Targeted Muscle Reinnervation of the brachial plexus region: A cadaveric study and case series

Introduction

Targeted Muscle Reinnervation (TMR) has been shown to prevent and treat neuropathic pain as well as enhance bioprosthetic function. A paucity of data and anatomical description exist regarding TMR in the setting of proximal amputations at the level of the brachial plexus region. In this work, the technique and anatomical description of TMR for proximal amputations at the shoulder level and above, with the corresponding brachial plexus nerve transfers and reconstruction, will be described as an anatomic reference and operative guide.

Methods

Cadaveric dissections of four shoulder and forequarter level amputations were performed. Major mixed motor and sensory nerve branches were identified, dissected, and tagged. Amputated peripheral nerves were then transferred to identified and labeled target motor nerves within the shoulder and chest levels via direct end-to-end coaptations per traditional TMR technique. A retrospective review was completed by our multi-institutional team including clinical case correlates for TMR performed at the described levels.

Results

A total of 8 TMR brachial plexus clinical cases were performed between 2016 and 2020 in a primary or secondary setting following oncologic resection or traumatic injuries. Follow-up ranged from 18 to 58 months, mean follow-up of 34.6 months. Six out of 8 patients require no narcotics, while 2 require supplemental narcotic use. One patient requires no pain medication. Four of the 7 patients utilize an EMG enhanced bioprosthetic. The eighth patient died from tumor recurrence.

Conclusions

Technical considerations for brachial plexus TMR surgery have been outlined with early follow-up data showing beneficial pain control and prosthetic outcomes.