Nerve Graft Research Articles

Effect of shorter nerve graft and selective motor branch of recipient nerve on nerve transfer surgery for elbow flexion in patients with brachial plexus injury.

The spinal accessory nerve (SAN) is commonly used as a donor nerve for reinnervation of elbow flexors in brachial plexus injury (BPI) reconstruction. However, no study has compared the postoperative outcomes between SAN-to-musculocutaneous nerve (MCN) transfer and SAN-to-nerve to biceps (NTB) transfer. Thus, this study aimed to compare the postoperative time to recovery of elbow flexors between the two groups. A total of 748 patients who underwent surgical treatment for BPI between 1999 and 2017 were retrospectively reviewed. Among them, 233 patients were treated with nerve transfer for elbow flexion. Two techniques were used to harvest the recipient nerve: the standard dissection technique and the proximal dissection technique. The postoperative motor power of elbow flexion was assessed every month for 24 months using the Medical Research Council (MRC) grading system. Survival and Cox regression analyses were used to compare the time to recovery (MRC grade ≥ 3) between the two groups. Of the 233 patients who underwent nerve transfer surgery, there were 162 patients in the MCN group and 71 patients in the NTB group. At 24 months after surgery, the MCN group had a success rate of 74.1%, and the NTB group had a success rate of 81.7% (p = 0.208). When compared with the MCN group, the NTB group had a significantly shorter median time to recovery (19 months vs 21 months, p = 0.013). Only 11.1% of patients in the MCN group regained MRC grade 4 or 5 motor power 24 months after nerve transfer surgery compared with 39.4% patients in the NTB group (p < 0.001). Cox regression analysis showed that the SAN-to-NTB transfer in combination with the proximal dissection technique was the only significant factor affecting time to recovery (HR 2.33, 95% CI 1.46-3.72; p < 0.001). SAN-to-NTB transfer in combination with the proximal dissection technique is the preferred nerve transfer option for restoration of elbow flexion in traumatic pan-plexus palsy.

Restoring the spontaneous smile through free functional muscle transfer. A systematic review and meta-analysis of the last twenty years’ experience

The recovery of the spontaneous smile has become a primary focus in facial reanimation surgery and its major determinant is the selected neurotizer. We aimed to compare the spontaneity outcomes of the most preferred neurotization methods in free functional muscle transfer for long-standing facial paralysis. The Embase, Ovid Medline, and PubMed databases were queried with 21 keywords. All clinical studies from the last 20 years reporting the postoperative spontaneity rate for specified neurotization strategies [cross-face nerve graft (CFNG), contralateral facial nerve (CLFN), motor nerve to the masseter (MNM), and dual innervation (DI)] were included. A meta-analysis of prevalence was performed using Freeman-Tukey double arcsine transformation, I2 statistic, and generic inverse variance with a random-effects model. Risk Of Bias In Non-randomized Studies of Interventions and Newcastle-Ottawa scale were used to assess bias and study quality. The literature search produced 2613 results and 473 unique citations for facial reanimation. Twenty-nine studies including 2046 patients were included in the systematic review. A meta-analysis of eligible data (1952 observations from 23 studies) showed statistically significant differences between the groups (CFNG: 0.94; 95% confidence interval [CI], 0.76-1.00, CLFN: 0.91; 95% CI, 0.49-1.00, MNM: 0.26; 95% CI, 0.05-0.54, DI: 0.98; 95% CI, 0.90-1.00, P<0.001). In pairwise comparisons, statistically significant differences were found between MNM and other neurotization strategies (P<0.001 in CFNG compared with MNM, P=0.013 for CLFN compared with MNM, P<0.001 for DI compared with MNM). DI- and CLFN-driven strategies achieved the most promising outcomes, whereas MNM showed the potential to elicit spontaneous smile at a lower extent. Our meta-analysis was limited primarily by incongruency between spontaneity assessment systems. Consensus on a standardized tool would enable more effective comparisons of the outcomes.

