Study for a Magnetic Endourethral Sphincter Against Stress Urinary Incontinence

Multicentric Pilot Study for the Application of a Magnetic Endourethral Sphincter for the Treatment of Secondary Stress Urinary Incontinence Damage to the Urethral Sphincter

A second no-random open interventional pilot study sponsored by Relief srl

The first pilot study, where the device was implanted on 6 human patients for 28 days, demonstrated that the magnetic urethral sphincter was successfully implanted and explanted in all patients (5 males and 1 female). All the procedures have proven ease of implantation and removal (6/6, 100%), decent simplicity of the activation and de-activation system and restoring an acceptable urinary continence. The majority of patients (5/6, 83.4%) reported a good tolerability of the sphincter. Unfortunately, only 1/6 patient (16.7%) was able to complete the 28 days cycle with the urinary sphincter in place: in the other 5 patients (83.3%) the sphincter migrated into the bladder due to the lack of a hooking system, which was not considered relevant in the design phase and during previous cadaver tests. This migration seemed caused by an oversized external magnet, producing a large force also in not optimized positioning, and by the anatomic variability of patients' urethral caliber. In one patient the sphincter stayed perfectly in place for all the 28 days; its position was checked after 10 days of the implantation by suprapubic ultrasound scan. This patient referred excellent urinary continence also with the sphincter in the "opened" configuration (without using the external magnet but by relying only on the valve flexibility), without urinary leaks during daily activities and sport activities too. No severe side effects or complications or infections occur after the migration of the device in the bladder and during its implantation/removal.

The final analysis of data and questionnaires showed that, to adapt the magnetic urethral sphincter to the clinical practice, a re-design is necessary in order to improve the anchoring system and to optimize the magnetic activation system, avoiding bladder migration of the device.

In this framework Relief re-designed the device by optimizing the external magnet, by improving the proximal anchoring system and by providing with a distal anchoring system. The new design was validated by test bench and on cadaver anatomies.

The primary objectives of the study were to assess the safety and reproducibility of the implantation of the magnetic endo-urethral sphincter, if the procedure was well tolerated by the patients, and if possible irritation symptoms due to the device presence emerged in patients with severe stress urinary incontinence where standard medical treatments failed.

Inclusion Criteria:

1. Male patients aged from 45 to 85 years-old suffering from secondary Stress Urinary Incontinence (SUI) to prostate surgery in which medical and rehabilitative treatment have failed;
2. women patients aged from 45 to 85 years-old suffering from SUI in which medical, rehabilitative and surgical treatment have failed;
3. sterile urine culture;
4. urodynamic test with evidence of sphincter dysfunction, Valsalva Leak Point Pressure (VLPP) < 60 cm H2O (water) and exclusion of detrusor over-activity;
5. flexible cystoscopy demonstrating sphincter dysfunction and excluding stenosis of the urethra or vesicourethral anastomosis.

Exclusion Criteria:

1. No-autonomous patients;
2. People where the use of magnetic field is not suggested (i.e. patients with pacemaker).
3. Patients with urinary infections;
4. Patients with intolerances to the materials included in the sphincter or to expected drug subministration.
5. Patients already participating a clinical study within the last 30 days.
6. Patients that already have devices/solutions or part of them for the treatment of urinary incontinence.