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Background: Muscle strain injury leads to a high risk of recurrent injury in sports and can cause long-term symptoms such as weakness and pain. Scar tissue formation after strain injuries has been described, yet what ultrastructural changes might occur in the chronic phase of this injury have not. It is also unknown if persistent symptoms and morphological abnormalities of the tissue can be mitigated by strength training. Purpose: To investigate if heavy resistance training improves symptoms and structural abnormalities after strain injuries. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 30 participants with long-term weakness and/or pain after a strain injury of the thigh or calf muscles were randomized to eccentric heavy resistance training of the injured region or control exercises of the back and abdominal muscle. Isokinetic (hamstring) or isometric (calf) muscle strength was determined, muscle cross-sectional area measured, and pain and function evaluated. Scar tissue ultrastructure was determined from biopsy specimens taken from the injured area before and after the training intervention. Results: Heavy resistance training over 3 months improved pain and function, normalized muscle strength deficits, and increased muscle cross-sectional area in the previously injured region. No systematic effect of training was found upon pathologic infiltration of fat and blood vessels into the previously injured area. Control exercises had no effect on strength, cross-sectional area, or scar tissue but a positive effect on patient-related outcome measures, such as pain and functional scores. Conclusion: Short-term strength training can improve sequelae symptoms and optimize muscle function even many years after a strain injury, but it does not seem to influence the overall structural abnormalities of the area with scar tissue. Registration: NCT02152098 (ClinicalTrials.gov identifier). [ABSTRACT FROM AUTHOR]

Background and Aim: Undesirable appearance of the scar tissue after aesthetic surgery can affect the outcomes and patient satisfaction. In recent years, early laser therapy had been encouraged to reduce the scar tissue formation. However, the available evidence regarding the outcomes of laser therapy utilizing combined lasers are limited. In the current study, the effects of combined laser therapy using pulsed dye laser (PDL) and fractional CO2 laser on the appearance of the scar tissue after aesthetic surgeries were investigated. Methods: There were 15 patients enrolled in the current study including 13 mammoplasty and 2 abdominoplasty patients. In mammoplasty, each breast was randomly assigned to the laser therapy or control group. In abdominoplasty, split scar design was used. In laser therapy group, at the end of the third postoperative week, PDL 585 nm was radiated. Furthermore, at the end of the sixth week, fractional CO2 laser was radiated. The patients were followed for 6 months after the last laser therapy session. Visual analogue scale was used to rate the appearance of the scar tissues by 3 surgeons blinded to the treatment of scars. The appearance of the scars was determined as poor, fair, good or excellent. Results: VAS averaged 5.5±0.8 in laser therapy group and 4.8±0.8 in the control group. The difference was not statistically significant (P=0.057). There was no scar with excellent appearance in the current study. All of the scars were fair and good in the laser therapy group. In the control group, 13 scars were fair. The difference was not significant (P=0.227). Conclusion: Early combined laser therapy using PDL and fractional CO2 laser was associated with improved appearance of the scar tissue in short-term follow up, however, the effects were not statistically significant. [ABSTRACT FROM AUTHOR]

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Abstract Background Lameness, low BCS and scar tissue in the skin covering the tuber spina scapulae are known as risk factors for shoulder ulcer in sows. In a two-step study, the predictive ability of pre-farrowing clinical examination and the preventive effect of rubber mats on the development of shoulder ulcers in at-risk sows were evaluated. Material and methods The study included 659 sows that were clinically examined one week before farrowing to distinguish risk sows from no-risk sows. Sows with a BCS ≤ 2 and/or a locomotion score > 3 and/or scar tissue in the skin covering the tuber spina scapulae were classified as at risk of developing shoulder ulcers. The at-risk sows were randomly assigned to either a prevention group in which sows were stalled in farrowing crates equipped with rubber mats, or a non-prevention group in which sows were stalled in standard crates. The shoulder areas were photographed during the first two weeks of the lactation period. Results The chance of developing a shoulder ulcer was significantly higher for at-risk sows than for non-at-risk sows (OR 5.55, p

Ameliorating blood–brain barrier disruption and altering scar formation dynamics are potential strategies that may improve post-stroke recovery. CD36 is a class B scavenger receptor that plays a role in innate immunity, inflammation and vascular dysfunction and regulates post-stroke injury, neovascularization, reactive astrogliosis and scar formation. By subjecting WT and CD36KO mice to different MCAo occlusion durations to generate comparable acute lesion sizes, we addressed the role of CD36 in BBB dysfunction, scar formation and recovery. The majority of stroke recovery studies primarily focus on motor function. Here, we employed an extensive behavioral test arsenal to evaluate psychological and cognitive endpoints. While not evident during the acute phase, CD36 deficient mice displayed significantly attenuated BBB leakage and scar formation at three months after stroke compared to wild-type littermates. Assessment of motor (open field, rotarod), anxiety (plus maze, light-dark box), depression (forced swim, sucrose preference) and memory tests (water maze) revealed that CD36 deficiency ameliorated stroke-induced behavioral impairments in activity, hedonic responses and spatial learning and strategy switching. Our findings indicate that CD36 contributes to stroke-induced BBB dysfunction and scar formation in an injury-independent manner, as well as to the chronic motor and neurophysiological deficits in chronic stroke. [ABSTRACT FROM AUTHOR]