Chitosan/hBMSC-ECM biomimetic nerve grafts containing orienting microchannels for peripheral nerve regeneration

Bone marrow mesenchymal stem cell extracellular matrix (BMSC-ECM) can promote peripheral nerve regeneration, and microphysical orientation is essential for peripheral nerve regeneration. In this study, human-derived BMSC-ECM (hBMSC-ECM) and microchannels were introduced into chitosan-based nerve grafts (OCS/ECM) to construct dual biomimetic nerve grafts of structure and composition. For comparison, the same procedure was applied to nerve grafts containing only orienting microchannels (OCS) and autogenous nerves. In vitro experiments showed that the prepared grafts had good blood compatibility and no cytotoxicity. In vivo studies demonstrated that OCS/ECM had better histocompatibility than OCS. The introduction of microchannels allowed chitosan nerve grafts to achieve similar repair effects as autologous nerve grafts in the functional recovery of rats with sciatic nerve defects. Further introduction of hBMSC-ECM may result in synergistic effects on structure and composition that could significantly promote the rate of nerve regeneration, myelination, and target muscle recovery. Dual biomimetic nerve grafts are attractive candidates for the treatment of critical nerve defects.

Improving outcomes in traumatic peripheral nerve injuries to the upper extremity.

Peripheral nerve lesions of the upper extremity are common and are associated with devastating limitations for the patient. Rapid and accurate diagnosis of the lesion by electroneurography, neurosonography, or even MR neurography is important for treatment planning. There are different therapeutic approaches, which may show individual differences depending on the injured nerve. If a primary nerve repair is not possible, several strategies exist to bridge the gap. These may include autologous nerve grafts, bioartificial nerve conduits, or acellular nerve allografts. Tendon and nerve transfers are also of major importance in the treatment of nerve lesions in particular with long regeneration distances. As a secondary reconstruction, in addition to tendon transfers, there is also the option for free functional muscle transfer. In amputations, the prevention of neuroma is of great importance, for which different strategies exist, such as target muscle reinnervation, regenerative peripheral nerve interface, or neurotized flaps. In this article, we give an overview of the latest methods for the therapy of peripheral nerve lesions.

Utilization Trends of Nerve Autograft Alternatives for the Reconstruction of Peripheral Nerve Defects.

Autologous nerve grafting is the time-honored reconstruction method for peripheral nerve gaps. However, it is associated with donor-site morbidities. A growing number of studies have demonstrated the effective use of decellularized nerve allograft and synthetic conduits, which are convenient options with no donor deficit. The specific aim of this study was to characterize changes in practice trends for peripheral nerve defect reconstruction. The authors queried the 2015 to 2020 Merative MarketScan Databases for patients who underwent nerve autograft, allograft, synthetic conduit, and/or vein graft reconstruction. Patient demographic data (ie, location, indication) and hospital characteristics (ie, facility, provider type) were recorded. Regression analysis identified changes in trends over the study period. A total of 4331 patients underwent one or more nerve gap reconstructive procedures over the study period. Since the introduction of allograft CPT code in 2018, segmented mixed effect longitudinal modeling revealed that allograft utilization significantly increased from 21.5% to 29.6% after 2018 ( P < 0.001), whereas nerve autograft use decreased from 18.6% to 15.8% and conduit use decreased from 60% to 54.7% ( P = 0.09 and P = 0.03, respectively). When stratifying autograft by size, use of autograft less than or equal to 4 cm significantly decreased from 10.6% to 7.7% after 2018 ( P = 0.03), and autograft greater than 4 cm did not. When stratifying by state, there is heterogeneity in utilization rates of each product. After creation of a designated allograft CPT code in 2018, there was an increase in allograft use with concomitant decrease in conduit and short length autograft use, suggesting that allograft replaced a portion of procedures used in short nerve gap reconstruction.

Comparison of Outcomes of Facial Reanimation Between the Use of Cross-facial Nerve Graft and the Masseteric Nerve as the Donor Nerve for Reinnervation of Gracilis Muscle Flap Transfer.

