Date: December 16, 1999
Interstitial Cystitis Network - Chat Log (
Topic: Medtronic's Interstim Procedure - Sacral Nerve Stimulation for the Treatment of Frequency, Urgency and Incontinence
Speaker: Dr. Steven Siegel, Metropolitan Urologic Specialists

<icnmgrjill> Greetings everyone and welcome to a special "ICN Meet the Expert" Chat for Thursday, December 16, 1999. Our guest speaker tonight is Dr. Steven Siegel, who I invited to appear to discuss Medtronic's Interstim surgical procedure. Approved by the FDA to treat frequency and urgency, Interstim has been used with some IC patients. Greetings Dr. Siegel and welcome to our ICN chat! We are so lucky to have a physician of your caliber come speak with us.

<drsiegel> It's nice to be here. I'm flattered and honored.

<icnmgrjill> We have a presentation to do first but, before we start that, let's learn a little bit more about your background, where you are practicing and what your interests are?

<drsiegel> I'm practicing in St Paul Minnesota with Metropolitan Urologic Specialists, and I'm the Director of the Continence Care Center of Minnesota. My interests are primarily in voiding dysfunction, neuro-urology and, of course, female urology. I currently treat a large number of IC patients.

-------------------------- Presentation Starts --------------------------

For a moment, put yourselves in my shoes. Thirteen years ago, as a new faculty member of the Cleveland Clinic Department of Urology, the sign on my office door read "Head, Section of Female Urology and Urodynamics" Over that, my secretary taped "Doogie Howser, M.D." My clinics were full of teary patients with IC who came from all over the Midwest, to what they must have felt was the court of last resort. And I was armed with nothing more than an ounce of compassion, a sincere desire to do good work, and an instinctual disdain for urethral dilatations! The then current issue of Campbell's Urology advocated hydrodistentions and intravesical oxychlorosine. There was also DMSO, with or without steroids or heparin. Antihistamines were the drugs of choice, with Elmiron available "for compassionate use" only. It seemed like everything I tried was of temporary or marginal benefit if any, and I was always pulling another rabbit out of my hat just to get the patients through another three months before the next visit. When those things didn't work, we even did cystectomies with bladder substitution (more tears). I was pretty depressed, and ready to try something different... and that led me to visit Dr. Richard Schmidt at the University of California, San Francisco. He ultimately changed my view of IC, and gave me insights that have lead to improving the lives of my patients.

One of the first test stimulation procedures I attempted was on a woman in her 20's, who I had known for years. She had disabling symptoms of pain and frequency. We had exhausted all our options, and more because I didn't know what else to do, we tried neurostimulation. I placed a temporary electrode in the S3 foramen, and sent her home for a week with an external stimulator. Her voids per day decreased by more than half, with corresponding increases in her voided volumes. Her pain was also significantly less, but not eliminated. She even noticed a dramatic change in bowel habits. These changes began almost immediately, and turned off like a light switch as soon as the temporary wire was removed. We were both in shock! And I had gone through a window from which there was no turning back.

These are some things I've learned from experiences like that. First, since the treatment only modulates nerve and muscle function, then, at least in the patients who respond, the urinary symptoms are probably a nerve and muscle disorder, and not a problem of the bladder per se. This is further validated by the immediate change in bladder capacity, and also by the unanticipated improvements of bowel function. It became obvious to me that since the same treatment can effect bladder and bowel function, the bowel dysfunction is an important part of the disorder. That explains why treatments directed solely at the end organ (the bladder) are rarely successful. I began to question patients carefully about bowel symptoms, and look for signs of pelvic muscle spasm on routine physical exams. Over time, I've appreciated the helpful role of other, less invasive forms of nerve and muscle modulation, including diet, relaxation techniques, pelvic floor muscle EMG biofeedback, myofascial release, and use of medications such as striated muscle relaxants, tricyclic antidepressants, and Metamucil for a variety of urinary disorders.

