Sliding mode coordinated control of hybrid electric vehicle via finite-time control technique.

During the transient mode switching process of the hybrid electric vehicle (HEV) from motor driving mode to hybrid driving mode, dynamic coordinated control of different components is essential to improve the vehicle comfort and dynamic performance. The key to highly quality mode switching control includes fast and stable speed and/or displacement tracking of the engine and motor. The transient mode switching stages of the HEV is divided in this paper. On this basis, by combing the nonlinear sliding mode control and the finite-time stability theory, the global fast integral terminal sliding mode controller (GFITSMC) is designed for the transition stages involving clutch slip. The GFITSMC consists of the global fast integral terminal sliding mode surface (GFITSMS) and the non-smooth reaching law (NSRL). In order to improve the controller convergence and anti-disturbance performance, the proposed controller is synthesized from the perspective of finite-time stability. It is proved that, with proper NSRL and GFITSMS parameters, the speed and displacement tracking error of the motor and engine can reach the sliding mode surface and further converge to zero in a finite time. Simulation and hardware-in-the-loop (HIL) tests are performed to validate the effectiveness of the proposed control method. Research results demonstrate that the proposed strategy not only achieves faster transient mode switching by improving the state trajectory tracking performance, but also reduces the longitudinal jerk caused by the transient mode switching significantly.

Extracellular Matrix/Glycopeptide Hybrid Hydrogel as an Immunomodulatory Niche for Endogenous Cardiac Repair after Myocardial Infarction.

The treatment of myocardial infarction (MI) remains a substantial challenge due to excessive inflammation, massive cell death, and restricted regenerative potential, leading to maladaptive healing process and eventually heart failure. Current strategies of regulating inflammation or improving cardiac tissue regeneration have limited success. Herein, a hybrid hydrogel coassembled by acellular cardiac extracellular matrix (ECM) and immunomodulatory glycopeptide is developed for endogenous tissue regeneration after MI. The hydrogel constructs a niche recapitulating the architecture of native ECM for attracting host cell homing, controlling macrophage differentiation via glycopeptide unit, and promoting endotheliocyte proliferation by enhancing the macrophage-endotheliocyte crosstalk, which coordinate the innate healing mechanism for cardiac tissue regeneration. In a rodent MI model, the hybrid hydrogel successfully orchestrates a proreparative response indicated by enhanced M2 macrophage polarization, increased angiogenesis, and improved cardiomyocyte survival, which alleviates infarct size, improves wall thicknesses, and enhances cardiac contractility. Furthermore, the safety and effectiveness of the hydrogel are demonstrated in a porcine MI model, wherein proteomics verifies the regulation of immune response, proangiogenesis, and accelerated healing process. Collectively, the injectable composite hydrogel serving as an immunomodulatory niche for promoting cell homing and proliferation, inflammation modulation, tissue remodeling, and function restoration provides an effective strategy for endogenous cardiac repair.

Transcatheter closure of perimembranous ventricular septal defect using a novel fully bioabsorbable occluder: multicenter randomized controlled trial.

Although the use of bioabsorbable occluder is expected to reduce the risk of metal occluder-related complications, it has not been approved due to incomplete degradation and new complications. Novel fully bioabsorbable occluders were designed to overcome such limitations. The aim of this study was to investigate the efficacy and safety of a fully biodegradable occluder in patients with ventricular septal defects. 125 patients with perimembranous ventricular septal defect (VSD) larger than 3 mm were screened from April 2019 to January 2020 in seven centers. 108 patients were enrolled and randomized into the bioabsorbable occluder group (n = 54 patients) and nitinol occluder group (n = 54). A non-inferiority design was utilized and all patients underwent transcatheter device occlusion. Outcomes were analyzed with a 24-month follow-up. All patients were successfully implanted and completed the trial. No residual shunt >2 mm was observed during follow-up. Transthoracic echocardiography showed a hyperechoic area corresponding to the bioabsorbable occluder which decreased primarily during the first year after implantation and disappeared within 24 months. Postprocedural arrhythmia was the only occluder-related complication with an incidence of 5.56% and 14.81% for the bioabsorbable and nitinol groups, respectively (P = 0.112). The incidence of sustained conduction block was lower in the bioabsorbable occluder group (0/54 vs. 6/54, P = 0.036) at 24-month follow-up. In conclusion, the novel fully bioabsorbable occluder can be successfully and safely implanted under echocardiography guidance and reduce the incidence of sustained postprocedural arrythmia. The efficacy and safety of this fully biodegradable occluder are non-inferior to that of a traditional nitinol one.

