Surgeons have known for a long time that a procedure called sympathectomy can treat excessive sweating in the hands and underarms.

Sympathectomy involves cauterizing (cutting and sealing) a portion of the sympathetic nerve chain that runs down the back inside the chest, parallel to the spine. This operation permanently interrupts the nerve signal that is causing the body to sweat excessively.

In the past, this was a complicated procedure because surgeons needed to make a major incision to reach the sympathetic chain. They either had to open the chest cavity or approach through the back, just below the neck. In either case, the risks related to major surgery generally were thought to outweigh any potential benefits. However, recent advances in visually-assisted endoscopic surgery have made it possible for surgeons to perform the procedure with only very small incisions—in fact, less than one inch each. Using a fiberoptic camera and small surgical instruments, the surgeon can locate and cut the right portion of the sympathetic chain in a relatively simple operation. 

The Procedure

Patients are placed under general anesthesia with their arms propped up at a 90-degree angle to the body. This provides access to the area just below the underarm, through which the operation is performed (see graphic above).

Starting on one side of the body, the anesthesiologist deflates the lung so that the surgeon will be able to get to the sympathetic nerve chain. He makes one or two small incisions underneath the armpit, usually between the second and third ribs.

A small camera device, or videoscope, is placed through the incision in order to see inside the chest and identify the sympathetic nerve chain. Through the scope, a cautery device to cut and seal the appropriate level, as determined in advance by the person’s symptoms, is placed. The incision is closed with sutures that will eventually dissolve on their own. The patient is usually released the same day, and usually can return to work or school within a few days.

Benefits and Risks

Patients with severe hyperhidrosis who have exhausted other medical treatments are finding that the surgery offers a permanent solution to their problem. In almost all cases, it cures excessive sweating in the hands and underarms, and many people experience the side benefit of decreased sweating in the feet. Moreover, the effect of the surgery is often immediate. Patients are often amazed when they wake up and find their hands warm and dry for the first time in years.

The risks associated with the procedure are minimal, but still need to be taken into account. Many people have reported experiencing side effects, either as a result of the procedure itself or from complications that may occur during the surgery.

These may include:

Compensatory Hyperhidrosis: This not not a complication per se but this is the most common side effect reported by people who undergo thoracoscopic sympathectomy. While they may no longer experience excessive sweating in their hands or underarms, they often notice that they sweat more in another part of the body, such as the chest, back, or legs. In effect, the body is "redirecting" the signal to sweat. This happens in up to half of patients who have the procedure — sometimes temporarily, sometimes permanently. However, most people report that they can cope with this to get the benefit of curing excessive sweating in the hands and underarms.

Gustatory Sweating: Although this is rare, some people experience increased sweating when they eat.

Horner’s Syndrome: Resulting from inadvertent damage to the highest nerves, this condition causes unilateral decreased facial sweating, drooping of the eyelid, and enlarged pupils. It is very rare and unlikely to happen when an experienced surgeon performs the procedure.

*Pneumothorax: Sometimes air or gas can collect in the chest cavity, which may cause the lung to collapse. In most cases, however, it does not pose a major problem and resolves itself spontaneously. Pneumothorax does prohibit someone from flying temporarily, which should be taken into account when travelling to a distant medical center for the procedure.

*Pain: Pain may be caused by the surgical instruments pressing on nerves along the ribs during surgery. Most people find that the pain is tolerable and resolves fairly quickly.

Even rarer complications are excessive bleeding and/or injury to the surrounding organs and tissues.

For most people, the benefits of the procedure far outweigh the risks. However, there are certain cases in which the surgery should not be performed. People who have severe heart and/or respiratory disease, a currently active infection, or extremely low heart rate may not be able to undergo thoracoscopic sympathectomy. Also, people who have had prior chest surgery generally are not good candidates.