Urgent-SQ implant in treatment of overactive bladder syndrome: 9-year follow-up study

Beyond Tissue replacement: The Emerging role of smart implants in healthcare

Smart implants are increasingly used to treat various diseases, track patient status, and restore tissue and organ function. These devices support internal organs, actively stimulate nerves, and monitor essential functions. With continuous monitoring or stimulation, patient observation quality and subsequent treatment can be improved. Additionally, using biodegradable and entirely excreted implant materials eliminates the need for surgical removal, providing a patient-friendly solution. In this review, we classify smart implants and discuss the latest prototypes, materials, and technologies employed in their creation. Our focus lies in exploring medical devices beyond replacing an organ or tissue and incorporating new functionality through sensors and electronic circuits. We also examine the advantages, opportunities, and challenges of creating implantable devices that preserve all critical functions. By presenting an in-depth overview of the current state-of-the-art smart implants, we shed light on persistent issues and limitations while discussing potential avenues for future advancements in materials used for these devices.

Adapting the Finetech-Brindley Sacral Anterior Root Stimulator for Bioelectronic Medicine. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021;2021:6406-6411. [PMID: 34892578 DOI: 10.1109/embc46164.2021.9630995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The Finetech-Brindley Sacral Anterior Root Stimulator (SARS) is a low cost and reliable system. The architecture has been used for various bioelectric treatments, including several thousand implanted systems for restoring bladder function following spinal cord injury (SCI). Extending the operational frequency range would expand the capability of the system; enabling, for example, the exploration of eliminating the rhizotomy through an electrical nerve block. The distributed architecture of the SARS system enables stimulation parameters to be adjusted without modifying the implant design or manufacturing. To explore the design degrees-of-freedom, a circuit simulation was created and validated using a modified SARS system that supported stimulation frequencies up to 600 Hz. The simulation was also used to explore high frequency (up to 30kHz) behaviour, and to determine the constraints on charge delivered at the higher rates. A key constraint found was the DC blocking capacitors, designed originally for low frequency operation, not fully discharging within a shortened stimulation period. Within these current implant constraints, we demonstrate the potential capability for higher frequency operation that is consistent with presynaptic stimulation block, and also define targeted circuit improvements for future extension of stimulation capability.

Frequency-Dependent Effects on Bladder Reflex by Saphenous Nerve Stimulation and a Possible Action Mechanism of Tibial Nerve Stimulation in Cats

Purpose

The present study determined the effects of saphenous nerve stimulation (SNS) at different stimulation frequencies on bladder reflex and explored a possible action mechanism of tibial nerve stimulation (TNS) on bladder activity in cats.

Methods

Two bipolar nerve cuff electrodes were implanted on the saphenous nerve and the contralateral tibial nerve in 13 cats, respectively. Multiple cystometrograms were obtained to determine the effects of single SNS at different frequencies and that of combined SNS and TNS on the micturition reflex by infusing normal saline.

Results

SNS at 1 Hz significantly reduced the bladder capacity (BC) to 59.8%±7.7% and 59.3%±5.8% of the control level at the intensity threshold (T) and 2T, respectively (P<0.05), while that at 20 Hz significantly increased the BC to 130.6%±4.2% of the control level at 6T (P<0.05). The TNS and SNS at 20 Hz did not significantly change the BCs at 1T (P>0.05), while combined stimulation at 1T significantly increased the BC to 122.7%±1.9% of the control level and induced an inhibitory effect which was similar to that TNS at 2T.

Conclusions

The current study revealed that SNS reduced and increased BC depending on different stimulation frequencies. The combined SNS and TNS maximized the clinical efficacy at a low intensity. Also, SNS may be a potential therapeutic mechanism of TNS.

Posterior tibial nerve stimulation for overactive bladder-techniques and efficacy

The ideal treatment for overactive bladder is still elusive. In those where medication fails to improve symptoms options include invasive treatments such as botulinum toxin-A, sacral neural stimulation or posterior tibial nerve stimulation. Scientific professional society guidelines advise percutaneous posterior tibial nerve stimulation as a third line treatment option only after multi-disciplinary team review as well as failure of both conservative and pharmacological management. The aim of this article is to review all techniques for tibial nerve stimulation and their efficacy.

Long-term real-life adherence of percutaneous tibial nerve stimulation in over 400 patients

Background

Percutaneous tibial nerve stimulation (PTNS) is used as a treatment to reduce the complaints of overactive bladder (OAB). Although it is rewarding therapy patients need maintenance treatment to preserve the beneficial effect.

Aim

This real‐life retrospective study was performed to assess the feasibility of PTNS adherence.

