A 42-year-old woman without a history of vomiting in infancy presented to the emergency department with postprandial abdominal distension and repeated vomiting but no abdominal pain. Laboratory examination showed normal results, including a normal serum Helicobacter pylori antibody level, except for mild anemia. Abdominal computed tomography (CT) showed gastric dilatation and wall thickening of the distal stomach (Fig. , asterisk, arrow). Endoscopy and contrast gastrography revealed gastric outlet obstruction due to stenosis of the antral and pyloric region (Fig. ), and a deep ulcer in the stenotic antrum (Fig. ). She was admitted to our hospital and treated with nasogastric tube drainage, fasting, and administration of a proton pump inhibitor. Three days later, her symptoms improved and she could start to take a liquid diet. Ten days after the initiation of treatment, she was asymptomatic and could eat a normal diet. Follow-up endoscopy performed on hospital day 12 showed a healing ulcer in the prepyloric region (Fig. ) and a distinct opening to the duodenum at the edge of the healing ulcer that was different from the original pylorus. Endoscopic ultrasonography (EUS) revealed circumferential thickening of the muscularis propria layer of the pylorus with a maximum thickness of over 10 mm (Fig. , arrowheads). Pathological examination of multiple biopsy specimens taken from the ulcer and surrounding mucosa showed no evidence of malignancy. Since the patient was asymptomatic, she was discharged from the hospital on hospital day 21. Additional follow-up endoscopic examinations revealed a clear double pylorus (Fig. , arrows). The endoscope could easily pass through both channels to the duodenum. Based on her clinical course and findings of clinical images, she was diagnosed as having gastric outlet obstruction due to AHPS that was improved by spontaneous double channel pylorus formation. Six months after onset, CT showed residual wall thickening of the distal stomach without gastric dilatation (Fig. , arrow) and EUS revealed residual circumferential thickening of the muscularis propria layer of the pylorus, indicating that she still had AHPS although she did not have any abdominal symptoms.\nOur patient's clinical and imaging findings suggested that the double pylorus formed in our patient in the following manner. When we retrospectively reviewed the endoscopic images from the EGD examination that the patient had undergone 1 year prior to the current admission, antral narrowing was observed. She may have had asymptomatic AHPS at that time. When the patient came to the emergency room, endoscopy and contrast gastrography revealed gastric outlet obstruction due to stenosis and a deep ulcer in the stenotic antrum. During the hospital admission, the deep ulcer made a fistula with the duodenum that would eventually become a double pylorus. After double pylorus formation, the patient no longer had symptoms of AHPS and she was discharged from the hospital.
We present a 66-year-old female who presented to surgical outpatient department with mild epigastric pain. She denied any history of peptic ulcer disease or use of ulcerogenic drugs, such as NSAIDs. Clinical examination revealed an otherwise fit patient; the abdominal examination was normal. The endoscopy showed no evidence of peptic ulceration but demonstrated a double pylorus (). The mucosa of the stomach as well as the duodenum appeared normal. The duodenum was easily entered via both pyloric channels. The patient was treated symptomatically and is now well. A follow-up endoscopy 6 weeks later demonstrated the same findings as the initial endoscopy.