Objective To analyze the risk factors and re-intervention strategies for mid- and long-term residual after arterial switch operation (ASO). Methods The clinical data of children with complex congenital heart disease who underwent ASO surgery in Shanghai Children’s Medical Center from January 2006 to June 2022 were retrospectively collected, and the risk factors for mid- and long-term residual after ASO were analyzed. Results A total of 952 children undergoing ASO were enrolled in this study, including 654 males and 298 females with an average age of (102.9±90.1) d and weight of (4.6±1.6) kg. There were 421 patients with D-transposition of the great arteries with intact ventricular septum (D-TGA/IVS), 357 patients with D-transposition of the great arteries with ventricular septal defect (D-TGA/VSD), and 174 patients with right ventricle double outlet combined with subpulmonary ventricular septal defect (Taussig-Bing malformation). Eighty-nine patients died early after the surgery, the mortality rate was 9.3%. The 746 surviving children were regularly followed up after the surgery (follow-up rate 86.4%), with a median follow-up time of 79.4 (12.0-188.0) months. During the follow-up, 53 children underwent surgical re-intervention due to residual, including 33 males and 20 females, with a median age of 62.5 (17.0-214.0) months. The median surgical weight was 19.0 (8.2-86.0) kg, and the mean time of re-intervention was 28.0-170.0 (77.5±45.4) months after the ASO. Residual problems included common trunk and branch stenosis of the pulmonary artery in 23 patients, right ventricular outflow tract (RVOT) obstruction in 11 patients, left ventricular outflow tract obstruction in 6 patients, aortic arch restenosis in 5 patients, aortic insufficiency in 5 patients, residual shunt of ventricular septal defect in 2 patients, and tricuspid valve insufficiency in 1 patient. The early postoperative mortality rate was 3.8% (2/53), with the causes of death being acute myocardial infarction due to coronary artery injury and acute left heart failure, respectively. The mean follow-up time of the surviving children was (52.4±28.6) months, and no mid- and long-term death occurred. Two patients underwent the third operations due to pulmonary restenosis. The multivariate analysis result showed that combined aortic arch surgery and early postoperative RVOT velocity>3 m/s were independent risk factors for mid- and long-term residual after ASO. Conclusion ASO is an ideal procedure for the treatment of D-TGA/IVS, D-TGA/VSD and Taussig-Bing malformations. Combined aortic arch surgery and early postoperative RVOT velocity>3 m/s are independent risk factors for mid- and long-term residual after ASO.

Objective To analyze the clinical efficacy of right midaxillary straight incision surgery in the treatment of doubly committed subarterial ventricular septal defect. Methods The clinical data of children with doubly committed subarterial ventricular septal defect who received surgeries in our hospital from August 2020 to July 2023 were analyzed retrospectively. All the children underwent surgical repair and were divided into two groups according to the incision position, including a right midaxillary straight incision group and a median incision group. The outcomes were compared between the two groups. Results A total of 187 patients were enrolled. There were 102 patients in the right midaxillary straight incision group, including 55 males and 47 females with a median age of 26.0 (5.0, 127.0) months and a median weight of 12.5 (5.1, 32.8) kg at surgery. There were 85 patients in the median incision group, including 37 males and 48 females with a median age of 4.0 (2.0, 168.0) months and a median weight of 6.7 (4.8, 53.9) kg at surgery. No mortality occurred in the study. There was no statistical difference between the two groups in the cardiopulmonary bypass time [(50.0±18.4) min vs. (46.1±15.7) min] or aortic cross-clamping time [(31.3±18.6) min vs. (26.3±17.5) min] (P>0.05). Compared to the median incision group, the time from the end of cardiopulmonary bypass to the closure of chest [(22.3±15.6) min vs. (37.1±13.4) min, P<0.001], postoperative hospital stay [(6.9±3.9) d vs. (8.6±3.6) d, P=0.002], the length of incision [(4.3±2.7) cm vs. (8.5±3.2) cm, P<0.001], drainage volume [(79.0±32.2) mL vs. (100.2±43.1) mL, P<0.001], and the pain score on the 2nd and the 3rd day after the operation were statistically better in the right midaxillary straight incision group (P<0.05). The medical experience and incision satisfaction scores at discharge of the right midaxillary straight incision group were higher (P<0.05). During the follow-up of 21.0 (1.0, 35.0) months, no residual shunt was detected and all patients in both groups had a normal cardiac function and mild or less valve regurgitation. Conclusion Compared to the median incision, minimally invasive right midaxillary straight incision for the repair of doubly committed subarterial ventricular septal defect offers comparable efficacy and reliability, with the added advantages of being minimally invasive, cosmetically superior, and promoting faster postoperative recovery.

