To establish a new model of total cavopulmonary connection (TCPC) by improving the vascular anastomosis between vena cava and pulmonary artery and to study the postoperative hemodynamic changes, a Y shaped prosthetic blood vessel was used, one limb of the prosthesic was anastomosed with vena cava, and the other to pulmonary artery in an end to side way. Then the proximal vena cava was ligated. The mean pulmonary artery pressure was kept at about 20mmHg, the hemodynamic parameters were measured. All dogs tolerated the operative procedure. It was found that pulmonary vascular resistance (PVR) showed a significantly negative correlation with cardiac output (CO), mean aortic pressure (mAoP), and the ratio of right/left pulmonary artery flow (RPF). The model was successfully developed without cardiopulmonary bypass, and the tricuspid valve and pulmonary artery valve were left untouched. Hemodynamic parameters remained stable. It will be useful in study of the circulation after TCPC operation.

Objective: To study blood distribution in extracardiac total cavopulmonary connection (ETCPC). Methods: To combine a bidirectional cavopulmonary anastomosis with a Gore-Tex extracardiac conduit interposition between the inferior vena cava and the main pulmonary artery, and to evaluate the changes of pulmonary blood distribution with SPECT in all surviving patients. Results: The cournts of pulmonary radionuclide was (313.7?40.1)?10 3 increased significantly after surgery (t=2.23, P

ObjectiveTo study the pulmonary arterial development over five years in patients underwent extracardiac total cavopulmonary connection (ETCPC).Methods43 survived patients,who had undergone ETCPC were examined with pulmonary perfusion at one month and five year following the operation.Central venous pressure (CVP) and arterial oxygenation saturation (SatO2 ％ ) were measured by right cardiac catheter,pulmonary arterial index (PAI) and pulmonary vascular resistance (PVR) were calculated.Pulmonary blood distribution were measured and calculated by 99m Tc-MAA perfusion imaging.ResultsThe PAI and PVR of the follow-up group reduced significantly ( t =2.41,P ＜ 0.05 ; t =2.08,P ＜ 0.05 ),CVP also reduced significantly ( t =2.69,P ＜ 0.05 ),but SatO2 ％ did not changed significantly.Total radionuclide counts and the ratio of rightorleft pulmonary perfusion did not change significantly.( t =0.38,P ＞ 0.05 ;t =1.12,P ＞ 0.05 ),but the ratio of the superior and inferior lobe decreased significantly( t =2.54,P ＜ 0.05 ).ConclusionThe weak pulsation and low dynamic of Fontan circulation also can promote pulmonary vascular development.However,the improvement of hemodynamic in pulmonary circulation at mid-term follow will not lead to an increased amount of pulmonary perfusion or oxygen supply,which is probably due to the massive opening of the arteriovenous shunt and increased futile circulation.

Objective: To explore the impact of Ischemic preconditioning (IPC) in aged experimental rats after myocardial ischemia-reperfusion (I/R) with its mechanism.
Methods: A total of 32 Wistar rats at the age of (21-23) months were divided into 4 groups, n=8 in each group.①Control group, the rats received cardiac perfusion for 180 min. ②I/R group, the rats received cardiac perfusion for 30 min, followed by ischemia for 30 min, then reperfusion for 120min.③IPC group, the rats received cardiac perfusion for 10 min, followed by ischemia and reperfusion 2 times (5 min in each time), then ischemia 30 min and reperfusion 120 min. ④ Enhanced IPC group, rats received cardiac perfusion for 10 min, followed by ischemia and reperfusion 4 times (5 min in each time), then ischemia 30 min and reperfusion 120 min. The recovery rate of cardiac output (CO), left ventricular developed pressure (LVDP) and the recovery rate of maximum rise and fall of left ventricular pressure (±dp/dtmax) at (30, 60, 90, 120) min after reperfusion were recorded respectively. The creatine kinase (CK-MB), superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were examined before ischemia and 120 min after reperfusion. The apical peroxisome proliferator-activated receptorγco-stimulatory factor 1α(PGC-1α) was examined by immuno-histochemistry.
Results: The MDA content, CK-MB, SOD activities LVDP and (±dp/dtmax) recovery were similar between IPC group and I/R group, P>0.05. While compared with I/R group, the Enhanced IPC group showed decreased CK-MB activity and MDA content, increased SOD activity and CO, LVDP and (±dp/dtmax) recovery rate, all P<0.01. The PGC-1αexpression was similar between IPC group and I/R group, P>0.05. While compared with I/R group, the Enhanced IPC group had increased PGC-1αexpression, P<0.01.
Conclusion: The cardiac IPC was weakened in aged rats which might be because of decreased PGC-1αexpression, the enhanced IPC may up-regulate PGC-1αexpression and therefore, protect the cardiac tissue in aged experimental rats.

