Impact of definitive surgery for esophageal atresia on long-term outcomes in patients with trisomy 18.

This study investigates the long-term outcomes of palliative and definitive surgeries for esophageal atresia (EA) in patients with trisomy 18 syndrome. A retrospective study included 25 cases undergoing EA surgery at our center between 2008 and 2022. The Palliative group (n = 16) comprised 13 cases with esophageal banding and 3 with tracheoesophageal fistula (TEF) division. The Definitive group (n = 9) included 5 cases with primary repair and 4 with staged repair following TEF division. The patient characteristics exhibited no significant differences between the groups. In the Definitive group, 56% (5/9) were successfully weaned off mechanical ventilation, compared with none in the Palliative group (p = 0.002). Survival-to-discharge rates were 31% (5/16) in the Palliative group and 67% (6/9) in the Definitive group. Home ventilator management was required for all 5 cases that required ventilation in the Palliative group, whereas only 17% (1/6) in the Definitive group needed it. The Palliative group also required continuous oral suction for persistent saliva removal, with two cases undergoing laryngotracheal separation. Overall, definitive surgery for EA in patients with trisomy 18 syndrome may provide enhanced respiratory stability, thereby improving the survival-to-discharge rate and overall quality of life for patients and their families.

Long- term outcomes of congenital tracheal stenosis after slide tracheoplasty.

PURPOSE: Long-term outcomes of slide tracheoplasty in patients with congenital tracheal stenosis (CTS) have rarely been reported. This study aimed to clarify the long-term outcomes of CTS after slide tracheoplasty. METHODS: The medical records of 33 patients who underwent slide tracheoplasty for CTS at our institution between January 2005 and July 2018, with a follow-up duration > 5 years, were retrospectively reviewed. Patients' characteristics, perioperative condition, operative management, postoperative course, tracheal stenosis rates and growth data, were collected from medical records. RESULTS: The median operative age, minimum tracheal diameter, length of stenosis, duration of hospital stays, and follow-up duration were 8 months, 2.4 mm, 35 mm, 39 days, and 90 months, respectively. One patient died of bleeding in the right lung at 126 months postoperatively. Among the 10 patients requiring postoperative tracheostomy, seven were successfully decannulated at a median of 65 months postoperatively. Tracheal stenosis rates improved postoperatively and were subsequently maintained. Growth impairment and psychomotor delay were observed in 9 and 16 patients, respectively with significant differences found only in cases with genetic abnormalities and not in tracheal stenosis severity. CONCLUSION: Slide tracheoplasty for CTS leads to favorable long-term outcomes. However, various associated anomalies may influence growth and psychomotor development, emphasizing the importance of adequate support.

Prognosis and clinical issues of esophageal atresia in extremely low birth weight neonates: a case series.

BACKGROUND: Esophageal atresia (EA) in extremely low birth weight (ELBW) neonates is rare. This report aims to clarify EA's clinical courses and prognosis in ELBW neonates and the clinical issues of long-term survival cases. METHODS: A retrospective analysis was conducted for 8 neonates diagnosed with esophageal atresia. Medical records of ELBW EA neonates treated at our institution were reviewed to assess patient demographics, clinical courses, and outcomes. Transferred patient data was obtained from their local physicians through questionnaires. RESULTS: EA in ELBW neonates were included in 8 of EA infants (7%). Fatal respiratory and cardiovascular complications of trisomy 18 and complications related to immaturity such as liver failure and pulmonary hypertension were associated with poor prognosis. During primary operations, gastrostomy and esophageal banding were performed together in 50% of the cases, while gastrostomy was performed alone in 25%. The esophageal anastomosis was not performed during any primary operation. All causes of death, except for 1 case, were due to non-surgical causes. A long-term survival case of 17 years postoperatively was included. CONCLUSION: Although ELBW EA has a poor prognosis, long-term survival is possible in some cases, so aggressive therapeutic intervention is considered essential. It is important to share information about the prognosis with parents and multidisciplinary specialists and to select an appropriate treatment strategy for each case.

Feasibility of dose-dense cisplatin-based chemotherapy in Japanese children with high-risk hepatoblastoma: Analysis of the JPLT3-H pilot study.

