As a shadowing medical student in family medicine clinics in Toronto, I’d seen patients with chronic pain of a neurogenic origin and always felt heartbroken. I’d looked on in helplessness as we consoled the patients and offered them physiotherapy, bedrest, and pain killers. We and the patients knew none of these options were curative, and subsequently tiptoed around that subject.
Fortunately, Health Canada approved a new solution earlier this year: a peripheral nerve stimulator called the Bioness StimRouter. It’s a minimally invasive neuromodulation device consisting of an implanted lead, an external pulse generator, and a hand-held wireless programmer. It uses programmed electrical pulses to stimulate an erratic peripheral nerve and retrains the brain to perceive sensations as non-painful. It’s excitingly the first peripheral nerve stimulator to be approved in Canada that offers a curative solution.
Two weeks ago, Dr. Michael Gofeld, MD, PhD, FRCPC, implanted the first StimRouter into Jay Derrig, a patient with neurogenic pain. Last Thursday, I met with them to hear about how it went.
Jay Derrig is a 63 year old social worker and counselor afflicted with meralgia paresthetica in his right leg. Essentially, the nerve that supplies surface sensation to the thigh (lateral femoral cutaneous nerve) was damaged by compression against his hip bone. For Jay, it was likely caused by unlucky anatomy combined with wearing his belt tight around his waist. The pain began with occasional numbness in his thigh that became chronic, and eventually developed into unrelenting burning pain. He’d been suffering from this for over 16 years and had seen multiple doctors for it to no avail. His hobbies of kayaking, cycling, and backpacking/sailing around the world with his wife became increasingly impossible.
“It was constant, and really quite intense to the point where sometimes I felt like I was going to fall, because I felt like I didn’t have any muscle, because there was so much pain,” Jay said.
We met 10 days after the implantation of the StimRouter, and there was no signs of this past. Incredibly, he was pain-free. He sent chills down my spine as he told his story of how the pain was replaced by a dull tingling. This Jay Derrig was cheerful, relaxed, and smiling. His eyes sparkled with a joy of life and his bright pink shirt spoke loudly about his light mood. He bantered constantly with Dr. Gofeld.
“I crossed my fingers that he will know what he’s doing and that he has a license to do this,” he said. Turning to Dr. Gofeld: “I asked you if you had a license and if I was your first patient and you tried to skirt around it.”
Dr. Gofeld replied: “I said honestly: I’ve been doing PNS for 15 years, but this specific technique on a live patient – you are my first.”
“Yes, well that must’ve been the drugs I was on, because I didn’t quite hear it that way!” laughed Jay.
Dr. Gofeld is a Chronic Pain Management physician at the Silver Centre for Pain Care in North York, Ontario, and an Associate Professor at the University of Toronto. He trained in Israel and has had 15 years of experience in using peripheral nerve stimulation for nerve injuries.
For Jay’s procedure, Dr. Gofeld inserted the StimRouter’s guide lead through a stab incision in Jay’s hip area and positioned it to the target nerve using ultrasound guidance.
When Jay felt the stimulation in the right place, he gave feedback to Dr. Gofeld. Dr. Gofeld then held the guide’s location, replaced it with the permanent lead, and locked it in place. It was then ready to be activated using the external pulse generator.
The procedure took just 34 minutes. Dr. Gofeld completed the same procedure in his second patient in just 17 minutes. It left only a pimple-sized wound on Jay’s hip.
After the procedure, Jay was fitted with personalized programs for the external pulse generator that changed the amplitude, frequency, and pulse width of the therapeutic signal. This gave him full control throughout the day to choose a program to suit his pain needs. He’s been using it on a 4-hours on, 15-minutes off cycle so far. Some patients have found that as time went on, they relied on the device less and less with reports of some patients completely not needing it. This is thought to be due to sensory nerve rewiring in the brain from the stimulation leading to a permanent alteration in the way the brain perceives the pain.
Dr. Gofeld was excited to finally have an on-label product to specifically do the job after years of MacGyvering other systems.
“I was disappointed with off-label devices because of technical problems and cumbersome procedural setup,” he said. “I switched to an open (surgical) method and had success, although it required an incision, exploration of the nerve, suturing, etc. Hence, it still had a long operation, the risk of complications and patient inconvenience.”
He had been using spinal cord stimulators off-label as a peripheral nerve stimulators with limited success. These devices were bulkier, needed trials with multiple surgeries, and were fully implanted. They were typically used on-label for failed back surgery syndrome, complex regional pain syndrome, painful ischemic peripheral vascular disease, and ischemic cardiac disease. They often worked temporarily as peripheral nerve stimulators, but they weren’t robust enough. The leads slipped off during the typical day-to-day movements and the implants lost their efficacy. The StimRouter, on the other hand, has two major advantages: its leads had barbs to hold position within tissue, and its wire is flexible and stretches to conform to the patient’s movements. This kept the implants in place to stimulate the target nerve, creating a more robust system.
Dr. Gofeld discovered Bioness’ technology at a conference and collaborated with them to develop an ultrasound-guided technique for lead placement. Since 2015, he’d been involved with the development of the procedure, performing hundreds of implantations on cadavers. The organization he founded (World Academy of Pain Medicine Ultrasonography) has taught physicians across the world how to perform the procedure.
Dr. Gofeld noted that while the StimRouter can now cure patients of chronic pain, the remaining barrier in Ontario is the access to the device.
“Spinal cord stimulation took years until there was an Ontario Health Technology Assessment recommendation for the Ministry to have a budget for them. It will be a long, long wait until hospitals will pay for the PNS devices. Now we have an option from military, WSIB, police, private insurance. It’s a very bizarre situation in the hospitals because the PNS procedure is covered, but the device is not.”
He expects that the cost of the device will be covered by the province in 3 years after accumulating evidence for its efficacy in Canadians. Jay’s device was covered by Bioness.
Jay’s wife, Bev, was thankful for his recovery. “He got the quality of his life back, which is important to us because we travel an enormous amount, and we go to the gym every day, and we’re very, very active. He was losing more and more of it because he couldn’t keep up. Now he can kayak as long as I can go and bike 22 kilometers in the morning and he doesn’t have to get off because his leg is bothering – he can do it all. Mentally, it really stimulated him a great deal because it gave him back his quality of life. Now he feels so happy.”
I was relieved to hear how their lives would return to normal, and touched to see how close they were to each other.
“14 and a half years, and we’ve never had a quarrel. No words, not ever,” she smiled.
Of course, Jay elaborated with his typical banter. “Actually, we just don’t talk to each other!”