Double mesh prosthesis that corrects defects in the abdominal wall and prevents adhesion formation at the peritoneal interface

New and innovative aspects

• The prosthesis is mainly suitable for repairing hernial defects in the abdominal wall but it is also useful for small recurrences of defects previously repaired with other biomaterials.
• The inner side of the mesh, in contact with the viscera does not produce erosion, avoiding the post-operation complications.
• These new meshes stimulate and modulate the patient tissue proliferation achieving a complete recovery.
• Prosthesis’ design improves the biomechanical resistance and flexibility. 

Main advantages of its use

• Wide application in the surgical field. Due to the high incidence of abdominal wall hernias, this is one of the most commonly performed surgical procedures.
• The prosthesis is manufactured with common biomaterial components. The manufacturing process is simple.
• High competitive technology on the market due to its low cost.

Specifications

Abdominal wall hernias are one of the most common conditions requiring surgery. From the 80´s, the use of meshes was generalized to avoid the eventrations, to reduce the pain and the percentage of recurrences. In spite of these advantages, the meshes can produce visceral erosion and intestinal perforations.

This research group has developed a new design of implantable prosthesis for abdominal surgery. The prosthesis proposed is formed of two meshes that may be of different porosity allowing that the integration tissue and vessels were able to infiltrate the mesh, making the prosthesis acts as a support or scaffold. The two meshes can have circular or rectangular shape and different sizes. They are joined together by a suture or heat seal, leaving a central zone of the prosthesis where the two meshes are in contact forming a shape similar to a "yo-yo".  This will induce the formation of dense connective tissue.  Around the joint area of the meshes, the two layers are free to overlap. It is the free lip of the upper smaller layer which is placed over the orifice or defect and then sutured to the recipient tissue. The other much larger mesh is threaded through the orifice to be repaired and placed inside it. This lower mesh does not need to be secured since it is pressed against the inside surface of the abdominal wall by the positive pressure of the abdominal cavity itself, and the viscera support the mesh acting as a containment wall. In this way the biomechanical resistance achieved is greater than that obtained using a simple implant secured to the defect's edges or slightly overlapping them.  This design also eliminates any possibility of a button hole hernia formation due to the detachment of the mesh when it simply occludes the hernial orifice. Moreover, the lower larger mesh is coated with a layer of smooth material such as polyurethane, Teflon or a biodegradable or non-biodegradable polymer to act as a barrier against adhesions and erosion leading to intestinal fistulas.  These last two components may be joined by an adhesive or preferably by moulding or heat sealing.

The prostheses may be made of a single material, preferably one that is well tolerated, such as polypropylene or polyester, and also achieves good biomechanical resistance.

This new prosthetic design has the added advantage that it is easy to position "over and under" the circular orifice of the hernia since, once the lower innermost mesh is in place, the outside mesh overlaps the edges of the orifice. Given the materials employed, its cost can be substantially lower than those presently on the market.

Applications

• Medical-surgical sector specialised on design, manufacturing and selling of surgical meshes. 
• Abdominal surgery