Deep hypothermic circulatory arrest (DHCA) technology is the basic means of organ protection in complex aortic arch surgeries, congenital heart disease surgeries, pulmonary endarterectomy and other operations. The establishment of DHCA in rat model is helpful to explore the influence of DHCA and its pathophysiological pathways. However, there are some problems in this process, such as imperfect monitoring, inaccurate management and non-standard heparinization during the experimental period. It is necessary to review relevant literatures on DHCA rat model, in order to establish a DHCA rat model with standardized operation, clear standards and mature technology.
Extracorporeal membrane oxygenation (ECMO) is a critical life support technique for patients with severe cardiopulmonary failure. Establishing a stable ECMO animal model is essential to further investigate the effects of ECMO on the body and provide assistance for optimizing ECMO management strategies and preventing complications in clinical practice. In recent years, rats have been widely used to establish ECMO models due to their low cost and good reproducibility. Therefore, this article provided a comprehensive review of literature on the ECMO rat model, including equipment and experimental management strategies. It offers a theoretical foundation for the development of a stable and mature ECMO rat model in the future.
Abstract： Objective To evaluate different shunting flow in varied conditions in a simulated adult cardiopulmonary bypass (CPB) model under normothermia. Methods We established the pseudo adult patient undergoing CPB at four different shunting states with devices of heartlung machine, heatcooler, an adult membrane oxygenator and arterial filter. In state 1, purge line of the arterial filter was open alone; In state 2, purge line combined with 6.5 mm tubing hemoconcentrator shunting was open; In state 3, purge line combined with 5 mm tubing hemoconcentrator was open; In state 4, purge line combined with blood cardioplegia shunting was open. The flow of preoxygenator and postfilter was recorded with ultrasonic flowmeter, and the pressure of purge line and postarterial filter was also detected. Results At state 1, when the pump flow was invariable, the percentage of the shunting flow increased with the increase of postfilter pressure. However, when the postfilter pressure was constant, the percentage of the shunting flow decreased with the increase of the pump flow. The purge line pressure increased with the increase of the postfilter pressure at a constant pump flow under state 1. The shunting flow of state 2 was the largest among all the four states. The shunting flow of state 3 was similar to that of state 4. All the purge line pressure was lower than the postfiler pressure of the circuit in the four states. Conclusion Under states of different shunting opening, different degrees of blood flow are diverted away from the arterial line. The shunting flow increases at a lower pump flow and a higher postfilter pressure. A flow probe located in the postfilter line may be necessary to monitor realtime arterial flow.
Working Group on Extracorporeal Life Support, National Center for Cardiovascular Quality Improvement developed guidelines on patient blood management for adult cardiovascular surgery under cardiopulmonary bypass, aiming to standardize patient blood management in adult cardiovascular surgery under cardiopulmonary bypass, reduce blood resource consumption, and improve patients outcomes. Forty-eight domestic experts participated in the development of the guidelines. Based on prior investigation and the PICO (patient, intervention, control, outcome) principles, thirteen clinical questions from four aspects were selected, including priming and fluid management during cardiopulmonary bypass, anticoagulation and monitoring during cardiopulmonary bypass, peri-cardiopulmonary bypass blood product infusion, and autologous blood infusion. Systemic reviews to the thirteen questions were performed through literature search. Recommendations were drafted using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. After five rounds of experts discussions between 2023 and 2024, 19 recommendations were finally formed.
Abstract： Objective To observe the expression changes of microRNA 1 （miRNA-1） and microRNA 21（miRNA-21） after ischemic preconditioning （IPC）, ischemic postconditioning （IPO） and remote ischemic preconditioning （RIPC）in an ischemia-reperfusion rat heart model in vitro, as well as the expression of their target protein heat shock protein 70 （HSP70） and programmed cell death 4 （PDCD4）, and evaluate whether miRNA are involved in endogenous cardio-protective mechanism. Methods The Langendorff-perfused Sprague-Dawley rat hearts were randomly assigned into one of the four groups, control group （CON group, n=12）, ischemia preconditioning group （IPC group， n=12）?, ischemia postconditioning group （IPO group， n=12） and remote ischemia preconditioning group （RIPC group，n=12）. Cardiac function was digitalized and analyzed. The expression of HSP70, PDCD4, B-cell lymphoma/leukemia-2 （Bcl-2） and Bax was detected by Western blotting. The expression of miRNA-1 and miRNA-21 was detected by real-time reverse transcriotion-polymerase chain reaction （RT-PCR）. Assessment of cardiac infarct size and myocardial apoptosis was determined using triphenyltetrazolium chloride （TTC） assay and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay （TUNEL） assay respectively. Results The expressions of miRNA-1 and miRNA-21 were up-regulated in IPC group, but the expression of miRNA-1 was down-regulated in RIPC group and IPO group （P＜0.05）. The expressionsof PDCD4, HSP70 and Bax were down-regulated in ‘conditioning’ groups compared with CON group （P＜0.05）. The expression of Bcl-2 was not statistically different among the four groups. The infarct size and the myocardial apoptosis in ‘conditioning’ hearts were significantly decreased compared with CON group （P＜0.05）. Conclusion The expressions of the miRNA-1 and miRNA-21 are different in IPC, RIPC and IPO groups, and their target proteins are not inversely correlated with the miRNAs in all the ‘conditioning’ groups.