Materials & methods

All patients who underwent PTNS were retrospectively included. We analyzed the following: indication, kind of treatments (pharmacologic and third‐line therapy) before and after PTNS treatment, time and reason for quitting therapy. Statistical analysis was done by performing competitive‐risk analysis and Kaplan‐Meier curves. Patients were categorized into four groups. Group 1: all patients; group 2: all patients on maintenance PTNS therapy (continuing after 12 weeks); group 3: patients on maintenance PTNS therapy excluding the following: (a) patients with initial good response who seized treatment due to death, (b) patient who successfully switched to transcutaneous stimulation, (c) patients who were cured of their OAB symptoms, or (d) patients who relocated; and group 4: group 3 but excluding those who stopped treatment because of nonmedical reasons (physical strain, inconveniencies associated with visiting the hospital).

Results

Four‐hundred two patients (70% female) with a median age of 70 years underwent PTNS. Underlying treatment indications were: OAB‐wet (54%) and OAB‐dry (29%). The median follow‐up (FU) of group 1 was 4 months. Fifty‐seven percent (N = 228) of the patients received maintenance PTNS therapy. Median FU in group 4 was 46 months (range, 3‐111 months). Over 40% of the maintenance patients stopped PTNS because of logistic reasons and physical strain during an FU time of 6 years.

Conclusion

The real‐world data described here with is in line with earlier published work in terms of the success rate of OAB treatment. However, over 40% quit their therapy due to nonmedical reasons.

Electrical neuromodulation in the management of lower urinary tract dysfunction: evidence, experience and future prospects

Lower urinary tract dysfunction (LUTD) is common and causes a spectrum of morbidity and decreased quality of life (QoL) for patients. LUTD can range from urinary retention to urge incontinence, and includes a variety of syndromes, with the most common and widely recognized being overactive bladder (OAB). The classic treatments of LUTD and OAB comprise different strategies including behavioral therapies, medications and minimally invasive or invasive surgical procedures. Generally, once patients have tried behavioral modifications and oral medical therapy, and have not experienced adequate relief of their symptoms, the next step is to consider minimally invasive therapies. In the last two decades since FDA approval, sacral nerve stimulation (SNS) has become an accepted intervention, with increasing use and evidence of effectiveness for LUTD, specifically OAB and non-obstructive urinary retention. SNS has shown both objective and subjective improvement in voiding symptoms in several randomized controlled trials (RCTs) when compared to sham or standard medical therapy. The main limitations for more extensive use include relatively high cost, implantation of a device and possibly reoperation secondary to adverse events (AE). Percutaneous tibial nerve stimulation (PTNS) is a less invasive, less direct and less expensive method for neuromodulation, which has also shown effectiveness in several randomized and non-randomized trials, including comparable improvement rates to anticholinergics in OAB management. However, the efficacy of PTNS is only maintained for a short period after the stimulation is delivered. This technique has a much lower rate of AE compared to SNS, but with the inconvenience of weekly visits for stimulation, although implantable devices are on the horizon. In this article we review the mechanism of action, indications, effectiveness and complications related to SNS and PTNS therapy for LUTD.

A pilot feasibility study of treating overactive bladder patients with percutaneous saphenous nerve stimulation

AIMS

Effective long-term treatment of overactive bladder (OAB) remains a significant clinical challenge. We present our initial experience with a new bladder neuromodulation method that electrically targets the saphenous nerve (SAFN).

METHODS

A total of 18 OAB patients (female, 55-84 years) were provided with percutaneous SAFN stimulation. The SAFN was targeted with a needle electrode inserted below the medial condyle of the tibia. Activation of the SAFN was confirmed by the patient's perception of paresthesia radiating down the leg. Electrical stimulation was applied for 30 min and subsequently repeated weekly for 3 months. The effects of stimulation were assessed by a 4-day bladder diary and quality-of-life questionaire (OAB-q).

RESULTS

Percutaneous SAFN stimulation was confirmed in all 16 patients who completed the study, and no adverse events were reported. Positive response to SAFN stimulation was achieved in 87.5% (14 of 16) of patients, as determined by either a minimum 50% reduction in bladder symptoms or a minimum 10 point increase in the HRQL total score.

CONCLUSIONS

Electrical activation of the SAFN was consistently achieved using anatomical landmarks and patient feedback. The procedure was well tolerated and, based on our small cohort of patients, appears efficacious, and safe. This pilot study provides early feasibility data that points to a promising new intervention for treating OAB.