In patients with facial paralysis, the free functional gracilis muscle transfer is preferred for facial reanimation. The choice of an adequate motor nerve to innervate the transplanted gracilis muscle is one of the procedure's key components. We present a comparative study between cross-facial nerve graft (CFNG) and masseteric nerve as donor nerves for reinnervated gracilis flap transfer in patients with complete facial paralysis. Retrospective analysis was performed on all patients with complete facial paralysis who had a free functional gracilis muscle transfer for facial reanimation between January 2014 and December 2021. Only those who received gracilis transfer reinnervated by either CFNG or masseteric nerve were included in this study. The smile excursion and lip angle were measured for evaluating the outcomes postoperatively. The inclusion criteria were met by a total of 21 free functional gracilis muscle transfers, of which 11 were innervated by CFNG and 10 by the masseteric nerve. Both surgical procedures resulted in a highly considerable smile excursion of the reanimated side and postoperative improvement of static or dynamic lip angle. Masseteric nerve coaptation led to greater smile excursion and more significant improvement of dynamic lip angle than CFNG. For patients who have complete facial paralysis, face reanimation can be successfully accomplished by free gracilis transfer reinnervated by the CFNG or the masseteric nerve. In particular, the masseteric nerve is a reliable choice for dynamic smile reanimation.

Characteristics and Management of Facial Nerve Schwannomas and Hemangiomas.

To characterize facial nerve (FN) schwannomas (FNSs) and FN hemangiomas (FNHs) and their clinical features and management strategies, and to describe the results of cable nerve grafting after FN sectioning during tumor removal. This retrospective study included 84 FNS cases and 42 FNH cases managed between July 1989 and July 2020 at a quaternary referral center for skull base pathology. Clinical details, locations, management, and results of cable nerve grafting at 1 year and during an average period of 3.12 years were evaluated. Sural nerve interpositioning was performed for patients who experienced FN paralysis for less than 1 year and underwent nerve sectioning during tumor removal. FNSs more often involved multiple segments compared with FNHs. The cerebellopontine angle and the mastoid segments were involved in 16 (19.1%) and 34 (40.5%) FNS cases, respectively; however, the cerebellopontine angle and the mastoid segments were involved in 0 and 7 (16.7%) FNH cases, respectively. Sectioned nerves of 99 patients (78.6%) were restored using interposition cable grafting. At the last follow-up evaluation, 56.3% of FNSs and 60.7% of FNHs attained House-Brackmann (HB) grade III. Lower preoperative HB grades were associated with poorer postoperative outcomes. For FNSs, the mean HB grades were 4.13 at 1 year postoperatively and 3.75 at the last follow-up evaluation (p = 0.001); however, for FNHs, the mean HB grades were 4.04 postoperatively and 3.75 at the last follow-up evaluation. Therefore, extradural coaptation yielded better outcomes. FNSs can occur along any part of the FN along its course, and FNHs are concentrated around the area of geniculate ganglion. The results of cable inter positioning grafts are better in patients with preoperative FN-HB-III or less when compared with higher grades. The outcome of the interpositioning continues to improve even after 1 year in extradural coaptation.

Micro/nano-patterns for enhancing differentiation of human neural stem cells and fabrication of nerve conduits via soft lithography and 3D printing

Topographical cues on materials can manipulate cellular fate, particularly for neural cells that respond well to such cues. Utilizing biomaterial surfaces with topographical features can effectively influence neuronal differentiation and promote neurite outgrowth. This is crucial for improving the regeneration of damaged neural tissue after injury. Here, we utilized groove patterns to create neural conduits that promote neural differentiation and axonal growth. We investigated the differentiation of human neural stem cells (NSCs) on silicon dioxide groove patterns with varying height-to-width/spacing ratios. We hypothesize that NSCs can sense the microgrooves with nanoscale depth on different aspect ratio substrates and exhibit different morphologies and differentiation fate. A comprehensive approach was employed, analyzing cell morphology, neurite length, and cell-specific markers. These aspects provided insights into the behavior of the investigated NSCs and their response to the topographical cues. Three groove-pattern models were designed with varying height-to-width/spacing ratios of 80, 42, and 30 for groove pattern widths of 1 μm, 5 μm, and 10 μm and nanoheights of 80 nm, 210 nm, and 280 nm. Smaller groove patterns led to longer neurites and more effective differentiation towards neurons, whereas larger patterns promoted multidimensional differentiation towards both neurons and glia. We transferred these cues onto patterned polycaprolactone (PCL) and PCL-graphene oxide (PCL-GO) composite ‘stamps’ using simple soft lithography and reproducible extrusion 3D printing methods. The patterned scaffolds elicited a response from NSCs comparable to that of silicon dioxide groove patterns. The smallest pattern stimulated the highest neurite outgrowth, while the middle-sized grooves of PCL-GO induced effective synaptogenesis. We demonstrated the potential for such structures to be wrapped into tubes and used as grafts for peripheral nerve regeneration. Grooved PCL and PCL-GO conduits could be a promising alternative to nerve grafting.

