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

Nerve Autograft: Preservation of a Lost Art

Nerve autografts involve the transplantation of a segment of the patient's own nerve to bridge a nerve gap. Autografts provide biological compatibility, support for axonal regeneration, and the ability to provide an anatomic scaffold for regrowth that other modalities may not match. Disadvantages of the autograft include donor site morbidity and the extra operative time needed to harvest the graft. Nevertheless, nerve autografts such as the sural nerve remain the gold standard in reconstructing nerve gaps, but a multitude of factors need to be favorable in order to garner reliable, consistent outcomes.

Therapeutic Electrical Stimulation for Surgeons: How it Works and How to Apply it

Electrical stimulation (ES) enhances peripheral nerve inherent regeneration capacity by promoting accelerated axonal outgrowth and selectivity toward appropriate motor and sensory targets. These effects lead to significantly improved functional outcomes and shorter recovery time. Electrical stimulation can be applied intra-operatively or immediately post-operatively. Active clinical trials are looking into additional areas of application, length of stimulation, and functional outcomes.

The Evolution of the Reconstructive Strategy for Elbow Flexion for Acute C5, C6 Brachial Plexus Injuries over Two Decades

BACKGROUND

 Over the course of the past two decades, improved outcomes following brachial plexus reconstruction have been attributed to newer nerve transfer techniques. However, key factors aside from surgical techniques have brought improved consistency to elbow flexion techniques in the latter decade.

METHODS

 One-hundred seventeen patients who underwent brachial plexus reconstruction from 1996 to 2006 were compared with 120 patients from 2007 to 2017. All patients were evaluated preoperatively and postoperatively to assess the recovery time and of elbow flexion strength.

RESULTS

 In the first decade, nerve reconstruction methods included proximal nerve grafting, intercostal nerve transfer, and Oberlin-I transfer. In the second decade, newer methods such as double fascicular transfer and ipsilateral C7 division transfer to the anterior division of upper trunk were introduced. About 78.6% of the first decade group versus 87.5% of the second decade group were able to reach M3 flexion strength (p = 0.04), with shorter time recovery to reach M3 in the 2nd decade. About 59.8% of the first decade group versus 65.0% of the second decade group were able to reach M4 (p = 0.28), but no significant difference in time of recovery. In both groups, the double fascicular nerve transfer had the highest impact when introduced in the second decade. More precise magnetic resonance imaging (MRI) techniques helped to diagnose the level of injury, the roots involved and evaluate the health of the donor nerves in preparation for intraplexus transfer.

CONCLUSION

 In addition to modified techniques in nerve transfers, (1) MRI-assisted evaluation and surgical exploration of the roots with (2) more judicious choice of donor nerves for primary nerve transfer were factors that ensured reliable and outcomes in the second decade.

Brain plasticity in neonatal brachial plexus palsies: quantification and comparison with adults' brachial plexus injuries

PURPOSE

To compare two populations of brachial plexus palsies, one neonatal (NBPP) and the other traumatic (NNBPP) who underwent different nerve transfers, using the plasticity grading scale (PGS) for detecting differences in brain plasticity between both groups.

METHODS

To be included, all patients had to have undergone a nerve transfer as the unique procedure to recover one lost function. The primary outcome was the PGS score. We also assessed patient compliance to rehabilitation using the rehabilitation quality scale (RQS). Statistical analysis of all variables was performed. A p ≤ 0.050 set as criterion for statistical significance.

RESULTS

A total of 153 NNBPP patients and 35 NBPP babies (with 38 nerve transfers) met the inclusion criteria. The mean age at surgery of the NBPP group was 9 months (SD 5.42, range 4 to 23 months). The mean age of NNBPP patients was 22 years (SD 12 years, range 3 to 69). They were operated around sixth months after the trauma. All transfers performed in NBPP patients had a maximum PGS score of 4. This was not the case for the NNBPP population that reached a PGS score of 4 in approximately 20% of the cases. This difference was statistically significant (p < 0.001). The RQS was not significantly different between groups.

CONCLUSION

We found that babies with NBPP have a significantly greater capacity for plastic rewiring than adults with NNBPP. The brain in the very young patient can process the changes induced by the peripheral nerve transfer better than in adults.

Fascicular shifting in the reconstruction of brachial plexus injuries: an anatomical and clinical evaluation

OBJECTIVE

Until recently, autologous sensory nerve grafting has remained the gold-standard technique in peripheral nerve reconstruction. However, there are several disadvantages to these grafts, such as donor site morbidity, limited availability, and a qualitative mismatch. Building on this shortage, a new concept, the fascicular shift procedure, was proposed and successfully demonstrated nerve regeneration in a rat nerve injury model. This approach involves harvesting a fascicular group distal to a peripheral nerve injury and shifting it to bridge the defect. The present study aimed to evaluate the clinical applicability of this technique in brachial plexus reconstruction.

METHODS

The supra- and infraclavicular nerves of the brachial plexus were bilaterally explored in 18 formalin-fixed cadaveric specimens. Following dissection, their fascicular shifting potential was evaluated. The medial antebrachial cutaneous and sural nerves were investigated and used as references for the required cross-sectional area of potential nerve grafts. Furthermore, 29 brachial plexus injuries, which qualified for surgical repair, were subjected to retrospective analysis. The intraoperatively measured lengths of the harvested and ultimately transplanted nerve grafts served as a basis to assess graft requirements in brachial plexus lesions.

RESULTS

The transplanted nerve grafts measured a total length of 51.9 ± 28.1 cm in brachial plexus injuries. The individual inserted nerve grafts averaged 10.3 ± 5.1 cm. In the anatomical exploration, the ulnar and median nerves qualified for fascicular shifting. Their fascicular graft lengths measured 26.6 ± 2.5 cm and 24.8 ± 5.2 cm, respectively. The long thoracic, suprascapular, musculocutaneous, thoracodorsal, and axillary nerves were not suitable for fascicular shifting. The sensory graft length of the medial antebrachial cutaneous nerve measured 20.6 ± 3.4 cm.

