The Value of Using a SkinFibroMeter for Diagnosis and Assessment of Secondary Lymphedema and Associated Fibrosis of Lower Limb Skin

Assessment of Intraday Variations in Skin Indentation Resistance

INTRODUCTION

Information about the mechanical properties of skin and their changes with age and other conditions is important to help characterize skin physiology and pathological changes. One method to obtain this information is to measure the force required to indent the skin to a specified indentation depth (FORCE). This process measures the tissue's resistance to indentation or its compressibility and is related to the tissue's elastic modulus. Since such measurements are made in clinical and other settings at various times of day (TOD), it is useful to estimate the extent of intraday variations in FORCE that may be expected. This report focuses on this issue.

METHOD

FORCE was self-measured on the volar forearm, 5 cm distal to the antecubital fossa, every two hours from 08:00 to 24:00 hours on two consecutive days by 12 medical students (six females and six males) who were trained in the measurement process using an indentation device (SkinFibroMeter). Variability in FORCE versus TOD was analyzed using the nonparametric Friedman test and differences between genders by the nonparametric Wilcoxon test. Differences between the first day (day 1) and the second day (day 2) were tested at each TOD. The whole-body fat percentage (FAT%) and water percentage (H2O%) were determined for each participant via bioimpedance measurements at 50 KHz.

RESULTS

The age and BMI of the combined group (mean ± SD) were 24.5 ± 1.5 years and 23.2 ± 3.3 kg/m2. The overall average FORCE (mean ± SD) for the day over the 16 hours was 84.1 ± 22.7 mN and for day 2, it was 83.4 ± 28.5 mN with no significant difference between day 1 and day 2. For females, the overall two-day average FORCE (mean ± SD) over the 16 hours was 81.8 ± 20.3 mN and for males, it was 85.7 ± 30.1 mN with no significant difference between them (p = 0.271). Overall, there was no statistically significant difference in FORCE among TOD (p = 0.568). FORCE was not correlated with either FAT%, HTO%, or BMI.

CONCLUSION

The findings indicate no statistically significant variation in indentation force in females, males, or combined concerning the TOD of the measurement or differences between consecutive days at corresponding times. This suggests that whether such measurements are done in a research setting or within a clinic, they can be done at various TOD with minimal expected variation for a given subject. However, an extension of these findings to persons with skin conditions or ages not herein evaluated must await further study.

Tissue Dielectric Constant and Skin Stiffness Relationships in Lower Extremity Lymphedema

Background: Lower extremity lymphedema or edema (LELE) may progressively transition from a state of excess tissue fluid to increased fat accumulation and collagen deposition, with tissue fibrosis and hardening. Such changes may lead to altered tissue water holding and thereby impact tissue dielectric constant (TDC). This study seeks to evaluate the relationship between TDC and tissue indentation force (TIF) in patients with LELE and assess the utility of the leg/arm TDC ratio (LAR) as an indicator of LELE. Methods and Results: Thirty females (49-91 years) with previously diagnosed LELE were evaluated during a scheduled session. TDC and TIF were measured 8 cm proximal to the medial malleolus on the medial and lateral aspects of both legs and on one forearm 8 cm distal to the antecubital fossa. The TDC-TIC relationship and the LAR were subsequently determined. Main results showed an absence of a significant correlation between TDC and TIF on medial or lateral leg sites but a positive correlation on the normal forearm site. Further, LAR values exceeded the published proposed threshold of 1.35 for 29/30 patients when using medial-side TDC values and 28/30 patients when using lateral-side TDC values. Conclusions: Findings suggest that for patients with LELE, TDC values are significantly elevated on medial and lateral standardized sites. The LAR determined using either medial or lateral sites that are similar to each other and have values consistent with a lymphedema threshold of 1.35. In edematous legs of the type evaluated herein, there is no apparent relationship between TDC values and indentation force.

Use of a novel indentometer to evaluate skin stiffness in healthy and diseased human skin

BACKGROUND

Mechanical behavior of the skin can be evaluated by different non-invasive methods. In this study, we applied a new measurement device based on indentometry to determine the skin mechanical properties in healthy individuals and in patients with systemic sclerosis (SSc).

MATERIAL AND METHODS

Three studies were performed. Study 1 included 100 healthy individuals (46 male and 54 female) divided into four age groups with mean ages of 21.5, 28.9, 51.2, and 69.3 years, respectively. Test sites were located on the center of the forehead and the middle of both volar forearms. Study 2 included 16 healthy individuals (two males and 14 females). Test sites were on both volar forearms. Measurements were made before and after the application of Vaseline and emulsion with 12% urea. Study 3 included 20 patients (one male and 19 females) with SSc and 60 age-matched healthy individuals (23 males and 37 females). Test sites were on the center of the forehead and the middle of both volar forearms. Skin stiffness was measured with skin Indentometer IDM 800 (Courage + Khazaka, Cologne, Germany) equipped with two probes with pin diameters of 3 and 5 mm, respectively. The stiffer the skin, the less deep the displacement by the indenter. The smaller the diameter, the deeper the pin will go into the skin when using the same force. In addition, the Corneometer CM 820 (Courage + Khazaka) was used to determine epidermal water content in study 2.

