Benign pyloric adenomyoma presented as gastric outlet obstruction: a case report and review of the literature.

BACKGROUND: Gastric adenomyoma is a rare benign tumor composed of glandular structures and smooth muscle fibers. While some classify gastric adenomyoma as a hamartoma, others view it as an abortive form of heterotopic pancreas. Despite its benign nature, there is a risk of malignant transformation. Predominantly found in the antrum, gastric adenomyoma affects all ages but is most common in adults aged 40-60 years. Symptoms are nonspecific, and its similarity to other lesions complicates diagnosis. This paper aims to provide a review of medical literature on gastric adenomyoma and its diagnosis and treatment methods, along with presenting an additional case report on the same topic. CASE PRESENTATION: We present the case of a 55-year-old Syrian man who experienced vomiting, weight loss, and chronic partial constipation. An obstructing mass in the pylorus was detected, and then an open surgery was performed to excise the lesion. A biopsy of the resected mass was obtained for histopathological examination. The final diagnosis of the lesion was pyloric-region adenomyoma with severe pyloric stenosis. After the successful surgery, the patient recovered without any recurrence or complications. CONCLUSIONS: Several diagnostic approaches are available, including radiological studies, endoscopic examination, and fine needle aspiration guided by endoscopic ultrasonography. Treatment options involve endoscopic submucosal dissection and complete laparotomy resection. Further studies and thorough reviews are recommended to better understand the best clinical practices. Practitioners should consider gastric adenomyoma when encountering a mural gastric lesion.

Congenital pyloric atresia associated with epidermolysis bullosa junctionalis: a novel lethal variant.

A term male baby was born vaginally to a primi mother. An antenatal ultrasound revealed polyhydramnios and a distended stomach in the baby. At birth, the baby had well-defined areas of peeling skin on the face and blisters on the forearm region. The abdominal X-ray revealed a single gastric bubble, which is consistent with pyloric atresia and needs surgery. Pyloroplasty was initially performed, but it was unsuccessful. Therefore, a feeding jejunostomy and gastrostomy were performed. However, the baby developed sepsis and septic shock and died at about 2 months of age. Skin biopsy revealed cleavage above the lamina densa, and genetic analysis indicated heterozygosity in ITGB4 exons 10 and 16, which are associated with epidermolysis bullosa junctionalis and pyloric atresia.

Gastritis cystica profunda in an unoperated stomach mimicking a pyloric submucosal tumor and causing anorexia: A case report and literature review.

BACKGROUND: Gastritis cystica profunda (GCP), commonly observed in remnant gastric anastomosis, is associated with developing gastric cancer. CASE: This case report describes a patient with GCP in a previously unoperated stomach that mimicked a pyloric submucosal tumor and caused anorexia, which is rare in clinical practice. PATIENT CONCERNS: A 72-year-old woman presented with loss of appetite and weight. DIAGNOSES: Gastroscopy detected a 20 mm diameter submucosal tumor near the pylorus. Computed tomography and magnetic resonance imaging identified a cystic lesion, unlike a usual submucosal tumor in the stomach. The diagnosis was difficult, even with endoscopic ultrasound-guided fine-needle aspiration. INTERVENTIONS: Surgery was performed for diagnosis and treatment. The lesion was resected using a submucosal dissection technique after an incision of the gastric wall during open laparotomy. Histopathological examination confirmed the diagnosis of GCP and revealed no dysplasia or cancer. OUTCOMES: Anorexia resolved after the surgery. Residual or recurrent lesions were not detected during follow-up examinations performed 1 year after surgery. LESSONS: GCP occurring in a previously unoperated stomach as a macroscopic lesion like a submucosal tumor causing some symptoms is rare. GCP is associated with a risk of developing cancer. Therefore, careful evaluation and management during treatment are required.

FDG PET/CT in Pancreatic Ductal Adenocarcinoma Arising From a Heterotopic Pancreas of the Pylorus.