Nobody knows exactly how neurostimulation works. The prevailing theory is that the symptoms of bladder and bowel dysfunction, with or without incontinence or pelvic pain, are due to an imbalance in the reflexes between the pelvic organs, the striated sphincter, and the pelvic floor. There is an up-regulation, or irritable focus in the central nervous system that perpetuates the symptoms of pain and muscle spasm. The electrical stimulation has the net effect of calming the irritable focus, and balancing the reflexes, resulting in more normal patterns of bladder and bowel function. Pain may be improved by decreasing muscle spasm, but also by interfering with abnormally increased pain inputs from C-fiber afferents to the central nervous system (the gate control hypothesis). It's interesting that symptoms of urgency, frequency, and urge incontinence can be managed in exactly the same way as symptoms of urinary retention. This has to do with the switching mechanism at the level of the sacral spinal cord. Too much inhibitory input from the brain leads to inability to relax the pelvic floor and to "turn-on" the bladder. Not enough inhibitory input from the brain causes the switch to be unstable, causing sudden relaxation of the pelvic floor and urgent bladder contractions. Neurostimulation works by balancing the inhibitory and facilitory influences on the switch.

As of this year, Interstim therapy is approved for debilitating and intractable symptoms of urge incontinence, urinary urgency and frequency, and non-obstructive urinary retention. The FDA approval was based on the international, multicenter "Medtronic 103" study, which is the subject of several publications and is detailed on the Interstim web site ( It is not approved for IC, but many patients with characteristic IC symptoms fit under the approved symptom categories. Interstim is not approved for treatment of pelvic pain in the absence of voiding symptoms, but I can offer some insight into that if asked. There is active research going on to define the role of Interstim therapy for primary bowel complaints such as fecal incontinence, rectal urgency-frequency, and chronic constipation. In my opinion, it would never be appropriate to consider Interstim as a first line, or initial treatment option. It is always better to try more conservative treatment options first, and consider Interstim if they prove to be unsuccessful or unacceptable to the patient.

Interstim isn't for everybody. Many IC patients who try the therapy don't benefit at all. That may be because IC is a symptom complex that has different causes, some of which may not be helped by neuromodulation. The ability to perform a test stimulation gives us a safe and completely reversible way to know with a high degree of certainty who will benefit from a permanent implant. We perform the test procedure under local anesthesia in the office. Diaries are used to objectively quantify voiding symptoms such as number of voids/day and voided volume/void. In addition, we monitor other symptoms such as pain and bowel function. When a significant impact on voiding symptoms can be shown for a long enough period of time during the trial phase, a decision can be made to go ahead with permanent implantation. Up to 80% of patients who undergo a permanent implant will do as well or better that they did with a temporary device.

I hope that gets our discussion going. I'm very happy with the improved ability to treat patients with voiding dysfunction using Interstim. I have also gained some important insights into other, more conservative options because of my experience. Maybe the best news of all is that this therapy is in its infancy. The more we learn about the mechanism of voiding dysfunction and the appropriate role of neuromodulation, the simpler, safer, and better the treatments will become.

-------------------------- Presentation Ends --------------------------

<icnmgrjill> Thank you Dr. Siegel. It's been clear in the last year in the IC community that the theory of IC as a bladder wall dysfunction is slowly fading in favor of a nerve or muscular cause of bladder and bowel symptoms. One of the things you mentioned in your presentation is that bowel symptoms improved. Now we know, as IC patients, that the great majority of us have irritable bowel. Is there a possibility that IBS is far more related to IC than we originally suspected. I hadn't heard of IBS also having a nerve/muscle connection?

<drsiegel> A thing that I find surprising, sometimes, is that when patients tell me about their bladder and bowel problems, and I confirm that they could be related, the patients say "I thought so!" It's as if their secretly held conviction and insight into their own body had been rejected by the medical community.

My belief is that the fundamental problem of some patients with IC is that they have an abnormal nerve or muscle environment that the bladder and bowel have to function in. In that sense, both the bladder and bowel are innocent bystanders that are caused to function abnormally because of the way the nerves and muscles are functioning.

<icnmgrjill> What are some of the potential causes for nerve/muscle problems in the pelvic area? scoliosis?

<drsiegel> Most of these dysfunctions probably start early in life during childhood. Toilet training casualties, unconscious holding of the pelvic muscles associated with fear, anxiety, sexual assault, or other injuries are all possible conditions that can cause pain and muscle spasm in the pelvic area. However, this may not be recognized or treated as similar injuries would be cared for in other parts of the body. Over time, if pelvic muscles are not used properly, it can lead to a change in the central nervous system that negatively effects the way that the bladder and bowel are managed. There may be other occasions where patients have an existing muscle spasticity problem (urgency, frequency, urge incontinence) that are often passed off as a "normal" variation of bladder behavior and, thus, don't get treated. This sets the stage and, at some point, the patient is basically an accident waiting to happen. Later in life, a simple event like a bladder infection, a fall, or a hemorrhoid can trigger very dramatic symptoms because of the changes in the nervous system.

