Objective To summarize the experiences of donor heart procurement of heart transplantation so as to improve the efficiency of donor heart protection. [WTHZ]Methods [WTBZ]From April 2002 to October 2006, sixtyone patients with endstage heart disease had undergone orthotopic heart transplantation. Donors were all male brain deaths, aged from 21 to 53, and 5 of them were older than 40. There were 6 cases in which the weight difference between donor and recipient＞20%, and the rest ≤±20%. Fortyfive cases had the same ABO blood type, and 16 had matching ABO blood type. Four donor hearts were procured under the condition of stable hemodynamics and enough oxygen after brain death(typeⅠ), fortyfour donor hearts were procured under the condition of brain death with acute hemorrhage and hypovolemia (typeⅡ), and 13 donor hearts were procured under the condition of brain death with cardiac arrest (typeⅢ). Twenty cases underwent standard transplantation procedure, one underwent total heart transplantation procedure and 40 underwent bicaval transplantation procedure. The donor heart cold ischemic period ranged from 52 to 347 min（92±31 min）, and 13 cases were more than 240 min. Results Two cases died of low cardiac output syndrome on 7th and 9th day after operation respectively, and their donor heart cold ischemic period were 327 and 293 min respectively. The rest of patients all recovered and discharged. One died of acute rejection on 18th month after operation because of rejecting immunosuppressive agents, and 1 died in traffic accident on 23rd month after transplantation. The rest 57 cases survived 6-59 months(mean 35 months), and had good life quality with NYHA cardiac function classification in 0-I grade. Conclusions Heart transplantation with donor aged over 40 may also have satisfactory results. Patients with endstage dilated cardiomyopathy can procure donor heartsfrom donors with heavy weight. Using different techniques to procure donor hearts may furthest reduce myocardial injury. Donor hearts which have been protected by myocardium protecting liquid for a long time should be used with caution.
Objective To establ ish the modified model of cervical heterotopic cardiac transplantation in rats for investigation of cardiac chronic rejection. Methods Forty healthy male Wistar rats, aged 10 weeks, weighing 250-300 g, were appl ied as the donor group, and forty healthy male SD rats, aged 10 weeks, weighing 300-350 g, served as the recipient group. The donors’ pulmonary artery was anastomosed to the reci pients’ right external jugular vein by non-suture cuff technique while the donors’ innominate artery was anastomosed to the recipients’ right common carotid artery by suture microvascular anastomosis. All recipients received cyclosporin to prevent acute allograft rejection. Results Forty consecutive successful transplantations were performed. Neither anastomosis leakage nor vessel obstruction occurred. The total operation time was 40-50 minutes. The time of cuff vascular anastomosis was 2-3 minutes and that of microvascular anastomosis was 9-12 minutes. All recipients survived for more than 30 days and all allografts were examined at 30 days after the transplantation. Pathological manifestations of allograft vessels were chronic rejection. Conclusion This modified model of cervical heterotopic cardiac transplantation is simple, practical and highly reproducible and is appl icable for investigation of chronic rejection in various organ transplantation studies.
Allogeneic mouse model of peritoneal heart transplant is a microscopic surgery on small animal with complex techniques. For a beginner, a learning curve of this surgical technique has to be experienced. The learning curve contains three stages:(1) to be familiar with the local anatomy of either donor or recipient mouse; (2) to be capable of collecting donor heart and well preparing the major peritoneal vessels of recipient; (3) to be skillful in the anastomosis of major vessels. The bottleneck of the learning curve is the valid skill of vascular anastomosis. The stepwise essentials are to "understand, be familiar, be accurate, and be quick" in the learning curve.
