Effect of Veau Class on Levator Veli Palatini Muscle Composition

OBJECTIVE

To examine levator veli palatini muscle composition in patients with nonsyndromic cleft palate and investigate the impact of Veau class.

DESIGN

Prospective cohort study.

SETTING

Tertiary care academic hospital.

PATIENTS/PARTICIPANTS

Thirteen patients with nonsyndromic cleft palate were recruited.

INTERVENTIONS

During primary palatoplasty, a sample of levator veli palatini muscle was excised and prepared for histological analysis.

MAIN OUTCOME MEASURES

Fat and collagen content were determined utilizing Oil Red and Sirius red stains, respectively, while muscle fiber cross-sectional areas were calculated from H&E-stained samples, with analysis using histomorphometric methods. Immunofluorescent staining of myosin heavy chain isoforms was performed.

RESULTS

Patients underwent repair at 10.8 months of age (interquartile range [IQR] 10.2-12.9). Fat content of the levator veli palatini muscle was low in both groups, ranging from 0% to 5.2%. Collagen content ranged from 8.5% to 39.8%; neither fat nor collagen content showed an association with Veau classes. Mean muscle fiber cross-sectional area decreased with increasing Veau class, from 808 µm2 (range 692-995 µm2) in Veau II to 651 µm2 (range 232-750 µm2) in Veau III (P = .02). There was also a nonsignificant decrease in proportion of type I muscle fibers with increasing Veau class (44.3% [range 31.4%-84.4%] in Veau II vs 35.3% [range 17.4%-61.3%] in Veau III).

CONCLUSIONS

Muscle fiber area in levator veli palatini muscles decreases in Veau III clefts in comparison to Veau II. The impact of these differences in velopharyngeal dysfunction requires further analysis of a larger cohort.

Impact of Neighborhood Deprivation and Social Vulnerability on Outcomes and Interventions in Patients with Cleft Palate

OBJECTIVE

To examine whether neighborhood disadvantage impacts length of follow-up, interventions, and outcomes for patients with cleft palate.

DESIGN

Retrospective cohort.

SETTING

Cleft Palate Craniofacial Institute Database at St. Louis Children's Hospital.

PATIENTS/PARTICIPANTS

Patients with cleft palate following in St. Louis Children's Hospital Cleft Palate Multidisciplinary Team Clinic.

INTERVENTIONS

Primary palatoplasty between 2012-2017. Patients were divided into quartiles across area deprivation index (ADI) and social vulnerability index (SVI), two validated, composite metrics of neighborhood disadvantage, to examine whether living in neighborhoods from different deprivation quartiles impacts outcomes of interest.

MAIN OUTCOME MEASURE

Follow-up through age 5, surgeries and surgical complications, speech, developmental, and behavioral outcomes.

RESULTS

205 patients were included. 39% of patients belonged to the most deprived ADI quartile, while 15% belonged to the most vulnerable SVI quartile. There were no differences between ADI or SVI quartiles in number of operations received (p ≥ 0.40). Patients in the most deprived ADI quartile were significantly more likely to have speech/language concerns (OR 2.32, 95% CI [1.20-4.89], p = 0.01). Being in a more vulnerable SVI quartile was associated with developmental delay (OR 2.29, 95% CI [1.04-5.15], p = 0.04). ADI and SVI quartile did not impact risk of loss to follow-up in the isolated and combined cleft lip and palate subgroups (p ≥ 0.21).

CONCLUSIONS

Neighborhood disadvantage impacts speech and developmental outcomes in patients with cleft palate despite comparable length of follow-up in multidisciplinary team clinic.

Impact of a Palatal Fistula After Cleft Palate Repair on Velopharyngeal Closure

PURPOSE

A palatal fistula is an adverse outcome of cleft palate repair. It is unknown if a palatal fistula will influence velopharyngeal closure, even after repair of the fistula. This study determines the effect of a soft palate fistula on the risk of developing velopharyngeal insufficiency.

METHODS

A retrospective chart review was conducted on patients who underwent primary cleft palate repair between 2000 and 2015, with complete records at 4 years of age. Fistulae involving the secondary palate following primary palatoplasty were classified as the soft or hard palate. A forced-entry multivariate logistic regression model was built to detect predictors of velopharyngeal dysfunction.

RESULTS

Records of 329 patients were analyzed with a mean follow-up of 8.7 years. A palatal fistula was identified in 89/329 patients (27%) and 29/329 patients (9%) underwent an independent fistula repair. Of the patients with fistula, 44% were located in the hard palate only and 56% had soft palate involvement. Compared to patients without a fistula, rates of velopharyngeal dysfunction were significantly higher in patients with a fistula involving the soft palate (OR 3.875, CI: 1.964-7.648, P < .001) but not in patients with a hard palate fistula (OR 1.140, CI: 0.497-2.613, P = .757). Veau class, age at primary repair, and syndromic status were not significant predictors of VPI (0.128≤P ≤ .975).

CONCLUSIONS

A palatal fistula involving the soft palate is a significant predictor for development of velopharyngeal dysfunction after primary palatoplasty. Surgical intervention, at the time of fistula repair, to add vascularized tissue may be indicated to prophylactically decrease the risk of velopharyngeal dysfunction.

A feasibility study transplanting macrophages to a segmental nerve injury

INTRODUCTION/AIMS

Promoting regeneration after segmental nerve injury repair is a challenge, but improving angiogenesis could be beneficial. Macrophages facilitate regeneration after injury by promoting angiogenesis. Our aim in this study was to evaluate the feasibility and effects of transplanting exogenous macrophages to a segmental nerve injury.

METHODS

Bone marrow-derived cells were harvested from donor mice and differentiated to macrophages (BMDM), then suspended within fibrin hydrogels to facilitate BMDM transplantation. BMDM survival was characterized in vitro. The effect of this BMDM fibrin hydrogel construct at a nerve injury site was assessed using a mouse sciatic nerve gap injury. Mice were equally distributed to "fibrin+Mφ" (fibrin hydrogels containing culture medium and BMDM) or "fibrin" hydrogel control (fibrin hydrogels containing culture medium alone) groups. Flow cytometry (n = 3/group/endpoint) and immunohistochemical analysis (n = 5/group/endpoint) of the nerve gap region were performed at days 3, 5, and 7 after repair.

RESULTS

Incorporating macrophage colony-stimulating factor (M-CSF) improved BMDM survival and expansion. Transplanted BMDM survived for at least 7 days in a nerve gap (~40% retained at day 3 and ~15% retained at day 7). From transplantation, macrophage quantities within the nerve gap were elevated when comparing fibrin+Mφ with fibrin control (~25% vs. 3% at day 3 and ~14% vs. 6% at day 7). Endothelial cells increased by about fivefold within the nerve gap, and axonal extension into the nerve gap increased almost twofold for fibrin+Mφ compared with fibrin control.

DISCUSSION

BMDM suspended within fibrin hydrogels at a nerve gap do not impair regeneration.

Multidisciplinary Optimal Outcomes Reporting and Team Clinic Retention in Isolated Nonsyndromic Cleft Palate

OBJECTIVE

Optimal Outcomes Reporting was recently introduced to categorize outcomes after cleft palate repair. We seek to propose an expanded version of Optimal Outcomes Reporting and to determine if correlation exists between the expanded outcomes and persistence with team care follow-up through age 9.

DESIGN

Retrospective cohort study.

SETTING

Cleft team at large pediatric hospital.

PATIENTS

Patients with isolated nonsyndromic cleft palate (n = 83) born from 2001-2012.

MAIN OUTCOME MEASURES

Patients who continued to present at age 5 or greater were assessed for optimal outcomes. Optimal outcomes were: surgery - no fistula or velopharyngeal insufficiency; otolaryngology - no obstructive sleep apnea or signs of chronic middle ear disease; audiology - no hearing loss; speech-language pathology - no assessed need for speech therapy.

RESULTS

Of the 83 patients identified, 41 were assessed for optimal outcomes. Optimal outcome in any discipline was not associated with follow-up through age 9 (0.112 ≤ p ≤ 0.999). For all disciplines, the group with suboptimal outcomes had a higher proportion of patients from geographic areas in the most disadvantaged quartile of social vulnerability index, with the strongest association in the group with suboptimal speech outcome (OR 6.75, 95% CI 0.841-81.1).

CONCLUSIONS

Optimal outcomes and retention in team clinic were not statistically significantly associated, but clinically relevant associations were found between patients in the most disadvantaged quartile of social vulnerability and their outcomes. A patient-centered approach, including caregiver education about long-term care for patients with cleft palate, would allow for enhanced resource utilization to improve retention for patients of concern.