<icnmgrjill> We also note patients who develop symptoms after childbirth or surgery. Would this fall into this definition too?

<drsiegel> There are two ways of looking at that. One is that a patient comes into the surgery with a background of inappropriate pelvic floor muscle behavior, similar to an athlete getting ready for some strenuous physical event, without doing the appropriate physical training. And then there is an unanticipated and dramatic triggering of even more abnormal muscle behavior in response to a normal insult, like childbirth or hysterectomy.

<drsiegel> The second way is that the injury that occurs as a result of the surgery causes muscle spasticity, kind of like throwing your back out. In these cases, you have to take the steps necessary to take care of the problem quickly. Heating pads, muscle relaxants, exercises, and physical therapy would all be reasonable things to do.

<drsiegel> A pelvic floor dysfunction might not be recognized as a common muscle problem. It gets treated as a urinary tract infection, or as urethral stenosis, or endometriosis, and on and on. The basic underlying dysfunction is never addressed and it becomes a chronic syndrome.

<icnmgrjill> Very much like what Dr. Weiss shared with us a few months ago. I find it very interesting that we're seeing such a change of direction in IC causation. Well, let's get to the important topic tonight which is Interstim. How long have you been using this procedure?

<drsiegel> For over ten years.

<icnmgrjill> Can you take us through a classic case study with a patient that has had or you feel is an appropriate candidate for Interstim? Are there some common characteristics that you look for in your patients?

<drsiegel> First of all the patient must have urinary frequency or urgency. They may have urge incontinence or may not and they may have pelvic pain or not. Usually, their symptoms are chronic in nature. In our study, the average length of time of prior symptoms for urge incontinence patients was 9 years.

<drsiegel> These patients usually have associated bowel complaints. They include either chronic constipation or fecal urgency and they often have had multiple surgeries to treat pelvic pain, such as a hysterectomy, laparoscopies, etc. They often have the "terrible triad": IC, endometriosis and IBS.

<drsiegel> Occasionally, these patients will also have a one sided nature pain of their pain. On physical examination, there is often very tangible evidence of pelvic floor muscle spasticity. They may not recognize that their pelvic floor muscle tone is increased at the time. During rectal exam or if we palpate the levator shelf, they may have marked tenderness or trigger points. They don't have the ability to change the tone of the pelvic floor muscles. They can't relax or contract them voluntarily. Usually, their urine shows no evidence of infection. During office cystoscopy, their bladder looks normal. And, if you do a urodynamic study, what you see if evidence of increased EMG activity of the pelvic floor during both the filling and voiding phase of urination. (EMG is the electrical activity of the pelvic floor muscle.)

<drsiegel> Often, when they try to void, they have an inefficient voiding pattern. Instead of voiding steadily, they may have interrupted urination (stopping, starting or straining). The often have a modest amount of urine left in the bladder at the end of urination.

<icnmgrjill> Okay, so you have a good candidate and, as you said in your presentation, considering Interstim is not the FIRST option to explore but, at this point, you and the patient feel that its appropriate. Can you walk through the test procedure.

<drsiegel> This is a short procedure. It's done on an out-patient basis with local anesthesia. An important part is that before the study is done, we ask patients to complete a baseline voiding diary. This is what we're going to use to compare and determine the effectiveness of the procedure on the patientís symptoms.

<drsiegel> We typically have the patient lie on a flat examining table (on their stomach), put two pillows under their hips, one pillow for their face, and one underneath their shins. We ask them to remove their socks so that we can look at the feet during the procedure. We wash off the area of the lower back, tailbone and buttocks with a sterile solution, and then feel the bony structures of the pelvis so that we can identify where the sacral openings (foramen) are.

<drsiegel> We numb the skin over the openings with lidocaine and then use a spinal needle to feel down to the back of the sacral bone, and then enter the openings where the sacral nerves lie. Most of the time, it is only uncomfortable when the skin and the back of the sacrum are being numbed. Other than that, it should be comfortable for the patient.