Objective    To analyze the outcomes of surgical repair for mixed total anomalous pulmonary venous connection (TAPVC). Methods    Between 2006 and 2018, a total of 51 patients with mixed TAPVC underwent surgery in our hospital. Patients with such associated anomalies as single ventricle and tetralogy of Fallot were excluded. There were 35 males and 16 females with a median age of 102.0 (59.0, 181.0) days and a median weight of 5.0 (4.1, 6.4) kg. Patients were divided into three categories based on the anatomy: "3+1" pattern (n=38, three pulmonary veins drained at one site, and the other drained at the opposite site); "2+2" pattern (n=9, the pulmonary veins from each lung joined to form a confluence and drained at separate sites); bizarre pattern (n=4, the anatomy could not be classified into the above two patterns). Results    There was no in-hospital death. The median follow-up was 41.0 (18.0, 86.5) months. Postoperative pulmonary venous obstruction occurred in 10 patients. Kaplan-Meier survival curves showed no statistically significant difference in postoperative pulmonary venous obstruction among the three groups (P=0.239). Cox risk regression showed that preoperative pulmonary venous obstruction was significantly associated with postoperative pulmonary venous obstruction (P=0.024). Conclusion    Mixed TAPVC has various anatomic morphologies and requires individualized surgery.

Objective    To compare the outcomes of sutureless technique and conventional technique in the surgical repair for infracardiac total anomalous pulmonary venous connection (TAPVC). Methods    The clinical data of 46 consecutive patients with infracardiac TAPVC undergoing surgical repair in our hospital between June 2014 and April 2019 were retrospectively analyzed. Patients with combined congenital cardiac anomalies such as single ventricle and tetralogy of Fallot were excluded. Patients were divided into a conventional technique group and a sutureless technique group according to the surgical techniques. There were 35 patients in the conventional technique group, including 28 males (80.0%) and 7 females (20.0%) with a median age of 21 (8, 42) d and a median weight of 3.6 (3.0, 4.0) kg. There were 11 patients in the sutureless technique group, including 8 males (72.7%) and 3 females (27.3%) with a median age of 14 (6, 22) d and a median weight of 3.5 (2.9, 3.6) kg. The curative effect of the two groups was compared. Results    There were 5 deaths (10.9%) in the conventional technique group, including 4 in-hospital deaths (8.7%) and 1 late death (2.2%). Overall mortality of the conventional technique group (14.3%, 5/35) was higher than that of the sutureless technique group (0.0%, 0/11), although the difference was not statistically significant (P=0.317). Cox regression analysis showed that sex (P=0.042), age at repair (P=0.028), cardiopulmonary bypass time (P=0.007), aortic cross-clamping time (P=0.018) and duration of ventilation (P=0.042) were risk factors for postoperative mortality. The median follow-up was 18.00 (5.00, 37.75) months. Postoperative pulmonary venous obstruction occurred in 22 patients of the conventional technique group, which was significantly more than that of the sutureless technique group (P=0.000). Conclusion    For infracardiac TAPVC, sutureless technique can reduce the incidence of postoperative pulmonary venous obstruction compared with conventional technique.

Objective:To summarized the experience of 149 cases of critical pediatric cardiac surgery in a single-center during the epidemic period, for providing a safe and feasible management strategy.Methods:Based on the epidemiological characteristics of COVID-19, a strategy consisting of 14 days of isolation was established for the arrangement of cardiac surgery in children during the epidemic period. Retrospective analysis of clinical data of 149 cases of critical cardiac surgery performed from January 23, 2020 to March 20, 2020 under the guidance of this strategy. The primary composite endpoint was death and suspected or confirmed COVID-19.Results:The median age of the children undergoing surgery was 136 days; 73(49.0%) cases were male. Twenty-one cases (14.1%) came from Shanghai, one case (0.7%) came from Hubei Province, and 127 cases (85.2%) came from areas other than Hubei and Shanghai. One patient (0.7%) outside Shanghai who had been isolated for less than 14 days carried emergency surgery under special protection; other 148 patients (99.3%) underwent elective early repair procedure. One patient (0.7%) died, and no COVID-19 was confirmed or suspected.Conclusion:During the COVID-19 epidemic, pediatric cardiac surgery can be safely performed using a specific management strategy, which can be used as a reference when major public health events occur.

