This repair will be more or less complete depending on the number of roots stump available to be repaired. The problems start with the very frequent association of root avulsion
that means no proximal stumps available to allow an anatomical reconstruction of the nerve gap with grafts.
In these situations the only option is to try to repair the distal part of a nerve which lack of its proximal connection by means of neurotizations.
Neurotization can be defined as a nerve transfer or nerve by pass in order to bring nerve sources out of the plexus to re-innervate distal stumps
no more connected with the proximal ones.
If in a multiple root avulsion lesions we can find at least one or two root’s stump the grafts will be distributed from the remaining roots to the
entire distal part of the plexus. This will be defined as an intraplexal neurotisation. Examples of extraplexal neurotisation are spinal accessory
nerve sutured to suprascapular nerve in avulsion of upper roots or intercostals nerves sutured to musculocutaneous nerve in total palsies or contralateral
healthy C7 root used to bring re-innervation to the avulsed roots.
Since to perform a neurotization we must intentionally section an healthy nerve, we must carefully evaluate the balance cost-benefit in order to concentrate on a
unique target a nerve or a portion of it avoiding to provoke a substantial loss of function at the donor site.
It is obvious that neurotization offer a limited repair and, especially in extended palsies, must be multiple (accessory nerve, intercostals nerves,
contralateral C7 etc).
Strategy of Repair
Upper palsies C5 C6 –C5 C6 C7
The C5 C6 lesion is very common. The roots can be ruptures or avulsed.
There are case were one root is avulsed and the other ruptured.
ONLY EXPLORATION OF THE ROOTS CAN GIVE AN EXACT VIEW OF THE SITUATION
The preferable way of repair is grafting between the good stump and the distal trunks . It implies a precise assessment of the
quality of the stumps , sometimes using chemical staining , often ,with experience , by clinical examination . Only grafting
can give a recovery of the whole muscle groups innervated by the upper roots .
Neurotizations can be very useful when the roots are avulsed or when they have a poor quality . The most common neurotizations are :
There are other , less common , neurotizations using Intercostal or Pectoralis nerves .
- Spinal Accessory nerve to Suprascapular nerve
- Median or Ulnar fascicle to Biceps or/and Brachialis nerves.
- One of Triceps branch to part of the Axillary nerve.
If we have 2 usable roots :
If we have 1 good root and one avulsed :
- C5 C6 (post) : posterior division of upper trunk
- C5 C6 (ant) : anterior division of upper trunk
- C5 to suprascapular nerve
- If C5 poor : Spinal accessory to SS nerve
- If C6 poor : biceps neurotization with ulnar nerve
If the 2 roots are avulsed :
- Neurotization of SS by Spinal Accessory
- Graft to upper trunk
- Sometimes neurotization Biceps with Ulnar nerve.
- Neurotization : SS by S. Acc
- Neurotization : Biceps by Ulnar nerve
- Neurotization : Axillary with Triceps branches
C5 C6 C7
The association of a C7 lesion makes the repair much more difficult in case of avulsion, as the ulnar nerve and the Triceps may be involved.
If we have 3 ruptures roots :
If we have only one or two roots intact
- Graft to upper and middle trunk
If we have 3 avulsions : difficult situation : each case is different
- Association of graft and neurotizations
- Spinal acc to SS in all cases
- Biceps reconstruction function of the quality of ulnar nerve. If no good : intercostal nerves transfer
- Problem with axillary, triceps, wrist extensors if they are all paralysed.
We have no possibility to repair by nerve surgery all the functions. Some neurotizations are possible in the arm (intercostal) or in the forearm (FCR, pronator) but it will be necessary to add some secondary tendon transfers (especially in the wrist).
Complete brachial plexus injury
When all roots and especially the lower (C8 T1) roots are injured, it is called complete brachial plexus.
(Photos – film )
In most cases, unfortunately, the lower roots are avulsed from the spinal. They have no chance of spontaneous recovery.
Up to now, the treatment of complete brachial plexus has been limited to repair by grafts or neurotizations of the upper plexus in order to recover movements in the shoulder and elbow. A part from the rare case where the lower roots were ruptured and could be repaired, the attempts of reinnervation of the hand muscles by grafts, or neurotizations by intercostal nerves have given very poor results and in most cases, the hand has been abandoned.
A new perspective has been operated by the chinese authors, using the contro-lateral C7 root. Although the CC7 transfer with graft has not changed dramatically the prognosis, its use with a direct coaptation to the lower has proven in many cases very effective (WANG).
We are now using this technique either alone or combining it with other techniques when possible.