Epithelial and ganglionic distribution at the distal rectal end in anorectal malformations: could it play a role in anastomotic adaptation?

PURPOSE: In anorectal malformations (ARMs), the epithelium of the distal rectal end is not well described. We histomorphologically evaluated epithelial and ganglionic distribution in the distal rectal end of ARMs resected during anorectoplasty to assess similarities and differences with normal anal canal structure. METHODS: In this single-center retrospective study, specimens from 60 ARM patients (27 males, 33 females) treated between 2008 and 2019 were evaluated. RESULTS: Epithelium type and alignment sequence as well as ganglionic distribution were similar in the distal rectal end and in a normal anal canal. Stratified columnar epithelium (anal transitional zone, ATZ) was seen in 49/60 (81.7%) cases and in all ARM types, including the no-fistula type. Anal crypts were identified in the stratified columnar epithelium (ATZ) of 46/49 (93.9%) patients. Regarding distal rectal end-resecting anorectoplasty, in 90% of patients, resection was performed distal to the Herrmann line. Ganglion cell distribution was exclusively proximal to the Herrmann line. CONCLUSION: Epithelial and ganglionic distribution was similar in the distal rectal end of ARMs and in a normal anal canal. The ATZ is the epithelial boundary between the rectum and skin in a normal anal canal. ATZ preservation could reproduce anal canal structure in ARM reconstruction.

Characteristics and treatment of congenital esophageal stenosis: A retrospective collaborative study from three Japanese children's hospitals.

BACKGROUND/PURPOSE: There is no consensus on treatment strategy of congenital esophageal stenosis (CES). This study aimed to assess appropriateness of the treatment we have provided to patients with CES over the past four decades. METHODS: We carried out a retrospective chart review of 83 CES patients treated at three children's hospitals between 1973 and 2015. Each patient underwent an initial treatment with either surgery or a series of dilation that was followed by surgery if dilation failed to improve esophageal transit. Demographic data, course of treatment, outcomes, and complications were analyzed. RESULTS: During this initial treatment, 19 and 64 patients underwent surgery and dilation, respectively. Out of the 64 patients who underwent dilations as an initial treatment, 26 patients eventually required surgery. Out of all patients who required surgery (19 initial treatments + 26 failed dilations), 29 had tracheobronchial remnants and 16 had fibromuscular hypertrophy. Six patients experienced esophageal perforation during dilation and ten experienced anastomotic leakage after surgery. No patients had swallowing difficulties at the latest follow up, 141(9-324) months. CONCLUSIONS: Dilation is recommended as an initial therapy, especially if histological diagnosis of CES is uncertain. Persistent swallowing difficulties after 2 series of dilation may be an indication for surgery. LEVELS OF EVIDENCE: level IV.

Histological features of complete tracheal rings in congenital tracheal stenosis.

PURPOSE: Congenital tracheal stenosis is a disease in which complete tracheal cartilage rings (CTCR) cause airway narrowing. Although tracheal cartilage malformation has been suggested as a cause of CTCR, no histological studies have been performed. Here, we report a comparison of the tissues from CTCR and normal tracheal cartilage. METHODS: Thirty-one infants who underwent slide tracheoplasty at our institution from May 2016 to August 2019 were included. Tissues from ten autopsy cases without tracheal lesions were used as controls. The survey items were tracheal cartilage cell density, cartilage thickness, and chondrocyte findings. RESULTS: The median cartilage cell density from cases was 23/125 × 125 µm2 and from controls was 23.5/125 × 125 µm2 (p = 0.90). The median cartilage thickness from cases was 689 µm and from controls was 840 µm (p = 0.11). Comparing the ventral and dorsal sides of the CTCR tissues, the cell density was significantly different (median ventral 23/125 × 125 µm2; median dorsal 19.5/125 × 125 µm2; p = 0.034). There were no significant findings in the chondrocytes of the CTCR tissues. CONCLUSION: CTCR tissues did not differ in cartilage density and thickness from normal tracheal cartilage.

AFP-L3 as a Prognostic Predictor of Recurrence in Hepatoblastoma: A Pilot Study.