CONCLUSIONS

In the surgical reconstruction of brachial plexus injuries, fascicular shifting of the ulnar and median nerves provides sufficient donor material. Even though potential donor length is limited in the radial nerve, it may still help to expand the surgical armamentarium in selected clinical scenarios. Overall, the fascicular shift procedure presents a novel alternative to allow modality-matched grafting in the reconstruction of large proximal nerve defects and was found to be an attractive option in brachial plexus reconstruction.

Restoring musculocutaneous nerve function in 146 brachial plexus operations – a retrospective analysis

INTRODUCTION

A brachial plexus lesion is a devastating injury often affecting young, male adults after traffic accidents. Therefore, surgical restoration of elbow flexion is critical for establishing antigravity movement of the upper extremity. We analyzed different methods for musculocutaneous reconstruction regarding outcome.

METHODS

We conducted a retrospective analysis of 146 brachial plexus surgeries with musculocutaneous reconstruction performed at our department from 2013 to 2017. Demographic data, surgical method, donor and graft nerve characteristics, body mass index (BMI) as well as functional outcome of biceps muscle based on medical research council (MRC) strength grades before and after surgery were analyzed. Multivariate analysis was performed using SPSS.

RESULTS

Oberlin reconstruction was the procedure performed most often (34.2%, n = 50). Nerve transfer and autologous repair showed no significant differences regarding outcome (p = 0.599, OR 0.644 CI95% 0.126-3.307). In case of nerve transfers, we found no significant difference whether reconstruction was performed with or without a nerve graft (e.g. sural nerve) (p = 0.277, OR 0.619 CI95% 0.261-1.469). Multivariate analysis identifies patient age as a strong predictor for outcome, univariate analysis indicates that nerve graft length > 15 cm and BMI of > 25 could lead to inferior outcome. When patients with early recovery (n = 19) are included into final evaluation after 24 months, the general success rate of reconstructions is 62,7% (52/83).

CONCLUSION

Reconstruction of musculocutaneous nerve after brachial plexus injury results in a high rate of clinical improvement. Nerve transfer and autologous reconstruction both show similar results. Young age was confirmed as an independent predictor for better clinical outcome. Prospective multicenter studies are needed to further clarify.

Research hotspots and trends for axon regeneration (2000-2021): a bibliometric study and systematic review

BACKGROUND

Axons play an essential role in the connection of the nervous system with the rest of the body. Axon lesions often lead to permanent impairment of motor and cognitive functions and the interaction with the outside world. Studies focusing on axon regeneration have become a research field with considerable interest. The purpose of this study is to obtain an overall perspective of the research field of axonal regeneration and to assist the researchers and the funding agencies to better know the areas of greatest research opportunities.

METHODS

We conducted a bibliometric analysis and Latent Dirichlet Allocation (LDA) analysis of the global literature on axon regeneration based on the Web of Science (WoS) over the recent 22 years, to address the research hotspots, publication trends, and understudied areas.

RESULTS

A total of 21,018 articles were included, which in the recent two decades has increased by 125%. Among the top 12 hotspots, the annual productions rapidly increased in some topics, including axonal regeneration signaling pathway, axon guidance cues, neural circuits and functional recovery, nerve conduits, and cells transplant. Comparatively, the number of studies on axon regeneration inhibitors decreased. As for the topics focusing on nerve graft and transplantation, the annual number of papers tended to be relatively stable. Nevertheless, the underlying mechanisms of axon regrowth have not been completely uncovered. A lack of notable research on the epigenetic programs and noncoding RNAs regulation was observed. The significance of cell-type-specific data has been highlighted but with limited research working on that. Functional recovery from neuropathies also needs further studies.

CONCLUSION

The last two decades witnessed tremendous progress in the field of axon regeneration. There are still a lot of challenges to be tackled in translating these technologies into clinical practice.

Age correlation in upper brachial plexus injury patients undergoing nerve transfer surgeries

•A patient's age can be a critical factor influencing the outcome following upper brachial plexus injury (BPI) reconstruction.•The favorable factor being younger patients with short denervation period.•In older patients early and more aggressive management for an optimal outcome.•This study supports the various correlation of age with the outcomes of upper brachial plexus reconstruction surgery.

Risk prediction model for unsuccessful elbow flexion recovery after nerve transfer surgery in patients with brachial plexus injury

OBJECTIVE

Nerve transfer surgery has been a mainstay treatment of brachial plexus injury, with varying success rates. Patients undergoing unsuccessful surgery are left with a useless limb for at least 2 years. Preoperative prediction has become a topic of interest to avoid an unsuccessful nerve transfer surgery. This study aimed to find strong predictive factors and develop a prediction model for unsuccessful functional elbow flexion recovery 2 years after a nerve transfer surgery in patients with brachial plexus injury.

METHODS

This retrospective study reviewed the medical records of 987 patients with traumatic brachial plexus injury who underwent brachial plexus surgery by five hand and microsurgery surgeons at a single tertiary care referral center from December 2001 to July 2018. Four hundred thirty-three patients were eligible for analysis. Patient demographic data, injury factors, surgical details, and postoperative factors were collected. Multivariable logistic regression was used to identify strong prognostic factors for unsuccessful nerve transfer surgery for elbow flexion. A simplified model was developed by rounding the coefficient to the nearest 0.5 score or an integer. Both original and simplified models were validated using the Hosmer-Lemeshow goodness-of-fit test and bootstrapping.

