Dorsal Root Entry Zone (DREZ) for Brachial Plexus Avulsion

What is Dorsal Root Entry Zone (DREZ)?

The DREZ procedure is an operation for patients who have pain that never seems to go away. This type of pain is often called chronic, intractable neuropathic pain. The DREZ procedure often produces a good effect for patients suffering from brachial plexus avulsion, sacral plexus avulsion, or spinal cord injury.

DREZ Dorsal Root Entry Zone

DREZ stands for dorsal root entry zone, which is the area of the spine where the surgery is performed. The dorsal root entry zone is the pain pathway to the brain. People feel pain when the pain signal passes from the part of the body that hurts to the brain along this dorsal root pathway.

The dorsal root is the sensory root of a spinal nerve and if this pain pathway is blocked, then the pain signal cannot reach the brain. In the DREZ procedure, this pathway is blocked deliberately to stop the pain signal from passing to the brain. The surgery interrupts the area where damaged nerves join the central nervous system, thereby interfering with inappropriate pain messages from nerves to the brain.

For example, if you cut your finger, the pain signal moves up a sensory nerve in your arm and across to your spinal column. Then it travels into your spinal cord through the dorsal root entry zone and finally into your brain. Only then do you feel the pain in your finger.

What is the goal?

The goal of a DREZ procedure is to relieve pain (by lesioning nerve cells of the spinal cord) that is unresponsive to medical treatment.

drez brachial plexus

What happens before surgery?

You will receive paperwork from Dr. Lad’s office with instructions and reminders regarding preparation to make before you have surgery. You will also have pre-anesthesia testing to make sure you are healthy enough to undergo the surgery. The anesthesiology team caring for you on the day of surgery will meet with you to review your medical history and answer any questions you may have. Dr. Lad will also visit you before the surgery to review the procedure and complete any necessary evaluations.

What happens during surgery?

A nurse will start your IV fluids and give you a medication to make sure you are comfortable. Once in the operating room, monitoring devices will be attached for your safety (blood pressure cuff, ECG, etc). In addition, the nerves that control strength are continuously monitored throughout the procedure to perform it as safely as possible. Dorsal Root Entry Zone requires general anesthesia which means this is done in the operating room with you completely asleep and the anesthesiologist monitoring you throughout the operation. During a DREZ lesioning, neurosurgeons create an opening in the bone and expose the spinal cord, a procedure called a laminectomy. The surgeon makes an incision in the spinal cord, locates the nucleus of the nerve using a surgical microscope, and then uses a radiofrequency current to interrupt the nerve signal. If it all goes well, the damage will stop the pain without causing dense numbness or injury to the nerve's motor function. This process is repeated at intervals along the spinal cord in the areas where the pain originates. Most patients experience relief of pain immediately after surgery and sustain good long term pain relief.

brachial plexus drez

What happens after Surgery?

Once the surgery is complete, you will be transferred to the recovery room. You will be closely monitored here by your anesthesiologist and specially trained nurses. Dr. Lad will then explain the results to your family in the waiting room and you will be transferred to the Intensive Care Unit.

Usually you will spend one night in the Intensive Care Unit (ICU). The following day you will be moved out of the ICU to a regular private room. On the first day after surgery, you will usually be allowed to get out of bed and have food and liquid. On the second or third day postoperatively, you will be discharged after you have been evaluated by physical therapy.

How do I take care of myself after surgery?

You will receive post-operative information from Dr. Lad’s office and from the Department of Surgery. Results of DREZ surgery, in terms of pain relief and incidence of complications, vary significantly from person to person. You will need to continue all preoperative pain medication. These will be slowly decreased by the physician who started them. Staples/sutures are removed 10 to 14 days after surgery. If you have any questions about what activities are safe or not safe, ask your surgeon.

What are the risks of surgery?

In up to 40% of operated patients, complications include changes in sensation observed in the lower part of the body, clumsiness and fatigue, and difficulty ambulating.

DREZ is an invasive procedure, and while safe in expert hands, does have potential rare/infrequent risks, including:

Cerebrospinal fluid leak
Stroke or hemorrhage (very rare)
Difficulty with balance

If at any time following your DREZ you notice:

Redness, swelling, drainage or foul odor from the surgical site
Excessive bleeding
Increase in pain at the surgical site
Fever of 101⁰F or higher with any of the above symptoms



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