Diagnose and treatment for Type D congenital esophageal atresia with tracheoesophageal fistula.

Importance: Type D esophageal atresia (EA) with tracheoesophageal fistula (TEF) is characterized by EA with both proximal and distal TEFs. It is a rare congenital anomaly with a very low incidence. Objective: To investigate diagnostic and treatment strategies for this rare condition. Methods: We retrospectively reviewed the clinicopathological features of patients with EA/TEF treated at our institution between January 2007 and September 2021. Results: Among 386 patients with EA/TEF, 14 (3.6%) had type D EA/TEF. Only two patients were diagnosed with proximal TEF preoperatively. Seven patients were diagnosed intraoperatively. Five patients were missed for diagnosis during the initial surgery but was later confirmed by bronchoscopy. During the neonatal period, seven patients underwent a one-stage repair of proximal and distal TEF via thoracoscopy or thoracotomy. Due to missed diagnosis and other reasons, the other 7 patients underwent two-stage surgery for repair of the proximal TEF, including cervical incision and thoracoscopy. Ten of the 14 patients experienced postoperative complications including anastomotic leakage, pneumothorax, esophageal stricture, and recurrence. Patients who underwent one-stage repair of distal and proximal TEF during the neonatal period showed a higher incidence of anastomotic leak (4/7). In contrast, only one of seven patients with two-stage repair of the proximal TEF developed an anastomotic leak. Interpretation: Type D EA/TEF is a rare condition, and proximal TEFs are easily missed. Bronchoscopy may aim to diagnose and determine the correct surgical approach. A cervical approach may be more suitable for repairing the proximal TEF.

Laparoscopic indocyanine green fluorescence imaging technique in rare type II cystic biliary atresia.

In recent years, it has been reported that indocyanine green can be used for intraoperative navigation in Kasai surgery. However, there are no reports of its application in surgery for rare type II cystic biliary atresia. We report a girl presented with jaundice and light-colored stools. Laboratory tests showed impaired liver function with elevated serum bilirubin and bile acid levels. The abdominal ultrasound and MRCP suggested a common hepatic duct cyst. A diagnosis of choledochal cyst was suspected and biliary atresia could not be excluded. Conservative treatment was unsatisfactory. Laparoscopic exploration with indocyanine green fluorescence was performed on the 38th day of her life, and intraoperative diagnosis of type II CBA was made because the common hepatic duct cyst and its downstream anatomical structures did not show fluorescence. The postoperative bilirubin and bile acid levels decreased significantly and she was discharged two weeks after surgery. This result suggests that indocyanine green can be safely used in laparoscopic surgery for type II CBA, which not only helps in the differential diagnosis of CBA and choledochal cyst, but also confirms bile flow in real time.

Clinical characteristics and prognosis of 69 cases of neonatal appendicitis.

Importance: Neonatal appendicitis (NA) is a rare and potentially fatal neonatal disease. However, misdiagnosis is common owing to atypical clinical manifestations and non-specific laboratory tests. Objective: The aim of this study was to summarize the clinical characteristics, treatments, and prognoses of infants with NA. Methods: This retrospective analysis included 69 patients diagnosed with NA admitted to Beijing Children's Hospital between 1980 and 2019. The patients were divided into surgical and non-surgical groups based on whether surgery was performed. Their clinical characteristics were analyzed using the chi-square test, t-test, or the Mann-Whitney U test. Results: The study included 47 males and 22 females with NA. The primary symptoms were abdominal distension (n = 36, 52.2%), fever (n = 19, 27.5%), refusal to feed or decreased feeding (n = 16, 23.2%), and vomiting (n = 15, 21.7%). Sixty-five patients underwent abdominal ultrasound examinations; 43 had definite appendiceal abnormalities, 10 had right lower abdominal adhesive masses, and 14 had neonatal enterocolitis manifestations. Twenty-nine and 40 patients were in the surgical and non-surgical groups, respectively. No statistically significant differences were observed between the groups regarding sex, age at onset, birth weight, admission weight, or hospitalization time. However, parenteral nutrition was prolonged in the surgical group (P = 0.001). Additionally, two patients (2.9%) died. Interpretation: NA is a rare neonatal disease with atypical clinical manifestations. Abdominal ultrasonography may aid in the diagnosis. Similarly, appropriate treatment can improve the prognosis.

