Flowmetry of left internal thoracic artery graft to left anterior descending artery: comparison between on-pump and off-pump surgery Fluxometria da artéria torácica interna esquerda na revascularização da artéria descendente anterior com e sem circulação extracorpórea

AbstractBackground: Off-pump coronary bypass grafting(OPCAB) has become a widely used technique. Coronaryflowmetry is the most common method employed to assessgraft patency, nevertheless, few studies compare flowpatterns between ONCAB and OPCAB surgery. Theobjective of this study was to compare flowmetry data in leftinternal mammary artery grafts bypasses to the left anteriordescendent artery.Methods: From March to September of 2010, thirty-five consecutive, non-randomized patients underwentCABG and were retrospectively evaluated. Ten patientswere located on group A (On Pump), and twenty-five ongroup B (Off Pump). The mean graft flow (MGF),pulsatile index (PI) and diastolic filling (DF) wereobtained using Transit Time Flowmetry (TTFM). TheFisher exact test, and Mann Whitney test were used,and a P value of < 0.05 was considered to indicatestatistical significance.Results: There were no deaths, AMI, re-interventions orPTCA in a 30-day period. The number of bypasses performedper patient was 2.3 ± 0.8 in the OPCAB group, and 2.2 ± 0.6in the ONCAB group, with no significant difference ( P=0.10).The median of mean flow was 23 ml/min on gr oup A, and 25ml/min on group B (P=0.34). Diastolic filling percentagewas 56% on group A, and 56.9% on group B (P=0.86).Pulsatile Index was 2.3 on group A, and 2.2 on group B(P=0.82).Conclusions: There was no difference between TTFMvalues (MF, PI and DF) in patients operated with or withoutcardiopulmonary bypass.Descriptors: Coronary artery bypass, off-pump.Myocardial revascularization. Coronary artery bypass.Flowmeters. Laser-doppler flowmetry.