Intestinal Infarction Caused by Thrombophlebitis of the Portomesenteric Veins as a Complication of Acute Gangrenous Appendicitis After Appendectomy: A Case Report

The clinical symptoms of pylephlebitis caused by acute appendicitis are varied and atypical, which leads to delayed diagnosis and poor outcomes. Here, we report a case of intestinal necrosis caused by thrombophlebitis of the portomesenteric veins as a complication of acute appendicitis after appendectomy. The patient had acute abdominal pain with tenderness and melena on the 3rd day after appendectomy for the treatment of gangrenous appendicitis. He was diagnosed with intestinal infarction caused by thrombophlebitis of the portomesenteric veins based on enhanced CT and diagnostic abdominal paracentesis. The patient was treated by bowel excision anastomosis and thrombectomy. After postoperative antibiotic and anticoagulation treatments, the patient recovered well and was discharged 22 days after the 2nd operation. A follow-up CT scan showed no recurrence of portomesenteric veins thrombosis 3 months later. Thrombophlebitis of the portomesenteric veins is a rare but fatal complication of acute appendicitis. For all the cases with acute abdominal pain, the possibility of thrombophlebitis should be considered as a differential diagnosis. Once pylephlebitis is suspected, enhanced CT scan is helpful for early diagnosis, and sufficient control of inflammation as well as anticoagulant therapy should be performed.