RESULTS

Indentometric (IDM) values of healthy subjects measured with both probes were lower on the forehead compared to volar forearms. There was no significant difference between both forearms. In all age groups, the IDM values on the male forearms were lower than on the female forearms whereas there was no significant difference on the forehead. In both sex and on all test locations a significant positive correlation between age and IDM values measured with both probes was observed. There was a significant positive correlation between IDM values measured with both probes. The application of moisturizers induced significant changes in epidermal water content whereas the IDM values remained unchanged. At both the forehead and volar forearms, the IDM values in patients with SSc were significantly lower compared to the healthy control skin.

CONCLUSION

The non-invasive indentometric method used can successfully distinguish the changes in normal skin mechanical properties related to age, sex, and anatomical location, as well as in patients with SSc. The method is not appropriate to study the changes related to epidermal hydration.

Lower Limb Lipedema-Superficial Lymph Flow, Skin Water Concentration, Skin and Subcutaneous Tissue Elasticity

Background: Lipedema of lower limbs is characterized by bilateral accumulations of excess adipose tissue starting from the ankle to the hips and buttocks. The studies with lymphoscintigraphy (LSC) and magnetic resonance (MR) lymphography show altered transport index and enlarged lymphatic vessels (LVs). Our studies aimed to investigate the superficial lymph flow, water accumulation, skin and subcutaneous tissue elasticity, and the possibility of using this information to diagnose lipedema. Methods and Results: Fifty patients with lipedema and 50 control subjects (women) were included. The Indocyanine Green (ICG) lymphography, LSC, skin water measurement, skin durometry, and deep tissue tonometry were done in all participants. ICG lymphography revealed: (1) Slower lymph flow in lipedema patients; after 3 minutes of feet movement in a horizontal position, the ICG-dyed lymph reached the upper calf level in 8% of lipedema patients compared with 56% in the control group (p ˂ 0.0001). (2) More than three LVs were noticed more often in lipedema patients. (3) The higher number of abnormal LV images at all limb levels and during each observation stage with a statistically significant number of foggy and dilated. (4) Statistically significant higher fluorescent intensity in all limb levels. Skin water concentration was higher in the feet in lipedema (p = 0.000189). Conclusion: Our studies have shown the differences in superficial lymph flow and water concentration between lipedema and normal limbs. Data proove the usefulness of ICG lymphography, skin water concentration and skin and subcutaneous tissue elasticity measurements in diagnosing lipedema.

The Vicious Circle of Stasis, Inflammation, and Fibrosis in Lymphedema

SUMMARY

Lymphedema is a progressive disease of the lymphatic system arising from impaired lymphatic drainage, accumulation of interstitial fluid, and fibroadipose deposition. Secondary lymphedema resulting from cancer treatment is the most common form of the disease in developed countries, affecting 15% to 40% of patients with breast cancer after lymph node dissection. Despite recent advances in microsurgery, outcomes remain variable and, in some cases, inadequate. Thus, development of novel treatment strategies is an important goal. Research over the past decade suggests that lymphatic injury initiates a chronic inflammatory response that regulates the pathophysiology of lymphedema. T-cell inflammation plays a key role in this response. In this review, the authors highlight the cellular and molecular mechanisms of lymphedema and discuss promising preclinical therapies.

Does Manual Lymphatic Drainage Add Value in Reducing Suprafascial Fluid Accumulation and Skin Elasticity in Patients With Breast Cancer-Related Lymphedema?

OBJECTIVE

The purpose of this study was to investigate the effectiveness of fluoroscopy-guided manual lymph drainage (MLD) versus that of traditional and placebo MLD, when added to decongestive lymphatic therapy (DLT) for the treatment of breast cancer-related lymphedema (BCRL) (EFforT-BCRL trial), on the suprafascial accumulation of lymphatic fluid and skin elasticity.

METHODS

In this multicenter, 3-arm, double-blind, randomized controlled trial (EFforT-BCRL trial), 194 participants (mean age = 61 [SD = 10] years) with unilateral BCRL were recruited. All participants received standardized DLT (education, skin care, compression therapy, exercises) and were randomized to fluoroscopy-guided, traditional, or placebo MLD. Participants received 60 min/d of treatment during the 3-week intensive phase and 18 sessions of 30 minutes during the 6-month maintenance phase. During this phase, participants were instructed to wear a compression garment, to perform exercises, and to perform a self-MLD procedure once daily. This study comprises secondary analyses of the EFforT-BCRL trial. Outcomes were the amount of fluid accumulation in the suprafascial tissues (local tissue water, extracellular fluid, and thickness of the skin and subcutaneous tissue) and skin elasticity at the level of the arm and trunk. Measurements were performed at baseline; after intensive treatment; after 1, 3, and 6 months of maintenance treatment; and after 6 months of follow-up.

