Brian P. Jacob, David C. Chen, Bruce Ramshaw, Shirin Towfigh (eds.) - The SAGES Manual of Groin Pain-Springer International Publishing (2016)

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all contribute to postoperative CGP development. Furthermore, perioperative
factors such as tissue and nerve trauma, seroma, hematoma, and
infection can all contribute to chronic pain. Some or all of these factors
can be present regardless of a mesh or non- mesh inguinal hernia repair
[ 1 ]. One must consider all of these risk factors when trying to determine
the reason for the development of CGP, but the focus of this chapter is
the role synthetic mesh may or may not play in the development of postoperative
CGP .
Mesh as a Foreign Body
There is no question that all synthetic mesh elicits an inflammatory
response. Whether that response is clinically significant is debatable.
Animal studies have shown that mesh in contact with nerves does cause
inflammatory changes characterized by an increase in fiber diameter and
increased nerve demyelination [ 2 ]. However, the clinical significance of
these findings in animals alone cannot be substantiated.
A translational study, “Mesh-Related SIN Syndrome. A Surreptitious
Irreversible Neuralgia and its Morphologic Background in the Etiology
of Post-Herniorrhaphy Pain” by Bendavid et al., has recently been published.
Given the title alone, one can surmise that the mesh is perceived
as the sole instigator of chronic pain, though perhaps not in the traditional
manner of being a foreign body that causes inflammation. In this
study, a scientific model was implemented comparing 10 explants of
virgin tissue of the posterior inguinal wall, 10 explants of scar tissue
from tissue repairs, and 10 explants from mesh repairs. Mesh was not
found to significantly inhibit or promote nerve growth in scar. However,
deformation of mesh was found to provide potential compartments for
entrapment of nerves and to create more surfaces for random nerve
ingrowth into the mesh. These issues can be further potentiated by contraction
and migration of mesh, which can occur after it is implanted [ 3 ].
Objective scientific findings from implanted mesh provide data to
support a convincing case for mesh-related chronic pain. However,
based on these findings, one should expect CGP to be an even larger
problem than it is currently. In fact, much of the existing clinical data
support the contrary. Therefore, despite evidence of the foreign body
reaction seen after synthetic mesh implantation, one must understand the
contemporary history and clinical data surrounding CGP to gain a full
perspective of this complex and multifactorial problem.