TPT 9.12 Impact of Diabetes Mellitus on Sternal Microcirculation Following Coronary Artery Bypass Graft and Aortic Valve Replacement Surgeries

Abstract Background Diabetes mellitus is a well-recognised risk factor for impaired wound healing and sternal wound complications following coronary artery bypass graft (CABG) and Aortic Valve Replacement (AVR) Surgeries. Microvascular dysfunction is thought to play a central role, but objective intraoperative and postoperative assessment of sternal microcirculation remains limited. Methods Sternal microcirculatory blood flow was assessed using laser Doppler flowmetry in patients undergoing median sternotomy for CABG and AVR Surgeries. Diabetic and non-diabetic patients were prospectively compared. Measurements were obtained at baseline and at predefined postoperative intervals. Microcirculatory flow patterns and recovery profiles were analysed between groups. Results Diabetic patients demonstrated significantly reduced baseline sternal microcirculatory flow compared with non-diabetic patients. Following sternotomy, diabetics exhibited a greater reduction in microcirculatory perfusion and a delayed recovery trajectory. Persistent impairment in postoperative microvascular flow was observed in the diabetic cohort, suggesting sustained microvascular dysfunction. These changes correlated with known clinical risk factors for impaired wound healing. Conclusion Diabetes mellitus is associated with significant impairment of sternal microcirculation before and after cardiac surgery. Laser Doppler flowmetry provides a sensitive, real-time method for detecting microvascular dysfunction and offers mechanistic insight into the increased risk of sternal wound complications in diabetic patients. This technique may have a future role in perioperative risk stratification and targeted wound-protective strategies.