The Outcome of Snare-Assisted Traction Endoscopic Full-Thickness Resection for the Gastric Fundus Submucosal Tumors Originating from the Muscularis Propria.

Aim: To explore the feasibility and effectiveness of snare-assisted traction endoscopic full thickness resection (EFTR) on gastric fundus submucosal tumors (SMTs). Methods: The clinical and pathological data of patients with gastric SMTs who underwent EFTR treatment at the Endoscopy Center of Kaifeng Central Hospital from January 2018 to June 2023 were collected. Among them, 36 patients underwent snare-assisted traction EFTR (SAT-EFTR) and 46 patients underwent standard EFTR (S-EFTR). The clinical baseline data, operative data, adverse events, and follow-up results of the two groups were collected and compared. Results: All patients successfully completed EFTR technique. There were 34 male and 48 female patients, with an average age of (56.62 ± 11.31) years. The average operation time was shorter in the snare-assisted EFTR group than the S-EFTR group (73.39 ± 31.33 minutes versus 92.89 ± 37.57 minutes, P = .014). In addition, the resection speed of the snare-assisted EFTR group was also significantly faster than that of the S-EFTR group (4.04 ± 2.23 versus 2.48 ± 0.93 mm2/min, P < .001). There was no statistically significant difference in the age, gender, lesion size, postoperative fasting duration, and postoperative hospitalization stay between the two groups (P > .05). One patient in the SAT-EFTR group developed delayed postoperative perforation which was close with purse­string suture technique. All patients were discharged successfully, and there was no recurrence or metastasis during the follow-up period. Conclusion: Snare-assisted traction of EFTR could shorten the operation time, reduce the difficulty of the operation, and improve the efficiency of the operation. At the same time, this method is simple and easy to learn, more suitable for beginners, and worthy of clinical promotion and application.

Gastric epithelial neoplasm of fundic-gland mucosa lineage: representative of the low atypia differentiated gastric tumor and Ki67 may help in their identification.

Background: Gastric epithelial neoplasm of the fundic-gland mucosa lineages (GEN-FGMLs) are rare forms of gastric tumors that encompass oxyntic gland adenoma (OGA), gastric adenocarcinoma of the fundic-gland type (GA-FG), and gastric adenocarcinoma of the fundic-gland mucosa type (GA-FGM). There is no consensus on the cause, classification, and clinicopathological features of GEN-FGMLs, and misdiagnosis is common because of similarities in symptoms. Methods: 37 cases diagnosed with GEN-FGMLs were included in this study. H&E-stained slides were reviewed and clinicopathological parameters were recorded. Immunohistochemical staining was conducted for MUC2, MUC5AC, MUC6, CD10, CD56, synaptophysin, chromograninA, p53, Ki67, pepsinogen-I, H+/K+-ATPase and Desmin. Results: The patients' ages ranged from 42 to 79 years, with a median age of 60. 17 were male and 20 were female. Morphologically, 19 OGAs, 16 GA-FGs, and two GA-FGMs were identified. Histopathological similarities exist between OGA, GA-FG, and GA-FGM. The tumors demonstrated well-formed glands, expanding with dense growth patterns comprising pale, blue-grey columnar cells with mild nuclear atypia. These cells resembled fundic gland cells. None of the OGA invaded the submucosal layer. The normal gastric pit epithelium covered the entire surface of the OGA and GA-FG, but the dysplasia pit epithelium covered the GA-FGM. Non-atrophic gastritis was observed in more than half of the background mucosa. All cases were diffusely positive for MUC6 and pepsinogen-I on immunohistochemistry. H+/K+-ATPase staining was negative or showed a scattered pattern in most cases. MUC5AC was expressed on the surface of GA-FGMs. p53 was focally expressed and the Ki67 index was low (1%-20%). Compared with OGA, GA-FG and GA-FGM were more prominent in the macroscopic view (p < 0.05) and had larger sizes (p < 0.0001). Additionally, GA-FG and GA-FGM exhibited higher Ki67 indices than OGA (p < 0.0001). Specimens with Ki-67 proliferation indices >2.5% and size >4.5 mm are more likely to be diagnosed with GA-FG and GA-FGM than OGA. Conclusion: GEN-FGMLs are group of well-differentiated gastric tumors with favourable biological behaviours, low cellular atypia, and low proliferation. Immunohistochemistry is critical for confirming diagnosis. Compared with OGA, GA-FG and GA-FGM have larger sizes and higher Ki67 proliferation indices, indicating that they play a critical role in the identification of GEN-FGML. Pathologists and endoscopists should be cautious to prevent misdiagnosis and overtreatment, especially in biopsy specimens.

