cC7 Transfer Research Articles

Cadaveric Feasibility Study on Modified Contralateral C7 Nerve Transfer for Targeted Recovery in Hemiplegic Arms.

Contralateral cervical seventh (cC7) nerve to C7 transfer has been proven effective for treating spastic upper limb. However, for those whose major impairment is not in the C7 area, cC7 nerve transfer to other nerves may achieve a better outcome. The aim of this study was to explore the optimal surgical approach for transferring cC7 to 1 or 2 nerves in a cadaveric study, and to evaluate possible applications for patients with hemiplegia. Modified cC7 transfer to 1 (5 procedures) or 2 nonadjacent (3 procedures) nerve roots was proposed, and success rates of direct coaptation through 2 surgical approaches-the superficial surface of longus colli (sLC) and the deep surface of longus colli (dLC) approach-were compared. The length, diameter, and distance of relevant nerves were also measured in 25 cadavers. Compared with the sLC approach, the distance of the dLC approach was 1.1 ± 0.3 cm shorter. The success rates for the sLC and dLC approaches were as follows: cC7 to C5 surgery, 94%, and reached 98%; cC7 to C6 surgery, 54% and 96%; cC7 to C7 surgery, 42% and 94%; cC7 to C8 surgery, 34% and 94%; cC7 to T1 surgery, 24% and 62%; cC7 to C5C7 surgery, 74% and 98%; cC7 to C6C8 surgery, 54% and 98%; and cC7 to C7T1 surgery, 42% and 88%. The dLC approach greatly improved the direct coaptation rate for cC7 nerve transfer. The modified cC7 nerve transfer procedures are technically feasible for further application in clinic.

Contralateral seventh cervical nerve transfer for central spastic arm paralysis: a systematic review and meta-analysis.

The specific benefits of a contralateral cervical 7 nerve transplant in people with spastic paralysis of the upper extremity caused by cerebral nerve injury are unclear. To evaluate the efficacy and safety of contralateral C7 nerve transfer for central spastic paralysis of the upper extremity, we conducted a comprehensive literature search and meta-analysis. PRISMA guidelines were used to search the databases for papers comparing the efficacy of contralateral cervical 7 nerve transfer vs. rehabilitation treatment from January 2010 to August 2022. The finishing indications were expressed using SMD ± mean. A meta-analysis was used to assess the recovery of motor function in the paralyzed upper extremity. The meta-analysis included three publications. One of the publications offers information about RCTs and non-RCTs. A total of 384 paralyzed patients were included, including 192 who underwent CC7 transfer and 192 who received rehabilitation. Results from all patients were combined and revealed that patients who had CC7 transfer may have regained greater motor function in the Fugl-Meyer score (SMD 3.52, 95% CI = 3.19-3.84, p < 0.00001) and had superior improvement in range of motion compared to the rehabilitation group (SMD 2.88, 95% CI = 2.47-3.29, p < 0.00001). In addition, the spasticity in the paralyzed upper extremity significantly improved in patients with CC7 transfer (SMD -1.42, 95% CI = -1.60 to -1.25, p < 0.00001). Our findings suggested that a contralateral C7 nerve transfer, which has no additional adverse effects on the healthy upper limb, is a preferable method to restore motor function.

Modified contralateral C7 transfer to restore ulnar nerve function without sacrificing median nerve recovery: an experimental study.

Contralateral C7 (cC7) transfer is a technique used in patients with total brachial plexus avulsion. An ulnar nerve graft (UNG) is usually used, as intrinsic function is not expected to be restored due to length of reinnervation required. In this study, we attempted to improve intrinsic function recovery by preserving the deep branch of the ulnar nerve (dbUN) and reanimating it with the anterior interosseous nerve (AIN) after cC7 transfer. Fifty-four rats were divided into the following three groups: Group A, traditional cC7 transfer to the median nerve with a UNG; Group B, cC7 transfer preserving and repairing the dbUN with the terminal branch of the AIN; Group C, same as Group B; however, the dbUN was coapted after 1 month with the AIN. At 3, 6 and 9 months postoperatively, the results of electrodiagnostic and histomorphometric examinations of the interosseous muscle were significantly better in Groups B and C, without affecting AIN recovery. In conclusion, the modified cC7 transfer technique can potentially improve intrinsic function recovery without affecting median nerve recovery.

