Ipsilateral C7 Root Research Articles

Transfer of a C7 Fascicle for the Pectoralis Major to the Suprascapular Nerve: A 3-Year Follow-Up Patient Series

Background: In patients with C5-C6 brachial plexus injury, spinal accessory nerve transfer to the suprascapular nerve is usually performed for the restoration of shoulder abduction. In order to minimize donor deficits, we transferred one fascicle of the ipsilateral C7 root, dedicated to the pectoralis major muscle, to the suprascapular nerve. Methods: Ten patients with a mean age of 33 years (range, 19 to 51 years) were operated on at a mean delay of 4 months after their trauma (range, 2 to 7 months). Patients had C5-C6 brachial plexus palsy with avulsed roots on spinal magnetic resonance imaging scan. In addition to the partial C7 transfer, patients sustained nerve transfers to the posterior branch of the axillary nerve and to the motor branches of the musculocutaneous nerve for the biceps and brachialis muscles. Results: At a mean follow-up of 36 months (range, 29 to 42 months), mean shoulder abduction and external rotation ranges of motion were, respectively, 99 degrees (range, 60 to 120 degrees; p = 0.001) and 58 degrees (range, 0 to 80 degrees; p = 0.001). In nine patients, shoulder abduction strength was graded M4, according the British Medical Research Council grading scale, against 1.6 kg (range, 1 to 2 kg), and was graded M3 in one patient. External rotation strength was graded M4 in nine patients and M3 in one patient. Residual strength of the pectoralis major muscle was graded M4+ in every patient. Conclusions: C7 partial transfer to the suprascapular nerve showed satisfactory results at long-term follow-up for active shoulder abduction and external rotation recovery in C5-C6 brachial plexus palsies. This technique replaced spinal accessory nerve transfer in the authors’ practice. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Direct transfer of C7 pectoral fascicles to the suprascapular nerve in C5/C6 brachial plexus palsies: an anatomical study.

We investigated a technique to reconstruct the suprascapular nerve in patients with C5/C6 brachial plexus palsies, using pectoral fascicles from the ipsilateral C7 root. Using a supraclavicular approach in eight cadavers, the suprascapular nerve was placed side by side with an anterior quadrant fascicle from the C7 root. Several criteria were assessed, including the fascicle length, the overlap between the two nerves and their respective diameters. The mean length of the C7 fascicles was 19.3 mm, with a mean overlap of 4.7 mm. The suprascapular nerve and the C7 fascicles had mean diameters of 2.2 mm and 2.1 mm, respectively. Pectoral fascicles from C7 seem to be an option for reconstruction of the suprascapular nerve in C5/C6 palsies. Clinical studies will be required to establish the potential limitations of this transfer, especially in cases with complex lesions of the suprascapular nerve.

Total ipsilateral C7 root neurotization to the upper trunk for isolated C5-C6 avulsion in obstetrical brachial plexus palsy: a preliminary technical report

C5-C6 root avulsion in obstetrical brachial plexus palsy (OBPP) is a rare injury with poor prognosis usually associated with breech delivery. The treatment is challenging and requires high microsurgical skills. The triple nerve transfer (spinal accessory nerve, ulnar fascicles, and triceps long or lateral head branch) represents the gold standard treatment. The total ipsilateral C7 nerve root neurotization is a promising technique, which has never been described in OBPP. The total ipsilateral C7 nerve root is used as a neurotizer transferred to the upper trunk as an alternative method to other intra- or extra-plexual reconstruction techniques. During brachial plexus surgical exploration, an intraoperative neurostimulation was performed to confirm the integrity of C7 and the lesion of C5 and C6. The entire C7 nerve root and the upper trunk are cut. The C7 root was transferred to the upper trunk with a fibrin sealant. This technique was easily performed with a single approach and avoided intercalated nerve grafts. The C7 nerve root provided a large number of nerve fibers with an adequate diameter to be transferred to the upper trunk. We illustrated this technique with a typical case of a child at 8 years of follow-up. The total ipsilateral transfer of the C7 root to the upper trunk is a viable alternative procedure for newborns with C5-C6 avulsion.

