Thrombocytopenia after liver transplantation.

Thrombocytopenia occurs in postoperative liver transplant patients, with platelet counts reaching a nadir on the third postoperative day. Significant bleeding episodes are not uncommon during the first five days postoperatively when platelet counts are low. This thrombocytopenia may be the result of platelet sequestration in the newly grafted liver. The sequestration phenomenon does not appear to be on the basis of antiplatelet antibody activity. Further work defining the time course of this organ sequestration and evaluating the possible release of previously sequestered platelets back into the circulation need to be done. Also, it may be productive to study medications known to inhibit platelet activation (ie, cyclooxygenase inhibitors, prostacyclin, and calcium channel blockers) with the intent of interrupting platelet adhesiveness-sequestration at the time of recirculation of the newly grafted liver.