Balloon dilatation for congenital esophageal stenosis associated with esophageal atresia.

PURPOSE: Congenital esophageal stenosis (CES) associated with esophageal atresia (EA) is rare, and no standard treatment has been established. We reviewed cases of EA-associated CES to assess the clinical characteristics and treatment outcomes, especially the feasibility of endoscopic dilatation. METHODS: We retrospectively examined patients with EA-associated CES. We also compared treatment outcomes of EA-associated CES with those of EA patients without CES who developed postoperative anastomotic stricture. RESULTS: Among 44 patients with EA, ten had CES (23%). Postoperative complications were not significantly different between EA patients with CES and those without CES but with anastomotic stricture. All CES patients underwent balloon dilatation as initial treatment. Eight of nine patients (89%) were successfully treated by dilatation only, and one patient underwent surgical resection. The median number of balloon dilatations for CES was five (2-17), which was higher than that for anastomotic stricture in patients without CES (p = 0.012). Esophageal perforation occurred in five patients with CES (5/9, 56%) after dilatation, but all perforations were successfully managed conservatively with an uneventful post-dilatation course. CONCLUSIONS: Twenty-three percent of patients with EA had CES. Although balloon dilatation for EA-associated CES required multiple treatments and carried a risk of perforation, balloon dilatation showed an 89% success rate and all perforations could be managed conservatively.

Tension-free thoracoscopic repair of congenital diaphragmatic hernia combined with a percutaneous extracorporeal closure technique: how to do it.

PURPOSE: Thoracoscopic repair (TR) of congenital diaphragmatic hernia (CDH) is associated with a higher recurrence rate than the conventional open method. We evaluated the effectiveness of our strategy for quality improvement, named "tension-free TR of CDH". METHODS: The subjects of this retrospective analysis were 11 consecutive patients with CDH who underwent TR at our hospital between 2017 and 2021. Tension-free TR of CDH included the proactive use of an oversized patch for dome-shaped reconstruction and gapless suturing. We developed a percutaneous extracorporeal closure technique for secure suturing using a commercially available needle. RESULTS: Patch repair was performed in 8 (73%) patients and none required conversion to open surgery because of technical difficulties. Recurrence developed in one patient (9%), who underwent successful reoperation via TR. All patients had an uneventful postoperative course. CONCLUSION: Tension-free TR combined with extracorporeal closure could reduce the difficulty of suturing and the risk of recurrence of CDH.

Regenerative medicine: current research and perspective in pediatric surgery.

The field of regenerative medicine, encompassing several disciplines including stem cell biology and tissue engineering, continues to advance with the accumulating research on cell manipulation technologies, gene therapy and new materials. Recent progress in preclinical and clinical studies may transcend the boundaries of regenerative medicine from laboratory research towards clinical reality. However, for the ultimate goal to construct bioengineered transplantable organs, a number of issues still need to be addressed. In particular, engineering of elaborate tissues and organs requires a fine combination of different relevant aspects; not only the repopulation of multiple cell phenotypes in an appropriate distribution but also the adjustment of the host environmental factors such as vascularisation, innervation and immunomodulation. The aim of this review article is to provide an overview of the recent discoveries and development in stem cells and tissue engineering, which are inseparably interconnected. The current status of research on tissue stem cells and bioengineering, and the possibilities for application in specific organs relevant to paediatric surgery have been specifically focused and outlined.

Treatment and follow-up of late onset intra hepatic bile duct stones in congenital biliary dilatation.

PURPOSE: The postoperative course after surgery for congenital biliary dilatation (CBD) has some complications. Intrahepatic bile duct (IHBD) stones were known as a late complication. We report on the treatment and long-term follow-up of postoperative IHBD stones in our department. METHODS: Patients who underwent CBD surgery at age 15 years or younger in our department were identified. Those followed up for 5 years or more were enrolled. Annual blood chemistry tests and abdominal ultrasonography were performed. Each patient's surgical procedure, IHBD stone diagnosis, treatments, and outcomes were retrospectively assessed. RESULTS: Fifty-one patients were analyzed. The median age at the last visit was 24 years (range 7-45 years), and the median age at CBD surgery was 3 years. Eight patients (16%) developed late-onset IHBD stones. The median age at onset was 25 years, and the median duration after surgery was 20 years. The initial treatment was double-balloon enteroscopy (DBE) in 4 cases, which resulted in stone removal in 3 of the 4 patients (75%). CONCLUSION: Since CBD may cause late-onset IHBD stones, continuous follow-up is required even in adulthood. In this study, DBE was effective and minimally invasive, and it is recommended as the initial treatment.

