Inflammatory Manifestations of Lymphedema

Increased Microvascular Filtration and Vascular Endothelial Growth Factor-D associated with Changed Lymphatic Vessel Morphology in Breast Cancer Treated Patients

Background

Vascular endothelial growth factors (VEGF) and inflammatory cytokines are indicated to be implicated in lymphedema development. We aimed to describe changes in microvascular filtration and VEGFs in a patient cohort vulnerable to breast cancer-related lymphedema development correlated with data on lymphatic morphology and function.

Methods

Consecutive node-positive breast cancer patients operated in the axilla and evaluated approximately 12 months after adjuvant locoregional radiotherapy were studied. Capillary filtration rate (CFR) and isovolumetric pressure of the arms were measured by strain gauge plethysmography, and 13 blood proteins were quantified by Luminex and Elisa technology in 28 patients and 18 healthy controls.

Results

The CFR was reduced in both arms from baseline to 1-year follow-up (ipsilateral: P = 0.016 and contralateral: P = 0.001). When stratifying lymphatic complications (morphologic abnormalities and/or breast cancer-related lymphedema), CFR reached a lower steady-state in the arms with normal morphology (I:P = 0.013 and C:P = 0.013) whereas the ipsilateral arm with lymphatic complications remained unchanged (P = 0.457). In patients with lymphatic abnormal vessels, the levels of VEGF-D were 86% higher than in patients with normal lymphatic vessels (P = 0.042), whereas levels of VEGFR-3 were 64% higher (P = 0.016).

Conclusions

Through one year of follow-up, CFR did not decrease in the lymphatic complicated treated arms as observed in noncomplicated treated arms. The patients had increased levels of VEGF-D and VEGFR-3. This correlation suggests that VEGF plays a role in the appearance of subcutaneous abnormal lymphatic vessels in the treated arms, which also maintain a fluid filtration/drainage mismatch up to one year after breast cancer treatment.

Breast Cancer-Related Lymphedema Results in Impaired Epidermal Differentiation and Tight Junction Dysfunction

Breast cancer-related lymphedema (BCRL) is characterized by skin changes, swelling, fibrosis, and recurrent skin infections. Clinical studies have suggested that lymphedema results in skin barrier defects; however, the underlying cellular mechanisms and the effects of bacterial contamination on skin barrier function remain unknown. In matched biopsies from patients with unilateral BCRL, we observed decreased expression of FLG and the tight junction protein ZO-1 in skin affected by moderate lymphedema or by subclinical lymphedema in which dermal backflow of lymph was identified by indocyanine green lymphography, relative to those in the controls (areas without backflow and from the unaffected arm). In vitro stimulation of keratinocytes with lymph fluid obtained from patients undergoing lymphedema surgery led to the same changes as well as increased expression of keratin 14, a marker of immature keratinocytes. Finally, using mouse models of lymphedema, we showed that similar to the clinical scenario, the expression of skin barrier proteins was decreased relative to that in normal skin and that colonization with Staphylococcus epidermidis bacteria amplified this effect as well as lymphedema severity. Taken together, our findings suggest that lymphatic fluid stasis contributes to skin barrier dysfunction in lymphedema.

Combination of Supramicrosurgical Lymphatico-Venular Anastomosis (sLVA) and Lymph-Sparing Liposuction in Treating Cancer-Related Lymphedema: Rationale for a Regional One-Stage Approach

Objective: Cancer-related lymphedema represents a potential complication of cancer treatment. The aim of this study is to evaluate the effectiveness of the combination of lymphatico-venular anastomosis and liposuction in the treatment of secondary lymphedema. Methods: We present a retrospective analysis of patients affected by cancer-related unilateral limb lymphedema. Inclusion criteria included previous neoplastic pathology with the consequent development of unilateral limb lymphedema, while the exclusion criteria included the presence of comorbidities and the persistence of cancer, as well as previous lymphatic surgery. The outcomes to be included were a reduction in the limb volume and lymphangitis rate, and an improvement in the quality of life. Patients' data were assessed before surgery and 1 year after surgery. Perioperative management included clinical and ultrasonographical evaluations. Under local anesthesia, lymphatico-venular anastomosis with the supramicrosurgical technique and the liposuction of the affected limb was performed in the same surgical session. Results: A total of 24 patients were enrolled in the study. One year after the surgery, an average volume reduction of 37.9% was registered (p = 0.0000000596). The lymphangitis rate decreased after surgery from 4.67 to 0.95 per year (p = 0.000007899). The quality-of-life score improved from 68.7 to 16 according to the LLIS scale. Conclusions: The combination of LVA and liposuction represents a valid strategy for treating cancer-related lymphedema, ensuring stable results over time. In addition, it can be performed under local anesthesia, resulting in being minimally invasive and well-tolerated by patients. This paper reports on the short-term efficacy of this combined technique.

Effects of complex decongestive therapy and aquatic physiotherapy on markers of the inflammatory process in individuals with lymphedema

BACKGROUND

Chronic lymphedema is a progressive and inflammatory disease caused by impaired lymphatic transport.

PURPOSE

This study evaluates the effects of complex decongestive therapy (CDT) and aquatic physiotherapy on markers of the inflammatory process and lower limb volumes in individuals with lymphedema.

METHODS

A randomized controlled clinical trial was carried out with three groups: patients with lymphedema submitted to CDT, patients with lymphedema submitted to aquatic physiotherapy, and control group of individuals without lymphedema. The evaluation was performed through blood count, CRP measurements, C3, C4 complement, measurement of serum levels of cytokines interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukins 4 (IL-4), 6 (IL-6), and 10 (IL-10), and the volume of a lower limb using the volume formula of a truncated cone. The study was registered with the Brazilian Clinical Trials Registry (RBR-4tpkszn).

RESULTS

Our work showed a reduction in the TNF-α levels of patients in the CDT group (p = .028). Significant differences were found between the control group and the CDT group for IL-10 (p = .049) and Monocytes (p = .039). No significant reduction in limb volume was found.

CONCLUSION

Our results show that CDT was able to significantly reduce the inflammatory marker TNF-α in patients with lymphedema, suggesting an anti-inflammatory effect of the therapy.

Vascularized Lymph Node Transfer Surgery for Successful Resolution of Long-Standing Lower Limb Lymphedema With Charles Excision: A Case Report

Lymphedema, a chronic condition characterized by abnormal swelling resulting from impaired lymphatic drainage, poses significant challenges in clinical management, especially when conventional therapies prove ineffective. This case report elucidates the successful resolution of long-standing lower limb lymphedema in a 35-year-old male through innovative surgical interventions. Despite enduring symptoms for 15 years and undergoing various treatments without improvement, the patient achieved remarkable relief following vascularized lymph node transfer surgery combined with Charles excision. This multidisciplinary approach aimed to restore lymphatic function and alleviate tissue bulk, addressing the condition's functional and cosmetic aspects. Preoperative evaluations, including imaging studies confirming grade IV lymphedema, guided surgical planning and contributed to the successful outcome. Postoperatively, despite wound dehiscence, prompt management facilitated satisfactory wound healing, underscoring the importance of meticulous postoperative care. This case underscores the significance of surgical intervention in managing refractory lymphedema and emphasizes the need for tailored treatment strategies to optimize patient outcomes. Further research and clinical experience are warranted to refine surgical techniques and identify optimal patient selection criteria, advancing the management of this challenging condition.

