Over the last few years, capsule endoscopy has been established as a fundamental device in the practicing gastroenterologist's toolbox. Its utilization in diagnostic algorithms for suspected small bowel bleeding, Crohn's disease, and small bowel tumors has been approved by several guidelines. The advent of double-balloon enteroscopy has significantly increased the therapeutic possibilities and release of multiple devices (single-balloon enteroscopy and spiral enteroscopy) aimed at improving the performance of small bowel enteroscopy. Recently, some important innovations have appeared in the small bowel endoscopy scene, providing further improvement to its evolution. Artificial intelligence in capsule endoscopy should increase diagnostic accuracy and reading efficiency, and the introduction of motorized spiral enteroscopy into clinical practice could also improve the therapeutic yield. This review focuses on the most recent studies on artificial-intelligence-assisted capsule endoscopy and motorized spiral enteroscopy.

Endoscopy is vital for diagnosis, assessing treatment response, monitoring and surveillance in patients with inflammatory bowel disease (IBD). With the growing importance of mucosal healing as a treatment target, the assessment of disease activity by endoscopy has been accepted as the standard of care for IBD. There are many endoscopic activity indices for facilitating standardized reporting of the gastrointestinal mucosal appearance in IBD, and each index has its strengths and weaknesses. Although most endoscopic indices do not have a clear-cut validated definition, endoscopic remission or mucosal healing is associated with favorable outcomes, such as a decreased risk of relapse. Therefore, experts suggest utilizing endoscopic indices for monitoring disease activity and optimizing treatment to achieve remission. However, the regular monitoring of endoscopic activity is limited in practice owing to several factors, such as the complexity of the procedure, time consumption, inter-observer variability, and lack of a clear-cut, validated definition of endoscopic response or remission. Although experts have recently suggested consensus-based definitions, further studies are needed to define the values that can predict long-term outcomes.

An appropriate post-polypectomy surveillance program requires the effectiveness of reducing colorectal cancer and safety. In addition, the post-polypectomy surveillance program should consider the burden of limited medical resource capacity, cost-effectiveness, and patient adherence. In this sense, a risk-stratified surveillance program based on baseline colonoscopy results is ideal. Major international guidelines for post-polypectomy surveillance, such as those from the European Union and the United States, have recommended risk-stratified surveillance programs. Both guidelines have recently been updated to better differentiate between high- and low-risk individuals. In both updated guidelines, more individuals have been downgraded to lower-risk groups that require less frequent or no surveillance. Furthermore, increased attention has been paid to the surveillance of patients who undergo serrated polyp removal. Previous guidelines in Japan did not clearly outline the risk stratification in post-polypectomy surveillance. However, the new colonoscopy screening and surveillance guidelines presented by the Japan Gastroenterological Endoscopy Society include a risk-stratified post-polectomy surveillance program. Further discussion and analysis of unresolved issues in this field, such as the optimal follow-up after the first surveillance, the upper age limit for surveillance, and the ideal method for improving adherence to surveillance guidelines, are warranted.

Recently, research on rectal neuroendocrine tumors (NETs) has increased during the last few decades. Rectal NETs measuring <10 mm without atypical features and confined to the submucosal layer have only 1% risk of metastasis, and the long-term survival probability of patients without metastasis at the time of diagnosis is approximately 100%. Therefore, the current guidelines suggest endoscopic resection of rectal NETs of <10 mm is regarded as a safe therapeutic option. However, there are currently no clear recommendations for technique selection for endoscopic resection. The choice of treatment modality for rectal NETs should be based on the lesion size, endoscopic characteristics, grade of differentiation, depth of vertical involvement, lymphovascular invasion, and risk of metastasis. Moreover, the complete resection rate, complications, and experience at the center should be considered. Modified endoscopic mucosal resection is the most suitable resection method for rectal NETs of < 10 mm, because it is an effective and safe technique that is relatively simple and less time-consuming compared with endoscopic submucosal dissection. Endoscopic submucosal dissection should be considered when the tumor size is >10 mm, suctioning is not possible due to fibrosis in the lesion, or when the snaring for modified endoscopic mucosal resection does not work well.