Novel Coronavirus Pneumonia (NCP) is a class B infectious disease, which is prevented and controlled according to class A infectious diseases. Recently, children′s NCP cases have gradually increased, and children′s fever outpatient department has become the first strategic pass to stop the epidemic. Strengthening the management of the fever diagnosis process is very important for early detection of suspected children, early isolation, early treatment and prevention of cross-infection. This article proposes prevention and control strategies for fever diagnosis, optimizes processes, prevents cross-infection, health protection and disinfection of medical staff, based on the relevant diagnosis, treatment, prevention and control programs of the National Health and Health Commission and on the diagnosis and treatment experience of experts in various provinces and cities. The present guidance summarizes current strategies on pre-diagnosis; triage, diagnosis, treatment, and prevention of 2019-nCoV infection in common fever, suspected and confirmed children, which provide practical suggestions on strengthening the management processes of children′s fever in outpatient department during the novel coronavirus pneumonia epidemic period.

Enterokinase is a class of serine proteases that specifically recognize the cleavage DDDDK sequences. Therefore, enterokinase has been widely used as a tool enzyme in the field of biomedicine. Currently, the expression level of enterokinase in Pichia pastoris is low, which hinders related practical applications. In this study, the effects of six different signal peptides SP1, SP2, SP3, SP4, SP7 and SP8 on the secretory expression of enterokinase in Pichia pastoris were studied. Compared with α-factor, SP1 significantly increased the secretory expression of enterokinase (from 6.8 mg/L to 14.3 mg/L), and the enterokinase activity increased from (2 390±212) U/mL to (4 995±378) U/mL in shaking flask cultures. On this basis, the enterokinase activity was further enhanced to (7 219±489) U/mL by co-expressing the endogenous protein Kex2. Moreover, the activity that the mutant strain with N-terminal fusion of three amino acids of WLR was increased to (15 145±920) U/mL with a high specific activity of (1 174 600±53 100) U/mg. The efficient secretory expression of enterokinase laid a foundation for its applications in near future.

Objective    To investigate the effects of a self-powered conduit in different patients’ models who underwent extracardiac Fontan procedure. Methods    Four children who underwent extracardiac Fontan procedure in Shanghai Children's Medical Center from 2011 to 2017 year were selected. Venae cavae and pulmonary arteries were reconstructed using Mimics 19.0®. In silico, a venturi conduit was introduced to the anastomosis of venae cavae and pulmonary artery. Then computational fluid dynamics simulation was performed using patients’ clinical data. Results    When inferior venae cavae were directly to or to the left of superior venae cavae, the venturi conduit could assist the return of venous blood and reduce the pressures of venae cavae about 0.5 mm Hg. And the pressure differences between venae cavae and pulmonary arteries were about –0.7 mm Hg, which suggested that the conduit could generate right ventricle-like effect. Conclusion    The venturi conduit can reduce the pressure of venae cavae, increase pulmonary circulation flow and improve Fontan hemodynamics.

Objective    Pulmonary vein banding was used to establish a piglet model of pulmonary vein stenosis. We investigated the pathomorphological alterations of pulmonary veins in the model and compared it with the vascular tissue of recurrent stenosis after total anomalous pulmonary venous connection (TAPVC). Methods    Ten pigs of 6 weeks old were selected and randomly divided into 2 groups: 5 in a sham operation group and 5 in a pulmonary vein banding group. The operation had two stages, in which thoracotomies through intercostal space were done respectively on both sides. Biocompatible materials were applied around the pulmonary veins in the experimental group. The same method was used in the sham group. But the pulmonary veins were not banded. Six weeks after the operation, the pulmonary veins of the animals were harvested for hematoxylin-eosin staining and immunofluorescence staining to observe the pathological alterations of pulmonary veins. The proliferative tissues of patients with recurrent stenosis after TAPVC repair were collected and observed by hematoxylin-eosin staining and immunofluorescence staining. Results    Both the sham operation group and the pulmonary vein banding group survived. But the pulmonary vein banding group had obvious clinical manifestations of pulmonary venous stenosis. Compared with the sham group, the pulmonary vein banding group showed intimal hyperplasia, decreased expression of endothelial marker and increased expression of mesenchymal markers, and co-expression of endothelial and mesenchymal markers in intimal cells. Human pathology also showed intimal hyperplasia and co-expression of endothelial and mesenchymal markers in intimal cells. Conclusion    The surgical pulmonary vein stenosis in piglets shows intimal hyperplasia and myofibroblasts, which was consistent with clinical pathology.