Estimating the Population Burden of Lymphedema

Multi-omics characterization of lymphedema-induced adipose tissue resulting from breast cancer-related surgery

Secondary lymphedema (LE) following breast cancer-related surgery is a life-long complication, which currently has no cure. LE induces significant regional adipose tissue deposition, requiring liposuction as a treatment. Here, we aimed to elucidate the transcriptional, metabolomic, and lipidomic signature of the adipose tissue developed due to the surgery-induced LE in short- and long-term LE patients and compared the transcriptomic landscape of LE adipose tissue to the obesity-induced adipose tissue. Adipose tissue biopsies were obtained from breast cancer-operated females with LE from the affected and non-affected arms (n = 20 patients). To decipher the molecular properties of the LE adipose tissue, we performed RNA sequencing, metabolomics, and lipidomics combined with bioinformatics analyses. Differential gene expression data from a cohort of lean and obese patients without LE was used for comparisons. Integrative analysis of functional genomics revealed that inflammatory response, cell chemotaxis, and angiogenesis were upregulated biological processes in the LE arm, indicating a sustained inflammation in the edematous adipose tissue; whereas, epidermal differentiation, cell-cell junction organization, water homeostasis, and neurogenesis were downregulated in the LE arm. Surprisingly, only a few genes were found to be the same in the LE-induced and the obesity-induced adipose tissue expansion, indicating a different type of adipose tissue development in these two conditions. In metabolomics analysis, we found reduced levels of a branched-chain amino acid valine in the LE arm and downregulation of the mRNA levels of its transporter SLC6A15. Lipidomics analyses did not show any significant differences between the LE and non-LE arms, suggesting that other factors affect the lipid composition of the adipose tissue more than the LE in these patients. Our results provide a detailed molecular characterization of adipose tissue in secondary LE after breast cancer-related surgery. We also show distinct differences in transcriptomic signatures between LE-induced adipose tissue and obesity-induced adipose tissue, but only minor differences in metabolome and lipidome between the LE and the non-LE arm.

Cross-Sectional Analysis of Patients Referred to a Tertiary Lymphatic Surgery Center

BACKGROUND

Secondary lymphedema has become an increasingly common reason for referral to plastic surgery. Understanding referral patterns for lymphedema patients is crucial to optimizing care.

PATIENTS AND METHODS

Patients referred to plastic surgery for lymphedema at a lymphatic surgery center between January 2016 and 2023 were identified. Primary outcomes of interest included clinical lymphedema staging and characteristics, patient demographics, and referral sources. Secondary outcomes were prior lymphedema treatment, agreement between referring provider and plastic surgeon's diagnosis, and patient disposition after surgical evaluation. Descriptive statistics and multivariate logistic regression analysis were performed.

RESULTS

A total of 285 patients with extremity edema were referred to plastic surgery; 60.0% of patients had prior malignancy, 45.6% of patients had undergone a prior lymph node procedure, and 40% had received radiation, while 56.8% of patients had previously seen occupational therapy. Body mass index (BMI, OR 1.09, p = 0.013), age (OR 1.25, p = 0.005), and prior physical or occupational therapy (OR 1.23, p = 0.011) were associated with later stages of lymphedema upon presentation, while prior radiation (OR 0.79, p = 0.006) and malignancy (OR 0.85, p = 0.034) were associated with earlier stages of lymphedema. Self-referral (27.4%), primary care (17.9%), and medical oncology (14.7%) were the most common referral sources. Lymphedema was confirmed in 68.1% of referrals, and 28.5% of these patients proceeded to surgery. Patients were more likely to be operative candidates if referred by primary care (RR 2.1, p = 0.006) or occupational therapy (RR 4.6, p = 0.010).

CONCLUSIONS

Referred patients ultimately undergo lymphedema surgery at relatively low rates, indicating that most referred patients are not ideal surgical candidates. Optimizing referral patterns through multidisciplinary education may enhance the referral process and improve access to lymphedema surgery.

Incidence of lymphedema among adults with cerebral palsy

BACKGROUND

Lymphedema is a chronic and progressive condition but is understudied among adults with cerebral palsy (CP).

OBJECTIVE

To compare the 2-year incidence of lymphedema between adults with versus without CP before and after accounting for multimorbidity, cancer diagnosis/treatment, and lymph node/channel surgery.

DESIGN

Retrospective cohort study.

SETTING

Nationwide commercial claims data from January 1, 2011 to December 31, 2017.

