A patient was readmitted on post-OP day 8 due to pain in the leg after a fem-pop in-situ bypass. This case shows how Transit Time Flow Measurement (TTFM) and High-Frequency Ultrasound (HFUS) were used as completion control during the reoperation.
Peripheral bypass reoperation: Detection of thrombus and side branches in graft
Case story
Patient information:
Patient medical history: Patient with PAD and Fontaine stage IV on the right side (Image 1).
Initial surgery: Fem-pop bypass using the great saphenous vein (SVG) in situ as graft. The surgery went uneventfully and TTFM showed 41 mL/min with a PI of 2.9 after ligation of all residual saphenous vein side branches that were visible on angio (Image 2).
Reoperation: Detection of thrombus and side branches in graft
On post-OP day 8, the patient experienced pain in the foot. Percutaneous ultrasound showed a distal occlusion of the SVG as well as flow in the vein side branch. The patient was readmitted for surgery and during the procedure, HFUS revealed a large open side branch and a thrombus in the vein graft (Image 3 and 4). The following TTFM readings were all performed on different parts of the SVG.
- TTFM at site M1 confirming significant flow in side branch (Image 5):
TTFM was first performed at site M1 proximally to the open side branch and the occluded area. TTFM at M1 showed 429 mL/min with a PI of 0.5 suggesting that a lot of the blood was flowing through the side branch. A large thrombus was identified in the SVG graft, possibly caused by the high flow in the side branch and low flow in the graft.
- TTFM at site M2 after thrombectomy and ligation of the side branch (Image 6):
A thrombectomy was performed and the side branch closed. TTFM at site M2, measured distally to the closed side branch, showed 122 mL/min with a PI of 2.4.
- TTFM at site M3 suggesting another side branch (Image 7):
TTFM was performed at site M3 close to the distal anastomosis, and yet again it showed reduced flow of 38 mL/min with a PI of 5.6. This suggested a second side branch located between M2 and M3.
- TTFM at site M4 showing acceptable flow (Image 8):
After ligating the second side branch, TTFM at site M4 showed 40 mL/min with a PI of 7.5. The high PI may be due to high resistance in the tibial trunk, hence, angioplasty of the tibial trunk was performed simultaneously. A final TTFM was performed with an acceptable flow and PI.
This case shows how TTFM and HFUS can provide helpful surgical guidance by identifying significant side branches and thrombus in lower limb in-situ bypasses.
Case attachments
Click images below to view.
MR angio from initial surgery
TTFM from initial surgery
Photo of open side branch and thrombus in SVG
HFUS of side branch and thrombus in SVG
TTFM at site M1
TTFM at site M2
TTFM and site M3
TTFM at site M4 showing the whole reoperation
Reference
Case example by Dr. Alexander Meyer, Department of General and Vascular Surgery, Johanniter Krankenhaus Rheinhausen, Germany.
Technology used
Medistim MiraQTM Vascular System with Medistim TTFM Probes and Medistim L15 High-Frequency Ultrasound Probe (HFUS).