Early detection of liver fibrosis with serum Mac-2 binding protein glycosylation-modified isomer (M2BPGi) during follow-up intestinal failure patients without intestinal failure-associated liver disease (IFALD).

PURPOSE: Mac-2 binding protein glycosylation-modified isomer (M2BPGi) is a new marker for hepatic fibrosis progression. We examined the relationship between serum M2BPGi levels and liver histological findings in intestinal failure (IF) patients without IF-associated liver disease (IFALD). METHODS: This study included IF patients without IFALD followed at our hospital. All patients underwent routine liver biopsies per protocol every 1-2 years. We examined M2BPGi levels and histological findings in relation to aspartate aminotransferase (AST) to platelet ratio index, fibrosis-4 index, and AST/ALT ratio. Liver fibrosis was evaluated based on the METAVIR score. RESULTS: Total 18 liver biopsies out of eight patients were included. The median age was 11.5 years. Mean M2BPGi was 0.44 cutoff index (COI) in patients with F0 fibrosis, 0.78 COI in patients with F1 fibrosis and 1.63 COI in patients with F2 fibrosis. Mean M2BPGi was significantly higher in patients with F2 versus F1 or F0 fibrosis (P < 0.016 and P < 0.028, respectively). M2BPGi levels were more strongly correlated with fibrosis stage than with other conventional fibrosis markers. CONCLUSION: Serum M2BPGi is a novel marker of liver fibrosis in patients with IF. It is useful for follow-up prior to IFALD. Serum M2BPGi levels can support the interpretation of liver status.

Development of a porcine acellular bladder matrix for tissue-engineered bladder reconstruction.

PURPOSE: Enterocystoplasty is adopted for patients requiring bladder augmentation, but significant long-term complications highlight need for alternatives. We established a protocol for creating a natural-derived bladder extracellular matrix (BEM) for developing tissue-engineered bladder, and investigated its structural and functional characteristics. METHODS: Porcine bladders were de-cellularised with a dynamic detergent-enzymatic treatment using peristaltic infusion. Samples and fresh controls were evaluated using histological staining, ultrastructure (electron microscopy), collagen, glycosaminoglycans and DNA quantification and biomechanical testing. Compliance and angiogenic properties (Chicken chorioallantoic membrane [CAM] assay) were evaluated. T test compared stiffness and glycosaminoglycans, collagen and DNA quantity. p value of < 0.05 was regarded as significant. RESULTS: Histological evaluation demonstrated absence of cells with preservation of tissue matrix architecture (collagen and elastin). DNA was 0.01 µg/mg, significantly reduced compared to fresh tissue 0.13 µg/mg (p < 0.01). BEM had increased tensile strength (0.259 ± 0.022 vs 0.116 ± 0.006, respectively, p < 0.0001) and stiffness (0.00075 ± 0.00016 vs 0.00726 ± 0.00216, p = 0.011). CAM assay showed significantly increased number of convergent allantoic vessels after 6 days compared to day 1 (p < 0.01). Urodynamic studies showed that BEM maintains or increases capacity and compliance. CONCLUSION: Dynamic detergent-enzymatic treatment produces a BEM which retains structural characteristics, increases strength and stiffness and is more compliant than native tissue. Furthermore, BEM shows angiogenic potential. These data suggest the use of BEM for development of tissue-engineered bladder for patients requiring bladder augmentation.

[Pediatric Multiple Endocrine Neoplasia Type 2B with Pheochromocytoma Diagnosed after Perforation of a Colonic Diverticulum : A Case Report].

A 12-year-old girl was found to have decending colon diverticulum perforation and retroperitoneal abscess on computed tomography (CT) carried out to determine the cause of fever and stomachache. CT-guided drainage tube placement was performed. She was suspected of having MEN2B from her specific facial appearance, Marfan-like body shape and lingual mucosa neuroma. Cervical ultrasonography and serum tumor marker revealed medullary thyroid carcinoma and metastasis to cervical lymph node. Genetic examination revealed a mutation of RET gene codon 918. Therefore, she was diagnosed as having MEN2B. Laboratory data showed elevated urinary catecholamines. Metaiodobenzylguanidine (MIBG) adrenal scintigraphy showed bilateral adrenal uptake and a definitive diagnosis of bilateral adrenal pheochromocytomas was made. Discharge from the drainage tube persisted and it was difficult to continue conservative treatment. Therefore, laparoscopic bilateral adrenalectomy and transverse colon colostomy were performed. Subsequently, total thyroidectomy and cervical lymph node dissection were performed. At five years of follow up, bilateral lung metastases were observed, but the serum calcitonin level was normal and the patient is under observation.

