Preoperative visualization of the greater occipital nerve with magnetic resonance imaging in candidates for occipital nerve decompression for headaches.

Occipital nerve decompression is effective in reducing headache symptoms in select patients with migraine and occipital neuralgia. Eligibility for surgery relies on subjective symptoms and responses to nerve blocks and Onabotulinum toxin A (Botox) injections. No validated objective method exists for detecting occipital headache pathologies. The purpose of the study is to explore the potential of high-resolution Magnetic Resolution Imaging (MRI) in identifying greater occipital nerve (GON) pathologies in chronic headache patients. The MRI protocol included three sequences targeting fat-suppressed fluid-sensitive T2-weighted signals. Visualization of the GON involved generating 2-D image slices with sequential rotation to track the nerve course. Twelve patients underwent pre-surgical MRI assessment. MRI identified four main pathologies that were validated against intra-operative examination: GON entanglement by the occipital artery, increased nerve thickness and hyperintensity suggesting inflammation compared to the non-symptomatic contralateral side, early GON branching with rejoining at a distal point, and a connection between the GON and the lesser occipital nerve. MRI possesses the ability to visualize the GON and identify suspected trigger points associated with headache symptoms. This case series highlights MRI's potential to provide objective evidence of nerve pathology. Further research is warranted to establish MRI as a gold standard for diagnosing extracranial contributors in headaches.

Timing of Autologous Tissue Breast Reconstruction Does Not Affect Free Flap Failure.

ABSTRACT: This study aimed to determine whether there is a difference in free flap failure based on the decision to undergo immediate versus delayed autologous tissue breast reconstruction after mastectomy. The National Surgical Quality Improvement Program database was queried for breast free flap procedures performed between 2015 and 2020. This study demonstrates that the decision to undergo immediate versus delayed autologous tissue breast reconstruction does not have a significant association with free flap failure. This remains true regardless of whether patients undergo unilateral mastectomy with reconstruction or whether patients choose to also undergo contralateral prophylactic mastectomy with reconstruction.

Amputated Digit Replantations: Critical Digit Ischemia Timing, Temperature, and Other Predictors of Survival.

INTRODUCTION: A common consideration for replantation success is the ischemia time following injury and the preservation temperature. A classic principle within the hand surgery community describes 12 hours of warm ischemia and 24 hours of cold ischemia as the upper limits for digit replantation; however, these limits are largely anecdotal and based on older studies. We aimed to compare survival data from the large body of literature to aid surgeons and all those involved in the replantation process in hopes of optimizing success rates. METHODS: The PubMed database was queried on April 4th, 2023, for articles that included data on digit replantation survival in terms of temperature of preservation and ischemia time. All primary outcomes were analyzed with the Mantel-Haenszel method within a random effects model. Secondary outcomes were pooled and analyzed using the chi-square statistic. Statistical analysis and forest plot generation were completed with RevMan 5.4 software with odds ratios calculated within a 95% confidence interval. RESULTS: Our meta-analysis identified that digits preserved in cold ischemia for over 12 hours had significantly higher odds of replantation success than the amputated digits replanted with 0-12 hours of warm ischemia time ( P ≤ 0.05). The odds of survival in the early (0-6 hours) replantation group were around 40% greater than the later (6-12 hours) replantation group ( P ≤ 0.05). Secondary outcomes that were associated with higher survival rates included a clean-cut amputation, increased venous and arterial anastomosis, a repair that did not require a vein graft, and replants performed in nonsmokers ( P ≤ 0.05). DISCUSSION: Overall, these findings suggest that when predicting digit replantation success, time is of the essence when the digit has yet to be preserved in a cold environment. This benefit, however, is almost completely diminished when the amputated digit is appropriately maintained in a cold environment soon after injury. In conclusion, our results suggest that there is potential for broadening the ischemia time limits for digit replant survival outlined in the literature, particularly for digits that have been stored correctly in cold ischemia.

Reduced Access to Acute Hand Care and Potential Role of Telemedicine in Tennessee During the COVID Pandemic.