The α-fetoprotein (AFP) level is a sensitive biomarker of active hepatoblastoma (HB). This study aimed to clarify whether the Lens culinaris agglutinin A-reactive fraction of AFP (AFP-L3) after complete resection is a prognostic predictor of HB recurrence. Fourteen HB patients who underwent complete resection of HB were divided into the recurrence group (RG, n=4) and the non-recurrence group (NRG, n=10). The AFP level and AFP-L3 before and after radical surgery were compared between the 2 groups. There was no significant difference in AFP levels in the early postoperative period between the 2 groups (P=0.54), and AFP was not an early prognostic factor for HB recurrence. At 2 months after surgery, the AFP-L3 fell below the detection limit only in the NRG (7/10 cases) (NRG=70.0% vs. RG=0%, P=0.03). In addition, there were some cases of recurrence in those whose AFP level decreased to the normal range, but none in those whose AFP-L3 fell below the detection limit. In conclusion, the AFP-L3 decreased earlier than did the AFP level; thus, the AFP-L3 after complete resection may be a predictor for HB recurrence.

Correction to: Two infant cases of intraperitoneal arterial hemorrhage due to a duplication cyst: a case report.

An amendment to this paper has been published and can be accessed via the original article.

Point mutagenesis in mouse reveals contrasting pathogenetic effects between MEN2B- and Hirschsprung disease-associated missense mutations of the RET gene.

Missense mutations of the RET gene have been identified in both multiple endocrine neoplasia (MEN) type 2A/B and Hirschsprung disease (HSCR: congenital absence of the enteric nervous system, ENS). Current consensus holds that MEN2A/B and HSCR are caused by activating and inactivating RET mutations, respectively. However, the biological significance of RET missense mutations in vivo has not been fully elucidated. In the present study, we introduced one MEN2B-associated (M918T) and two HSCR-associated (N394K and Y791F) RET missense mutations into the corresponding regions of the mouse Ret gene by genome editing (RetM919T , RetN396K and RetY792F ) and performed histological examinations of Ret-expressing tissues to understand the pathogenetic impact of each mutant in vivo. RetM919T/+ mice displayed MEN2B-related phenotypes, including C-cell hyperplasia and abnormal enlargement of the primary sympathetic ganglia. Similar sympathetic phenotype was observed in RetM919T/- mice, demonstrating a strong pathogenetic effect of the Ret M918T by a single-allele expression. In contrast, no abnormality was found in the ENS of mice harboring the Ret N394K or Y791F mutation. Most surprisingly, single-allele expression of RET N394K or Y791F was sufficient for normal ENS development, indicating that these RET mutants exert largely physiological function in vivo. This study reveals contrasting pathogenetic effects between MEN2B- and HSCR-associated RET missense mutations, and suggests that some of HSCR-associated RET missense mutations are by themselves neither inactivating nor pathogenetic and require involvement of other gene mutations for disease expressivity.

Switch to Extracorporeal Membrane Oxygenation During Cardiac and Tracheal Repair.

Simultaneous repair of congenital tracheal and cardiovascular lesions remains challenging in small patients. We describe two infants weighing less than 3 kg who underwent successful tracheoplasty with concomitant correction of complex heart anomalies. In both operations, cardiopulmonary bypass was switched to extracorporeal membrane oxygenation after cardiac repair to optimize hemostatic function with transfusion and maintain activated clotting time at 200 to 240 seconds. Slide tracheoplasty was performed in a bloodless field, which prevented intraoperative hemorrhage from running down the divided lower trachea into the lung and causing airway obstruction. Both patients were weaned from extracorporeal support during surgery and extubated within 9 days.

Two infant cases of intraperitoneal arterial hemorrhage due to a duplication cyst: a case report.