Objective To investigate the effects of Stichopus variegatus mucopolysaccharide on plasma nitric oxide (NO) and serum endothelin(ET) after angioplasty in rabbits. Methods 50 New Zealand rabbits were randomly divided into four groups: Stichopus group, simvastatin group, model group and normal group. Endothelium of iliac arteries in Stichopus group, simvastatin group and model group were denuded by balloon catheter and the rabbits were fed with 2%cholesterol, 3%lard and 3%yolk mixed forage for six weeks, and then, atherosclerotic stenosis was showed by iliac angiography.When transluminal balloon angioplasty was done, from then on the feeds was changed from high cholesterol to ordinary forage. Stichopus (0.5g?kg -1?d -1) and simvastatin (0.5mg?kg -1?d -1) were given by gastric canal. While NaCl solution (0.9%) was given in model group. All rabbits were fed in separate cages and free drinking. After four weeks since transluminal balloon angioplasty, blood was collected from carotid artery to measure the changes of concentrations of endothelin(ET) and nitric oxide(NO). Examination of pathology by optical and electron microscope were done at same time. Results After four weeks since transluminal angioplasty, the concentration of plasm ET in model group increased significantly compared with the normal group(114.86?24.89 ng?L -1 vs 75.62?9.68 ng?L -1) and serum NO decreased significantly(37.50? 12.79?mol?L -1 vs 106.37?18.01 ?mol?L -1).The concentration of plasm ET in model group was higher than that in the simvastatin groups and Stichopus groups(114.86?24.89 ng?L -1 , 81.08?14.71 ng?L -1 and 83.34?11.41 ng?L -1 ,respectively),and the concentration of serum NO decreased obviously(95.63?8.62 ?mol?L -1,98.80?9.06 ?mol?L -1 and 37.50?12.79 ?mol?L -1,respectively). Conclusion After iliac arterial TA the concentrations of plasm ET were increased and the serum NO were decreased, the endothelial function fell into disorder. The Stichopus variegatus mucopolysaccharide had the effects of improving the endothelial function after angioplasty in rabbits by adjustment of plasm ET and serum NO.

Objective To summarize the experience of application of artificial chordae transplantation in mitral valve repair.Methods One hundred and five patients with mitral regurgitation due to mitral degeneration,underwent mitral valve repair with artificial chordae transplantation.Operative technique included simple Gore-Tex artificial chordae transplantation in 25 cases,artificial chordae transplantation plus quadrangular resection of the posterior leaflet in 67 cases,artificial chordae transplantation plus quadrangular resection of the posterior leaflet and Sliding technique in 13 cases.Results No early death occurred after operation.The postoperative complications were caused in 30 patients including sinus bradycardia in 8 cases,supraventricular tachycardia in 20 cases,late cardiac tamponade in onecase,pacemarker implantation in one case.Hospital time was 9-21 (14 ±4) d.Follow-up was done to 96 patients for 3 months to 5 years with a follow-up rate of 91.4％(96/105).Among 96 cases,one died of cerebral infarction after 13 months,one died from accident while the remaining were alive,74 cases were with cardiac function (NYHA) of grade Ⅰ and 20 cases with grade Ⅱ.No regurgitation was found in 92 cases,mild regurgitation in 2 cases.There were no artificial chordae ruptures.Conclusions The key to improve the early and midterm results of artificial chordae transplantation are to choose patients strictly,to grasp proper surgical skills,to do a good job in intraoperative shaping effect evaluation and the myocardial protection during extracorporeal circulation.

