Brachial plexus injury: factors affecting functional outcome in spinal accessory nerve transfer for the restoration of elbow flexion

Resect, rewire, and restore: Nerve transfer salvage of neurological deficits associated with soft tissue tumors in a retrospective cohort series at a tertiary reconstructive center

AIMS

We aimed to explore the effectiveness of nerve transfer as an intervention to restore neurological deficits caused by extremity tumors through direct nerve involvement, neural compression, or as a consequence of oncological surgery.

METHODS

A retrospective cohort study of consecutive cases was conducted, including all patients who underwent nerve transfers to restore functional deficits in limbs following soft tissue tumor resection. The threshold for a successful nerve transfer was a BMRC motor grade of 4/5 and sensory grade of 3-3+/4 with protective sensation.

RESULTS

In total, 29 nerve transfers (25 motor and 4 sensory) were completed in 11 patients, aged 12-70 years at referral, over a 6-year period to 2020. This included 22 upper limb and 3 lower limb motor nerve transfers. The timing of delayed nerve transfer reconstructions was 1-15 months following primary oncological resection, with immediate simultaneous reconstructions performed in 4 cases. The threshold for success was achieved in 82% of upper limb and 33% of lower limb motor nerve transfers, while all sensory transfers were successful in restoring protective sensation.

CONCLUSION

Nerve transfer surgery, a well-established technique in restoring deficits following traumatic nerve injury, is further demonstrably relevant in extremity oncological reconstruction, especially as it can be performed remotely to the tumor location or resection site and introduces a healthy nerve or fascicle to rapidly reinnervate distal muscles without sacrificing major function. This study further illustrates the importance of early recognition and referral to specialist services where multi-disciplinary surgical resection and reconstructive planning can be conducted.

LEVEL OF EVIDENCE

IV Clinical Case Series.

Clinical and functional outcome after different surgical approaches for brachial plexus injuries: Cohort study

Introduction

Brachial plexus injury (BPI) can result in complete loss of neurological function and reduces the quality of life. Nerve transfer, nerve grafting, external neurolysis, and free functional muscle transfer are several management options that determine the eventual outcomes. Despite various methods of treatment, hardly any literature compares directly the result of these treatment options. This study aimed to analyze differences in clinical and functional outcomes after a reconstructive surgery.

Methods

A cohort retrospective study was conducted on traumatic brachial plexus injured patients aged from 17 to 65 years at one hospital in Surabaya, Indonesia, from January 2009 to December 2019. All patients were divided into 4 groups depending on the types of surgery. The clinical outcomes were measured using elbow and shoulder muscle strength, elbow and shoulder range of motion (ROM), and pain level (measured using Visual Analog Scale/VAS); the functional outcomes were measured using the overall quality of life using the DASH (disabilities of the arms, shoulder, and hand) score.

Results

This study included 316 patients comprising of 256 males with an average age of 27.53 ± 11.37, an average time from injury to surgery of 17.74 ± 35.82 months, and average follow-up duration of 59.89 ± 37.68 months. Most cases were caused by road traffic accidents (77.22%) and most were total arm type of BPI injury (70.7%). There was no significant difference in the mean values of study parameters except in VAS (p = 0.042) as nerve grafting resulted in less pain than external neurolysis (2.27 ± 1.03 vs. 3.68 ± 1.93, respectively; p = 0.017). Besides, nerve transfer procedure also resulted in less pain compared to external neurolysis (2.99 ± 1.84 vs. 3.68 ± 1.93, respectively; p = 0.036).

Conclusion

We found no significant difference between types of surgery and the postsurgical outcome. A wider multicenter study was required to define the clinical and functional outcomes clearly.

The proteome of distal nerves: implication in delayed repair and poor functional recovery

Chronic denervation is one of the key factors that affect nerve regeneration. Chronic axotomy deteriorates the distal nerve stump, causes protein changes, and renders the microenvironment less permissive for regeneration. Some of these factors/proteins have been individually studied. To better delineate the comprehensive protein expression profiles and identify proteins that contribute to or are associated with this detrimental effect, we carried out a proteomic analysis of the distal nerve using an established delayed rat sciatic nerve repair model. Four rats that received immediate repair after sciatic nerve transection served as control, whereas four rats in the experimental group (chronic denervation) had their sciatic nerve repaired after a 12-week delay. All the rats were sacrificed after 16 weeks to harvest the distal nerves for extracting proteins. Twenty-five micrograms of protein from each sample were fractionated in SDS-PAGE gels. NanoLC-MS/MS analysis was applied to the gels. Protein expression levels of nerves on the surgery side were compared to those on the contralateral side. Any protein with a P value of less than 0.05 and a fold change of 4 or higher was deemed differentially expressed. All the differentially expressed proteins in both groups were further stratified according to the biological processes. A PubMed search was also conducted to identify the differentially expressed proteins that have been reported to be either beneficial or detrimental to nerve regeneration. Ingenuity Pathway Analysis (IPA) software was used for pathway analysis. The results showed that 709 differentially expressed proteins were identified in the delayed repair group, with a bigger proportion of immune and inflammatory process-related proteins and a smaller proportion of proteins related to axon regeneration and lipid metabolism in comparison to the control group where 478 differentially expressed proteins were identified. The experimental group also had more beneficial proteins that were downregulated and more detrimental proteins that were upregulated. IPA revealed that protective pathways such as LXR/RXR, acute phase response, RAC, ERK/MAPK, CNTF, IL-6, and FGF signaling were inhibited in the delayed repair group, whereas three detrimental pathways, including the complement system, PTEN, and apoptosis signaling, were activated. An available database of the adult rodent sciatic nerve was used to assign protein changes to specific cell types. The poor regeneration seen in the delayed repair group could be associated with the down-regulation of beneficial proteins and up-regulation of detrimental proteins. The proteins and pathways identified in this study may offer clues for future studies to identify therapeutic targets.

Nerve Graft Length and Recovery of Elbow Flexion Muscle Strength in Patients With Traumatic Brachial Plexus Injuries: Case Series

BACKGROUND

Traumatic brachial plexus injuries cause long-term maiming of patients. The major target function to restore in complex brachial plexus injury is elbow flexion.

OBJECTIVE

To retrospectively analyze the correlation between the length of the nerve graft and the strength of target muscle recovery in extraplexual and intraplexual nerve transfers.

METHODS

A total of 51 patients with complete or near-complete brachial plexus injuries were treated with a combination of nerve reconstruction strategies. The phrenic nerve (PN) was used as axon donor in 40 patients and the spinal accessory nerve was used in 11 patients. The recipient nerves were the anterior division of the upper trunk (AD), the musculocutaneous nerve (MC), or the biceps branches of the MC (BBs). An index comparing the strength of elbow flexion between the affected and the healthy arms was correlated with the choice of target nerve recipient and the length of nerve grafts, among other parameters. The mean follow-up was 4 yr.

RESULTS

Neither the choice of MC or BB as a recipient nor the length of the nerve graft showed a strong correlation with the strength of elbow flexion. The choice of very proximal recipient nerve (AD) led to axonal misrouting in 25% of the patients in whom no graft was employed.

