Implantable Tibial Nerve Stimulation Devices for Treatment of Overactive Bladder - Episode 6
OAB experts share their experience with reimplantation of a tibial nerve stimulation device (eCoin).
Scott MacDiarmid, MD, FRCPSC: Let me comment on the redos [reimplantations], because that was one of the things you wanted to ask me. With Judy, my research nurse who is doing all of these with me, it was almost the same. You prep the patient the same, you do the same markings, you put in the same local anesthetic, and you open up the same incision. There’s a bit of a scar between the incision, and the eCoin is purposely below it. Because if you’ve ever had a wound infection, which I did once, it’s still 1 cm-plus away from the top of the eCoin, so you can clear up the wound infection and not get the eCoin. I had that exact patient with a positive culture of staph.
But with that little area, there’s an easy technique to spread that and open that up, and the pseudocapsule is very easy to find. You make a little scalpel blade, you open it up, use your scissors to open up a pseudocapsule like you’re used to, for instance with sacral nerve stimulation, and you slip it out, put in a new one, and say, “We’re closing it again.” There are a few tricks, but overall, the replacement is easy and equally safe. It’s a little more challenging, but it’s easy to do and safe. We’ve got 1-year data. We did the feasibility study. We finished that, it was 1-year follow up, then we [removed the devices from those patients]. We had a large cohort of 23 patients who had one reimplanted and were followed again for a year, and the data basically look the same. In fact, it looked a little better, but it might have been on patient selection on responders. But they did very well when you replace it.
Alexandra Rogers, MD: And all of those were done in the office, which speaks to the fact that it’s achievable to do these exchanges.
Scott MacDiarmid, MD, FRCPSC: Yes, in the office.
Alexandra Rogers, MD: You’re not changing the stimulation amount of scar or impedance that’s occurring because you’re not messing with that bottom stimulation area. And certainly, people who are going to choose to have another eCoin responded the first go-round because the responder rate is 82% at 6 months, and a 36% dry rate.
My last question on reimplants is, when we did the pivotal study, we were very mindful of lateral shifting before encapsulation off the nerve. I’m excited that with the reimplants, you shouldn’t have to worry about lateral shifting off the nerve because you’re putting it into that existing pocket.
Scott MacDiarmid, MD, FRCPSC: Yes, that won’t be going anywhere. You’re right, it’s in the capsule. It’s like a little glove.
Transcript edited for clarity.