RS02 - Intraoperative Vascular Mapping During Hemodialysis Access Surgery Improves Patient Eligibility for Arteriovenous Fistula Creation

Objectives: Currently, there is no consensus on how best to evaluate the suitability of vessels for arteriovenous fistula (AVF) creation. Preoperative sonographic vascular mapping performed by a vascular imaging facility is commonly utilized despite the lack of evidence on AVF outcomes. The goal of this study was to evaluate the utility of intraoperative vascular mapping performed by the operating surgeon during access creation.

Methods: A retrospective review of all patients that had AVF creation between 2020 and 2021 in an academic medical center was performed. We identified 197 patients that had intraoperative sonographic venous mapping done by the operating surgeon. The measurements of vein diameter on the intraoperative duplex (IOD) were compared to the measurements of the vein in the same anatomic location on preoperative duplex (POD) done by a vascular lab.
Selection of AVF creation site was based on the IOD vein diameter (≥2mm) utilizing distal to proximal and superficial veins first approach: radiocephalic (RC-AVF), then brachiocephalic (BC-AVF), before considering brachiobasilic (BB-AVF) or AVG.

Results: Out of 197 patients, 109 (55%) had RC-AVF, 47(24%) BC-AVF and 41(21%) BB-AVF; 86% had regional anesthesia and 14% were done under local. The mean diameter of the veins used for AVF creation measured 3.6 ± 0.82mm on the IOD vs. 2.4 ± 0.89mm when same veins were measured on POD, (p < 0.001). The difference in measurements was similar in all anatomic sites; forearm cephalic: 3.5±.73mm vs. 2.2+.79mm, upper arm cephalic: 3.8 ±.9mm vs. 2.7±.8mm, upper arm basilic: 3.8±.9mm vs. 2.9±9mm. IOD measurements in patients who had regional anesthesia was 3.3±1mm vs. 3.6±0.8mm in patients who had local, p=0.09. Based on POD measurements alone, 141(72%) patients would have AVF created in the same anatomical location, 19(34%) patients would have received ipsilateral/contralateral BC-AVF instead of RC-AVF and 29(52%) patients would have BB-AVF instead of fistula utilizing superficial veins. 8(14%) patients had no suitable veins and would require arteriovenous graft creation. The maturation rates in patients who had different type of AVF created based on IOD were similar to the rest of the cohort, (78% vs.88%, p=0.2)

Conclusions: Intraoperative ultrasonographic venous mapping is a useful tool to evaluate vessel suitability and should be used routinely during AVF creation as it may increase the rate of distal fistula creation and lower the rate of graft placement. The cost-effectiveness and utility of preoperative duplex should be reevaluated.