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.
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.
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 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.
ObjectiveTo analyze the safety and efficacy of vacuum-assisted venous drainage (VAVD) in cardiac surgery under cardiopulmonary bypass (CPB).MethodsA total of 180 patients from 3 centers between November 17, 2017 and October 1, 2018 were enrolled and randomly assigned to a VAVD group and a gravity drainage (GD) group by 1∶1 ratio. During the open-heart surgery under CPB, the VAVD group completely relied on VAVD, and the GD group used conventional GD. The primary endpoint was arterial flow before CPB, 15 min after aortic cross-clamping and rewarming to 36 °C of nasopharyngeal temperature. The secondary endpoints included hematocrit, hemoglobin concentration, blood product transfusion, etc. The safety endpoint was free hemoglobin concentration, etc.ResultsThe full analysis set contained 175 patients, 87 in the VAVD group and 88 in the GD group. Patients in the VAVD group were aged 52.8±12.0 years, and males accounted for 55.2%; patients in the GD group were aged 51.4±12.1 years, and males accounted for 59.1%. The demographic characteristics between the two groups were not statistically different. Compared to the GD group, the VAVD group could provide comparable arterial flow in CPB [average of 3 time points, 2.37±0.22 L/(min·m2) vs. 2.41±0.25 L/(min·m2), P=0.271], while not elevating free hemoglobin concentration.ConclusionVAVD can provide enough venous drainage, while not elevating free hemoglobin concentration or damaging blood.
ObjectiveTo evaluate the safety and efficacy of peripheral cannulation for cardiopulmonary bypass (CPB) in patients with reoperation of congenital heart disease. MethodsThe perioperative data of patients with congenital heart disease who underwent reoperation in Fuwai Hospital from 2019 to 2020 were retrospectively collected. They were divided into two groups according to the cannulation methods: a central group and a peripheral group. The prognosis of the patients was analyzed. Results A total of 80 patients were collected, including 43 patients in the central group, and 37 pateints in the peripheral group. In the central group, the median age was 18 (14, 32) years, and 21 patients were male. The median age of the peripheral group was 16 (10, 27 ) years, and 18 patients were male. The CPB time in the peripheral group was 201 (164, 230) min, which was longer than that in the central group [143 (97, 188 ) min, P＜0.001]. The lactate after CPB in the peripheral group was statistically higher than that in the central group [2 (1, 2 ) mmol/L vs. 1 (1, 1) mmol/L, P=0.002]. The dosage of albumin use during CPB in the peripheral group was statistically higher than that in the central group [10 (0, 20) g vs. 0 (0, 0) g, P=0.004]. There was no statistical difference in the postoperative dosage of red blood cells use [0 (0, 2) U vs. 0 (0, 0) U, P=0.117], mechanical ventilation time [14 (11, 19) h vs. 13 (10, 15) h, P=0.296], ICU stay time [43 (23, 80) h vs. 40 (20, 67) h, P=0.237] or postoperative hospital stay time [10 (7, 12) d vs. 8 (7, 10) d, P=778] between the two groups. ConclusionIt’s safe and efficient to establish CPB through peripheral cannulation in patients with complex congenital heart disease undergoing reoperation.
ObjectiveTo describe the outcomes of extracorporeal membrane oxygenation (ECMO) for patients after aortic surgery and to summarize the experience. Methods The clinical data of patients who received ECMO support after aortic surgery in Fuwai Hospital from 2009 to 2020 were retrospectively analyzed. The patients who received an aortic dissection surgery were allocated into a dissection group, and the other patients were allocated into a non-dissection group. The in-hospital and follow-up survival rates were compared between the two groups, and the causes of death were analyzed. ResultsA total of 22 patients were enrolled, including 17 patients in the dissection group [13 males and 4 females, with a median age of 54 (46, 61) years] and 5 patients in the non-dissection group [3 males and 2 females, with a median age of 51 (41, 65) years]. There was no statistical difference in the age and gender between the two groups (P>0.05). The in-hospital survival rate (11.8% vs. 100.0%, P=0.001) and follow-up survival rate (11.8% vs. 80.0%, P=0.009) of the patients in the dissection group were significantly lower than those in the non-dissection group. The causes of death in the dissection group included massive bleeding and disseminated intravascular coagulation (3 patients), ventricular thrombosis (1 patient), irreversible brain injury (2 patients), visceral malperfusion syndrome (4 patients) and irreversible heart failure (5 patients). ConclusionECMO after aortic dissection surgery is associated with high mortality, which is related to the pathological features of aortic dissection and severely disrupted coagulation system after the surgery. For these patients, strict indication selection and optimal management strategy are important.
Objective To discuss the safety and validity of pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) patients with severe right heart failure (RHF). Methods PEA procedures were performed on 36 patients in Fu Wai Hospital from January 2015 to April 2016. There were 28 males and 8 females, with a mean age of 46.56±11.85 years. According to the New York Heart Association (NYHA) cardiac function classification, 36 patients were divided into preoperative severe RHF group (grade Ⅲ-Ⅳ,n=28) and preoperative without severe RHF group (grade Ⅱ,n=8). Hemodynamic parameters before and after PEA were recorded and 3-18 months' follow-up was done. Results All the patients having PEA surgeries had an obvious decrease of mean pulmonary arterial pressure (from 49.53±13.14 mm Hg to 23.58±10.79 mm Hg) and pulmonary vascular resistance (from 788.46±354.60 dyn·s/cm5 to 352.89±363.49 dyn·s/cm5, bothP<0.001). There was no in-hospital mortality among all the patients. Persistent pulmonary hypertension occurred in 2 patients, perfused lung in 2 patients, pericardial effusion in 2 patients. No mortality was found during the follow-up period. All patients improved to NYHA grade Ⅰ-Ⅱ (WHO grade Ⅰ-Ⅱ), and only 2 patients remained in the NYHA grade Ⅲ (P<0.01). Conclusion The CTEPH patients having PEA surgeries had an obvious improvement in both their hemodynamics results and postoperative heart function, which in return could improve their quality of life.
ObjectiveTo explore the safety and feasibility of the establishment method and management strategy of prolonged support model with veno-venous extracorporeal membrane oxygenation (V-V ECMO) under dual lumen cannula (DLC) in conscious sheep.MethodsThree adult male sheep were selected. An Avalon Elite DLC was inserted into the superior vena cava, right atrium, and inferior vena cava through the right jugular vein and was connected with centrifugal pump and oxygenator to establish the extracorporeal membrane oxygenation circuit. All the 3 sheep were transferred into the monitoring cage after operation and were ambulatory after anesthesia recovery. Hemodynamic parameters and extracorporeal membrane oxygenation performance were measured every day.ResultsAll three sheep survived to the end of the experiment (7 days). In the whole process of the experiment, the basic vital signs of the experimental sheep were stable, and no serious bleeding or thrombotic events occurred. During the experiment, hemoglobin concentration and platelet count were relatively stable, plasma free hemoglobin was maintained at a low level, extracorporeal membrane oxygenation flow rate was stable, and oxygenation performance of oxygenator was good.ConclusionProlonged V-V ECMO model in conscious sheep under DLC is feasible and stable.