Complications of contralateral C-7 transfer through the modified prespinal route for repairing brachial plexus root avulsion injury: a retrospective study of 425 patients

In this report, the authors review complications related to the modified prespinal route in contralateral C-7 transfer for repairing brachial plexus nerve root avulsion injury and suggest a prevention strategy.A retrospective, nonselected amalgamation of every case of modified contralateral C-7 transfer through the prespinal route was undertaken. The study population comprised 425 patients treated between February 2002 and August 2009. The patients were managed according to a standardized protocol by one senior professor. The surgical complications were grouped into one of the following categories: those associated with tunnel making through the prespinal route, those related to the dissection and transection of the contralateral C-7 nerve root, and those that occurred in the postoperative period.The study population included 379 male and 46 female patients whose average age was 21 years (range 3 months to 56 years). A total of 401 patients were diagnosed with traumatic brachial plexus injury, the leading cause of which was motor vehicle accident, and 24 patients were diagnosed with obstetrical brachial plexus palsy. The contralateral C-7 nerve root was cut at the proximal side of the division portion of the middle trunk in 15 cases and sectioned at the distal end of the anterior and posterior divisions in 410 cases. The overall incidence of complications was 5.4% (23 of 425). Complications associated with making a prespinal tunnel occurred in 12 cases, including severe bleeding due to vertebral artery injury during the procedure in 2 cases (0.47%), temporary recurrent laryngeal nerve palsy in 5 cases (1.18%), pain and numbness in the donor upper extremity during swallowing in 4 cases (0.94%), and dyspnea caused by thrombosis of the brainstem 42 hours postoperatively in 1 case (0.24%); this last patient died 38 days after the operation. Complications related to exploration and transection of the contralateral C-7 nerve root occurred in 11 cases, including deficiency in extensor strength of the fingers and thumb in 4 cases (0.94%) due to injury to the posterior division of the lower trunk, unbearable pain on the donor upper extremity in 3 cases (0.71%), Horner's syndrome in 2 children (0.47%) who suffered birth palsy, a section of C-6 nerve root mistaken as C-7 in l case (0.24%), and atrophy of the sternocostal part of the pectoralis major in 1 case (0.24%).The most serious complications of using the modified prespinal route in contralateral C-7 transfer were vertebral artery laceration and injury to the posterior division of the lower trunk. The prevention of such complications is necessary to popularize this surgical procedure and attain good long-term clinical results.