Objective This study describes the protective effect of myocardial isehemic post- conditioning on ischemic-reperfused myocardium (I/ R) of diabetic rat and its Signaling mechanism. Methods Healthy SD rats weighing 25O-30Og were divided into 6 groups; (1) Blank control; (2) Ischemia-reperfusion; (3) Post conditioning; (4) Diabetic postconditioning ; (5) Diabetic ischemia-reperfusion; ( 6) Diabetic blank control group. Ten rats in each group were randomly selected. Introduction of diabetic rat model: 65 mg/kg STZ was injected into the intraperitoneal cavity, until 2 consecutive blood glucose measurements≥ 16.65 mmol/L were reached after48h. The diabetic model was successful when rats had following symptoms, such as more drinking, more eating, polyuria, weight loss and epilation. Langendorff isolated rat heart perfusion was used for the experiment. Following parameters were measured and compared: Coronary perfusion flow, myocardial infarct size, western blot for measurement of P-Akt, changes in myocardium and mitochondrian observed by Electron microscopy. Results Blood glucose concentration in diabetic group was (23. 15±2. 16) mmol/L and (4. 16±0. 31) mmol/L in non-diabetic group. There was a significant difference (P <0. 01) between the two groups. There were more coronary flow in post-conditioning groups (Post group and Dpost group) than ischemia-reperfusion groups (IR group and DIR group) (6.5±1.2、5.6±1.0 vs. 3.4±1.0、2.0±1.3). The myocardial infarction size was smaller in post-conditioning groups than in ischemia-reperfusion groups (25.2±2.1、34.2±3.6 vs. 47.5±3.5 、65.2±4.5). There was more expression of P-Akt and the myocardial fibers and mitochondrian in post-conditioning groups were better preserved. Conclusion Postconditioning has protective effects in diabetic rat hearts. The mechanism may be associated with Akt activation.

Objective Explore the value of video-assisted thoracoscopic extended thymectomy in the treatment of myasthenia gravis.Methods This is a prospective randomized control study.Fifty-four patients who were confirmed to be MG preoperatively from 2005 to 2008 were divided into VATS group(27 cases)and thoracotomy group(27cases).Thymectomy and dissection of all faity tissue anterior to pericardium were performed in both groups.Results When compared with thoacotomy group,VATS group had less blood loss,shorter postoperative hospital stay and time of postoperative chest drainge tube left.One patient was converted to open surgery because of the injury to the brachiocephalic vein.During a period of followed-up 624 months,symptom was improved in 81% of the patients in VATS group and 85% in thoractomy group(P>0.05).Conclusion Extened thymectomy with VATS is safe and feasible with the advantage of less invasion,less surgical trauma and pain,lower rate of complication and good curative effect.

Objective Ascending aortic dissection(AAD),for which the pathogenesis remains unknown,is life-threatening.Matrix metalloproteinase-9(MMP-9)and the pathological changes of vascular smooth muscle cells(VSMCs)have been reported to have roles the pathogenesis.The study examined the expression of matrix metalloproteinase-9(MMP-9)and the pathological changes of,VSMCs in patients with AAD.Methods AAD samples were taken from 35 patients(disease group)in acute phase during aortic replacement operation for AAD and control samples were corresponding part of ascending aorta(control group,n=21)collected from the donor hearts for transplantation.Transmission electron microscepe,hematoxylin-eosin(H-E)staining.Mallory staining were used for observing the pathological changes of VSMCs and matrix in the affected aortic wall.The immunohistochemicai staining of MMP-9 was carried out in both groups and semi-quantified by staining intensity analysis.The affected patients were further grouped according to the diameter of dissected aorta as with a AAD of <55 mm or with a AAD of≥55 mm.The associations of clinical factors,such as smoking status,hypertensive disease and aneurysm diameter,with the expression of MMP-9 were analyzed.Results Increased synthetic function of VSMCs with decreased density,disrupted elastic fibers and fibrosis in the dissected aortic wall were observed in the disease group,but not in the control group.MMP-9 was scarcely expressed in the aortic wall of the patients in the control group,though it was notably expressed in the VSMCs of disease group.Both subgroups presented more MMP-9 than the control group(both P<0.001).In the disease group,sub-group with a AAD diameter of ≥55 mm presented more MMP-9 than that with a diameter of <55 mm(P<0.05).MMP-9 expression was positively correlated with a history of hypertension(P<0.01)or a great aneurysm diameter(P<0.05).MMP-9 expression was not associated with age,smoking status or other clinical factors.Conclusion Increased secretion of VSMCs and the expression of MMP-9 induced by elevated blood pressure may lead to the destruction of matrix proteins.The resulting fibrosis of the aortic wall would decrease the tensile strength of the wall.When the fibrotic aortic wall dilated further,the increased expression of MMP-9 would aggravate the damage to the wall.It can be speculated that acute AAD would occur as a result of partial tearing of the aortic intima.