CONCLUSION

The length of the nerve graft is not a negative factor for obtaining good muscle recovery for elbow flexion when using PN or spinal accessory nerve as axon donors in traumatic brachial plexus injuries.

Human motor endplate remodeling after traumatic nerve injury

OBJECTIVE

Current management of traumatic peripheral nerve injuries is variable with operative decisions based on assumptions that irreversible degeneration of the human motor endplate (MEP) follows prolonged denervation and precludes reinnervation. However, the mechanism and time course of MEP changes after human peripheral nerve injury have not been investigated. Consequently, there are no objective measures by which to determine the probability of spontaneous recovery and the optimal timing of surgical intervention. To improve guidance for such decisions, the aim of this study was to characterize morphological changes at the human MEP following traumatic nerve injury.

METHODS

A prospective cohort (here analyzed retrospectively) of 18 patients with traumatic brachial plexus and axillary nerve injuries underwent biopsy of denervated muscles from the upper extremity from 3 days to 6 years after injury. Muscle specimens were processed for H & E staining and immunohistochemistry, with visualization via confocal and two-photon excitation microscopy.

RESULTS

Immunohistochemical analysis demonstrated varying degrees of fragmentation and acetylcholine receptor dispersion in denervated muscles. Comparison of denervated muscles at different times postinjury revealed progressively increasing degeneration. Linear regression analysis of 3D reconstructions revealed significant linear decreases in MEP volume (R = -0.92, R2 = 0.85, p = 0.001) and surface area (R = -0.75, R2 = 0.56, p = 0.032) as deltoid muscle denervation time increased. Surprisingly, innervated and structurally intact MEPs persisted in denervated muscle specimens from multiple patients 6 or more months after nerve injury, including 2 patients who had presented > 3 years after nerve injury.

CONCLUSIONS

This study details novel and critically important data about the morphology and temporal sequence of events involved in human MEP degradation after traumatic nerve injuries. Surprisingly, human MEPs not only persisted, but also retained their structures beyond the assumed 6-month window for therapeutic surgical intervention based on previous clinical studies. Preoperative muscle biopsy in patients being considered for nerve transfer may be a useful prognostic tool to determine MEP viability in denervated muscle, with surviving MEPs also being targets for adjuvant therapy.

Cost-Effectiveness Analysis of Combined Dual Motor Nerve Transfers versus Alternative Surgical and Nonsurgical Management Strategies to Restore Shoulder Function Following Upper Brachial Plexus Injury

BACKGROUND

Restoration of shoulder function is an important treatment goal in upper brachial plexus injury (UBPI). Combined dual motor nerve transfer (CDNT) of spinal accessory to suprascapular and radial to axillary nerves demonstrates good functional recovery with minimal risk of perioperative complications.

OBJECTIVE

To evaluate the cost-effectiveness of CDNT vs alternative operative and nonoperative treatments for UBPI.

METHODS

A decision model was constructed to evaluate costs ($, third-party payer) and effectiveness (quality-adjusted life years [QALYs]) of CDNT compared to glenohumeral arthrodesis (GA), conservative management, and nontreatment strategies. Estimates for branch probabilities, costs, and QALYs were derived from published studies. Incremental cost-effectiveness ratios (ICER, $/QALY) were calculated to compare the competing strategies. One-way, 2-way, and probabilistic sensitivity analyses with 100 000 iterations were performed to account for effects of uncertainty in model inputs.

RESULTS

Base case model demonstrated CDNT effectiveness, yielding an expected 21.04 lifetime QALYs, compared to 20.89 QALYs with GA, 19.68 QALYs with conservative management, and 19.15 QALYs with no treatment. The ICERs for CDNT, GA, and conservative management vs nontreatment were $5776.73/QALY, $10 483.52/QALY, and $882.47/QALY, respectively. Adjusting for potential income associated with increased likelihood of returning to work after clinical recovery demonstrated CDNT as the dominant strategy, with ICER = -$56 459.54/QALY relative to nontreatment. Probabilistic sensitivity analysis showed CDNT cost-effectiveness at a willingness-to-pay threshold of $50 000/QALY in 78.47% and 81.97% of trials with and without income adjustment, respectively. Conservative management dominated in <1% of iterations.

CONCLUSION

CDNT and GA are cost-effective interventions to restore shoulder function in patients with UBPI.

Results of Phrenic Nerve Transfer to the Musculocutaneous Nerve Using Video-Assisted Thoracoscopy in Patients with Traumatic Brachial Plexus Injury: Series of 28 Cases

BACKGROUND

The phrenic nerve can be transferred to the musculocutaneous nerve using video-assisted thoracoscopy, aiming at the recovery of elbow flexion in patients with traumatic brachial plexus injuries. There are few scientific papers in the literature that evaluate the results of this operative technique.

OBJECTIVE

To evaluate biceps strength and pulmonary function after the transfer of the phrenic nerve to the musculocutaneous nerve using video-assisted thoracoscopy.

METHODS

A retrospective study was carried out in a sample composed of 28 patients who were victims of traumatic injury to the brachial plexus from 2008 to 2013. Muscle strength was graded using the British Medical Research Council (BMRC) scale and pulmonary function through spirometry. Statistical tests, with significance level of 5%, were used.

RESULTS

In total, 74.1% of the patients had biceps strength greater than or equal to M3. All patients had a decrease in forced vital capacity and forced expiratory volume in 1 s, with no evidence of recovery over time.

CONCLUSION

Transferring the phrenic nerve to the musculocutaneous nerve using video-assisted thoracoscopy may lead to an increase in biceps strength to BMRC M3 or greater in most patients. Considering the deterioration in the parameters of spirometry observed in our patients and the future effects of aging in the respiratory system, it is not possible at the moment to guarantee the safety of this operative technique in the long term.

Recovery of Elbow Flexion after Nerve Reconstruction versus Free Functional Muscle Transfer for Late, Traumatic Brachial Plexus Palsy: A Systematic Review

BACKGROUND

In late presentation of brachial plexus trauma, it is unclear whether donor nerves should be devoted to nerve reconstruction or reserved for free functional muscle transfer. The authors systematically reviewed recovery of elbow flexion after nerve reconstruction versus free functional muscle transfer for late, traumatic brachial plexus palsy.

METHODS

A systematic review was performed using the PubMed, Embase, and Cochrane databases to identify all cases of traumatic brachial plexus palsy in patients aged 18 years or older. Patients who underwent late (≥12 months) nerve reconstruction or free functional muscle transfer for elbow flexion were included. Age, time to operation, and level of brachial plexus injury were recorded. British Medical Research Council grade for strength and range of motion were evaluated for elbow flexion.