PARTICIPANTS

Adults ≥18 years old with and without CP with at least 12 months of continuous health plan enrollment, defined as the baseline period, were included for analysis. The 12-month baseline period was used to establish information on preexisting lymphedema (for exclusion), presence of cancer, including radiation treatment and lymph node surgery, and the Whitney Comorbidity Index (WCI).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

The 2-year incidence rate (IR) and IR ratio (IRR) of lymphedema were evaluated. Cox regression estimated the hazard ratio (HR) of 2-year lymphedema after adjusting for age, gender, WCI, cancer diagnosis/treatment, and lymph node/channel surgery.

RESULTS

The 2-year IR of lymphedema was 5.73 (95% confidence interval [CI] = 4.59-6.88) for adults with CP (n = 9922) and 1.81 (95% CI = 1.79-1.83) for adults without CP (n = 12,932,288); the IRR was 3.17 (95% CI = 2.59-3.87) and the adjusted HR was 2.43 (95% CI = 1.98-2.98). There was evidence of effect modification by gender, age, and WCI score. All HRs were elevated, but men with versus without CP had higher HRs than women with versus without CP; HRs for adults with versus without CP were higher for younger participants and those with lower WCI scores.

CONCLUSIONS

Adults with CP had a higher 2-year rate of lymphedema compared with those without CP. Men with CP had a disproportionately higher rate than women with CP when compared with their gender-based reference cohorts without CP.

Andrographolide promotes lymphangiogenesis and lymphatic vessel remodeling to alleviate secondary lymphedema

Lymphedema, a prevalent, multifaceted, and chronic ailment, is mainly managed through physical manipulation and suffers from a lack of specific pharmacological treatments. Secondary lymphedema is mainly caused by impaired lymphatic drainage. Therapeutic lymphangiogenesis is a promising strategy in the treatment of lymphedema. Andrographolide, a natural product from Andrographis paniculata, is unknown whether andrographolide promotes lymphangiogenesis to improve secondary lymphedema. By using the murine tail lymphedema model, we demonstrated that andrographolide can reduce the thickness of subcutaneous tissue in the mice's tail and enhance lymphatic drainage. Moreover, immunofluorescence staining showed that the number of capillary lymphatic vessels in the ANDRO25 group was significantly more than that in the ANDRO50 and Model groups. Near-infrared lymphography images showed that highlighted sciatic lymph nodes could be seen in the ANDRO25 and ANDRO50 groups. In vitro, andrographolide could promote the proliferation and migration of LEC. In conclusion, andrographolide enhanced the recovery of lymphatic vessels, and promoted lymphatic drainage in the murine tail lymphedema model by promoting the proliferation of lymphatic endothelial cells, thereby reducing the symptoms of lymphedema. This suggested andrographolide may be used as a potential therapeutic drug or medical food ingredient to help patients with secondary lymphedema.

Primary LYmphedema Multidisciplinary Approach in Patients Affected by Primary Lower Extremity Lymphedema

Background: Primary lymphedema is a chronic condition caused by a developmental abnormality of the lymphatic system, leading to its malfunction. Various surgical options, including physiologic and excisional procedures, have been proposed. The aim of this study was to present a comprehensive algorithm for the treatment of primary lower extremity lymphedema: the Primary LYmphedema Multidisciplinary Approach (P-LYMA). Methods: Nineteen patients were treated following the P-LYMA protocol. Patients underwent pre- and postoperative complex decongestive therapy (CDT). A variety of physiologic and excisional procedures were performed, either independently or in combination. The primary outcome was to assess the circumferential reduction rate (CRR). The Lymphedema Quality of Life Score (LeQOLiS), reduction in the number of cellulitis episodes, and complications were recorded. Results: The mean CRR was 73 ± 20% at twelve months postoperatively. The frequency of cellulitis episodes per year decreased from a mean of 1.9 ± 0.8 preoperatively to 0.4 ± 0.6 during follow-up. Two patients experienced minor complications. The mean hospitalization time was 5 days. Patients' quality of life, as measured by the LeQOLiS, significantly improved from 70.4 ± 12 preoperatively to 24 ± 14 at twelve months postoperatively. Conclusions: The P-LYMA algorithm maximizes surgical outcomes and improves the quality of life in patients with primary lymphedema. CDT is essential for optimizing results.

Lymphatic System Development and Function

PURPOSE OF REVIEW

This review delves into recent advancements in understanding generalized and organ-specific lymphatic development. It emphasizes the distinct characteristics and critical anomalies that can impair lymphatic function. By exploring developmental mechanisms, the review seeks to illuminate the profound impact of lymphatic malformations on overall health and disease progression.