Transferencia ipsilateral de la raíz C7 del plexo braquial. A propósito de un caso y revisión de la literatura

The C7 root in brachial plexus injuries has been used since 1986, since the first description by Gu at that time. This root can be used completely or partially in ipsilateral or contralateral lesions of the brachial plexus. A review of the literature and the case report of a 21-month-old girl with stab wounds to the neck and section of the C5 root of the right brachial plexus are presented. A transfer of the anterior fibres of the ipsilateral C7 root was performed. At 9 months there was complete recovery of abduction and external rotation of the shoulder.

End-to-side neurorraphy using different donor nerves for reconstructing brachial plexus injury: an experimental study in a rat model

Objective To evaluate the effectiveness of end-to-side coaptation using different donor nerves in nerve reconstruction of brachial plexus injuries. Methods Ninety SD rats were subjected to brachial plexus upper trunk injury and randomized into 5 goups.The right musculocutaneous nerves of 4 groups were reonstructed by both end-to-side and end-to-end neurorraphy using phrenic nerve and ipsilateral C7 root respectively.Another group served as control without any nerve reconstruction.Electrophysiologic and histologic examinations,accompanied with behavioral tests were performed in the 1st,2nd and 3rd month postoperatively.Results By the end of the experiment at 3rd month postoperatively,regenerative signs indicated that reinnervation was possible by end-to-side neurotization.However its outcomes were significantly inferior to these of the end-to-end neurorrhaphy (P ＜ 0.05).The use of the ipsilateral C7 root as a donor nerve in the end-to-side neurorrhaphy resulted in least regeneration judging by behavioral tests,compound muscle action potential and neuromorphometry(P＜0.05). Conclusion It is possible to reconstruct the musculocutaneous nerves in rats of brachial plexus injury by end-to-side neurorraphy.The efficacy of various donor nerves is distinct.The phrenic nerve served as a better motor nerve in end-to-side coaptation,comparing with the ipsilateral C7 root.End-to-side neurorrhaphy cannot achieve the same results as end-to-end neurorraphy,and therefore should be used with caution as an alternative for brachial plexus reconstruction. Key words: Nerve regeneration; End-to-side neurorraphy; Experimental study

Triceps Brachii Reinnervation in Primary Reconstruction of the Adult Brachial Plexus: Experience in 25 Cases

Elbow flexion and shoulder abduction are the primary goals in brachial plexus surgery; however, reinnervation of the triceps is also an objective to be considered, as restoration of elbow extension improves the stabilization of the elbow and can provide a more powerful grasp. This study aims to demonstrate the author's experience with restoration of elbow extension function in cases of brachial plexus surgery in adults. Records of 25 patients sustaining traumatic brachial plexus injuries who were treated surgically with reinnervation of the triceps were reviewed. Nine techniques were employed, including posterior cord reconstruction and nerve transfers using donors such as the ipsilateral C7 root, phrenic nerve, medial pectoral nerve, intercostal nerves, the spinal accessory nerve, and a motor fascicle of the ulnar nerve. The targeted structure was the radial nerve or the branch to the long head of the triceps. Twenty-one subjects (83%) obtained triceps reinnervation, and good results (M3 or better) were observed in 19 cases (76%). M4 grade was noted in 36% of the cases, M3 grade in 40%, M2 grade in 8%, M1 grade in 8%, and M0 grade in 8% of the patients. The best outcomes were observed in the cases presenting a C5 to C7 palsy and those in which the nerve to the triceps was chosen as the transfer target. Reinnervation of the triceps can be achieved in most patients if adequate donor and recipient nerves are carefully selected based on an individual case-specific decision.

