The currently used heart valve prosthesis are still far from the ideal one in anticoagulation and longevity. The construction of tissue engineering heart valve leaflets are carried out recently. This article reviews the progress of tissue engineering heart valve leaflets in implanting materials, seeded cells, animal experiment and basic research. It also discusses the benefits and feasibility of tissue engineering heart valve leaflets.

Objective　To observe the morphological changes of brain and to analyze the cause of coma after open-heart surgery in cases suffered from congenital heart disease.　Methods　Twenty six autopsy cases were collected from Jan. 1973 to Sep. 1999 in Fuwai Hospital. Their duration of coma was 1 day to 40 days and all of them died earlier later following cardiac surgery. Their surgical procedure, extracorporeal circulation time, and other clinical records and autopsy findings were reviewed. 　Results　The brain lesions included intracranial hemorrhages (n＝11), cerebral edema (n＝11), encephalitis and encephalomingitis (n＝3), and cerebromalacia (n＝1). Intracranial hemorrhages occurred in epidural (n＝3), subdural (n＝3), subarachoid spaces (n＝4), and intracerebral parenchyma (n＝1). The causes of coma were deduced as follows: lower cardiac output (n＝7), air embolism (n＝3), pneumonia (n＝3) and other infections (n＝2), pulmonary hypertension (n＝2), and the unknown causes of coma (n＝9). But the 6 out of the last 9 cases showed longer duration (more than 100 min) of extracorporeal circulation. Intracranial hemorrhages occurred more frequently in cases with waking period than those without after cardiac operation, and vice versa the cerebral edema. 　Conclusion　Intracranial hemorrhage and cerebral edema were the main changes of brain in the patients suffered from coma, but its causes were complex and difficult to analyze. These results suggest that further improved heart preservation, shorter time of extracorporeal circulation and effective treatment of infection would be benefit to the prevention of coma.

Objective　To summarize the treatment of 7 cases of severe coronary artery disease with CO2 laser transmyocardial revascularization(TMLR).　Methods　The mean preoperative angina class (Canadian Cardiovascular Society, CCS), number of diseased coronary arteries were 3.6±0.7 and 2.8±0.6 respectively. All the patients underwent left anterolateral thoracotomy through the fifth intercostal space under general anesthesia, the left ventricule was exposed and then TMLR was performed. The mean channels in TMLR was 32.5. 　Results　The symptoms of angina disappeared during the first postoperative month, with no relapse reported in the first follow-up year. There was significant difference in the angina class (P＜0.05), ejection fraction also increased. The ischemia region of the heart decreased through the single photon emission computed tomographic(SPECT) test.　Conclusion TMLR can relieve angina and improve life quality of patients with severe coronary artery disease. It can accelerate the recovery of dormant myocardium and enhance the contractility.

Lung injury was one of the most complications after extracorporeal circulation. As a result of blood exposure to the surface of the extracorporeal circulation circuit, the complements and leukocytes were activated. The activated neutrophil adhered to endothelial cells and released many inflammatory mediators, as protease, oxygen free radicals, arachidonic acid metabolites. All of these inflammatory mediators caused lung injury. In vivo and in vitro, many studies demonstrated that leukocyte depletion in extracorporeal circulation of heart operation could reduce lung injury and improve lung function. Leukocyte depletion could reduce pulmonary resistance, particularly effective in patients with a low preoperative oxygenation capacity and in those for whom an extended period of extracorporeal circulation was required.

The rapid cooling contracture in myocardial protection is getting more and more attention. Rapid cooling contracture is referred to as the undepolarized myocardial contracture induced by rapid cooling, which is related with the sudden increase of Ca2+. The Ca2+ released from sarcoplasmic reticulum subsequently causes myocardial contracture through the myofilaments sliding. Its deleterious effects include: more energy consumption, impaired cardiac function, Ca2+ overload, et al. And some investigators have put forward some principals to prevent the bad influences of rapid cooling contracture.