Objective To investigate the effect of alltrans retinoic acid (atRA) on proliferative artery disease after heart transplantation. Methods Heterotopic heart transplantation model was established by Ono model with 16 inbred healthy male Wistar rats as donors and 16 SD rats as recipients. The rats were divided into chronic rejection group and atRAtreated group by complete random design, and there were 8 rats in each group. Rats in chronic rejection group were given Cyclosporine A 10 mg/(kg·d) by subcutaneous injection after operation, and those in atRAtreated group were given Cyclosporine A 10 mg/(kg·d) in the same way and atRA 10mg/(kg·d) by gavage. The transplanted hearts of rats were taken out 60 days after the transplantation. HE stain, masson stain and Van Gieson were done to analyze the rejection of transplanted hearts, the degree of vascular stenosis and myocardial fibrosis respectively.Immunohistochemistry was used to test proliferating cell nuclear antigen (PCNA). Results The area of myocardial fibrosis in chronic rejection group was obviously larger than that in atRAtreated group（63.99%±11.91% vs.34.68%±6.34%）, and there was significant difference between two groups（t=8.377，P=0.000）. The index of vascular stenosis in chronic rejection group was higher than that in atRAtreated group（62.86±17.18 vs. 40.10±8.20）. Vascular stenosis in atRAtreated group alleviated significantly, and there was significant difference between two groups（t=3.913, P=0.006）. The PCNA positive cells in chronic rejection group were obviously more than that in atRAtreated group（60.17±17.74 vs. 33.96±8.65）, and there was significant difference between two groups（t=5.387, P≤0.001）. There was a positive correlation between the PCNA positive cell ratio and the index of vascular stenosis（r=0.854, P=0.007）. Conclusion Alltrans retinoic acid can inhibit vascular disease after heart transplantation by cell proliferative pathway.
Objective To analyze the relation between preoperative pulmonary artery pressure(PAP) and postoperative complications in heart transplant patients, and summarize the experience of perioperative management of pulmonary hypertension (PH), to facilitate the early period heart function recovery of postoperative heart transplant patients. Methods A total of 125 orthotopic heart transplant patients were divided into two groups according to preoperative pulmonary arterial systolic pressure(PASP) and pulmonary vascular resistance(PVR), pulmonary [CM(1583mm]hypertension group (n=56): preoperativePASPgt;50 mm Hg or PVRgt;5 Wood·U; control group (n=69): preoperative PASP≤50 mmHg and PVR≤5 Wood·U. Hemodynamics index including preoperative cardiac index (CI)，preoperative and postoperative PVR and PAP were collected by SwanGanz catheter and compared. The extent of postoperative tricuspid regurgitation was evaluated by echocardiography. Postoperative pulmonary hypertension was treated by diuresis，nitrogen oxide inhaling，nitroglycerin and prostacyclin infusion, continuous renal replacement therapy(CRRT)and extracorporeal membrane oxygenation(ECMO). Results All patients survived except one patient in pulmonary hypertension group died of multiorgan failure and severe infection postoperatively in hospital. Acute right ventricular failure occurred postoperatively in 23 patients, 10 patients used ECMO support, 10 patients with acute renal insufficiency were treated with CRRT. 124 patients were followed up for 2.59 months，7 patients died of multiple organ failure, infection and acute rejection in follow-up period, the survivals in both groups have normal PAP, no significant tricuspid regurgitation. No significant difference in cold ischemia time of donor heart, cardiopulmonary bypass(CPB) and circulation support time between both groups; but the patients of pulmonary hypertension group had longer tracheal intubation time in comparison with the patients of control group (65±119 h vs. 32±38 h, t=2.17，P=0.028). Preoperative PASP，mean pulmonary artery pressure(MPAP) and PVR in pulmonary hypertension group were significantly higher than those in control group, CI was lower in pulmonary hypertension group ［PASP 64.30±11.50 mm Hg vs. 35.60±10.20 mm Hg; MPAP 43.20±8.50 mm Hg vs. 24.20±7.20 mm Hg; PVR 4.72±2.26 Wood·U vs. 2.27±1.24 Wood·U; CI 1.93±0.62 L/（min·m2） vs. 2.33±0.56 L/（min·m2）; Plt;0.05］. Postoperative early PASP, MPAP and PVR in pulmonary hypertension group were significantly higher than those in control group (PASP 35.40±5.60 mm Hg vs. 31.10±5.70 mm Hg, MPAP 23.10±3.60 mm Hg vs. 21.00±4.00 mm Hg, PVR 2.46±0.78 Wood·U vs. 1.79±0.62 Wood·U; Plt;0.05). Conclusion Postoperative right heart insuficiency is related to preoperative pulmonary hypertension in heart transplant patients. Donor heart can quickly rehabilitate postoperatively by effectively controlling perioperative pulmonary hypertension with good follow-up results.