Buccal Myomucosal Flap Repair for Velopharyngeal Dysfunction

BACKGROUND

Velopharyngeal dysfunction (VPD) is the incomplete separation of the nasal and oral cavities during speech sound production that can persist following primary palatoplasty. Surgical technique used in management of VPD (palatal re-repair versus pharyngeal flap or sphincter pharyngoplasty) is often dictated by the preoperative velar closing ratio and closure pattern. Recently, buccal flaps have increased in popularity in management of VPD. Here, the authors investigate the effectiveness of buccal myomucosal flaps in the treatment of VPD.

METHODS

A retrospective review was performed of all patients undergoing secondary palatoplasty with buccal flaps at a single center between 2016 and 2021. Preoperative and postoperative speech outcomes were compared. Speech assessments included perceptual examinations, graded on a four-point scale of hypernasality, and speech videofluoroscopy, from which the velar closing ratio was obtained.

RESULTS

A total of 25 patients underwent buccal myomucosal flap procedures for VPD at a median of 7.1 years after primary palatoplasty. Patients had significantly increased velar closing postoperatively (95% versus 50%; P < 0.001) and improved speech scores ( P < 0.001). Three patients (12%) had continued hypernasality postoperatively. There were no occurrences of obstructive sleep apnea.

CONCLUSIONS

Treatment of VPD with buccal myomucosal flaps leads to improved speech outcomes without the risk of obstructive sleep apnea. Traditionally, palatal re-repair techniques have been used for smaller preoperative velopharyngeal gaps; however, the addition of buccal flaps allows for anatomical velar muscle correction for patients with a larger preoperative velopharyngeal gap.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

What do patients want to know about gender-affirming surgery? Analysis of common patient concerns and online health materials

PURPOSE

Patients considering gender-affirming surgery often utilize online health materials to obtain information about procedures. However, the distribution of patient concerns and content of online resources for gender-affirming surgery have not been examined. We aimed to quantify and comprehensively analyze the most searched questions of patients seeking gender-affirming surgery and to examine the quality and readability of associated websites providing the answers.

METHODS

Questions were extracted from Google using the search phrases "gender-affirming surgery," "transgender surgery," "top surgery," and "bottom surgery." Questions were categorized by topic and average search volume per month was determined. Websites linked to questions were categorized by type, and quality of the health information was evaluated utilizing the DISCERN instrument (16-80). Readability was assessed with the Flesch Reading Ease Score and Flesch-Kincaid Grade Level.

RESULTS

Ninety questions and associated websites were analyzed. Common questions were most frequently answered by academic websites (30%). Topics included cost (27%), technical details of surgery (23%), and preoperative considerations (11%). Median (interquartile range) DISCERN score across all website categories was 42 (18). The mean readability was of a 12th-grade level, well above the grade six reading level recommended by the American Medical Association.

CONCLUSIONS

Online gender-affirming surgery materials are difficult to comprehend and of poor quality. To enhance patient knowledge, informed consent, and shared decision-making, there is a substantial need to create understandable and high-quality online health information for those seeking gender-affirming surgery.

Improving the Care of Our Patients: Twenty-Three Years of the James Barrett Brown Resident Research Day

BACKGROUND

James Barrett Brown was one of the founders of Plastic and Reconstructive Surgery as a specialty in the United States. Susan Mackinnon started the James Barrett Brown Resident Research Day in 1997 in his honor to serve as an annual opportunity for trainees to present their research to the Division and a visiting contemporary leader in plastic surgery. We sought to determine the proportion of Resident Research Day projects that have progressed to publication.

METHODS

Available internal records from 1998 to 2019 were used to identify presenters and projects. Academic productivity of presenters was estimated with the h-index from the Scopus database.

RESULTS

One hundred forty-five students, residents, and fellows presented 276 projects at Resident Research Day from 1998 to 2019. These presentations were associated with 144 unique peer-reviewed publications, representing 52% of the presented projects. They were published an average of 1.8 years after presentation, and the presenter was the first or last author on 67% of them. The current average h-index of trainees who published at least 1 project (8.3) is significantly higher than the h-index of those who did not (5.0, P < 0.001).

CONCLUSIONS

The James Barrett Brown Resident Research Day not only honors the legacy of Brown but also enhances scholarly activity of trainees. The opportunity to present and publish research teaches project planning, implementation, and data analysis, followed by manuscript preparation and the publication process. This important skill set can provide the foundation for the academic careers of future leaders in plastic surgery.

Loss of Gata1 decreased eosinophils, macrophages, and type 2 cytokines in regenerating nerve and delayed axon regeneration after a segmental nerve injury

The immune system has garnered attention for its role in peripheral nerve regeneration, particularly as it pertains to regeneration across segmental injuries. Previous work demonstrated that eosinophils are recruited to regenerating nerve and express interleukin-4, amongst potential cytokines. These results suggest a direct role for eosinophils in promoting nerve regeneration. Therefore, we further considered eosinophils roles in nerve regeneration using a segmental nerve injury and Gata1 knockout (KO) mice, which are severely eosinophil deficient, compared to wild-type BALB/c mice (WT). Mice receiving a sciatic nerve gap injury demonstrated distinct cytokine expression and leukocytes within regenerating nerve. Compared to controls, Gata1 KO regenerated nerves contained decreased expression of type 2 cytokines, including Il-5 and Il-13, and decreased recruitment of eosinophils and macrophages. At this early time point during ongoing regeneration, the macrophages within Gata1 KO nerves also demonstrated significantly less M2 polarization compared to controls. Subsequently, motor and sensory axon regeneration across the gap injury was decreased in Gata1 KO compared to WT during ongoing nerve regeneration. Over longer observation to allow for more complete nerve regeneration, behavioral recovery measured by grid-walk assessment was not different comparing groups but modestly delayed in Gata1 KO compared to WT. The extent of final axon regeneration was not different amongst groups. Our data provide additional evidence suggesting eosinophils contribute to nerve regeneration across a nerve gap injury, but are not essential to regeneration in this context. Our evidence also suggests eosinophils may regulate cytokines that promote distinct macrophage phenotypes and axon regeneration.

Electrical stimulation or tacrolimus (FK506) alone enhances nerve regeneration and recovery after nerve surgery, while dual use reduces variance and combines strengths of each in promoting enhanced outcomes

INTRODUCTION/AIMS

Repaired nerve injuries can fail to achieve functional recovery. Therapeutic options beyond surgery, such as systemic tacrolimus (FK506) and electrical stimulation (E-stim), can improve recovery. We tested whether dual administration of FK506 and E-stim enhances regeneration and recovery more than either therapeutic alone.

METHODS

Rats were randomized to four groups: E-stim, FK506, FK506 + E-stim, and repair alone. All groups underwent tibial nerve transection and repair. Two sets of animals were created to measure outcomes of early nerve regeneration using nerve histology (n = 36) and functional recovery (n = 42) (21- and 42-day endpoints, respectively). Functional recovery was measured by behavioral analyses (walking track and grid walk) and, at the endpoint, muscle mass and force.

RESULTS

Dual E-stim and FK506 administration produced histomorphometric measurements of nerve regeneration no different than either therapeutic alone. All treatments were superior to repair alone (FK506, P < .0001; E-stim, P < .05; FK506 + E-stim, P < .05). The E-stim and FK506 + E-stim groups had improved behavioral recovery compared with repair alone (at 6 weeks: E-stim, P < .05; FK506 + E-stim, P < .01). The FK506 group had improved recovery based on walking-track analysis (at 6 weeks: P < .001) and muscle force and mass (P < .05). The concurrent use of both therapies ensured earlier functional recovery and decreased variability in functional outcomes compared with either therapy alone, suggesting a moderate benefit.

DISCUSSION

Dual administration of FK506 and E-stim showed minimal additive effects to further improve regeneration or recovery compared with either therapy alone. The data suggest the combination of FK506 and E-stim appears to combine the relative strengths of each therapeutic.

Incidence and Management of Facial Paralysis After Skull Base Trauma, an Administrative Database Study

OBJECTIVE

Report the incidence of and treatment patterns for facial nerve palsy after skull base fracture.

STUDY DESIGN

Retrospective cohort study.

SETTING

IBM MarketScan Commercial Database (2006-2019).

PATIENTS

Human subjects with skull base fracture, per International Classification of Diseases-9th and 10th Revisions-Clinical Modification diagnosis codes.

MAIN OUTCOME MEASURES

The primary outcomes were the incidence and median time to facial nerve palsy diagnosis within 30 days of skull base fracture. Secondary outcomes were treatments (corticosteroids, antivirals, facial nerve decompression, botulinum toxin, and facial reanimation), demographics, and rates of hearing loss, vertigo, tympanic membrane rupture, cerebrospinal fluid leak, comorbidities, and loss of consciousness.

