Newly developed medical instruments utilizing optical technology and therapeutic devices have significantly contributed to the evolution of gastrointestinal endoscopy. These products, developed through close collaboration between medical and engineering professionals, have played a crucial role in the diagnosis and treatment of gastrointestinal diseases. The integration of innovative technologies through these collaborative efforts provides a paradigm shift in gastrointestinal endoscopy. However, medical device developments require complex and time-intensive processes, which include stages such as conceptualization, business partnership with compatible companies, regulatory approval, and marketing. The formation of an industry-academia-government project team is mandatory in achieving completion of such medical devices. This review outlines the current status and future perspectives of the medical-engineering collaboration in the field of gastrointestinal endoscopy, supplemented by practical case studies.

Red dichromatic imaging (RDI) is an image-enhanced endoscopic technique that uses a narrow bandwidth of two long wavelengths: amber at 610 nm and red at 640 nm. These wavelengths effectively highlight relatively thick blood vessels with diameters of 500 µm or more in the deep mucosa to the submucosa. RDI clearly visualizes blood vessels in the submucosa that are at risk of bleeding, allowing the endoscopist to avoid vascular damage during ESD. In cases where bleeding occurs, RDI makes the bleeding point distinctly recognizable, depicting the bleed in yellow. This feature facilitates reliable and stress-free hemostatic treatment. Notably, there have been no complications associated with the use of RDI during ESD.

A 97-year-old woman experienced recurrent episodes of cholelithic cholecystitis and cholangitis resulting from a stone in the common bile duct. She was hospitalized as a result of choledocholithiasis in the common bile duct. The right wall of the esophagus in the middle thoracic region was perforated during insertion of the endoscope for ERCP. We decided to close the perforation endoscopically, considering the infeasibility of a surgery owing to the patientʼs multiple comorbidities and advanced age. The perforation was closed with a clip without any gaps, and the patient showed a favorable outcome.

After confirming the absence of leakage on esophagography, the stone was removed endoscopically, and the patient was discharged from the hospital. We report a case in which esophageal perforation was successfully treated without surgery.

A 19-year-old man presented to our department with right lower abdominal pain. CT revealed a target sign in the ascending colon, indicative of intussusception. Given the absence of peritonitis and CT findings showing contrast enhancement of the intussuscepted colonic wall, emergency radioscopic colonoscopy was performed to reduce the intussusception. Following three weeks of treatment, a second colonoscopy was conducted to confirm the absence of any other underlying pathology. A preoperative diagnosis of adult idiopathic intussusception was established, with the cecum identified as the lead point invaginating into the ascending colon. Subsequently, a single port laparoscopic retroperitoneal fixation was performed to prevent recurrence. The patient has remained free of recurrence for 11 months post-surgery. While idiopathic intussusception is uncommon in adults, endoscopic reduction should be considered to avoid intestinal resection, which results in excessive surgical intervention, particularly in cases without signs of intestinal necrosis. It is important to conduct a thorough examination of the intestinal tract via a second colonoscopy prior to surgical intervention to identify any underlying causes of intussusception.

A 65-year-old male underwent colonoscopy as part of a medical checkup, revealing a 15 mm flat submucosal tumor-like lesion in the descending colon. Biopsy of this area confirmed a diagnosis of mucosa-associated lymphoid tissue(MALT) lymphoma. PET-CT showed no substantial accumulation in the descending colon, and there were no signs of distant or lymph node metastases. Consequently, the patient has been diagnosed with colorectal MALT lymphoma Lugano International Classification Stage Ⅰ. Primary treatment involved eradication therapy for H. pylori. However, 4 months after the therapy, an endoscopic examination revealed no notable change in the lesionʼs morphology. With full informed consent, ESD was performed for local cure. Histopathologic findings of the resected specimen showed an aggregation of atypical lymphocytes within the mucosa-specific layer, with no prominent lymphoepithelial lesions. Immunostaining showed CD20 (+), CD79a (+), and bcl-2(+), confirming the diagnosis, and the margins were negative. The patient has been recurrence-free for 2 years and 3 months since the ESD has been conducted.

A man in his 60s presented with a positive fecal occult blood test during a health checkup. He underwent lower gastrointestinal endoscopy, revealing multiple polyps distributed throughout his entire large intestine. This led to the decision for endoscopic treatment. During the procedure, two pedunculated polyps were found entangled in the ascending colon. Both polyps displayed signs of ischemia, appearing dark purple, and the pedicles were under tension. Considering the potential risk of perforation, the procedure was ceased after observation-only, and surgical resection was deemed necessary. Subsequently, while conducting preoperative marking with an endoscope, both lesions had spontaneously detached, resulting in ulcers on the pedicles. No abdominal symptoms were observed throughout the disease course, and no melena or tumor excretion was confirmed. This case represents a rare and valuable instance of the simultaneous dislodgement of two colonic polyps observed over time with an endoscope.