A novel leadless, miniature implantable Tibial Nerve Neuromodulation System for the management of overactive bladder complaints

BACKGROUND

Overactive bladder is a chronic condition affecting lower urinary tract function that has a significant negative impact on QoL.

OBJECTIVE

Evaluation of the BlueWind implantable tibial nerve system performance and safety in refractory OAB.

DESIGN, SETTING, AND PARTICIPANTS INTERVENTION

A 6-month multi-center prospective intervention study.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Objective assessment was done by voiding diary parameters including voids/day, volume voided/day, urgency assessment, leaking episodes/day, pads used/day, leak severity, and clinical success defined as a ≥50% reduction in the number of leaks/day or number of voids/day or number of episodes with degree of urgency >2 or a return to <8 voids/day on a 3 Day diary. Subjective assessment was based on OAB-q including HRQL and symptom severity score. Safety was evaluated by adverse event (AE) analysis.

RESULTS AND LIMITATIONS

Thirty-four of the 36 implanted subjects completed the study. One subject withdrew voluntarily and one developed inflammation necessitating removal of the system. In the remaining subjects, 71% experienced clinical success at 6 months. Leaks/day, leak severity, and pad changes/day decreased significantly over time with 27.6% of urge incontinence subjects that became "dry." Voids/day, degree of urgency, volume/void, pads changed improved significantly. All quality of life aspects (concern, coping, sleep, and social) improved as well as symptom severity scores measured by the OAB-q. Adverse events included: implant site pain (13.9%), suspected infection (22.2%), and procedural wound complications (8.3%).

CONCLUSIONS

The BlueWind implantable tibial nerve stimulator is a safe, minimally invasive system that affords OAB patients significant improvements.

PATIENT SUMMARY

The performance and safety of the BlueWind RENOVA™ implantable tibial nerve neuromodulator for OAB was tested. Our preliminary results demonstrate that the system has a low risk safety profile and may be considered an effective treatment option for OAB management.

An Enhanced Method of Transcutaneously Stimulating the Tibial Nerve for the Treatment of Overactive Bladder

Transcutaneous electrical nerve stimulation (TENS) can be used to electrically stimulate the tibial nerve for the purpose of treating overactive bladder. Although clinical benefits can be achieved, the overall therapeutic efficacy of TENS is limited. Inconsistent activation of the intended neural target and co-activation of cutaneous sensory fibers are considered key limiting factors. In this study, we propose a novel approach that combines TENS with an implanted, electrically-conductive nerve cuff to reduce the stimulation amplitude needed to activate the tibial nerve. This enhanced version of TENS (called eTENS) was designed using a computational model of the rat tibial nerve and subsequently tested in anesthetized rats. Our computational model showed that eTENS can reduce the nerve activation threshold by a factor of up to 2.6. Similar effects were also achieved by in vivo experiments (1.4 ± 0.1-fold decrease, n = 5). Among various design parameters, spatial alignment between the surface electrode and the nerve cuff was identified as an important factor. Our results show that eTENS can improve the selective activation of the rat tibial nerve, but further work is needed to evaluate its use in clinical therapies.

Effectiveness of percutaneous tibial nerve stimulation in the treatment of overactive bladder syndrome

Overactive bladder syndrome (OAB) is a common condition affecting adults and children worldwide, resulting in a substantial economic and psychological burden. Percutaneous tibial nerve stimulation (PTNS) is derived from acupuncture used in Chinese traditional medicine and was first described in the early 1980s. It is a neuromodulation technique used to modulate bladder function and facilitate storage. Being a minimally invasive, easily applicable, but time-consuming treatment, future developments with implantable devices might be the solution for the logistical problems and economic burden associated with PTNS on the long term. This nonsystematic review provides a current overview on PTNS and its effectiveness in the treatment of OAB for both adults and children.

Clinical utility of neurostimulation devices in the treatment of overactive bladder: current perspectives

Objectives

This review describes the evidence from established and experimental therapies that use electrical nerve stimulation to treat lower urinary tract dysfunction.

Methods

Clinical studies on established treatments such as percutaneous posterior tibial nerve stimulation (P-PTNS), transcutaneous electrical nerve stimulation (TENS), sacral nerve stimulation (SNS) and sacral anterior root stimulation (SARS) are evaluated. In addition, clinical evidence from experimental therapies such as dorsal genital nerve (DGN) stimulation, pudendal nerve stimulation, magnetic nerve stimulation and ankle implants for tibial nerve stimulation are evaluated.

