Warp-Knit Prosthetic Porous Structure for Strength and Tissue Ingrowth

The patent combines polyester monofilaments (providing mechanical strength) with polypropylene monofilaments (providing porosity and flexibility) in a single knit structure. This composite approach allows the prosthesis to simultaneously achieve lightweight properties, macroporous structure for tissue ingrowth, and sufficient mechanical strength to resist fracture during suturing and under intra-abdominal pressure.

The patent creates different mechanical properties in different regions of the knit structure by using alternating rows of different monofilament types. The polyester rows provide strength and stiffness for fracture resistance, while the polypropylene rows provide flexibility and porosity for tissue conformity. This local differentiation allows the single prosthesis to simultaneously exhibit both pliancy for conformity and strength for fracture resistance.

The patent incorporates polypropylene monofilaments which inherently create a macroporous structure with high porosity that facilitates tissue ingrowth. However, to compensate for the mechanical weakness of highly porous structures, the patent combines these with polyester monofilaments that provide the necessary structural integrity and mechanical strength, creating a composite knit that maintains both high porosity and sufficient strength.

The patent employs a periodic knitting pattern where rows of polyester monofilaments and rows of polypropylene monofilaments alternate in a regular sequence. This periodic structure, defined by specific guide bar patterns on the warp knitting machine, ensures uniform distribution of mechanical properties throughout the prosthesis, resulting in homogeneous shear force distribution at fixation points while maintaining relatively simple manufacturing through standardized machine operations.