Dissected LIMA discovered by use of TTFM & HFUS


“Great benefit in graft patency verification. Very accurately able to detect dissection as the problem.” (Ref. operating surgeon) This case from the Request Study describes how the combined use of Transit Time Flow Measurement (TTFM) and High-Frequency Ultrasound (HFUS) revealed a dissected LIMA. These insights helped the surgeon identify the issue and address it appropriately.

Pre-Op Angio indicated that the patient had a moderate to severe lesion (50-75%) proximally in the LAD, CX was calcified proximally, and the RCA was occluded proximally.


Patient Information

  • 83-year-old male
  • BMI 26
  • Hypertension, High cholesterol, NSTEMI 22 years ago, Stable angina

Technology Used

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

Intraoperative Guidance

The surgical plan was to perform a LIMA-LAD and create a Y-graft with a SVG sequential branch to OM and the PDA. (Image 1)

Upon completion of the graft the different segments were checked with TTFM. The SVG graft was good, as was the proximal part of the LIMA. All anastomoses were checked with HFUS and all good. Poor TTFM values in the distal LIMA segment and HFUS of the distal anastomosis led to scan of the LIMA body, where a dissection was discovered. Location of the poor TTFM reading is indicated on the graft schematic above. (Image 2)

The annotated HFUS measurements (Image 3) show how the dissection was located and diagnosed.

The first measurement shows the LAD anastomosis and a collapsed portion of the LIMA.

The second measurement, (Image 4) acquired slightly proximal from the first measurement, shows the dissection in the LIMA and the false lumen is annotated.

Using this insight, the surgical team was able to accurately locate the dissection and replace the damaged portion with a part of the SVG graft.

The TTFM measurement (Image 5) shows the improved results after the collapsed part of the LIMA had been replaced with the SVG (Image 6). The revised graft schematic shows the final construction and the location where the TTFM measurement was captured.

Case Attachments