A fully biodegradable polydioxanone occluder for ventricle septal defect closure.

Ventricular septal defect (VSD) is one of the commonest congenital heart diseases (CHDs). Current occluders for VSD treatment are mainly made of nitinol, which has the risk of nickel allergy, persistent myocardial abrasion and fatal arrythmia. Herein, a fully biodegradable polydioxanone (PDO) occluder equipped with a shape line and poly-l-lactic acid PLLA membranes is developed for VSD closure without the addition of metal marker. PDO occluder showed great mechanical strength, fatigue resistance, geometry fitness, biocompatibility and degradability. In a rat subcutaneous implantation model, PDO filaments significantly alleviated inflammation response, mitigated fibrosis and promoted endothelialization compared with nitinol. The safety and efficacy of PDO occluder were confirmed in a canine VSD model with 3-year follow-up, demonstrating the biodegradable PDO occluder could not only effectively repair VSD, induce cardiac remodeling but also address the complications associated with metal occluders. Furthermore, a pilot clinical trial with five VSD patients indicated that all the occluders were successfully implanted under the guidance of echocardiography and no adverse events occurred during the 3-month follow-up. Collectively, the fully bioresorbable PDO occluder is safe and effective for clinical VSD closure and holds great promise for the treatment of structural CHDs.

Neuroblastoma Suppressor of Tumorigenicity 1 Mediates Endothelial-to-Mesenchymal Transition in Pulmonary Arterial Hypertension Related to Congenital Heart Disease.

Endothelial-to-mesenchymal transition (EndMT) plays a critical role in the flow-induced vascular remodeling process, such as pulmonary arterial hypertension (PAH) related to congenital heart disease (CHD). NBL1 (neuroblastoma suppressor of tumorigenicity 1) is a secreted glycoprotein that has been implicated in CHD-PAH by aggravating the phenotypic transformation of smooth muscle cells. However, the underlying mechanisms regarding the interplay between NBL1 and endothelial cells in CHD-PAH remain to be fully elucidated. Thus, we aimed to identify the potential effect of NBL1 on EndMT using a novel flow-associated PAH model with Nbl1 knockout rats. The phenotype of EndMT was detected using RNA sequencing and further examined using western blotting and immunostaining of pulmonary arteries. Our observations demonstrated that the novel strategy of Nbl1 knockout effectively attenuated flow-associated PAH through downregulation of EndMT to some extent. Mechanistic experiments were established on human pulmonary artery endothelial cells to confirm that EndMT was induced by NBL1 in vitro. After 7 days' stimulation with NBL1, concentrations of EndMT-related biomarkers and downstream transcription factors were quantified using RNA sequencing, western blotting, and immunocytochemistry. Both in vitro and in vivo experiments supported the imbalance of increased TGF-ß (transforming growth factor-ß) and dysregulation of BMP (bone morphogenetic protein) signaling by NBL1. Blocking the canonical TGF-ß pathway efficiently preserved endothelial function upon NBL1 stimulation. These data suggested that NBL1 aggravated flow-associated PAH by inducing EndMT via the TGF-ß and BMP signaling pathway. Thus, antagonizing NBL1 and rebalancing TGF-ß and BMP signaling may be a suitable therapeutic target for CHD-PAH.

Cost-effectiveness of Vitamin A supplementation among children in three sub-Saharan African countries: An individual-based simulation model using estimates from Global Burden of Disease 2019.

