Double Fascicular Transfer Using Partially Injured Donor Nerves: Is It Powerful Enough to Restore Elbow Flexion in Acute Brachial Plexus Injuries?

Assessment, management, and rehabilitation of traumatic peripheral nerve injuries for non-surgeons

Electrodiagnostic evaluation is often requested for persons with peripheral nerve injuries and plays an important role in their diagnosis, prognosis, and management. Peripheral nerve injuries are common and can have devastating effects on patients' physical, psychological, and socioeconomic well-being; alongside surgeons, electrodiagnostic medicine specialists serve a central function in ensuring patients receive optimal treatment for these injuries. Surgical intervention-nerve grafting, nerve transfers, and tendon transfers-often plays a critical role in the management of these injuries and the restoration of patients' function. Increasingly, nerve transfers are becoming the standard of care for some types of peripheral nerve injury due to two significant advantages: first, they shorten the time to reinnervation of denervated muscles; and second, they confer greater specificity in directing motor and sensory axons toward their respective targets. As the indications for, and use of, nerve transfers expand, so too does the role of the electrodiagnostic medicine specialist in establishing or confirming the diagnosis, determining the injury's prognosis, recommending treatment, aiding in surgical planning, and supporting rehabilitation. Having a working knowledge of nerve and/or tendon transfer options allows the electrodiagnostic medicine specialist to not only arrive at the diagnosis and prognosticate, but also to clarify which nerves and/or muscles might be suitable donors, such as confirming whether the branch to supinator could be a nerve transfer donor to restore distal posterior interosseous nerve function. Moreover, post-operative testing can determine if nerve transfer reinnervation is occurring and progress patients' rehabilitation and/or direct surgeons to consider tendon transfers.

The Evolution of the Reconstructive Strategy for Elbow Flexion for Acute C5, C6 Brachial Plexus Injuries over Two Decades

BACKGROUND

 Over the course of the past two decades, improved outcomes following brachial plexus reconstruction have been attributed to newer nerve transfer techniques. However, key factors aside from surgical techniques have brought improved consistency to elbow flexion techniques in the latter decade.

METHODS

 One-hundred seventeen patients who underwent brachial plexus reconstruction from 1996 to 2006 were compared with 120 patients from 2007 to 2017. All patients were evaluated preoperatively and postoperatively to assess the recovery time and of elbow flexion strength.

RESULTS

 In the first decade, nerve reconstruction methods included proximal nerve grafting, intercostal nerve transfer, and Oberlin-I transfer. In the second decade, newer methods such as double fascicular transfer and ipsilateral C7 division transfer to the anterior division of upper trunk were introduced. About 78.6% of the first decade group versus 87.5% of the second decade group were able to reach M3 flexion strength (p = 0.04), with shorter time recovery to reach M3 in the 2nd decade. About 59.8% of the first decade group versus 65.0% of the second decade group were able to reach M4 (p = 0.28), but no significant difference in time of recovery. In both groups, the double fascicular nerve transfer had the highest impact when introduced in the second decade. More precise magnetic resonance imaging (MRI) techniques helped to diagnose the level of injury, the roots involved and evaluate the health of the donor nerves in preparation for intraplexus transfer.

CONCLUSION

 In addition to modified techniques in nerve transfers, (1) MRI-assisted evaluation and surgical exploration of the roots with (2) more judicious choice of donor nerves for primary nerve transfer were factors that ensured reliable and outcomes in the second decade.