Femoral Mononeuropathy Secondary to Retroperitoneal Hematoma in the Acute Rehabilitation Setting: A Case Report

Case Diagnosis: A 61-year-old male with a history of cardiac arrest and right medullary hypoxic brain injury developed retroperitoneal hematoma secondary to anticoagulation therapy with therapeutic IV heparin resulting in bilateral femoral mononeuropathy and quadricep weakness.

Case Description or Program Description: Our patient presented to the ED for cardiac arrest and was treated with targeted temperature therapy after transport to the cath lab. The patient was treated with intravenous heparin, and rapidly developed right leg weakness and sensory changes over the anterior thighs bilaterally. CABG was delayed by these complications, but was performed two weeks later. Postoperative weakness of both the left arm and leg were noted, increasing concern for stroke. After work-up for nerve injury, the patient was found to have bilateral retroperitoneal hematomas with bilateral femoral nerve compression.

Setting: Inpatient Acute Rehabilitation Hospital

Assessment/Results: Head CT status post CABG revealed acute infarcts in right frontal lobe, bilateral medial cerebellum, left lateral cerebellum, and occipital lobes consistent with ischemic stroke. Abdominal CT revealed bilateral retroperitoneal hematomas with extravasation of right psoas muscle and left iliopsoas consistent with the patient’s pattern of femoral mononeuropathy. On presentation to acute rehab, the patient had a Berg score of 23/56, a MOCA of 18/22, and required maximum assist for all ADLs and gait. After 18 days in acute rehab he had a Berg score of 37/56, a MOCA of 21/22, and required minimum assistance for all ADLs and gait.

Discussion (relevance): Intravenous heparin is a commonly used anticoagulant with known risks of bleeding, including retroperitoneal hematoma. While the occurrence of spontaneous retroperitoneal hematoma is rare, it should be considered when any patient on anticoagulation demonstrates new nerve damage in the distribution of the femoral nerve. Rapid detection and treatment of a bleed can help reduce symptom severity and recovery time.

Conclusions: Heparin can rarely induce retroperitoneal bleeding and hematoma formation leading to isolated femoral neuropathy.