Background： Poor healing wounds or postoperative infection after open-heart surgery are most commonly seen, especially in secondary surgery for heart diseases, with an incidence rate of 2.2% after a valve replacement...Background： Poor healing wounds or postoperative infection after open-heart surgery are most commonly seen, especially in secondary surgery for heart diseases, with an incidence rate of 2.2% after a valve replacement surgery. If not treated in time or the infection progresses, it can lead to sternal infection, even mediastinal and pericardial infection, causing a higher mortality rate. It becomes a really troublesome and complicated case when a poor healing occurs in midsternal incision after the heart valve surgery and a higher medical cost may be needed. Methods From January 2009 to February 2013, 162 patients who underwent heart valve surgery through midsternal incision approach and had a poor healing of wound were observed for prospective randomized controlled trial. The patients were randomly assigned to a vacuum sealing drainage group （n = 81） who received vacuum sealing drainage for healing of the wound or a control group （n = 81） who received traditional treating for the infected wound. Their therapeutic effects, healing time and treatment costs, etc were compared. Results Two patients from the vacuum sealing drainage group came back to hospital for repair due to dehiscence of the incision after discharge, and no patient died. Six patients from the control group came back to hospital for repair due to dehiscence of the incision after discharge, two came back to hospital for surgery due to chronic osteomyelitis, and one patient died two weeks later after surgery due to severe chest infection. Wound healing time for vacuum sealing drainage group was 14.6 ± 3.6 days, which was significantly shorter than that of the control group （21.2 ± 7.8 days, P 〈 0.05）, while the medical costs showed no significant difference between the two groups （P 〉 0.05）. Seventy-eight patients （96.29%） in the vacuum sealing drainage group showed a good healing of the wound and sternum after a six-month follow-up. Conclusion The use of vacuum sealing drainage technique in poor-healing wounds after heart v展开更多
Introduction:We sought to investigate whether the development of sub-pulmonic systolic anterior motion(SAM)may be inherent to the anatomy of the the mitral valve(MV)or affected by external factors,such as a dilated ri...Introduction:We sought to investigate whether the development of sub-pulmonic systolic anterior motion(SAM)may be inherent to the anatomy of the the mitral valve(MV)or affected by external factors,such as a dilated right ventricle or chest abnormalities in d-looped transposition of the great arteries post atrial switch operation(d-TGA/AtS).Methods:Analysis was performed of clinical and cardiac imaging studies acquired on 19 adult patients with d-TGA/AtS(age 42±6 years old,56%male)between 2015–2019.Echocardiography data included mitral apparatus anatomy,and CT/MRI data included biventricular dimensions,function,and Haller index(HI)for pectus deformity.Results:Patients with leaflet SAM(n=6)compared to patients without SAM(n=13)had higher MV protrusion height(2.3±0.5 vs.1.5±0.4 cm,p≤0.01)and longer anterior MV leaflet length(3.1±0.4 cm vs.2.6±0.3 cm p≤0.05),when compared to those without.CT/MRI showed higher sub-pulmonic left ventricular ejection fraction(LVEF)in the SAM group(71%±8%vs.54%±7%,respectively).RV size and function,significant chest deformity(HI>3.5),presence of a ventricular lead pacemaker,and septal thickness did not play a role in development of SAM.Conclusions:An elongated mitral apparatus is associated with the development of SAM,and the development of left ventricular outflow tract obstruction(LVOTO),in d-TGA/AtS.LV hyperkinesia is associated with SAM.Systemic RV dimensions,septal thickness,and degree of chest deformity did not differ significantly between subjects with SAM and those without.展开更多
To solve the problems existing in the flow characteristics of steam turbine unit, the influence of valve overlap degree on nozzle governing steam turbine had been studied. The combined flow characteristics of given va...To solve the problems existing in the flow characteristics of steam turbine unit, the influence of valve overlap degree on nozzle governing steam turbine had been studied. The combined flow characteristics of given valve overlap degree were obtained for a 600MW steam turbine unit by the method of theoretical calculation combined with simulation test, and the influence of valve overlap degree on governing stage efficiency and steam chest pressure had been also analyzed. This paper discussed the selection of rational overlap degree and introduced a new method of building model for governing stage efficiency of steam turbine in constant pressure operation condition, which provided theoretical guidance for optimization research on nozzle governing steam turbine operation.展开更多
