Santa Hattori

Iatrogenic perforation associated with therapeutic colonoscopy: A multicenter study in Japan

Background and Aim:  Colonic perforation is the serious accidental complication. The aim of this study is to analyze the clinical presentation and management of recent iatrogenic perforations during therapeutic colonoscopy.

Safer endoscopic gastric mucosal resection: preoperative proton pump inhibitor administration.

Background and Aim:  Control of bleeding is crucial in improving the safety of endoscopic mucosal resection (EMR), and intragastric acidity has a great impact on hemostasis and blood coagulation. Proton pump inhibitors (PPI) are potent suppressors of gastric acid; however, PPI need to be continuously administered orally for several days, and thus initial effects may be insufficient if PPI is only administered immediately after EMR. The aim of this study was to determine whether preoperative administration of PPI prior to EMR can elevate intragastric acidity, facilitate better control of intraoperative bleeding (complete coagulation and hemostasis), prevent postoperative bleeding, and facilitate healing of artificial ulcers.

Prospective evaluation of the proportion of sessile serrated adenoma/polyps in endoscopically diagnosed colorectal polyps with hyperplastic features

Background and study aims: Sessile serrated adenoma/polyps (SSA/Ps) are considered precursors of colorectal cancers with microsatellite instability. However, it is still difficult to differentiate SSA/Ps from hyperplastic polyps endoscopically; therefore, the prevalence of SSA/Ps remains uncertain in clinical practice. This study aimed to clarify the proportion of SSA/Ps in endoscopically diagnosed colorectal polyps with hyperplastic features (E-HPs). Patients and methods: Patients aged ≥ 40 years undergoing colonoscopy for standard clinical indications at our center were prospectively enrolled between June 2013 and May 2014. During colonoscopy, 0.05 % indigo carmine dye was sprayed throughout the colorectum to highlight lesions. All detected lesions were diagnosed by high definition magnifying narrow-band imaging and were resected endoscopically or surgically, apart from rectosigmoid E-HPs ≤ 5 mm. The number of rectosigmoid E-HPs ≤ 5 mm was recorded, and some were resected for use as tissue samples. Results: A total of 343 patients (male: 42.9 %; mean age: 61.5 years) were included. Among 3838 E-HPs (distal: 96.4 %) detected in 294 patients, 792 were resected and analyzed. All of 21 SSA/Ps identified in 17 patients were included in E-HPs, and the overall proportion of SSA/Ps in E-HPs was 2.7 %. However, this proportion increased with the size of E-HPs (≤ 5 mm: 0.7 %; 6 – 9 mm: 29.0 %; ≥ 10 mm: 70 %) and was higher in the proximal colon than in the distal colorectum (10.9 % vs. 0.9 %). In addition, no SSA/P was found in the rectum, and no SSA/P had cytological dysplasia. Conclusions: The overall proportion of SSA/Ps in E-HPs was 2.7 %, although this proportion was higher in the proximal colon and increased with the size of E-HPs. SSA/Ps were common in routine colonoscopy, with a prevalence of at least 5.0 %. Study registration: UMIN000010832.

Clinical and endoscopic evaluations of sessile serrated adenoma/polyps with cytological dysplasia: Evaluation of SSA/P with cytological dysplasia

Although sessile serrated adenoma/polyps (SSA/Ps) are considered to be premalignant lesions and rapidly progress to carcinomas after they develop cytological dysplasia (CD), a treatment strategy for SSA/Ps in Asian countries is still being debated and has not yet been established. The present study aimed to propose a treatment strategy for SSA/Ps.

Atlas of Neoplastic Lesions

These lesions refer to multiple areas of the esophagus not staining with iodine when sprayed with iodine stain. Lesions that do not stain with iodine include areas of inflammation, atypical epithelium, intraepithelial cancers, and invasive cancers, whereas squamous cell carcinoma is extremely likely with a positive pink color sign, a pink color change following iodine staining. Multiple Lugol-voiding lesions are seen in individuals with ALDH2 deficiency who habitually consume alcohol, and they are at an increased risk of multiple cancers of the esophagus and laryngopharyngeal region.