Dorsal Root Ganglion (DRG) Stimulator

Dorsal root ganglion (DRG) stimulation therapy is a new type of neurostimulation therapy designed to manage difficult-to-treat chronic pain in specific areas of the lower body, such as the foot, knee, hip or groin.

There's currently one U.S. company that manufactures a Dorsal Root Ganglion stimulator: Proclaim™ DRG (Abbott). The battery is internal and surgically implanted.

Many doctors will recommend a DRG stimulator for pudendal neuralgia, but it was not designed for that purpose. We suspect doctors lead toward this type because they have been implanted them for a long time and the procedure is simulator to implanting a Spinal Cord Stimulator (SCS) which doctors have done for decades.

Regrettably, because Peripheral Nerve Stimulators are a newer kind of neuromodulation, doctors will claim that the DRG treats pudendal neuralgia better than PNS. One doctor even said that "the medical literuature supports this" We have not found this to be the case.

There is more risk with the DRG because the lead does wind around the spinal cord. If it breaks, it is very difficult to find a surgeon to remove the broken piece because it is so close to the spinal cord. Most patients are left with no choice but to leave the broken lead in their bodies.

However, there are pudendal neuralgia patients who say that the DRG Stimulator has helped their pain and it is easy to find a doctor with extensive experience implanted them. It is almost impossible to find a doctor with any experience implanting a peripheral stimulator (PNS) and we have not find any who will agree to train under n experienced doctor. States in the U.S. do not require doctors to train on living people so most patients who opt for a PNS will be the first living person upon whom a doctor will conduct the procedure with is unsettling.

So we will publish as much information here about the DRG as we can find through our research.

As patients, the first fact to point out that the battery is permanently internally surgergically implanted. This is important due to the fact that a person will have this for the rest of their lives and the battery will have to be replaced every five years or so.

As a reminder, Peripheral Nerve Stimulators PNS have External Batteries.

Sacral Nerve Stimulators have surginal implanted Internal Batteries same as the DRG.

-SNS is the only stimulator that effectively corrects IC, bladder pain, and fecal incontinence

PNA wants women and men to have all information regarding stimulators so that they, along with the doctors, can make fully information medical decisios.

Dorsal root ganglions (DRGs) emerge from the dorsal root bundles of the spinal nerve’s dorsal column. DRGs carry sensory messages from various receptors at peripheral nerves to the spine then to the brain for a pain response. Dorsal Root Ganglion/Nerve root exiting the spinal cord.

DRG Proclaim™ is indicated to manage Moderate to severe chronic intractable in the lower limbs in adult patients with Types I and II CRPS pain in specific areas of the lower body, such as the foot, knee.

Through research and talking to pudendal neuralia members on the nurmerous Facebook Pudendal Neuralgia Group, PNA has determinted that the vast majority of pain management doctors recommend DRG before any other type of neuromodulation. We are rsearching to determine why this is the case as the DRG is not designed to treat specific peripheral nerve pain such as pudenal neuralgia.

Magnetic Resonance Imaging (MRI) Compatibility

The current Proclaim IPG is MRI-conditional using 50 cm leads for head and extremity MRI using prescribed parameters when placed below the T10 level.230 Placing the device into “MRI mode” restricts energy transmission into the IPG and potential damage to the BluetoothTM technology.

The Procedure

Implantation of a Dorsal Root Ganglion stimulator is a two-step process that involves first implanting the stimulator, and then a pulse generator to power it. To implant the stimulator, an incision is made in the patient's back; the wires with electrodes on the end are fed through and positioned on the spinal cord. Exact placement depends on the area of pain.

To implant the pulse generator, an incision is made in the buttocks or abdomen, and the generator is placed between layers of skin and muscle. An extension wire is run from the spine to whichever area the generator is placed in. Incisions are closed with either staples or sutures. The procedure takes 2 tp 4 hours, and the patient usually goes home on the same day.

The DRG leads are not implanted inside the spinal coloumn Some doctors use DRGS to treat pudendal neuralgia pain. After trial is approved, the battery (look for size) is surgically, permanently implanted under skin in lower back.

Risks/Complications

The major categories were device-related complications, procedural complications, patient complaints, surgically managed complications, serious adverse events, and other.

Complications and Effects of Dorsal Root Ganglion Stimulation in the Treatment of Chronic Neuropathic Pain

The most frequent complications were hardware-related and included broken and migrated leads

(Figure 1 and Figure 4).

