大澤 博之

Gastric mucosal changes associated with long-term potassium-competitive acid blocker and proton pump inhibitor (PPI) therapy may raise concern. In contrast to that for PPIs, the evidence concerning the safety of long-term potassium-competitive acid blocker use is scant. Vonoprazan (VPZ) is a representative potassium-competitive acid blocker released in Japan in 2015. In order to shed some comparative light regarding the outcomes of gastric mucosal lesions associated with a long-term acid blockade, we have reviewed six representative gastric mucosal lesions: fundic gland polyps, gastric hyperplastic polyps, multiple white and flat elevated lesions, cobblestone-like gastric mucosal changes, gastric black spots, and stardust gastric mucosal changes. For these mucosal lesions, we have evaluated the association with the type of acid blockade, patient gender, Helicobacter pylori infection status, the degree of gastric atrophy, and serum gastrin levels. There is no concrete evidence to support a significant relationship between VPZ/PPI use and the development of neuroendocrine tumors. Current data also shows that the risk of gastric mucosal changes is similar for long-term VPZ and PPI use. Serum hypergastrinemia is not correlated with the development of some gastric mucosal lesions. Therefore, serum gastrin level is unhelpful for risk estimation and for decision-making relating to the cessation of these drugs in routine clinical practice. Given the confounding potential neoplastic risk relating to H. pylori infection, this should be eradicated before VPZ/PPI therapy is commenced. The evidence to date does not support the cessation of clinically appropriate VPZ/PPI therapy solely because of the presence of these associated gastric mucosal lesions.

BACKGROUND/AIMS: Underwater endoscopic mucosal resection (UEMR) is the standard resection method for superficial non-ampullary duodenal tumors (SNADETs). We developed a novel UEMR technique that creates an anchor by protruding the distal fold with a saline injection (UEMR-A). The aim of this study was to clarify the usefulness of UEMR-A compared to conventional UEMR (UEMR-C). METHODS: This retrospective observational study included patients who underwent UEMR for SNADETs. RESULTS: A total of 141 patients were included and divided into UEMR-A (n=54) and UEMR-C (n=87) groups. Lesion resection was performed significantly more frequently by an expert endoscopist in the UEMR-C group compared to the UEMR-A group (p<0.001). The procedure time for UEMR-A was significantly shorter than that for UEMR-C (p=0.018), despite the additional time required for submucosal injection. The R0 resection rate was significantly higher in the UEMR-A group than in the UEMR-C group (p=0.004). The horizontal margins were significantly clearer in the UEMR-A group than in the UEMR-C group (p=0.018). Multivariate analysis revealed that the use of UEMR-A was the only significant positive factor for R0 resection. CONCLUSIONS: The UEMR-A technique for SNADETs appears to improve R0 resection rates and reduce procedure times compared to the UEMR-C technique.

BACKGROUND: Gastroesophageal reflux disease (GERD) symptoms frequently recur after cessation of acid blockers. The presence of a hiatal hernia may worsen GERD symptoms and increase the risk of esophageal malignancy. The aim of this study is to clarify the timing and predictors for recurrence of GERD symptoms after cessation of vonoprazan (VPZ) therapy. METHODS: A retrospective observational study involved 86 patients who underwent cessation of VPZ therapy for symptomatic GERD. Collated data from medical record review included the endoscopic findings and Izumo scale score. RESULTS: The mean duration of continuous VPZ therapy before cessation was 7.9 months. GERD symptoms requiring the resumption of VPZ therapy recurred in 66 of 86 patients (77%). Kaplan-Meier analysis showed that overall recurrence-free rates at 6 months, one and two years after VPZ cessation were 44%, 32% and 23%, respectively. Alcohol use, the presence of a hiatal hernia and long-term therapy for more than six months were identified as significant positive predictors for symptomatic recurrence. Notably, hiatal hernia had the highest hazard ratio in both univariate and multivariate analyses. The recurrence-free rate in patients with a hiatal hernia was much lower at 6 months than in patients without a hiatal hernia (15% and 51%, respectively p = 0.002). After the symptomatic recurrence, GERD symptoms improved significantly after one-month VPZ therapy. CONCLUSION: The rate of symptomatic recurrence after VPZ cessation in patients with GERD is considerable. Cessation of acid suppression therapy should be cautious in patients with both a hiatal hernia and GERD.