Whole rat stomach decellularisation using a detergent-enzymatic protocol.

BACKGROUND: Conditions leading to reduced gastric volume are difficult to manage and are associated to poor quality-of-life. Stomach augmentation using a tissue-engineered stomach is a potential solution to restore adequate physiology and food reservoir. Aim of this study was to evaluate the decellularisation of whole rat stomach using a detergent-enzymatic protocol. METHODS: Stomachs harvested from rats were decellularised through luminal and vascular cannulation using 24-h detergent-enzymatic treatment and completely characterized by appropriate staining, DNA and Extracellular matrix -component quantifications. RESULTS: The detergent-enzymatic protocol allows a complete decellularisation of the gastric tissue, with a complete removal of the DNA with two cycles as confirmed by both quantifications and histological analysis. Extracellular matrix components, collagen, fibronectin, laminin and elastin, were optimally preserved by the treatment, while glycosaminoglycans were reduced. CONCLUSION: Gastric tissue can be efficiently decellularised. Scaffolds retained original structure and important components that could enhance integration with other tissues for in vivo transplant. The use of naturally derived material could be potentially considered for the treatment of both congenital and acquired conditions.

Regeneration Process of an Autologous Tissue-Engineered Trachea (aTET) in a Rat Patch Tracheoplasty Model.

The treatment of long-tracheal lesion is difficult because there are currently no viable grafts for tracheal replacement. To solve this problem, we have developed an autologous Tissue-Engineered Trachea (aTET), which is made up of collagenous tissues and cartilage-like structures derived from rat chondrocytes. This graft induced successful long-term survival in a small-animal experiment in our previous study. In this study, we investigated the regeneration process of an aTET to attain reproducible success. We prepared an aTET by using a specially designed mold and performed patch tracheoplasty with an aTET. We assigned twenty-seven rats to three groups according to the three types of patch grafts used: aTET patches (the aTET group), fresh tracheal autograft patches (the Ag group), or polylactic acid and polycaprolactone copolymer sheets (the PPc group). In each group, gross and histological evaluations were performed at 1 month (n = 3), 3 months (n = 3), and 6 months (n = 3) after implantation. We obtained high survival rates in all groups, but only the PPc group attained thick tracheal walls with granular tissues and no tracheal regeneration. On the other hand, the aTET and Ag groups reproducibly achieved complete tracheal regeneration in 6 months. So, an aTET could be a promising candidate for tracheal regeneration grafts.

Impact of Total Parenteral Nutrition on Preoperative Management of Pediatric Living-Donor Liver Transplantation for Biliary Atresia Under 2 Years Old.

BACKGROUND: Liver failure and gastrointestinal bleeding occur in the end-stage of biliary atresia (BA). Living-donor liver transplantation (LDLT) is a standard treatment in Japan. Our program actively provides pre-transplant total parenteral nutrition (TPN) for such patients, and here we report its efficiency and safety. METHODS: Patients with BA for whom LDLT was indicated were identified. Those with a long-term external central venous catheter and TPN, longer than 4 weeks before LDLT, were analyzed. Ascites was controlled with diuretics. TPN indications, efficacy, and complications were assessed along with patient growth, biochemical markers, and gastrointestinal bleeding. RESULTS: Fourteen patients were included in the study, of whom 8 were girls and 6 were boys. The median age at LDLT was 0.9 years. Body weight (BW) at TPN initiation averaged 6799 g, and the median serum total bilirubin was 9.5 mg per dL. The median catheterization duration was 54 days, and 1 patient received home TPN. Indications for TPN were gastrointestinal bleeding and/or massive esophageal varices in 4 patients and poor nutritional status in 10 patients. No complications were observed except for 1 catheter infection and 1 catheter occlusion. The median final body weight before LDLT was 7906 g. The mean rate of BW gain was significantly higher after TPN than before (149 vs 32 g/wk, respectively, P = .0002). Mean prothrombin time and levels of albumin, cholinesterase, and total bilirubin were not significantly different at the start and end of TPN. CONCLUSIONS: Pre-transplant TPN was safe and effective for patients with end-stage BA.

Plasma Concentration of Antifungal Agent Micafungin for Pediatric Living Donor Liver Transplantation.