ABSTRACT: Malignant transformation of heterotopic pancreas is extremely rare. We describe FDG PET/CT findings in a case of pancreatic ductal adenocarcinoma arising from a heterotopic pancreas in the submucosa of the pylorus with peripyloric lymph node metastasis and elevated serum carbohydrate antigen 19-9 level. The heterotopic pancreatic adenocarcinoma showed intense FDG uptake, and the peripyloric lymph node metastasis showed mild FDG uptake. This case indicates that heterotopic pancreatic adenocarcinoma should be included in the differential diagnosis of FDG-avid gastric submucosal lesions, especially in patients with elevated serum carbohydrate antigen 19-9 level.

Variations in the origin of the infrapyloric artery: A systematic review and meta-analysis.

BACKGROUND: The infrapyloric artery (IPA) supplies the pylorus and the large curvature of the antrum. Its common origin points include the gastroduodenal artery (GDA) and right gastroepiploic artery (RGEA). The prevalence of variations in IPA origins can be of interest to gastric cancer surgeons who wish to increase their understanding of this vessel. The primary aim of this study was to perform a systematic review and meta-analysis on the origin of the IPA. The secondary aims were to assess imaging identification accuracy, to identify IPA morphological features, and to explore the relationship of IPA origin and clinicopathological characteristics. METHODS: Electronic databases, currently registered studies, conference proceedings and the reference lists of included studies were searched through March 2023. There were no constraints based on language, publication status, or patient demographics. Database search, data extraction and risk of bias assessment were performed independently by two reviewers. The point of origin of the IPA was the primary outcome. Secondary outcomes were imaging identification accuracy, relationship between IPA origin and clinicopathological characteristics, and IPA morphological features. A random-effects meta-analysis of the prevalence of different IPA origins was conducted. Secondary outcomes were narratively synthesized given the heterogeneity of studies reporting on these. RESULTS: A total of 7279 records were screened in the initial search. Seven studies were included in the meta-analysis, assessing 998 patients. The IPA arose most frequently from the anterior superior pancreaticoduodenal artery (ASPDA), with a pooled prevalence of 40.4% (95% CI 17.1-55.8%), followed by the RGEA with a pooled prevalence of 27.6% (95% CI 8.7-43.7%), and the GDA with a pooled prevalence of 23.7% (95% CI 6.4-39.7%). Cases of multiple IPAs had a pooled prevalence of 4.9% (95% CI 0-14.3%). The IPA was absent in 2.6% (95% CI 0-10.3%) of cases and arose from the posterior superior pancreaticoduodenal artery (PSPDA) in the remaining 0.8% (95% CI 0 - 6.1%). Distance between the pylorus and the proximal branch of the IPA and distance from the pylorus to the first gastric branch of the RGEA when the IPA originated from the ASPDA and RGEA were longer than when the IPA originated from the GDA. The IPA is a small vessel (<1 mm), and its origin is not related to clinicopathological characteristics including patient sex, age, and tumor stage and location. CONCLUSIONS: Surgeons must be aware of the most common origin points of the IPA. Recommendations for future study include the stratification of IPA origin according to demographic characteristics, and further investigation into IPA morphological parameters such as tortuosity, course and relation to adjacent lymph nodes, aiding the creation of a standardized classification system pertaining to the anatomy of this vessel.

[Research progress in anti-reflux reconstructions and mechanism after proximal gastrectomy].

The electrophysiological activity of the gastrointestinal tract and the mechanical anti-reflux structure of the gastroesophageal junction are the basis of the anti-reflux function of the stomach. Proximal gastrectomy destroys the mechanical structure and normal electrophysiological channels of the anti-reflux. Therefore, the residual gastric function is disordered. Moreover, gastroesophageal reflux is one of the most serious complications. The emergence of various types of anti-reflux surgery through the mechanism of reconstructing mechanical anti-reflux barrier and establishing buffer zone, and the preservation of, the pacing area and vagus nerve of the stomach, the continuity of the jejunal bowel, the original gastroenteric electrophysiological activity of the gastrointestinal tract, and the physiological function of the pyloric sphincter, are all important measures for gastric conservative operations. There are many types of reconstructive approaches after proximal gastrectomy. The design based on the anti-reflux mechanism and the functional reconstruction of mechanical barrier, and the protection of gastrointestinal electrophysiological activities are important considerations for the selected of reconstructive approaches after proximal gastrectomy. In clinical practice, we should consider the principle of individualization and the safety of radical resection of tumor to select a rational reconstructive approaches after proximal gastrectomy.

