Premalignant/malignant histology in excised choledochal cyst specimens from children. Experience and literature review.

BACKGROUND: Dysplasia, carcinoma in situ, and other malignant transformation or premalignant/malignant histopathology (PMMH) seem uncommon in pediatric choledochal cyst (CC). A literature review and the authors' experience are presented. METHODS: All reports about PMMH in CC patients 15 years old or younger published in English and all cases of PMMH in specimens excised from CC patients 15 years old or younger by the authors were reviewed. RESULTS: Of 20 published reports, PMMH was adenocarcinoma (n = 4), sarcoma (n = 4), and dysplasia (n = 12). Treatment for malignancies was primary pancreaticoduodenectomy (PD; n = 2) or cyst excision/hepaticojejunostomy (Ex/HJ; n = 6). Outcomes at the time of writing for malignancies: 2 deaths, 4 survivors after follow-up of 2 years, and 2 lost to follow-up. No dysplasia case has undergone malignant transformation. The authors have experienced 7 cases of PMMH; adenocarcinoma in situ (AIS; n = 1) and dysplasia (n = 6). CONCLUSIONS: The present study identified the youngest cases of AIS and dysplasia from specimens excised when they were 3 years old and 4 months old, respectively. Both are published for the first time as evidence that PMMH can complicate CC in young patients. Long-term protocolized postoperative follow-up is mandatory when PMMH is diagnosed in pediatric CC.

Prospective evaluation of common hepatic duct histopathology at the time of choledochal cyst excision ranging from children to adults.

PURPOSE: To evaluate common hepatic duct just distal to the HE anastomosis (d-CHD) prospectively for mucosal damage, inflammation, fibrosis, dysplasia, carcinoma in situ, malignant transformation, effects of serum amylase, and symptoms at presentation in CC cases ranging from children to adults. METHODS: Cross-sections of d-CHD obtained at cyst excision 2018-2023 from 65 CC patients; 40 children (< 15 years old), 25 adults (≥ 15) were examined with hematoxylin and eosin, Ki-67, S100P, IMP3, p53, and Masson's trichrome to determine an inflammation score (IS), fibrosis score (FS), and damaged mucosa rate (DMR; damaged mucosa expressed as a percentage of the internal circumference). RESULTS: Mean age at cyst excision ("age") was 18.2 years (range: 3 months-74 years). Significant inverse correlations were found for age and DMR (p = 0.002), age and IS (p = 0.011), and age and Ki-67 (p = 0.01). FS did not correlate with age (p = 0.32) despite significantly increased IS in children. Dysplasia was identified in a 4-month-old girl with cystic CC. Serum amylase was elevated in high DMR subjects. CONCLUSIONS: High DMR, high IS, and evidence of dysplasia in pediatric CC suggest children are at risk for serious sequelae best managed by precise histopathology, protocolized follow-up, and awareness that premalignant histopathology can arise in infancy.

Testicular appendage torsion in children.

BACKGROUND: Testicular appendage torsion (TAT) is a medical emergency that presents as an acute scrotum, usually in children and preadolescents. In previous reports of TAT, most cases have been treated conservatively, but some necessitate surgical treatment. Our aim was to examine the incidence, clinical examination findings, etiology, and treatment of TAT. METHODS: We retrospectively reviewed records of all patients with TAT (aged ≤15 years) treated at the Juntendo University Urayasu Hospital between January 2012 and September 2020. Surgical treatment was performed when a diagnosis of testicular torsion could not be completely ruled out or if pain recurred after conservative treatment. Patients with a hard scrotum or scrotal erythema were hospitalized for conservative treatment. Data regarding age, diagnosis, blood test results, and clinical findings were analyzed. RESULTS: Among 101 boys with TAT, the median age was 10 years. The incidence of TAT varied significantly according to age and was highest among patients aged 8-11 years. Sixty-seven boys (66.3%) underwent inpatient surgical treatment, 10 boys (9.9%) received inpatient conservative treatment, and 24 boys (23.8%) received outpatient conservative treatment. The median duration of hospitalization was significantly shorter among those who underwent surgery (2.0 days) than among those who received inpatient conservative treatment group (3.5 days). CONCLUSIONS: Operations were short, uncomplicated, and safe; they shortened the hospital stay; and they would certainly prevent recurrence of TAT and testicular torsion on one side. Furthermore, we recommended that TAT patients presenting with signs of severe inflammation, such as hard scrotum or scrotal erythema, receive early surgical treatment to minimize duration of hospitalization.

