Risk factors of portal vein system thrombosis after splenectomy: a meta-analysis

The primary aim of the present study was to explore risk factors for portal vein system thrombosis following splenectomy.

A systematic search of PubMed, Embase and Cochrane libraries was conducted to identify original studies that fulfilled the inclusion criteria. Raw data on potential risk factors for portal vein system thrombosis after splenectomy were extracted for meta-analysis. Subsequently, a sensitivity analysis was conducted to verify the stability of the results.

Eighteen studies with 626 thrombosis events from 1807 splenectomy met the inclusion criteria. Larger spleen volume (SMD 0.44, P = 0.000), broader splenic vein diameter (WMD 2.30, P = 0.000), broader portal vein diameter (WMD 2.08, P = 0.000), a lower velocity of portal blood flow (WMD -0.91, P = 0.001), decreased platelet count (WMD -5.14, P = 0.007), decreased white blood cell (WMD -0.40, P = 0.027), decreased haemoglobin (WMD -9.14, P = 0.002), ascites (OR 1.81, P = 0.003) and bleeding history before surgery (OR 1.88, P = 0.002) were identified to be factors that exacerbated the risk of portal vein system thrombosis after splenectomy. Sex, age, preoperative prothrombin time, postoperative platelet count, postoperative D-dimer, operation time and intraoperative blood loss, did not increase the risk of thrombosis.

Larger spleen volume, broader splenic vein diameter, broader portal vein diameter, a lower velocity of portal blood flow, ascites, bleeding history before surgery, decreased platelet count, white blood cell and haemoglobin may increase the risk of portal vein system thrombosis.