Restless legs-a little known symptom of abdominal vascular compression syndromes

Compression of the iliac veins, the left renal vein and the vena cava as well as compression of the femoral veins may result in a venous congestion of the legs.

If the left common iliac vein is the only affected vessel (May Thurner syndrome), the symptoms may be restricted to the left leg. If the May Thurner syndrome is lasting for a longer time the venous outflow from the right pelvic axis may become reduced since the influx of additional venous blood across the midline organs towards the territory of the right internal iliac vein may demand priority over the drainage of the right external iliac vein, which is the continuation of the femoral vein, the main vein of the leg. This is the beginning of the congestion of the femoral vein and thus the entire leg. In such a situation the right leg may be as severely affected as the left leg.

The symptoms become worse if the left renal vein is compressed too since the main collateral route for this vein is the left ovarian or spermatic vein which pours large volumes of blood from the kidney towards the pelvic circulation. This may produce an additional overflow for the iliac veins, especially when a May Thurner syndrome exists-which is very common.

If the vena cava is compressed, then the outflow from both pelvic hemispheres is hampered affecting both legs.

The congestion is usually felt as tension and later as pain starting at the inner (medial) region of the upper thigh and later on involving the entire leg especially the calve. Not rarely the legs swell, especially at the end of the day after being upright for many hours.

Many patients develop then the mechanism to help the return of the blood across the compression sites. They start a walking around to activate the muscle pump to press the blood across the compressions. This may be interpreted as nervousness or attention deficit/hyperactivity disorder.

While lying in bed the patients may start moving the legs, flexing their hips and knees and stretch them again moving the toes up and down to activate the muscle pump without walking. This is often perceived as restless leg. Often such patients are referred to a neurologist since this is frequently regarded a neurological disorder.

In many cases however this is the clinical symptom of abdominal vascular compression syndromes.

If you suffer from restless leg syndrome and no neurological cause could be established, ask for a quantitative functional colour Doppler ultrasound of your legs, pelvic and abdominal vessels to check for compression of the left renal vein, the vena cava, the iliac veins and femoral veins.

The causal treatment of these compressions is possible by specific training, medication or surgery.