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Mitchell et al. Plast Aesthet Res 2023;10:35 https://dx.doi.org/10.20517/2347-9264.2023.14 Page 9 of 12

thus will rely solely on whatever elbow flexion motor function is restored.

Hand function
The CC7 nerve root transfer is an integral part of this third reconstructive method. Targeting the median
nerve, the CC7 transfer looks to restore hand function and sensation. The brachial plexus of the unaffected
side is explored utilizing an incision just superior and parallel to the clavicle extending cranially along the
posterior border of the sternocleidomastoid if needed. Branches of the external jugular vein are identified
and preserved. Further dissection exposes the supraclavicular brachial plexus. The inferior muscle belly of
the omohyoid is retracted and serves as a landmark for the C7 root. Once identified, CC7 is dissected
distally until the anterior and posterior divisions of the middle trunk are exposed. The anterior trunk is
sharply divided for transfer. For these CC7 limbs to reach their intended target, an interposition nerve
autograft is required. To achieve this, sural, saphenous, or a reversed ipsilateral vascularized ulnar nerve
graft can be harvested. Once collected, the CC7 donor is tunneled subcutaneously between the contralateral
neck incision to a midaxial incision on the affected arm using a specialized nerve passer. In this midaxial
dissection of the injured side, the median nerve is isolated for coaptation. Microsurgical coaptation of the
anterior division of the middle trunk of CC7 to the median nerve is then completed [7,46]

In their study of 111 such transfers, Songcharoen et al. reported that 30% of patients attained finger and
[52]
wrist flexion MRC grades of M3 . Yang et al. reported similar outcomes, with 36% achieving M3 finger
flexion and 38% achieving M3 wrist flexion. M4 finger and wrist flexion strength were recovered by only 7%
[53]
and 11% of patients, respectively . While regaining hand motion is notoriously difficult, this technique has
fallen out of favor in many regions of the world. Sammer et al. in 2012 published a series of fifteen patients
who underwent hemi-CC7 to median nerve transfers with greater than two-year follow-up. Only three out
of the fifteen showed electromyographic signs of reinnervation, but none were able to regain M3 grip
strength . These underwhelming outcomes have been replicated by other recent publications [55,56] .
[54]
Regarding contralateral arm deficits following CC7 transfer, triceps and wrist extensor weakness occurred in
less than 3% of patients. Sensory deficits were seen primarily in the index finger and were transient in
[52]
nature, resolving within seven months . This technique has a steep learning curve and its use is noticeably
more prevalent in the region of its development [7,57] .

Hand sensation
The CC7 transfer to the median nerve provides the secondary benefit of hand sensory reinnervation. A
recent meta-analysis reported 56% of patients recovered S3 sensation . These results surpass reported
[53]
sensation recovery following supraclavicular and ICN sensory rami transfer to the median nerve [31,32] .

Graftable C5
Strategy alterations when a viable C5 nerve root is present involve grafting C5 to the posterior division of
the middle and lower trunk. This aims to reinnervate axillary and radial motor nerve function,
reconstituting shoulder abduction, elbow extension, and wrist extension. Additional support for shoulder
stability is obtained through the standard SAN to SSN transfer. PN can be similarly transferred for elbow
flexion while CC7 to the median nerve as above for wrist flexion, digit flexion and hand sensation .
[7]

DISCUSSION
Pan-brachial plexus injuries present a challenging clinical problem with severe impairment of motor and
sensory function to the upper extremity. In this review, we have presented three general approaches to
performing reconstructions for these challenging patients [Table 1]. Most strategies aim to maximize
shoulder and elbow function, while prioritization of hand function and sensation are variable. As seen in