RESULTS

A full, original prognostic model from a stepwise backward logistic regression consisted of a BMI ≥ 23 kg/m2 (p = 0.015), smoking (p = 0.046), total arm-type injury (p = 0.033), donor nerve (p < 0.001), associated upper-extremity fracture (p = 0.013), and associated ipsilateral vascular injury (p = 0.095). The areas under the receiver operating characteristic curve of the original and simplified models were 0.765 and 0.766, respectively. The Hosmer-Lemeshow test showed good agreement of predicted and observed probability of the original (p = 0.49) and simplified (p = 0.19) models. Bootstrapping estimated an average optimism (1.9%) in the original model and minimal optimism (0.1%) in the simplified model.

CONCLUSIONS

The prediction model for failed elbow flexion recovery after nerve transfer surgery in traumatic brachial plexus injury was developed with good predictive value and internal validity. An alternative treatment, i.e., primary free functioning muscle transfer, should be offered in preoperative counseling in cases of a very high risk of failure.

Nerve transfers for brachial plexus injuries: grading of volitional control

OBJECTIVE

After brachial plexus injuries (BPIs), nerve transfers are used to restore lost muscle function. Brain plasticity underlies the process of regaining volitional control, which encompasses disconnection of the original donor nerve-related programs and reconnection to acceptor nerve programs. To the authors' knowledge, the levels of disconnection and reconnection have never been studied systematically. In this study, the authors developed a novel 4-point plasticity grading scale (PGS) and assessed the degree of volitional control achieved, identifying clinical correlations with this score.

METHODS

Patients with BPI who underwent a phrenic, spinal accessory, median, and/or ulnar fascicle nerve transfer to restore biceps and deltoid function were asked to maximally contract their target muscle as follows: 1) by using only the donor nerve program, and 2) by activating the target muscle while consciously trying to avoid using the donor nerve, with assessment each time of the Medical Research Council (MRC) scale grade for muscle strength. The authors' PGS was used to rate the level of volitional control achieved. PGS grade 1 represented the lowest independent volitional control, with MRC grade 4 obtained in response to the donor command and MRC grade 0 in response to the acceptor command (minimum brain plasticity), whereas PGS grade 4 was no noticeable contraction in response to the donor command and MRC grade 4 in response to the acceptor command (maximum brain plasticity).

RESULTS

In total, 153 patients were studied. For biceps restoration, the phrenic nerve was used as a donor in 44 patients, the spinal accessory nerve in 40 patients, and the median and/or ulnar fascicles in 44 patients. A triceps branch was used to restore deltoid function in 25 patients. The level of volitional control achieved was PGS grade 1 in 1 patient (0.6%), grade 2 in 21 patients (13.7%), grade 3 in 103 patients (67.3%), and grade 4 in 28 patients (18.3%). The median PGS grade did not differ significantly between the four donor nerves. No correlations were observed between age, time from BPI to surgery, duration of follow-up, or compliance with rehabilitation and PGS grade.

CONCLUSIONS

Just around 20% of the authors' patients developed a complete disconnection of the donor program along with complete independent control over the reinnervated muscle. Incomplete disconnection was present in the vast majority of the patients, and the level of disconnection and control was poor in approximately 15% of patients. Brain plasticity underlies patient ability to regain volitional control after a nerve transfer, but this capacity is limited.

Acellular nerve grafts supplemented with induced pluripotent stem cell-derived exosomes promote peripheral nerve reconstruction and motor function recovery

Peripheral nerve injury is a great challenge in clinical work due to the restricted repair gap and weak regrowth ability. Herein, we selected induced pluripotent stem cells (iPSCs) derived exosomes to supplement acellular nerve grafts (ANGs) with the aim of restoring long-distance peripheral nerve defects. Human fibroblasts were reprogrammed into iPSCs through non-integrating transduction of Oct3/4, Sox2, Klf4, and c-Myc. The obtained iPSCs had highly active alkaline phosphatase expression and expressed Oct4, SSEA4, Nanog, Sox2, which also differentiated into all three germ layers in vivo and differentiated into mature peripheral neurons and Schwann cells (SCs) in vitro. After isolation and biological characteristics of iPSCs-derived exosomes, we found that numerous PKH26-labeled exosomes were internalized inside SCs through endocytotic pathway and exhibited a proliferative effect on SCs that were involved in the process of axonal regeneration and remyelination. After that, we prepared ANGs via optimized chemical extracted process to bridge 15 mm long-distance peripheral nerve gaps in rats. Owing to the promotion of iPSCs-derived exosomes, satisfactory regenerative outcomes were achieved including gait behavior analysis, electrophysiological assessment, and morphological analysis of regenerated nerves. Especially, motor function was restored with comparable to those achieved with nerve autografts and there were no significant differences in the fiber diameter and area of reinnervated muscle fibers. Taken together, our combined use of iPSCs-derived exosomes with ANGs demonstrates good promise to restore long-distance peripheral nerve defects, and thus represents a cell-free strategy for future clinical applications.

•

IPSCs-derived exosomes provide a novel cell-free strategy with the regenerative power of iPSCs.

•

ANGs supplemented with iPSCs-derived exosomes show enhanced peripheral repair and accelerated motor functional recovery.

•

IPSCs-derived exosomes provide equivalent histological morphology to autologous nerve transplantation.

Nerve transfer with 3D-printed branch nerve conduits

Background

Nerve transfer is an important clinical surgical procedure for nerve repair by the coaptation of a healthy donor nerve to an injured nerve. Usually, nerve transfer is performed in an end-to-end manner, which will lead to functional loss of the donor nerve. In this study, we aimed to evaluate the efficacy of 3D-printed branch nerve conduits in nerve transfer.

Methods

Customized branch conduits were constructed using gelatine-methacryloyl by 3D printing. The nerve conduits were characterized both in vitro and in vivo. The efficacy of 3D-printed branch nerve conduits in nerve transfer was evaluated in rats through electrophysiology testing and histological evaluation.