Cardiogenic shock (CS) describes a physiological state of end-organ hypoperfusion characterized by reduced cardiac output in the presence of adequate intravascular volume. Mortality still remains exceptionally high. Veno-arterial extracorporeal membrane oxygenation (VA ECMO) has become the preferred device for short-term hemodynamic support in patients with CS. ECMO provides the highest cardiac output, complete cardiopulmonary support. In addition, the device has portable characteristics, more familiar to medical personnel. VA ECMO provides cardiopulmonary support for patients in profound CS as a bridge to myocardial recovery. This review provides an overview of VA ECMO in salvage of CS, emphasizing the indications, management and further direction.
Objective To investigate the effect of N-acetylcysteine (NAC) on the apoptosis during myocardial ischemia reperfusion injury in rats’ heart transplantation, and to explore the possible role of NAC in myocardial apoptosis. Methods Sixty healthy male Lewis rats (weighing, 200-220 g) were randomly divided into 3 groups, 20 rats each group (10 donors and 10 recipients). In control group, 1 mL normal saline was infused via inferior vena cava at 30 minutes before donor harvesting; in donor preconditioning group, NAC (300 mg/kg) was infused via inferior vena cava at 30 minutes before donor harvesting, but no treatment in recipients; and in recipient preconditioning group, NAC (300 mg/kg) was infused via inferior vena cava at 30 minutes before recipient transplantation, but no treatment in donors. Heart transplantation was established in each group. Blood was drawn at 6 and 24 hours after reperfusion for analysis of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) as markers of graft injury; myocardial tissue was harvested to determine the superoxide dismutase (SOD) and lipid hydroperoxide (LPO) activity at 24 hours after reperfusion and to observe the histology and ultrastructural changes. Graft active Caspase-3 protein expression was measured by immunohistochemistry staining, and apoptosis index (AI) was calculated by TUNEL. Results The heart transplantation operation was successfully completed in all groups, and the rats survived to the end of the experiment. The serum levels of AST, ALT, and LDH in donor and recipient preconditioning groups were significantly lower than those in control group at 6 hours after reperfusion (P lt; 0.05); the levels of AST and ALT in donor preconditioning group and the levels of AST and LDH in recipient preconditioning group were significantly lower than those in control group at 24 hours (P lt; 0.05); and no significant difference was found between donor and recipient perconditioning groups (P gt; 0.05). The levels of AST, ALT, and LDH at 24 hours were significantly lower than those at 6 hours in each group (P lt; 0.05) except the level of ALT in recipient preconditioning group (P gt; 0.05). SOD activity and SOD/LPO in donor and recipient preconditioning groups were significantly higher than those in control group (P lt; 0.05), but no significant difference between donor and recipient preconditioning groups (P gt; 0.05); there was no significant difference in LPO activity among 3 groups (P gt; 0.05). Histological staining and transmission electron microscope showed that myocardial injury in recipient preconditioning group was obviously lighter than that in donor preconditioning group and control group. Active Caspase-3 in recipient pretreatment group was significantly higher than that in donor preconditioning group and control group (P lt; 0.05). AI of donor and recipient preconditioning groups was significantly lower than that of control group (P lt; 0.05), but no significant difference was found between donor and recipient preconditioning groups (P gt; 0.05). Conclusion NAC can relieve ischemia reperfusion injury in rats’ heart transplantation by improving myocardial SOD content, and reducing active Caspase-3 activity and AI, which has a protective effect on myocardial cell of donor heart.
On January 7, 2022, the University of Maryland Medical Center reported that the world’s first gene-edited pig heart was successfully transplanted into a 57-year-old man with end-stage heart disease, causing a global attention. The first gene-edited pig heart transplanted into a human successfully survived for 59 d without showing early signs of rejection, creating a history of xenotransplantation and marking a key step forward the clinical development of xenotransplantation. This article focuses on the role of gene editing in alleviating immune rejection, summarizes the case of xenotransplantation at the Maryland Medical Center, and outlines the current status of xenotransplantation and the unresolved issues of xenotransplantation. It is expected that xenotransplantation can successfully enter the clinic in the near future.