Scientific Abstract Presentations: Migraine and Peripheral Nerve Session 1 Friday, October 10 Fri, Oct 10 2:00-3:30 p.m. CDT

Purpose The supercharged end-to-side (SETS) nerve transfer has emerged as a promising technique in peripheral nerve surgery. This approach aims to rapidly introduce a pool of donor axons that "babysit" the target muscles while awaiting the delayed arrival of regenerating axons originating from the recipient nerve. However, the mechanistic underpinnings of this process remain poorly defined in large part due to the challenges in creating a model that more accurately represents the chronic denervation state seen clinically and the challenges in individually labelling the donor and recipient axons pools. This study seeks to address these critical knowledge gaps by evaluating the SETS transfer in a chronically denervated rodent forelimb model and using florescent protein-encoding adeno-associated viruses (AAVs) to label and evaluate the donor and recipient axon pools.

Methods A SETS model was developed to mimic chronic denervation seen clinically. In the experimental group, the right median nerve was transected mid-brachium and sutured to a reversed, 2 cm contralateral sciatic nerve graft with its distal end implanted within the pectoralis major to prevent aberrant regeneration. An ulnar-to-median nerve SETS transfer performed at the same time via an epineurial window in the distal median nerve stump. After 10 weeks, the median nerve was repaired by coapting the distal graft to the distal median nerve.

The negative control followed the same procedure but omitted the end-to-side transfer. An additional control group lacked subsequent median nerve repair. The positive control involved immediate median nerve transection and repair with a graft.

Eight weeks post-surgery, intra-neural AAV injections were performed. Five microliters of AAV.Php.EB.Tdtomato was injected into the ulnar nerve, and five microliters of AAV.Php.EB.EGFP into the median nerve. At euthanasia (22 weeks), median and ulnar nerves were exposed and individually stimulated at 100 Hz, and resulting grip strength was measured. The Kruskal-Wallis H test was used for statistical analysis followed by Post-Hoc Dunn's Test using an alpha of 0.05.

Results Median nerve grip strength was significantly greater in experimental group vs negative control group (1.89 N vs. 1.31 N, p<0.05), confirming a babysitting effect conferred by SETS transfer. Both viral vectors demonstrated robust expression in nerves and muscles, enabling visualization of selective motor endplate innervation.

Conclusions Delayed primary repair with immediate distal SETS transfer allowed us to overcome the size limitations in rats and accurately model the temporal separation in donor vs recipient axon reinnervation of target muscles that occurs clinically. Grip strength arising specifically from delayed reinnervation via the proximal repair site was potentiated by the presence of distal SETS, providing the first convincing experimental evidence of a "babysitting effect". Pending histologic data evaluating NMJ reinnervation with individually tagged donor and recipient axons populations will allow us to confirm this mechanism.

Introduction: Pudendal nerve entrapment (PNE) is a debilitating cause of chronic pelvic and perineal pain, often impairing daily activities, sexual function, and overall quality of life. Surgical decompression can be highly effective for patients refractory to conservative management. Traditional approaches have frequently involved partial or complete sectioning of key ligaments, sacrotuberous (STL) and sacrospinous (SSL) ligaments, raising concerns about pelvic instability. Recent advances in intraoperative neurophysiological monitoring and a heightened emphasis on maintaining pelvic floor integrity have driven the development of ligament-sparing surgical techniques. This retrospective study presents our experience with a transgluteal, ligament-sparing approach for pudendal nerve decompression at the Alcock's canal, or beneath the piriformis muscle at the sciatic outlet.

Methods: A retrospective analysis was performed on 57 patients (39 men, 18 women) undergoing 75 decompression procedures for clinically diagnosed PNE between 2022 and 2024. Inclusion criteria included a positive diagnostic pudendal nerve block (≥50% pain relief), pain refractory to conservative management (≥3 months), and localization of entrapment via clinical exam and imaging. All patients underwent transgluteal nerve decompression at Alcock's canal and/or the sciatic outlet, sparing the STL and SSL. Intraoperative compound muscle action potential (CMAP) measurements and triggered electromyography (EMG) monitored nerve function pre- and post-neurolysis. Pain, functional status, and patient-reported improvement (categorized as no/minimal, moderate, or significant) were assessed at 3, 6, and 12 months postoperatively.

Results: 24 patients presented with bilateral symptoms and 33 with unilateral involvement. The median time from consultation to surgery was 193 days (Q1-Q3 range = 106-435 days). Intraoperatively, nerve compression was frequently attributed to hypertrophic or varicose internal pudendal veins, fibrotic bands, and scarring in Alcock's canal or at the sciatic outlet. Preserving the STL and SSL permitted multi-level nerve decompression and maintaining pelvic floor support. The median amperage that recorded a waveform decreased significantly from a median of 3 mA pre-decompression to 0.5 mA post-decompression (Z-score = -5, p<0.0001), suggesting effective neural release. Of the 53 patients available for follow-up, only 2 (3.77%) reported minimal or no improvement, while 19 (35.85%) reported moderate improvement, and 32 (60.37%) reported significant improvement in symptoms. 73.5 % of the patients achieved sustained, clinically meaningful pain relief without any symptom recurrence. Notably, there were no cases of pelvic instability or ligamentous compromise.

Conclusion: These findings support a shift in surgical practice toward ligament-sparing transgluteal decompression for PNE. Despite historical concerns that partial ligament sectioning is necessary to adequately decompress the pudendal nerve, our results demonstrate that thorough neurolysis and vascular management can be achieved without sacrificing the STL or SSL. The significant improvements in nerve conduction correlate with favorable postoperative outcomes, underscoring the utility of real-time neurophysiological CMAP monitoring. These findings affirm that ligament preservation is feasible for the majority of PNE cases and may usher in an important shift in surgical management, offering patients enduring pain relief and improved quality of life.

