Dorsal Root Entry Zone (DREZ) Lesioning

Dorsal root entry zone (DREZ) lesioning is surgery when a sensory nerve detaches from the spinal cord.

It is a treatment option when nonsurgical treatments have not worked to relieve nerve pain and other symptoms. DREZ lesioning destroys the area where damaged nerves join your central nervous system. This prevents pain messages from traveling from your nerves to your brain.

DREZ lesioning is an advanced pain management procedure. UPMC surgeons use the latest techniques to provide safe, effective care.

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What Is Dorsal Root Entry Zone (DREZ) Lesioning?

Dorsal root entry zone (DREZ) lesioning is a surgery used to treat pain coming from a sensory nerve. It is an option when nonsurgical treatments have not helped. It can relieve pain and other symptoms caused by a sensory nerve detaching from the spinal cord.

When sensory nerves get avulsed (torn away) from the spinal cord, it can cause abnormal pain sensations. DREZ lesioning destroys the area where damaged nerve fibers join your central nervous system — the dorsal root.

What is a dorsal root entry zone?

Sensory nerves carry sensory information from your body to your brain through the spinal cord. Your dorsal root entry zone is the part of the spinal cord where these nerves attach. They send sensory signals, which the spinal cord transmits to your brain.

What happens if the nerve is injured at the root entry zone?

When a nerve is injured or detached from the spinal cord, nerve cells can send abnormal signals to the brain, which sometimes interprets these signals as pain.

Conditions we treat with DREZ lesioning

Conditions that cause abnormal sensory signals and pain include:

• Brachial plexus avulsion
• Sacral plexus avulsion
• Spinal cord injury

Why Would I Need DREZ Lesioning?

If you have had an injury to your sensory nerves that is causing severe, debilitating nerve pain, your surgeon may recommend DREZ lesioning. 

Who is a candidate for DREZ lesioning?

If you are having severe, debilitating pain after a nerve injury, you may be a candidate for DREZ lesioning. It is an option if nonsurgical care has not helped relieve your pain.

However, DREZ lesioning is a complex procedure, so it is only appropriate for certain patients. Your doctor will let you know if you are a candidate for DREZ lesioning.

Alternatives to DREZ lesioning

Alternatives to DREZ lesioning include nonsurgical treatments, such as:

• Nerve blocks.
• Pain medicine.
• Steroid injections.

What Are the Risks and Complications of DREZ Lesioning?

As with any surgery, DREZ lesioning comes with some risks.

Possible complications include:

• Bleeding or infection at your incision site.
• Blood clots.
• Nerve damage.
• No improvement or a return of symptoms.
• Problems with anesthesia.

What Should I Expect from DREZ Lesioning?

Before: How to prepare for DREZ lesioning

Before surgery, you will meet with your surgical team and have a physical exam. Your surgical team will order testing for you to complete before surgery.

Presurgical tests often include:

• Blood or urine tests — These studies ensure you are healthy enough for surgery. They also check for signs of illness or infection.
• Electrocardiogram (ECG or EKG) — This test records the electrical activity of your heart. They show abnormal rhythms (arrhythmias or dysrhythmias) and can sometimes detect heart muscle damage. EKGs are often performed before surgery to check your heart health and identify potential problems.
• MRI — This diagnostic procedure combines large magnets, radio frequencies, and a computer to produce detailed images of organs and structures within your body. Before DREZ lesioning, your surgeon will order an MRI to precisely locate the damaged spinal nerve roots.
• X-ray — Your doctor may order an x-ray to learn more about the condition of the bones and tissues in your spine.

Before your procedure, your doctor will explain the process and answer your questions.

