动静脉瘘(AVF)是大多数血液透析依赖患者的最佳血管通路形式;然而,它容易形成损害效用和寿命的狭窄。虽然有许多因素影响这些狭窄的发展,病理性血流相关现象也可能引起内膜增生的形成,因此狭窄。计算了六名头端AVF患者的重复CFD衍生阻力,在吻合口周围用交织的镍钛诺支架治疗,以解决通路功能障碍。三维徒手超声系统用于获得患者特定的流量分布和几何形状,在执行CFD模拟以复制AVF中的流动现象之前,这使得计算流体力学推导的阻力成为可能。我们介绍了6例患者,他们在治疗前后进行了检查,我们的结果显示耐药性下降了77%,在手术干预后记录,以解决通路功能障碍。发现有问题的AVF具有高抗性,特别是在静脉段。无临床问题报告的AVF,和临床通畅,在静脉段有低阻力。似乎与动脉段的临床问题/通畅性和阻力值没有任何关系。识别沿电路的电阻变化允许识别狭窄,独立于使用标准超声标准确定的。我们的探索性研究表明,CFD衍生的耐药性是一个有希望的指标,可以对患病的AVF进行非侵入性鉴定。管道分析能够对AVF进行定期监测,以帮助进行手术计划和结果。进一步展示其临床实用性。
Arteriovenous fistula (AVF) is the optimal form of vascular access for most haemodialysis dependant patients; however, it is prone to the formation of stenoses that compromise utility and longevity. Whilst there are many factors influencing the development of these stenoses, pathological flow-related phenomena may also incite the formation of intimal hyperplasia, and hence a stenosis. Repeated
CFD-derived resistance was calculated for six patient who had a radiocephalic AVF, treated with an interwoven nitinol stent around the juxta-anastomotic region to address access dysfunction. A three-dimensional freehand ultrasound system was used to obtain patient-specific flow profiles and geometries, before performing
CFD simulations to replicate the flow phenomena in the AVF, which enabled the calculation of
CFD-derived resistance. We presented six patient cases who were examined before and after treatment and our results showed a 77% decrease in resistance, recorded after a surgical intervention to address access dysfunction. Problematic AVFs were found to have high resistance, particularly in the venous segment. AVFs with no reported clinical problems, and clinical patency, had low resistance in the venous segment. There did not appear to be any relationship with clinical problems/patency and resistance values in the arterial segment. Identifying changes in resistance along the circuit allowed stenoses to be identified, independent to that determined using standard sonographic criteria. Our exploratory study reveals thatCFD-derived resistance is a promising metric that allows for non-invasive identification of diseased AVFs. The pipeline analysis enabled regular surveillance of AVF to be studied to aid with surgical planning and outcome, further exhibiting its clinical utility.