RESULTS

At the level of the arm, there was a significant improvement over time in the 3 groups for most of the outcomes. At the level of the trunk, no remarkable improvement was noted within the individual groups. No significant interaction effects (between-group differences) were present. Only skin elasticity at the level of the arm, evaluated through palpation, showed a significant interaction effect.

CONCLUSION

All 3 groups showed similar improvements in response to DLT regardless of the type of MLD that was added. The effect of the addition of MLD to other components of DLT for reducing local tissue water and extracellular fluid or skin thickness and for improving skin elasticity and fibrosis in participants with chronic BCRL was limited.

IMPACT

Although MLD has been applied all over the world for many years, evidence regarding its added value in reducing arm volume in patients with BCRL is lacking. These results show that adding MLD to other components of DLT has limited value in reducing local tissue water and extracellular fluid or skin thickness and in improving skin elasticity and fibrosis in patients with chronic BCRL. To date, there is no clinical indication to continue including time-consuming MLD in physical therapist sessions for patients with chronic BCRL.

Temporal Changes in Subcutaneous Fibrosis in Patients with Lower Extremity Lymphedema Following Surgery for Gynecologic Cancer: A Computed Tomography-Based Quantitative Analysis

Lymphedema causes inflammation, which provokes fibrosis within the epifascial tissue. Temporal change in fibrosis according to severity of the lymphedema has not been widely investigated. We aimed to study the quantitative changes in epifascial fibrosis during lymphedema treatment using computed tomography (CT). Forty-five patients (mean age: 57.75 ± 11.12 years) who developed lymphedema following gynecologic surgery were included in this retrospective study. Two weeks of complete decongestive therapy and continued self-bandaging or compression garments were prescribed under regular follow-up monitoring. Lower-extremity epifascial fibrosis was quantitatively analyzed on the initial and follow-up CT scans. Circumference, skin fibrosis, subcutaneous tissue, and fibrosis ratio were calculated in the axial scan. Based on the change in lymphedema severity, we divided subjects into ‘improved’ and ‘aggravated’ groups. The affected lower extremities showed higher circumference, more skin fibrosis and subcutaneous tissue, and higher fibrosis ratio than the unaffected sides on initial CT scan. At follow-up, compared to the aggravated group, the improved group showed significant decreases in fibrosis of skin and subcutaneous tissue and fibrosis ratio. Subcutaneous fibrosis was reversible with volume resolution of lymphedema. Therapeutic approaches should be established on the basis of the reversible nature of fibrotic changes in patients with lower extremity lymphedema.

Use of a novel Indentometer to evaluate skin induration in localized scleroderma and psoriasis vulgaris

INTRODUCTION

Diseased skin in localized scleroderma (LS) and plaque psoriasis (PPs) is characterized by induration that can be evaluated by non-invasive bioengineering methods. In this study, we applied a new measurement device based on indentometry to determine the changes of skin mechanical properties in patients with LS and PPs.

MATERIAL AND METHODS

A total of 30 sclerodermatous plaques in 12 patients with LS and 46 psoriatic plaques in 19 patients with PPs were measured with Indentometer IDM 800 (Courage + Khazaka, Cologne, Germany). The device measures the penetration depth of the probe indenter (pin) into the skin in mm. We used two probes with pin diameters 3 and 5 mm, respectively. The stiffer the skin, the less deep is the displacement by the indenter. The smaller the diameter, the deeper the pin will go into the skin when using the same force. The measurements were made on diseased skin and in adjacent normal skin served as control. In addition, the psoriatic plaques were measured before and after treatment.

RESULTS

The sclerodermatous skin and the psoriatic skin showed lower Indentometer values compared to adjacent normal skin as measured with both probes. This suggests that diseased skin is stiffer than healthy skin. The values of psoriatic plaques increased after treatment applied that correlates with the clinical improvement. The Indentometric readings significantly negatively correlated with clinical scores of skin induration. There was a significant correlation between the measurements with probe 3 mm and probe 5 mm.

CONCLUSION

The non-invasive method used is appropriate for objective and quantitative determination of the degree of skin induration in LS and PPs as well as for assessment of the disease evaluation and treatment efficacy.

