Sacral nerve stimulation in the elderly

Updates on the use of neuromodulation in geriatric patients

PURPOSE OF REVIEW

In light of the updated AUA/SUFU guidelines on the diagnosis and treatment of overactive bladder (OAB), increased utilization of advanced therapies is expected in the coming years. The primary aim of this review is to summarize existing outcome and safety data on the use of neuromodulation in geriatric patients, as well as highlight recent advances in neuromodulation that may be particularly advantageous in the geriatric population.

RECENT FINDINGS

There are mixed data demonstrating efficacy of sacral neuromodulation by decade of life, with older individuals most often demonstrating lower odds of progressing to stage 2 implantation. However, a large majority of patients still undergo stage 2 implantation with no significant increase in complications reported when compared to younger cohorts. Neuromodulation is broadening to have wider indications outside of OAB, which may be particularly beneficial in the elderly population (fecal incontinence, nonobstructive urinary retention, and constipation). Posterior tibial nerve stimulation remains a well tolerated and efficacious treatment for OAB, with new FDA-approved implantable devices joining the commercial market, which may expand access for elderly populations.

SUMMARY

The data are encouraging and support the use of neuromodulation in geriatric patients.

Axonics® system for treatment of overactive bladder syndrome and urinary urgency incontinence

Introduction: Overactive bladder and urge urinary incontinence affect millions of women and men and results in billions of dollars in health-care expenses. First- and second-line therapy includes behavioral modifications and/or pharmacotherapies however, many patients' symptoms remain or progress on these treatments. There has been concern regarding the detrimental side effects of the most widely prescribed medications for these bladder symptom management.Areas covered: As a result, there has been increased interest in continuous sacral neuromodulation, an FDA approved therapy for refractory urinary urgency and urge urinary incontinence. In this article, we specifically review current research on the efficacy and patient/provider satisfaction and safety profile of the Axonics® System. In addition, we address the current state of sacral neuromodulation and potential future direction and applicability.Expert opinion: The Axonics® system is a safe effective device for the treatment of overactive bladder and urinary urge incontinence. Additionally, it affords patient's the convenience of a rechargeable, compact, MRI safe system. It should be noted that the rechargeable system, while allowing for approximately 15 years of battery and lead life, may have its challenges in terms of charge burden. Furthermore, this system is easily adapted for experienced implanters of sacral neuromodulating devices.

Overactive Bladder in Frail Older Adults

Overactive bladder (OAB) and frailty are multidimensional syndromes, and the prevalence of both increases with age. Little evidence exists for a direct association between OAB and frailty, but urinary urgency may well be a precursor of frailty in older people. Frail older adults are no less deserving of treatment than fit older adults, and lifestyle, behavioral, and pharmacological interventions remain the primary options for treatment, with some evidence for efficacy. Data on onabotulinumtoxinA therapy or percutaneous tibial nerve stimulation in frail older adults are sparse. Frail older adults are often excluded from drug trials, but evidence is accumulating that antimuscarinics and, to a lesser extent, beta-adrenergic agonists are safe, well-tolerated, and effective in older adults. Cognitive impairment associated with frailty should not be used as justification for avoiding the use of antimuscarinics. More studies are required to better understand the association between OAB and frailty, as both are associated with poor outcomes and may be amenable to intervention. Drug trials for OAB treatments should be encouraged to include frail older adults, as this population is highly affected yet often excluded.

Analysis of the Correlation Between the Clinical Effect of Sacral Neuromodulation and Patient Age: A Retrospective Multicenter Study in China

OBJECTIVES

This study aimed to evaluate whether patients stratified by age have the same level of benefits after a sacral neuromodulation (SNM) procedure for refractory lower urinary tract dysfunction.