Contralateral C7 nerve transfer in the treatment of upper-extremity paralysis: a review of anatomical basis, surgical approaches, and neurobiological mechanisms.

The previous three decades have witnessed a prosperity of contralateral C7 nerve (CC7) transfer in the treatment of upper-extremity paralysis induced by both brachial plexus avulsion injury and central hemiplegia. From the initial subcutaneous route to the pre-spinal route and the newly-established post-spinal route, this surgical operation underwent a series of innovations and refinements, with the aim of shortening the regeneration distance and even achieving direct neurorrhaphy. Apart from surgical efforts for better peripheral nerve regeneration, brain involvement in functional improvements after CC7 transfer also stimulated scientific interest. This review summarizes recent advances of CC7 transfer in the treatment of upper-extremity paralysis of both peripheral and central causes, which covers the neuroanatomical basis, the evolution of surgical approach, and central mechanisms. In addition, motor cortex stimulation is discussed as a viable rehabilitation treatment in boosting functional recovery after CC7 transfer. This knowledge will be beneficial towards improving clinical effects of CC7 transfer.

Contralateral C7 transfer to axillary and median nerves in rats with total brachial plexus avulsion

BackgroundContralateral cervical 7 nerve (cC7) was used to repair two recipient nerves simultaneously for patients with total brachial plexus avulsion (TBPA).ObjectiveTo evaluate the effect of cC7 transfer to axillary and median nerves in rats with TBPA.MethodsEighty S-D rats were divided into 4 groups randomly on average. Group A: cC7-median nerve, Group B: cC7-axillary nerve, Group C: cC7-median and axillary nerves, Group D: TBPA without repair. The evaluation tools included behavioral tests, electromyogram (EMG), measurement of cross-sectional area of muscle fiber, nerve fiber count and gene expression assay.ResultsThe effective rates of EMG were 90 and 70% in Flexor Carpi Radialis (FCR) in Group A and C, while 70 and 60% in deltoid (DEL) in Group B and C, respectively. In behavioral test, the differences of effective rates between groups were not significant. The mean cross-sectional area of FCR in Group A or C was significantly larger than that in Group D. Either the number of median or axillary nerve fibers in Group A, B or C was statistically more than that in Group D. No matter for FCR or DEL, there were no significant differences in the ratios of relative expression of Muscle Atrophy F-box(MAFBOX)and Muscle RING Finger 1(MURF1)among these groups.ConclusionCompared with cC7 transfer to median nerve, cC7 transfer to both median and axillary nerves did not affect median nerve recovery. The deltoid muscle also could be restored. The recovery proportion of axillary nerve was less than that of median nerve.

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.

Outcome of contralateral C7 transfers to different recipient nerves after global brachial plexus avulsion.

IntroductionContralateral cervical seventh nerve root (CC7) transfer has been widely applied for treatment of traumatic brachial plexus injury. The purpose of the study was to evaluate outcomes of patients with global brachial plexus avulsion (GBPA) after CC7 transfer and compare the recoveries of median nerve as the only recipient nerve and one of the multiple recipient nerves.MethodsA retrospective review of 51 patients treated with CC7 transfers after GBPA was carried out. The British Medical Research Council (MRC) grading system and range of joint motion (ROM) were used for motor and sensory assessment.ResultsThe effective rates of FCR were 57.7%, 45.5%, and 36.4% in CC7 transfer to median nerve (CC7‐Md), CC7 transfer to median nerve and biceps branch (CC7‐Md+Bic) and CC7 transfer to median nerve and triceps branch (CC7‐Md+Tric) groups, respectively. There were no statistical differences no matter in FCR or FDS among groups. The effective rate in biceps had no significant difference with that in triceps. The effective sensory recovery rate was 65.4%, 54.5%, and 36.4% in CC7‐Md, CC7‐Md+Bic, and CC7‐Md+Tric groups. There were no statistical differences in the sensory effective recovery rate among groups. All the ROMs were improved significantly after surgery. The improvement of ROM of elbow flexion after surgery in CC7‐Md+Bic group was significantly larger than that of elbow extension after surgery in CC7‐Md+Tric group (p = 0.047).ConclusionsThe CC7 transfer contributed to the functional improvement of the hand and wrist for the patients with global brachial plexus avulsion. The whole CC7 could be used to repair more than one recipient nerve (including median nerve) without affecting the recovery of median nerve. When CC7 was used to repair two nerves, biceps branch might be preferred to choose as one recipient nerve rather than triceps branch.