Results

The results obtained showed that a single nerve stump could form a complex nerve network in the 3D-printed multibranch conduit. A two-branch conduit was 3D printed for transferring the tibial nerve to the peroneal nerve in rats. In this process, the two branches were connected to the distal tibial nerve and peroneal nerve. It was found that the two nerves were successfully repaired with functional recovery.

Conclusions

It is implied that the two-branch conduit could not only repair the peroneal nerve but also preserve partial function of the donor tibial nerve. This work demonstrated that 3D-printed branch nerve conduits provide a potential method for nerve transfer.

Reconstruction of C5-C8 (T1 Hand) Brachial Plexus Paralysis in a Series of 52 Patients

PURPOSE

A C5-C8 brachial plexus root injury, also known as a T1 hand, is associated with paralysis of shoulder abduction or external rotation and elbow flexion, accompanied by variable elbow, wrist, thumb, or finger extension deficits. We report the results of reconstruction for C5-C8 brachial plexus paralysis in 52 patients operated upon within 12 months of injury and having at least 24 months of follow-up.

METHODS

We considered surgery to be indicated if, by the fifth month after trauma, shoulder abduction and external rotation and elbow flexion remained paralyzed. Root grafting was possible in 35% of the patients and was performed concomitantly with nerve transfers. Shoulder motion was reconstructed by transferring the spinal accessory to the suprascapular nerve. Elbow flexion was restored by transferring fascicles from either the median or ulnar nerve to the biceps motor branch. When needed, elbow extension was reconstructed by transferring 1 motor branch of the flexor carpi ulnaris to the triceps lower medial head motor branch. Wrist extension was restored by transferring the distal anterior interosseous nerve to the extensor carpi radialis brevis motor branch.

RESULTS

Within 12 months of injury, we observed preserved or spontaneous recovery of elbow, wrist, finger, and thumb extension in 25%, 12%, 50%, and 68% of patients, respectively. After surgical reconstruction, improved range of motion for shoulder, elbow flexion, and wrist extension scoring at least M3 was present in 90% of our patients. All 10 patients in whom a motor branch of the flexor carpi ulnaris was used for triceps reconstruction recovered elbow extension, while flexor carpi ulnaris function was preserved.

CONCLUSIONS

In approximatively 90% of our patients, distal nerve transfers resulted in functional recovery of shoulder abduction, elbow flexion or extension, and wrist extension.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Evidence-Based Approach to Timing of Nerve Surgery: A Review

ABSTRACT

Events causing acute stress to the health care system, such as the COVID-19 pandemic, place clinical decisions under increased scrutiny. The priority and timing of surgical procedures are critically evaluated under these conditions, yet the optimal timing of procedures is a key consideration in any clinical setting. There is currently no single article consolidating a large body of current evidence on timing of nerve surgery. MEDLINE and EMBASE databases were systematically reviewed for clinical data on nerve repair and reconstruction to define the current understanding of timing and other factors affecting outcomes. Special attention was given to sensory, mixed/motor, nerve compression syndromes, and nerve pain. The data presented in this review may assist surgeons in making sound, evidence-based clinical decisions regarding timing of nerve surgery.

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.

Brain changes after peripheral nerve repair: limitations of neuroplasticity

Neuroplasticity is the capacity of the central nervous system to adapt to external or internal stimuli. It is being increasingly recognized as an important factor which contributes to the successful outcome of nerve transfers. Other much more well-known factors are the number of axons that cross the coaptation site, the interval between trauma and repair, and age. Neuroplasticity is mediated by synaptic and neurotransmitter changes which underlie activation of previously existing but low-active connections in the brain. Dendritic sprouting and axonal elongation might also take place, but is likely less prominent. We review different factors that play a role in neuroplasticity and functional regeneration after specific nerve transfers. These factors include, amongst others, the distance between cortical areas of the donor and receptor neurons; the presence versus absence of pre-existing low-active inter-neuronal connections; gross versus fine movement restoration; rehabilitation; brain trauma and also very important: the age. The potential for plastic adaptation should be taken into consideration if the surgical strategy and post-operative rehabilitation are planned, as its influence on results cannot be denied.

Adipose tissue stem cells in peripheral nerve regeneration-In vitro and in vivo

After peripheral nerve injury, Schwann cells (SCs) are crucially involved in several steps of the subsequent regenerative processes, such as the Wallerian degeneration. They promote lysis and phagocytosis of myelin, secrete numbers of neurotrophic factors and cytokines, and recruit macrophages for a biological debridement. However, nerve injuries with a defect size of >1 cm do not show proper tissue regeneration and require a surgical nerve gap reconstruction. To find a sufficient alternative to the current gold standard-the autologous nerve transplant-several cell-based therapies have been developed and were experimentally investigated. One approach aims on the use of adipose tissue stem cells (ASCs). These are multipotent mesenchymal stromal cells that can differentiate into multiple phenotypes along the mesodermal lineage, such as osteoblasts, chondrocytes, and myocytes. Furthermore, ASCs also possess neurotrophic features, that is, they secrete neurotrophic factors like the nerve growth factor, brain-derived neurotrophic factor, neurotrophin-3, ciliary neurotrophic factor, glial cell-derived neurotrophic factor, and artemin. They can also differentiate into the so-called Schwann cell-like cells (SCLCs). These cells share features with naturally occurring SCs, as they also promote nerve regeneration in the periphery. This review gives a comprehensive overview of the use of ASCs in peripheral nerve regeneration and peripheral nerve tissue engineering both in vitro and in vivo. While the sustainability of differentiation of ASCs to SCLCs in vivo is still questionable, ASCs used with different nerve conduits, such as hydrogels or silk fibers, have been shown to promote nerve regeneration.

Comparison Between Supraclavicular Versus Video-Assisted Intrathoracic Phrenic Nerve Section for Transfer in Patients With Traumatic Brachial Plexus Injuries: Case Series

BACKGROUND

The phrenic nerve has been extensively reported to be a very powerful source of transferable axons in brachial plexus injuries. The most used technique used is supraclavicular sectioning of this nerve. More recently, video-assisted thoracoscopic techniques have been reported as a good alternative, since harvesting a longer phrenic nerve avoids the need of an interposed graft.