Results

SNS and P-PTNS have been investigated with high-quality studies that have shown proven efficacy for the treatment for overactive bladder (OAB). SARS has proven evidence-based efficacy in spinal cord patients and increases the quality of life. TENS seems inferior to other OAB treatments such as SNS and P-PTNS but is noninvasive and applicable for ambulant therapy. Results from studies on experimental therapies such as pudendal nerve stimulation seem promising but need larger study cohorts to prove efficacy.

Conclusion

Neurostimulation therapies have proven efficacy for bladder dysfunction in patients who are refractory to other therapies.

Significance

Refinement of neurostimulation therapies is possible. The aim should be to make the treatments less invasive, more durable and more effective for the treatment of lower urinary tract dysfunction.

A New Implanted Posterior Tibial Nerve Stimulator for the Treatment of Overactive Bladder Syndrome: 3-Month Results of a Novel Therapy at a Single Center

PURPOSE

This study was designed to investigate the safety and performance of a new implantable system for tibial nerve stimulation for overactive bladder symptoms.

MATERIALS AND METHODS

A battery-free stimulation device for tibial nerve stimulation (BlueWind Medical, Herzliya, Israel) was implanted in 15 patients. Safety and efficacy assessments were done at 3 months after activation with a 3-day bladder diary, a 24-hour pad test and 2 quality of life questionnaires.

RESULTS

Two males and 13 females were enrolled in the study. Mean age was 54 years (range 19 to 72). Five of 15 patients were previously treated with percutaneous tibial nerve stimulation and 12 experienced urgency urinary incontinence. Median operative time was 34 minutes. At 3 months of followup a significant change was seen in 24-hour frequency from a mean ± SD of 11.8 ± 3.5 to 8.1 ± 2.0 times per day (p = 0.002), the number of severe urinary urgency episodes from 6.5 ± 5.1 to 2.0 ± 2.1 times per day (p = 0.002), the number of severe incontinence episodes from 2.8 ± 5.2 to 0.3 ± 0.4 episodes per day (p = 0.017), urinary loss per day from 243 ± 388 to 39 ± 55 gm (p = 0.038) and improvement in quality of life. After implantation, 3 patients received prolonged antibiotic treatment and 3 received pain medication for 1 week. In 1 patient the device was explanted due to pain and swelling suspicious for infection, although tissue cultures did not reveal a bacterial infection.

CONCLUSIONS

This novel posterior tibial nerve stimulator is safe and easy to implant with good clinical results.

Posterior tibial nerve stimulation using a wirelessly powered system in anesthetized cats

Posterior Tibial Nerve Stimulation (PTNS) is an effective overactive bladder (OAB) therapy where electrical pulses are typically delivered once per week in a 12-week stimulation regime. While the mechanism of action remains unknown, effective long-term delivery of PTNS has recently become a subject of concern. To this end, a multi-contact electrode was surgically placed in the hind limb region of anesthetized cats to (1) investigate the feasibility of using a wirelessly powered system to stimulate PTN afferents and (2) characterize implant-driven effects of stimulation frequency on modulating bladder activity. Using an isovolumetric model, short-duration, supra-threshold stimulation trials were applied with frequencies ranging from 2-20 Hz. The results provide first pre-clinical evidence of frequency-dependent modulation of bladder function supporting the use of a novel therapeutic approach that can be clinically translated to potentially address multiple symptoms of lower urinary tract system.

Inhibition and Excitation of Bladder Function by Tibial Nerve Stimulation Using a Wirelessly Powered Implant: An Acute Study in Anesthetized Cats

PURPOSE

Tibial nerve stimulation is a minimally invasive neuromodulation treatment of overactive bladder. However, in addition to our limited understanding of the underlying mechanisms, there are also questions regarding the long-term delivery of tibial nerve stimulation therapy in patients. We aimed to characterize the effects of stimulation frequency using a wirelessly powered implantable stimulation device.

METHODS AND MATERIALS

Six α-chloralose anesthetized adult male cats were used in this study. A multicontact lead was surgically implanted subcutaneously in the hind limb and used to stimulate the tibial nerve. Using an isovolumetric bladder a short duration of electrical pulses was applied at amplitudes 3 times the motor threshold and at frequencies from 2 to 20 Hz.

RESULTS

Implant driven stimulation of the tibial nerve resulted in frequency dependent activation of bladder reflexes. Low frequency tibial nerve stimulation (2 Hz) consistently evoked excitatory responses (mean ± SE 32.9% ± 3.8%). In contrast, higher frequency tibial nerve stimulation (6 to 20 Hz) inhibited bladder function (overall mean 14.9% ± 2.4%). Although low foot motor thresholds were achieved at initial implantation (mean 0.83 ± 0.05 mA), a notable elevation in threshold amplitude was observed 5 hours after implantation.

