Comparing Intraoperative Flow Measurement in Both off-Pump Coronary Artery Bypass and on-Pump Coronary Artery Bypass Graft Patients

Abstract
Background: Patent bypass grafts are fundamental to successful coronary artery bypass grafting. We studied the use of transit-time flow measurement to determine its ability to detect technical errors in grafts, to measure the mean flow norms, and to compare flow in both on-pump and off-pump CABG procedures.
Aim of Study: To compare conduit flow in a standardized type of CABG and OPCAB using the Left Internal Mammary Artery (LIMA) and vein grafts.
Patients and Methods: This study was conducted on 60 patients requiring coronary artery bypass surgery classified into 2 equal groups:
•Group A: (Conventional CABG), who were approached through on pump CABG.
•Group B: (OPCAB), whom approached without cardiopul-monary bypass machine.
Results: There was no statistical difference between the two groups in baseline pre-operative characteristics regarding their age, sex, NYHA class and EF%.
In Group (A), the MGF was (39.51±5.26) and PI values were (2.33±0.64). While in Group (B), the MGF was (32.71± 6.47) and PI measurements were (2.71±1.22). The MGF for the occluded grafts in Group A was (14.33±3.21) ml min and (12.75±2.87) in Group B (p=.522). The corresponding PI values were (8.03±1.0) for Group A and (8.85±1.67) for Group B (p=0.489).
Conclusions: TTFM technique is a highly valuable equip-ment. Mean flow is lower in the OPCAB group with higher pulsatility index than the conventional CABG group, which raises suspicion about the long term patency of OPCAB grafts.