Vein dissection in a forearm AV fistula

This case shows how intraoperative Transit Time Flow Measurement (TTFM) and High-Frequency Ultrasound (HFUS) revealed a dissection in the outflow vein resulting in immediate revision.

Case story

Patient information

  • 51-year-old male
  • 2019 myocardial infarction (LAD Stenting)
  • 2022 PCI (2 stents)
  • Hypertonus and Hyperlipidemia (Lipoprotein α: 107mg/dl)
    → Indication: Lipoprotein Apheresis

Intraoperative completion control

The surgical plan was to create a radio-cephalic side-to-end fistula. Preoperative vessel mapping showed a suitable artery and a good cephalic vein at the forearm. The initial transit time flow measurement (Image 1) after the creation of the fistula showed acceptable flow but no thrill. The flow quickly decreased to values below 100 mL/min.

High-frequency ultrasound was used to identify the cause for the low flow revealing a dissection in the outflow vein proximal to the anastomosis. The videos below show the transverse view of the dissection including a floating vein valve and the longitudinal view visualizing the bloodstream pumping against an occlusion.

Video 1: Transverse view

Video 2: Longitudinal view

Revision

The resected vein was cut open to inspect the dissection (Image 2). The Cimino fistula was abandoned, and a new forearm fistula was created more proximally (Image 3).

The final TTFM showed adequate flow. There were also a good thrill and murmur (Image 4 and Image 5).

Summary

TTFM assisted in identifying flow issues and HFUS helped in identifying the problem. Final TTFM assured the surgeon that the flow was adequate for maturation of the fistula.

Case attachments

Click images below to view.
MiraQ device screen capturing precise measurement data

Initial TTFM showing acceptable flow but no thrill

Initial TTFM showing acceptable flow but no thrill

Resected vein cut open to inspect the dissection

Resected vein cut open to inspect the dissection

Resected vein cut open to inspect the dissection

Capture of a vascular procedure

New forearm fistula created more proximally

New forearm fistula created more proximally

Vascular probe used in medical procedure

Probe placement on outflow vein

Probe placement on outflow vein

Medistim Flow graph

Final TTFM showing acceptable flow

Final TTFM showing acceptable flow

MiraQ device screen capturing precise measurement data
Image 1

Image 1

Resected vein cut open to inspect the dissection
Image 2

Image 2

Capture of a vascular procedure
Image 3

Image 3

Vascular probe used in medical procedure
Image 4

Image 4

Medistim Flow graph
Image 5

Image 5

Technology used

Medistim MiraQTM Vascular System with Medistim TTFM probes and Medistim L15 Ultrasound Probe.

MiraQ device screen capturing precise measurement data

Initial TTFM showing acceptable flow but no thrill

Initial TTFM showing acceptable flow but no thrill

Resected vein cut open to inspect the dissection

Resected vein cut open to inspect the dissection

Resected vein cut open to inspect the dissection

Capture of a vascular procedure

New forearm fistula created more proximally

New forearm fistula created more proximally

Vascular probe used in medical procedure

Probe placement on outflow vein

Probe placement on outflow vein

Medistim Flow graph

Final TTFM showing acceptable flow

Final TTFM showing acceptable flow