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terminal cutaneous portion of the saphenous nerve; nerve which would mimic those likely to benefit from a
(2) the vastus lateralis branch of the femoral nerve; (3) the VNG in humans.
deep peroneal nerve distal to the extensor hallucis longus Although VNGs can potentially significantly improve
branch; (4) the posterior cutaneous nerve of the thigh; results, the major limitation is the lack of donor sites.
(5) the pudendal nerve; (6) the tibial nerve; (7) the lateral VNGs perform best in long proximal gaps of large nerves,
plantar nerve; (8) the medial plantar nerve; and (9) the but harvesting such a large donor nerve is associated
sciatic nerve, with one of the profunda artery perforators. with significant morbidity. Although this may be partially
However, nerves 5‑9 are not suitable for VNGs because be solved by the use of cable grafting, the donor nerves
of their short length or functional importance, unless available still may not be sufficient, require multiple donor
an amputated limb or limb stump becomes available for sites, complex procedures, and high morbidity.
harvesting of donor nerves. Consequently, nerves 1‑4 are
regarded as possible donor nerves. The deep peroneal
nerve is the longest available with the least morbidity FUTURE DIRECTIONS
together with the sural nerve. The other versatile donor
is the LFCN. Vascularized nerve allografts, which are associated with
immunosuppression, a well‑known facilitator of nerve
Nonvascularized to vascularized wound bed regeneration, will likely become a useful tool in nerve
Experimental studies have shown that in a normally reconstruction with VNGs. Coupling VNGs with NVNGs
vascularized bed, VNGs and NVNGs are equivalent for which surround them may be an option for larger nerves.
the treatment of short gaps of thin nerves. As suggested Prefabricated nerve grafts may also play a role, as the
[92]
by Breidenbach and Terzis, a poorly vascularized bed delay in reconstruction caused by prefabrication may be
can be transformed into a well‑vascularized bed by flap compensated by improved regeneration.
transfer and a NVNG placed into it with similar results.
This is a practice that resembles well‑established flap REFERENCES
transfers in heavily scarred beds for tendon gliding or
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scar‑tethered nerves. Many free or local options exist, 1. Phillipeaux JM, Vulpian A. Note on the trial of a lingual nerve trunk graft
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technique can replace a VNG only when its sole indication 2. Bunnell S, Boyes JH. Nerve grafts. Am J Surg 1939;44:64‑75.
Klar E. About experiences and successes in application of plastic bridging
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4. Seddon HJ. The use of autologous grafts for the repair of large gaps in
HOW SHOULD WE CONSIDER THE peripheral nerves. Br J Surg 1947;35:151‑67.
NERVE INCORPORATED IN A FLAP? 5. Tarlov IM, Epstein JA. Nerve grafts: the importance of an adequate blood
supply. J Neurosurg 1945;2:49‑71.
6. Strange FG. An operation for nerve pedicle grafting; preliminary
Sensate or innervated flaps may provide a model for communication. Br J Surg 1947;34:423‑5.
studying VNGs in the clinical setting. Innervated muscles 7. Taylor GI, Ham FJ. The free vascularized nerve graft. Plast Reconstr Surg
1976;57:413‑26.
show very efficient reinnervation even when radiated or 8. Lind R, Wood MB. Comparison of pattern of early revascularisation of
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placed in poorly vascularized beds. This is likely due conventional versus vascularized nerve grafts in canine. J Reconstr Microsurg
to fact that a nerve included in a flap is in fact a VNG. 1986;2:229‑34.
Innervated flaps may be used to investigate the extent 9. Penkert G, Bini W, Samii M. Revascularization of nerve grafts: an experimental
study. J Reconstr Microsurg 1988;4:319‑25.
and speed of recovery of vascularized nerves transferred 10. Sunderland S. Nerves and Nerve Injuries. 2nd ed. Edinburgh: Churchill
with flaps, either for reinnervation of the flap or to bridge Livingstone; 1978.
composite defects that include nerves and soft tissues. 11. Brooks D. The place of nerve‑grafting in orthopedic surgery. J Bone Joint Surg Am
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12. Seddon HJ. Nerve grafting. J Bone Joint Surg Br 1963;45:447‑61.
CONCLUSION 13. Best TJ, Mackinnon SE, Bain JR, Makino A, Evans PJ. Verification of a free
vascularized nerve graft model in the rat with application to the peripheral
Whether it is worthwhile to perform a nerve graft and nerve allograft. Plast Reconstr Surg 1993;92:516‑25.
when remains controversial: VNGs do not have a real place 14. el‑Barrany WG, Marei AG, Vallée B. Anatomic basis of vascularised
nerve grafts: the blood supply of peripheral nerves. Surg Radiol Anat
in our reconstructive algorithm, resting in a limbo between 1999;21:95‑102.
‘grafts’ and flaps. They are referred to as ‘grafts’ despite 15. Lux P, Breidenbach W, Firrel J. Determination of temporal changes in
being vascularized, although by definition they possess a blood flow in vascularized and nonvascularized nerve grafts in the dog.
vascular pedicle and should be called ‘flaps’. Plast Reconstr Surg 1988;82:133‑44.
16. Mani GV, Shurey C, Green CJ. Is early vascularization of nerve grafts
Following this review, the authors conclude that VNGs necessary? J Hand Surg Br 1992;17:536‑43.
do perform better than conventional nerve grafts by 17. Settergren CR, Wood MB. Comparison of blood flow in free vascularized
versus nonvascularized nerve grafts. J Reconstr Microsurg 1984;1:95‑101.
providing faster and better regeneration. However, this 18. Appenzeller O, Dhital KK, Cowen T, Burnstock G. The nerves to blood
improvement in regeneration becomes relevant only in vessels supplying blood to nerves: the innervations of vasa nervorum. Brain Res
certain situation such as those shown in Table 1. The 1984;304:383‑6.
failure of several experimental studies to demonstrate an 19. Cowen T, MacCormick DE, Toff WD, Burnstock G, Lumley JS. The effect
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histochemical study of degeneration and regrowth of perivascular adrenergic
No model to date has reproduced a long gap in a thick nerves. Blood Vessels 1982;19:65‑78.

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