Wednesday, March 7, 2007

Direct repair (nerve grafting), neurotization, and end-to-side neurorrhaphy in the treatment of the brachial plexus injury.

(J Neurosurg 2007 Mar;106:391-399)


1 comment:

Coordinator said...

In this series of 168 brachial plexus injury patients, 95 (57%) had adequate 2-year follow-up and were evaluated as to the effect different repair techniques had on outcome. The techniques compared included nerve grafting, intraplexal nerve transfers, extraplexal nerve transfers, and end-to-side neurorrhaphy. The best results were seen after graft repair, with 79% of grafted elements having an M3 or better outcome. Intraplexal nerve transfers faired better than extraplexal transfers for both the axillary (68% vs. 47%) and musculocutaneous nerve (94% vs. 50%). Examining Table 5, the majority of extraplexal transfers for the axillary nerve were from the intercostals (16/20), and for the musculocutaneous nerve from the spinal accessory (26/30). It is uncertain if interposition grafts were required for these transfers. These extraplexal transfers were compared to intraplexal transfers to the axillary and musculocutaneous nerves. Intraplexal transfers were from a combination of the medial pectoral, thoracodorsal, and long thoracic nerves (35/35).

Because of incomplete follow-up in 43% of patients, as well as the likelihood that patients undergoing extraplexal transfers were more likely to have a more severe injuries to begin with (e.g., one would tend not to harvest intercostals for transfer to the axillary nerve if multiple intraplexal donors are available), their conclusion that intraplexal transfers per se have a better chance of success than extraplexal donors is uncertain. Also, one may argue that their extraplexal donor group does not represent the more common extraplexal donors used by other authors (intercostals to musculocutaneous, ulnar/median fascicles to the biceps/brachialis branches, triceps branch to axillary, and spinal accessory to suprascapular).

Presumably as a result of their poorer outcomes after extraplexal nerve transfer, in 14 patients where no intraplexal nerve was available for axillary nerve coaptation, they performed an end-to-side neurorrhapy of the axillary nerve to either the ulnar or median nerves (13/14) via an epineurial window. Fascicles were not cut and transferred during these procedures. Their axillary nerve results were comparable to the intraplexal transfers: 64% had good function after end-to-side repair. The authors concluded that end-to-side neurorrhaphy may be better than extraplexal transfer.

Regarding the axillary nerve outcomes in Figure 3, a successful result was defined as M3 or better function with at least 45 degrees of abduction and/or flexion. However, because they did not specifically account for scapular rotation and possible contribution from the supraspinatus to this 45 degrees, one cannot make strong conclusions as to the efficacy of each technique. Nevertheless, it is promising that end-to-side neurorrhaphy of the axillary nerve can potentially yield significant reinnervation.