Implantable Pain Control Devices: The Inside Story

WebMD Live Events Transcript

When pain controls your life, implantable devices from nerve stimulators to intrathecal drug delivery systems can help conquer pain from within. Pain management expert Leo Kapural, MD, PhD, explained how these devices work, who can benefit from them, and more when he joined us on Dec. 9, 2004.

The opinions expressed herein are the guests' alone and have not been reviewed by a WebMD physician. If you have questions about your health, you should consult your personal physician. This event is meant for informational purposes only.

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MODERATOR:
Welcome to WebMD Live, Dr. Kapural. Thanks for joining us today. How long have implantable pain devices been in use?

KAPURAL:
They've been around for a relatively long time. I remember that a mentor of mine, Dr. Stanton Hicks, implanted one in 1981, but the design and the quality of those devices were not that great and the failure rate was incredibly higher. Over the last six years the devices became so well made that we are now very comfortable in implanting, especially spinal cord stimulating systems.

MODERATOR:
What are the primary types of implantable devices used to treat chronic pain?

KAPURAL:
There are two groups of implantable devices:

• Spinal cord and peripheral nerve stimulators, which use electric current to decrease the pain.
• Intrathecal and epidural subcutaneous devices, referred to as pumps.

MEMBER QUESTION:
How would you know you're a candidate for the implant? What qualifications are there or is it just up to the pain management doctor?

KAPURAL:
Well, there are certain pains that respond to stimulation, and some pains that do not. For example, acute pain following surgery would not respond to spinal cord stimulation. Inflammatory pains in general would not respond to spinal cord stimulation. On the other hand, if you have a pain from nerve injury, that in general responds to stimulation.

It's a different story with intrathecal devices, like the pumps, where a large range of those pains do respond to intrathecal infusion.

MODERATOR:
So how is the decision made to use one type instead of another?

KAPURAL:
On initial evaluation we examine the patient, look into all of the diagnostic evaluations done in the past, and then we come up with an idea of where the pain is coming from and then decide which way to go. In addition, a psychological evaluation is done to determine if the patient is fit to have an implantable device.

MEMBER QUESTION:
I am scheduled to have the temporary stimulator in my lower back tomorrow morning. What can I expect?

KAPURAL:
The temporary stimulation, or trial stimulation, determines if the electrical stimulation will be successful in treating your pain. Therefore when we implant the spinal cord stimulator with a temporary lead with a battery, we leave the patient home for seven to 14 days to try that device, and he has to report back to us on two different entities: pain relief and functional capacity, or how well they can do things.

So what you can expect tomorrow during the trial is the positioning of that device in your back and then after that you will be discharged from the outpatient setting and left for at least a week to try that stimulating device.

MEMBER QUESTION:
How long does the procedure take?

KAPURAL:
To position the lead for the trial takes only 20 to 40 minutes. To have a full implant after we find out the trial was successful takes about 2 hours. For the pump it's similar, about two hours for the whole procedure.

MODERATOR:
Is this why a trial run is done with a stimulator? Not just to place the leads but also to test for effectiveness?

KAPURAL:
Yes, exactly. The trial is essential to see how successful stimulation will be.

MODERATOR:
So a trial lasts seven to 14 days?

KAPURAL:
Trials should last at least seven days. The reason I do recommend a trial longer than seven days is that we can better assess improvement in functional capacity of the patients.

MODERATOR:
Is there any comparable trial for intrathecal drug delivery systems?

KAPURAL:
Yes, and we do it at the Cleveland Clinic inpatient, in the hospital. We place a temporary catheter in the patient's back and admit them for two or three days to adjust the level of medication delivered. When they have satisfactory pain relief, we pull the catheter out and send them home and set them up later for implant of the pump.

Chronic Pain: Implantable Pain Control Devices (cont.)

MODERATOR:
Can you explain how the stimulators are implanted?

KAPURAL:
The lead is positioned either by percutaneous approach or surgical approach. The percutaneous approach uses an epidural needle to position a tiny (like a hair), lead into the epidural space. That lead may have multiple electricals on it.

Once the lead is positioned in the epidural space, small cuts are made, less than one inch, in the middle of the back and about an inch and a half in the buttock area. This is where the battery will be positioned, or the generator. Later the generator and the lead are connected together with a connector extension under the skin.

During the procedure the patient is awakened and stimulation tried to make sure that they have perfect coverage of all of the painful areas, with what we call pleasurable tingling; that's the feeling they have from the stimulator.

Once everything is in place, both of those incisions are closed and patients stay for a short time in recovery and then go home.

