Iliac Artery Compression in Cyclists: Mechanisms, Diagnosis and Treatment

Exertional Lower Extremity Pain in a Triathlete Caused by External Iliac Artery Endofibrosis: A Case Report

CASE

This report describes a 25-year-old female professional triathlete with right external iliac artery endofibrosis (EIAE) that was definitively diagnosed on contrast-enhanced magnetic resonance images obtained immediately after treadmill running. The EIAE was treated by percutaneous transluminal angioplasty. By 8 weeks after surgery, she had no symptoms of claudication or pain in the right thigh after a 1-hour running session. There has been no recurrence in 1 year postoperatively.

CONCLUSION

EIAE is a rare condition and difficult to diagnose in a timely manner because symptoms and radiographic imaging features appear only during intense exercise. Our patient was successfully treated with percutaneous transluminal angioplasty.

Patient-specific risk factors for reintervention following primary endovascular treatment of iliac artery disease

OBJECTIVE

Predictive models for reintervention may guide clinicians to optimize selection, education, and follow-up of patients undergoing endovascular iliac revascularization. Although the impact of lesion- and device-related characteristics on iliac restenosis and reintervention risk is well-defined, data on patient-specific risk factors are scarce and conflicting. This study aimed to explore the value of patient-related factors in predicting the need for clinically driven target-vessel revascularization (CD-TVR) in patients undergoing primary endovascular treatment of iliac artery disease.

METHODS

Consecutively enrolled patients undergoing endovascular revascularization for symptomatic iliac artery disease at a tertiary vascular referral center between January 2008 and June 2020 were retrospectively analyzed. Primary and secondary outcomes were CD-TVR occurrence within 24 months and time to CD-TVR, respectively. Patients who died or did not require CD-TVR within 24 months were censored at the date of death or at 730 days, respectively. Multiple imputation was used to account for missing data in primary analyses.

RESULTS

A total of 1538 iliac interventions were performed in 1113 patients (26% females; 68 years). CD-TVR occurred in 108 limbs (74 patients; 7.0%) with a median time to CD-TVR of 246 days. On multivariable analysis, increasing age was associated with lower likelihood of CD-TVR (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.50-0.83; P = .001) and decreased risk of CD-TVR at any given time (hazard ratio [HR], 0.66; 95% CI, 0.52-0.84; P = .001). Similarly, a lower likelihood of CD-TVR (OR, 0.75; 95% CI, 0.59-0.95; P = .017) and decreased risk of CD-TVR at any given time (HR, 0.73; 95% CI, 0.58-0.93; P = .009) were observed with higher glomerular filtration rates. Lastly, revascularization of common vs external iliac artery disease was associated with lower likelihood of CD-TVR (OR, 0.48; 95% CI, 0.24-0.93; P = .030) and decreased risk of CD-TVR at any given time (HR, 0.48; 95% CI, 0.25-0.92; P = .027). No associations were observed between traditional cardiovascular risk factors (sex, hypertension, higher low-density lipoprotein cholesterol, higher hemoglobin A1c, smoking) and CD-TVR.

CONCLUSIONS

In this retrospective cohort study, younger age, impaired kidney function, and external iliac artery disease were associated with CD-TVR. Traditional markers of cardiovascular risk were not seen to predict reintervention.

External Iliac Artery Endofibrosis: A Discussion on Two Unique Cases

Iliac artery endofibrosis (IAE), as the name suggests, involves subintimal fibrosis of the iliac artery. IAE is most commonly associated with competitive athletics, particularly cycling, and remains a rather underappreciated diagnosis in the clinical setting. We present two unique and distinct presentations of IAE in competitive athletes. The first case involves a 38-year-old male cyclist who initially presented with complaints of a bulge at the right groin and acute onset monoplegia and paresthesia associated with exertion of the right lower extremity. This patient was referred to vascular surgery and underwent right common iliac artery and proximal common femoral artery endarterectomy with patch angioplasty and Fogarty embolectomy. Case 2 involves a 50-year-old female triathlete who presented with left lower extremity claudication of a more chronic course, with symptoms beginning approximately four years prior. The pain radiated to her upper thigh and was associated with exertion, restricting her exercise tolerance and return to training. After a diagnosis of IAE was made, she was referred to vascular surgery for a left iliofemoral bypass.

