Contralateral C7 Nerve Root Transfer Research Articles

Treatment of Complete Brachial Plexus Injuries Using Double Free Muscle Transfer

The purpose of this study was to examine the surgical outcomes of double free muscle transfer (DFMT) performed in patients with complete brachial plexus injury (BPI). We retrospectively analyzed the outcomes of DFMT for 12 patients with complete BPI who were followed up for more than 2 years after the final muscle transplantation. Their mean age was 29 years (range, 18-41). Three patients underwent contralateral C7 nerve root transfer before the DFMT. The range of motion (ROM) of the shoulder, elbow, and fingers was measured. Patient-reported outcome measures, including Disability of the Shoulder, Arm, and Hand (DASH) scores and visual analog scale (VAS) scores for pain, were also examined. The mean shoulder ROM against gravity was 22° ± 8° in abduction and 33° ± 5° in flexion. Seven patients underwent phrenic nerve (PhN) transfer to the suprascapular nerves, and five exhibited asymptomatic lung impairment on spirography more than 2 years after PhN transfer. The mean elbow ROM against gravity was 111° ± 9° in flexion and -32° ± 7° in extension. All patients obtained elbow flexion >90° against a 0.5-kg weight. All patients obtained touch sensation and two recognized warm and cold sensations in the affected palm. The mean total active motion of the affected fingers was 44° ± 11°. All patients exhibited hook function of the hands. The mean preoperative and postoperative DASH scores were 70.3 ± 13.4 and 51.8 ± 15.9, respectively. The mean pain VAS score was 28 ± 31 at the final follow-up. Double free muscle transfer provided patients with complete brachial plexus palsy with good elbow flexion and hand hook functions. Therapeutic IV.

Retracted: Overexpression of Neuregulin-1 (NRG-1) Gene Contributes to Surgical Repair of Brachial Plexus Injury After Contralateral C7 Nerve Root Transfer in Rats

Retracted on the author's request: "We would like to withdraw our manuscript. We restarted the project for further study last year, we found that the results in this study are not solid enough and need to be further explored." Reference: Zong-Qiang Wang, Dian-Hui Xiu, Gui-Feng Liu, Jin-Lan Jiang. Overexpression of Neuregulin-1 (NRG-1) Gene Contributes to Surgical Repair of Brachial Plexus Injury After Contralateral C7 Nerve Root Transfer in Rats.Med Sci Monit 2018; 24: 5779-5787; DOI: 10.12659/MSM.908144.

Extradural Contralateral C7 Nerve Root Transfer in a Cervical Posterior Approach for Treating Spastic Limb Paralysis: A Cadaver Feasibility Study.

Anatomic study in nine fresh-frozen cadavers. To confirm the anatomical feasibility of transferring the extradural ventral roots (VRs) and dorsal roots (DRs) of contralateral C7 nerves to those of the ipsilateral C7 nerves respectively through a cervical posterior approach. The contralateral C7 nerve root transfer technique makes breakthrough for treating spastic limb paralysis. However, its limitations include large surgical trauma and limited indications. Nine fresh-frozen cadavers (four females and five males) were placed prone, and the feasibility of exposing the bilateral extradural C7 nerve roots, separation of the extradural C7 VR and DR, and transfer of the VR and DR of the contralateral C7 to those of the ipsilateral C7 on the dural mater were assessed. The pertinent distances and the myelography results of each specimen were analyzed. The acetylcholinesterase (AChE) and antineurofilament 200 (NF200) double immunofluorescent staining were preformed to determine the nerve fiber properties. A cervical posterior midline approach was made and the laminectomy was performed to expose the bilateral extradural C7 nerve roots. After the extradural C7 VR and DR are separated, the VR and DR of the contralateral C7 have sufficient lengths to be transferred to those of the ipsilateral C7 on the dural mater. The myelography results showed that the spinal cord is not compressed after the nerve anastomosis. The AChE and NF200 double immunofluorescent staining showed the distal ends of the contralateral C7 VRs were mostly motor nerve fibers, and the distal ends of the contralateral C7 DRs were mostly sensory nerve fibers. Extradural contralateral C7 nerve root transfer in a cervical posterior approach for treating spastic limb paralysis is anatomically feasible. 5.

Analysis of human acellular nerve allograft combined with contralateral C7 nerve root transfer for restoration of shoulder abduction and elbow flexion in brachial plexus injury: a mean 4-year follow-up.

