Objective: The objective of this study is to compare the mechanical characteristics of a series of suburethral tapes marketed for the treatment of stress urinary incontinence, often considered to be identical in the clinical practice.
Material and method: Six suburethral tapes were studied: TVT (Gynecare-Ethicon, USA), IVS (Tyco Healthcare, USA), Sparc (AMS, USA), Uretex (Sofradim, France distributed by BARD), I-stop (CL médical, France), and Uratape (Porgès, France). The surface was studied by scanning electron microscopy. Mechanical properties were evaluated on an Instron traction apparatus equipped with a 500 Newton transducer and elongation was performed at a rate of 10 mm/min. Deformation curves, Young's elastic modulus, and maximum load were calculated. Possible release of particles was investigated by weighing each sample before and after gentle 0.01 kN traction.
Results: From a purely mechanical point of view, completely opposite properties were observed. The maximum load ranged from 0.012 +/- 0.002 to 0.047 +/- 0.013 kN. Young's elastic modulus ranged from 4.31 +/- 1.1 to 41.99 +/- 14.3 Mpa. Maximum deformity ranged from 31% to 108%. Release of particles was estimated, according to the tape, to represent a variation of the initial weight of between 0.01% and 8.5%.
Conclusion: It is difficult to compare tapes that are theoretically marketed for the same application, suggesting that the same tape should probably not be used for the same application. Clinicians must more extensively evaluate the required properties. The authors believe that tapes with a high elastic modulus should be proposed for transobturator procedures to provide real perineal support, while tapes with a lower elastic modulus should be used for retropubic techniques.