External Iliac Artery Endofibrosis and Revascularization in a Female Triathlete: A Case Report

Case Diagnosis: A 63-year-old female triathlete with endofibrosis of the left external iliac artery.

Case Description or Program Description: A high-level age group triathlete presented to our office in December 2023 for evaluation of chronic, intermittent left lower extremity pain radiating from the left gluteal region into the anterolateral thigh, lateral calf and foot, and foot paresthesia. Symptoms were exacerbated by running, walking, and stairs. Physical exam showed left calf atrophy, left iliacus hypertrophy, diminished femoral and absent popliteal, dorsalis pedis, and posterior tibial pulses, and subtle mottled appearance of the left foot. MRIs of the left hip, left ankle, and lumbar spine were unremarkable. Bilateral lower extremity EMG/NCS was normal. A pre- and post-exercise ABI showed moderate left-sided arterial occlusive disease consistent with an inflow obstruction. The patient was referred to vascular surgery, and a CTA revealed complete long segment occlusion of the left external iliac artery with reconstitution of the left common femoral artery via collaterals and complete occlusion of the left popliteal artery with reconstitution of the infrapopliteal vessels via collaterals. She was managed conservatively with daily 81mg aspirin, 10mg atorvastatin, BID rivaroxaban 2.5mg, and graded exercise therapy.

Setting: Outpatient physiatry.

Assessment/Results: The patient has improved with progressive aerobic exercise in conjunction with goal-directed pharmacotherapy. She was advised to avoid prolonged deep hip flexion to promote perfusion and encourage collateral vessel formation.

Discussion (relevance): Endofibrosis is an intimal subendothelial nonatherosclerotic fibrosis resulting in luminal wall thickening and stenosis. This is most commonly found in young, healthy male endurance cyclists, but has been seen in otherwise healthy endurance athletes such as triathletes and runners. Surgery is generally recommended via angioplasty and endarterectomy, though less is known about non-surgical revascularization and rehabilitation.

Conclusions: Further information is needed to shorten time to diagnosis and standardize noninvasive/nonsurgical treatment protocols for external iliac endofibrosis.