Inhibitory mechanisms of docosahexaenoic acid on carbachol-, angiotensin II-, and bradykinin-induced contractions in guinea pig gastric fundus smooth muscle.

We studied the inhibitory actions of docosahexaenoic acid (DHA) on the contractions induced by carbachol (CCh), angiotensin II (Ang II), and bradykinin (BK) in guinea pig (GP) gastric fundus smooth muscle (GFSM), particularly focusing on the possible inhibition of store-operated Ca2+ channels (SOCCs). DHA significantly suppressed the contractions induced by CCh, Ang II, and BK; the inhibition of BK-induced contractions was the strongest. Although all contractions were greatly dependent on external Ca2+, more than 80% of BK-induced contractions remained even in the presence of verapamil, a voltage-dependent Ca2+ channel inhibitor. BK-induced contractions in the presence of verapamil were not suppressed by LOE-908 (a receptor-operated Ca2+ channel (ROCC) inhibitor) but were suppressed by SKF-96365 (an SOCC and ROCC inhibitor). BK-induced contractions in the presence of verapamil plus LOE-908 were strongly inhibited by DHA. Furthermore, DHA inhibited GFSM contractions induced by cyclopiazonic acid (CPA) in the presence of verapamil plus LOE-908 and inhibited the intracellular Ca2+ increase due to Ca2+ addition in CPA-treated 293T cells. These findings indicate that Ca2+ influx through SOCCs plays a crucial role in BK-induced contraction in GP GFSM and that this inhibition by DHA is a new mechanism by which this fatty acid inhibits GFSM contractions.

Electrophysiology, molecular modelling, and functional analysis of the effects of dietary quercetin and flavonoid analogues on Kir6.1 channels in rat stomach fundus smooth muscle.

Flavonoids, ubiquitously distributed in the plant world, are regularly ingested with diets rich in fruit, vegetables, wine, and tea. During digestion, they are partially absorbed in the stomach. The present work aimed to assess the in vitro effects of quercetin and ten structurally related flavonoids on the rat gastric fundus smooth muscle, focussing on ATP-dependent K+ (Kir6.1) channels, which play a central role in the regulation of resting membrane potential, membrane excitability and, consequently, of gastric motility. Whole-cell currents through Kir6.1 channels (IKir6.1) were recorded with the patch-clamp technique and the mechanical activity of gastric fundus smooth muscle strips was studied under isometric conditions. Galangin ≈ tamarixetin > quercetin > kaempferol > isorhamnetin ≈ luteolin ≈ fisetin > (±)-taxifolin inhibited pinacidil-evoked, glibenclamide-sensitive IKir6.1 in a concentration-dependent manner. Morin, rutin, and myricetin were ineffective. The steric hindrance of the molecule and the number and position of hydroxyl groups on the B ring played an important role in the activity of the molecule. Molecular docking simulations revealed a possible binding site for flavonoids in the C-terminal domain of the Kir6.1 channel subunit SUR2B, in a flexible loop formed by residues 251 to 254 of chains C and D. Galangin and tamarixetin, but not rutin relaxed both high K+- and carbachol-induced contraction of fundus strips in a concentration-dependent manner. Furthermore, both flavonoids shifted to the right the concentration-relaxation curves to either pinacidil or L-cysteine constructed in strips pre-contracted by high K+, rutin being ineffective. In conclusion, IKir6.1 inhibition exerted by dietary flavonoids might counterbalance their myorelaxant activity, affect gastric accommodation or, at least, some stages of digestion.

Mechanosensitive enteric neurons in the guinea pig gastric fundus and antrum.