Endofibrosis as a Causative Agent of the Peripheral Artery Disease: A Report of Two Cases for Professional Cyclists

Endofibrosis is a rare disease that predominantly affects athletes and is caused by a gradual occlusion of the (usually iliac) artery due to a thickening of the intima. From our experience, we report in this article two cases with the entity of endofibrosis in females around 30 years old. The first case presented with acute limb ischemia, and the second one was with pain in the leg during exercise. In addition, both cases are professional cyclists. They were eventually diagnosed with endofibrosis and underwent surgical procedures. They are now pursuing their professional career successfully. Last but not least, endofibrosis might be classified as an occupational disease, particularly, in the case of professional athletes or cyclists.

Evaluating Arterial Blood Flow Limitation Using Muscle Oxygenation and Cycling Power

OBJECTIVE

To explore the combination of measuring muscle oxygenation with near-infrared spectroscopy (NIRS) and cycling power during provocative incremental exercise for the detection of iliac arterial blood flow limitation (IAFL) in an otherwise healthy, well-trained cyclist.

DESIGN

Case report and methodological pilot study.

SETTING

University research setting.

PATIENT

A well-trained amateur competitive male cyclist, aged 31 years, presenting with symptoms consistent with IAFL, but in whom diagnostic imaging was equivocal.

INTERVENTIONS

Four ramp incremental cycling tests performed on separate days to exercise intolerance, in a randomized order, in either typical race position (RP) or modified upright position (UP).

MAIN OUTCOME

A novel ratio of unilateral cycling power to NIRS-derived muscle oxygenation termed "power-deoxygenation factor" was measured during provocative incremental exercise and compared with other NIRS-derived measures of vascular responsiveness and performance outcomes across the 2 body position conditions.

RESULTS

The power-deoxygenation factor was able to show clinically important, progressive differences between the affected and unaffected limbs, coinciding with worsening performance impairments related to the body position that were not detected with traditional measures of vascular responsiveness taken after exercise.

CONCLUSIONS

This method was used to detect bilateral differences consistent with IAFL in a cyclist where traditional diagnostic criteria were equivocal, but subsequent intraoperative findings confirmed the diagnosis. A similar screening test could be performed noninvasively and without requiring specialized medical care. Future work should investigate the validity and sensitivity of this methodology to improve the ability to identify and monitor athletes with IAFL.

Short- and Long-Term Results of Operative Iliac Artery Release in Endurance Athletes

OBJECTIVE

Endurance athletes may develop intermittent claudication due to sport-related flow-limitations of the iliac artery (FLIA) caused by arterial kinking. This study investigated short- and long-term efficacy of an operative release for iliac artery kinking.

METHODS

Between 1996 and 2015, all patients diagnosed and operated with FLIA due to iliac artery kinking without significant arterial stenosis (<15%) or excessive arterial length (vessel length to straight ratio <1.25) were included. Short-term follow up consisted of cycling tests including ankle-brachial index with flexed hip (ABI_flexed) and echo-Doppler examinations (peak systolic velocity, PSV) before and 6-18 months after surgery. Additionally, short-term and long-term efficacy were evaluated using questionnaires.

RESULTS

A total of 142 endurance athletes (155 legs, 88.4% male, median age 26, (22-31; interquartile range)) were available for analysis. In the short-term, symptoms were reduced in 83.9% of the patients with an overall 80.3% satisfaction rate. Power during a maximal cycling test improved from 420 (384-465) to 440 (400-485) Watt (P<.05). Symptom free workload increased from 300 (235-352) to 400 (332-460) Watt (P<.001). Post-exercise ABI_flexed increased from 0.53 (0.39-0.62) to 0.57 (0.47-0.64) (P<.05) and PSV with flexed hip decreased from 1.98 (1.58-2.51) to 1.60 (1.20-2.15) m/s (P<.001). Postoperative imaging revealed (minor) kinking in 37%, mostly a-symptomatic. Long-term results were evaluated after a median 15.2 (10.9-19.5) years. The athletes cycled an additional 125.500 (72.00-227.500) kilometres. This is approximately equal to the 131.000 (98.250-220.000) cycled kilometres before the diagnosis of FLIA. On the long-term, a total of 63.9% reported persistent reduction of complaints with an overall 59.1% satisfaction rate. Eight patients needed a reintervention of which six were considered failures and two were considered as newly developed FLIA.

CONCLUSION

An operative iliac artery release for sport-related functional kinking in the absence of stenosis of excessive vessel length is short-term and long-term effective in most athletes.

Extrinsic compression of the right external iliac artery secondary to iliac vein stenting

Symptomatic extrinsic compression of the external iliac artery (EIA) is a rare complication of surgical intervention. Previous cases of EIA compression have presented in the postoperative period after orthopedic surgery or vascular stenting. We report a case of right EIA compression postvenous stenting causing acute limb ischemia.

