Factors Predicting Long‐term Responses to Splenctomy in Patients with Idiopathic Thrombocytopenic Purpura

Abstract

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder for which appropriate diagnostic treatments are uncertain. The response to splenectomy varies from 60% to 90%, and the remaining patients relapse and require further treatment. Therefore, it is important to predict the outcome of splenectomy before and after surgery. The objective of this study was to evaluate the efficacy of splenectomy in patients diagnosed with ITP. From 1988 to 2004, we splenectomized 32 patients with ITP; 17 underwent laparoscopic splenectomy (LS) and 15 underwent conventional open splenectomy (OS). For analysis, patients were separated retrospectively into two groups: the "responding group," those who showed good outcomes with splenectomy, and the "non-responding group," those who did not show good outcomes with splenectomy. Blood samples were examined before and immediately after surgery (day 0) and on postoperative days (POD) 1, 3, 5, and 7. The median follow-up was 8.3 years (range: 1-16 years). The overall 5- and 10-year survival rates after splenectomy were 96.9% (one death). The responding group included 24 patients (75%), and the non-responding group included 7 (21.9%). Platelet counts in the responding group increased gradually until POD 7, and although platelet counts in the non-responding group were almost constant until POD 5, they subsequently decreased until POD 7. Average platelet counts in the responding and non-responding groups were 269 and 124 x 10(9)/l on POD 7, respectively (P < 0.05). The pre- to post-surgery ratio of platelet counts were almost the same as the result of the actual data. Platelet counts during the long-term follow-up for the responding and non-responding groups were related to those noted on discharge. A high platelet count on POD 7 was associated with a good response to splenectomy, but age at surgery, the time interval between diagnosis and splenectomy, and prior responses to corticosteroid were not. We suggest that long-term outcomes of splenectomy can easily be predicted by platelet counts on POD 7.