RESULTS

The 30-day incidence of facial nerve palsy after skull base trauma was 1.0% (738 of 72,273 patients). The median (95% confidence interval [CI]) time to diagnosis was 6 (6-7) days, and only 22.9% were diagnosed within 1 day. There were significantly higher rates (risk difference, 95% CI) of hearing loss (26%, 22-29%), tympanic membrane rupture (6.3%, 4.5-8.1%), cerebrospinal fluid leak (6.4%, 4.5-8.3%), comorbidity (14%, 10.4-17.6%), and loss of consciousness (24.3%, 20.7-27.9%). Loss of consciousness was associated with longer median (95% CI) time to facial nerve palsy diagnosis: 10 (9-10) days. Corticosteroids were the most common treatment but only reported for less than one-third of patients. Only eight patients underwent facial nerve decompression.

CONCLUSIONS

Facial nerve palsy after skull base fracture is associated with higher comorbidity, and the diagnosis is often delayed. Few patients were treated with surgery, and there are inconsistencies in the types and timing of treatments.

Incidence of Nerve Injury After Extremity Trauma in the United States

BACKGROUND

Traumatic peripheral nerve injuries cause chronic pain, disability, and long-term reductions in quality of life. However, their incidence after extremity trauma remains poorly understood.

METHODS

The IBM® MarketScan® Commercial Database from 2010 to 2015 was used to identify patients aged 18 to 64 who presented to emergency departments for upper and/or lower extremity traumas. Cumulative incidences were calculated for nerve injuries diagnosed within 2 years of trauma. Cox regression models were developed to evaluate the associations between upper extremity nerve injury and chronic pain, disability, and use of physical therapy or occupational therapy.

RESULTS

The final cohort consisted of 1 230 362 patients with employer-sponsored health plans. Nerve injuries were diagnosed in 2.6% of upper extremity trauma patients and 1.2% of lower extremity trauma patients. Only 9% and 38% of nerve injuries were diagnosed by the time of emergency department and hospital discharge, respectively. Patients with nerve injuries were more likely to be diagnosed with chronic pain (hazard ratio [HR]: 5.9, 95% confidence interval [CI], 4.3-8.2), use physical therapy services (HR: 10.7, 95% CI, 8.8-13.1), and use occupational therapy services (HR: 19.2, 95% CI, 15.4-24.0) more than 90 days after injury.

CONCLUSIONS

The incidence of nerve injury in this national cohort was higher than previously reported. A minority of injuries were diagnosed by emergency department or hospital discharge. These findings may improve practitioner awareness and inform public health interventions for injury prevention.

The Effects of Intraoperative Electrical Stimulation on Regeneration and Recovery After Nerve Isograft Repair in a Rat Model

Background: Therapeutic electrical stimulation (ES) applied to repaired nerve is a promising treatment option to improve regeneration. However, few studies address the impact of ES following nerve graft reconstruction. The purpose of this study was to determine if ES applied to a nerve repair using nerve isograft in a rodent model could improve nerve regeneration and functional recovery. Methods: Adult rats were randomized to 2 groups: "ES" and "Control." Rats received a tibial nerve transection that was repaired using a tibial nerve isograft (1.0 cm length), where ES was applied immediately after repair in the applicable group. Nerve was harvested 2 weeks postrepair for immunohistochemical analysis of axon growth and macrophage accumulation. Independently, rats were assessed using walking track and grid-walk analysis for up to 21 weeks. Results: At 2 weeks, more robust axon regeneration and greater macrophage accumulation was observed within the isografts for the ES compared to Control groups. Both walking track and grid-walk analysis revealed that return of functional recovery was accelerated by ES. The ES group demonstrated improved functional recovery over time, as well as improved recovery compared to the Control group at 21 weeks. Conclusions: ES improved early axon regeneration into a nerve isograft and was associated with increased macrophage and beneficial M2 macrophage accumulation within the isograft. ES ultimately improved functional recovery compared to isograft repair alone. This study supports the clinical potential of ES to improve the management of nerve injuries requiring a nerve graft repair.

Short-Duration, Pulsatile, Electrical Stimulation Therapy Accelerates Axon Regeneration and Recovery following Tibial Nerve Injury and Repair in Rats

BACKGROUND

Repair of nerve injuries can fail to achieve adequate functional recovery. Electrical stimulation applied at the time of nerve repair can accelerate axon regeneration, which may improve the likelihood of recovery. However, widespread use of electrical stimulation may be limited by treatment protocols that increase operative time and complexity. This study evaluated whether a short-duration electrical stimulation protocol (10 minutes) was efficacious to enhance regeneration following nerve repair using rat models.

METHODS

Lewis and Thy1-green fluorescent protein rats were randomized to three groups: 0 minutes of electrical stimulation (no electrical stimulation; control), 10 minutes of electrical stimulation, and 60 minutes of electrical stimulation. All groups underwent tibial nerve transection and repair. In the intervention groups, electrical stimulation was delivered after nerve repair. Outcomes were assessed using immunohistochemistry, histology, and serial walking track analysis.

RESULTS

Two weeks after nerve repair, Thy1-green fluorescent protein rats demonstrated increased green fluorescent protein-positive axon outgrowth from the repair site with electrical stimulation compared to no electrical stimulation. Serial measurement of walking tracks after nerve repair revealed recovery was achieved more rapidly in both electrical stimulation groups as compared to no electrical stimulation. Histologic analysis of nerve distal to the repair at 8 weeks revealed robust axon regeneration in all groups.

CONCLUSIONS

As little as 10 minutes of intraoperative electrical stimulation therapy increased early axon regeneration and facilitated functional recovery following nerve transection with repair. Also, as early axon outgrowth increased following electrical stimulation with nerve repair, these findings suggest electrical stimulation facilitated recovery because of earlier axon growth across the suture-repaired site into the distal nerve to reach end-organ targets.

CLINICAL RELEVANCE STATEMENT

Brief (10-minute) electrical stimulation therapy can provide similar benefits to the 60-minute protocol in an acute sciatic nerve transection/repair rat model and merit further studies, as they represent a translational advantage.

Variability and Excess in Opioid Prescribing Patterns After Cleft and Craniosynostosis Repairs

OBJECTIVE

To critically analyze pediatric opioid prescription patterns after cleft and craniosynostosis repairs.

DESIGN

Observational study 1) retrospectively reviewing pediatric opioid prescriptions from July 2018 to June 2019 and 2) prospectively surveying patients about actual opioid use from August 2019 to February 2020.

SETTING

Academic tertiary care pediatric hospital.

PATIENTS

133 pediatric patients undergoing cleft lip and/or palate or craniosynostosis repairs. Prospective surveys were offered at postoperative visits; 45 of 69 eligible patients were enrolled.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Opioid doses prescribed at discharge and actual home opioid use.

RESULTS

90 patients with cleft lip and/or palate and 43 patients with craniosynostosis were included. Median prescribed opioid doses were 10.3 for cleft lip and/or palate procedures (range 0-75), and 14.3 for craniosynostosis repairs (range 0-50). In patients with cleft lip and/or palate, there was a negative correlation between age at surgery and prescribed opioid doses (r_s  =  -0.228, p  =  0.031). 45 patients completed surveys of home opioid use. No patients used more than 10 doses. Forty percent used no opioids at home, 33% used 1 to 2 doses, 18% used 3 to 5 doses, and 9% used 6 to 10 doses.

CONCLUSIONS

Opioid prescriptions vary widely after common craniofacial procedures. Younger patients with cleft lip and/or palate may be more likely to be prescribed more doses. Actual home opioid use is less than prescribed amounts, with most patients using five or fewer doses. A prescribing guideline is proposed.

IL-4 expressing cells are recruited to nerve after injury and promote regeneration

Interleukin-4 (IL-4) has garnered interest as a cytokine that mediates regeneration across multiple tissues including peripheral nerve. Within nerve, we previously showed endogenous IL-4 was critical to regeneration across nerve gaps. Here, we determined a generalizable role of IL-4 in nerve injury and regeneration. In wild-type (WT) mice receiving a sciatic nerve crush, IL-4 expressing cells preferentially accumulated within the injured nerve compared to affected sites proximal, such as dorsal root ganglia (DRGs), or distal muscle. Immunohistochemistry and flow cytometry confirmed that eosinophils (CD45+, CD11b+, CD64-, Siglec-F+) were sources of IL-4 expression. Examination of targets for IL-4 within nerve revealed macrophages, as well as subsets of neurons expressed IL-4R, while Schwann cells expressed limited IL-4R. Dorsal root ganglia cultures were exposed to IL-4 and demonstrated an increased proportion of neurons that extended axons compared to cultures without IL-4 (control), as well as longer myelinated axons compared to cultures without IL-4. The role of endogenous IL-4 during nerve injury and regeneration in vivo was assessed following a sciatic nerve crush using IL-4 knockout (KO) mice. Loss of IL-4 affected macrophage accumulation within injured nerve compared to WT mice, as well as shifted macrophage phenotype towards a CD206- phenotype with altered gene expression. Furthermore, this loss of IL-4 delayed initial axon regeneration from the injury crush site and subsequently delayed functional recovery and re-innervation of neuromuscular junctions compared to wild-type mice. Given the role of endogenous IL-4 in nerve regeneration, exogenous IL-4 was administered daily to WT mice following a nerve crush to examine regeneration. Daily IL-4 administration increased early axonal extension and CD206+ macrophage accumulation but did not alter functional recovery compared to untreated mice. Our data demonstrate IL-4 promotes nerve regeneration and recovery after injury.