Umbilical microflora and pediatric surgery.

INTRODUCTION: In pediatric surgery, the umbilicus with humid environment prone to bacterial colonization has become the most common site of entrance into the peritoneum. However, the umbilical flora in children has never been reported. This study aimed to describe the characteristics of umbilical microflora in children before antiseptic skin preparation. PATIENTS AND METHODS: We prospectively reviewed all children (age, ≤ 15 years) undergoing surgical procedures using umbilical access between April 2020 and June 2021. Before antiseptic skin preparation, culture swabs were taken from the umbilicus. Data on age, sex, and surgical procedure as well as microflora results and clinical findings were analyzed. RESULTS: Overall, data on 123 children aged between 9 days and 15 years (median: 3 years) were obtained. In the umbilicus, the most frequent colonizing bacteria were coagulase-negative Staphylococcus species and Corynebacterium. The isolation of intestinal bacteria from children aged ≤ 3 years was significantly increased (P = 0.03). The results of the multidrug resistance test revealed that the bacteria from the umbilicus exhibited a high frequency of cefazolin (CEZ) resistance (46.1%). No postoperative surgical site infection was recorded in our study. CONCLUSIONS: This prospective study is the first report to investigate the umbilical microflora in over 100 children. In this study, a large spectrum of both resident and transient microflora was cultured from the umbilicus. This umbilical microflora was similar to previous reports of adult microflora except in children aged ≤ 3 years. Our data suggest that in children ≤ 3 years, preoperative and postoperative antibiotics should be chosen by considering CEZ resistance and intestinal bacteria. The result of umbilical microflora would be useful to select the antibiotics for treatment of surgical site infection (SSI), and the culture swabs from the umbilicus before the operation for the children at high risk for SSI are highly recommended.

A predictive scoring system for small diaphragmatic defects in infants with congenital diaphragmatic hernia.

PURPOSE: To develop a predictive score for small diaphragmatic defects in infants with congenital diaphragmatic hernia (CDH) for determining thoracoscopic surgery indication. METHODS: The Japanese CDH Study Group cohort was randomly divided into derivation (n = 397) and validation (n = 396) datasets. Using logistic regression, a prediction model and weighted scoring system for small diaphragmatic defects were created from derivation dataset and validated with validation dataset. RESULTS: Six weighted variables were selected: no hydramnios, 1 point; 1 min Apgar score of 5-10, 1 point; apex type of the lung (left lung is detected radiographically in apex area), 1 point; oxygenation index < 8, 1 point; abdominal nasogastric tube (tip of the nasogastric tube is detected radiographically in the abdominal area), 2 points; no right-to-left flow of ductus arteriosus, 1 point. In validation dataset, rates of small diaphragmatic defects for Possible (0-3 points), Probable (4-5 points), and Definite (6-7 points) groups were 36%, 81%, and 94%, respectively (p < 0.001). Additionally, sensitivity, specificity, positive predictive value, and C statistics were 0.78, 0.79, 0.88, 0.76, and 0.45, 0.94, 0.94, 0.70 for Probable and Definite groups, respectively. CONCLUSION: Our scoring system effectively predicted small diaphragmatic defects in infants with CDH.

Prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia: a systematic review and meta-analysis.

PURPOSE: This study aimed to evaluate prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia (CDH). METHODS: A systematic literature search was performed to identify relevant observational studies that evaluated the ability of lung-to-head ratio (LHR), observed-to-expected LHR (o/e-LHR), observed-to-expected total fetal lung volume (o/e-TFLV), lung-to-thorax transverse area ratio (L/T ratio), intrathoracic herniation of the liver and the stomach, and side of diaphragmatic hernia, using a threshold for the prediction of mortality in fetuses with CDH. Study quality was assessed using the QUADAS-2 tool. Hierarchical summary receiver operating characteristic curves were constructed. RESULTS: A total of 50 articles were included in this meta-analysis. The QUADAS-2 tool identified a high risk of bias in more than one domain scored in all parameters. Among those parameters, the diagnostic odds ratio of mortality with o/e-LHR < 25%, o/e-TFLV < 25%, and L/T ratio < 0.08 were 11.98 [95% confidence interval (CI) 4.65-30.89], 11.14 (95% CI 5.19-23.89), and 10.28 (95% CI 3.38-31.31), respectively. The predictive values for mortality were similar between the presence of liver herniation and retrocardiac fetal stomach position. CONCLUSIONS: This systematic review suggests that o/e-LHR, o/e-TFLV, and L/T ratio are equally good predictors of neonatal mortality in fetuses with isolated CDH.

