Postoperative pulmonary vascular growth in patients with congenital diaphragmatic hernia.

BACKGROUND: Postoperative pulmonary growth in congenital diaphragmatic hernias (CDH) remains unclear. We investigated postoperative pulmonary vascular growth using serial lung perfusion scintigraphy in patients with CDH. METHODS: Neonates with left CDH who underwent surgery and postoperative lung perfusion scintigraphy at our institution between 2001 and 2020 were included. Patient demographics, clinical courses, and lung scintigraphy data were retrospectively analyzed by reviewing medical records. RESULTS: Twenty-one patients with CDH were included. Of these, 10 underwent serial lung scintigraphy. The ipsilateral perfusion rate and median age on the 1st and serial lung scintigraphy were 32% (34 days) and 33% (3.6 years), respectively. Gestational age at prenatal diagnosis (p = 0.02), alveolar-arterial oxygen difference (A-aDO2) at birth (p = 0.007), and preoperative nitric oxide (NO) use (p = 0.014) significantly correlated with the 1st lung scintigraphy. No other variables, including operative approach, were significantly correlated with the 1st or serial scintigraphy findings. All patients improved lung perfusion with serial studies [Difference: + 7.0 (4.3-13.25) %, p = 0.001, paired t-test]. This improvement was not significantly correlated with preoperative A-aDO2 (p = 0.96), NO use (p = 0.28), or liver up (p = 0.90). The difference was significantly larger in patients who underwent thoracoscopic repair than in those who underwent open abdominal repair [+ 10.6 (5.0-17.1) % vs. + 4.25 (1.2-7.9) %, p = 0.042]. CONCLUSION: Our study indicated a postoperative improvement in ipsilateral lung vascular growth, which is possibly enhanced by a minimally invasive approach, in patients with CDH.

Impact of the novel coronavirus infection on pediatric surgery: an analysis of data from the National Clinical Database.

PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic limited the delivery of medical resources. Although surgeries are triaged according to disease severity and urgency, a delay in diagnosis and surgery can be detrimental. We conducted this study to analyze data on the impact of the COVID-19 pandemic on pediatric surgery for different diseases or disorders. METHODS: We compiled and compared data on pediatric surgical cases from 2018 to 2020, using the National Clinical Database. The number of diseases, severity, complication rates, mortality rates by disease/disorder, and the COVID-19 pandemic areas were analyzed. RESULTS: The total number of cases of pediatric surgery in 2018, 2019, and 2020 was 50,026, 49,794, and 45,621, respectively, reflecting an 8.8% decrease in 2020 from 2018 and an 8.4% decrease in 2020 from 2019. A decrease was observed when the number of patients with COVID-19 was high and was greater in areas with a low infection rate. There was a marked decrease in the number of inguinal hernia cases. The number of emergency room visits and emergency surgeries decreased, but their relative proportions increased. CONCLUSIONS: The COVID-19 pandemic decreased the number of pediatric surgeries, reflecting the limitations of scheduled surgeries and infection control measures.

Treatment courses and outcomes of oesophageal atresia in patients with trisomy 18: a case series of 271 patients from a nationwide database in Japan.

OBJECTIVE: To describe characteristics, treatments and clinical outcomes of patients with trisomy 18 and oesophageal atresia, using a nationwide database in Japan. DESIGN: Descriptive study using a retrospective cohort. SETTING: A nationwide inpatient database including 90% of hospitals with neonatal intensive care units in Japan. PATIENTS: Patients hospitalised within a day after birth for both oesophageal atresia and trisomy 18 between July 2010 and March 2020. INTERVENTIONS: Radical surgery for oesophageal atresia. MAIN OUTCOME MEASURES: Characteristics, treatment course and outcomes. RESULTS: Among 271 patients with both oesophageal atresia and trisomy 18, 70 patients underwent radical surgery for oesophageal atresia. Patients who underwent radical surgery were less likely to have severe cardiac anomalies (17% vs 32%; p=0.020), but more likely to undergo cardiac surgery (21% vs 9.5%; p=0.012) than those who did not. The overall in-hospital mortality was lower (54% vs 79%; p<0.001) and the median age at death was higher (210 days vs 39 days; p<0.001) in patients who underwent radical surgery than the others. Postoperative mortality within 30 days after radical surgery was 5.7%. Patients who underwent radical surgery were likely to be discharged to home (50% vs 18%; p<0.001), whereas the age at home discharge (median 314 days vs 216 days; p=0.19) and the requirement for each home treatment did not differ significantly by radical surgery. CONCLUSION: This study provides information that will aid the clinical decision-making process for patients with oesophageal atresia and trisomy 18. Radical surgery may be a safe and feasible treatment option.

