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.