BACKGROUND: Intraperitoneal arterial hemorrhage without trauma is extremely rare. We report two infant cases of intraperitoneal arterial hemorrhage due to intestinal duplication. CASE PRESENTATION: In case 1, a 2-month-old girl experienced sudden intraperitoneal hemorrhage from the middle colic artery with no apparent trauma. Hemostasis was achieved with suturing of the hemorrhage point, but the cause of hemorrhage was still unknown. Computed tomography after the first operation revealed a duodenal duplication cyst and a pseudopancreatic cyst. Percutaneous drainage of the pseudopancreatic cyst was performed, and the contents had high pancreatic amylase. As the size of the duodenal duplication cyst also decreased with this drainage, we suspected that the duodenal duplication cyst was connected to the pseudopancreatic cyst and the arterial hemorrhage. We hypothesized that the pancreatic juice inside the duplication cyst leaked into the intraperitoneal cavity and caused rupture of the arterial wall. Therefore, marsupialization of the duodenal duplication was performed to evacuate the pancreatic juice contained in the cyst toward the native duodenum. The postoperative course was uneventful. In case 2, a 6-month-old boy experienced sudden intraperitoneal hemorrhage without trauma. The hemorrhage site was identified as the ileocecal artery, and hemostasis was achieved with sutures. Tissue near the hemorrhage point was biopsied, because the cause of arterial wall rupture was still unknown. The biopsied tissue was found to be intestinal mucosa. The patient had recurrent abdominal pain after the first operation, and computed tomography showed a duplication cyst located near the hemorrhage point. Therefore, we resected the intestinal duplication. Pathology results showed that the intestinal duplication contained intestinal mucosa, ectopic gastric mucosa, and pancreatic tissue. The postoperative course was uneventful. CONCLUSION: Intraperitoneal arterial hemorrhage without trauma is an extremely rare condition, and identifying its cause is difficult. To our knowledge, this is the first report of intraperitoneal arterial hemorrhage due to intestinal duplication. In cases of unexplained intraperitoneal arterial hemorrhage in infants, intestinal duplication near the hemorrhage point should be suspected.

Potential role of the PD-L1 expression and tumor-infiltrating lymphocytes on neuroblastoma.

PURPOSE: The programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway has garnered much attention for its roles in clinical oncology. The aim of this study was to examine the clinical impact of the PD-L1 expression and tumor-infiltrating lymphocytes (TILs) on neuroblastoma. METHODS: We evaluated the PD-L1 expression and TIL status in 31 patients with neuroblastoma who underwent a biopsy or resection by an immunohistochemical analysis. Furthermore, we performed the serial analysis of the PD-L1 status before and after chemotherapy in 15 patients. RESULTS: Among the 31 cases, 11 (35%) showed a positive PD-L1 expression. The survival analysis showed a trend toward an association between PD-L1 positivity and a decreased overall survival. PD-L1 positivity tended to be associated with higher levels of tumor markers. In the serial analysis of the PD-L1 status, positivity was noted in 8 of 15 patients before chemotherapy and 6 after chemotherapy. Notably, all four patients with a positive PD-L1 status both before and after chemotherapy had recurrence, and 3 of them died during the follow-up period. CONCLUSION: Our findings suggest that the PD-L1 tumor expression might be a good biomarker for the treatment of neuroblastoma patients, especially for advanced neuroblastoma.

Mechanism of pancreatic juice reflux in pancreaticobiliary maljunction: A fluid dynamics model experiment.

BACKGROUND: Pancreatic juice reflux to the common bile duct and gallbladder is observed in the pancreaticobiliary maljunction (PBM), and various pathological conditions occur in the biliary tract. However, the mechanism of pancreatic juice reflux has not been discussed yet. This study aimed to investigate the mechanism of this phenomenon from the perspective of the fluid dynamics theory. METHODS: A fluid dynamics model of PBM without biliary dilatation having gallbladder function and of the pressure of sphincter of Oddi was developed. Water (as bile juice and pancreatic juice) was flowed to these models with a flow rate similar to that in humans. Pancreatic and bile juice flow and bile duct pressure were observed in three phases of gallbladder function. Moreover, the same experiment was performed in the PBM without biliary dilatation model without gallbladder. RESULTS: Pancreatic juice reflux could be observed when the gallbladder was passively expanded with the pressure in the bile duct lower than that in the sphincter of Oddi. However, pancreatic juice reflux was not observed in the model without gallbladder. CONCLUSIONS: Gallbladder function may be strongly involved in pancreatic juice reflux in PBM without biliary dilatation. Cholecystectomy may be able to stop the reflux of pancreatic juice.

