Long-term outcome of percutaneous endovascular stenting in external iliac artery endofibrosis.

BACKGROUND: External iliac artery endofibrosis (EIAE) is a rare vascular disease which has been traditionally seen in avid cyclists. The conventional approach has been surgery, although no high-quality evidence suggests superiority of surgery over percutaneous endovascular intervention. There are limited data on the efficacy of stenting in EIAE. METHODS: Over a 14-year period, we treated 10 patients (13 limbs) with EIAE with stents. These patients had declined surgery. The mean follow up was 8.4 ± 3.3 years. There were eight women. Five patients were competitive runners, three were cyclists, and two were triathletes. The mean age was 40.7 ± 2.9 years and body mass index was 19.46 ± 1.6. Intravascular ultrasound (IVUS) was used in eight limbs. RESULTS: Procedural success was achieved in all. The recurrence of symptoms occurred in three patients at a mean of 9.3 ± 2.1 months postindex intervention. The other seven patients remained symptom free. IVUS revealed a pathognomonic finding which we termed 'perfect circle appearance'. It results from symmetric or asymmetric hypertrophy of one or more layers of the arterial wall leading to negative remodeling, which creates a distinct echo dense structure contrasting itself from the luminal blood's echoluscent appearance. It is identical to IVUS images of diffuse venous stenosis with important implications in the treatment technique. CONCLUSIONS: We conclude that stenting in EIAE is safe and effective with a good long-term outcome. It can be an alternative to surgery, particularly in those patients who refuse a surgical approach. The IVUS image is pathognomonic and 'sine qua non' of EIAE.

Iliac artery endofibrosis: diagnostic dilemna and treatment options.

BACKGROUND: External iliac artery endofibrosis (EIAE) is an uncommon pathology, predominantly occurring in cyclists, caused by thickening of the external iliac artery intima. Symptoms are exercise-dependent and typically consist of pain, muscle cramps and loss of strength in the affected limb at (sub)maximal effort. As other musculo-skeletal as well as conditional problems might cause similar complaints diagnosis is not always easy or straightforward. CASE SUMMARY AND DISCUSSION: We reviewed four cases of (semi-)professional cyclists referred to our department in 2021 because of suspicion of EIAE. In all symptoms only occurred at (sub)maximal effort. All had lowering of ABI on the affected side at a dynamic stress test on the bike. Imaging using CTA, MRA or dynamic angiogram was abnormal in all patients, showing signs suspicious for endofibrosis but of different kind and at different locations. Open surgical repair was performed in all cases by a procedure tailored to the type of lesion. Two patients were treated by a saphenous vein patch angioplasty, in one patient a shortening of the vessel and end-to-end anastomosis was performed and in the fourth patient a spiral saphenous vein graft bypass was placed. Postoperative course was uneventful and exercise was resumed after four weeks in all patients. CONCLUSION: Correct diagnosis is essential in the treatment of EIAE. A complete and multidisciplinary pathway should be followed to distinguish vascular from non-vascular causes. Correct lesion localization is crucial and besides CTA or MRA, more sophisticated techniques such as dynamic angiography or intravascular ultrasound might be needed.

Short- and long-term outcomes after endarterectomy with autologous patching in endurance athletes with iliac artery endofibrosis.

OBJECTIVE: Endurance athletes such as cyclists may develop intermittent claudication owing to iliac artery endofibrosis after long-lasting extreme hemodynamic challenges. This study investigated short-term (<1.5 years) and long-term (>5 years) satisfaction and safety after a surgical endarterectomy and autologous patching. METHODS: Data of endurance athletes who underwent an endarterectomy for flow limitation of the iliac artery owing to endofibrosis between 1997 and 2015 in one center were studied. Maximal cycling exercise tests, ankle-brachial index with flexed hips, echo-Doppler examination (peak systolic velocity), and contrast-enhanced magnetic resonance angiography were performed before and 6 to 18 months after surgery. Short-term and long-term satisfaction were evaluated using questionnaires. Potential patch dilatation was assessed using echo-Doppler. RESULTS: Analysis of 68 patients (79 legs; 55.7% males, median age at the time of surgery, 34 years; interquartile range, 26-41 years) demonstrated that cycling workload at symptom onset improved from 226 ± 97 to 333 ± 101 (P < .001) Watts. Peak workload increased from 326 ± 111 to 352 ± 93 Watts (P < .001). Ankle-brachial index with flexed hips increased from 0.34 (interquartile range [IQR], 0.00-0.47) to 0.59 (IQR, 0.51-0.69; P < .001). Peak systolic velocity with extended and flexed hip decreased from 2.04 m·sec-1 (IQR, 1.52-2.56 m·3sec-1) to 1.25 m·sec-1 (IQR, 0.92-1.62 m·sec-1; P < .001) and 2.40 m·sec-1 (IQR, 1.81-2.81 m·sec-1) to 1.15 m·sec-1 (IQR, 0.97-1.60 m·sec-1; P < .001), respectively. Thirty-day major complication rate was 5.1% (hematoma requiring evacuation nLegs = 2, septic bleeding from deep infection nLegs = 1, and iliac occlusion requiring thrombectomy nLegs = 1). In the short term, 91.2% of patients reported symptom reduction with a 93.7% overall satisfaction rate. After a median of 11.1 years (IQR, 7.8-17.6 years), the overall satisfaction was 91.7%; 94.5% of patients reported persistent symptom reduction. Patch dilatation of >20 mm was observed in two patients. Linear mixed model analysis revealed no alarming patch dilatation in the long term. CONCLUSIONS: Endarterectomy with an autologous patch for intermittent claudication owing to iliac artery endofibrosis in endurance athletes shows high rates of patient satisfaction and symptom reduction in both the short and long term. The risk of surgical complications or patch dilatation is mild. A surgical intervention for flow limitation of the iliac artery owing to endofibrosis is safe and successful.