The healing of deep skin wounds is a complex phenomenon evolving according with a fine spatiotemporal regulation of different biological events (hemostasis, inflammation, proliferation, remodeling). Due to the spontaneous evolution of damaged human dermis toward a fibrotic scar, the treatment of deep wounds still represents a clinical concern. Bioengineered full-thickness skin models may play a crucial role in this direction by providing a deep understanding of the process that leads to the formation of fibrotic scars. This will allow (i) to identify new drugs and targets/biomarkers, (ii) to test new therapeutic approaches, and (iii) to develop more accurate in silico models, with the final aim to guide the closure process toward a scar-free closure and, in a more general sense, (iv) to understand the mechanisms involved in the intrinsic and extrinsic aging of the skin. In this work, the complex dynamic of events underlaying the closure of deep skin wound is presented and the engineered models that aim at replicating such complex phenomenon are reviewed. Despite the complexity of the cellular and extracellular events occurring during the skin wound healing the gold standard assay used to replicate such a process is still represented by planar in vitro models that have been largely used to identify the key factors regulating the involved cellular processes. However, the lack of the main constituents of the extracellular matrix (ECM) makes these over-simplistic 2D models unable to predict the complexity of the closure process. Three-dimensional bioengineered models, which aim at recreating the closure dynamics of the human dermis by using exogenous biomaterials, have been developed to fill such a gap. Although interesting mechanistic effects have been figured out, the effect of the inflammatory response on the ECM remodelling is not replicated yet. We discuss how more faithful wound healing models can be obtained by creating immunocompetent 3D dermis models featuring an endogenous ECM.

An analysis of scar tissue is necessary to understand the pathological tissue conditions during or after the wound healing process. Hematoxylin and eosin (HE) staining has conventionally been applied to understand the morphology of scar tissue. However, the scar lesions cannot be analyzed from a whole slide image. The current study aimed to develop a method for the rapid and automatic characterization of scar lesions in HE-stained scar tissues using a supervised and unsupervised learning algorithm. The supervised learning used a Mask region-based convolutional neural network (RCNN) to train a pattern from a data representation using MMDetection tools. The K-means algorithm characterized the HE-stained tissue and extracted the main features, such as the collagen density and directional variance of the collagen. The Mask RCNN model effectively predicted scar images using various backbone networks (e.g., ResNet50, ResNet101, ResNeSt50, and ResNeSt101) with high accuracy. The K-means clustering method successfully characterized the HE-stained tissue by separating the main features in terms of the collagen fiber and dermal mature components, namely, the glands, hair follicles, and nuclei. A quantitative analysis of the scar tissue in terms of the collagen density and directional variance of the collagen confirmed 50% differences between the normal and scar tissues. The proposed methods were utilized to characterize the pathological features of scar tissue for an objective histological analysis. The trained model is time-efficient when used for detection in place of a manual analysis. Machine learning-assisted analysis is expected to aid in understanding scar conditions, and to help establish an optimal treatment plan.

Scar tissues have been important factors in determining the progression of myocardial diseases and the development of adverse cardiac failure outcomes. Accurate segmentation of the scar tissues can be helpful to the clinicians for risk prediction and better evaluation of cardiovascular diseases. Our goal is to apply topology data analysis toward machine learning algorithms to confirm the geometry of scar tissue, in addition to gaining better visualization and quantification of the scar tissue present. We have introduced architecture for integrating geometry in the form of topology toward machine learning. Morphological image processing was carried out to define the regions of the endocardial wall. We implemented convolutional neural networks on delayed enhancement cardiac computed tomography images for the recognition of scar tissue. Segmented two-dimensional images were stacked up to build the geometry of the scar area for visualization purposes. Mathematical calculations were executed for the validation of the scar tissue in addition to performing morphological image processing and marking the scar tissue present on the endocardial wall of the left ventricular. We applied convolutional neural network over convolution and pooling the layers with small sizes; we achieved 89.23% accuracy, 91.11% sensitivity, and 87.75% specificity, and found the dissimilarity distance between the normal endocardial tissue distances to be 9.37. This new concept in this study contributes toward a better understanding of scar structure and transmural variation of the endocardial wall of the left ventricular. [ABSTRACT FROM AUTHOR]