BACKGROUND: Pediatric living-donor liver transplantation (LDLT) candidates often receive long-term antibiotic treatment. Micafungin has been used as an antifungal agent after LDLT, but the adequate dose after pediatric LDLT was unknown. Here, we report micafungin blood concentrations after pediatric LDLT and discuss its safety and adequate dosing. METHODS: Pediatric patients with data on micafungin concentrations after LDLT were identified. Those with surgical complications were excluded. All patients received standard tacrolimus-based immunosuppression. A micafungin dose of 1 mg/kg was administered once daily for 10 days starting on postoperative day (POD) 1. The trough and peak micafungin blood concentrations were evaluated on PODs 1, 4, 7, and 10. Beta D glucan levels and liver function tests were assessed to determine micafungin effectiveness and safety. RESULTS: Ten patients were enrolled, with a median age of 1.2 years. The median graft vs body weight ratio was 2.7%. The primary diseases were biliary atresia (n = 7), Alagille syndrome (n = 2), and progressive familial intrahepatic cholestasis type 2 (n = 1). Mean peak micafungin levels were 4.47, 6.27, 5.47, and 5.47 µg/mL on PODs 1, 4, 7, and 10, respectively. Mean trough levels were 2.03, 1.88, and 2.66 µg/mL on PODs 4, 7, and 10, respectively. The micafungin half-lives were 13.7, 14.7, and 14.0 hours on PODs 4, 7, and 10, respectively. Beta D glucan levels were 4.4 pg/mL and 3.7 pg/mL before and after transplantation, respectively, indicating no significant difference (P = .3). No clinical fungal infections were observed. CONCLUSION: Micafungin administration is safe and effective after pediatric LDLT.

Clinical Implications of Serum Mac-2 Binding Protein in Patients After Living Donor Liver Transplantation for Biliary Atresia.

BACKGROUND: Patients who undergo pediatric living donor liver transplantation (LDLT) sometimes develop graft fibrosis. Recently, Mac-2 binding protein glycosylation-modified isomer (M2BPGi) was developed as a new marker of hepatic fibrosis progression. We performed this study to examine the relationship between serum M2BPGi levels and liver histologic findings in patients after LDLT for biliary atresia. METHODS: Patients aged <19 years who underwent LDLT for biliary atresia at our institution and followed up for at least 1 year after LDLT were eligible. There were 56 patients in this study. Pathologic findings of the last available biopsy were assessed. Portal vein (PV) stenosis was confirmed with angiography. M2BPGi levels were compared with pathologic fibrosis scores and PV stenosis findings. RESULTS: The mean age at transplant was 4.3 years. The mean observation period was 8.6 years. In terms of the degree of liver fibrosis, F0 was observed in 7 patients, F1 in 36, and F2 in 13. The median serum M2BPGi value was 0.8 cut-off index (COI) overall and 0.60 COI for F0, 0.74 COI for F1, and 1.07 COI for F2. The mean M2BPGi value in F2 was higher than that in F0 (P = .016) and F1 (P = .012). Mean serum M2BPGi values were 1.57 COI (0.29 COI) in patients with PV complications (n = 5) and 0.72 COI in patients without PV complications (n = 51) (P = .0001). CONCLUSION: M2BPGi is a novel marker for liver fibrosis in patients after pediatric LDLT. It is especially useful for follow-up of pediatric patients after LDLT to support liver biopsy interpretation.

Potential risks associated with laparoscopic gastrostomy in patients with the COL4A1 variant: Two case reports.

The COL4A1 (collagen Type 4 alpha1) pathogenic variant is associated with porencephaly and schizencephaly and accounts for approximately 20% of these patients. This gene variant leads to systemic microvasculopathy, which manifests as brain, ocular, renal, and muscular disorders. However, only a few patients with surgical interventions have been reported and the potential surgical risks are unknown. Here, we present the cases of two female patients between 7 and 8 years of age who were diagnosed with the COL4A1 variant and underwent laparoscopy-assisted percutaneous endoscopic gastrostomy (LAPEG) for oral dysphagia. Their primary brain lesions were caused by porencephaly and paralysis, which are caused by multiple cerebral hemorrhages and infarctions, and both patients had refractory epileptic complications. Although LAPEG was successfully performed in both patients without any intraoperative complications, one patient developed alveolar hemorrhage postoperatively and required mechanical ventilation. Thus, careful perioperative management of patients with the COL4A1 variant is important.

