[Ischemic Necrosis Caused by Retroanastomotic Hernia after Subtotal Gastrectomy].

After gastrojejunostomy, a small space can occur between the jejunum at the anastomosis site, the transverse mesocolon, and retroperitoneum, which may cause an intestinal hernia. This report presents a rare case of intestinal ischemic necrosis caused by retroanastomotic hernia after subtotal gastrectomy. A 56-year-old male was admitted to Kangwon National University Hospital with melena, abdominal pain, and nausea. His only relevant medical history was gastrectomy due to stomach cancer. Endoscopic findings revealed subtotal gastrectomy with Billroth-II reconstruction and a bluish edematous mucosal change with necrotic tissue in afferent and efferent loops including the anastomosis site. Abdominopelvic CT showed strangulation of proximal small bowel loops due to mesenteric torsion and thickening of the wall of the gastric remnant. Emergency laparotomy was performed. Surgical findings revealed the internal hernia through the defect behind the anastomosis site with strangulation of the jejunum between 20 cm below the Treitz ligament and the proximal ileum. Roux-en-Y anastomosis was performed, and he was discharged without complication. Retroanastomotic hernia, also called Petersen's space hernia, is a rare complication after gastric surgery, cannot be easily recognized, and leads to strangulation.