Anatomic basis of vascularised nerve grafts: the blood supply of peripheral nerves

Abstract

The present study was carried out on 30 cadavers (5 fresh, 20 preserved adult and 5 fresh stillborn) following injection of red latex through the subclavian and common iliac arteries. The blood supply to the peripheral nerves was studied in general, together with the vascular pedicles to the ulnar, saphenous, sural, deep and superficial peroneal nerves, and the superficial branch of the radial nerve. The nutrient arteries supplying the peripheral nerves came from either the adjacent axial artery or the fasciocutaneous or muscular arteries. They formed anastomotic channels in the epineurium and penetrated it to form a continuous longitudinal artery. Based on the presence of absence of dominant arterial pedicles, five patterns of blood-supply to the nerves could be identified. I: no dominant arterial pedicle; II: only one dominant artery (e.g. artery with a diameter more than 0.8 mm and accompanying the nerve for most of its length); III: only one dominant vessel that divided into ascending and descending branches to supply the nerve; IV: multiple dominant pedicles; V: multiple dominant arterial pedicles forming a continuous artery that accompanied the nerve. The arterial pedicles to the ulnar, saphenous and deep peroneal nerves and the superficial branch of the radial n. had mean diameters of over 0.8 mm, thus being suitable for microvascular anastomosis. Those to the sural nerve were not present in two thirds of the dissected cadavers. In 10% of the cadavers the superficial peroneal nerve had an arterial pedicle that accompanied the nerve for less than two cm with a mean diameter less than 0.8 mm. The ulnar nerve could be very suitable as a donor vascularized nerve graft as it had a dominant vascular pedicle in all the cases studied; however, its use should be restricted to C8 and T1 root damage of the brachial plexus. The superficial branch of the radial n. might be suitable for vascularized nerve grafting, but this is difficult in practice since the radial artery is a major limb artery. The saphenous nerve had a dominant arterial pedicles in all the cadavers dissected and could be the most suitable as a donor vascularized nerve graft, unlike the sural nerve which did not have a dominant arterial pedicle in two-thirds of the specimens. The deep and superficial peroneal nerves may also be unsuitable since the former is accompanied by a major limb vessel while the latter had a dominant vascular pedicle that accompanied the nerve for only a short distance in 10% of the dissected cadavers.