Computed Tomography-Based Quantitative Analysis of Fibrotic Changes in Skin and Subcutaneous Tissue in Lower Extremity Lymphedema Following Gynecologic Cancer Surgery

Background: Lymphedema produces protein-rich fluids that aggravate inflammation in the skin and subcutaneous tissue. Inflammation then induces fibroadipose tissue deposition and fibrosis. However, few methods have been developed to evaluate the severity of fibrosis. Therefore, we aimed to evaluate the subcutaneous fibrotic changes in lower extremity lymphedema following gynecologic cancer surgery using an image analysis tool, the FIJI software. Methods and Results: Seventy-four patients with lymphedema following gynecologic surgery were enrolled in this study. We quantitatively analyzed the cross-sectional area (CSA) of soft tissue compartments, including subcutaneous tissue with the skin, muscle volume, fibrotic changes in subcutaneous tissue, and the perimeter of skin boundaries. The limb circumference and the CSA of the subcutaneous tissue and skin on the affected side were significantly larger than those on the unaffected side. Fibrotic changes showed the same trend. However, muscle volume patterns were different from those of the other compartments. Some patients showed lower muscle volume on the unaffected side than on the affected side. Circumference and cellulitis significantly affected the extent of fibrotic changes in the skin and subcutaneous tissues. Age and duration of lymphedema did not affect fibrosis. Conclusion: Fibrosis of subcutaneous regions with the skin can be quantitatively calculated using an image analysis tool in lower extremity lymphedema following gynecologic cancer surgery. Edema and cellulitis increase fibrotic changes in the subcutaneous tissue with the skin.

Liposuction in cancer-related lower extremity lymphedema: an investigative study on clinical applications

Background

Lymphedema is a progressive, noncurable condition consisting of increases in subcutaneous fat and interstitial fluid in the limbs and fibrosis during later stages. The disease most commonly affects the limbs following injury to or removal of the lymph nodes. The aim of this study was to investigate the therapeutic outcomes of liposuction for cancer-related lower extremity lymphedema.

Methods

Sixty-two patients with cancer-related lymphedema in the unilateral lower extremity were recruited for this study, and all patients underwent liposuction. The volume of hemorrhage and lipids, the operation time, and the volume changes of the affected extremity were compared by applying the t tests, and the subjective feelings of patients were compared with the chi-square tests.

Results

The total lipid volume was 2539 ± 1253.5 ml, and the hemorrhage volume was 828 ± 311.8 ml. For the comparison of objective indices, (1) the percent volume differences (PVDs) before surgery, intraoperatively, and at the 3-month follow-up were 5.5 ± 12.2 vs. 11.6 ± 18.4 vs. 43.2 ± 23.7, P < 0.05, respectively; (2) greater lipid volumes and higher liposuction rates were observed for female patients, as was a smaller volume of hemorrhage; (3) greater hemorrhage volumes were observed in patients with a history of recurrent erysipelas; and (4) greater lipid volumes and liposuction rates (LRs) and smaller hemorrhage volumes were observed for stage II than for stage III patients.

Conclusions

Liposuction is an effective therapy for cancer-related lower extremity lymphedema. Sex, stage, and recurrent erysipelas history influence the course and effect of liposuction.

Skin biomechanical and viscoelastic properties measured with MyotonPRO in different areas of human body

BACKGROUND

There is still a lack of clinically practical device, which allows to perform rapid and accurate examination of the skin condition. For this reason, suitability of the MyotonPRO for the assessment of skin biomechanical and viscoelastic parameters was evaluated in this study. The aim of the study was to establish the reference values of five parameters measured by MyotonPRO various locations of human skin.

MATERIALS AND METHODS

Oscillation frequency, dynamic stiffness, logarithmic decrement, mechanical stress relaxation and creep were measured at three different skin locations (clavicula, volar forearm and shin), using L-shape short and medium arm probes in 32 young female volunteers. Mean values of obtained parameters recorded by both probes were compared among three skin locations while reliabilities of measurements were assessed. Additionally, relationships between all recorded parameters were examined RESULTS: There were no statistically significant differences between the mean values of five measured parameters obtained with both probes in all investigated areas. However, statistically significant differences of mean values of almost all parameters measured among three places examined were found. Despite considerable differences in mean values of obtained parameters, there were visible strong correlations between some studied parameters in all three investigated areas of skin.

CONCLUSION

It was demonstrated in all locations studied that the higher value of oscillation frequency corresponds to the higher value of dynamic stiffness, moreover such tissue recovers faster to its initial shape, and it was characterized by lower creep values. Such results indicate the existence of identical relationships between the same studied parameters in different areas of skin.

Light emitting diode-red light for reduction of post-surgical scarring: Results from a dose-ranging, split-face, randomized controlled trial

Scarring has significant esthetic and functional consequences for patients. A need exists for anti-scarring therapeutics. Light emitting diode-red light (LED-RL) has been shown to modulate skin fibrosis. The aim of this study is to evaluate the safety and efficacy of LED-RL to reduce post-operative scarring. Cutaneous Understanding of Red-light Efficacy on Scarring was a randomized, mock-controlled, single-blind, dose-ranging, split-face phase II clinical trial. Starting 1 week post-surgery, patients received LED-RL irradiation and temperature-controlled mock therapy to incision sites at fluences of 160, 320 or 480 J/cm2 , triweekly for 3 weeks. Efficacy was assessed at 1, 3 and 6-12 months. The primary endpoint was difference in scar pliability between LED-RL-treated and control sites. Secondary outcomes included Patient and Observer Scar Assessment Scale, collagen and water concentration, and adverse events. There were no significant differences in scar pliability between treated and control scars. At certain fluences, treated scars showed greater improvements in observer rating and scar pliability, reflected by greater reductions in induration, from baseline to 6 months compared to control scars. Treatment-site adverse events included blistering (n = 2) and swelling (n = 1), which were mild and resolved without sequelae. LED-RL phototherapy is safe in the early postoperative period and may reduce scarring.

