Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_892_Библиотеки_им_академика_М_И_Перельмана

In the case of the transected nerve, such as from iatrogenic nerve sectioning, nerve resection during tumor resection, or penetrating trauma, primary repair of the nerve allows for the best chance for return of nerve function. Primary repair offers a single neurorrhaphy, as opposed to multiple sites of neurorrhaphy with cable grafting repair. Evidence from histologic studies has demonstrated decreasing number of viable axons at each neurorrhaphy. Electrophysiologic studies have also shown bet­ter outcomes from axonal regeneration with end-to-end suture repair [23]. Two con­ditions must be met for primary neurorrhaphy to result in successful outcomes: both proximal and distal nerve ends must exist, and direct nerve coaptation must be per­formed in the absence of tension. Tension leads to diminished perfusion and neural regeneration [24]. A defect of up to 18mm of missing nerve can be repaired primar­ily, although this may necessitate mastoidectomy and rerouting of the nerve to achieve a tension-free repair. If the repair is under tension, it is likely to be unsuc­cessful, and nerve grafting would be a better option to consider [5, 23, 25]. Timing of repair in traumatic nerve transections is critical and should be performed as early as possible. Wallerian degeneration begins within 24h and is complete at 72h. During the rst 72h after injury, the nerve segments can be stimulated intraopera­tively, and identication of branches is easier in the unscarred environment. The axons regenerate at a rate of about 1mm per day allowing for axonal growth to eventually reach the neuromuscular junction.