Editing Nerve injury (section)

== Operative principles ==

* Excellent exposure - identify the normal nerve, before carrying dissection forward or back
* Tourniquet up for no longer than 30 mins if intra-operative nerve stimulation is planned
* Really there are two things you are likely to find: neuroma in continuity, or nerve stumps
* Neuroma-in-continuity: 
** Intra-operative nerve action potentials will be helpful, because inspection/palpation does not predict histology or outcomes, and can determine recovery before that recovery is seen either clinically or via electromyogram
** If NAP is present across a lesion, don't resect - probably better off with neurolysis alone
** If no NAP, probably needs resection and surgical repair
* Nerve stumps
** Nerve repair or reconstruction is indicated
* Microsurgery should be used to repair
** Sharply remove neuroma and scar tissue, until normal fascicular structures are seen (this pattern is called les yeux d'escargot - snail's eyes)
** Divide protruding fascicles until they lie flush with epineurial sheath - ensure no overlapping of fascicles
** End to end repair or interpositional grafting - 8-0, 9-0 or 10-0 suture should be used
** Tension-free
** Ensure the suture only connects epineurium, and not fascicles - will lead to intraneural neuroma
** Often only two or three interrupted sutures required
** Fibrin glue may be used to reinforce the suture line
* Neurolysis
** Releasing scar tissue surrounding the injured nerve
** Indicated for neuroma in continuity, with intact NAP conduction
* Nerve graft
** Most frequent source is sural nerve
** Suture in reversed orientation, which ensures that axons will not be lost to small side branches in the nerve graft