Turbulences on the Road to Glory

Gähwiler Roman^1,2, Werder Robert³

¹ Department for Vascular Medicine/Angiology, Hospital Lachen/SZ, Switzerland
² Berit SportClinic, Speicher/AR, Switzerland
³ Sports Medicine Nottwil, Swiss Olympic Medical Center Nottwil, Switzerland

Case History

A 30-year-old professional female triathlete has been sent to our vascular clinic for a second opinion due to exercise induced leg pain while cycling. She described a feeling of premature fatigue and cramping sensations in her left leg. These symptoms occured particularly while cycling in the aerodynamic position at maximum level of exertion and were reproducible each time after provocation of 4-5 minutes. The affected muscle groups had been identified by the patient as quadriceps, hamstrings, and calf. Similar complaints on the contralateral right side have been denied. Besides that, she suffers from an exercise-induced bronchoconstriction which is well-controlled by the application of Symbicort 400/12 Turbohaler. She is otherwise healthy.
As an Olympic level triathlete she cycles around 10 000 kilometers a year. In the course of her professional career she completed approximately 80 000 kilometers on the bike (training and competitions).
Finally, there is no history of premature cardiovascular disease such as myocardial infarction or strokes in under 65-year-old first-grade relatives.

Schlüsselwörter: Radfahren, Endofibrose, Beinschmerzen, Leistung, Arterie

Differential Diagnosis

The field of differential diagnosis is wide open and ranges from neurological conditions, to orthopedic pathologies, as well as rare vascular entities. As a result, a careful and multivariate clinical examination is key in order to determine the correct diagnostic pathway. Therefore, differentials include neurological conditions such as entrapment of cutaneous branches of the femoral nerve, neurogenic claudication due to functional vertebral body sliding (spondylolisthesis), or lumbar radiculopathy. Orthopedic differentials encompass sacro-iliac joint pathologies, hip impingement, tenosynovitis, metabolic myopathies, and neoplasms. Finally, non-traumatic exercise induced leg pain may also origin from vascular diseases such as atherosclerosis, fibromuscular dysplasia, aneurysms, venous thromboembolic events, and vascular compression syndromes such as endofibrosis. In order to evaluate the symptoms and narrow the bandwidth of potential diagnosis, a diagnostic algorithm might be valuable. [1]

In the present case the clinical examination in resting and supine position was rather inconspicuous. There were no imminent pathologies of the lower back or the sacro-iliac-, hip-, knee-, or ankle-joint. Furthermore, foot geometry and visual gait-analysis remained unremarkable. Additionally, there was no loss of sensation attributed to specific dermatomes, Lasègue’s maneuvers were unsuspicious, and reflexes were normal. Pedal pulses could be palpated bilaterally, skin temperature in both legs was similar, and there was no delay in capillary refill. The auscultation of the inguinal vessels did not bring up any turbulent blood flow patterns. Finally, segmental pulse-wave oscillography and ankle-brachial indices (ABI) revealed normal values for the left (1.17), and the right (1.19) leg, respectively.

Additional Tests

There has been an extensive clinical examination under resting conditions. Since symptoms occur exclusively in situations of maximal pedaling power, an individualized exercise test has been added. In this regard, the athlete had to perform a stress test on her own bike with her personal settings referring to the height of handlebars, saddle, and click-pedals. After a short warm-up period she could provoke the symptoms in her left leg after five minutes of all-out pedaling. Ankle-brachial indices were measured immediately (<1 minute after completion of the exercise test) and revealed a significant ABI-drop to 0.45 in the left leg. Furthermore, the amplitude of the pulse-wave oscillography at the left ankle level displayed almost a zero-line. Finally, duplex sonography pictured a mild grade of thickening of the posterior vessel wall in the left external iliac artery whereas peak systolic blood flow velocity measurements before and after the exercise test demonstrated an increase from 141 cm/s to 426 cm/s which suggested an arterial stenosis of at least 80%.
In summary, a flow limitation of the left iliac artery has been suspected. Consequently, a contrast-enhanced magnetic resonance angiography had to confirm the diagnosis.

 

Final Diagnosis

The 30-year-old professional female triathlete suffers from an endofibrosis of the left external iliac artery.

Management and Discussion

Endofibrosis is a specific exercise-induced vascular condition which presumably affects almost 20% of professional cyclists. [1,5] Hence, it is a very important differential diag­nosis in sports medicine practice. Since endofibrosis is not treated as equivalent to atherosclerosis, the first step of management is to make the clear distinction between these two entities. Considering atherosclerosis, one would be in favor to place a stent into the iliac artery. In the case of endofibrosis, that might be fatal due to the high risk of stent fractures in case the elite athlete intends to return to the previous level of performance. With reference to models of atherogenesis, atherosclerotic plaque formation develops at a focal region of decreased hemodynamic shear stress around the small curvature of the vessel, whereas endofibrosis occurs at focal regions of increased shear localized on the greater curvature. [3,4]
In fact, lately there are no evidence-based guidelines available regarding the optimal diagnosis and management of endofibrosis of the external iliac artery. Nevertheless, in 2016 INSITE collaborators (INternational Study group for Identification and Treatment of Endofibrosis) published a Delphi consensus study about the symptomatology and the investigations required to confirm the diagnosis of iliac endofibrosis. [5] The INSITE collaborators agreed that leg weakness, thigh pain, and resolution of symptoms within five minutes after cessation of exercise are decisive clinical hallmarks of the diagnostic process. Furthermore, ABI-reduction of at least 0.3 and/or ABI <0.54 demonstrate a positive predictive value and almost 100% specificity for the presence of a vascular pathology such as endofibrosis. [5,6]