The efficacy of the postnatal nasogastric tube position as a prognostic marker of left-sided isolated congenital diaphragmatic hernia.

PURPOSE: The prenatal diagnosis of the stomach position in congenital diaphragmatic hernia (CDH) has been a reliable prognostic factor, but few studies have focused on the postnatal position. We therefore evaluated the significance of the nasogastric (NG) tube position just after birth. METHODS: The Japanese CDH Study Group database enrolled 1037 CDH neonates over 15 years. In our multicenter retrospective study, 464 cases of left-sided isolated CDH with prenatal diagnoses were divided into two groups: NG tube below the diaphragm (BD; n = 190) or above the diaphragm (AD; n = 274). The primary outcome was the 90-day survival rate, and the secondary outcomes were mechanical ventilation duration, hospitalization duration, and recurrence rate. RESULTS: The BD group had a significantly higher 90-day survival rate (98.4 vs. 89.4%, p < 0.001), shorter mechanical ventilation (11 vs. 19 days, p < 0.001), shorter hospitalization (38 vs. 59 days, p < 0.001), and lower recurrence rate (p = 0.002) than the AD group. A multivariate analysis showed that BD (adjusted odds ratio, 3.68; 95% confidence interval 1.02-13.30) was a favorable prognostic factor for the 90-day survival. CONCLUSION: The assessment of the NG tube position revealed it to be a reliable prognostic factor of left-sided isolated CDH. Therefore, it should be included as a routine assessment.

Changes in postoperative quality of life of pediatric total colonic aganglionosis patients: effect of pull-through technique.

AIM: To assess mid-/long-term quality of life (QOL) of total colonic aganglionosis (TCA) patients. METHODS: Modified pre-existing QOL assessment tools for general lifestyle (GL), bowel function (BF), and mental health (MH) were administered to postoperative TCA patients from five institutions, who were at least 7 years old to compare Duhamel (with pouch) and Swenson/Soave (without pouch) techniques between children (Ch 7-12 years old), teenagers (Tn 13-19), and adults (Ad 20 and over). For MH, caregivers were also interviewed, but separately. Maximum scores were 12 for GL/MH and 18 for BF. RESULTS: There were 32 subjects. GL and BF scores increased significantly from Ch (GL 4.8 ± 2.5, BF: 11.3 ± 4.6) to Tn (GL 7.8 ± 2.6, BF 16.2 ± 3.0); scores for MH did not change significantly. Mean caregiver MH scores were significantly lower than mean subject MH scores for all age groups (subject scores: 10.1, 10.7, 10.7 versus caregiver scores: 6.8, 7.8, 8.1 for Ch, Tn, Ad, respectively). PT technique/presence of a pouch did not influence the incidence of enterocolitis or QOL scores. CONCLUSION: MH responses showed subjects felt better than caregivers believed. This discrepancy could cause conflict despite steadily improving GL/BF. QOL was unaffected by PT technique/presence of a pouch.

Quality of life after type-A esophageal atresia surgery: changes over time and effect of pre-anastomotic elongation.

AIM: To assess mid-/long-term postoperative quality of life (QOL) of esophageal atresia (EA) patients. METHODS: Modified gastrointestinal quality-of-life index surveys were administered to postoperative EA patients who were at least 7 years old at evaluation to assess three topics about general lifestyle (GL), five topics about EA, and four topics about mental health (MH). For MH, caregivers were also interviewed, but separately. Subjects were divided according to age: children (7-12 years old), teenagers (13-19), and adults (20 and over) and compared according to Foker or Kimura elongation (FK) or bougienage stretching (BS). RESULTS: There were 22 patients evaluated. Responses for GL, EA, and MH did not differ significantly between age groups, but MH responses by caregivers for subjects who were children or teenagers scored significantly lower than responses they made themselves. For primary esophageal elongation technique (PET), age at esophagoesophagostomy was significantly higher in FK. Despite FK scoring 15.1 versus 12.4 for BS during EA evaluation, this difference was not statistically significant. CONCLUSION: Changes in QOL responses according to age were unremarkable. However, discrepancies in MH indicate that subjects felt better than their caregivers thought. PET did not appear to influence QOL.

