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 (ABI_Flexed) 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: ABI_Flexed 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 ABI_Flexed. Conversely, ABI_Flexed measurements alone conferred significantly worse test characteristics (AUC 0.717, p < 0.001).

Conclusion: NIRS may serve as a diagnostic adjunct in patients with possible FLIA.

L’endofibrose est une pathologie vasculaire du sportif de haut niveau, principalement le cycliste, mais aussi le coureur ou le skieur de fond, le joueur de rugby ou de football. Elle est définie comme un épaississement progressif du mur endothélial de l’artère, le plus souvent iliaque, par un matériel fibrotique. Vingt-quatre cas cliniques d’endofibrose du cycliste ont été relevés dans les services de chirurgie vasculaire et de radiologie du centre hospitalier universitaire de Bordeaux et Langon entre 1991 et 2002. Ont été évalués le diagnostic histologique et le suivi à long terme des patients en fonction des différentes options thérapeutiques dont ils ont bénéficié (chirurgie ou angioplastie). Ce travail a permis de mettre en évidence d’une part les difficultés diagnostiques de cette pathologie : il est nécessaire de réaliser l’examen clinique et les explorations vasculaires selon une démarche uniforme permettant ainsi d’éviter le retard diagnostique. D’autre part, les difficultés thérapeutiques rencontrées sont nombreuses avec entre autres des patients souvent demandeurs de solutions thérapeutiques radicales. Il semble dans ce travail que le traitement par angioplastie avec endoprothèse donnerait des résultats bénéfiques. Le développement de méthodes de diagnostic comme la méthode Delphi permettrait d’avoir un consensus fiable de la part d’experts reconnus dans cette pathologie.

Objective: Endurance athletes are prone to develop flow limitations in iliac arteries (FLIA). Especially in cyclists and ice speed skaters, excessive hemodynamic loading coupled with hip hyperflexion may cause kinking in lengthened iliac arteries necessitating surgical correction. This study investigated the short-term (≤1.5 years) and long-term (≥5 years) satisfaction of operative shortening of the iliac artery in endurance athletes.

Methods: All patients who were diagnosed and operated for FLIA owing to lengthened and kinked iliac arteries between 1997 and 2015 in one center were analyzed. Short-term follow-up consisted of an incremental maximal cycling test, ankle-brachial index with flexed hips, echo-Doppler examination with peak systolic velocity measurements and contrast-enhanced magnetic resonance angiography before and 6 to 18 months after surgery. Both short- and long-term satisfaction were assessed using questionnaires.

Results: A total of 83 patients (90 operated legs; 96.7% males; median age of 34 years at the time of surgery; interquartile range [IQR], 29-47) were analyzed. In the short-term, 87.5% reported symptom reduction with an 86.4% overall satisfaction rate. Symptom-free cycling improved from 272 ± 84 W to 384 ± 101 W (P < .001), whereas the maximal workload increased from 419 ± 72 W to 428 ± 67 W (P = .01). The ankle-brachial index with flexed hips increased from 0.55 (IQR, 0.45-0.65) to 0.62 (IQR, 0.52-0.74; P = .008), and the peak systolic velocity measured with hips flexed decreased from 2.50 m/s (IQR, 1.77-3.13 m/s) to 1.57 m/s (IQR, 1.20-2.04 m/s; P < .001). After a median of 12 years (IQR, 9.0-15.4 years), symptoms were still decreased in 84.1% of patients with an 81.2% overall satisfaction rate (79.5% response rate). Three patients needed a reintervention (recurrent FLIA, n = 2; failure, n = 1).

Conclusions: Operative shortening of a lengthened and kinked iliac artery causing FLIA is successful both in the short- and long-term.

Introduction: Endurance athletes, especially speed skaters and cyclists, may suffer from  pain, early fatigue and a powerless feeling in the legs when cycling above specific 
exercise intensities. These complaints are associated with a disturbed balance between  the required and the actual blood flow. The causes of a disturbed balance are iliac 
vascular diseases, such as stenosis and kinkings. These abnormalities cause, amongst  others, a relative decrease in blood supply to the active tissues.  

Aim: This study investigates whether the pain, powerless feeling and early fatigue can be measured by use of independent pedal force measurements during an incremental 
maximal cycling exercise test. Beside that, this study investigates whether the location of the iliac artery can be determined. 
 
Materials and Methods: In total, n=28 cycling related patients with a left unilateral iliac artery disease and n=9 control subjects participate in this retrospective study. The 
patients were subdivided in respect to the affected common iliac artery (LC), external iliac artery (LE) and the combination of both (LCE). The group sizes were respectively 
n=5, n=16 and n=7. All performed a maximum voluntary incremental exercise test on a bicycle ergometer (LODE ® Excalibur Sport (925900)). Pedal force was measured for both 
legs using strain gauges, implemented in the crank of the cycle ergometer.  
 
Two types of (derivative) parameters were assessed: parameters as a function of the 
pedal revolution (1) and parameters as a function of the ergometer load (2). The 
parameters were:  

1. Maximum-, minimum and Δpedal force and as a function of a revolution
2. Maximum-, minimum pedal force, crank angle of maximum and minimum force, the mean power of revolution, mean power of 90-degree crank angle phase, the 
   mean power of cycling-related-muscle phases and the mean power of muscle phases nourished by the internal and external iliac arteries. 

The pedal force parameters as a function of the revolution were analysed by determination of the proportion of patients with the healthiest leg as the strongest leg, in 
relation to the patients with the abnormal leg as the strongest leg. All pedal force parameters as a function of the ergometer load were post-processed by a algorithm based upon a least summed square fitting technique, in order to asses the data by two linear fits with a forced intersection at the inflection point. The slopes of both linear fits were analysed for all study groups. 
 
Results: The results of (1) reveal a suspicious tendency; affected legs perform better at low intensities, and the healthy legs pull by at higher exercise intensity levels. The 
results of (2) reveal significant different slopes for low and high exercise intensities for the patients’ left leg exerted mean power of two phases of the pedal revolution, namely 
the 90-180°-phase and the 180-270°-phase (CI=[.134,.668] & p=0.004 and CI=[-.067, -.222] & p<0.001).  For patients with an abnormal left common iliac artery (LC and LCE), the slope of the difference between the mean power of the left and right leg during the 341-128°-phase at high exercise intensities is significantly lower than this slope at low exercise intensities (LC: CI=[.003,.859] & p=0.049, and LCE: CI=[.059,.434] & p=0.011). For controls and patients with a left singular abnormality in the external iliac artery, this significance is not observed.