Renal function after off-pump versus on-pump coronary artery bypass grafting

Abstract

Background

Renal dysfunction is a well-recognized major complication after coronary artery bypass grafting. Off-pump coronary artery bypass theoretically appears to have less impact on renal function. We estimated preoperative and postoperative creatinine clearance as a marker of renal dysfunction in patients undergoing off-pump and on-pump coronary artery bypass.

Methods

Thirty patients undergoing coronary artery bypass were randomly allocated to undergo either on-pump (n = 15) or off-pump surgery (n = 15). The two groups had similar preoperative demographic characteristics. Serum creatinine and creatinine clearance were measured for 4 days postoperatively and the results were compared with preoperative levels.

Results

The rise in serum creatinine on postoperative day 1 was 0.28 mgċdL⁻¹ in the on-pump group and 0.22 mgċdL⁻¹ in the off-pump group (p = 0.27); on postoperative day 4 it was 0.15 mgċdL⁻¹ and 0.10 mgċdL⁻¹, respectively, (p = 0.28). Similarly, the fall in creatinine clearance was 17.34 mLċmin⁻¹ in the on-pump group and 19.62 mLċmin⁻¹ in the off-pump group on postoperative day 1 (p = 0.42), and 10.9 and 10.94 mLċmin⁻¹, respectively, on postoperative day 4 (p = 0.64).

Conclusion

Renal function is not affected by the technique of coronary artery bypass surgery, whether with or without cardiopulmonary bypass, in spite of the theoretical advantage of off-pump surgery. Our study suggests that off-pump coronary artery bypass surgery does not confer significant protection from postoperative renal dysfunction in low-risk patients, when compared with on-pump surgery.