A new image processor called EVIS X1 was introduced in 2020. It integrates novel image-enhanced endoscopic images, texture- and color-enhanced imaging (TXI), and red dichromatic imaging (RDI). TXI has been shown to improve the visibility of neoplastic lesions in the gastrointestinal tract and is expected to improve the lesion detection rate in clinical practice. Owing to its unique principle allowing easier visualization of bleeding points, RDI has been found to reduce the psychological stress of endoscopists compared with white-light imaging, especially for intraoperative bleeding during ESD. The usefulness of RDI for hemostasis in gastrointestinal bleeding other than ESD should be investigated in the future.

The development of new endoscopic processors and image-enhanced endoscopy is expected to provide evidence for daily practice and to advance gastrointestinal endoscopic diagnosis and treatment.

A representative disorder of esophageal motility disorder (EMD) is achalasia. Achalasia is an idiopathic EMD characterized by incomplete relaxation of the lower esophageal sphincter and peristaltic dysfunction of the esophagus. Symptoms, such as dysphagia, regurgitation of esophageal contents, chest pain, and weight loss, significantly decrease the patientsʼ quality of life. If achalasia is suspected based on symptoms, diagnostic procedures, such as esophagography, upper gastrointestinal endoscopy, and chest and abdominal CT, are performed, with esophageal manometry confirming the diagnosis. In many cases of achalasia, prolonged disease duration leads to esophageal dilation and bending, disappearance of primary peristalsis, and chronic esophagitis due to stasis of the esophageal contents. These changes are irreversible and some patients may develop esophageal cancer. Therefore, if achalasia is diagnosed, highly effective treatments should be administered at an early stage. Treatment options for achalasia include endoscopic balloon dilation, surgical procedures (laparoscopic Heller-Dor surgery), and peroral endoscopic myotomy (POEM). Currently, POEM, which provides permanent effects with a single treatment, is important. As of December 2023, approximately 6,500 cases have been successfully performed in Japan. This article provides an overview of the diagnosis and treatment of EMD.

A 63-year-old man was admitted to our hospital with dysphagia. Esophagogastroduodenoscopy revealed a white protruding lesion with keratinization in the lower thoracic esophagus and an esophagobronchial fistula on the left wall of the esophagus, 28 cm from the incisors. Based on the endoscopic findings, esophageal verrucous carcinoma (VC) was suspected. However, the diagnosis could not be confirmed by repeated endoscopic biopsies. Therefore, we performed a boring biopsy along the esophagobronchial fistula, and the immunohistochemistry of the specimens showed an extremely well-differentiated squamous carcinoma with papillary proliferation of the epithelium compressing the surrounding connective tissue while retaining the basement membrane. CT revealed no evidence of distant metastases. Based on these findings, we diagnosed an unresectable esophageal VC with invasion into the left main bronchus. Endoscopic boring biopsy is an effective method for the histological diagnosis of unresectable esophageal VC.

Benign esophageal stenosis significantly impairs patientʼs QOL. Herein, we present a case of benign esophageal stenosis refractory to repeated endoscopic balloon dilation. Recurrent deviation was evident despite adequate stent placement, posing a significant challenge for further endoscopic intervention. Fortunately, good clinical outcomes were achieved in this case by utilizing the “stent-in-stent” technique, where a fully covered self-expandable metallic stent was placed within an existing, uncovered, self-expandable metallic stent.

A 43-year-old woman was referred to our healthcare facility for evaluation of a submucosal tumor-like elevation that was discovered in the appendiceal orifice during colonoscopy conducted to investigate hematochezia. During the colonoscopy, an elevated lesion displaying a characteristic “volcano sign” and a Type I pit were observed in the same location. Abdominal CT revealed a target-like structure situated within the wall of the appendix, although no evidence of neoplastic lesions was visible. Based on these findings, the patient was diagnosed with appendiceal intussusception. Given the possibility of a malignant lesion, a laparoscopic ileocecal resection was performed. Histopathological examination revealed appendiceal endometriosis. It is crucial to consider endometriosis in the differential diagnosis of appendiceal intussusception.

Primary malignant lymphomas of the bile duct are rare. We report a case of primary diffuse large B-cell lymphoma (DLBCL) of the common bile duct (CBD) in an 88-year-old man who presented with obstructive jaundice. Contrast-enhanced CT revealed dilated perihilar bile duct and distal bile duct wall thickening, with slight contrast enhancement. Bile cytology and biopsy of the distal bile duct stricture were performed using ERCP to obtain a definitive diagnosis and sufficient number of specimens.

Bile cytology and biopsy specimens suggested malignant lymphoma. Bile duct specimen and flow cytometry analysis revealed a CD3-negative, CD20 (L26)-positive, CD45RO (UCHL-1)-negative, CD79a-positive, and CD45 (LCA)-positive large B-cell lymphoma. FDG-PET/CT showed no FDG accumulation, excluding the CBD. Based on these results, primary DLBCL of the CBD was diagnosed. ERCP biopsy is important in the diagnosis of primary DLBCL of the CBD.

Endoscopic clipping is a commonly used and simple hemostatic method for the treatment of colonic diverticular bleeding (CDB). CBD clipping methods are classified as direct or indirect: the former involves capturing the vessel directly, while the latter involves closing the diverticular orifice in a zipper-like manner. A large multicenter cohort study in Japan (CODE BLUE-J Study) revealed that direct CDB clipping was associated with a reduced risk of rebleeding (within 30 days and 1 year) after endoscopic treatment and decreased blood transfusion requirement compared with indirect clipping. However, no associations were seen in the active bleeding or left-sided CDB groups. These results suggest that direct CDB clipping is effective in cases with a stable visual field and endoscope manipulability. Various devices are available to stabilize the endoscopic view and manipulability against the bleeding point, such as water immersion observation using a water jet scope with a transparent hood. We believe that these devices will enable effective direct CDB clipping in a larger number of cases.

Treatment of hepatolithiasis in patients with surgically altered anatomy is challenging, and percutaneous transhepatic biliary drainage (PTBD) is performed as a standard therapy. Recent evidence suggests that balloon endoscopy-assisted endoscopic retrograde cholangiopancreatography (BE-ERCP) and endoscopic ultrasonography-guided biliary drainage (EUS-BD) is effective and safe for the treatment of hepatolithiasis. Herein, we present an overview of endoscopic procedures for the treatment of hepatolithiasis using BE-ERCP and EUS-BD.

In recent years, there have been significant advances in the endoscopic resection (ER) procedures of superficial nonampullary duodenal epithelial tumors (SNADETs). A preoperative endoscopic diagnosis is thus deemed necessary in determining the indication for subsequent ER. For the histologic and endoscopic diagnosis of SNADETs, understanding the mucin phenotype is inevitable. Recently, two diagnostic algorithms for the differential diagnosis of SNADETs from nonneoplastic lesions under magnifying endoscopy with narrow-band imaging have been proposed. In addition, various endoscopic approaches have been proposed to differentiate low- and high-grade adenomas/carcinomas, including white light endoscopy, magnifying image-enhanced endoscopy, and endocytoscopy. These methods, however, have not been standardized with respect to the classification of their findings and the validation of their diagnostic accuracy. Moreover, there are still concerns with respect to the histologic criteria required to establish a SNADETs diagnosis. Standardization in the histologic and endoscopic diagnosis of SNADETs is needed.