[Massive thrombosis of the superior mesenteric artery following splenectomy. A coincidence?]

Postsplenectomy thrombocytosis is a well recognised complication about which there is little published information. Therefore, postoperative complications of this effect have not been emphasised. An experience with a case of superior mesenteric artery thrombosis and small intestinal ischemia following splenectomy is reported. We reviewed the literature, but we wasn't able to find any case, whereas the association between splenectomy and mesenteric or portal vein thrombosis is well known. Pathogenesis of postsplenectomy thrombocytosis is poorly understood. Theories to explain it include removal of the splenic sequestration effect or removal of a regulatory humoral factor produced by the spleen. Both mechanisms could be operative at the same time, explaining the observation that some patients develop thrombocytosis related complications soon after surgery, while others after a longer time. The literature on the thromboembolic risk of postsplenectomy thrombocytosis is inconclusive and no studies have established whether patients with thrombocytosis following splenectomy should be treated with anticoagulants or antiplatelet medications in order to prevent thrombotic complications. Certainly, a recommendation for the routine use of these drugs cannot be made on the basis of one observation, but the need for controlled studies must be stressed.