AV Access Surgery Products >   Guide to Vessel Sizes and Flow Ranges Flow-Based Vascular Access Management Handbook

Best Practice:

Measure flow during vascular access creation to ensure that initial flows are within well-established ranges to achieve fistula maturation and prosthetic graft patency rates.

Surgical Access Creation

As vascular surgeons experience increasing pressure to create AV fistulas, maturation of a viable AV access is key to long-term hemodialysis. However, it is reported that a significant number of AV fistulas do not mature (up to 60 %) and 17% fail within the first three months.¹ In both cases, valuable time is lost in commencing hemodialysis through an AV fistula.

Measuring flow intraoperatively at the time of an AV fistula construction offers added assurance that out-of-range flows and other potential anomalies do not jeopardize post-op patency. Moreover, studies demonstrate that quantitative flow information at the time of fistula creation can predict successful fistula maturation.^2,3,4  Similarly, measuring flow during surgery for PTFE grafts can predict patency.⁴

Flow-directed Fistula Construction

Successful maturation of autogenous arteriovenous fistulas (AVFs) are is critical to their use as an AVF for hemodialysis. Intraoperative flow measurements at time of fistula construction foreshadow successful maturation.

Flow-directed Prosthetic Vascular Access Graft Construction

Direct intraoperative flow measurements on newly inserted prosthetic ePTFE grafts are not possible due to air in the ePTFE graft walls (air blocks ultrasound transmission). Therefore, arterial flow into the graft is measured on the artery proximal to the arterial/graft anastomosis. If the distal artery is not ligated, distal arterial flow is occluded during measurement. After construction of the graft/venous anastomosis, distal outflow is measured in the vein with proximal venous flow occluded, if the vein has not been ligated.

Recommended Flowprobe Sizes

References

1. Beathard GA, “Early and Late Hemodialysis Arteriovenous Fistula Failure,”
2. Berman, SS et al, “Predicting Arteriovenous Fistula Maturation with Intraoperative Blood Flow Measurements,” J Vasc Access 2008; 9(4):241-7.
3. Lin, CH et al, “Correlation of Intraoperative Blood Flow Measurement with Autogenous Arteriovenous Fistula Outcome.” J Vasc Surg. 2008; 48: 167-172 (7637AH)
4. Johnson, CP et al, “Prognostic Value of Intraoperative Blood Flow Measurements in Vascular Access Surgery,” Surgery 1998;124:729-38. (1504AH)

All AV access creation references