Surgical management and outcomes of traumatic global brachial plexus injury: A concise review and our center approach.

Global brachial plexus injury (GBPI) mainly affects adults and causes severe life-changing consequences that lead to the deterioration of patients' quality of life. Several surgical approaches have been described and reported in the literature to improve patients' functional ability. A literature review is done on PubMed/MEDLINE and Embase using specific keywords to retrieve relevant articles assessing different surgical approaches for GBPI management. Inclusion and exclusion criteria were applied, and eligible articles were included in the review. The literature survey revealed that various surgical options had been used to manage GBPI patients. In this concise review, we discuss and compare the different surgical approaches related to GBPI and its outcome in terms of restoring elbow flexion and extension, shoulder abduction, and wrist and hand function. The primary surgical intervention relies mainly on transferring single or multiple nerves with/without nerve grafts to restore the function of the targeted muscle. Different techniques using a variety of nerve donors and recipients are compared to assess the functional outcomes of each option. Moreover, further options are addressed for delayed GBPI injuries or failed nerve transfer procedures, as in free functional muscle transfer techniques. In addition, information about brachial plexus injury cases faced in our center is presented along with our center's approach to diagnosing and managing partial and GBPI cases.

Intraoperative diagnosis of facial schwannomas: a multicenter summation of clinical experience, preoperative avoidance, and intraoperative management protocol.

Preoperative differentiation of facial nerve schwannoma (FNS) from vestibular schwannoma (VS) can be challenging, and failure to differentiate between these two pathologies can result in potentially avoidable facial nerve injury. This study presents the combined experience of two high-volume centers in the management of intraoperatively diagnosed FNSs. The authors highlight clinical and imaging features that can distinguish FNS from VS and provide an algorithm to help manage intraoperatively diagnosed FNS. Operative records of 1484 presumed sporadic VS resections between January 2012 and December 2021 were reviewed, and patients with intraoperatively diagnosed FNSs were identified. Clinical data and preoperative imaging were retrospectively reviewed for features suggestive of FNS, and factors associated with good postoperative facial nerve function (House-Brackmann [HB] grade ≤ 2) were identified. A preoperative imaging protocol for suspected VS and recommendations for surgical decision-making following an intraoperative FNS diagnosis were created. Nineteen patients (1.3%) with FNSs were identified. All patients had normal facial motor function preoperatively. In 12 patients (63%), preoperative imaging demonstrated no features suggestive of FNS, with the remainder showing subtle enhancement of the geniculate/labyrinthine facial segment, widening/erosion of the fallopian canal, or multiple tumor nodules in retrospect. Eleven (57.9%) of the 19 patients underwent a retrosigmoid craniotomy, and in the remaining patients, a translabyrinthine (n = 6) or transotic (n = 2) approach was used. Following FNS diagnosis, 6 (32%) of the tumors underwent gross-total resection (GTR) and cable nerve grafting, 6 (32%) underwent subtotal resection (STR) and bony decompression of the meatal facial nerve segment, and 7 (36%) underwent bony decompression only. All patients undergoing subtotal debulking or bony decompression exhibited normal postoperative facial function (HB grade I). At the last clinical follow-up, patients who underwent GTR with a facial nerve graft had HB grade III (3 of 6 patients) or IV facial function. Tumor recurrence/regrowth occurred in 3 patients (16%), all of whom had been treated with either bony decompression or STR. Intraoperative diagnosis of an FNS during a presumed VS resection is rare, but its incidence can be reduced further by maintaining a high index of suspicion and undertaking further imaging in patients with atypical clinical or imaging features. If an intraoperative diagnosis does occur, conservative surgical management with bony decompression of the facial nerve only is recommended, unless there is significant mass effect on surrounding structures.

Plexiform Schwannoma of Digital Nerve.