Purpose: Loss of sensation is a common consequence following mastectomy in both breast reconstruction and gender-affirming surgery, leading to a reduced quality of life, impaired sexual health, and functional limitations. Nerve preservation and reinnervation techniques, such as the use of nerve allografts or direct coaptation, have been utilized to improve sensory outcomes. This study aims to compare sensory outcomes in patients undergoing targeted nipple areola complex (NAC) reinnervation (TNR) with direct-to-implant (DTI) breast reconstruction using nerve allografts and gender-affirming mastectomy (GAM) utilizing direct coaptation.

Methods: Patients undergoing DTI reconstruction (n=32) and GAM (n=74) were prospectively followed at Weill Cornell Medicine and Massachusetts General Hospital from January 2023 to December 2024. Quantitative Sensory Testing (QST) with monofilament, pinprick, 2-point discrimination, vibration, temperature, and pressure was completed preoperatively and at 1, 3, 6, and 12 months postoperatively. Student t-tests were used to determine differences in sensation compared to baseline and between DTI and GAM patients at each timepoint.

Results: Preoperative sensation was comparable between groups (p>0.05). Postoperatively, monofilament testing was significantly better at the chest and NAC in GAM patients at each timepoint (p<0.05). At 12 months, all sensory tests were significantly better at the chest in patients with GAM except for pressure, which was similar between groups. Pinprick, vibration, and cold temperature detection was significantly better at the NAC in patients with GAM, while 2-point discrimination, heat detection, and pressure were similar. At 12 months, all sensory tests had returned to baseline in the GAM group except chest pressure, chest and NAC heat detection, and NAC pinprick. In DTI patients, vibration had reached baseline at 12 months.

Conclusions: TNR resulted in improved sensation in DTI reconstruction and GAM patients, with GAM returning and DTI approaching the preoperative baseline sensation by 12 months. These findings suggest that nerve reinnervation techniques facilitate sensory recovery. While both groups showed notable sensory improvements, GAM patients exhibited more rapid recovery across various sensory modalities.

Purpose: Peripheral nerve injuries (PNI) are common lesions worldwide, particularly among trauma patients. For neurotmesis, the most severe form of PNI, the gold standard treatment is microsurgical neurorrhaphy (MN). However, its effectiveness is often limited by the slow regeneration of neurons and by Wallerian degeneration. In order to obtain better nerve healing and optimal functional results following PNI, the combination of MN with other therapeutic approaches has increasingly been investigated, with electroacupuncture being hypothesized as a promising option. Therefore, the objective of this study was to assess the regenerative effects of electroacupuncture as an adjunctive therapy for PNI using a murine model.

Methods: Between February 2022 and January 2025, fourteen male Wistar rats were included in the study. All animals underwent a microsurgical procedure on the right sciatic nerve to mimic a PNI, followed by an end-to-end MN. Then, the animals were randomly divided into two groups: a control group (n = 7) and an electroacupuncture (EA) group (n = 7). The EA group received two 20-minute sessions of electroacupuncture per week for 12 weeks on the right leg, while the control group received no additional interventions beyond the surgery. The primary outcome was the sensory function of the nerve, evaluated at week 12 through peripheral nerve examinations assessing responses to Pain, Heat, and Pressure, measured using a five-point scale (from 0 to 4). We also assessed motor function using the Sciatic Function Index (SFI), calculated through walking-track analysis of footprints at weeks 3, 6, 9, and 12. Also, after the animals were put down, histological studies of their nerves were done using Hematoxylin and Eosin (HE) staining to check for angiogenesis and Masson's Trichrome (MT) staining to check for Schwann cell count.

Results: Based on our analysis, the EA group had significantly higher Pain response values than the control group 12 weeks after surgery (3.17 ± 0.69 vs. 1.57 ± 0.90, p = 0.006). A similar enhanced response was observed in the Pressure test (2.17 ± 0.89 vs. 0.43 ± 0.49, p = 0.005) and in the Heat test (1.5 ± 1.1 vs. 0 ± 0, p = 0.03). However, for motor function measured by the SFI, no significant differences were found across the four timepoints (p = 0.36, p = 0.37, p = 0.17, p = 0.12). Histological analysis with MT staining revealed a 96% increase in Schwann cell count distal to the injury in the EA group (p = 0.00007), while HE staining showed no significant differences in angiogenesis between the groups.

Conclusion: Overall, our findings indicate that electroacupuncture is an effective adjunctive therapy following MN for PNI, as it consistently improved sensory functions across all examinations, and demonstrated a greater Schwann cell count distal to the lesion, suggesting enhanced myelination after the intervention.

Purpose: Ultrasound is routinely used to assess peripheral nerves in the lower extremity due to its low cost, accessibility, and rapid examination time. However, its use in evaluating neuromas, benign tumors of nerve tissue, remains underutilized despite its great potential as a noninvasive imaging tool. Ultrasound also provides a unique opportunity to visualize nerve reconstruction techniques, including targeted muscle reinnervation (TMR), regenerative peripheral nerve interface (RPNI), and their combination, TMRpni, which are often performed alongside osseointegrated implant (OI) prosthesis placement to manage nerve pain. In this study, we aimed evaluate neuromas and assess the effectiveness of TMRpni in preventing neuroma formation using ultrasound in OI patients.

Methods: This was a single-institutional prospective observational study of patients with lower-limb OI prostheses. Lower extremity nerve ultrasounds with 2-D grayscale and doppler were completed at post-operative follow-up visits following OI prosthesis implantation. The sciatic nerve was targeted for imaging in above-the-knee amputees, while the common peroneal, tibial, and sural nerves were targeted for below-the-knee amputees. Neuromas found on ultrasound were reported in square millimeters (mm2) and pain was assessed with targeted palpation using the ultrasound probe.