Electrophysiologic recovery of the abductor pollicis brevis after contralateral C7 nerve transfer in 95 patients with global brachial plexus avulsion

In this study, we investigated the electrophysiologic recovery of the abductor pollicis brevis (APB) muscle after contralateral seventh cervical (cC7) nerve transfer for the treatment of global brachial plexus avulsion (GBPA). We retrospectively analyzed the electromyography records of 95 patients with GBPA, comprising 81 men and 14 women, focusing on the motor unit potential (MUP) recovery of the APB. All patients underwent cC7–median nerve (MN) transfer. The cC7 nerve was transferred to the MN alone in 58 patients (One-Nerve Group), whereas 37 patients underwent cC7 transfer to the MN and another nerve (Two-Nerve Group). Fifty-three patients (MUP Group) exhibited MUP recovery of the APB, whereas 42 patients did not (No-MUP Group). The MUP Group comprised 32 patients from the One-Nerve Group and 21 patients from the Two-Nerve Group. The mean age of the MUP Group was significantly lower than that of the No-MUP Group. In summary, electrophysiologic recovery of the APB was common in patients with GBPA after cC7–MN transfer, indicating that it may be possible to restore the function of the intrinsic muscles of the hand after GBPA. The rehabilitation strategy for patients with GBPA, which overlooks the restoration of intrinsic hand muscle function, may require amendment.

Construction of Chinese peripheral nerve society and progress in repair and reconstruction of peripheral nerve injury

The peripheral nerve group of the reparative and reconstructive surgery committee (branch of Chinese association of rehabilitation medicine) was established in 1995. Major research progress has been made in the repair, regeneration, and reconstruction of peripheral nerve injury. Professor GU Yudong initiated the contralateral cervical7 root (CC7) transfer for the treatment of total brachial plexus root injury in 1986. Now this method has been applied safely and effectively for 30 years with profound progress and refinement. In addition, the repair and reconstruction of peripheral nerve injury had achieved great development such as the treatment of spastic paralysis of upper limb, CC7 transfer using a modified prespinal route, the reconstruction of bladder function after spinal cord injury, the development of acellular allograft nerve, the small gap suture technique, the functioning free gracilis muscle transplantation, and contralateral S 1 transfer which have been widely used in clinical application with good outcomes. With the progress of the biological manufacturing of peripheral nerve bio-materials and the remodeling of central nervous system after brachial plexus injury, a novel peripheral neuroscience research field was growing up. It is still a challenge for surgeons and scholars in this field to insist on the popularization and improvement of peripheral nerve repair and reconstruction by microsurgical technique, and to make efforts to transform the results of peripheral nerve research into clinical practice.

Super-selective cervical nerve root stimulation in contralateral C7 transfer: An intraoperative study

