Oral trypsin inhibitor can improve reflux esophagitis after distal gastrectomy concomitant with decreased trypsin activity

Background The pathogenesis of reflux esophagitis is not well understood and remains controversial. Distal gastrectomy serves as a model to assess the role of duodenal reflux with low gastric acidity in the development of reflux esophagitis. We investigated the clinical usefulness and antitrypsin activity after treatment with a trypsin inhibitor, camostat mesilate, against the reflux esophagitis after distal gastrectomy reconstructed with Billroth-I anastomosis. Methods Twenty-eight patients with gastroesophageal reflux disease after distal gastrectomy were prescreened according to esophageal pH level and trypsin activity, and consequently 11 patients were enrolled in the present clinical study. Esophageal and duodenal washings were aspirated for the evaluation of the pretreatment trypsin activity. Then 100 mg of camostat mesilate was administered orally. At 30 and 120 minutes after the administration, duodenal washings were aspirated for the evaluation of posttreatment trypsin activity. Thereafter, 300 mg of camostat mesilate was administered orally 3 times daily for a 4-week period. On the 28th day of administration, the grade of reflux esophagitis (Los Angeles classification) was re-evaluated under endoscopy and the esophageal washings were aspirated for the evaluation of trypsin activity. Results The trypsin activities in the duodenum both at 30 and 120 minutes after oral ingestion of camostat mesilate were decreased significantly in comparison with those in the pretreatment period in each patient (P < .001). In 6 of 7 patients with detectable trypsin activity in the esophagus, the activities after the 28th day of treatment were lower than those in the pretreatment period, and the symptoms were milder than those before treatment (P < .05). Furthermore, endoscopic evaluation showed that 40% of patients were grade B, C, and D after treatment (28th day), whereas 70% of patients were grade B, C, and D before the treatment. Conclusions Oral administration of trypsin inhibitor can improve reflux esophagitis after distal gastrectomy concomitant with decreased trypsin activity.