Human acellular nerve allograft applications have increased in clinical practice, but no studies have quantified their influence on reconstruction outcomes for high-level, greater, and mixed nerves, especially the brachial plexus. The authors investigated the functional outcomes of human acellular nerve allograft reconstruction for nerve gaps in patients with brachial plexus injury (BPI) undergoing contralateral C7 (CC7) nerve root transfer to innervate the upper trunk, and they determined the independent predictors of recovery in shoulder abduction and elbow flexion. Forty-five patients with partial or total BPI were eligible for this retrospective study after CC7 nerve root transfer to the upper trunk using human acellular nerve allografts. Deltoid and biceps muscle strength, degree of shoulder abduction and elbow flexion, Semmes-Weinstein monofilament test, and static two-point discrimination (S2PD) were examined according to the modified British Medical Research Council (mBMRC) scoring system, and disabilities of the arm, shoulder, and hand (DASH) were scored to establish the function of the affected upper limb. Meaningful recovery was defined as grades of M3-M5 or S3-S4 based on the scoring system. Subgroup analysis and univariate and multivariate logistic regression analyses were conducted to identify predictors of human acellular nerve allograft reconstruction. The mean follow-up duration and the mean human acellular nerve allograft length were 48.1 ± 10.1 months and 30.9 ± 5.9 mm, respectively. Deltoid and biceps muscle strength was grade M4 or M3 in 71.1% and 60.0% of patients. Patients in the following groups achieved a higher rate of meaningful recovery in deltoid and biceps strength, as well as lower DASH scores (p < 0.01): age < 20 years and age 20-29 years; allograft lengths ≤ 30 mm; and patients in whom the interval between injury and surgery was < 90 days. The meaningful sensory recovery rate was approximately 70% in the Semmes-Weinstein monofilament test and S2PD. According to univariate and multivariate logistic regression analyses, age, interval between injury and surgery, and allograft length significantly influenced functional outcomes. Human acellular nerve allografts offered safe reconstruction for 20- to 50-mm nerve gaps in procedures for CC7 nerve root transfer to repair the upper trunk after BPI. The group in which allograft lengths were ≤ 30 mm achieved better functional outcome than others, and the recommended length of allograft in this procedure was less than 30 mm. Age, interval between injury and surgery, and allograft length were independent predictors of functional outcomes after human acellular nerve allograft reconstruction.

C7 transfer in a posterior intradural approach for treating hemiplegic upper-limbs: hypothesis and a cadaver feasibility study

Objective: Contralateral C7 nerve root transfer surgery has been successfully applied to rescue motor function of a hemiplegic upper extremity in patients with central neurological injury. This surgical technique is challenging, and limited anatomical space makes it difficult to manipulate tissues and may lead to higher complication rates. The authors hypothesis a new surgical route in which cervical nerve roots of both donor and recipient sides are exposed from a posterior intradural approach and neurorrhaphy is performed easily and clearly. The feasibility of this operation is tested in a cadaver model.Methods: A fresh cadaver was placed prone. After a standard midline incision and extensive cervical laminectomy, the dura and arachnoid were widely opened, and the spinal nerve roots of C6, C7, and C8 were exposed bilaterally. Nerve grafting was attempted between pairs of donor and recipient nerve roots on contralateral sides of the spinal cord. After completion of neurorrhaphy, the dura was closed.Results: Precise neurorrhaphy could be performed intradurally between posterior and anterior nerve roots of C7 on both sides. Multiple anastomoses of C7 to various nerve roots on the contralateral side could also be performed within the same surgical field with an interposition nerve graft.Conclusion: The posterior intradural repair idea affords many advantages, the pathway is shorter and more straightforward, which provides more access to multiple nerve roots repair in one surgical field, and is more familiar to many neurosurgeons and spine surgeons. It may potentially be adapted for clinical use.

Overexpression of Neuregulin-1 (NRG-1) Gene Contributes to Surgical Repair of Brachial Plexus Injury After Contralateral C7 Nerve Root Transfer in Rats.