INTRODUCTION: Previous studies have identified that there is limited, although expanding, access to acute hand care in Tennessee. Because of the rapid changes that occurred in health delivery and access during the coronavirus disease pandemic, we reassessed access to acute hand care, with particular interest in the utilization of telemedicine to assess if this increased access. METHOD: We surveyed Tennessee hospitals listed by the Tennessee Hospital Association on their management of hand trauma and availability of telemedicine programs. Census data including population demographics such as race, age, income, and county size were merged with the survey data. Descriptive analysis was performed comparing the 2021 cohort with the historic 2018 cohort and between counties that had hand care versus counties that had no hand care. RESULT: Survey response rate was 71.4% (n = 80 of 112). Telemedicine was used in 80% of the hospitals for other specialties but was not used for hand care. Overall, counties that offered hand trauma care reduced from 60% to 26% from 2018 to 2021 ( P < 0.001). This change was associated with a significant reduction of acute hand care among counties that were classified micropolitan (from 56.3% to 6.7%, P < 0.01). Percentage of hand specialists on staff and 24/7 specialists availability remained low and were similar to the availability in 2018. CONCLUSIONS: There was a decrease of acute hand care access in Tennessee during the coronavirus disease pandemic despite widespread utilization of telemedicine for other specialty consults. Expansion of telemedicine in acute hand care, targeted to micropolitan areas, may help to reduce variability in access to care.

Systematic Review and Meta-Analysis of Global Neuroma Incidence in Upper Extremity Amputees.

BACKGROUND: Neuromas substantially decrease a patient's quality of life and obstruct the use of prosthetics. This systematic review and meta-analysis aimed to determine the global incidence of neuroma formation in upper extremity amputees. METHODS: A literature search was performed using 3 databases: Web of Science, MEDLINE, and Cochrane. Inclusion criteria for the systematic review were those studies investigating only upper extremity amputees and reported postamputation neuroma. A random-effects, inverse-variance analysis was conducted to determine the pooled proportion of neuromas within the upper extremity amputation population. Critical appraisal using the JBI Checklist for Studies Reporting Prevalence Data of each individual article were performed for the systematic review. RESULTS: Eleven studies met the inclusion criteria collating a total of 1931 patients across 8 countries. More than three-fourth of patients are young men (77%; age range, 19-54 years) and had an amputation due to trauma. The random-effects analysis found the pooled combined proportion of neuromas to be 13% (95% confidence interval, 8%-18%). The treatment of neuroma is highly variable, with some patients receiving no treatment. CONCLUSIONS: The pooled proportion of neuroma incidence in the 1931 patients was 13%. With the known global prevalence of upper extremity amputees, this translates to nearly 3 million amputees suffering from a neuroma globally. Increasing training in preventative surgical methods could contribute to lowering this incidence and improving the outcomes of this patient population.

Effect of a Perioperative Educational Video in Patients Undergoing Mohs Reconstruction: A Randomized Clinical Trial.

BACKGROUND: Skin cancer is the most common type of cancer in the United States, and most are treated with Mohs micrographic surgery (MMS) by fellowship-trained dermatologic surgeons. Complex reconstruction in cosmetically and functionally sensitive areas often requires a plastic surgery consult. The uncertainty regarding reconstructive options and cosmetic appearance is difficult emotionally and cognitively for patients. OBJECTIVES: To improve patient understanding about MMS reconstruction with plastic surgeons, we investigated the utility of a multimedia presentation during perioperative education. METHODS: A randomized clinical trial was conducted at a hospital-affiliated outpatient MMS clinic and surgery center in the United States. Patients in the intervention arm were given a tablet or Web site link to watch a multimedia presentation about reconstruction after MMS. All patients were given a questionnaire about their understanding of MMS reconstruction and satisfaction with the reconstructive care they received. RESULTS: A total of 46 patients were recruited for the study and completed the questionnaire. Of these patients, 22 were randomized to the test intervention arm, and the remaining 24 were in the control group. Among participants in the test intervention arm, feedback regarding the platform was positive with more than 90% of patients reporting that the video was engaging, useful, and easy to understand. Patient understanding and satisfaction scores in the test intervention arm ranked higher across all domains than those of the control group. CONCLUSIONS: This randomized clinical trial showed increases in patient understanding and satisfaction among patients undergoing MMS reconstruction with the implementation of a perioperative educational video.