The Utilization of e-Health in Lymphedema Care: A Narrative Review

Background: Electronic health (e-Health), refers to technologies that can be utilized to enhance patient care as well as collect and share health information. e-Health comprises several umbrella terms, including telehealth, mobile health, e-Health, wearables, and artificial intelligence. The types of e-Health technologies being utilized in lymphedema (LE) care are unknown. Method: In this narrative review, a search of published research on the utilization of e-Health technologies in LE-related care was conducted. Results: Five different types of e-Health modalities were found (robotics, artificial intelligence, electronic medical records, smart wearable devices, and instructive online information) spanning 14 use cases and 4 phases of care (preventative, diagnostic, assessment, and treatment phases). Broad e-Health utilization examples were found including robotic-assisted surgery to reduce the likelihood of LE after lymphadenectomy, machine learning to predict patients at risk of filarial-related LE, and a novel wearable device prototype designed to provide lymphatic drainage. Conclusions: e-Health has reported merit in the prevention, diagnoses, assessment, and treatment of LE with utilization demonstrating cutting edge applicability of e-Health for achieving optimal patient care and outcomes. As technology continues to advance, additional research into the utilization of e-Health in LE care is warranted.

Interruption of Lymph Flow Worsens the Skin Inflammation Caused by Saprophytic Staphylococcus epidermidis

Lymphedema is often complicated by chronic inflammation, leading to fibrosis, fat deposition, and inhibition of lymphangiogenesis. This study aimed to verify whether lymphedema itself or together with commensal bacterial flora infection contributes to the severity of local inflammation. Edema was induced by interruption of the lymph flow in the rat's hind limb. Immune cell infiltrates were examined by flow cytometry and immunohistochemistry. Nine-day edema alone did not affect immune cell content in the skin but resulted in a decrease in CD4+ T helper lymphocytes and monocytes in the draining popliteal lymph nodes. In turn, local saprophytic Staphylococcus epidermidis infection of the edematous limb resulted in dense infiltrates of CD68+ macrophages and monocytes, MHC class II antigen-presenting cells, CD90+ stem cells, thymocytes, and immature B cells in the skin, accompanied by a simultaneous reduction in density of CD4+ T helper lymphocytes and monocytes, OX62+ dendritic cells, CD68+ macrophages and monocytes, HiS48+ granulocytes, CD90+ stem cells, thymocytes, and immature B cells in the draining popliteal lymph nodes. These results indicate that the combination of edema and saprophytic bacteria infection induces severe inflammation in the peripheral tissues and results in a delay of antibacterial protection processes in neighboring lymphatic organs.

Increased infiltration of CD4+ T cell in the complement deficient lymphedema model

BACKGROUND

Lymphedema is an intractable disease that can be caused by injury to lymphatic vessels, such as by surgical treatments for cancer. It can lead to impaired joint mobility in the extremities and reduced quality of life. Chronic inflammation due to infiltration of various immune cells in an area of lymphedema is thought to lead to local fibrosis, but the molecular pathogenesis of lymphedema remains unclear. Development of effective therapies requires elucidation of the immunological mechanisms involved in the progression of lymphedema. The complement system is part of the innate immune system which has a central role in the elimination of invading microbes and acts as a scavenger of altered host cells, such as apoptotic and necrotic cells and cellular debris. Complement-targeted therapies have recently been clinically applied to various diseases caused by complement overactivation. In this context, we aimed to determine whether complement activation is involved in the development of lymphedema.

RESULTS

Our mouse tail lymphedema models showed increased expression of C3, and that the classical or lectin pathway was locally activated. Complement activation was suggested to be involved in the progression of lymphedema. In comparison of the C3 knockout (KO) mouse lymphedema model and wild-type mice, there was no difference in the degree of edema at three weeks postoperatively, but the C3 KO mice had a significant increase of TUNEL+ necrotic cells and CD4+ T cells. Infiltration of macrophages and granulocytes was not significantly elevated in C3 KO or C5 KO mice compared with in wild-type mice. Impaired opsonization and decreased migration of macrophages and granulocytes due to C3 deficiency should therefore induce the accumulation of dead cells and may lead to increased infiltration of CD4+ T cells.

CONCLUSIONS

Vigilance for exacerbation of lymphedema is necessary when surgical treatments have the potential to injure lymphatic vessels in patients undergoing complement-targeted therapies or with complement deficiency. Future studies should aim to elucidate the molecular mechanism of CD4+ T cell infiltration by accumulated dead cells.

A 3D biomimetic model of lymphatics reveals cell-cell junction tightening and lymphedema via a cytokine-induced ROCK2/JAM-A complex

Impaired lymphatic drainage and lymphedema are major morbidities whose mechanisms have remained obscure. To study lymphatic drainage and its impairment, we engineered a microfluidic culture model of lymphatic vessels draining interstitial fluid. This lymphatic drainage-on-chip revealed that inflammatory cytokines that are known to disrupt blood vessel junctions instead tightened lymphatic cell-cell junctions and impeded lymphatic drainage. This opposing response was further demonstrated when inhibition of rho-associated protein kinase (ROCK) was found to normalize fluid drainage under cytokine challenge by simultaneously loosening lymphatic junctions and tightening blood vessel junctions. Studies also revealed a previously undescribed shift in ROCK isoforms in lymphatic endothelial cells, wherein a ROCK2/junctional adhesion molecule-A (JAM-A) complex emerges that is responsible for the cytokine-induced lymphatic junction zippering. To validate these in vitro findings, we further demonstrated in a genetic mouse model that lymphatic-specific knockout of ROCK2 reversed lymphedema in vivo. These studies provide a unique platform to generate interstitial fluid pressure and measure the drainage of interstitial fluid into lymphatics and reveal a previously unappreciated ROCK2-mediated mechanism in regulating lymphatic drainage.

Treatment with YIGSR peptide ameliorates mouse tail lymphedema by 67 kDa laminin receptor (67LR)-dependent cell-cell adhesion

Impaired microcirculation can cause lymphatic leakage which leads to a chronic swelling in the tissues of the body. However, no successful treatment gives any protection against lymphedema due to the lack of well-revealed pathophysiology of secondary lymphedema. Binary image of laminin immunohistochemical expression revealed that distribution of laminin expression localized during surgically induced lymphedema. 67 kDa laminin receptor (67LR) mRNA expression showed a peak at during lymphedema exacerbation. Since the response of 67LR molecules may affect the prevention of inflammation and edema, here we have hypothesized that 67LR ligand of YIGSR peptide could permit reconstructive environment for amelioration of lymphedema and evaluated the effect of YIGSR in a mouse tail model of lymphedema. Indeed, intra-abdominal injections of YIGSR for the first 3 days after inducing lymphedema in the mouse tail model reduced the tail lymphedema on day 14 by 27% (P = 0.035). Histology showed that YIGSR treatment protected lymphedema impairment in epidermis and dermis, and it also inhibited the expansion of intercellular spaces and enhanced especially cell adhesion in the basement membrane as revealed by transmission electron microscopy. Interestingly, the treatment also reduced the local expression of transforming growth factor (TGF)β. Further elucidation of the mechanisms of 67LR-facilitated lymphangiogenesis contributes to find potential targets for the treatment of lymphedema.

[Obesity and secondary lymphedema]

Obesity causes all types of lymphedema to deteriorate. Obesity-associated lymphedema is by now the most frequent secondary lymphedema and constitutes an entity in its own right. Obesity and its comorbidities, due to mechanical and inflammatory effects, decrease lymphatic transport and create a vicious circle of lymph stasis, local adipogenesis, and fibrosis. The therapeutic strategy must therefore address both lymphedema and obesity and its comorbidities.

Detection of Mast Cells in Human Superficial Fascia

The recent findings showed that the superficial fascia is a fibrous layer in the middle of hypodermis, richly innervated and vascularized, and more complex than so far demonstrated. This study showed the presence of mast cells in the superficial fascia of the human abdomen wall of three adult volunteer patients (mean age 42 ± 4 years; 2 females, 1 male), by Toluidine Blue and Safranin-O stains and Transmission Electron Microscopy. Mast cells are distributed among the collagen bundles and the elastic fibers, near the vessels and close to the nerves supplying the tissue, with an average density of 20.4 ± 9.4/mm². The demonstration of the presence of mast cells in the human superficial fascia highlights the possible involvement of the tissue in the inflammatory process, and in tissue healing and regeneration processes. A clear knowledge of this anatomical structure of the hypodermis is fundamental for a good comprehension of some fascial dysfunctions and for a better-targeted clinical practice.