BACKGROUND: Vitamin A Supplementation (VAS) is a cost-effective intervention to decrease mortality associated with measles and diarrheal diseases among children aged 6-59 months in low-income countries. Recently, experts have suggested that other interventions like large-scale food fortification and increasing the coverage of measles vaccination might provide greater impact than VAS. In this study, we conducted a cost-effectiveness analysis of a VAS scale-up in three sub-Saharan African countries. METHODS: We developed an individual-based microsimulation using the Vivarium simulation framework to estimate the cost and effect of scaling up VAS from 2019 to 2023 in Nigeria, Kenya, and Burkina Faso, three countries with different levels of baseline coverage. We calibrated the model with disease and risk factor estimates from the Global Burden of Disease 2019 (GBD 2019). We obtained baseline coverage, intervention effects, and costs from a systematic review. After the model was validated against GBD inputs, we modeled an alternative scenario where we scaled-up VAS coverage from 2019 to a level that halved the exposure to lack of VAS in 2023. Based on the simulation outputs for DALYs averted and intervention cost, we determined estimates for the incremental cost-effectiveness ratio (ICER) in USD/DALY. FINDINGS: Our estimates for ICER are as follows: $860/DALY [95% UI; 320, 3530] in Nigeria, $550/DALY [240, 2230] in Kenya, and $220/DALY [80, 2470] in Burkina Faso. Examining the data for DALYs averted for the three countries over the time span, we found that the scale-up led to 21 [5, 56] DALYs averted per 100,000 person-years in Nigeria, 21 [5, 47] DALYs averted per 100,000 person-years in Kenya, and 14 [0, 37] DALYs averted per 100,000 person-years in Burkina Faso. CONCLUSIONS: VAS may no longer be as cost-effective in low-income regions as it has been previously. Updated estimates in GBD 2019 for the effect of Vitamin A Deficiency on causes of death are an additional driver of this lower estimate of cost-effectiveness.

Propensity-matched comparison of balloon-expandable and self-expanding valves for transcatheter aortic valve replacement in a Chinese population.

Background: Balloon-expandable valves (BEV) and self-expanding valves (SEV) for transcatheter aortic valve replacement (TAVR) have shown promising results in Western populations. Herein, we comparatively evaluated their hemodynamics and early clinical outcomes in a Chinese population. Methods: One hundred seventy-eight patients with symptomatic aortic stenosis who had undergone transfemoral TAVR using SEV (n=153; Venus-A, 97; VitaFlow, 56) or BEV (n=25; Sapien3) from September 2020 to April 2021 were retrospectively enrolled, and 25 pairs were propensity-score matched for 10 baseline variables. The primary study outcomes were aortic valve hemodynamics and postoperative complications at discharge and 3-month follow-up. Results: TAVR was successful in all patients. Compared with SEV group, the BEV group had similarly distributed baseline characteristics, procedural time, hospital stay, new pacemaker implantation, and paravalvular regurgitation grade. We also observed that the BEV group had lower rates of balloon pre-dilation (60% vs. 92%, P=0.018), post-dilation (0 vs. 20%, P=0.050) and second valve implantation (0 vs. 24%, P=0.022); higher mean transaortic gradient (14.3±6.1 vs. 10.8±4.9, P=0.030) and proportion of patients with elevated gradients (20% vs. 0, P=0.050) at discharge; and similar rehospitalization, mean transaortic gradient, new pacemaker implantation, and paravalvular regurgitation grade than the SEV group at the 3-month follow-up. There were no deaths in either group. However, the proportion of patients with elevated gradients in SEV group was higher at 3 months than before discharge (24% vs. 0, P=0.022). Conclusions: BEV and SEV for transfemoral TAVR appear comparably safe and effective, with high device success and favorable 3-month clinical outcomes. However, the transaortic gradient and new pacemaker implantation in the SEV group increased during follow-up, warranting larger studies with longer-term follow-up.

Initial experiences of transapical beating-heart mitral valve repair with a novel artificial chordal implantation device.

BACKGROUND: Severe mitral regurgitation (MR) is associated with progressive heart failure and impairment of survival. Degenerative MR accounts for most MV repair surgeries. Conventional mitral valve repair surgery requires cardiopulmonary bypass and is associated with significant morbidity and risks. Transapical beating-heart mitral valve repair by artificial chordae implantation with transesophageal echocardiography (TEE) guidance has the potential to significantly reduce surgical morbidity. We report the first-in-human experience of degenerative MR repair using a novel artificial chordae implantation device (MitralstitchTM system). METHODS: Ten patients with severe MR underwent transapical artificial chordae implantation using MitralstitchTM system. The procedure was performed through a small left thoracotomy under general anesthesia and TEE guidance. Patients underwent transthoracic echocardiography and other assessments during the follow-up. RESULTS: All 10 patients with an average age of 63.7 ± 9.6 years successfully received transapical artificial chordae implantation. Their MR reduced from severe to none or trace in five patients, mild in five patients before discharge. Five patients received one artificial chordal implantation, four patients received two, and one patient received three and edge-to-edge repair by locking two of them. The safety and efficacy endpoint were achieved in all patients at 1-month follow-up. At 1-year follow-up, six patients had mild MR, three patients had moderate MR, one patient had recurrence of severe MR and underwent surgical repair. CONCLUSIONS: The results of this first-in-human study show safety and feasibility of transapical mitral valve repair using MitralStitch system. Patient selection and technical refinement are crucial to improve the outcomes.

