李波
中国医学科学院阜外医院 麻醉科
BACKGROUND:Cardiopulmonary bypass is the basis of open heart surgery. Through simulation-based learning, residents may receive structured training of cardiopulmonary bypass techniques. Therefore, we built a high-fidelity, tissue-based simulation model for cardiopulmonary bypass cannulation/decannulation training.METHODS:The core of the model is a whole block of cadaveric animal heart and lung. The discarded membrane oxygenators are used as blood reservoirs. The tubing and suckers recycled from animal experiments are washed and reused. To set up the model, the cadaveric heart and lung are placed into a container of appropriate size. The "arterial" tubing is connected with a pressure gauge, the distal aorta, the superior vena cava, and arterial cannula, respectively. The "venous" tubing is composed of three independent catheters, respectively, for the practice of venous cannulation, for the connection of sucker and for the practice of placing left atrial/ventricular vent. All tubes are installed on the roller pumps to maintain the correct flow direction. A technician should be responsible for operating the heart-lung machine, clamping and releasing the specific segments of tubing, adjusting the pressure, and cooperating with the trainees to practice.RESULTS:Using the simulation model, 18 residents underwent cardiopulmonary bypass techniques training, with an average satisfaction of 8.94 points. The mean score on the overall fidelity of the simulation model assessed by nine experienced cardiothoracic surgeons was 8.67 points.CONCLUSION:The tissue-based simulation model has a certain degree of realism. Cardiac surgery residents can practice necessary cardiopulmonary bypass cannulation/decannulation techniques by this model.
Perfusion 2020
OBJECTIVE:Many countries are facing a shortage of cardiac surgeons, who are crucial in meeting the demands of growing number of patients in need of coronary artery bypass grafting. This situation poses a serious challenge, especially in China. The purpose of this study is to determine whether cardiac surgeons are suitable for training in coronary artery anastomosis at an earlier stage in their career.METHODS:We divided 12 cardiac surgeons with no prior experience in coronary artery anastomosis into senior and junior groups for training and assessment. All trainees received training in coronary artery anastomosis for a defined period. We performed in vivo and in vitro examinations before and after training, respectively. Additionally, we assessed individual surgical performance of surgeons by using performance rating scores, including different aspects of surgical skills rated on a five-point scale.RESULTS:The post-training scores (overall, junior, senior) were significantly higher than the pre-training scores (overall, junior, and senior). We observed no differences in pre-training and post-training scores between the junior and senior groups.CONCLUSION:Senior surgeons did not had any significant advantages over junior surgeons with respect to coronary artery anastomosis in the absence of training. Junior surgeons achieved the same results as the senior surgeons after training.
Anatolian journal of cardiology 2020
Pulmonary arterial hypertension (PAH) is a chronic and severe cardiopulmonary disorder. Mice are a popular animal model used to mimic this disease. However, the evaluation of right ventricular pressure (RVP) and pulmonary artery pressure (PAP) remains technically challenging in mice. RVP and PAP are more difficult to measure than left ventricular pressure because of the anatomical differences between the left and right heart systems. In this paper, we describe a stable right heart hemodynamic measurement method and its validation using healthy and PAH mice. This method is based on open-chest surgery and mechanical ventilation support. It is a complicated procedure compared to closed chest procedures. While a well-trained surgeon is required for this surgery, the advantage of this procedure is that it can generate both RVP and PAP parameters at the same time, so it is a preferable procedure for the evaluation of PAH models.
Journal of visualized experiments : JoVE 2019
BACKGROUND:A "boot camp" program is commonly adopted in surgical skills training. Due to a shortage of cardiac surgeons, establishment of a well-designed training curriculum for cardiac surgery residents is needed in developing countries.METHODS:We established a comprehensive 3-module training curriculum, including: (1) the cardiopulmonary bypass establishment technique, (2) coronary artery anastomosis and (3) basic surgical skills of thoracoscopy. Each module was designed for one technique, with a training time of 1 week. Each module included theoretical knowledge learning, demonstration by senior surgeons, and practice through simulators and in vivo animal experiment. A series of questionnaires were used to assess the training effect.RESULTS:We organized 50 person-times of training. The overall satisfaction of residents participating in the entire 3-module training was 7.88 points (from a full score of 10 points). The satisfaction of each module was 8.94, 8.13, and 7.63, respectively. The survey suggested the training could increase trainees' confidence in the operation (P < 0.05). Some trainees also proposed some suggestions for the further improvement of the curriculum.CONCLUSIONS:It is feasible to develop a multimodule comprehensive surgical skill training curriculum for cardiac surgery residents in China, whose confidence can be effectively enhanced.