Short- and long-term results of operative iliac artery release in endurance athletes.

OBJECTIVE: Endurance athletes can develop intermittent claudication due to sports-related flow limitations of the iliac artery (FLIA) caused by arterial kinking. In the present study, we investigated the short- and long-term efficacy of an operative release for iliac artery kinking. METHODS: Between 1996 and 2015, all patients with a diagnosis of FLIA due to iliac artery kinking without substantial arterial stenosis (<15%) or an excessive arterial length (vessel length to straight ratio, <1.25) who had undergone surgery were included. The short-term follow-up protocol consisted of cycling tests, the ankle brachial index with a flexed hip, and Doppler echography examinations to determine the peak systolic velocity before and 6 to 18 months after surgery. Additionally, the short- and long-term efficacy were evaluated using questionnaires. RESULTS: A total of 142 endurance athletes (155 legs; 88.4% male; median age, 26 years; interquartile range [IQR], 22-31 years) were available for analysis. In the short term, the symptoms had decreased in 83.9% of the patients, with an overall 80.3% satisfaction rate. Power during a maximal cycling test had improved from 420 W (IQR, 378-465 W) to 437 W (IQR, 392-485 W; P < .001). The symptom-free workload had increased from 300 W (IQR, 240-340 W) to 400 W (IQR, 330-448 W; P < .001). The postexercise ankle brachial index with a flexed hip had increased from 0.53 (IQR, 0.40-0.61) to 0.57 (IQR, 0.47-0.64; P = .002), and the peak systolic velocity with a flexed hip had decreased from 1.88 m/s (IQR, 1.45-2.50 m/s) to 1.52 m/s (IQR, 1.19-2.07 m/s; P < .001). Postoperative imaging studies revealed some degree kinking in 33.9%, mostly asymptomatic. The long-term results were evaluated after a median of 15.2 years (IQR, 10.9-19.5 years). The athletes had cycled an additional 125.500 km (IQR, 72.00-227.500 km), which was approximately equal to the 131.000 km (IQR, 98.250-220.000 km) cycled before the diagnosis of FLIA. On the long term, 63.9% of the athletes reported persistent reduction of complaints, with an overall 59.1% satisfaction rate. Eight patients had required reintervention, six because of treatment failure and two because of newly developed FLIA. CONCLUSIONS: Operative iliac artery release for sports-related functional kinking in the absence of stenosis or an excessive vessel length was effective for most athletes in the short and long term.

Exercise induced leg pain due to endofibrosis of external iliac artery.

Due to monotonous movement patterns, muscular hypertrophy, and increased cardiac output peripheral vasculature of athletes are subject to extreme stresses during athletic performance. Individuals suffering from exercise induced non-traumatic lower leg pain may display underlying vascular pathology such as external iliac artery endofibrosis. Therefore, it is essential in the course of to discriminate vascular from non-vascular findings and prime the correct diagnostic path within the course of clinical examination. In this regard, interdisciplinary thinking and profound knowledge in exercise-associated pathologies of the musculoskeletal, nervous and vascular system is indispensable. Consequently, provocation testing displays an indispensable diagnostic tool and has to be continued until symptoms occur, or complete exhaustion is attained. Finally, selective assessment of conservative and surgical treatment options, as well as its ethical evaluation, are of major importance in order to protect, preserve and promote the health and physical integrity of our patients who are keen to perform.