RECENT FINDINGS

The introduction of genome sequencing, single-cell transcriptomic analysis, and advanced imaging technologies has significantly enhanced our ability to identify and characterize developmental defects within the lymphatic system. As a result, a wide range of lymphatic anomalies have been uncovered, spanning from congenital abnormalities present at birth to conditions that can become life-threatening in adulthood. Additionally, recent research highlights the heterogeneity of lymphatics, revealing organ-specific developmental pathways, unique molecular markers, and specialized physiological functions specific to each organ. A deeper understanding of the unique characteristics of lymphatic cell populations in an organ-specific context is essential for guiding future research into lymphatic disease processes. An integrated approach to translational research could revolutionize personalized medicine, where treatments are precisely tailored to individual lymphatic profiles, enhancing effectiveness and minimizing side effects.

[Evidence of modern diagnostic, conservative, and surgical therapy of secondary lymphoedema]

BACKGROUND

Secondary lymphoedema (SL) is one of the most common and, at the same time, most significant consequences and complications of modern oncological therapy. Although a thorough patient history and physical examination are sufficient to substantiate a suspicion, it is essential to perform functional imaging of the lymphatic system for a targeted diagnosis and determination of severity. For this purpose, techniques such as MR and ICG lymphography as well as ultra-high-frequency ultrasound examinations have been developed and validated in recent years. The selective use of these techniques has allowed for individualized indications and successful stage-dependent treatment using (super)microsurgical techniques to restore regional lymphatic drainage in the context of intensified conservative therapy.

METHOD

Systematic review of the literature on the diagnosis and treatment of SL with subsequent analysis and classification of the results into evidence levels according to the Oxford Centre for Evidence-Based Medicine and the GRADE Scale.

RESULTS

The established and validated diagnosis of SL includes imaging (ICG fluorescence lymphography, MR lymphography and Tc-99 functional lymphoscintigraphy) in case of a clinical suspicion and in high-risk patients. Complex physical decongestion therapy (CPE) is superior to physical therapy or compression alone. (Super)microsurgery of SL allows for a postoperative reduction in the frequency of CPE, a reduction of erysipelas rates, a volume reduction of the lymphomatous extremity and, if carried out prophylactically, a lower incidence of SL. Suction-assited lipectomy can produce long-term, stable reductions in circumference and an improvement in quality of life.

CONCLUSION

Patients with SL benefit from conservative therapy with regular re-evaluation. Patients with a high risk for SL or with clinical deterioration or persistent symptoms under guideline-based conservative therapy can benefit from (super)microsurgical therapy after an individualized functional diagnostic evaluation of the lymphatic system. Excisional dermolipectomies or lympholiposuctions are available and effective for advanced and refractory stages.

Lymphedema: Current Strategies for Diagnostics and Management

ABSTRACT

Lymphedema (LE) is characterized by the accumulation of lymph in the extremities, impairing functionality and quality of life. Despite its prevalence, accurate diagnoses and management remains complex because of inconsistencies in diagnostic criteria and limited epidemiological studies. This review aims to address this gap by providing a comprehensive overview of LE classifications, diagnostic approaches, and current management strategies. By synthesizing existing knowledge, this study seeks to contribute to a deeper understanding of LE for improvement of clinical consistency and education.

Effects of Lymphaticovenous Anastomosis on Quality of Life, Body Image, and Spiritual Health in Lymphedema Patients: A Prospective Cohort Study

BACKGROUND

Lymphedema is a debilitating condition that significantly affects quality of life due to its chronic nature and visible symptoms. Lymphaticovenous anastomosis (LVA) has emerged as a promising surgical intervention, yet its effects on body image and spiritual health alongside physical symptoms have not been thoroughly examined. This study evaluates the efficacy of LVA in improving symptoms, quality of life (QOL), body image, and spiritual well-being in lymphedema patients.

METHODS

A prospective cohort study was conducted at Kaohsiung Chang Gung Memorial Hospital, Taiwan, involving 44 patients with lymphedema undergoing LVA surgery. Evaluations were made pre-surgery, one month post-surgery, and six months post-surgery using the 36-Item Short Form Health Survey (SF-36), Multidimensional Body-Self Relations Questionnaire-Appearance Scales (MBSRQ-AS), and a spiritual health scale. Statistical analysis was performed using one-way repeated measures ANOVA.

RESULTS

Significant improvements were observed in lymphedema symptoms and QOL measures at six months post-operation. SF-36 results showed enhanced scores in nearly all domains, particularly in physical functioning and role-physical. The appearance orientation scores from the MBSRQ-AS significantly increased, indicating improved perceptions in some dimensions of body image.

