Use of the right internal mammary artery and the great saphenous vein for left anterior descending artery revascularization in patients whose left internal mammal artery cannot be used: a study based on transit-time flow measurement.

BACKGROUND

Owing to the high patency, the use of the left internal mammary artery (LIMA) for left anterior descending artery (LAD) grafting has been a cornerstone of coronary artery bypass grafting surgery (CABG). However, for some patients whose LIMA cannot be used, surgeons have to choose other conduit materials to revascularize the LAD. The purpose of this study was to explore the differences in different conduit materials used for LAD in terms of parameters measured by transit-time flow measurement (TTFM) and the early graft patency detected by computed tomography angiography.

METHODS

We retrospectively collected the data of 410 patients who underwent isolated primary OPCAB with intraoperative TTFM data. According to the strategy of the LAD revascularization, 410 patients were assigned to three groups: a left internal mammal artery (LIMA) group (n = 333), a right IMA (RIMA) group (n = 34) and a great saphenous vein (SVG) group (n = 43). The baseline and perioperative blood parameters were compared for the three groups, as well as the early graft patency rates.

RESULTS

Compared with the LIMA-LAD group, the SVG-LAD group had a significantly higher mean graft flow volume (MGF) (37.15 ± 23.29 vs 29.71 ± 20.94 ml/min, P = 0.036), however, had a lower value of pulse index (PI) (2.07 ± 0.62 vs 2.65 ± 1.01, P<0.001). There was no significant difference between the two groups in terms of DF (P>0.05). Compared with the RIMA-LAD group, the SVG-LAD group just had a lower value of PI (2.07 ± 0.62 vs 2.56 ± 0.96, P = 0.029). However, there was no significant difference between the two groups in terms of MGF and DF (P>0.05). Compared with the LIMA-LAD group, the RIMA-LAD group had a slightly lower value of DF (70.76 ± 11.87 vs 74.06 ± 7.09, P = 0.018), while there was no difference in terms of MGF and PI between the two groups (P>0.05). The patency rate of the LIMA-LAD group was 98.72% (309/313), that of RIMA-LAD group was 97.06% (33/34), and that of SVG-LAD group was 100%. There was no difference among the three groups in patency rate (P = 0.405).

CONCLUSIONS

SVG-LAD has a higher intraoperative MGF and a lower value of the PI than both LIMA-LAD and RIMA-LAD. RIMA has a higher preoperative blood flow and a lower value of the PI than LIMA; however, there were no significant difference between RIMA grafted to LAD and LIMA grafted to LAD in terms of MGF, PI and DF. In situ skeletonized RIMA did not increase blood flow compared to pedicled LIMA.