Noninvasive, objective evaluation of lower extremity lymphedema severity using shear wave elastography: A preliminary study

BACKGROUND

Increased skin and subcutaneous tissue stiffness in patients with early-stage lymphedema has been reported. The purpose of this study was to examine the use of shear wave elastography (SWE) for evaluating lower extremity lymphedema (LEL).

METHODS

For 10 lower extremities of normal controls and 72 limbs of patients with gynecological cancer whose lymphatic function was categorized into six stages based on the range of dermal backflow (DBF) observed in indocyanine green (ICG) lymphography, SWE was performed and shear wave velocity (SWV) of the dermis and three layers of subcutaneous tissue at the thigh and calf were recorded. Twenty-five patients underwent thigh tissue histological and dermal thickness examinations.

RESULTS

The strongest correlation between the ICG DBF stage and SWV during SWE was observed on the dermal layer of the thigh (p < 0.01, R = 0.67). There was a significant correlation between the dermal thickness of the thigh and the ICG DBF stage (p < 0.01, R = 0.87) and also between the dermal thickness of the thigh and SWV (p < 0.01, R = 0.73).

CONCLUSION

Noninvasive, objective evaluation of LEL severity using SWE was well correlated with lymphatic function as determined by ICG lymphography. The DBF changes in the dermis of the thigh best reflected the changes in lymphatic function. Dermal thickness variations may partially account for differences in SWV.

Comparison of different MyotonPRO probes for skin stiffness evaluation in young women

BACKGROUND

Stiffness of skin is widely used parameter in many research areas, for example cosmetic industry, dermatology or rheumatology for assessing of skin condition as well as changes occurring in skin. In this pioneering study, we conducted measurements of skin stiffness using MyotonPRO -novel tool, which was mainly used to evaluate biomechanical properties of muscles, ligaments and tendons. We expected that MyotonPRO , which shows great reproducibility in previous studies, will also be able to measure skin stiffness.

MATERIALS AND METHODS

Four replaceable probes designed by MyotonPRO (L-shape short and medium arm, standard cylindrical flat-end probe and the same standard probe with disc attachment ) were tested for measurement of skin stiffness in young women (30 healthy females) at three different locations (clavicula, volar forearm and shin).

RESULTS

There was no significant difference between stiffness values obtained with L-shape short and L-shape medium arm probes in all investigated areas. Stiffness values recorded by regular probe and regular probe with disc attachment differ significantly from those collected with L-shape probes. There was also significant difference between values of stiffness obtained by standard with disc attachment and standard probes.

CONCLUSION

Both L-shape probes show a great reliability for skin stiffness assessment. Therefore, MyotonPRO can be considered a reliable device for assessing skin stiffness.

Physical activity level and age contribute to functioning problems in patients with breast cancer-related lymphedema: a multicentre cross-sectional study

PURPOSE

Breast cancer survivors face a high risk of developing breast cancer-related lymphedema (BCRL). Besides physical symptoms such as swelling, BCRL can have a psychosocial impact and lead to problems in daily functioning. Understanding contributing variables to problems in functioning yields possibilities to improve treatment modalities and consequently patients' quality of life. Therefore, the aim of this study was to explore the association between patient-, lymphedema-, and cancer treatment-related variables with problems in functioning in patients with BCRL.

METHODS

A cross-sectional study was performed in 185 patients with BCRL. Problems in daily functioning (dependent variable) were evaluated with the Lymph-ICF-UL questionnaire. Following independent variables were analysed by bi-variate and multivariable analyses, including a stepwise regression analysis: patient-related variables (age, BMI, physical activity level, education), lymphedema-related variables (excessive arm volume, duration of lymphedema, total pitting score, presence of hand edema, hardness of the tissue, lymphedema stage), and cancer treatment-related variables (type of surgery, surgery at the dominant side, radiotherapy, chemotherapy, hormone therapy, immunotherapy, TNM-classification).

RESULTS

The Lymph-ICF-UL mean total score was 38% (± 21), representing a moderate amount of problems in general functioning. Multivariable regression analyses revealed that lower physical activity level and lower age are contributing factors to more problems in daily functioning. Stepwise regression analysis indicated that up to 8% of the variance in problems in functioning could be explained by physical activity level and age of patients with BCRL.

CONCLUSION

Especially patients with low physical activity level and younger patients experience more problems in functioning. For the determination of certain causal interactions, future longitudinal studies including other independent variables that might explain a higher amount of problems in functioning in this population, are warranted.

