Lower limb bypass: Convincing results using TTFM as completion control

Case 1: Fem-Pop bypass with in-situ vein graft

In this case the surgeon wanted to perform the procedure as minimally invasive as possible. The bypass was performed by using the great saphenous vein (SVG) in situ and ligating all the side branches endoscopically. The surgeon did the completion control with Transit Time Flow Measurement (TTFM) to confirm adequate flow distally and the lack of side branches. He then performed an angiogram according to his previous routine to verify that the findings with TTFM were correct as his intention was to be able to skip angio and the use of contrast media in the future when doing this procedure.

Patient information

  • 57-year-old male
  • Diagnosis: Critical limb threatening ischemia (CLTI) due to occlusion of the superficial femoral and popliteal arteries

Surgical procedure

After vein mapping and locating the sites for the proximal and distal anastomosis, 10 cm incisions were made proximally and distally (Image 1). The side branches on the SVG were ligated endoscopically and valve lysis was performed (Image 1 and 2).

Completion control with TTFM

After completion of the proximal and distal anastomosis, the surgeon placed a 4 mm flow probe on the vessel at the proximal site showing 133 mL/min with a PI of 1.7 (Image 3 and 4).

To check for presence of side branches, he occluded the graft percutaneously several times with his finger while moving the pressure point distally along the graft and at the same time measuring the flow volume at the proximal site. A strong reduction in flow each time he occluded the graft confirmed that all the side branches were clipped.

3 minutes after he had measured the flow proximally, TTFM was performed at the distal site showing adequate flow of 156 mL/min with a PI of 1.3 (Image 5 and 6).

Case 2: Comparing Doppler vs. TTFM as completion control

The surgeon completed an open bypass procedure as normal on another patient and was satisfied with the Doppler signal at the end of the case. He then used TTFM and noticed low flow at the distal site, 89 mL/min with a PI of 1.5 (Image 7).

After a critical review of the bypass, it was detected that one area had an intermittent pulse. He opened the side branch and noticed there was a retained valve. The valve was removed and the side branch was closed. Flow volume was then remeasured which had increased to 110 mL/min with a PI of 1.9 (Image 8).

Really great information intra-OP that changed how I performed today and will hopefully prolong the patency of this long segment bypass.

Comments from Dr. Yacob regarding TTFM as quality assessment of the graft patency.

“Really great information intra-OP that changed how I performed today and will hopefully prolong the patency of this long segment bypass.”

Case attachments

Click images below to view.
Medical procedure

Case 1: Proximal incision and endoscopic ligation of valves via proximal site

Case 1: Proximal incision and endoscopic ligation of valves via proximal site

Procedure image capure

Case 1: Endoscopic ligation of valves

Case 1: Endoscopic ligation of valves

Surgical procedure on arm

Case 1: Probe placement at proximal site

Case 1: Probe placement at proximal site

MiraQ device display with comprehensive data readouts

Case 1: TTFM at proximal site

Case 1: TTFM at proximal site

Flow probe used during a surgical procedure

Case 1: Probe placement at distal site

Case 1: Probe placement at distal site

view of screen showing transit time flow measurement (TTFM)

Case 1: TTFM at distal site

Case 1: TTFM at distal site

Screen of the MiraQ instrument featuring recorded data metrics

Case 2: TTFM at distal site

Case 2: TTFM at distal site

TTFM of distal graph

Case 2: TTFM remeasured at distal site

Case 2: TTFM remeasured at distal site

Medical procedure
Image 1

Image 1

Procedure image capure
Image 2

Image 2

Surgical procedure on arm
Image 3

Image 3

MiraQ device display with comprehensive data readouts
Image 4

Image 4

Flow probe used during a surgical procedure
Image 5

Image 5

view of screen showing transit time flow measurement (TTFM)
Image 6

Image 6

Screen of the MiraQ instrument featuring recorded data metrics
Image 7

Image 7

TTFM of distal graph
Image 8

Image 8

Reference

Case example provided by Dr. Michael Yacob, Kingston General Hospital, Kingston, Ontario, Canada.

Technology used

Medistim VeriQTM System with Medistim QuickFitTM TTFM probes 3 and 4 mm.

Medical procedure

Case 1: Proximal incision and endoscopic ligation of valves via proximal site

Case 1: Proximal incision and endoscopic ligation of valves via proximal site

Procedure image capure

Case 1: Endoscopic ligation of valves

Case 1: Endoscopic ligation of valves

Surgical procedure on arm

Case 1: Probe placement at proximal site

Case 1: Probe placement at proximal site

MiraQ device display with comprehensive data readouts

Case 1: TTFM at proximal site

Case 1: TTFM at proximal site

Flow probe used during a surgical procedure

Case 1: Probe placement at distal site

Case 1: Probe placement at distal site

view of screen showing transit time flow measurement (TTFM)

Case 1: TTFM at distal site

Case 1: TTFM at distal site

Screen of the MiraQ instrument featuring recorded data metrics

Case 2: TTFM at distal site

Case 2: TTFM at distal site

TTFM of distal graph

Case 2: TTFM remeasured at distal site

Case 2: TTFM remeasured at distal site