Contralateral C7 Root Research Articles

Retro Oesophageal Transfer of Contralateral C7 in Birth Brachial Plexus Injury - A Retrospective Study.

Background: Presence of available healthy nerve roots on the injured side determines the outcome after nerve reconstruction. Paucity of nerve roots warrants contralateral C7 harvest for optimal results. We aim to study the risks and benefits of retro oesophageal transfer of contralateral C7 root in infants with birth brachial plexus injury. Methods: Study was carried out from 2017 to 2022 in 13 children who have undergone retro oesophageal transfer of contralateral C7 root to affected side. Follow-up period ranged from 8 to 60 months after the surgery. Motor power assessment was done using by active movement scale. Results: Average active movement score for abduction was found to be 6, elbow flexion 5.7, elbow extension 5.8, wrist extension 3, wrist flexion 4, finger flexion 4.8 and finger extension 3.8, respectively. No neurological deficits, limb length anomaly noted in the normal upper limb after contralateral C7 harvest. Conclusions: Retro oesophageal transfer of contralateral C7 is a safe technique in birth brachial plexus injury. The advantage of retro oesophageal transfer is reduction in the length of nerve grafts, thus helping in early neurotisation of distal forearm and hand muscles. The large axonal output from contralateral C7 can be used to reconstruct different nerves without any residual deficits on the normal side. Level of Evidence: Level IV (Therapeutic).

Contralateral C7 Nerve Transfer

Complex brachial plexus injuries with multiple or complete root avulsions make intraplexic reconstruction impossible in some cases. Such cases necessitate the use of extraplexic nerve donors such as the spinal accessory nerve or intercostal nerves. The contralateral C7 root represents a donor with a high axon count and can be used as an axon source in such cases. We summarise current indications, surgical technique and functional results after a contralateral C7 transfer in cases of brachial plexus injury, describing some of our own cases and including a selective literature review.

Long-Term Outcome of 118 Acute Total Brachial Plexus Injury Patients Using Free Vascularized Ulnar Nerve Graft to Innervate the Median Nerve.

The restoration of finger movement in total brachial plexus injuries (BPIs) is an ultimate challenge. Pedicled vascularized ulnar nerve graft (VUNG) connecting a proximal root to distal target nerves has shown unpredictable outcomes. We modified this technique by harvesting VUNG as a free flap to reinnervate median nerve (MN). We analyzed the long-term outcomes of these methods. From years 1998 to 2015, 118 acute total brachial plexus patients received free VUNG to innervate the MN. Patients were followed up at least 5 years after the initial surgery. Donor nerves included the ipsilateral C5 root (25 patients) or contralateral C7 root (CC7 = 93 patients). Recovery of finger and elbow flexion was evaluated with the modified Medical Research Council system. Michigan Hand Score and Quick-DASH were used to represent the patient-reported outcomes. For finger flexion, ipsilateral C5 transfer to MN alone yielded similar outcomes to MN + MCN (musculocutaneous nerve), while CC7 had significantly better finger flexion when coapted to MN alone than to MN + MCN. Approximately 75% patients were able to achieve finger flexion with nerve transfer alone. For elbow flexion, best outcome was seen in the ipsilateral C5 to MCN and MN. In acute total BPI, the priority is to identify the ipsilateral C5 root to innervate MN, with concomitant innervation of MCN to establish the best outcomes for finger and elbow flexion. CC7 is more reliable when used to innervate one target (MN). III.

