Acute Retroperitoneal Hematoma After Psoas Catheter Placement in a Patient with Myeloproliferative Thrombocytosis and Aspirin Therapy.

Retroperitoneal hematoma is a rare complication of psoas catheter placement, typically occurring several days after placement and in the setting of anticoagulation. We present the case of a patient with a history of myeloproliferative thrombocytosis receiving aspirin therapy who underwent total hip arthroplasty with preoperative psoas catheter placement complicated by immediate development of a large retroperitoneal hematoma. It is likely that the combination of aspirin therapy and thrombocytosis paradoxically placed the patient at increased risk for hemorrhagic complications. Regional techniques should be used cautiously in patients with myeloproliferative disorders, even in the presence of supraphysiologic platelet counts.