In advanced stages, vascular reconstructive surgery with the use of venous patch may be indicated. If the disease is detected at an earlier stage, less invasive surgical treatment, consisting of release of the iliac artery, is possible and it might…
Bron
Verkorte titel
Aandoening
Sport-Related Flow-Limiations in the Iliac Artery
Ondersteuning
Onderzoeksproduct en/of interventie
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Uitkomstmaten
Primaire uitkomstmaten
Reproducibility:
1. Difference (paired T-test when normally distributed)
2. Agreement (intra-class correlation coefficients, (ratio) limits of agreement and coefficients of variation, Bland-Altman)
Diagnosis:
1. Difference (paired T-test when normally distributed)
2. Model for detecting sport-related flow-limitation (GLM/GLMNET; ROC curve)
Posture:
1. Difference (paired T-test when normally distributed)
Surgery:
1. Difference (paired T-test when normally distributed)
Achtergrond van het onderzoek
Background
A professional cyclist cycles approximately 25,000 km a year and flexes the hip 8,000,000 a year, while leg blood flow is in the range of 10-15 liters a minute. This poses a substantial hemodynamic load on the iliac artery. As a result a proportion of endurance athletes develop a limitation in leg circulation due to arterial narrowing in this iliac artery. An early ‘Lancet’ study of the department of Sports Medicine of Máxima Medical Center (MMC) found that 20% of professional cyclists were suffering from such a sport-related Flow Limitation in the Iliac Artery (FLIA) necessitating treatment. The incidence in recreational cyclists is unknown. But with 849,000 recreational cyclists in the Netherlands that cycle over 3,000 km a year with an impressive 1,000,000 hip flexions many of them come to the same mileage as a professional cyclist posing them at risk for FLIA. If untreated, FLIA may have a pronounced impact on quality of life. Professional careers are almost always ended. In a substantial subset of cyclists abnormalities become more pronounced. This may even lead to complete occlusions, with severe symptoms in daily life .
Problem definition
Clinical experience suggests that early detection and treatment leads to better outcome. If diagnosed at a late stage, treatment by changes in sports rhythm or limited surgery will not suffice anymore. The only options left are continue living with the complaints or to undergo extensive and risky reconstructive vascular surgery. Early diagnosis is thus of paramount importance. Unfortunately, diagnosis is often missed. There is a wide range of differential diagnoses in the early stage of FLIA and even if doctors suspect FLIA currently available diagnostic tools lack sensitivity. The best single functional test is the maximal provocative exercise test on a cycle ergometer followed by measuring blood pressure in a competitive posture. In the rare case that the problem is unilateral, the sensitivity is 73%. If the problem is bilateral, the sensitivity is only 43%. Imaging techniques are more sensitive but they differ highly from normal routine. They have a long learning curve and are restricted to specialist centres. Therefore, new innovative techniques are required, that can be easily applied during exercise when the complaints occur. Ultimately, this test can be used for screening purposes and allocate patients to more complex diagnostic imaging tests in specialist centres.
Solution
Complaints reported in the early stage of FLIA are powerless and painful feelings in the leg muscles when cycling above a certain exercise threshold, rapidly disappearing at rest. Therefore, pedal power measurements (PPM) may be able to quantify the complaints and hence contribute to the diagnosis.
Impeded arterial leg circulation results in a drop in levels of muscle tissue oxygenation. Near-infrared Spectroscopy (NIRS) is an innovative technique that indirectly measures oxygenation in the muscle. Consequently, NIRS may be able to detect alterations in levels of oxygen that are associated with the level of arterial narrowing. We recently reported proof of concept studies regarding the potential diagnostic role of both PPM and NIRS in patients with diagnosed sport-related FLIA.
Aim of the project
In this project, we will develop an exercise test combining all relevant diagnostic techniques. The aim is to reach 90% sensitivity and 90% specificity to detect sport-related FLIA. We will study the characteristics of this new panel of tests in healthy individuals as well as patients, using the more complex imaging tests as a gold standard. Moreover, as an addition in patients with solely functional kinking, we will assess the differences in reoxygenation pattern in posture change (normale posture and competitive). In addition, we will assess the differences after surgerical treatment.
