Vascular Malformations - Treatment
The type and extent of treatment for
a vascular malformation depends on three
things: the type of lesion, the location of the lesion, and it's depth. Generally,
a superficial lesion can be treated with a laser and the size of the vessels determines which
laser is appropriate. For small vessels, a flashlamp pumped dye laser
is used (pulse dye laser, tunable dye laser). For intermediate vessels,
a laser with a longer exposure time (copper vapor or KTP laser) works
best. Very large vessels call for a continuous wave Nd:YAG laser.
Since lasers can't penetrate very deeply
(less than 1-3mm), deep lesions need to
be surgically removed. Since these are vascular lesions and blood loss is a potential
hazard, they were previously considered extremely dangerous and usually inoperable.
Recent advances in technology makes treatment of these lesions possible. The excision
can be done with an electrically-heated scalpel, called a thermoscalpel,
or with contact laser surgery. The heat from these instruments seals some
of the vessels and helps control bleeding. The surgeon should however
have extensive experience in this type of surgery since despite these
advances, this type of surgery is difficult.
Compound lesions should be initially
treated with a laser to remove the superficial
component and then followed with surgical removal for the deep component.
One, two, or even three laser treatments, spaced six weeks apart, may be necessary.
Laser surgery is almost always done before surgical removal so that there is more skin
available for reconstruction. Surgical removal of the deep component should
follow 6-to-8 weeks after laser surgery is completed.
Venular Malformations (Portwine Stains):
Since, portwine stains are superficial lesions, laser treatment forms
the mainstay of treatment. Portwine stains in certain locations respond
better than others. Facial lesions on the sides of the face and neck seem
to respond the best. Upper lip lesions, lower arm, and leg lesions respond
With cobblestone formation, due to the
larger size of the vessels, these types of
portwine stains will require more thermal energy to destroy the blood vessels.
Unfortunately, the risk of scarring increases. The type of laser used will depend on the physician
treating the lesion. It's best to avoid continuous wave lasers such as
the Argon laser or the Argon dye laser or the Krypton laser, since it's
more difficult to prevent scarring with these lasers and the surgeon needs
a considerable amount of experience in their use. Currently, only a few
surgeons have extensive experience with these lasers. The lasers we generally
recommend are the copper vapor, or frequency doubled Nd:YAG (KTP or KDP)
laser with robotic scanner. The use of a scanner is essential.
The intervals between treatments and
the number of treatments necessary is controversial.
As long as the lesion continues to fade, treatment should continue. An average of 6 to 8 treatments
are usually necessary but up to 20 treatments may be required for maximal
fading. The portwine stain will continue to fade for six months and, in
some patients, for up to a year after a single treatment. Unfortunately,
it's common for the portwine stain to recur after several years. Once
the lesion is reduced as much as possible, a touch-up treatment can be
done when the lesion becomes noticeable again.
Most agree that between 15% and 20% of
all lesions respond completely to treatment.
A further 60% will lighten considerably with treatment and the remaining 20% will lighten only slightly
or not at all.
In general, the risk of permanent complications
from laser treatment is low and
considered safe. Only 5 percent of patients have reported some form of complication from the flashlamp pumped dye
laser.These include a whitening of the skin (hypopigmentation), a temporary
darkening of the skin (hyperpigmentation), and thinning of the skin (atrophic
scarring). Less than 1 percent have hypertrophic scarring (thick scar).
The complications seen with the other types of lasers are similar, but
the incidence of scarring is probably a little higher. The rate of complications
may also vary from surgeon to surgeon, depending on his or her experience
with the laser.
The use of anesthesia during the treatment
of children with portwine stains remains controversial. Some surgeons
believe that treatment has been rendered virtually painless with the use
of topical anesthetic creams such as Emla, making general anesthesia unnecessary.
Other surgeons, including ourselves, prefer to use general anesthesia.
The risks of general anesthesia in a healthy child is extremely low and
the laser procedure is considerably more painful than we acknowledge.
There are other advantages to general anesthesia:
- It's less costly and more convenient. Since you can treat the entire lesion
at the same time, it eliminates multiple, successive surgeries and their
related costs. <br>
- It's a more humane way of administering treatment. Even with Emla or local
anesthesia, the child may not tolerate more than a short period of treatment.