Background Context: Anterior lumbar interbody fusion (ALIF) exposes the anterior aspect of the spine through a retroperitoneal approach. Access to the anterior spine requires mobilization of intra-abdominal viscera/vasculature, which can become complicated as scarring and/or adhesions develop from prior abdominal surgical interventions, increasing risk of intraoperative complications. The literature suggests that "significant prior abdominal surgery" is a relative contraindication of ALIF surgery; however, there is no consensus within the literature as to what defines "major/significant" abdominal surgeries. Additionally, the association between the number of prior abdominal surgeries and perioperative complications in ALIF surgery has not been explored within the literature.Purpose: This study seeks to explore the association between perioperative complications of ALIF surgery and the type (major and/or minor) and number of prior abdominal surgeries.Design: A retrospective cohort study was performed to examine perioperative complications in ALIF patients with or without prior history of abdominal surgery.Patient Sample: All consecutive patients undergoing ALIF with or without a history of prior abdominal surgery from 2008 to 2018 at a single tertiary center were evaluated. Patients under the age of 18, patients with spinal malignancy, or patients who had ALIF above L3 were excluded.Outcome Measures: Perioperative complications included intraoperative complications during ALIF surgery and postoperative complications within 90 days of ALIF surgery. Intraoperative complications include vascular injury, ureter injury, retroperitoneal hematoma, etc. Postoperative complications include urinary tract infection, revision of abdominal scar, ileus, deep vein thrombosis, pulmonary embolism, etc. Other outcome measures include readmission within 90 days, length of ALIF surgery, and length of hospital stay.Methods: Electronic medical records of 660 patients who underwent ALIF between 2008 and 2018 were retrospectively reviewed. Patient demographics, Charleston Comorbidity Index (CCI), level of fusion, past abdominal surgical history, use of access surgeon during exposure, intraoperative, and postoperative complications were collected. Predictors of intraoperative and postoperative complications were analyzed using simple and multivariable logistic regression. Statistical analysis was performed using JMP 14.0 (SAS, Cary, NC, USA) software.Results: After controlling for age, length of ALIF, gender, multilevel ALIF, and the use of an access surgeon, there was no significant association between the type of prior abdominal surgery (major and/or minor) and intraoperative complications on multivariable logistic regression analysis (Minor: odds ratio [OR]=1.68; 95% confidence interval [CI]: 0.58-4.86 & Major: OR=1.99; 95% CI: 0.80-4.91). On multivariable logistic regression, the odds of developing an intraoperative complication increases by 52% for each additional prior abdominal surgery after adjusting for age, length of ALIF, gender, multilevel ALIF, and the use of an access surgeon (OR=1.52, 95% CI: 1.10-2.11). Iliac vein laceration was the most common intraoperative complication (n=27, 4%). Neither the type (major and/or minor) nor the number of prior abdominal surgeries were significant predictors of postoperative complications (Minor: OR=1.29; 95% CI: .72-2.31, Major: OR=1.24; 95% CI: 0.77-2.00, & Number: OR=1.03; 95% CI: .84-1.26).Conclusion: With each additional prior abdominal surgery, accumulation of scarring and adhesions can likely obscure anatomical landmarks and increase the risk of developing an intraoperative complication. Therefore, the number of prior abdominal surgeries should be taken into consideration during planning and operative exposure of the anterior spine via a retroperitoneal approach. [ABSTRACT FROM AUTHOR]

Autogenic free fat tissue (FFT) is widely used in neurosurgery. Since the 1960s, there has been discussion on the usefulness of fat graft in spinal surgery. Unfortunately, fat undergoes atrophy, fibrosis, and rebuild, and up to 55% of primary volume disappears. This review focuses on the following aspects: development of radiological assessment, evaluation of morphological changes, and the influence of fat graft on outcome. Fat graft in the spinal canal disappears after degeneration processes. High amounts of collagen in the studied tissue and proliferation of blood vessels were observed. Use of fat as a filler and dural sac sealer is well grounded; however, the prevention of scar formation is uncertain. The use of fat does not eliminate adhesion and scar formation near the dural sac. Meanwhile, as the results of the discussed studies show, routine use of fat graft in prevention of scar formation cannot be justified. [ABSTRACT FROM AUTHOR]

Background: Tendon injuries occur frequently in human and equine athletes. Treatment options are limited, and the prognosis is often poor with functionally deficient scar tissue resulting. Fetal tendon injuries in contrast are capable of healing without forming scar tissue. Embryonic stem cells (ESCs) may provide a potential cellular therapeutic to improve adult tendon regeneration; however, whether they can mimic the properties of fetal tenocytes is unknown. To this end, understanding the unique expression profile of normal adult and fetal tenocytes is crucial to allow validation of ESC-derived tenocytes as a cellular therapeutic. Methods: Equine adult, fetal and ESC-derived tenocytes were cultured in a three-dimensional environment, with histological, morphological and transcriptomic differences compared. Additionally, the effects on gene expression of culturing adult and fetal tenocytes in either conventional two-dimensional monolayer culture or three-dimensional culture were compared using RNA sequencing. Results: No qualitative differences in three-dimensional tendon constructs generated from adult, fetal and ESCs were found using histological and morphological analysis. However, genome-wide transcriptomic analysis using RNA sequencing revealed that ESC-derived tenocytes' transcriptomic profile more closely resembled fetal tenocytes as opposed to adult tenocytes. Furthermore, this study adds to the growing evidence that monolayer cultured cells' gene expression profiles converge, with adult and fetal tenocytes having only 10 significantly different genes when cultured in this manner. In contrast, when adult and fetal tenocytes were cultured in 3D, large distinctions in gene expression between these two developmental stages were found, with 542 genes being differentially expressed. Conclusion: The information provided in this study makes a significant contribution to the investigation into the differences between adult reparative and fetal regenerative cells and supports the concept of using ESC-derived tenocytes as a cellular therapy. Comparing two- and three-dimensional culture also indicates three-dimensional culture as being a more physiologically relevant culture system for determining transcriptomic difference between the same cell types from different developmental stages. [ABSTRACT FROM AUTHOR]