Results: Our study included 24 nerves imaged from 10 amputees (2 transfemoral, 8 transtibial). The mean time of imaging from surgery was 18 months (range: 4-40 months). Nerves imaged included two sciatic, three common peroneal, four superficial peroneal, four deep peroneal, five sural, and six tibial nerves. There were 7 nerves that received TMRpni and 17 nerves that received no nerve reconstruction during osseointegration implantation. In nerves without TMRpni, ultrasound identified 10 hypoechoic nodules consistent with neuromas (59%) while 7 nerves tapered smoothly into the surrounding musculature (41%). Median neuroma size in the non-TMRpni group was 62 mm2 (range: 13.8-289 mm2). Patients experienced symptomatic neuromas upon sonopalpation in 3 of the 10 neuromas (30%). Of the seven nerves with TMRpni, ultrasound detected intact coaptation between the motor nerve branches and sensory branches of TMRpni in 6 nerves (86%). Intact coaptations were observed up to 16 months post-reconstruction without pain to sonopalpation. One 12.4 mm2 neuroma was identified at one TMRpni coaptation 14 months after reconstruction and direct sonopalpation elicited pain.

Conclusions: Ultrasound proved effective in evaluating neuroma formation and TMRpni outcomes in amputees with osseointegrated prostheses. Neuromas were detected in 59% of unreconstructed nerves, while TMRpni demonstrated intact coaptation in most cases, with one reconstruction failure observed at 14 months after surgery. Ultrasound enabled real-time identification of symptomatic neuromas using sonopalpation unlike magnetic resonance imaging techniques. These findings support the potential role of ultrasound in long-term monitoring of nerve reconstruction efficacy and neuroma prevention.

Purpose: Ultrasound is routinely used to assess peripheral nerves in the lower extremity due to its low cost, accessibility, and rapid examination time. However, its use in evaluating neuromas, benign tumors of nerve tissue, remains underutilized despite its great potential as a noninvasive imaging tool. Ultrasound also provides a unique opportunity to visualize nerve reconstruction techniques, including targeted muscle reinnervation (TMR), regenerative peripheral nerve interface (RPNI), and their combination, TMRpni, which are often performed alongside osseointegrated implant (OI) prosthesis placement to manage nerve pain. In this study, we aimed evaluate neuromas and assess the effectiveness of TMRpni in preventing neuroma formation using ultrasound in OI patients.

Methods: This was a single-institutional prospective observational study of patients with lower-limb OI prostheses. Lower extremity nerve ultrasounds with 2-D grayscale and doppler were completed at post-operative follow-up visits following OI prosthesis implantation. The sciatic nerve was targeted for imaging in above-the-knee amputees, while the common peroneal, tibial, and sural nerves were targeted for below-the-knee amputees. Neuromas found on ultrasound were reported in square millimeters (mm2) and pain was assessed with targeted palpation using the ultrasound probe.

Results: Our study included 24 nerves imaged from 10 amputees (2 transfemoral, 8 transtibial). The mean time of imaging from surgery was 18 months (range: 4-40 months). Nerves imaged included two sciatic, three common peroneal, four superficial peroneal, four deep peroneal, five sural, and six tibial nerves. There were 7 nerves that received TMRpni and 17 nerves that received no nerve reconstruction during osseointegration implantation. In nerves without TMRpni, ultrasound identified 10 hypoechoic nodules consistent with neuromas (59%) while 7 nerves tapered smoothly into the surrounding musculature (41%). Median neuroma size in the non-TMRpni group was 62 mm2 (range: 13.8-289 mm2). Patients experienced symptomatic neuromas upon sonopalpation in 3 of the 10 neuromas (30%). Of the seven nerves with TMRpni, ultrasound detected intact coaptation between the motor nerve branches and sensory branches of TMRpni in 6 nerves (86%). Intact coaptations were observed up to 16 months post-reconstruction without pain to sonopalpation. One 12.4 mm2 neuroma was identified at one TMRpni coaptation 14 months after reconstruction and direct sonopalpation elicited pain.

Conclusions: Ultrasound proved effective in evaluating neuroma formation and TMRpni outcomes in amputees with osseointegrated prostheses. Neuromas were detected in 59% of unreconstructed nerves, while TMRpni demonstrated intact coaptation in most cases, with one reconstruction failure observed at 14 months after surgery. Ultrasound enabled real-time identification of symptomatic neuromas using sonopalpation unlike magnetic resonance imaging techniques. These findings support the potential role of ultrasound in long-term monitoring of nerve reconstruction efficacy and neuroma prevention.

Purpose: Ultrasound is routinely used to assess peripheral nerves in the lower extremity due to its low cost, accessibility, and rapid examination time. However, its use in evaluating neuromas, benign tumors of nerve tissue, remains underutilized despite its great potential as a noninvasive imaging tool. Ultrasound also provides a unique opportunity to visualize nerve reconstruction techniques, including targeted muscle reinnervation (TMR), regenerative peripheral nerve interface (RPNI), and their combination, TMRpni, which are often performed alongside osseointegrated implant (OI) prosthesis placement to manage nerve pain. In this study, we aimed evaluate neuromas and assess the effectiveness of TMRpni in preventing neuroma formation using ultrasound in OI patients.

Methods: This was a single-institutional prospective observational study of patients with lower-limb OI prostheses. Lower extremity nerve ultrasounds with 2-D grayscale and doppler were completed at post-operative follow-up visits following OI prosthesis implantation. The sciatic nerve was targeted for imaging in above-the-knee amputees, while the common peroneal, tibial, and sural nerves were targeted for below-the-knee amputees. Neuromas found on ultrasound were reported in square millimeters (mm2) and pain was assessed with targeted palpation using the ultrasound probe.

