Carpal Tunnel Decompression

This surgical procedure aims to relieve patient’s symptoms by taking away compression of the median nerve at the wrist. In the procedure, the flexor retinaculum which forms the roof of the carpal tunnel is divided to allow more room for the median nerve.

What are the types of surgical treatments available?

For a relatively simple procedure, there are a wide variety of techniques that are used to decompress the median nerve. All aim to divide the flexor retinaculum. Some use the endoscope, while others use large incisions. The following is a description of the technique used by Prof Owler. It is a common open technique that can be performed under local anaesthesia, although in most cases patients prefer a short general anaesthetic.

Related condition to carpal tunnel decompression

Carpal Tunnel Decompression

What is a day only procedure?

Except in some circumstances, the operation is performed as a day only procedure. A day only procedure does not involve an overnight admission. In most instances, it will be performed in the morning. The patient will need to come into hospital an hour or so prior to the surgery. They will be told the exact time by the hospital, usually on the day before the surgery. Patients need to ensure that if they have MRI scans then they should bring those with them when they come to hospital.

The patient is discharged a few hours after the surgery when the nursing staffs are satisfied. As they will have had a general anaesthetic and will have had an operation on their hand, the patient must not drive. They will need to make arrangements for transport to and from the hospital with a friend or relative.

How is a carpal tunnel decompression performed?

The site of the surgery is checked with the patient prior to the operation. The operation is usually performed under a short general anaesthetic. The region of the wrist is scrubbed and cleaned with antimicrobial solution. The incision is usually around 2-3cm in length and is made in the palm just below the wrist crease. The thickened connective tissue of the flexor retinaculum is then divided. It springs apart to reveal the median nerve. It is then important to check the region above and below the incision to check that the nerve is well decompressed in these areas.

After making sure that there is no bleeding, the wound is washed and then sutured together using interrupted nylon sutures. The wound is cleaned, and a dressing applied. The patient is then awoken from the anaesthetic and recovered.

What happens after surgery?

The patient is observed in the day stay suite before being discharged home. On discharge the patient is usually given a script for post-operative analgesic medications. The dressing should remain intact for 48 hours. After that time the dressings should be removed. The wound can be cleaned and can get wet but should not be soaked in a bath or pool for at least 2 weeks after surgery.

What are the risks of surgery?

carpal tunnel decompression surgery risk

While the operation is a relatively small operation, it still has risk. These include a risk of infection of the wound that can usually be simply treated with antibiotics. There is a small risk of wound haematoma formation.

The skin in this region is quite thick. Some people may have a thick or even painful scar. It may be possible to reduce scarring by gentle massage of the region (this should be avoided in the first week after surgery) and using some skin care creams to soften the skin.

The median nerve is on view at surgery and there is a risk of damaging the nerve leading to numbness and weakness. However, injury to the main nerve itself is exceedingly rare. A small branch of the nerve which may occasionally run in an unusual course may be more at risk of injury. This branch, called the recurrent motor branch of the median nerve, supplies some of the muscles that move the thumb. Injury to this branch, which is rare, can be a significant problem for the patient. The thumb and its strength are important for grip and therefore being unable to pick-up or grasp objects can be disabling for the patient. Therefore, although this is rare, patients should be aware of this potential complication.

As the operation is performed under a general anaesthetic, there is a small risk of complications related to the anaesthetic itself.

What are the chances of improvement after carpal tunnel surgery?

The outcome from the surgery is dependent on the pre-operative symptoms and their severity. Overall, more than 90% of patients will be very satisfied with the results of surgery. The remaining patients often have improvement, although sometimes this is not as much as is hoped for. There is a small percentage (1-2%) who may have more pain or numbness, or experience a complication that makes the patient feel worse than prior to the surgery.

Patients with mild to moderate symptoms will do best. These patients generally have paraesthesia and numbness that occur at night and during certain activities such as driving. These symptoms tend to resolve very quickly.

Patients with wasting and severe weakness of the thumb muscles do not do as well and will require more time and exercise to attempt to improve the strength in these muscles.

Patients who have constant numbness will also improve, although it is uncommon for numbness to resolve completely, and if it does resolve, it often takes a matter of months to do so.

What follow-up is required after surgery?

The sutures need to be removed 10-14 days after the surgery, and patients are asked to return to their GP for removal of the sutures. This also provides an opportunity for the wound to be reviewed by their doctor.

Patients are encouraged to return to see Prof Owler around 4-6 weeks after the surgery to ensure that the recovery is proceeding as planned and discuss any concerns. An appointment will be made for you shortly after the procedure has been performed.

Important Information

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