Gastroblastoma of the Pylorus: A Case Report and Review of the Literature.

Gastroblastoma is an extremely rare biphasic tumor that typically occurs in the stomach in patients between the ages of 10 and 30. Only 16 cases have been reported previously. These tumors are important to diagnose and distinguish from more aggressive neoplasms; although numbers are small, prognosis appears excellent overall with complete excision, with only occasional metastasis and/or local recurrence. We report a case of gastroblastoma in a 26-year-old male arising from the pylorus and extending through the first and second portions of the duodenum. This is the first case to be reported from this specific location.

[Current status of lymph node dissection in pyloric-preserving gastrectomy for early gastric cancer].

With the gradual increase in the diagnosis rate of early gastric cancer, clinicians must consider prevention of gastric anatomical structure and physiological function while ensuring the radical treatment of the tumor. Pylorus-preserving gastrectomy is a function- preserving operation that preserves the pylorus, inferior pyloric vessel, and the vagus nerve in patients with early middle gastric cancer. One of the major controversies at present is the thoroughness of limited lymph node dissection for pyloric-preserving gastrectomy. Various studies have reported that the lymph node metastasis rate of early middle gastric cancer was low, especially in the suprapyloric region, inferior pylorus and the upper pancreatic region. Partial lymph node dissection is required for vascular and neurological protection, which is also safe and feasible in studies reported by major centers. Many clinical studies have been carried out in Japan and Korea, and postoperative follow-up has gradually increased evidence, providing the basis for the safety of lymph node dissection. In large case studies comparing pylorus- preserving gastrectomy with traditional distal gastrectomy, the incidence of postoperative morbidity, such as dumping syndrome, bile reflux esophagitis, weight loss, and malnutrition is low. Sentinel lymph node navigation technology is gradually applied to the diagnosis and treatment of early gastric cancer, and its clinical application value still needs further research.

Aberrant pancreas adenocarcinoma in the stomach: A case report and literature review.

RATIONALE: Aberrant pancreatic tissue in the gastrointestinal tract is a relatively common finding. However, malignant transformation is extremely rare. Herein, we report a case of ectopic pancreatic ductal adenocarcinoma in the stomach wall. PATIENT CONCERNS: A 38 year old male presented with nausea, bloating, abdominal distention and weight loss for 4 months. DIAGNOSES: Endoscopy of upper gastrointestinal tract was performed twice with 2 months interval and a stenotic pyloric part was observed with a suspected submucosal lesion. It was sampled both times, however the pathology findings of the mucosal biopsies were unremarkable with no identifiable neoplastic structures. CT scan and MRI was performed and showed a thickened pyloric wall with a submucosal lesion 15 × 15 mm in diameter. Blood levels of tumor markers carcinoembrionic antigen and carbohydrate antigen 19-9 were within a normal range. INTERVENTIONS: Pyloric stenosis progressed and the patient underwent a Billroth type I distal gastric resection with D2 lymphadenectomy. Pathologic examination revealed a well differentiated ductal adenocarcinoma arising in the heterotopic pancreatic tissue (Heinrich type III). The resection margins and lymph nodes were free of tumor. The patient received adjuvant chemotherapy with 6 courses of XELOX. OUTCOMES: No disease recurrence is reported in 12 months follow-up. LESSONS: Aberrant pancreatic ductal adenocarcinoma in the stomach is a rare finding, however this pathology should be included in the differential diagnosis of gastric submucosal lesion causing pyloric stenosis.

Pylorus-preserving versus Pylorus-resecting: Impact on dynamic changes of nutrition and body composition in pancreatic cancer patients before and after pancreatoduodenectomy.