Results: Our study included 24 nerves imaged from 10 amputees (2 transfemoral, 8 transtibial). The mean time of imaging from surgery was 18 months (range: 4-40 months). Nerves imaged included two sciatic, three common peroneal, four superficial peroneal, four deep peroneal, five sural, and six tibial nerves. There were 7 nerves that received TMRpni and 17 nerves that received no nerve reconstruction during osseointegration implantation. In nerves without TMRpni, ultrasound identified 10 hypoechoic nodules consistent with neuromas (59%) while 7 nerves tapered smoothly into the surrounding musculature (41%). Median neuroma size in the non-TMRpni group was 62 mm2 (range: 13.8-289 mm2). Patients experienced symptomatic neuromas upon sonopalpation in 3 of the 10 neuromas (30%). Of the seven nerves with TMRpni, ultrasound detected intact coaptation between the motor nerve branches and sensory branches of TMRpni in 6 nerves (86%). Intact coaptations were observed up to 16 months post-reconstruction without pain to sonopalpation. One 12.4 mm2 neuroma was identified at one TMRpni coaptation 14 months after reconstruction and direct sonopalpation elicited pain.

Conclusions: Ultrasound proved effective in evaluating neuroma formation and TMRpni outcomes in amputees with osseointegrated prostheses. Neuromas were detected in 59% of unreconstructed nerves, while TMRpni demonstrated intact coaptation in most cases, with one reconstruction failure observed at 14 months after surgery. Ultrasound enabled real-time identification of symptomatic neuromas using sonopalpation unlike magnetic resonance imaging techniques. These findings support the potential role of ultrasound in long-term monitoring of nerve reconstruction efficacy and neuroma prevention.

Purpose: Visualizing axonal regeneration along injured nerves is not possible with currently available imaging modalities, severely limiting accurate diagnosis and effective management of peripheral nerve injuries. We investigated if imaging macrophages, which infiltrate injured nerves during Wallerian degeneration, could allow for non-invasive characterization of peripheral nerve injuries. Specifically, we evaluated the use of the PET agent [11C]CPPC, which binds to the colony stimulating factor 1 receptor (CSF1R) expressed by monocytes and proliferating macrophages, as a novel nerve imaging agent.

Methods and Materials: Ten male Lewis rats were divided into two surgical groups: unilateral sciatic nerve transection with repair using a 3cm isograft (n=5) or sciatic transection without repair, in which a 3cm isograft was coapted only to the distal stump (n=5). All animals underwent contralateral sham surgery. At 4 weeks post-intervention, animals received an intravenous injection of [11C]CPPC, and radioactivity was quantified using an automated gamma counter. To examine differential uptake along the sciatic nerve, nerves were analyzed in 3 segments: the sciatic nerve proximal to the site of injury, the nerve graft, and the sciatic nerve distal to the injury site. [11C]CPPC uptake, expressed as percent injected dose per segment (%ID/segment), was compared between groups using Kruskal-Wallis tests with post-hoc Dunn tests.

Results: Relative to sham segments, injured sciatic nerves from both unrepaired and repaired animals demonstrated significantly greater [11C]CPPC uptake within the graft (unrepaired: 4.1x uptake, p<0.05; repaired: 2.7x uptake, p<0.05) and distal sciatic segments (unrepaired: 3.9x uptake, p<0.05; repaired: 2.8x uptake, p<0.05). Uptake in both unrepaired and repaired nerves was significantly higher in segments distal to the site of injury compared to segments proximal to the injury site (p<0.05). Relative to repaired nerves, unrepaired nerves demonstrated greater uptake within the graft (1.7x uptake, p<0.05) and in the distal sciatic segment (1.3x uptake, p<0.05).

Conclusion: [11C]CPPC effectively labeled macrophage content within injured nerves, with higher uptake observed in unrepaired nerves compared to repaired nerves and in distal versus proximal segments. These findings suggest that [11C]CPPC PET imaging of CSF1R may be a promising non-invasive approach for the characterization of peripheral nerve injuries and the monitoring of axonal regeneration following repair.

PURPOSE: High-resolution MRI of peripheral nerves, or magnetic resonance (MR) neurography, can facilitate nerve visualization for surgical planning and symptom evaluation(1), but is currently under-utilized in the field of plastic surgery. Additionally, despite the importance of peripheral nerve anatomy to plastic surgeries, limited tools are available to the surgical trainee to demonstrate the correct three-dimensional nerve anatomy, branching patterns, and relationship to surrounding structures. The head and neck represents a region with a complex network of peripheral nerves that provide important functionality, including facial strength, sensation, gustation, and mastication; damage to these nerves can be potentially debilitating to patients. While early exploration suggests MR neurography may be useful in the face and neck region(2), identifying nerves in the head and face on MRI has previously been technically challenging due to their small size and branching patterns. This research creates a high-resolution, freely available, interactive MR neurography atlas of the face and neck as a clinical and educational tool to 1) facilitate education of nerve anatomy in the head and neck, and 2) demonstrate the feasibility of applying MR neurography in this region.

MATERIALS AND METHODS: Healthy volunteers (n=8, 7 Female, mean 25.5 years) underwent 3.0-Tesla MR neurography of the head and neck from September 2021 to April 2024 at 0, 12, 24, and 36 hours post infusion with ferumoxytol (iron-oxide nanoparticle) for vascular suppression (127.5mg iron; half-life=14 hours).(3) Two-dimensional and three-dimensional fluid-sensitive, fat-suppressed sequences were acquired with submillimeter resolution and reconstructed using deep-learning algorithms for improved image quality (AIRTM Recon DL). Three radiologists independently reviewed exams to select the highest quality and most anatomically representative cases, forming the basis for the atlas. A previously developed brachial plexus atlas (https://www.hss.edu/MRNatlas) was expanded to include the head and neck using RadStax web-based software.

RESULTS: Excellent vascular suppression was achieved in 8 subjects. Image stacks are being generated for each major nerve in the face and neck, with labels for 49 muscles and 121 nerves. The atlas is currently being developed in-house and will be made available on an institutional server alongside the brachial plexus atlas.

