TIGR® Matrix was developed to take advantage of the process whereby mechanical load induces remodeling of soft tissue, termed dynamic remodeling. After initial wound closure, the increasing compliance of the mesh results in a gradual transition of load from the mesh to the tissue. Long-term strength retention combined with the dynamic remodeling-based design opens up new opportunities in soft tissue repair.

Mechanics

This design was developed to compensate optimally for the soft tissue’s lack of strength during each phase of wound-healing (closure, granulation and remodeling).¹ Accordingly, the mesh degrades in several stages, each with different characteristics, described below.

Characteristic strength and compliance

Multistage mechanics are achieved by arranging two fibers with different degradation characteristics in an interlocking knitting pattern.

1. Strength and stability of the mesh is high in the initial wound-healing phases (closure and granulation).
2. Macro porosity throughout the mesh allows for good integration during granulation.
3. As the granulation phase transitions into the remodeling phase, the elasticity of the mesh gradually increases.
4. Movement dynamics during remodeling stimulates the regeneration of tissue.
5. The result of this dynamic remodeling is a more structured, and hence stronger, connective tissue.

 

Materials

The family of polymers used in the mesh is well known in the surgical community for its resorbability and biocompatibility since the 1970s. At first glance, visually the two fibers appear quite similar, but their resorption characteristics differ significantly.

 

 

Fast resorbing fiber

• Locks the knitting pattern during initial wound-closure
• Loses mechanical strength in a couple of weeks
• Completely resorbs in 4 months
• Copolymer of glycolide, lactide and trimethylene carbonate

Slow resorbing fiber

• Acts as tissue reinforcement during remodeling
• Strong for at least 6 months
• Completely resorbs in 3 years
• Copolymer of lactide and trimethylene carbonate

 

Degradation and resorption

Stages

1. Initially, the mesh is rigid owing to the locked knitting pattern and polymer design.
2. After a couple of weeks, there is no strength left in the fast resorbing fibers. However, the long-term resorbable fibers remain to reinforce the tissue with a more elastic characteristic
3. Three years after implantation, there is no trace left of the mesh.

The following illustration shows the dynamic interaction between TIGR® Matrix and soft tissue during the different wound healing phases.

 

 

Process

Both fibers degrade by bulk hydrolysis. After degradation the fibers are excreted by the human body through natural means. The figure below depicts these metabolic pathways.

 

 

Sterilization

TIGR® Matrix is sterilized with ethylene oxide (EtO) and is for single use only.

Packaging

TIGR® Matrix is packed in a double-pouch system to ensure sterility and to protect it from degradation.

• Inner pouch (sterile barrier)
  • The mesh is sterile.
  • The outside of the inner pouch is non-sterile.
  • Made of Tyvek® and polyethylene.
• Outer pouch (moisture barrier)
  • The outer pouch prevents moisture from coming into contact with the mesh.
  • The atmosphere in the outer pouch is extremely dry.
  • Made of aluminum.

 

 

1. Schultz S. et al. 2005, World Wide Wounds; Kingsnorth N. et al. 2013, Management of Abdominal Hernias; Junge U. et al. 2001, Hernia
2. Data on file, in vitro resorption.
3. Three-year results from a preclinical implantation study of a long-term resorbable surgical mesh with time-dependent mechanical characteristics H. Hjort, T. Mathisen, A. Alves, G. Clermont, J. P. Boutrand, Hernia, 16(2):191–197, 2012