Tiam Mana Saffari

41 THE ROLE OF VASCULARIZATION IN NERVE REGENERATION 2 intraneural hypervascularization proximal to the site of nerve injury 63 . Although the increased blood flow does not directly implicate for patient management, it may reflect neovascularization and provide insight into pathophysiological processes after nerve injury treatments or serve as a potential prognostic tool, as it is known that the number of endoneurial capillaries significantly increases after nerve injury 64 . Implementing ultrasound as prognostic tool in future clinical trials would allow for direct measurement of the vascularization. Technical challenges The most frequently used VNGs are the saphenous and sural nerve graft, due to their dominant arterial pedicles and the acceptable donor site morbidity 19 . Several other VNGs, as described above, are associated with higher donor site morbidity or are mainly used in free flap reconstructions and not solely as nerve grafts. In very specific patients with brachial plexus avulsions of C8 and T1, the ulnar nerve can be used as a VNG based on the superior collateral artery 65 (Figure 3). Figure 3. Vascularized ulnar nerve graft (VUNG) harvest. Depicted is the harvest of the ulnar nerve (small arrow), based on the superior ulnar collateral artery (SUCA, denoted with large arrow, A) in a patient with a C8-T1 brachial plexus root avulsion. B denoted a close-up view of the SUCA joining the ulnar nerve (ulnar nerve denoted with small arrow, SUCA denoted with large arrow). The completion of the harvest of the entire length of the ulnar nerve based on the SUCA measured approximately 30 cm (C, SUCA denoted with arrow). The VUNG was used to graft the C6 root to the lateral cord. In D the vascular anastomosis of the SUCA to the thoracoacromial trunk was depicted.