RESULTS

Thirty-three studies met criteria, for a total of 103 patients (nerve reconstruction, n = 53; free functional muscle transfer, n = 50). There were no differences across groups regarding surgical age (time from injury) and preoperative elbow flexion. For upper trunk injuries, 53 percent of reconstruction patients versus 100 percent of muscle transfer patients achieved grade M3 or greater strength, and 43 percent of reconstruction patients versus 70 percent of muscle transfer patients achieved grade M4 or greater strength. Of the total brachial plexus injuries, 37 percent of reconstruction patients versus 78 percent of muscle transfer patients achieved grade M3 or greater strength, and 16 percent of reconstruction patients versus 46 percent of muscle transfer patients achieved grades M4 or greater strength.

CONCLUSION

In late presentation of traumatic brachial plexus injuries, donor nerves should be reserved for free functional muscle transfer to restore elbow flexion.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Nerve transfer versus muscle transfer to restore elbow flexion after pan-brachial plexus injury: a cost-effectiveness analysis

OBJECTIVE Pan-brachial plexus injury (PBPI), involving C5-T1, disproportionately affects young males, causing lifelong disability and decreased quality of life. The restoration of elbow flexion remains a surgical priority for these patients. Within the first 6 months of injury, transfer of spinal accessory nerve (SAN) fascicles via a sural nerve graft or intercostal nerve (ICN) fascicles to the musculocutaneous nerve can restore elbow flexion. Beyond 1 year, free-functioning muscle transplantation (FFMT) of the gracilis muscle can be used to restore elbow flexion. The authors present the first cost-effectiveness model to directly compare the different treatment strategies available to a patient with PBPI. This model assesses the quality of life impact, surgical costs, and possible income recovered through restoration of elbow flexion. METHODS A Markov model was constructed to simulate a 25-year-old man with PBPI without signs of recovery 4.5 months after injury. The management options available to the patient were SAN transfer, ICN transfer, delayed FFMT, or no treatment. Probabilities of surgical success rates, quality of life measurements, and disability were derived from the published literature. Cost-effectiveness was defined using incremental cost-effectiveness ratios (ICERs) defined by the ratio between costs of a treatment strategy and quality-adjusted life years (QALYs) gained. A strategy was considered cost-effective if it yielded an ICER less than a willingness-to-pay of $50,000/QALY gained. Probabilistic sensitivity analysis (PSA) was performed to address parameter uncertainty. RESULTS The base case model demonstrated a lifetime QALYs of 22.45 in the SAN group, 22.0 in the ICN group, 22.3 in the FFMT group, and 21.3 in the no-treatment group. The lifetime costs of income lost through disability and interventional/rehabilitation costs were $683,400 in the SAN group, $727,400 in the ICN group, $704,900 in the FFMT group, and $783,700 in the no-treatment group. Each of the interventional modalities was able to dramatically improve quality of life and decrease lifelong costs. A Monte Carlo PSA demonstrated that at a willingness-to-pay of $50,000/QALY gained, SAN transfer dominated in 88.5% of iterations, FFMT dominated in 7.5% of iterations, ICN dominated in 3.5% of iterations, and no treatment dominated in 0.5% of iterations. CONCLUSIONS This model demonstrates that nerve transfer surgery and muscle transplantation are cost-effective strategies in the management of PBPI. These reconstructive neurosurgical modalities can improve quality of life and lifelong earnings through decreasing disability.

Timing of surgery in traumatic brachial plexus injury: a systematic review

OBJECTIVEIdeal timeframes for operating on traumatic stretch and blunt brachial plexus injuries remain a topic of debate. Whereas on the one hand spontaneous recovery might occur, on the other hand, long delays are believed to result in poorer functional outcomes. The goal of this review is to assess the optimal timeframe for surgical intervention for traumatic brachial plexus injuries.METHODSA systematic search was performed in January 2017 in PubMed and Embase databases according to the PRISMA guidelines. Search terms related to "brachial plexus injury" and "timing" were used. Obstetric plexus palsies were excluded. Qualitative synthesis was performed on all studies. Timing of operation and motor outcome were collected from individual patient data. Patients were categorized into 5 delay groups (0-3, 3-6, 6-9, 9-12, and > 12 months). Median delays were calculated for Medical Research Council (MRC) muscle grade ≥ 3 and ≥ 4 recoveries.RESULTSForty-three studies were included after full-text screening. Most articles showed significantly better motor outcome with delays to surgery less than 6 months, with some studies specifying even shorter delays. Pain and quality of life scores were also significantly better with shorter delays. Nerve reconstructions performed after long time intervals, even more than 12 months, can still be useful. All papers reporting individual-level patient data described a combined total of 569 patients; 65.5% of all patients underwent operations within 6 months and 27.4% within 3 months. The highest percentage of ≥ MRC grade 3 (89.7%) was observed in the group operated on within 3 months. These percentages decreased with longer delays, with only 35.7% ≥ MRC grade 3 with delays > 12 months. A median delay of 4 months (IQR 3-6 months) was observed for a recovery of ≥ MRC grade 3, compared with a median delay of 7 months (IQR 5-11 months) for ≤ MRC grade 3 recovery.CONCLUSIONSThe results of this systematic review show that in stretch and blunt injury of the brachial plexus, the optimal time to surgery is shorter than 6 months. In general, a 3-month delay appears to be appropriate because while recovery is better in those operated on earlier, this must be considered given the potential for spontaneous recovery.

Nerve Transfers to Restore Elbow Function

The purpose of this article is to provide an overview of the various nerve transfer options for restoration of elbow function. This article describes nerve transfer strategies for elbow flexion and extension including the indications, limitations, and expected outcomes based on current literature.

Motor Nerve Transfers

Brachial plexus and peripheral nerve injuries are exceedingly common. Traditional nerve grafting reconstruction strategies and techniques have not changed significantly over the last 3 decades. Increased experience and wider adoption of nerve transfers as part of the reconstructive strategy have resulted in a marked improvement in clinical outcomes. We review the options, outcomes, and indications for nerve transfers to treat brachial plexus and upper- and lower-extremity peripheral nerve injuries, and we explore the increasing use of nerve transfers for facial nerve and spinal cord injuries. Each section provides an overview of donor and recipient options for nerve transfer and of the relevant anatomy specific to the desired function.

Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics

Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering 'excellent' and 'good' muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery.

Upper brachial plexus injury in adults: comparative effectiveness of different repair techniques

OBJECT

Adult upper trunk brachial plexus injuries result in significant disability. Several surgical treatment strategies exist, including nerve grafting, nerve transfers, and a combination of both approaches. However, no existing data clearly indicate the most successful strategy for restoring elbow flexion and shoulder abduction in these patients. The authors reviewed the literature to compare outcomes of the three surgical repair techniques listed above to determine the optimal approach to traumatic injury to the upper brachial plexus in adults.

METHODS

Both PubMed and EMBASE databases were searched for English-language articles containing the MeSH topic "brachial plexus" in conjunction with the word "injury" or "trauma" in the title and "surgery" or "repair" as a MeSH subheading or in the title, excluding pediatric articles and those articles limited to avulsions. The search was also limited to articles published after 1990 and containing at least 10 operated cases involving upper brachial plexus injuries. The search was supplemented with articles obtained through the "Related Articles" feature on PubMed and the bibliographies of selected publications. From the articles was collected information on the operation performed, number of operated cases, mean subject ages, sex distribution, interval between injury and surgery, source of nerve transfers, mean duration of follow-up, year of publication, and percentage of operative success in terms of elbow flexion and shoulder abduction of the injured limb. The recovery of elbow flexion and shoulder abduction was separately analyzed. A subanalysis was also performed to assess the recovery of elbow flexion following various neurotization techniques.