Doel van het onderzoek
In advanced stages, vascular reconstructive surgery with the use of venous patch may be indicated. If the disease is detected at an earlier stage, less invasive surgical treatment, consisting of release of the iliac artery, is possible and it might also be possible to prevent progression of the disease by adaptations in sports. Therefore, it is of substantial clinical importance to develop new, more sensitive measurement techniques to detect these subtle flow limitations.
Near Infrared Spectroscopy:
Techniques that measure the direct (patho)physiological effect of a flow limitation during exercise might be promising. Near-infrared spectroscopy (NIRS) provides an optical estimate of (muscle) tissue oxy- and deoxyhemoglobin concentration. As the instrument is small and the measurements are noninvasive and in real time, it can be used during and after exercise.
NIRS has been used to determine the presence and severity of peripheral atherosclerotic vascular disease (PAD). To our knowledge, no literature exists on the use of NIRS in athletes with iliac artery flow limitations.
We expect that the reoxygenation pattern during recovery gives great diagnostic information regarding this entity. Regarding the posture change in patients with solely functional kinking, we expect improved reoxygenation to even normal values in the region of controls. Regarding surgery we expect improved reoxygenation values.
Pedal Power Measurements:
A major complaint of cyclists with flow limitations is of loss of power in the affected leg. Therefore, pedal power measurement (PPM) may provide additional diagnostic value. It is assumed that healthy participants distribute the power equally between both legs independent of the total power generated. For patients with unilateral arterial flow limitations, it is expected that the power generated by the affected leg will not increase proportional at exercise intensities that demand more blood flow than can be supplied by the affected arteries. The healthy leg might compensate and give extra power. Therefore, variables that quantify the power difference between both legs at different intensities may provide added diagnostic value. Regarding the posture change in patients with solely functional kinking, we expect improved pedal power measurements. Regarding surgery we expect improved pedal power measusrements.
Onderzoeksopzet
Regarding
1. (t0) Baseline assessment;
2. (t1=t0 + 0 days) maximal exercise test 1;
3. (t2=t1 < 24 days) maximal exercise test 2.
Onderzoeksproduct en/of interventie
The study is designed as a prospective observational study without any invasive measurements. After written and oral informed consent, t0 and t1 measurements will be performed. If the participant is willing to perform an extra test (reproducibility, posture change and surgery) a second test is planned within preferably 4 weeks (or 1 year post-operation). t0 consists of physical examination, diagnosis of sport-related vascular problem (or healthy control without sport-related vascular problem) followed by a maximal exercise test. t1 consists of the same maximal exercise test.
Publiek
Wetenschappelijk
Belangrijkste voorwaarden om deel te mogen nemen (Inclusiecriteria)
1. Male or female aged>18;
2. Endurance athlete for at least three years ≥ 5 hours per week of training
3. Unilateral- or bilateral pain, cramp and/or powerlessness in the leg or legs during (sub)-maximal exercise which disappears within a few minutes after ceasing exercise;
4. Proved sport-related flow-limitations as a result of kinking and/or intravascular lesions, diagnosed with duplex-Doppler echography examination
For control subjects the same in and exclusion criteria except those regarding to sport-related flow limitations
Belangrijkste redenen om niet deel te kunnen nemen (Exclusiecriteria)
1. No operative vascular reconstruction in the iliac region
2. No diagnosed heart failure according to the New-York Heart Association stage>1
3. Cardiovascular risk
4. Atherosclerosis
5. Lumbar herniated discs
6. Complaints do not seem to be restricted to one muscle group or tendon;
For control subjects the same in and exclusion criteria except those regarding to sport-related flow limitations
Opzet
Deelname
Voornemen beschikbaar stellen Individuele Patiënten Data (IPD)
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Andere (mogelijk minder actuele) registraties in dit register
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In overige registers
Register | ID |
---|---|
NTR-new | NL8557 |
Ander register | nWMO : n/a nWMO; n13.12022013 |