ObjectiveWe designed this study using super-selective intraoperative cervical nerve root stimulation aiming to support decision making about complete or partial contralateral C7 (cC7) nerve root transfer in patients with multiple cervical root avulsion injury. MethodsSuper-selective intraoperative stimulations of anterior, lateral, medial and posterior aspect of C5–C8 nerve roots were performed. Compound muscle action potentials (CMAP) were recorded in the lateral part of the deltoid (DM), long head of biceps brachii (BCM), brachioradial (BRM), long head of triceps brachii (TCM), and extensor digitorum communis (EDC) muscle. Muscle strength was documented immediately after cC7 transfer procedures and on scheduled follow-up visits according to the Medical Research Council (MRC) scale. ResultsIn the DM, stimulation of the posterior aspect of C5 resulted in the largest CMAP amplitudes (2.0 mV ± 1.9; 80% ± 28.3). The BCM CMAPs induced by the different aspects of C6 all revealed homogenous stimulation results. Stimulation of the lateral aspect of C7 induced the largest amplitude of TCM CMAPs (1.3 mV ± 1.0; 67.1% ± 43.3). CMAP amplitudes of individual muscles and individual contributions of cervical nerve roots to the TCM varied between subjects. Overall donor side morbidity was low, no permanent motor deficit occurred. ConclusionA super-selective intraoperative cervical nerve root stimulation may help minimize donor side morbidity in transfer procedures. Individual differences of cervical nerve root innervation pattern need to be addressed in future electrophysiological studies. SignificanceOur study outlines individual differences of cervical nerve root innervation pattern.

Contralateral C-7 transfer: is direct repair really superior to grafting?

It is not uncommon for a severe traumatic brachial plexus injury to involve all 5 roots, resulting in a flail upper limb. In such cases, surgical reconstruction is often palliative, providing only rudimentary function. Nerve transfers are the mainstay of reconstructive strategies due to the predominance of root avulsions. Consistent results are obtained only for restoration of shoulder stability and elbow flexion, whereas restoring useful hand function remains a challenge. The transfer of the contralateral C-7 (cC-7) is commonly used in an attempt to restore basic hand function, but results are notoriously unreliable and inconsistent. Shu-feng Wang and colleagues recently proposed a potentially more successful permutation of this procedure. They advocated direct approximation of the cC-7 to the lower trunk on the paralyzed side, thus avoiding the interposition of nerve grafts. This technique involves a lengthy dissection of the cC-7 transfer across the midline via a prespinal route, as well as extensive mobilization of the ipsilateral lower trunk by cutting a subset of its branches, adducting the arm, and (if necessary) shortening the humerus. Each of these steps is indispensable to achieve direct approximation of the nerve ends. Many surgeons have tried to emulate Wang's strategy. However, the technical difficulties involved have forced recourse to interposition of nerve grafts once again. The authors report their observations in the first 22 patients in whom they performed this procedure. Direct cC-7 repair via the prespinal route was performed in 12 patients. Shortening of the humerus was necessary in 9 of these 12 patients. In 10 patients, a direct repair was not feasible and nerve grafting was performed. The median follow-up period was 26 months for the direct coaptation group and 28.5 months for the nerve graft group. In the direct repair group, 10 of the 12 patients regained Medical Research Council Grade 3 flexion of the wrist and of the middle, ring, and little fingers, while the remaining 2 patients had Grade 2 function. Flexion appeared 12-14 months after the operation. At the latest follow-up, these patients could activate the wrist and hand without requiring significant augmentation maneuvers in the donor limb. In contrast, repair requiring interposition grafts resulted in Grade 3 strength in only 2 of 10 patients, while 7 had Grade 2 strength, and 1 experienced failure. In all grafted cases, the patient had to forcibly contract the contralateral pectoralis major and triceps muscles to produce the weak movements on the reconstructed side. In this small series, the authors demonstrated a distinct advantage associated with the avoidance of grafts when transferring the cC-7 to restore hand function. The authors conclude that efforts to achieve direct approximation of the donor C-7 and the recipient lower trunk are necessary and justified.

Motor and Sensory Cortical Changes after Contralateral Cervical Seventh Nerve Root (CC7) Transfer in Patients with Brachial Plexus Injuries.