To prepare for the procedure, you should:

• Fast for a certain period before the procedure. Your doctor will tell you how long to fast (usually overnight).
• Have any tests that your doctor requires. For example, your doctor may request a blood test before the procedure to determine how long it takes your blood to clot.
• Tell your doctor if you are sensitive or allergic to medicine, iodine, latex, tape, or anesthetic agents (local and general).
• Tell your doctor about all medicines (prescription and over-the-counter) and herbal or other supplements you are taking.
• Tell your doctor if you have any other health issues. Your care team may need to take certain precautions during surgery for your safety.
• Tell your doctor if you have a history of bleeding disorders or if you are taking any medicines that affect blood clotting. You may need to stop some of the medicines before the procedure.

On the day of your procedure, bring your photo ID and health insurance card(s). Leave valuables such as cash and jewelry at home.

After your procedure, you will stay in the hospital for several nights. You should bring toiletries, a robe, slippers, a cell phone and charger, medicines, and a change of clothes. You should also arrange for someone to drive you home from the hospital after your care team discharges you.

How long does DREZ lesioning take?

DREZ lesioning is a complex procedure that requires a precise approach. It typically takes 5 to 7 hours but may take longer.

During your DREZ lesioning procedure

When you arrive at the hospital, you will meet with your care team for final preparations.

You will receive an IV and general anesthesia, so you will sleep through the procedure. Your anesthesiologist will make sure that you are comfortable and do not feel any pain.

After you are asleep, your surgeon will:

• Make an incision in your back to access your spine.
• Perform a procedure called a laminectomy to remove the back of your spinal bone (lamina) and expose your spinal cord.
• Open the membrane covering your spinal cord, called the dura.
• Use presurgical MRI images to find the dorsal root entry zone. They will identify where your nerves have detached from your spinal cord.
• Use radiofrequency energy to create precise lesions in the dorsal root entry zone. This destroys the nerve cells triggering pain signals and blocks the signals from getting to your brain.
• Create additional lesions in other areas of the spine where the pain originates. Depending on your health issue, your surgeon will create between 40 and 120 lesions. 

Throughout your procedure, your surgeon will monitor how well your spinal cord functions to reduce the risk of complications. 

After your procedure, your surgeon will close your incision and make sure your condition is stable.

Recovery after DREZ lesioning

After your procedure, the care team will monitor you in the recovery area as you wake up. You will need to spend several nights in the hospital. You will need someone to drive you home from the hospital after your care team discharges you.

Some people have severe pain soon after surgery. However, the pain tends to get better quickly. Your care team will help you manage discomfort during your hospital stay.

Before you go home, your doctor will tell you:

• How to care for your incision and watch for signs of infection or complications.
• What medicines you need to take.
• When or if you should begin physical therapy.
• When to call your doctor or 911 if you have certain symptoms.
• When you can return to your normal activities.
• Which movements are safe and which movements to avoid.

What is the recovery time after DREZ lesioning?

Because your surgery involves an incision that exposes your spinal cord, complete recovery typically takes several months. Your doctor will let you know when it is safe for you to resume normal activities.

When to call your doctor about post-op problems

You should let your surgeon know if you have:

• A fever of more than 100.0°F.
• Difficulty breathing.
• Difficulty with walking or keeping your balance.
• New or increasing shortness of breath.
• Numbness, tingling, pain, or weakness in your arms or legs.
• Pain, redness, bleeding, drainage, or increased swelling at your incision site.
• Severe pain that does not respond to medicine.

What is the prognosis after DREZ lesioning?

Although DREZ lesioning is not a cure for nerve damage, it can help to reduce or eliminate chronic pain. This helps restore quality of life and reduces your need for pain medicines and other treatments.

What is the success rate of DREZ lesioning?

Most patients experience pain relief shortly after surgery and sustain good pain relief for at least a year after the procedure.

Why Choose UPMC for DREZ Lesioning?

UPMC surgeons use the least invasive, most effective approach to treat all spinal nerve disorders. Our team has pioneered some of the latest approaches to DREZ lesioning. We use advanced devices and techniques — promoting safer surgeries, improved outcomes, and enhanced quality of life.

By UPMC Editorial Staff. Last reviewed on 2025-03-18 by John Moossy, MD.