OBJECTIVE

To compare grafting vs phrenic nerve transfer via thoracoscopy with respect to mean elbow strength at final follow-up.

METHODS

A retrospective analysis was conducted among patients who underwent phrenic nerve transfer for elbow flexion at 2 centers from 2008 to 2017. All data analysis was performed in order to determine statistical significance among the analyzed variables.

RESULTS

A total of 32 patients underwent supraclavicular phrenic nerve transfer, while 28 underwent phrenic nerve transfer via video-assisted thoracoscopy. Demographic characteristics were similar in both groups. A statistically significant difference in elbow flexion strength recovery was observed, favoring the supraclavicular phrenic nerve section group against the intrathoracic group (P = .036). A moderate though nonsignificant difference was observed favoring the same group in mean elbow flexion strength. Also, statistical differences included patient age (P = .01) and earlier time from trauma to surgery (P = .069).

CONCLUSION

Comparing supraclavicular sectioning of the nerve vs video-assisted, intrathoracic nerve sectioning to restore elbow flexion showed that the former yielded statistically better results than the latter, in terms of the percentage of patients who achieve at least level 3 MRC strength at final follow-up. Furthermore, larger scale prospective studies assessing the long-term effects of phrenic nerve transfers remain necessary.

Electrical stimulation to enhance peripheral nerve regeneration: Update in molecular investigations and clinical translation

Peripheral nerve injuries are common and frequently result in incomplete functional recovery even with optimal surgical treatment. Permanent motor and sensory deficits are associated with significant patient morbidity and socioeconomic burden. Despite substantial research efforts to enhance peripheral nerve regeneration, few effective and clinically feasible treatment options have been found. One promising strategy is the use of low frequency electrical stimulation delivered perioperatively to an injured nerve at the time of surgical repair. Possibly through its effect of increasing intraneuronal cyclic AMP, perioperative electrical stimulation accelerates axon outgrowth, remyelination of regenerating axons, and reinnervation of end organs, even with delayed surgical intervention. Building on decades of experimental evidence in animal models, several recent, prospective, randomized clinical trials have affirmed electrical stimulation as a clinically translatable technique to enhance functional recovery in patients with peripheral nerve injuries requiring surgical treatment. This paper provides an updated review of the cellular physiology of electrical stimulation and its effects on axon regeneration, Level I evidence from recent prospective randomized clinical trials of electrical stimulation, and ongoing and future directions of research into electrical stimulation as a clinically feasible adjunct to surgical intervention in the treatment of patients with peripheral nerve injuries.

A single session of brief electrical stimulation enhances axon regeneration through nerve autografts

Nerve graft reconstruction of gap defects may result in poor clinical outcomes, particularly with long regeneration distances. Electrical stimulation (ES) of nerves may improve outcomes in such patients. A single session of ES at 20 Hz for 1 h significantly enhances axon regeneration in animals and human subjects after nerve crush or nerve transection and repair. The objectives of this study were to evaluate if ES enhances axon regeneration through nerve grafts and if there is added benefit of a second, delayed session of ES (serial ES) on axon regeneration as compared to a single session only of ES. In female rats, a gap defect was created in the hindlimb common peroneal (CP) nerve and immediately reconstructed with a 10 mm nerve autograft (Experiment 1) or a 20 mm nerve autograft (Experiment 2). In Experiment 1, rats were randomized to 1 h of CP nerve ES or sham stimulation. In Experiment 2, rats were randomized to control (sham ES + sham ES), single ES (ES + sham ES), or serial ES (ES + ES), which consisted of an initial 1 h session of either ES or sham stimulation of the CP nerve, followed by a second 1 h session of ES or sham stimulation of the CP nerve 4 weeks later. In both experiments, after a 6 week period of nerve regeneration, CP neurons that had regenerated axons distal to the autograft were retrograde labelled for enumeration, and the CP nerve distal to the autograft was harvested for histomorphometry. In Experiment 1, rats that received CP nerve ES had statistically significantly more motor (p < .05) and sensory (p < .05) neurons that regenerated axons distal to the 10 mm nerve autograft, with more myelinated axons on histomorphometry (p < .001). Similarly, in Experiment 2, significantly more motor (p < .01) and sensory (p < .05) neurons regenerated axons distal to the 20 mm nerve autograft after a single session or two sessions of CP nerve ES. There was no significant difference in the number of regenerated motor or sensory neurons between rats with 20 mm CP nerve autografts receiving either one or two sessions of CP nerve ES (p > .05). In conclusion, a single session of ES enhances axon regeneration following nerve autografting with no added effect of a second, delayed session of ES. These findings support previous studies in animals and humans of the robust effect of a single session of ES in promoting nerve regeneration following injury and repair.

Outcomes of Elbow Flexion Reconstruction in Patients Older than 50 with Traumatic Brachial Plexus Injury

BACKGROUND

There is controversy regarding the effectiveness of brachial plexus reconstruction for elbow function in older patients, as reported outcomes are generally poor. The purpose of this study was to evaluate elbow function outcomes in patients older than 50.

METHODS

Fifty-eight patients older than 50 years underwent nerve grafting, transfers, or free functioning muscle transfer to improve elbow function after traumatic brachial plexus injury. Patients were evaluated preoperatively and postoperatively for elbow flexion strength and range of motion; Disabilities of the Arm, Shoulder and Hand scores; pain; concomitant trauma; severity of trauma; and type of reconstruction.

