| Facial
Venous Malformations (cavernous
hemangioma) |
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| Extremity
Venous Malformations (cavernous hemangioma) |
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Venous malformations (cavernous hemangiomas)
are the most common symptomatic vascular
malformations (birthmark). These common
birthmarks usually become symptomatic in older
children or young adults, with bluish skin
discoloration, local swelling, and pain.
The
characteristic physical finding of this
vascular birthmark is a soft and easily
compressible soft-tissue mass (or swelling)
that is associated with bluish skin
discoloration. Increasing engorgement with
dependency is typical. These birthmarks can be
small and localized or extensive and involve
the entire extremity or body part.
Do
venous malformations cause any health problems
?. Although
venous malformations are considered benign
entities, some extensive venous malformations
can result in significant morbidity,
particularly those in the head and neck (eg,
airway involvement). Some of large head and
neck venous malformations are associated with
sinus pericranii and developmental
intracranial venous anomalies. Large
pharyngeal, laryngeal, and deep cervical-oropharyngeal
venous malformations can expand to compress
the airway and cause significant deviation
that requires tracheostomy in most cases.
Extremity venous malformations may be
associated with a limb-length discrepancy,
particularly if the malformation is large.
Bone venous malformations can cause structural
weakening of the osseous shaft and pathologic
fractures. Involvement of a joint by a venous
malformation may result in
hemosiderin-arthropathy due to repeated
intraarticular bleeding, which is typically
seen in the knee. Venous malformations
of the gastrointestinal tract most commonly
cause chronic bleeding and anemia. Lesions
that involve the foregut can be associated
with portal venous anomalies (absence of the
portal vein, portal hypertension, etc).
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Are venous malformations familial
Conditions? Most venous malformations are
not familial conditions. However, a rare form of
venous malformation (birthmark) called "Glomangioma"
or "Glomovenous malformation" is an
autosomal dominant disorder that is
characterized by multiple, often tender, blue
nodular skin venous malformations. Familial
cutaneous mucosal venous malformation is another
familial but rarely seen condition which is also
associated with multiple venous malformations.
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Glomovenous
malformation (arm) |
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How
can venous malformations be diagnosed?. The
diagnosis of a venous malformation (vascular
birthmark) is usually straightforward at
clinical examination, although indeterminate
lesions are usually confirmed with imaging
studies. Imaging is also used to assess the
extent of the abnormality, as well as possible
associated abnormalities. The most typical
radiographic finding is a soft-tissue mass or
prominence containing phleboliths (small
calcifications). Bone changes are seen in some
cases. Ideal diagnostic test is MRI. Aside from
a small percentage of venous malformations,
high-flow vascular signal voids and flow-related
enhancement are not features of venous
malformations. Fluid-fluid levels may rarely be
present, although these are more suggestive of a
low-flow vascular anomaly with a lymphatic
origin (eg, lymphatic malformation). Venous
malformations are high-signal intensity lesions
on T2-weighted images and low-signal intensity
lesions on T1-weighted MRI; they have lobulated
margins and multiple, rounded, signal voids that
represent phleboliths. Phleboliths are usually
better demonstrated on plain radiographs or CT
scans.
Venous malformations may involve only the
skin, or they can extend into the muscles,
joints, and bone (similar to any other
birthmark). Prominent or dysplastic draining
veins may be identified with either MRI or
direct intralesional contrast agent injections.
Enhancement of the abnormal vascular channels is
typically seen on MRI after the intravenous
administration of gadolinium based contrast
material. The contrast enhancement pattern
allows the differentiation of venous
malformations from other low-flow anomalies,
particularly lymphaticmalformations (enhancement
is more patchy and central in venous
malformations, whereas no enhancement or minimal
peripheral enhancement is seen in lymphatic
malformations).
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In the head and neck, venous malformations
should also be differentiated from brachial
cleft cysts, foregut duplication cysts, and
thyroglossal duct cysts. If a venous
malformation
(cavernous hemangioma) involves a joint, the
joint is best assessed with MRI, in terms of
articular cartilage damage. The compartment
syndrome is a particular concern after
sclerotherapy in the extremity venous
malformations. Therefore, the determination of
the precise anatomic relationship between the
venous malformation and the neurovascular bundles
is mandatory on MRI. If a cervicofacial venous
malformation (cavernous hemangioma) is found,
the patient should be assessed for the
possibility of sinus pericranii, which may be
best performed with carotid arteriography and/or
direct intralesional injections of the contrast
agent. Although the demonstration of such a
sinus has been reported with MRA, conventional
angiography (digital subtraction angiography [DSA])
is usually required for complete evaluation of
the intracranial circulation.
