Authors' reply: Risk factors for portal venous thrombosis after splenectomy in patients with cirrhosis and portal hypertension (Br J Surg 2010; 97: 910–916)

Sir We would like to thank Dr Marco and colleagues for their interest in our report. We initially suspected that the increased incidence of portal venous thrombosis (PVT) after splenectomy in patients with cirrhosis might be a result of disturbed haemostasis1. However, poor liver function (Child–Pugh score, Model for End-Stage Liver Disease score, prothrombin time) was not found to be a significant risk factor for postoperative PVT in patients with cirrhosis in this study (P = 0·061). Kawanaka and colleagues2 demonstrated that the incidence of PVT after splenectomy in patients with cirrhotic was decreased by prophylactic administration of antithrombin III concentrates, suggesting that abnormal haemostasis could be a risk factor for PVT in these patients. Prophylactic administration of antithrombin III is routinely carried out within the first few days in patients at high risk of PVT in our institution, and the incidence of PVT after splenectomy in patients with cirrhosis thus remains low. Further studies are needed to confirm the involvement of the various factors (such as protein S and protein C) that contribute to peculiar thrombophilic conditions in the development of PVT after splenectomy in patients with cirrhosis. The purpose of this study was to clarify the incidence and characteristics of PVT after splenectomy in patients with cirrhosis. The associated risk factors with regard to liver function, portal hypertension and splenectomy were assessed in light of the need for prophylactic anticoagulation therapy for PVT within the first few days after splenectomy. The preoperative and operative clinical factors were reviewed in this study. Median(s.d.) platelet counts on postoperative day 14 were higher in the PVT group than in the non-PVT group (360(35) × 103versus 201(13)/µl respectively). However, the contribution of the low platelet count to the hypercoagulability and subsequent formation of PVT after splenectomy was not determined.