Topical captopril: a promising treatment for secondary lymphedema

Transforming growth factor-beta 1 (TGF-β1)-mediated tissue fibrosis is an important regulator of lymphatic dysfunction in secondary lymphedema. However, TGF-β1 targeting can cause toxicity and autoimmune complications, limiting clinical utility. Angiotensin II (Ang II) modulates intracellular TGF-β1 signaling, and inhibition of Ang II production using angiotensin-converting enzyme (ACE) inhibitors, such as captopril, has antifibrotic efficacy in some pathological settings. Therefore, we analyzed the expression of ACE and Ang II in clinical lymphedema biopsy specimens from patients with unilateral breast cancer-related lymphedema (BCRL) and mouse models, and found that cutaneous ACE expression is increased in lymphedematous tissues. Furthermore, topical captopril decreases fibrosis, activation of intracellular TGF-β1 signaling pathways, inflammation, and swelling in mouse models of lymphedema. Captopril treatment also improves lymphatic function and immune cell trafficking by increasing collecting lymphatic pumping. Our results show that the renin-angiotensin system in the skin plays an important role in the regulation of fibrosis in lymphedema, and inhibition of this signaling pathway may hold merit for treating lymphedema.

Pheno-Endotyping Antrochoanal Nasal Polyposis

PURPOSE OF REVIEW

Antrochoanal polyps (ACPs) are benign polypoid lesions arising from the inner wall of the maxillary sinus and extending into the choana. Although the diagnosis and treatment strategies of ACP have changed since this entity was first described, the underlying pathogenic mechanism of APC is poorly understood. This article reviews the current knowledge of the etiology, inflammatory parameters, and microscopic findings of ACP.

RECENT FINDINGS

The inflammatory pattern of ACP appears to center around a neutrophilic inflammation T1-dominant endotype. Apart from the inflammatory component of ACP, at the microscopic level, the presence of tissue remodeling, mostly fibrin deposition and edema, and cysts in the epithelium and lamina propria has been described. Although the origin of this T1-dominant endotype immune response of ACPs is not entirely clear, it could be related to a lymphatic obstruction mechanism. This review serves to define a phenotype of ACP with potential endotypes based on the characteristics of the inflammatory parameters, microscopic findings, and hypotheses about the pathogenesis of ACP.

Lymphatic-draining nanoparticles deliver Bay K8644 payload to lymphatic vessels and enhance their pumping function

Dysfunction of collecting lymphatic vessel pumping is associated with an array of pathologies. S-(-)-Bay K8644 (BayK), a small-molecule agonist of L-type calcium channels, improves vessel contractility ex vivo but has been left unexplored in vivo because of poor lymphatic access and risk of deleterious off-target effects. When formulated within lymph-draining nanoparticles (NPs), BayK acutely improved lymphatic vessel function, effects not seen from treatment with BayK in its free form. By preventing rapid drug access to the circulation, NP formulation also reduced BayK's dose-limiting side effects. When applied to a mouse model of lymphedema, treatment with BayK formulated in lymph-draining NPs, but not free BayK, improved pumping pressure generated by intact lymphatic vessels and tissue remodeling associated with the pathology. This work reveals the utility of a lymph-targeting NP platform to pharmacologically enhance lymphatic pumping in vivo and highlights a promising approach to treating lymphatic dysfunction.

Does Venipuncture Increase Lymphedema by Triggering Inflammation or Infection? An Experimental Rabbit Ear Lymphedema Model Study

Background: Recent guidelines recommend avoiding venipuncture to prevent lymphedema for breast cancer patients. This study investigated whether single or multiple sterile venipuncture procedures develop a systemic inflammation or infection and increase lymphedema in the rabbit ear lymphedema model. Methods and Results: Eighteen New Zealand white female rabbits were included. The right ear lymphedema model was created by surgical procedure; then, rabbits were divided into three randomized groups. Single and multiple venipuncture procedures were applied at least the 60th day after surgery for Group I and II, respectively. Group III was a control group. C-reactive protein (CRP) and procalcitonin (PCT) levels were analyzed to determine inflammation and infection. Ear thickness measurements were applied using a vernier caliper to assess the differences in lymphedema between the ears. All rabbits were euthanized on the 90th day after surgery. Histopathological analysis was performed to evaluate lymphedema by measuring tissue thicknesses. Ear thickness measurements showed that ear lymphedema was developed and maintained with surgical operation in all groups (p < 0.05). There was no difference in the ear thickness measurements between and within-groups results (p > 0.05). CRP and PCT levels were below the lower detection levels in all groups. According to the differences of histopathological ear distances, there were significant differences within-groups for all groups (p < 0.05), and no differences were identified between groups (p > 0.05). Conclusion: This experimental study demonstrated that single or multiple sterile venipuncture procedures did not trigger infection or inflammation and did not exacerbate ear lymphedema in the rabbit ear lymphedema model.

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.

Plasma Cytokines/Chemokines as Predictive Biomarkers for Lymphedema in Breast Cancer Patients

Breast cancer-related lymphedema (BCRL) occurs in ~ 40% of patients after axillary lymph node dissection (ALND), radiation therapy (RT), or chemotherapy. First-line palliative treatment utilizes compression garments and specialized massage. Reparative microsurgeries have emerged as a second-line treatment, yet both compression and surgical therapy are most effective at early stages of LE development. Identifying patients at the highest risk for BCRL would allow earlier, more effective treatment. Perometric arm volume measurements, near-infrared fluorescent lymphatic imaging (NIRF-LI) data, and blood were collected between 2016 and 2021 for 40 study subjects undergoing treatment for breast cancer. Plasma samples were evaluated using MILLIPLEX human cytokine/chemokine panels at pre-ALND and at 12 months post-RT. A Mann-Whitney t-test showed that G-CSF, GM-CSF, IFN-2α, IL-10, IL-12p40, IL-15, IL-17A, IL-1β, IL-2, IL-3, IL-6, and MIP-1β were significantly higher at pre-ALND in those presenting with BCRL at 12 months post-RT. MIP-1β and IL-6 were significantly higher at pre-ALND in those who developed dermal backflow, but no BCRL, at 12 months post-RT. Plasma IL-15, IL-3, and MIP-1β were elevated at 12 months after RT in those with clinical BCRL. These findings establish BCRL as a perpetual inflammatory disorder, and suggest the use of plasma cytokine/chemokine levels to predict those at highest risk.

Lymphatic endothelial cell RXRα is critical for 9-cis-retinoic acid-mediated lymphangiogenesis and prevention of secondary lymphedema

Secondary lymphedema is a debilitating disease characterized by abnormal soft tissue swelling and caused by lymphatic system dysfunction. Despite a high prevalence of secondary lymphedema after cancer treatments, current management is supportive and there are no approved therapeutic agents that can thwart disease progression. We have previously demonstrated that 9-cis-retinoic acid (9-cisRA) has the potential to be repurposed for lymphedema as it mitigates disease by promoting lymphangiogenesis at the site of lymphatic injury. Although the efficacy of 9-cisRA has been demonstrated in previous studies, the mechanism of action is not completely understood. In this study, we demonstrate that when RXRα is specifically deleted in lymphatic endothelial cells, 9-cisRA fails to induce lymphangiogenesis in vitro and prevent pathologic progression of postsurgical lymphedema in vivo. These findings demonstrate that downstream nuclear receptor RXRα plays a critical role in the therapeutic efficacy of 9-cisRA in postsurgical lymphedema.