RESULTS

As regards the restoration of elbow flexion, nerve grafting led to significantly better outcomes than either nerve transfer or the combined techniques (F = 4.71, p = 0.0097). However, separating the Oberlin procedure from other neurotization techniques revealed that the former was significantly more successful (F = 82.82, p < 0.001). Moreover, in comparing the Oberlin procedure to nerve grafting or combined procedures, again the former was significantly more successful than either of the latter two approaches (F = 53.14; p < 0.001). In the restoration of shoulder abduction, nerve transfer was significantly more successful than the combined procedure (p = 0.046), which in turn was significantly better than nerve grafting procedures (F = 5.53, p = 0.0044).

CONCLUSIONS

According to data in this study, in upper trunk brachial plexus injuries in adults, the Oberlin procedure and nerve transfers are the more successful approaches to restore elbow flexion and shoulder abduction, respectively, compared with nerve grafting or combined techniques. A prospective, randomized controlled trial would be necessary to fully elucidate differences in outcome among the various surgical approaches.

The medial cord to musculocutaneous (MCMc) nerve transfer: a new method to reanimate elbow flexion after C5-C6-C7-(C8) avulsive injuries of the brachial plexus--technique and results

The aim of this paper is to report on our ample experience with the medial cord to musculocutaneous (MCMc) nerve transfer. The MCMc technique is a new type of neurotization which is able to reanimate the elbow flexion in multilevel avulsive injuries of the brachial plexus provided that at least the T1 root is intact. A series of 180 consecutive patients, divided into four classes according to the quality of hand function, is available for a long-term follow-up after brachial plexus surgery. The patients enrolled for the study have in common a brachial plexus palsy showing multiple cervical root avulsive injuries at two (C5-C6), three (C5-C6-C7) and four (C5-C6-C7-C8) levels. The reinnervation of the musculocutaneous nerve is obtained via an end-to-end transfer from two donor fascicles located in the medial cord. The selected fascicles are those directed principally to the flexor carpi radialis, ulnaris and, to a lesser degree, the flexor digitorum profundus. Under normal anatomic conditions, they are located in the medial cord, and their site corresponds to the inverted V-shaped bifurcation between the internal contribution of the median nerve and the ulnar nerve. The technique has no failure and no complications when the hand shows a normal wrist and finger flexion and a normal intrinsic function. In case of suboptimal conditions of the hand, the technique has proved technically more challenging, but still with 67% satisfactory results. In the four-root avulsive injuries, however, this method shows its limitations and an alternative strategy should be preferred when possible. EMG analysis shows a reinnervation in both the biceps and the brachialis muscles, explaining the high quality of the observed results. Moreover, this technique theoretically offers the possibility of a "second attempt" at a more distal level in case of failure of the first surgery. This procedure is quick, safe, extremely effective and easily feasible by an experienced plexus surgeon. The ideal candidate is a patient harbouring a C5-C6 avulsive injury of the upper brachial plexus with a normally functioning hand.

Skin derived precursor Schwann cells improve behavioral recovery for acute and delayed nerve repair

Previous work has shown that infusion of skin-derived precursors pre-differentiated into Schwann cells (SKP-SCs) can remyelinate injured and regenerating axons, and improve indices of axonal regeneration and electrophysiological parameters in rodents. We hypothesized that SKP-SC therapy would improve behavioral outcomes following nerve injury repair and tested this in a pre-clinical trial in 90 rats. A model of sciatic nerve injury and acellular graft repair was used to compare injected SKP-SCs to nerve-derived Schwann cells or media, and each was compared to the gold standard nerve isograft repair. In a second experiment, rats underwent right tibial nerve transection and received either acute or delayed direct nerve repair, with injections of either 1) SKP-SCs distal to the repair site, 2) carrier medium alone, or 3) dead SKP-SCs, and were followed for 4, 8 or 17weeks. For delayed repairs, both transected nerve ends were capped and repaired 11weeks later, along with injections of cells or media as above, and followed for 9 additional weeks (total of 20weeks). Rats were serially tested for skilled locomotion and a slip ratio was calculated for the horizontal ladder-rung and tapered beam tasks. Immediately after nerve injury and with chronic denervation, slip ratios were dramatically elevated. In the GRAFT repair study, the SKP-SC treated rats showed statistically significant improvement in ladder rung as compared to all other groups, and exhibited the greatest similarity to the sham controls on the tapered beam by study termination. In the ACUTE repair arm, the SKP-SC group showed marked improvement in ladder rung slip ratio as early as 5weeks after surgery, which was sustained for the duration of the experiment. Groups that received media and dead SKP-SCs improved with significantly slower progression. In the DELAYED repair arm, the SKP-SC group became significantly better than other groups 7weeks after the repair, while the media and the dead SKP-SCs showed no significant improvement in slip ratios. On histomorphometrical analysis, SKP-SC group showed significantly increased mean axon counts while the percent myelin debris was significantly lower at both 4 and 8weeks, suggesting that a less inhibitory micro-environment may have contributed to accelerated axonal regeneration. For delayed repair, mean axon counts were significantly higher in the SKP-SC group. Compound action potential amplitudes and muscle weights were also improved by cell therapy. In conclusion, SKP-SC therapy improves behavioral recovery after acute, chronic and nerve graft repair beyond the current standard of microsurgical nerve repair.

Spinal to accessory nerve transfer in traumatic brachial plexus palsy: is body mass index a predictor of outcome?

INTRODUCTION

Several factors that affect functional recovery after surgery in severe brachial plexus lesions have been identified, i.e., time to surgery and presence of root avulsions. The body mass index (BMI) of the patient could be one of these possible factors. The objective of the present paper is to systematically study the relationship between BMI and the outcome of abduction following spinal accessory to suprascapular nerve transfer.

METHODS

We retrospectively studied 18 cases that followed these inclusion criteria: (1) Male patients with a spinal accessory to suprascapular nerve transfer as the only procedure for shoulder function reanimation; (2) at least C5-C6 root avulsion; (3) interval between trauma and surgery less than 12 months; (4) follow-up was at least 2 years; (5) no concomitant injury of the shoulder girdle. Pearson correlation analysis and linear regression was performed for BMI versus shoulder abduction.

RESULTS

The mean range of post-operative abduction obtained across the entire series was 49.7° (SD ± 30.2). Statistical evaluation revealed a significant, negative moderately strong correlation between BMI and post-operative range of shoulder abduction (r = -0.48, p = 0.04). Upon simple linear regression, time to surgery (p = 0.04) was the only statistically significant predictor of abduction range negatively correlated.

