Biomedical subjects

Rintaro Narisawa

Publications and source records attributed to Rintaro Narisawa.

3 recordsLinked to original sources

PubMed2003

Prophylactic clip application does not decrease delayed bleeding after colonoscopic polypectomy.

BACKGROUND: The most common major complication of colonoscopic polypectomy is postpolypectomy hemorrhage. Although several factors have been implicated in the occurrence of hemorrhage, accurate prediction of delayed bleeding remains difficult. This randomized controlled trial evaluated the efficacy of prophylactic clip application for prevention of delayed postpolypectomy bleeding. METHODS: Postpolypectomy ulcers created by colonoscopic removal of polyps (mean size 7.8 [4.0] mm) with the endoscopic mucosal resection technique were randomly assigned to prophylactic clip placement (n = 205) or no clip (n = 208). Baseline characteristics of the patients and polyps excised were comparable between the groups. Delayed bleeding was defined as the postprocedure passage of bloody stool or massive hematochezia. The site of delayed bleeding was identified at emergent colonoscopy. RESULTS: Delayed bleeding was identified from 2 ulcers in each group from 1 to 4 days after resection (mean 2.3 days). Delayed bleeding occurred from 0.98% of ulcers in the clip group and 0.96% in the non-clip group (p > 0.9999). No patient with delayed bleeding required transfusion or surgery. CONCLUSIONS: Prophylactic clip placement did not decrease the occurrence of delayed bleeding after colonoscopic polypectomy.

Adenocarcinoma↗

PubMed2002

Gastric carcinoid tumors without autoimmune gastritis in Japan: a relationship with Helicobacter pylori infection.

In Japan, most cases of gastric carcinoid tumor (GCT) are unassociated with either autoimmune gastritis (AIG) showing type-A chronic atrophic gastritis (CAG-A) or Zollinger-Ellison syndrome (ZES). However, the pathogenesis of this tumor remains unknown. Recent studies have determined that Helicobacter pylori infection induces gastric carcinoid in Mongolian gerbils and that H. pylori lipopolysaccharide exerts a mitogenic effect on ECL cells. We examined five patients with histologically diagnosed GCT, 40 patients with H. pylori-positive gastric ulcer (Hp+GU), 24 patients with H. pylori-positive duodenal ulcer (Hp+DU), and 12 patients with AIG showing CAG-A topographically. We compared the prevalence of H. pylori infection, and the levels of gastrin and pepsinogen (PG) in the serum of patients with GCT with those of patients with Hp+GU, or Hp+DU, and AIG. We also investigated the histological characteristics of the tumor and the gastric corpus mucosa in the GCT patients. The levels of serum gastrin and PG I and II were measured using an RIA kit. In all five (100%) patients with GCT, H. pylori infection was present, without any evidence of AIG or ZES. The serum levels of gastrin in the GCT patients were higher than those in either Hp+GU or Hp+DU patients and lower than those in the AIG patients. In contrast, serum PG I levels and the PG I/II ratio were lower in the GCT group than in the Hp+GU or Hp+DU groups. Histologically, all GCTs were ECL cell tumors and peritumoral corporal mucosal atrophy was observed in four of the five patients with GCT. In conclusions, H. pylori infection and hypergastrinemia were found in the patients with GCT without AIG. This finding suggests that H. pylori infection may induce corporal mucosal atrophy and hypergastrinemia that can produce a GCT with time.

Adult↗

PubMed2002

What is an appropriate indication for endoscopic papillary balloon dilation?

OBJECTIVE: There are a number of views on the indication for endoscopic papillary balloon dilation (EPBD) in the management of bile duct stones. In this study, we have evaluated the efficacy and safety of EPBD compared with endoscopic sphincterotomy (EST). DESIGN: Prospective randomized trial. SETTING: One university hospital and one general hospital. PARTICIPANTS AND MAIN OUTCOME MEASURES: One hundred and forty patients were randomly allocated to EPBD or EST. Outcomes and complications were observed for a median period of 30 months. RESULTS: Both treatment approaches finally achieved similar success rates and needed similar numbers of treatment sessions for patients with stones less than 10 mm in diameter. However, for patients with stones of 10 mm or more, EPBD required a significantly greater mean number of treatment sessions than EST (2.4 vs 1.6, P < 0.01). Early complications occurred in seven EPBD (four pancreatitis, two cholangitis and one basket impaction) and eight EST (three pancreatitis, two bleeding and three cholangitis) patients. Late complications occurred in four EPBD (three recurrent bile duct stones and one cholecystitis) and six EST (three recurrent stones and three cholecystitis) patients. CONCLUSIONS: EPBD has little risk of bleeding. The technique removed small bile duct stones just as easily as did EST. These two procedures had approximately the same risk of pancreatitis and incidence of recurrent bile duct stones. Therefore, both procedures appear to be appropriate treatments for small bile duct stones. Whether or not EPBD becomes an established treatment will depend on further long-term studies.

Adult↗