麻豆传媒

Despite its increasing use for bladder and bowel dysfunction, sacral neuromodulation (SNM) has a substantial failure rate, due often to device malfunction. Within 5 years of initial implantation, one in three patients had some form of reintervention, either revision or removal, according to a Research Letter published online in

In a statewide data review of almost 5,000 SNM procedures -- done for all indications during 2008-2015 -- Bilal Chughtai, MD, of New York-Presbyterian/Weill Cornell Medical College in New York City, and colleagues found that almost 15% of patients needed device revision or removal within the first year of implantation.

"At this time, we need to focus our energies on determining which patients can benefit from a sacral neuromodulator," Chughtai told 麻豆传媒. "We urgently need an all-inclusive device registry that can help understand who would benefit the most from this therapy."

The mean age of the 4,946 SNM recipients, drawn from the New York Statewide Planning and Research Cooperative System, was 60.7, and 79.7% of the total were female. The primary indication for SNM was wet overactive bladder, affecting 2,534 patients (51.2%). Within 1 year, 592 of 4,313 evaluable patients (13.7%) required reintervention. Within 3 years, 767 of 2,920 patients (26.3%) needed reintervention, and within 5 years, 575 of 1,514 (33.0%) required reintervention.

The most common indications for reintervention were treatment or device failure -- in year 1, 278 of 592 patients (47.0%) and 280 of 592 patients (47.3%), respectively. At 5 years, 190 of 575 reinterventions (33.0%) were associated with treatment failure and 367 of 575 (63.8%) to device malfunctions. Pain was an infrequent reason, and infections were not reportable.

"One in 3 patients had some form of reintervention -- either revision or removal -- within 3 to 5 years of initial device placement, which is in stark contrast to the manufacturer's reported device survival probability of 97.9% over a 3-year period," the researchers wrote. No significant differences emerged between high- and low-volume hospitals or surgeons. "Even in the hands of high-volume surgeons, the invasive surgical reintervention rate remains very high."

Chughtai said that although the rates of reintervention were much higher than expected, especially when considering the low rates acknowledged by manufacturers, some patients do well with the device. "So the technology should not be ruled out as a treatment for bladder and bowel dysfunction, but patients need to be counseled about potential high rates of reinterventions and possible failures."

In a 2015 Medicare Chughtai and associates had reported an 11.3% reintervention rate for NSM at 90 days, which rose to 33% at 5 years. More recently, a by Steven Siegel and colleagues reported a 5-year therapeutic success rate for urge incontinence at 5 years of only 67%.

Asked for his perspective, Michael J. Kennelly, MD, of the Carolinas HealthCare System in Charlotte, NC, who was not involved with the study, noted that it included patients across all four urinary-fecal indications for SNM: "It's a mixed bag who they were treating. And some patients can have several different things that you're trying to improve. In the future we need better-defined groups for what we're trying to achieve."

Kennelly added that some patients have abnormal sensory awareness from the device's electrical energy and ask for it to be removed. And all therapies for overactive bladder, particularly advanced ones such as SNM, have different risk-benefit profiles. "We have to understand that overactive bladder is a long-term condition, and as with all implantable devices, we have to continue to monitor recipients for adverse events," he said.

In addition, the realistic aim is not always to eliminate the problem: "You're not curing it; you're getting it under control to a level where's it's no longer at the front of the patient's brain."

While people are looking for a single-fix monotherapy -- "a one-and-done" -- the management of urinary incontinence often requires a multifaceted approach involving individual patient factors, medications, lifestyle adjustments, and implantable devices, Kennelly added. "Too often we pit these therapies against one another when really they're complementary."

The researchers noted that study limitations included the lack of generalizability of state-based findings to the entire U.S. population, and possible misclassification due to billing codes.

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