CONCLUSIONS

Analysis of this series suggests that a high BMI of patients undergoing brachial plexus surgery is a negative predictor of outcome, albeit less important than others like time from trauma to surgery. Nevertheless, the BMI of patients should be taken into consideration when planning surgical strategies for reconstruction.

Stem cell salvage of injured peripheral nerve

We previously developed a collagen tube filled with autologous skin-derived stem cells (SDSCs) for bridging long rat sciatic nerve gaps. Here we present a case report describing a compassionate use of this graft for repairing the polyinjured motor and sensory nerves of the upper arms of a patient. Preclinical assessment was performed with collagen/SDSC implantation in rats after sectioning the sciatic nerve. For the patient, during the 3-year follow-up period, functional recovery of injured median and ulnar nerves was assessed by pinch gauge test and static two-point discrimination and touch test with monofilaments, along with electrophysiological and MRI examinations. Preclinical experiments in rats revealed rescue of sciatic nerve and no side effects of patient-derived SDSC transplantation (30 and 180 days of treatment). In the patient treatment, motor and sensory functions of the median nerve demonstrated ongoing recovery postimplantation during the follow-up period. The results indicate that the collagen/SDSC artificial nerve graft could be used for surgical repair of larger defects in major lesions of peripheral nerves, increasing patient quality of life by saving the upper arms from amputation.

A systematic review of nerve transfer and nerve repair for the treatment of adult upper brachial plexus injury

Nerve reconstruction for upper brachial plexus injury consists of nerve repair and/or transfer. Current literature lacks evidence supporting a preferred surgical treatment for adults with such injury involving shoulder and elbow function. We systematically reviewed the literature published from January 1990 to February 2011 using multiple databases to search the following: brachial plexus and graft, repair, reconstruction, nerve transfer, neurotization. Of 1360 articles initially identified, 33 were included in analysis, with 23 nerve transfer (399 patients), 6 nerve repair (99 patients), and 4 nerve transfer + proximal repair (117 patients) citations (mean preoperative interval, 6 ± 1.9 months). For shoulder abduction, no significant difference was found in the rates ratio (comparative probabilities of event occurrence) among the 3 methods to achieve a Medical Research Council (MRC) scale score of 3 or higher or a score of 4 or higher. For elbow flexion, the rates ratio for nerve transfer vs nerve repair to achieve an MRC scale score of 3 was 1.46 (P = .03); for nerve transfer vs nerve transfer + proximal repair to achieve an MRC scale score of 3 was 1.45 (P = .02) and an MRC scale score of 4 was 1.47 (P = .05). Therefore, for elbow flexion recovery, nerve transfer is somewhat more effective than nerve repair; however, no particular reconstruction strategy was found to be superior to recover shoulder abduction. When considering nerve reconstruction strategies, our findings do not support the sole use of nerve transfer in upper brachial plexus injury without operative exploration to provide a clear understanding of the pathoanatomy. Supraclavicular brachial plexus exploration plays an important role in developing individual surgical strategies, and nerve repair (when donor stumps are available) should remain the standard for treatment of upper brachial plexus injury except in isolated cases solely lacking elbow flexion.

Dose-dependent facilitation of peripheral nerve regeneration by bone marrow-derived mononuclear cells: a randomized controlled study: laboratory investigation

OBJECT

Bone marrow-derived stem cells enhance the rate of regeneration of neuronal cells leading to clinical improvement in nerve injury, spinal cord injury, and brain infarction. Recent experiments in the local application of bone marrow-derived mononuclear cells (BM-MNCs) in models of sciatic nerve transection in rats have suggested their beneficial role in nerve regeneration, although the effects of variable doses of stem cells on peripheral nerve regeneration have never been specifically evaluated in the literature. In this paper, the authors evaluated the dose-dependent role of BM-MNCs in peripheral nerve regeneration in a model of sciatic nerve transection in rats.

METHODS

The right sciatic nerve of 60 adult female Wistar rats (randomized into 2 test groups and 1 control group, 20 rats in each group) underwent transection under an operating microscope. The cut ends of the nerve were approximated using 2 epineural microsutures. The gap was filled with low-dose (5 million BM-MNCs/100 μl phosphate-buffered saline [PBS]) rat BM-MNCs in one group, high-dose (10 million BM-MNCs/100 μl PBS) rat BM-MNCs in another group, and only PBS in the control group, and the approximated nerve ends were sealed using fibrin glue. Histological assessment was performed after 30 days by using semiquantitative and morphometric analyses and was done to assess axonal regeneration, percentage of myelinated fibers, axonal diameter, fiber diameter, and myelin thickness at distal-most sites (10 mm from site of repair), intermediate distal sites (5 mm distal to the repair site), and site of repair.

RESULTS

The recovery of nerve cell architecture after nerve anastomosis was far better in the high-dose BM-MNC group than in the low-dose BM-MNC and control groups, and it was most evident (p < 0.02 in the majority of the parameters [3 of 4]) at the distal-most site. Overall, the improvement in myelin thickness was most significant with incremental dosage of BM-MNCs, and was evident at the repair, intermediate distal, and distal-most sites (p = 0.001).

CONCLUSIONS

This study emphasizes the role of BM-MNCs, which can be isolated easily from bone marrow aspirates, in peripheral nerve injury and highlights their dose-dependent facilitation of nerve regeneration.

Use of long autologous nerve grafts in brachial plexus reconstruction: factors that affect the outcome

BACKGROUND

Using grafts directed to distal targets in brachial plexus reconstruction has the advantage over proximal targets of avoiding axonal dispersion. A long graft (more than 10 cm) is needed to reach most distal targets. The objective of this article is to identify factors associated with good versus poor outcomes in a clinical series of long grafts used for distal brachial plexus reconstruction.

METHODS

In 34 patients with a flail arm, 47 sural grafts >10 cm long were followed for ≥2 years postoperatively. Surgical technique included standard supraclavicular exposure of the proximal brachial plexus and its branches, the phrenic nerve and spinal accessory nerve. Distal target nerves were exposed via an incision starting at the axilla, following the gap between the biceps and triceps. Cases achieving a good result were statistically compared against those with a poor result as to the donor nerve/root, target nerve, patient age and weight, time from trauma to surgery, graft length and long-term rehabilitation quality.

FINDINGS

A good outcome was observed with 23 grafts (48.9%), but 66.7% of the 30 long grafts done within 6 months of trauma yielded a good result. Only 1 of 15 patients with the lowest quality rehabilitation score experienced a good result (6.6%) versus all 12 patients with the highest rating (p < 0.001). Trauma-to-surgery time was roughly half as long in those with a good result (4.7 vs. 9.0 months, p < 0.001). No other inter-group differences were observed.

CONCLUSIONS

The results of a series of distal brachial plexus target reinnervations with long grafts is presented and analyzed. According to them, time from trauma to surgery and an adequate postoperative rehabilitation are important predictors of outcome.

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

OBJECTIVE

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.