BackgroundSurgeons usually transfer the contralateral C7 to the median nerve on the injured side via a nerve graft to recover sensation and movement in a paralyzed hand. The purpose of our study was to determine whether NRG-1 affects the recovery of nerve function in brachial plexus injury after contralateral C7 nerve root transfer in a rat model.Material/MethodsAn injury model of left brachial plexus and contralateral C7 nerve root transfer was established. Four weeks after the operation, NRG-1 expression was examined by reverse transcription quantitative polymerase chain reaction and Western blot analysis. The diameter rate differences of the healthy limb and affected limb were estimated. The postoperative mass of the left latissimus dorsi, triceps, extensor carpi radialis brevis, and musculus extensor digitorum were examined. The number of nerve fibers and typical area of the affected side were assessed. Postoperative left motor nerve conduction velocity (MNCV) and motor nerve action potential (MNAP) were tested by use of a biological information recording and collecting system.ResultsEukaryotic expression plasmid of pcDNA4/myc/A-NRG-1 was successfully constructed, and NRG-1 was overexpressed. Compared with the model group, the NRG-1 group had a lower rate of differences of the limbs; higher mass of left latissimus dorsi, triceps, extensor carpi radialis brevis, and musculus extensor digitorum; more nerve fibers and larger typical area in the affected side, left MNCV, and MNAP; and wider CSA of the left triceps.ConclusionsThese results demonstrated that NRG-1 can promote recovery of nerve function in brachial plexus injury after contralateral C7 nerve root transfer in rats.

Contralateral C7 Nerve Root Transfer for Function Recovery in Adults: A Meta-analysis.

Background:Root avulsion to all 5 roots of the brachial plexus is a common presentation and keeps a major reconstructive challenge. The contralateral C7 (CC7) nerve transfer has been used in treating brachial plexus avulsion injury (BPAI) since 1986. However, the effectiveness of the procedure remains a subject of controversy. The aim of this meta-analysis was to study surgical outcomes regarding motor and sensory recovery after CC7 nerve transfer.Methods:Chinese or English (i.e., “contralateral c-7”, “contralateral c7”, “c7 nerve root”, and “seventh cervical nerve root”) keywords were used for a literature search for articles related to CC7 nerve transfer in several databases (i.e., PubMed, Cochrane, Embase, CNKI, CQVIP, and Wanfang Data). Clinical research articles were screened, and animal studies as well as duplicate publications were excluded. Muscle strength and sensory recovery were considered to be effective only when the scores on the United Kingdom Medical Research Council scale were equal to or higher than M3 and S3, respectively.Results:The overall ipsilateral recipient nerve recovery rates were as follows: the efficiency rate for muscle strength recovery after CC7 nerve transfer was 0.57 (95% confidence interval [CI]: 0.48–0.66) and for sensory recovery was 0.52 (95% CI: 0.46–0.58). When the recipient nerve was the median nerve, the efficiency rate for muscle strength recovery was 0.50 (95% CI: 0.39–0.61) and for sensory was 0.56 (95% CI: 0.50–0.63). When the recipient nerve was the musculocutaneous nerve and the radial nerve, the efficiency rate for muscle strength recovery was 0.74 (95% CI: 0.65–0.82) and 0.50 (95% CI: 0.31–0.70), respectively.Conclusions:Transfer of CC7 nerves to musculocutaneous nerves leads to the best results. CC7 is a reliable donor nerve, which can be safely used for upper limb function reconstruction, especially for entirely BPAI. When modifying procedures, musculocutaneous nerves and median nerve can be combined as recipient nerves.

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.

Transfert robot-assisté de la racine C7 du côté controlatéral sain : étude de faisabilité sur cadavre

Patients with cerebral palsy and spastic hemiplegia may have extremely poor upper extremity function. Unfortunately, many current therapies and treatments for patients with spastic hemiplegia offer very limited improvements. One innovative technique for treating these patients is to use a contralateral C7 nerve root transfer to neurotize the C7 nerve root in the affected limb. This may result not only in less spasticity in the affected limb, but also improved control and motor function vis-a-vis the new connection to the normal cerebral hemisphere. However, contralateral C7 transfers can require large incisions and long nerve grafts. The aim of this study was to test the feasibility of a contralateral C7 nerve root transfer procedure with the use of a minimally invasive robot-assisted technique. In a cadaveric experiment, both sides of C7 root were dissected. The right recipient C7 root was resected as proximally as possible, while the left donor C7 root was resected as distally as possible. With the use of the robot Da Vinci SIy (Intuitive Surgical™, Sunnyvale, CA, USA), we were able to eliminate the large incision and use a much shorter nerve graft when performing the contralateral C7 nerve transfer.

