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Published on: November 24, 2014
Transit time flow measurement in on-pump and off-pump coronary artery surgery
Christoph Schmitz1, Osman Ashraf, Wolfgang Schiller
1Department of Cardiac Surgery, Heart Center, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany. c.schmitz@uni-bonn.de
Insights
Transit time flow measurement is valuable for assessing coronary artery bypass graft patency. Coronary artery bypass without cardiopulmonary bypass showed reduced troponin I release, indicating myocardial benefit despite lower flow measurements.
Area of Science:
- Cardiovascular Surgery
- Surgical Technology
- Graft Patency Assessment
Background:
- Transit time flow measurement (TTFM) is crucial for evaluating graft function during coronary artery bypass (CAB) surgery.
- Graft dysfunction can arise from technical errors, necessitating reliable intraoperative assessment methods.
Purpose of the Study:
- To retrospectively analyze intraoperative TTFM measurements in patients undergoing CAB with and without cardiopulmonary bypass.
- To compare TTFM parameters and myocardial injury markers between on-pump and off-pump CAB procedures.
Main Methods:
- Retrospective review of 896 patients undergoing double- or triple-vessel disease surgery.
- Analysis of 2247 grafts from 695 on-pump (Group A) and 201 off-pump (Group B) CAB patients.
- Measurement of mean graft flow (mL/min) and Troponin I levels.
Main Results:
- Lower mean graft flows were observed in off-pump CAB (Group B) compared to on-pump CAB (Group A) for both LITA-LAD and SVG-LAD grafts.
- Significantly reduced Troponin I release was found in off-pump CAB patients (median 1.2 µg/L) versus on-pump CAB patients (median 7.8 µg/L).
Conclusions:
- Intraoperative TTFM is a valuable tool for assessing coronary graft patency in both on-pump and off-pump CAB.
- Off-pump CAB demonstrates a potential myocardial benefit, evidenced by decreased Troponin I release, despite lower intraoperative TTFM flows.
Objective:
Transit time flow measurement is frequently used during coronary artery bypass with and without cardiopulmonary bypass to detect graft dysfunction resulting from technical errors.
Methods:
Intraoperative transit time flow measurement measurements of 896 patients requiring surgery for double- or triple-vessel disease were reviewed retrospectively. Six-hundred and ninety-five patients were operated on-pump (Group A: coronary artery bypass with cardiopulmonary bypass), and 201 patients off-pump (Group B: coronary artery bypass without cardiopulmonary bypass). Transit time flow measurement measurements were analyzed for mean flow (mL/min). In total, measurements of 2247 grafts were analyzed.
Results:
Transit time flow measurement flows were lower in coronary artery bypass without cardiopulmonary bypass patients (left internal thoracic artery to left anterior descending artery: Group A, 37 [31, 40] mL/min vs Group B, 24 [20, 26] mL/min; saphenous vein graft to left anterior descending artery: Group A, 46.5 [40, 56] mL/min vs Group B, 21 [14, 57] mL/min. Troponin I release was reduced in the coronary artery bypass without cardiopulmonary bypass patients, with median values of 7.8 [7.0, 8.3] microg/L in Group A and 1.2 [0.9, 2.3] microg/L in Group B.
Conclusion:
Evaluation of transit time flow measurement is valuable in determining coronary graft patency after coronary artery bypass with cardiopulmonary bypass and coronary artery bypass without cardiopulmonary bypass. Decreased troponin I release suggests a myocardial benefit of coronary artery bypass without cardiopulmonary bypass compared to coronary artery bypass with cardiopulmonary bypass, although the intraoperative transit time flow measurement flow measurements are markedly lower.
