Venous Malformations

The venous malformations (VM) may affect all types of tissue. These are the vascular anomalies more commonly affecting the venous walls. These are deformed and dilated. VM generally evolve slowly, can be stable for long periods except for sporadic episodes of growth. These vascular anomalies are often isolated and non hereditary. If they affect the members, they can be confused with the Klippel-Trenaunay Syndrome.  


What is the cause of a Venous Malformation? 

They are rarely of hereditary nature. They are caused by genetic defects. Since 1999, belgian researchers have identified various chromosomal mutations that cause Venous Malformations. In 2009 they published their latest findings identifying the genes that cause the majority of VM. 


What parts of the body can be affected?  

Most frequently they are cutanous or they affect the mucouse. However, all body tissue and organs can potentially be affected as well: intestines, liver, or even muscles and bones. They are more often touching the face (for instance the jaw, cheek or lips), or the neck. Many facial malformations of large volume are associated to asymtomatic intra-cranial venous malformations.

The cavernous malformation (or cavernous angioma) affecting the brain (1 person for every 200) are often times constantly evolving. They can be the root cause for certain types of epilepsy, of trombosis or haemorrhage. They are serious pathological venous angiomes.


How do you recognize a Venous Malformation? 

Venous Malformations can be localized or diffuse, superficial or deep. They can be identified by their swelling in Trendelenburg position. When they are deep, the visible affected surface is not correlated to their actual volume inside the body. Those that are superficial may present the aspect of bluish pockets which also swell under muscle effort and emptied under compression, movement or during a change of position. They are considered low-flow malformations and they are soft, often cold to the contact: unlike the Arteriovenous Malformations (AVM), when the doctor palpates during auscultation the Venous Malformations don't present a thrill or are warm. On those cases where they are superficial lesions, small hard nodules (phleboliths) are noticeable to the touch: these are stigma of thrombosis.


When should you consult with a specialist?

Whenever a Venous Malformation affects critical areas like those close to the eyes, the face in general or the neck it is important to consult with a specialist as early as possible. Similarly when they are affecting the feet or hands. Moreover, the engagement of a specialist is fundamental if an internal organ is affected: intestines, liver or brain for instance. 


What are the possible complications?

Venous Malformations will grow slowly but progressively with age, with possible sudden growth periods, for instance in the event of a trombosis. There are various factors that can impact and accelerate growth, including an injury, hormonal changes (puberty, pregnancy, birth control pills) or the wrong surgical intervention in the area. Under agression or injury it is also common to see a Venous Malformation bleeding. In some rare cases there are associated coagulation problems.

The venous distension may cause aesthetic problems. Malformations affecting the brain or the intestines can generate spontanous bleedings of fatal consequences.

Depending on the area of the body affected, it is also possible to suffer breathing problems, visual impairment or general pain that can be a serious handicap. 


How are they diagnosed?

The patient's history and physical examination are usually sufficient to diagnose a Venous Malformation. Their blue color is typical. Venous malformations are usually painful, especially in the morning at sunrise or if they are the subject of trauma or injury. 

Color Doppler and MRI are both relevant examinations to confirm the diagnostic. A CT scan (scanner) can also be helpful. Venous malformations of the digestive tract are diagnosed by endoscopy: the endoscope (flexible tube with a light beam from optical fiber or a camera) is, depending on the location of the lesion, introduced into the mouth or the rectum.


What are the possible treatments?

The treatment for asymptomatic venous malformations will typically be conservative in nature, in order to contain the evolution. In the case where the VM affects the upper or lower limbs, wearing a suitable elastic support for compression may be very beneficial. It appears that a low-dose of aspirin seems to minimize phlébothromboses, commonly called phlebitis. 

In case of severe pain, or when there is a functional or serious aesthetic damage the most appropriate treatment is sclerotherapy. This procedure involves injecting a sclerosing solution that reduces the size of the abnormal veins; it is performed by an interventional radiologist. It may require several sessions, with an interval of 1 to 3 months between each.

It is conceivable to resort to surgery (resection) when sclerotherapy is ineffective or to repair aesthetic issues. In very superficial forms of malformations, the laser treatment may also be effective.

In addition, recent findings also demonstrated the efficacy of a drug (rapamycin) in the treatment of some Venous Malformations, see the press release of the Vascular Malformation Center of Saint-Luc for details. 


What are the associated Syndromes

The Syndrome Blue Rubber Bleb Naevus (also called Bean's Syndrome) consists of multiple malformations of the skin and internal organs. The size of these blue and rubbery lesions varies: the size of a pinhead to several centimeters in diameter. They may be located in the trunk and limbs, as well as in the gastrointestinal tract: they can cause bleeding and anemia. The lesions tend to grow and multiply over time and can be very painful.

The Maffucci Syndrome is a sporadic disease that combines skin nodules considered venous and multiple enchondromas (benign bone tumors). Enchondromas develop during childhood and cause deformities due to abnormal bone development. They can develop into malignant bone tumors. The diagnosis is made with clinical examination and conventional radiographs.

The Glomangiomatose Bailey (or multiple glomangiomatose) is disseminated venous dysplasia, delimited by bluish masses resembling syndrome Bean but are firmer to the touch. It's not a tumor but a skin lesion that resembles a malformation. This type of injury causes severe pain. Its location is not deep in contrast Syndrome Bean.