Protease-activated receptors are potential regulators in the development of arterial endofibrosis in high-performance athletes.

OBJECTIVE: High-performance athletes can develop symptomatic arterial flow restriction during exercise caused by endofibrosis. The pathogenesis is poorly understood; however, coagulation enzymes, such as tissue factor (TF) and coagulation factor Xa, might contribute to the fibrotic process, which is mainly regulated through activation of protease-activated receptors (PARs). Therefore, the aim of this explorative study was to evaluate the presence of coagulation factors and PARs in endofibrotic tissue, which might be indicative of their potential role in the natural development of endofibrosis. METHODS: External iliac arterial specimens with endofibrosis (n = 19) were collected during surgical interventions. As control, arterial segments of the external iliac artery (n = 20) were collected post mortem from individuals with no medical history of cardiovascular disease who donated their body to medical science. Arteries were paraffinized and cut in tissue sections for immunohistochemical analysis. Positive staining within lesions was determined with ImageJ software (National Institutes of Health, Bethesda, Md). RESULTS: Endofibrotic segments contained a neointima, causing intraluminal stenosis, which was highly positive for collagen (+150%; P < .01) and elastin (+148%; P < .01) in comparison with controls. Intriguingly, endofibrosis was not limited to the intima because collagen (+213%) and elastin (+215%) were also significantly elevated in the media layer of endofibrotic segments. These findings were accompanied by significantly increased α-smooth muscle actin-positive cells, morphologically compatible with the presence of myofibroblasts. In addition, PAR1 and PAR4 and the membrane receptor TF were increased as well as coagulation factor X. CONCLUSIONS: We showed that myofibroblasts and the accompanying collagen and elastin synthesis might be key factors in the development of endofibrosis. The special association with increased presence of PARs, factor X, and TF suggests that protease-mediated cell signaling could be a contributing component in the mechanisms leading to endofibrosis.

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.

The Investigation and Management of Iliac Artery Endofibrosis: Lessons Learned from a Case Series.

OBJECTIVE/BACKGROUND: The objective was to summarise the lessons learned, and evolution in local practice over the last 7 years, in the investigation and surgical management of iliac artery endofibrosis. METHODS: This was a retrospective case series. A case note review of consecutive patients investigated for suspected iliac artery endofibrosis by a single surgeon, over a 7 year period, was undertaken. Included were cases of first presentation and those who had previously undergone intervention. RESULTS: Some 63 patients were referred with suspected endofibrosis in the period 2011-17, four of whom had previously undergone surgery for the condition. After investigation of both limbs, 50 symptomatic limbs in 46 patients had a confirmed diagnosis; amongst those 46 patients, iliac artery endofibrosis was found in a further six asymptomatic, contralateral limbs. Individuals were diagnosed at a median age of 36 years (range 18-52 years) and typically presented with thigh claudication, foot numbness, and limb weakness on exercise. The median delay to diagnosis was 3 years (range 0-14 years). Complete external iliac artery occlusion was a feature in three cases. Overall, 27 limbs in 25 patients underwent operative repair; a further five limbs in four patients underwent operative repair at other centres internationally. There were three post-operative superficial wound infections (11%) and one below knee deep vein thrombosis (4%). Symptoms resolved in 23 cases (85%) with a median follow up of 2.1 years (range 65 days-5.7 years). Of the four limbs developing recurrent symptoms, two had undergone surgery for an occluded external iliac artery. CONCLUSION: Surgical repair in the medium term appears effective in resolving symptoms in most patients. Further investigation is needed to establish the durability of surgery and to delineate the natural history of the disease.

Diagnosis and Management of Iliac Artery Endofibrosis: Results of a Delphi Consensus Study.

OBJECTIVE: Iliac endofibrosis is a rare condition that may result in a reduction of blood flow to the lower extremity in young, otherwise healthy individuals. The data to inform everyday clinical management are weak and therefore a Delphi consensus methodology was used to explore areas of consensus and disagreement concerning the diagnosis and management of patients with suspected iliac endofibrosis. METHODS: A three-round Delphi questionnaire approach was used among vascular surgeons, sports physicians, sports scientists, radiologists, and clinical vascular scientists with experience of treating this condition to explore diagnosis and clinical management issues for patients with suspected iliac artery endofibrosis. Analysis is based on 18 responses to round 2 and 14 responses to round 3, with agreement reported when 70% of respondents were in agreement. RESULTS: Initially there was agreement on the typical symptoms at presentation and the need for an exercise test in the diagnosis. Round 3 clarified that duplex ultrasound was a useful tool in the diagnosis of endofibrosis. There was consensus on the most appropriate type of surgery (endarterectomy and vein patch) and that endovascular interventions were inadvisable. The final round helped to inform aspects of the natural history and post-operative surveillance. Progression of the disease was likely with continued exercise but cessation may prevent progression. Surveillance after surgery is generally recommended yearly with at least a clinical assessment. CONCLUSIONS: There is broad agreement about the presenting symptoms and the investigations required to confirm (or exclude) the diagnosis of iliac endofibrosis. There was consensus on the surgical approach to repair. Disagreement existed about the specific diagnostic criteria that should be applied during non-invasive testing and about post-operative care and resumption of exercise.