基金supported by Medical Scientific Research Foundation of Guangdong Province(No. B2013019)grants from Administration of Traditional Chinese Medicine of Guangdong Province (No. 20121258 & No. 20132075)
文摘Background： Poor healing wounds or postoperative infection after open-heart surgery are most commonly seen, especially in secondary surgery for heart diseases, with an incidence rate of 2.2% after a valve replacement surgery. If not treated in time or the infection progresses, it can lead to sternal infection, even mediastinal and pericardial infection, causing a higher mortality rate. It becomes a really troublesome and complicated case when a poor healing occurs in midsternal incision after the heart valve surgery and a higher medical cost may be needed. Methods From January 2009 to February 2013, 162 patients who underwent heart valve surgery through midsternal incision approach and had a poor healing of wound were observed for prospective randomized controlled trial. The patients were randomly assigned to a vacuum sealing drainage group （n = 81） who received vacuum sealing drainage for healing of the wound or a control group （n = 81） who received traditional treating for the infected wound. Their therapeutic effects, healing time and treatment costs, etc were compared. Results Two patients from the vacuum sealing drainage group came back to hospital for repair due to dehiscence of the incision after discharge, and no patient died. Six patients from the control group came back to hospital for repair due to dehiscence of the incision after discharge, two came back to hospital for surgery due to chronic osteomyelitis, and one patient died two weeks later after surgery due to severe chest infection. Wound healing time for vacuum sealing drainage group was 14.6 ± 3.6 days, which was significantly shorter than that of the control group （21.2 ± 7.8 days, P 〈 0.05）, while the medical costs showed no significant difference between the two groups （P 〉 0.05）. Seventy-eight patients （96.29%） in the vacuum sealing drainage group showed a good healing of the wound and sternum after a six-month follow-up. Conclusion The use of vacuum sealing drainage technique in poor-healing wounds after heart v
文摘Introduction:We sought to investigate whether the development of sub-pulmonic systolic anterior motion(SAM)may be inherent to the anatomy of the the mitral valve(MV)or affected by external factors,such as a dilated right ventricle or chest abnormalities in d-looped transposition of the great arteries post atrial switch operation(d-TGA/AtS).Methods:Analysis was performed of clinical and cardiac imaging studies acquired on 19 adult patients with d-TGA/AtS(age 42±6 years old,56%male)between 2015–2019.Echocardiography data included mitral apparatus anatomy,and CT/MRI data included biventricular dimensions,function,and Haller index(HI)for pectus deformity.Results:Patients with leaflet SAM(n=6)compared to patients without SAM(n=13)had higher MV protrusion height(2.3±0.5 vs.1.5±0.4 cm,p≤0.01)and longer anterior MV leaflet length(3.1±0.4 cm vs.2.6±0.3 cm p≤0.05),when compared to those without.CT/MRI showed higher sub-pulmonic left ventricular ejection fraction(LVEF)in the SAM group(71%±8%vs.54%±7%,respectively).RV size and function,significant chest deformity(HI>3.5),presence of a ventricular lead pacemaker,and septal thickness did not play a role in development of SAM.Conclusions:An elongated mitral apparatus is associated with the development of SAM,and the development of left ventricular outflow tract obstruction(LVOTO),in d-TGA/AtS.LV hyperkinesia is associated with SAM.Systemic RV dimensions,septal thickness,and degree of chest deformity did not differ significantly between subjects with SAM and those without.
文摘To solve the problems existing in the flow characteristics of steam turbine unit, the influence of valve overlap degree on nozzle governing steam turbine had been studied. The combined flow characteristics of given valve overlap degree were obtained for a 600MW steam turbine unit by the method of theoretical calculation combined with simulation test, and the influence of valve overlap degree on governing stage efficiency and steam chest pressure had been also analyzed. This paper discussed the selection of rational overlap degree and introduced a new method of building model for governing stage efficiency of steam turbine in constant pressure operation condition, which provided theoretical guidance for optimization research on nozzle governing steam turbine operation.
