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Wednesday, August 01, 2007

What Happened to South African Cyclist Ryan Cox?

Breaking news on Wednesday from Team Barloworld was that one of their South African cyclists, 28 year old Ryan Cox, passed away in Kempton Park following complications from surgery he had in France three weeks ago. The actual cause of death is unclear at this point.

Cox complained of powerlessness and pain in his left leg at the end of some races. He sought the help of a French doctor who correctly diagnosed Cox's vascular lesion in his left external iliac artery. The problem was first documented in the scientific literature, mostly by a French Canadian doctor named Francois Mosimann, and for the first time in 1985.

It is unclear why the artery in the thigh undergoes this change, but several morphological changes take place that result in the artery becoming thicker, elongated, and when the hip is flexed (as during cycling), the artery becomes kinked or looped upon itself. The primary problem is that the thickening of the artery causes stenosis, which is is a narrowing of the of the artery diameter. The consequence of this is that blood flow becomes limited to any limbs or tissues that are downstream of that artery.

In the case of Ryan Cox, the external iliac artery was excessively long, which predisposes it to this kinking/looping - think of a hosepipe that gets small kinks that obstruct flow of water down it. The result is that the cyclist experiences pain and powerlessness in the affected leg during high intensity exercise, although the symptoms subside when exercise is stopped or the exercise intensity decreases. The condition occurs in quite a high proportion of professional cyclists - a study published in 2004 reported that "one in five" had some evidence of a flow limitation! Not all require surgery, however.

A big problem with this condition is that it apparently goes undetected by physiotherapists and medical doctors because they are unfamiliar with it. In addition, they cannot reproduce the symptoms by physical examination, as only cycling at high intensities will cause the onset of the symptoms. So the medical practitioner must first know about this condition, and second really must know exactly what they are looking for to diagnose this condition as diagnosis requires sophisticated imaging techniques such as echo-doppler, arterial digital subtraction angiography, magnetic resonance imaging and angiography.

Again, it is unclear what causes this, and at this point it is unclear why Ryan Cox experienced complications from the surgery, as normally the outcomes from surgery appear to be positive. To expand a little on the surgery, he apparently had a 6 cm section of the external iliac artery removed, with the resultant two ends being anastamosed (joined) to reform the artery. The possibility is then that this weakened area was damaged, perhaps through excessive activity soon after surgery. Apparently, Cox was doing some gardening and light static exercises, both of which would involve bending, possibly damaging the the repaired area of the artery. As a result, it would rupture, and he'd bleed into the pelvis, causing Cox to lose enough blood to pass out.

We mourn the loss of this young cyclist and offer our condolences first to his family and friends, and also to South African (and all) cycling fans.