"Over the last six years the devices became so well made that we are now very comfortable in implanting, especially spinal cord stimulating systems. "

MEMBER QUESTION:
Could such a device be used for the chronic pain of osteoarthritis?

KAPURAL:
Well, the electrical stimulation no, but the intrathecal pump, yes, it has been used before and it can be used in severe arthritis.

MEMBER QUESTION:
Are implantable devices appropriate for chronic migraines (daily pain that varies from dull to severe/throbbing)? Has an implantable device ever been used to prevent or abort chronic migraine attacks?

KAPURAL:
First of all, it has to be determined what types of headaches. If this is a classical migraine, my answer is no, but if you have a headache in the back of the head, occipital headaches, we do implant here at the Cleveland Clinic some of those peripheral nerve stimulators for headaches in the back of the head.

MEMBER QUESTION:
How effective are the spinal cord stimulators? If you insert them in 100 patients, how many will get significant improvement? I will have one inserted next month.

KAPURAL:
There are quite a few studies looking into the success rate of the spinal cord stimulation. It depends on what kind of disease the patients have, but studies from the Cleveland Clinic on RSD show a success rate of about 60 to 70 percent. On the other hand, if you have failed back surgery syndrome, the success rate is somewhat lower, in the range of 50 to 60 percent.

 

MODERATOR:
For those not familiar with these systems, can you please explain how they work?

KAPURAL:
The intrathecal pump is just a very expensive pump that slowly delivers concentrated morphine, local anesthetic, or other medication into the intrathecal space, which is nearby the spinal cord. By delivering those medications, the pain receptors in the spinal cord get blocked, therefore the pain subsides.

MODERATOR:
What is the advantage to this method of drug delivery?

KAPURAL:
The patients are frequently more awake, function better, receive much, much less systemic medication, and frequently they are more cost effective than oral or IV medication, in the long run, for severe chronic pain.

MEMBER QUESTION:
With people like me already taking a lot of painkillers, can we switch to the pump and not have withdrawal symptoms?

KAPURAL:
That's a good question. We develop a whole protocol for how we do this here at the Cleveland Clinic. The patient comes in and we transition them slowly to intrathecal infusion. That's not the major problem.

MEMBER QUESTION:
I have fibromyalgia combined with myofascial pain, which have made cysts in my joints and muscles. Are there any such devices that could benefit me? I am so sick of taking painkillers. I also cannot take the usual treatment for the fibro of antidepressants; I get a violent reaction. Are there better reactions to any drugs (anti-inflammatory) when dispersed through a pump?

KAPURAL:
It's possible, but we would have to look at all the diagnostic procedures that you have had up to now and examine you. Secondly, if it is effective, it may be effective for either of your conditions, and trials should be tried before implant. If you are already on a large amount of oral medications, you should see someone in interventional pain management.

MEMBER QUESTION:
Could someone with epidural fibrosis and degenerative disk disease benefit from these devices? I've been a chronic pain patient for over four years now and have had numerous nerve root blocks and most recently bilateral lumbar facet injections. They last about a month and then I'm back to eight or nine on the pain scale.

Chronic Pain: Implantable Pain Control Devices (cont.)

KAPURAL:
These are two groups of question. First, can someone that has degeneration of the disk and epidural fibrosis or scar tissue benefit from those devices, and my answer is yes. We have to look into the ratio of pain coming from the degenerative disk or the epidural adhesions. That can only be done during initial evaluation.

The second question was if you can get longer pain relief, and I understand you have had a series of injections. You can have something called facet radio frequency ablation, which should give you longer pain relief than a plain block.

MODERATOR:
What is radio frequency ablation?

KAPURAL:
This is just using a high-energy source around the tip of the radio frequency needle to ablate a small sensory nerve, which gives enervation to that particular facet.

MEMBER QUESTION:
I have had radio frequency ablation twice with no success. Will this determine if the stimulator will work?

KAPURAL:
No, unfortunately not. The initial evaluation and the trial will determine if the stimulator will work.

MEMBER QUESTION:
My pump has a kink in it. Should it be turned off or turned down until surgery? It is running at 6.552 mg/day.

KAPURAL:
It depends where the kink is. The physician who is managing the pump should determine where the kink is and if you are getting any medication. If he wants to he can convert you to oral medication until surgery and decide the next best appropriate approach during surgical procedure, because the kinks can be solved in several different ways during surgery.

MEMBER QUESTION:
I am in constant back pain, mostly sciatic right and left. I am thinking a pain pump inserted will help me. I can't take this pain much longer. I am taking Vicodin and now Percoset, which help, but I am woozy from it. How many times do they have to refill the pump if I get it? I hate taking strong pain medications and can't afford them either.