Robot-assisted C7 nerve root transfer from the contralateral healthy side: A preliminary cadaver study

Patients with cerebral palsy and spastic hemiplegia may have extremely poor upper extremity function. Unfortunately, many current therapies and treatments for patients with spastic hemiplegia offer very limited improvements. One innovative technique for treating these patients is the use a contralateral C7 nerve root transfer to neurotize the C7 nerve root in the affected limb. This may result not only in less spasticity in the affected limb, but also improved control and motor function vis-a-vis the new connection to the normal cerebral hemisphere. However, contralateral C7 transfers can require large incisions and long nerve grafts. The aim of this study was to test the feasibility of a contralateral C7 nerve root transfer procedure with the use of a prevertebral minimally invasive robot-assisted technique. In a cadaver, both sides of the C7 root were dissected. The right recipient C7 root was resected as proximally as possible, while the left donor C7 root was resected as distally as possible. With the use of the da Vinci ® SI surgical robot (Intuitive Surgical ™, Sunnyvale, CA, USA), we were able to eliminate the large incision and use a much shorter nerve graft when performing contralateral C7 nerve transfer.

Transdiscal C6-C7 contralateral C7 nerve root transfer in the surgical repair of brachial plexus avulsion injuries.

Repair of complete brachial plexus avulsion injuries may require contralateral C7 nerve root transfer. The available techniques might allow direct neuroraphy in about 50 % of cases but the others require interposing nerve grafts or humeral shaft shortening. We aimed to see if transdiscal C6-C7 contralateral C7 nerve root transfer is technically feasible and if it allows direct coaptation with the contralateral nerve roots in 100 % of cases. In ten fresh-frozen adult cadavers, the C7 nerve root was sectioned just before it connects with other brachial plexus branches and re-routed though the C6-C7 disc space to the contralateral side. A complete C6-C7 discectomy was performed and the disc space kept open with the aid of an autologous iliac crest bone graft. Transdiscal C6-C7 contralateral C7 nerve root transfer is technically feasible. In our cadavers, it provided 5.3 ± 1.2 SDcm of extra length that allowed direct coaptation with the contralateral nerve roots, mainly C8 and T1. Transdiscal C6-C7 contralateral C7 nerve root transfer is technically feasible. In our dissections it lengthens the available C7 nerve root stump by 5.3 ± 1.2SDcm. The increase was 4 cm versus the retropharyngeal route making direct coaptation with the contralateral C8 and T1 nerve roots possible.

Outcome of contralateral C7 transfer to two recipient nerves in 22 patients with the total brachial plexus avulsion injury

The treatment of total brachial plexus avulsion injury is difficult with unfavorable prognosis. This report presents our experience on the contralateral C7 (CC7) nerve root transfer to neurotize two recipient nerves in the patients with total BPAI. Twenty-two patients underwent CC7 transfer to two target nerves in the injured upper limb. The patients' ages ranged from 13 to 48 years. The entire CC7 was transferred to pedicled ulnar nerve in the first stage. The interval between trauma and surgery ranged from 1 to 13 months. The ulnar nerve was transferred to recipients (median nerve and biceps branch or median nerve and triceps branch) at 2-13 months after first operation. The motor recovery of wrist and finger flexor to M3 or greater was achieved in 68.2% of patients, the sensory recovery of median nerve area recovered to S3 or greater in 45.5% of patients. The functional recovery of elbow flexor to M3 or greater was achieved in 66.7% of patients with repair of biceps branch and 20% of patients with repair of the triceps branch (P < 0.05). There were no statistical differences in median nerve function recovery at comparisons of the age younger and older than 20-years-old and the intervals between trauma and surgery. In conclusion, the use of CC7 transfer for repair two recipient nerves might be an option for treatment of total BPAI. The functional recovery of the repaired biceps branch appeared to be better than that of the triceps branch.