In recent years, there has been a notable rise in cases of Helicobacter pylori(HP)-uninfected and HP-eradicated early gastric cancer and, posing challenges for endoscopic diagnosis. Consequently, there is an immediate need for new diagnostic modalities for early gastric cancer. This study investigated the movement of red blood cells in gastric microvessels during gastric magnification endoscopy. We developed a novel diagnostic method for analyzing blood flow velocity using gastric magnification endoscopy images. This dynamic diagnostic modality has been investigated to date. In a pilot study, the authors reported a significant reduction in blood flow velocity in early gastric cancer compared to patchy redness and background gastric mucosa. Subsequently, we developed a software program capable of automated blood flow velocity analysis, enhancing the objectivity of the analysis method. This paper outlines the process of analyzing blood flow velocity in magnified gastric endoscopic images using a software program and underscores its utility in the diagnosis of early gastric cancer.

ERCP and related procedures are essential for diagnosing and treating pancreaticobiliary diseases. However, ERCP is associated with several adverse events, with post-ERCP pancreatitis (PEP) being a more frequently encountered adverse event than others. Understanding the PEP risk factors, including patient-related and procedural, is imperative for preventing this complication. Elevated intraductal pancreatic duct and tissue pressure and pancreatic fluid congestion resulting from papillary edema are potential contributing factors to PEP. Placement of prophylactic pancreatic duct stent prevents the increase in intraductal pancreatic pressure caused by papillary edema and is effective in PEP prevention, particularly in high-risk cases. This paper outlines the PEP-associated risk factors and describes the prophylactic pancreatic ductal stenting procedure.

Objectives: The multi-institutional, single-arm, confirmatory trial JCOG0607 showed excellent efficacy of endoscopic submucosal dissection (ESD) for the expanded indication of intramucosal intestinal-type early gastric cancer (EGC), which consists of two groups: lesions >2 cm if clinical finding of ulcer(cUL)-negative, or those ≤3 cm if cUL-positive because of the expected low risk of lymph node metastasis. However, the proportion of noncurative resections (NCR) requiring additional surgery was high (32.4%). This post hoc analysis aimed to explore the clinical factors associated with NCR.

Methods: As the expanded indication includes two different groups, we explored the clinical factors associated with NCR separately in cUL-negative (>2 cm) and cUL-positive (≤3 cm) groups using the log-linear model.

Results: Two hundred and sixty cUL-negative and 206 cUL-positive EGCs were analyzed. The proportions of NCR were 33.8% in the cUL-negative group and 29.6% in the cUL-positive group. A multivariable analysis demonstrated that moderately differentiated predominant histology diagnosed in pretreatment biopsy (risk ratio [RR] 1.93, 95% confidence interval [CI] 1.34-2.77, P < 0.001) and lesion in the upper stomach (RR 1.75, 95% CI 1.03-2.96, P = 0.038) in the cUL-negative EGCs, and tumor size >2 cm (RR 1.78, 95% CI 1.22-2.58, P = 0.003) and female sex (RR 1.62, 95% CI 1.07-2.44, P = 0.021) in the cUL-positive EGCs were independent factors associated with NCR.

Conclusions: Clinical risk factors associated with NCR were different between cUL-negative and cUL-positive EGCs. To avoid NCR, we need to take these factors into account when deciding expanded indications for ESD.

The predecessor of the World Endoscopy Organization (WEO) was the International Society of Endoscopy (ISE), which was founded in 1966. At the 3^rd ISE Congress in 1974, its official name was changed to the Organisation Mondiale dʼEndoscopie Digestive (OMED). In 2010, OMED was renamed WEO, which remains to this day. The International WEO Congress has been held since 2017. The first World Congress of Endoscopy was held in India (ENDO 2017), the second in Brazil (ENDO 2020), and the third in Kyoto, Japan (ENDO 2022). The fourth event (ENDO 2024) will take place in Seoul, South Korea. The goal and mission of the WEO are to provide safe, high-quality endoscopic medicine worldwide through endoscopic education and training activities and to promote international academic and research activities through its global network. The WEO has been involved in educational activities in developing countries in Southeast Asia and South America and has recently become actively involved in education and training activities in African countries. It has established training centers tailored to the local needs of African countries and plans to conduct training courses in partnership with base hospitals in India.