Methods for epidemiological studies in competitive cycling: an extension of the IOC consensus statement on methods for recording and reporting of epidemiological data on injury and illness in sport 2020

In 2020, the IOC released a consensus statement that provides overall guidelines for the recording and reporting of epidemiological data on injury and illness in sport. Some aspects of this statement need to be further specified on a sport-by-sport basis. To extend the IOC consensus statement on methods for recording and reporting of epidemiological data on injury and illness in sports and to meet the sport-specific requirements of all cycling disciplines regulated by the Union Cycliste Internationale (UCI). A panel of 20 experts, all with experience in cycling or cycling medicine, participated in the drafting of this cycling-specific extension of the IOC consensus statement. In preparation, panel members were sent the IOC consensus statement, the first draft of this manuscript and a list of topics to be discussed. The expert panel met in July 2020 for a 1-day video conference to discuss the manuscript and specific topics. The final manuscript was developed in an iterative process involving all panel members. This paper extends the IOC consensus statement to provide cycling-specific recommendations on health problem definitions, mode of onset, injury mechanisms and circumstances, diagnosis classifications, exposure, study population characteristics and data collection methods. Recommendations apply to all UCI cycling disciplines, for both able-bodied cyclists and para-cyclists. The recommendations presented in this consensus statement will improve the consistency and accuracy of future epidemiological studies of injury and illness in cycling.

Overview of arterial pathology related to repetitive trauma in athletes

BACKGROUND/OBJECTIVE

Sport-related vascular trauma is an important consequence of increased physical activity. Repetitive, high-intensity movements predispose athletes to vascular disease, including arterial pathology, by exerting increased pressure on neurovascular structures. This is an important source of morbidity in an otherwise young and healthy population. Arterial pathology associated with repetitive trauma is often misdiagnosed as musculoskeletal injury. This article increases awareness of sport-related arterial disease by reviewing the symptomatology, investigation, and treatment modalities of this pathology. In addition, prognostic outcomes specific to the athlete are discussed.

RESULTS

Arterial thoracic outlet syndrome and vascular quadrilateral space syndrome are associated with athletes involved in overhead throwing exercises. Sport-related arterial pathology of the lower limb include external iliac artery endofibrosis (EIAE), popliteal artery entrapment syndrome (PAES), and adductor canal syndrome. Vascular stress and kinking secondary to vessel tethering are important contributors to pathology in EIAE. Chronic exertional compartment syndrome must also be considered, presenting with clinical features similar to PAES. In addition, athletes are predisposed to blunt mechanical trauma. Hypothenar hammer syndrome is one such example, contributing to a high burden of morbidity in this population.

CONCLUSIONS

In arterial thoracic outlet syndrome and vascular quadrilateral space syndrome, surgery is advocated in symptomatic individuals, with postoperative outcomes favorable for the athlete. Acute limb ischemia may occur as a result of secondary thrombosis or embolization, often without preceding claudication. PAES and adductor canal syndrome are associated with functional entrapment in the athlete, secondary to muscular hypertrophy. Surgical exploration may be indicated. Poorer outcomes are noted when this process is associated with vascular reconstruction. Surgical treatment of EIAE follows failure of conservative management, with limited data available on postoperative prognosis. Investigations for all these conditions should be targeted based on clinical suspicion. A delay in diagnosis can have severe consequences on return to competition in these high-functioning individuals.

MRI to investigate iliac artery wall thickness in triathletes

OBJECTIVES

Endofibrosis was first described in endurance athletes. This rare disease is characterized by intimal hyperplasia of iliac arteries. Due to non-specific symptoms diagnosing could be very challenging and delayed. This represents a serious problem not only for affected athletes but also for consulting physicians. The aim of this study was to analyze intimal thickness of iliac arteries using non-contrast magnetic resonance imaging (MRI) in competitive triathletes suffering from exercise induced leg pain consistent with symptoms caused by endofibrosis.

METHODS

18 highly trained triathletes (16 triathletes, 12 male) with a mean age of 45.4 ± 10.2 years were investigated by non-contrast MRI. We divided subjects into two groups: 10 complaint about exercise- induced leg pain and 7 were free of any symptoms. In all 10 symptomatic athletes consulting physicians excluded musculoskeletal or neurological disorders before and we suspected endofibrosis. One patient was excluded from statistical analysis due to a known recurrent external iliac artery (EIA) occlusion after surgical repair 6 month ago.

