Tiam Mana Saffari

40 CHAPTER 2 difficult. Nevertheless, others have endeavored describing techniques to repair defects of larger than 12 cm 60,61 . Similarly, Terzis and Kostopoulos found good to excellent sensory return, depending on the injury, after VNG reconstruction of 21 cases with upper extremity nerve injuries in which NVNGs had failed. 57 . In their lower extremity cases with injuries at the level of the knee or thigh, these same techniques were applied to regain muscle strength when denervation time was less than six months in patients reconstructed with large nerve grafts and regained remarkable muscle strength of at least M4, mostly in traction avulsion injuries 56 . Unfortunately, these results have yet to be duplicated. VNGs are also often used in the reconstruction of proximal nerve lesions, such as traumatic brachial plexus injuries (BPI) 16 . In the largest BPI case series to date, 151 reconstructions for posttraumatic BPI were described 55 . Free and pedicled vascularized ulnar grafts were used for reconstruction and concluded that patients with long denervation times (>12months) yielded inferior results compared with those that were operated earlier (<6 months) 55 . A similar study found unsatisfying recovery of elbow f lexion and wrist extension after BPI when repaired around 4.6 months after trauma 52 . While there was no direct comparison to NVNGs in these studies, the importance of denervation time was well-stated and described as less receptivity of the neuromuscular junction when nerve repair is delayed for a long period of time 62 . It is accepted that outcomes are correlated with both the time course and the degree of denervation, however, an exact cut off point has not been defined, which may be worthwhile to evaluate. With no direct comparison to NVNGs, conclusions on the superiority of VNGs is only speculated and not proven. To summarize, the above mentioned studies have used VNGs to repair large nerve defects to improve outcomes in complex and unique cases. Ideally, clinical studies comparing VNGs to NVNGs should be randomized and involve patients with similar injuries, nerve graft repair and follow-up times. Due to diversity in cases, critical analysis has not been feasible to date, recognizing a still existing clinical problem. Moreover, reconstructions are evaluated mostly by investigating axonal regeneration via Tinel’s sign, EMG return and functional motor recovery. While these outcome measurements are clinically relevant, they are not a direct reflection of the applied vascularization. Very recent research investigated the use of ultrasound to describe