Insulin therapy for hyperglycemia in neonatal sepsis using a preterm mouse model.

BACKGROUND: Stress-induced hyperglycemia is a frequent complication of neonatal sepsis. Hyperglycemia induces oxidative stress and immunosuppression. We investigated the glucose kinetics and effect of insulin administration during stress-induced hyperglycemia in a neonatal sepsis mouse model. METHODS: A stock cecal slurry (CS) solution was prepared from adult cecums and 3.0 mg of CS/g (LD40 ) was administered intraperitoneally to 4-day-old FVB mouse pups. Blood glucose levels were measured at 1.5, 3, 6, and 9 h post-sepsis induction and compared with basal levels. Two different doses of ultrafast-acting insulin were administered subcutaneously, and blood glucose levels and survival rates were monitored. RESULTS: Blood glucose levels were significantly higher than those of baseline levels with a peak at 3 h, which progressively decreased from 6 to 9 h post-sepsis induction. Insulin treatment reduced post-sepsis-induced hyperglycemia at 1.5 and 3 h. The mortality rate of CS-only pups (39%) was similar to that of CS + 1 U/kg insulin pups (60%). However, the mortality rate of CS + 5 U/kg insulin pups (82%) was significantly higher than that of CS-only pups. CONCLUSIONS: Marked hyperglycemia was induced immediately after post-sepsis induction, and the high-dose insulin treatment increased mortality post-induction. Stress-induced hyperglycemia could therefore be a physiological and protective response for preterm sepsis, and aggressive treatment of this hyperglycemia might be contraindicated.

Risk factors for the recurrence of perineal canal.

PURPOSE: The aim of this study was to investigate risk factors for recurrence in the perineal canal (PC). METHODS: Patients with PC who underwent operations were enrolled in this study and were divided into recurrence and non-recurrence groups. Preoperative infection, the age at the operation, the presence of colostomy and the treatment procedure for fistula were retrospectively investigated. Regarding the treatment procedure for fistula, either closure of the rectal wall with stitches or ligation of fistula in the rectum was performed. These factors were compared between the two groups. RESULTS: Six of 17 patients with PC who underwent surgical treatment had recurrence. There were no significant differences in the incidence of preoperative infection, age at operation or presence of colostomy (p = 0.60, 0.38, 1.00, respectively). In the recurrence group, all patients were treated by closure of the rectal wall. In the non-recurrence group, five were treated by the closure of the rectal wall with stitches and six by ligation of the fistula. There was a significant association between recurrence and the treatment procedure for fistula (p = 0.04). CONCLUSION: Closure of the rectal wall with stitches is a risk factor for the recurrence of PC.

Mice conditionally expressing RET(C618F) mutation display C cell hyperplasia and hyperganglionosis of the enteric nervous system.

Medullary thyroid carcinoma (MTC) develops from hyperplasia of thyroid C cells and represents one of the major causes of thyroid cancer mortality. Mutations in the cysteine-rich domain (CRD) of the RET gene are the most prevalent genetic cause of MTC. The current consensus holds that such cysteine mutations cause ligand-independent dimerization and constitutive activation of RET. However, given the number of the CRD mutations left uncharacterized, our understanding of the pathogenetic mechanisms by which CRD mutations lead to MTC remains incomplete. We report here that RET(C618F), a mutation identified in MTC patients, displays moderately high basal activity and requires the ligand for its full activation. To assess the biological significance of RET(C618F) in organogenesis, we generated a knock-in mouse line conditionally expressing RET(C618F) cDNA by the Ret promoter. The RET(C618F) allele can be made to be Ret-null and express mCherry by Cre-loxP recombination, which allows the assessment of the biological influence of RET(C618F) in vivo. Mice expressing RET(C618F) display mild C cell hyperplasia and increased numbers of enteric neurons, indicating that RET(C618F) confers gain-of-function phenotypes. This mouse line serves as a novel biological platform for investigating pathogenetic mechanisms involved in MTC and enteric hyperganglionosis.