RESULTS

Mean wall thickness (T) of all 17 subjects was 1.34 ± 0.11mm for the common iliac artery (CIA) and 1.74 ± 0.18mm for the EIA. We found no significant differences by comparing T of symptomatic (s) and asymptomatic (a) legs. There were no significant differences in mean ratio of patent artery to whole artery between the symptomatic and asymptomatic legs for the CIA (0.81 vs 0.82, p = 0.87) and for the EIA (0.71 vs 0.72, p = 0.78). MRI shows a thickening of the left EIA (4.41mm) in the patient who suffered from recurrent occlusion of the left EIA and after surgical repair and histological examination confirmed an endofibrotic lesion.

CONCLUSION

Non-contrast MRI seems to be an appropriate diagnostic tool to exclude endofibrosis in triathletes, but it cannot be recommended as initial screening modality for athletes suffering from exercise-induced leg pain.

Varicose vein appearance caused by perforating vein incompetence detected after intense cycling

The role of incompetent perforating veins in the aetiology of varicose veins is not well understood. Anecdotally, competitive cyclists appeared to be more prone to varicose veins than the general population. We present a case of a 63-year-old amateur competitive cyclist who acutely developed a painful varicosity of her left calf while straining during a hill climb in 106-mile cycle race. Duplex ultrasonography has shown an underlying incompetent perforating vein, feeding the varicosity directly through the underlying muscle. With no other significant venous reflux in either leg, we believe this case shows a clear causative association between the stresses put across the lower leg during competitive cycling and developing a varicose vein via an incompetent perforating vein. We believe this should lead to further investigations as to any link between cycling, perforator vein incompetence and the development of varicose veins.

Adductor Canal Compression Syndrome in a 46-Year-Old Female Patient Leading to Acute External Iliac, Femoral, and Popliteal Artery Thrombosis and Critical Ischemia: A Case Report

The adductor canal compression syndrome is one of the several rare nontraumatic causes of arterial occlusions, which may lead to critical ischemia of the lower limb. We report the case of a 46-year-old athletic woman, who suffered from activity-related paresthesia and sharp pain in the left upper and lower leg for 2 years. Imaging and neurological investigations of the spine remained without pathological findings that would explain the patient's complaints. Actually, the patient presented with symptoms of critical lower limb ischemia. Magnetic resonance angiography revealed nearly complete thrombotic occlusion of the common femoral artery and the arteries of the lower leg. An emergency surgery was performed, revealing an external compression of the superficial femoral artery in the adductor canal. Subsequently, a thrombectomy was performed and a venous bypass graft was installed. No postoperative complications occurred, the patient recovered well and could return to her activities of daily living about 3 weeks after the surgery. The adductor canal compression syndrome results from a local anomalous musculotendinous band or hypertrophic musculature surrounding the passing structures. It mainly occurs in athletes exposed to repetitive stress, especially runners and skiers, and may lead to thrombosis followed by critical lower extremity ischemia. The lack of obvious symptoms during routine physical examination often impedes rapid diagnosis and timely therapy. Considering the high thrombotic risk, attention should be paid to this rare cause of lower limb pain to prevent the patient from critical lower extremity ischemia and potential limb loss due to consecutive acute thrombotic occlusions.

External Iliac Artery Vasospasm in an Elite Female Runner

A 33-year-old elite female runner presented to a tertiary care sports medicine clinic with a 2-year history of progressive anterior thigh and circumferential leg pain with associated foot paresthesias brought on by high-intensity running. She had both external iliac artery vasospasm and chronic exertional compartment syndrome. External iliac artery vasospasm is a rare cause of exertional leg pain, particularly in the running population. This case highlights the unique features of this condition, addresses the multidisciplinary approach that led to the accurate diagnoses, and demonstrates that more than 1 etiology for exertional leg pain can coexist in an athlete.

Intravascular ultrasound imaging as a novel tool for the diagnosis of endofibrosis

Given the rise of high-intensity sport athletes and the paucity of literature on endofibrosis, we describe a novel adjunctive imaging technique to aid in diagnosis. A 41-year-old female triathlete presented with exercise-limiting claudication. Results of lower extremity magnetic resonance angiography, provocative Doppler, angiogram, and digital subtraction angiography with papaverine were nondiagnostic. Intravascular ultrasound imaging was able to delineate an abnormal segment of the proximal external iliac artery with intimal hypertrophy. We report intravascular ultrasound imaging as a superior imaging modality to definitively diagnose endofibrosis and assist proper planning and operative treatment of patients with endofibrosis.