Indocyanine green fluorescence imaging localization: A helpful addition to laparoscopic dissection and division of rectourethral fistulae.

BACKGROUND: Rectourethral fistulae (RUF) are the most prevalent type of anorectal malformations in boys, with various surgical treatment methods investigated in recent years. Currently, research is focused on preventing urethral damage or urethral diverticulum formation caused by imprecise dissection during the laparoscopically assisted anorectal pull-through (LAARP) technique. This study aimed to determine the efficacy of indocyanine green (ICG) fluorescence imaging to improve the localization and separation of the RUF during laparoscopic surgery. METHODS: ICG was intrarectally injected through a pre-inserted gastric tube at the distal enterostomy port to locate the fistula. This retrospective analysis included children with RUF who were treated surgically with ICG fluorescence imaging localization-assisted LAARP between January and June 2022. We investigated the patient demographics, perioperative conditions, and subsequent follow-up results. RESULTS: Four patients underwent ICG-assisted LAARP. Their median age was 80 days (range, 63-120) and the median duration of each procedure was 145 min (range, 120-165). Postoperatively, the duration of catheter retention and hospital stay was eight days. The children's prognosis was based on the follow-up outcomes of gastrointestinal, urinary tract function, and imaging examination. None of the included patients was diagnosed with urinary diverticulum, urinary tract injury, anal stricture, or rectal prolapse. CONCLUSIONS: Injection of ICG at the end of the rectum during LAARP surgery is a feasible adjunct for locating the RUF, providing a greater degree of accuracy for laparoscopic separation and resection of fistulae, thereby decreasing the risk of urological complications.

Preliminary exploration of the efficacy of laparoscopic fluorescence cholangiography (LFC) in the diagnosis of biliary atresia compared with intraoperative cholangiography (IOC).

BACKGROUND: Intraoperative cholangiography (IOC) has been the gold standard for diagnosing biliary atresia (BA). Our study attempted to diagnose BA using laparoscopic fluorescein cholangiography (LFC). METHODS: We retrospectively included 18 patients with preoperative suspected BA as the case group and 4 without extrahepatic biliary obstruction requiring laparoscopic surgery as the control group. All patients received indocyanine green (ICG) intravenously at 0.05 mg/Kg. The first 6 patients in the case group underwent IOC and LFC simultaneously, and the control group completed LFC. The imaging characteristics of LFC were recorded and summarized by the conventional and fluorescence mode of the endoscopic fluorescence imaging system (DPM-ENDOCAM-03). On this basis, 12 patients in the case group were diagnosed as BA according to LFC without IOC, and all 18 patients completed open Kasai surgery to confirm the diagnosis. RESULTS: Laparoscopic fluorescence mode in BA detected liver fluorescence but no visualization of the extrahepatic bile ducts. However, the extrahepatic bile ducts in the control group were visible. Based on the imaging characteristics summarized from the LFC of the first 6 cases with BA in the case group, the remaining 12 cases who only underwent LFC were also successfully diagnosed with BA. Furthermore, the formation of hepatic hilar fibrous mass was found in all the patients during the open Kasai procedure, which confirmed the BA diagnosis. CONCLUSIONS: LFC appears as a specific pattern in BA and may be used for intraoperative diagnosis of BA. It has the advantages of simplicity, short time-consuming, and no radiation damage.

Structural insights into Nirmatrelvir (PF-07321332)-3C-like SARS-CoV-2 protease complexation: a ligand Gaussian accelerated molecular dynamics study.

Coronavirus 3C-like protease (3CLpro) is found in SARS-CoV-2 virus, which causes COVID-19. 3CLpro controls virus replication and is a major target for target-based antiviral discovery. As reported by Pfizer, Nirmatrelvir (PF-07321332) is a competitive protein inhibitor and a clinical candidate for orally delivered medication. However, the binding mechanisms between Nirmatrelvir and 3CLpro complex structures remain unknown. This study incorporated ligand Gaussian accelerated molecular dynamics, the one-dimensional and two-dimensional potential of mean force, normal molecular dynamics, and Kramers' rate theory to determine the binding and dissociation rate constants (koff and kon) associated with the binding of the 3CLpro protein to the Nirmatrelvir inhibitor. The proposed approach addresses the challenges in designing small-molecule antiviral drugs.

Indocyanine green fluorescence imaging localization-assisted thoracoscopy revision surgery after repair of esophageal atresia.

