AV Access Workflow including TTFM & HFUS


Based on his extensive experience using Transit Time Flow Measurement (TTFM) and High-Frequency Ultrasound (HFUS) during vascular surgery, Dr. Alexander Meyer published a study in 2019 called, “Determinants of successful arteriovenous fistulae creation including intraoperative transit time flow measurement” 1.

Subsequently, in 2022 Dr. Meyer collaborated with Medistim to create a recommended workflow for quality control during forearm fistula creation. This workflow is informed by Dr. Meyer’s experience and available clinical data, which includes the aformentioned 2019 publication.

Recommended workflow for quality control during AV fistula creation

As a result of Dr. Meyer’s years of experience in vascular surgery, he developed this recommended AV Access workflow.2



This workflow is developed for creation of forearm fistulas but can in principle also be used for brachiocephalic fistulas. Note that the recommended blood flow volume in upper arm fistulas might be higher than for forearm fistulas.

Publication Abstract



The prevalence of hemodialysis patients is increasing, and it is important to create the arteriovenous fistula as early as possible to avoid hemodialysis by central venous catheter. International guidelines recommend arteriovenous fistula as the vascular access of first choice. Arteriovenous fistulae are associated with a failure rate of 23%. The success of an arteriovenous fistula can be evaluated intraoperatively by physical examination and by measuring the blood flow.


The aim of the study is to describe the predictive value of various factors for fistula maturation in the context to the current literature.


We report on a prospective cohort study of 41 patients, undergoing a primary arteriovenous fistula at the upper extremity. The primary endpoint of the study was the successful fistula maturation after 6 weeks.


The intraoperative measurement of the blood flow in the outflow vein has been identified as the unique significant parameter for the fistula maturation.


The predictive value of intraoperative flow measurement is superior to intraoperative physical examination and could help reduce the fistula dysmaturation rate. Intraoperative transit time flow measurement is an easy method and can be used to predict successful fistula maturation in a high percentage rate

Technology Used

Medistim MiraQTM Vascular System with HFUS and TTFM probes (PS and PV series).


1 Determinants of successful arteriovenous fistulae creation including intraoperative transit time flow measurement, Meyer A, Flicker E, König ST and Vetter AS, J Vasc Access. 2020 May;21(3):387-394.

2 Publication and workflow provided by Dr. Alexander Meyer, Head of the Department of Vascular Surgery, Johanniter-Krankenhaus Duisburg Rheinhausen, Germany.