Estimating the population at high risk for tuberculosis through household exposure in high-incidence countries: a model-based analysis.

BACKGROUND: Household contacts of people with pulmonary tuberculosis (TB) have greater risk of developing TB. Recent guidelines conditionally recommended TB preventive treatment (TPT) for household contacts of any age living in TB high-incidence countries, expanding earlier guidance to provide TPT to household contacts under five. The all-age population of household contacts has not been estimated. METHODS: Our model-based estimation included 20 countries with >80% of incident TB globally in 2019. We developed country-specific distributions of household composition by age and sex using bootstrap resampling from health surveys and census data. We incorporated age-, sex-, year-, and location-specific estimates of pulmonary TB incidence from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019 to estimate the population in each country sharing a household with someone with incident pulmonary TB, and quantified uncertainty using a Monte Carlo approach. FINDINGS: We estimate that 38 million [95% uncertainty interval (UI) 33- 43 million] individuals lived in a household with someone with incident pulmonary TB in 2019 in these 20 countries. Children under five made up 12% of the population with household exposure, while adults were 65%. Zimbabwe, Mozambique, Zambia, and Pakistan had the highest proportion of the population with household exposure, while India had the highest number of contacts (11·4 million, 95% UI 9·7-13·4 million). INTERPRETATION: Expanding TPT evaluation to household contacts of all ages in high-incidence countries could include a population more than 7-times larger than the under-5 contacts previously prioritized. This would substantially increase the impact of household contact investigation on reducing TB morbidity and mortality. FUNDING: JMR is supported by the National Institute of Allergy and Infectious Diseases (K01 AI138620). This research was funded in part by a 2020 developmental grant from the University of Washington / Fred Hutch Center for AIDS Research, an NIH funded program under award number AI027757 which is supported by the following NIH Institutes and Centers: NIAID, NCI, NIMH, NIDA, NICHD, NHLBI, NIA, NIGMS, NIDDK. This work was funded in part by the National Science Foundation (DMS-1839116).

A novel double-balloon catheter for percutaneous balloon pulmonary valvuloplasty under echocardiographic guidance only.

BACKGROUND: Percutaneous balloon pulmonary valvuloplasty (PBPV) is the procedure of choice for uncomplicated severe or symptomatic pulmonary stenosis. Echocardiography (echo)-guided PBPV can completely avoid the use of radiation and contrast agents compared to fluoroscopy-guided PBPV. Although we have confirmed that echo-guided PBPV is feasible in humans, the poor visibility of the traditional catheter under echo greatly limits the promotion of this new technology. METHODS: We produced a novel double-balloon catheter to make the catheter easy to be detected by echo through adding a guiding balloon at the distal end of the catheter. Echo-guided PBPV was performed on thirty healthy swine using either a novel catheter or a traditional catheter to evaluate the feasibility and safety of the novel double-balloon catheter. The feasibility was evaluated by the success rate of balloon inflation at the pulmonary valve annulus and the operating time. The safety was evaluated by the frequency of balloon slippage and the incidence of complications. RESULTS: There were no significant between-group differences in terms of weight and the ratio of balloon diameter to pulmonary annulus diameter. The success rate was 93.3% and 60% in the novel and traditional groups, respectively. The novel group had significantly (p<0.05) lower mean procedure time (6.33±6.86min vs 24.8±9.79min) and lower frequency of balloon slippage (0.07±0.26 vs 0.53±0.52), arrhythmia (0.07±0.26 vs 0.47±0.52), and tricuspid regurgitation (6.7% vs 40%) than the traditional group. No myocardial hematoma or pericardial tamponade occurred in the novel catheter group. CONCLUSION: Although further studies and improvements are required, the study results indicate that the novel double-balloon catheter for echo-guided PBPV is feasible and safe.