BACKGROUND:Artificial chordae transplantation and saddle ring annuloplasty are the key steps in mitral valvuloplasty. However, there are no large-size studies addressing the safety, validity and efficacy of these treatments in China.
OBJECTIVE:To summarize the efficacy and safety of artificial chordae transplantation and saddle ring annuloplasty in the treatment of degenerative mitral regurgitation.
METHODS:Eighty-five patients with degenerative mitral regurgitation underwent mitral valve repair with artificial chordae (Gore-Tex sutures) transplantation and saddle ring (SJMTM rigid saddle-shaped) annuloplasty from January 2009 to May 2013 in General Hospital of Shenyang Area Military Command, China. Operative technique included simple artificial chordae transplantation in 41 cases, artificial chordae transplantation plus quadrangular resection of the posterior leaflet in 22 cases, artificial chordae transplantation plus quadrangular resection of the posterior leaflet and sliding technique in 23 cases. Al cases received saddle ring annuloplasty.
RESULTS AND CONCLUSION:Fol ow-up after treatment was done among 78 patients for 6 months to 4 years, with a fol ow-up rate of 91.7%(78/85). Among the 78 cases, one case died of cerebral infarction after 13 months, one died from accident, and the remaining 76 were alive. According to the evaluation of cardiac function (NYHA), 59 cases were in grade I and 17 cases were in grade II. Color ultrasound displayed that, no regurgitation was found in 67 cases, and mild regurgitation in 9 cases. The echocardiography showed that postoperative left atrium diameter (P<0.05 or P<0.01), left ventricular end-diastolic diameter (P<0.05 or P<0.01), left ventricular end-systolic diameter (P<0.05 or P<0.01), and the ratio of regurgitation beam area and left atrial area (P<0.05 or P<0.01), mean pulmonary artery pressure (P<0.05 or P<0.01) were significantly decreased compared with that before operation. Ejection fraction was significantly increased after operation (P<0.05 or P<0.01). No systolic anterior motion occurred. The postoperative complications included sinus bradycardia in 12 cases and paroxysmal supraventricular tachycardia in 25 cases, late cardiac tamponade in 1 case at 1 week postoperatively, and pacemarker implantation in 1 case (who exhibited bradycardia-tachycardia syndrome before operation). There was no ring rupture, ring avulsion, hemolysis, left ventricular outflow tract infarction and artificial chordae rupture or splitting. No cases needed reoperation on valve replacement. Application of artificial chordae transplantation and saddle ring annuloplasty is a safe and effective means for treating degenerative mitral regurgitation, with excellent midterm outcomes.

Objective To summarize the prevention and treatment experience of complications of cardiac myxoma excision.Methods Cardiac myxoma excision were performed in 215 cases under general anesthesia,cardiopulmonary bypass and cardiac arrest condition.Results Two cases died from severe low cardiac output syndrome which eventually caused multiple organ failure.The remaining 213 cases were cured and discharged.Among 213 cases,low cardiac output syndrome occurred in 35 cases,re-open chest for bleeding was performed in 8 cases,30 cases in arrhythmia (including paroxysmal supraventricular tachycardia in 20 cases and ventricular premature in 10 cases),no vital organs embolism occurred.Follow-up was done to 200 patients for 1-8 years with a follow-up rate of 93.9％ (200/213).In 200 cases,1 case died from lung cancer,1 case recurred and was cured after re-operation.The remaining patients had no obvious abnormalities.Conclusion As the particularity of surgical treatment of cardiac myxoma,it is essential to take prevention measures to reduce complications of cardiac myxoma excision in perioperative periods.

Objective To study the long-term effect of total right heart bypass on pulmonary perfusion after extracardiac total cavopulmonary connection (ETCPC).Methods Fifty-three patients (29males,24 females; average age (10.8±6.1) years) undergoing ETCPC from March 1990 to December 2005were retrospectively analyzed.Forty-three patients had full set of pulmonary perfusion data at 1 month and 5years postoperation.The perfusion ratios of each lung segment were calculated based on 99Tcm-MAA radionuclide imaging.The PVR and pulmonary artery index were calculated from angiocardiography measurements.All data were compared with paired t test.Results Compared with the early postoperative data,the perfusion ratio of superior/inferior segment(0.72±0.20 vs 0.75±0.01; t =2.54,P＜0.05),the PVR ((142.98±2.61) vs (146.95±2.54) dyn · s · cm-5; t=2.08,P＜0.05; 1 dyn · s · cm-5 =0.1 kPa · s · L-1) and vena cava pressure ((9.35±0.24) vs (9.95±0.23) mmHg; t=2.69,P＜0.05; 1 mmHg=0.133 kPa) decreased significantly in follow-up data; while the ratio of posterior basal segment perfusion increased significantly (0.12±0.00 vs 0.10±0.03; t=2.16,P＜0.05).The arterial oxygen saturation ((92.70±0.30)％ vs (92.86±0.29) ％ ; t =1.12,P＞0.05),the total pulmonary nuclear counts ((701.91 ± 8.26) × 103 vs (698.93 ± 12.0) ×103 ; t=0.38,P＞0.05) and the perfusion ratio of inferior vena cava to the right lung (0.61±0.06 vs 0.60±0.06 ; t =0.74,P ＞ 0.05) were similar between the two terms of follow-up.The early angiographic and radionuclide perfusion studies did not match in 5 patients.Conclusions Hypostatic redistribution of pulmonary blood flow is the characteristics in long-term follow-up of ETCPC patients.The radionuclide imaging is superior to angiocardiography in revealing functional pulmonary blood perfusion.