BACKGROUND: The SIOPEL-4 study has demonstrated that dose-dense cisplatin-based chemotherapy dramatically improves outcome in children with high-risk hepatoblastoma in western countries. However, the feasibility and safety of this regimen have not been clarified in Japanese patients. METHODS: A pilot study, JPLT3-H, was designed to evaluate the safety profile of the SIOPEL-4 regimen in Japanese children with newly diagnosed hepatoblastoma with either metastatic disease or low alpha-fetoprotein. RESULTS: A total of 15 patients (three female) were enrolled. Median age was 2 years (range, 0-14). Three patients were PRETEXT II (where PRETEXT is PRETreatment EXTent of disease), six PRETEXT III, and six PRETEXT IV. All patients had lung metastasis, none had low alpha-fetoprotein. Eight patients completed the prescribed treatment, and seven patients discontinued therapy prematurely, four due to progressive disease and three due to causes other than severe toxicity. Grade 4 neutropenia was documented in most patients in preoperative cycles A1-3 (11/15 in A1, 9/11 in A2, and 7/11 in A3) and in all considering all cycles. Grade 3-4 thrombocytopenia and grade 3 anemia were also frequently observed. Patients experienced several episodes of grade 3 febrile neutropenia, but none had grade 4 febrile neutropenia or severe infections. One patient had grade 3 heart failure only in the first cycle. Other grade 3 or 4 toxicities were hypomagnesemia, anorexia, nausea, mucositis, liver enzyme elevation, fever, infection, and fatigue. There were no unexpected severe toxicities. CONCLUSION: The toxicity profile of JPLT3-H was comparable to that of SIOPEL-4. Dose-dense cisplatin-based chemotherapy may be feasible among Japanese patients with high-risk hepatoblastoma.

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.

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.

An anterior cricoid split and long-term silastic T-tube stenting for children with severe subglottic stenosis.

PURPOSE: The management of subglottic stenosis (SGS) remains challenging. Although laryngotracheal reconstruction with a costal cartilage graft (LTR) has been widely performed, restenosis with cicatricial tissue may require long-term stenting, especially in patients with severe SGS. An anterior cricoid split (ACS) with long-term stenting has been shown to be useful for patients with mild SGS. Thus, we evaluated the clinical outcomes of patients, including severe SGS, who underwent ACS compared to those with LTR. METHODS: A retrospective chart review was conducted in 25 patients with severe SGS (Grades III and IV) who underwent initial laryngoplasty (ACS or LTR) in our hospital from January 2009 to April 2018. RESULTS: 17 patients (8 with Grade III and 9 with Grade IV) underwent ACS, and 8 (6 with Grade III and 2 with Grade IV) underwent LTR. The median duration of stenting was 11 months (range: 0.8-50) in the ACS group and 12 months (range: 0.4-29) in the LTR group. Thirteen of 17 patients (76.5%) in the ACS group were decannulated, whereas 4 of 8 patients (50%) in the LTR group were decannulated (p = 0.2). CONCLUSION: ACS might be useful even for children with severe SGS. The optimal duration of stenting should be investigated further.

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.

An update in the management of pediatric sarcoma.

PURPOSE OF REVIEW: Nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) is a rare subgroup of malignancy in childhood that is composed of a variety of soft tissue and bony tumors. Prognosis for resectable localized disease is usually good and improved with systemic treatment. However, survival from locally advanced and metastatic disease remains poor. There have been numerous preclinical and clinical studies to define histopathology, biology, and genetic alteration of sarcomas. The purpose of this review is to clarify the progress in the management of NRSTS. RECENT FINDINGS: Genomic analysis, including the use of next-generation sequencing, has revealed fusion transcripts or specific genetic alterations which provide diagnostic biomarkers and potential targets for novel therapies. SUMMARY: Most cases are sporadic, but some are associated with genetic predispositions. Most present as a painless mass and diagnosis is frequently delayed because of a low index of suspicion. There is a wide array of histopathological subtypes. Investigations usually involve core, incisional or excisional biopsy for tissue diagnosis, and cross-sectional and nuclear imaging for staging. Management of pediatric sarcoma is largely dependent on the patient's histopathological diagnosis, age, disease stage, and co-morbidities but usually involves a combination of systemic and local therapies. Preclinical studies and phase I/II trials of newer targeted therapies are ongoing.

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.

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.

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.

Timing and outcome of stoma closure in very low birth weight infants with surgical intestinal disorders.