CONCLUSIONS

LVA surgery significantly enhances physical and psychological outcomes in patients with lymphedema, with marked improvements in symptoms, QOL, and body image perceptions. The findings suggest that while LVA is effective in addressing the physical and psychological aspects of lymphedema, it does not impact spiritual dimensions. This underscores the need for holistic approaches in the management of lymphedema to address all facets of patient well-being.

Personalizing Locoregional Therapy in Patients With Breast Cancer in 2024: Tailoring Axillary Surgery, Escalating Lymphatic Surgery, and Implementing Evidence-Based Hypofractionated Radiotherapy

The management of axillary lymph nodes in breast cancer is continually evolving. Recent data now support omitting axillary lymph node dissection (ALND) in most patients with metastases in up to two sentinel lymph nodes (SLNs) during upfront surgery and those with residual isolated tumor cells after neoadjuvant chemotherapy (NACT). In the upfront surgery setting, ALND is still indicated, however, in patients with clinically node-positive breast cancer or more than two positive SLNs and, after NACT, in case of residual micrometastases and macrometastases. Omission of the sentinel lymph node biopsy (SLNB) can be considered in many postmenopausal patients with small luminal breast cancer, particularly when axillary ultrasound is negative. Several randomized controlled trials (RCTs) are currently aiming at eliminating the remaining indications for ALND and also establishing omission of SLNB in a broader patient population. The movement to deescalate axillary staging is in part because of the association between ALND and lymphedema, which is swelling of an extremity because of lymphatic damage and obstructed lymphatic drainage. To reduce the risk of developing this condition, patients undergoing ALND can undergo reverse mapping of the axilla and immediate reconstruction or bypass of the lymphatics from the involved extremity. Decongestion and compression are the foundation of conservative treatment for established lymphedema, while lymphovenous bypass and lymph node transfer are surgical procedures to address the physiologic dysfunction. Radiotherapy is an essential component of breast locoregional therapy: more than three decades of radiation research has optimized treatment according to patient's risk of local recurrence while substantially reducing the number of treatment visits. High-quality RCTs have shown the efficacy and safety of hypofractionation-more than 2Gy radiation dose per treatment (fraction)-significantly reducing the burden of radiotherapy treatment for many patients with breast cancer. In 2024, guidelines recommend no more than 15-16 fractions for whole-breast and nodal radiotherapy, with some recommending five fractions for whole-breast radiotherapy. In addition, simultaneous integrated boost (SIB) has been shown to be noninferior to sequential boost with regards to ipsilateral breast tumor recurrence with similar or reduced long-term side effects, also reducing overall treatment length. Further RCTs are underway investigating other indications for five fractions, including SIB and regional node irradiation, such that, in future, it may be possible for the majority of breast radiotherapy patients to be treated with a 1-week course. This manuscript serves to outline the latest updates on axillary surgical staging, lymphatic surgery, and evidence-based radiotherapy in the treatment of breast cancer.

Surgical management of lymphedema: prophylactic and therapeutic operations

Purpose of Review

Lymphedema is chronic limb swelling from lymphatic dysfunction and is currently incurable. Breast-cancer related lymphedema (BCRL) affects up to 5 million Americans and occurs in one-third of breast cancer survivors following axillary lymph node dissection. Compression remains the mainstay of therapy. Surgical management of BCRL includes excisional procedures to remove excess tissue and physiologic procedures to attempt improve fluid retention in the limb. The purpose of this review is to highlight surgical management strategies for preventing and treating breast cancer-related lymphedema.

Recent findings

Immediate lymphatic reconstruction (ILR) is a microsurgical technique that anastomoses disrupted axillary lymphatic vessels to nearby veins at the time of axillary lymph node dissection (ALND) and has been reported to reduce lymphedema rates from 30% to 4-12%.

Summary

Postsurgical lymphedema remains incurable. Surgical management of lymphedema includes excisional procedures and physiologic procedures using microsurgical technique. Immediate lymphatic reconstruction has emerged as a prophylactic strategy to prevent lymphedema in breast cancer patients.

TRPV4-Expressing Tissue-Resident Macrophages Regulate the Function of Collecting Lymphatic Vessels via Thromboxane A2 Receptors in Lymphatic Muscle Cells

Rationale

TRPV4 channels are critical regulators of blood vascular function and have been shown to be dysregulated in many disease conditions in association with inflammation and tissue fibrosis. These are key features in the pathophysiology of lymphatic system diseases, including lymphedema and lipedema; however, the role of TRPV4 channels in the lymphatic system remains largely unexplored. TRPV4 channels are calcium permeable, non-selective cation channels that are activated by diverse stimuli, including shear stress, stretch, temperature, and cell metabolites, which may regulate lymphatic contractile function.