Prolymphangiogenic Effects of 9-cis Retinoic Acid Are Enhanced at Sites of Lymphatic Injury and Dependent on Treatment Duration in Experimental Postsurgical Lymphedema

Background: Patients undergoing surgical treatment for solid tumors are at risk for development of secondary lymphedema due to intraoperative lymphatic vessel injury. The damaged lymphatic vessels fail to adequately regenerate and lymphatic obstruction leads to fluid and protein accumulation in the interstitial space and chronic lymphedema develops as a result. There are currently no effective pharmacological agents that reduce the risk of developing lymphedema or treat pre-existing lymphedema, and management is largely palliative. The present study investigated the efficacy of various 9-cis retinoic acid (9-cis RA) dosing strategies in reducing postsurgical lymphedema by utilizing a well-established mouse tail lymphedema model. Methods and Results: Short-duration treatment with 9-cis RA did not demonstrate a significant reduction in postoperative tail volume, nor an improvement in lymphatic clearance. However, long-term treatment with 9-cis RA resulted in decreased overall tail volume, dermal thickness, and epidermal thickness, with an associated increase in functional lymphatic clearance and lymphatic vessel density, assessed by LYVE-1 immunostaining, compared with control. These effects were seen at the site of lymphatic injury, with no significant changes observed in uninjured sites such as ear skin and the diaphragm. Conclusions: Given the reported results indicating that 9-cis RA is a potent promoter of lymphangiogenesis and improved lymphatic clearance at sites of lymphatic injury, investigation of postoperative 9-cis RA administration to patients at high risk of developing lymphedema may demonstrate positive efficacy and reduced rates of postsurgical lymphedema.

Application of probiotics, prebiotics and synbiotics in patients with breast cancer: a systematic review and meta-analysis protocol for randomised controlled trials

INTRODUCTION

Breast cancer has become a common tumour that threatens women's physical and mental health. Microbial agents play an important role in maintaining the balance of gut microbiota and modulating intestinal immunity, anti-inflammatory and antioxidant effects. Available evidence points to a strong association between them and breast cancer. However, there has been no systematic review of the effects of microbial agents in patients with breast cancer. This protocol aims to explore the effectiveness and safety of probiotics, prebiotics and synbiotics in patients with breast cancer.

METHODS AND ANALYSIS

We will search the following electronic databases for relevant randomised controlled trials: PubMed, EMBASE, Cochrane Library and Web of Science. Grey literature and reference lists of original studies will also be searched to avoid omissions. We will use the Cochrane Collaboration's Risk of Bias tool to assess the quality of the included studies. The primary outcomes include patients' arm oedema volume, changes in gut microbiota composition and anthropometric parameters. Two independent reviewers will perform literature screening, data extraction and risk of bias assessment. Data synthesis will be performed using descriptive analysis or meta-analysis. The quality of the evidence for each outcome will be assessed using the Grading of Recommendations Assessment, Development and Evaluation tool.

ETHICS AND DISSEMINATION

The data for systematic reviews are derived from published original studies and do not require review and approval by the ethics committee. The results will be disseminated through a peer-reviewed journal and conferences.

PROSPERO REGISTRATION NUMBER

CRD42022311502.

Restoration of lymph flow by flap transfer can prevent severe lower extremity lymphedema after inguino-pelvic lymphadenectomy

PURPOSE

Severe lymphedema is difficult to treat because of the associated extensive scar formation. Therefore, preventing scar formation might alleviate the severity of lymphedema following lymphadenectomy. In this study, we evaluated the usefulness of flap transfer, performed immediately after lymphadenectomy, for preventing scar formation.

METHODS

Twenty-three patients with subcutaneous malignancy in a lower extremity, who underwent inguino-pelvic lymphadenectomy, were divided into groups based on whether flap transfer was performed. The severity of lymphedema was categorized according to the ratio of the circumference of the affected extremity to that of the unaffected extremity, as mild (< 20% increase in volume), moderate (20-40%), or severe (> 40%).

RESULTS

In the 18 patients who underwent lymphadenectomy without flap transfer, lymphedema was classified as mild in 7, moderate in 7, and severe in 4. In the five patients who underwent lymphadenectomy with flap transfer, lymphedema was classified as mild in 4 and moderate in 1. This difference between the groups did not reach significance.

CONCLUSIONS

The findings of this study suggest that flap transfer may help prevent scar formation and contribute to the restoration of lymph flow after lymphadenectomy.

A Prospective Study on the Safety and Efficacy of Vascularized Lymph Node Transplant

PURPOSE

While vascularized lymph node transplant (VLNT) has gained popularity, there are a lack of prospective long-term studies and standardized outcomes. The purpose of this study was to evaluate the safety and efficacy of VLNT using all available outcome measures.

METHODS

This was a prospective study on all consecutive patients who underwent VLNT. Outcomes were assessed with 2 patient-reported outcome metrics, limb volume, bioimpedance, need for compression, and incidence of cellulitis.

RESULTS

There were 89 patients with the following donor sites: omentum (73%), axilla (13%), supraclavicular (7%), groin (3.5%). The mean follow-up was 23.7±12 months. There was a significant improvement at 2 years postoperatively across all outcome measures: 28.4% improvement in the Lymphedema Life Impact Scale, 20% average reduction in limb volume, 27.5% improvement in bioimpedance score, 93% reduction in cellulitis, and 34% of patients no longer required compression. Complications were transient and low without any donor site lymphedema.

CONCLUSIONS

VLNT is a safe and effective treatment for lymphedema with significant benefits fully manifesting at 2 years postoperatively. Omentum does not have any donor site lymphedema risk making it an attractive first choice.

Breast Cancer Treatment Decreases Serum Levels of TGF-β1, VEGFR2, and TIMP-2 Compared to Healthy Volunteers: Significance for Therapeutic Outcomes?

Various complications from a breast cancer treatment, in the pathogenesis of which excessive tissue fibrosis plays a leading role, are a common pathology. In this study, the levels of TGF-β1, VEGFR-2, and TIMP-2 were determined by the immuno-enzyme serum analysis for patients during the long-term period after breast cancer treatment as potential markers of fibrosis. The single-center study enrolled 92 participants, which were divided into two age-matched groups: (1) 67 patients following breast cancer treatment, and (2) 25 healthy female volunteers. The intergroup analysis demonstrated that the patients after breast cancer treatment showed a decrease in the serum levels of TGF-β1 (U = 666, p < 0.001) and TIMP-2 (U = 637, p < 0.001) as compared to the group of healthy volunteers. The levels of VEGFR-2 in these groups were comparable (U = 1345, p = 0.082). It was also found that the type of treatment, the presence of lymphedema, shoulder joint contracture, and changes in lymphoscintigraphy did not affect the levels of TGF-β1, VEGFR-2, and TIMP-2 within the group of patients after breast cancer treatment. These results may indicate that these biomarkers do not play a leading role in the maintenance and progression of fibrosis in the long-term period after breast cancer treatment. The reduced levels of TGF-β1 and TIMP-2 may reflect endothelial dysfunction caused by the antitumor therapy.

Evaluation of Abdominal Fat Ratio in Patients with Breast Cancer-Related Lymphedema: A Controlled Study

Background: This study aimed to investigate the possible relationship between breast cancer-related lymphedema and central obesity, which is known to be effective in metabolic syndrome and chronic inflammation. Methods and Results: Thirty-six patients (18 lymphedemas, 18 control) enrolled in the study. There was no statistically significant difference in demographic data between the two groups except body mass index (BMI) distribution (p = 0.008). Although 50% of the patients in the study group were obese, this rate was 5.6% in the control group. Although there was a significant difference between the study and control groups in terms of abdominal circumference measurement, there was no significant difference between total and abdominal fat amount and ratios. When BMI and abdominal circumference measurements were evaluated together to predict lymphedema, the area under the curve in abdominal circumference measurement was higher than BMI (0.715 vs. 0.659). In receiver operating characteristic curve analysis, 107 cm of abdominal circumference measurement was determined as cutoff value for lymphedema, with 55% sensitivity and 89% specificity (Youden index: 0.44). Conclusion: Abdominal circumference measurement can be evaluated together with BMI in determining the risk of lymphedema.