Journal of cardiac surgery 2019
BACKGROUND:The mechanism by which atrial fibrosis leads to the production and maintenance of atrial fibrillation (AF) is unclear. Myocardial biopsies, which have often been used in previous studies, are taken from a single site and do not always reflect the overall condition of atrial fibrosis.AIMS:The aim of this study was to investigate the location of fibrosis in the atria induced by mitral regurgitation (MR) and its effect on atrial electrophysiology and vulnerability to AF.METHODS:Nineteen pigs were divided into three groups. The control group (n=6) underwent a sham operation, and the experimental groups underwent an MR induction operation and were observed for 3 (n=7) or 6 (n=6) months. All the animals were tested for vulnerability to AF. Then, the atria were divided into 12 regions: 6 in the left atrium (LA) and 6 in the right atrium (RA). The conduction velocities (CVs) and effective refractory periods (ERPs) in different regions were examined by electroanatomic mapping, and fibrosis in different regions was examined by Masson staining.RESULTS:With the duration of MR, fibrosis (3.11% ± 0.08% in the control group, 5.85% ± 0.42% in the 3-month group and 8.17% ± 0.23% in the 6-month group, P<.001), vulnerability to AF (0/6 in the control group, 2/7 in the 3-month group and 5/6 in the 6-month group, P<.05) and the effective refractory period (220.1±1.1 ms in the control group, 244.4±1.4 ms in the 3-month group and 289.0±8.9 ms in the 6-month group, P<.001) were increased, while the conduction velocity (1.39±0.16 m/s in the control group, 1.04±0.05 m/s in the 3-month group and 0.89±0.02 m/s in the 6-month group, P<.001) was reduced. These pathophysiological changes were not uniform in different regions of the atria (3.83% ± 0.25% in right atrial fibrosis vs 8.22% ± 0.83% in left atrial fibrosis, P<.001; 5.09% ± 0.34% in the right atrium vs 11.76% ± 0.52% in the left atrium, P<.001). A negative correlation was identified between fibrosis and conduction velocity (P<.001 in the 3-month and 6-month groups), but no correlation was found between fibrosis and the effective refractory period (P=.829 in the 3-month group and P=.093 in the 6-month group). Susceptibility to AF was associated with the dispersion of atrial fibrosis (P=.023).CONCLUSIONS:With the duration of MR, atrial fibrosis increased, and the degree of increase was not uniform among different areas of the atria. The dispersion of atrial fibrosis may contribute to increased susceptibility to AF by influencing the conduction velocity rather than the effective refractory period.
Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology 2019
OBJECTIVES:Surgical intervention is the main treatment for a ruptured congenital sinus of Valsalva aneurysm (SVA). However, reports on the surgical experience are scarce. We retrospectively analysed the cases of our centre to summarize our 10-year experience.METHODS:A total of 286 patients who were diagnosed with a congenital ruptured SVA and underwent surgical repair between 2007 and 2016 were identified for the analysis. Follow-up data (mean ± standard deviation: 49.6 ± 34.9 months) were obtained from outpatient department records and telephone calls.RESULTS:The SVAs originated from the right coronary sinus (79.7%), the non-coronary sinus (19.6%) and the left coronary sinus (0.7%) but ruptured into the right ventricle (58.4%) and the right atrium (41.3%). The most commonly associated deformities were a ventricular septal defect (46.3%), aortic valve regurgitation (33.2%) and tricuspid regurgitation (20.3%). The SVA defect was closed by direct suturing (9.1%) or patching (90.9%) through an incision in the cardiac chamber involved or a transaortic approach. The mean postoperative hospital stay duration was 7.2 days, and 98.6% of the patients were discharged in New York Heart Association functional class I or II. The incidence rate of short-term complications was 5.7%. There were 4 late deaths, and 9 patients required rehospitalization due to surgery-related events. The estimated 10-year survival rate was greater than 90% according to the Kaplan-Meier survival curve.CONCLUSIONS:Surgical repair is an effective and safe treatment for a ruptured SVA. The majority of patients who undergo surgical repair can survive for a long time.