Delayed Versus Immediate Breast Reconstruction in the Ambulatory Surgery Setting: A Cross-Sectional Analysis of the Nationwide Ambulatory Surgery Sample.

BACKGROUND: Breast reconstruction remains an important part of a patient's journey after the diagnosis of breast carcinoma and treatment with mastectomy. Although inpatient immediate breast reconstruction has been described, there is a paucity information about whether similar procedures are performed in the ambulatory setting. OBJECTIVE: The authors sought to investigate rates and patterns for delayed and immediate breast reconstruction in the ambulatory surgery setting using nationally representative data from 2016 to 2019. METHODS: Using the Nationwide Ambulatory Surgery Sample database, we identified patients with an International Statistical Classification of Disease and Related Health Problems, Tenth Revision, procedure code for breast reconstruction. Demographic and clinical characteristics were recorded for each encounter of breast reconstruction, and linear regression and logistic regression were used to assess for trends and disparities. RESULTS: National weighted estimates for ambulatory breast reconstruction increased by 15.6% from 89 237 in 2016 to 103 134 in 2019, resulting in 377 109 procedures during the study period. Inflation-adjusted total charges for ambulatory breast reconstruction were $14 billion between 2016 and 2019, or 1.7% of overall charges for ambulatory surgery. Immediate reconstruction was performed in 34.7% (95% CI, 33.4%-36.1%) of cases and increased by 46.9% from 26 930 in 2016 to 39 559 in 2019. Racial disparities were observed in access, comorbidities, and spending. CONCLUSIONS: Our findings indicate a moderate increase in ambulatory breast reconstruction with a substantial growth in the performance of immediate breast reconstruction in the ambulatory setting.

Implantable, Bioresorbable Radio Frequency Resonant Circuits for Magnetic Resonance Imaging.

Magnetic resonance imaging (MRI) is widely used in clinical care and medical research. The signal-to-noise ratio (SNR) in the measurement affects parameters that determine the diagnostic value of the image, such as the spatial resolution, contrast, and scan time. Surgically implanted radiofrequency coils can increase SNR of subsequent MRI studies of adjacent tissues. The resulting benefits in SNR are, however, balanced by significant risks associated with surgically removing these coils or with leaving them in place permanently. As an alternative, here the authors report classes of implantable inductor-capacitor circuits made entirely of bioresorbable organic and inorganic materials. Engineering choices for the designs of an inductor and a capacitor provide the ability to select the resonant frequency of the devices to meet MRI specifications (e.g., 200 MHz at 4.7 T MRI). Such devices enhance the SNR and improve the associated imaging capabilities. These simple, small bioelectronic systems function over clinically relevant time frames (up to 1 month) at physiological conditions and then disappear completely by natural mechanisms of bioresorption, thereby eliminating the need for surgical extraction. Imaging demonstrations in a nerve phantom and a human cadaver suggest that this technology has broad potential for post-surgical monitoring/evaluation of recovery processes.

Longitudinal traumatic peripheral nerve injury recovery: quantitative description, classification and prediction.

Aim: Repair of peripheral nerves is recommended following transection. Systematic evaluation of longitudinal recovery in injury models is needed to improve patient management. Gompertz function provided straightforward interpretation and prediction of recovery outcomes. Materials & methods: Behavioural sciatic function index, measured 3 days post injury, and weekly for 12 weeks following full nerve transection and repair (n = 6) as well as crush injuries (n = 6). Results: Gompertz parametrization provided early classification between types of traumatic peripheral nerve injuries following surgical repair. Results distinguished injury nerves (A: p < 0.01; Ti: p < 0.05; Ic: p < 0.05 and outcome: p < 0.01). Early prognostication of outcomes (crush: 5.5 ± 0.3 and cut/repair: 8 ± 1 weeks) preceded current methods. Conclusion: Our findings identify injury type, state of recovery and early prognostication of outcome.