Revision surgery for the complications after repair of esophageal atresia is often complex because of previous surgeries and chest infections and thus requires surgical expertise. This study describes surgical experiences with the use of indocyanine green (ICG) fluorescence imaging localization-assisted thoracoscopy during revision surgery, including recurrent tracheoesophageal fistula (rTEF) (8 cases, one of which was esophageal-pulmonary fistula) and delayed esophageal closure (1 case). We performed fistula repair and esophageal reconstruction according to the indications of ICG. The application of this method avoids the excessive trauma caused by freeing the trachea and esophagus. Contrast imaging taken one week and one month after surgery indicated no spillover of the contrast agent from the esophagus, except in 1 case. Indocyanine green fluorescence imaging localization-assisted thoracoscopy is worth promoting for revision surgery after esophageal atresia repair.

Comprehensive Analysis of Gut Microbiota and Fecal Bile Acid Profiles in Children With Biliary Atresia.

Background: Biliary atresia (BA) is the most common cholestatic liver disease in neonates. Herein, we aimed at characterizing the gut microbiota and fecal bile acid profiles of BA patients, defining the correlations between them, and evaluating the relationship between the clinical pathogenesis and changes in the gut microbiota and bile acid profiles. Methods: A total of 84 fecal samples from BA patients (n = 46) and matched healthy controls (HCs, n = 38) were subjected to sequencing by 16S rRNA gene amplification, and fecal bile acid were analyzed by targeted metabolomics. Findings: Compared with the controls, a structural separation of the intestinal flora of BA patients was uncovered, which was accompanied by changes in the composition of fecal bile acids. In the BA group, Actinobacillus, Monoglobus, and Agathobacter were enriched in patients without cholangitis (p < 0.05). Selenomonadaceae and Megamonas were more abundant in patients without recurrent cholangitis episodes (p < 0.05), while Lachnospiraceae and Ruminococcaceae were enriched in patients with multiple recurrences of cholangitis (p < 0.05). Postoperative jaundice clearance was associated with Campylobacter and Rikenellaceae (p < 0.05), and tauroursodeoxycholic acid was associated with jaundice clearance (p < 0.001). Conclusion: BA patients are characterized by different compositions of gut microbiota and bile acids, and their interaction is involved in the process of liver damage in BA, which may be closely related to the occurrence of postoperative cholangitis and jaundice clearance.

Growth assessments for children with recurrent tracheoesophageal fistulas.

PURPOSE: To assess the growth status of children with recurrent tracheoesophageal fistula (rTEF), and determine the possible risk factors of growth retardation (GR). METHODS: The medical records of 83 patients with rTEF who underwent surgical repair were retrospectively analyzed. The patients were retrospectively divided into two groups according to whether they had GR. The clinical variables were compared between the GR and non-GR groups. Univariate and multivariable logistic regression analysis were performed to identify the risk factors for GR. RESULTS: Eighty-three children diagnosed with rTEF were included in this study. After a median follow-up of 31.4 (19.8, 48.7) months, GR occurred in 28 patients (33.7%). Among them, six patients with only weight for age Z score (WAZ) < -2SD, five patients with only height for age Z score (HAZ) < -2SD, and six patients with only BMI for age Z score (BAZ) < -2SD, while seven patients with both WAZ and HAZ < -2SD and four patients with both WAZ, HAZ and BAZ < -2SD. Multivariate logistic regression analysis showed that birth weight, anastomotic stricture and dysphagia after rTEF repair were independent risk factors with OR of 0.325 (0.119, 0.891), 4.396 (1.451, 13.324) and 5.341 (1.153, 24.752) for GR, respectively. CONCLUSIONS: GR is a common complication after rTEF repair. Birth weight, anastomotic stricture and dysphagia after rTEF repair are independent risk factors affecting growth.

Exploratory application of indocyanine green quantification in biliary atresia observational study.