Analysis of Results of Contralateral Hemi-C7 Root Used for Restoring Hand Function in Global Birth Brachial Plexus Palsy

To analyze the outcome of the use of contralateral hemi-C7 for the restoration of hand function in patients with birth brachial plexus global palsy. From 2004 to 2017, 19 infants with Narakas types III and IV birth brachial plexus palsy underwent transfer of contralateral hemi-C7 (posterior division of the contralateral C7 root) to the lower trunk or medial cord on the affected side. All the patients were evaluated for shoulder function using the Gilbert and Mallet scores, elbow flexion using the modified Medical Research Council score for children, and hand function using the Raimondi score. After the surgery, the children were followed-up at 3-month intervals for the first year and6-month intervals thereafter. Hand function achieving Raimondi scores of 3-5 was considered a useful outcome. The patients were followed-up for a mean duration of 88 months, with a minimum of 35 and a maximum of 192 months of follow-up. All patients attained a Gilbert score of ≥3, whereas 9 patients attained a score of ≥4. Similarly, all patients attained a minimum aggregate Mallet score of 15, and 9 patients attained a score of ≥20. All patients attained a modified Medical Research Council score of ≥3, used for assessing elbow flexion. Useful hand function was attained in 73% (14/19) of the cases (a Raimondi score of ≥3). There was no clinically recorded deficit on the donor side. Contralateral hemi-C7 transfer in infants with brachial plexus root avulsions helped regain useful hand function in 73% (14/19) of the children treated. Therapeutic IV.

Transfer of the peroneal component of the sciatic nerve in total brachial plexus lesion: An anatomical feasibility study

Closed brachial plexus lesions (BPLs) are generally associated with a traumatic mechanism of forced traction between the neck and the shoulder-arm complex. For brachial plexus reconstruction different techniques have been proposed with donor motor nerves like intercostal nerves, or the ipsilateral cervical plexus, the phrenic nerve, the contralateral C7 root, and many others.Despite all these surgical possibilities, the overall recovery is generally poor and not satisfactory. The principal drawback is linked to the loss of upper limb proprioception, in a way that dramatically influences even a good motor recovery, so in complete BPLs the sensory loss still represents a debilitating problem. In this anatomical feasibility study, the possibility to transfer the peroneal component of the sciatic nerve as a donor for complete BPLs has been evaluated. This technique would conceptually bring an important motor and sensory contribution to the upper limb using pure motor and sensory branches of the sciatic nerve. Performing immediate tendon transfer for foot drop palsy could significantly decrease the morbidity of the surgical procedure.

Contralateral C7 transfer via both ulnar nerve and medial antebrachial cutaneous nerve to repair total brachial plexus avulsion: a preliminary report

Aim: After brachial plexus injuries, sacrifice of the contralateral C7 (cC7) root from the non-injured side is well tolerated and various schemes to innervate the injured side from the cC7 root have been used. Objective: To demonstrate the surgical outcomes from transferring the cC7 to the affected side via both the ulnar nerve and medial antebrachial cutaneous nerve (MACN).Methods: A retrospective study of 16 adult patients sustaining total brachial plexus avulsion who underwent this procedure. The British Medical Research Council (MRC) grading system and the disabilities of the arm, shoulder, and hand (DASH) questionnaire scoring were used to evaluate the recovery.Results: About 68.75% of the patients achieved functional recovery of elbow flexion to M3 or better and 43.75% achieved motor recovery of wrist and finger flexion to M3 or better. Sensation in the median nerve territory recovered to S2 or better in 68.75%. The DASH scores after surgery were significantly lower than those before surgery.Conclusions: cC7 transfer via both ulnar and MACNs is an effective and safe procedure in patients sustaining total injuries of brachial plexus.

Contralateral C7 transfer to lower trunk via a subcutaneous tunnel across the anterior surface of the chest and neck for total brachial plexus root avulsion: a cadaveric study