Can Diffusion Tensor Imaging Apparent Diffusion Coefficient Diagnose Carpal Tunnel Syndrome? A Systematic Review and Meta-Analysis.

Magnetic resonance diffusion tensor imaging (DTI) can detect microstructural changes in peripheral nerves. Studies have reported that the median nerve apparent diffusion coefficient (ADC), a quantification of water molecule diffusion direction, is sensitive in diagnosing carpal tunnel syndrome (CTS). Five databases were searched for studies using ADC to investigate CTS. Apparent diffusion coefficient (measured in mm2/s) were pooled in random-effects meta-analyses. Twenty-two studies met criteria yielding 592 patients with CTS and 414 controls. Median nerve ADC were measured at the level of the distal radioulnar joint (CTS ADC: 1.11, 95% CI: 1.07-1.15, I2 = 54%; control ADC: 1.04, 95% CI: 1.01-1.07, I2 = 57%), pisiform (CTS ADC: 1.39, 95% CI: 1.37-1.42, I2 = 0%; control ADC: 1.27, 95% CI: 1.23-1.31, I2 = 59%), hamate (CTS ADC: 1.40, 95% CI: 1.36-1.43, I2 = 58%; control ADC: 1.27, 95% CI: 1.25-1.28, I2 = 47%), and as an combination of several measurements (CTS ADC: 1.40, 95% CI: 1.37-1.47, I2 = 100%; control ADC: 1.39, 95% CI: 1.24-1.53, I2 = 100%). Median nerve ADC is decreased in individuals with CTS compared to controls at the levels of the hamate and pisiform. ADC cut-offs to diagnose CTS should be established according to these anatomic levels and can be improved through additional studies that include use of a wrist coil.

Pulmonary Embolism Risk After Cosmetic Abdominoplasty and Functional Panniculectomy.

BACKGROUND: Tighter abdominal wall reconstruction may increase intra-abdominal pressure, which can decrease lower extremity venous return. Decreased venous return through the inferior vena cava has been demonstrated to increase risk of deep vein thrombosis. OBJECTIVES: Tighter abdominal wall plication during cosmetic abdominoplasty compared with functional panniculectomy may increase these risks. The purpose of this study was to determine whether cosmetic abdominoplasty increases risk for thromboembolic events compared with functional panniculectomy. METHODS: Retrospective cohort study was conducted using the National Surgical Quality Improvement Program database for excision of excessive subcutaneous infraumbilical skin and soft tissue at participating hospitals between 2015 and 2019. Procedures performed for cosmetic abdominoplasty versus functional panniculectomy were compared for occurrences of postoperative pulmonary embolism (PE). RESULTS: During the study interval, 11,137 patients underwent excision of excessive infraumbilical abdominal skin, including 57.4% (n = 6397) patients undergoing functional panniculectomy and 42.6% (n = 4740) patients undergoing cosmetic abdominoplasty. Patients undergoing functional panniculectomy were significantly more likely to have comorbidities than those undergoing cosmetic abdominoplasty ( P < 0.001). The risk for postoperative PE was independently associated with cosmetic abdominoplasty ( P < 0.001), elevated body mass index ( P = 0.001), preoperative recent weight loss ( P = 0.006), and concurrent hernia repair ( P = 0.049). Most PE events occurred outpatient after discharge (87.2%), and the average postoperative time from surgery until PE was 10.5 ± 6.7 days. CONCLUSIONS: Cosmetic abdominoplasty has greater than 4 times the risk of postoperative PE than functional panniculectomy. Risk of PE is further increased by concurrent hernia repair, elevated body mass index, and rapid weight loss in the immediate preoperative period. It may be advisable to caution patients to delay abdominal excisional body contouring procedures until their weight has plateaued.

Breast Reconstruction Free Flap Failure: Does Platelet Count Matter?