CONCLUSIONS: An interactive MR neurography atlas is developed to depict nerves and their innervated muscles in the face and neck. Plastic surgery trainees may utilize this atlas as a clinical and educational reference to better understand peripheral nerve anatomy. This may also facilitate increased use of MR neurography within the field of plastic surgery as a valuable tool for surgical planning and symptom evaluation.

REFERENCES: 1. Thawait SK, Wang K, Subhawong TK et al. Peripheral nerve surgery: the role of high-resolution MR neurography. AJNR Am J Neuroradiol. 2012 Feb;33(2):203-10. 2. Remy K, Hazewinkel MHJ, Knoedler L, Sneag DB, Austen WG Jr, Gfrerer L. Aetiologies of iatrogenic occipital nerve injury and outcomes following treatment with nerve decompression surgery. J Plast Reconstr Aesthet Surg. 2024 Aug;95:349-356. 3. Queler SC, Tan ET, Geannette C, Prince M, Sneag DB. Ferumoxytol-enhanced vascular suppression in magnetic resonance neurography. Skeletal Radiol. 2021 Nov;50(11):2255-2266.

Introduction: Rib sparring scalenectomy (RSS) for supraclavicular (SC) brachial plexus decompression has been used to treat neurogenic thoracic outlet syndrome (NTOS), but there are limited studies describing objective clinical outcomes. Here, we demonstrate clinical improvement for patients undergoing RSS for NTOS based on QuickDASH (QD) scores.

Methods: This is a single center, retrospective study, evaluating NTOS patients who underwent primary unilateral RSS through a SC approach between the dates of June 2023 & December 2024. All surgeries were performed by a single surgeon. Paired student t-test was used to compare mean pre- and postoperative QD scores as well as differences in QD score subsets. Linear regression was used to evaluate the relationship between patient demographics and surgical factors on change in QD scores as well as overall postoperative scores.

Results: A total of 13 patients were included in the study (average age 38 [SD18.9 years]; 10 (76.9%) females). The average time from diagnosis of NTOS to index surgery was 37.5 (SD 29.7 months). Most patients (92.3%) had European Association of Neurosurgical Societies (EANS) type I NTOS consisting of motor weakness/atrophy. Only one patient (7.7%) had type II NTOS as defined as an anatomic abnormality causing pain/sensory symptoms only. Nearly half (53.8%) underwent subsequent infraclavicular (IC) decompression at time of surgery, while 4 patients (30.8%) underwent distal nerve decompression. Average follow-up was 148.5 (SD109.8 days). No patients underwent subsequent revision surgery. Average preoperative QD score was 48.46 (interquartile range [IQR], 36.36 to 57.96) and average postoperative QD score was 29.2 (IQR, 19.32-43.19). The mean difference in pre- and final postoperative QD scores was (19.27 ± 14.10, p<0.001). Additionally, on QD breakdown patients reported significant reduction in pain (p=0.002) and improvement in sleep (p=0.018) & ability to socialize with friends/family (p=0.033). No relationship was found between patient demographic data and change in QD scores; however, age >65 years (p=0.005) and history of psychiatric diagnosis (p=0.01) were associated with overall higher final postoperative QD scores.

Summary Points: NTOS patients undergoing supraclavicular decompression via scalenectomy demonstrate significant improvements in QD scores. Advanced age and psychiatric diagnosis may attribute overall higher postoperative scores, however, do not significantly impact changes from baseline preoperative scores.

Background: Facial nerve palsy (FNP) is a debilitating condition that significantly impacts pediatric patients undergoing brain tumor resection, with an incidence of iatrogenic injury as high as 20%. Despite advancements in reconstructive and rehabilitative strategies, outcomes remain highly variable. A comprehensive evaluation of patient demographics, treatment modalities, and prognostic indicators is essential to optimize management and improve long-term outcomes. Methods: This retrospective cohort study analyzes 1068 pediatric patients diagnosed with FNP at St. Jude Hospital from 2014 to 2024. Data were extracted from medical records, including demographic information, tumor diagnosis, clinical presentation, treatment approaches (surgical interventions, physical therapy, adjunctive therapies), and long-term outcomes. Comparative statistical analyses, including chi-square tests for categorical variables and t-tests/ANOVA for continuous variables, were performed to identify prognostic factors influencing recovery. Results: Preliminary findings suggest significant variability in recovery rates based on etiology, treatment modality, and timing of intervention. Certain prognostic factors, including patient age, tumor type, and severity of initial palsy, were associated with differential outcomes. The study also evaluates the efficacy of various reconstructive and rehabilitative strategies, providing insights into best practices for optimizing facial function. Conclusion: This study represents the largest cohort analysis of pediatric FNP patients at a single institution and provides critical insights into the demographic and clinical profiles of affected patients. By identifying key prognostic factors and effective treatment strategies, these findings can guide more personalized, evidence-based approaches to FNP management. The results contribute to the existing literature and have the potential to improve long-term functional and psychosocial outcomes for pediatric patients with FNP. Significance: Understanding the factors that influence FNP recovery and treatment efficacy can inform clinical decision-making, enhance patient counseling, and refine surgical and rehabilitative approaches, ultimately improving quality of life for affected children.

Purpose: Managing osteomyelitis (OM) in amputees with osseointegrated implants (OI) requires balancing infection control with implant retention. This study evaluates antibiotic regimens, surgical management, and implant outcomes in OI patients who developed OM.

Methods: A retrospective review of 127 OI patients (2017-2023) identified OM cases by positive intraoperative bone cultures or radiographic evidence of infection (i.e., X-ray, CT, MRI). Empiric and targeted antibiotic regimens were categorized, and treatment outcomes, including clearance, recurrence, and implant survival, were analyzed using descriptive statistics.