Influence of surgical volume on the mortality and morbidity of gastrointestinal perforation in children.

PURPOSE: To clarify the influence of surgical volume on the mortality and morbidity of gastrointestinal perforation in children in Japan. METHODS: We collected data on pediatric patients with gastrointestinal perforation between 2017 and 2019, from the National Clinical Database. The surgical volumes of various institutions were classified into three groups: low (average number of surgeries for gastrointestinal perforation/year < 1), medium (≥ 1, < 6), and high (≥ 6). The observed-to-expected (o/e) ratios of 30-day mortality and morbidity were calculated for each group using an existing risk model. RESULTS: Among 1641 patients (median age, 0.0 years), the 30-day mortality and morbidity rates were 5.2% and 37.7%, respectively. The 30-day mortality rates in the low-, medium-, and high-volume institutions were 4.9%, 5.3%, and 5.1% (p = 0.94), and the 30-day morbidity rates in the three groups were 26.8%, 39.7%, and 37.7% (p < 0.01), respectively. The o/e ratios of 30-day mortality were 1.05 (95% confidence interval [CI] 0.83-1.26), 1.08 (95% CI 1.01-1.15), and 1.02 (95% CI 0.91-1.13), and those of 30-day morbidity were 1.72 (95% CI 0.93-2.51), 1.03 (95% CI 0.79-1.28), and 0.95 (95% CI 0.56-1.33), respectively. CONCLUSION: Surgical volume does not have significant impact on the outcomes of pediatric gastrointestinal perforation in Japan.

Non-classical Monocytes Enhance the Efficacy of Immune Checkpoint Inhibitors on Colon Cancer in a Syngeneic Mouse Model.

BACKGROUND/AIM: The response rate to immune checkpoint inhibitors (ICIs) is approximately 10%-30% and only in a few cancer types. In the present study, we determined whether non-classical monocytes (NCMs) could enhance ICI efficacy in colon cancer using a syngeneic mouse model. MATERIALS AND METHODS: The MC38 C57BL/6 mouse colon cancer model was used. Cells collected from the bone marrow of C57BL/6 mice were cultured, and NCMs were fractionated by cell sorting and administered via the tail veins to the mice implanted with MC38 cells. The anti-mouse PD-L1 antibody was administered three times, and tumor volume and overall survival were observed. RESULTS: More tumors were eradicated and more complete response occurred, after cotreatment with ICIs and NCMs than after treatment with ICIs alone. Moreover, no efficacy was observed when NCMs were administered alone. CONCLUSION: NCMs enhance ICI efficacy. The underlying mechanisms and clinical applications will be studied in the future.

Outcomes Following Laparoscopic Versus Open Surgery for Pediatric Intussusception: Analysis Using a National Inpatient Database in Japan.

BACKGROUND: Laparoscopic surgery for pediatric intussusception has recently become more common as an alternative to open surgery. However, the differences in outcomes between laparoscopic and open surgery remain unclear. Thus, this study aimed to compare short-term surgical outcomes and recurrence rates between patients treated with laparoscopic and open surgery for pediatric intussusception. METHODS: Patients aged <18 years who underwent laparoscopic (n = 192) and open (n = 416) surgery for intussusception between April 2016 and March 2021 were retrospectively identified using a Japanese nationwide inpatient database. Propensity-score overlap weighting analyses were conducted to compare the outcomes between the laparoscopic and open surgery groups. The outcomes included in-hospital morbidity, reoperation, readmission for intussusception, bowel resection, the diagnosis of Meckel's diverticulum, duration of anesthesia, postoperative length of hospital stay, and total hospitalization costs. RESULTS: The laparoscopic surgery group was older, heavier, and had fewer congenital malformations and emergency admissions than the open surgery group did. Overlap weighting analyses showed no significant differences in in-hospital morbidity (odds ratio [95% confidence interval], 0.88 [0.35-2.23]), reoperation (1.88 [0.24-14.9]), readmission for intussusception within 30 days (0.80 [0.12-5.30]) and 1 year (0.90 [0.28-2.93]), bowel resection (0.69 [0.46-1.02]), the diagnosis of Meckel's diverticulum (0.97 [0.50-1.90]), duration of anesthesia (difference, 11 [-1-24] minutes), postoperative length of stay (difference, -1.9 [-4.2-0.4] days), or total hospitalization costs (difference, 612 [ -746-1970] US dollars) between the groups. CONCLUSIONS: In this large nationwide cohort, no significant differences in outcomes were observed between laparoscopic and open surgery. Laparoscopic surgery is an acceptable treatment option for pediatric intussusception. LEVELS OF EVIDENCE: Level III.