BACKGROUND: Indocyanine green (ICG) is known to facilitate real-time imaging of the bile outflow during the Kasai procedure. This study explored more possibilities for applying ICG quantification in biliary atresia (BA). METHODS: We enrolled nine BA patients in this study. All patients received intravenous ICG injections before surgery and underwent Kasai operation. With a fluorescence imaging system (Nanjing Nuoyuan, REAL-IGS FLI-108) to observe the ICG and quantify the ICG fluorescence intensity (ICG-FI) changes of the hepatic portal fibrous tissue and the liver during the operation. As a short-term prognosis assessment, we monitored the postoperative ICG metabolism time in stool and used the jaundice-free (TBIL < 2 mg/dl) at 1-3 months after the operation. RESULTS: The average age of the patients at the time of surgery was 73 days. There were no adverse reactions after ICG injection. All patients were observed ICG-FI increased after the dissection of hepatic portal fibrous tissue, and the ICG-FI of the liver decreased during the operation. They all received standardized treatment after surgery. Four patients completely metabolized ICG within about two weeks (no fluorescence detected in stool), and the other five were longer than two weeks. Five patients achieved a jaundice-free outcome in the short-term postoperatively, and the other four did not. CONCLUSIONS: It is feasible to quantify ICG-FI in real-time to evaluate the anatomical degree of hepatic portal fibrous tissue in BA. The variations of ICG-FI in the liver and postoperative ICG metabolism time may be related to prognosis.

Esophageal elongation by bougienage and delayed primary thoracoscopic anastomosis for pure esophageal atresia without tracheoesophageal fistula.

PURPOSE: We aim to share our experience of esophageal elongation by bougienage and delayed primary thoracoscopic anastomosis for pure esophageal atresia (EA) without tracheoesophageal fistula (TEF). METHODS: Fifteen patients with pure EA treated with delayed primary thoracoscopic anastomosis combined with or without esophageal elongation by bougienage were retrospectively analyzed. RESULTS: Four patients were managed without bougienage, and their surgical repair was performed thoracoscopically after natural esophageal growth. Among the remaining 11 patients, the average tension-free distance before elongation was 5 (4.5-6) vertebral bodies, and the mean age at the start and end of the bougienage period was 123 (63-280) days and 173 (106-350) days, respectively, with an average duration of 50 (29-82) days. The average age at the definitive operation in this series was 184 (107-385) days, with a mean operative duration of 186 (95-300) min. Neither anastomotic leakage nor TEF occurred, and oral feeding was partially or completely established in 13 patients during hospitalization. Among all patients, one was lost to follow-up, and others were followed up with an average duration of 47.7 (9.8-97.1) months. All patients had different degrees of anastomosis stricture, and 8 patients had gastroesophageal reflux. Oral feeding was completely established in 12 patients; however, tube feeding was required in 2 patients. CONCLUSIONS: The management of pure EA is complicated and inconclusive. Esophageal elongation by bougienage and delayed primary thoracoscopic anastomosis for long-gap pure EA without TEF is safe and effective.

Indocyanine green localization for laparoscopic duodenal web excision.

BACKGROUND: A duodenal web refers to partial or complete obstruction of the duodenum due to a membranous web. When looking at the serosal side of the intestine during duodenal web excision, especially during laparoscopic surgery, determining the web origin might be challenging. This study aimed to determine the efficacy of intraduodenum indocyanine green injection and near-infrared light during laparoscopic surgery in enhancing the ability to identify duodenal web localization. METHODS: We used intraduodenum indocyanine green injection to unequivocally recognize the duodenal web and facilitate laparoscopic excision. The clinical analysis was based on a male neonatal case with duodenal web admitted to our hospital. After the patient was placed in the supine position, 5 mL of ICG was injected via a 6-Fr nasogastric tube. The fluorescence was visualized in the white light and near-infrared light dual-mode of the camera system, localizing the duodenal precisely and in real-time. RESULTS: Laparoscopically, the duodenal web was accurately identified and removed with intraduodenum indocyanine green visualization under near-infrared light. The procedure was completed successfully, and the patient showed good postoperative outcomes. CONCLUSIONS: Intraduodenum indocyanine green injection during laparoscopic surgery is a feasible adjuvant for duodenal web localization, showing improvements in terms of outcomes compared to previous methods of determining the duodenal web location.

The largest report on thoracoscopic surgery for recurrent tracheoesophageal fistula after esophageal atresia repair.

