Ask the Doctor: Ryan Cox and iliac artery endofibrosis
By Dawn M. Richardson MD FACEP
Barloworld’s Ryan Cox died on August 1st from complications related to his recent surgery to treat a condition known as iliac artery endofibrosis. Since the death of the 28-year-old cyclist, I’ve received several questions about the problem that led to his surgery and the complications that ultimately took his life.
Iliac artery endofibrosis is surprisingly common among elite cyclists and speedskaters. Indeed, two of the men on the Colavita-Sutter Home squad have undergone this same procedure within the last year: Charles Dionne and Hayden Godfrey. Both, thankfully, have had successful recoveries. Godfrey put me in touch with his vascular surgeon, Professor Justin Roake of Christchurch Vascular Group in New Zealand. Why certain athletes?
Arterial disease is usually an illness of elderly smokers, who damage their arteries in much the same way coronary arteries are narrowed by plaque; through years of uncontrolled high blood pressure, smoking and high cholesterol. It made no sense to me why young elite athletes would suffer similar atherosclerosis and need the same surgery. I figured that arterial disease in cyclists must be a genetic defect that is only manifested by the high-blood-flow state of endurance sports. I was only partially correct.
The aorta is the largest artery in the human body; it leaves the heart with oxygen rich blood and passes behind the lower abdomen. It splits into two common iliac arteries at the level of the fourth lumbar vertebrae in the lower back. The Common iliac artery then splits into the internal and external iliac arteries at the level of the fifth lumber vertebrae. The internal iliac artery supplies blood to the pelvis and buttocks and the external iliac artery continues to the groin.
In 1986 Chevalier et al of the Service de Chirurgie Vasculaire et Thoracique in Angers, France, gave one of the earliest academic descriptions of iliac artery endofibrosis among elite bicycle racers in the Annals of Vascular Surgery.
Iliac artery endofibrosis, in elite cyclists, most often affects the external iliac artery, only rarely surfacing in the common iliac artery. The reason for this is because these are subject to the stress of repetitive motion of hip flexion by the psoas muscle in the aerodynamic position of endurance cycling. The common and external iliac arteries are repetitively flexed under high flow during training over many years. This is not a natural physiologic position and presents a unique stress when combined with high blood flow.
Arteries are composed of three layers, intima, media and adventitia. The intima lines the inside of the blood vessel and contains mostly elastic tissue, which has some give that allows the artery to change shape. The media contains muscle and fibers that allow the artery to dilate when blood is pumped. The adventitia contains fibroelastic tissue.
In traditional arterial disease, a cholesterol plaque builds up and sticks to the blood vessel side of the intimal layer. In iliac artery endofibrosis that fibrous tissue starts growing within the intimal layer, which leads to a loss of elasticity, an inability of the artery to change diameter with high-blood-flow state, and eventually to a constriction of the artery itself.
Recognizing the problem
What are the symptoms of iliac artery endofibrosis? Godfrey described a numb feeling in his leg, not particularly painful. He described it as the same numb feeling as if one had fallen asleep on one’s arm. He also noticed a sudden loss of power output in the numb leg. The numbness stopped when he backed off. This is known in medical parlance as intermittent claudication. He found it more reproducible in the time trial position; the more flexed the worse it felt.
Godfrey found it very frustrating and it took a year from the onset of his symptoms to get a diagnosis. There are several ways to diagnosis the condition including ultrasound, CT scan, angiogram, or blood pressure checks of the ankle of the affected leg before and after exercise.
Godfrey had his ankle blood pressure checked at rest and then jumped on a bicycle ergometer. There was no blood pressure in the affected ankle after exercise. The CT scan showed he was born with what is known as a tortuous common iliac artery–that is, instead of going straight towards his legs it meandered more like a lazy river. The CT scan didn’t show how bad the narrowing was, but ultrasound pinpointed the exact location of the constriction to his common iliac artery. Surgery was his only option if he wished to continue racing bicycles.
There are several surgical options including an autogenous graft (the use of tissue taken from elsewhere in the patient’s own body), synthetic graft or bypassing the artery itself. In young otherwise healthy patients, an autogenous graft is often the best option; it is less likely to cause problems, including infection. In some cases they will simply remove the bad tissue from the lining of the artery.
Godfrey’s damaged common iliac artery was repaired using a graft taken from the saphenous vein, the largest vein near the ankle. His common iliac artery was filleted open and showed the typical thickening of endofibrosis. The saphenous vein patch was also filleted open and sewn in to give the artery more capacity.
The artery will still be subject to pressure from psoas muscle hip flexion, and widening it will allow blood to flow more freely under this stress.
Recovery and possible complications
I was surprised by the recovery time after surgery-it seemed remarkably short. There is, however, some variation on the recommended recovery time. Professor Roake advised early, cautious mobilization. Godfrey spent two days lying down, a week on the couch and the second week he started walking around. Professor Roake said he expected the graft to be healed in two to three weeks.
By the beginning of the third week Godfrey started on the rollers for 10 minutes at a time and the fourth week he started riding outdoors. The fifth week he resumed training, and he is on good form 4 months after surgery.
What surgical complication may have lead to Cox’s tragic death? All of the vascular surgeons I spoke with mentioned the same rare but known complication-infection of the graft. This is much more likely with a synthetic graft but can occasionally happen with an autogenous graft as well. It’s possible that the graft became infected postoperatively and gradually compromised some of the stitching. This may have lead to slow bleeding into the space behind the abdominal cavity for some time before obvious symptoms of internal bleeding developed. Iliac artery endofibrosis is a mysterious disease that has probably lead many cyclists to believe that they simply can’t compete anymore and thus leave the sport. If you are suffering from a reproducible numbness and loss of power in one leg, seek medical advice. Corrective surgery is not without its risks, but has lead to a return of form for several top professional cyclists.
Dawn Richardson is a board-certified emergency medicine physician practicing at Roger Williams Medical Center in Providence, Rhode Island, and is a clinical instructor in emergency medicine at the Warren Alpert Medical School of Brown University . Send your questions to her at email@example.com. Richardson serves as physician for the Colavita-Sutter Home presented by Cooking Light cycling team.Important note
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