[Efficacy of capecitabine/cisplatin chemotherapy after failure of all conventional therapies in patients with advanced gastric cancer].

There is no standard therapy for advanced gastric cancer patients who had already failed treatment with major anti-cancer drugs including fluoropyrimidine, cisplatin, taxans, and irinotecan. We report the results of treatment with capecitabine and cisplatin(XP)after the failure of all other conventional therapies. A total of five advanced gastric cancer patients were treated. The median age was 59 years(range, 46-76); there were 3male and 2 female patients; performance status was 0/1/2: 2/2/ 1 patients, respectively. The median duration from start of first-line chemotherapy to XP was 653 days(range, 372-1,107). Three patients were treated after fourth-line therapy and two patients after fifth-line therapy. All of the patients had received S-1, cisplatin, irinotecan, paclitaxel, and docetaxel previously. Patients received 80mg/m2 of cisplatin intravenously on day 1, and 1,000mg/m2 of capecitabine orally twice a day from day 1 to day 14 followed by a 7-day rest period. Treatment courses were between 2 to 5. Median time to progression was 107 days. Median overall survival was 245 days. One PR and one SD were reported. All reported adverse events were manageable. XP is considered one of the effective regimens for advanced gastric cancer after all conventional therapies have failed.

[A case of HER2-positive advanced gastric cancer successfully treated with a combination of capecitabine, cisplatin, and trastuzumab as first-line chemotherapy].

We report a case of human epidermal growth factor receptor(HER)2-positive advanced gastric cancer successfully treated with a combination of capecitabine, cisplatin(CDDP), and trastuzumab as first-line chemotherapy. A 66-year-old woman diagnosed as having advanced gastric cancer underwent chemotherapy after abdominal computed tomography (CT)revealed multiple metastases to the liver, lung, lymph nodes, and peritoneum. Histopathological examination indicated a type 3, tub1, cT3(SS), N3, H1, P1, M1(LYM, PUL), cStage IV gastric tumor. Because overexpression of HER2 protein was observed in primary tumor immunostaining, combination therapy of capecitabine+CDDP+trastuzumab was administered as first-line chemotherapy. After 4 courses, CT scans revealed decreased primary tumor size, liver lesion, lymph nodes, and elimination of the lung lesion, thereby suggesting a partial response(PR). The grade 3 adverse events were neutropenia, anemia, and anorexia. After discontinuation of CDDP because of elevation of serum creatinine levels, combination therapy with capecitabine and trastuzumab was continued.

[A case of advanced gastric cancer with para-aortic lymph node metastasis successfully treated with preoperative S-1/Lentinan chemotherapy followed by curative gastrectomy].

We report a case of advanced gastric cancer successfully treated with preoperative S-1/Lentinan (LTN)chemotherapy followed by curative gastrectomy. The patient was a 75-year-old man with right hypochondralgia. Endoscopic examination revealed a huge type 2 gastric cancer in the middle body of the stomach. Abdominal computed tomography (CT) revealed multiple perigastric lymph node metastases and bulky para-aortic lymph node metastases. The clinical diagnosis was cT 4N3M1( LYM) with cStage IV. We thought a complete resection would be difficult, so he was treated with S-1( 80 mg/m2 day 1-28/q6w) and LTN (2 mg weekly) in May 2010. After 3 courses, the primary lesion was markedly reduced, and gastric endoscopic biopsy showed no malignant lesion. After 4 courses, abdominal CT showed no lymph node swelling at the perigastric and para-aortic areas. After 5 courses, distal gastrectomy with D2 lymphadenectomy was performed. The histological diagnosis was ypT2( MP) N0M0, Stage IB. Histological features of the primary tumor and lymph nodes were judged to be Grade 2 and Grade 3, respectively. After surgery, S-1/LTN treatment was continued for 1 year. During this period, there were no serious adverse events. The patient has been in good health without recurrence for 28 months after surgery.

[A case of paclitaxel-resistant recurrent gastric cancer responsive to S-1 plus docetaxel].