Plexiform schwannoma is an uncommon benign tumour that grows in a plexiform pattern. We report a 47-year-old man with a mass on the palmar aspect of the metacarpophalangeal joint of the right index finger that had been growing gradually for more than 10 years. The mass was palpated from the distal carpal tunnel to the ulnar aspect of the proximal interphalangeal joint of the index finger, with tingling and numbness sensation. The tumour was a multinodular tumour involving the first common palmar digital nerve to the ulnar proper palmar digital nerve. It was resected and reconstructed with a sural nerve graft. Plexiform schwannoma is rare in the digital nerve, with only six cases reported. Generally, classic schwannomas can be enucleated without causing neurologic deficits; however, plexiform schwannoma may require nerve resection. There have been reports of recurrence of plexiform schwannoma; definitive resection and long-term follow-up are necessary. Level of Evidence: Level V (Therapeutic).

Updates in peripheral nerve surgery of the upper extremity: diagnosis and treatment options.

The loss of function resulting from peripheral nerve injuries confers a significant burden to the patient and society. The treatment of peripheral nerve injuries requires an accurate diagnosis and formulation of a functional reconstructive plan. Advances in peripheral nerve imaging complement electrodiagnostic studies, and provide us with detailed information regarding the status of nerve injury, repair, and regeneration in order to prognosticate recovery and determine the need for surgical intervention. When direct nerve repair is not possible, the methods for bridging a nerve gap are the nerve autograft, allograft and conduit. While current research supports the use of conduits and nerve allografts for shorter nerve gaps, the nerve autograft still remains the gold standard for bridging a nerve gap. When direct nerve repair or nerve grafting fails, or is anticipated to be insufficient, nerve transfers are an alternative for reconstruction. Knowledge of axonal counts, upper limb innervation patterns, location and clustering of upper limb peripheral nerves allows for the design of new nerve transfers. The options of nerve transfers for radial, ulnar and median nerve injuries are outlined, as well as their outcomes. Nerve transfers are an attractive option for restoring motor and sensory function while minimizing donor site morbidity. However, one must consider their limitations, and preserve donor sites for secondary tendon transfer options. This article presents the latest information regarding the imaging of peripheral nerves, methods to bridge a nerve gap, and nerve transfers to aid the peripheral nerve surgeon in choosing a reconstructive plan.

An effective technique in nerve defect repair: Analysis of sliding epineural tube graft technique and comparison with autologous nerve graft and turn-over epineural tube graft techniques

An effective technique in nerve defect repair: Analysis of sliding epineural tube graft technique and comparison with autologous nerve graft and turn-over epineural tube graft techniques

Neurovascular injury from supracondylar fractures in children: a 10-year experience of 762 cases.

We evaluated the management of supracondylar paediatric fractures at our institution over a 10-year period in this retrospective cohort study. In total, 762 children with a supracondylar fracture were treated. The mean age of injury was 5.2 years. The incidence of documented nerve and/or vascular injury was 8.3%. A total of 26 patients had early plastic surgeon involvement; of these, 25 had an open exploration. Eight patients required vein grafting for brachial artery reconstruction for intimal tears. There was one nerve rupture requiring repair and 12 children underwent neurolysis. There were 17 late referrals to the plastic surgery service, of which three were explored (two neurolysis, one neuroma resection and sural nerve grafting). In all cases of nerve injury, the deficit took 7.9 months to recover, indicating a more significant injury than neurapraxia. Early exploration of supracondylar fractures allows direct visualization of the extent of neurovascular injury and immediate intervention.Level of evidence: IV.

Retrograde peripheral nerve regeneration from sensory to motor pathways in rats: a new experimental concept in nerve repair