BACKGROUND: Although thoracoscopic surgery has become the routine surgical method for esophageal atresia/tracheoesophageal fistula (EA/TEF), thoracoscopic treatment for recurrent tracheoesophageal fistula (rTEF) is far from popularized. OBJECTIVES: We aimed to explore the safety and efficacy of thoracoscopic treatment for rTEF with a large-cohort study. METHODS: We retrospectively analyzed the clinical characteristics and outcomes of 103 consecutive patients who underwent thoracoscopic surgery for rTEF by one surgeon after EA/TEF repair at two different institutions in China from 2014 to 2021. RESULTS: One hundred and three pediatric patients (67 boys) were enrolled and the primary operations were performed via thoracoscopic (n = 75, 72.82%) or open surgery (n = 28, 27.18%). The median age at rTEF diagnosis was 5 (3, 10) months after the primary repair. Patients were diagnosed with recurrent fistula to the trachea (n = 97, 94.17%), bronchi (n = 4, 3.88%), and lung parenchyma (n = 2, 1.94%), and all of them underwent thoracoscopic surgery at a median age of 7 (5, 14) months with a median weight of 6200 (4870, 7650) g. After the repair of rTEF, the incidence of esophageal leakage, esophageal stricture, and TEF recurrence were 12.8%, 33.4%, and 10.8%, respectively. After the follow-up, 87 patients survived, 6 died, and 10 were lost to follow-up. CONCLUSIONS: The results of thoracoscopic surgery for rTEF were comparable with previously reported thoracotomy surgery. Owing to the clear field during the operation, rapid patient recovery and esthetic results, the thoracoscopic approach could be a better choice for experienced pediatric surgeons. LEVEL OF EVIDENCE: LEVEL IV.

Thoracoscopic repair for esophageal pulmonary fistula after esophageal atresia repair.

BACKGROUND: Esophageal pulmonary fistula is a special type of acquired tracheoesophageal fistula that occurs after esophageal atresia/tracheoesophageal fistula repair. Thoracotomy is the surgical repair method currently in use, but postoperative outcomes are unclear. Therefore, we aimed to explore the preliminary safety, effectiveness, and feasibility of thoracoscopic surgical repair of esophageal pulmonary fistula. METHODS: We retrospectively collected data from all patients with esophageal atresia/tracheoesophageal fistula at Beijing Children's Hospital from January 2017 to October 2021, and the clinical characteristics of patients with esophageal pulmonary fistula were analyzed. Clinical information was recorded, and follow-up was performed. RESULTS: Seven patients (five boys and two girls) were diagnosed as esophageal pulmonary fistula. All patients underwent multiple esophageal surgeries and had esophageal strictures before surgical repair. Clinical manifestations included cough, expectoration, and recurrent pneumonia. Esophagography indicated the location of the fistula with a 100% positive rate, while the positive rate of flexible bronchoscopy and chest computed tomography was 57% (4/7) and 43% (3/7), respectively. Surgical repair was achieved using thoracoscopy with an average operation time of 172 min. All patients developed esophageal strictures, four of which had refractory esophageal strictures and underwent esophageal dilations ranged from 5 to 56 times before this surgery, but anastomotic leakage or acquired esophageal pulmonary fistulas were absent post-surgery. After a median follow-up of 22 months, all patients survived, and the symptoms were well controlled. CONCLUSIONS: Esophageal pulmonary fistula is a rare complication of atresia/tracheoesophageal fistula repair. Thoracoscopic surgery is still possible even after previous multiple surgeries in the chest with significant complications and satisfactory results can be achieved in the short term. LEVEL OF EVIDENCE: Level III.

A universal in silico V(D)J recombination strategy for developing humanized monoclonal antibodies.