Repair of type IV laryngotracheoesophageal cleft (LTEC) on ECMO.

PURPOSE: A type IV laryngotracheoesophageal cleft (LTEC) is a very rare congenital malformation. Type IV LTEC that extends to the carina have poor prognosis and are difficult to manage. We present our experience with surgical repair in such a case using extracorporeal membranous oxygenation (ECMO). METHODS: A male infant, who was diagnosed with Goldenhar syndrome, showed severe dyspnea and dysphagia. Laryngoscopy indicated the presence of LTEC. The patient was transferred to our institute for radical operation 26 days after birth. Prior to surgery, a balloon catheter was inserted in the cardiac region of stomach through the lower esophagus to block air leakage, to maintain positive pressure ventilation. We also performed observations with a rigid bronchoscope to assess extent of the cleft, and diagnosed the patient with type IV LTEC. After bronchoscopy, we could intubate the tracheal tube just above the carina. Under ECMO, repair of the cleft was performed by an anterior approach via median sternotomy. RESULTS: The patient was intubated via nasotracheal tube and paralysis was maintained for 2 weeks, using a muscle relaxant for the first 3 days. Two weeks after surgery, rigid bronchoscopy showed that the repair had been completed, and the tracheal tube was successfully extubated without tracheotomy. CONCLUSIONS: Although insertion of a balloon catheter is a very simple method, it can separate the respiratory and digestive tracts. This method allowed for positive pressure ventilation and prevented displacement of the endotracheal tube until ECMO was established. As a result, we safely performed the operation and the post-operative course was excellent.

Dilatation of the common channel in pediatric congenital biliary dilatation remaining after radical operation.

BACKGROUND: In congenital biliary dilatation, the protein plug is likely impacted, especially in a dilated common channel. However, nobody has discussed whether this dilatation of common channel remains after radical operation. The aim of this study was to investigate the situation of the dilated common channel after radical operation. METHODS: The status of the common channel was investigated at radical operation and follow-up. We then evaluated whether dilation of the common channel remained postoperatively. Moreover, the association between status of the common channel and postoperative pancreatic complication was evaluated. RESULTS: Postoperative condition of the common channel was able to be evaluated ultrasonographically in 42 patients. The common channel was dilated at the time of operation in 18 patients and remained dilated postoperatively in 11 of these 18 patients. Dilatation of the common channel was not identified in any patients without dilatation at the time of operation. No patients in this series showed any postoperative pancreatic complications, even if a dilated common channel remained. CONCLUSIONS: Dilatation of the common channel can remain postoperatively in congenital biliary dilatation, but does not appear to be associated with postoperative pancreatic complications.

Clinical features and risk factors of bile duct perforation associated with pediatric congenital biliary dilatation.

PURPOSE: This study aimed to investigate the clinical features and risk factors of bile duct perforation in pediatric congenital biliary dilatation (CBD) patients. METHODS: CBD patients, whose initial symptom was abdominal pain, were enrolled in this study and were divided into perforated and non-perforated groups. The clinical features of the perforated group were investigated. Moreover, the age at operation, sex, and morphologic features of the extrahepatic bile duct were compared between the groups. RESULTS: Fifteen cases of bile duct perforation (10.4%) were identified among the 144 CBD patients who had abdominal pain. Majority of bile duct perforation occurred in patients aged < 4 years. The median duration from onset of abdominal pain to bile duct perforation was 6 (4-14) days. Age at onset [< 4 years old; P = 0.02, OR 13.9, (1.663, 115.3)], shape of extrahepatic bile duct [non-cystic type; P = 0.009, OR 8.36, (1.683, 41.5)], and dilatation of the common channel [P = 0.02, OR 13.6, (1.651, 111.5)] were risk factors of bile duct perforation. CONCLUSIONS: Emergent bile duct drainage might be planned to prevent bile duct perforation if CBD patients have the abovementioned risk factors and experience persistent abdominal pain lasting for a few days from onset.

