Bilateral internal mammary artery grafting: Comparison between different surgical techniques.

Background: Increasing evidence continues to demonstrate a survival advantage for bilateral internal mammary artery (BIMA) over single internal mammary artery (SIMA) for coronary artery bypass grafting (CABG). However, there are still doubts about which surgical strategy is the best one to use with BIMA grafting. This study aims to compare immediate and mid-term outcomes with BIMA CABG, using different surgical techniques, through transit-time flow measurement (TTFM) and clinical follow-up.

Methods: In this retrospective study, there were included 170 consecutive patients who underwent CABG between February 2011 and June 2014 in one single center. Patients were 95.9% men with a mean age of 58.8±8.6 years (range 35-78). The global cohort was then divided in subgroups: the in situ / composite "Y" graft subgroups and the off-pump / on-pump subgroups. TTFM assessment was used in 100% of the grafts. Mid-term follow-up was complete in 100% of patients.

Results: In 57.6% of patients, BIMA were used in situ: right internal thoracic artery (RIMA) to left anterior descending artery (LAD) and left internal thoracic artery (LIMA) to circumflex (Cx) branches and in 42.4% of patients, RIMA was anastomosed to LIMA in a "Y" shape: LIMA to LAD and RIMA to Cx branches. RIMA/LIMA-LAD and RIMA/LIMA-OM grafts mean flow and mean pulsatility index were 35.4 ml/min and 2.6, and 29.6ml/min and 2.6, respectively. There were no differences on in situ or "Y" shape grafts regarding pulsatility index. There were also no differences regarding pulsatility index and morbidity between surgeries performed off or on-pump. In a mean follow-up time of 18.8 months, 97.6% of patients had complete angina relief and there was no mortality.

Conclusions: CABG surgery with BIMA grafting can be safely performed, even in patients with multiple risk factors, without compromising grafts quality, regardless the surgical technique.