CONCLUSIONS

To our knowledge this study provides the first evidence of frequency dependent modulation of bladder function in anesthetized cats. The inhibitory influence of tibial nerve stimulation at frequencies above 6 Hz transitioned to an excitatory effect at 2 Hz. Taken together these preclinical data support the feasibility of using a wirelessly powered implantable device to potentially modulate bladder function in patients.

Does percutaneous tibial nerve stimulation improve global pelvic function in women with faecal incontinence?

AIM

Percutaneous tibial nerve stimulation (PTNS) is a minimally invasive treatment for faecal incontinence. Many patients with faecal incontinence have coexisting pelvic floor disorders such as urinary incontinence and vaginal symptoms. We utilized a pelvic floor assessment tool to analyse any effect of PTNS on global pelvic floor function.

METHODS

Patients with faecal incontinence attending our institution who had failed to respond sufficiently to biofeedback were offered a course of PTNS. Patients underwent pre- and post-stimulation assessment with a validated electronic Personal Assessment Questionnaire - Pelvic Floor (ePAQ-PF) for pelvic floor disorders. Scores were compared to assess the effect of treatment on global pelvic floor function.

RESULTS

During the study period pre- and post-stimulation ePAQ-PF data were available for 60 patients (55% of all patients starting PTNS). In this cohort there was a significant improvement in bowel continence, bowel related quality of life, irritable bowel syndrome and bowel evacuation with a large effect size for continence and bowel related quality of life. There was also a significant improvement in non-bowel related symptoms, including urinary pain and stress incontinence, urinary related quality of life and bowel related sexual function. Sixty-five per cent of those who answered the question reported improvement in global health after stimulation.

CONCLUSION

For patients presenting with faecal incontinence, PTNS appears to have a positive effect on bowel related function in approximately two-thirds of patients. However, for treatment responders, improvement appears to relate mainly to improvement in bowel related function rather than a global pelvic floor effect.

Understanding clinic options for overactive bladder

Overactive bladder (OAB) is a symptom complex of urinary frequency, nocturia and urgency with or without urgency incontinence that adversely impacts patient's quality of life. Conservative management begins in the outpatient clinic, often with significant improvement and patient satisfaction. In this review we will discuss the evaluation of OAB and review treatment options focusing on behavioral modification, medical therapy, and neuromodulation. These treatment options are offered in a stepwise fashion, remembering that more than one may be needed and can be used concomitantly.

Urinary Incontinence in the Young Woman: Treatment Plans and Options Available

Urinary incontinence is a common and distressing condition, which, although not life-threatening, is known to have a significant effect on quality of life. The incidence of urinary incontinence increases with age and while stress urinary incontinence is more common in younger women, symptoms suggestive of overactive bladder are more common with increasing age. All women complaining of incontinence require simple investigation, and many will benefit from conservative and medical treatments, which may be instituted in primary care. Further investigation in the secondary-care setting should be reserved for those women with refractory or unusual symptoms. The aim of this paper is to review the epidemiology and pathophysiology of common causes of urinary incontinence in younger, premenopausal women, and to review the current algorithms for investigation and management. In addition, treatment paradigms covering conservative, medical and surgical treatment for stress urinary incontinence and overactive bladder will be reviewed.

Posterior tibial nerve stimulation as treatment for the overactive bladder

OBJECTIVE

To evaluate the efficacy of posterior tibial nerve stimulation (PTNS) as a treatment for the overactive bladder (OAB) resistant to medical treatment.

PATIENTS AND METHODS

The study included 60 patients, comprising 55 women (92%) and five men (8%) with a mean (SD) age of 41.4 (10.8) years, who presented to the Urology Department of Benha University Hospital from June 2010 to October 2012. All patients were assessed initially by taking a history, a physical examination, urine analysis, routine laboratory investigations, and a urodynamic evaluation in the form of flowmetry, cystometry, and a pressure-flow study in some cases. A voiding diary (daytime and night-time frequency, voiding volume, and leakage episodes) was completed by all patients, and all underwent 12 sessions of PTNS using a personal computer-based system, and were reassessed after the sixth session, at the end of the course, and at 3 and 6 months after the last session, using the same methods as in the baseline visit.

RESULTS

There was a statistically significant improvement in all the variables assessed. No infection or failure of the PTNS mechanism was detected while using the technique, but there were rare instances of minor bleeding and a temporary painful feeling at the insertion site.

CONCLUSION

PTNS is safe, and gives statistically significant improvements in the patient's assessment of OAB symptoms.