BackgroundRestoration of hand function after total brachial plexus root avulsion (tBPRA) is a difficult problem in surgical management. A new modified approach in repairing tBPRA is to use a subcutaneous tunnel across the anterior surface of the chest and neck, and then transfer the contralateral C7 root (cC7) to the lower trunk. However, the anatomical details of this method have not yet been fully described and assessed. The objective of this study was to quantitatively describe the nerve transfer using a cadaveric surgical simulation.Materials and methodsBrachial plexuses were dissected from 12 adult cadavers, producing 24 sides of brachial plexuses for nerve transfer experiments. We performed simulated cC7 transfers to the lower trunk via a subcutaneous tunnel across the anterior surface of the chest and neck. Measurements of the nerves were made and transfers quantitatively documented.ResultsWith the affected shoulder and arm in a neutral position, cC7 and C8-T1 could be sutured directly together in 75% of the cadavers. A nerve graft length of 4.6 ± 1.18 cm was needed to bridge the gap in the remaining cadavers. For cadavers where distal cC7 was directly connected with the lower trunk, 54.17% could be sutured, and an average nerve graft length of 3.9 cm was needed in the remains.ConclusionsFor surgical management of total tBPRA, transfer of the cC7 nerve to the C8-T1 or lower trunk via a subcutaneous tunnel across the chest and neck will likely be superior to a conventional cC7 root transfer in the clinic. This approach shortens the nerve graft needed and nerve regeneration distance, decreases the number of neurorrhaphy sites, and makes full use of the donor nerves, which may benefit hand flexion restoration.

Total brachial plexus injury: contralateral C7 root transfer to the lower trunk versus the median nerve.

Contralateral C7 (cC7) root transfer to the healthy side is the main method for the treatment of brachial plexus root injury. A relatively new modification of this method involves cC7 root transfer to the lower trunk via the prespinal route. In the current study, we examined the effectiveness of this method using electrophysiological and histological analyses. To this end, we used a rat model of total brachial plexus injury, and cC7 root transfer was performed to either the lower trunk via the prespinal route or the median nerve via a subcutaneous tunnel to repair the injury. At 4, 8 and 12 weeks, the grasping test was used to measure the changes in grasp strength of the injured forepaw. Electrophysiological changes were examined in the flexor digitorum superficialis muscle. The change in the wet weight of the forearm flexor was also measured. Atrophy of the flexor digitorum superficialis muscle was assessed by hematoxylin-eosin staining. Toluidine blue staining was used to count the number of myelinated nerve fibers in the injured nerves. Compared with the traditional method, cC7 root transfer to the lower trunk via the prespinal route increased grasp strength of the injured forepaw, increased the compound muscle action potential maximum amplitude, shortened latency, substantially restored tetanic contraction of the forearm flexor muscles, increased the wet weight of the muscle, reduced atrophy of the flexor digitorum superficialis muscle, and increased the number of myelinated nerve fibers. These findings demonstrate that for finger flexion functional recovery in rats with total brachial plexus injury, transfer of the cC7 root to the lower trunk via the prespinal route is more effective than transfer to the median nerve via subcutaneous tunnel.

Is it necessary to use the entire root as a donor when transferring contralateral C7nerve to repair median nerve?

If a partial contralateral C7 nerve is transferred to a recipient injured nerve, results are not satisfactory. However, if an entire contralateral C7 nerve is used to repair two nerves, both recipient nerves show good recovery. These findings seem contradictory, as the above two methods use the same donor nerve, only the cutting method of the contralateral C7 nerve is different. To verify whether this can actually result in different repair effects, we divided rats with right total brachial plexus injury into three groups. In the entire root group, the entire contralateral C7 root was transected and transferred to the median nerve of the affected limb. In the posterior division group, only the posterior division of the contralateral C7 root was transected and transferred to the median nerve. In the entire root + posterior division group, the entire contralateral C7 root was transected but only the posterior division was transferred to the median nerve. After neurectomy, the median nerve was repaired on the affected side in the three groups. At 8, 12, and 16 weeks postoperatively, electrophysiological examination showed that maximum amplitude, latency, muscle tetanic contraction force, and muscle fiber cross-sectional area of the flexor digitorum superficialis muscle were significantly better in the entire root and entire root + posterior division groups than in the posterior division group. No significant difference was found between the entire root and entire root + posterior division groups. Counts of myelinated axons in the median nerve were greater in the entire root group than in the entire root + posterior division group, which were greater than the posterior division group. We conclude that for the same recipient nerve, harvesting of the entire contralateral C7 root achieved significantly better recovery than partial harvesting, even if only part of the entire root was used for transfer. This result indicates that the entire root should be used as a donor when transferring contralateral C7 nerve.