TRIAL REGISTRATION

The study makes part of a double-blind, multi-center, randomized controlled trial (EFforT-BCRL trial), which is registered in clinicaltrials.gov (NCT02609724). CME reference S58689, EudraCT Number 2015-004822-33.

The Unresolved Pathophysiology of Lymphedema

Lymphedema is the clinical manifestation of impaired lymphatic transport. It remains an under-recognized and under-documented clinical condition that still lacks a cure. Despite the substantial advances in the understanding of lymphatic vessel biology and function in the past two decades, there are still unsolved questions regarding the pathophysiology of lymphedema, especially in humans. As a consequence of impaired lymphatic drainage, proteins and lipids accumulate in the interstitial space, causing the regional tissue to undergo extensive and progressive architectural changes, including adipose tissue deposition and fibrosis. These changes are also associated with inflammation. However, the temporal sequence of these events, the relationship between these events, and their interplay during the progression are not clearly understood. Here, we review our current knowledge on the pathophysiology of lymphedema derived from human and animal studies. We also discuss the possible cellular and molecular mechanisms involved in adipose tissue and collagen accumulation during lymphedema. We suggest that more studies should be dedicated to enhancing our understanding of the human pathophysiology of lymphedema to pave the way for new diagnostic and therapeutic avenues for this condition.

Comparison of a novel algorithm quantitatively estimating epifascial fibrosis in three-dimensional computed tomography images to other clinical lymphedema grading methods

No method has yet been approved for detecting lymphedema fibrosis before its progression. This study assessed the feasibility of computed tomography-based estimation of fibrosis. This observational, cross-sectional study included patients with lymphedema affecting one limb. Three types (maximum, mean, minimum) of computed tomography reticulation indexes were digitally calculated from trans-axial images using absorptive values, and the computed tomography reticulation indexes compared with clinical scales and measurements. Of 326 patients evaluated by at least one of lymphoscintigraphy, bio-electrical impedance, and computed tomography, 24 were evaluated by all three. The mean number of computed tomography scans in these patients was 109. Sixteen patients had breast cancer, seven had gynecologic cancers, and one had primary lymphedema. Mean computed tomography reticulation index (r = 0.52, p < 0.01) and maximal computed tomography reticulation index (r = 0.45, p < 0.05) were significantly associated with time from initial limb swelling to computed tomography. Mean computed tomography reticulation index (r = 0.86, p < 0.01), minimal computed tomography reticulation index (r = 0.79, p < 0.01), and maximal computed tomography reticulation index (r = 0.68, p < 0.01) were significantly associated with International Society of Lymphedema substage. Minimal computed tomography reticulation index correlated with 1-kHz-based bio-electrical impedance ratio (r = -0.46, p < 0.05) and with standardized proximal limb circumference difference ratio (r = 0.45, p < 0.05) of both limbs. Maximal computed tomography reticulation index had a sensitivity of 0.78, specificity of 0.60, and areas under the curve of 0.66 in detecting lymphoscintigraphic stage IV. The algorithm utilizing three-dimensional computed tomography images of epifascial fibrosis may be used as a marker for lymphedema duration, limb swelling, International Society of Lymphedema substage, and interstitial lymphatic fluids of lymphedema. The current approach shows promise in providing an additional method to assist in characterizing and monitoring lymphedema patients.

Using Thermography in the Diagnostics of Lymphedema: Pilot Study

Purpose: The aim of the study was to evaluate the usefulness of thermography in the diagnosis of lymphedema. Methods: The study included 43 women after axillary dissection caused by breast cancer, whose mean age was 64.4 ± 7.8 years. The subjects were divided into two groups, with the criterion for division being the appearance of secondary lymphedema. The size of lymphedema was verified by Limb Volumes Professional 5.0; body surface temperatures were registered using a thermal camera. Results: In the control group, the difference in the volume of the limb on the operated side and the contralateral limb was 7.5 ± 77.7 mL (3.6%). The temperature on the nonoperated side tended to be higher than on the opposite side. In the test group, the difference in size between the limbs was 54.5 ± 312.7 mL (29.3%). In the case of mild or moderate edema, a reverse tendency was observed. While measuring the difference in the mean surface temperatures of both limbs belonging to two groups, a significance of differences at the level of p = 0.04 was observed. Moreover, a negative Spearman correlation coefficient (-0.34) was observed between the size of secondary lymphedema and the surface temperature. Conclusion: Noninvasive thermography can provide a valuable supplementary tool in the diagnostics of secondary lymphedema.

