TTFM & HFUS confirms hematoma in LIMA


Knowing whether an underperforming conduit should be rejected or not is very valuable information. This case from the Request Study describes how the combined use of Transit Time Flow Measurement (TTFM) and High-Frequency Ultrasound (HFUS) allowed the surgeon to make informed decisions before proceeding.

Patient Information

  • 52-year-old woman
  • BMI 41,8
  • Hypertension, hyperlipidemia, DM II
  • Stable angina
  • Active MI – diffuse disease


Technology Used

Medistim MiraQTM Cardiac System with QuickFitTM TTFM probes (PS series) and L15 HFUS probe.

Intraoperative Guidance

The surgical plan was to perform an On-pump procedure with three targets:

  • Radial – OM/OM2

During harvesting of the LIMA, a TTFM was performed with the LIMA in situ. The results were unsatisfactory. As shown by the tracing in Image 1, the mean flow was zero, PI very high (20,1) and the DF% was low (35%). Measurement recorded with MAP at 77mmHg.

Instead of discarding the LIMA as a conduit Imaging was performed to determine the cause of the poor flow measurement.

Imaging revealed a narrowing in the LIMA due to a hematoma (Image 2). No dissection or other damage to the vessel was detected. Based on this data the surgeon decided to continue with the plan and use the LIMA for the LAD target.

Imaging was also employed to identify the best location for the anastomosis on the LAD.

The TTFM measurement (Image 3) shows the flow post-protamine. The parameters are generally good (mean flow = 22ml/min, PI = 2,3 and DF% = 69%), indicating a well-functioning and patent graft.

This case shows how the combination of TTFM and HFUS was used to identify a flow complication in the LIMA and correctly classify it as non-issue. The surgeon could continue as planned with the LIMA-LAD graft and saved valuable time avoiding having to use a back-up conduit.


Case Attachments