PATIENTS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Anatomic study in cadaver of the motor branch of the musculocutaneous nerve

This study of 80 cadavers demonstrates that the anatomic position of the motor branch of the musculocutaneous nerve with respect to that of the sensitive branch of the same nerve is lateral in more than 88% of cases in humans.The distance from plexus to the separation into the motor and sensitive fascicles was 8-9 cm long.Given the lateral position of the motor component of the musculocutaneous nerve, the nerves that are going to be used to neurotize this area can be directed so as to increase the efficacy of the results for the flexor function of the arm.

INTRODUCTION

Brachial plexus lesions produce great morbidity and are relatively frequent in young adults. Innervating the coracobrachial, biceps and anterior brachial muscles, the musculocutaneous nerve is one of the priorities for nerve neurotization when plexus root avulsion occurs because it is essential for arm flexion. This nerve has both a motor and sensitive component, and the anatomic positions of the two components have not been much studied. When performing a neurotization anastomosis to the musculocutaneous nerve, being able to identify the motor component of the graft and attach it to the motor component of the musculocutaneous nerve could avoid a loss of many motor axons which would otherwise occur if the graft were attached to the sensitive component.

OBJECTIVE

The present paper is based on a topographic anatomic study to locate and obtain the objective positioning of the motor branch of the musculocutaneous nerve in humans, as well as measure its length from the origin in the brachial plexus to the separation of both fascicles into branches.

MATERIAL AND METHODS

The study was performed in 40 cadavers, dissecting the musculocutaneous nerve along its course and measuring the distance from its emergence from the plexus until the separation between its motor and sensitive branches in both arms so as to be able to determine the positioning of the motor fascicle with respect to the sensitive fascicle.

RESULTS

The distance from plexus to the separation into the motor and sensitive fascicles was 8.8 cm on the left side and 8.95 cm on the right side. The position of the motor branch with respect to the sensitive branch was lateral in more than 85% of the studied nerves, all the way from its origin in the brachial plexus until the definitive separation between both branches, on both the right and the left sides.

CONCLUSION

If the nerves that are to be used for neurotization of the musculacutaneous nerve are directly taken to the lateral fascicle of that nerve, which is generally the motor component, the treatment should be effective and should avoid the loss of motor axons resulting from anastomosing to the sensitive fascicle.

Novel strategies in brachial plexus repair after traumatic avulsion

Clinical trials in spinal cord injury (SCI) can be affected by many confounding variables including spontaneous recovery, variation in the lesion type and extend. However, the clinical need and the paucity of effective therapies has spawned a large number of animal studies and clinical trials for SCI. In this review, we suggest that brachial plexus avulsion injury, a longitudinal spinal cord lesion, is a simpler model to test methods of spinal cord repair. We explore reconstructive techniques currently explored for the repair of brachial plexus avulsion and focus on the use of olfactory ensheathing cell transplantation as an adjunct treatment in brachial plexus repair.

Obturator Nerve Transfer as an Option for Femoral Nerve Repair

OBJECTIVE

Nerve transfers have proved to be an important addition to the armamentarium in the repair of brachial plexus lesions, but have been used sparingly for lower extremity nerve repair. Here, we present what is believed to be the first description of a successful transfer of the obturator nerve to the femoral nerve.

CLINICAL PRESENTATION

A 45-year-old woman presented with a complete femoral nerve lesion after removal of a large (15-cm) schwannoma of the retroperitoneum involving the lumbar plexus.

INTERVENTION

The obturator nerve was transferred to the distal stump of the femoral nerve in the retroperitoneal space at the inguinal ligament three months post-injury. At 2 years post-repair, the patient demonstrated 4 out of 5 return (Medical Research Council grade) of quadriceps function and was able to walk nearly normally.

CONCLUSION

In cases in which there are extensive gaps in the femoral nerve, transfer of the obturator nerve provides an option to traditional nerve graft repair.

Motoneuron survival after chronic and sequential peripheral nerve injuries in the rat

OBJECT

Surgical repair of peripheral nerves following chronic nerve injury is associated with poor axonal regeneration and outcome. An underlying possibility is that chronic injuries may increase motoneuron cell death. The hypothesis that substantial motoneuron death follows chronic and sequential nerve injuries was tested in adult rats in this study.

METHODS

Thirty adult male Lewis rats underwent bilateral multistage surgeries. At initial surgery, Fast Blue (FB) tracer was injected at a nerve-crush injury site in the right control femoral motor nerve. The left femoral motor nerve was transected at the same level and either capped to prevent regeneration (Group 1), or repaired to allow axonal regeneration and reinnervation of the target quadriceps muscle (Group 2) (15 rats in each group). After 8 weeks in 6 rats/group, the left femoral nerve was cut and exposed to FB just proximal to prior nerve capping or repair and the rats were evaluated for FB-labeled motoneuron counts bilaterally in the spinal cord (this was considered survival after initial injury). In the remaining 9 animals/group, the left nerve was recut (sequential injury), exposed to FB, and repaired to a fresh distal saphenous nerve stump to permit axonal regeneration. Following another 6 weeks, Fluoro-Gold, a second retrograde tracer, was applied to the cut distal saphenous nerve. This allowed us to evaluate the number of motoneurons that survived (maintained FB labeling) and the number of motoneurons that survived but that also regenerated axons (double labeled with FB and Fluoro-Gold).

RESULTS

A mean number of 350 and 392 FB-labeled motoneurons were found after 8 weeks of nerve injury on the right and the left sides, respectively. This indicated no significant cell death due to initial nerve injury alone. A similar number (mean 390) of motoneurons were counted at final end point at 14 weeks, indicating no significant cell death after sequential and chronic nerve injury. However, only 50% (mean 180) of the surviving motoneurons were double labeled, indicating that only half of the population regenerated their axons.

CONCLUSIONS

The hypothesis that significant motoneuron cell death occurs after chronic and or sequential nerve injury was rejected. Despite cell survival, only 50% of motoneurons are capable of exhibiting a regenerative response, consistent with our previous findings of reduced regeneration after chronic axotomy.

Use of stem cells to augment nerve injury repair

OBJECTIVE

The purpose of this review is to summarize the basic science literature related to chronic nerve injuries, and to then use this as the background to provide emerging insights into the promising role of cellular therapy for nerve injury repair.

METHODS

The literature pertinent to the experimental and clinical aspects of chronic nerve injury was reviewed, as was emerging literature and our own recent experience in using cellular therapy to repair injured nerves.

RESULTS

Peripheral nerves have the potential to regenerate axons and reinnervate end organs. Yet, outcome after peripheral nerve injury, even after nerve repair, remains relatively poor. The single most important quantitative contributor to poor motor recovery is chronic denervation of the distal nerve. Chronic denervation is common because of the often extensive injury zone that prevents any axonal outgrowth or (even if outgrowth occurs) the relatively slow rate of regeneration. As a consequence, the distal nerve remains chronically devoid of regrowing axons. In turn, prolonged denervation of Schwann cells (SCs) seems to be the critical factor that makes them unreceptive for axonal regeneration. Regenerative success was demonstrated when denervated SCs were replaced with healthy SCs cultured from a secondary nerve. This cell-replacement strategy is, however, limited in the clinical setting by the inability to obtain sufficient numbers of cells and the requirement for sacrifice of additional nerve tissue. We, along with several other groups, have therefore begun investigating stem cell therapies to improve the regenerative environment.