Results: Among 127 patients reviewed, 11 (8.7%) were diagnosed with OM. The median follow-up time for all OI patients was 2.6 years (IQR: 2.1). Infection clearance was achieved in 82% of OM patients, though 64% experienced recurrence. Empiric regimens most commonly included beta-lactams (n = 3, 100% clearance, 67% recurrence) and glycopeptides with beta-lactamase inhibitors (n = 3, 100% clearance, 67% recurrence). Targeted therapy predominantly involved beta-lactams (n = 6, 83% clearance, 50% recurrence), with escalation to fluoroquinolones or lipopeptides (n = 2), achieving 100% clearance but 100% recurrence. Median total antibiotic duration was 43 days (IQR: 9.5). Surgical debridement was performed in 73% of cases (median: 1 debridement, mean: 1.9 ± 1.5). Implant exchange was required in 36% of OM cases, but implant survival with revision was achieved in 55%. Across all 127 OI patients, the implant exchange rate was 3.1% (n = 4).

Conclusion: Although some OM patients experienced recurrence, initial infection clearance was achieved in most cases, and implant exchange was needed in only four patients. Beta-lactams were the primary antibiotic class, occasionally escalating to fluoroquinolones or lipopeptides. Encouragingly, over half of infected implants were salvaged through revision surgery, underscoring the potential for implant retention despite infections. Further studies are needed to refine antibiotic regimens and surgical strategies for optimal long-term outcomes.

Purpose: Managing osteomyelitis (OM) in amputees with osseointegrated implants (OI) requires balancing infection control with implant retention. This study evaluates antibiotic regimens, surgical management, and implant outcomes in OI patients who developed OM.

Methods: A retrospective review of 127 OI patients (2017-2023) identified OM cases by positive intraoperative bone cultures or radiographic evidence of infection (i.e., X-ray, CT, MRI). Empiric and targeted antibiotic regimens were categorized, and treatment outcomes, including clearance, recurrence, and implant survival, were analyzed using descriptive statistics.

Results: Among 127 patients reviewed, 11 (8.7%) were diagnosed with OM. The median follow-up time for all OI patients was 2.6 years (IQR: 2.1). Infection clearance was achieved in 82% of OM patients, though 64% experienced recurrence. Empiric regimens most commonly included beta-lactams (n = 3, 100% clearance, 67% recurrence) and glycopeptides with beta-lactamase inhibitors (n = 3, 100% clearance, 67% recurrence). Targeted therapy predominantly involved beta-lactams (n = 6, 83% clearance, 50% recurrence), with escalation to fluoroquinolones or lipopeptides (n = 2), achieving 100% clearance but 100% recurrence. Median total antibiotic duration was 43 days (IQR: 9.5). Surgical debridement was performed in 73% of cases (median: 1 debridement, mean: 1.9 ± 1.5). Implant exchange was required in 36% of OM cases, but implant survival with revision was achieved in 55%. Across all 127 OI patients, the implant exchange rate was 3.1% (n = 4).

Conclusion: Although some OM patients experienced recurrence, initial infection clearance was achieved in most cases, and implant exchange was needed in only four patients. Beta-lactams were the primary antibiotic class, occasionally escalating to fluoroquinolones or lipopeptides. Encouragingly, over half of infected implants were salvaged through revision surgery, underscoring the potential for implant retention despite infections. Further studies are needed to refine antibiotic regimens and surgical strategies for optimal long-term outcomes.

PURPOSE: Following mastectomy, patients often experience numbness in the breast due to the sacrifice of sensory nerves. Neurotization aims to restore sensation by surgically coapting donor nerves in the reconstructed breast to recipient nerves in the chest wall. This pilot study is the first to quantify the recovery of tactile and thermal sensation over time relative to baseline in patients undergoing mastectomy with immediate dual-neurotized autologous reconstruction.

METHODS: Patients scheduled for mastectomy with deep inferior epigastric perforator (DIEP) flap reconstruction were prospectively enrolled. During reconstruction, dual-nerve coaptation was performed using two thoracoabdominal donor nerves and the anterior cutaneous and lateral branches of the T3/T4 recipient nerves.

Patients underwent neurosensory testing preoperatively and at 3, 6, and 9 months postoperatively. Tactile sensation was assessed across nine breast regions using a pressure-specified sensory device. Thermal sensation was evaluated across five breast regions using hot (52°C) and cold (12°C) packs. Sensation scores at each time point were compared to preoperative baseline values, with all patients serving as their own controls. Statistical analysis was performed using paired t-tests, with the significance level set at α = 0.05.

RESULTS: Overall, 29 breasts were included in the study. Tactile sensation progressively improved over time, starting at 48.7% of baseline at 3 months postoperatively, increasing to 69.5% by 6 months, and reaching 70.9% by 9 months (p < 0.001). The outer superior area demonstrated the greatest sensory recovery, reaching 94.1% of baseline by 9 months, which was not significantly different from preoperative scores (p = 0.265). This was followed by the outer medial region (87.7%), outer lateral region (81.4%), and outer inferior region (72.7%). In contrast, the nipple-areola complex (NAC) exhibited the lowest tactile recovery, reaching only 57.5% of baseline by 9 months (p < 0.001).

For thermal recovery, 56%, 72%, and 73% of breast regions correctly perceived heat sensation at 3, 6, and 9 months postoperatively, while only 38%, 46%, and 43% correctly perceived cold sensation. Subanalysis at 9 months revealed that heat perception was highest in the superior and medial regions, while cold perception was highest in the superior and lateral regions. In contrast, the NAC demonstrated the poorest thermal sensory recovery, with only 43.8% of patients perceiving heat correctly and 6.3% perceiving cold correctly by 9 months.