Objective

To characterize the expression of TRPV4 channels in collecting lymphatic vessels and to determine the extent to which these channels regulate the contractile function of lymphatics.

Methods and Results

Pressure myography on intact, isolated, and cannulated lymphatic vessels showed that pharmacological activation of TRPV4 channels with GSK1016790A (GSK101) led to contractile dysregulation. The response to GSK101 was multiphasic and included, 1) initial robust constriction that was sustained for ≥1 minute and in some instances remained for ≥4 minutes; and 2) subsequent vasodilation and partial or complete inhibition of lymphatic contractions associated with release of nitric oxide. The functional response to activation of TRPV4 channels displayed differences across lymphatics from four anatomical regions, but these differences were consistent across different species (mouse, rat, and non-human primate). Importantly, similar responses were observed following activation of TRPV4 channels in arterioles. The initial and sustained constriction was prevented with the COX inhibitor, indomethacin. We generated a controlled and spatially defined single-cell RNA sequencing (scRNAseq) dataset from intact and microdissected collecting lymphatic vessels. Our data uncovered a subset of macrophages displaying the highest expression of Trpv4 compared to other cell types within and surrounding the lymphatic vessel wall. These macrophages displayed a transcriptomic profile consistent with that of tissue-resident macrophages (TRMs), including differential expression of Lyve1 , Cd163 , Folr2 , Mrc1 , Ccl8 , Apoe , Cd209f , Cd209d , and Cd209g ; and at least half of these macrophages also expressed Timd4. This subset of macrophages also highly expressed Txa2s , which encodes the thromboxane A2 (TXA2) synthase. Inhibition of TXA2 receptors (TXA2Rs) prevented TRPV4-mediated contractile dysregulation. TXA2R activation on LMCs caused an increase in mobilization of calcium from intracellular stores through Ip3 receptors which promoted store operated calcium entry and vasoconstriction.

Conclusions

Clinical studies have linked cancer-related lymphedema with an increased infiltration of macrophages. While these macrophages have known anti-inflammatory and pro-lymphangiogenic roles, as well as promote tissue repair, our results point to detrimental effects to the pumping capacity of collecting lymphatic vessels mediated by activation of TRPV4 channels in macrophages. Pharmacological targeting of TRPV4 channels in LYVE1-expressing macrophages or pharmacological targeting of TXA2Rs may offer novel therapeutic strategies to improve lymphatic pumping function and lymph transport in lymphedema.

Perturbed collagen metabolism underlies lymphatic recanalization failure in Gata2 heterozygous deficient mice

Lymphedema has become a global health issue following the growing number of cancer surgeries. Curative or supportive therapeutics have long been awaited for this refractory condition. Transcription factor GATA2 is crucial in lymphatic development and maintenance, as GATA2 haploinsufficient disease often manifests as lymphedema. We recently demonstrated that Gata2 heterozygous deficient mice displayed delayed lymphatic recanalization upon lymph node resection. However, whether GATA2 contributes to lymphatic regeneration by functioning in the damaged lymph vessels' microenvironment remains explored. In this study, our integrated analysis demonstrated that dermal collagen fibers were more densely accumulated in the Gata2 heterozygous deficient mice. The collagen metabolism-related transcriptome was perturbed, and collagen matrix contractile activity was aberrantly increased in Gata2 heterozygous embryonic fibroblasts. Notably, soluble collagen placement ameliorated delayed lymphatic recanalization, presumably by modulating the stiffness of the extracellular matrix around the resection site of Gata2 heterozygous deficient mice. Our results provide valuable insights into mechanisms underlying GATA2-haploinsufficiency-mediated lymphedema and shed light on potential therapeutic avenues for this intractable disease.

Arm lymphedema after vascularized lymph node harvest following Covid-19 vaccination

There is evidence that COVID-19 vaccines may affect the lymphatic system. We report a case of a 40-year-old female who had undergone lymph node transfer for treating primary lymphedema of the legs. Six months later, the patient developed lymphedema of the right arm closely related to mRNA vaccination against COVID-19.

The Role of Inflammation in Lymphedema: A Narrative Review of Pathogenesis and Opportunities for Therapeutic Intervention

Lymphedema is a chronic and progressive disease of the lymphatic system characterized by inflammation, increased adipose deposition, and tissue fibrosis. Despite early hypotheses identifying lymphedema as a disease of mechanical lymphatic disruption alone, the progressive inflammatory nature underlying this condition is now well-established. In this review, we provide an overview of the various inflammatory mechanisms that characterize lymphedema development and progression. These mechanisms contribute to the acute and chronic phases of lymphedema, which manifest clinically as inflammation, fibrosis, and adiposity. Furthermore, we highlight the interplay between current therapeutic modalities and the underlying inflammatory microenvironment, as well as opportunities for future therapeutic development.