CONCLUSION

There are several avenues of stem cell-based approaches to peripheral nerve repair. One of these, skin-derived precursor cells, are easily accessible, autologous adult stem cells that can survive and myelinate in the peripheral nerve environment and become SC-like in their apparent differentiation.

PHRENIC NERVE TRANSFER IN THE RESTORATION OF ELBOW FLEXION IN BRACHIAL PLEXUS AVULSION INJURIES

OBJECTIVE

Phrenic nerve transfer has been used for treating lesions of the brachial plexus since 1970. Although, today, surgeons are more experienced with the technique, there are still widespread concerns about its effects on pulmonary function. This study was undertaken to evaluate the effectiveness and safety of this procedure.

METHODS

Fourteen patients with complete palsy of the upper limb were submitted to phrenic nerve transfer as part of a strategy for surgical reconstruction of their plexuses. Two patients were lost to follow-up, and 2 patients were followed for less than 2 years. Of the remaining 10 patients, 9 (90%) were male. The lesions affected both sides equally. The mean age of the patients was 24.8 years (range, 14–43 years), and the mean interval from injury to surgery was 6 months (range, 3–9 months). The phrenic nerve was always transferred to the musculocutaneous nerve, and a nerve graft (mean length, 8 cm; range, 4.5–12 cm) was necessary in all cases.

RESULTS

There was no major complication related to the surgery. Seven patients (70%) recovered functional level biceps strength (Medical Research Council grade ≥3). All of the patients exhibited a transient decrease in pulmonary function tests, but without clinical respiratory problems.

CONCLUSION

On the basis of our small series and data from the literature, we conclude that phrenic nerve transfer in well-selected patients is a safe and effective procedure for recovering biceps function.

Practical considerations concerning the use of stem cells for peripheral nerve repair

In this review the authors intend to demonstrate the need for supplementing conventional repair of the injured nerve with alternative therapies, namely transplantation of stem or progenitor cells. Although peripheral nerves do exhibit the potential to regenerate axons and reinnervate the end organ, outcome following severe nerve injury, even after repair, remains relatively poor. This is likely because of the extensive injury zone that prevents axon outgrowth. Even if outgrowth does occur, a relatively slow growth rate of regeneration results in prolonged denervation of the distal nerve. Whereas denervated Schwann cells (SCs) are key players in the early regenerative success of peripheral nerves, protracted loss of axonal contact renders Schwann cells unreceptive for axonal regeneration. Given that denervated Schwann cells appear to become effete, one logical approach is to support the distal denervated nerve environment by replacing host cells with those derived exogenously. A number of different sources of stem/precursor cells are being explored for their potential application in the scenario of peripheral nerve injury. The most promising candidate, transplant cells are derived from easily accessible sources such as the skin, bone marrow, or adipose tissue, all of which have demonstrated the capacity to differentiate into Schwann cell-like cells. Although recent studies have shown that stem cells can act as promising and beneficial adjuncts to nerve repair, considerable optimization of these therapies will be required for their potential to be realized in a clinical setting. The authors investigate the relevance of the delivery method (both the number and differentiation state of cells) on experimental outcomes, and seek to clarify whether stem cells must survive and differentiate in the injured nerve to convey a therapeutic effect. As our laboratory uses skin-derived precursor cells (SKPCs) in various nerve injury paradigms, we relate our findings on cell fate to other published studies to demonstrate the need to quantify stem cell survival and differentiation for future studies.

Skin-derived precursor cells enhance peripheral nerve regeneration following chronic denervation

While peripheral nerves demonstrate the capacity for axonal regeneration, outcome following injury remains relatively poor, especially following prolonged denervation. Since axon-deprived Schwann cells (SCs) in the distal nerve progressively lose their ability to support axonal growth, we took the approach of using skin-derived precursor cells (SKPs) as an accessible source of replacement SCs that could be transplanted into chronically denervated peripheral nerve. In this study, we employed a delayed cross-reinnervation paradigm to assess regeneration of common peroneal nerve axons into the chronically denervated rodent tibial nerve following delivery of SKP-derived SC (SKP-SCs). SKP-SC treated animals exhibited superior axonal regeneration to media controls, with significantly higher counts of regenerated motorneurons and histological recovery similar to that of immediately repaired nerve. Improved axonal regeneration correlated with superior muscle reinnervation, as measured by compound muscle action potentials and wet muscle weights. We therefore conclude that SKPs represent an easily accessible, autologous source of stem cell-derived Schwann cells that show promise in improving regeneration through chronically injured nerves.

Nerve transfers for severe nerve injury

Nerve transfers are becoming used increasingly for repair of severe nerve injures, especially brachial plexus injuries, where the proximal spinal nerve roots have been avulsed from the spinal cord. The procedure essentially involves the coaptation of a proximal foreign (donor) nerve to the distal denervated (recipient) nerve, so that the latter's end-organs will be reinnervated by the donated axons. Cortical plasticity appears to play an important physiologic role in the functional recovery of the reinnervated muscles. This article provides the indications for nerve transfer, principles for their use, and a comprehensive survey on various intraplexal and extraplexal nerves that have been used for transfer to repair clinical nerve injuries. Specific transfers to reanimate muscles denervated by the common patterns of brachial plexus are emphasized, including expected clinical outcomes based on the existing literature.

Expression of ATF3 and axonal outgrowth are impaired after delayed nerve repair

Background

A delay in surgical nerve repair results in impaired nerve function in humans, but mechanisms behind the weakened nerve regeneration are not known. Activating transcription factor 3 (ATF3) increases the intrinsic growth state of injured neurons early after injury, but the role of long-term changes and their relation to axonal outgrowth after a delayed nerve repair are not well understood. ATF3 expression was examined by immunohistochemistry in motor and sensory neurons and in Schwann cells in rat sciatic nerve and related to axonal outgrowth after transection and delayed nerve repair (repair 0, 30, 90 or 180 days post-injury). Expression of the neuronal cell adhesion molecule (NCAM), which is expressed in non-myelinating Schwann cells, was also examined.

Results

The number of neurons and Schwann cells expressing ATF3 declined and the length of axonal outgrowth was impaired if the repair was delayed. The decline was more rapid in motor neurons than in sensory neurons and Schwann cells. Regeneration distances over time correlated to number of ATF3 stained neurons and Schwann cells. Many neurofilament stained axons grew along ATF3 stained Schwann cells. If nerve repair was delayed the majority of Schwann cells in the distal nerve segment stained for NCAM.

Conclusion

Delayed nerve repair impairs nerve regeneration and length of axonal outgrowth correlates to ATF3 expression in both neurons and Schwann cells. Mainly non-myelinating Schwann cells (NCAM stained) are present in distal nerve segments after delayed nerve repair. These data provide a neurobiological basis for the poor outcomes associated with delayed nerve repair. Nerve trunks should, if possible, be promptly repaired.

