Abdominal wall

Question 1

What properties of mesh are taken into account when deciding on mesh?

Answer 1

1) Tensile strength
- law of lapace (diameter x pressure / 4 x wall thickness)

2) Pore size
- Main determinant of pore size (> 75microm to allow infiltration of macrophages, fibroblasts and blood vessels)

3) Weight
- weight of polymer and amount of material used

4) Reactivity and biocompatibility
- foreign body reaction (amount of material - larger pore size, less reactivity)
- collagen replaced from type III to I (stronger) but this is reduced with mesh

5) Elasticity
- natural elasticity of abdominal wall is 35%
- light weight mesh is 15-35% and heavy weight is 5-15%

6) Constitution
- Monofilament, multifilament, patch

7) Shrinkage
- Occurs due to contraction around the scar tissue

Question 2

What is loss of domain in the context of an incisional hernia?

Answer 2

Percentage of abdominal cavity contents that lie within the hernia sac.

Therefore when these contents are returned, there is a need to restore the integrity of the abdominal wall (botox 1 month prior, progressive pneumoperitoneum or component techniques).