Sacral neuromodulation eases symptoms in kids amid high reoperation rates

Despite high rates of reoperation, most children on sacral neuromodulation (SNM) devices either continue to use these tools or experience symptom improvements enough to permit device removal in the moderate term, according to a new study.

“We sought to assess the need for secondary surgeries in our larger cohort of SNM patients to better understand complication rates and explantation for symptom improvement over longer follow up,” the researchers said.

“We hypothesized that longer follow-up would be associated with more secondary surgeries and further that patient factors such as low body mass index (BMI) and attention-deficit/hyperactivity disorder (ADHD) would be associated with lead dislodgement/fracture requiring revision,” they added.

The study included 187 paediatric patients (median age at placement, 9.7 years; 25 percent male) on SNM who were followed for complications, such as infections or nonfunctioning devices, requiring secondary surgeries for implant revision or removal. Seven participants did not receive permanent lead implants due to poor response in the trial period; the remaining 180 patients had permanent devices.

Over a median follow-up of 3.9 years, a total of 154 secondary surgeries related to the implanted devices took place in 110 patients (61 percent). Eighty-three reoperations in 59 patients were for device revision, while 71 were for permanent device removals. [J Pediatr Urol 2021;17:72.e1-72.e7]

Forty-four removals were explantations due to symptom improvement after parents or guardians expressed interest in trying a ≥6-month trial period without device and found the resulting symptom profile favourable. These favourable removals occurred a median of 4.0 years after initial placement.

Overall, 110 procedures in 78 patients were conducted for unfavourable reasons such as battery depletion (8 percent; n=9), broken/displaced lead (59 percent; n=65), explantations for ineffective devices (15 percent; n=17), pain (12 percent; n=13), and infections (5 percent; n=6).

Of the 110 patients needing secondary surgeries, 31 had more than one such procedures, accounting for 49 percent (n=75) of all secondary surgeries. One patient needed five revisions for broken/displaced leads, which was the most common reason for serial revision. Of note, one patient who needed repeated revision had ADHD.

However, Fisher’s exact test did not identify ADHD as a significant correlate of the frequency of device removal or revision for either favourable (p=0.32) or unfavourable (p=0.38) reasons.

In contrast, follow-up time emerged as a significant correlate of revision or removal. For example, those who were followed for ≥2 years were significantly more likely to have secondary operations due to symptom improvement/resolution (30 percent vs 7 percent; p<0.01) or for unfavourable reasons (52 percent vs 18 percent; p<0.01).

“While SNM in children carries a high reoperation rate whether for complication or symptom improvement, the majority of these patients with previously refractory symptoms either continue to use their device or have had significant symptom improvement permitting device explantation at moderate term,” the researchers said.

“[W]e still cannot determine if patient symptom improvement and resolution is a result of SNM intervention, or the natural history of bladder and bowel dysfunction in these patients with previously severe refractory symptoms. Discerning this would require a comparison group, ideally in randomized fashion,” they added.