Mesenteric venous thrombosis in familial free protein S deficiency.

Protein S deficiency reportedly is associated with a high risk for thromboembolism, but mesenteric venous thrombosis is a rare manifestation of this hereditary disorder. We describe an additional case of mesenteric venous thrombosis in a 25-yr-old man with type I protein S deficiency. Total protein S level remained just below the normal range, but free protein S level was less than 10% of normal. Family study revealed that his father had had the same type of disorder. We have reviewed six well-documented cases of mesenteric venous thrombosis with protein S deficiency. It is particularly interesting that those with type I deficiency have had no previous thrombotic episodes (p < 0.05). Our patient was successfully treated with extended bowel resection, but unusual perioperative management was required. Because of extremely edematous mesentery and small bowel, we had to treat him with the abdomen wide open for 2 days between the primary and second laparotomies.