Intra-operative Graft Blood Flow Measurements for Composite and Sequential Coronary Artery Bypass Grafting

Abstract

Objectives Intraoperative assessment of coronary artery bypass grafts (CABG) anastomotic quality can be performed using transit-time flowmetry (TTF). The aim of this study was to compare on- versus off-pump coronary graft TTF and early postoperative outcomes. Materials and methods Between January 2009 and January 2010, 521 distal graft flows were assessed using TTF measurements in 253 consecutive patients undergoing primary isolated CABG surgery. Data were analyzed using multilevel models accounting for clustering among surgeons and grafts performed in the same patient. Results Mean age was 66 ± 10 years and 22% were female (n = 55) with 34% diabetics (n = 86) and 40% pre-operative myocardial infarction (MI) (n = 101). The surgeries were performed off-pump in 67% (n = 170) with sequential vein grafts in 57% (n = 144) of patients. Off-pump patients had higher pre-operative left ventricular ejection fractions (LVEF), fewer urgent surgeries, fewer distal anastomoses, and fewer sequential vein grafts (all p<0.001). Intra-operative coronary graft TTF measurements were lower in sequential vein grafts performed off-pump versus on-pump. More patients in the on-pump group needed milrinone or dobutamine 24-48 h postoperatively (p = 0.005). Independent predictors of lower TTF included female gender and off-pump surgery, whereas predictors of better TTF were pre-operative MI, larger coronary diameter at the site of the distal anastomosis, and sequential vein grafting. Conclusions Lower intra-operative TTF measurements were found in sequential vein grafts in offpump CABG. However, off-pump patients experienced similar short-term outcomes compared to on-pump patients.

Microcirculatory response during on-pump versus off-pump coronary artery bypass graft surgery

“…of heparin per kilogram were administered and ACT was aimed to be greater than 300 seconds. Following revascularisation, patency of the grafts was assessed in all patients by transit-time flowmetry (TTF) with a MediStim flowmeter (Medtronic Inc., Newport, CA, USA), 26 then the chest was closed and the patient transferred intubated to the intensive care unit (ICU).…”

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

“…Similar findings were present in studies comparing those two surgical techniques. 14 Moreover, in our study we did not compare the technique that was chosen to dissect the LIMA, which could affect those results.…”

Improving coronary artery bypass grafting: a systematic review and meta-analysis on the impact of adopting transit-time flow measurement

“…A study which evaluated off-pump versus on-pump CABG found lower overall TTFM values to be associated with an increased incidence of low cardiac output syndrome ( P = 0.049). Off-pump surgery was not associated with higher PI or lower diastolic filling %, and no differences were found in 30-day mortality and MI between patients who underwent off-pump versus on-pump CABG [72]. One study reported higher MGF and lower PI in off-pump procedures [62], while another study showed no differences in TTFM parameters between on-pump and off-pump [52].…”