ObjectiveTo investigate the clinical efficacy of off-pump coronary artery bypass grafting, and summarize the experience of nursing care in the treatment. MethodsWe retrospectively analyzed the clinical data of 25 patients undergoing off-pump coronary artery bypass surgery between January 2010 and December 2012. The therapeutic effect of the surgical method and the care management measures were summarized and analyzed. ResultsAll the operations were successful without any deaths. The Mean operation time was (209.85±38.41) miniutes; Blood infusion volume averaged (1 311.23±423.70) mL; Drainage volume was (491.98±142.46) mL; The mean ICU monitoring time was (4.22±1.23) days; Hospitalization lasted for (10.10±1.89) days; And the mean number of bypass was 4.00±0.51. Two patients had high temperature and coughing after surgery, and were cured through intravenous dripping and atomization sputum suction. Two had slight injury infection and were controlled with antibiotics. Two could not endure the pain which was relieved by sauteralgyl. One patient with thoracic pain due to neural stimulation was relieved by glycerin trinitrate. ConclusionThe off-pump coronary artery bypass surgery is advantageous in having less trauma, less bleeding, shorter hospital stay and lower hospital costs. The preoperative, intraoperative and postoperative care should be prepared to ensure the smooth implementation of the surgery and improve therapeutic effect.
External support stent is a potential means for restricting the deformation and reducing wall stress of the vein graft, thereby improving the long-term patency of the graft in coronary artery bypass surgery. However, there still lacks a theoretical reference for choosing the size of stent based on the diameter of graft. Taking the VEST (venous external support) stent currently used in the clinical practice as the object of study, we constructed three models of VEST stents with different diameters and coupled them respectively to a model of the great saphenous vein graft, and numerically simulated the expansion-contraction process of the vein graft under the constraint of the stents to quantitatively evaluate the influence of stent size on the radial deformation and wall stress of the vein graft. The results showed that while the stent with a small diameter had a high restrictive effect in comparison with larger stents, it led to more severe concentration of wall stress and sharper changes in radial deformation along the axis of the graft, which may have adverse influence on the graft. In order to solve the aforementioned problems, we ameliorated the design of the stent by means of changing the cross-sectional shape of the thick and thin alloy wires from circle into rectangle and square, respectively, while keeping the cross-sectional areas of alloy wires and stent topology unchanged. Further numerical simulations demonstrated that the ameliorated stent evidently reduced the degrees of wall stress concentration and abrupt changes in radial deformation, which may help improve the biomechanical environment of the graft while maintaining the restrictive role of the stent.