gms | German Medical Science

Introduction: The incidence of apical uterine prolapse increases with age. After conservative treatment options have been exhausted, surgical correction with the use of alloplastic material often follows. Laparoscopic cervicosacropexy is often performed, and different materials (tacks vs. sutures) can be used to fix the mesh material to the cervix for apical fixation.

The aim of this in-vitro study was to compare the biomechanical properties for fixation of the mesh to the cervix with single-button sutures (group 1), non-absorbable tacks (group 2) and absorbable tacks (group 3).

Methods: The biomechanical in-vitro testing was performed on porcine, non- embalmed, fresh and unfrozen cadaver uteri (Figure 1 [Fig. 1]). In a two-column material testing machine (Instron 5565^®) a total of 28 trials were conducted in three groups on fresh porcine uteri. Each group evaluated the cervical mesh fixation with a different fixation device: Group 1 (n=10) evaluated three interrupted sutures, group 2 (n=10) three titanium tacks (ProTack), and group 3 (n=8) three absorbable tacks (AbsorbaTack) (Figure 2 [Fig. 2]). The mesh used for cervical fixation are composed of nonabsorbable, biostable polyvinylidene-fluoride (PVDF) monofilaments.

All trials were conducted until failure of the mesh, tissue or fixation device occurred. Primary endpoints were biomechanical properties maximum load (N), displacement at failure (mm) and stiffness (N/mm). Mode of failure was evaluated as a secondary endpoint.

Results: Significant differences were found between all three groups in terms of maximum load: Group 1 (three single-button sutures) showed a maximum load of 64 ± 15 N, group 2 (three titanium tacks) 41 ± 10 N and group 3 (three absorbable tacks) reached a maximum load of 15 ± 8 N. The most common mode of failure for group 1 and 2 was a net tear or rip under 80-times of maximum load. In group 3, the limiting factor in all tests was a pull-out of the absorbable tacks.

Conclusion: Fixation of the PVDF mesh with three single-button sutures is superior to fixation with three titanium tacks as well as absorbable tacks in terms of maximum load. The suture carries 1.5 times the load of titanium tacks and 4.2 times the load of absorbable tacks. All three fixation options can withstand the physiological load of 10 N, but absorbable tacks are the weakest fixation methods. Single-button sutures are the significantly stronger and less expensive, but could increase operating time (when fixating the mesh) by factor 9 compared to tacks. Possible risks of the tacks are not considered in this in vitro analysis.

Conflict of interest: Sebastian Ludwig: FEG Textiltechnik mbH, Aachen – Gutachtertätigkeit