European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery 2019
OBJECTIVES:The hybrid ablation via transdiaphragmatic approach (convergent procedure) is a newly emerging treatment for atrial fibrillation. However, the results reported by different centres are controversial. The purpose of this study is to investigate the efficacy and safety of the convergent procedure by performing a meta-analysis.METHODS:We searched the PubMed, EMBASE and Cochrane Library databases and calculated the pooled estimates. The I2 test, χ2 test and meta-regression analysis were performed to evaluate the heterogeneity. Funnel plots were used to detect publication bias. Trim-and-fill method was performed to identify possible asymmetry.RESULTS:In total, 6 observational studies involving 478 patients were identified for the final analysis. The pooled estimated rate of sinus rhythm maintenance within 12 months was 84.3% (χ2 = 14.69, P = 0.012). The meta-regression analysis showed that the mean duration of atrial fibrillation affected the heterogeneity. Two additional studies need to be trimmed according to the trim-and-fill method. The pooled estimate was 60.2% after filling. The overall complication rate was 9.0%, and the mortality rate was 1.7%.CONCLUSIONS:The efficacy of the convergent atrial fibrillation procedure is relatively satisfactory. However, the overall complication incidence is relatively high, and the procedural mortality rate is unacceptable.
Interactive cardiovascular and thoracic surgery 2019
The porcine mitral regurgitation (MR) model is a common cardiovascular animal model. Standardized manufacturing processes can improve the uniformity and success rate of the model, and systematic research can evaluate its potential use. In this study, 17 pigs were divided into an experimental group (n=11) and a control group (n=6). We used a homemade retractor to cut the mitral chordae via the left atrial appendage to establish a model of MR; the control group underwent a sham surgery. The model animals were followed for 30 months after the surgery. Enlargement and fibrosis of the left atrium were significant in the experimental group compared with those in the control group, and left atrial systolic function decreased significantly. In addition, model animals showed preserved left ventricular systolic function. There were no differences in left atrial potential or left ventricular myocardial fibrosis between the two groups. Atrial fibrillation susceptibility in the experimental group was higher than that in the control group. Our method enables the simple and effective production of a MR model with severe reflux that can be used for pathophysiological studies of MR, as well as for the development of preclinical surgical instruments and their evaluation. This model could also be used to study atrial fibrillation and myocardial fibrosis but is not suitable for studies of heart failure.
Experimental animals 2018
miR-155 is one of the most important miRNAs and plays a very important role in numerous biological processes. However, few studies have characterized this miRNA in mice under normal physiological conditions. We aimed to characterize miR-155 in vivo by using a comparative analysis. In our study, we compared miR-155 knockout (KO) mice with C57BL/6 wild type (WT) mice in order to characterize miR-155 in mice under normal physiological conditions using many evaluation methods, including a reproductive performance analysis, growth curve, ultrasonic estimation, haematological examination, and histopathological analysis. These analyses showed no significant differences between groups in the main evaluation indices. The growth and development were nearly normal for all mice and did not differ between the control and model groups. Using a comparative analysis and a summary of related studies published in recent years, we found that miR-155 was not essential for normal physiological processes in 8-week-old mice. miR-155 deficiency did not affect the development and growth of naturally ageing mice during the 42 days after birth. Thus, studying the complex biological functions of miR-155 requires the further use of KO mouse models.
PloS one 2017
Cardiac fibrosis, as a pathological process, plays an important role in various cardiac diseases. microRNA-155 (miR-155) is one of the most important miRNAs, and previous studies have shown that it is a regulatory factor in various fibrotic diseases. However, the mechanism by which miR-155 affects myocardial fibrosis remains unclear. In this study, we aim to establish the biological function of miR-155 in myocardial fibrosis induced by diabetes in mice. We used normal C57BL/6 wild type (WT) and miR-155 knockout (KO) mice to establish the diabetic model by intraperitoneal injection of streptozotocin, and we utilized echocardiography to evaluate the cardiac function at 30 and 60 days post-modeling. Hematoxylin-eosin (HE) and sirius-red (SR) staining were used to evaluate the degree of myocardial lesions. Furthermore, we extracted cardiac fibroblasts (CFs) from the WT mice and transfected them with miR-155 inhibitors, mimics and negative control siRNAs to analyze the specific mechanism involved in the development of myocardial fibrosis. The results showed that miR-155 deficiency could prevent cardiac fibrosis induced by diabetes in mice and also that attenuated collagen synthesis is induced by high glucose (HG) in CFs. We found that miR-155 regulated cardiac fibrosis via the TGF-β1-Smad 2 signaling pathway. These findings suggest that miR-155 may be a therapeutic target for preventing cardiac fibrosis induced by diabetes.
Molecular bioSystems 2016
