Vascular Malformations in the Limbs - Frequently asked questions

I noticed my affected arm or leg is smaller than the unaffected arm or leg.  Why does this happen?

This most often occurs because the venous malformation involves much of the muscle in the affected arm or leg.  This results in less than optimal growth and strength of the muscle.  Also, you may tend to favour the unaffected arm or leg causing a difference in muscle size and strength.  

Will I benefit from exercises for my smaller arm or leg?

Yes, you may benefit from strengthening exercises and activities.  This may not increase the muscle size but should improve the muscle function.  

What is the difference between a venous malformation and Klippel-Trenaunay syndrome?

A venous malformation is a slow flow vascular malformation and is one component of Klippel-Trenaunay syndrome (KTS).  A venous malformation can occur on its own, independently of KTS.  

KTS is a complex combined slow flow vascular malformation which most commonly affects a leg.  It has 3 components: a port-wine stain (a capillary malformation) in the skin, varicose veins (a type of venous malformation) and increased growth of bone or soft tissue (which for example can increase the length of an affected leg).  Lymphatic malformations including abnormalities of lymphatic flow may be present in KTS.  

Is a venous malformation associated with an increased risk of blood clots?

Yes, a venous malformation can be, however is not always, associated with an increased risk of blood clots.  Blood testing is useful in identifying patients who may have an abnormality of blood clotting in their venous malformation.  Many blood clots are small and some are only identified on scans such as magnetic resonance imaging and ultrasound and cause no problems.  Some patients who have frequent, troublesome pain and are identified on blood testing as having blood clotting abnormalities may be treated with blood thinning injections.  

How many injection sclerotherapy treatment sessions are needed to treat a venous malformation?

Usually, several injection sclerotherapy treatments are required.  This is to ensure that good closure of the malformation is achieved.  Treatments need to be at frequent intervals to prevent re-opening of the venous malformation.  The number of treatments is determined by the improvement in symptoms.  At SickKids, we initially arrange 3 injection sclerotherapy treatments at 6 week intervals and then decide if further treatment is required.  

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