Pacemaking in the lymphatic system

Lymphatic collecting vessels exhibit spontaneous phasic contractions that are critical for lymph propulsion and tissue fluid homeostasis. This rhythmic activity is driven by action potentials conducted across the lymphatic muscle cell (LMC) layer to produce entrained contractions. The contraction frequency of a lymphatic collecting vessel displays exquisite mechanosensitivity, with a dynamic range from <1 to >20 contractions per minute. A myogenic pacemaker mechanism intrinsic to the LMCs was initially postulated to account for pressure-dependent chronotropy. Further interrogation into the cellular constituents of the lymphatic vessel wall identified non-muscle cell populations that shared some characteristics with interstitial cells of Cajal, which have pacemaker functions in the gastrointestinal and lower urinary tracts, thus raising the possibility of a non-muscle cell pacemaker. However, recent genetic knockout studies in mice support LMCs and a myogenic origin of the pacemaker activity. LMCs exhibit stochastic, but pressure-sensitive, sarcoplasmic reticulum calcium release (puffs and waves) from IP3R1 receptors, which couple to the calcium-activated chloride channel Anoctamin 1, causing depolarisation. The resulting electrical activity integrates across the highly coupled lymphatic muscle electrical syncytia through connexin 45 to modulate diastolic depolarisation. However, multiple other cation channels may also contribute to the ionic pacemaking cycle. Upon reaching threshold, a voltage-gated calcium channel-dependent action potential fires, resulting in a nearly synchronous calcium global calcium flash within the LMC layer to drive an entrained contraction. This review summarizes the key ion channels potentially responsible for the pressure-dependent chronotropy of lymphatic collecting vessels and various mechanisms of IP3R1 regulation that could contribute to frequency tuning.

Association between Bioimpedance Spectroscopy and Magnetic Resonance Lymphangiography in the Diagnosis and Assessment of Lymphedema

BACKGROUND

 This study assesses associations between bioimpedance spectroscopy (BIS) and magnetic resonance lymphangiography (MRL) in the staging and assessment of lymphedema.

METHODS

 Adults who received MRL and BIS between 2020 and 2022 were included. We collected fluid, fat, and lymphedema severity ratings, and measured fluid stripe thickness, subcutaneous fat width, and lymphatic diameter on MRL. BIS lymphedema index (L-Dex) scores were collected from patient charts. We assessed sensitivity and specificity of L-Dex scores to detect MRL-identified lymphedema, and examined associations between L-Dex scores and MRL imaging measures.

RESULTS

 Forty-eight limbs across 40 patients were included. L-Dex scores had 72.5% sensitivity and 87.5% specificity for detecting MRL-defined lymphedema, with a 96.7% estimated positive predictive value and 38.9% negative predictive value. L-Dex scores were associated with MRL fluid and fat content scores (p ≤ 0.05), and lymphedema severity (p = 0.01), with better discrimination between fluid than fat content levels on pairwise analysis, and poor discrimination between adjacent severity levels. L-Dex scores were correlated with distal and proximal limb fluid stripe thickness (distal: rho = 0.57, p < 0.01; proximal: rho = 0.58, p < 0.01), partially correlated with distal subcutaneous fat thickness when accounting for body mass index (rho = 0.34, p = 0.02), and were not correlated with lymphatic diameter (p = 0.25).

CONCLUSION

 L-Dex scores have high sensitivity, specificity, and positive predictive value for the identification of MRL-detected lymphedema. L-Dex has difficulty distinguishing between adjacent severity levels of lymphedema and a high false negative rate, explained in part by reduced discrimination between levels of fat accumulation.

The relationship of kinesiophobia in patients with lymphedema: a case-control investigation

Introduction

Kinesiophobia and lymphedema appear to be related conditions, and it is important to understand this relationship, as many of the symptoms and comorbidities presented by individuals with lower limb lymphedema are prevented and treated through movement, thus constituting kinesiophobia as a barrier to intervention. The objective of this study is, therefore, to evaluate and analyze the kinesiophobic beliefs reported by individuals with and without lower limb lymphedema, regarding the agreement, severity and differences found, and to establish levels of kinesiophobia.

Methods

A case-control study with a total sample of 80 participants (40 with lower limb lymphedema and 40 without) was performed. Both groups (with and without lymphedema) were characterized anthropologically, sociodemographically, and clinically. In the case group, lymphedema was evaluated. Participants in both groups completed the Tampa Scale for Kinesiophobia - 13 items (TSK-13).

