Transit time flowmetry in coronary surgery--an important tool in graft verification

Area of Science:

• Cardiovascular Surgery
• Surgical Technology
• Quality Assurance in Medicine

Background:

• Coronary artery bypass grafting (CABG) is a common cardiac surgical procedure.
• Off-pump coronary artery bypass grafting (OPCAB) is increasingly preferred due to comparable or superior outcomes and cost-effectiveness compared to on-pump coronary artery bypass grafting (ONCAB).
• Ensuring graft quality is paramount for successful CABG outcomes.

Purpose of the Study:

• To analyze the experience and utility of Transit Time Flow Measurement (TTFM) in the first 1000 coronary artery bypass grafting (CABG) operations at a single center.
• To evaluate the incidence of graft revisions based on TTFM findings in both OPCAB and ONCAB procedures.
• To assess the impact of TTFM on graft quality assurance in a large cohort of CABG patients.

Main Methods:

• A retrospective analysis of the first 1000 CABG patients (September 1998 - September 2003) at Cardiovascular Clinic, University Clinical Centre Tuzla.
• Routine intraoperative use of TTFM for all grafts in both OPCAB and ONCAB procedures as a quality assurance measure.
• Graft revision criteria included low mean flow (MF), pulsatility index (PI) > 5, and poor diastolic flow pattern.

Main Results:

• A total of 1394 grafts in the OPCAB group and 1478 grafts in the ONCAB group were assessed using TTFM.
• Graft revisions were performed in 2.72% of grafts (7.07% of patients) in the OPCAB group and 1.75% of grafts (5.45% of patients) in the ONCAB group.
• The Left Anterior Descending (LAD) artery graft was the most frequently revised in both groups, with no statistically significant difference in revision rates between OPCAB and ONCAB.

Conclusions:

• TTFM is a valuable tool for intraoperative graft assessment in CABG, particularly in OPCAB surgery where technical challenges are greater.
• While graft revisions were slightly more common in OPCAB, TTFM identified suboptimal grafts in over 5% of patients in both groups, underscoring its importance.
• TTFM helps identify grafts likely to be occluded at surgery, contributing to improved quality assurance, although it doesn't guarantee long-term patency.