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neurolysis involving the epineurium and if necessary the Products based on hyaluronic acid (HA) have proved
perineurium. to be more effective. Initial preclinical studies have
documented their anti‑adhesion properties and safety.
[34]
Another key factor is the number of previous operations, HA is marketed alone as Hyaloglide (R)[35] or associated to
simple external neurolysis is indicated after the first carboxy‑methylcellulose (CMC, Seprafilm ).
(R) [36]
recurrence while a vascularized flap with a more extensive
neurolysis is indicated following multiple failed surgical However, there is no consensus on the actual effect of
treatments. anti‑adhesion devices. According to some researchers they
reduce collagen deposition by interfering with granulocyte
Type I injuries, where scar tissue hampers gliding, should diapedesis and blocking the synthesis of interleukin‑1,
be managed by external neurolysis if the intraneural which is crucial for fibroblast activation, whereas others
[37]
echostructure is normal, anti‑adhesion gel, vein‑wrapping, deny an effect on cytokines and admit only to a physical
or thin flap coverage may be sufficient.
barrier action. [38]
In type II lesions (neuromas‑in‑continuity), where US CMC has subsequently been associated with other
depicts a lack of structural homogeneity inside the molecules, including phosphatidylethanolamine a nonionic
nerve, more extensive neurolysis may be required, with molecule whose tensioactive properties provide
epineurectomy and rarely, internal neurolysis under tissue lubrication and a mechanical barrier to restore
magnification. These patients also require deep nerve gliding. CMC‑PE has also been shown to reduce
[39]
transposition, coverage with thick vascularized flaps, and perineural adhesions; it is already available on the market
restoration of a suitable gliding bed.
and has proven to be highly effective in preventing the
Patients with continuous pain due to an earlier traumatic formation of abdominal, spinal and tendon adhesions. [40]
injury to superficial nerves triggered by external stimuli, In 2005, another macromolecule, polyethylene glycol oxyde (PEO),
and those undergoing revision of a failed prior revision was associated with CMC to enhance its anti‑adhesion
procedure, require deep nerve transposition and coverage effect. Preclinical studies have documented its ability
with thick vascularized flaps providing both biological and to reduce protein, hence collagen, deposition on
mass effects. [32]
tissue. [40,41] However, there is no conclusive evidence for
Relevant clinical data, including pain type (due to external its effectiveness in the peripheral nervous system. A single
compression, continuous, or movement‑related) and paper has demonstrated its safety and effectiveness
cause of the lesion, can indicate the most appropriate in an animal model (Tos et al., paper submitted).
management strategy. Patients with pain due to direct A representative image of gel application after neurolysis
trauma may benefit from the bulk effect of a flap or is shown in Figure 2b.
from nerve relocation to a deep, protected area, whereas Collagen‑based products have recently been developed
simple neurolysis with application of anti‑adhesion devices for wrapping around injured nerves. [42,43] These products
is preferable in simple traction neuropathy, where pain is are theorized to form a microenvironment within the
more often secondary to external traction.
compressed nerve, which keeps nerve growth factors
Early active movement after surgery is indicated to within the epineurium to enhance nerve gliding, and
prevent adhesion recurrence. which are subsequently slowly absorbed.
The next section describes the main techniques used A recent study of a small sample with a short follow‑up
in the treatment of scarring neuropathy and painful describes a novel nerve‑wrapping technique for the
neuroma‑in‑continuity with residual nerve function after upper extremities using a type I collagen conduit wrap.
neurolysis. Its effectiveness is similar to that of other anti‑adhesion
devices, but it entails a lower fewer risk of complications
SURGICAL MANAGEMENT AFTER compared to wrapping the nerve in autologous tissue
NEUROLYSIS such as vein (Neura Wrap; Integra LifeSciences, Plainsboro,
NJ, USA). [43]
Commercial gels and anti‑adhesion devices There are therefore several different types of anti‑adhesion
These devices are used to restore the lost gliding surface. devices, but scant information as to which is the most
Since 1970, when intraperitoneal anti‑adhesion devices effective at the clinical and preclinical level, even though
were first introduced, a number of products characterized all seem to limit perineural scarring formation without
by different shapes and chemical compositions have any particular side effects. A major advantage is their
been developed to limit perineural scar formation. Gels fast application and less invasive surgical dissection,
developed specifically for peripheral nerve‑tissue began to without the need for further procedures (and possible
be produced in 2000. Early anti‑adhesion gels were based attendant injury), which considerably reduces operating
on collagen‑dextran (ADCON‑T/N) and were initially used time compared to the surgical approaches described
in spinal surgery. Preclinical application to rat peripheral above. Notably, there are no clinical trials comparing the
[34]
nerve achieved a satisfactory reduction of perineural effectiveness of the two approaches. A recent case review
scarring. These gels were, however, abandoned after has advanced the proposal to apply anti‑adhesion devices
reports of wound dehiscence and dural fistula formation. [33] in cases where the nerve, released from the scar, appears

160 Plast Aesthet Res || Vol 2 || Issue 4 || Jul 15, 2015