Acute Limb Ischemia Secondary to Patent Foramen Ovale-Mediated Paradoxical Embolism: A Case Report and Systematic Review of the Literature.

Background: Paradoxical embolism is the translocation of a thrombus originating in the systemic venous circulation into the arterial circulation through a cardiac defect, most commonly a patent foramen ovale (PFO). PFO exists in 15-35% of the adult population. The most common manifestation is cerebrovascular accident; acute limb ischemia is much rarer.

Methods: A 67-year-old woman with multiple confounding risk factors for hypercoagulability presented with grade IIb left lower limb ischemia secondary to thromboembolism through a previously silent PFO. Management included urgent embolectomy, prophylactic fasciotomy, postoperative anticoagulation, and PFO closure. A systematic literature review of PFO-mediated acute limb ischemia was performed to identify the patient populations most commonly affected, the anatomic distribution of emboli, and patient management.

Results: Forty-three reports including 51 patients with first-time PFO-mediated paradoxical embolism were identified. Fifty-one percent were men, and the average age at presentation was 54 years. Multiple limbs were affected in 14 patients (27.5%), and a propensity for the lower limbs (72%) and left-sided circulation (82%) was noted. Deep venous thromboembolism was identified in 36 patients (71%). Immediate anticoagulation was instituted in 31 patients. Embolectomy and/or fibrinolysis were performed in 45 patients (88%).

Conclusions: Acute limb ischemia is a rare manifestation of PFO-mediated paradoxical embolism that requires a high index of suspicion for diagnosis. Middle-aged individuals appear to be more commonly affected, and acute limb ischemia most often occurs in the lower limbs and left-sided circulation, with the potential to affect multiple extremities simultaneously. Prompt identification and surgical embolectomy with prophylactic fasciotomy can facilitate successful outcomes. Perioperative management should include anticoagulation and may include workup with echocardiography, duplex ultrasound, and hypercoagulability testing.