Effect of Ipsilateral C7 Nerve Root Transfer on Restoration of Rat Upper Trunk Muscle and Nerve Function After Brachial Plexus Root Avulsion

The effects of ipsilateral cervical nerve root transfer on the restoration of the rat upper trunk muscle and nerve brachial plexus root avulsion were studied. After simulated root avulsion of the upper trunk brachial plexus, 120 rats were randomly divided into 4 groups: (A) ipsilateral C7 root transfer group; (B) Oberlin group; (C) phrenic nerve group; and (D) no axillary nerve restoration group. At 3, 6, and 12 weeks postoperatively, Ochiai score, Barth feet overreaching test, Terzis grooming test, and indices of neurotization were determined in 10 rats from each group. Twelve weeks postoperatively, nearly all the behavioral, neuroelectrophysiological, and histological outcomes of the axillary nerve and deltoid muscle and some of the indices of musculocutaneous nerve and biceps brachii function in the ipsilateral C7 group were superior to those in the other 3 groups. No significant difference was found between the ipsilateral C7 group and the other 3 groups in recovery rate of wet biceps muscle weight. No significant difference was found between the ipsilateral C7 group and the Oberlin group in the recovery of the axillary nerve compound muscle action potential and biceps brachii cell size. No significant difference was found between the ipsilateral C7 group and the phrenic nerve and no axillary nerve restoration groups in amplitude recovery rate of musculocutaneous nerve compound muscle action potential. No significant difference was found between the ipsilateral C7 and the Oberlin groups in the early recovery of musculocutaneous nerve compound muscle action potential, but recovery was significantly better in the ipsilateral C7 group at 12 weeks. Ipsilateral C7 root transfer can improve the quality of restoration of muscle and nerve function in the rat upper trunk after brachial plexus root avulsion.

An experimental study on outcome of ipsilateral C7 nerve root transfer to repair the root avulsion of the brachial plexus

To experimentally compare the treatment outcome of the injured upper limb of the root avulsion of C5 and C6 of the brachial plexus repaired by ipsilateral C7 nerve root transfer and other three multiple nerve transfers. One hundred and twenty SD rats of simulated C5 and C6 root avulsion randomly divided into 4 groups, and 30 each underwent various combined nerve transfers. Group A: the ipsilateral C7 root transferred to the upper trunk of brachial plexus and the spinal accessory nerve to the suprascapular nerve; Group B: partial fascicles of the ulnar nerve transferred to the biceps branch (Oberlin's procedure), the spinal accessory to the suprascapular and branches to the triceps long head to the axillary nerve; Group C: the phrenic transferred to the musculocutaneous, cervical plexus motor branches to the lower trunk (axillary nerve) of brachial plexus and the spinal accessory nerve to the suprascapular nerve; Group D: the phrenic transferred to the musculocutaneous and the spinal accessory nerve to the suprascapular nerve. Neurotization outcomes were evaluated at 3, 6 and 12 weeks postoperatively by comparing changes of behavioral tests (Ochiai clinical scores, Barth Foot-fault test and Terzis grooming test), neurophysiological investigations and muscular histology. At 3 weeks after operation, no significant difference was found between Group A and other three control groups in the three behavioral evaluations. Neurophysiologic investigations of the axillary nerve showed that Group A was superior to the other three groups. Muscular histological outcome of the axillary nerve and deltoid muscle showed that Group A was superior to the Group C and D, while no significant difference was found between Group A and B. Except that the thruput of regenerating medullated musculocutaneous nerve fibers of Group A was superior to Group C, neurophysiological and histological outcome of the musculocutaneous nerve and biceps showed that no significant difference was found between Group A and other three groups. At 12 weeks postoperatively, nearly all the behavioral, neurophysiological and histological determination showed that Group A was superior to the other three groups. Ipsilateral C7 transfer to the upper trunk of brachial plexus combined with the spinal accessory nerve to the suprascapular nerve is found to be significantly effective on treatment of the root avulsion of C5 and C6 of the brachial plexus.