Marjolin's ulcers are rare and aggressive malignant transformations seen in scar tissue and chronic wounds. The majority of the malignant transformations are due to squamous cell carcinoma. Here, Trudie Young gives an overview of the condition -- its incidence, pathophysiology, clinical presentation and diagnosis as well as therapeutic management options and treatment plans required to ensure optimal care and good quality of life for patients with Marjolin's ulceration. [ABSTRACT FROM AUTHOR]

Objective: High-intensity laser therapy (HILT) combined with photobiomodulation therapy (PBMT) using a diode or CO2 laser was administered after extraction of the left first molar in rats. Effects on socket preservation (preservation of the alveolar bone and healing time after extraction) were evaluated histopathologically. Background: Irradiation using a diode or CO2 laser has been shown to hasten wound healing, but the effects remain controversial. Methods: Five-week-old male Wistar rats that underwent extraction of the left maxillary first molar were divided into three groups: diode laser irradiation (diode group), CO2 laser irradiation (CO2 group), and no laser irradiation (control group). HILT (27 J) was performed immediately after tooth extraction to enhance blood coagulation, followed by PBMT (0.7 J) 1 day later to enhance healing. Tissues, including the extraction socket, were removed en bloc 3, 5, 7, 10, and 21 days postextraction to determine the morphological characteristics of wound healing and the distribution of myofibroblasts involved in scar formation. Results: In the diode and CO2 groups, new bone formation and cancellous bone maturation were observed at an early stage of wound healing. The number of myofibroblasts was significantly lower in the laser treatment groups than the control (p < 0.001), and both treatment groups had a significantly higher alveolar crest height (p < 0.01), with almost no concavity in the mucosa of the extraction wound. Conclusions: Combined HILT and PBMT following tooth extraction hastened wound healing and preserved alveolar crest height, suggesting a role in socket preservation. [ABSTRACT FROM AUTHOR]

Objective: High-intensity laser therapy (HILT) combined with photobiomodulation therapy (PBMT) using a diode or CO2 laser was administered after extraction of the left first molar in rats. Effects on socket preservation (preservation of the alveolar bone and healing time after extraction) were evaluated histopathologically. Background: Irradiation using a diode or CO2 laser has been shown to hasten wound healing, but the effects remain controversial. Methods: Five-week-old male Wistar rats that underwent extraction of the left maxillary first molar were divided into three groups: diode laser irradiation (diode group), CO2 laser irradiation (CO2 group), and no laser irradiation (control group). HILT (27 J) was performed immediately after tooth extraction to enhance blood coagulation, followed by PBMT (0.7 J) 1 day later to enhance healing. Tissues, including the extraction socket, were removed en bloc 3, 5, 7, 10, and 21 days postextraction to determine the morphological characteristics of wound healing and the distribution of myofibroblasts involved in scar formation. Results: In the diode and CO2 groups, new bone formation and cancellous bone maturation were observed at an early stage of wound healing. The number of myofibroblasts was significantly lower in the laser treatment groups than the control (p < 0.001), and both treatment groups had a significantly higher alveolar crest height (p < 0.01), with almost no concavity in the mucosa of the extraction wound. Conclusions: Combined HILT and PBMT following tooth extraction hastened wound healing and preserved alveolar crest height, suggesting a role in socket preservation. [ABSTRACT FROM AUTHOR]

Background: In general, chronic problems of soft tissues (muscles, tendons, ligaments) are due to scarring or degeneration. Astym therapy (Performance Dynamics, Inc. Muncie, Indiana) has been reported to address tendinopathy by stimulating regeneration in soft tissues (muscles, tendons, ligaments) and the resorption of unwanted scar tissue that causes pain and limits mobility.Purpose: To analyze the effectiveness of Astym therapy in the treatment of musculoskeletal problemsMethods: A narrative review of the literature on the topic was carried out. A Cochrane Library and PubMed (MEDLINE) search related to the role of Astym therapy was analyzed. The only language searched was English. Scientific meeting abstracts and other sources of evidence were not considered. The main criteria for selection were articles that were focused on the role of Astym therapy.Results: Astym therapy seems to be useful for the treatment of chronic ankle sprains, Achilles tendon tendinopathy, hamstring tendinopathy, elbow tendinopathy, and the stiff total knee arthroplasty. Astym therapy also appears to be useful to gain range of motion, muscle strength, and function in patients with cerebral palsy, and after mastectomy.Conclusions: Astym therapy seems to activate a regenerative response in degenerative tendinopathy and eliminate or reduce the scar tissue/fibrosis that causes pain and limitation of mobility. Based on the positive findings of the emerging published research further study is warranted to confirm the benefits of Astym therapy on a variety of musculoskeletal disorders. [ABSTRACT FROM AUTHOR]