Brief Electrical Stimulation Accelerates Axon Regeneration and Promotes Recovery Following Nerve Transection and Repair in Mice

BACKGROUND

Clinical outcomes following nerve injury repair can be inadequate. Pulsed-current electrical stimulation (ES) is a therapeutic method that facilitates functional recovery by accelerating axon regeneration. However, current clinical ES protocols involve the application of ES for 60 minutes during surgery, which can increase operative complexity and time. Shorter ES protocols could be a strategy to facilitate broader clinical adoption. The purpose of the present study was to determine if a 10-minute ES protocol could improve outcomes.

METHODS

C57BL/6J mice were randomized to 3 groups: no ES, 10 minutes of ES, and 60 minutes of ES. In all groups, the sciatic nerve was transected and repaired, and, in the latter 2 groups, ES was applied after repair. Postoperatively, changes to gene expression from dorsal root ganglia were measured after 24 hours. The number of motoneurons regenerating axons was determined by retrograde labeling at 7 days. Histomorphological analyses of the nerve were performed at 14 days. Function was evaluated serially with use of behavioral tests up to 56 days postoperatively, and relative muscle weight was evaluated.

RESULTS

Compared with the no-ES group, both ES groups demonstrated increased regeneration-associated gene expression within dorsal root ganglia. The 10-minute and 60-minute ES groups demonstrated accelerated axon regeneration compared with the no-ES group based on increased numbers of labeled motoneurons regenerating axons (mean difference, 202.0 [95% confidence interval (CI), 17.5 to 386.5] and 219.4 [95% CI, 34.9 to 403.9], respectively) and myelinated axon counts (mean difference, 559.3 [95% CI, 241.1 to 877.5] and 339.4 [95% CI, 21.2 to 657.6], respectively). The 10-minute and 60-minute ES groups had improved behavioral recovery, including on grid-walking analysis, compared with the no-ES group (mean difference, 11.9% [95% CI, 3.8% to 20.0%] and 10.9% [95% CI, 2.9% to 19.0%], respectively). There was no difference between the ES groups in measured outcomes.

CONCLUSIONS

A 10-minute ES protocol accelerated axon regeneration and facilitated functional recovery.

CLINICAL RELEVANCE

The brief (10-minute) ES protocol provided similar benefits to the 60-minute protocol in an acute sciatic nerve transection/repair mice model and merits further studies.

T-box transcription factor 21 is expressed in terminal Schwann cells at the neuromuscular junction

INTRODUCTION/AIMS

Terminal Schwann cells (tSCs) are nonmyelinating Schwann cells present at the neuromuscular junction (NMJ) with multiple integral roles throughout their lifespan. There is no known gene differentiating tSCs from myelinating Schwann cells, making their isolation and investigation challenging. In this work we investigated genes expressed within tSCs.

METHODS

A novel dissection technique was utilized to isolate the tSC-containing NMJ band from the sternomastoid muscles of S100-GFP mice. RNA was isolated from samples containing: (a) NMJ bands (tSCs with nerve and muscle), (b) nerve, and (c) muscle, and microarray genetic expression analysis was conducted. Data were validated by quantitative real-time polymerase chain reaction (qRT-PCR) and immunofluorescent staining. To identify genes specific to tSCs compared with other NMJ components, analysis of variance and rank-order analysis were performed using the Partek Genomic Suite.

RESULTS

Microarray analysis of the tSC-enriched NMJ band revealed upregulation (by 4- to 12-fold) of several genes unique to the NMJ compared with muscle or nerve parts alone (P < .05). Among these genes, Tbx21 (or T-bet) was identified, which showed a 12-fold higher expression at the NMJ compared with sciatic nerve (P < .002). qRT-PCR analysis showed Tbx21 mRNA expression was over ninefold higher (P < .05) in the NMJ relative to muscle and nerve. Tbx21 protein colocalized with tSCs and was not noted in myelinating SCs from sciatic nerve.

DISCUSSION

We found TBX21 to be expressed in tSCs. Additional studies will be performed to determine the functional significance of TBX21 in tSCs. These studies may enhance the investigative tools available to modulate tSCs to improve motor recovery after nerve injury.

Using an Intake Form and Clinic Dashboard to Tailor and Improve the Cleft Team Clinic Visit for Families

BACKGROUND

Multidisciplinary cleft care protocols commonly do not incorporate family needs, concerns, and preferences.

SOLUTION

A family-centered model would incorporate family needs, concerns, and preferences with a view toward lessening burden of care while achieving outcomes important to families.

WHAT WE DO

Our Intake Form helps us adapt visits to better meet families' needs, and our Dashboard enables Team Coordinators to direct efficient patient flows, lessening wait times and care burden.

Long-Term Effects of Nasoalveolar Molding in Patients With Unilateral Cleft Lip and Palate: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of this systematic review and meta-analysis was to investigate long-term treatment effects of nasoalveolar molding (NAM) in patients with unilateral cleft lip and palate (UCLP).

DESIGN

Included manuscripts met the following criteria: (1) involved patients with UCLP who received NAM; (2) included comparison group(s) who either received non-NAM passive presurgical infant orthopedic appliances (PSIO) or who did not receive any PSIO; (3) reported at least one objective or validated measure of nasolabial, craniofacial, or palatal form; and (4) had patient follow-up beyond 4 years of age.

RESULTS

A total of 12 studies were included in this review. Meta-analyses were possible for Asher-McDade parameters and cephalometric measurements. Compared to patients who did not receive any PSIO, those who underwent NAM therapy were more likely to have good to excellent frontal nasal form (Risk ratio: 2.4, 95% CI: 1.24-3.68) and vermillion border (Risk ratio: 1.8, 95% CI: 1.19-2.71). However, there were no statistically significant differences in cephalometric measurements between these groups. Additionally, there were no statistically significant differences between patients receiving NAM versus non-NAM PSIO. There was insufficient evidence to determine the impact of NAM on dental arch development.

CONCLUSIONS

The preponderance of evidence in this review suggests that NAM produces benefits in nasolabial aesthetic form when compared with no appliance-based presurgical treatment. However, there is insufficient evidence to conclude whether NAM produces such benefits when compared with other passive PSIOs.

Mind the Gap: Alveolar Bone Graft Revision in the Era of Computed Tomography

OBJECTIVE

To determine the rate of revision alveolar bone grafting (ABG) in patients with cleft lip and palate (CLP) before and after the introduction of postoperative computed tomography (CT).

DESIGN

Retrospective case-control study analyzing the incidence of revision ABG in patients with and without postoperative CT scans for graft success evaluation.

SETTING

Academic tertiary care pediatric hospital.

PATIENTS

Eighty-seven patients with CLP or cleft lip and alveolus treated with autologous iliac crest bone grafting for alveolar clefts over a 10-year period (January 2009 to March 2019) with minimum 6-month follow-up. Fifty patients had postoperative CT evaluation; 37 did not.

INTERVENTIONS

Postoperative CT to determine ABG success, versus standard clinical examination and 2-dimensional radiographs.

MAIN OUTCOME MEASURES

Requirement for revision ABG, defined as failure of the original graft by clinical or radiographic examination.

RESULTS

Fifty-eight percent of patients underwent a postoperative CT scan at median interval of 10 months after surgery. Patients with postoperative CT evaluation had a 44% rate of revision ABG (22/50) for inadequate graft take, compared to 5% (2/37) in patients without postoperative CT (P < .001; 95% CT, 31%-58% in the CT group, 1%-16% in the non-CT group).

CONCLUSIONS

Computed tomography evaluation after ABG is associated with a significantly increased revision rate for inadequate graft take. The presence of a secondary palatal fistula at the time of original ABG is not associated with revision requirement. Lack of standardized dental and orthodontic records complicates the study of ABG outcomes and presents an area for systems-based improvement.

Evaluation of Discipline-Specific Outcomes Through a Multidisciplinary Team Clinic for Patients With Isolated Cleft Palate

OBJECTIVE

To describe the incidence and timing of provider-specific interventions for children with isolated cleft palate.