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

Contralateral C7 nerve root transfer to neurotize the upper trunk via a modified prespinal route in repair of brachial plexus avulsion injury

In this report, we present our experience on the repair of brachial plexus root avulsion injuries with the use of contralateral C7 nerve root transfers with nerve grafting through a modified prespinal route. The outcomes of the contralateral C7 nerve root transfer to neurotize the upper trunk and C5/C6 nerve roots of the total or near total brachial plexus nerve root avulsion injury in a series of 41 patients were evaluated. The contralateral C7 nerve root that was dissected to the distal end of the divisions, along with the sural nerve graft, were placed underneath the anterior scalene and longus colli muscles, and then passed through the retro-esophageal space to neurotize the recipient nerve. The mean length of the dissected contralateral C7 nerve root was 6.5 ± 0.7 cm, and the mean length of sural nerve graft was 6.8 ± 1.9 cm. The suprascapular nerve was neurotized additionally by the phrenic nerve or the terminal motor branch of accessory nerve in some patients. The mean length of the follow-up was 47.2 ± 14.5 months. The muscle strength was graded M4 or M3 for the biceps muscle in 85.4% of patients, for the deltoid muscle in 82.9% of patients, and for the upper parts of pectoral major in 92.7% of patients. The functional recovery of shoulder abduction in the patients with the additional suprascapular nerve neurotization was remarkably improved. The modified prespinal route could significantly reduced the length of nerve graft in the contralateral C7 nerve root transfer to the injured upper trunk in brachial plexus root avulsion injury, and it may improve the functional outcomes, which deserves further investigations.

Electrophysiological study of the dominant motor innervation to the extensor digitorum communis muscle and long head of triceps brachii at posterior divisions of brachial plexus

Restoration of elbow and finger extension function is still challenging in management of complete brachial plexus avulsion injury, mainly because of fewer available donor nerves for transfer to the radial nerve. Selective neurotization could be a potentially alternative for overcoming this dilemma. This study was designed to identify the innervation dominance of the extensor digitorum communis muscle (EDCM) and long head of the triceps brachii (LTB) at the level of division of brachial plexus. From February 2008 to October 2009, 17 patients with complete brachial plexus avulsion injury underwent the procedure of contralateral C7 nerve root transfer. The posterior divisions of brachial plexus on the healthy donor side were intraoperatively stimulated and the compound muscle action potentials (CMAPs) from the extensor digitorum communis muscle and long head of triceps brachii were recorded by an electrophysiological device. In 13 out of 17 patients (76.5%), the maximal amplitude of CMAP from EDCM was induced by stimulation of the posterior division of lower trunk (PDLT). The mean amplitudes of CMAP from EDCM with stimulation of the posterior division of upper trunk (PDUT), middle trunk (PDMT), and PDLT were 0.64 ± 0.95, 1.64 ± 1.56, and 5.32 ± 4.67 mV (P < 0.05), respectively. The maximal amplitude of CMAP from LTB was induced mainly by stimulation of the PDMT) and PDLT (6 out of 11 and 5 out of 11 patients). The mean amplitudes of CMAP from LTB with stimulation of the PDUT, PDMT, and PDLT were 0.15 ± 0.24, 5.20 ± 4.27, and 7.48 ± 9.90 mV, respectively. The differences of CMAPs between stimulation of PDUT and other two divisions were significant (P < 0.05). From the electrophysiological point of view, this study showed that the PDLT was the major motor division innervating EDCM, and the PDMT and PDLT shared the similar proportion of LTB innervation.

Contralateral C7 nerve root transfer in treatment of cerebral palsy in a child: Case report

A 4-year-old girl who sustained the hemiplegic cerebral palsy and subsequent spasticity in the left upper extremity underwent the C7 nerve root rhizotomy and the contralateral C7 nerve root transfer to the ipsilateral middle trunk of brachial plexus through an interpositional sural nerve graft. In a 2-year follow-up, the results showed a reduction in spasticity and an improvement in extension power of the elbow, the wrist, and the second to fifth fingers. Scores from both Quality of Upper Extremity Skills Test and Modified Ashworth Scale tests had been significantly improved during follow-up. The outcomes from this case provided the evidence that combined the C7 nerve root rhizotomy and contralateral healthy C7 nerve root transfer to the ipsilateral middle trunk of brachial plexus not only partially released flexional spasticity but also strengthened extension power of the spastic upper extremity in children with the cerebral palsy.