Background: Excision of extensive scar tissue (EEST) may be required in certain cases of revision reverse total shoulder arthroplasty (RTSA). Neurovascular structures are at a higher risk of iatrogenic direct injury in these cases. We describe a technique to expose and protect the musculocutaneous and axillary nerves in a series of revision RTSA cases that required EEST.Methods: Between 2004 and 2013, 83 revision RTSA procedures were identified in our database. Of these, 18 cases (22%) who underwent concomitant nerve exploration for EEST preventing glenoid exposure, preventing reduction of the humeral component, or causing instability of the implanted RTSA, were included. All patients were observed for a minimum of two  years or until reoperation. Patient-reported outcome scores (PROMs), range of motion (ROM), and complication rates were analyzed.Results: Patients had significant pain relief and improvement in PROMs post-operatively. Two patients (11%) required another revision surgery because of infection (one patient with glenoid loosening; one patient with stem loosening). Two patients (11%) had instability successfully managed with closed reduction. Two patients (11%) had a clinically evident post-operative nerve injury. Both cases were neurapraxias (1 partial brachial plexopathy and 1 partial isolated axillary nerve injury) and experienced complete neurologic recovery at last follow-up.Conclusions: Complete permanent nerve injuries resulting from direct surgical trauma during revision RTSA requiring EEST can be avoided using the technique presented here. Despite proper exposition of the nerves, partial temporary neurapraxic injuries may occur. Patients who underwent this procedure experienced significant improvements in shoulder pain and function with complication rates consistent to those previously reported in revision RTSA. [ABSTRACT FROM AUTHOR]

Scar often occurred during wound repair. It was known that there were differences in collagen structure in dermal tissues at millimeter scale and micron scale, however, it was not known whether there were differences in collagen structure in dermal tissues at nanoscale during wound repair. In order to compare the difference at nanoscale, skin samples from patients were selected, the control groups were the normal skin from the same patients. These samples were tested by the small angle X-ray scattering techniques (SAXS) and wide angle X-ray scattering (WAXS) techniques. The transmission electron microscopy (TEM) was used as a comparison. The results showed that there were not only significantly differences between the normal tissue and scar tissue, but also between the center and the margin of the scar tissue at nanoscale by SAXS and WAXS, which was not demonstrated by other studies. These findings demonstrated that the SAXS and WAXS were excellent tools to detect the collagen structure at nanoscale and the orientation of the collagen alignment, which was beneficial for skin tissue engineering and skin regenerative medicine. [ABSTRACT FROM AUTHOR]

The foreign body reaction is a complex biological process leading to the insulation of implanted artificial materials through a capsule of scar tissue. In particular, in chronic implantations of neural electrodes, the prediction of the scar tissue evolution is crucial to assess the implant reliability over time. Indeed, the capsule behaves like an increasing insulating barrier between electrodes and nerve fibers. However, no explicit and physically based rules are available to computationally reproduce the capsule evolution. In addition, standard approaches to this problem (i.e., Vandermonde-based and Lagrange interpolation) fail for the onset of the Runge phenomenon. More specifically, numerical oscillations arise, thus standard procedures are only able to reproduce experimental detections while they result in non physical values for inter-interval times (i.e., times before and after experimental detections). As a consequence, in this work, a novel framework is described to model the evolution of the scar tissue thickness, avoiding the onset of the Runge phenomenon. This approach is able to provide novel approximating functions correctly reproducing experimental data (R2≃0.92) and effectively predicting inter-interval detections. In this way, the overall performances of previous approaches, based on phenomenological fitting polynomials of low degree, are improved.

A certain cell type can be isolated from different organs in the adult body that can differentiate into ectoderm, mesoderm, and endoderm, providing significant support for the existence of a certain type of small, vascular-associated, pluripotent stem cell ubiquitously distributed in all organs in the adult body (vaPS cells). These vaPS cells fundamentally differ from embryonic stem cells and induced pluripotent stem cells in that the latter possess the necessary genetic guidance that makes them intrinsically pluripotent. In contrast, vaPS cells do not have this intrinsic genetic guidance, but are able to differentiate into somatic cells of all three lineages under guidance of the microenvironment they are located in, independent from the original tissue or organ where they had resided. These vaPS cells are of high relevance for clinical application because they are contained in unmodified, autologous, adipose-derived regenerative cells (UA-ADRCs). The latter can be obtained from and re-applied to the same patient at the point of care, without the need for further processing, manipulation, and culturing. These findings as well as various clinical examples presented in this paper demonstrate the potential of UA-ADRCs for enabling an entirely new generation of medicine for the benefit of patients and healthcare systems.

Purpose. The paper reports the results of a comparative study of strength-elastic properties of the skin of the upper and lower eyelids, eyebrows, conjunctiva as well as those of free transplants (excess skin of the upper eyelid, skin of the posterior surface of the auricle, the inner surface of the shoulder, the lip mucosa) in normal conditions and scar deformations. Material and methods. In the study 210 standard-size samples were cut from tissues removed during reconstructive plastic surgeries of traumas and burns of the eye and eye adnexa. In order to determine the biomechanical parameters, the samples were loaded until a rupture using the Autograph Universal Testing Machine (Shimadzu, Japan) and checked for the tension-deformation dependence. This dependence was used to calculate the elasticity modulus, the tensile strength, and the maximum longitudinal deformation of the examined tissue. Results. The obtained results revealed differences in strength-elastic parameters of the skin of the upper and the lower eyelids and also the eyebrow area. It was determined, that the elasticity modulus (E) of scardeformed skin in the eyebrow area (Е=6.3±2.1 MPa) was higher than that of the lower eyelid area (Е=4.3±0.8 MPa) and the upper eyelid area (Е=3.6±0.5 MPa). The elasticity modulus of the skin of the inner surface of the shoulder (Е=4.0±0.5 MPa) is close to that of the scar-deformed skin of the lower eyelid, while the value of E for the posterior surface of the auricle is close to that of the upper eyelid scar-deformed skin (Е=2.5±0.4 MPa). The maximum rigidity was found to characterize the conjunctiva with burn-induced scars (Е=3.8±2.0 MPa), while the minimum rigidity was displayed by the conjunctiva of eyes with traumatic lesions without scars (Е=0.7±0.2 MPa). The elasticity modulus of lip mucosa (E=2.2±0.3 MPa), close to the respective parameter of scar-deformed conjunctiva (Е=1.9±0.4 MPa), shows that, from the biomechanical point of views, this tissue can be regarded as fully suitable for plastic surgery of the conjunctiva. Conclusions. Matching biomechanical parameters of periorbital area tissues and free transplants should be considered when choosing the transplants and developing the treatment plan of reconstructive plastic surgeries of traumatic scar deformities of eyelids and the conjunctiva.