Results

Individuals with lower limb lymphedema had higher TSK-13 scores than their matched group without lymphedema. The items belonging to the activity avoidance subscale had the highest agreement and score in both groups. Differences between groups were mainly established for items belonging to the somatic focus subscale, showing that individuals with lower limb lymphedema have kinesiophobic beliefs related to the perceived severity of their lymphedema. The prevalence of kinesiophobia was increased in both groups, but the severity was mild.

Conclusions

Considering the apparent tendency of people with lower limb lymphedema to present kinesiophobia and movement-limiting beliefs regarding the condition, greater attention should be paid to its assessment, prevention and treatment from a multidisciplinary and multimodal perspective, which takes into account the multiplicity of factors inherent to kinesiophobia and lymphedema and thus reduce their impact on the management of lymphedema.

Editorial for the Special Issue "Vasorum Lymphaticorum: From the Discovery of the Lymphatic System to the New Perspectives in Microsurgical Reconstruction and Patient Rehabilitation"

Lymphedema is a complex clinical condition that appears as a result of the failure of the lymphatic system function, and it is characterized by edema, fibrosis, and adipose deposition [...].

Current and Developing Lymphatic Imaging Approaches for Elucidation of Functional Mechanisms and Disease Progression

Study of the lymphatic system, compared to that of the other body systems, has been historically neglected. While scientists and clinicians have, in recent decades, gained a better appreciation of the functionality of the lymphatics as well as their role in associated diseases (and consequently investigated these topics further in their experimental work), there is still much left to be understood of the lymphatic system. In this review article, we discuss the role lymphatic imaging techniques have played in this recent series of advancements and how new imaging techniques can help bolster this wave of discovery. We specifically highlight the use of lymphatic imaging techniques in understanding the fundamental anatomy and physiology of the lymphatic system; investigating the development of lymphatic vasculature (using techniques such as intravital microscopy); diagnosing, staging, and treating lymphedema and cancer; and its role in other disease states.

Advances in lymphedema: An under-recognized disease with a hopeful future for patients

Lymphedema has traditionally been underappreciated by the healthcare community. Understanding of the underlying pathophysiology and treatments beyond compression have been limited until recently. Increased investigation has demonstrated the key role of inflammation and resultant fibrosis and adipose deposition leading to the clinical sequelae and associated reduction in quality of life with lymphedema. New imaging techniques including magnetic resonance imaging (MRI), indocyanine green lymphography, and high-frequency ultrasound offer improved resolution and understanding of lymphatic anatomy and flow. Nonsurgical therapy with compression, exercise, and weight loss remains the mainstay of therapy, but growing surgical options show promise. Physiologic procedures (lymphovenous anastomosis and vascularized lymph node transfers) improve lymphatic flow in the diseased limb and may reduce edema and the burden of compression. Debulking, primarily with liposuction to remove the adipose deposition that has accumulated, results in a dramatic decrease in limb girth in appropriately selected patients. Though early, there are also exciting developments of potential therapeutic targets tackling the underlying drivers of the disease. Multidisciplinary teams have developed to offer the full breadth of evaluation and current management, but the development of a greater understanding and availability of therapies is needed to ensure patients with lymphedema have greater opportunity for optimal care.

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.

Prevalence and Prognostic Role of Lymphedema in Patients with Deep Venous Thrombosis and Thrombophlebitis

Background: Deep venous thrombosis (DVT) poses a substantial disease burden. Lymphedema may present with similar symptoms making the diagnosis process more difficult. Data on the epidemiology of lymphedema are lacking. Methods: The German nationwide inpatient sample served to analyze all patients hospitalized owing to DVT and/or thrombophlebitis (referred to as DVT) of the legs in Germany between 2005 and 2020. We stratified these patients for additional lymphedema and analyzed the impact of lymphedema on adverse in-hospital events. Results: Overall, 1,136,574 hospitalizations related to DVT were recorded in Germany during 2005-2020 (53.3% women; 51.3% aged ≥70 years). Lymphedema was coded in 9974 (0.9%) patient-cases (82.0% not elsewhere classified, 17.7% secondary lymphedema). Annual numbers of hospitalizations with lymphedema among DVT patients increased from 450 (2005) to 613 (2016) (β 0.57; 95% confidence interval [CI]: 0.48-0.66], p < 0.001) and decreased thereafter. Despite similar age, DVT patients with lymphedema had higher prevalence of cardiovascular diseases, chronic organ failure, and all types of investigated cancer. Prevalence of pulmonary embolism (PE) with shock/CPR (4.1% vs. 1.5%), acute renal failure (6.7% vs. 2.5%), and stroke (5.2% vs. 4.2%) was higher in DVT patients with lymphedema than without. Lymphedema was independently associated with PE with shock/CPR (OR: 2.1; 95% CI: 1.9-2.3) as well as death (OR: 1.3; 95% CI: 1.2-1.4). Conclusions: Comorbidity conditions like cancer, obesity, and cardiovascular risk factors, and also infectious complications, were more prevalent in DVT patients with lymphedema than in those without. Lymphedema was independently associated with severe in-hospital complications, particularly when its genesis was related to severe comorbidities.

