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injury as well as an incomplete outcome (partial sensate negative role should be reconsidered. In pediatric patients,
recovery, up to hypothenar region, and M3 only for finger special regenerative and brain adaptive properties should
abduction‑adduction) in a lower (forearm) ulnar nerve be considered. The pediatric patient in Magdi Sherif and
[10]
injury. Amr stimulates further comments. Even ulnar nerve
lesions that have the worst outcome in adults, seem
The patients were 6 adult men (4 ulnar nerve and 2 median to produce better outcomes in children. In their series,
nerve injuries), one woman (ulnar) and an 8‑year‑old girl Magdi Sherif and Amr. showed electrical conduction in
[10]
(median). With the exception of the child (patient number both grafts due to child’s regenerative capability. They
4), they all underwent surgical repair 1 month after initial also reported “minimal intrinsic muscle wasting” as an
trauma. Optimal results were achieved in median nerves effect of possible damage to the donor nerve produced
and in the pediatric patient. Interestingly, among the five by end‑to‑side surgical coaptation (the so‑called “escape
ulnar nerves treated: (1) two showed good results (the effect”). Interestingly, this is the only clinical report of this
former, unexpected, from the Magdi Sherif and Amr. fearful complication of axonal escape from the donor ulnar
[10]
series, a more proximal injury at arm level, and the latter in that series. Finally, the last technical concern could be
our case of high voltage injury, but it was more distal risen regarding the number of bridge grafts (“cables”)
and required only a neurolysis); (2) another produced a needed to produce the best result; even, in this case,
mediocre recovery (even if the injury was located more Magdi Sherif and Amr. make the correct comment: the
[10]
distally at forearm level); and (3) the remaining 2 achieving treated cases suggest that higher quantity should not be
poor results.
a valid concern to attract more axons and one cable is
Time may also be affecting against both proximal repair enough.
and distal babysitting; experimental evidences claim Cross nerve grafts in the palm, such as in patient
the role of decreasing the recruitment of Schwann cells number one by Magdi Sherif and Amr., as connecting
[10]
together with lower production of growth factors when pure motor branches, produce better results. We agree
Wallerian degeneration is in process. [12‑14] Patient number that this could due to a pure motor axonal component
three has the best outcome for the most proximal injury as well as due to decreased distance for regenerating
as an earlier combined treatment possibly led to better fibers from the donor nerve. We add that the higher
results than the same treatment in a more distal injury number of axons in the motor branch of the ulnar
repaired later.
nerve could also be claimed as a cause. However, the
From a clinical point of view, it can be said that proximal authors noted a difficult dissection of the deep
[10]
ulnar injuries maintain their black legend of poor recovery ulnar motor branch, owing to the presence of closer
prognosis while median nerve injuries have a better important anatomical structures. Moreover, there is
chance. This occurs especially in case of old (more than a lack of description of the surgical technique: the
two months) injuries. authors do not explain where the cable between the
median thenar and ulnar motor branch is positioned
Cross nerve grafts above the wrist have proven ineffective whether subcutaneous or deep.
in bringing axons distally to protect effectors in both
Kayikcioglu’s et al. and one case from our series. In We believe that Magdi Sherif and Amr. have refined
[10]
[9]
[10]
Magdi Sherif and Amr. series, three cases treated by the original technique, and their recommendations
nerve bridging above the wrist showed good results should be followed when applying this technique of
in one median nerve (a child, see below for further babysitting. We recommend one cable grafting, use
considerations) and an ulnar nerve (M4), as well as of stimulator, and most distal grafting to avoid fiber
mediocre results in another ulnar nerve. This could escape and muscle wasting in the territory of the
be explained by worse prognosis dealing with a ulnar donor nerve. Another negative factor to be struggled
nerve; time from injury could also have had a negative is time, which produces a decrease in neurite growth
influence, whereas the good result (M4) in the other case factors and Schwann cells migration. This could be
remains surprising. achieved through a microsurgical approach coupled
with basic sciences applications, such as gene therapy
These considerations could also apply to our series: two and tissue engineering with scaffolds and regenerating
ulnar nerves, the former showing poor outcome, the latter cells. Moreover, early exploration of nerve injuries
[25]
a complete recovery. Some other recommendations must could also help in struggle against time and Wallerian
be taken into consideration, too, such as selecting pure degeneration, its rationale is based on both
[26]
motor donor fibers through electrostimulation following experimental evidences of early neuronal death as far
[16]
Jabaley’s et al. topographical anatomy.
[27]
as in motor ventral horn and in dorsal root ganglia
However, another consideration is that there is no and more recent clinical data from early brachial plexus
[28]
consensus about the negative influence of sensate fibers. exploration and repair. Regardless of final outcomes,
Some authors’ [17,18] experience agrees with this last coupling of (a) both neurons (neuroprotection) and
[27]
opinion, but several other and more recent experimental effectors (babysitting in wrist or palm) [9,10] is preferred
[2]
experiences [19‑22] do not. In these studies, sensate fibers to (b) traditional repair through grafts or distal
produce end‑to‑side regeneration and reinnervation of neurotization [29‑31] could be regarded as the future in
distal muscle. [23,24] Thus, we believe that sensate fibers’ management of proximal nerve injuries.
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