Thoracoscopic repair of congenital diaphragmatic hernia in neonates: findings of a multicenter study in Japan.

PURPOSE: We compared the efficacy of thoracoscopic repair (TR) with that of open repair (OR) for neonatal congenital diaphragmatic hernia (CDH). METHODS: The subjects of this multicenter retrospective cohort study were 524 infants with left-sided isolated CDH, diagnosed prenatally, and treated at one of 15 participating hospitals in Japan between 2006 and 2018. The outcomes of infants who underwent TR and those who underwent OR were compared, applying propensity score matching. RESULTS: During the study period, 57 infants underwent TR and 467 underwent OR. Ten of the infants who underwent TR required conversion to OR for technical difficulties and these patients were excluded from the analysis. The survival rate at 180 days was similar in both groups (TR 98%; OR 93%). Recurrence developed after TR in 3 patients and after OR in 15 patients (TR 7%, OR 3%, p = 0.40). The propensity score was calculated using the following factors related to relevance of the surgical procedure: prematurity (p = 0.1), liver up (p < 0.01), stomach position (p < 0.01), and RL shunt (p = 0.045). After propensity score matching, the multivariate analysis adjusted for severity classification and age at surgical treatment revealed a significantly shorter hospital stay (odds ratio 0.50) and a lower incidence of chronic lung disease (odds ratio 0.39) in the TR group than in the OR group. CONCLUSIONS: TR can be performed safely for selected CDH neonates with potentially better outcomes than OR.

Optimal timing of surgery in infants with prenatally diagnosed isolated left-sided congenital diaphragmatic hernia: a multicenter, cohort study in Japan.

PURPOSE: To date, there is no compelling evidence of the optimal timing of surgery for congenital diaphragmatic hernia (CDH). This study aimed to establish the optimal timing of surgery in neonates with isolated left-sided CDH. METHODS: This multicenter cohort study enrolled 276 patients with isolated left-sided CDH at 15 institutions. Based on the timing of surgery, the patients were classified into four groups [< 24 h (G1), 24-47 h (G2), 48-71 h (G3), and ≥ 72 h (G4)]. The clinical outcomes were compared among the groups using a logistic regression model, after adjusting for potential confounders, such as disease severity. RESULTS: Multivariate analyses showed that G2 also had a lower mortality rate than the other groups. In mild and severe cases, there were no significant differences in mortality across the four groups. In moderate cases, G2 resulted in significantly increased survival rates, compared with G1. CONCLUSION: The study results suggest that surgery within 24 h of birth is not recommended for patients with moderate severity CDH, that there is no benefit in the delay of surgery for more than 72 h in mild severity CDH patients, and that there is no definite optimal time to perform surgery in severe cases of CDH.

Best pre-ductal PaO2 prior to extracorporeal membrane oxygenation as predictor of mortality in patients with congenital diaphragmatic hernia: a retrospective analysis of a Japanese database.

PURPOSE: Predicting lethal pulmonary hypoplasia in infants with congenital diaphragmatic hernia (CDH) before extracorporeal membrane oxygenation (ECMO) initiation is difficult. This study aimed to predict lethal pulmonary hypoplasia in patients with CDH prior to ECMO. METHODS: This was a multicenter cohort study involving neonates prenatally diagnosed with isolated unilateral CDH (born 2006-2020). Patients who required ECMO due to respiratory insufficiency were included in this study. Patients who underwent ECMO due to transient disorders were excluded from analysis. Blood gas analysis data within 24 h of birth were compared between survivors and non-survivors. Predictive abilities were assessed for factors with significant differences. RESULTS: Overall, 34 patients were included (18 survivors and 16 non-survivors). The best pre-ductal PaO2 was significantly lower in non-survivors than in survivors (50.4 [IQR 30.3-64.5] vs. 67.5 [IQR 52.4-103.2] mmHg, respectively; p = 0.047). A cutoff PaO2 of 42.9 mmHg had a sensitivity, specificity, and positive predictive value of 50.0%, 94.4%, and 88.9%, respectively, to predict mortality. CONCLUSION: The best PaO2 within 24 h after birth predicted mortality following ECMO initiation. This should be shared to families and caregivers to optimize the best interests of the infants with CDH.