Previous animal studies demonstrated that the sensory and motor functions in ipsilesional upper limbs that had been reconstructed by CC7 transfer eventually associated with the contralesional brain cortices that had originally mediated the functions of the ipsilesional upper limbs before brachial plexus injury (BPI). Our hypothesis was that the same findings would be seen in humans. Four patients with total BPI treated with CC7 transfer were included. Changes in the locations of the activated areas in the primary motor (M1) and somatosensory (S1) cortices corresponding to the motor outputs to and sensory inputs from the ipsilesional limbs were investigated using functional near-infrared spectroscopy (fNIRS) 2-3 years and 6-7 years after surgery. One patient was excluded from the evaluation of motor function after CC7 transfer. The motor and sensory functions of the ipsilesional upper limb in all patients were still controlled by the ipsilesional brain hemisphere 2-3 years after CC7 transfer. The reconstructed motions of the ipsilesional upper limbs correlated with the contralesional M1 in one patient and the bilateral M1s in another patient (both of whom demonstrated good motor recovery in the ipsilesional upper limbs) and with the ipsilesional M1 in a third patient with poor motor recovery in the ipsilesional upper limb. Sensory stimulation of the ipsilesional hands 6-7 years after CC7 transfer activated the contralesional S1 in two patients who achieved good sensory recovery in the ipsilesional hands but activated the ipsilesional S1 in the other two patients with poor sensory recovery of the ipsilesional hands. Transhemispheric transposition of the activated brain cortices associated with the recovery of motor and sensory functions of the ipsilesional upper limbs was seen in patients with CC7 transfer as has been reported for animal models of CC7 transfer.

Dynamic alterations of the levels of tumor necrosis factor-α, interleukin-6, and interleukin-1β in rat primary motor cortex during transhemispheric functional reorganization after contralateral seventh cervical spinal nerve root transfer following brachial plexus avulsion injuries.

The transfer of a contralateral healthy seventh cervical spinal nerve root (cC7) to the recipient nerve in the injured side is considered a reliable and effective procedure for restoration of the physiological functions of an injured hand after brachial plexus root avulsion injury (BPAI). Growing evidence shows that the transhemispheric cortical reorganization is induced after cC7 nerve transfer surgery. However, little is known about the underlying molecular mechanism. Proinflammatory cytokines reportedly play an important role in the neural plasticity. We hypothesize that proinflammatory cytokines are involved in the transhemispheric functional reorganization after cC7 transfer. In the present study, we investigated the level of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in the rat primary motor cortex after cC7 transfer following BPAI by enzyme-linked immunosorbent assay. The results showed that, in the sham group, no statistical significance was observed between the level of TNF-α, IL-6, and IL-1β at each time point after the operation compared with that at day 0, respectively. However, in the unrepaired and repaired groups, the level of TNF-α, IL-6, and IL-1β changed dynamically. The study is the first to provide evidence for the involvement of proinflammatory cytokines in transhemispheric functional reorganization after cC7 transfer following BPAI, which are useful for understanding the underlying mechanism.

The Surgical Strategy for the Treatment of Total Brachial Plexus Avulsion Injury Patient

Objective: The total brachial plexus avulsion injury (BPAI) patients were treated in many organizations in the world, but the results reported differ significantly regarding different surgical strategy. Thus, this study aimed to evaluate the outcomes of different methods of nerve transfer and to determine a relatively optimal surgical strategy for treatment of total BPAI patients. Methods: A retrospective review was conducted on 73 patients with total BPAI who were treated with nerve transfer. The elbow flexion was reconstructed in 73 patients with phrenic nerve (PN) or intercostal nerves (ICNs) or contralateral C7 (cC7) transfer. The shoulder abduction was reconstructed in 73 patients with spinal accessory nerve (SAN) or ICNs transfer or both. Elbow extension was reconstructed in 35 patients with ICNs or cC7 transfer. Wrist and finger flexion were reconstructed in 73 patients with cC7 transfer. Wrist and finger extension were reconstructed in 31 patients with ICNs transfer. The mean follow-up period was 7.3 years. Results: The effective recovery rate were 79.5% in elbow flexion, 76.7% in shoulder abduction, 45.7% in elbow extension, 54.8% in wrist and finger flexion, 57.5% in median nerve area sensation, and 38.7% in wrist and finger extension. No significant difference was found in elbow flexion recovery between the patients with PN, ICN, or cC7 transfer. Shoulder abduction was significantly better in patients with SAN combined with ICNs transfer while no significant difference was found between the patients with anterior or posterior approach SAN transfer. Elbow extension was significantly better in patients with ICNs transfer. Entire cC7 transfer achieved significantly better recovery in wrist and finger flexion than partial cC7 transfer. Conclusion: For the treatment of total BPAI patients, we recommend PN transfer for elbow flexion, SAN combined with ICNs transfer for shoulder abduction, ICNs transfer for elbow extension, entire cC7 transfer for wrist and finger flexion, and ICNs transfer for finger extension, whereas for the elder or PN-injured patients, we recommend SAN combined with ICNs transfer for shoulder abduction, entire cC7 transfer for elbow flexion and wrist and finger flexion, and ICNs transfer for elbow extension and wrist and finger extension.

