New Prediction Model for Platelet Increase After Non-Trauma Splenectomy

Although splenectomy causes significant increase in platelet count, little is known about its kinetics and final status of platelet count. This study sought to revisit the kinetics of post-splenectomy platelet count and attempted to establish a prediction model of post-splenectomy platelet count. Data of 103 consecutive patients who underwent splenectomy with or without resection of adjacent organs were reviewed. Postoperative kinetics of platelet count was investigated and prediction model of its final status was established. The study cohort consisted of patients with diseased liver group (n = 28) and with normal liver group (n = 75). Platelet count increased rapidly during the initial 1 month and reached plateau at approximately 3 months after splenectomy. The degree of increase in platelet count was significantly higher in the diseased liver group, while the final platelet count reached within normal range in both of the two groups. Regression analysis confirmed that platelet increase rate at 3 months was predictable with relatively high accuracy using the following formula: 1.667 + 0.006 × (spleen volume per body surface mL/m²)–0.030 × (preoperative platelet count, 10⁴/mm³) (r = 0.849, P < 0.001). Acceptable performance of this formula was also confirmed in a validation cohort (r = 0.904, P < 0.001). Post-splenectomy increase in platelet count is significantly higher in patients with diseased liver. The final degree of increase in platelet count may be predictable with high accuracy using preoperative platelet count and spleen volume index.