Percutaneous aortic balloon valvuloplasty under echocardiographic guidance solely.

BACKGROUND: Percutaneous balloon aortic valvuloplasty (PBAV) is an alternative to surgical valvulotomy for the treatment of congenital aortic stenosis (AS). This article aims to summarize our preliminary experience on feasibility and safety of PBAV under only echocardiographic guidance in patients with congenital AS. METHODS: Clinical data from 20 consecutive patients with aortic valve stenosis who underwent PBAV under only echocardiographic guidance at Fuwai Hospital from January 2016 to January 2019 were analyzed retrospectively. Median age of patients was 18.38±15.88 years and 65% of the patients were male. Aortic annulus diameter was 18.40±3.25 mm and balloon diameter was 17.38±3.89 mm, with B/A ratio of 0.93±0.06. RESULTS: All the patients successfully underwent PBAV. The peak transaortic gradient (TG) significantly decreased from 81.59±24.91 (range, 58-112) mmHg preoperatively to 36.32±12.83 (range, 16-51) mmHg (P=0.000) immediately post operation, without significant difference in aortic regurgitation (AR). At mean 24.31±17.35 months follow-up, peak TG was 37.06±13.52 (range, 21-58) mmHg which was not significantly different from the immediate postoperative value (P=0.65). CONCLUSIONS: In this retrospective, single center study, systematic use of Doppler echocardiography as only guidance modality for PBAV was feasible and associated with a high success rate and a very low complication rate.

Percutaneous transcatheter closure of atrial septal defect guided by transthoracic echocardiography in outpatients / 中国胸心血管外科临床杂志

@#Objective    To assess the feasibility and safety of percutaneous transcatheter closure of atrial septal defect (ASD) guided by transthoracic echocardiography (TTE) in outpatients. Methods    From December 2016 to June 2018, 50 simple ASD patients underwent TTE-guided transcatheter closure in the outpatient operating room of our hospital (a TTE group) including 22 males and 28 females at the age of 16-48 (27.40±6.95) years. Fifty patients with simple ASD treated with the guidance of conventional fluoroscopy during the same period were treated as a control group, including 22 males and 28 females at the age of 15-48 (28.58±6.96) years. Both groups were re-examined by TTE during follow-up at 1 month, 3 months, 6 months and 1 year. Results    The mean age, body weight, the size of ASD and occluder and success rate had no statistical difference between the two groups (P>0.05). Compared with the control group, the TTE group had significantly lower mean operation time (P<0.01) and less cost (P<0.01) since patients need not to be hospitalized. No related complications were found in the TTE group during follow-up. Conclusion    Percutaneous transcatheter closure of ASD guided by TTE appears safe and effective for outpatients, and can significantly reduce the cost.

A Novel Wire Is Effective for Echo-Guiding Percutaneous Atrial Septal Defect Closure: A Preclinical Study.

Objective: To assess the effectiveness of a novel ultrasound wire for echo-guiding percutaneous atrial septal defect (ASD) closure in a sheep model. Methods: After right lateral thoracotomy, ASDs were created in 20 sheep by transseptal needle puncture followed by balloon dilatation. Animals were evenly randomized into 2 groups to undergo ASD closure using echography as the only imaging tool with either COOK wire (control group) or new ultrasound wire (study group). The total procedural time, passing time (time needed for the guide wire to enter the left atrium), frequency of delivery sheath dropping into the right atrium, frequency of arrhythmias, and 1-week rate of complications were compared between the two groups. Results: All animals survived defect creation procedures uneventfully. ASD devices were successfully implanted in all sheep. Compared with the control group, the study group had significantly (P < 0.05) lower mean procedure time (15.36 ± 4.86 versus 25.82 ± 7.85 min), lower mean passing time (2.69 ± 0.82 versus 5.58 ± 3.34 min), lower frequency of the guide wire dropping into the right atrium (0% versus 40%), and lower frequency of atrial (4.41 ± 2.61 versus 9.60 ± 3.68) or ventricular premature contractions (0.75 ± 0.36 versus 1.34 ± 0.68), respectively, without serious complications up to one week. Conclusion: The novel ultrasound specialized guide wire was effective in echo-guiding percutaneous ASD closure.

Feasibility and effectiveness of percutaneous balloon mitral valvuloplasty under echocardiographic guidance only.

