Int Urogynecol J (2007) 18: 183–187 DOI 10.1007/s00192-006-0130-x ORIGINAL ARTICLE Masoumeh Rezapour . Giacomo Novara . Peter A. Meier . Joerg Holste . Susanne Landgrebe . Walter Artibani A 3-month preclinical trial to assess the performance of a new TVT-like mesh (TVTx) in a sheep model Received: 18 August 2005 / Accepted: 13 March 2006 / Published online: 21 April 2006 # International Urogynecology Journal 2006 Abstract The objective of this study was to evaluate in a sheep model the performance of a new polypropylene mesh (TVTx), which is intended as a less invasive treatment for female stress urinary incontinence. Eight female sheep were used in this study, each one being implanted with eight TVTx samples. At each time-point (weeks 1, 2, 4, and 12) seven TVTx were pulled out, while one TVTx was carefully dissected for histological investigations. One TVTx and one TVT, moreover, were inserted and immediately pulled out for obtaining the initial pullout forces in all sheep. The initial pullout values of TVT and TVTx were overlapping. The pullout forces of TVTx were >5 N (500 g) and increasing from weeks 1 to 12 (p<0.001). Histology revealed good tissue integration of TVTx in the tissue within 12 weeks after implantation. No abnormal histolog- ical findings were observed. This data could support the realization of a clinical trial with the TVTx mesh. Keywords Stress urinary incontinence . Tension-free vaginal tape . TVT, Sheep model Introduction The tension free vaginal tape (TVT) procedure was first described in 1996 by Ulmsten for the treatment of stress urinary incontinence [1]. TVT consists of a 1.1×45-cm Prolene (polypropylene) mesh that is inserted as a pubourethral sling for support of the midurethra. Since its introduction, more than 650,000 procedures with TVT have been performed worldwide. A recent Cochrane review concluded that the cure rates after TVT placement were similar to those after open abdominal retropubic suspension with a low complication rate [2]. Five-year follow up studies showed a cure rate of 85%, preliminary analysis of 7-year results reported cure rates as high as 81% [3]. With the intent to reduce the invasiveness of the procedure, a new mesh, the TVTx, was developed. It took 2 years of testing different materials and mechanisms of inserting an implant to obtain the current prototype. In cooperation with the University of Uppsala, multiple designs had to be tested mechanically and in cadaver wetlabs to fulfill the requirements of a less invasive, effective treatment for stress urinary incontinence, that uses less foreign material. Extensive discussions with surgeons let to the current prototype. It consists of a shorter polypropylene mesh tape (the same material like standard TVT), which is coated on both ends with an absorbable fleece material (Ethisorb). Ethisorb is a composite of Vicryl and PDS, just used in other Ethicon products like Dura patch. The Ethisorb coated ends of the TVTx stiffen the mesh to aid for tactile insertion and increase the friction to help keep the tape in place in the short term. So TVTx can be placed without passing the whole TVT passage and without penetrating the abdominal wall. The present preclinical trial aims at evaluating the performance of the TVTx mesh in a sheep model. Materials and methods Mesh The prototype of TVTx consists of a 1.1×12-cm PRO- LENE mesh tape, the same material of the standard TVT, which is coated on both ends with an absorbable fleece material (ETHISORB). Ethisorb is a composite of Vicryl M. Rezapour Department of Women’ s & Children’ s Health Obstetrics & Gynecology, Uppsala University, Uppsala, Sweden G. Novara . W. Artibani (*) Department of Oncological and Surgical Sciences, Urology Clinic, University of Padua, Via Giustiniani 2-35128, Padua, Italy e-mail: walterartibani@libero.it Tel.: +39-049-8212720 Fax: +39-049-8218757 P. A. Meier . J. Holste . S. Landgrebe ETHICON GmbH, R&D Europe, Hamburg, Germany