DESIGN

This was a retrospective cohort study involving review of medical records.

SETTING

Multidisciplinary team care clinic at a tertiary academic children's hospital between January 2000 and July 2019.

PATIENTS

Patients with isolated nonsyndromic cleft palate seen by an American Cleft Palate-Craniofacial Association-approved team; 138 children were included.

MAIN OUTCOME MEASURES

Study outcomes included incidence of secondary velopharyngeal management, tympanostomy tube insertion, speech therapy, hearing loss, dental/orthodontic treatment, and psychology interventions. Provider-specific outcomes were calculated for patients at ages 0 to 3, 3 to 5, and >5 years.

RESULTS

Median follow-up time was 7.0 years (interquartile range: 3.3-11.8 years). At their last team assessment, 42% of patients still had conductive hearing loss. The rate of tympanostomy tube insertions not done alongside a palatoplasty was highest for ages 3 to 5 and dropped after new American Academy of Otolaryngology-Head and Neck Surgery Foundation guidelines in 2013 (P = .015); 54% of patients received speech-language therapy during follow-up. Palatoplasty, psychology, and dental/orthodontic treatment were all less common than speech or ENT treatment (P < .01). Secondary palatoplasty was performed in 31 patients (22%). Patients who received speech, dental/orthodontic, or psychology intervention followed up longer than those who did not (9.8 vs 2.1 years, P < .001).

CONCLUSION

Half of the patients terminated team follow-up by age 7, suggesting that burden of care outweighed perceived benefits of continued follow-up for many families. These results can be used to adjust protocols for children with isolated cleft palate.

Macrophage roles in peripheral nervous system injury and pathology: Allies in neuromuscular junction recovery

Peripheral nerve injuries remain challenging to treat despite extensive research on reparative processes at the injury site. Recent studies have emphasized the importance of immune cells, particularly macrophages, in recovery from nerve injury. Macrophage plasticity enables numerous functions at the injury site. At early time points, macrophages perform inflammatory functions, but at later time points, they adopt pro-regenerative phenotypes to support nerve regeneration. Research has largely been limited, however, to the injury site. The neuromuscular junction (NMJ), the synapse between the nerve terminal and end target muscle, has received comparatively less attention, despite the importance of NMJ reinnervation for motor recovery. Macrophages are present at the NMJ following nerve injury. Moreover, in denervating diseases, such as amyotrophic lateral sclerosis (ALS), macrophages may also play beneficial roles at the NMJ. Evidence of positive macrophages roles at the injury site after peripheral nerve injury and at the NMJ in denervating pathologies suggest that macrophages may promote NMJ reinnervation. In this review, we discuss the intersection of nerve injury and immunity, with a focus on macrophages.

Macrophage-Derived Vascular Endothelial Growth Factor-A Is Integral to Neuromuscular Junction Reinnervation after Nerve Injury

Functional recovery in the end target muscle is a determinant of outcome after peripheral nerve injury. The neuromuscular junction (NMJ) provides the interface between nerve and muscle and includes non-myelinating terminal Schwann cells (tSCs). After nerve injury, tSCs extend cytoplasmic processes between NMJs to guide axon growth and NMJ reinnervation. The mechanisms related to NMJ reinnervation are not known. We used multiple mouse models to investigate the mechanisms of NMJ reinnervation in both sexes, specifically whether macrophage-derived vascular endothelial growth factor-A (Vegf-A) is crucial to establishing NMJ reinnervation at the end target muscle. Both macrophage number and Vegf-A expression increased in end target muscles after nerve injury and repair. In mice with impaired recruitment of macrophages and monocytes (Ccr2-/- mice), the absence of CD68+ cells (macrophages) in the muscle resulted in diminished muscle function. Using a Vegf-receptor 2 (VegfR2) inhibitor (cabozantinib; CBZ) via oral gavage in wild-type (WT) mice resulted in reduced tSC cytoplasmic process extension and decreased NMJ reinnervation compared with saline controls. Mice with Vegf-A conditionally knocked out in macrophages (Vegf-Afl/fl; LysMCre mice) demonstrated a more prolonged detrimental effect on NMJ reinnervation and worse functional muscle recovery. Together, these results show that contributions of the immune system are integral for NMJ reinnervation and functional muscle recovery after nerve injury.SIGNIFICANCE STATEMENT This work demonstrates beneficial contributions of a macrophage-mediated response for neuromuscular junction (NMJ) reinnervation following nerve injury and repair. Macrophage recruitment occurred at the NMJ, distant from the nerve injury site, to support functional recovery at the muscle. We have shown hindered terminal Schwann cell (tSC) injury response and NMJ recovery with inhibition of: (1) macrophage recruitment after injury; (2) vascular endothelial growth factor receptor 2 (VegfR2) signaling; and (3) Vegf secretion from macrophages. We conclude that macrophage-derived Vegf is a key component of NMJ recovery after injury. Determining the mechanisms active at the end target muscle after motor nerve injury reveals new therapeutic targets that may translate to improve motor recovery following nerve injury.

Liposomes embedded within fibrin gels facilitate localized macrophage manipulations within nerve

BACKGROUND

Understanding the role of macrophages at discrete spatial locations during nerve regeneration after injury is important. But, methodologies that systemically manipulate macrophages can obscure their roles within discrete spatial locations within nerve.

NEW METHOD

Liposomes were embedded within fibrin gels to construct a delivery system that facilitated macrophage-specific manipulations at a sole spatial region, as macrophages accumulated within the fibrin. Clodronate liposomes were characterized for their toxicity to specific cells composing nerve in vitro, then tested for macrophage-specific depletion in vivo. This delivery system using clodronate liposomes was used to repair a mouse sciatic nerve gap to evaluate its efficacy and effects.

RESULT

Clodronate liposomes showed specific toxicity to macrophages without affecting dorsal root ganglia (DRG)-derived neurons, endothelial cells, or Schwann cells in culture. The delivery system demonstrated sustained release of liposomes for more than 7 days while still retaining liposomes within the fibrin. In vivo, the delivery system demonstrated macrophages were targeted by liposomes, and the use of clodronate liposomes minimized macrophage accumulation within fibrin, while not affecting macrophage accumulation within DRG. Nerve regeneration across the nerve gap repaired using this delivery system was associated with decreased angiogenesis, Schwann cell accumulation, axon growth, and reinnervation of affected muscle.

COMPARISON WITH EXISTING METHODS

This delivery system allowed specific perturbation of macrophages locally in nerve. This method could be applicable across species without the need for genetic manipulations or systemic pharmaceuticals.

CONCLUSION

Liposomes embedded within fibrin gels locally target macrophages at the site of nerve injury, which enables greater precision in conclusions regarding their roles in nerve.

T cells modulate IL-4 expression by eosinophil recruitment within decellularized scaffolds to repair nerve defects

Decellularized nerve, or acellular nerve allografts (ANAs), are an increasingly used alternative to nerve autografts to repair nerve gaps to facilitate regeneration. The adaptive immune system, specifically T cells, plays a role in promoting regeneration upon these ANA scaffolds. However, how T cells promote regeneration across ANAs is not clear. Here, we show that T cells accumulate within ANAs repairing nerve gaps resulting in regulation of cytokine expression within the ANA environment. This in turn ultimately leads to robust nerve regeneration and functional recovery. Nerve regeneration across ANAs and functional recovery in Rag1KO mice was limited compared to wild-type (WT) mice. Prior to appreciable nerve regeneration, ANAs from Rag1KO mice contained fewer eosinophils and reduced IL-4 expression compared to ANAs from WT mice. During this period, both T cells and eosinophils regulated IL-4 expression within ANAs. Eosinophils represented the majority of IL-4 expressing cells within ANAs, while T cells regulated IL-4 expression. Finally, an essential role for IL-4 during nerve regeneration across ANAs was confirmed as nerves repaired using ANAs had reduced regeneration in IL-4 KO mice compared to WT mice. Our data demonstrate T cells regulate the expression of IL-4 within the ANA environment via their effects on eosinophils. STATEMENT OF SIGNIFICANCE: The immune system has been emerging as a critical component for tissue regeneration, especially when regeneration is supported upon biomaterials. The role of T cells, and their roles in the regeneration of nerve repaired with biomaterials, is still unclear. We demonstrated that when nerves are repaired with decellularized nerve scaffolds, T cells contribute to regeneration by regulating cytokines. We focused on their regulation of cytokine IL-4. Unexpectedly, T cells do not produce IL-4, but instead regulate IL-4 by recruiting eosinophils, which are major cellular sources of IL-4 within these scaffolds. Thus, our work demonstrated how IL-4 is regulated in a model biomaterial, and has implications for improving the design of biomaterials and understanding immune responses to biomaterials.