Decreased incidence of intussusception during the COVID-19 pandemic. Trends in pediatric surgical emergencies.

PURPOSE: Recent reports suggest that the COVID-19 pandemic may be influencing disease morbidity. The purpose of this study was to investigate pandemic-related changes in the incidence of pediatric surgical emergencies. METHODS: Data from patients with one of 8 typical conditions considered to be pediatric emergencies who presented at 3 hospitals close to central Tokyo were collated retrospectively from accident and emergency (AE) department records for 2020 and compared with data for 3 years prior to 2020. RESULTS: All subjects had similar demographic profiles. The total number of pediatric AE attendances from 2017 to 2020 was 2880 (2017: n = 600, 2018: n = 736, 2019: n = 817, and 2020: n = 727). Annual attendances were similar. Of the 8 conditions, there were significantly less cases of intussusception in 2020 than previously (23/727; 3.1% versus 132/2153; 6.1%) p < 0.01 and the number of emergency surgical interventions for intussusception was also significantly less in 2020 (0/23; 0% versus 13/132; 9.8%) p < 0.01. CONCLUSION: The implementation of preventative measures to combat the COVID-19 pandemic in 2020 would appear to have influenced the etiopathogenesis of intussusception enough to significantly decrease its overall incidence and the requirement for emergency surgical intervention.

Defined serum-free culture of human infant small intestinal organoids with predetermined doses of Wnt3a and R-spondin1 from surgical specimens.

PURPOSE: Refinement of organoid technology is important for studying physiology and disease of the intestine. We aimed to optimize defined serum-free conditions for human infant small intestinal (SI) organoid culture with predetermined doses of Wnt3a and Rspo1 from surgical specimens. We further assessed whether intestinal specimens could be stored before use as a source of organoids. METHODS: Different doses of Wnt3a and Rspo1 in a serum-free medium were tested to establish a condition in which surgically resected SI cells grew as organoids over multiple passages. The expression of marker genes for stem and differentiated cells was assessed by quantitative polymerase chain reaction. We also investigated the organoid-forming efficiency of cells in degenerating intestines stored at 4 °C for various intervals post-resection. RESULTS: We determined the doses of Wnt3a and Rspo1 required for the continuous growth of infant SI organoids with multi-differentiation potential. We revealed that, despite the time-dependent loss of stem cells, tissues stored for up to 2 days preserved cells capable of generating amplifiable organoids. CONCLUSION: SI cells can be grown as organoids under defined conditions. This could provide a reproducible and customizable method of using surgical specimens for the study of intestinal maturation and their relevance to pediatric diseases.

Risk factors for pneumothorax associated with isolated congenital diaphragmatic hernia: results of a Japanese multicenter study.

PURPOSE: This study aimed to elucidate the clinical characteristics of neonates with congenital diaphragmatic hernia (CDH) associated with pneumothorax and evaluate the risk factors for the development of pneumothorax. METHODS: A retrospective cohort study was conducted in the 15 institutions participating in the Japanese CDH Study Group. A total of 495 neonates with isolated CDH who were born between 2011 and 2018 were analyzed in this study. RESULTS: Among the 495 neonates with isolated CDH, 52 (10.5%) developed pneumothorax. Eighteen (34.6%) patients developed pneumothorax before surgery, while 34 (65.4%) developed pneumothorax after surgery. The log-rank test showed that the cumulative survival rate was significantly lower in patients with pneumothorax than in those without pneumothorax. Univariate analysis revealed significant differences between patients with pneumothorax and those without pneumothorax with regard to the best oxygenation index within 24 h after birth, mean airway pressure (MAP) higher than 16 cmH2O, diaphragmatic defect size, and need for patch closure. Multiple logistic regression analysis indicated that only the MAP was associated with an increased risk of pneumothorax. CONCLUSIONS: The cumulative survival rate was significantly lower in isolated CDH patients with pneumothorax than in those without pneumothorax. A higher MAP was a risk factor for pneumothorax in CDH patients.

Perforation in pediatric non-complicated appendicitis treated by antibiotics: the real incidence.