13 patients had one or more defect leads (39% of implanted systems). Of these, 11 cases
were confirmed to have fractures, which occurred at the anchor, the implantable pulse
generator (IPG), or in one of the loops (Figure 5A-B).
2 patients The remaining 2 cases had loss of paresthesia and pain-relieving effect in addition
to high impedance, which indicated lead fracture, though the leads were not examined
further during revision.
5 patients were found to have migration of leads. In 2 of these cases, implanters had elected
not to anchor the 14 leads due to previous fracture in relation to the anchor, leading to
subsequent migration. Except these two cases, anchors were used in all other implantations.
The median time from implantation to explantation was 413 days (n=14; interquartile
range = 237 to 665 days).
2 patients, whose systems were explanted due to migrated leads (Figure 1) had previously
experienced several revisions caused by broken leads, and both therefore refusedfurther
revisions and were explanted.
4 patients (12% of implanted systems), it was not possible to remove the entire lead
during revision. The lead broke during removal, leaving the tip with one or more
metal parts in the root canal or epidural space (Figure 6A).
As shown in Figure 6B, one lead was removed with considerable amounts of scar tissue
debris, illustrating the risk of the lead getting stuck in the root canal.
7 patients, replacement of broken leads was not possible due to either obstructive lead
fragmentsor scar tissue.
In 3 patients, persistent or repeated attempts to replace leads resulted in -- These included
2 cases of damage to the nerve root, permanent nerve damage. resulting in increased
neuropathic pain.
1 case of medullary (the innermost or central portion of an organ in contrast to the cortex)
damage resulting in new neuropathic pain, tetraparesis, and bladder dysfunction.
3 patients were explanted because of loss of or substantial waning of effect.
1 patient experienced slight worsening of pain after implant in spite of a successful trial period.

Excerpt of Removal of DRG

"In four patients (12%), lead removal left fragments in the root canal due to lead fracture, and three patients suffered permanent nerve damage during attempts to replace broken leads" 2

"Conclusions: This study suggests a significant, clinically relevant effect of DRG stimulation on neuropathic pain, but also demonstrates substantial problems with maintenance and revision of currently available systems. Consequently, treatment with equipment marketed specifically for DRG stimulation is currently paused in Denmark."

The major categories were device-related complications, procedural complications, patient complaints, surgically managed complications, serious adverse events, and other.The major categories were device-related complications, procedural complications, patient complaints, surgically managed complications, serious adverse events, and other.The DRG has been an attractive target for pharmacologic, surgical, and electrical pain modulation for decades. Exponential technologic advancements in traditional SCS are moving toward precisely treating the region of pain distribution with fewer off-target effects. DRG stimulation is a leap in this direction with the ability to target discrete subdermatomal foci.29,30

Furthermore, DRG stimulation may alleviate chronic pain via different mechanisms of action than traditional SCS.31 The excitement surrounding this new technology should, however, proceed with caution as there are many unknowns. At a time when nonopioid alternatives are urgently needed, the benefits associated with this new modality may outweigh the risks of complications. As the total number of procedures performed during this time period (ie, a denominator) is unknown, a complication incidence could not be estimated. However, extrapolating numbers based on estimates of the number of individuals trained and controversial requirements that each of those individuals vouch to perform at least six implants, it is likely that the risks and complication rate are much lower than those associated with chronic opioid therapy and spine surgery.32

Despite its limitations, the MAUDE database is one resource which can aid in the early detection of safety issues with new technology, though, large multisite studies are necessary to more accurately identify complication rates. Our results should spur future study into modifications of the DRG stimulation device and procedural technique to reduce complications, while still maintaining the advantages of this promising new th

https://pubmed.ncbi.nlm.nih.gov/32539189/

Insufficient FDA Requirements to Implant Stimulators

Currently the FDA does not require doctors to observe and train under a highly experienced doctor nor does the FDA require doctors then to implant stimulators under the supervision of a highly experienced doctors as is the case with all other specialties and procedures we are aware of. The only requirement is a training with a speaker and a presentation, much like PowerPoint. Doctors can practice on cadaveres if they choose. This FDA approval of no training on living patients is unacceptable and needs to need as soon as possible. There will be challenges because the faster a doctor can start to implant a medical device, the faster the doctor, the company, and the hospital can starting making money. There are many documentaries and books and this serious problem.

Important anecdotal Information

PNA is not against using DRG for pudendal neuralgia, but it was not designed for the condition. Also, it's very similar to Spinal Cord Simulators with which doctors have extensive experience, so there is very little training required.