The CCL2/CCR2 axis is critical to recruiting macrophages into acellular nerve allograft bridging a nerve gap to promote angiogenesis and regeneration

Acellular nerve allografts (ANAs) are increasingly used to repair nerve gaps following injuries. However, these nerve scaffolds have yet to surpass the regenerative capabilities of cellular nerve autografts; improved understanding of their regenerative mechanisms could improve design. Due to their acellular nature, both angiogenesis and diverse cell recruitment is necessary to repopulate these scaffolds to promote functional regeneration. We determined the contribution of angiogenesis to initial cellular repopulation of ANAs used to repair nerve gaps, as well as the signaling that drives a significant portion of this angiogenesis. Wild-type (WT) mice with nerve gaps repaired using ANAs that were treated with an inhibitor of VEGF receptor signaling severely impaired angiogenesis within ANAs, as well as hampered cell repopulation and axon extension into ANAs. Similarly, systemic depletion of hematogenous-derived macrophages, but not neutrophils, in these mice models severely impeded angiogenesis and subsequent nerve regeneration across ANAs suggesting hematogenous-derived macrophages were major contributors to angiogenesis within ANAs. This finding was reinforced using CCR2 knockout (KO) models. As macrophages represented the majority of CCR2 expressing cells, a CCR2 deficiency impaired angiogenesis and subsequent nerve regeneration across ANAs. Furthermore, an essential role for CCL2 during nerve regeneration across ANAs was identified, as nerves repaired using ANAs had reduced angiogenesis and subsequent nerve regeneration in CCL2 KO vs WT mice. Our data demonstrate the CCL2/CCR2 axis is important for macrophage recruitment, which promotes angiogenesis, cell repopulation, and subsequent nerve regeneration and recovery across ANAs used to repair nerve gaps.

Proposed Federal Bill to Mandate Insurance Coverage for Children With Congenital Anomalies

The Ensuring Lasting Smiles Act was reintroduced in United States Congress in March 2019. If enacted, the bill will substantially limit private insurers' ability to deny coverage for the medically necessary treatment of congenital anomalies, including cleft palate and craniofacial anomalies. Coverage denials are currently a barrier to care for these individuals, especially for patients residing in states lacking coverage mandates. The purpose of this article is to describe the issues underlying the proposed federal legislation and provide a policy discussion to better inform cleft and craniofacial providers about pending legislation relevant to their practice.

Evaluation of Multidisciplinary Team Clinic for Patients With Isolated Cleft Lip

OBJECTIVE

To report the incidences of secondary lip and nose operations, otolaryngology procedures, speech-language therapy, neurodevelopmental concerns, and dental and orthodontic issues in children with isolated cleft lip to inform multidisciplinary cleft team protocols.

SETTING

An American Cleft Palate-Craniofacial Association-approved team at a tertiary academic children's hospital.

DESIGN

Retrospective cohort study of patients evaluated through longitudinal clinic visits by a multidisciplinary cleft palate and craniofacial team between January 2000 and June 2018.

PATIENTS, PARTICIPANTS

Children with nonsyndromic cleft lip with or without cleft alveolus (n = 92).

RESULTS

Median age at final team visit was 4.9 years (interquartile range: 2.4-8.2 years). Secondary plastic surgery procedures were most common between ages 3 and 5 (135 per 1000 person-years), and the majority of these procedures were minor lip revisions. The rate of tympanostomy tube insertion was highest before age 3 (122 per 1000 person-years). By their final team visit, 88% of patients had normal hearing and 11% had only slight to mild conductive hearing loss. No patients had speech errors attributable to lip abnormalities. Psychological interventions, learning disabilities, and dental or orthodontic concerns were uncommon.

CONCLUSIONS

Most patients with isolated cleft lip may not require long-term, longitudinal evaluation by cleft team specialists. Cleft teams should develop limited follow-up protocols for these children to improve resource allocation and promote value-based care in this patient population.

One Multidisciplinary Cleft and Craniofacial Team's Experience in Shifting to Family-Centered Care

Family-centered care is a high-priority focus area in health care and is associated with increased family satisfaction and quality of life, better health outcomes and family follow-up, decreased burden of care, and improved efficiency of resource utilization. Motivated by our aim to improve clinic efficiency and patient retention, our multidisciplinary cleft palate and craniofacial center has been undergoing a complex family-centered reorganization over the past 3 years. We seek to share our experience in hope the information will be a useful starting point to other teams in structuring their own family-centered improvements. We suggest the following stepwise method to achieve a more family-centered process: (1) gathering preintervention data, (2) brainstorming challenges with stakeholders, (3) brainstorming solutions with stakeholders, (4) implementation, (5) follow-up and troubleshooting, (6) further implementation, and (7) gathering postintervention data. Additionally, we found the use of institutional resources added substantial value to our efforts.

Gpr126/Adgrg6 contributes to the terminal Schwann cell response at the neuromuscular junction following peripheral nerve injury

Gpr126/Adgrg6 is an adhesion G protein-coupled receptor essential for Schwann cell (SC) myelination with important contributions to repair after nerve crush injury. Despite critical functions in myelinating SCs, the role of Gpr126 within nonmyelinating terminal Schwann cells (tSCs) at the neuromuscular junction (NMJ), is not known. tSCs have important functions in synaptic maintenance and reinnervation, and after injury tSCs extend cytoplasmic processes to guide regenerating axons to the denervated NMJ. In this study, we show that Gpr126 is expressed in tSCs, and that absence of Gpr126 in SCs (SC-specific Gpr126 knockout, cGpr126) results in a NMJ maintenance defect in the hindlimbs of aged mice, but not in young adult mice. After nerve transection and repair, cGpr126 mice display delayed NMJ reinnervation, altered tSC morphology with decreased S100β expression, and reduced tSC cytoplasmic process extensions. The immune response promoting reinnervation at the NMJ following nerve injury is also altered with decreased macrophage infiltration, Tnfα, and anomalous cytokine expression compared to NMJs of control mice. In addition, Vegfa expression is decreased in muscle, suggesting that cGpr126 non-cell autonomously modulates angiogenesis after nerve injury. In sum, cGpr126 mice demonstrated delayed NMJ reinnervation and decreased muscle mass following nerve transection and repair compared to control littermates. The integral function of Gpr126 in tSCs at the NMJ provides the framework for new therapeutic targets for neuromuscular disease.

Comparison of Myelin-Associated Glycoprotein With Vincristine for Facial Nerve Inhibition After Bilateral Axotomy in a Transgenic Thy1-Gfp Rat Model

IMPORTANCE

Aberrant synkinetic movement after facial nerve injury can lead to prominent facial asymmetry and resultant psychological distress. The current practices of neuroinhibition to promote greater facial symmetry are often temporary in nature and require repeated procedures.

OBJECTIVE

To determine whether myelin-associated glycoprotein (MAG), a specific neuroinhibitor, can prevent neuroregeneration with efficacy comparable with that of vincristine, a well-established neurotoxin.

DESIGN, SETTING, AND PARTICIPANTS

Rats transgenic for Thy-1 cell surface antigen-green fluorescent protein (Thy1-Gfp) were randomized into 3 groups. Each rat received bilateral crush axotomy injuries to the buccal and marginal mandibular branches of the facial nerves. The animals received intraneural injection of saline, MAG, or vincristine.

MAIN OUTCOMES AND MEASURES

The animals were imaged via fluorescent microscopy at weeks 1, 3, 4, and 5 after surgery. Quantitative fluorescent data were generated as mean intensities of nerve segments proximal and distal to the axotomy site. Electrophysiological analysis, via measurement of compound muscle action potentials, was performed at weeks 0, 3, 4, and 5 after surgery.

RESULTS

A total of 12 rats were included in the study. Administration of MAG significantly reduced fluorescent intensity of the distal nerve in comparison with the control group at week 3 (mean [SD], MAG group: 94 [11] intensity units vs control group: 130 [11] intensity units; P < .001), week 4 (MAG group: 81 [19] intensity units vs control group: 103 [9] intensity units; P = .004), and week 5 (MAG group: 76 [10] intensity units vs control group: 94 [10] intensity units; P < .001). In addition, rats treated with MAG had greater fluorescent intensity than those treated with vincristine at week 3 (mean [SD], MAG group: 94 [11] intensity units vs vincristine group: 76 [6] intensity units; P = .03), although there was no significant difference for weeks 4 and 5. At week 5, both MAG and vincristine demonstrated lower distal nerve to proximal nerve intensity ratios than the control group (control group, 0.94; vs MAG group, 0.82; P = .01; vs vincristine group; 0.77; P < .001). There was no significant difference in amplitude between the experimental groups at week 5 of electrophysiological testing.