Risk factors for postoperative anastomotic leakage after repair of esophageal atresia: a retrospective nationwide database study.

PURPOSE: Postoperative anastomotic leakage is the most frequent short-term complication of esophageal atresia repair in neonates. We conducted this study using a nationwide surgical database in Japan to identify the risk factors for anastomotic leakage in neonates undergoing esophageal atresia repair. METHODS: Neonates diagnosed with esophageal atresia between 2015 and 2019 were identified in the National Clinical Database. Postoperative anastomotic leakage was compared among patients to identify the potential risk factors, using univariate analysis. Multivariable logistic regression analysis included sex, gestational age, thoracoscopic repair, staged repair, and procedure time as independent variables. RESULTS: We identified 667 patients, with an overall leakage incidence of 7.8% (n = 52). Anastomotic leakage was more likely in patients who underwent staged repairs than in those who did not (21.2% vs. 5.2%, respectively) and in patients with a procedure time > 3.5 h than in those with a procedure time < 3.5 h (12.6% vs. 3.0%, respectively; p < 0.001). Multivariable logistic regression analysis identified staged repair (odds ratio [OR] 4.89, 95% confidence interval [CI] 2.22-10.16, p < 0.001) and a longer procedure time (OR 4.65, 95% CI 2.38-9.95, p < 0.001) as risk factors associated with postoperative leakage. CONCLUSION: Staged procedures and long operative times are associated with postoperative anastomotic leakage, suggesting that leakage is more likely after complex esophageal atresia repair and that such patients require refined treatment strategies.

A case of Hirschsprung's disease with segmental dilatation of the colon.

BACKGROUND: Segmental dilatation of the colon (SDC) is a rare disease that is characterized by an abrupt segment of dilated colon between regions of normal-sized colon. We herein report a case of SDC associated with Hirschsprung's disease (HD). CASE PRESENTATION: The patient developed abdominal distension soon after birth, and enema examination showed localized intestinal dilatation from the descending colon to the sigmoid colon with significant caliber changes on both the oral and anal sides of the dilated colon. The findings of the rectal mucosal biopsy were consistent with HD. We considered this case to be a combination of HD and SDC and performed laparoscopic-assisted Soave pull-through with resection of the dilated colon when the patient was 7 months old. Resected specimens showed steep caliber changes on the oral and anal sides of the dilated colon. In the pathological examination, no ganglion cells were found in the submucosa on the anal side of the dilated colon. Based on the above findings, we finally made the diagnosis of HD with SDC. CONCLUSION: In HD with a characteristic dilated colon, the possibility of SDC should be considered.

Oral Antibiotics and Organ Space Infection after Appendectomy and Intravenous Antibiotics Therapy for Complicated Appendicitis in Children.

BACKGROUND: There is little consensus regarding management after appendectomy for complicated appendicitis in children. Recent literature suggests that patients may be safely discharged without oral antibiotics after adequate intravenous antibiotics therapy. We conducted a nationwide retrospective cohort study comparing the proportion of postoperative organ space infection between patients discharged with and without oral antibiotics after appendectomy followed by intravenous antibiotics therapy for complicated appendicitis. METHODS: Using the Diagnosis Procedure Combination database, we identified patients between 3 and 18 years of age who had undergone appendectomy for complicated appendicitis between July 2010 and March 2018. Propensity score-matched analyses were performed to compare outcomes between the groups with and without oral antibiotics. The primary outcome was readmission due to organ space infection within 60 days of discharge and the secondary outcome was 60-day readmission due to any reason. Additionally, we conducted a stabilized inversed probability of treatment weighting analysis as a sensitivity analysis. RESULTS: We identified 13,100 eligible patients who had received oral antibiotics (n = 3,501) and who had not received oral antibiotics (n = 9,599). Propensity score matching created 2,769 pairs. Readmissions due to organ space infection were 3.4% and 5.2% in the nonusers and users of oral antibiotics, respectively (p = 0.007). The oral antibiotics users also had a significantly higher proportion of readmission due to any reason than the nonusers (5.5 vs. 7.4%, p = 0.004). The sensitivity analyses demonstrated consistent results. CONCLUSION: Among children who had undergone appendectomy for complicated appendicitis, oral antibiotics following discharge after adequate intravenous antibiotics therapy may increase organ space infection.