CONCLUSION: This is the first study to evaluate sensory outcomes following mastectomy and dual-neurotized DIEP reconstruction. Our findings provide a baseline reference for physicians considering dual-nerve neurotization and can inform preoperative counseling. Patients can expect to recover approximately 73% of tactile sensation, 73% of heat perception, and 43% of cold perception by nine months postoperatively. Additionally, patients should be advised that the NAC demonstrates the poorest sensory recovery among all breast regions.

PURPOSE: Following mastectomy, patients often experience numbness in the breast due to the sacrifice of sensory nerves. Neurotization aims to restore sensation by surgically coapting donor nerves in the reconstructed breast to recipient nerves in the chest wall. This pilot study is the first to quantify the recovery of tactile and thermal sensation over time relative to baseline in patients undergoing mastectomy with immediate dual-neurotized autologous reconstruction.

METHODS: Patients scheduled for mastectomy with deep inferior epigastric perforator (DIEP) flap reconstruction were prospectively enrolled. During reconstruction, dual-nerve coaptation was performed using two thoracoabdominal donor nerves and the anterior cutaneous and lateral branches of the T3/T4 recipient nerves.

Patients underwent neurosensory testing preoperatively and at 3, 6, and 9 months postoperatively. Tactile sensation was assessed across nine breast regions using a pressure-specified sensory device. Thermal sensation was evaluated across five breast regions using hot (52°C) and cold (12°C) packs. Sensation scores at each time point were compared to preoperative baseline values, with all patients serving as their own controls. Statistical analysis was performed using paired t-tests, with the significance level set at α = 0.05.

RESULTS: Overall, 29 breasts were included in the study. Tactile sensation progressively improved over time, starting at 48.7% of baseline at 3 months postoperatively, increasing to 69.5% by 6 months, and reaching 70.9% by 9 months (p < 0.001). The outer superior area demonstrated the greatest sensory recovery, reaching 94.1% of baseline by 9 months, which was not significantly different from preoperative scores (p = 0.265). This was followed by the outer medial region (87.7%), outer lateral region (81.4%), and outer inferior region (72.7%). In contrast, the nipple-areola complex (NAC) exhibited the lowest tactile recovery, reaching only 57.5% of baseline by 9 months (p < 0.001).

For thermal recovery, 56%, 72%, and 73% of breast regions correctly perceived heat sensation at 3, 6, and 9 months postoperatively, while only 38%, 46%, and 43% correctly perceived cold sensation. Subanalysis at 9 months revealed that heat perception was highest in the superior and medial regions, while cold perception was highest in the superior and lateral regions. In contrast, the NAC demonstrated the poorest thermal sensory recovery, with only 43.8% of patients perceiving heat correctly and 6.3% perceiving cold correctly by 9 months.

CONCLUSION: This is the first study to evaluate sensory outcomes following mastectomy and dual-neurotized DIEP reconstruction. Our findings provide a baseline reference for physicians considering dual-nerve neurotization and can inform preoperative counseling. Patients can expect to recover approximately 73% of tactile sensation, 73% of heat perception, and 43% of cold perception by nine months postoperatively. Additionally, patients should be advised that the NAC demonstrates the poorest sensory recovery among all breast regions.

Introduction: Microsurgical nerve repair has traditionally focused on mechanical reconnection methods like direct neurorrhaphy and nerve grafting, but these often yield incomplete functional recovery. Recent insights into regenerative medicine highlight the crucial role of macrophage-driven inflammation and immune modulation in peripheral nerve repair through the chemokine CCL2 (MCP-1). This review proposes a paradigm shift in microsurgery-from a purely structural approach to a bioactive strategy, enhancing nerve healing through intraoperative modulation of CCL2 signaling. We hypothesize that incorporating molecular interventions could accelerate nerve regeneration and functional recovery, while reducing postoperative neuropathic pain.

Objective: This paper evaluates the role of CCL2 as a bioactive modulator in nerve regeneration. We aim to establish a scientific and clinical basis for integrating CCL2-based therapies into microsurgical protocols, representing a breakthrough in nerve repair strategies.

Methods: A literature review was conducted using PubMed to assess CCL2's role in nerve regeneration, macrophage recruitment, neuroinflammation, neurite outgrowth, and functional recovery. The review included in vitro studies, rodent nerve injury models (such as crush, transection, graft, and spinal cord injury), and investigations into CCL2's mechanisms of action through knockout and overexpression models. Insights from ongoing laboratory experiments focused on nerve regeneration strategies, macrophage modulation, and bioactive materials. The data was analyzed to identify opportunities for leveraging CCL2 in bioactive microsurgical interventions.

Results: A significant portion of current research focuses on the effects of CCL2 on nerve repair mechanisms through macrophage recruitment and neurite outgrowth promotion. Specifically, CCL2 is shown to mediate neuron-macrophage interactions involved in pro-regenerative macrophage activation. While many investigations concentrate on CCL2's isolated effects on neuroinflammation and nerve regeneration, other research explores its role within more complex scenarios, such as nerve grafting or cellular therapies. Such studies suggest that CCL2-CCR2 signaling is essential for macrophage accumulation in nerve allografts, supporting the hypothesis that exogenous CCL2 could enhance graft integration. Studies utilizing acellular nerve allografts (ANAs) have shown that CCL2 is critical for recruiting macrophages into the graft, promoting angiogenesis, and ultimately leading to improved nerve regeneration. Pre-conditioning approaches, such as transplanting mesenchymal stromal cells (MSCs) stimulated to release CCL2, show promise for improved nerve regeneration in transection models, indicating a compounded benefit when combining cellular therapies with CCL2-mediated effects. Additionally, CCL2 modulation appears to influence post-injury pain behaviors. Collectively, these findings support the feasibility of leveraging CCL2 intraoperatively to accelerate nerve healing and improve microsurgical results.

