Risk Factors of Chylothorax After Congenital Heart Surgery in Infants: A Single-Centre Retrospective Study.

Background: Studies of chylothorax after congenital heart disease in infants are rare. Chylothorax has a higher incidence in infancy, but its risk factors are not well understood. Objective: The purpose of this study is to investigate the risk factors of chylothorax after congenital heart surgery in infants. Methods: This retrospective study included 176 infants who underwent congenital heart disease surgery at the Guangdong Cardiovascular Institute, China, between 2016 and 2020. According to the occurrence of chylothorax, the patients were divided into a control group (n = 88) and a case group (n = 88). Univariate and multivariate logistic regression were performed to analyse the incidence and influencing factors of chylothorax after congenital heart surgery in infants. Results: Between 2016 and 2020, the annual incidence rate fluctuated between 1.55% and 3.17%, and the total incidence of chylothorax was 2.02%. Multivariate logistic regression analysis showed that postoperative albumin (p = 0.041; odds ratio [OR] = 0.095), preoperative mechanical ventilation (p = 0.001; OR = 1.053) and preterm birth (p = 0.002; OR = 5.783) were risk factors for postoperative chylothorax in infants with congenital heart disease. Conclusion: The total incidence of chylothorax was 2.02% and the annual incidence rate fluctuated between 1.55% and 3.17% between 2016 and 2020. Premature infants, longer preoperative mechanical ventilation and lower albumin after congenital heart surgery may be risk factors for chylothorax. In addition, infants with chylothorax are inclined to be infected, need more respiratory support, use a chest drainage tube for longer and remain longer in hospital.

Phelan-McDermid Syndrome in Pediatric Patients With Novel Mutations: Genetic and Phenotypic Analyses.

Background: PhelanrMcDermid syndrome (PMS) is an uncommon autosomal dominant inherited developmental disorder. The main characteristics are hypotonia, intellectual disability, autism spectrum disorder, autism-like behaviors and tiny facial deformities. Most cases are caused by the deletion of the 22q13 genomic region, including the deletion of SHANK3. Methods: Genetic and phenotype evaluations of ten Chinese pediatric patients were performed. The clinical phenotypes and genetic testing results were collected statistically. We analyzed the deletion of the 22q13 genomic region and small mutations in SHANK3 (GRCh37/hg19) and performed parental genotype verification to determine whether it was related to the parents or was a novel mutation. Results: The age of the patients diagnosed with PMS ranged from 0 to 12 years old. Nine of the pediatric patients experienced Intellectual Disability, language motion development delay and hypotonia as prominent clinical features. One subject had autism, two subjects had abnormal electroencephalogram discharge and one subject was aborted after fetal diagnosis. Three patients had a SHANK3 mutation or deletion. All but the aborted fetuses had intellectual disability. Among the ten patients, a deletion in the 22q13 region occurred in seven patients, with the smallest being 60.6 kb and the largest being >5.5 Mb. Three patients had heterozygous mutations in the SHANK3 gene. Conclusion: All ten patients had novel mutations, and three of these were missense or frameshift mutations. For the first time reported, it is predicted that the amino acid termination code may appear before protein synthesis. The novel mutations we discovered provide a reference for clinical research and the diagnosis of PMS.

Preparation and evaluation of a silk fibroin-polycaprolactone biodegradable biomimetic tracheal scaffold.

In tracheal tissue engineering, the construction of tracheal scaffolds with adequate biodegradable mechanical capacity and biological functions that mimic the structure of a natural trachea is challenging. To explore the feasibility of preparing biomimetic degradable scaffolds with C-type cartilage rings and an inner tracheal wall of polycaprolactone and silk fibroin. A mold was made according to the diameter of a rabbit trachea, and a silk fibroin tube and polycaprolactone ring attached to the tube were obtained by solution casting. The ring was fixed to the tube at a specific spacing using electrostatic spinning technology to construct a biomimetic tracheal scaffold; its porous structure was observed by scanning electron microscopy, its degradation properties were determined by in vitro enzymatic hydrolysis and its mechanical properties were obtained by pressure testing. The composite scaffold was transplanted subcutaneously into a rabbit model, and the scaffold was taken at 1, 2, and 4 weeks after surgery for sectioning to observe pre-vascularization. The Medical Ethics Committee of Guangdong Provincial People's Hospital approved the study. The general view of the biomimetic scaffold: the polycaprolactone ring was fixed firmly on the outer wall of the silk fibroin tube; the two corresponded in size, and they fitted closely. The surface of the polycaprolactone ring was smooth and dense, while the surface of the silk fibroin tube could be seen as a uniform porous structure. Scanning electron microscopy showed that the surface and profile of the fibroin tube had a uniform pore size and distribution. The pores were connected to form a network. In vitro, enzymatic hydrolysis experiments confirmed that the fibroin was degraded easily, with most being degraded at the end of week 1. The degradation slowed at 2, 3, and 4 weeks, while the degradation of polycaprolactone was extremely slow. A compression test showed that the compressive resistance of the silk fibroin-polycaprolactone biomimetic scaffolds was much better than that of the rabbit trachea at close thickness. In the tissue staining experiments, as the material degraded, fibrous tissues and blood vessels grew to replace the material, allowing the scaffold to obtain a blood supply and better mechanical properties. A quantitative analysis of CD31 showed that the results for the vascularization of the scaffold were better at 4 weeks than at 2 weeks following subcutaneous grafting (P < .05). The results confirmed that it is feasible to prepare porous, degradable silk fibroin-polycaprolactone biomimetic scaffolds with good mechanical properties and epithelial biological functions by mold casting.

The Application of a Bone Marrow Mesenchymal Stem Cell Membrane in the Vascularization of a Decellularized Tracheal Scaffold.

Airway stenosis is a common problem in the neonatal intensive care unit (NICU) and pediatric intensive care unit (PICU). A tissue-engineered trachea is a new therapeutic method and a research hotspot. Successful vascularization is the key to the application of a tissue-engineered trachea. However, successful vascularization studies lack a complete description. In this study, it was assumed that rabbit bone marrow mesenchymal stem cells were obtained and induced by ascorbic acid to detect the tissue structure, ultrastructure, and gene expression of the extracellular matrix. A vascular endothelial cell culture medium was added in vitro to induce the vascularization of the stem cell sheet (SCS), and the immunohistochemistry and gene expression of vascular endothelial cell markers were detected. At the same time, vascular growth-related factors were added and detected during SCS construction. After the SCS and decellularized tracheal (DT) were constructed, a tetrandrine allograft was performed to observe its vascularization potential. We established the architecture and identified rabbit bone marrow mesenchymal stem cell membranes by 14 days of ascorbic acid, studied the role of a vascularized membrane in inducing bone marrow mesenchymal stem cells by in vitro ascorbic acid, and assessed the role of combining the stem cell membranes and noncellular tracheal scaffolds in vivo. Fourteen experiments confirmed that cell membranes promote angiogenesis at gene level. The results of 21-day in vitro experiments showed that the composite tissue-engineered trachea had strong angiogenesis. In vivo experiments show that a composite tissue-engineered trachea has strong potential for angiogenesis. It promotes the understanding of diseases of airway stenosis and tissue-engineered tracheal regeneration in newborns and small infants.