Background/Aims: Metastases of malignant melanoma (MM) are rare and associated with poor prognosis. The objective of this study was to analyze the clinical and endoscopic characteristics of gastric metastases of MM by systematically reviewing cases and case series involving patients diagnosed using upper gastrointestinal endoscopy.
Methods: The PubMed and LILACS databases were searched. Reports containing individual patient data were included. Outcomes such as clinical data, endoscopic findings, treatments, and survival were analyzed.
Results: A total of 88 studies with individual data from 113 patients with gastric metastases of MM were included. The primary sites of MM were the skin (62%), eyes (10%), and mucous membranes (6%). Most patients (56%) had multiple metastases in the stomach, located predominantly in the gastric body (approximately 80%). The overall survival rate at 2 years was 4%. There was a significant reduction in the survival of patients with multiple gastric metastases compared to that of patients with single metastasis (hazard ratio, 0.459; 95% confidence interval, 0.235-0.895; p=0.022).
Conclusions: Gastric metastases of MM have a poor prognosis, especially in patients with multiple implants in the stomach. Additional studies are needed to verify whether ocular and mucosal melanomas are associated with a higher risk of gastric metastases than that of cutaneous melanomas.

Background/Aims: Intralesional steroid injections have been administered as prophylaxis for stenosis after esophageal endoscopic submucosal dissection. However, this method carries a risk of potential complications such as perforation because a fine needle is used to directly puncture the postoperative ulcer. We devised a new method of steroid intralesional infusion using a spray tube and evaluated its efficacy and safety.
Methods: Intralesional steroid infusion using a spray tube was performed on 27 patients who underwent endoscopic submucosal dissection for superficial esophageal cancer with three-quarters or more of the lumen circumference resected. The presence or absence of stenosis, complications, and the number of endoscopic balloon dilations (EBDs) performed were evaluated after treatment.
Results: Although stenosis was not observed in 22 of the 27 patients, five patients had stenosis and dysphagia requiring EBD. The stenosis in these five patients was relieved after four EBDs. No complications related to intralesional steroid infusion using the spray tube were observed.
Conclusions: Intralesional steroid infusion using a spray tube is a simple and safe technique that is adequately effective in preventing stenosis (clinical trial number, UMIN000037567).

Background/Aims: Endoscopic wound suturing is an important factor that affects the ability to remove large and full-thickness lesions during endoscopic resection. We aimed to evaluate the effect of a traction metal clip with a fishhook-like device on wound sutures after endoscopic resection.
Methods: From July 2020 to April 2021, patients who met the enrollment criteria were treated with a fishhook-like device during the operation to suture the postoperative wound (group A). Patients with similar conditions and similar size wounds who were treated with a “purse-string suture” to suture the wounds were retrospectively analyzed as the control group (group B). Difference in the suture rate, adverse events, time required for suturing, and number of metal clips were compared between the two groups.
Results: The time required for suturing was 7.72±0.51 minutes in group A and 11.50±0.91 minutes in group B. This difference was statistically significant (F=13.071, p=0.001). The number of metal clamps used in group A averaged 8.1 pieces/case, and the number of metal clamps used in group B averaged 7.3 pieces/case. This difference was not statistically significant (F=0.971, p=0.331).
Conclusions: The traction metal clip with the fishhook-like device is ingeniously designed and easy to operate. It has a good suture effect on the wound after endoscopic submucosal dissection and effectively prevents postoperative adverse events.

Background/Aims: Capsule enteroscopy (CE) and intestinal ultrasonography (IUS) are techniques that are currently used for investigating small-bowel (SB) diseases. The aim of this study was to compare the main imaging findings and the lesion detection rate (LDR) of CE and IUS in different clinical scenarios involving the SB.
Methods: We retrospectively enrolled patients who underwent CE and IUS for obscure gastrointestinal bleeding (OGIB), complicated celiac disease (CeD), and suspected or known inflammatory bowel disease (IBD). We evaluated the LDR of both techniques. The accuracy of IUS was determined using CE as the reference standard.
Results: A total of 159 patients (113 female; mean age, 49±19 years) were enrolled. The LDR was 55% and 33% for CE and IUS (p<0.05), respectively. Subgroup analysis showed that the LDR of CE was significantly higher than that of IUS in patients with OGIB (62% vs. 14%, p<0.05) and CeD (55% vs. 35%, p<0.05). IUS showed a similar LDR to CE in patients with suspected or known IBD (51% vs. 46%, p=0.83).
Conclusions: CE should be preferred in cases of OGIB and CeD, whereas IUS should be considered an early step in the diagnosis and follow-up of IBD even in patients with a proximal SB localization of the disease.