PURPOSE: Very low birth weight infants (VLBWIs) are at risk of surgical intestinal disorders including necrotizing enterocolitis (NEC), focal intestinal perforation (FIP), and meconium-related ileus (MRI). We conducted this study to verify whether the timing of stoma closure and that of enteral nutrition establishment after stoma closure in VLBWIs differ among the most common disorders. METHODS: A retrospective multicenter study was conducted at 11 institutes. We reviewed the timing of stoma closure and enteral nutrition establishment in VLBWIs who underwent stoma creation for intestinal disorders. RESULTS: We reviewed the medical records of 73 infants: 21 with NEC, 24 with FIP, and 25 with MRI. The postnatal age at stoma closure was 107 (28-359) days for NEC, 97 (25-302) days for FIP, and 101 (15-264) days for MRI (p = 0.793), and the postnatal age at establishment of enteral nutrition was 129 (42-381) days for NEC, 117 (41-325) days for FIP, and 128 (25-308) days for MRI (p = 0.855). The body weights at stoma closure were 1768 (620-3869) g for NEC, 1669 (1100-3040) g for FIP, and 1632 (940-3776) g (p = 0.614) for MRI. There were no significant differences among the three groups. CONCLUSIONS: The present study revealed that the time and body weights at stoma closure and the postoperative restoration of bowel function in VLBWIs did not differ among the three diseases.

Predictive factor for intraoperative tumor rupture of Wilms tumor.

PURPOSE: For Wilms tumor, intraoperative tumor rupture with wide tumor spillage during surgical manipulation raises the classification to stage 3. Then, postoperative chemotherapy must be more intensive, and abdominal radiotherapy is added. Therefore, intraoperative tumor rupture should be avoided if possible. However, predictive factors for intraoperative tumor rupture have not been sufficiently described. Here we examined the risk factors for intraoperative tumor rupture. METHODS: Patients with Wilms tumor who underwent treatment according to the National Wilms Tumor Study or the Japanese Wilms Tumor Study protocol at our institution were reviewed retrospectively. Collected cases were categorized into two groups: the ruptured group and the non-ruptured group. Risk factors for intraoperative tumor rupture, including the ratio of the tumor area to the abdominal area in a preoperative single horizontal computed tomography slice (T/A ratio), were investigated in both groups. RESULTS: The two groups were not different in age, body weight, tumor laterality, sex, or histological distribution. The T/A ratio in the ruptured group was significantly higher than that in the non-ruptured group. Receiver operating characteristic curve analysis identified a discriminative value for a T/A ratio >0.5. CONCLUSION: The T/A ratio can be a predictive factor for intraoperative tumor rupture of Wilms tumor.

Risk factors for surgical intestinal disorders in VLBW infants: Case-control study.

BACKGROUND: Very low-birthweight (VLBW) infants (VLBWI) are at increased risk for surgical intestinal disorders including necrotizing enterocolitis (NEC), focal intestinal perforation (FIP) and meconium-related ileus (MRI). The aim of this study was to identify disease-specific risk factors for surgical intestinal disorders in VLBWI. METHODS: A retrospective multicenter case-control study was conducted at 11 institutes. We reviewed VLBWI who underwent laparotomy for intestinal disorders including perforation and intractable bowel obstruction. The surgical disorders were classified into four categories (NEC, FIP, MRI, others) based on the macroscopic findings at operation. In order to identify risk factors, two matched controls for each subject were chosen based on gestational age and birthweight. OR and 95%CI were calculated using a conditional logistic regression model and a multivariate model. RESULTS: A total of 150 cases (NEC, n = 44; FIP, n = 47; MRI, n = 42; others, n = 17) and 293 controls were identified. The cases and controls were similar in terms of gestational age and birthweight (cases/controls, 26.7 ± 2.5/26.5 ± 2.6 weeks; 790 ± 256/795 ± 257 g). On multivariate modeling, disease-specific risk factors were as follows: female (OR, 0.23; 95%CI: 0.06-0.89), respiratory distress syndrome (OR, 35.7; 95%CI: 2.48-514) and patent ductus arteriosus (OR, 10.9; 95%CI: 1.51-79.3) for NEC; outborn delivery (OR, 5.47; 95%CI: 1.48-20.2) for FIP; and twin pregnancy (OR, 4.25; 95%CI: 1.06-17.1), PROM (OR, 6.85; 95%CI: 1.33-35.4) and maternal steroid (OR, 0.23; 95%CI: 0.07-0.79) for MRI. CONCLUSIONS: Different risk factors were identified for NEC, FIP and MRI, suggesting that each disease has a different etiology, and that different strategies are required to prevent these diseases.