PURPOSE: The incidence of perforation during antibiotic therapy (AT) of children triaged as non-complicated acute appendicitis (NC-Ap) was investigated. METHODS: Abdominal ultrasonography (US) and/or computed tomography (CT) scans from cases of perforation identified at appendectomy for failed AT were reassessed blindly by a panel of board-certified specialists for any evidence of pre-AT morbidity suggestive of perforation. RESULTS: Of 521 cases triaged as NC-Ap, symptoms resolved with AT in 452 cases (86.8%). All 69/521 (13.2%) cases with persistent symptoms had urgent appendectomy, and 12/521 (2.3%) were found to have perforated. Blind reassessment of US and/or CT scans from these cases identified seven with evidence of perforation when they were triaged as NC-Ap. Thus, the actual incidence of perforation during AT for NC-Ap was actually 12-7 = 5/521 (0.95%). CONCLUSIONS: Perforation is generally believed to be a complication of AT, but inappropriate triaging of cases for AT can bias results by artificially inflating the number of perforations, in this study, by more than double. We are the first to assess the unbiased incidence of perforation during AT for NC-Ap, by reassessing pre-AT US and/or CT scans. The incidence of perforation during AT is actually negligible.

Comparison of laparoscopic percutaneous extraperitoneal closure versus conventional herniotomy in extremely low birth weight infants.

PURPOSE: Laparoscopic percutaneous extraperitoneal closure (LPEC) has become routine for repairing pediatric inguinal hernia (IH). Reports on the effective repair of IH in challenging cases, such as extremely low birth weight infants (ELBWI) who become symptomatic soon after birth and have surgery before 1 year of age, are rare; and conventional herniotomy (CH) in ELBWI requires extensive experience of neonatal surgery. We compared LPEC with CH for treating ELBWI with IH. METHODS: Consecutive ELBWI with IH treated by either LPEC (n = 17) or CH (n = 22) before 1 year of age between 2012 and 2017 were reviewed. LPEC were performed by consultant pediatric surgeons (CPS; n = 3) with experience of at least 200 cases each. In CH, 11 cases were treated by CPS and 11 by CPS-supervised surgical trainees. RESULTS: There were no intraoperative complications. Operative time and anesthesia time for bilateral IH repairs were both shorter in LPEC. Postoperative sequelae were recurrence (LPEC; n = 1; repaired by redo LPEC 2 months after the initial repair) and intravenous rehydration (CH; n = 1; for persistent post-anesthetic vomiting). Recovery was unremarkable in all cases without additional analgesia. CONCLUSION: LPEC would appear to be a viable option for treating IH in ELBWI, especially bilateral cases.

Hirschsprung's disease in the laparoscopic transanal pull-through era: implications of age at surgery and technical aspects.

AIM: Detailed implications of age at laparoscopic transanal pull-through (LTAPT) on postoperative bowel function (POBF) in Hirschsprung's disease (HD) are somewhat obscure because of a spectrum of factors. METHODS: Age at surgery was used to categorize 106 consecutive postoperative HD cases treated by our modified LTAPT (JLTPAT) between 1997 and 2015; group A: < 3 months old (n = 31); group B: 3-11 months old (n = 44); group C: 1-3 years old (n = 19); and group D: ≥ 4 years old (n = 12). POBF was assessed by reviewing outpatient records 1, 3, 5, 7, and 10 years after JLTAPT prospectively and scoring each of 5 criteria on a scale of 0-2; best score = 10. RESULTS: Only operative time was statistically longer in group D versus groups A, B, and C. Differences in gender ratios, blood loss, duration of follow-up, and POBF scores were not statistically significant. Mean POBF scores over time were: group A: 6.8, 7.6, 8.4, 8.6, and 8.4; group B: 7.1, 7.8, 8.3, 8.5, and 9.0; group C: 6.9, 7.9, 8.1, 8.3, and 8.6; group D: 7.0, 7.4, 8.2, 8.1, and 8.5, respectively. CONCLUSION: Age at JLTAPT was not correlated with POBF in HD.

The High Incidence of Bacteremia in Children Undergoing Surgery Can Be Prevented by Bifidobacterium Supplementation.

Major surgical procedures can alter intestinal microbiota and disrupt the intestinal barrier function, leaving the patient at risk for infection. Probiotics are defined as live microorganisms that confer a health benefit on the host when administered in adequate amounts. Although the efficacy of administering probiotics perioperatively to adults has been reported, the clinical significance of probiotics in children undergoing surgery is still unclear. This study provides a brief overview of our randomized controlled trial of preoperative probiotic administration to children, and discusses the relationship between probiotics and their effects in the perioperative period, particularly focusing on bacteremia.