Percutaneous Discectomy (PLDD, LASE, Nucleoplasty)
This is a generic description of a variety of different minimally invasive techniques used to decompress a herniated disc as an alternative to an open surgical procedure. Typically these procedures are performed through a needle or a very small cannula and do not involve a significant incision of the skin. There are multiple different surgical techniques which have been described for percutaneous discectomy. Percutaneous Laser Disc Decompression (PLDD) is one of the minimally invasive surgical approaches for removal of a disc herniation. This treatment involves the placement of a cannula into a damaged disc and through it tissue is removed. The cannula is a small tube, similar to a straw that houses the tools needed to fix the disc. These tools can include a means of seeing inside the disc, as well as the tools used to remove the disc materiel. The basic idea behind this treatment is that by removing a small amount of tissue from the inside of the disc we can reduce the internal pressure within the disc, thereby decreasing the force pushing the disc material through the defect or weakened portion of the disc outer wall. .
Annuloplasty is a generic description for repair of the outer wall of the disc which can be damaged from trauma or degeneration. IDET is one potential approach, but there are a number of other modalities today that may potentially repair the outer wall of the disc. Some physicians have experimented with the use of PRP injections and others are working with the injection of natural sealants to repair the outer wall of the disc. Annuloplasty does not address the increased pressure within the disc, which can result in a disc herniation or re-tearing of the disc wall.
Intradiscal Electrothermal Annuloplasty (IDET)
IDET or intradiscal electrothermal annuloplasty is used to treat tear in the outer wall of a disc. When a disc tears, some of the fluid or disc material can leak out and irritate the nerves in your spine. This fluid can cause inflammation and thereby pain. To control the pain the tear needs to be sealed so the irritant is once again contained within your disc. In addition, when the disc tears, small blood vessels and more importantly nerves begin to grow in and around the tear, causing the back pain associated with this condition. This treatment, which is an alternative to open back surgery, involves the insertion of a needle into the center of the disc. We use the needle to introduce a coil that is steered to the location of the tear. A small section of this coil or wire can be heated using radiofrequency energy. Heating of the outer wall of the disc causes controlled scarring, which will seal the tear in your disc. The heating of the disc may also destroy the nerve endings that your body grew into the tear. In general the results with IDET have been good in properly selected patients. One of the major benefits to this procedure is that if it doesn’t work, you still have the option of open back surgery.
Unfortunately this therapy has been often misused and therefore many physicians do not believe in its effectiveness. Instead of only offering the treatment to patients who fit the strict criteria, patients were given this option even when they weren’t ideal candidates.
Patients who have both a disc herniation and an annular tear typically require treatment of both portions of this injury for an optimal outcome. Dr. Kloth feels strongly that to prevent the disc from re-tearing, any coexisting disc herniation should be removed to reduce the pressure on the outer wall of the disc. In addition, once the disc herniation is decompressed, using a percutaneous discectomy approach, strengthening of the outer wall with IDET, can help prevent re-herniation or recurrent injury of the disc. Combining these minimally invasive procedures can treat both the patient’s herniated disc and annular tear, and thereby enhance the results of each treatment.
Minimally Invasive Lumbar Decompression (MILD)
Minimally Invasive Lumbar Decompression is used to treat a painful condition called spinal stenosis. Spinal stenosis describes a condition of when there is narrowing of the spinal canal which can cause pain in the back and lower extremities. Traditional decompression of this stenosis via an open surgical technique can lead to instability of the spine. This instability must be fixed by performing a surgery known as a fusion (often these two open surgeries are performed simultaneously with markedly increased risks). Minimally invasive lumbar decompression was invented to provide a more conservative, less invasive approach for decompression of spinal stenosis. The MILD procedure removes overgrown ligament in the back of the spine (which is called the ligamentum flavum), and to a lesser degree, overgrown bone. This procedure does not aim to treat all of the damage seen at that spinal level but is instead meant to provide just enough decompression of the stenotic area to decrease the chronic pain that these patients suffer from. By limiting what is removed from the area, the risk of instability is minimized and patients are hopefully able to avoid more invasive fusion surgery. Studies to date have shown good results with very low risk.
Spinal Cord Stimulation
Spinal cord stimulation involves the placement of small leads (or catheter with metal contacts) into the epidural space to electrically stimulate the nerves within the spinal cord. This does not cure the underlying injury but rather treats the pain associated with the injury. This treatment is typically reserved for patients who have undergone extensive treatment but are left with chronic pain. The goal of this therapy is to change the sensation the patient is feeling from a painful one to a soothing tingling sensation. It is a distraction therapy, giving the patient a different sensation to feel rather than the pain.
After your physician has determined that you are an appropriate candidate for this treatment, they will schedule you for a trial. A trial is required to determine the best position for the leads (at which spinal level) and to determine whether this therapy will result in symptomatic relief before the final implant is performed. During the trial the leads will be inserted and then attached to an external programmer (remote) that you will wear for the duration of the trial. The average trial lasts approximately 5-7 days, and during that period you will come into the office frequently for evaluation and when necessary, the stimulation pattern will be adjusted to provide optimum results. At the end of the trial period, the leads will be removed and you and Dr. Kloth will decide whether or not the trial was successful. In some cases, trial leads are sewn into position for later permanent implantation; this approach is typically used when a longer trial is desired.
If the trial is deemed a success, you will be scheduled for permanent implantation of the stimulator device. This will include implanting the leads and a generator. The trial, the removal of the trial leads, and the permanent implant are all typically done on an outpatient basis. Spinal cord stimulation is an effective treatment for many conditions including chronic radiculopathy, failed back syndrome, complex regional pain syndromes, and a variety of nerve injuries or other neuropathic pain conditions.
There are three major companies that produce spinal cord stimulators. For additional information on each company please see their websites.
Boston Scientific http://www.bostonscientific.com/us/patients/chronic-pain.html
St. Jude Medical http://www.poweroveryourpain.com/
Peripheral Nerve Stimulation
Peripheral nerve stimulation involves the stimulation of a peripheral nerve via a percutaneously inserted lead or a surgically implanted lead sewed directly to the nerve. The purpose, similar to spinal cord stimulation, is to replace the pain with a soothing tingling sensation. Peripheral nerve stimulation also requires a trial before permanent implantation. For more information, please see the section on Spinal Cord Stimulation.
Peripheral Nerve Field Stimulation
Peripheral nerve field stimulation is a relatively new technique and involves placement of stimulator leads into the subcutaneous tissue (just underneath the skin) to stimulate the distal nerve endings and provide a “field” of stimulation in the area of pain. Many patients find this to be highly effective and in fact for some conditions this appears to provide greater relief than traditional spinal cord stimulation (i.e. – groin pain). Peripheral nerve field stimulation is controversial because of the limited evidence associated with this therapy at this time. Peripheral nerve field stimulation also requires a trial before permanent implantation.
Spinal Drug Delivery Systems
Spinal drug delivery systems, otherwise known as intrathecal pumps (or more simply pumps), are implanted devices that deliver medications directly into the spinal fluid. Before undergoing a permanent implant of this device, patients must undergo a successful trial. Once the permanent pump is in place, patients will come to the office every 30-90 days for refills of the implanted device (depending on the medication and dosage).
The pumps major advantage is that by delivering medication directly into the spinal fluid, the patient receives a much lower dosage than is required orally and this is associated with lower side effects and improved pain control for many patients. These devices can be used for more severe and chronic forms of pain that do not respond to more conservative treatment. These pumps can also deliver spinal medications which helps to reduce the spasticity associated with multiple sclerosis, brain injury, or spinal cord injury. They are also extremely helpful in treating cancer pain.