Objective To investigate the effect of adenosine on pulmonary injury after extracorporeal circulation. Methods Twelve mongrel dogs were randomly divided into two groups, the test group and control group. The model of extracorporeal circulation was established. In the test group and control group, adenosine(50μg/kg*min) and normal saline were infused before extracorporeal circulation respectively. Hemodynamics, right cardiac function and arterial blood gas were assessed. Lung water and malondialdehyde content were assessed. Histological evaluation was also made. Results　There were no differences between the two groups with respect to heart rate, mean systemic artery pressure, left atrial pressure, and central venous pressure. In the test group, pulmonary vascular resistance was lower and right cardiac function improved remarkably; arterial oxygen pressure (PaO2) was also higher, less lung water was observed and the malondialdehyde content in the pulmonary tissue was lower (P＜0.05,P＜0.01). Histological evaluation of the test group revealed normal pulmonary architecture without abundant intra-alveolar neutrophils. Conclusion Adenosine can attenuate ischemia-reperfusion lung injury and right cardiac insufficiency caused by extracorporeal circulation. At a proper dose, there was no significant effect on systemic hemodynamics.

Objective To review and sum up experience of surgical repair of single ventricle. Methods Since January 1973 to December 1999, 47 patients with single ventricle have been repaired. Right ventricle type was 17 patients, left ventricle type was 14, and unrecorded type was 16. Surgical procedure consisted of pulmonary banding 1, Fontan operation 23, and bidirection superior cavopulmonary anastomosis 23. Results Seven patients died. The motality was 15%. There was no death in bidirection superior cavopulmonary anastomosis patients. Conclusion For the single ventricle, early surgical intervention is required to prevent pulmonary congestion and severe cyanosis. The bidirection superior cavopulmonary anastomosis can improve single ventricle function secondary to pressure and volume load to decrease surgical mortality and to minimize the risk factors for subsequent Fontan operation.

The coronary collateral circulation is an alternative source of blood supply to the myocardium jeopardized by failure of the original vessel to provide adequate flow. Angiogenesis growth factors induce angiogenesis to promote collateral circulation, been demonstrated in a number of different animal test and phase Ⅰ clinical experience to induce collateralization in the ischemic area and improve cardiac function. Although there are several unsolved questions, the pharmacologic use of angiogenesis growth factors will represent a viable therapeutic alternative for the patients with ischemic heart disease.

Current bioprosthetic heart valves implanted with viable human cells can be categorized into two basic designs, tissue engineering heart valve and porcine aortic valve implanted with viable human cells. Tissue engineering heart valve is constructed by seeding a synthetic polyglycolic acid fiber based biodegradable scaffold with viable human autologous cells. The fibroblasts are first seeded on valve scaffold. When the fibroblasts reached confluence, endothelial cells are seeded onto the surface of leaflets and grown into a single monolayer. Porcine aortic valve implanted with viable human cells is generated by removing native cells from tissue and then repopulating the tissue with viable human autologous cells. The method of removing native cells from fresh porcine aortic valve comprises subjecting the valve tissue to a hypotonic/hypertonic treatment, then treating the valve tissue with an enzyme-based solution. Isolated cell lines are cultured and thereafter such a valve matrix is implanted with fibroblasts, followed by endothelial cells. Bioprosthetic heart valves implanted with viable human cells do not produce and adverse immune response by the recipient upon implant, and possesses the regenerative capabilities.

Objective To observe the characteristic, mechanisms and the change of pathophysiology about thoracic explosive injury from an explosive device. Methods Seventy-three millimetres prefabricated steel-ball bomb was used to be the center of explosion. According to the distance from each group to the center of explosion, 30 sheep were randomly divided into 5 groups. The injuries of thoracic wall, lung and surrounding organs were observed from fragments and blast wave. Results The mortality of thoracic explosive injury on the ground testing was 56.7%.Most of fragment wounds were blind wound. The track of wounds was often complicated and curved. The major associated injuries were myocardial contusion, splenic-hepatic rupture and gastric-enteric rupture. There were much severe pulmonary hemorrhage and lung edema. The parameters of trauma were well correlated with the severity of thoracic injury.　Conclusion The parameters of trauma were well correlated with the severity of thoracic injury. The characteristic of thoracic injury from explosive device was more complicated and severe.