Most elite athletes are accustomed to experiencing a certain degree of muscle pain and fatigue during high-intensity exercise. Recently, however, a subset of athletes (particularly cyclists, rowers, and triathletes) have reported symptoms of leg pain and weakness from an unexpected cause; damage to the arteries of the pelvis, groin, or lower leg.

This damage, or arteriopathy, appears to cause the arteries to stretch, narrow or kink in such a way that during high-intensity exercise the athlete experiences decreased blood flow due to the constriction or obstruction of the artery in the affected leg. This lack of blood flow, or ischemia, causes pain, burning, weakness, and powerlessness during exercise. In cyclists, this damage most often occurs in the iliac arteries, particularly the external iliac artery.

Causes

The first research on iliac arteriopathy in elite cyclists came out of France in the 1980s and has been growing steadily ever since. Researchers and surgeons speculate that a combination of factors may cause the external iliac arteries to be damaged, including:

  • An extremely high blood flowRepetitive hip flexionAn aerodynamic cycling position

Together these factors result in a continuous, repetitive flexing of the artery while under pressure. This stress, over hundreds of hours of high-intensity training, may cause damage to the various layers of the artery wall, or may cause the artery to be stretched, or kinked. Some surgeons have found a tough fibrous tissue build-up on the inside layer of the damaged artery. This fibrous tissue not only narrows the artery but also prevents it from dilating during exercise. The result is a decreased blood flow to the legs that are often only noticeable during high-intensity exercise.

Symptoms

I took an interest in this condition after I began experiencing symptoms of weakness, pain, and powerlessness in my right thigh while cycling at a high intensity. A competitive cyclist for over 20 years, I knew that this wasn’t simply muscle fatigue or any sort of soft tissue injury. When I tried to explain the sensations I felt, the only adjective that seemed appropriate was “suffocation.” I felt as though the muscles in my leg were suffocating.

Not long after I began researching my symptoms I stumbled upon some obscure research on vascular issues in cyclists, including iliac artery problems showing up in pro cyclists. I eventually took my suspicions and a pile of research abstracts to my doctors and began the process of getting a diagnosis.

During this time, I spoke with several other cyclists across the country who were also diagnosed with external iliac arteriopathy. They all described similar symptoms to mine. They reported feelings of pain, numbness, weakness and a lack of power—typically in the thigh or calf—that went away when they backed off and returned when they went hard. Six of the seven athletes I spoke with experienced symptoms only in one leg. I was fortunate to get diagnosed quickly; many that I spoke with had symptoms for years before finding a doctor familiar with the problem.

Diagnosis

Diagnosis is often difficult because most doctors aren’t familiar with this condition and wouldn’t suspect vascular problems in a fit athlete. Many athletes are misdiagnosed as having compartment syndrome or an overuse, soft tissue injury and are initially referred to physical therapy, which fails to solve the problem.

There are several imaging studies that can help diagnose a narrowing in the arteries to the legs. An ankle-brachial index (ABI) test before and after exercise is the least invasive test to get an initial diagnosis. This test measures blood pressure at the ankles and in the arm at rest and then after exercise. A normal resting ankle-brachial index is 1 or 1.1 and anything below that is abnormal. Athletes with arteriopathy generally have normal readings at rest, but after exercise (treadmill running or cycling) the ankle pressure in the affected leg drops dramatically, indicating reduced blood flow.

Other tests used to detect the location and degree of the narrowing may include:

  • An exercise duplex ultrasoundComputed tomography angiography (CTA)Magnetic resonance angiography (MRA)Extremity arteriography

Treating External Iliac Arteriopathy

Unless an athlete is ready to settle down into a sedentary lifestyle, the current treatment recommendation for this condition is the surgical repair of the damaged artery. External iliac arteriopathy has been most commonly treated by vascular surgeons with a procedure that involves opening or removing the narrowed section of the artery and placing a synthetic patch or natural tissue graft over the artery. Other possible surgical interventions include bypassing the damaged artery or simply releasing the inguinal ligament or psoas muscle attachments to the artery, which have also been implicated in compressing or kinking the external iliac artery. The best treatment option seems to depend upon the exact location and cause of the damage as well as the athlete’s long-term goals.

Surgical Outcomes

All of the cyclists I spoke with opted for a surgical intervention that included a tissue graft or patch. They all told me that the recovery was remarkably short, although the first two weeks are anywhere from quite uncomfortable to extremely uncomfortable. One former Olympian told me, “No one tells you how much it hurts when they cut through your abdominal muscles.”

Depending upon the type of surgical procedure performed, the athlete may be walking within two weeks, cycling easily on a trainer by week three and perhaps on the road in four to six weeks—although some athletes told me that their rehab took as much as two to three months.

There are always risks of surgery and this procedure comes with the standard set, including the risk of infection, tissue rejection, the return of the symptoms, or worse. In 2007, cyclist Ryan Cox died just weeks after surgery to repair his iliac artery. Because this procedure is still fairly new, there are no studies of the long-term outcomes in the cyclists who had this surgery. One cyclist I talked to said that he still feels odd aches and pains a year after his surgery and another told me that some of her symptoms have returned 5 years after surgery.

While almost all of the athletes I talked with told me they are glad they had the surgery and would do it again, it’s a major decision and one I don’t take lightly. I’m still doing my research, gathering information, and talking with athletes and surgeons on a regular basis. I’m finding that the best diagnostic procedure and the type of surgery recommended is highly dependent upon which surgeon you ask; they all seem to have a favorite procedure or type of graft or patch. I’ve been “offered” a graft from my saphenous vein (the large vein near the ankle), a Dacron patch, a bovine tissue graft (yes, from a cow), a bypass around the narrowed artery, and even a stent.

Clearly, this is not a common procedure and no one knows exactly the best approach. Outside of Europe, a handful of vascular surgeons who I’ve spoken with have performed this procedure on U.S. cyclists. Dr. Ken Cherry, a vascular surgeon at the University of Virginia presented a paper on this condition at the Society for Vascular Surgery meeting in 2008.