Introduction Lumbar and leg pain can be caused by many factors, including scar tissue in the epidural space. Epidural fibrosis may cause chronic radicular low back pain. Adhesions in the epidural space may occur due to surgical or non-surgical reasons. Epidural adhesiolysis, i.e., neuroplasty, eliminates the pain-causing effects of scar tissue by releasing the nerve from the scar tissue or decompressing the nerve. In light of this information, this study was conducted to evaluate the effectiveness of percutaneous epidural neuroplasty interventions performed in the algology clinic in patients with lumbar epidural fibrosis who have and have not undergone lumbar surgery. Methods The sample of this retrospective study consisted of 72 patients with chronic radicular low back pain, finding fibrosis in the epidural region on contrast-enhanced magnetic resonance imaging (MRI), filling defect after epidurogram, and caudal epidural neuroplasty. Patients' visual analog scale (VAS) and Oswestry disability index (ODI) scores, pregabalin, duloxetine, and opioid doses were evaluated before and one month and six months after having neuroplasty. Results The VAS and ODI scores and pregabalin, duloxetine, and opioid doses decreased significantly in patients who had had caudal epidural neuroplasty at post-procedure endpoints compared to before the procedure (p<0.001). The paired temporal comparisons of the data of the patients who underwent epidural neuroplasty procedures before the procedure, one month after the procedure, and six months after the procedure revealed significant differences in the VAS and ODI scores (p<0.001). Additionally, the analysis of patients' VAS scores revealed that the pre-procedure VAS scores decreased significantly more one month after the procedure in patients without a history of lumbar surgery than in patients with a history of lumbar surgery. Conclusions The findings of our study demonstrated that fluoroscopy-guided percutaneous epidural neuroplasty alleviated pain and improved physical functions and quality of life. In conclusion, percutaneous epidural neuroplasty is a safe and effective treatment method for patients with lumbar epidural fibrosis., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Ege et al.)

Tendon injuries are very common and disrupt the transmission of forces from muscle to bone, leading to impaired function and quality of life. Successful restoration of tendon function after injury is a challenging clinical problem due to the pathological, scar‐mediated manner in which the tendons heal. Currently, there are no standard treatments to modulate scar tissue formation and improve tendon healing. A major limitation to the identification of therapeutic candidates has been the reliance on terminal endpoint metrics of healing in pre‐clinical studies, which require a large number of animals and result in destruction of the tissue. To address this limitation, we have identified quantification of scar tissue volume (STV) from ultrasound (US) imaging as a longitudinal, non‐invasive metric of tendon healing. STV was strongly correlated with established endpoint metrics of gliding function including gliding resistance and metatarsophalangeal (MTP) flexion angle. However, no associations were observed between STV and structural or material properties. To define the sensitivity of STV to identify differences between functionally discrete tendon healing phenotypes, we utilized S100a4 haploinsufficient mice (S100a4GFP/+), which heal with improved gliding function relative to wild‐type (WT) littermates. A significant decrease in STV was observed in S100a4GFP/+ repairs, relative to WT at day 14. Taken together, these data suggest US quantification of STV as a means to facilitate the rapid screening of biological and pharmacological interventions to improve tendon healing, and identify promising therapeutic targets, in an efficient, cost‐effective manner. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2476–2485, 2019 [ABSTRACT FROM AUTHOR]

Introduction: Acellular dermal matrix (ADM) is commonly used to treat burn injuries and wounds. In this study, we aimed to analyze the structural and biomechanical characteristics of an ADM from human scars. Methods: We randomly selected human mature scars, human proliferative scars, and human normal skin as experimental specimens. Split-thickness dermal grafts were obtained using a free-hand graft knife. Samples were subjected to cell lysis to obtain ADMs. Structural analysis was performed via light microscopy, fluorescence microplate reader and scanning electron microscopy. Thereafter, human epithelial stem cells were incubated on these ADMs. Finally, the biomechanical characteristics of the ADMs were analyzed using a tensile machine. Results: Normal skin ADM fibers were arranged in order, whereas proliferative scar ADM fibers were dense and disordered, and mature scar ADM fibers were porous and slightly disordered. The residual DNA of three ADM meet the residual DNA standard of biological material. After incubating human epithelial stem cells on ADMs, cells grew in an aggregated state in both normal skin ADMs and mature scar ADMs; however, cells adhered only on the surface of proliferative scar ADMs. No significant differences were observed in the Young's modulus, relaxation slope, creep slope, creep, or maximum tensile stress among the three ADMs, although significant differences in stress–strain elongation and relaxation were noted. Conclusions: Our findings showed that mature scar ADMs were similar to proliferative scar ADMs, showing a slight lag compared with normal skin ADMs, providing insights into the biomechanical features of these scar tissues. ADM Acellular dermal matrix H&E Hematoxylin and eosin PBS Phosphate-buffered saline SEM Scanning electron microscopy [ABSTRACT FROM AUTHOR]