FUNCTIONAL OUTCOME OF BRACHIAL PLEXUS RECONSTRUCTION AFTER TRAUMA

OBJECTIVE

Traumatic brachial plexopathies can be devastating injuries. In addition to motor and sensory deficits, pain and functional limitations can be equally debilitating. We sought to evaluate functional outcome and quality of life using statistically validated tools.

METHODS

The authors identified a consecutive series of patients who underwent surgical repair of a brachial plexus injury by the same surgeon between 1997 and 2004 at the McGill University Health Center. Participating patients were sent a package containing the Short Form 36, the Disability of the Arm, Shoulder, and Hand questionnaire, a pain visual analog scale, and an additional question on their satisfaction with the surgery. Data was recorded and analyzed using statistical software (SPSS version 13.0 for Windows; SPSS, Inc., Chicago, IL).

RESULTS

Thirty-one patients with a mean age of 32.7 years at the time of injury participated in this study. The mean time to surgery was 7.5 months, and the mean follow-up period was 42.7 months. Patients who underwent surgery within 6 months of injury scored consistently better on the Disability of the Arm, Shoulder, and Hand questionnaire (P = 0.03) and the Short Form 36 subscale scores. There was no difference between supra- and infraclavicular injuries; however, patients with root avulsion injuries were more likely to have pain (P = 0.04) and scored lower on the Disability of the Arm, Shoulder, and Hand questionnaire (P = 0.05).

CONCLUSION

Statistically validated tools can be used to evaluate the quality of life, upper extremity function, and pain after brachial plexus repairs. Root avulsion injuries and delayed surgical repair correlated negatively with functional outcomes.

Direct repair (nerve grafting), neurotization, and end-to-side neurorrhaphy in the treatment of brachial plexus injury

Object

The authors present the long-term results of nerve grafting and neurotization procedures in their group of patients with brachial plexus injuries and compare the results of “classic” methods of nerve repair with those of end-to-side neurorrhaphy.

Methods

Between 1994 and 2006, direct repair (nerve grafting), neurotization, and end-to-side neurorrhaphy were performed in 168 patients, 95 of whom were followed up for at least 2 years after surgery. Successful results were achieved in 79% of cases after direct repair and in 56% of cases after end-to-end neurotization. The results of neurotization depended on the type of the donor nerve used. In patients who underwent neurotization of the axillary and the musculocutaneous nerves, the use of intraplexal nerves (motor branches of the brachial plexus) as donors of motor fibers was associated with a significantly higher success rate than the use of extraplexal nerves (81% compared with 49%, respectively, p = 0.003). Because of poor functional results of axillary nerve neurotization using extraplexal nerves (success rate 47.4%), the authors used end-to-side neurorrhaphy in 14 cases of incomplete avulsion. The success rate for end-to-side neurorrhaphy using the axillary nerve as a recipient was 64.3%, similar to that for neurotization using intraplexal nerves (68.4%) and better than that achieved using extraplexal nerves (47.4%, p = 0.19).

Conclusions

End-to-side neurorrhaphy offers an advantage over classic neurotization in not requiring sacrifice of any of the surrounding nerves or the fascicles of the ulnar nerve. Typical synkinesis of muscle contraction innervated by the recipient nerve with contraction of muscles innervated by the donor was observed in patients after end-to-side neurorrhaphy.

Heterotopic nerve transfers: recent trends with expanding indication

There has been increasing enthusiasm for heterotopic nerve transfers for brachial plexus palsy as well as peripheral mononeural dysfunction. The concept of nerve transfer surgery is not new; the first publications on the topic date back to the early 1900s. A wide variety of potential donor nerves are available including the intercostal nerves, the spinal accessory nerve, the phrenic nerve, the ipsilateral medial pectoral nerve, partial ulnar nerve, partial median nerve, thoracodorsal nerve, radial nerve to the triceps, and the ipsilateral C7 or the contralateral C7 nerve roots. Treatment strategies include avoidance of interposed nerve grafting, isolated motor recipient nerve, early transfer, neurorrhaphy close to target motor end plates, and similar diameter between donor nerve and recipient nerves.

An anatomic study of the spinal accessory nerve: Extended harvest permits direct nerve transfer to distal plexus targets

An anatomic study of the distal spinal accessory nerve (SAN) to determine the number of myelinated axons and feasibility of posterior harvest for direct neurotization of distal targets was performed. Ten fresh human cadavers were studied. A supraclavicular approach was performed followed by a posterior approach. The relationship of the SAN to bony landmarks (T1 spinous process, acromioclavicular joint, posterolateral corner of the acromium, and angle at the superior medial border of the scapula) as well as maximal harvestable length was recorded. After posterior dissection, the SAN was mobilized and the ability to reach both anterior infraclavicular and posterior targets was assessed. Axon counts were also performed at the proximal, mid, and distal points along the course of the nerve. The posteriorly harvested SAN was identified reliably with respect to bony landmarks. When harvested posteriorly, the SAN could reach the infraclavicular part of the brachial plexus (i.e., terminal branches), and posteriorly, the suprascapular nerve (SSN) both proximal and distal to the suprascapular ligament, the latter for selective reinnervation of the infraspinatus branch. The average number of myelinated fibers at the proximal end of the nerve was 1,328 axons, at the mid-way point was 1,021 axons, and at terminal end of the nerve was 817 axons. Harvest of the SAN from a posterior approach based on these landmarks is feasible, allowing direct transfer of the nerve to the infraclavicular brachial plexus and to the SSN both proximal and distal to the suprascapular ligament, without the use of interposition nerve grafts.

Improved Technique for Harvesting the Accessory Nerve for Transfer in Brachial Plexus Injuries

Objective:

The accessory nerve is frequently used as a donor for nerve transfer in brachial plexus injuries. In currently available techniques, nerve identification and dissection is difficult because fat tissue, lymphatic vessels, and blood vessels surround the nerve. We propose a technique for location and dissection of the accessory nerve between the deep cervical fascia and the trapezius muscle.

Methods:

Twenty-eight patients with brachial plexus palsy had the accessory nerve surgically transplanted to the suprascapular nerve. To harvest the accessory nerve, the anterior border of the trapezius muscle was located 2 to 3 cm above the clavicle. The fascia over the trapezius muscle was incised and detached from the anterior surface of the muscle, initially, close to the clavicle, then proximally. The trapezius muscle was detached from the clavicle for 3 to 4 cm. The accessory nerve and its branches entering the trapezius muscle were identified. The accessory nerve was sectioned as distally as possible. To allow for accessory nerve mobilization, one or two proximal branches to the trapezius muscle were cut. The most proximal branch was always identified and preserved. A tunnel was created in the detached fascia, and the accessory nerve was passed through this tunnel to the brachial plexus.

Results:

In all of the cases, the accessory nerve was easily identified under direct vision, without the use of electric stimulation. Direct coaptation of the accessory nerve with the suprascapular nerve was possible in all patients.

Conclusion:

The technique proposed here for harvesting the accessory nerve for transfer made its identification and dissection easier.