Narrowing effect of off-pump CABG on the LIMA-LAD anastomosis: epicardial ultrasound assessment.

Aim: Effects of off-pump CABG on LIMA-LAD anastomotic dimensions vs. on-pump CABG assessed by epicardial ultrasound imaging.

Material And Methods: LIMA-LAD anastomoses were performed off-pump in 38 patients and on-pump in 12. Intra-operative imaging was by a GE Vivid 7 ultrasound scanner and i13L transducer. Length of the anastomosis (DA), LAD diameters at the toe (D1) and heel (D3) of the anastomosis, the reference downstream LAD (D2) were measured in diastole by two-dimensional imaging (B-mode). Relationships between these dimensions were compared between on- and off-pump patients.

Results: In off-pump patients, D3 dimension was smaller than D1 (p=0.004). Both D3 and D1 were smaller than D2 (p<0.01). Ratio D3/D2 was smaller than D1/D2 (p=0.009). In on-pump patients, these ratios were similar. D3/D2 ratio was smaller in off- than in on-pump patients (p=0.01), D1/D2 were similar in the two groups.

Conclusion: Off-pump CABG may cause a narrowing of the coronaries, especially at the anastomotic heel. The anastomotic technique at the heel may have to be modified to improve its patency.