Outcome of Contralateral C7 Nerve Transfer in the Treatment of Total Brachial Plexus Root Avulsion Injury Patient

Objective: The objective of this study was to evaluate the outcome of patients treated with contralateral C7 (cC7) transfer and to determine the factors that affect the outcome of this procedure. Materials and Methods: A retrospective review of 73 patients with total brachial plexus root avulsion injury (BPAI) who underwent cC7 transfer was conducted. All of the surgeries were performed by 2 stages, and the pedicled ulnar nerve was the bridged nerve. The 73 patients were divided into 2 groups according to different number of the recipient nerves. In group 1 (51 patients), the cC7 nerve was used to transfer to median nerve only. The entire cC7 was used in 11 patients; the posterior division together with the lateral part of the anterior division was used to transfer to median nerve in 15 patients; and the anterior or the posterior division alone was used to transfer to median nerve in 25 patients. In group 2, the cC7 nerve was used to transfer to 2 nerves simultaneously. The entire cC7 was used to transfer to median nerve and biceps branch in 12 patients and to median nerve and triceps branch in 10 patients. The mean follow-up period was 7.3 years. Results: The efficient of these 73 patients was 54.8% in wrist and finger flexor, 57.5% in median nerve area sensation, 66.7% in the elbow flexor, and 20% in the elbow extensor. The patients with entire cC7 root transfer achieved significantly better recovery than the patients with partial cC7 root transfer. The best function recovery could be induced if the interval between 2 stages was 4 to 8 months. Functional recovery of biceps branch was significantly better than that of triceps branch. Conclusion: Contralateral C7 transfer is an effective procedure in treating total BPAI patients. If transferred to single nerve, the entire C7 root transfer can obtain significantly better recovery, and we emphasize using the entire root as the donor. The optimal interval between 2 surgery stages is 4 to 8 months. If transferred to 2 nerves, the 2 recipient nerves should be collaborative in motor function.

Passage through the carotid sheath: An alternative path to the pre-spinal route for direct repair of contralateral C7 to the lower trunk in total brachial plexus root avulsion injury.

Context:In surgical management of global brachial plexus injuries, direct repair of contralateral C7 (cC7) to the anterior division of the lower trunk, can produce good extrinsic finger flexion. The pitfalls associated with the pre-spinal passage have, perhaps, proved to be a deterrent for using this technique routinely.Aims:The aim of this study is to demonstrate an alternative to pre-spinal route for cC7 transfer in brachial plexus avulsion injuries.Methods:We noted that the mobilised lower trunk, which reaches the level of the scalenus anterior by passage deep to the clavicle, can be brought to the suprasternal notch when brought out from below the clavicle. This area was dissected in two cadavres, and safe passage was found through the carotid sheath with the common carotid artery medially and the internal jugular vein with the vagus nerve laterally. The cC7 root dissected medial to the scalenus anterior muscle can be directly transferred along this path to the subcutaneous plane at the suprasternal notch. This study allowed us to execute a direct repair in ten clinical cases of global brachial plexus injuries. In each case, the passage was prepared rapidly and uneventfully. The repair was technically simple and could be performed comfortably using suitable fine suture materials. In none of these cases, did we need to shorten the humerus.Results:The clinical outcome of this technique is awaited.Conclusions:We advocate carotid sheath route to approximate the cC7 to the injured lower trunk in global palsies, as the risks associated with the pre-spinal route can be readily avoided.

Restoration of ulnar nerve motor function by pronator quadratus motor branch: an anatomical study.