Conclusion: Incorporating bioactive molecular interventions into microsurgery shifts nerve repair beyond just structural reconstruction. Targeting CCL2 intraoperatively may enhance macrophage-driven repair, graft integration, and functional recovery. Our ongoing research aims to validate this approach through preclinical studies assessing exogenous CCL2 delivery, fluorescent microscopy to analyze macrophage infiltration and axon growth, and the development of bioactive microsutures or hydrogels for sustained intraoperative release. Modulating CCL2 intraoperatively may significantly enhance peripheral nerve regeneration, advancing microsurgical nerve repair with clinical applications.

Purpose Lower extremity gunshot wounds (GSWs) are significant traumatic events associated with significant patient morbidity and mortality. Alongside evaluation for vascular injury (1) and fractures, (2) examination of neurologic function is critical. Development of peripheral nerve injury (PNI) may result in permanent disability for patients. Limited data exists on epidemiology and predictors of PNIs, a gap this study aims to fill.

We hypothesize that concomitant dislocations or open injuries are associated with posttraumatic PNIs. We also predict that vascular procedures may signal an increased risk of nerve injury.

Methods We retrospectively queried patients within the Duke University Health System between January 2014 and June 2024 (3, 4) for presentations of lower extremity gunshot wound trauma. Patient demographics were captured. Characteristics and trauma, including injury components and surgical interventions, were noted. Nerve injuries within 180 days were also captured, and PNI characteristics were charted.

Results Overall, 2,552 patients presented with lower extremity GSWs, with 2,124 (83.2%) males at a median age of 29.7 years [24.2,43.9]. Injuries most often had open wound (1,534, 60.1%) or fracture (1,254, 49.1%) components, with 909 (35.6%) polytraumas. GSWs most often damaged the leg (1,073 42.0%), knee (380, 14.9%), or foot (373, 14.6%).

PNIs were reported in 38 (1.5%) patients, with 22 (57.9%) requiring immediate surgical repair and 16 (42.1%) undergoing delayed repair. The sciatic nerve (16, 42.1%) and tibial nerve (5, 13.2%) were predominantly impacted.

Open, vascular, dislocation, or amputation components to injury were more frequent in patients with PNIs (all p<0.05). PNI patients also had higher requirements for immediate fasciotomy, vascular grafting, and other major vascular procedures (all p<0.05). While surgical fracture reduction at any level was not associated with PNIs, the need for other procedural interventions on the ankle and leg, including debridement and decompression, was significant (p<0.05).

On logistic regression, dislocation (p=0.021, OR=13.07, 95% CI=0.67-82.53) or open (p=0.028, OR=2.70, 95% CI=1.15-6.93) wound components independently raised odds of PNI. Requiring a vascular graft was also a significant predictor of nerve injury (p=0.043, OR=5.14, 95% CI=1.01-22.92), although other procedures did not increase the frequency of PNI.

Conclusions PNIs after lower extremity GSWs were diagnosed in 1.5% of patients. All patients required surgical intervention, with 57.9% undergoing immediate repair. Dislocation or open components significantly raised the odds of PNIs, as did the need for vascular grafting. Patients who present with concerning trauma characteristics should be cautiously scrutinized for the development of lower extremity neuropathy.

References 1. Sadjadi J, Cureton EL, Dozier KC, Kwan RO, Victorino GP. Expedited treatment of lower extremity gunshot wounds. J Am Coll Surg. 2009;209(6):740-5. Epub 2009/12/05. 2. Bartlett CS. Clinical update: gunshot wound ballistics. Clin Orthop Relat Res. 2003(408):28-57. Epub 2003/03/05. 3. Hurst JH, Liu Y, Maxson PJ, Permar SR, Boulware LE, Goldstein BA. Development of an electronic health records datamart to support clinical and population health research. J Clin Transl Sci. 2020;5(1):e13. Epub 2021/05/06. 4. Horvath MM, Rusincovitch SA, Brinson S, Shang HC, Evans S, Ferranti JM. Modular design, application architecture, and usage of a self-service model for enterprise data delivery: the Duke Enterprise Data Unified Content Explorer (DEDUCE). J Biomed Inform. 2014;52:231-42. Epub 2014/07/23.

Purpose Patients with nerve pain who present for nerve decompression surgery oftentimes also experience concomitant headache disorders such as migraine. It is unclear whether a family history of migraine influences preoperative patient characteristics that could help determine candidacy for surgery. This study aims to explore this association.

Methods Patients who underwent screening for nerve decompression surgery between September 2012 and December 2025 at two institutions were enrolled in this prospective cohort study. Information regarding demographics, family history of HDs, migraine and nerve pain characteristics, and associated symptoms were collected preoperatively. A univariate and multivariable linear regression analysis was conducted to examine the association of a family history of migraine with patients' preoperative characteristics.

Results Among 1,113 patients, 667 (59.9%) reported a positive family history of migraine, while 446 (40.1%) did not. The average age of migraine onset was significantly younger in those with a family history of migraine (19.42 years) as compared to those without (29.64 years) (p<0.001). A significantly higher proportion of patients with a positive family history of migraine reported symptoms of aura before or during pain episodes, including nausea, vomiting, sensitivity to light or noise, blurred or double vision, and difficulty with concentration (p<0.01). A significantly greater proportion of patients with a family history of migraine described their migraine pain as "aching," "squeezing," "stabbing," or constricting," whereas those without a family history were more likely to characterize their pain as "throbbing," (p<0.05). Additionally, patients without a family history of migraine were significantly more likely to report an inciting head or neck injury requiring medical treatment (p=0.01) and concurrent nerve pain with their migraine pain (p<0.05).

Conclusion Our findings suggest that patients with and without a family history of migraine differ in their preoperative pain characteristics and associated symptoms. Patients without a family history were more likely to report a history of head or neck trauma and describe throbbing pain, while those with a family history experienced an earlier symptom onset and symptoms of aura. Distinguishing between how these groups present preoperatively may improve patient selection for nerve decompression surgery and optimize treatment for those with underlying non-migrainous pain.