Atraumatic chylous ascites: systematic review on symptoms and causes.

Chylous ascites, or chylaskos, is a rare form of ascites characterized by a milky-appearing fluid containing high levels of triglycerides. Its incidence ranges from 1 in 20,000 to 1 in 187,000 admissions at large tertiary referral hospitals. Therapeutic interventions and trauma are well-known causes of chylous ascites. In a cohort of 1,103 patients undergoing abdominal surgery, the incidence of postoperative chylous ascites was reported to be 1.1%. When retroperitoneal, esophageal, gastric, or cytoreductive surgeries were performed, the postoperative incidence was even higher, amounting to 7.4%. Apart from oncologic thoacic and abdominal surgery, chylous ascites can also occur fter abdominal aortic surgery and very rarely after donor ephrectomy. In contrast to the direct injury of lymphatic vessels during surgery, the hyperextension and hyperflexion of the body during a blunt abdominal trauma entail a rupture of lymphatic vessels, thus causing chylous ascites. An additional cause of indirect injury leading to the development of chylous ascites is radiotherapy. Abdominal radiation is thought to induce fibrosis of the lymphatic vessels within the small bowel and the mesentery, causing obstruction and subsequent extravasation of chylous. In patients after radiation of the whole abdomen for gynecologic malignancies, the incidence was reported to be as high as 3%. The most common clinical presentation of chylous ascites is supposed to be increasing painless abdominal distension. Less frequently, postinterventional and posttraumatic chylous ascites can induce an acute abdomen. Although the clinical features and causes of chylous ascites secondary to surgery or trauma are familiar to most clinicians, little is known about the incidence, etiology, and distribution of different clinical symptoms of atraumatic chylous ascites. The incidental finding of a few milliliters of chylous ascites during a routine inguinal hernia repair in a 28-year-old man finally leading to the diagnosis of non-