ABSTRACT Background The polarity of nerve grafts does not interfere with axon growth. Our goal was to investigate whether axons can regenerate in a retrograde fashion within sensory pathways and then extend into motor pathways, leading to muscle reinnervation. Methods Fifty-four rats were randomized into four groups. In Group 1, the ulnar nerve was connected end-to-end to the superficial radial nerve after neurectomy of the radial nerve in the axilla. In Group 2, the ulnar nerve was connected end-to-end to the radial nerve distal to the humerus; the radial nerve then was divided in the axilla. In Group 3, the radial nerve was divided in the axilla, but no nerve reconstruction was performed. In Group 4, the radial nerve was crushed in the axilla. Over 6 months, we behaviorally assessed the recovery of toe spread in the right operated-upon forepaw by lifting the rat by its tail and lowering it onto a flat surface. Six months after surgery, rats underwent reoperation, nerve transfers were tested electrophysiologically, and the posterior interosseous nerve (PIN) was removed for histological evaluation. Results Rats in the crush group recovered toe spread between 5 and 8 days after surgery. Rats with nerve transfers demonstrated electrophysiological and histological findings of nerve regeneration but no behavioral recovery. Conclusions Ulnar nerve axons regrew into the superficial radial nerve and then into the PIN to reinnervate the extensor digitorum communis. We were unable to demonstrate behavioral recovery because rats cannot readapt to cross-nerve transfer.

Using the Neuromuscular Junction Cellular Response to Predict Functional Recovery after Nerve Grafting in a Mouse Experimental Model.

Functional recovery following peripheral nerve injury worsens with increasing time of denervation before repair. Denervated muscle undergoes progressive atrophy that limits the extent to which motor endplates can be reinnervated. The aims of this study were to assess nerve injuries reconstructed at different time points and to identify various neural and muscle-based markers to predict functional outcome, including an in-depth look at the neuromuscular junction (NMJ). Adult wild-type C57BL/6J mice underwent surgery on the sciatic nerve and were divided into 5 groups: (1) nerve cut and repaired, (2) acute (nerve cut and immediately repaired with a 1-cm autograft), (3) subacute (nerve grafted 2 weeks after injury), (4) delayed (nerve grafted 4 weeks after injury), (5) nerve cut and capped. Functional recovery was measured by treadmill and electrodiagnostic tests. Nerves were harvested for histologic evaluation, and leg muscles, for histologic evaluation and NMJ immunofluorescent staining of motor endplate innervation and terminal Schwann cells (tSCs). The delayed graft group performed worst in nearly all parameters. The subacute graft group shared more similarities with the acute group, especially the tSC response (subacute, 48%; acute, 51%) and motor endplate innervation pattern (subacute, 75%; acute, 72%). The only parameters to elucidate differences were muscle weight and motor endplate fragmentation. Traditional axon count failed to capture differences among the 3 groups. The tSC activity and NMJ innervation pattern can be used as predictive markers of functional recovery that capture differences among acute, subacute, and delayed nerve injuries. The tSC activity at the NMJ displayed by immunohistochemical methods can accurately reflect target muscle innervation over time. This can be used as a predictor of reinnervation when timing of nerve reconstruction is delayed, which can be a critically needed tool in clinical scenarios.

Evaluation of Long-Term Surgical and Patient-Reported Outcomes after Pediatric Facial Reanimation.

Outcomes of pediatric facial reanimation beyond 10 years are not known. This cross-sectional study evaluated long-term surgical and patient-reported outcomes of adults who underwent smile reconstruction as children with either a cross-face nerve graft (CFNG) or masseter nerve transfer at least 10 years previously. Commissure excursion was quantified with FACE-Gram software at 3 time points: preoperatively, early postoperatively within 2 years, and at long-term follow-up. Patient-reported outcomes were evaluated with validated questionnaires (Facial Clinimetric Evaluation Scale, FACE-Q 1.0) and thematic analysis of semistructured interviews. Results are reported as median (interquartile range [IQR]). A total of 42 patients were included (26 women and 16 men). Median long-term follow-up was 19.3 years (IQR, 8.8 years) for CFNG and 17.6 years (IQR, 5.8 years) for masseter nerve transfer. For both groups, commissure excursion increased significantly from preoperative to early postoperative time points and remained stable at long-term follow-up (P < 0.0001). Commissure excursion at long-term follow-up between the 2 groups was not significantly different (CFNG, 5.0 mm [IQR, 9.4 mm]; masseter nerve transfer, 8.4 mm [IQR, 4.1 mm]); P > 0.05). For patient-reported outcomes, median Facial Clinimetric Evaluation Scale score was 72 of 100, and 95% of respondents agreed with the statement "I am pleased with the result" on the FACE-Q 1.0. Overall quality of life was rated at 7 of 10 or greater by 97% of participants, and all participants would recommend the surgery to other children. Pediatric facial reanimation with CFNG or masseter nerve transfer reliably improves commissure excursion with longevity beyond 10 years. Adult patients report overall high satisfaction and social functioning.

