Securing a Fem-Pop Bypass by using TTFM and HFUS


Performing quality control during peripheral bypass surgery is important to secure optimal patency of the graft to avoid re-operation or secondary intervention. In this case, Transit Time Flow Measurement (TTFM), High-Frequency Ultrasound (HFUS), and angio verified distal flow before closing the wounds.

Patient information

• 67-year-old male
• Occlusion of the left superficial femoral artery
• Vascular ulcer above left ankle
(Figure 1)

Fem-pop bypass procedure

A femoral popliteal bypass was performed using the SVG in situ (Figure 2). Prior to the bypass procedure, an endarterectomy of the SFA was performed as it was occluded. The SFA was then ligated and a part of it was removed and used as a patch to increase the diameter of the DFA. After the patchplasty, the SVG was anastomosed proximally to the DFA and distally to the distal popliteal artery (Figure 3).

TTFM at the proximal anastomosis

With the distal end of the graft clamped, the first TTFM performed close to the proximal anastomosis shows a flow of 185 mL/min and a low Pulsatility Index (PI). The PI indicates the level of resistance in the vessel/graft. The low PI, in this case, indicates that there is at least one open side branch in the graft which is common with in-situ bypasses (Figure 4).

Detection and ligation of side branches with angio and HFUS

Angio was performed with a Glow ’N’ Tell tape to locate the side branches in the SVG. HFUS was then used to pinpoint the side branches making the incisions as small as possible (Figure 5). Two side branches were ligated before the final TTFM was performed.

TTFM at the distal anastomosis

After ligating the side branches, TTFM was performed close to the distal anastomosis. The TTFM shows a good flow of 147mL/min and a PI of 1,3 (Figure 6 and Figure 7).

Post-Op one week after surgery

On day 7, a clear improvement of the wound can be seen by concomitant reperfusion syndrome with swelling of the leg (Figure 8).


In this case, Transit Time Flow Measurement and High-Frequency Ultrasound were beneficial to secure optimal flow distally to the foot:
• TTFM to determine outflow resistance and the presence of side branches
• HFUS guidance in pinpointing side branches and enabling smaller incisions
• TTFM verifying adequate flow


Case example provided by Dr. Alexander Meyer, Department of General and Vascular Surgery, Johanniter Krankenhaus Rheinhausen, Germany.

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