OBJECTIVE: Percutaneous balloon mitral valvuloplasty (PBMV) is the treatment of choice in patients with isolated mitral stenosis. This study aimed to assess the feasibility of PBMV under echocardiography guidance only of isolated mitral stenosis (MS). METHODS: From October 2016 to Dec 2017, 20 consecutive patients with severe MS underwent PBMV with echocardiography as the only imaging modality at a single center. Outpatient follow-up including chest radiography, electrocardiography, and transthoracic echocardiography was conducted at 1, 3,6, and 12 months after the procedure. RESULTS: All 20 patients successfully underwent PBMV under echocardiography guidance without radiation and contrast agent. Among them, 2 patients were pregnant, 5 had chronic renal failure, and 1 had history of allergy to contrast. Mitral transvalvular pressure gradient measured at catheterization dropped from 13.35 ± 2.85 mm Hg to 5.10 ± 1.17 mm Hg (P < .01). Mitral valve area increased from 0.82 ± 0.10 cm2 pre-PBMV to 1.88 ± 0.24 cm2 post-PBMV (P < .01). Mean balloon diameter was 26.63 ± 0.93 mm. Mild mitral regurgitation developed in 6 patients. Mean follow-up duration was 6.27 ± 3.12 months. At last follow-up, mitral valve area remained high (1.71 ± 0.14 cm2 ) and mean transmitral pressure gradient low (6.07 ± 1.03 mm Hg). No pericardial effusion or peripheral vascular complications occurred. CONCLUSION: In this small experience, PBMV could be successfully performed under only echocardiography guidance and appeared safe and effective while avoiding radiation and contrast agent use.

Hybrid Balloon Valvuloplasty for the Treatment of Severe Congenital Aortic Valve Stenosis in Infants.

BACKGROUND: Surgical or percutaneous interventional treatment of severe congenital aortic valve stenosis (CAS) in early infancy remains challenging. This single-center, retrospective study analyzed midterm outcomes of a hybrid balloon valvuloplasty procedure through the ascending aorta by way of median sternotomy, including cases with improved technique. METHODS: Included were 45 consecutive infants (aged <90 days) with CAS and selected for biventricular repair who underwent hybrid balloon valvuloplasty in a hybrid or ordinary operating room from October 2010 to March 2016. Patients were assessed at 1, 3, 6, and 12 months and yearly thereafter. RESULTS: Hybrid balloon valvuloplasty was successful in all patients, with the last 8 treated in an ordinary operating room under only echocardiography guidance with a new sheath. Thirty-two patients were successfully rescued from low heart rate or left ventricular systolic dysfunction, or both, by cardiac massage under direct visualization; none required cardiopulmonary bypass. The degree of new aortic insufficiency was mild in 7 patients and changed from mild to moderate in 1 patient. Aortic valve pressure gradient decreased from 70.6 ± 17.5 mm Hg preoperatively to 15.2 ± 4.2 mm Hg immediately postoperatively (p < 0.001). Fluoroscopy time was 4.8 ± 2.3 minutes. At a median of 32.1 months (range, 1 to 68 months) follow-up, all patients were alive and healthy. Aortic valve pressure gradient remained low (19.1 ± 5.2 mm Hg). Left ventricular ejection fraction increased from 0.515 ± 0.134 (range, 0.21 to 0.70) preoperatively to 0.633 ± 0.035 (range, 0.58 to 0.75; p < 0.001). No aortic insufficiency developed, and no patient required reintervention. CONCLUSIONS: For infants with severe CAS, hybrid balloon valvuloplasty through the ascending aorta by way of a median sternotomy appears efficacious and safe up to midterm follow-up.

Midterm outcome of percutaneous balloon aortic valvuloplasty guided by single echocardiography for congenital aortic stenosis / 中国胸心血管外科临床杂志