Aim: Chronic persistent pain (CPP) is an important public health problem and its pathophysiology and the risk factors are still not clear. Scar tissues forming after any type of injury, trauma, and surgery may lead to chronic pain. In this case-control study, we aimed to evaluate surgical scar tissues can be related to forming CPP in our patient population. Methods: To assess the relation between surgery and CPP, two common chronic pain diseases were examined; fibromyalgia (FMS) as the most common non-mechanical CPP, and chronic low back pain (CLBP) as the most common mechanical CPP. For this purpose, 75 FMS, 57 CLBP patients and 47 healthy controls were recruited. All of the participants were examined, their demographic characteristics, symptoms, medical history of surgeries, and comorbid diseases were reported. Results: The frequency of surgical procedures was similar in both patient groups (p>0.05), but were higher than the controls in both patients' group (p<0.001). The mean pain VAS score was similar in both patient groups (p=0.825). These scores were higher in the patients with history of the multiple surgical procedures than the patients with history of single surgical procedure (p=0.043) which was not related to the type of surgical procedure (p>0.05). Conclusion: Scar tissues after surgery may cause a local or distant chronic pain. Chronic pain was more frequent in patients who experienced multiple operations. [ABSTRACT FROM AUTHOR]

Abstract Cutaneous wound healing consists of three main phases: inflammation, re-epithelialization, and tissue remodeling. During normal wound healing, these processes are tightly regulated to allow restoration of skin function and biomechanics. In many instances, healing leads to an excess accumulation of fibrillar collagen (the principal protein found in the extracellular matrix - ECM), and the formation of scar tissue, which has compromised biomechanics, tested using ramp to failure tests, compared to normal skin (Corr and Hart, 2013 [1]). Alterations in collagen accumulation and architecture have been attributed to the reduced tensile strength found in scar tissue (Brenda et al., 1999; Eleswarapu et al., 2011). Defining mechanisms that govern cellular functionality and ECM remodeling are vital to understanding normal versus pathological healing and developing approaches to prevent scarring. CD44 is a cell surface adhesion receptor expressed on nearly all cell types present in dermis. Although CD44 has been implicated in an array of inflammatory and fibrotic processes such as leukocyte recruitment, T-cell extravasation, and hyaluronic acid (the principal glycosaminoglycan found in the ECM) metabolism, the role of CD44 in cutaneous wound healing and scarring remains unknown. We demonstrate that in an excisional biopsy punch wound healing model, CD44-null mice have increased inflammatory and reduced fibrogenic responses during early phases of wound healing. At wound closure, CD44-null mice exhibit reduced collagen degradation leading to increased accumulation of fibrillar collagen, which persists after wound closure leading to reduced tensile strength resulting in a more severe scarring phenotype compared to WT mice. These data indicate that CD44 plays a previously unknown role in fibrillar collagen accumulation and wound healing during the injury response. Highlights • CD44 deletion accelerates the inflammatory response but delays the fibrotic response during early phases of wound healing. • Spatial and temporal distribution of FAP+, but not total mesenchymal cells or α-SMA+ fibroblasts, is CD44 dependent. • CD44-dependent collagenolysis regulates fibrillar collagen accumulation during early phases of wound healing and in vitro. • CD44 deletion increases the fibrogenic response and reduces the tensile strength of scar tissue. [ABSTRACT FROM AUTHOR]

Nested graft is a surgical technique that allows to manage difficult-to-treat medical conditions such as chronic cutaneous ulcers, thanks to the high efficacy it has in reverting the fibroblasts senescence. Because of its peculiar regenerative property, nested graft is a surgical technique suitable also for the treatment of cutaneous ulcers developing on fibrotic scar tissue. We reported the case of a 45-year-old man, drug-addict, with a large ulcer on the back of the right forearm in the context of scar fibrotic tissue. This lesion resulted from a previous heroin extravasation treated with a dermo-epidermal skin graft, that was accidentally scratched away by mechanical trauma. After several therapeutic failures with topical medications, we decided to treat the ulcer performing a skin graft using the nested graft technique. No adverse events were reported by the patient during or after the surgery. At the clinical evaluation performed three years later the wound was completely healed. Nested graft represents a safe and easy-to-use technique that can be successfully used to treat ulcers on scar tissue, ensuring the achievement and the long-term maintenance of optimal resistance and aesthetic results. • The extravasation of drugs is a possible cause of skin ulcers. • Treatment of skin ulcers on fibrotic tissue is challenging. • Nested graft, by promoting tissue regeneration, allows the healing of skin ulcers on scar tissue. [ABSTRACT FROM AUTHOR]

It has been demonstrated that scar tissue and fibrosis may increase the likelihood of developing malignancies. Specifically, scar tissue has been linked to the occurrence and progression of lung cancer (LC), though the precise mechanisms necessitate further research for explanation. Lung scarring can stem from various causes, with carcinogenesis on scarring lesions in pulmonary tuberculosis (PTB) being the most frequent (accounting for approximately 75% of cases). Notably, having previously cured, PTB is the second most common risk factor for LC after smoking, with approximately 3% of PTB patients experiencing LC as a secondary condition. This essay will delve into the mechanisms, treatment, and prognosis of tuberculosis scar carcinoma (TSC)., (© 2023. The Author(s).)

