Petersen's space hernia as an immediate complication in a patient undergoing gastric bypass: a case report.

Petersen's space hernias are common internal hernias following laparoscopic gastric bypass surgery, occurring when intestinal loops protrude through the space between the mesentery of the alimentary limb and the transverse mesocolon. A 43-year-old female with a history of hypertension underwent a revisional Roux-en-Y gastric bypass due to weight regain and severe gastroesophageal reflux disease. Postoperatively, she developed abdominal pain, and an urgent diagnostic laparoscopy was performed, revealing a nearly complete herniation of the alimentary limb through Petersen's mesenteric defect. Based on these findings, an urgent laparotomy was subsequently performed to reduce the herniated bowel and close the defect. Her postoperative course was uneventful, and she was discharged without complications. Despite the closure of Petersen's mesenteric defect, vigilance for hernia remains crucial due to the risk of severe complications. Advances in preventive techniques show promise, but prompt diagnosis and intervention are essential for improving patient outcomes.