Analysis of Options for Mitigating Hemodialysis Access–Related Ischemic Steal Phenomena

Abstract

Steal phenomena associated with brachial bridge grafts for hemodialysis access may compromise blood flow to the forearm. This work is designed to investigate and compare, by means of a simple mathematical model, the potential of six surgical procedures to alleviate steal. A flow model based on an electrical analogue was developed. An untapered 6-mm prosthetic brachial-axillary access (PBAA) was selected as the prototype configuration, and the theoretical effect of six access modifications on forearm flow was analyzed. Major simplifications include the use of Poiseuille's law for estimating arterial resistance and ignoring the contribution of collateral circulation. Intra-operative flow measurements using a Transonic flowmeter were obtained in two individuals undergoing treatment for a steal syndrome. The flow model predicts that the greatest increase in distal flow is achieved by the distal revascularization-interval ligation (DRIL) procedure, followed by a 6-mm axillobrachial artery bypass graft without interval ligation, the conversion of the PBAA to an axillary-axillary loop access, and the conversion to an axillary-brachial access. Intra-operative measurements in two patients agreed closely with theoretical calculations. A simple flow model provides a tractable framework for comparing procedures designed to avoid or treat steal phenomena. Distal revascularization without interval ligation and the conversion of a PBAA to an axillary-axillary loop access or an axillary brachial access can be effective alternatives to the DRIL procedure in selected clinical settings.