Synthetic Meshes

1.) Made of polypropylene (PPM),2.) Polytetrafluoroethylene (PTFE), 3.) Polyester4.) Combinations of above5.) IN combination with an absorbable component.

1.) Most all of these are overengineered and are four to five times stronger than the force required to burst the abdominal wall.

2.) Many different companies have their own respective products and most are different from one another even though they may be made out of the same material.

1.) Heavy weight Mesh ( Marlex)2.) The restricted mobility = development of a strong scar plate that

surrounded the mesh.3.) Scarring causes shrinkage of heavyweight PPM of up to 40% a.) Stiffness and discomfort and pain

Lightwer weight meshesa.) Decrease in inflammatory response b.) Decreased stiffness, c.) Less shrinkage, d.) Fewer complaints from patients.

THEREFORE:1.) If you choose a PPM = lightweight mesh if possible. 2.) IF polypropylene is decreased= hard to handle. a.) Therefore add an absorbable componentEXAMPLE 1 . Vypro mesh is PPM plus Vicryl. This product is not available in

the United States but Ethicon has now introduced EXAMPLE 2: Ultrapro to the United States, which is a lightweight PPM plus

Monocryl

Other:1.) DO NOT PLACE against the viscera since there will be actual

ingrowth of the bowel into the mesh. A.) fistula, B.) Extrusion, C.) Difficult subsequent surgeries. THERFORE:1.) Ethicon has introduced a PPM coated with the Interceed anti-

adhesion barrier. a.) The barrier prevents ingrowth of viscerab.) Allows safe intraperitoneal placement,.

2.) Sepra Mesh is another PPM with a protective coating that allows it to be placed against the viscera.

No long-term clinical data are available for either of these coated meshes.

1.) Various forms of PTFE from different companies, 2.) Can safely be placed in the peritoneal cavity 3.) No ingrowth of viscera into the mesh. 4.) A unique dual-sided mesh (Dual Mesh) was introduced by

W. L. Gore in 1994 ( large pore size on the ingrowth side and a microporous

structure on the other side that goes against the bowel). ***

5.) Does not allow actual ingrowth of the viscera, = Future surgeries much safer and

a.) Eliminates fistula and erosion. 6.) Little memory and thus are harder to manipulate, the

advantage of the composite mesh (which has a memory ring and PPM

7.) ??? Higher infection rate than other prosthetics, a.) More likely that the infection occurs when the ePTFE is only

covered by fat and skin (not fascia) b.) After placement and any wound problem will thus readily

expose the mesh to the chance of infection. c.) Once infected, it is very difficult to salvage ePTFE as

opposed to PPM, which sometimes can be salvaged.

Ethicon (Mersilene) Bard (Dacron) Very good track record in France (Rives and later

Stoppa). Don’t place in contact with the viscera; a.) Ingrowth, b.) Fistula, c.) Difficult subsequent surgery are potential

problems.

The biggest advantage to polyester mesh over PPM a.) Soft and supple and conforms readily. b.) It does not stiffen and harden as much as

heavyweight PPM.

High infection rate in North America a.) Technique of placement of the mesh???.

A newer type of polyester mesh (Parietex) a.) Collagen membrane on one side that

acts as an antiadhesion barrier and thus it can be placed intraperitoneally.

b. Just like the coated PPM, = fragmenting of the antiadhesion barrier and the potential for ingrowth and subsequent erosion and fistula.

Goal: 1.) take human or animal tissue, get rid of the

cellular component to avoid allergic reaction, and then stabilize the protein structure so it can act as a scaffold.

2.) These products are thus collagen implants that allow native fibroblasts to deposit more collagen to then make a “biologic” mesh.

3.) Meshes are expensive and have been brought to market without long-term evaluation as a permanent solution for hernia repair.

Surgisis: Porcrine gut submucosa Alloderm: Cadaver dermisPermachol: Porcrine dermis