High-Output Stoma Leading to the Diagnosis of Antiphospholipid Syndrome.

Diverting stoma (DS) is widely created in colorectal surgery. High-output stoma (HOS) is a major complication of DS, which can lead to dehydration and thrombosis. Additionally, antiphospholipid syndrome (APS) is a risk factor for thrombosis, and it rarely occurs in men. Herein, we describe a case of multiple thromboses caused by chronic dehydration after HOS. A 48-year-old man visited our hospital with fever and lower abdominal pain; he was diagnosed with sigmoid diverticulitis. He underwent laparoscopic high anterior resection for relapsing diverticulitis and diverting ileostomy during the same operation. On postoperative day 1, an output of 3,000 mL/day was observed from the ileostomy. The stoma output exceeded 2,000 mL/day, which was diagnosed as HOS, and chronic dehydration persisted despite supplementation and restriction of oral water intake. Three months postoperatively, a computed tomography scan before ileostomy closure showed multiple thrombi in the inferior vena cava, right common iliac vein, and pulmonary artery. After antithrombotic therapy, ileostomy closure was performed. As lupus anticoagulant was positive twice and APS was diagnosed, antithrombotic therapy was changed from warfarin to direct oral anticoagulants. Thrombosis did not recur 6 months postoperatively. This is the first report of a case wherein APS was present in the background of thrombosis caused by HOS or chronic dehydration. It is important to be cautious about APS when there is thrombosis after HOS to select appropriate therapeutic agents.