Hemodynamic Assessment of Distal Revascularization Interval Ligation

This study will involve identification of patients with ischemic steal who are deemed candidates for distal revascularization with interval ligation (DRIL), followed by prospective data collection of intraoperative noninvasive data at key points in the operation. After informed consent, chart review will be performed to identify patient characteristics as well as details of their presentation of steal syndrome, including symptomatology, duration, characteristics of contributory arteriovenous access, and preoperative data including upper extremity/forearm pressures, fistula flow data, and finger pressures with and without fistula compression. Patients will have noninvasive intraoperative measurement of bilateral forearm blood pressure measurements using automated blood pressure cuffs within sterile bands on the operative side as well as the contralateral ("control") side. Automated blood pressure measurements will then be performed at four time points in the operation, simultaneously on both arms (operative versus control): 1. After surgical exposure but before any intervention has been performed, 2. After clamping of the brachial artery after dissection and control of the vessel to assess for the effect of interval ligation (IL) alone on the forearm blood pressure. 3. After performance of the distal revascularization (DR) but BEFORE interval ligation of the brachial artery. 4. After completion of the procedure, including both distal revascularization AND interval ligation (DRIL). The performance of blood pressure measurements will not alter the performance of the operation, nor will this have any influence on intraoperative decision-making. Intraoperative patient positioning and set-up will be unaffected by the addition of a distal forearm blood pressure cuff for data acquisition. Neither the pre-operative selection or post-operative care will be influenced by participation in this study, nor by the data acquired. It should be noted that this technique is intermittently used as standard of care when needed in current practice. Patients will be assessed for symptom improvement and DRIL patency at their standard 14 day, 3 month, 6 month, 9 month and 1 year follow up visits.