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

In this report, we present the findings of reinnervation of the thenar muscle in five patients who underwent the contralateral C7 nerve root transfers for repair of total brachial plexus root avulsions. Five (2 children and 3 adults) of 32 patients who received two-staged procedures of the contralateral C7 nerve root transfers to the median nerves showed reinnervation of thenar muscle were evaluated. The patients also received other procedures including the intercostal nerve transfer to the musculocutaneous nerve, the spinal accessory nerve to the suprascapular nerve, and the ipsilateral phrenic nerve to the musculocutaneous nerve before the contralateral C7 nerve root transfers. The patients were followed up from 24 to 118 months after surgery. Varied degrees of functional restorations were achieved after different procedures. The strength of abductor pollicis brevis (APB) muscle with Grade M2 was found in four patients. The incomplete interference pattern in the APB muscle was detected by electromyogram (EMG) in two patients, and the minority motor unit potential (MUP) was detected in other two patients. The strength of APB muscle was found with Grade M1 in one patient with EMG showing MUP. The findings from our series show reinnervation of thenar muscles after repair of the median nerve with the contralateral C7 nerve root transfer, which provides evidence for further investigation of reconstruction of the brachial plexus root avulsion injury with this procedure.

Prevention and management of the complication of contralateral C7 nerve root transfer through the prespinal route to repair the brachial plexus nerve root avulsion injury

Objective To investigate the occurrence, prevention and management of surgical complication of contralateral C7 nerve root transfer through the prespinal route to repair the brachial plexus nerve root avulsion injury. Methods From Feb. 2002 to Aug. 2009, 425 patients were performed the contralateral C7 nerve root transfer through the prespinal route with this procedure. There were 379 males and 46 females,with the average age of 21 years (range, 3 months to 56 years). The contralateral C7 nerve root was sectioned at the distal of the middle trunk in 15 cases, at the distal of the anterior and posterior division in 410 patients. The surgical complications related to the health C7 nerve root section and the make of tunnel through the prespinal route and others were analyzed retrospectively. Results The incidence rate of complication was 5.2%(22/425). The surgical complications related to the make of prespinal route including 2 cases had the severe bleeding during the operation because of vertebral artery injury; transitory laryrecurrent nerve palsy occurred in 5 cases, the pain and numbness occurred on the donor upper limber in 4 cases when the patients swallowed. The complications related to the section of contralateral C7 nerve root including the extension of finger and thumb was dysfunction in 5 patients after the operation, 3 cases had the severely pain on the health upper limber, Horner's sign occurred on donor side in 2 children suffered birth palsy, and C6 nerve root was mistaken sectioned as C7 in 1 case. Other serious perioperative complication including the thromboses of the cerebral trunk occurred in 1 case 42 hours postoperative and died in hospital 38 days after the operation. Conclusion The procedure of contralateral C7 nerve root transfer through the prespinal route is safe. The effective method to prevent this complication occurrence is to expose the origin segment of vertebral artery when making prespinal route. Key words: Brachial plexus; Nerve transfer; Postoperative complications

Low-Dose FK506 After Contralateral C7 Transfer to the Musculocutaneous Nerve Using Two Different Tubes

The purpose of this project was to study the effect of a subimmunosuppressive dose of FK506 (0.7 mg/kg per day) on nerve regeneration along a long nerve gap (4 cm), using the contralateral C7 nerve root transfer model for musculocutaneous nerve neurotization. Two types of tubes were applied to the nerve gap: a polycaprolactone tube and a collagen tube. Twenty adult male Sprague-Dawley rats were divided into 4 groups (n = 5). A polycaprolactone was used in groups 1 and 3 and a collagen tube in groups 2 and 4. Groups 1 and 2 were daily administered a subimmunosuppressive dose of FK506. Animals were euthanized on day 30. Evaluation consisted of behavioral assessment, needle electromyography studies, biceps muscle weight measurements, and qualitative and quantitative morphometry. Groups 1 and 2 showed higher mean values for fiber counts, axon diameters, myelin thickness and myelin area in C7, better functional evaluation results, and higher biceps weight left to right ratio than groups 3 and 4. There was no evidence of reinnervation potentials, and there were no axons detectable inside the tube lumen in any of the study groups. The present study demonstrated that there was nonsignificant improvement of the functional recovery, after systemic administration of a low dose of FK506. This was attributed to 3 factors: length of nerve gap; duration of follow up; and dose of FK506. However, FK506-treated animals tended to be in a more advanced stage of nerve regeneration compared with the control groups.