Sympathectomy
Author/s: Laurie L. Barclay
Definition of Sympathectomy
Sympathectomy is a surgical procedure that destroys nerves in the sympathetic nervous
system. The procedure is done to increase blood flow and decrease long-term pain in
certain diseases that cause narrowed blood vessels. It can also be used to decrease
excessive sweating. This surgical procedure cuts or destroys the sympathetic ganglia,
collections of nerve cell bodies in clusters along the thoracic or lumbar spinal cord.
Purpose of Sympathectomy
The autonomic nervous system that controls unwilled (involuntary) body functions, such
as breathing, sweating, and blood pressure, are divided into the sympathetic and the
parasympathetic nervous systems. The sympathetic nervous system speeds the heart rate,
narrows (constricts) blood vessels, and raises blood pressure. Blood pressure is
controlled by means of nerve cells that run through sheaths around the arteries. The
sympathetic nervous system can be described as the "fight or flight" system
because it allows us to respond to danger by fighting off an attacker or by running away.
When danger threatens, the sympathetic nervous system increases heart and respiratory
rate, increases blood flow to muscles, and decreases blood flow to other areas, such as
skin, digestive tract, and limb veins. The net effect is an increase in blood pressure.
Sympathectomy is performed to relieve intermittent constricting of blood vessels
(ischemia) when the fingers, toes, ears, or nose are exposed to cold (Raynaud's
phenomenon). In Raynaud's phenomenon, the affected extremities turn white, then blue, and
red as the blood supply is cut off. The color changes are accompanied by numbness,
tingling, burning, and pain. Normal color and feeling are restored when heat is applied.
The condition sometimes occurs without direct cause but it is more often caused by an
underlying medical condition, such as rheumatoid arthritis. Sympathectomy is usually less
effective when Raynaud's is caused by an underlying medical condition. Narrowed blood
vessels in the legs that cause painful cramping (claudication) are also treated with
sympathectomy.
Sympathectomy may be helpful in treating reflex sympathetic dystrophy (RSD), a
condition that sometimes develops after injury. In RSD, the affected limb is painful
(causalgia) and swollen. The color, temperature, and texture of the skin change. These
symptoms are related to prolonged and excessive activity of the sympathetic nervous
system.
Because sweating is controlled by the sympathetic nervous system, sympathectomy is also
effective in treating excessive sweating (hyperhidrosis) of the palms, armpits, or face.
Precautions
To determine whether sympathectomy is needed, a reversible block of the affected nerve
cell (ganglion) should be done. A reversible ganglion block interrupts nerve impulses by
means of steroid and anesthetic injected into it. If the block has a positive effect on
pain and blood flow in the affected area, the sympathectomy will probably be helpful. The
surgical procedure should be performed only if conservative treatment has not worked.
Conservative treatment includes avoiding exposure to stress and cold, physical therapy,
and medications.
Sympathectomy is most likely to be effective in relieving the pain of reflex
sympathetic dystrophy if it is done soon after the injury occurs. However, increased
benefit from early surgery should be balanced against time needed to promote spontaneous
recovery and response to conservative treatment.
Description
Sympathectomy was traditionally done as an inpatient surgical procedure under general
anesthesia. An incision was made on the mid-back, exposing the ganglia to be cut. Recent
techniques are less invasive and may be done under local anesthesia and as outpatient
surgery. If only one arm or leg is affected, it may be treated with a percutaneous
radiofrequency technique. In this technique, the surgeon locates the ganglia by a
combination of x ray and electrical stimulation. The ganglia are destroyed by applying
radio waves through electrodes on the skin.
Sympathectomy for hyperhidrosis can be done by making a small incision under the armpit
and introducing air into the chest cavity. The surgeon inserts a fiber optic tube
(endoscope) that projects an image of the operation on a video screen. The ganglia can
then be cut with fine scissors attached to the endoscope. Laser beams can also be used to
destroy the ganglia.
Preparation
As with any surgery, patients should discuss expected results and possible risks with
their surgeons. They should tell their surgeons all medications they are taking and all
their medical problems, and they should be in good general health. To improve general
health, the patient may be asked to lose weight, give up smoking or alcohol, and get the
proper sleep, diet, and exercise. Immediately before the surgery, patients will not be
permitted to eat or drink, and the surgical site will be cleaned and scrubbed.
Aftercare
The surgeon will inform the patient about specific aftercare needed for the technique
used. Doppler ultrasonography, a test using sound waves to measure blood flow, can help to
determine whether sympathectomy has had a positive result.
Risks
Side effects of sympathectomy may include decreased blood pressure while standing,
which may cause fainting spells. After sympathectomy in men, semen is sometimes ejaculated
into the bladder, which may impair fertility. After a sympathectomy done by inserting an
endoscope in the chest cavity, patients may experience chest pain with deep breathing.
This problem usually disappears within two weeks. They may also experience pneumothorax
(air in the chest cavity).
In 30% of cases, surgery for hyperhidrosis may cause increased sweating on the chest.
In 2% of cases, this surgery causes increased sweating in other areas, including increased
facial sweating while eating. Other complications occur less frequently. These
complications include Horner's syndrome, a condition of the nervous system that causes the
pupil of the eye to close, the eyelid to droop, and sweating to decrease on one side of
the face. Other rare complications are nasal blockage and pain of the nerves supplying the
skin between the ribs.
Normal results
Some studies report that sympathectomy relieves causalgia in as many as 75% of cases.
The studies also show that it relieves hyperhidrosis in more than 90% of cases. The less
invasive procedures cause very little scarring. Most patients stay in hospital for less
than one day and return to work within the week. |
