Establishing an endoscopic diagnostic process system (M-system) for gastric MALT lymphoma of superficial-spreading type.

OBJECTIVE: Gastric mucosa-associated lymphoid tissue lymphoma is a rare disease, which is associated with a low endoscopic diagnostic accuracy even on tissue biopsy. We aimed to establish a diagnostic process system (M-system) using detailed magnifying endoscopy images to improve the diagnostic efficiency of this disease. METHODS: First, 34 cases from 16 patients with the diagnosis of mucosa-associated lymphoid tissue lymphoma were collected as the study group. The control group included randomly selected patients who were diagnosed with early differentiated carcinoma, undifferentiated carcinoma or inflammation. Then, the endoscopic images of these patients were analyzed by senior physicians. Finally, the M-system was established based on the data extracted from the images reviewed, and its diagnostic efficiency for mucosa-associated lymphoid tissue lymphoma was validated by the junior physicians. RESULTS: A series of elements with high sensitivity and specificity for the diagnosis of mucosa-associated lymphoid tissue lymphoma on endoscopic images were extracted for the establishment of the M-system. Using the M-system, the diagnostic accuracy, sensitivity, specificity and correct indices of mucosa-associated lymphoid tissue lymphoma rose from 65.4 to 79.4%, 41.2 to 76.5%, 73.5 to 80.4% and 0.147 to 0.569%, respectively, all of which were statistically significant. CONCLUSIONS: The M-system can improve the diagnostic accuracy of mucosa-associated lymphoid tissue lymphoma of the superficial-spreading type on detailed magnifying endoscopy. This would help in the early diagnosis of the disease and treatment, which would translate into improved clinical outcomes.

Hybrid Dry Powders for Rapid Sealing of Gastric Perforations under an Endoscope.

Effective wound sealing is key to prevent postoperative complications arising from gastric endoscopic submucosal dissection (ESD). Accurate delivery of the adhesive to wet and dynamic tissues and rapid action of the adhesive onsite should be considered for endoscopic operation. A hybrid dry powder (HDP) strategy, characterized by decoupling of powder gelation and tissue adhesion, for rapid sealing of wet tissues is presented. HDPs carrying oppositely charged polyelectrolytes become a hydrogel layer over the target tissue by absorbing the surrounding water and forming strong electrostatic interactions between heterogeneous components. Strong adhesion is realized through hydrogen bonding between the adhesive component, poly(acrylic acid), and the tissue. Wet tissue adhesion can be achieved in a few seconds (adhesion strength of ∼30 kPa to porcine skin). Notably, the HDP-assembled hydrogel can maintain a low swelling rate and resist degradation in acidic aqueous environments (pH 1). Furthermore, HDPs can be delivered to target tissues by spraying via an endoscope. The results of in vivo experiments indicate that healing of gastric ESD perforations by sealing with the powder-assembled hydrogel is as effective as that by sealing with clips. This strategy is expected to facilitate the development of fast-acting hydrogel-based adhesives for endoscopic operation.