Common Femoral Artery Curvature During Hip Flexion.

PURPOSE: To assess the conformational changes of the common femoral artery (CFA) during hip joint flexion in patients without atherosclerosis. METHODS: Patients who underwent digital subtraction angiography for suspicion of arterial endofibrosis between 2007 and 2011 were retrospectively searched. Angiographic images were analyzed by two independent readers. The CFA was divided into four segments of equal length, and the segment containing the folding point was noted. Segments 1 and 2 were located in the proximal half of the CFA and segments 3 and 4 in the distal half. Readers assessed the CFA angulation, located the arterial folding point, and classified the CFA curvature as harmonious, or as a moderate or severe plication. RESULTS: Forty patients were included. The Lin concordance correlation coefficients, used to evaluate inter-observer variability, were 0.90 (95% CI [0.83; 0.96]), 0.96 (95% CI [0.93; 0.98]) and 0.96 (95% CI [0.94; 0.98]) for the measures of the CFA angle during flexion, of the length between the superficial circumflex iliac artery and the folding point, and of the length between the folding point and the femoral bifurcation, respectively. The CFA curvature was described as harmonious in 12 patients, moderate plication in 14 patients, and severe plication in 14 patients. The CFA folding point was located on segment 1, 2 and 3 in 6, 26 and 8 patients, respectively; no folding point was located on segment 4. CONCLUSION: In these patients with non-atheromatous disease, hip flexion yielded most frequently a harmonious curvature or a moderate plication of the CFA.

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.

Diagnosing Sport-Related Flow Limitations in the Iliac Arteries Using Near-Infrared Spectroscopy.

Background: A flow limitation in the iliac arteries (FLIA) in endurance athletes is notoriously difficult to diagnose with the currently available diagnostic tools. At present, a commonly used diagnostic measure is a decrease in ankle brachial index with flex hips (ABIFlexed) following a maximal effort exercise test. Near-infrared spectroscopy (NIRS) is a non-invasive technique that measures skeletal muscle oxygenation as reflected by the balance of O2 delivery from microvascular blood flow and O2 uptake by metabolic activity. Therefore, NIRS potentially serves as a novel technique for diagnosing FLIA. The purpose of this study is to compare the diagnostic accuracy of NIRS-derived absolute, amplitude, and kinetic variables in legs during and after a maximal exercise test with ABIFlexed. Methods: ABIFlexed and NIRS were studied in 33 healthy subjects and 201 patients with FLIA diagnosed with echo-Doppler. Results: After maximal exercise, NIRS kinetic variables, such as the half value time and mean response time, resulted in a range of 0.921 to 0.939 AUC for the diagnosis of FLIA when combined with ABIFlexed. Conversely, ABIFlexed measurements alone conferred significantly worse test characteristics (AUC 0.717, p < 0.001). Conclusions: NIRS may serve as a diagnostic adjunct in patients with possible FLIA.

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.

Test-retest reliability of skeletal muscle oxygenation measurement using near-infrared spectroscopy during exercise in patients with sport-related iliac artery flow limitation.

The ankle-brachial index is an accurate tool for detecting claudication in atherosclerotic patients. However, this technique fails to identify subtle flow limitations of the iliac arteries (FLIA) in endurance athletes. Near-infrared spectroscopy (NIRS) is a noninvasive technique that measures skeletal muscle tissue oxygenation status. The aim of the present study is to examine the absolute and relative test-retest reliability of NIRS and evaluate its potential as a diagnostic tool in FLIA. NIRS-derived exercise variables were analyzed during exercise and recovery in FLIA 17 patients and 19 healthy controls. The relative reliability of absolute variables (such as the maximal value) were slight to yet predominantly substantial (intraclass correlation coefficient [ICC], ICC range: 0.06-0.76) with good to excellent absolute reliability (absolute limits of agreement [ALoA], ALoA range: 0.8 ± 10.2 to 0.7 ± 13.1; coefficient of variation [CV], CV range: 5%-11%). Absolute values encompassing signal amplitudes showed moderate to almost perfect relative reliability (ICC range: 0.51-0.89) and poor to good absolute reliability (ALoA range: -1.3 ± 7.0 to -2.5 ± 15.7; CV range: 15%-32%). Kinetic variables showed moderate to almost perfect relative reliability for most recovery kinetics variables (ICC range: 0.54-0.86) with fair to good absolute reliability (ALoA range: 0.4 ± 12.2 to 3.9 ± 37.9; CV range: 18%-27%). Particularly, kinetic variables showed significant differences between patients and healthy subjects. NIRS is found to be a reliable method for examining muscle tissue oxygenation variables. Given the significant differences in especially recovery kinetics between normal subjects and patients, NIRS may contribute to diagnosing FLIA in endurance athletes.