<drsiegel> Once the opening of the bone is entered with the spinal needle, we start to stimulate the needle with a battery operated screener (like a TENS unit), and the patient will feel sensations such as vibration or pulling in the rectum, vagina, or the base of the scrotum. Sometimes patients say, "I want to marry this device!" In addition to that, we will see characteristic movements of the muscles of the pelvic floor that are triggered by the stimulation. We call that a "bellows." There may also be some winking of the anal sphincter, which we call a "clamp." There may be some movement of the leg, foot or toes, depending upon which nerve is being stimulated. This should be comfortable for the patient.

<drsiegel> Many times that patient will immediately feel a release of muscle tension as the nerves are being stimulated, and they will know exactly when the "right spot" is being stimulated. They will want more stimulation. Once we've found the spot (usually the third opening on the left or right side of the sacrum), we slide a pacing wire, which is a little thicker than human hair, through the opening in the center of the spinal needle. We withdraw the needle, leaving the wire in place. The wire is taped to the patient's skin using a special dressing. At this point, it's connected to an external stimulator box, which can be worn on the patientís belt or hemline.

<icnmgrjill> How long is the trial device worn?

<drsiegel> We usually like to have the device in for a minimum of three days, or as long as a week. When we find the proper candidate for the therapy, the patient doesn't want the device removed. They literally will cry when we take the wires out.

<icnmgrjill> Are there any risks to the trial procedure?

<drsiegel> The risks are pain during the procedure and the possibility that it might not be successful. For technical reasons, it might need to be repeated at some point. Some of the patients have experienced temporary pain, which is a shocking or shooting sensation. This, rarely, can last for several days following the removal of the wire. No patients have ever experienced permanent nerve damage as a result of the procedure in the entire world's experience.

<icnmgrjill> Yes, I understand that Interstim has been used throughout Europe.

<drsiegel> This device has been approved in Canada, Europe and Australia for several years before it was approved here.

<icnmgrjill> Now, let's say that we have a successful trial and the patient agrees to have the device permanently implanted.

<drsiegel> The beauty of the temporary trial is that patients will experience what the stimulation feels like and will be able to gauge the impact on their symptoms. We can use the diaries that the patient completes during the trial stimulation phase to make an objective determination as to how much the therapy has impacted their symptoms. Generally, we will want to consider implantation only for patients who have had a dramatic improvement during the trial procedure.

<icnmgrjill> What's your research showing in terms of success rates?

<drsiegel> If a person has a successful test stimulation and goes on to implant, 80% will do as well or better with the permanent device as they did during the trial.

<icnmgrjill> We've had several IC patients online who have had the trials and, in some cases, the surgical implants. For example, one has had a complete reduction in their frequency. No change in her pain, but a dramatic improvement in frequency and urgency. Are you finding that the pain, over the long term, has improved for patients overall?

<drsiegel> I would say that there is a significant impact on pain. However, to say that this is a reliable treatment for the pain of IC is an overstatement. This therapy is a modulating therapy. It doesn't actually cure the patient or permanently change the physiology that is causing their symptoms. It is very likely that a number of different therapies will also be necessary in conjunction with this. Some patients have had excellent long lasting relief of their pain, but certainly not all of the patients. The 103 study I mentioned earlier definitely showed that there was long term relief of urge incontinence, frequency-urgency, and retention.

<icnmgrjill> Can you tell us a bit about the surgical experience that patients go through?

<drsiegel> The surgery is done under a general anesthesia. There are two incisions: one down the middle of the back over the sacrum (2.5 to 3" long) and one in the upper buttocks, where the generator is placed. The surgery takes about 1.5 to 2 hours, the patients usually stay in the hospital over night, and are able to go home the next day. Sometimes, a patient may have more pain after the surgery and they need to stay in the hospital a little longer.

<drsiegel> Usually, we initiate the stimulation after one week. The patient has to go through some programming to determine what settings the stimulation works best at. The patient has the ability to turn the stimulation up or down using a hand held programmer, but all of the components of the device are inside the body. Most of the patients are able to return to work within a couple of weeks.

<icnmgrjill> Risks???

<drsiegel> The main risk is infection, which happened in about 6% of the patients in the study. If one of the incisions becomes infected, that might result in having to remove the device. But, the good news about that is that once the infection is healed, they will have the opportunity to have the implant done at another time.

