External iliac artery endofibrosis is a recognized cause of exertional leg claudication in young, high-endurance athletes. However, significant diagnostic delays often occur owing to the inability of standard testing to replicate exercise-induced symptoms. We present a case of bilateral external iliac artery endofibrosis in an ultramarathon runner who was successfully treated with bilateral external iliac artery patch angioplasty using the great saphenous veins. This case highlights the diagnostic difficulties involved and emphasizes the importance of maintaining a high level of clinical suspicion for iliac artery endofibrosis in athletes who experience exertional lower extremity symptoms.

Iliac artery endofibrosis (IAE) is a rare cause of leg pain in young, healthy endurance athletes, particularly in male competitive cyclists. The prevailing hypothesis suggests that it is due to mechanical trauma of the iliac artery from long-standing hip flexion. In this case, a 40-year-old male endurance cyclist presented with bilateral thigh pain and worsening leg fatigue upon maximal exertion. Yet, the physical exam at rest was negative for claudication and peripheral pulses were intact. For this reason, IAE is poorly recognized and remains a difficult diagnosis as it requires testing at near-maximal exertion to reveal symptoms. After the patient was referred to the vascular clinic, imaging revealed intimal thickening of the left common iliac artery but with no evidence of stenoses bilaterally. Management typically begins conservatively but true resolution of symptoms can necessitate vascular intervention.

Background:
External iliac artery endofibrosis is a non-atherosclerotic disease. It affects young individuals, particularly cyclists.

Materials and Methods:
A systematic literature review was conducted to highlight the intriguing aspects of this pathology and a total of 493 patients were retrieved to whom we added two patients
treated at our institution.

Results: 434 (87%) of the patients were cyclists, 7 (3.6%) triathletes (practicing cycling, running, and swimming), (1.4%) runners, and 18 (8.2%) other. Both limbs were equally involved, and no dominant limb was noted. Twenty-four works and fifty-eight patients were analyzed; in 51.7% (n=30) of cases, the left lower limb was involved, and in 48.3% (n=28) of cases, the right lower limb was involved. The external iliac artery was involved in 90% of cases, however, 30 patients (10%) presented an unusual location, isolated or associated with the lesion beginning on the common iliac artery (5%) or extending to the femoral artery. In addition, the quadricipital artery and the profunda femoris artery can be affected, modifying the haemodynamic conclusions of the complementary examinations Professional cyclists who annually cover an average distance of 10,400 kilometres (range 4,200 min. - 27,500 max. kilometres) were preferentially affected. While the total mileage accumulated since the start of training is a factor that should be considered, we believe that the intensity of the training plays an even more crucial role in the development of the lesion. Noticeably, only 10 (2%) patients had specific atherosclerotic risk factors such as cigarette smoking or mild dyslipidemia. The main symptoms were buttock claudication and calf pain (37% and 30%, respectively). Historically angiography was the diagnostic method of choice in 53% of cases; however, in the recent decades CT and MRI were preferentially used. 71% of the patients were treated with endofibrosectomy, a patch was added in 13 (3%). An Iliofemoral bypass graft was performed in 29% of the patients. Five-year primary and secondary patency rates either for endofibrosectomy or bypass graft reached 90%.

Conclusions: Surgical treatment is the gold standard. Patients unwilling to undergo surgery may opt for less invasive treatments such as percutaneous transluminal angioplasty with stent positioning which seems however, to have suboptimal long-term results.

In the past four decades, reports of an unusual vascular disease affecting young and otherwise healthy endurance athletes have begun to emerge. This rare entity has been coined as external iliac artery endofibrosis (EIAE). It has been primarily described in high-level competitive cyclists, suggesting a biomechanical etiology given the repetitive flexion and extension of the hip joint associated with cycling. Patients present with symptoms of claudication at peak levels of exertion, levels not usually achievable by the untrained individual. Lesions are predominantly isolated to the external iliac artery (EIA), and histologic examination reveals endothelial thickening and fibrosis without evidence of atherosclerosis. Cases of EIAE have been overwhelmingly described in male athletes, with a paucity of reports in females. We herein describe two cases of elite female athletes afflicted by EIAE and review the current literature pertaining to this entity in females. Both patients consented to publication of their case details and images