麻豆传媒

Sacral neuromodulation (SNM) is effective -- at least in the short term -- for patients with a type of urinary tract dysfunction, according to Swiss investigators.

In a sham-controlled, double-blind study, 60 eligible patients with neurogenic lower urinary tract dysfunction (NLUTD) -- i.e., with urgency frequency syndrome, urgency incontinence, or chronic urinary retention -- had a neural stimulator implanted into the sacral foramina S3 or S4 for 2 months, reported Thomas M. Kessler, MD, of Balgrist University Hospital of the University of Zurich, and colleagues. The stimulator remained on for half the patients for an additional 2 months (the SNM ON group), and was turned off for the other half (SNM OFF).

As the team reported in , 2 months after the intervention 76% of the the SNM ON group had improvement of at least 50% in key bladder diary variables compared with baseline, while the condition of patients in the SNM OFF group deteriorated compared with baseline and resulted in treatment failure in 42%.

The odds ratio of the univariate association between SNM ON allocation and treatment success was 4.35 (95% CI 1.43-13.21, P=0.009), the researchers said. When adjusting for age, sex, and NLUTD type, the corresponding odds ratio in favor of SNM ON was 6.57 (95% CI 1.80-23.94, P=0.004).

"This trial found that SNM was effective and without device-related side effects once the testing and optimization phases were complete in our group of highly selected neurologic patients," Kessler and co-authors wrote. "The randomized study design not only proved SNM-specific treatment effects but also the need for continuous SNM."

The researchers noted that although SNM is a well-established therapy for non-NLUTD, there is a lack of randomized controlled trials to show benefit in patients with NLUTD.

The current study was conducted in four Swiss centers and included 124 patients with symptomatic refractory NLUTD. Their median age was about 50, and most were women. Patient neurologic conditions included spinal cord injury, multiple sclerosis, Parkinson's disease, spina bifida, cerebrovascular event, cerebral palsy, herniated disc, and pelvic surgery, as well as other neurologic diseases.

Patients first underwent a testing phase to determine whether they would positively respond to neural stimulation (via a minimally invasive lead placed into the sacral foramina). A total of 65 patients had a clinically relevant positive response (i.e., ≥50% improvement in key bladder diary variables, such as the number of voids or leakages). A permanent neurostimulator was then implanted in 60 of those patients, who proceeded into the intervention stage of the study.

There were 11 adverse events, six of which resulted in patients dropping out of the study, but there were no dropouts during the intervention phase.

Quality of life was also assessed by the Qualiveen questionnaire, which consists of 30 items grouped in four domains (inconvenience, restrictions, fears, and impact on daily life) using 5-point scales (with 0 representing asymptomatic). Among all the patients assigned to the intervention, the questionnaire scores changed from a mean of 1.76 to 1.09.

And irrespective of whether patients were in the SNM ON or SNM OFF groups, improvements were seen in the number of voids, leakages, and maximum storage detrusor pressure in those with urinary frequency syndrome; in postvoid residual, number and volumes of catheterizations, mean voided volume, and leakages in the chronic urinary retention group; and in the catheterization number and volume and number of leakages in the combined group, the researchers noted.

There were no differential effects in quality of life, bladder diary outcomes, or urodynamic outcomes in univariate or in multivariate analyses between the SNM ON and SNM OFF groups.

Limitations of the study, the investigators said, included that it involved a heterogenous neurologic population and was not powered for neurologic disease-specific analysis. In addition, given the preselection of SNM responders, the trial design induced a selection bias for the randomized controlled trial part and hampered the generalizability of overall effects and responder rates in the general NLUTD population.

"Although our trial was small, our data close a relevant knowledge gap with respect to short-term efficacy," Kessler and colleagues concluded, adding that future studies are needed to investigate SNM in longer trials and in different and larger NLUTD patient groups.

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