OBJECTIVES: To investigate if different methods of pancreatoduodenectomy (with or without pyloric preservation) would have different impacts on postoperative nutrition and body composition changes among pancreatic cancer patients. METHODS: Demographic and clinicopathological data, perioperative data were collected, body composition (e.g. skeletal muscle cross-sectional area [CSA], visceral fat area [VFA]) were evaluated with abdominal CT before and after surgery. Sarcopenia patients' proportion changes were also recorded. RESULTS: The hospital stay in the PRPD group was significantly less than that in the PPPD group (p < 0.05). A significant difference was found in CSA, skeletal muscle index (SMI), VFA, VFA/CSA and albumin (ALB) in both groups between preoperative, 3, and 12 months after surgery. The loss of visceral fat in the PRPD group was more prominent than that in the PPPD group at 3 months and 12 months after surgery (p < 0.05). VFA/CSA was higher in the PPPD group than in the PRPD group (3 months: p < 0.05, 12 months: p < 0.001). The proportion of sarcopenic patients increased significantly over time in the PPPD and PRPD groups (p < 0.001). CONCLUSIONS: Postoperative CSA and VFA continued to significantly decrease in both PPPD and PRPD groups, while the incidence of sarcopenia continued to increase. Compared with PRPD, PPPD has a protective effect on visceral fat. PPPD may contribute to better maintaining visceral fat mass and blood ALB levels. CT quantification can be an objective and effective method to evaluate the nutritional status of pancreatic cancer patients during the pre- and postoperative period and can provide a useful objective basis for guiding clinical treatment.

Feasibility and safety of inserting transient biodegradable stents in the pylorus during pylorus-preserving gastrectomy for gastric cancer: a preliminary study in a porcine for proof of concept.

BACKGROUND: To evaluate whether insertion of self-biodegradable stent into the pylorus to prevent delayed-gastric emptying after pylorus-preserving gastrectomy is feasible and safe through porcine experiment. METHODS: Self-biodegradable dumbbell-shaped pyloric stents were designed from absorbable suture materials: poly(glycolide-co-caprolactone) (PGCL) or poly-p-dioxanone (PPDO). After gastrotomy on ten pigs, each stent was inserted: two shams, four PGCL stents, and four PPDO stents. Body weight (Bwt), body temperature (BT), complete blood cell (CBC) count, and plain X-ray were evaluated. On postoperative day (POD) 13, euthanasia was performed for histologic evaluation. RESULTS: Operation was successfully performed in all ten pigs. Without tagging suture, both stents migrated before POD 3. The migration was delayed up to POD 13, when the tagging sutures (-t) were applied between stent and stomach wall. Self-degradation of PGCL started from POD 3, and stents were completely excreted from the abdomen by POD 8. Although PPDO were also weakened as self-degradation progressed, its shape was maintained in gastrointestinal tract for 13 days. Unexpected sudden death occurred in the pig with PPDO-t2 on POD 10, which is more likely due to acute volvulus rather than stent-related complication. There was no significant difference between three groups in terms of Bwt, BT, CBC, and histology (sham vs. PGCL vs. PPDO, all p > 0.05). CONCLUSION: The concept of biodegradable stents made of absorbent suture material seems feasible in porcine experiment. Among them, PGCL which has shown rapid absorption, appears to be a more suitable material for transient pyloric absorbable stent when considering safety aspect.

[Hybrid laparo-endoscopic gastric resection for non-epithelial pyloric tumor]. / Opyt gibridnoi laparo-endoskopicheskoi rezektsii zheludka pri neepitelial'noi opukholi piloricheskoi zony.

In January 2020, a patient with a gastrointestinal stromal tumor of the antrum located in close proximity to the pylorus underwent a hybrid laparo-endoscopic organ-sparing gastric resection. There were no intraoperative and postoperative complications. Control endoscopic and X-ray examination of the stomach confirmed normal motor and evacuation function of the stomach. To date, follow-up period is more than 1.5 years. The patient has no complaints. This case demonstrates clear advantages of hybrid access in certain clinical situations, such as localization in anatomically difficult areas and near functional sphincters. Surgical approach ensured pylorus-sparing resection with favorable postoperative result.

