Anatomical and Mechanical Safety of the Tissue Anchoring System (TAS®) for Sacrospinous Ligament Fixation

Sacrospinous ligament fixation (SSLF) is an established procedure for pelvic organ prolapse (POP) repair, yet the suture placement involves risks of neurovascular injury. The Tissue Anchoring System (TAS^®; Promedon) was developed to standardize SSLF and reduce associated risks. This study presents the assessment of anatomical safety margins of the TAS^® following fixation by both expert and novice operators, as well as its mechanical fixation strength.

Two POP surgeons with different experience levels placed TAS^® anchors bilaterally in the anterior portion of the SSL in 10 female cadavers (20 fixation points). A blinded assessor measured SSL dimensions and distances to the ischial spine (IS), inferior gluteal artery (IGA), internal pudendal artery (IPA), pudendal nerve (PN), and levator ani nerve (LAN). Fixations ≥ 0.10 cm from all structures were defined as safe. Pull-out strength was tested after anatomical measurements, with 10 N as the safety threshold.

Median anchor-to-structure distances were IS 2.4 cm (2.0-3.1), IGA 2.8 cm (2.3-3.0), IPA 2.9 cm (2.5-3.3), PN 3.0 cm (2.7-3.4), and LAN 1.1 cm (0.7-1.5). Nineteen of the 20 TAS^® were ≥ 0.10 cm from all structures; one TAS^® placed by the novice was 0.7 cm from LAN. No appreciable differences were seen between right and left sacrospinous ligament sides or operators. Mean pull-out force was 54.3 N.

Fixation of TAS^® achieved safe, reproducible placement within the SSL and provided great mechanical strength. Results were consistent across sides and operators, although anatomical and surgical training remains essential for safe clinical use.