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.

Current Understanding of Pathological Mechanisms of Lymphedema

Significance: Lymphedema is a common disease that affects hundreds of millions of people worldwide with significant financial and social burdens. Despite increasing prevalence and associated morbidities, the mainstay treatment of lymphedema is largely palliative without an effective cure due to incomplete understanding of the disease. Recent Advances: Recent studies have described key histological and pathological processes that contribute to the progression of lymphedema, including lymphatic stasis, inflammation, adipose tissue deposition, and fibrosis. This review aims to highlight cellular and molecular mechanisms involved in each of these pathological processes. Critical Issues: Despite recent advances in the understanding of the pathophysiology of lymphedema, cellular and molecular mechanisms underlying the disease remains elusive due to its complex nature. Future Directions: Additional research is needed to gain a better insight into the cellular and molecular mechanisms underlying the pathophysiology of lymphedema, which will guide the development of therapeutic strategies that target specific pathology of the disease.

Immediate Lymphatic Reconstruction to Prevent Breast Cancer-Related Lymphedema: A Systematic Review

Significance: Lymphedema is chronic limb swelling from lymphatic dysfunction. The condition affects up to 250 million people worldwide. In breast cancer patients, lymphedema occurs in 30% who undergo axillary lymph node dissection (ALND). Recent Advances: Immediate lymphatic reconstruction (ILR), also termed Lymphatic Microsurgical Preventing Healing Approach (LyMPHA), is a method to decrease the risk of lymphedema by performing prophylactic lymphovenous anastomoses at the time of ALND. The objective of this study is to assess the risk reduction of ILR in preventing lymphedema. Critical Issues: Lymphedema has significant effects on the quality of life and morbidity of patients. Several techniques have been described to manage lymphedema after development, but prophylactic treatment of lymphedema with ILR may decrease risk of development to 6.6%. Future Directions: Long-term studies that demonstrate efficacy of ILR may allow for prophylactic management of lymphedema in the patient undergoing lymph node dissection.

Retrograde Lymph Flow in the Lymphatic Vessels in Limb Lymphedema

OBJECTIVE

Retrograde movement of lymph due to damaged and/or incompetent valves in the lymphatic vessels has been considered a pathological feature of lymphedema. This study aimed to determine the prevalence of retrograde lymph flow and the characteristics of patients with this condition using indocyanine green (ICG) lymphography.

METHODS

An audit of 679 patients with upper or lower limb swelling who underwent ICG lymphography was undertaken over a 4-year period. Harvey's technique was applied to identify retrograde flow in the lymph collecting vessel during ICG lymphography. The characteristics of patients with retrograde lymph flow were recorded.

RESULTS

Twenty-one patients (3.7%, lower limb: n=19, upper limb: n=2) were identified as having retrograde flow in lymph collecting vessels out of 566 confirmed lymphedema patients (lower limb: n=275, upper limb: n=291). Of the two patients with upper limb lymphedema, one had a short segment of retrograde lymph flow in the forearm. The other patient with upper limb lymphedema and one patient with lower limb lymphedema were previously diagnosed with Lymphedema-Distichiasis Syndrome. Of the remaining 18 patients with lower limb lymphedema and retrograde lymph flow, nine had initiating insect bites with lymphangitis and three had palpable benign enlarged inguinal lymph nodes evident prior to lower limb swelling onset. None had cancer-related lower limb lymphedema.

CONCLUSIONS

Retrograde lymph flow with valve incompetence in the lymph collecting vessels was a rare finding in upper limb lymphedema and a relatively uncommon in lower limb lymphedema, contradicting conventional understanding of pathological changes in lymphedema. ICG lymphography identified anticipated retrograde lymph flow in two patients with Lymphedema-Distichiasis. In the remaining patients, retrograde lymph flow may have resulted from toxic or asymptomatic lymphangitis but no association with secondary cancer-related lymphedema. These findings have implication for conservative management as well as lymphovenous anastomosis surgery where both ends of a transected lymph collecting vessel would be potential targets for anastomoses.

TGF-β1 mediates pathologic changes of secondary lymphedema by promoting fibrosis and inflammation

Background

Secondary lymphedema is a common complication of cancer treatment, and previous studies have shown that the expression of transforming growth factor‐beta 1 (TGF‐β1), a pro‐fibrotic and anti‐lymphangiogenic growth factor, is increased in this disease. Inhibition of TGF‐β1 decreases the severity of the disease in mouse models; however, the mechanisms that regulate this improvement remain unknown.

Methods

Expression of TGF‐β1 and extracellular matrix molecules (ECM) was assessed in biopsy specimens from patients with unilateral breast cancer‐related lymphedema (BCRL). The effects of TGF‐β1 inhibition using neutralizing antibodies or a topical formulation of pirfenidone (PFD) were analyzed in mouse models of lymphedema. We also assessed the direct effects of TGF‐β1 on lymphatic endothelial cells (LECs) using transgenic mice that expressed a dominant‐negative TGF‐β receptor selectively on LECs (LEC^DN‐RII).

Results

The expression of TGF‐β1 and ECM molecules is significantly increased in BCRL skin biopsies. Inhibition of TGF‐β1 in mouse models of lymphedema using neutralizing antibodies or with topical PFD decreased ECM deposition, increased the formation of collateral lymphatics, and inhibited infiltration of T cells. In vitro studies showed that TGF‐β1 in lymphedematous tissues increases fibroblast, lymphatic endothelial cell (LEC), and lymphatic smooth muscle cell stiffness. Knockdown of TGF‐β1 responsiveness in LEC^DN‐RII resulted in increased lymphangiogenesis and collateral lymphatic formation; however, ECM deposition and fibrosis persisted, and the severity of lymphedema was indistinguishable from controls.

Conclusions

Our results show that TGF‐β1 is an essential regulator of ECM deposition in secondary lymphedema and that inhibition of this response is a promising means of treating lymphedema.

Relationship between lymphedema after breast cancer treatment and biophysical characteristics of the affected tissue

The treatment of breast cancer is often complicated by lymphedema of the upper limbs. Standard lymphedema evaluation methodologies are not able to measure tissue fibrosis. The ultrasound aspects related to tissue microstructures of lymphedema are neglected in clinical evaluations. The objective of this study was to identify and measure the degree of impairment, topography, and biophysical alterations of subcutaneous lymphedema tissue secondary to the treatment of breast cancer by ultrasonography. Forty-two women at a mean age of 58 (±9.7) years, with unilateral lymphedema due to breast cancer treatment, were evaluated. The upper limbs were divided into affected (affected by lymphedema) and control (contralateral limb). Each limb was subdivided into seven areas, defined by perimetry, evaluated in pairs. The biophysical characteristics thickness, entropy, and echogenicity were evaluated by ultrasonography. The results showed a significant difference in the echogenicity and thickness variables between the affected and unaffected upper limb, in all the extent of the upper limb, while entropy showed no significant difference. The findings indicate that the data presented were consistent both in identifying and measuring the degree of impairment and biophysical changes in the subcutaneous tissue of lymphedema secondary to the treatment of breast cancer.

Hypoxia and Hypoxia-Inducible Factors in Lymphedema

Lymphedema is a chronic inflammatory disorder characterized by edema, fat deposition, and fibrotic tissue remodeling. Despite significant advances in lymphatic biology research, our knowledge of lymphedema pathology is incomplete. Currently, there is no approved pharmacological therapy for this debilitating disease. Hypoxia is a recognized feature of inflammation, obesity, and fibrosis. Understanding hypoxia-regulated pathways in lymphedema may provide new insights into the pathobiology of this chronic disorder and help develop new medicinal treatments.

Healthcare Practitioners' Knowledge of Lymphedema

Objectives

Lymphedema is neglected in medical education, and a review on healthcare practitioners' (HCPs) knowledge is necessary to shed light on gaps and to provide evidence for establishing educational programs on lymphedema.

