For children with difficulty controlling urination – and their families – sacral neuromodulation can be a last-resort option with welcome benefit, says John Pope IV, M.D., a pediatric urologist at Monroe Carell Jr. Children’s Hospital at Vanderbilt.
The sacral neuromodulation (SN) procedure involves surgical placement of a small device that provides electrical stimuli to the sacral nerve supporting bladder control. Vanderbilt is one of only a few centers offering SNM to pediatric patients, building on its successes in adult populations.
“Typically, this is end-stage treatment,” Pope said. “We’ve tried everything else and nothing is helping the incontinence or bladder frequency or urgency. We’ve tried meds, behavioral therapy, biofeedback and nothing has worked.”
“A high percentage of our patients would do it again in a heartbeat.”
Ultimately, SNM brings relief.
“It’s very successful. Patient satisfaction is fantastic. A high percentage of our patients would do it again in a heartbeat.”
Pope is a part of the Sacral Neuromodulation Alliance for Pediatric Patients (SNAPP), a group of three institutions that pooled data and presented long-term outcomes of SNM at the Societies for Pediatric Urology annual meeting.
The team found that among 196 children with refractory voiding dysfunction who underwent successful SNM procedures, nine out of 10 reported improvements of 75 percent or greater at their last follow-up visit.
Of 40 patients who had their device removed, 60 percent were because the patients had regained bladder or bowel control and the device was no longer needed.
Temporary Placement for Lasting Results
The results highlight a major difference between SNM procedures in children versus adults: duration.
“In adults, these devices are typically in for life. They don’t outgrow the problem,” Pope explained. “In kids, they get better. We’ve found we can turn the device off and monitor, and ultimately remove the device.”
Pope and his SNAPP colleagues attribute this to the neuroplasticity of the pediatric nervous system. The researchers have found children simply don’t have a long-term need once their neuromuscular pathways mature.
“After about three years, we will try to wean them off the device. We’ll turn it down or off and see if symptoms recur,” Pope said. “On average it takes about five years to get to the point where we can turn it off so their symptoms don’t recur. We’ll leave it off for a year and either take it out at that point – or turn it back on.”
The SNAPP team is currently working to refine the optimal timing for removal and other best practices. They are studying whether younger children may need SNM longer than older children, and potential variations in SNM duration for different kinds of bladder and bowel dysfunction.
Two-Stage Procedure, Careful Monitoring
Not all children will be candidates for the implant, Pope cautions.
Using urodynamic measurements, patients with hyperactive bladder or poor bladder emptying were found to have better responses to SNM devices than patients without either condition. Among the first to perform SNM in children, the Vanderbilt team has been selective in choosing candidates for the involved procedure.
Children receive the same InterstimTM device that is used for adults. The two-stage placement procedure requires careful monitoring from the child and their caregivers.
Initially, the device is placed for a trial period. Surgeons confirm nerve stimulation in the operating room and leave an external wire accessible that can be activated using a smartphone-like device.
Following a period of 7 to 10 days, if the results are successful, the child will return to the operating room for final device placement.
Despite the overall success rate, insurance coverage has been a challenge, Pope said.
Policies often require patients to keep strict diaries after initial device placement to demonstrate at least 50-percent symptom improvement.
“One hundred percent of our patients have gone on to the second stage and had the device implanted. Even with those data though, we have to do the trial for insurance,” Pope said.
Customizable for Personalized Care
Monitoring the device is a team effort that requires frequent contact with nurses and office staff to discuss symptoms. Maintenance of a bowel and bladder diary is mandatory to inform device programming, he said.
Urologists may adjust pulse frequency, width, rate, or amplitude for the (typically) four electrodes and finetune SNM for each patient to help personalize the device and maximize its value.
“We want to set the amplitude as low as possible to get a therapeutic effect and conserve battery life,” Pope said.
With pediatric SNM in its infancy, Pope says the procedure still has a 30-percent revision rate. The most common complication is device malfunction due to lead breakage, especially in slimmer children who lack fatty tissue to protect the adult-sized device.
Still, the benefit persists, Pope said.
“They are some of the most grateful and emotionally effusive patients that we have,” he said of the SNM recipients. “These are the kids and parents who come in literally crying for joy because it’s made such an impact on their life. It’s life-changing.”