Transferência de nervos (neurotizações) no tratamento das lesões traumáticas do plexo braquial

Brachial plexus avulsion injuries are usually caused by car and motorcycle accidents. Their consequences are devastating and represent a challenge to the surgeons who assist these patients. Positive results of this procedure depend on the interval between the injury and the definitive treatment. The treatment of brachial plexus avulsion injuries invariably involves the use of neurolysis, direct nerve repair, nerve grafts, and neurotization procedures. Several nerves have been used as donors in neurotizations. In general, there are two types of donor: extraplexal (intercostal, spinal accessory, and phrenic nerves, motor branches of the cervical plexus, and contralateral C7 root) and intraplexal (proximal spinal nerve stumps or collateral motor branches of the preserved brachial plexus). In fact, the intraplexal neurotization represents the classical form of nerve transfers.

Comparative study of intercostal nerve transfer to lower trunk and contralateral C7 root transfer in repair of total brachial plexus injury in rats

The aim of this study is to compare the treatment outcome of nerve transfer using intercostal nerves (ICNs) or contralateral C7 (cC7) root in rats. Ninety adult Sprague-Dawley rats were randomly divided into three groups of 30 each: group A (cC7 root transfer), group B (ICNs transfer), and group C (control). Electrophysiological examination, muscle tension test, neuromorphology, and muscle fiber cross-sectional area measurements obtained from the three groups were compared to evaluate neurotization outcome 4, 8, and 12 weeks postoperatively. Median nerve regeneration and the flexor digitorum superficialis (FDS) muscle functional recovery of group B were worse than group A from comparison of both groups' parameters. Neurotization of ICNs to the lower trunk is difficult to replace cC7 root transfer to the median nerve for restoration of hand function in total brachial plexus injury (BPI). Therefore, at present, the more important implication of the comparative study is that traditional cC7 root transfer remains the mainstay strategy to repair forearm flexor muscle function.

Update on shoulder reconstruction in BPI

The shoulder joint is the foundation for excellent upper extremity function. It contributes to stability and basic movements like rotation and elevation of the arm. Shoulder fusion should not be accepted even for total palsy, and nerve repair should be recommended as long as an available donor nerve exists. In planning the reconstructive procedure for shoulder function, accurate biomechanical analysis of individual glenohumeral (GH) and scapulothoracic (ST) joint is imperative, especially concerning serratus anterior muscle (SA) function. Priority of nerve repair and selection of donor nerve for shoulder function are the most important key points especially in C5~7, C5~8 and total palsy depending on accompanying reconstruction of elbow and finger function including conventional nerve transfer (NT) and free muscle transfer. Many previous articles of shoulder reconstruction with nerve repair following brachial plexus injuries were concluded from global shoulder motion that combine GH and ST motion, and emphasized only suprascapular nerve (SSN) repair. I emphasized SSN and long thoracic nerve (LTN) repair except in C56 palsy. The axillary nerve (Ax) can be ignored because simple AX palsy does not result in serious paralysis of shoulder function. Postoperative range of shoulder motions following SSN repair, in decreasing order according to individual donor nerve was; phrenic never (PN), spinal accessory nerve (SAN), C5 root and contralateral C7 (CC7 ) root. For LTN repair; the decreasing order of post operative range of shoulder joint movements were intercostal nerve (ICN), PN, SAN, C5 root and CC7 root. PN to SSN and ICN to LTN transfer achieved the most satisfactory outcome in total palsy; however, other combinations of nerve repair and AX repair did not provide significantly better shoulder motion. Dynamic shoulder XP is useful to differentiate between GH and ST motion for pre- and postoperative evaluation. I will introduce our techniques of the representative nerve repairs for shoulder reconstruction.

