What does flow limitation to the iliac artery (FLIA) entail?
- BF limitation during exercise
- Burning, heavy, tight, powerless sensations
- Compression and kinking of the artery leads to decreased BF, decreased o2 delivery, and increased symptoms
- Functional limitations lead to structural limitations
- It is progressive
Who is at risk for FLIA?
- Young, very fit endurance athletes like cyclists, skaters, and runners
**Uncommon sport condition
What are the risk factors for FLIA?
- Repetitive, exaggerated hip flexion
- High lifetime training volume
- Anatomical predispositions
- Psoas muscle hypertrophy
- Moving positions of the artery
- Narrowing of the inguinal canal
What causes the symptoms for FLIA? How/when do the symptoms present?
- Energetic demand is greater than the o2 supply
- Ischemia of the artery leads to hypoxia, then the claudication symptoms
- Symptoms present in the working muscles
- Symptoms increase with duration and intensity
- Symptoms resolve within ~5 mins of rest
What is endofibrosis?
Narrowing of the artery via thickening of the arterial walls due to repeated vascular stress.
Why is a patient history important when diagnosing FLIA?
Since symptoms are non-specific, you need to rule out any other common conditions before considering FLIA while understanding the demands of the patient’s sport.
How do you functionally assess FLIA?
- Hold the kinked position after exercise. If they still feel pain, there is a flow limitation
- Measure ankle brachial pressure index, which takes the ratio between ankle and tibial BP. If the ratio is low, there is a flow limitation. Normal ratios range from 1-1.39.
- Measure the oxygenation of the muscle. If there is reduced recovery after exercise, there is a flow limitation.
What does turbulent BF through a vessel indicate?
Movement through a narrow artery, which points towards a flow limitation.
What are some ways to examine the iliac artery?
- Magnetic resonance imaging
- CT scan
- Ultrasound
What are some ways to manage FLIA?
- Fit the bike better so the hip angle is opened during exercise
- Avoid pulling up on pedals
- Strength training can relieve some of the functional causes of pain
- Low intensity cycling in the bent over position
- High intensity cycling in an upright position
What are the types of surgeries available for FLIA? What does each surgery fix?
- Arterial release - for kinks and fixations
- Shortening - for excessive length and tortuosity
- Patch reconstruction - for endofibrosis
What is the proposed plan for returning to sport after a vascular problem?
6 week gradual recovery, and return to competition training after 6 wks.
At 16wks, athletes should be at their original training load.
What does adductor canal compression entail?
Superficial compression of the femoral artery and vein due to hypertrophied quad and adductor muscles.
What are the symptom presentations for adductor canal compression?
Artery: pain, burning, weakness
Vein: swelling, heaviness, congestion
Nerve: numbness, weakness, paresthesia
**mechanism for claudication is the same as FLIA.
How do you diagnose adductor canal compression?
- Provocative cycling exercise
- Check oxygenation after an isometric squeeze
- CT scan
How do you manage adductor canal compression?
- Surgical: release the surrounding fascia and widen the vessels
- Conservative: 6wks gradual return to exercise
What does popliteal artery entrapment syndrome (PAES) entail?
Compression of the popliteal artery, vein, and nerve, either structurally or functionally.
What is the difference between structural and functional PAES? How does this differ from FLIA?
Structural: artery is trapped by surrounding structures, path is determined by genetics.
Functional: activity leads to symptoms.
**Functional problems do not lead to structural problems like FLIA.
What are the symptom presentations of PAES?
- Claudication
- Swelling and fullness
- Paresthesia
How do you diagnose PAES?
- Provocative testing
- Ultrasound imaging
- MRA and CT scans
How do you manage PAES?
- Soft tissue treatments
- Botox injections
- Surgical decompression
- Vascular repair (rerouting, bypass)
What are the return to sport guidelines for PAES?
Medical supervision and gradual increases in activity for the first 6wks, unsupervised progression for the following 6 wks.
What does chronic exertional compartment syndrome (CECS) entail?
The compression of the fascial compartments of the lower leg, specifically the anterior and deep posterior compartments. Increased BF expands the volume of the compartments while inelastic fascia limits the expansion, leading to vein, artery, and nerve compression.
What are the symptoms of CECS?
- Claudication (same mechanism as FLIA)
- Paresthesia and fullness
- Gradual onset during training
- Rapid recovery
- Commonly bilateral presentation (different from the other conditions)