Traditional views consider scar tissue formed in the lesion epicenter after severe spinal cord injury (SCI) as both a physical barrier and chemical impediment for axonal regeneration. Recently, a controversial opinion suggested that astrocyte scar formation aids rather than prevents axonal regeneration in the CNS. Here, following complete transection of the thoracic spinal cord (T8) in rats, we found that scar tissue showed greater growth factor expression at 2 weeks than 8 weeks post-SCI. Further, tandem mass tag (TMT)-based quantitative proteomic analysis revealed that the components of scar tissue formed in the subacute phase are quite different from that formed in the chronic phase. We also found significantly increased axonal regrowth of sensory axons into the lesion center after chronically formed scar tissue was removed. This indicates that scar tissue formed at the chronic phase actually inhibits axonal regeneration, and that chronic removal of scar tissue may have clinical significance and benefit for SCI repair. Taken together, our study suggests that the features and roles of subacute and chronic scar tissues formed post-SCI is different and scar tissue-targeted strategies for spinal cord regeneration cannot be generalized. [ABSTRACT FROM AUTHOR]

Abstract: Following traumatic brain injury, there is no restoration of the lost nervous tissue, mainly due to the formation of a scar. One promising strategy to overcome this hurdle is grafting scaffolds that can disturb the scar blockade, enabling cell invasion into the wound. The aragonite skeleton of corals is useful scaffolds for testing this strategy, being supportive for neural cells in culture. The purpose of this work was to check if a contact between a coralline scaffold and an injured nervous tissue affects scar formation and if this effect can be regulated by engineering the scaffold's surface topology. To address that, hippocampal slices were cultivated on a coral skeleton having two distinct surface shapes: (1) intact skeleton pieces (ISP): porous, microrough surface; (2) grained skeleton (GS): nonporous, macrorough surface. On ISP, slices deformed by engulfing the scaffold's outer surface without penetrating the pores, yet, they preserved their coherence. By contrast, on GS slices were flat, but broken into interconnected small segments of tissue. In addition, whereas on ISP astrocytes were significantly more active and diffusely distributed, on GS reactive astrocytes tightened into a single <90 μm wide scar‐like stripe at the slice's periphery. Hence, by grafting coralline scaffolds of predesigned surface roughness and porosity into brain wounds, control over scar tissue formation can be gained, providing an opportunity for cell migration and damage repair. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2295–2306, 2018. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Post-infarction myocardial scar causes adverse left ventricular remodelling and negatively affects the prognosis. We sought to investigate whether scar extent and location obtained by cardiac magnetic resonance may affect the reverse remodelling and survival of heart failure patients undergoing surgical ventricular reconstruction. METHODS: From January 2011 to December 2015, 151 consecutive patients with previous myocardial infarction and left ventricular remodelling underwent surgical ventricular reconstruction at our Institution, of which 88 (58%) patients had a preoperative protocol-standardized late gadolinium enhancement (LGE)-cardiac magnetic resonance examination during the week before surgery. We excluded 40 patients with devices (26%), 15 patients with irregular heart rhythm (permanent atrial fibrillation, 10% not included in the device group) or mixed contraindications (severe claustrophobia or presence of material magnetic resonance not compatible). Among the 145 survivors, 11 patients received an implantable cardioverter defibrillator after surgery (mostly for persistent low ejection fraction) and were excluded as well, yielding a total of 59 patients (48 men, aged 65 ± 9 years) who repeated a protocol-standardized LGE-cardiac magnetic resonance examination even 6 months postoperatively and therefore represent the study population. Patients were grouped according to the presence of LGE in the antero-basal left ventricular segments (Group A) or the absence of LGE in the same segments (Group B). The postoperative left ventricular end-systolic volume index was considered the primary end-point. RESULTS: After surgery, left ventricular end-systolic volume index and end-diastolic volume index significantly decreased (P < 0.001, for both), while diastolic sphericity index and ejection fraction significantly increased (P = 0.015 and P < 0.001, respectively). The presence of LGE in the antero-basal left ventricular segments (10 patients, Group A) was the only independent predictor of outcome (P = 0.02) at multivariate analysis, being the postoperative left ventricular end-systolic volume index significantly higher compared to that of patients of Group B (49 patients) (78 ± 26 ml/m2 vs 55 ± 20 ml/m2, P = 0.003). Furthermore, patients with a postoperative left ventricular end-systolic volume index >60 ml/m2 showed a higher risk of cardiac events (hazard ratio = 3.67, P = 0.02). CONCLUSIONS: In patients undergoing surgical ventricular reconstruction, LGE scar location affects the left ventricular reverse remodelling, which in turn might limit the survival benefit. [ABSTRACT FROM AUTHOR]