RESUMO
Background: Atherosclerosis, which is one of the leading causes of death all over the world, can create major or minor thromboembolic complications with the exponentially increasing diabetic status. Despite all the studies, the mechanism by which endothelial damage in atherosclerosis is triggered in diabetic setting is still not fully understood. Methods: In this study, tissue factor (TF), which is thought to act together in the formation of vasular endothelial growth factor (VEGF-A) and coagulopathy in diabetic atherosclerotic patients, may be an important indicator in this regard, a total of 100 cases who were undergone off-pump coronary artery bypass (OPCAB) which were at same risk group examined by dividing into diabetic status. Early postoperative process and biochemical parameters analyzed in terms of TF and VEGF-A levels measured before and after the operation. Results: TF and VEGF-A expression of the T1DM group were statistically high compared to non-diabetics. Significantly longer hospital stays with changes in TF and VEGF-A were found in patients in the diabetic group compared to pre- and postoperatively, respectively; TF (95% CI: 0.879-0.992; p = 0.025), VEGF-A (95% CI: 0.964-0.991; p = 0.001) and hospital stay (95% CI: 1.96-7.49; p = 0.0001). Preoperatively measured carotid intima-media thickness (CT) was higher in diabetics and was significantly associated with atrial fibrillation (AF), (r = 0.873). Surgical team and protocols were same and OPCAB procedures were routinely applied to all patients in our clinic. No minor or major events were observed in any of the cases. Conclusion: TF and VEGF-A values in patients with diabetic atherosclerosis may be important in the early detection of thromboembolic complications.
RESUMO
PURPOSE: This study aims to quantify the patient-specific hemodynamics of complex conduit routing configurations of coronary artery bypass grafting (CABG) operation which are specifically suitable for off-pump surgeries. Coronary perfusion efficacy and local hemodynamics of multiple left internal mammary artery (LIMA) with sequential and end-to-side anastomosis are investigated. Using a full anatomical model comprised of aortic arch and coronary artery branches the optimum perfusion configuration in multi-vessel coronary artery stenosis is desired. METHODOLOGY: Two clinically relevant CABG configurations are created using a virtual surgical planning tool where for each configuration set, the stenosis level, anastomosis distance and angle were varied. A non-Newtonian computational fluid dynamics solver in OpenFOAM incorporated with resistance boundary conditions representing the coronary perfusion physiology was developed. The numerical accuracy is verified and results agreed well with a validated commercial cardiovascular flow solver and experiments. For segmental performance analysis, new coronary perfusion indices to quantify deviation from the healthy scenario were introduced. RESULTS: The first simulation configuration set;-a CABG targeting two stenos sites on the left anterior descending artery (LAD), the LIMA graft was capable of 31 mL/min blood supply for all the parametric cases and uphold the healthy LAD perfusion in agreement with the clinical experience. In the second end-to-side anastomosed graft configuration set;-the radial artery graft anastomosed to LIMA, a maximum of 64 mL/min flow rate in LIMA was observed. However, except LAD, the obtuse marginal (OM) and second marginal artery (m2) suffered poor perfusion. In the first set, average wall shear stress (WSS) were in the range of 4 to 35 dyns/cm2 for in LAD. Nevertheless, for second configuration sets the WSS values were higher as the LIMA could not supply enough blood to OM and m2. CONCLUSION: The virtual surgical configurations have the potential to improve the quality of operation by providing quantitative surgical insight. The degree of stenosis is a critical factor in terms of coronary perfusion and WSS. The sequential anastomosis can be done safely if the anastomosis angle is less than 90 degrees regardless of degree of stenosis. The smaller proposed perfusion index value, O(0.04 - 0) × 102, enable us to quantify the post-op hemodynamic performance by comparing with the ideal healthy physiological flow.