BACKGROUND: Microvascular free tissue transfer is an increasingly popular modality for autologous tissue breast reconstruction. However, flap failure remains an ominous risk that continues to plague surgeons and patients even in the setting of meticulous surgical technique and monitoring. Venous and arterial thromboses are the leading causes of free flap failure. The purpose of this study was to determine whether thrombocytosis is associated with breast free flap failure. METHODS: A retrospective study was conducted of breast reconstruction with free flaps in North America between 2015 and 2020 using the National Surgical Quality Improvement Program database. Patient comorbidities and preoperative laboratory tests were used to determine risk factors for free flap failure. RESULTS: During the study interval, 7522 female patients underwent breast reconstruction with free flaps, and flap failure occurred in 2.7% patients (n = 203). In multivariate regression analysis, breast free flap failure was significantly higher in patients smoking cigarettes within the past year (P = 0.030; AOR, 1.7) and dyspnea on moderate exertion or at rest (P = 0.025; AOR, 2.6). Furthermore, each 50 K/mcL elevation in platelet count was independently associated with an increased odds of flap failure (P < 0.001; AOR, 1.2). Patients experienced significantly higher rates of flap failure with platelet counts greater than 250 K/mcL (P = 0.004), which remained significant through progressively increasing thresholds up to 450 K/mcL. CONCLUSIONS: Platelet count greater than 250 K/mcL is associated with progressively increasing risk of free flap failure in breast reconstruction. Future studies of personalized patient anticoagulation protocols based on hemostatic metrics may improve free flap survival after autologous tissue breast reconstruction.

Postamputation Residual Limb Pain Severity and Prevalence: A Systematic Review and Meta-Analysis.

Background: Individuals with an extremity amputation are predisposed to persistent pain that reduces their quality of life. Residual limb pain is defined as pain that is felt in the limb after amputation. Methods: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review of 5 databases from inception to June 2020 was performed and is registered under the PROSPERO ID: CRD42020199297. Included studies were clinical trials with residual limb pain assessed at a minimum follow-up of 1 week. Meta-analyses of residual limb pain prevalence and severity were performed with subgroups of extremity and amputation etiology. Results: Twenty clinical trials met criteria and reported on a total of 1347 patients. Mean patient ages ranged from 38 to 77. Residual limb pain prevalence at 1 week, 1 month, 3 months, 6 months, 1 year, and 2 years, respectively, was 50%, 11%, 23%, 27%, 22%, and 24%. Mean residual limb pain severity at the 6 months or longer follow-up was 4.19 out of 10 for cancer amputations, 2.70 for traumatic amputations, 0.47 for vasculopathy amputations, 1.01 for lower extremity amputations, and 3.56 for upper extremity amputations. Conclusions: Residual limb pain severity varies according to the etiology of amputation and is more common after upper extremity amputation than lower extremity amputations. The most severe pain is reported by patients undergoing amputations due to cancer, followed by traumatic amputations, while vascular amputation patients report lower pain severity. Promising methods of reducing long-term pain are preoperative pain control, nerve or epidural blocks, use of memantine, calcitonin-containing blocks, and prophylactic nerve coaptations.