Methods

This systematic review was performed based on the PRISMA guideline in PubMed, Scopus, Web of Science, and Google Scholar databases. There was no limitation on the type of lymphedema or HCPs. The quality assessment was performed based on QATSDD. Data regarding study characteristics, questionnaire context, and findings of the study were summarized from each article.

Results

After the screening, 16 articles were included that 12 were cross-sectional, two were qualitative, and two were interventional pilot studies. Breast cancer and other cancer-related lymphedema, lymphatic filariasis, and podoconiosis were included, and the majority of articles were focused on primary HCPs. The overall knowledge was low and average in five and 11 articles, respectively, and prior education was a significant factor related to higher knowledge of lymphedema in two studies.

Conclusion

Structured education of lymphedema is needed to increase the knowledge of HCPs and to enhance their collaboration in multidisciplinary care teams. Improvement of HCPs' knowledge may lead to better outcomes of lymphedema patients' management which are neglected.

Communication, construction, and fluid control: lymphoid organ fibroblastic reticular cell and conduit networks

Fibroblastic reticular cells (FRCs) are a crucial part of the stromal cell infrastructure of secondary lymphoid organs (SLOs). Lymphoid organ fibroblasts form specialized niches for immune cell interactions and thereby govern lymphocyte activation and differentiation. Moreover, FRCs produce and ensheath a network of extracellular matrix (ECM) microfibers called the conduit system. FRC-generated conduits contribute to fluid and immune cell control by funneling fluids containing antigens and inflammatory mediators through the SLOs. We review recent progress in FRC biology that has advanced our understanding of immune cell functions and interactions. We discuss the intricate relationships between the cellular FRC and the fibrillar conduit networks, which together form the basis for efficient communication between immune cells and the tissues they survey.

Biochemical and mechanical signals in the lymphatic vasculature

Lymphatic vasculature is an integral part of the cardiovascular system where it maintains interstitial fluid balance. Additionally, lymphatic vasculature regulates lipid assimilation and inflammatory response. Lymphatic vasculature is composed of lymphatic capillaries, collecting lymphatic vessels and valves that function in synergy to absorb and transport fluid against gravitational and pressure gradients. Defects in lymphatic vessels or valves leads to fluid accumulation in tissues (lymphedema), chylous ascites, chylothorax, metabolic disorders and inflammation. The past three decades of research has identified numerous molecules that are necessary for the stepwise development of lymphatic vasculature. However, approaches to treat lymphatic disorders are still limited to massages and compression bandages. Hence, better understanding of the mechanisms that regulate lymphatic vascular development and function is urgently needed to develop efficient therapies. Recent research has linked mechanical signals such as shear stress and matrix stiffness with biochemical pathways that regulate lymphatic vessel growth, patterning and maturation and valve formation. The goal of this review article is to highlight these innovative developments and speculate on unanswered questions.

FLASH proton radiotherapy spares normal epithelial and mesenchymal tissues while preserving sarcoma response

In studies of electron and proton radiotherapy, ultrahigh dose rates of FLASH radiation therapy appear to produce fewer toxicities than standard dose rates while maintaining local tumor control. FLASH-proton radiotherapy (F-PRT) brings the spatial advantages of PRT to FLASH dose rates (>40 Gy/sec), making it important to understand if and how F-PRT spares normal tissues while providing anti-tumor efficacy that is equivalent to standard-proton radiotherapy (S-PRT). Here we studied PRT damage to skin and mesenchymal tissues of muscle and bone and found that F-PRT of the C57BL/6 murine hind leg produced fewer severe toxicities leading to death or requiring euthanasia than S-PRT of the same dose. RNAseq analyses of murine skin and bone revealed pathways upregulated by S-PRT yet unaltered by F-PRT, such as apoptosis signaling and keratinocyte differentiation in skin, as well as osteoclast differentiation and chondrocyte development in bone. Corroborating these findings, F-PRT reduced skin injury, stem cell depletion, and inflammation, mitigated late effects including lymphedema, and decreased histopathologically detected myofiber atrophy, bone resorption, hair follicle atrophy, and epidermal hyperplasia. F-PRT was equipotent to S-PRT in control of two murine sarcoma models, including at an orthotopic intramuscular site, thereby establishing its relevance to mesenchymal cancers. Finally, S-PRT produced greater increases in TGF-β1 in murine skin and the skin of canines enrolled in a phase 1 study of F-PRT versus S-PRT. Collectively, these data provide novel insights into F-PRT-mediated tissue sparing and support its ongoing investigation in applications that would benefit from this sparing of skin and mesenchymal tissues.

The Effects of Synbiotic Supplementation on Serum Anti-Inflammatory Factors in the Survivors of Breast Cancer with Lymphedema following a Low Calorie Diet: A Randomized, Double-Blind, Clinical Trial

BACKGROUND AND AIM

Breast cancer-related lymphedema (BCRL) is a treatment-related inflammatory complication in breast cancer survivors (BCSs). This study was aimed to evaluate the effect of synbiotic supplementation on serum concentrations of IL-10, TGF-β, VEGF, adiponectin, and edema volume among overweight or obese BCSs with lymphedema following a low-calorie diet (LCD).

METHOD

In a randomized double-blind, controlled clinical trial, 88 obese and overweight BCSs women were randomized to synbiotic supplement (n = 44) or placebo (n = 44) groups and both groups followed an LCD for 10 weeks. Pre- and post-intervention comparisons were made regarding the anti-inflammatory markers which included IL-10, TGF-β, VEGF, adiponectin, edema volume, and anthropometric measurements. Also, the same factors were analyzed to find inter-group disparities.

RESULTS

There were no significant differences among participants in the baseline, except for IL-10 and adiponectin. Post-intervention, no significant differences were observed regarding the anti-inflammatory markers, including IL-10, VEGF, adiponectin, and TGF-β between the groups. After 10 weeks of intervention edema volume significantly decreased in the synbiotic group; additionally, anthropometric measurements (body weight, BMI, body fat percent, and WC) decreased in both groups significantly (P < 0.001 and P < 0.005; respectively).

CONCLUSION

Synbiotic supplementation coupled with an LCD in a 10-week intervention had beneficial effects on increasing the serum TGF-β, IL-10, and adiponectin levels in women with BCRL. It also reduced arm lymphedema volume. Therefore, synbiotic supplementation can be effective in improving health status in BCRL patients.

Patient-specific surgical options for breast cancer-related lymphedema: technical tips

In order to provide a physiological solution for patients with breast cancer-related lymphedema (BCRL), the surgeon must understand where and how the pathology of lymphedema occurred. Based on each patient's pathology, the treatment plan should be carefully decided and individualized. At the authors' institution, the treatment plan is made individually based on each patient's symptoms and relative factors. Most early-stage patients first undergo decongestive therapy and then, depending on the efficacy of the treatment, a surgical approach is suggested. If the patient is indicated for surgery, all the points of lymphatic flow obstruction are carefully examined. Thus a BCRL patient can be considered for lymphaticovenous anastomosis (LVA), a lymph node flap, scar resection, or a combination thereof. LVA targets ectatic superficial collecting lymphatics, which are located within the deep fat layer, and preoperative mapping using ultrasonography is critical. If there is contracture on the axilla, axillary scar removal is indicated to relieve the vein pressure and allow better drainage. Furthermore, removing the scars and reconstructing the fat layer will allow a better chance for the lymphatics to regenerate. After complete removal of scar tissue, a regional fat flap or a superficial circumflex iliac artery perforator flap with lymph node transfer is performed. By deciding the surgical planning for BCRL based on each patient's pathophysiology, optimal outcomes can be achieved. Depending on each patient's pathophysiology, LVA, scar removal, vascularized lymph node transfer with a sufficient adipocutaneous flap, and simultaneous breast reconstruction should be planned.

