Novel beagle model of gastric local fibrotic target lesions for the evaluation and training of endoscopic techniques.

BACKGROUND: Novel endoscopic techniques used in the treatment of gastric lesions with local submucosal fibrosis need preclinical evaluation and training due to safety limitations. Therefore, the purpose of our study was to establish an animal model of gastric local fibrotic target lesions and assess its feasibility in the evaluation and training of endoscopic techniques. METHODS: In six experimental beagles, a 50% glucose solution was injected into three submucosal areas of the fundus, body, and antrum of the stomach to create gastric local fibrotic target lesions (experimental group). On post-injection day (PID) 7, the injection sites were assessed endoscopically to confirm the presence of submucosal fibrosis formation, and the dental floss clip traction assisted endoscopic submucosal dissection (DFC-ESD) procedure was performed on the gastric local fibrotic target lesions to confirm its feasibility after endoscopic observation. The normal gastric mucosa of six control beagles underwent the same procedure (control group). All the resected specimens were evaluated by histological examination. RESULTS: All 12 beagles survived without postoperative adverse events. On PID 7, 16 ulcer changes were observed at the injection sites (16/18) under the endoscope, and endoscopic ultrasonography confirmed the local submucosal fibrosis formation in all ulcer lesions. The subsequent DFC-ESD was successfully performed on the 32 gastric target lesions, and the mean submucosal dissection time in the ulcer lesions was greater than that in the normal gastric mucosa (15.3 ± 5.6 vs. 6.8 ± 0.8 min; P < 0.001). There was no difference in rates of en bloc resection, severe hemorrhage, or perforation between the two groups. Histological analysis of the ulcer lesions showed the absence of epithelial or muscularis mucosae and extensive submucosal fibrous tissue proliferations compared with normal gastric mucosa. Overall, endoscopists had high satisfaction with the realism and feasibility of the animal model. CONCLUSION: We developed a novel animal model of gastric local fibrotic target lesions to simulate difficult clinical situations, which strongly appeared to be suitable for the preclinical evaluation and learning of advanced endoscopic techniques.

Magnetic ring-assisted endoscopic submucosal dissection for gastric lesions with submucosal fibrosis: A preliminary study in beagle model.

BACKGROUND: During endoscopic submucosal dissection (ESD) for gastric lesions with fibrosis, appropriate traction could provide clear submucosal dissection visualization to improve safety and efficiency of procedures. Therefore, the aim of this study was to evaluate the feasibility of magnetic ring-assisted ESD (MRA-ESD) for gastric fibrotic lesions. METHOD: In the eight healthy beagles, 2-3 mL of 50% glucose solution was injected into submucosal layer of the stomach to induce gastric fibrotic lesions. A week after submucosal injection, two endoscopists at different levels performed MRA-ESD or standard ESD (S-ESD) for gastric simulated lesions, respectively. The magnetic traction system consisted of external handheld magnet and internal magnetic ring. The feasibility and procedure outcomes of the magnetic traction system were mainly evaluated. RESULTS: Forty-eight gastric simulated lesions with ulceration were confirmed to have submucosal fibrosis formation by preoperative endoscopic ultrasonography. The magnetic traction system could be easily established, only took 1.57 min, and allowed excellent submucosal visualization. The total procedure time was significantly shorter in the MRA-ESD group than in the S-ESD group for both endoscopists (mean: 46.83 vs. 25.09 min, p < 0.001), and this difference was accentuated in non-skilled endoscopist. There was significant difference between two groups in bleeding and perforation rates. Histological analysis showed the depth of resected specimens was a little deeper around the fibrotic portion in the S-ESD group (p < 0.001). CONCLUSION: The magnetic ring-assisted ESD technique may be an effective and safe treatment for gastric fibrotic lesions and may shorten the endoscopic learning curve for non-skilled endoscopists.

Experimental Study on Gastric Labeling by Magnetic Detector Combined With Magnetic Bead.

OBJECTIVE: Preoperative labeling of gastric cancer is an important means to determine the surgical margin. At present, there are many commonly used labeling methods. However, which is more accurate and has fewer complications remains to be studied. Through animal experiments, this study explored the feasibility, accuracy, and safety of a magnetic detector combined with magnetic beads for the preoperative labeling of gastric cancer. METHODS: A total of 10 beagle dogs were included in the study. Each dog was randomly labeled with magnetic beads in the gastric body and antrum. After labeling, the magnetic detector was used to explore the gastric serosa surface, and the positioning titanium clip was released at the detected magnetic bead. The main monitoring index was to measure the distance between the labeled magnetic beads and the positioning titanium clamped. The secondary indexes were detection time, magnetic induction intensity, magnetic bead shedding rate, mucosal injury rate, bleeding, and leukocyte and C-reactive protein levels before and 24 hours after the operation. RESULTS: All 10 beagle dogs completed the marking and exploration successfully. The average distance between the magnetic beads and the positioning titanium clip in 20 cases was 5.90±2.36 mm. The average detection time was 1.60±0.69 min, and the average magnetic induction intensity was 3.76±1.11 mT. No magnetic beads were found to fall off, 1 case had a mild mucosal injury, and 2 cases had a small amount of bleeding when releasing the positioning titanium clip. The white blood cells before and 24 hours after the operation were 7.43±0.94(×10 9 /L) versus 7.79±0.67(×10 9 /L) ( P =0.34). The C-reactive protein before and 24 hours after the operation were 5.24±0.97 µg/mL versus 5.95±1.02 µg/mL ( P =0.13). CONCLUSION: A magnetic detector combined with magnetic beads for gastric cancer labeling is feasible, accurate, and safe. It is expected to be further applied in the clinic.

A prospective, open-labeled, and randomized trial for assessing safety and clinical utility of gastric biopsies during emergency gastroscopy for patients with bleeding gastric ulcers.

OBJECTIVE: There is no consensus on whether a gastroscopic biopsy is necessary during the emergency treatment of gastrointestinal (GI) diseases such as gastric ulcer bleeding. In this study, we examined the clinical utility and safety of an emergency gastroscopic biopsy for the assessment of gastric ulcer bleeding. METHODS: We enrolled 150 patients with a single bleeding gastric ulcer after emergency gastroscopy (EG) from April 2020 to April 2022. The patients were randomly divided into the biopsy and no biopsy groups, and they were followed-up until June 2022 to examine whether recurrent gastric ulcer bleeding had occurred. RESULTS: Re-bleeding occurred in 15 out of 150 (10%) patients. We diagnosed malignancies in 17 (11.3%) patients and validated 14 (9.3%) of them during the initial gastroscopy procedure. Factors that could predict the occurrence of gastric ulcer re-bleeding with biopsy during EG included an absence of ischemic heart disease (odds ratio [OR] = 0.395, confidence interval [CI]: 0.24-0.65, p ≤ .005), renal disease (OR = 1.74, CI: 0.77-1.59, p ≤ .005), and using warfarin or oral anticoagulants (OR = 11.953, CI: 3.494-39.460, p ≤ .005). No significant differences were observed in 60-day bleeding (p = .077) and the duration of hospitalization (p = .700) between the two groups. CONCLUSIONS: Patients undergoing biopsy during EG did not exhibit an increased risk of re-bleeding compared with those who did not undergo a biopsy. An early biopsy facilitates an early pathologic diagnosis, early clinical intervention, safe discharge of low-risk patients, and improved outcomes in high-risk patients.