Objective The early causes of death were analyze in 2349 patients who had undergone heart valve replacement.Methods Methods From January 1995 to December 2007,2349 patients with heart valve diseases received heart valve replacement.1109 cases were male and 1240 were female.The mean age of the patients was(41±19)years old.1962 cases had rheumatic heart valve disease,308 had congenital heart valve disease,39 had infective endocarditis,29 underwent reintervention by heart valve replacement,11 had Marfan syndrome.34 cases with coronary heart disease underwent heart valve prosthesis implantation and coronary artery bypass grafting.Mitral valve replacement(MVR)was performed in 1333 patients,aortic valve replacement(AVR)in 271,double valves replacement(DVR)in 736 and tricuspid valve replacement(TVR)in 9.There were 3075 mechanical valves and 10 bioprosthetic valves.Results From 1995 to 1999,death occurred in 16 of the 235 cases,early mortality rate was 6.81%.From 2000 to 2004,death occurred in 35 of the 1087 cases,early mortality rate was 3.22%.From 2005 to 2007,there were 29 deaths among 1027 cases,with an early mortality rate of 2.82%.Overall early mortality rate was 3.40%.The early mortality rate was 2.32%(31 in 1333 cases)in patients who underwent MVR,3.32% (9 in 271)in patients who underwent AVR,5.24%(40 in 736)in patients who underwent DVR,5.50%(7 in 127)with LVEDD≥70 mm,4.60%(14 in 304)with LVEF<0.40,2.14%(9 in 419)with NYHA class II,2.42%(37 in 1529)with NYHA class Ⅲ,and 8.48%(34 in 401)with NYHA class IV.The causes of 80 deaths were low cardiac output syndrome in 31 cases(38.8%),renal failure in 14 cases(17.5%),arrhythmia in 10 cases(12.5%),pulmonary infections in 8 cases (10.0%).cerebrovascular accidentin 5(6.3%),left ventricular rupture in 5(6.3%),multisystem and organ failure in 5(6.3%),and other cause in 2 cases(2.5%).Conclusion The causes of early death after heart valve replacement are low cardiac output syndrome,renal failure,arrhythmia,pulmonary infection,cerebrovascular accident,left ventricular rupture and multisystem and organ failure.

Objective Minimally invasive technique was used in the treatment of pectus carinatum. Indication, techni-cal details and perioperative complication are discussed in this paper. Methods From March 2008 to January 2009, 6 patients with pectus carinatum underwent minimal invasive operation by using the principle of Nuss procedure in which pressure applied through a curved steel bar that was placed subcutaneously anterior to the sternum, via lateral thoracic incisions. Preoperative CT scan were performed and Hailer index was used as operative indication. Results The average age of patients was (13.6 ± 1.94) years (range, 10 - 16 years). They were all males. The mean operation time was (104.17 ± 15.63) minutes. The av-erage blood loss was (5.17±2.56) ml. The mean hospital stay was (5.67±0.82) days. Postoperative follow-up was 1 -11 months. Displacement of the stablizer was the only complication that was corrected by further fixation procedure. COnClusion The minimally invasive technique for the treatment of peetus earinatum is safe and effective with minimal complications. It can be selected as an alternative techniques and the appropriate age for this procedure is 10-16 years.