Contralateral C7 transfer to lower trunk via the prespinal route in the repair of brachial plexus injury: An experimental study in rats

Contralateral C7 (cC7) root transfer to reconstruct brachial plexus injury (BPI) has been widely used. A revised technique that cC7 root was transferred to lower trunk via the prespinal route with direct neurorrhaphy has been reported clinically. The aim of this experimental study was to develop an animal model of the modified surgical approach in order to obtain quantification index of postoperative nerve regeneration and muscle morphology. Sixty adult Sprague-Dawley rats randomized into experimental and control groups of 30 each. In the experimental group, after total brachial plexus injury (BPI) the cC7 root was transferred to lower trunk via the prespinal route with direct neurorrhaphy, and in the control group the brachial plexus was only exposed without intervention. Electrophysiological study, muscle tension test, neuromorphology, muscle wet weight, and muscle fiber cross-sectional area measurements were obtained 4, 8, and 12 weeks postoperatively. Median and ulnar nerve regeneration and the forearm flexor muscles functional recovery were obtained by cC7 root transfer to lower trunk via the prespinal route when measured at 12 weeks following the operation though the parameters had not recovered to normal value. We concealed the control and experimental groups from those who did the evaluations.

Surgical treatment for total root avulsion type brachial plexus injuries by neurotization: A prospective comparison study between total and hemicontralateral C7 nerve root transfer

Purpose: We conducted a clinical study to evaluate the effects of neurotization, especially comparing the total contralateral C7 (CC7) root transfer to hemi-CC7 transfer, on total root avulsion brachial plexus injuries (BPI). Methods: Forty patients who received neurotization for BPI were enrolled in this prospective study. Group 1 (n = 20) received hemi-CC7 transfer for hand function, while group 2 (n = 20) received total-CC7 transfer. Additional neurotization included spinal accessory, phrenic, and intercostal nerve transfer for shoulder and elbow function. The results were evaluated with an average of 6 years follow-up. Results: Group 1 had fewer donor site complications (15%) than group 2 (45%); group 2 had significantly better hand M3 and M4 motor function (65%) than group 1 (30%; P = 0.02). There was no difference in sensory recovery. Significantly, better shoulder function was obtained by simultaneous neurotization on both suprascapular and axillary nerves. Conclusions: Total-CC7 transfer had better hand recovery but more donor complications than hemi-CC7. Neurotization on both supra-scapular and axillary nerves improved shoulder recovery. © 2013 The Authors. Microsurgery published by Wiley Periodicals, Inc. Microsurgery 34:91–101, 2014.

The Effectiveness of Contralateral C7 Nerve Root Transfer for the Repair of Avulsed C7 Nerve Root in Total Brachial Plexus Injury: An Experimental Study in Rats

The aim of this study was to evaluate the feasibility and effectiveness of transferring the contralateral C7 root to repair avulsed C7 nerve root. Thirty rats were randomized into three groups. In group A, rats underwent whole-root avulsion of the left brachial plexus and contralateral C7 root transfer to the avulsed C7 nerve root. In group B, rats underwent whole-root avulsion and contralateral C7 root transfer to the radial nerve. In group C, rats underwent whole-root avulsion of the left brachial plexus without nerve transfer. Functional outcomes were measured by electrophysiological studies, muscle tetanus contraction force, muscle mass, and histology. Six months postoperatively, increased amplitude and shortened latency of compound muscle action potentials, larger maximum tetanic contractile tension, heavier muscle mass, and larger cross-sectional area of the muscle fibers were observed in the triceps, extensor carpi radialis brevis, and extensor digitorum in groups A and B when compared with group C (p < 0.01). There were no significant differences between group A and B (p > 0.05). Contralateral C7 nerve transfer to repair avulsed C7 nerve root was feasible and effective in this rat model. It should be considered as an option for the treatment of brachial plexus injuries.

