This case from the REQUEST study describes how the combined use of Transit Time Flow Measurement (TTFM) and High-Frequency Ultrasound (HFUS) revealed a compromised anastomosis, enabling the surgeon to handle the situation appropriately.
Purse string effect revealed by TTFM and HFUS
Case story
Patient information
- 71-year-old male
- BMI 27.1
The patient was originally scheduled for an on-pump CABG with three grafts:
- LIMA-DIAG-LAD
- LIMA-Y-RIMA-OM-PL
- SVG-PDA
Intraoperative completion control with TTFM and HFUS
The LIMA grafts were uneventful, but TTFM of the SVG-PDA provided unsatisfactory results. The mean flow was of 14 mL/min was lower than expected and PI was high (4,5). DF% was also slightly low for this type of graft (46%), see Image 1. Everything indicated that there was an issue with the graft.
HFUS confirmed that the issue was an over-sutured anastomosis to the PDA. The annotations in Image 1 show how the opening of the anastomosis is narrowed by the sutures.
During revision a new and wider anastomosis was made using a piece of vein. The new connection was made to the RCA.
Post revision
TTFM and HFUS post revision showed an improved result as seen in Image 2. Mean flow and DF% is up while PI is down. A dobutamine test was performed and flow was observed to increase to 29 mL/min and PI held at 3.8. This was also confirmed with troponin levels close to zero.
This case shows how the combination of TTFM and HFUS gives both an indication that something might be wrong with a graft and how imaging can help the surgeon identify and correct the issue.
Case attachments
Click images below to view.
Initial TTFM with corresponding image of purse string effect
TTFM and HFUS post revision
Reference
Registry for Quality Assessment with Ultrasound Imaging and Transit-time Flow Measurement in Cardiac Bypass Surgery
Taggart DP et al. Intraoperative transit-time flow measurement and high-frequency ultrasound assessment in coronary artery bypass grafting. J Thorac Cardiovasc Surg. 2019; 159: 1283-1292.
DOI: https://doi.org/10.1016/j.jtcvs.2019.05.087
Technology used
Medistim MiraQ™ Cardiac System and QuickFit™ TTFM Probes and L15 High-Frequency Ultrasound Probe.
