Role of splenectomy in patients with refractory or relapsed thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) was once uniformly fatal. Therapeutic plasma exchange in combination with immunosuppressive and anti-platelet agents, however, have resulted in improved survival rates of greater than 80% for patients with TTP. In spite of aggressive plasma exchange and adjuvant therapy, a number of TTP patients are refractory to treatment. In addition, up to 40% of TTP patients who initially respond to therapy eventually relapse. Alternative therapies such as splenectomy have been used with varying degrees of success in refractory and relapsing TTP patients. The usefulness of splenectomy in preventing relapse of TTP or treating those patients who are refractory to plasma exchange remains controversial. We present a single institution's experience with 14 patients who underwent splenectomy for refractory (six patients) or relapsed (eight patients) TTP since 1984. In both patient groups, splenectomy induced stable long-term remissions. Six of six (100%) patients who were refractory to plasma exchange, survived to be discharged from the hospital, apparently free of disease. Four of eight patients (50%) who had a splenectomy for relapsing TTP went into a complete remission and had no further relapses of their disease. Moreover, in relapsing patients who failed to experience long-term remission, the relapse rate after splenectomy was 0.3 events per patient year compared to 1.0 events per patient year prior to splenectomy. We conclude that splenectomy is a reasonable treatment option for TTP patients refractory to standard plasma exchange therapy or who have experienced multiple and/or complicated relapses. We believe this is the first series that demonstrates efficacy of splenectomy in plasma exchange-refractory TTP.