Contexte: Les personnes subissant une amputation d'un membre sont prédisposées à des douleurs persistantes réduisant leur qualité de vie. La douleur du membre résiduel est définie comme étant la douleur ressentie dans le membre après l'amputation. Méthodes: Une revue systématique conforme à PRISMA de 5 bases de données depuis leur création jusqu'en juin 2020 a été effectuée et enregistrée sous l'ID PROSPERO: CRD42020199297. Les études incluses étaient des essais cliniques avec douleur du membre résiduel évaluée à un suivi minimum de 1 semaine. Des méta-analyses sur la prévalence et la sévérité de la douleur du membre résiduel ont été réalisées avec des sous-groupes en fonction du membre et de la cause de l'amputation. Résultats: 20 essais cliniques satisfaisaient les critères et portaient sur un total de 1347 patients. Les âges moyens des patients étaient compris entre 38 et 77 ans. La prévalence de la douleur du membre résiduel à 1 semaine, 1 mois, 3 mois, 6 mois, 1 an et 2 ans était, respectivement, de 50%, 11%, 23%, 27%, 22%, et 24%. La sévérité moyenne de la douleur du membre résiduel aux suivis de 6 mois ou plus a été de 4,19 sur 10 pour les amputations pour cancer, 2,70 pour les amputations post traumatisme, 0,47 pour les amputations liées à une vasculopathie, 1,01 pour les amputations du membre inférieur et 3,56 pour les amputations du membre supérieur. Conclusions: La sévérité de la douleur du membre résiduel varie en fonction du motif de l'amputation, et elle est plus fréquente après une amputation du membre supérieur qu'après des amputations du membre inférieur. La douleur la plus sévère a été décrite par des patients subissant une amputation à cause d'un cancer, suivie des amputations traumatiques, alors que les patients ayant subi une amputation pour cause vasculaire signalent une sévérité plus faible. Des méthodes prometteuses de réduction de la douleur à long terme sont le contrôle préopératoire de la douleur, les blocs nerveux et épiduraux, l'utilisation de la mémantine, de blocs contenant de la calcitonine et la coaptation prophylactique des nerfs.

Free Tissue Transfer during the COVID-19 Pandemic: A Proposed Evidence-Based Protocol for Early Discharge.

BACKGROUND: As free tissue transfer outcomes improve, institutions are examining early discharge protocols. "Early" is generally defined as between one and five days postoperatively, which correlates with the timing of most major complications and most opportunities for flap salvage. Given the trend towards early discharge, the need for healthcare cost reductions and shortage of ICU beds during a viral pandemic, we aimed to propose an evidence-based protocol to select patients for discharge within 72 h of free tissue transfer. METHODS: A retrospective review of all patients who underwent free tissue transfer at Vanderbilt University Medical Center, Tennessee, USA since the onset of the COVID-19 (2020-2021) pandemic was performed. Patients were included for review if they were discharged within 72 h of surgery. Literature relating to expedited discharge after free tissue transfer was also reviewed. RESULTS: Six patients met inclusion criteria for retrospective review. None suffered intraoperative or postoperative inpatient complications and all were discharged within 72 h postoperatively. There were no flap failures within 30 d of reconstruction. CONCLUSION: This study reviews a patient cohort undergoing free tissue transfer during the COVID-19 pandemic. These cases were reviewed for factors that may have contributed to their postoperative success after discharge within 72 hours. These data points were combined with published evidence on risks for failure after free flap reconstruction to design a protocol to select patients for early discharge. The benefits of early discharge include reducing healthcare costs, risks of inpatient hospitalization, and ICU utilization, which is of paramount importance in the midst of a global pandemic..

Anatomic Comparison of Recipient Nerves for Deep Inferior Epigastric Perforator Flap Neurotization: A Randomized Control Trial.

INTRODUCTION: Although neurotization has the potential to improve sensory outcomes after autologous breast reconstruction, this technique remains controversial. There is debate regarding the clinical outcomes and the recipient nerve of choice. This histoanatomical study aims to quantitatively compare the sensory components of the recipient nerves involved in neurotization of the deep inferior epigastric perforator flap. METHODS: Subjects undergoing bilateral autologous breast reconstruction were enrolled. Transected nerve specimens underwent immunohistochemical staining with antibodies against neurofilament 1 and choline acetyltransferase for total and motor neurons within the axons, respectively. Photomicrographs were captured, and axons were analyzed using ImageJ. Sensory axons were calculated as equal to the difference between the total and cholinergic axonal counts. RESULTS: Thirty-eight nerves from 19 subjects were included. The overall mean sensory axon count was 1246.3 (±1171.9) in the lateral cutaneous branch (LCB) of the fourth intercostal nerve and 1123.8 (±1213.0) in the anterior cutaneous branch (ACB) of the third intercostal nerve.The fourth LCB presented with an additional 10.9% sensory axonal count (P > 0.05). On average, sensory fibers constituted 36.7% and 31.7% of all fibers in the third ACBs and fourth LCBs, respectively. CONCLUSIONS: This study provides anatomic and histological evidence that the fourth LCB and third ACB contain comparable mean numbers of sensory axons. Both constitute adequate recipient nerves for coaptation in deep inferior epigastric perforator reinnervation to achieve optimal sensory return after breast reconstruction. The fourth LCB should be preferable when the third ACB remains intact to preserve any native breast flap sensation.