As soon as the diagnosis of endofibrosis has been established, an individually tailored treatment strategy based on the specific characteristics of the underlying type of endofibrosis needs to be defined. In fact, there are several mechanisms which might induce a flow limitation of the iliac artery such as:
• arterial kinking
• excessive vessel lengthening
• intravascular narrowing due to pathological vessel-wall remodelling such as intimal hyperplasia, or a combination with one another. [7]

First-line treatment should entail non-operative approaches in order to reduce biomechanical shear stress to the iliac vessel wall for a period of at least 3 months. To that effect, the reduction of cardiac output (lowering of training intensity/duration), a «bike fitting» (less hip flexion by raising handlebars and saddle-position), and alteration of click-pedal technique (recruitment of gluteal muscle group instead of activation of psoas major musculature) might improve symptoms. As a matter of fact, these conservative approaches often do not result in satisfactory symptom control within a high-performance setting. Consequently, surgical options have to be assessed, but they come with various medico-ethical considerations. [1] First, athletes normally do not experience symptoms while performing tasks of daily life or submaximal exertion. Second, patients who intend to take up high-performance sport after potential surgical vascular repair are usually between 20-35 years old and might be compromised in their freedom of choice due to a competitive social environment (e.g. coaches, sponsors, etc.). Third, there is still limited scientific data regarding the choice of the optimal treatment option and its long-term results. Therefore, if kinking or elongation of the iliac artery is present, a surgical approach may focus on arterial release and vessel shortening. Whenever no excessive vessel lengthening coexists and an intravascular lesion such as intimal-hyperplasia can be visualized, the surgical strategy of choice would be an endarterectomy followed by vein-patch angioplasty. [8] Concerning the latter the overall satisfaction in a cohort of 68 endurance athletes based on a median follow-up of 11.1 years was 91.7%. [7]
Our 30-year-old female triathlete aimed to qualify for the Olympic Games in Paris 2024. In the course of the treatment, several adverse turbulences occurred, such as re-stenosis after endarterectomy and patch-angioplasty in 2022 which has been addressed by drug-coated balloon-angioplasty in January 2023. Unfortunately, symptom relief was not satisfactory to pursue the athletic career on the intended level of performance. Thus, revision surgery in July 2023 was inevitable. Meanwhile, the athlete was able to perform constantly on a high level. Nonetheless, she did not fulfill the qualification requirements to participate at the upcoming Olympics (yet).

Correspondence

Dr. med. Dr. sc. med. Roman Gähwiler
Head of Angiology, Spital Lachen/SZ
Oberdorfstrasse 41, 8853 Lachen/SZ
Phone: 055 451 31 11
roman.gaehwiler@spital-lachen.ch

References

1. Gähwiler R, Hirschmüller A, Grumann T, Isaak A, Thalhammer C. Exercise induced leg pain due to endofibrosis of external iliac artery. Vasa. 2021 Feb;50(2):92-100. doi: 10.1024/0301-1526/a000909. Epub 2020 Sep 15. PMID: 32930655.
2. Schep G, Schmikli SL, Bender MH, Mosterd WL, Hammacher ER, Wijn PF. Recognising vascular causes of leg complaints in endurance athletes. Part 1: validation of a decision algorithm. Int J Sports Med. 2002 Jul;23(5):313-21. doi: 10.1055/s-2002-33141. PMID: 12165881.
3. Cunningham KS, Gotlieb AI. The role of shear stress in the pathogenesis of atherosclerosis. Lab Invest. 2005 Jan;85(1):9-23. doi: 10.1038/labinvest.3700215. Erratum in: Lab Invest. 2005 Jul;85(7):942. PMID: 15568038.
4. Chevalier JM, Enon B, Walder J, Barral X, Pillet J, Megret A, Lhoste P, Saint-André JP, Davinroy M. Endofibrosis of the external iliac artery in bicycle racers: an unrecognized pathological state. Ann Vasc Surg. 1986 Nov;1(3):297-303. doi: 10.1016/S0890-5096(06)60123-4. PMID: 3504340.
5. INSITE Collaborators (INternational Study group for Identification and Treatment of Endofibrosis). Diagnosis and Management of Iliac Artery Endofibrosis: Results of a Delphi Consensus Study. Eur J Vasc Endovasc Surg. 2016 Jul;52(1):90-8. doi: 10.1016/j.ejvs.2016.04.004. Epub 2016 May 17. PMID: 27209899.
6. Schep G, Schmikli SL, Bender MH, Mosterd WL, Hammacher ER, Wijn PF. Recognising vascular causes of leg complaints in endurance athletes. Part 1: validation of a decision algorithm. Int J Sports Med. 2002 Jul;23(5):313-21. doi: 10.1055/s-2002-33141. PMID: 12165881.
7. van Hooff M, Colenbrander FFC, Bender MHM, Loos MMJA, Brini A, Savelberg HHHCM, Scheltinga MR, Schep G. Short- and long-term outcomes after endarterectomy with autologous patching in endurance athletes with iliac artery endofibrosis. J Vasc Surg. 2023 Aug;78(2):514-524.e2. doi: 10.1016/j.jvs.2023.03.501. Epub 2023 Apr 14. PMID: 37060932.
8. Peach G, Schep G, Palfreeman R, Beard JD, Thompson MM, Hinchliffe RJ. Endofibrosis and kinking of the iliac arteries in athletes: a systematic review. Eur J Vasc Endovasc Surg. 2012 Feb;43(2):208-17. doi: 10.1016/j.ejvs.2011.11.019. Epub 2011 Dec 19. PMID: 22186674.