Petersen hernia is a rare internal hernia that occurs after Roux-en-Y (R-Y) reconstruction. To our knowledge, there are a few reports on internal hernia, especially Petersen hernia after open gastrectomy for gastric cancer. Two rare cases of Petersen hernia are presented in this report. A man in his 70s was referred to our hospital due to a complaint of postprandial sudden abdominal pain. He had a history of open total gastrectomy with R-Y jejunal reconstruction through the antecolic route for gastric corpus cancer. On computed tomography (CT), bowel obstruction and strangulation of the small intestine were suspected. Emergency laparotomy was done, and an internal herniation of the small intestine through Petersen space was observed. A man in his 50s was referred to our hospital due to a complaint of severe sudden abdominal pain. He had a history of open gastrectomy and abdominal/lower intrathoracic esophageal resection with R-Y jejunal reconstruction of an antecolic jejunal limb for esophagogastric junction carcinoma. On CT, internal herniation of the small intestine was suspected. During emergency laparotomy, an internal herniation of the bowel through the Petersen space was observed. Though history of R-Y reconstruction surgery may be helpful, preoperative diagnosis of Petersen hernia is difficult to establish. Here we present two rare cases of this type of internal hernia.

Pancreatic invasive ductal adenocarcinoma (PDAC) has a poor prognosis, and the detection of PDAC during the early stage is thought to improve prognosis. In this study, we retrospectively investigated pancreatic morphological abnormalities that lead to the early diagnosis of PDAC with computed tomography (CT) imaging. In total, 41 out of 308 patients diagnosed with pancreatic cancer between 2011 and 2017 in our institution were enrolled. As a control group for the group with pancreatic cancer, 4277 patients without pancreato-biliary diseases were enrolled. We retrospectively reviewed and analyzed the clinical data including patient characteristics, the clinical course and preoperative CT imaging with pancreatic morphological features. Out of 41 patients, 24 patients (58.5%) showed local K-shaped constriction of the pancreatic parenchyma “K-sign” on preoperative CT images. Eight patients (19.5%) showed localized fatty change. Out of 4277 control patients, seven patients (0.16%) showed K-sign. “K-sign” may be used for the early diagnosis of PDAC by CT imaging.

Purpose There is no standardized surveillance protocol after intraductal papillary mucinous neoplasm (IPMN) resection. We report the findings of a large-scale survey in Japan, investigating the independent predictors of secondary invasive tumors by analyzing the epidemiology of secondary tumors of the remnant pancreas after initial IPMN resection. Methods An institutional questionnaire about the remnant pancreas after pancreas resection was distributed at the 41st Annual Meeting of the Japanese Society of Pancreatic Surgery in Tokyo. We retrospectively analyzed the patient data including pathological diagnosis, postoperative outcomes, and evaluation methods. Results Redo pancreatectomy was performed for secondary disease in 213 (1.4%) of a total 15,777 patients. Eighty-eight of these 213 patients had undergone initial resection of IPMN. The types of secondary tumors after IPMN resection significantly depended on those of the primary tumors. Through short-interval and long-term follow-up, most of the secondary tumors were detected within 1-4 years. Logistic regression analysis revealed that the initial pathological diagnosis of invasive IPMN was an independent predictor of secondary invasive tumors in the remnant pancreas. Conclusion Primary invasive IPMN proved to be a significant predictor of secondary invasive IPMN. Both short-interval and long-term follow-up may help to determine the prognosis of patients after IPMN resection.