BACKGROUND: Coping with the ingested food, the gastric regions of fundus, corpus, and antrum display different motility patterns. Intrinsic components of such patterns involving mechanosensitive enteric neurons (MEN) have been described in the guinea pig gastric corpus but are poorly understood in the fundus and antrum. METHODS: To elucidate mechanosensitive properties of myenteric neurons in the gastric fundus and antrum, membrane potential imaging using Di-8-ANEPPS was applied. A small-volume injection led to neuronal compression. We analyzed the number of MEN and their firing frequency in addition to the involvement of selected mechanoreceptors. To characterize the neurochemical phenotype of MEN, we performed immunohistochemistry. KEY RESULTS: In the gastric fundus, 16% of the neurons reproducibly responded to mechanical stimulation and thus were MEN. Of those, 83% were cholinergic and 19% nitrergic. In the antrum, 6% of the neurons responded to the compression stimulus, equally distributed among cholinergic and nitrergic MEN. Defunctionalizing the sensory extrinsic afferents led to a significant drop in the number of MEN in both regions. CONCLUSION: We provided evidence for MEN in the gastric fundus and antrum and further investigated mechanoreceptors. However, the proportions of the chemical phenotypes of the MEN differed significantly between both regions. Further investigations of synaptic connections of MEN are crucial to understand the hardwired neuronal circuits in the stomach.

[Clinical and pathological characteristics of gastric adenocarcinoma of fundic gland type].

To analyze the clinical, endoscopic and pathological feature of gastric adenocarcinoma of fundic gland type (GA-FG) (18 cases) collected from Sir Run Run Shaw Hospital, affiliated with Zhejiang University School of Medicine and Taizhou Hospital of Zhejiang Province from January 2019 to July 2022. There were 18 cases of patient of GA-FG, including male 12 cases, female 6 cases, aged from 38 to 78 years old, with average age of 60.5 years old. Gastroscopy showed that bulging or flat lesions of gastric fundus were 0.2-5.5 cm in size, and the mucosal surface was smooth, redness or rough. Histologic examination showed that tumor cells were dominated by chief cells and scattered with a few oxyntic cells, formed a complex gland that anastomoses each other, and infiltrated to the submucosa. The results of immunohistochemistry showed that tumor cells were positive for the expression of mucin-6 (MUC6) and Pepsinogen 1, and partial expression of synaptophysin (Syn). GA-FG is a rare type of gastric adenocarcinoma with good differentiation, and currently only a few cases have been reported, and often easily been misdiagnosed or missed. Therefore, to master the characteristics of clinic and pathology is helpful to improve the ability of clinical pathologists in differential diagnosis.

An evaluation of the use of double-curved endoscopes for gastric gastrointestinal stromal tumors.

BACKGROUND: Endoscopic full-thickness resection (EFTR) is a standard treatment method for gastric gastrointestinal stromal tumors (gGISTs). Evidence of the safety and efficacy of a double-curved endoscope (DCE) in EFTR of gGISTs is limited. We aimed to compare the operative outcomes of DCE versus single-curved endoscopes (SCE) in EFTR of gGISTs. MATERIAL AND METHODS: This retrospective observational study was conducted at four Chinese tertiary institutes. From January 2019 to November 2021, 104 patients who underwent EFTR by SCE (n = 57) or DCE (n = 47) were enrolled. One-to-one propensity score matching (PSM) was performed between the two groups to compare the demographics and operative outcomes. RESULTS: All gGISTs were resected successfully with no recurrence during follow-up. The median (range) tumor size was 1.2 (0.5, 3.5) cm in DCE and 2.0 (0.6, 4.8) cm in SCE (p < .001), and the procedure time was shorter in the DCE group than in the SCE group (50.0 min vs. 62.0 min, p < .05). After PSM, 41 pairs were selected, and no difference was noted in demographics. The procedure time was also shorter in the DCE group than in the SCE group (50.0 min vs. 55.0 min, p < .05). Subgroup analysis showed that the DCE group had a shorter procedure time in the gastric fundus than the SCE group (47.0 min vs. 55.0 min, p < .05). In multiple linear regression analysis, significant factors related to prolonged procedure time were the type of endoscope of SCE and larger tumor size (p < .05). CONCLUSIONS: EFTR of gGISTs using DCE is safe and effective. Compared with SCE, DCE had an advantage in terms of operative time, especially in the gastric fundus.