Quantification of Interstitial Cells of Cajal in the Gastric Muscle of Patients with Gastroparesis at Per-Oral Endoscopic Pyloromyotomy: A Novel Approach for Future Research in Pathogenesis of Gastroparesis.

BACKGROUND: The role of Interstitial Cells of Cajal (ICC) in the pathogenesis of gastroparesis has been suggested by previous studies due to their involvement in the transmission of neuronal signaling to the smooth muscles of the GI tract. However, studies have been limited by the inability to obtain a gastric muscle sample, since routine endoscopy can only biopsy the mucosa. We present a new technique of muscle biopsy during per-oral endoscopic pyloromyotomy (GPOEM), a novel endoscopic procedure for treatment of gastroparesis. PATIENTS AND METHODS: All enrolled patients had diagnosed gastroparesis and had biopsies of the muscular layer at the antrum/pylorus during POEM. All GPOEM procedures took place from August 2019 to December 2019. Various demographic, disease-related, and procedure-related data were collected from chart review. ICC in the biopsy specimen was examined and quantitated. RESULTS: Through this method, we readily expose the gastric muscle of 21 patients through dissection of a gastric submucosal tunnel during GPOEM and provide reliable muscle sample for ICC quantification. Average number of ICC were higher in clinical responders (88 ICC ± 63 vs. 39 ICC ± 24, p = 0.02), defined as those who experienced significant improvement in nausea and vomiting symptoms after GPOEM. CONCLUSIONS: This study provides a reliable novel biopsy method for safely biopsy gastric muscle for quantitating the number of gastric ICC in patients with gastroparesis. The number of ICC may be related to the outcome of GPOEM therapy. However, further studies with larger number of patients are needed to confirm the results.

[A Case of Inverted LECS for GIST Near the Pylorus Ring].

Laparoscopy and endoscopy cooperative surgery(LECS)is a surgical procedure to avoid excessive resection of the gastrointestinal wall and preserve its function. For gastrointestinal stromal tumors(GIST)near the cardia and pylorus ring, the function of the cardia and pylorus can be preserved by minimum excision and hand-sewn suture closures. Here, we report a case successfully treated with inverted LECS for GIST near the pylorus ring. The patient was a 58-year-old male. Upper gastrointestinal endoscopy had revealed a 45 mm sized SMT near the pylorus ring. Biopsy by EUS-FNA indicated gastric GIST. The tumor was separated from the pylorus ring and inverted LECS was performed. The defect was closed with hand-sewn sutures, forming an L-shape. The postoperative course was good and he was discharged from hospital 10 days after surgery. It is considered that devising the direction of closure by means of the LECS procedure can preserve the pyloric function without passage obstruction or stasis, even for gastric GIST near the pylorus ring.

Open versus laparoscopic pyloromyotomy for pyloric stenosis.