Identification of odontogenic ameloblast associated as a novel target gene of the Wnt/ß-catenin signaling pathway.

The Wnt/ß-catenin signaling pathway plays a key role in development and carcinogenesis. Although some target genes of this signaling have been identified in various tissues and neoplasms, the comprehensive understanding of the target genes and their roles in the development of human cancer, including hepatoma and colorectal cancer remain to be fully elucidated. In this study, we searched for genes regulated by the Wnt signaling in liver cancer using HuH-7 hepatoma cells. A comparison of the expression profiles between cells expressing an active form of mutant ß-catenin and cells expressing enhanced green fluorescent protein (EGFP) identified seven genes upregulated by the mutant ß-catenin gene (CTNNB1). Among the seven genes, we focused in this study on ODAM, odontogenic, ameloblast associated, as a novel target gene. Interestingly, its expression was frequently upregulated in hepatocellular carcinoma, colorectal adenocarcinoma, and hepatoblastoma. We additionally identified a distant enhancer region that was associated with the ß-catenin/TCF7L2 complex. Further analyses revealed that ODAM plays an important role in the regulation of the cell cycle, DNA synthesis, and cell proliferation. These data may be useful for clarification of the main molecular mechanism(s) underlying these cancers.

A case of right hypodysplastic kidney and ectopic ureter associated with bicornuate uterus in a prepubertal girl.

Congenital anomalies of the kidney and urinary tract (CAKUT) are frequently associated with Mullerian anomalies. This can be explained by the fact that Mullerian duct elongation depends on the preformed Wolffian duct during embryogenesis. While CAKUT such as unilateral renal agenesis and multicystic dysplastic kidney are commonly identified prenatally by routine ultrasound, the diagnosis of Mullerian anomalies is often delayed, increasing the risk of complications such as endometriosis or pelvic inflammatory disease. Herein, we report a case of a premenarchal girl who had initially been diagnosed with right multicystic dysplastic kidney. She presented with continuous urinary incontinence at 4 years old and further evaluation by contrast-enhanced computed tomography, cystoscopy, colposcopy, ureterography, and hysterosalpingography led to the final diagnosis of right hypodysplastic kidney and ectopic ureter associated with bicornuate uterus. A strong family history of uterine malformations prompted the examination of the uterus. Genetic testing was suggested but the family declined. She is planned to be referred to a gynecologist at puberty for further assessment. The recognition and screening rate of concurrent Mullerian anomalies in CAKUT patients varies between institutions. Screening for Mullerian anomalies in prediagnosed CAKUT girls may enable to provide timely counseling and to prevent gynecological complications.

Perioperative outcomes of thyroid cancer surgery in children and adults: a nationwide inpatient database study in Japan.

BACKGROUND: Little is known about perioperative outcomes after pediatric thyroidectomy. This study was performed to compare perioperative outcomes between children and adults undergoing thyroid cancer surgery using a nationwide inpatient database in Japan. METHODS: Using the Japanese Diagnosis Procedure Combination database, we identified patients aged 0 to 40 years with thyroid cancer who underwent thyroidectomy from July 2010 to March 2020. To compare the occurrence of in-hospital morbidities including local complications (e.g., recurrent laryngeal nerve paralysis, postoperative bleeding), duration of anesthesia, postoperative length of stay, and total hospitalization costs between children (0-18 years) and adults (19-40 years), we used multivariable logistic regression analysis for the occurrence of in-hospital morbidities and linear regression for other outcomes. RESULTS: For 16,016 eligible patients (666 children vs. 15,350 adults), no significant differences between the two groups were found in any in-hospital morbidity (5.4% vs. 5.9%; adjusted odds ratio [OR], 0.80; 95% confidence interval [CI], 0.57-1.14; P = 0.23), local complications (5.0% vs. 5.5%; OR, 0.80; 95% CI, 0.55-1.15; P = 0.22), recurrent laryngeal nerve paralysis (2.1% vs. 2.4%; OR, 0.78; 95% CI, 0.45-1.35; P = 0.37), or postoperative bleeding (1.7% vs. 1.4%; OR, 0.99; 95% CI, 0.53-1.87; P = 0.98). Children showed a longer duration of anesthesia (difference, 20 minutes; 95% CI, 13-27; P < 0.001) and higher total costs (difference, 445 US dollars; 95% CI, 239-651; P < 0.001) than adults. CONCLUSION: This large nationwide cohort study showed no significant difference in perioperative complications between children and adults undergoing thyroid cancer surgery.

