Recurrent Acute Limb Ischemia and Direct Oral Anticoagulant Failure: A Case of Suspected Antiphospholipid Syndrome Triggered by Mechanical Compression.

Acute limb ischemia is a vascular emergency that requires prompt diagnosis and treatment to avoid permanent tissue loss and possible amputation. Recurrent arterial thrombosis in a relatively young patient, especially while on anticoagulation, should raise concern for an underlying hypercoagulable state. We present the case of a 40-year-old woman with type 2 diabetes mellitus, hyperlipidemia, and heavy tobacco use who developed acute right lower extremity ischemia after sitting with her legs crossed for several hours during an episode of severe vomiting and diarrhea. She underwent emergent thromboembolectomy and was discharged on apixaban and aspirin. About two weeks later, she returned with recurrent right lower extremity ischemia despite reported compliance with anticoagulation and was found to have multifocal arterial thrombosis requiring repeat thromboembolectomy and pedal arch angioplasty. Her postoperative leukocytosis was felt to be reactive and related to ischemia-reperfusion injury rather than infection. Because of recurrent arterial thrombosis despite apixaban therapy, further workup for antiphospholipid syndrome was initiated, and she was transitioned to heparin with recommendation for long-term warfarin therapy. This case highlights that mechanical compression may have contributed to the initial lower extremity ischemic event; however, the subsequent recurrent arterial thromboses, particularly at anatomically distinct sites despite direct oral anticoagulant (DOAC) therapy, were more concerning for an underlying systemic hypercoagulable state such as antiphospholipid syndrome in the setting of additional vascular risk factors.