Mechanisms underlying the cell-matrixed nerve grafts repairing peripheral nerve defects

Decellularized extracellular matrix (dECM), with its distinct biological properties, has gained significant attention as a natural biomaterial. Leveraging its potentials, we successfully developed a three-dimensional matrix-based oriented nerve graft by encapsulating a fibrous scaffold with multilayered conformationally intact and biologically active human bone marrow mesenchymal stem cell-derived decellularized extracellular matrix (hBMSC-dECM). Convincingly, the hBMSC-dECM group exhibited comparable functional recoveries to the autograft group by postoperative week 12. In the comprehensive analysis, the molecular regulations in the hBMSC-dECM group were more intricate and nuanced compared to the autograft group. Nevertheless, both groups displayed similar molecular regulatory processes in terms of vascularization and extracellular matrix. Notably, the hBMSC-dECM group demonstrated sustained high levels of regulation in axon and myelin regeneration at week 12, while the immunomodulation returned to the normal levels after peaking at week 2. Collectively, our findings illustrated the satisfactory construction of a cell-matrixed nerve graft that established a microenvironment conducive to nerve regeneration, and elucidated the distinct molecular regulation patterns and characteristics associated with different repair modes.

Phrenic Nerve Transfer to Musculocutaneous Nerve: An Anatomical and Histological Study.

To restore elbow flexor muscle function in case of traumatic brachial plexus avulsion, the phrenic nerve transfer to the musculocutaneous nerve has become part of clinical practice. The nerve transfer can be done by means of video-assisted thoracic surgery without nerve graft or via supraclavicular approach in combination with an autograft. This study focuses on a detailed microscopic and macroscopic examination of the phrenic nerve. It will allow a better interpretation of existing clinical results and, thus, serve as a basis for future clinical studies. An anatomical study was conducted on 28 body donors of Caucasian origin (female n = 14, male n = 14). A sliding caliper and measuring tape were used to measure the diameter and length of the nerves. Sudan black staining was performed on 15 µm thick cryostat sections mounted on glass slides and the number of axons was determined by the ImageJ counting tool. In 23 individuals, the phrenic nerve could be examined on both sides. In 5 individuals, however, only one side was examined. Thus, a total of 51 nerves were examined. The mean length of the left phrenic nerves (33 cm (29-38 cm)) was significantly longer compared to the mean length of the right phrenic nerves (30 cm (24-33 cm)) (p < 0.001). Accessory phrenic nerves were present in 9 of 51 (18%) phrenic nerves. The mean number of phrenic nerves axons at the level of the first intercostal space in body donors with a right accessory phrenic nerve was significantly greater compared to the mean number of phrenic nerves axons at the same level in body donors without a right accessory phrenic nerve (3145 (range, 2688-3877) vs. 2278 (range, 1558-3276)), p = 0.034. A negative correlation was registered between age and the nerve number of axons in left (0.742, p < 0.001) and right (-0.273, p = 0.197) phrenic nerves. The mean distance from the upper edge of the ventral ramus of the fourth cervical spinal nerve to the point of entrance of the musculocutaneous nerve between the two parts of the coracobrachialis muscle was 19 cm (range, 15-24 cm) for the right and 20 cm (range, 15-25 cm) for the left arm. If an accessory phrenic nerve is available, it presumably should be spared. Thus, in that case, a supraclavicular approach in combination with a nerve graft would probably be of advantage.

Surgical Approach to Brachial Plexus Root Repair: A Case Study with Literature Review

This article presents a clinical case study of a 32-year-old patient with brachial plexus trauma following a motorcycle accident, as well as a review of the relevant literature on surgical approaches to brachial plexus root repair. The case study highlights the patient's symptoms, initial assessments, further investigations, surgical management, and post-operative results. The literature review synthesizes the main surgical approaches used in the repair of brachial plexus injuries, highlighting direct root repair techniques, nerve grafts, nerve transfers, as well as their results and complications. This study contributes to the body of knowledge on surgical options for brachial plexus injuries, highlighting the importance of post-operative rehabilitation and long- term follow-up in improving patients' functional recovery.