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

INTRODUÇÃO: A cirurgia de revascularização do miocárdio (RM) sem circulação extracorpórea (CEC) é uma técnica amplamente utilizada. A fluxometria coronariana é a técnica mais usada para avaliação dos enxertos, porém, poucos estudos comparam os dados fluxométricos na RM com e sem CEC. O objetivo deste estudo foi comparar as variáveis fluxométricas dos enxertos de artéria torácica interna esquerda para a artéria descendente anterior em pacientes submetidos à RM com e sem CEC. MÉTODOS: Entre março e setembro de 2010, foram analisados retrospectivamente 35 pacientes consecutivos, não randomizados, submetidos à RM. Foram alocados 10 pacientes no grupo A (com CEC) e 25 no grupo B (sem CEC). O fluxo médio do enxerto (FME), o índice pulsátil (PI) e a porcentagem de enchimento diastólico (ED) foram obtidos por meio da fluxometria por tempo de trânsito. Foi utilizado o teste exato de Fisher e Mann-Whitney, sendo considerado estatisticamente significante PBACKGROUND: Off-pump coronary bypass grafting (OPCAB) has become a widely used technique. Coronary flowmetry is the most common method employed to assess graft patency, nevertheless, few studies compare flow patterns between ONCAB and OPCAB surgery. The objective of this study was to compare flowmetry data in left internal mammary artery grafts bypasses to the left anterior descendent artery. METHODS: From March to September of 2010, thirtyfive consecutive, non-randomized patients underwent CABG and were retrospectively evaluated. Ten patients were located on group A (On Pump), and twenty-five on group B (Off Pump). The mean graft flow (MGF), pulsatile index (PI) and diastolic filling (DF) were obtained using Transit Time Flowmetry (TTFM). The Fisher exact test, and Mann Whitney test were used, and a P value of < 0.05 was considered to indicate statistical significance. RESULTS: There were no deaths, AMI, re-interventions or PTCA in a 30-day period. The number of bypasses performed per patient was 2.3 ± 0.8 in the OPCAB group, and 2.2 ± 0.6 in the ONCAB group, with no significant difference (P=0.10). The median of mean flow was 23 ml/min on group A, and 25 ml/min on group B (P=0.34). Diastolic filling percentage was 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 TTFM values (MF, PI and DF) in patients operated with or without cardiopulmonary bypass