- The treatment is much more painful than originally thought, and the trauma
for the child is considerable, especially when many treatments are required
over a number of years.
Midline Venular Malformations
Fifty percent of all midline venular malformations will disappear spontaneously
within the first few years of life. If it does not disappear and the child
has some other elective procedure such as the insertion of tubes or a
tonsillectomy, it's not unreasonable to treat this lesion with a flashlamp
pumped dye laser. Since the vessels are very small, a low power setting
on the laser is used and the risk of complications is extremely low. The
lesion will usually respond to one or two treatments and almost all of
these lesions disappear completely with treatment. Unlike venular malformations,
these are unlikely to return.
Generally, the type of treatment will depend on the depth of the lesion,
its location, and its extent of involvement A superficial venous malformation,
or the superficial component of a compound venous malformation should
be treated with a Nd:YAG laser since the vessels that make up a venous
malformation are generally large. This laser, more than any of the others
has the highest risk of complications. However, in experienced hands,
it's a safe and effective laser. Generally, 2 or sometimes 3 lasers treatments,
6-8 weeks apart, are necessary.
Immediately after treatment, the area
swells considerably but this resolves within 5-6 days with little or no
pain. Complications include whitening of the skin, (hypopigmentation),
temporary darkening of the skin (hyperpigmentation), and scarring.
Remember, laser treatment only takes
care of the superficial component. A lesion with a deep component therefore
needs to be surgically removed. Venous malformations are the most difficult
to remove. They involve large areas of tissue and bleed more than any
other lesion during surgery, since they are made up of a large number
of dilated vessels with very thin walls. It may also be necessary to sacrifice
certain structures such as muscle and skin since they are frequently involved.
A thermoscalpel is used to remove this type of lesion to minimize the
risk of bleeding and here, more than with any other type of lesion, it's
important that the surgeon be skilled in the removal of this type of lesion.
Sclerotherapy is very useful, especially
in very extensive lesions or in lesions involving limbs. It's important
to have a skilled interventional radiologist do the procedure since many
complications may result. Multiple treatments are often necessary and
the results vary depending on the skill of the radiologist. Since one
can't cure the lesion with this technique, our intention is to control
it with interventional radiology.
Arteriovenous malformations are difficult to manage since the risks of
recurrence are extremely high. Before treatment, it's important to determine
the location of the core and its extent. Three tests can provide this
information: a conventional MRI, a MRA (magnetic resonance angiogram),
or a special angiogram (digital subtraction angiogram).
Definitive treatment involves surgical
removal of the entire core of the lesion. With localized lesions this
is possible and should result in a cure.With more extensive lesions complete
removal becomes much more difficult if not impossible. In these cases,
embolization, with or without surgery, should be considered. The surgeon
can block (embolize) the blood supply of the arteriovenous malformation
before surgery by injecting foreign particles such as gel foam, or PVA
(polyvinyl alcohol) This procedure is done 24 to 48 hours before surgery
to help reduce bleeding during surgery. If the excision is complete, the
lesion shouldn't recur. If the affected overlying skin is not removed
the lesion is likely to recur. If the core of the lesion isn't removed
entirely, it unfortunately recurs. It's best to treat these lesions as
early as possible and completely remove them since at this stage the core
is much smaller and more easily identifiable, making the chances of success
greater. Occasionally, one is not able to completely remove the core,
either due to the fact that it is too extensive, or technically not possible.
In these cases, embolization may control the lesion and alleviate the
symptoms for a period of time. However, since this is not likely to be
complete, the lesion will eventually recur.
Lymphatic malformations that involve superficial structures, such as the
inside of the mouth, the tongue, and skin may only need laser treatment.
Since these vesicles are usually connected to deeper vessels, if a laser
is used, the lesion should be vaporized all the way through to the deeper
vesicles to completely remove it. Recurrence is frequent, and several
treatments may be necessary since it's difficult to reach all of the deeper
vesicles. Superficial mucosal lesions and lesions on the tongue can be
vaporized with the C02 laser with good results but may have to be repeated.
With deep-seated lymphatic lesions , surgical removal works best. This
can however be extremely difficult since it is difficult to appreciate
the full extent of the lesion at surgery.
The type of treatment necessary for mixed malformations depend on the
various vessels involved.