BACKGROUND: Infantile hypertrophic pyloric stenosis (IHPS) is a disorder of young children (aged one year or less) and can be treated by laparoscopic (LP) or open (OP) longitudinal myotomy of the pylorus. Since the first description in 1990, LP is being performed more often worldwide. OBJECTIVES: To compare the efficacy and safety of open versus laparoscopic pyloromyotomy for IHPS. SEARCH METHODS: We conducted a literature search on 04 February 2021 to identify all randomised controlled trials (RCTs), without any language restrictions. We searched the following electronic databases: MEDLINE (1990 to February 2021), Embase (1990 to February 2021), and the Cochrane Central Register of Controlled Trials (CENTRAL). We also searched the Internet using the Google Search engine (www.google.com) and Google Scholar (scholar.google.com) to identify grey literature not indexed in databases. SELECTION CRITERIA: We included RCTs and quasi-randomised trials comparing LP with OP for hypertrophic pyloric stenosis. DATA COLLECTION AND ANALYSIS: Two review authors independently screened references and extracted data from trial reports. Where outcomes or study details were not reported, we requested missing data from the corresponding authors of the primary RCTs. We used a random-effects model to calculate risk ratios (RRs) for binary outcomes, and mean differences (MDs) for continuous outcomes. Two review authors independently assessed risks of bias. We used GRADE to assess the certainty of the evidence for all outcomes. MAIN RESULTS: The electronic database search resulted in a total of 434 records. After de-duplication, we screened 410 independent publications, and ultimately included seven RCTs (reported in 8 reports) in quantitative analysis. The seven included RCTs enrolled 720 participants (357 with open pyloromyotomy and 363 with laparoscopic pyloromyotomy). One study was a multi-country trial, three were carried out in the USA, and one study each was carried out in France, Japan, and Bangladesh. The evidence suggests that LP may result in a small increase in mucosal perforation compared with OP (RR 1.60, 95% CI 0.49 to 5.26; 7 studies, 720 participants; low-certainty evidence). LP may result in up to 5 extra instances of mucosal perforation per 1,000 participants; however, the confidence interval ranges from 4 fewer to 44 more per 1,000 participants. Four RCTs with 502 participants reported on incomplete pyloromyotomy. They indicate that LP may increase the risk of incomplete pyloromyotomy compared with OP, but the confidence interval crosses the line of no effect (RR 7.37, 95% CI 0.92 to 59.11; 4 studies, 502 participants; low-certainty evidence). In the LP groups, 6 cases of incomplete pyloromyotomy were reported in 247 participants while no cases of incomplete pyloromyotomy were reported in the OP groups (from 255 participants). All included studies (720 participants) reported on postoperative wound infections or abscess formations. The evidence is very uncertain about the effect of LP on postoperative wound infection or abscess formation compared with OP (RR 0.59, 95% CI 0.24 to 1.45; 7 studies, 720 participants; very low-certainty evidence). The evidence is also very uncertain about the effect of LP on postoperative incisional hernia compared with OP (RR 1.01, 95% CI 0.11 to 9.53; 4 studies, 382 participants; very low-certainty evidence). Length of hospital stay was assessed by five RCTs, including 562 participants. The evidence is very uncertain about the effect of LP compared to OP (mean difference -3.01 hours, 95% CI -8.39 to 2.37 hours; very low-certainty evidence). Time to full feeds was assessed by six studies, including 622 participants. The evidence is very uncertain about the effect of LP on time to full feeds compared with OP (mean difference -5.86 hours, 95% CI -15.95 to 4.24 hours; very low-certainty evidence). The evidence is also very uncertain about the effect of LP on operating time compared with OP (mean difference 0.53 minutes, 95% CI -3.53 to 4.59 minutes; 6 studies, 622 participants; very low-certainty evidence). AUTHORS' CONCLUSIONS: Laparoscopic pyloromyotomy may result in a small increase in mucosal perforation when compared with open pyloromyotomy for IHPS. There may be an increased risk of incomplete pyloromyotomy following LP compared with OP, but the effect estimate is imprecise and includes the possibility of no difference. We do not know about the effect of LP compared with OP on the need for re-operation, postoperative wound infections or abscess formation, postoperative haematoma or seroma formation, incisional hernia occurrence, length of postoperative stay, time to full feeds, or operating time because the certainty of the evidence was very low for these outcomes. We downgraded the certainty of the evidence for most outcomes due to limitations in the study design (most outcomes were susceptible to detection bias) and imprecision. There is limited evidence available comparing LP with OP for IHPS. The included studies did not provide sufficient information to determine the effect of training, experience, or surgeon preferences on the outcomes assessed.

Genotype-phenotype correlations on epidermolysis bullosa with congenital absence of skin: A comprehensive review.

Congenital absence of skin (CAS) is a clinical sign associated with the main types of epidermolysis bullosa (EB). Very few studies have investigated the genetic background that may influence the occurrence of this condition. Our objective was to investigate genotype-phenotype correlations on EB with CAS through a literature revision on the pathogenic variants previously reported. A total of 171 cases (49 EB simplex, EBS; 23 junctional EB, JEB; and 99 dystrophic EB, DEB), associated with 132 pathogenic variants in eight genes, were included in the genotype-phenotype analysis. In EBS, CAS showed to be a recurrent clinical sign in EBS with pyloric atresia (PA) and EBS associated with kelch-like protein 24; CAS was also described in patients with keratins 5/14 alterations, particularly involving severe phenotypes. In JEB, this is a common clinical sign in JEB with PA associated with premature termination codon variants and/or amino acid substitutions located in the extracellular domain of integrin α6ß4 genes. In DEB with CAS, missense variants occurring close to non-collagenous interruptions of the triple-helix domain of collagen VII appear to influence this condition. This study is the largest review of patients with EB and CAS and expands the spectrum of known variants on this phenomenon.