RESULTS

The average age of the patients was 57.8 years, and the average follow-up was 24.0 months. The average modified British Medical Research Council elbow flexion grade improved significantly from 0.26 to 2.63. Thirty-three patients (60 percent) achieved functional flexion greater than or equal to M3 postoperatively, compared to zero patients preoperatively. There was no correlation between age and modified British Medical Research Council grade. Active elbow range of motion improved significantly postoperatively, with no effect of age on flexion motion. More patients achieved greater than or equal to M3 flexion with nerve transfers (69 percent) compared to free functioning muscle transfer (43 percent). Patients had worse outcomes with high-energy injuries. The mean Disabilities of the Arm, Shoulder and Hand score decreased from 51.5 to 49.6 postoperatively, and the average pain score decreased from 5.0 to 4.3.

CONCLUSION

Brachial plexus reconstruction for elbow function in patients older than 50 can yield useful flexion.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Increasing Nerve Autograft Length Increases Senescence and Reduces Regeneration

BACKGROUND

Nerve grafting with an autograft is considered the gold standard. However, the functional outcomes of long (>3 cm) nerve autografting are often poor. The authors hypothesized that a factor contributing to these outcomes is the graft microenvironment, where long compared to short autografts support axon regeneration to different extents.

METHODS

A rat sciatic nerve defect model was used to compare regeneration in short (2 cm) and long (6 cm) isografts. Axon regeneration and cell populations within grafts were assessed using histology, retrograde labeling of neurons regenerating axons, immunohistochemistry, quantitative reverse transcriptase polymerase chain reaction, and electron microscopy at 4 and/or 8 weeks.

RESULTS

At 8 weeks, for distances of both 1 and 2 cm from the proximal coaptation (equivalent regenerative distance), long isografts had reduced numbers of regenerated fibers compared with short isografts. Similarly, the number of motoneurons regenerating axons was reduced in the presence of long isografts compared with short isografts. Considering the regenerative microenvironments between short and long isografts, cell densities and general populations within both short and long isografts were similar. However, long isografts had significantly greater expression of senescence markers, which included senescence-associated β-galactosidase, p21, and p16, and distinct chromatin changes within Schwann cells.

CONCLUSIONS

This study shows that axon regeneration is reduced in long compared with short isografts, where long isografts contained an environment with an increased accumulation of senescent markers. Although autografts are considered the gold standard for grafting, these results demonstrate that we must continue to strive for improvements in the autograft regenerative environment.

Outcomes of shoulder abduction after nerve surgery in patients over 50 years following traumatic brachial plexus injury

PURPOSE

There is controversy regarding the effectiveness of brachial plexus reconstruction in older patients, as outcomes are thought to be poor. The aim of this study is to determine the outcomes of shoulder abduction obtained after nerve reconstruction in patients over the age of 50 years and factors related to success.

METHODS

Forty patients over the age of 50 years underwent nerve surgery to improve shoulder function after a traumatic brachial plexus injury. Patients were evaluated pre- and postoperatively for shoulder abduction strength and range of motion (ROM); Disability of the Arm, Shoulder and Hand (DASH) scores; pain; age bracket; gender; body mass index (BMI); delay from injury to operation; concomitant trauma; severity of trauma; and type of reconstruction.

RESULTS

The average age was 58.2 years (range 50-77 years) with an average follow-up of 18.8 months. The average modified British Medical Research Council (BMRC) shoulder abduction grade improved significantly from 0.23 to 2.03 (p < 0.005). Fourteen patients achieved functional shoulder abduction of ≥ M3 postoperatively. There was no correlation between age or age range stratification and BMRC grade or those obtaining useful shoulder abduction ≥ M3. Active shoulder abduction improved significantly from 18.25° to 40.64°, with no difference on the basis of age or age stratification. There were improved modified BMRC grades with nerve transfers versus nerve grafts. Less patients achieved ≥ M3 function if surgery was delayed > 6 months. The mean DASH score decreased from 45.3 to 40.7 postoperatively, and the average pain score decreased from 3.7 to 3.0. Patients with a higher postoperative BMRC grade for shoulder abduction had improved postoperative DASH scores and VAS for pain (p = 0.011 and 0.005, respectively).

CONCLUSION

Brachial plexus nerve reconstruction for shoulder abduction in patients over the age of 50 years can yield useful BMRC scores and ROM, and age should not be used to exclude nerve reconstruction in these patients.

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.

Timing of rehabilitation in children with obstetric upper trunk brachial plexus palsy

OBJECTIVES

The initiation timing of rehabilitation in children with obstetric brachial plexus palsy is controversial. The aim of the present study is to evaluate the effectiveness of rehabilitation timing to the functional outcomes of patients with obstetric upper trunk brachial plexus palsy.

MATERIAL AND METHODS

Twenty-nine patients, who did not previously received any rehabilitation programme but attended our outpatient clinic, were included for the study. The electrophysiological findings, obstetric characteristics, and demographic features of the patients were recorded. The range of motion (ROM) of shoulders, elbows, and wrists and the strength of the muscles associated with these joints were evaluated. Modified Mallet Scale (MMS) was used for functional evaluation. A 4-week rehabilitation programme was performed twice at 2-month intervals. Patients were divided into three groups according to their ages as follows: 1-3 years old (group 1), 3-5 years old (group 2), and 5-7 years old (group 3). The ROMs, muscle strengths, and MMS scores of the patients were all evaluated.

RESULTS

Two out of 29 patients were female (6.9%) and 27 were male (93.1%). All 29 patients had right upper extremity palsy (100%). The MMS scores, ROMs, and muscle strength of the upper extremities had improved in all the groups following the standardized rehabilitation programme.

CONCLUSIONS

A rehabilitation programme is the best choice of treatment before surgical procedures in patients with mild to moderate obstetric upper trunk brachial plexus palsy regardless of age and the initiation time.

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.

Age as a Predictor of Long-Term Results in Patients with Brachial Plexus Palsies Undergoing Surgical Repair

BACKGROUND

Among other factors, like the time from trauma to surgery or the number of axons that reach the muscle target, a patient's age might also impact the final results of brachial plexus surgery.