"Through my experiences and talking to others with pudendal neuralgia, it seems like about 90%-95% of doctors recommend the Proclaim DRG (Abbott). Many have a spine model with the battery in their offices. I spoke to two pain management doctors and asked if they would instead consider implanting a Peripheral Nerve Stimulator. Both refused. I asked both why. The first said that he had no experience with PNS and that the DRG worked just as well. I have not found credible published studies stating this but if you find one please contact this site immediatley. We want science. The other doctor told me that the medical literature stated that DRG was superior to PNS for pundendal neuralgia. I have found no such evidence."

The second doctor I saw took nine months to book an appointment, spent seven minutes with me, did not exam me, never sat down, talked fast and was rude and condescending. His assistant told me he was very busy, saw 25 patients on Mondays and did procedures the rest of the week.

We have a for-profit healthcare system instead of a national healthcare system like Europe, Australia, and Canada.

I hesitate to know the truth, but 25 times the charge of an office visit plus many implants a day for four days adds up to a lot of money, but very little patient interaction, care, or real medical practicing. This doctor is one of the most highly regarded in that state. All the pain management doctors there know each other, so we must "walk the line" to advocate for ourselves, ask questions, but not alienate doctors. Hopefully we can help improve the U.S. pain management culture to become more pro-patient care"

Many pain management doctors feel if they are experienced at implants in the shoulder or knee, they know enough to implant a neurostimulator next to the pudendal nerve. As laypeople, we can not yet confirm this or not. We need to do interviews, but it does not seem truthful. It would be easy to hit the pudendal nerve, cause trauma and scar tissue to the surrounding area which is a cause of PN, or worse nick/cut the pudendal artery or vein.

The average "introducer/tunneling needle" used to find the pudendal nerve is 12-14 gauge. The smaller the number, the larger the needle.

In our limited conversations with doctors and patients regarding the pain when the doctor inserts the introducer/tunneling needle, all patients said it was painful. Doctors have to move the needle around, sometimes even pull it out and retunnel.

I talked to the sales person of one of the four PNS companies. He felt the pain warranted twilight sleep while the doctors found the correct position and inserted the lead through the introducer adjacent to the pudendal nerve, to THEN wake up the patient and test the PNS and lead placement. This seems like a more compassionate approach and we are interviewing doctors now.

Under "Real Stories" the first is of a young woman, 29, who had a PNS implanted and the experienced was

extremely painful and failed. The entire implant felt out during the first night. We suspect it was a failure because she was the doctor's first pudendal neuralgia living patient -- not a Powerpoint presentation or cadaver. The patient was afraid to ask the doctor how many stimulator devices he had implanted into living paitents for pudendal neuralgia.

_____

Complications of Dorsal Root Ganglion Stimulation for the Treatment of Chronic Neuropathic Pain3

Abstract

"The dorsal root ganglion (DRG) stimulation is less affected by postural changes, and there may be less loss of efficacy noted over time with traditional stimulation, and may not require parasthesia to induce pain relief. This chapter includes discussions of the anatomy of the DRG, indications for the procedure of DRG simulation, technical approaches with pictures, potential complications, and strategies for preventing complications. The critical role of the primary sensory neurons and the DRG in the development of chronic neuropathic pain have been well elucidated. The most frequent complications were hardware-related and included broken or migrated leads. The authors felt that the frequency of DRG lead fractures and problems relating to revisions of dysfunctional DRG systems was considerably higher than usually observed with spinal cord stimulation systems. There is a clear learning curve for the DRG stimulation procedure and more experienced clinicians seem to have fewer complications than those performing the procedure rarely." 3

Ultrasound safer than Fluoroscopy

"There are no large studies comparing ultrasound and fluoroscopic guidance for the placement of PNS. Nerve blocks for peripheral nerves have been described using both ultrasound and fluoroscopy. Key factors to consider include the size of the lead, need for entrance at a distance from the target nerve to allow for appropriate lead placement, planning placement of the lead(s) parallel or crossing in relation to the nerve and tunneling needed. Ultrasound has the advantage of direct visualization of the nerve with a dynamic view of lead placement, enabling accurate determination of the distance between the PNS lead(s) and the target nerve." 1

Ultrasound also does not release any radiation.