BACKGROUND: Humanization of mouse monoclonal antibodies (mAbs) is crucial for reducing their immunogenicity in humans. However, humanized mAbs often lose their binding affinities. Therefore, an in silico humanization method that can prevent the loss of the binding affinity of mAbs is needed. METHODS: We developed an in silico V(D)J recombination platform in which we used V(D)J human germline gene sequences to design five humanized candidates of anti-tumor necrosis factor (TNF)-α mAbs (C1-C5) by using different human germline templates. The candidates were subjected to molecular dynamics simulation. In addition, the structural similarities of their complementarity-determining regions (CDRs) to those of original mouse mAbs were estimated to derive the weighted interatomic root mean squared deviation (wRMSDi) value. Subsequently, the correlation of the derived wRMSDi value with the half maximal effective concentration (EC50) and the binding affinity (KD) of the humanized anti-TNF-α candidates was examined. To confirm whether our in silico estimation method can be used for other humanized mAbs, we tested our method using the anti-epidermal growth factor receptor (EGFR) a4.6.1, anti-glypican-3 (GPC3) YP9.1 and anti-α4ß1 integrin HP1/2L mAbs. RESULTS: The R2 value for the correlation between the wRMSDi and log(EC50) of the recombinant Remicade and those of the humanized anti-TNF-α candidates was 0.901, and the R2 value for the correlation between wRMSDi and log(KD) was 0.9921. The results indicated that our in silico V(D)J recombination platform could predict the binding affinity of humanized candidates and successfully identify the high-affinity humanized anti-TNF-α antibody (Ab) C1 with a binding affinity similar to that of the parental chimeric mAb (5.13 × 10-10). For the anti-EGFR a4.6.1, anti-GPC3 YP9.1, and anti-α4ß1 integrin HP1/2L mAbs, the wRMSDi and log(EC50) exhibited strong correlations (R2 = 0.9908, 0.9999, and 0.8907, respectively). CONCLUSIONS: Our in silico V(D)J recombination platform can facilitate the development of humanized mAbs with low immunogenicity and high binding affinities. This platform can directly transform numerous mAbs with therapeutic potential to humanized or even human therapeutic Abs for clinical use.

Identifying and validating molecular subtypes of biliary atresia using multiple high-throughput data integration analysis.

Background: Biliary atresia (BA) is the most common form of severe neonatal obstructive jaundice. The etiology and pathogenesis of BA are multifactorial, and different factors may interact to produce heterogeneous pathological features and clinical outcomes. Despite different pathological features, all patients received the same treatment strategy. This study performed integrative clustering analysis based on multiple high-throughput datasets to identify the molecular subtypes of BA and provide a new treatment strategy for personalized treatment of the different subtypes of BA. Methods: The RNA sequence dataset GSE122340 in the Gene Expression Omnibus (GEO) database was downloaded; 31 BA and 20 control normal liver tissues were collected at our center for transcriptome sequencing, and clinical and follow-up data of BA patients were available. Molecular subtypes were identified using integrated unsupervised cluster analysis involving gene expression, biliary fibrosis, and immune enrichment scores based on the transcriptome dataset, and the results were validated using independent datasets. Results: Based on the results of the integrated unsupervised clustering analysis, four molecular subtypes were identified: autoimmune, inflammatory, virus infection-related, and oxidative stress. The autoimmune subtype with a moderate prognosis was dominated by autoimmune responses and morphogenesis, such as the Fc-gamma receptor and Wnt signaling pathway. The biological process of the inflammatory subtype was mainly the inflammatory response, with the best prognosis, youngest age at surgery, and lowest liver stiffness. The virus infection-related subtype had the worst prognosis and was enriched for a variety of biological processes such as viral infection, immunity, anatomical morphogenesis, and epithelial mesenchymal transition. The oxidative stress subtype was characterized by the activation of oxidative stress and various metabolic pathways and had a poor prognosis. The above results were verified independently in the validation sets. Conclusions: This study identified four molecular subtypes of BA with distinct prognosis and biological processes. According to the pathological characteristics of the different subtypes, individualized perioperative and preoperative treatment may be a new strategy to improve the prognosis of BA.

Retrospective analysis of pneumothorax after repair of esophageal atresia/tracheoesophageal fistula.

BACKGROUND: To analyze the possible causes, treatment and outcomes of postoperative pneumothorax in patients with Gross type C esophageal atresia/tracheoesophageal fistula (EA/TEF). METHODS: Medical records of patients with Gross type C EA/TEF who were diagnosed and treated in Beijing Children's Hospital from January 2007 to January 2020 were retrospectively collected. They were divided into 2 groups according to whether postoperative pneumothorax occurred. Univariate and multivariate logistic regression analysis were performed to identify risk factors for pneumothorax. RESULTS: A total of 188 patients were included, including 85 (45 %) in the pneumothorax group and 103 (55 %) in the non-pneumothorax group. Multivariate logistic regression analysis showed that postoperative anastomotic leakage [P < 0.001, OR 3.516 (1.859, 6.648)] and mechanical ventilation [P = 0.012, OR 2.399 (1.210, 4.758)] were independent risk factors for pneumothorax after EA/TEF repair. Further analysis of main parameters of mechanical ventilation after surgery showed that none of them were clearly related to the occurrence of pneumothorax. Among the 85 patients with pneumothorax, 33 gave up after surgery and 52 received further treatment [conservative observation (n = 20), pleural puncture (n = 11), pleural closed drainage (n = 9), both pleural puncture and closed drainage (n = 12)]. All of the 52 patients were cured of pneumothorax at discharge. CONCLUSIONS: Anastomotic leakage and postoperative mechanical ventilation were risk factors for pneumothorax after repair of Gross type C EA/TEF, but the main parameters of mechanical ventilation had no clear correlation with pneumothorax. After symptomatic treatment, the prognosis of pneumothorax was good.