@#Objective To analyze the midterm outcome of patients with congenital aortic stenosis undergoing percutaneous balloon aortic valvuloplasty (PBAV) by single echocardiographic guidance. Methods The clinical data of 12 patients with congenital aortic stenosis who underwent PBAV by single echocardiographic guidance at Fuwai Hospital from January 2016 to November 2017 were retrospectively analyzed. There were 7 males and 5 females with an average age of 18.27±15.30 years. The preoperative peak pressure gradient was 61.8–110.0 (80.30±24.50) mm Hg, and 50% of patients had aortic regurgitation. Results All patients successfully underwent PBAV. Aortic annulus diameter was 18.65±3.17 mm and balloon diameter was 17.62±3.77 mm, with balloon diameter to annulus diameter ratio of 0.92±0.07. The peak transaortic gradient was 16-51 (36.72±12.33) mm Hg immediately after procedure, which was significantly different from the preoperation (P=0.000). During the follow-up period, the peak transaortic gradient was 21-58 (37.06±13.52) mm Hg, and there was no significant difference between the follow-up and immediate postoperation (P=0.310). Immediately after procedure and during follow-up, 58% of patients had aortic regurgitation, which was not statistically different from the preoperation (P=0.682). Conclusion Systematic use of Doppler echocardiographic guidance for PBAV is feasible, and that it is associated with a high success rate and a very low complication rate.

Clinical investigation of percutaneous closure of patent ductus arteriosus under echocardiography guidance / 中国胸心血管外科临床杂志

@#Objective    To assess the efficacy and safety of percutaneous closure of patent ductus arteriosus (PDA) solely under echocardiography guidance. Methods    We retrospectively analyzed the clinical data of 200 patients who received the percutaneous closure of PDA under echocardiography guidance in Fuwai Hospital from August 2013 to April 2016. According the different approach, they were divided into 2 groups: a femoral artery approach group (n=143) and a femoral vein approach group (n=57). In the femoral artery approach group, there were 42 males and 101 females aged 3.20±5.63 years. In the femoral vein group, there were 10 males and 47 females aged 7.30±11.36 years. All Patients were treated by percutaneous PDA closure solely under echocardiography guidance. The follow-up was performed at one month after the operation by echocardiography, chest radiograph and electrocardiogram. Results    All 200 patients were successfully treated with percutaneous closure of PDA. The patients’ gender, in-hospital stay, rates of occluder  detachment were similar between the two groups (P>0.05). Compared with the femoral vein approach group, the femoral artery approach group had a younger age (3.20±5.63 years vs. 7.30±11.36 years, P<0.001), less body weight (14.25±11.54 kg vs. 24.25±19.14 kg, P<0.001) and shorter diameter of PDA (3.06±0.79 mm vs. 5.93±0.68 mm, P<0.001) and PDA occluders (5.43±1.00 mm vs. 12.14±0.54 mm, P<0.001), but had higher hospitalization expenses (32 108.2±3 100.2 yuan vs. 25 120.7±3 534.1 yuan, P<0.001). In the femoral vein approach group, one patient was closed under radiation guidance because guide wires could not pass through PDA. One patient in the femoral artery approach group suffered from occluder detachment at one day after operation and was cured by transthoracic minimally invasive PDA occlusion. There were no complications of occluder detachment, residual shunt, pericardial effusion or left pulmonary stenosis during the follow-up. Conclusion    Echocardiography-guided percutaneous PDA closure is safe and effective, while the proper interventional approach should be chosen by the anatomical features of PDA.

Clinical results of ultrasound-guided thoracoscopic atrial septal defect closure / 中国胸心血管外科临床杂志

@#Objective     To analyze the safety and effectiveness of ultrasound-guided thoracoscopic atrial septal defect (ASD) closure. Methods     We prospectively collected the clinical data of 12 patients with ASD treated by ultrasound-guided thoracoscopic ASD closure in Fuwai Hospital from January to September 2017. The characteristics of the patients' ASD and operation, operation safety and effectiveness, postoperative complications and follow-up results were analyzed. Results     Among the 12 patients, 10 were successfully treated with ultrasound-guided thoracoscopic ASD closure. Two patients switched to ASD repair under thoracoscopy-assisted cardiopulmonary bypass. The size of the ASD was 17-40 (27.22±8.97) mm and the size of the occluder was 36 (30-42) mm. The average postoperative length of hospital stay was 6 days. There were no complications such as arrhythmia, bleeding and pericardial effusion after operation. The average follow-up was 6 (3-10) months after the operation. During the follow-up, no Ⅲ-degree conduction block, occluder dislocation, residual shunt or cardiac pericardial effusion was found. Conclusion     Ultrasound-guided thoracoscopic ASD closure is a minimally invasive, safe and effective treatment. This technique provides a new minimally invasive surgical option for patients with large defect diameter and poor edge condition.