Perioperative outcomes of laparoscopically assisted anorectoplasty versus conventional procedures for anorectal malformation: a retrospective nationwide database study.

PURPOSE: This study aimed to compare the perioperative outcomes of laparoscopically assisted anorectoplasty (LAARP) and conventional procedures (CPs) for anorectal malformation (ARM) using a national inpatient database in Japan. METHODS: Using the Diagnosis Procedure Combination database, we identified patients who underwent anorectoplasty for high- or intermediate-type ARMs from 2010 to 2019. Primary outcomes were postoperative rectal prolapse, anal stenosis, and general complications. Secondary outcomes were the duration of anesthesia and length of hospital stay. We performed 1:2 propensity score-matched analyses to compare the outcomes between the LAARP and CP groups. RESULTS: We identified 1005 eligible patients, comprising 286 and 719 patients who underwent LAARP and CP, respectively. The propensity score-matched groups included 281 patients with LAARP and 562 with CP. The LAARP group showed a higher proportion of rectal prolapse (21.4% vs. 8.5%; odds ratio, 2.91; 95% confidence interval [CI], 1.89-4.48; p < 0.001) and longer duration of anesthesia (462 min vs. 365 min; difference, 90 min; 95% CI 43-137; p < 0.001) than the CP group. No significant differences were found in other outcomes. CONCLUSION: LAARP had worse outcomes than CP in terms of rectal prolapse. Thus, we propose that LAARP may require technical refinement to improve patient outcomes.

Ectopic gallbladder with congenital biliary dilatation: a pediatric case report.

BACKGROUND: An ectopic gallbladder is a rare anomaly and can result in the misinterpretation of imaging findings and clinical confusion. Knowledge of such anomalies facilitates accurate diagnoses and prompt management. We report a pediatric case of an ectopic gallbladder concomitant with congenital biliary dilatation (CBD). CASE PRESENTATION: A 9-year-old girl was referred to our hospital for elevated liver enzyme levels. Following physical examination and a review of medical imaging findings, she was diagnosed with Todani type IV-A CBD. We could not visualize the gallbladder by abdominal ultrasonography, CT, and MRI scans; therefore, we suspected gallbladder agenesis. A laparoscopic excision of the extrahepatic bile duct was performed to treat the CBD. Neither a gallbladder nor a cystic duct were revealed on the liver undersurface. Therefore, gallbladder agenesis was considered as a diagnosis based on preoperative imaging and intraoperative findings. However, during dissection of the hepatic hilum, a cyst-like structure was found on the ventral side of the common hepatic duct, slightly to the right, and a small additional duct that originated from the cystic structure was found. Upon incision, a small amount of bile was drained from the small duct. Thus, the cystic structure was diagnosed as an ectopic gallbladder with hypoplasia. Following the removal of the ectopic gallbladder, the extrahepatic bile duct was excised. Subsequently, laparoscopic Roux-en-Y hepaticojejunostomy was performed without any complications. Postoperative histopathological evaluations of the resected specimen revealed Rokitansky-Aschoff sinuses in the resected cystic lesion. The pathological investigations confirmed the diagnosis of an ectopic gallbladder. Following an uneventful postoperative course, the patient was discharged on day nine. CONCLUSIONS: To our knowledge, this is the first pediatric case report describing an ectopic gallbladder concomitant with CBD. If the gallbladder cannot be detected in a preoperative imaging examination, it is important to consider the possibility of an ectopic gallbladder.

Laparoscopic approach for abdominal neuroblastoma in Japan: results from nationwide multicenter survey.