Clinical comparison between thoracoscopic and thoracotomy repair of Gross type C esophageal atresia.

BACKGROUND: To compare the clinical outcomes between thoracoscopic approach and thoracotomy surgery in patients with Gross type C Esophageal atresia (EA) and tracheoesophageal fistula (TEF). METHODS: Patients with Gross type C EA/TEF who underwent surgery from January 2007 to January 2020 at Beijing Children's Hospital were retrospectively analyzed. The patients were divided into two groups according to surgical approaches. The perioperative factors and postoperative complications were compared among the two groups. RESULTS: One hundred and ninety patients (132 boys and 58 girls) with a median birth weight of 2975 (2600, 3200) g were included. The primary operations were performed via thoracoscopic (n = 62) and thoracotomy (n = 128) approach. After comparison of clinical characteristics between the two groups, we found that there were statistically significant differences in associated anomalies, method of fistula closure, duration of mechanical ventilation after surgery, feeding option before discharge, management of pneumothorax, and prognosis (all P < 0.05). To a certain extent, thoracoscopic surgery reduced the incidence of anastomotic leakage and increased the incidence of anastomotic stricture in this study. However, there were no statistically significant differences between the two groups in terms of operative time, postoperative pneumothorax, anastomotic leakage, anastomotic stricture, and recurrent tracheoesophageal fistula (all P > 0.05). CONCLUSIONS: Thoracoscopy surgery for Gross type C EA/TEF is a safe and effective, minimally invasive technique with comparable operative time and incidence of postoperative complications.

Development of a structure-based computational simulation to optimize the blocking efficacy of pro-antibodies.

The on-target toxicity of monoclonal antibodies (Abs) is mainly due to the fact that Abs cannot distinguish target antigens (Ags) expressed in disease regions from those in normal tissues during systemic administration. In order to overcome this issue, we "copied" an autologous Ab hinge as an "Ab lock" and "pasted" it on the binding site of the Ab by connecting a protease substrate and linker in between to generate a pro-Ab, which can be specifically activated in the disease region to enhance Ab selectivity and reduce side effects. Previously, we reported that 70% of pro-Abs can achieve more than 100-fold blocking ability compared to the parental Abs. However, 30% of pro-Abs do not have such efficient blocking ability. This is because the same Ab lock linker cannot be applied to every Ab due to the differences in the complementarity-determining region (CDR) loops. Here we designed a method which uses structure-based computational simulation (MSCS) to optimize the blocking ability of the Ab lock for all Ab drugs. MSCS can precisely adjust the amino acid composition of the linker between the Ab lock and Ab drug with the assistance of molecular simulation. We selected αPD-1, αIL-1ß, αCTLA-4 and αTNFα Ab as models and attached the Ab lock with various linkers (L1 to L7) to form pro-Abs by MSCS, respectively. The resulting cover rates of the Ab lock with various linkers compared to the Ab drug were in the range 28.33-42.33%. The recombinant pro-Abs were generated by MSCS prediction in order to verify the application of molecular simulation for pro-Ab development. The binding kinetics effective concentrations (EC-50) for αPD-1 (200-250-fold), αIL-1ß (152-186-fold), αCTLA-4 (68-150-fold) and αTNFα Ab (20-123-fold) were presented as the blocking ability of pro-Ab compared to the Ab drug. Further, there was a positive correlation between cover rate and blocking ability of all pro-Ab candidates. The results suggested that MSCS was able to predict the Ab lock linker most suitable for application to αPD-1, αIL-1ß, αCTLA-4 and αTNFα Ab to form pro-Abs efficiently. The success of MSCS in optimizing the pro-Ab can aid the development of next-generation pro-Ab drugs to significantly improve Ab-based therapies and thus patients' quality of life.

Correction: Development of a structure-based computational simulation to optimize the blocking efficacy of pro-antibodies.

[This corrects the article DOI: 10.1039/D1SC01748A.].