Refractory Overactive Bladder (OAB) patients have traditionally been treated by both Sacral Nerve Stimulation (SNS) and Percutaneous Tibial Nerve Stimulation (PTNS). Although effective, SNS is invasive and laborious, whereas repetitive PTNS is burdensome.  The BlueWind RENOVA iStim™ System is a novel miniature, leadless, battery-less, implantable tibial nerve stimulator, which provides a minimally invasive therapy focusing on a patient-centric home treatment.  The pulse generator implant is wirelessly powered by a wearable unit that controls the therapeutic parameters and is worn by the patient during home treatment. A Clinician Programmer is used to remotely set individual stimulation parameters and assess compliance with therapy.
A pivotal trial is being conducted to evaluate the safety and efficacy of the RENOVA iStim System for treating refractory OAB patients.

One hundred and nighty five (195) women suffering from wet OAB will be enrolled in this prospective, single arm, open-label study. The study is being conducted at ~30 centers in the United States, Europe and Israel. The device is implanted in the lower leg during a minimally invasive procedure in which it is secured superficial to the tibial neurovascular bundle, just below the fascia.  Suturing to the fascia mitigates any risk of migration and permits patients to be mobile.  The implant is activated ~4 weeks after implantation. The patient is instructed to apply the wearable unit (figure 1) and perform daily treatments at home for 30-120 minutes per day. Voiding diary data, quality of life questionnaires and patient satisfaction questionnaires are collected at 6 and 12 months after device activation and are compared to baseline.

A total of 41 patients, mean age 60.15 (SD: 12.3, N=39), have been implanted with the device in 7 centers in Europe, and 7 centers in the US. The 41 implanted patients demonstrated mean baseline of 5.88 UUI/day and 10.07 voids/day. 
Out of the 41 implanted patients, 13 have reached 6 months post system activation and 10 have reached 12 months. To date, no Serious Adverse Events related to the device or procedure occurred. Overall, 2 device related AEs and 4 procedure related AEs occurred. None of the procedure related AEs were related to the surgical wound.

To date, the implantation procedure and therapy yield a favorable safety profile.

The aim of the BlueWind RENOVA iStim System is to refine the currently available therapies for refractory OAB patients, by providing a treatment that is less invasive, more durable and patient-centric. Early results appear to be promising. This implantable tibial nerve technology with wireless energy potentially offers a long-term treatment option for this chronic medical condition, without the need for any battery changes in the implantable component.  This patient-controlled home stimulation may also provide longer, more frequency stimulation sessions, customizable to a patient's needs, and perhaps eliciting more rapid clinical improvement.