BACKGROUND: Some neuroblastoma (NB) cases are suitable for minimally invasive surgery (MIS), but indication and technical issue are unclear. We assessed the current status of MIS for abdominal NB after mass screening period in Japan. METHODS: Preliminary questionnaires requesting the numbers of NB cases that underwent MIS from 2004 to 2016 were sent to 159 Japanese institutes of pediatric surgery. The secondary questionnaires were then sent to the institutions that reported MIS cases of NB in order to collect detailed data. RESULTS: One hundred and thirty-four (84.2%) institutions responded to the preliminary questionnaires, and 83 (52.2%) reported managing operative cases. The total number of operative cases was 1496. MIS was performed for 175 (11.6%) cases, of which the completed forms of 140 patients were returned, including 100 abdominal NB cases. The male/female ratio was 51/49. Forty-seven cases underwent a laparoscopic biopsy, and 2 (4.3%) cases were converted to laparotomy due to bleeding. Sixty-five cases underwent MIS for radical resection, and 7 (10.8%) were converted to laparotomy. The reasons for open conversion were bleeding and severe adhesion. Regarding open conversion, there were no significant relationships between conversion and neo-adjuvant chemotherapy, biopsies, stage, size, or MYCN amplification. We found no relationship between resectability and vascular encasement in this study. There was relationship between the resected tumor size and the patients' height, which was expressed using the following formula: [Formula: see text] (x, patients height, y, tumor size; p = 0.004219, SE: 1.55566). Postoperative complications after radical resection were recognized in 7 (10.8%) cases. CONCLUSIONS: MIS was performed in limited cases of abdominal NB. A laparoscopic biopsy with careful attention to bleeding is feasible. The resected tumor size was shown to correlate with the patients' height. Tumor size within 6 cm of maximum diameter can be resected safely.

Optimal treatment of pneumothorax in adolescents with Marfan syndrome.

PURPOSE: Pneumothorax often develops in patients with Marfan syndrome (MFS). Here, we examined the effects of conservative and surgical pneumothorax treatments in children with MFS. METHODS: In this study, 23 patients, less than 20 years old, diagnosed with both MFS and pneumothorax between 1999 and 2019 were included. All data were collected retrospectively from patients' medical records. RESULTS: In total, 18 of 23 patients (78%) had relapsed pneumothorax either on the ipsilateral or contralateral side. Among these 18 patients, 6 (26%) patients had multiple relapses. Conservative and surgical treatments of pneumothorax were attempted in 33 and 29 lungs, respectively. The conservative treatment was attempted as a definitive therapy in 21 lungs. Twelve conservative treatments (57%) failed, which required surgical intervention. In 9 lungs (43%) with successful conservative treatment, 6 (67%) had ipsilateral relapses. In contrast to the above findings, only 4 (13%) ipsilateral relapses were observed in 29 surgical treatments. CONCLUSIONS: Our study revealed a low response and high relapse rate when MFS adolescents who diagnosed pneumothorax were subjected to the conservative treatment modality. Thus, we recommend surgical intervention as the first line of therapy to treat pneumothorax in adolescents diagnosed with MFS. LEVEL OF EVIDENCE: Ⅲ (Treatment Study).

A new method of primary engineering of esophagus using orthotopic in-body tissue architecture.

PURPOSE: Tissue engineering of esophagus is required for management of long-gap esophageal atresia (LGEA). Collagenous connective tissue membranes fabricated by in-body tissue architecture (iBTA), called biosheets, can repair esophageal defects and generate tissues similar to native esophagus. However, iBTA requires second-stage surgery because of heterotopic preparation of biosheets. Our aim was to develop orthotopic iBTA for primary engineering of the esophagus by interposing a tubular mold to the esophageal defect. METHOD: The cervical esophagus of six rats was transected. An acrylic tube (internal diameter 2.6 mm, length 7.0 mm) was inserted and fixed between the ends of the upper and lower esophagus, and a 3 mm-long esophageal defect was created. Four weeks later, the rats were sacrificed for histological analysis. RESULTS: Postoperatively the rats could intake liquid food. After four weeks, the esophageal defects were filled with regenerated tissues. Histologically the new esophageal walls stained positive for collagen type I. The inner surfaces were covered with stratified squamous epithelium that expressed pan-cytokeratin. In only one of six rats, regeneration of muscular-like tissue was suggested by positive immunohistochemical staining for desmin. CONCLUSION: Orthotopic iBTA can regenerate a substitute esophagus with esophageal epithelium and collagenous wall. This technique may be a novel treatment for esophageal atresia with gaps of various lengths including LGEA.