Midurethral slings are currently composed from polypropylene (PP). PP has been proven to cause reduced complications, mainly due to the fact that it is inert, it does not migrate, it is not allergic, and is not causing inflammatory reactions. Nevertheless, common complications related to PP tapes are postoperative voiding problems, tape erosions in the vagina or adjacent organs, recurrent urinary infections, etc. Therefore, it is of paramount value to discover novel materials with different and if possible close to zero complications profile in the management of stress urinary incontinence (SUI). It seems that polyvinylidene fluoride (PVDF) can theoretically be a useful alternative in SUI treatment. PVDF has been massively used in other prosthetic fields of medicine (cardiac valves, orthopedics) and it is related with reduced rates of rejection, erosion, inflammatory reactions, pain or dysfunction. 
The aim of the study is to present the initial experience of our department with the use of PVDF tapes in the surgical treatment of SUI, in terms of feasibility, complications, and short-term efficacy.

This is a prospective cohort study performed in a tertiary academic urogynecologic unit. All patients who presented with pure SUI, or predominantly stress mixed urinary incontinence were invited to participate in the study. Inclusion criteria were: (a) age > 18-years-old, (b) Greek speakers, (c) women with at least moderate degree SUI/MUI. All patients had clinical examination, standardized cough test, pad test. Symptoms were measured with the use of ICS-ICIQ questionnaire, PFDI, PISQ-12, and EQ-5D, PGI-I. All patients underwent full urodynamics invstigation (uroflowmetry, filling cystometry, pressure-flow studies, and urethral profilometry). All patients had pelvic floor sonographic evaluation (PFUS: urethral mobility assessment and bladder wall thickness (BWT) assessment). All patients had transobturator mid-urethral sling (PVDF) with a standardised inside-out technique: tensioning of the tape was accomplished with a Hegar 8 dilator; peri-operative intravenous cefalosporin & metronidazole were administered; indwelling catheter was kept overnight and removed the following morning; a trial of free voiding and sonographic measurement of the post-void residual (PVR) was performed 3-6 hours after catheter removal; the patients were discharged at 1st post-operative day on oral antibiotics and analgesics. Post-operatively, the Clavier-Dindo scale was used to record the complications during the first 30 days. Then, all patients were examined 3 months post-operatively with: (a) clinical exam and standardized stress test, (b) check for tape erosions, (c) ICIQ-OAB, (d) VAS pain score, (e) VAS hispareunia  score. Statistical analysis was performed with MedCalc. Paired t-test was used to compare pre- and post-operative results. p<0.05 was considered statistical significant.

24 patients were recruited. Mean age was 65.2±9.3 years-old. None of the patients had signs of bladder outlet obstruction in uroflowmetry and pressure-flow studies, there were 8/24(33.3%) patients with DO. PFUS identified 15/24 (62.5%) patients with increased urethral mobility, whereas 5/24 (20.8%) patients had mean BWT >6mm. Mean operative time was 30±14min. Mean post-operative hospitalization was 2.2±1.4 days. Complications were: 1 patient with unsuccessful trial of void who managed to void 5 days later, 1 patient with an episode of uncomplicated UTI. There were no complications >grade II according to Clavier-Dindo scale. In the 3 months examination, 22/24 (91.7%) had a negative stress test. There was statistically significant improvement in the ICS-ICIQ questionnaire (p<0.05) in the PGI-I score (p<0.05). No tape erosions into the vagina were identified. No post-operative pain or hispareunia was reported from any of the patients

Incontinence surgery is facing a challenge for constant improvement of techniques and materials used. Initial appoaches with polypropylene meshes of various types and knit had as a result that numerous varieties of materials were gradually abandoned from clinical practice because of increased complication or decreased success rates. Macroporous type I PP tapes were established as the ideal type of material for suburethral incontinence operations. Nevertheless, inherent disadvantages of PP tapes are the erosions, the migration, and the diminishing of the successful outcome over time. This study provides initial insight to the use of PVDF tapes. Early experience seems to be promising with results comparable to those of the PP tapes.

Initial experience with the use of PVDF tapes as sub-urethral slings appears to be satisfactory in terms of safety, functionality, and effectiveness. Large, prospective, non-inferiority studies have to be performed in order to clarify the exact performance of these tapes in the field of pelvic surgery.

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