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1st MR image shows an extensive venous
malformation ("cavernous hemangioma"
in the leg (bright signals). Post-contrast MR angiography
(2nd image) of the lower
extremities after IV administration of
gadolinium demonstrates a large area of contrast
opacification in the left thigh with patent
appearing normal deep veins. It is important to
image in multiple phases after intravenous
contrast injection to see in various
opacification phases in these patients to
evaluate these lesions fully. Conventional
arteriograpies usually do not show the
malformation or demonstrate a subtle late
contrast filling in most patients.
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The diagnosis of a gastrointestinal venous
malformation (gastrointestinal vascular
birthmark) is problematic. Because MRI is not
sensitive enough to depict small
gastrointestinal venous malformations,
endoscopic examination of the gastrointestinal
system is usually required. Patients with large
intraabdominal venous malformations should also
be examined to rule out portal hypertension.
When a patient presents with gastrointestinal
bleeding and when BRBNS is suspected, the
presence of characteristic cutaneous vascular
lesions (soft, blue, sometimes nodular lesions)
should be assessed. Angiography may be necessary
if the diagnosis remains in doubt or when
associated anomalies, such as sinus pericranii
or small arteriovenous fistulas
(AVFs), are
suspected. The venous channels are usually
faintly filled-in on venous-phase angiograms.
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Varicoid form venous malformation
(low flow vascular birthmark) in the calf. T2
weighted coronal image (image#1)
demonstrates bright T2 signal abnormalities
representing venous varicose veins extending
into the muscles. Contrast enhanced MR
angiography was performed in this case in
multiple phases. 1st phase image (image#2)
shows leg runoff arteries (tibial arteries) and
relatively early opacification of the venous
birthmark. Delayed phase MRA shows progressive
filling of the malformation with contrast
material and also draining tibial
veins. |
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Do Venous Malformations cause bone
deformities?
Venous malformations may cause changes in the
bones depending on the size of the lesion, as
well as the degree of direct contact with the
bony structures. This radiographic image (1st
image) shows
multiple small calcifications (phleboliths),
associated with osseous deformities involving the radius
and ulna. The ulna is deformed and
shortened. Increased soft tissue densities are
seen representing soft tissue low-flow
malformations.
Sagittal MRI of the knee
(2nd image) demonstrates
significant joint surface irregularity and
increased joint effusion in a patient with a
venous malformation (slow-flow vascular
birthmark) in the knee. Chronic bleeding into
the joint may cause significant joint damage in
some patients and may require aggressive
approach to eliminate this sequela.
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Treatment?
Treatment options for patients with venous
malformation or "cavernous hemangioma"
include:
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1-
Sclerotherapy
Sclerotherapy
is generally considered less invasive and more
effective treatment modality. Most patients (approximately 60-80%)
benefit from sclerotherapy. Please click the
subtitle to read more about sclerotherapy
procedure.
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2- Surgery. Surgical excision
should only be considered for superficial small
lesions. Attempts to excise large venous
malformations usually cause significant
morbidity and also cause significant scar
formation (see the photo, venous
malformation of the chest wall following
failed surgical attempts). Therefore,
surgical excision should be used for
lesions that do not involve significant
muscle groups or bones and should only be
performed by an experienced surgeon. On
the other hand, despite successful removal
in many cases, most lesions recur
after surgery. |
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3- Radiofrequency
ablation:
Radiofrequency ablation for treatment of
symptomatic low-flow vascular
malformations is recently published by van
der Linden et al (JVIR 2005;16:747-750):
In this report, total 3 patients (all
reportedly diagnosed with capillary venous
malformation, all in the lower
extremities) were treated with
radiofrequency ablation. The paper
reported no complications. All patients
were reported to be treated successfully,
although one patient became symptomatic
after a year. Radiofrequency
ablation is commonly used for cancers of
the liver, kidneys, lung and bone.
However, I believe that radiofrequency
ablation may also be a therapeutic option
for patients who are not good surgical or
sclerotherapy candidates or for patients
with failed sclerotherapy and/or
surgery.
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