Assessment of Skin Properties in Chronic Lymphedema: Measurement of Skin Stiffness, Percentage Water Content, and Transepidermal Water Loss

Background: Lymphedema (LE) is a chronic progressive protein-rich edema of the soft tissues. Measurement of extracellular fluid of the affected limbs is widely used in detecting LE; however, quantification of the skin alterations and early tissue changes in LE lacks approaches. Methods and Results: Ninety-one patients with LE were assessed. Measurement of transepidermal water loss (TEWL), skin stiffness (SF), and percentage water content (PWC) was assessed on five predetermined skin sites. The value of TEWL, SF, and PWC increased significantly in lymphedematous skin compare with controls, indicating damaged function and texture of the affected skin. Both PWC ratio and SF ratio strongly correlated with LE stage. High correlations were found among instruments assessing tissue fluid. Conclusions: Assessment of the skin parameters has contributed new information about the functional and structural alterations in chronic lymphedematous skin. Quantification of skin properties changes could be a valuable supplement to diagnosis and evaluation of chronic LE.

The Neglected Leg Lymphatic Vascular Changes in the Pathomechanism of Delayed Onset Muscle Soreness in Runners

Background: Delayed onset muscle soreness (DOMS) in runners is classified as a leg muscle strain injury and presents with tenderness or stiffness to palpation and movement limitation. Most attention is directed at muscles but not at the mass of other limb soft tissues, including their lymphatic vasculature, although they undergo mechanical stress and bruises, edema, nail destruction, and pains contributing to symptoms. Methods and Results: The study was done on lower limbs of long-distance runners suffering from DOMS complaints. There were 16 runners, 11 males and 5 females, age 22-28, practicing long-distance running over the last 5 years, with body mass index (BMI) 23 ± 4. Inclusion criteria: three to five marathon runs per year and daily 3-5 km slow runs. Last long distance run 3 to 7 days before the investigation. Controls were six subjects initiating running, of the same age group and BMI. Testing of blood and lymph flow was done before and after standard ergometer 300 W 30 minutes cycling. The measurement methods were leg and big toe venous plethysmography, big toe capillary Doppler, tonometry of skin and deep tissues, lymphoscintigraphy, and indocyanine green (ICG) fluorescent lymphography. (a) Strain gauge plethysmography of the calf and big toe revealed a two- to three-times higher venous capacity in runners than in controls, (b) the increased toe venous capacity was confirmed by point Doppler recordings showing two- to three-times higher blood capillary flow compared to controls, (c) lymphoscintigraphy revealed retention of tracer in feet, dilated superficial and deep lymphatics, and enlarged popliteal and inguinal lymph nodes, and (d) ICG lymphograms showed confluents of accumulated fluid in foot and calf subcutaneous tissue with fluorescence level reaching 40%-50% compared to 20% in controls. Conclusion: Our results show that, 3-5 days after run, not only muscles but also skin and subcutaneous tissue reveal major tissue fluid accumulation, an overload bringing about functional lymphatic transport insufficiency. This may be an additional factor responsible for DOMS symptoms.

A dose-ranging, parallel group, split-face, single-blind phase II study of light emitting diode-red light (LED-RL) for skin scarring prevention: study protocol for a randomized controlled trial

BACKGROUND

Skin fibrosis is a significant global health problem that affects over 100 million people annually and has a profoundly negative impact on quality of life. Characterized by excessive fibroblast proliferation and collagen deposition, skin fibrosis underlies a wide spectrum of dermatologic conditions ranging from pathologic scars secondary to injury (e.g., burns, surgery, trauma) to immune-mediated diseases. Effective anti-scarring therapeutics remain an unmet need, underscoring the importance of developing novel approaches to treat and prevent skin fibrosis. Our in vitro data show that light emitting diode-red light (LED-RL) can modulate key cellular and molecular processes involved in skin fibrosis. In two phase I clinical trials (STARS 1 and STARS 2), we demonstrated the safety and tolerability of LED-RL at fluences of 160 J/cm² up to 480 J/cm² on normal human skin.

METHODS/DESIGN

CURES (Cutaneous Understanding of Red-light Efficacy on Scarring) is a dose-ranging, randomized, parallel group, split-face, single-blind, mock-controlled phase II study to evaluate the efficacy of LED-RL to limit post-surgical skin fibrosis in subjects undergoing elective mini-facelift surgery. Thirty subjects will be randomly allocated to three treatment groups to receive LED-RL phototherapy or temperature-matched mock irradiation (control) to either periauricular incision site at fluences of 160 J/cm², 320 J/cm², or 480 J/cm². Starting one week post-surgery (postoperative days 4-8), treatments will be administered three times weekly for three consecutive weeks, followed by efficacy assessments at 30 days, 3 months, and 6 months. The primary endpoint is the difference in scar pliability between LED-RL-treated and control sites as determined by skin elasticity and induration measurements. Secondary outcomes include clinical and photographic evaluations of scars, 3D skin imaging analysis, histological and molecular analyses, and adverse events.