2 Complications and Effects of Dorsal Root Ganglion Stimulations in the Treatment of Chronic
Neuropathic Pain

University of Southern Denmark - A Nationwide Cohort Study in Denmark

Horan, Mattias; Jacobsen, Anne Helene; Scherer, Christian; Rosenlund, Christina; Gulisano,

Helga Angela; Søe, Morten; Sørensen, Jens Christian Hedemann; Meier, Kaare; Blichfeldt-

Eckhardt, Morten Rune

Published in: Neuromodulation DOI: 10.1111/ner.13171 Publication date:2021

https://findresearcher.sdu.dk/ws/files/170824068/ner.13171.pdf

3 Robert M. Levy MD, PhD Department of Neurosurgery at the University of Florida College of Medicine–Jacksonville

Book Editor(s):Serdar Erdine MD, FIPP, Peter S. Staats MD, MBA, APIPP, FIPP

First published: 04 August 2022 by Wiley i. Wiley s a global provider of content and content-enabled workflow solutions in areas of scientific, technical, medical, and scholarly research.

https://doi.org/10.1002/9781119757306.ch52

____

Pudendal Neuralgia Alliance

contact@pudendalneuralgiaalliance.org

Paid for by volunteer until 501c3 status granted by IRS

Dorsal Root Ganglion (DRG) Stimulator

Magnetic Resonance Imaging (MRI) Compatibility

​

(Figure 1 and Figure 4).

13 patients had one or more defect leads (39% of implanted systems). Of these, 11 cases were confirmed to have fractures, which occurred at the anchor, the implantable pulse generator (IPG), or in one of the loops (Figure 5A-B).

2 patients The remaining 2 cases had loss of paresthesia and pain-relieving effect in addition to high impedance, which indicated lead fracture, though the leads were not examined further during revision.

5 patients were found to have migration of leads. In 2 of these cases, implanters had elected not to anchor the 14 leads due to previous fracture in relation to the anchor, leading to subsequent migration. Except these two cases, anchors were used in all other implantations.

The median time from implantation to explantation was 413 days (n=14; interquartile range = 237 to 665 days).

2 patients, whose systems were explanted due to migrated leads (Figure 1) had previously experienced several revisions caused by broken leads, and both therefore refusedfurther revisions and were explanted.

4 patients (12% of implanted systems), it was not possible to remove the entire lead during revision. The lead broke during removal, leaving the tip with one or more metal parts in the root canal or epidural space (Figure 6A).

As shown in Figure 6B, one lead was removed with considerable amounts of scar tissue debris, illustrating the risk of the lead getting stuck in the root canal.

7 patients, replacement of broken leads was not possible due to either obstructive lead fragmentsor scar tissue.

In 3 patients, persistent or repeated attempts to replace leads resulted in -- These included 2 cases of damage to the nerve root, permanent nerve damage. resulting in increased neuropathic pain.

1 case of medullary (the innermost or central portion of an organ in contrast to the cortex) damage resulting in new neuropathic pain, tetraparesis, and bladder dysfunction.

3 patients were explanted because of loss of or substantial waning of effect.

1 patient experienced slight worsening of pain after implant in spite of a successful trial period.

​

​

13 patients had one or more defect leads (39% of implanted systems). Of these, 11 cases
were confirmed to have fractures, which occurred at the anchor, the implantable pulse
generator (IPG), or in one of the loops (Figure 5A-B).

2 patients The remaining 2 cases had loss of paresthesia and pain-relieving effect in addition
to high impedance, which indicated lead fracture, though the leads were not examined
further during revision.

5 patients were found to have migration of leads. In 2 of these cases, implanters had elected
not to anchor the 14 leads due to previous fracture in relation to the anchor, leading to
subsequent migration. Except these two cases, anchors were used in all other implantations.

The median time from implantation to explantation was 413 days (n=14; interquartile
range = 237 to 665 days).

2 patients, whose systems were explanted due to migrated leads (Figure 1) had previously
experienced several revisions caused by broken leads, and both therefore refusedfurther
revisions and were explanted.

4 patients (12% of implanted systems), it was not possible to remove the entire lead
during revision. The lead broke during removal, leaving the tip with one or more
metal parts in the root canal or epidural space (Figure 6A).

As shown in Figure 6B, one lead was removed with considerable amounts of scar tissue
debris, illustrating the risk of the lead getting stuck in the root canal.

7 patients, replacement of broken leads was not possible due to either obstructive lead
fragmentsor scar tissue.

In 3 patients, persistent or repeated attempts to replace leads resulted in -- These included
2 cases of damage to the nerve root, permanent nerve damage. resulting in increased
neuropathic pain.

1 case of medullary (the innermost or central portion of an organ in contrast to the cortex)
damage resulting in new neuropathic pain, tetraparesis, and bladder dysfunction.