TITLE:
Mesh-Related SIN Syndrome. A Surreptitious Irreversible Neuralgia and Its Morphologic Background in the Etiology of Post-Herniorrhaphy Pain
AUTHORS:
Robert Bendavid, Wendy Lou, Andreas Koch, Vladimir Iakovlev
KEYWORDS:
Polypropylene, Mesh, Mesh Pores, Hernia, Pain, Nerves, SIN Syndrome
JOURNAL NAME:
International Journal of Clinical Medicine,
Vol.5 No.13,
July
21,
2014
ABSTRACT: Purpose: The
ubiquitous use of synthetic materials in hernia surgery has brought about a new
clinical syndrome: Surreptitious Irreversible Neuralgia (SIN). It is surreptitious
because it is of slow onset, unsuspected and enigmatic to clinicians; irreversible
because the pain is progressive, unrelenting and unresponsive to treatment.
Removal of the mesh does not guarantee pain relief. Neuralgia following mesh
insertion, when it occurs, remains a poorly understood phenomenon. Methods: Ten
specimens in each group: virgin tissue, scar tissue and explanted mesh from the
posterior inguinal wall were examined histologically to assess nerve density,
nerve size and nerve and vessel ingrowth into the deformed mesh and within its
pores. Results: There was no significant difference in nerve density between
virgin, scar and mesh samples. All of the explanted meshes had nerves within
the scar tissue encasing the mesh (interstitial infiltration). Nerve ingrowth
through the pores of the mesh (micro-entrapment) was detected in 90% of the
explanted mesh specimens. Additionally, nerves were detected entrapped within
the folds and deformations of mesh explants. Ingrown vessels showed congestion
and focal fibrin thrombi. Conclusion: The presence of mesh does not
significantly affect nerve density, while the nerves and their terminal ends
are in a vulnerable position about the mesh and within its pores. These pores
need to be viewed as “mini-compartments” of biological tissue where the
vasculature, nerves and their receptors are exposed to potential mechanical and
chemical factors: scarring, entrapment, compression, tugging, deformation,
contraction, hypoxia/acidosis, inflammation and edema.