Objective To compare the results of mitral valve reconstruction and replacement as treatments for moderate to severe ischemic mitral regurgitation(IMR), and report the mid-term outcome. Methods From June 2002 to May 2008, 83 pa-tients with moderate IMR(35 cases) and severe IMR (48 cases) underwent coronary artery bypass grafting(CABG) combined with mitral valvuloplasty (MVP) (n = 43) or mitral valve replacement (MVR) (n = 40). There were 49 males and 34 females with a mean age of (59.3±7.5) years(51 -77years). The procedures of MVP included annuloplasty with a Dacron or autologous per-icardium ring in 21cases, commissural annuloplasty in 9, quadrangular resection of the posterior leaflet in 9 and using St. Jude mitral annuloplasty ring in 4. In the cases underwent MVR, 28 patients received mechanical prostheses and 12 received biopros-theses. Results 30-day mortality rate was 2.3% for MVP and 5.0% for MVR (P >0.05). The 30-day complication rate was similar for the 2 groups but mechanical ventilation time was longer for MVR patients. Mild MR ocurred in 6 patients with MVP (P <0.05). Sevonty-six patients were followed by outpatient department visit or telephone for (20.2 ± 4.9) months (3 - 60 months). During the follow-up period, 7 patients with MVP had mild insufficiency but free off etber complications. All the valve prothesis functioned well. However, 3 cases had thromboembolic complications and 7 late deaths were recorded in MVR group. Five-year complication-free survival rate was 90% for MVP group and 61% for MVR. Conclusion MVP resulted in excellent durability and provided significant mid-term survival benefit over MVR. MVP should be the first choice for patients with chronic IMR.

Objective To compare the results of transcatheter intervention (TI) and surgical operation (SO) in the pri-mary treatment for pulmonary atrcsia with intact ventricular septum (PA/IVS). Methods From January 2006 to May 2009, 25 patients (20 male,5 female) with PA/IVS were treated. The age at treatment was from 2 days to 8 months. The body weight was from 2.1 kg to 6.7 kg. All patients had mild to moderate hypoplasia of the right ventricle (the Z-valvue of the tricuspid valve: from -2 to 1.5) with tripatite right ventricle and without coronary artery-right ventricular fistula. Eight patients under-went TI and 17 patients underwent SO. Results The primary procedure was successful in 7 patients (88%) in TI group and in 16 patients (94%) in SO group. There were 2 deaths (1 in each group). There was no significant difference regarding re-sidual pulmonary stenosis between two groups. The ventilation time and the days of hospital stay were shorter in TI group than in SO group. All the survivors were followed up for 3-36 months. One patient required repeat balloon dilation in TI group. While in SO group, one required reoperation and one required balloon dilation for PS, and 2 patients were waiting for balloon dilation. Twenty-one patients have achieved complete biventricular circulation. Two patients were scheduled for Glenn shunt operation later (1 in each group). Conclusion For PA/IVS patients with mild or moderate right ventricle hypoplasia, tran-scatheter intervention is a better alternative than surgical operation in the primary treatment.