OBJECTIVE

To identify (1) any correlations between age and the 2 outcomes: elbow flexion strength and shoulder abduction range; (2) whether childhood vs adulthood influences outcomes; and (3) other baseline variables associated with surgical outcomes.

METHODS

Twenty pediatric patients (under age 20 yr) who had sustained a traumatic brachial plexus injury were compared against 20 patients, 20 to 29 yr old, and 20 patients, 30 yr old or older. Univariate, univariate trend, and correlation analyses were conducted with patient age, time to surgery, type of injury, and number of injured roots included as independent variables.

RESULTS

A statistically significant trend toward decreasing mean strength in elbow flexion, progressing from the youngest to oldest age group, was observed. This linear trend persisted when subjects were subdivided into 4 age groups (&lt;20, 20-29, 30-39, ≥40). There were no differences by age group in final shoulder abduction range or the percentage achieving a good shoulder outcome.

CONCLUSION

Our data suggest that age is somehow linked to the outcomes of brachial plexus surgery with respect to elbow flexion, but not shoulder abduction strength. Increasing age is associated with steadily worsening elbow flexion outcomes, perhaps indicating the need for earlier surgery and/or more aggressive repairs in older patients.

Current concepts in plasticity and nerve transfers: relationship between surgical techniques and outcomes

OBJECTIVE Neuroplasticity is analyzed in this article as the capacity of the CNS to adapt to external and internal stimuli. It is being increasingly recognized as an important factor for the successful outcome of nerve transfers. Better-known factors are the number of axons that cross the coaptation site, the time interval between trauma and repair, and age. Neuroplasticity is mediated initially by synaptic and neurotransmitter changes. Over time, the activation of previously existing but lowly active connections in the brain cortex contributes further. Dendritic sprouting and axonal elongation might also take place but are less likely to be prominent. METHODS The authors reviewed different factors that play roles in neuroplasticity and functional regeneration after specific nerve transfers. RESULTS The authors found that these different factors include, among others, the distance between cortical areas of the donor and receptor neurons, the presence versus absence of preexisting lowly active interneuronal connections, gross versus fine movement restoration, rehabilitation, brain trauma, and age. CONCLUSIONS The potential for plasticity should be taken into consideration by surgeons when planning surgical strategy and postoperative rehabilitation, because its influence on results cannot be denied.

The phrenic nerve as a donor for brachial plexus injuries: is it safe and effective? Case series and literature analysis

BACKGROUND

Controversy exists surrounding the use of the phrenic nerve for transfer in severe brachial plexus injuries. The objectives of this study are: (1) to present the experience of the authors using the phrenic nerve in a single institution; and (2) to thoroughly review the existing literature to date.

METHODS

Adult patients with C5-D1 and C5-C8 lesions and a phrenic nerve transfer were retrospectively included. Patients with follow-up shorter than 18 months were excluded. The MRC muscle strength grading system was used to rate the outcome. Clinical repercussions relating to sectioning of the phrenic nerve were studied. An intense rehabilitation program was started after surgery, and compliance to this program was monitored using a previously described scale. Statistical analysis was performed with the obtained data.

RESULTS

Fifty-one patients were included. The mean time between trauma and surgery was 5.7 months. Three-quarters of the patients had C5-D1, with the remainder C5-C8. Mean post-operative follow-up was 32.5 months A MRC of M4 was achieved in 62.7% patients, M3 21.6%, M2 in 3.9%, and M1 in 11.8%. The only significant differences between the two groups were in graft length (9.8 vs. 15.1 cm, p = 0.01); and in the rehabilitation compliance score (2.86 vs. 2.00, p = 0.01).

CONCLUSIONS

Results of phrenic nerve transfer are predictable and good, especially if the grafts are short and the rehabilitation is adequate. It may adversely affect respiratory function tests, but this rarely correlates clinically. Contraindications to the use of the phrenic nerve exist and should be respected.

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.

Alternatives to sural nerve grafts in the upper extremity

BACKGROUND

The sural nerve is the most common nerve graft donor despite requiring a second operative limb and causing numbness of the lateral foot. The purposes of this study were to review our experience using nerve autografts in upper extremity nerve reconstruction and develop recommendations for donor selection.

METHODS

A retrospective case series study was performed of all consecutive patients undergoing nerve grafting procedures for upper extremity nerve injuries over an 11-year period (2001-2012).

RESULTS

Eighty-six patients received 109 nerve grafts over the study period. Mean patient age was 42.9 ± 18.3 years; 57 % were male. There were 51 median (59 %), 26 ulnar (30 %), 14 digital (13 %), 13 radial (16 %), and 3 musculocutaneous (4 %) nerve injuries repaired with 99 nerve autografts (71 from upper extremity, 28 from lower extremity). Multiple upper extremity nerve autograft donors were utilized, including the medial antebrachial cutaneous nerve (MABC), third webspace branch of median, lateral antebrachial cutaneous nerve (LABC), palmar cutaneous, and dorsal cutaneous branch of ulnar nerve. By using an upper-extremity donor, a second operative limb was avoided in 58 patients (67 %), and a second incision was avoided in 26 patients (30 %). The frequency of sural graft use declined from 40 % (n = 17/43) to 11 % (n = 7/64).

CONCLUSIONS

Our algorithm for selecting nerve graft material has evolved with our growing understanding of nerve internal topography and the drive to minimize additional incisions, maximize ease of harvest, and limit donor morbidity. This has led us away from using the sural nerve when possible and allowed us to avoid a second operative limb in two thirds of the cases.

Influence of body mass index on the outcome of brachial plexus surgery: are there any differences between elbow and shoulder results?

BACKGROUND

Body mass index (BMI) has recently been identified as a predictor of outcomes following reconstructive surgery of shoulder palsies. In this study, we sought to determine if the same holds true for the reconstruction of elbow flexion.

