On-site testing of sutured organs: An experimental set up to cyclically tighten sutures

• Published in: Journal of the mechanical behavior of biomedical materials Vol. 109; p. 103803
• Main Authors: Pascoletti, Giulia, Pressanto, Maria Chiara, Putame, Giovanni, Terzini, Mara, Audenino, Alberto L., Zanetti, Elisabetta M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.09.2020
• Subjects: Animals; Biomechanical Phenomena; Creep; Distraction; Failure; Horses; Neuropathy; Rupture; Suture Techniques; Suture testing; Sutures; Tensile Strength; Tissue relaxation; Distraction; Suture testing; Neuropathy; Creep; Tissue relaxation; Failure
• ISSN: 1751-6161; 1878-0180; 1878-0180
• DOI: 10.1016/j.jmbbm.2020.103803

A number of surgical practices are aimed to compensate for tissue relaxation or weakened/atrophied muscles by means of suture prostheses/thread lifts. The success rate of these procedures is often very good in the short term, while it is quite variable among subjects and techniques in the middle-long term. Middle-long term failures are mostly related to suture distraction, loosening or wear, coming from repeated loading cycles. In this work, an experimental device to perform ex vivo tests on prosthetic sutures has been set up. An equine laryngoplasty has been used as a benchmark, being representative of sutures aimed to compensate for atrophied muscles. The peculiarity of this experimental set up is that the suture is on-site and it has been tightened with known, repeated loads, which do not depend on thread deformation at different load levels. Preliminary tests have been performed applying over 3000 load cycles and finally a tensile test up to rupture. Force/displacement curves obtained with this experimental set up have been reported and parameters useful to classify the biomechanical performance of sutures versus time (mainly its creep behaviour), have been outlined. Results have outlined that the organ-suture system undergoes significant creep over 3000 cycles, and this should be taken into account in order to foresee its long-term behaviour; in addition, the suture anchorage to cartilage should be improved. The experimental set up can be used to perform on-site testing of sutures, taking into account the compliance and creep response at both suture anchorage ends, in order to compare different surgeries and different kinds of thread. [Display omitted] •Tensile sutures/thread lifts are commonly used in the clinical practice.•The respective success rate is highly variable and little is known about the respective medium-long term behaviour.•An experimental device to cyclically tighten sutures has been designed.•Output data after cyclic loading allow the quantification of suture loosening and reduced thread strength due to wear.•Different surgical techniques can be objectively compared.