Biology Reference
In-Depth Information
spontaneous regeneration potential of peripheral nerves and the best efforts
and modern surgical techniques, functional restoration is often incomplete
and clinical results are still unsatisfactory (
Battiston et al., 2009; Scholz
et al., 2009
).
Peripheral nerve injury may result in injury without gaps or injury with
gaps between the nerve stumps. When there is no gap or the gap is short
(
5 mm or less), as in simple injuries, the common surgical approach is a
direct suture of the two stumps (end-to-end suture) (
Terzis et al., 1997
).
For longer nerve gaps, when nerve injury resulted in substance loss
between the two nerve stumps, this direct suturing under tension leads to
very poor clinical results (
Dvali &Mackinnon, 2003
) and a segment of nerve
or other materials must be used to bridge the gap.
The demonstration, in the early 1970s, that grafting of an autogenous
nerve segment to bridge a nerve defect leads to better clinical results than
suturing the two stumps under tension (
Millesi, 1970
), opened a new era
in peripheral nerve surgery making it possibly the most successful surgical
approach to complex lesions that before would have been unfathomable.
There are three types of conventional bridging materials:
i.
Autologous nerve grafts
. Nerve autografts have seen extensive clinical
employment over the past 30 years. A nerve graft provides an ideal con-
duit for regenerating axons because it provides a scaffold which con-
tains Schwann cell basal laminae, and moreover, these Schwann cells
produce growth factors (
Lundborg, 2004
). Autogenous nerve grafting
can be performed with nonvascularized autogenous nerve, vascularized
nerve, interpositional conduits, and nerve allografts. However, it has
several disadvantages, including an extra incision for the removal of
a healthy sensory nerve, and the removal of a healthy sensory nerve
which will result in a sensory deficit. Finally, donor graft material is lim-
ited, particularly for managing extensive lesions which require several
lengths of nerve graft.
ii.
Non-nervous biological grafts
. Conduits made by small segments of an
artery were first successfully employed by Bungner (
Bungner, 1891
).
However, interest shifted then to veins for their larger availability
and reduced side effects related to their withdrawal (
Wrede, 1909
).
Similar to veins, also the use of skeletal muscle autografts for nerve repair
was already reported many years ago (
Fawcett &Keynes, 1990; Keynes,
Hopkins, & Huang, 1984
). The idea of employing muscle fibers
for axonal regeneration is on the similarities between the muscle
basal
lamina and the endoneurial tubes (
Fawcett & Keynes, 1990;