Rescuing the negative effects of aging in burn wounds using tacrolimus applied via microcapillary hydrogel dressing.

INTRODUCTION: Delays in treatment of burn injuries can lead to significant morbidity, loss of function, and poor aesthetic appearance. Preventing conversion from partial- to full-thickness burns may help mitigate these sequelae. The pathophysiology of burn wound conversion remains unknown, but an overactive immune response is thought to be implicated. The purpose of this study was to determine whether downregulating the immune response via tacrolimus can decrease burn wound conversion. METHODS: Assembly of the microfluidic hydrogels was achieved by embedding microfibers within a hydrogel scaffold composed of a gelatin-alginate blend. Tacrolimus stock solution for intraperitoneal injection was made by re-suspending powdered tacrolimus in DMSO at 10 mg/mL. 24 young (2-4 months) and 24 old (>16 months) mice were given partial thickness burns. The treatment cohort received either tacrolimus ointment with a hydrogel dressing (6 young and 6 old) or an intraperitoneal injection of a tacrolimus solution (6 young and 6 old), while the control cohort only received either only the microcapillary hydrogel dressing or an intraperitoneal injection of saline. Mice were euthanized at day 3 after injury and skin samples were taken. Burn depth was evaluated using Vimentin immunostaining. RESULTS: In old mice, intraperitoneal injection of tacrolimus was able to significantly reduce burn wound depth compared to intraperitoneal injection of saline (p = 0.011). Similarly in old mice, topical hydrogel with tacrolimus was able to significantly reduce burn wound depth compared to hydrogel alone (p < 0.001). Topical hydrogel with tacrolimus was able to mitigate the detrimental effects of older age on wound conversion, such that burn wounds of older mice treated with tacrolimus hydrogel dressing had similar burn depths as younger mice (p = 0.240). CONCLUSIONS: Utilizing a combination treatment of tacrolimus and microcapillary hydrogel is able to rescue the negative effects of aging and prevent partial- to full-thickness burn wound conversion. Hopefully these findings will encourage deeper investigation into the possible therapeutic advantages of utilizing immunosuppressive agents to decrease morbidity after burn injuries. Future research will need to specifically investigate IL-2 as an inhibitory target in the acute inflammatory cascade of burn injury.

A Systematic Review and Meta-analysis on the Incidence of Patients With Lower-Limb Amputations Who Developed Symptomatic Neuromata in the Residual Limb.

BACKGROUND: Neuromata developed after major extremity amputation can cause pain, limit the use of prosthetics, and negatively affect the quality of life. The frequency of postamputation neuroma varies widely. The objective of this study was to determine the incidence of patients who developed symptomatic neuromata after lower-limb amputation through a systematic review and meta-analysis. METHODS: A systematic review of the literature was performed on 4 major databases. Studies that reported the incidence of symptomatic neuroma in lower-limb amputees were included. A meta-analysis was performed to calculate the pooled incidence of neuromata. RESULTS: Thirteen studies consisting of 1329 patients were included in this meta-analysis. The reported incidence of patients who developed symptomatic neuromata ranged between 4% and 49%. The median duration of follow-up was 8.6 years (interquartile range, 2.0-17.4 years). The pooled percentage (95% confidence interval [CI]) of lower-limb amputees who developed symptomatic neuromata was 19% (12%-29%). In studies with a duration of follow-up at least 3 years, the pooled percentage (95% CI) of lower-limb amputees who developed symptomatic neuromata was 30% (22%-40%). In studies with a follow-up period of fewer than 3 years, the pooled percentage (95% CI) of neuroma incidence was 3% (2%-6%). CONCLUSIONS: In summary, the overall incidence of patients who developed symptomatic neuromata was 19% or approximately 1 in 5 lower-limb amputees. Symptomatic neuromata are more commonly diagnosed when the follow-up period is longer than 3 years. These findings suggest that neuroma after amputation might be underestimated in studies with a short duration of follow-up.