DISCUSSION

LED-RL is a therapeutic modality of increasing importance in dermatology, and has the potential to limit skin fibrosis clinically by decreasing dermal fibroblast activity and collagen production. The administration of LED-RL phototherapy in the early postoperative period may optimize wound healing and prevent excessive scarring. The results from this study may change the current treatment paradigm for fibrotic skin diseases and help to pioneer LED-RL as a safe, non-invasive, cost-effective, portable, at-home therapy for scars.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03795116 . Registered on 20 December 2018.

Cardiac Lymphatic Dysfunction Causes Drug-Eluting Stent–Induced Coronary Hyperconstricting Responses in Pigs In Vivo

Objective—

We have previously demonstrated that coronary adventitial inflammation plays important roles in the pathogenesis of coronary vasomotion abnormalities, including drug-eluting stent (DES)–induced coronary hyperconstricting responses. Importantly, the adventitia also harbors lymphatic vessels, which may prevent inflammation by transporting extravasated fluid and inflammatory cells. We thus aimed to examine the roles of coronary adventitial lymphatic vessels in the pathogenesis of DES-induced coronary hyperconstricting responses in a porcine model in vivo.

Approach and Results—

We performed 2 experimental studies. In protocol 1, 15 pigs were divided into 3 groups with or without DES and with bare metal stent. Nonstented sites 20 mm apart from stent implantation also were examined. In the protocol 2, 12 pigs were divided into 2 groups with or without lymphatic vessels ligation followed by DES implantation at 2 weeks later (n=6 each). We performed coronary angiography 4 weeks after DES implantation, followed by immunohistological analysis. In protocol 1, the number and the caliber of lymphatic vessels were greater at only the DES edges after 4 more weeks. In protocol 2, coronary hyperconstricting responses were further enhanced in the lymphatic vessels ligation group associated with adventitial inflammation, Rho-kinase activation, and less adventitial lymphatic vessels formation. Importantly, there were significant correlations among these inflammation-related changes and enhanced coronary vasoconstricting responses.

Conclusions—

These results provide evidence that cardiac lymphatic vessel dysfunction plays important roles in the pathogenesis of coronary vasoconstrictive responses in pigs in vivo.

Tissue Structure and Edema Fluid Events During Treatment of Lymphedema of Limbs with a Manual Pressure-Calibrated Device, Linforoll

Background: Linforoll is a device composed of handpiece with roller and pressure sensor connected wireless to the computer displaying the pressure curve of the applied force. In a previous study, we proved it to regulate the applied force according to the hydromechanic conditions of the massaged tissues. Standardization of massage based on applied force was repeatable in the same patient; it decreased limb volume and provided evident increase in tissue elasticity. Methods and Results: In this study, we measured additional parameters useful for the understanding of tissue and fluid events and approval of the device for general practice. These were skin stiffness, subcutaneous tissue stiffness independent of skin, skin water concentration, changes in skin temperature, skin capillary blood flow, subcutaneous tissue fluid pressure, volume of the moved edema fluid, and visualization of movement on indocyanine green (ICG) lymphography. Measurements were done before and during the massage. The data were obtained from a group of 20 patients with obstructive lymphedema of lower limbs during the Linforoll massage. There was a lack of significant changes in skin stiffness, skin water concentration, skin surface temperature, and capillary blood flow, but evident increase in the subcutaneous tissue elasticity (tonometry) and lymphography-shown flow of the edema fluid. Conclusions: The skin tissue hydromechanic parameters remained normal proving lack of destructive changes under high massaging pressures. The obtained data evidently show that not the skin but the subcutis accumulated edema fluid that can successfully be moved proximally under pressures of 80-120 mmHg.

Reproducibility of the durometer and myoton devices for skin stiffness measurement in healthy subjects

BACKGROUND

Clinical assessment of skin stiffness is unreliable in many applications. The durometer, an industrial device to measure hardness, has previously been applied in scleroderma. The Myoton is a noninvasive handheld device for assessing soft tissue biomechanical parameters.

MATERIALS AND METHODS

We evaluated the reproducibility of both devices in six healthy subjects in the volar forearm, dorsal forearm, upper arm, shin, and calf bilaterally. The intraclass correlation coefficient (ICC) was used as a measure of reproducibility among three observers.

RESULTS

The interobserver intraclass correlation coefficient (ICC) of overall stiffness for the Myoton was 0.74 [95% confidence interval (CI) 0.45-1.00] and 0.71 [0.39-1.00] for the durometer. Coefficient of variation (CV) for the Myoton was 6.4% [range 1.3-12.1] and 7.6% [range 4.4-13.8] for the durometer. Myoton and durometer values had a Pearson correlation of 0.69. The intraobserver Myoton ICC was 0.89 [0.74-1.00] and CV 3.1% [range 1.6-5.0]. The 95% confidence minimal detectable change by the Myoton for a single observer is 32.4 N/m, which is 7.6% of the average subject's overall stiffness.

CONCLUSION

The Myoton demonstrated high reproducibility, particularly in the overall stiffness parameter, and merits further investigation to assess disease progression and treatment efficacy.