Experiment on endoscopic balloon dilation for esophageal stenosis after endoscopic submucosal dissection in pigs

Background and aim Endoscopic balloon dilation (EBD) is effective for esophageal stenosis caused by ESD. However, an efficient EBD method has not been established. We, therefore, conducted EBD experiments on porcine esophageal stenosis models. Methods Study 1: in dilation models (day 22 after ESD), the thickness of the outer muscle layer (as an index of the extension effect) and the area of muscle fiber bundle necrosis in the inner muscle layer (as an index of thermal damage) were evaluated. Study 2: in restenosis models (day 43 after ESD), the thickness of the fibrous plexus (as an index of restenosis) was evaluated. In total, 12 porcine models were created. Results Study 1: the thickness of the outer muscle layer was 1243 +/- 322 mu m in surrounding locations and it was 803 +/- 145 mu m beneath the laceration (p = 0.005). In cases of muscular layer injury, the area of necrosis was 15,500 +/- 10400 mu m(2) in surrounding locations and it was 40,200 +/- 12900 mu m(2) at the laceration site (p < 0.001). Study 2: the thickness of the fibrous plexus was 1359 +/- 196 mu m in surrounding locations and it was 1322 +/- 136 mu m(2) in the laceration scar site (p = 0.74). Conclusion Since thermal damage persists until the completion of stenosis, EBD in the initial stage should be carefully performed. An extension effect was observed only at the laceration site and it later returned to a status similar to that of surrounding locations. Additional intervention would be required for preventing restenosis

Relationships of early esophageal cancer with human papillomavirus and alcohol metabolism

BACKGROUND It is well known that an alcohol consumption habit together with inactive heterozygous aldehyde dehydrogenase-2 (ALDH2) is an important risk factor for the development of esophageal squamous cell carcinoma (ESCC). It remains controversial whether human papillomavirus (HPV) infection contributes to the occurrence/development of ESCC. There has been no study in which the relationship between ESCC and HPV in addition to alcohol dehydrogenase-1B (ADH1B) and ALDH2 genotypes was evaluated. AIM To evaluate relationships between HPV infection and development of esophageal cancer, particularly early esophageal cancer, based on ADH1B/ALDH2 polymorphisms. METHODS We conducted an exploratory retrospective study using new specimens, and we enrolled 145 patients who underwent endoscopic resection for superficial ESCC and had been observed for more than two years by both physical examination and endoscopic examination in Hokkaido University Hospital. Saliva was collected to analyze genetic polymorphisms of ADH1B/ALDH2. We performed in situ hybridization for resected specimens to detect HPV by using an HPV type 16/18 probe. RESULTS HPV was detected in 15 (10.3%) of the 145 patients with ESCC. HPV-positive rates in inactive ALDH2*1/*2 and ALDH2*1/*1 + *2/*2 were 10.8% and 9.8%, respectively (P = 1.00). HPV-positive rates in slow-metabolizing ADH1B*1/*1 and ADH1B*1/*2 + *2/*2 were 12.0% and 10.0%, respectively (P = 0.72). HPV-positive rates in the heavy or moderate alcohol consumption group and the light or rare consumption group were 11.1% and 8.7%, respectively (P = 0.68). HPV-positive rates in the heavy smoking group and the light or no smoking group were 11.8% and 8.3%, respectively (P = 0.59). The 3-year incidence rates of secondary ESCC or head and neck cancer after initial treatment in the HPV-positive and HPV-negative groups were 14.4% and 21.4% (P = 0.22), respectively. CONCLUSION In the present situation, HPV status is considered to be less important than other risk factors, such as alcohol consumption, smoking habit, ADH1B/ALDH2 polymorphisms, and HPV status would therefore have no effect on ESCC risk management

Eradication of Helicobacter pylori may improve dyspepsia in the elderly for the long term

Background Therapy for eradication of Helicobacter pylori (H. pylori) improves symptoms of H. pylori-associated dyspepsia (HPD), but the effects of eradication in elderly patients are unclear. The aim of our study was to investigate dyspepsia symptoms and long-term effects of eradication in elderly patients. Methods This retrospective study included 496 patients who received H. pylori eradication therapy. The patients were divided into a group of elderly patients (group E: >= 65 years old) and a group of non-elderly patients (group N: < 65 years old). Abdominal symptoms were evaluated using a questionnaire about abdominal symptoms before eradication and after eradication (1-2 months and more than one year). Dyspepsia was defined as a score of 4 points or more for at least one of 4 items (postprandial fullness, early satiety, epigastric pain, and hunger pain). Improvement of symptoms was defined on the basis of changes in Global Overall Systems scores. Results There were no differences in abdominal symptoms before eradication between the two groups. Successful eradication improved symptoms in patients with dyspepsia within 2 months (in 75.6% (56/74) of the patients in group N and in 64.5% (20/31) of the patients in group E). The questionnaire showed that 80% (32/40) of the patients in group N and 60% (12/20) of the patients in group E had long-term relief of dyspepsia. The scores for abdominal symptoms in group E continued to improve for a mean period of 54.8 months after eradication. Conclusions Eradication of H. pylori age-independently improved dyspepsia symptoms for the long term

Optical biopsy for esophageal squamous cell neoplasia by using endocytoscopy

Background Endocytoscopy (ECS) enables microscopic observation in vivo for the gastrointestinal mucosa; however, there has been no prospective study in which the diagnostic accuracy of ECS for lesions that have not yet undergone histological diagnosis was evaluated. We conducted a surveillance study for patients in a high-risk group of esophageal squamous cell carcinoma (ESCC) and evaluated the in vivo histological diagnostic accuracy of ECS. Methods This study was a multicenter prospective study. We enrolled 197 patients in the study between September 1, 2019 and November 30, 2020. The patients first underwent white light imaging and narrow band imaging, and ultra-high magnifying observation was performed if there was a lesion suspected to be an esophageal tumor. Endoscopic submucosal dissection (ESD) was later performed for lesions that were diagnosed to be ESCC by ECS without biopsy. We evaluated the diagnostic accuracy of ECS for esophageal tumorous lesions. Results ESD was performed for 37 patients (41 lesions) who were diagnosed as having ESCC by ECS, and all of them were histopathologically diagnosed as having ESCC. The sensitivity [95% confidence interval (CI)] was 97.6% (87.7-99.7%), specificity (95% CI) was 100% (92.7-100%), diagnostic accuracy (95% CI) was 98.9% (94.0-99.8%), positive predictive value (PPV) (95% CI) was 100% (91.4-100%) and negative predictive value (NPV) (95% CI) was 98.0% (89.5-99.7%). Conclusions ECS has a high diagnostic accuracy and there were no false positives in cases diagnosed and resected as ESCC. Optical biopsy by using ECS for esophageal lesions that are suspected to be tumorous is considered to be sufficient in clinical practice