Chylous peritonitis with small bowel obstruction.

Chylous ascites may present with a number of abdominal complications1,2. We present a case of chylous peritonitis presenting as small bowel obstruction.

Case Report

A 44 year old male presented to the accident and emergency unit with crampy abdominal pain of a two days duration, worse over the previous day. He had a background history of a partial oesophago-gastric resection for Boerhaave's syndrome some months earlier. On examination there was marked abdominal distension with epigastric tenderness. Plain abdominal X-ray showed a large fluid filled loop suggestive of a volvulus. CT scan (fig 1) confirmed a volvulus of the small bowel with a twist of mesentry root and likely venous obstruction.

At laparotomy there was a volvulus around a band from the apex of the anti-mesenteric border of the small bowel to the fourth part of the duodenum. The entire small bowel was dusky with venous engorgement but viable. There was striking engorgement of the lymphatics in the wall of the small bowel and 400ml of milky chylous fluid free in the peritoneal cavity. The patient made an uneventful recovery after surgery.

Discussion

Chylous peritonitis is the extravasation of milky chyle into the peritoneal cavity. This can occur de novo as a result of trauma or obstruction of the lymphatic system. An existing clear ascitic fluid can turn chylous as a secondary event. A true chylous effusion is defined as the presence of ascitic fluid with high fat (triglyceride) content, usually higher than 110 mg/dL.

Chylous fluid in the peritoneal cavity is a rare clinical condition that occurs as a result of disruption of the abdominal lymphatics. Multiple causes have been described (table I). Congenital chylous ascites is the commonest cause of chyloperitoneum in young children. Other causes in children include idiopathic or obstructive lesions caused by malrotation, intussusception, incarcerated hernia, lymphangioma, blunt trauma, liver disease, and tuberculosis. In children, malrotation and volvulus contribute to chylous ascites3. Volvulus of the midgut may result in several manifestations. Venous and lymphatic obstructions occur first because of lower intravascular pressures. Vascular congestion leads to bowel oedema and possible oozing of blood, causing melaena. Lymphatic congestion causes the formation of a mesenteric cyst and chylous ascites.

Table I

Causes of Chylous fluid
Abdominal surgery Blunt abdominal trauma Malignant neoplasm's - Hepatoma, small bowel lymphoma, Small bowel angiosarcoma, and retroperitoneal lymphoma Spontaneous bacterial peritonitis Cirrhosis - Up to 0.5% of patients with ascites from cirrhosis may have chylous ascites. Pelvic irradiation Peritoneal dialysis Abdominal tuberculosis Carcinoid syndrome Congenital defects of lacteal formation

Milky ascites is subdivided into three groups: True chylous ascites - Fluid with high triglyceride content, Chyliform ascites - Fluid with a lecithin-globulin complex due to fatty degeneration of cells, and Pseudochylous ascites - Fluid that is milky in appearance due to the presence of pus. Dietary chylomicrons are absorbed in the small intestines and gradually pass along larger omental lymphatics to the cisterna chyli located anterior to the second lumbar vertebra. The cisterna is joined by the descending thoracic, right and left lumbar, and liver lymphatic trunks, and, collectively, these form the thoracic duct, which passes through the aortic hiatus and courses through the right posterior mediastinum and eventually enters the venous system. The thoracic duct carries lymphatic drainage from the entire body, except for the right side of the head and neck, right arm, and right side of thorax. Chylous effusions develop when these channels are injured or obstructed. Abdominal distension is the most common symptom, and rarely, it may present as acute peritonitis.

As chylous peritonitis is a manifestation rather than a disease, the prognosis depends on the treatment of the underlying disease or cause. Few cases presenting as chylous peritonitis are reported in literature

Three cases presenting as acute appendicitis have been reported4,5.