The traditional surgical approach to repair of brachial plexus lesions involves use of whole segment ulnar nerve graft for contralateral seventh cervical (cC7) nerve root transfer, which sabotages the possibility of ulnar nerve recovery. We assessed the anatomical feasibility of a new approach that involves preservation of the motor branch of ulnar nerve (MBUN), for a later stage repair using the recovered pronator quadratus motor branch (PQMB), subsequent to the cC7 transfer procedure. Twenty-seven adult cadaver arms and one side of fresh adult cadaver were used in this study. The anterior interosseous nerve and its PQMB, as well as the motor and sensory branches of the ulnar nerve were dissected. The distances from the end of PQMB to the mid-point of a line joining the radial styloid and ulnar styloid, as well as to the point of divergence of the ulnar nerve, were measured. The MBUN was dissected from distal to proximal and the maximum length was measured. The diameter and number of axons of the nerve branches were also recorded. The distance from the end of the PQMB to the midpoint of the radial styloid and ulnar styloid was 6.04 ± 0.52cm, and that to the point of divergence of the ulnar nerve was 8.02 ± 0.63cm. The maximum length of the MBUN after its dissociation was 9.70 ± 1.38cm. The mean diameters of axons of the MBUN and PQMB were 0.09 ± 0.02cm and 0.05 ± 0.01cm, respectively. The corresponding mean numbers of axons were 2913 ± 624 and 757 ± 183, respectively. The results indicate that the PQMB is suitable for transferring to the MBUN without nerve graft. This anatomical study paves the way for further testing of this new procedure after cC7 transfer in clinical settings.

Expressions of miR-132, miR-134, and miR-485 in rat primary motor cortex during transhemispheric functional reorganization after contralateral seventh cervical spinal nerve root transfer following brachial plexus avulsion injuries.

The transfer of a contralateral healthy seventh cervical spinal nerve root (cC7) to the recipient nerve in the injured side is considered a promising procedure for restoration of the physiological functions of an injured hand after brachial plexus root avulsion injury (BPAI). Growing evidence shows that transhemispheric cortical reorganization plays an important role in the functional recovery of the injured arm after cC7 nerve transfer surgery. However, the molecular mechanism underlying the transhemispheric cortical reorganization after cC7 transfer remains elusive. In the present study, we investigated the expression of miR-132, miR-134, and miR-485 in the rat primary motor cortex after cC7 transfer following BPAI by quantitative PCR. The results demonstrated the dynamic alteration in the expression of miR-132, miR-134, and miR-485 in the primary motor cortex of rats after cC7 transfer following BPAI. It indicates that microRNAs are involved in the dynamic transhemispheric functional reorganization after cC7 root transfer following BPAI. Together, this study is the first to provide evidence for the involvement of microRNAs during dynamic transhemispheric functional reorganization after cC7 transfer following BPAI. The results are useful for understanding the mechanism underlying transhemispheric functional reorganization after contralateral seventh cervical spinal nerve root transfer following BPAI.

Outcome of contralateral C7 nerve transferring to median nerve

Background Contralateral C7 (cC7) transfer had been widely used in many organizations in the world, but the outcomes were significantly different. So the purpose of the study was to evaluate the outcome of patients treated with cC7 transferring to median nerve and to determine the factors affecting the outcome of this procedure. Methods A retrospective review of 51 patients with total root avulsion brachial plexus injuries who underwent cC7 transfer was conducted. All of the surgeries were performed with two surgery stages and median nerve was the recipient nerve. The cC7 nerve was used in three different ways. The entire C7 root was used in 11 patients; the posterior division together with the lateral part of the anterior division was used in 15 patients; the anterior or the posterior division alone was used in 25 patients. The mean follow-up period was 6.9 years. Results The efficiency of the surgery in these 51 patients was 49.02% in motor and 62.75% in sensory function. The patients with entire C7 root transfer obtained significantly better recovery in both motor and sensory function than the patients with partial C7 transfer. The best function recovery could be induced if the interval between the two surgery stages was 4-8 months. Conclusions cC7 transfer is an effective procedure in repairing median nerve. But using the entire C7 root transfer can obtain better recovery; so we emphasize using the entire root as the donor. The optimal interval between two surgery stages is 4-8 months.