Self-expandable metal stent of esophagogastric junction versus pyloric area obstruction in advanced gastric cancer patients: Retrospective, comparative, single-center study.

Upper gastrointestinal stenting is a palliative treatment for relieving symptoms such as nausea, vomiting, and dietary intake in patients with obstruction due to inoperable advanced stomach cancer. Self-expandable metal stent (SEMS) implantation for malignant obstruction has recently become more effective, safer, and less expensive than operative modality. It also has better short-term outcomes, particularly a shorter hospital stay and a more rapid return to oral intake, than surgical treatment. However, there is no comparative analysis regarding the efficacy, side effects, and survival rate of stenting between the esophagogastric junction (EGJ) and pyloric obstructions.To compare the prognoses and complications after SEMS implantation between EGJ and pyloric obstructions in advanced gastric cancer.Among advanced gastric cancer patients with gastrointestinal obstruction diagnosed from January 2008 to December 2017 at the Gastroenterology Department of Chungnam National University Hospital, 42 and 76 patients presented with EGJ (EGJ obstruction group) and gastric pyloric obstructions (pyloric obstruction group), respectively. We retrospectively reviewed the survival period, changes in food intake, and complications of these patients before and after SEMS placement.The prevalences of aspiration pneumonia were 11.9% (5/42) and 2.6% (2/76) in the EGJ and pyloric obstruction groups, respectively, before SEMS placement (P value: .041). Other symptoms associated with gastric malignant obstruction were not statistically different between the groups. Success rate and adverse events did not significantly differ between the EGJ and pyloric obstruction groups. There was no difference in frequency of stent reinsertion procedures performed owing to reobstruction, but the reprocedure average period was statistically significantly longer in the EGJ obstruction group [EGJ obstruction: 158.3 days (±42.4); pyloric obstruction: 86.0 days (±29.1)] (P value: .022). As an index of improved dietary status, the Gastric Outlet Obstruction Scoring System score was not significantly different between the groups before and after SEMS placement.The EGJ and pyloric obstruction groups did not significantly differ in prognosis or complication rates. However, EGJ stent was more stable than pyloric stent when reobstruction was considered.

AQP5 enriches for stem cells and cancer origins in the distal stomach.

LGR5 marks resident adult epithelial stem cells at the gland base in the mouse pyloric stomach1, but the identity of the equivalent human stem cell population remains unknown owing to a lack of surface markers that facilitate its prospective isolation and validation. In mouse models of intestinal cancer, LGR5+ intestinal stem cells are major sources of cancer following hyperactivation of the WNT pathway2. However, the contribution of pyloric LGR5+ stem cells to gastric cancer following dysregulation of the WNT pathway-a frequent event in gastric cancer in humans3-is unknown. Here we use comparative profiling of LGR5+ stem cell populations along the mouse gastrointestinal tract to identify, and then functionally validate, the membrane protein AQP5 as a marker that enriches for mouse and human adult pyloric stem cells. We show that stem cells within the AQP5+ compartment are a source of WNT-driven, invasive gastric cancer in vivo, using newly generated Aqp5-creERT2 mouse models. Additionally, tumour-resident AQP5+ cells can selectively initiate organoid growth in vitro, which indicates that this population contains potential cancer stem cells. In humans, AQP5 is frequently expressed in primary intestinal and diffuse subtypes of gastric cancer (and in metastases of these subtypes), and often displays altered cellular localization compared with healthy tissue. These newly identified markers and mouse models will be an invaluable resource for deciphering the early formation of gastric cancer, and for isolating and characterizing human-stomach stem cells as a prerequisite for harnessing the regenerative-medicine potential of these cells in the clinic.