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Where symptoms are transient and related only to exercise, non- invasive vascular studies such as ankle brachial pressure index (ABPI) before and after provocative exercise may reveal the abnormality. In the absence of equipment a simple clinical test is to ask the patient to hop on the spot until symptoms are repro- duced. Ideally the exercise should replicate the conditions experi- enced by the athlete ie. the runner complaining of pain on slopes should be tested on an inclined treadmill, the rower on an ergo- rower. Loss of pulses, reduced systolic pressure on the affected leg or a significantly lowered ABPI post exercise compared to the nor- mal limb raises the suspicion of an arterial cause for the pain (the exact ABPI cut off point for diagnosis of PAES has not been estab- lished). Slick testing procedures are required to get blood pressure readings within the first minute of recovery because in mild cases flow will return quickly to the artery once the provocative testing has halted and the limb is returned to a neutral position.
Continuous-wave Doppler ultrasonography may reveal a change in flow or pulse loss during passive dorsiflexion or active plan- tarflexion. The results may be misleading however, as pulse dis- appearance has been noted in normal asymptomatic athletes. If the index of suspicion for arterial impingement is high referral to a vascular specialist is required. Duplex flow studies (ultrasound) allow visualisation of the artery with simultaneous monitoring of arterial flow. This may reveal the lesion with the use of provoca- tive manoeuvres however the sensitivity of the testing is likely to be higher after exercise at a time of high blood flow. Magnetic res- onance angiogram (MRA) or standard arteriogram will usually con- firm the site of the lesion and differentiate it from adductor canal syndrome. Management: As the condition is thought to be progressive due to regular trauma to the artery, an increase in vascular occlusion is expected over time together with a heightened risk of emboli- sation. Surgery involves exploration and decompression and may require simple release of fascial or musculotendinous slips through to thrombectomy or endarterectomy and saphenous vein grafting. Following an initial period of recovery the patient will make a graduated return to non-provocative physical activity with an eventual return to sport. Patients are advised to maintain ade- quate flexibility of soleus and gastrocnemious.
2. Adductor canal syndrome Definition: Mechanical stenosis or occlusion of the femoral artery in the aponeurotic tunnel (Hunter’s canal) in the middle third of the thigh thought to be due to the scissor-like action of adductor magnus and vastus medialis. The condition is usually associated with anatomical abnormality combined with muscle or tendon hypertrophy. It may present as acute occlusion with or without thrombosis. Presentation: The condition is rare but has been reported in ath- letes, skiers, and runners. Symptoms depend on severity, mild cases experience intermittent muscle pains or cramps distal to the lesion (ie. calf) and related to activity. Commonly the complaint is of calf pain or numbness in the toes. For this reason mild cases may be mistaken for nerve entrapment. The condition may progress rapidly if a thrombus forms at the occluded vessel. At this stage the diagnosis becomes more straightforward as the patient presents with typical claudication symptoms. Assessment: The condition in its early stages will often present with the same symptoms as PAES. Indeed it is difficult to differ-
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entiate between the two clinically. As the lesion exists on the AFP axis the condition may be revealed during exercise testing for EIAE or PAES. Exercise testing is only relevant if all other clinical tests (including resting ABPI) prove negative and the symptoms are stable, purely exercise induced and mild. In the presence of an arterial lesion, results may reveal lowered post exercise systolic pressure and ABPI results on the affected leg (compared to the normal side). In advanced cases there may be pain during normal daily activity (ie. walking), pulses may be reduced or absent at the foot. The foot may be cold or blanch white with minimal repetitive dorsiflexion/plantarflexion exercise at the ankle. ABPI at rest may be lowered. (< 0.9 see table 2). Management: Acute cases should be referred immediately to the vascular surgeon. Delays in recognition should be avoided. Irreversible damage to the limb may occur if the condition pro- gresses rapidly (usually in association with thrombus). Arteriogram or MRA will confirm diagnosis and differentiate it from PAES. Emergency surgery is performed to explore and repair the affected portion of the artery (endarterectomy with a saphe- nous vein patch or via saphenous vein bypass).
3. External iliac artery endofibrosis (EIAE) and com- mon iliac artery endofibrosis (CIAE) Definition: A fibrous arterial lesion distinct pathologically from atherosclerosis leading to asymmetrical stenosis or narrowing of the external iliac artery. The condition is occasionally found to affect the common iliac artery. Presentation: EIAE affects principally high mileage cyclists or triathletes leading to reduced flow to the affected limb at times of maximal effort. There are reports in the literature of marathon runners, fell runners, speed skaters and weight lifters who have been diagnosed with the condition. Afflicted athletes will usually complain of thigh pain. Calf pain is rare and this generally differ- entiates the condition clinically from PAES and adductor canal problems. There is usually no pain at rest except in advanced cases. Numbness in the affected limb is often described. Symptoms occur commonly at times of maximal effort such as sprinting, climbing or time trialling (cyclists). Competitors will often describe a ‘loss of force’ or having to ride or run with ‘one leg’. The symptoms rapidly diminish if the exercise level is reduced marginally. Cyclists report being able to ride ’all day’ at low or moderate levels of effort without experiencing symptoms. The condition is thought to be related abnormal haemodynamic stress combined with kinking and tethering of the artery, leading to ves- sel wall injury. The symptoms commonly mimic pain of muscu- loskeletal or neural origin often leading to long delays in diagno- sis. It is not uncommon for these athletes to have seen a variety of medical practitioners and been subjected to lengthy periods of ‘treatment’ for non-existent conditions such as sacro-iliac dys- function or ‘muscle imbalance’. Some even report offers of spinal surgery (6). Assessment: Physical and vascular tests at rest are usually nor- mal. A bruit (abnormal sound indicating turbulence) may be detected on auscultation over the external iliac artery. Ankle to brachial pressure at rest falls within normal limits. The sufferer should be assessed initially using a maximal exercise test to reproduce the symptoms. Post-exercise ABPI should be repeated within the first minute following termination of the test. Post- exercise systolic blood pressure may be lowered on the affected side resulting in abnormal ABPI (<0.66). This test will reveal the