The Kinetics of Lymphatic Dysfunction and Leukocyte Expansion in the Draining Lymph Node during LTB4 Antagonism in a Mouse Model of Lymphedema

The mechanisms of lymphedema development are not well understood, but emerging evidence highlights the crucial role the immune system plays in driving its progression. It is well known that lymphatic function deteriorates as lymphedema progresses; however, the connection between this progressive loss of function and the immune-driven changes that characterize the disease has not been well established. In this study, we assess changes in leukocyte populations in lymph nodes within the lymphatic drainage basin of the tissue injury site (draining lymph nodes, dLNs) using a mouse tail model of lymphedema in which a pair of draining collecting vessels are left intact. We additionally quantify lymphatic pump function using established near infrared (NIR) lymphatic imaging methods and lymph-draining nanoparticles (NPs) synthesized and employed by our team for lymphatic tissue drug delivery applications to measure lymphatic transport to and resulting NP accumulation within dLNs associated with swelling following surgery. When applied to assess the effects of the anti-inflammatory drug bestatin, which has been previously shown to be a possible treatment for lymphedema, we find lymph-draining NP accumulation within dLNs and lymphatic function to increase as lymphedema progresses, but no significant effect on leukocyte populations in dLNs or tail swelling. These results suggest that ameliorating this loss of lymphatic function is not sufficient to reverse swelling in this surgically induced disease model that better recapitulates the extent of lymphatic injury seen in human lymphedema. It also suggests that loss of lymphatic function during lymphedema may be driven by immune-mediated mechanisms coordinated in dLNs. Our work indicates that addressing both lymphatic vessel dysfunction and immune cell expansion within dLNs may be required to prevent or reverse lymphedema when partial lymphatic function is sustained.

Lymphedema alters lipolytic, lipogenic, immune and angiogenic properties of adipose tissue: a hypothesis-generating study in breast cancer survivors

Later stages of secondary lymphedema are associated with the massive deposition of adipose tissue (AT). The factors driving lymphedema-associated AT (LAT) expansion in humans remain rather elusive. We hypothesized that LAT expansion could be based on alterations of metabolic, adipogenic, immune and/or angiogenic qualities of AT. AT samples were acquired from upper limbs of 11 women with unilateral breast cancer-related lymphedema and 11 healthy women without lymphedema. Additional control group of 11 female breast cancer survivors without lymphedema was used to assess systemic effects of lymphedema. AT was analysed for adipocyte size, lipolysis, angiogenesis, secretion of cytokines, immune and stem cell content and mRNA gene expression. Further, adipose precursors were isolated and tested for their proliferative and adipogenic capacity. The effect of undrained LAT- derived fluid on adipogenesis was also examined. Lymphedema did not have apparent systemic effect on metabolism and cytokine levels, but it was linked with higher lymphocyte numbers and altered levels of several miRNAs in blood. LAT showed higher basal lipolysis, (lymph)angiogenic capacity and secretion of inflammatory cytokines when compared to healthy AT. LAT contained more activated CD4+ T lymphocytes than healthy AT. mRNA levels of (lymph)angiogenic markers were deregulated in LAT and correlated with markers of lipolysis. In vitro, adipose cells derived from LAT did not differ in their proliferative, adipogenic, lipogenic and lipolytic potential from cells derived from healthy AT. Nevertheless, exposition of preadipocytes to LAT-derived fluid improved their adipogenic conversion when compared with the effect of serum. This study presents results of first complex analysis of LAT from upper limb of breast cancer survivors. Identified LAT alterations indicate a possible link between (lymph)angiogenesis and lipolysis. In addition, our in vitro results imply that AT expansion in lymphedema could be driven partially by exposition of adipose precursors to undrained LAT-derived fluid.

Lymphatic Senescence: Current Updates and Perspectives

Simple Summary

The lymphatic system is involved in tissue homeostasis, immune processes as well as transport of lipids, proteins and pathogens. Aging affects all physiological systems. However, it is not well studied how aging affects the lymphatic vasculature. Therefore, this review aims at investigating how senescence could lead to changes in the structure and function of the lymphatic vessels. We report that lymphatic senescence is associated with alterations in lymphatic muscles and nerve fibers, lymphatic endothelial cells membrane dysfunction, as well as changes in lymphatic pump, acute inflammation responses and immune function.

Abstract

Lymphatic flow is necessary for maintenance of vital physiological functions in humans and animals. To carry out optimal lymphatic flow, adequate contractile activity of the lymphatic collectors is necessary. Like in all body systems, aging has also an effect on the lymphatic system. However, limited knowledge is available on how aging directly affects the lymphatic system anatomy, physiology and function. We investigated how senescence leads to alterations in morphology and function of the lymphatic vessels. We used the strategy of a review to summarize the scientific literature of studies that have been published in the area of lymphatic senescence. Searches were carried out on PubMed and Web of Science using predefined search queries. We obtained an initial set of 1060 publications. They were filtered to 114 publications based on strict inclusion and exclusion criteria. Finally, the most appropriate 57 studies that specifically addressed lymphatic senescence have been selected for the preparation of this review. Analysis of the literature showed that lymphatic senescence is associated with alterations in lymphatic muscles and nerve fibers, lymphatic glycocalyx function of lymphatic endothelial cells, effects of chronic ultraviolet light exposure and oxidative stress as well as changes in lymphatic pump, acute inflammation responses and immune function. The current review underscores the relevance of the understudied area of lymphatic senescence. Continued research on the impact of aging on the structure and function of the lymphatic vasculature is needed to provide further insights to develop innovative clinical diagnostic—and treatment—modalities as well as to reduce the morbidity associated with diseases related to the lymphatic system.

Is There a Relationship Between Insulin Resistance and Breast Cancer-Related Lymphedema? A Preliminary Study

Background: High blood insulin levels, insulin resistance (IR), and obesity are components of metabolic syndrome (MetS). The literature has indicated a high risk of breast cancer in patients with MetS. However, no studies have been conducted evaluating the relationship between breast cancer-related lymphedema (BCRL), one of the most frequently encountered postbreast cancer treatment conditions, and IR. Therefore, the aim of this study was to evaluate whether there is a relationship between BCRL and IR. Methods and Results: A total of 28 patients diagnosed with breast carcinoma were included in this preliminary study. Patients were divided into BCRL (n = 15; mean age: 55.2 ± 11.2 years) and non-BCRL (control) groups (n = 13; mean age: 55.17 ± 6.57 years). Body mass index (BMI), waist and hip circumference, and fasting blood glucose and blood insulin levels of all patients were recorded. The Homeostasis Model Assessment (HOMA) test was used for the calculation of IR measurement with a value of 2.5 taken as an indicator of IR. Parameters were compared between groups. BMI, waist circumference measurements, blood insulin, and HOMA-IR levels were statistically significantly higher in the BCRL group than the control group (p < 0.05). HOMA-IR values >2.5 were found in 14 patients in the BCRL group. In the control group, only three patients had IR based on HOMA-IR criteria (p = 0.000). Hip circumference measurements and fasting blood glucose levels were similar between the groups (p > 0.05). Conclusions: BCRL appears to be associated with waist circumference, fasting blood insulin level, and HOMA-IR levels. In routine clinical practice, evaluation of IR may be important in the follow-up of this patient population.

Lymphödem, Inflammation und neue Therapieansätze

Der fehlende Abtransport eiweißreicher interstitieller Flüssigkeit führt zu den bekannten klinischen Zeichen der Lymphödems an der Haut, die im Wesentlichen durch eine Fibrosierung ausgelöst werden. Bisher basiert die Therapie auf der mechanischen Anregung des Lymphtransports durch die komplexe physikalische Entstauung (KPE) oder operativen Maßnahmen, um das Ödem zu reduzieren. Der komplexe Ablauf der Entzündungsvorgänge im Gewebe wurde in den vergangenen Jahren untersucht und zeigt die zentrale Bedeutung von T-Lymphozyten, Makrophagen, LTB4 und diversen Zytokinen. Ausgehend von diesen Erkenntnissen gibt es Erfolg versprechende Therapieansätze mit Ketoprofen, Hydroxytyrosol und weiteren Immunmodulatoren.