MATERIALS AND METHODS

This retrospective study comprised 211 patients with refractory lower urinary tract dysfunction who had been treated with SNM and recruited from multiple medical centers across China. Patients were grouped according to age: <40 (n = 58), 40-64 (n = 94), and > 64 (n = 59) years. Data were compared using voiding diaries and subjective scores pre-operatively, post-implantation of a stage I tined lead, and during a short-term follow-up period postimplantation of a stage II implanted pulse generator.

RESULTS

In all groups, voiding diary data and subjective scores improved significantly over different periods. Residual urine improved in the 40-64 and > 64-year-old age groups. Quality of life scores improved in the <40-year-old age group. Voiding diary data among age groups varied at baseline; however, average urinary frequency did not differ at the last follow-up. Urgency and sexual life scores differed at baseline and these differences had resolved at the last follow-up. O'Leary-Sant and Pelvic Pain and Urgency/Frequency Symptoms Scale scores did not differ at baseline; however, significant differences were observed at the last follow-up.

CONCLUSIONS

SNM success is unrelated to age, and age alone should not be considered a limiting factor in SNM. For older patients, an overactive bladder appears a better indication for SNM treatment; however, further studies are required to confirm this finding.

Pathophysiology of the Underactive Bladder: Evolving New Concepts

PURPOSE OF REVIEW

Underactive Bladder (UAB) is an emerging concept of voiding dysfunction, building on a tradition of often overlapping and confusing terminologies describing the patient experience, urodynamic function, and pathophysiology. This confusion of symptoms with function with pathology has hampered development of an effective disease model.

RECENT FINDINGS

As with other urinary symptoms, the relationship of voiding symptoms to urodynamic dysfunction is variable. Efforts are underway to formally define UAB as a collection of symptoms related to voiding. Defined as voiding symptoms, UAB cannot be reliably linked to detrusor underactivity (DU) nor to detrusor weakness.

SUMMARY

Progress will be made by characterizing the functional disorders underlying UAB symptoms, examining the biology of these linkages, re-conceptualizing urinary control as one part of a more global biologic adaptive physiology, and determining the relationships of central and peripheral pathologies leading to disrupted control mechanisms.

Does patient age impact outcomes of neuromodulation?

AIMS

We evaluated whether patients stratified by age have the same level of risks/benefits after a staged neuromodulation procedure for refractory voiding symptoms.

METHODS

Urologic diagnosis, complications, and revisions were collected from medical records of adults enrolled in our prospective observational study. Symptoms were assessed over 2 years with diaries, Interstitial Symptom-Problem Indices (ICSI-PI), and the Overactive Bladder Questionnaire-SF (OAB-q SF). 12-item Short-Form Health Survey (SF-12v2®) mental (MCS) and physical (PCS) component summaries evaluated quality of life. Data were examined with Pearson Chi-square or Fisher's Exact test, Kruskal-Wallis tests, and repeated measures analyses.

RESULTS

Patients (83% female) were grouped by age (years): <40 (n = 46), 40-64 (n = 146), and ≥65 (n = 136). Urge incontinence was predominant in the older groups and more patients <40 had interstitial cystitis/painful bladder syndrome (IC/PBS). In the <40, 40-64, and ≥65 groups, respectively, generator implant (91%, 88%, and 89%) and explant (15%, 12%, and 10%) rates were similar. Complications (24%, 14%, and 9%; P = 0.031) and revisions (20%, 5%, and 6%; P = 0.0025) differed. For the three respective groups, urinary frequency (P < 0.0001 for all), nocturia (P < 0.0001 for all), incontinence episodes (P < 0.0001 for all), urgency (P = 0.0474, P < 0.0001, P = 0.0020), ICSI-PI (P = 0.0015, P < 0.0001, P < 0.0001), and OAB-q scores improved over time. Incontinence severity improved in those >65 (P = 0.0015). SF-12 PCS improved in those 40-64 (P = 0.0482) and MCS scores improved in the <40 and 40-64 age groups (P = 0.013 and P = 0.0440, respectively).

CONCLUSIONS

These data suggest that neuromodulation success is not age dependent, however continued study is needed to confirm findings.