P1354POSTOPERATIVE MATURATION AND CHANGES IN CARDIAC FUNCTION DIFFER BETWEEN TYPES OF VASCULAR ACCESS
Authors: Hashimoto Koji , Kanno Taro , Kamijo Yuji , Kanno Yutaka 
Published: June 2020

Abstract

Background and Aims
The blood flow of vascular access can be increased about tens of times after access creation. If the flow of vascular access is too low, vascular access does not provide sufficient circulation for hemodialysis and sometimes gets thrombosed. However, if the flow of vascular access is too high, it can result in high cardiac output and trigger heart failure. Although patients receiving hemodialysis require vascular access with necessary and sufficient flow, the actual change in flow after access creation is not well known. We investigated the relationships among preoperative factors, types of vascular access, clinical courses of access maturation, and changes in cardiac function.

Method
This single-center retrospective observational study included patients who underwent vascular access-related surgery, except thrombectomy, in 2016. Diameters and flow volumes of the brachial artery were examined using Doppler ultrasound before surgery and 1 week, 12 months, and 24 months after surgery. Cardiac functions were assessed using sonography at the same timepoints. Patients’ background information and data related to surgery, such as anastomosis size, were extracted from medical records. The obtained data were statistically analyzed.

Results
Fifty-eight patients [37 arteriovenous fistula (AVF), 10 arteriovenous graft (AVG), and 11 partial replacement using grafts (PR)] participated in this study. Diameters of the brachial artery increased from 4.7 mm to 5.4 mm at 1 week after access surgery. Blood flows of the brachial artery also increased from 106 mL/min to 699 mL/min. Blood flow through AVG at 1week was significantly higher than that through AVF (940 ml/min vs. 589 ml/min). Although blood flow through AVF at 12 and 24 months after access creation was significantly increased than that at 1 week after access creation, blood flow through AVG at 12 and 24 months after access creation did not show significant changes, and blood flow through PR at 12 and 24 months after access creation was significantly decreased. AVG and PR required more catheter intervention for vascular access than AVF during this observational period. Preoperative blood flow of the brachial artery and cardiac outputs were positively correlated to postoperative blood flow through AVF. However, this relationship was not observed in AVG and PR cases. The amount of cardiac output increased from 4.2 L/min before surgery to 4.4 L/min and 4.6 L/min at 12 and 24 months, respectively, although not significantly. Cardiac output at 24 months after surgery significantly increased only in AVF cases.

Conclusion
The clinical maturation course after vascular access creation surgery differs between AVF and AVG cases. Because blood flow through AVF is likely to increase gradually after access creation, surgeons should consider cardiac stresses related to vascular access, especially in cases with high-flow brachial artery or high cardiac output before surgery. Blood flow through AVG is not likely to increase in the long course. However, because blood flow through AVG just after access creation is high, regardless of the brachial artery size, surgeons should consider the risk of arteriovenous access-related ischemic steal syndrome after surgery especially in cases with severe arteriosclerosis. PR is not likely to affect blood flow volume of accesses and cardiac function.