Lymphstase und Fettgewebshypertrophie – Pathophysiologische Zusammenhänge und therapeutische Optionen

Angeborene oder erworbene, iatrogene, traumatische oder postinfektiöse Störungen des Lymphabflusses führen aufgrund der Lymphstase im Laufe der Zeit zu Gewebeveränderungen wie Fibrosierung und vermehrter lokaler Fettgewebebildung. Häufig kommt es hierdurch zu einer extremen Volumenzunahme der betroffenen Extremität, die nicht durch das Lymphödem allein, sondern vor allem durch die massive Fettgewebshypertrophie bedingt ist. Lymphgefäße und Lymphknoten sind immer in Fettgewebe eingebettet. Dieses perilymphatische Fettgewebe ist essenziell für die lymphatische wie auch immunologische Funktion des Lymphsystems, da das Lymphsystem Fettsäuren als primäre Energiequelle nützt. Kommt es nach Lymphadenektomie und/oder Unterbrechung von Lymphgefäßen zur Lymphstase in der betroffenen Extremität, signalisiert diese einen gesteigerten Energiebedarf für die notwendige Immunantwort und die chronische Inflammation verursacht eine Überstimulation der Fettgewebsproliferation, um ausreichend Energie zur Verfügung stellen zu können. In der Folge kommt es zu weiteren pathophysiologischen Veränderungen, die die Drainagefunktion und damit die Lymphstase weiter verschlechtern. Es hat sich ein Circulus vitiosus aus Lymphstase, Fettgewebsproliferation und Fibrosierung entwickelt.

Da die komplexe Entstauungstherapie diesen Zustand allein nicht wesentlich verbessern kann, kommen therapeutisch zusätzliche gewebereduzierende operative Verfahren, in erster Linie die Liposuktion, ggf. in Kombination mit mikrochirurgischen Operationstechniken, zum Einsatz.

Changes in Tracheal Respiratory Mucosa After Thyroidectomy: A Rat Model

BACKGROUND/AIM

This study aimed to investigate changes in the tracheal mucosa after thyroidectomy, that can be a cause of post-thyroidectomy discomfort.

MATERIALS AND METHODS

Forty rats were divided into normal controls and 3 surgical groups: (i) thyroid isthmectomy with cauterization, (ii) isthmectomy by a cold instrument without hemostasis, and (iii) sham (exposure of the trachea and thyroid gland without thyroidectomy by dissection through pretracheal fascia). Animals were euthanized at 1 and 4 weeks. Mucosal edema and glandular hyperplasia were measured. Mucin production and basal cell activities were evaluated by mucin 5AC (MUC5AC) and keratin 5 (KRT5) using immunofluorescence staining.

RESULTS

Larger mucosal areas were observed in all surgical groups at 1 and 4 weeks. More submucosal glandular hyperplasia was noted in the group with isthmectomy without hemostasis. MUC5AC and KRT5 expressions were significantly higher in the surgical groups.

CONCLUSION

The tracheal mucosa may change after surgery, which could explain postoperative discomfort after thyroidectomy.

Lymph Node to Vein Anastomosis (LNVA) for lower extremity lymphedema

The microsurgical options for lower limb lymphedema is a challenge. In search to improve the overall result, we hypothesized it would be beneficial to add the functioning lymph nodes to vein anastomosis (LNVA) in addition to lymphovenous anastomosis (LVA). This is a retrospective study of 160 unilateral stage II & III lower extremity lymphedema comparing the outcome between the LNVA + LVA group and the LVA only group from May 2013 to June 2018. MRI was used to identify the functioning lymph nodes. Patient outcome, including lower extremity circumference, body weight, bio impedance test, and other data were analyzed to evaluate whether lymph nodes to vein anastomosis (LNVA) improved outcome. The LNVA + LVA group showed significantly better results for circumference reduction rate, body weight reduction rate, and extracellular fluid reduction rate of the affected limb as compared to the LVA only group for both stage II and III lymphedema. The MRI imaging revealed that 9 cases had no identifiable lymph nodes of the affected limb and 54 cases with a nonfunctioning lymph node upon exploration despite positive imaging. Correlation showed the lymph node size needed to be at least 8 mm in the MRI to be functional. The LNVA + LVA approach for lymphedema has the benefit of better reduction as compared to LVA alone in the lower limb as well as the suprapubic region. Preoperative MRI will help to identify the functioning lymph node by increasing the overall probability of positive outcome.

Calorie restriction and synbiotics effect on quality of life and edema reduction in breast cancer-related lymphedema, a clinical trial

BACKGROUND

Little evidence exists regarding the clinical value of synbiotics in the management of post-treatment complications of breast cancer especially breast cancer-related lymphedema (BCRL). This study aimed to investigate the effects of synbiotic supplementation along with calorie restriction on quality of life and edema volume in patients with BCRL.

METHODS

This randomized, placebo-controlled, clinical trial was conducted on 135 overweight and obese women with BCRL aged 18-65 years old. Participants were randomly allocated to receive a calorie-restricted diet plus 109 CFU synbiotic supplement (CRS group; n = 45) or placebo (CRP group; n = 45), daily for 10 weeks. Also, a control group (n = 45) with no intervention was included in the trial. All of the participants received Complete Decongestive Therapy for lymphedema treatment. The quality of life score, edema volume and body mass index (BMI) were measured at baseline and end of the trial.

RESULTS

A total of 121 subjects completed the trial. CRS group showed a significant decrease in the total quality of life score (P = 0.004), and it's psychosocial (P = 0.022) and functional (P = 0.002) domain scores, as well as edema volume (P = 0.002) and BMI (P < 0.001) in comparison to the control. However, there were no significant differences in changes in trial outcomes between the CRS and CRP groups.

CONCLUSION

Synbiotic supplementation along with a low-calorie diet was effective in quality of life, edema volume, and BMI improvement; mostly due to low-calorie diet. It seems that adding a dietitian consultation on the lymphedema management strategy may provide a better result in lymphedema control.

Low-Intensity Resistance Training and Compression Garment in the Management of Breast Cancer-Related Lymphedema: Single-Blinded Randomized Controlled Trial

There is limited evidence regarding the combined effect of exercise and compression garment on breast cancer-related lymphedema (BCRL). Therefore, we investigate the effect of low-intensity resistance training alone or in combination with a compression garment on lymphedema volume, self-reported lymphedema symptoms, and shoulder mobility and function. A total of 60 women with unilateral BCRL were randomly assigned to low-intensity resistance exercises (Rex group, n = 30) or exercises and compression garment (Rex-Com-group, n = 30). Both groups take part in exercises program consisted of 10-12 repetitions at 50 to 60% of one repetition maximum (IRM), three times weekly, for 8 weeks. The primary outcome was lymphedema volume determined by percentage reduction of excess limb volume (ELV). Secondary outcomes were lymphedema symptoms (pain, heaviness, and tightness) and shoulder mobility and function using the disabilities of the arm, shoulder, and hand (DASH) questionnaire. All measurements were standardized and performed before (week 0, W0), after the intervention (week 8, W8), and at follow-up (week 12, W12). A significant reduction in percentage of ELV (p < 0.01), pain severity (p < 0.05), a sensation of heaviness (p < 0.05) and tightness (p < 0.001), and improvement in shoulder range of motion (p < 0.05) and function on DASH scores (p < 0.05) were observed at W8 and W12 in both groups. However, no between-group differences were observed over time. These findings suggest that low-intensity resistance training, irrespective of garment use, can effectively reduce limb volume and lymphedema symptoms, and increase shoulder mobility and function.