Beathard Gerald A, Jennings William C, Malik Jan, Wasse Haimanot, Dolmatch Bart L, Ross John, Shenoy Surendra, Pabir Roy-Chaudhury, Sachdeva Bharat, Rajan Dheeraj, Niyyar Vandana Dua, Nassar George M, Peden Eric, Lee Timmy, McLennan Gordon, Shahverdyan Robert
Department of Medicine, University of Texas Medical Branch, Galveston, TX, USA.
Department of Surgery, University of Oklahoma College of Medicine, Tulsa, OK, USA.
J Vasc Access. 2025 Jul;26(4):1151-1160. doi: 10.1177/11297298241272166. Epub 2024 Sep 19.
A more accurate descriptive and clinically useful diagnosis based upon pathophysiology for what is commonly referred to as venous outflow stenosis is inflow-outflow imbalance. In these cases, the total outflow capacity of the AV access is inadequate to handle the inflow volume (Qa) without an increase in pressure. The relative inadequacy of the access outflow capacity in comparison to Qa results in increased outflow resistance and a proportional increase in intraluminal pressure. The clinical indicators associated with venous stenosis are the resulting manifestations of this imbalance. The point at which this occurs is dependent upon variations in these two parameters-Qa and outflow resistance. The variations in these two parameters are considerable and reciprocal. Excessive Qa results in or can lead to an entire list of serious problems that adversely affect patient morbidity and mortality. Most studies dealing with AV access Qa reduction have been for the treatment of an existing condition rather than its prevention; however, prevention of disease rather than waiting for its development is an important tenet of medical practice. The resulting clinical picture of inflow-outflow imbalance is taken as an indication for corrective treatment. In the past, in most cases this has meant angioplasty to open the outflow if it is reduced; however, this clinical picture may be associated with an excessive Qa and angioplasty in these cases creates the risk for a further increase in Qa. It is the authors' opinion that access flow measurements should be a part of the evaluation of these cases prior to planning treatment. Using this information, a bimodal approach to primary treatment should be adopted involving either angioplasty for cases with a low or normal Qa or flow reduction in cases with an elevated Qa.
对于通常所说的静脉流出道狭窄，基于病理生理学得出的更准确的描述性且对临床有用的诊断是流入-流出失衡。在这些情况下，动静脉内瘘的总流出能力不足以在不增加压力的情况下处理流入量（Qa）。与Qa相比，内瘘流出能力相对不足会导致流出阻力增加以及管腔内压力成比例增加。与静脉狭窄相关的临床指标就是这种失衡的结果表现。这种情况发生的点取决于这两个参数——Qa和流出阻力的变化。这两个参数的变化很大且相互关联。过高的Qa会导致或可能导致一系列严重问题，对患者的发病率和死亡率产生不利影响。大多数关于降低动静脉内瘘Qa的研究都是针对现有病症的治疗而非预防；然而，预防疾病而非等待其发展是医学实践的一项重要原则。流入-流出失衡所产生的临床情况被视为进行矫正治疗的指征。过去，在大多数情况下，这意味着如果流出减少则进行血管成形术以开通流出道；然而，这种临床情况可能与过高的Qa有关，在这些情况下进行血管成形术会有Qa进一步增加的风险。作者认为，在规划治疗之前，通路血流测量应成为这些病例评估的一部分。利用这些信息，应采用双模式的初始治疗方法，对于Qa低或正常的病例采用血管成形术，对于Qa升高的病例采用减少血流的方法。
