Summary:
Japan - Does off-pump coronary artery bypass grafting preserve renal function? A new study reported in Circulation Journal, published by the Japanese Circulation Society looked at the influence of coronary artery bypass surgery technique upon kidney function.
Dr. Nobuhiko Hayashida and his colleagues at the Department of Surgery, Kurume University investigated the effects of coronary artery bypass graft surgery performed with and without cardiopulmonary bypass ("heart-lung" machine) on several variables of kidney function.
It is well known that the use of cardiopulmonary bypass (CPB) influences kidney function and occasionally results in kidney failure following cardiac surgery.
It was hypothesized by the researchers in Japan that coronary artery bypass grafting (CABG) without cardiopulmonary bypass may avoid this and preserve perioperative kidney function.
The researchers enrolled 52 patients undergoing coronary artery bypass grafting without cardiopulmonary bypass (OPCAB group) and matched them for kidney function and prognostic variables with 53 patients undergoing conventional coronary artery bypass grafting using cardiopulmonary bypass(CABG group).
The OPCAB group had significantly less increase in creatinine levels (0.16 +/- 0.05 vs 0.45 +/- 0.06 mg/dl; p = 0.01) and greater creatinine clearance (81.6 +/- 7.3 vs 56.3 +/- 4.8ml/min; p = 0.01) postoperatively. Postoperative recovery of free water clearance was more prompt in the OPCAB group.
As excessive retention of body fluids may have an adverse effect on lung function, parameters of respiratory function were also assessed, including duration of ventilator dependence and intensive care unit stay.
The duration of ventilator dependence and intensive care unit stay was significantly shorter, and blood transfusion requirements were significantly less in the OPCAB group.
The beating heart (also known as "off pump" or OPCAB) technique preserved glomerular filtration rate and prevented the increase in creatinine levels. The results of this study suggest that the beating heart technique enables earlier patient recovery and gives superior kidney protection compared to conventional coronary artery bypass grafting using the "heart-lung" machine.
This study by the Japanese researchers corroborates at least a half dozen studies which have shown a protective effect of the "off pump" technique on the kidneys in patients with kidney dysfunction (renal insufficiency).
For a more comprehensive discussion about the potential benefits of beating heart coronary artery bypass grafting in the setting of kidney dysfunction, please consult your cardiologist, kidney specialist and cardiac surgeon.