Long-term results of thenar muscle reanimation after contralateral C7 root transfer in repair of total brachial plexus avulsion injury

Objective To evaluate the long-term functional recovery of thenar muscles following contralateral C7 transfer in total brachial plexus root avulsion injuries. Methods Five patients treated with contralateral C7 transfer to the median nerve for brachial plexus root avulsion were follow-up for 24 to 118 months.Affected limb function,electrophysiologic evidence of recovery and the motor and sensory function of the recipient nerves in the affected limb were evaluated. Results Varied degrees of functional restorations were achieved in these 5 patients ( 2 children and 3 adults).The strength of abductor pollicis brevis (APB) muscle was M2 in four patients and M1 in one patient.The incomplete interference pattem in the APB muscle was detected by electromyogram (EMG) in two patients,while few motor unit potential (MUP) was detected in three patients.Sensory recovery reached S3 in 4 cases and S2 in one case. Conclusion Contralateral C7 nerve root transfer to the median nerve can result in thenar muscle reinnervation to certain extent in patients with brachial plexus total avulsions. Key words: Brachial plexus; Nerve transfer; Follow-up studies; Thenar muscle; Root avulsion

Reinnervation of thenar muscle after repair of total brachial plexus avulsion injury with contralateral C7 root transfer: report of five cases

Reinnervation of thenar muscle after repair of total brachial plexus avulsion injury with contralateral C7 root transfer: report of five cases

BDNF and GAP43 contribute to dynamic transhemispheric functional reorganization in rat brain after contralateral C7 root transfer following brachial plexus avulsion injuries

It is known that contralateral seventh cervical nerve (C7) root transfer after brachial plexus avulsion injuries (BPAI) causes interhemispheric cortical functional reorganization. However, the potential mechanisms and the role of neurotrophic factors and/or growth-associated protein expression in the process of cerebral reorganization are not well understood. The present study identified the expression of brain-derived neurotrophic factor (BDNF) and growth-associated protein 43 (GAP43) mRNA in primary motor cortex after contralateral C7 root transfer following BPAI. BDNF and GAP43 mRNA levels were significantly increased in brain samples at both 6 and 9 months after contralateral C7 root transfer following BPAI, in comparison with the samples from the rats with BPAI only. These findings indicate that BDNF and GAP43 may play an important role during the dynamic transhemispheric functional reorganization.

Contralateral C7 transfer for the treatment of upper obstetrical brachial plexus palsy

The use of contralateral C7 is seldom indicated in infants with obstetrical brachial plexus palsy (OBPP). The purpose of this study was to evaluate the value of contralateral C7 transfer in infants with upper OBPP in order to define the application and outcome of this transfer in these infants more optimally. Over a 5-year period, 15 infants with upper brachial plexus injuries underwent transfer of the contralateral C7 as part of the primary surgical reconstruction. The common trunk of the contralateral C7 root was transferred to the upper trunk or lateral cord on the affected side with nerve graft. The efficacy of the surgery and effects of patient age at the time of nerve transfer were analyzed. Patients were followed up for a mean duration of 46.8 months. Noteworthy function (≥M2+) was gained in 11 of 15 patients, and sensory function (≥S3, MRC grading system) was gained in all patients. Age was not the factor related to the outcome of this surgery. Contralateral C7 transfer is an effective procedure for the restoration of upper limb function in infants with OBPP and root avulsions.

Transfer of the Platysma Motor Branch to the Accessory Nerve in a Patient With Trapezius Muscle Palsy and Total Avulsion of the Brachial Plexus: Case Report

To report on the successful use of a platysma motor nerve transfer to the accessory nerve in a patient with concomitant trapezius and brachial plexus palsy. A 20-year-old man presented with total avulsion of the right brachial plexus combined with palsies of the accessory and phrenic nerve. The patient was operated on 4 months after his injury. The accessory nerve was repaired via direct transfer of the platysma motor branch. The contralateral C7 root was connected to the musculocutaneous nerve, and the hemihypoglossal nerve was grafted to the suprascapular nerve. Two intercostal nerves were attached to the triceps long head motor branch. Within 20 months of surgery, the patient regained full reinnervation of the upper trapezius muscle. Elbow flexion scored M3+, and 30° active shoulder abduction was observed. Triceps reinnervation was poor. Platysma motor branch transfer to the accessory nerve is a viable alternative to reinnervate the trapezius muscle.