Experimental validation of laryngotracheal growth and recurrent laryngeal nerve preservation after partial cricotracheal resection in a growing rabbit model.

PURPOSE: The aim of this study was to confirm laryngotracheal growth and recurrent laryngeal nerve (RLN) preservation after partial cricotracheal resection (PCTR) in a growing rabbit model by performing the procedure in pediatric animals. METHODS: Six female Japanese white rabbits, 12 weeks of age, underwent PCTR. The course of the RLN was evaluated during surgery (n = 3). Endoscopic and histologic examinations were performed at 22 weeks of age (n = 6). Four non-operated rabbits, 22 weeks of age, underwent endoscopic and histologic examinations as controls. RESULTS: The RLN was preserved at the esophageal side and entered the larynx behind the cricothyroid joint after PCTR. Endoscopic examination showed normal vocal cord movements and the large reconstructed subglottis. Histologically, sufficient submucosal vessels and cartilage growth were identified at the reconstructed larynx. The median inside luminal area at the anastomotic site in the PCTR group was 24.8 mm2 (range 21.8-29.0 mm2), and that at the cricoid cartilage and trachea in the control group was 23.4 mm2 (range 20.0-26.6 mm2) and 25.6 mm2 (range 22.9-28.8 mm2), respectively. CONCLUSION: No interference with laryngotracheal growth was seen, and RLN preservation was confirmed after PCTR. Use of PCTR in the pediatric age group seems appropriate.

Bronchoscopic assessments and clinical outcomes in pediatric patients with tracheomalacia and bronchomalacia.

BACKGROUND: Tracheomalacia and bronchomalacia (TM/BM) are one of the serious causes of airway obstruction in infants and children. This study reviewed our bronchoscopic assessments and clinical outcomes in pediatric patients with TM/BM, and investigated risk factors of surgical intervention for TM/BM. METHODS: Fifty-seven consecutive patients who were diagnosed as TM/BM by bronchoscopy between 2009 and 2013 were reviewed retrospectively. They were divided into two groups according to the presence (group E, n = 26) or absence (group N, n = 31) of acute life-threatening events and extubation failure (ALTE/EF). The severity of TM/BM was evaluated by Oblateness Index which was obtained from bronchoscopic images. RESULTS: Oblateness Index was significantly higher in Group E than in Group N. Patients in Group E underwent surgical intervention for TM/BM more frequently, and had significantly longer intubation period and hospital stay. Clinical symptoms of ALTE/EF, Oblateness Index ≥ 0.70, and multiple malacic lesions were significant risk factors indicating surgical events in patients with TM/BM. CONCLUSIONS: Patients with TM/BM who had ALTE/EF had more severe malacic lesions indicating surgical intervention, and worse clinical outcomes. Oblateness Index is a simple and semi-quantitative index for bronchoscopic assessment of TM/BM, and can be one of the prognostic tools to predict clinical severity of pediatric TM/BM.

3-Dimensional computed tomography imaging of the ring-sling complex with non-operative survival case in a 10-year-old female.

We report a case of a 10-year-old female patient who survived ring-sling complex without surgery. The patient had congenital wheezing from the neonatal period and was treated after a tentative diagnosis of infantile asthma. The patient suffered from allergy and was hospitalized several times due to severe wheezing, and when she was 22 months old, she was diagnosed with ring-sling complex. We used a segmental 4 mm internal diameter of the trachea for 3-dimensional computed tomography (3D-CT). Bronchial asthma is considered an exacerbating factor in infantile period and frequently required treatment with bronchodilator. After the age of 10, the patient had recurrent breathing difficulties during physical activity and during night time, and this condition was assessed to be related to the pressure from the blood vessel on the ring. We repeated the 3D-CT evaluation later and discovered that the internal diameter of the trachea had grown to 5 mm. Eventually, patient's breathing difficulties disappeared after the treatment of bronchial asthma and restriction of physical activities. Our patient remained in stable condition without undergoing any surgical procedures even after she passed the age of 10.