External iliac artery Endofibrosis in a professional cyclist.

We present a case of a 30-year-old female professional cyclist who presented with right thigh claudication while performing high-intensity efforts. Based on the typical clinical history and the presence of a smooth long segment diffuse narrowing in the right external iliac artery on non-contrast magnetic resonance angiography, a diagnosis of external iliac artery endofibrosis or "cyclist's iliac syndrome" was made. Supplementary Information: The online version contains supplementary material available at 10.1007/s12055-022-01349-8.

Bicycle exercise ankle brachial index recovery time as a novel metric for evaluating the hemodynamic significance of external iliac endofibrosis in competitive cyclists.

Subtle radiographic findings can increase the challenge of diagnosing external iliac artery endofibrosis. We evaluated a new metric, the bicycle exercise ankle brachial index recovery time (BART), in a cohort of cyclists with symptomatic external iliac artery endofibrosis. BART was defined as the time required in minutes for the ankle brachial index to return to 0.9 after a period of exercise. Surgical correction resulted in an improvement in BART postoperatively (4.5 ± 4.1 vs 9.1 ± 4.3 minutes; P < .001), with improved values correlating with better patient satisfaction. Documentation of the BARTs before and after surgical treatment provides an additional measure of postoperative hemodynamic improvement.

Peripheral Vascular Imaging Focusing on Nonatherosclerotic Disease.

A variety of nonatherosclerotic diseases affect the arteries of the pelvis and lower extremities. Chronic repetitive traumatic conditions, such as popliteal entrapment and external iliac artery fibroelastosis, vasculitis and connective tissue diseases, and noninflammatory vascular diseases, are a few of the more commonly encountered nonatherosclerotic peripheral vascular diseases. Ultrasound, computed tomography angiography, and magnetic resonance angiography are essential in the initial assessment and management of patients with peripheral vascular disease.

Bilateral external iliac artery thrombosis due to endofibrosis in a 33-year-old female triathlete.

External iliac artery endofibrosis is a rare disease predominantly affecting young, elite male athletes. This case involves a 33-year-old female triathlete who presented initially with lower extremity claudication during training. After completing a triathlon 1 year later, the patient experienced acute-onset pain in both legs. Computed tomography angiography showed abrupt occlusion of the bilateral proximal external iliac arteries. The patient underwent a right and left external iliac artery reconstruction using the ipsilateral great saphenous vein and reported significant improvement of claudication symptoms. The case highlights a rare complication of acute bilateral arterial thrombosis.

Pedal power measurement as a diagnostic tool for functional vascular problems.

BACKGROUND: Cyclists with flow limitations in the iliac arteries complain of pain and loss of power. To investigate whether pedal power measurement has added value in diagnosing the underlying cause of flow limitations in the iliac arteries, we explored the sensitivity and specificity of various pedal power measurement variables. Moreover, it was assessed what the added value of pedal power measurement is compared to diagnosis based on the conventional ankle-brachial blood pressure index. METHODS: 25 healthy participants and 45 patients with unilateral arterial flow limitations were recruited. Participants received Echo-Doppler examination to determine the condition of the iliac arteries. Subsequently, participants performed a maximal cycle ergometer test. During the cycling test the exerted left and right pedal power was measured. From these measurements several variables were derived to diagnose arterial flow limitations. A receiver operating characteristics curve based on a predicted cross-validated model was used to select the variable with the highest predictive value and its cut-off value. FINDINGS: The mean power difference between both legs relative to the exerted power at 95% of the maximal power showed the best predictive value with a sensitivity of 0.76 and a specificity of 0.88. Combining the pedal power measurement and ankle-brachial blood pressure index resulted in a sensitivity of 0.91 and a specificity of 0.88. INTERPRETATION: Pedal power measurement improves sensitivity of diagnosis of iliac artery flow limitations, without increasing the burden of clinical investigation to the patients.