<drsiegel> Another risk is lack of effectiveness. About 20% of the patients won't have the same benefit they received during the trial. Other problems that can occur include pain at the generator site or pain where the lead electrode is implanted. These are "new" pains. They are usually not as intense, and can resolve with programming. Occasionally, the patient may need to have a re-operation to resolve this. Overall, the need to have a 2nd operation to fix a problem with initial implant is 30-40%. That is equal to the re-operation rate required in other neural stimulator procedures. It's important to note that all of the patients that required re-operation either completely resolved their problem or allowed the patient to go back to their former state of health. In other words, they didn't get worse.

<icnmgrjill> Folks...let's take some questions from the floor. What's the youngest and oldest age of patients treated with Interstim?

<drsiegel> As far as I'm aware, the youngest are teenagers and the oldest

are in their seventies. The device was only approved for people over 16 years of age.

<icnmgrjill> Where are the surgeries being performed in the US. Do people

have to go to MN to have it done? How can we find a doctor in our area who knows about this?

<drsiegel> There has been a concerted effort since 1997 to train both urologists and urogynecologists all over the country to provide this therapy. As of now, there have been about 80 physicians that have completed training and their are at least 40 physicians who have already performed multiple implants. The best way to find a physician in your area is to go to the Interstim web site ( and request a physician referral list.

<icnmgrjill> How about men? Are you treating men with similar symptoms of IC or prostatitis with this?

<drsiegel> Absolutely! Twenty percent of the 103 study were male patients and they had the same or similar symptoms, though some of the men had been diagnosed with prostatitis or prostatodynia or had failed prostate surgeries to improve their urine stream.

<icnmgrjill> Will this help with sex (i.e. making sex more comfortable and pain free)?

<drsiegel> A large proportion of these patients have pelvic muscle spasms and, therefore, they have pain with intercourse. If they are modulated so that their spasms are decreased, then sex does become more pleasurable for them.

<icnmgrjill> Debbie B wants to know if you know Dr. Hassouna from Toronto Western Hospital. She says that she had Interstim done by him almost eight months ago and is now back to work and doing wonderfully?

<drsiegel> Dr. Hassouna is one of the greatest researchers and surgeons for IC in North America and is a pioneer for Interstim.

<icnmgrjill> Can the Interstim device create a permanent remodeling of the pelvic floor resulting in a permanent regression of symptoms?

<drsiegel> Great question. When we first started doing this work, there was hope that a permanent regression would occur. The experience has been that once the device is turned off, or the battery wears out, that the patients symptoms return in a matter of weeks. Batteries can last between six to ten years before requiring an easy replacement procedure.

<icnmgrjill> One of the criticisms of the surgery was that the generator moves, in part because there's nothing other than muscle to anchor it to. Has that improved?

<drsiegel> We had a higher rate of complications related to position of the generator when it was positioned in the abdomen. Since 1997, most generators are positioned in the upper buttocks and the rate of problems related to the position of the generator has been greatly decreased.

<icnmgrjill> As a urologist who is definitely sympathetic to the journey that an IC patient and family undertakes, what do you think is the most important thing that a patient can do for their self care and recovery?

<drsiegel> #1 Don't give up. Have faith that your symptoms can be improved. Seek treatments that have the potential to be effective, like this or other therapies that are being developed.

<icnmgrjill> And what about patients who don't feel like that they can bring options like this to their physicians. How would recommend that they approach their MD, particularly if they are of the old school... of DMSO or nothing.

<drsiegel> If your attempts to bring new information to your doctor are unsuccessful, have faith. This information is increasingly available in journals and meetings. If your physician isn't interested in thinking about newer treatments, seek another one.

<icnmgrjill> Here's another question.. Is lead migration improving?

<drsiegel> Lead migration was a problem early on in the study, but we changed the lead design. This eliminated the problem of migration.

<icnmgrjill> Last question of the night! What are you excited about in the future of IC and other urology diseases? Where would you like to be ten years from now?

<drsiegel> The future of IC involves developing an understanding of neuromuscular dysfunction, and a de-emphasis of the bladder as a cause of the problem. The increasing comfort on the part of the medical community with these concepts will lead to a willingness to initiate successful conservative treatments early, rather than late in the course of the illness. And, lastly, further refinement of the techniques of nerve stimulation will evolve to the point where the procedure can be completed on an outpatient basis, is minimally invasive, with an even greater likelihood of resolving the patients symptoms.

Dr. Steven Siegel currently see's IC patients at:
Metropolitan Urologic Specialists
280 North Smith St., Suite 658
St. Paul, MN 55102
Toll free Phone: 1-800-685-7328

He will take e-mail questions at:


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