KAPURAL:
First, regarding the question about bilateral sciatica, the question is if stimulation is more appropriate than the pump. This should be decided during the trial.

Secondly, will you be better off with the pump than oral medications? Probably yes, if you require large amounts of oral medications.

MEMBER QUESTION:
I have just been diagnosed with arachnoiditis. I will be seeing a pain management doctor this month. Will a stimulator and/or morphine pump help with this problem?

KAPURAL:
Yes. A pump is more likely than the stimulator to help, if it's diffused arachnoiditis.

MEMBER QUESTION:
Is a stimulator out of the question for someone with a pacemaker?

KAPURAL:
It can be done. There are certain frequencies that we can adjust so that a stimulator can be used with a pacemaker.

MEMBER QUESTION:
How do doctors determine which medications are used in the pumps?

KAPURAL:
There's something called the panel of experts who came up with an algorithm for what to use first, second, third, and so on. We know from our clinical experience that certain medications are better for certain diseases and this is how we base our approach for intrathecal delivery systems.

MEMBER QUESTION:
Are there any side effects to internal devices like these? What risks are involved?

KAPURAL:
Any of the implantable devices that deals with either epidural or intrathecal space can possibly produce, as a complication: nerve damage, bleeding, infection, and possible headaches, which can last for relatively short time periods.

MEMBER QUESTION:
I believe doctors need to do a better job explaining the side effects; I have had nausea, bowel problems, and hallucinations since my pump was put in me in 2001.

KAPURAL:
I was referring before to the complications of the procedure itself. Continuous infusion of the pump should not produce long-term side effects. I'm saying this with relative confidence because we can do rotation in the pump, changing the medication to another medication that will not cause such a side effect. It's not necessary to have any side effects from the medication or the intrathecal pump. You should have either replacement or adjustment of the medication in your pump to some other medicine.

"Will you be better off with the pump than oral medications? Probably yes, if you require large amounts of oral medications."

MEMBER QUESTION:
I am currently a patient at a pain management clinic. About a year ago I received a microlaminectomy/discectomy L3-4, L5-S1, and revision of a prior fusion L4-5. I was then told that I would benefit from a spinal cord stimulator and had gotten approval from worker's comp for the spinal cord stimulator (SCS). The trial stimulator was placed and I got reasonable benefit from it. Now worker's comp says they will not approve the insertion of the permanent SCS because of spinal stenosis in the whole lumbar region. The reason was that there is no evidence that an SCS will help a person with spinal stenosis. I find this to be ridiculous since the trial worked. What are your opinions on this?

Chronic Pain: Implantable Pain Control Devices (cont.)

KAPURAL:
First of all, if you had significant benefit from the stimulator trial, that means more than 50 percent of pain relief, I would think you would benefit from spinal cord stimulation.

As far as the diagnoses are concerned, you may have several diagnoses regarding the MRI I just heard about, so spinal stenosis may be just one of them. I do not see the reason why you wouldn't get a spinal cord stimulator system if you had this response to it during the trial.

MEMBER QUESTION:
What is the life span of a stimulator?

KAPURAL:
The current systems have different life spans. Medtronic's synergy battery can last for about four to five years; on the other hand, Advanced Bionics' system came with rechargeable batteries, which may last a little bit longer and can be recharged every week. I heard that Medtronic is coming up with a new rechargeable battery that may last 10 years.

The battery is replaced by very simple replacement surgery that just involves opening the pocket, taking the old battery out and putting the new one in.

On the other hand, current programmable pumps last about five years.

MEMBER QUESTION:
How will I know when my battery needs replacing in my pump?

KAPURAL:
With the new pumps and the stimulators, when they are interrogated using our remote programmer, we can exactly see how much life is left in the stimulator or the pump battery. Alternatively, older pumps do ring with short beeps once the battery life is coming toward the end.

 

MEMBER QUESTION:
Can it be used for diabetics with back pain and neuropathy?

KAPURAL:
Yes. We feel that the spinal cord stimulation, particularly, is very helpful in diabetic neuropathy. In addition, they may have another benefit: better control of diabetes. We wrote about it this year in the journal Anesthesia Analgesia .

We have two theories why patients with type 2 diabetes would benefit. First, because spinal cord stimulation releases some molecules, like nitric oxide, which induce production of your own insulin. We also think that the stimulation decreases levels of substances that will increase the glucose in the circulation.

MEMBER QUESTION:
Does this device help sciatica pain also?

KAPURAL:
Sciatica is a term; it just describes the pain that goes down the legs to the feet. There can be numerous sources of the pain and that has to be evaluated in detail before any treatment is implemented.

