果视而不见。
■根据代表性静脉直径和血流的超声监测参数(腕部动静脉瘘:≥4毫米和>400毫升/分钟;肘动静脉瘘:≥5毫米和>500毫升/分钟)定义的第10周的瘘成熟。早期超声扫描数据的混合多变量逻辑回归模型用于预测10周时动静脉瘘不成熟和6个月时瘘衰竭。
■在研究窗口中总共创建了333个动静脉瘘(47.7%的腕部,52.3%弯头)。两周前,37(11.1%)动静脉瘘失败(血栓形成),但是到了10周,333例动静脉瘘中的219例(65.8%)已经成熟(腕部60.4%,67.2%弯头)。在那些未成熟的瘘管中观察到持续较低的流速和静脉直径。动静脉瘘不成熟模型可以使用第4周扫描数据进行优化构建,瘘静脉直径和流速是解释腕部瘘成熟失败的最重要变量(阳性预测值60.6%,95%置信区间43.9%至77.3%),而肘动静脉瘘的阻力指数和流速最显著(阳性预测值66.7%,95%置信区间48.9%至84.4%)。与不成熟相反,这两个模型对腕部和肘部的瘘管成熟预测更可靠[阴性预测值为95.4%(95%置信区间91.0%至99.8%)和95.6%(95%置信区间91.8%至99.4%),分别]。对原始SONAR队列(SONAR-12M研究)的一个子集(n=192)进行额外的随访和建模,辅助的原发性和继发性通畅性动静脉瘘在6个月时分别为76.5,80.7和83.3.瘘静脉大小,流速和阻力指数可以识别6个月时的原发性通畅性衰竭,具有与10周动静脉瘘成熟衰竭相似的预测能力,但腕部置信区间较宽(阳性预测值为72.7%,95%置信区间46.4%至99.0%)和肘部(阳性预测值57.1%,95%置信区间20.5%至93.8%)。这些模型,此外,在识别辅助的原发性和继发性通畅失败方面表现不佳,可能是因为在超声监测中被确定为有风险的动静脉瘘的一部分随后进行了成功的抢救干预,而没有诉诸早期超声数据。
■尽管早期超声可以非常有效地预测瘘管成熟和长期通畅,它仅在识别那些可能在6个月内保持不成熟或失败的瘘管方面具有中等优势。与比预期更好的瘘管通畅率(通过成功的抢救进一步改善)有关,我们估计,一项将早期超声引导介入治疗与标准治疗进行比较的随机对照试验需要至少1300个瘘管,且仅能使患者获益极小.
■本试验注册为ISRCTN36033877和ISRCTN17399438。
■该奖项由美国国立卫生与护理研究所(NIHR)卫生技术评估计划(NIHR奖参考:NIHR135572)资助,并在《卫生技术评估》中全文发表;卷。28号24.有关更多奖项信息,请参阅NIHR资助和奖励网站。
对于晚期肾病患者,血液透析最好由“动静脉瘘”提供,通过手术将静脉连接到手腕或肘部的动脉上而产生。然而,这些需要大约2个月才能完全发展(“成熟”),十分之三的人没有这样做。我们询问是否可以使用瘘管的早期超声扫描来识别那些不太可能成熟的瘘管。这将使我们能够决定是否可行,随机试验,以确定使用早期超声波是否允许我们“抢救”否则会失败的瘘管。我们邀请成年人在创建瘘管后的最初几周内对其进行连续超声扫描。然后,我们分析了我们是否可以使用早期扫描的数据来识别那些在第10周之前不会成熟的瘘管。在制造的333个瘘管中,大约三分之二的人在第10周达到到期日。我们发现,瘘管产生4周后的超声扫描可以可靠地识别那些将要成熟的瘘管。然而,那些预测会失败的瘘管,大约三分之一的人最终在没有进一步干预的情况下成熟了,即使不知道早期扫描显示了什么,另有三分之一在后期通过手术或X射线引导治疗成功获救。对瘘管进行早期超声扫描可以保证它将成熟并提供无故障的透析。然而,因为扫描在识别不太可能成熟的瘘管方面很差,我们不建议使用它们来证明早期手术或X线引导治疗的合理性,因为我们期望这将改善结局.