METHODS

Forty patients who had undergone partial ulnar-to-biceps nerve transfer (Oberlin's procedure) for shoulder palsy were assessed and compared against 18 previously reported patients who had undergone reconstruction for elbow palsies. The British Medical Research Council (BMRC) scale and an index dividing shoulder abduction strength in the affected arm by healthy arm were recorded. All patients had undergone surgery within 12 months of injury and had ≥ 12 months of follow-up.

RESULTS

M4 or M3 biceps strength was obtained in 90 % of patients. Final strength on the affected side averaged 5.8 kg, versus 20.2 kg on the normal side, for a mean recovery index score of 0.30. In this sample of 40 patients, BMI did not predict percentage strength or BMRC grade recovery. Neither did age, number of roots involved, the affected side, nor time to surgery. Comparing patients with elbow versus shoulder reconstruction, there were no differences, except that patients undergoing Oberlin's procedure had a statistically longer duration of time between injury and surgical repair (7.4 vs 5.1 months, p < 0.006).

CONCLUSIONS

Our data suggest that proximal muscle re-innervation is functionally more dependent upon BMI than distal re-innervation, likely because proximal muscles must support the weight of the entire extremity, while more distal muscles do not. BMI should be taken into consideration when planning surgery.

Long-nerve grafts and nerve transfers demonstrate comparable outcomes for axillary nerve injuries

PURPOSE

To compare the functional and EMG outcomes of long-nerve grafts to nerve transfers for complete axillary nerve palsy.

METHODS

Over a 10-year period at a single institution, 14 patients with axillary nerve palsy were treated with long-nerve grafts and 24 patients were treated with triceps-to-axillary nerve transfers by the same surgeon (S.W.W.). Data were collected prospectively at regular intervals, beginning before surgery and continuing up to 11 years after surgery. Prior to intervention, all patients demonstrated EMG evidence of complete denervation of the deltoid. Deltoid recovery (Medical Research Council [MRC] grade), shoulder abduction (°), improvement in shoulder abduction (°), and EMG evidence of deltoid reinnervation were compared between cohorts.

RESULTS

There were no significant differences between the long-nerve graft cohort and the nerve transfer cohort with respect to postoperative range of motion, deltoid recovery, improvement in shoulder abduction, or EMG evidence of deltoid reinnervation.

CONCLUSIONS

These data demonstrate that outcomes of long-nerve grafts for axillary nerve palsy are comparable with those of modern nerve transfers and question a widely held belief that long-nerve grafts do poorly. When healthy donor roots or trunks are available, long-nerve grafts should not be overlooked as an effective intervention for the treatment of axillary nerve injuries in adults with brachial plexus injuries.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

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.

A literature review of intercostal-to-musculocutaneous-nerve transfers in brachial plexus injury patients: Does body mass index influence results in Eastern versus Western countries?

Background:

A wide range of results have appeared in the literature for intercostal nerve transfers in brachial plexus patients. Oriental countries generally have a lower body mass index (BMI) than their occidental counterparts. We analyzed published series of intercostal nerve transfers for elbow reinnervation to determine if a difference in outcomes exists between Eastern and Western series that could be inversely related to BMI.

Methods:

A PubMed search was conducted. Inclusion criteria were: (1) time from trauma to surgery <12 months, (2) minimum follow-up one year, (3) intercostal to musculocutaneous nerve transfer the only surgical procedure performed to reestablish elbow flexion, and (4) males comprising more than 75% of cases. Two groups were created: Series from western countries, including America, Europe, and Africa; and series from Asia. Pearson correlation analysis was performed to assess for the degree of correlation between percent responders and mean national BMI.

Results:

A total of 26 series were included, 14 from western countries and 12 from Eastern countries, encompassing a total of 274 and 432 surgical cases, respectively. The two groups were almost identical in mean age, but quite different in mean national BMI (26.3 vs. 22.5) and in the percentage of patients who achieved at least a Medical Research Council (MRC) level 3 (59.5% vs. 79.3%). Time from trauma to surgery was slightly shorter in Eastern (3.4 months) versus Western countries (5.0 months).

Conclusions:

The percentage of responders to intercostal to musculocutaneous nerve transfer was inversely correlated with the mean national BMI among male residents of the country where the series was performed.

Upper brachial plexus injuries: grafts vs ulnar fascicle transfer to restore biceps muscle function

BACKGROUND

Nerve transfers or graft repairs in upper brachial plexus palsies are 2 available options for elbow flexion recovery.

OBJECTIVE

To assess outcomes of biceps muscle strength when treated either by grafts or nerve transfer.

METHODS

A standard supraclavicular approach was performed in all patients. When roots were available, grafts were used directed to proximal targets. Otherwise, a distal ulnar nerve fascicle was transferred to the biceps branch. Elbow flexion strength was measured with a dynamometer, and an index comparing the healthy arm and the operated-on side was developed. Statistical analysis to compare both techniques was performed.

RESULTS

Thirty-five patients (34 men) were included in this series. Mean age was 28.7 years (standard deviation, 8.7). Twenty-two patients (62.8%) presented with a C5-C6 injury, whereas 13 patients (37.2%) had a C5-C6-C7 lesion. Seventeen patients received reconstruction with grafts, and 18 patients were treated with a nerve transfer from the ulnar nerve to the biceps. The trauma to surgery interval (mean, 7.6 months in both groups), strength in the healthy arm, and follow-up duration were not statistically different. On the British Medical Research Council muscle strength scale, 8 of 17 (47%) patients with a graft achieved ≥ M3 biceps flexion postoperatively, vs 16 of 18 (88%) post nerve transfers (P = .024). This difference persisted when a muscle strength index assessing improvement relative to the healthy limb was used (P = .031).

CONCLUSION

The results obtained from ulnar nerve fascicle transfer to the biceps branch were superior to those achieved through reconstruction with grafts.