CONCLUSIONS AND RELEVANCE

Lower facial asymmetry and synkinesis are common persistent concerns to patients after facial nerve injury. Using the Thy1-Gfp rat, this study demonstrates effective inhibition of neuroregeneration via intraneural application of MAG in a crush axotomy model, comparable with results with vincristine. By potentially avoiding systemic toxic effects of vincristine, MAG demonstrates potential as an inhibitor of neural regeneration for patients with synkinesis.

LEVEL OF EVIDENCE

NA.

What is Normal? Neuromuscular junction reinnervation after nerve injury

INTRODUCTION

In this study we present a reproducible technique to assess motor recovery after nerve injury via neuromuscular junction (NMJ) immunostaining and electrodiagnostic testing.

METHODS

Wild-type mice underwent sciatic nerve transection with repair. Hindlimb muscles were collected for microscopy up to 30 weeks after injury. Immunostaining was used to assess axons (NF200), Schwann cells (S100), and motor endplates (α-bungarotoxin). Compound motor action potential (CMAP) amplitude was used to assess tibialis anterior (TA) function.

RESULTS

One week after injury, nearly all (98.0%) endplates were denervated. At 8 weeks, endplates were either partially (28.3%) or fully (71.7%) reinnervated. At 16 weeks, NMJ reinnervation reached 87.3%. CMAP amplitude was 83% of naive mice at 16 weeks and correlated with percentage of fully reinnervated NMJs. Morphological differences were noted between injured and noninjured NMJs.

DISCUSSION

We present a reproducible method for evaluating NMJ reinnervation. Electrodiagnostic data summarize NMJ recovery. Characterization of wild-type reinnervation provides important data for consideration in experimental design and interpretation.

Comparing electrical stimulation and tacrolimus (FK506) to enhance treating nerve injuries

INTRODUCTION

Neuroenhancing therapies are desired because repair of nerve injuries can fail to achieve recovery. We compared two neuroenhancing therapies, electrical stimulation (ES) and systemic tacrolimus (FK506), for their capabilities to enhance regeneration in the context of a rat model.

METHODS

Rats were randomized to four groups: ES 0.5 mA, ES 2.0 mA, FK506, and repair alone. All groups underwent tibial nerve transection and repair, and outcomes were assessed by using twice per week walking track analysis, cold allodynia response, relative muscle mass, and nerve histology.

RESULTS

Electrical stimulation and FK506 groups demonstrated improved functional recovery and myelinated axon counts distal to the repair compared with repair alone. Electrical stimulation provided improvements in nerve regeneration that were not different from optimized FK506 systemic administration.

DISCUSSION

Providing ES after nerve repair improved regeneration and recovery in rats, with minimal differences in therapeutic efficacy to FK506, further demonstrating its clinical potential to improve management of nerve injuries.

Cleft and Craniofacial Multidisciplinary Team Clinic: A Look at Attrition Rates for Patients With Complete Cleft Lip and Palate and Nonsyndromic Single-Suture Craniosynostosis

OBJECTIVE

To evaluate attrition rates prior to expected completion of team care for children with complete cleft lip and palate (cleft) or nonsyndromic single-suture craniosynostosis (synostosis).

DESIGN

A single-institution retrospective review of attendance data from 2002 to 2016.

SETTING

Single cleft and craniofacial center in the United States.

PATIENTS/PARTICIPANTS

A sample of 983 patients with either cleft or synostosis. Patients who were more than 2 to 3 years from their last visit were considered lost to follow-up. Patients with cleft older than 16 years or synostosis over 11 years were considered graduated from team care.

RESULTS

Survival analysis shows that in our patients with cleft, 25% leave before age 8 and over 60% are lost from team by age 16. In patients with synostosis, 25% leave before age 6 and 45% are lost by age 11. Cox regression showed underrepresented minorities being 1.7 times more likely to become lost in the cleft group (hazard ratio: 1.66, 95% confidence interval [CI]: 1.01-2.74).

CONCLUSIONS

Overall, attrition rates were high at our institution. Many patients are lost to follow-up prior to receiving key medical interventions. Improved family education and personalized care are needed to help ensure continuity of care.

Median to radial nerve transfer after traumatic radial nerve avulsion in a pediatric patient

This case report describes an isolated radial nerve avulsion in a pediatric patient, treated by combination sensory and motor median to radial nerve transfers. After traumatic avulsion of the proximal radial nerve, a 12-year-old male patient underwent end-to-end transfer of median nerve branches to flexor carpi radialis and flexor digitorum superficialis to the posterior interosseous nerve and extensor carpi radialis nerve, respectively. He underwent end-to-side sensory transfer of the superficial radial sensory to the median sensory nerve. Pronator teres to extensor carpi radialis brevis tendon transfer was simultaneously performed to power short-term wrist extension. Within months after surgery, the patient had regained 9-10/10 sensation in the hand and forearm. In the following months and years, he regained dexterity, independent fine-finger and thumb motions, and 4-5/5 strength in all extensors except the abductor pollicis longus muscle. He grew 25 cm without extremity deformity or need for secondary orthopedic procedures. In appropriate adult and pediatric patients with proximal radial nerve injuries, nerve transfers have advantages over tendon transfers, including restored independent fine finger motions, regained sensation, and reinnervation of multiple muscle groups with minimal donor sacrifice.

The accumulation of T cells within acellular nerve allografts is length-dependent and critical for nerve regeneration

Repair of traumatic nerve injuries can require graft material to bridge the defect. The use of alternatives to bridge the defect, such as acellular nerve allografts (ANAs), is becoming more common and desired. Although ANAs support axon regeneration across short defects (<3 cm), axon regeneration across longer defects (>3 cm) is limited. It is unclear why alternatives, including ANAs, are functionally limited by length. After repairing Lewis rat nerve defects using short (2 cm) or long (4 cm) ANAs, we showed that long ANAs have severely reduced axon regeneration across the grafts and contain Schwann cells with a unique phenotype. But additionally, we found that long ANAs have disrupted angiogenesis and altered leukocyte infiltration compared to short ANAs as early as 2 weeks after repair. In particular, long ANAs contained fewer T cells compared to short ANAs. These outcomes were accompanied with reduced expression of select cytokines, including IFN-γ and IL-4, within long versus short ANAs. T cells within ANAs did not express elevated levels of IL-4, but expressed elevated levels of IFN-γ. We also directly assessed the contribution of T cells to regeneration across nerve grafts using athymic rats. Interestingly, T cell deficiency had minimal impact on axon regeneration across nerve defects repaired using isografts. Conversely, T cell deficiency reduced axon regeneration across nerve defects repaired using ANAs. Our data demonstrate that T cells contribute to nerve regeneration across ANAs and suggest that reduced T cells accumulation within long ANAs could contribute to limiting axon regeneration across these long ANAs.

Negative-Pressure Wound Therapy in Infants and Children: A Population-Based Study

BACKGROUND

Although the safety and benefits of negative-pressure wound therapy (NPWT) have been clearly demonstrated in the adult population, studies evaluating the safety and describing the use of NPWT in the pediatric population have been limited. Given this paucity, the goals of this study were to (1) evaluate the literature dedicated to NPWT use in infants and children and (2) leverage a population-level analysis to describe the experience of NPWT use in the pediatric population.

MATERIALS AND METHODS

We performed a literature review and analyzed the Truven Health Analytics MarketScan Commercial Claims Databases from 2006 to 2014 to identify infants and children treated with NPWT. We evaluated patient characteristics, indications, complications before and after NPWT placement, and health care utilization within 30 d of NPWT placement.

RESULTS

We identified 457 articles, 11 of which fit our inclusion criteria. Most studies (65.2%) were case reports or series with less than 10 patients. In addition, we identified 3184 patients aged younger than of 18 y who were treated with NPWT between 2006 and 2014. Serious incident complications within 30 d after NPWT placement were rare (bleeding 0.6%, septicemia 0.5%, and sepsis 0.5%).

CONCLUSIONS

Despite the lack of robust studies, NPWT is widely used for many indications and across different ages and providers. Given the low incidence of serious complications, we conclude that NPWT use in infants and children is safe and can be effectively used by different providers spanning surgical and nonsurgical disciplines.

Anatomic characteristics of supraorbital and supratrochlear nerves relevant to their use in corneal neurotization

BACKGROUND

Corneal denervation can lead to opacification and blindness. A new treatment technique, surgical corneal neurotization, transfers healthy donor nerve, (most commonly contralateral supratrochlear or supraorbital) to the affected limbus to prevent corneal destruction and improve healing potential of the cornea following insult. We examine gross and histomorphometric anatomy of the supratrochlear and supraorbital nerves relevant to their use in corneal neurotization.