Successful prevention of secondary burn progression using infliximab hydrogel: A murine model.

INTRODUCTION: Burn injury remains a serious cause of morbidity and mortality worldwide. Severity of burns is determined by the percentage of burned area compared to the body surface area, age of patient, and by the depth of skin and soft tissue involvement; these factors determine management as well as prospective outcomes. The pathophysiology of partial- to full-thickness burn conversion remains poorly understood and is associated with a worse overall prognosis. Recent studies have demonstrated that an altered inflammatory response may play a significant role in this conversion and therefore a reduction in early inflammation is crucial to ultimately decreasing burn severity and morbidity. We hypothesize that the application of a microcapillary gelatin-alginate hydrogel loaded with anti-TNF-α (infliximab) monoclonal antibodies to a partial-thickness burn will reduce inflammation within partially burned skin and prevent further progression to a full-thickness burn. METHODS: Assembly of the microfluidic hydrogels is achieved by embedding microfibers within a hydrogel scaffold composed of a gelatin-alginate blend, which is then soaked in a solution containing anti-TNF-α antibodies for drug loading. 12 young (2-4 months) and 12 old (>16 months) mice were given partial thickness burns. The treatment cohort received the anti-TNF-α infused hydrogel with an occlusive dressing and the control cohort only received an occlusive dressing. Mice were euthanized at post-burn day 3 and skin samples were taken. Burn depth was evaluated using Vimentin immunostaining. RESULTS: All mice in the treatment cohort demonstrated decreased conversion of burn from partial to full thickness injury (old = p < 0.01, young = p < 0.001) as compared to the control group. Old mice had greater depth of burn than young mice (p < 0.001). There were greater eosinophils in the treatment cohort for both young and old mice, but it did not reach statistical significance. CONCLUSION: The application of a novel microcapillary gelatin-alginate hydrogel infused with anti-TNF-α antibody to partial thickness burns in mice showed reduction in partial to full thickness burn secondary progression as compared to controls using this murine model; this promising finding might help decrease the high morbidity and mortality associated with burn injuries.

Noninvasive diffusion MRI to determine the severity of peripheral nerve injury.

OBJECTIVE: Primary repair of peripheral nerves is recommended following transection; however, patient management following repair is challenged by a lack of biomarkers to nerve regeneration. Previous studies have demonstrated that diffusion magnetic resonance imaging (MRI) may provide viable biomarkers of nerve regeneration in injury models; though, these methods have not been systematically evaluated in graded partial transections and repairs. METHODS: Ex vivo diffusion MRI was performed in fixed rat sciatic nerve samples 4 or 12 weeks following partial nerve transection and repair (25% cut = 12, 50% cut = 12 and 75% cut = 11), crush injuries (n = 12), and sham surgeries (n = 9). Behavioral testing and histologic evaluation were performed in the same animals and nerve samples for comparison. RESULTS: Diffusion tractography provided visual characterizations of nerve damage and recovery consistent with the expected degree of injury within each cohort. In addition, quantitative indices from diffusion MRI correlated with both histological and behavioral evaluations, the latter of indicated full recovery for sham and crush nerves and limited recovery in all partially transected/repaired nerves. Nerve recovery between 4 and 12 weeks was statistically significant in partial transections 50% and 75% depth cuts (p = 0.043 and p = 0.022) but not for 25% transections. INTERPRETATION: Our findings suggest that DTI can i) distinguish different degrees of partial nerve transection following surgical repair and ii) map spatially heterogeneous nerve recovery (e.g., due to collateral sprouting) from 4 to 12 weeks in partially transected nerves.