title: Comparison of graft-reinforced repairs and suture repair using a novel biomechanical test.
abstract: OBJECTIVE
  The aim of this study was to determine the feasibility of a novel biomechanical test for evaluating mesh-reinforced repair compared to suture-reinforced repair using an animal model. We hypothesized that the fatigue life of a mesh reinforced repair would be greater than that of xenograft reinforced repair and suture-only repair.
  
  
  METHODS
  Wistar rats were randomly assigned to undergo a ventral hernia repair using sutures or one of the three mesh materials representative of incorporation, encapsulation and resorption host responses (Gynemesh, Pelvisoft and Surgisis®, respectively). All surviving animals were killed at 90 days and specimens containing the prosthesis-tissue interface were exposed to cyclic forces. The number of cycles to failure (fatigue life) was compared between groups using a Cox regression model.
  
  
  RESULTS
  Of 40 randomly assigned animals, 11 died before 90 days. After randomizing an additional 5 rats, a total of 34 rats were killed at 90 days. The proportions of specimens that failed before 10,000 cycles were 25% (2/8), 50% (4/8), 62.5% (5/8) and 70% (7/10) in the Gynemesh, Surgisis, Pelvisoft, and suture control groups, respectively. In addition, the median number of cycles to failure was >10,000 in the Gynemesh group, >6,923 in the Surgisis group, 1133 in the Pelvisoft group and 741 in the control group. After adjustment for cross-sectional area, the risk of failure in the suture control group was higher than in all of the reinforced repair groups combined with an adjusted hazard ratio of 2.58 (95% CI 0.96 - 6.97), and was statistically significantly higher than in the Gynemesh group with an adjusted hazard ratio of 6.67 (95% CI 1.30 - 34.48).
  
  
  CONCLUSIONS
  We present a novel biomechanical test that can be used to compare mesh materials in an animal model prior to use in humans. In this animal model, after adjusting for cross-sectional area, suture reinforced repair has a higher risk of failure than graft reinforced repair.
authors.affiliation: Department of Gynecology and Obstetrics, University of Tennessee Health Science Center, Memphis, TN, USA.
authors.forename: Hafsa U
authors.initials: HU
authors.lastname: Memon
authors.affiliation: Division of Gynecologic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA.
authors.forename: Sherif A
authors.initials: SA
authors.lastname: El-Nashar
authors.affiliation: Division of Orthopedic Research, Mayo Clinic, Rochester, MN, USA.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Thoreson
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Weaver
authors.affiliation: Division of Gynecologic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA.
authors.forename: John B
authors.initials: JB
authors.lastname: Gebhart
authors.affiliation: Division of Gynecologic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA. trabuco.emanuel@mayo.edu.
authors.forename: Emanuel C
authors.initials: EC
authors.lastname: Trabuco
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D005240:Feasibility Studies; D005260:Female; D006555:Hernia, Ventral / Q000601:surgery*; D064593:Heterografts; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013526:Surgical Mesh; D013536:Suture Techniques; D014945:Wound Healing
keywords: Biomechanical testing; Polypropylene; Tensile strength; Ventral hernia model; Xenograft