BIOMECHANICAL STUDY OF UTEROSACRAL LIGAMENTS AFTER PLATELET RICH PLASMA INJECTION
E. Chrysanthopoulou1,2, K.I. Nikolopoulos1,2, Ch. Spiliopoulou,3, V. Pergialiotis1, Laskarina-Maria Korou1 , D. Perrea1, Sr. Kourkoulis3 , S.K. Doumouchtsis1,2,4
1 Laboratory of Experimental Surgery and Surgical Research N.S. Christeas, National and Kapodistrian University of Athens, Greece
2 Department of Obstetrics and Gynaecology, Queen's Hospital, BHR University Hospitals NHS Trust
3 National Technical University of Athens, Greece
4Department of Obstetrics and Gynaecology , Epsom and St Helier University Hospitals NHS Trust
•Pelvic organ prolapse (POP) affects many women with physical and psychological impact as well as quality of life.
•~ 30% of women over the age of 50 have uterine prolapse (1).
•Several surgical treatments have been used.
•The FDA has published concerns about the use of synthetic meshes in view of potentially severe complications.
•The regenerative abilities of plasma, an autologous substance with adhesive, healing and haemostatic properties at low cost, appear to be a promising concept.
•Experimental confirmation of the efficacy of PRP may facilitate the design and conduct of clinical studies on the reinforcement of USL.
•Our study aimed to investigate the effect of PRP on the biomechanical properties of the USL in an experimental animal model.
•Approval by the Ethics Committee of the National and Kapodistrian University of Athens, (registration number: 1516015885 - 04/02/2016).
•Seventeen Wistar rats were used (weight 220-245 g, age <9 months old) and were randomly assigned to the following groups:
-Control group: 7 nulliparous
-Group A: 3 multiparous
-Group B: 7 multiparous with PRP injection.
•PRP was prepared according to a standardized research (2). PRP injected into the USLs, after they were surgically exposed. These rats were ready for biomechanical investigation 6 weeks after the injection.
•The same surgical technique was used in all rats.
•The biomechanical tests were performed using an electromechanical testing loading frame (MTS Insight, MTS Systems, Eden Prairie, MN), equipped with a properly calibrated load-cell of capacity equal to 50 N. The sacrum-uterus complex was placed horizontally. A hook was used to apply the force to the ligaments. It was placed between the body of the uterus and the rectum and was attached to an upper clamp. A second clamp fixed to the base of the loading frame was used to keep the sacrum immobilized.
•The tests were implemented under displacement-control loading mode at a rate equal to 0.4 mm/min.
•The displacement was imposed continuously and monotonically and the tests were terminated when fracture of one of the USLs occurred.
•Test is terminated, when one of the ligaments ruptures.
The raw data recorded during the tests were the load imposed and the displacement, both as functions of time. Taking advantage of these data it was possible to determine critical biomechanical properties of the tissue including the ultimate load, the elongation at failure and the stiffness of the tissue, using commercially available software.
•A very interesting finding involves the stiffness of the multiparous PRP group, as it appears significantly increased compared to the respective properties of the multiparous, and it correlates well with that of the control group.
•The force-displacement curves obtained are shown in Fig.1 for all three classes of specimens.
•A relatively short non-linear portion at the very beginning is followed by a linear portion until almost the ultimate force. This linear portion is terminated when failure starts as it is indicated by the non-linearly descending portion of the graph.
•In this model the maximal force generated before failure represents the maximal load the ligament can bear.
•The numerical data for the ultimate load and the stiffness of the tissue are recapitulated in Table 1.
•Considering the nature of the experiments, the scattering is rather acceptable and only one of the tests (marked red in Table 1) appears to be influenced by biased errors.
•No definite result can be drawn for the ultimate force, indicating perhaps that additional tests should be implemented.
•The stiffness for Group B is significantly increased compared to the respective quantity of Group A.
•The stiffness for Group B approaches well that of Control Group.
•PRP has healing properties that are triggered by the abundance of growth factors and cellular elements, which are involved in the healing process. Its use in tendon healing has been supported from several studies in orthopaedics and plastic surgery.
•We developed a protocol for the study of USL, with the potential enhancing role of PRP on injured ligaments.
•Although this is a pilot study and the number of models is small, PRP can be a promising treatment for management of prolapse.