Dissecting aneurysm of common iliac artery in a long-distance runner

We present an unusual case of a long-distance runner suffering from acute dissection of a common iliac artery (CIA) aneurysm with endofibrotic lesions. He suffered from acute pelvic and abdominal pain after exercise. Computed tomography angiography confirmed the dissecting aneurysm of the left CIA without signs of rupture. After cutdown, resection of the CIA and iliac bifurcation as well as bypass grafting was performed. Histologic examination confirmed endofibrotic lesions without calcifications. Complicated iliac artery aneurysm could be the result of endofibrotic lesions. Clinicians should keep this in mind, even if physical examination findings and the ankle-brachial index are normal at rest and after exercise.

Iliac artery endofibrosis in a middle-aged female long-distance runner

Exercise-induced iliac artery endofibrosis is a recently described abnormality of the external iliac artery that typically affects younger, healthy endurance athletes. Characteristic of the initially termed cyclist's iliac syndrome is lower limb pain during exercise with rapid recovery after exercise. This clinically complicated case describes an older female long-distance runner in whom an incorrect diagnosis of fibromuscular dysplasia was originally made when she presented with claudication and thrombosis of the right external iliac artery. A thrombectomy and bilateral balloon angioplasty were performed; however, her symptoms persisted. Four months later, she unexpectedly complained of dual calf claudication, a diagnosis of exercise-induced iliac artery endofibrosis was made, and a bilateral prosthetic graft bypass procedure was performed, which resulted in a good outcome.

An unusual case of leg pain in a competitive cyclist: a case report and review of the literature

Cycling has become a popular recreational and competitive sport. The number of people participating in the sport is gradually increasing. Despite being a noncontact, low-impact sport, as many as 85% of athletes engaged in the sport will suffer from an overuse injury, with the lower limbs comprising the majority of these injuries. Up to 20% of all lower extremity overuse injuries in competitive cyclists are of a vascular source. A 39-year-old competitive cyclist had a 5-year history of thigh pain during cycling, preventing him from competing. The patient was eventually diagnosed with external iliac artery endofibrosis. After conservative treatment failed, the patient underwent corrective vascular surgery with complete resolution of his symptoms and return to competitive cycling by 1 year. Since its first description in 1985, there have been more than 60 articles addressing external iliac artery endofibrosis pathology.

Lower limb vascular dysfunction in cyclists

Sports-related vascular insufficiency affecting the lower limbs is uncommon, and early signs and symptoms can be confused with musculoskeletal injuries. This is also the case among professional cyclists, who are always at the threshold between endurance and excess training. The aim of this review was to analyze the occurrence of vascular disorders in the lower limbs of cyclists and to discuss possible etiologies. Eighty-five texts, including papers and books, published from 1950 to 2012, were used. According to the literature reviewed, some cyclists receive a late diagnosis of vascular dysfunction due to a lack of familiarity of the medical team with this type of dysfunction. Data revealed that a reduced blood flow in the external iliac artery, especially on the left, is much more common than in the femoral and popliteal arteries, and that vascular impairment is responsible for the occurrence of early fatigue and reduced performance in cycling.

[Postexercise duplex ultrasound to diagnose external iliac endofibrosis]

Arterial endofibrosis is a disease of recent discovery which concerns high-performance athletes, predominantly competitive cyclists. The preferential location is the external iliac artery. The symptoms are diverse (pain, edema, paresthesia), always linked to an effort. The diagnosis may be delayed due to atypical symptoms in athletes. Complementary tests are measure of the systolic pressure index after exercise, duplex ultrasound, CT angiography, MR angiography and arteriography. We report a case of endofibrosis where late diagnosis was established with postexercise duplex ultrasound, while CT angiography and arteriography failed to reveal characteristic abnormalities.

Tissue loss secondary to extrinsic compression of common iliac artery from uterine leiomyoma: a case report and review of the literature

BACKGROUND

Uterine leiomyomas are commonly reported to cause deep venous thrombosis and rarely arterial compression.

CASE

A 48-year-old woman was transferred to our institution with acute right lower limb ischemia and tissue loss. She underwent urgent iliac thrombectomy and was subsequently found to have right common iliac artery compression by a large uterine leiomyoma. She underwent successful resection of the tumor followed by endovascular iliac stent placement.

CONCLUSION

This case emphasizes the importance of preoperative imaging when possible in the setting of acute arterial ischemia to evaluate for sources of extrinsic compression. Management requires correction of the etiology of extrinsic compression.