MEMBER QUESTION:
How do the insurance companies feel about these devices?

KAPURAL:
Interestingly enough, we don't have any problems getting approval, either the spinal cord stimulators or the pumps.

"We do implant stimulators for severe chronic pelvic pain in the female population. These are the patients who had severe endometriosis for years, were operated on many, many times, with chronic pelvic pain ongoing. We found those patients do respond well to spinal cord stimulation."

MEMBER QUESTION:
I had a herniated disk, the biggest one my neurosurgeon had ever seen. While waiting for surgery I woke to my legs being useless. I was then sent immediately to surgery and the pain relief was a HUGE help but I still have pain and I lost a great deal of use of my right leg. There is so much more to this story but my main question is would I be eligible for this device and what would the cost be? I am now taking around 12 to 15 Advil a day and my doctor seems to think that's all I need.

KAPURAL:
It has to be determined if permanent nerve damage happened. Usually nerves do grow back to a certain degree, so if it was more than one year after surgery, you should be evaluated and then determine if you are a good candidate for any of those implantable devices. I'm thinking mostly stimulators here.

By the way, we do implant stimulators for severe chronic pelvic pain in the female population. These are the patients who had severe endometriosis for years, were operated on many, many times, with chronic pelvic pain ongoing. We found those patients do respond well to spinal cord stimulation.

MEMBER QUESTION:
I have syringomyelia with syrinx, rheumatoid arthritis, bulging discs, and herniated discs. Will all this pain be helped with this device?

KAPURAL:
You may be a better candidate for an intrathecal pump. However, you need to be evaluated by a qualified intervention pain physician to make this decision.

MEMBER QUESTION:
I heard the Cleveland Clinic has the best pain center in the country. Can I get in to see a doctor within a few weeks?

Chronic Pain: Implantable Pain Control Devices (cont.)

KAPURAL:
Yes. We changed our policies and we are trying to get a new evaluation in about a 10 to 15 day time period. We expanded the staff more recently and we are the largest pain management department in the country, and the largest educational fellowship. So yes, I think we can fit you in relatively early. The phone number is 216-444-PAIN.

MEMBER:
I'm moving to Cleveland!

MEMBER QUESTION:
Do you have a web site, and can I make an appointment online?

KAPURAL:
The web site is clevelandclinic.org. If you go to clevelandclinic.org/painmanagement you can get information on all the pain devices and the Cleveland Clinic physicians.

MEMBER QUESTION:
How can I find a pain specialist in my area of Reading, Pa., who is knowledgeable in intrathecal drug delivery devices?

KAPURAL:
There are a couple of sources where you can actually find a physician in the area. If you go to Medtronic or ANS, those are the two largest companies who make the stimulators and pumps. They have a list of physicians who are implanting their devices.

MEMBER QUESTION:
I saw a Medical Miracles tape about pain management. Can I get a copy of it? Who can I call?

KAPURAL:
This was produced by the local TV station, and they looked into certain advanced procedures in all kinds of medical branches. That was produced about a year ago. That tape can be acquired for free by calling the same number I mentioned: 216-444-PAIN.

MODERATOR:
What is new for pain or coming in the near future?

KAPURAL:
We are looking into other types of electrical stimulation these days and at the Cleveland Clinic, as I mentioned before, we try to treat occipital neuralgias as well as other peripheral nerve injuries using different types of implantable electrical stimulation devices. So over the last several years, we increased the number of indications for spinal cord stimulation and peripheral nerve stimulation.

MEMBER QUESTION:
Do you have a conference for physicians to attend, where they can learn more about pain management?

KAPURAL:
Yes. If the physician is in internal medicine, rehabilitation, or primary care, we do have our conference for internal medicine and primary care physicians, which is every summer here in Cleveland. For the interventional pain management physicians, a workshop and conference is held every February in Orlando, Fla. It has become the best pain management interventional workshop and symposium in the world.

MEMBER QUESTION:
How can the physicians register for it? When is it?

KAPURAL:
You can go to our web site, clevelandclinic.org/painmanagmenet. Information for both of those meetings is on our web site. Or you can call my office and I would be glad to give you information about both of these venues.

MODERATOR:
We are almost out of time. Before we wrap things up for today, do you have any final words for us, Dr. Kapural?

KAPURAL:
I just wanted to say that we've come a long way with implantable devices, and over the last five years they've become very safe and effective treatment for severe chronic pain. Hopefully issues with the payers will not prevent us from using those for the good of the patient.

MODERATOR:
Our thanks to Cleveland Clinic pain management expert Leonardo Kapural, MD, PhD, for joining us.