Objective Explore the reversibility and potential molecular mechanisms of pulmonary hypertension in pa-tients with complete transposition of the great arteries (cTGA) combined with ventricular septal defect (VSD) in comparison with those with simple VSD. Methods Twenty-four patients with pulmonary hypertension (mean pulmonary arterial pressure was greater than 30 mmHg) were enrolled in our study, in which 10 patients suffered from cTGA with VSD, and the rest 14 pa-tients suffered from simple VSD. Lung specimens were taken from the right middle lobe of lung before cardiopulmonary bypass. The extent of pulmonary hypertension was then graded according to the Heath-Edwards classification. ELISA was used to exam-ine the expression of eNOS, iNOS, ET-1, ET-AR, ET-BR, MMP-2, MMP-9 and TIMP in all the specimens. Results No statistically significant differences in age, height, weight, the size of VSD, and the pulmonary artery pressure before operation were found between the groups. The level of hemoglobin, aortic and pulmonary arterial oxygen saturation, and the reduction value of pulmonary arterial pressure after surgery were significantly higher in the cTGA patients than that in the simple VSD pa-tients (P < 0.05). All patients had grade 0 - Ⅱ Heath-Edwards changes in their lung biopsy samples. The expression of eNOS and MMP-2 was significantly lower in the TGA group than that in the simple VSD group [eNOS: (280.13 ± 101.92) ng/mg vs. (488.41±249.6) ng/mg, P<0.05; MMP-2:(31.68±15.36)ng/mg vs. (69.28±49.12)ng/mg, P<0.05]. There were no statistically significant differences between the two groups regarding the expression of iNOS, ET-1, ET-AR, ET-BR,MMP-9 or TIMP. Conclusion The imbalance of the NOS/ET system and the MMP/TIMP system involves in the development of pulmonary hypertension in patients with TGA combined with VCD. In patients with cTGA, the high oxygenation state in pul-monary circulation may decrease the expression of MMP2 and eNOS, and may affect the progress of pulmonary hypertension to a certain extent.

Objective To compare the results of surgical repair for congenitally corrected transposition of the great arter-ies(ccTGA) with pulmonary stenosis(PS), and to analyze the risk factors that may affect early results and surgical technique. Methods From Aug. 2001 to Dec. 2008, 21 patients with ccTGA and PS were treated in our hospital. They aged 3.5 months to 6.3 years [(31 ± 18) months], weighted 6.28 kg [(13.1± 6.5) kg]. Fifteen cases had paramembranous ventricular sep-tal defect (VSD), 1 noncommitted VSD and 5 subpulmonary VSD. The repairs comprised of Senning and Rastelli operation. RV-PA reconstruction was done by xenopericardial conduit in 13 patients. RV-PA direct anastomosis plus pericardial patch in 6 patients and homograft patch with autopulmonary valve in 2 patients. Results All the patients were alive. During 2 - 5 years follow-up, blood flow rate in superior vena cava increased to 1.8 - 2.2 m/s in 3 cases. One of them needed reoperation to re-lease the stenosis and the rest 2 were in follow-up. Tow patients had right ventricular outlet obstruction with a pressure gradient of 30 -45 mmHg were in follow-up. There was no other stenosis and valve insufficiency. Conclusion Double-Switch opera-tion is practical and impressive in treating of CCTGA with PS. It is important to evaluate the size of VSD and the reconstruction of RV-PA. But it still need more cases and longer time to evaluate the long-term effects.

Objective To review our clinical experience with 41 reoperatioas of prosthetic heart valve dysfunction be-tween October 1996 and October2008. Methods There were 16 malas and 25 females with an average age of (44.5±12.6)years. All 41 patients underwent reoperation under hypothermic cardiopulmonary bypass, including 38 heart valve replace-ments, 2 disc rotations and cut of the excessive knot in 1 case. There were 13 emergency and 28 elective procedures. Results The median time for extubation was 15.3 hours and tracheostomy was needed in 5 cases. There were 6 deaths, all of which occurred in emergency cases, with a mortality rate of 15.4%. No death occurred in patients implanted with a bioprosthetic valve previously. Postoperative complications included 1 infective endocarditis, 1 intractable hiccup and 1 wound infection. Conclusion Prosthetic heart valve dysfunction is catastrophic. Early diagnosis and reoperation is mandatory.