METHODS

For each of nine adult cadaver heads, bilateral supraorbital and supratrochlear nerves were dissected from the supraorbital rim to the anterior hairline. The following data were recorded for each nerve: exit from the orbit through a notch versus foramen; horizontal distance from midline at the supraorbital rim; and distance from orbital exit to first branching point. Samples of all left supraorbital and supratrochlear nerves were obtained at the level of the supraorbital rim and at points 3 cm and 6 cm distally for histomorphometric analysis. Myelinated axon counts were determined for each sample.

RESULTS

Four supraorbital foramina, 14 supraorbital notches, two supratrochlear foramina, and 15 supratrochlear notches were identified. Average supraorbital and supratrochlear distances to midline were 26.5 mm and 21 mm respectively. Average myelinated axon counts for both nerves were greater at the orbital rim (supraorbital: 6018, supratrochlear: 2533) than at 6 cm distally (supraorbital: 1621, supratrochlear: 1112).

CONCLUSIONS

Anatomic dissection shows relative close approximation of the supraorbital and supratrochlear nerves, with a high proportion of both nerves exiting the orbit through foramina. The supraorbital nerve at the orbital rim contains the greatest number of myelinated axons.

Hypothalamic Sirt1 protects terminal Schwann cells and neuromuscular junctions from age-related morphological changes

Neuromuscular decline occurs with aging. The neuromuscular junction (NMJ), the interface between motor nerve and muscle, also undergoes age‐related changes. Aging effects on the NMJ components—motor nerve terminal, acetylcholine receptors (AChRs), and nonmyelinating terminal Schwann cells (tSCs)—have not been comprehensively evaluated. Sirtuins delay mammalian aging and increase longevity. Increased hypothalamic Sirt1 expression results in more youthful physiology, but the relationship between NMJ morphology and hypothalamic Sirt1 was previously unknown. In wild‐type mice, all NMJ components showed age‐associated morphological changes with ~80% of NMJs displaying abnormalities by 17 months of age. Aged mice with brain‐specific Sirt1 overexpression (BRASTO) had more youthful NMJ morphologic features compared to controls with increased tSC numbers, increased NMJ innervation, and increased numbers of normal AChRs. Sympathetic NMJ innervation was increased in BRASTO mice. In contrast, hypothalamic‐specific Sirt1 knockdown led to tSC abnormalities, decreased tSC numbers, and more denervated endplates compared to controls. Our data suggest that hypothalamic Sirt1 functions to protect NMJs in skeletal muscle from age‐related changes via sympathetic innervation.

Clinical relevance of terminal Schwann cells: An overlooked component of the neuromuscular junction

The terminal Schwann cell (tSC), a type of nonmyelinating Schwann cell, is a significant yet relatively understudied component of the neuromuscular junction. In addition to reviewing the role tSCs play on formation, maintenance, and remodeling of the synapse, we review studies that implicate tSCs in neuromuscular diseases including spinal muscular atrophy, Miller-Fisher syndrome, and amyotrophic lateral sclerosis, among others. We also discuss the importance of these cells on degeneration and regeneration after nerve injury. Knowledge of tSC biology may improve our understanding of disease pathogenesis and help us identify new and innovative therapeutic strategies for the many patients who suffer from neuromuscular disorders and nerve injuries.

Roles of the Microsurgeon and Anesthesiologist in the Treatment of Neonatal Upper Extremity Arterial Thrombosis: A Case Report

We present a rare case of a newborn with spontaneous, noniatrogenic arterial thromboembolism in the right brachial artery and accompanying ischemic changes to the right upper extremity, who was successfully treated with microsurgical intervention and ultrasound-guided infraclavicular brachial plexus block with a continuous infusion of ropivacaine for 48 hours. This case report highlights the emerging role of both the microsurgeon and anesthesiologist in management of spontaneous neonatal arterial thromboembolism.

Photographic Standards for Patients With Facial Palsy and Recommendations by Members of the Sir Charles Bell Society

Importance

There is no widely accepted assessment tool or common language used by clinicians caring for patients with facial palsy, making exchange of information challenging. Standardized photography may represent such a language and is imperative for precise exchange of information and comparison of outcomes in this special patient population.

Objectives

To review the literature to evaluate the use of facial photography in the management of patients with facial palsy and to examine the use of photography in documenting facial nerve function among members of the Sir Charles Bell Society-a group of medical professionals dedicated to care of patients with facial palsy.

Design, Setting, and Participants

A literature search was performed to review photographic standards in patients with facial palsy. In addition, a cross-sectional survey of members of the Sir Charles Bell Society was conducted to examine use of medical photography in documenting facial nerve function. The literature search and analysis was performed in August and September 2015, and the survey was conducted in August and September 2013.

Main Outcomes and Measures

The literature review searched EMBASE, CINAHL, and MEDLINE databases from inception of each database through September 2015. Additional studies were identified by scanning references from relevant studies. Only English-language articles were eligible for inclusion. Articles that discussed patients with facial palsy and outlined photographic guidelines for this patient population were included in the study. The survey was disseminated to the Sir Charles Bell Society members in electronic form. It consisted of 10 questions related to facial grading scales, patient-reported outcome measures, other psychological assessment tools, and photographic and videographic recordings.

Results

In total, 393 articles were identified in the literature search, 7 of which fit the inclusion criteria. Six of the 7 articles discussed or proposed views specific to patients with facial palsy. However, none of the articles specifically focused on photographic standards for the population with facial palsy. Eighty-three of 151 members (55%) of the Sir Charles Bell Society responded to the survey. All survey respondents used photographic documentation, but there was variability in which facial expressions were used. Eighty-two percent (68 of 83) used some form of videography. From these data, we propose a set of minimum photographic standards for patients with facial palsy, including the following 10 static views: at rest or repose, small closed-mouth smile, large smile showing teeth, elevation of eyebrows, closure of eyes gently, closure of eyes tightly, puckering of lips, showing bottom teeth, snarling or wrinkling of the nose, and nasal base view.

Conclusions and Relevance

There is no consensus on photographic standardization to report outcomes for patients with facial palsy. Minimum photographic standards for facial paralysis publications are proposed. Videography of the dynamic movements of these views should also be recorded.

Level of Evidence

NA.

Nerve stepping stone has minimal impact in aiding regeneration across long acellular nerve allografts

INTRODUCTION

Acellular nerve allografts (ANAs) yield less consistent favorable outcomes compared with autografts for long gap reconstructions. We evaluated whether a hybrid ANA can improve 6-cm gap reconstruction.

METHODS

Rat sciatic nerve was transected and repaired with either 6-cm hybrid or control ANAs. Hybrid ANAs were generated using a 1-cm cellular isograft between 2.5-cm ANAs, whereas control ANAs had no isograft. Outcomes were assessed by graft gene and marker expression (n = 4; at 4 weeks) and motor recovery and nerve histology (n = 10; at 20 weeks).

RESULTS

Hybrid ANAs modified graft gene and marker expression and promoted modest axon regeneration across the 6-cm defect compared with control ANA (P < 0.05), but yielded no muscle recovery. Control ANAs had no appreciable axon regeneration across the 6-cm defect.

DISCUSSION

A hybrid ANA confers minimal motor recovery benefits for regeneration across long gaps. Clinically, the authors will continue to reconstruct long nerve gaps with autografts. Muscle Nerve 57: 260-267, 2018.

Systemic Preoperative Antibiotics with Mandible Fractures: Are They Indicated at the Time of Injury?

Mandible fractures are the most common result of facial trauma. The proximity of oral flora to the site of both the injury and resulting surgical instrumentation makes managing infection a unique challenge. The benefit of antibiotic prophylaxis at the time of surgical treatment of mandible fractures is well established. However, the routine use of antibiotics between the time of injury and surgery is of unclear benefit. We aim to define the role of antibiotics in the preoperative period: from the time of injury to surgical intervention. Demographic and clinical data were collected retrospectively on all patients who were treated for mandible fracture by the Division of Plastic and Reconstructive Surgery at our institution between 2003 and 2013. The use of both preoperative (between injury and surgery) and perioperative (at the time of surgery) systemic antibiotics was recorded along with the incidence of postoperative infections and other complications. Complete data were available for 269 patients. Of the 216 patients who received preoperative antibiotics, 22 (10%) developed an infection postoperatively. Of the 53 patients who did not receive preoperative antibiotics, 2 (4%) developed infection ( p  = 0.184). Likewise, preoperative antibiotics were not significantly associated with hardware complication rates. In our retrospective review, the use of antibiotics between injury and surgical repair had no impact on postoperative infection rates. These data suggest that preoperative antibiotic use may actually be associated with an increased incidence of postoperative infection. Our results do not support the routine use of antibiotics between injury and surgical repair in patients with mandible fractures.