Bilateral skeletonized IMAs used as "in situ" grafts for different coronary territories: long-term propensity matching study.

Introduction: Bilateral internal mammary arteries (BIMAs) are the most advanced surgical option for coronary artery bypass grafting (CABG). This study compares outcomes between patients receiving skeletonized BIMAs as in situ grafts for different coronary territories and those undergoing CABG with a single internal mammary artery (SIMA).

Methods: Between 2013 and 2023, 7543 patients underwent CABG for multivessel coronary artery disease at our institution. BIMA grafting was performed in 1133 patients (15.02%), with in situ BIMA grafting in 283 patients (3.75%). The right internal mammary artery (RIMA) was used for the right coronary artery, and the left internal mammary artery (LIMA) for the left anterior descending artery. Propensity score matching yielded 280 patients in each group for comparison. Primary outcomes were 30-day and 10-year all-cause mortality. Secondary outcomes included length of hospital stay, incidence of postoperative major adverse cardiovascular and cerebrovascular events (MACCE), sternal wound infection, and the need for subsequent revascularization.

Results: There was no 30-day postoperative mortality, perioperative MACCE, or deep sternal wound infection in either group. Mean follow-up was 9.78 ± 0.62 years. The 10-year survival rate was significantly higher in the in situ BIMA group (86.07 ± 3.0%) compared to the SIMA group (78.6 ± 4.1%, p < 0.05).

Conclusion: Skeletonized BIMA grafting improves long-term survival compared to SIMA grafting, rendering traditionally accepted limitations for BIMA usage irrelevant. These findings support the broader adoption of BIMA grafting in CABG.

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Supplementary information: The online version contains supplementary material available at 10.1007/s12055-025-01979-8.