Transit-time flow measurement parameters after protamine infusion in CABG surgeries

Area of Science:

• Cardiovascular Surgery
• Vascular Physiology

Background:

• Protamine sulfate is used to reverse heparin anticoagulation after cardiopulmonary bypass.
• Its potential effects on graft hemodynamics are not fully understood.
• Accurate graft flow assessment is crucial for surgical success.

Purpose of the Study:

• To evaluate the impact of protamine sulfate on graft blood flow.
• To compare transit-time flow measurement (TTFM) parameters before and after protamine administration.

Main Methods:

• Observational study (2018-2020) of 575 patients and 1686 grafts.
• Utilized TTFM to assess graft patency, measuring mean graft flow (MGF), pulsatility index (PI), and diastolic flow (DF).
• Compared TTFM values pre- and post-protamine, analyzing all conduits, on-pump vs. off-pump, and specifically saphenous vein grafts (SVG).

Main Results:

• Protamine administration led to a non-significant decrease in MGF across all grafts.
• Saphenous vein grafts (SVG) showed increased PI, while left internal thoracic artery (LITA) grafts had reduced diastolic flow (DF).
• Off-pump surgery demonstrated no statistically significant changes in TTFM parameters post-protamine.

Conclusions:

• Protamine sulfate induced variations in TTFM values, though generally within normal ranges.
• Graft flow parameters remained largely stable despite protamine administration.
• Recommend performing graft flow measurements prior to protamine infusion to obtain baseline values.