We report the case of a patient with paclitaxel (PTX) -resistant recurrent gastric cancer who was effectively treated with S-1 plus docetaxel( DOC). A 62-year-old woman underwent total gastrectomy for Stage IV advanced gastric cancer (type 4, por 2>sig, pT4a (SE), pN3a, pP1, CY1) in 2009. Although S-1 was administered as first-line chemotherapy, recurrent peritoneal metastasis was diagnosed 22 months after surgery. S-1 plus irinotecan (CPT-11) was administered as second-line chemotherapy, and this was followed by weekly PTX (80 mg/m2) as third-line chemotherapy. However, computed tomography (CT) showed increased ascites and peritoneal wall thickening in the pelvis. As the tumor proved resistant to PTX, making the treatment ineffective, S-1( 80 mg/m2, day 1-14, q3w) plus DOC( 40 mg/m2, day 1, q3w) was initiated. Two months later, the ascites and peritoneal wall thickening in the pelvis disappeared. Twelve months after initiation of S-1 plus DOC chemotherapy, no sign of recurrence has been noted.

[Analysis of combination chemotherapy with docetaxel and nedaplatin for esophageal cancer].

PURPOSE: There is no standard second line regimen for metastatic or recurrent esophageal cancer. We investigated the feasibility of combination chemotherapy with Docetaxel (DOC) and Nedaplatin (CDGP) as a second-line regimen for metastatic or recurrent esophageal cancer. MATERIALS AND METHODS: Patients received DOC (60 mg/m2 intravenously) on day 1 and subsequently CDGP(70 mg/m2 intravenously) on day 1 of each 4-week period thereafter. We analyzed the toxicity and efficacy in 9 patients treated with combination chemotherapy with DOC and CDGP. RESULT: The observed Grade 3-4 toxicities were neutropenia and anemia. Three patients had stable disease and 6 patients had progressive disease. The median progression free survival and overall survival were 4.3 and 8.1 months, respectively. CONCLUSION: Combination chemotherapy with DOC and CDGP is considered a feasible second line regimen for metastatic or recurrent esophageal cancer.

Factors Associated With Adverse Outcomes Following Duodenal Atresia Surgery in Neonates: A Retrospective Study.

Objectives There is limited evidence on the infants' postoperative complications who have undergone surgical repair of duodenal atresia and stenosis. This study aimed to identify the factors associated with poor surgical outcomes after the initial repair. Methods We retrospectively reviewed the data of 82 patients who underwent surgery for duodenal atresia and stenosis between January 1994 and December 2013 at our institution. Gestational age, birth weight, fetal growth, and other associated anomalies were recorded. Multivariate regression analyses were used to identify the factors associated with surgical outcomes, including postoperative complications and time to full oral intake. Results The median gestational age was 37.6 weeks, with 30 (37%) preterm (<37 weeks) and 11 (13%) early preterm (<34 weeks) infants. The median birth weight was 2531 g, with 27 (33%) patients < 2000 g and 10 (12%) patients < 1500 g. Postoperative surgical complications were identified in 18 (22%) cases, of which 12 (15%) required additional operations. Multivariate regression analysis revealed that a combination of very low birth weight (<1500 g) and early preterm was significantly associated with both surgical and non-surgical postoperative complications (p = 0.0028 and 0.021, respectively) and a prolonged time to full oral intake postoperatively (p = 0.013). Conclusion Very low birth weight and early preterm were significantly associated with postoperative complications and a prolonged time to full oral intake.

Ileocecal valve-sparing surgery for duplication cysts in the terminal ileum: two case reports and literature review.

BACKGROUND: Duplication cysts close to the ileocecal valve are usually treated with ileocecal resection. However, loss of the ileocecal valve will lead to problems, especially in infants. Mucosectomy of the cyst would be a better alternative that preserves the ileocecal valve. We report two cases of duplication cyst in the terminal ileum successfully treated with mucosectomy. CASE PRESENTATION: Case 1. A 3-month-old boy with bilious emesis and abdominal distention was referred to our hospital with a diagnosis of small bowel obstruction caused by an abdominal cyst. Computed tomography revealed a cystic mass compressing the terminal ileum and causing mechanical small bowel obstruction. His general condition deteriorated quickly; emergency laparotomy was performed. Although the small intestines were dilated and partially twisted, there was no necrosis. Following intestinal decompression, a cystic mass adjacent to the terminal ileum was confirmed on the mesenteric side. Cyst mucosectomy was performed to preserve the ileocecal valve. CASE 2: A 5-month-old boy with sudden onset of hematochezia was referred to our hospital with a diagnosis of intussusception. Following unsuccessful contrast enemas, emergency surgery was performed. A cystic mass adjacent to the terminal ileum was confirmed; there was no intussusception. Cyst mucosectomy was performed. Both patients had an uneventful postoperative course. CONCLUSIONS: Cyst mucosectomy, which preserves the ileocecal valve, is safe and effective for treating duplication cysts in the terminal ileum.