Efficacy of Neonatal Porcine Bone Marrow-Derived Mesenchymal Stem Cell Xenotransplantation for the Therapy of Hind Limb Lymphedema in Mice

Lymphedema is an intractable disease with few effective therapeutic options. Autologous mesenchymal stem cell (MSC) transplantation is a promising therapy for this disease. However, its use is limited by the cost and time for preparation. Recently, xenotransplantation of porcine MSCs has emerged as an alternative to autologous MSC transplantation. In this study, we aimed to clarify the usefulness of neonatal porcine bone marrow-derived MSC (NpBM-MSC) xenotransplantation for the treatment of lymphedema. One million NpBM-MSCs were xenotransplanted into the hind limbs of mice with severe lymphedema (MSC transplantation group). The therapeutic effects were assessed by measuring the femoral circumference, the volume of the hind limb, the number and diameter of lymphatic vessels in the hind limb, and lymphatic flow using a near-infrared fluorescence (NIRF) imaging system. We compared the effects using mice with lymphedema that did not undergo NpBM-MSC transplantation (negative control group). The condition of the transplanted NpBM-MSCs was also evaluated histologically. The femoral circumference and volume of the hind limb had been normalized by postoperative day (POD) 14 in the MSC transplantation group, but not in the negative control group (P = 0.041). NIRF imaging revealed that lymphatic flow had recovered in the MSC transplantation group by POD 14, as shown by an increase in luminance in the hind limb. Histological assessment also showed that the xenotransplantation of NpBM-MSC increased the proliferation of lymphatic vessels, but they had been rejected by POD 14. The xenotransplantation of NpBM-MSCs is an effective treatment for lymphedema, and this is mediated through the promotion of lymphangiogenesis.

The Top 100 Most-Cited Articles on the Treatment of Lymphedema

A multitude of articles have been published on lymphedema management. We aim to identify the 100 most-cited articles on the management of lymphedema and perform a bibliometric analysis. In July 2023, a title-specific search was made on the Scopus database using "lymphedema" as the primary search term. The top 100 most-cited articles were reviewed. The top 100 most-cited articles on lymphedema received a mean citation of 81.7 ± 71.9 per article (range of 11.0 to 420.0). The publication dates ranged from 1977 to 2015. Most of the articles were original (63.0%), interventional studies (35.0%), randomized controlled trials (RCTs) (31.0%), and systematic reviews (32.0%). The largest number of articles (31) were found between 2007 and 2011. The top 10 articles' citation counts ranged from 164 to 420 (mean of 244.7 ± 83.9 citations). Five of these 10 articles were published between the years 1990 and 2000. Twenty-five countries contributed to the 100 most-cited articles. The United States produced the most number of articles (n = 32), followed by Italy (n = 11), Sweden, and Turkey, with seven articles each. Four of the top 10 articles were RCTs; the remaining six were systematic, retrospective, and prospective studies. The New England Journal of Medicine published two of these top 10 articles. Retrospective studies had the highest mean citation with 196.5, followed by RCTs with 100.9. We identified the 100 most-cited articles that depict the advancement in treatment methods for lymphedema. This extensive information directory can be an excellent source for further research.

Physiotherapy practice in lymphoedema in South Africa: A survey

Background

Lymphoedema is a chronic condition that is increasing in prevalence and requires specialised management to avoid possible life-threatening complications.

Objectives

To describe the perceived knowledge of physiotherapists about lymphoedema and its management, the lymphoedema patient load seen by physiotherapists, and the current treatment approaches of physiotherapists in South Africa when managing lymphoedema.

Method

A quantitative study using self-administered, online questionnaires were distributed among physiotherapists.

Results

Knowledge of lymphoedema management is perceived to be lacking among physiotherapists. Physiotherapists are getting limited referrals and spending little time managing patients with lymphoedema. Only a few physiotherapists have post-graduate education in lymphoedema management, thus international treatment standards still need to be met.

Conclusion

In order to meet international standards and patient needs, future research investigating the physiotherapy perspective is needed in lymphoedema management.

Clinical implications

Educational bodies and policymakers may use this data to facilitate improvement in physiotherapy management of the condition and provision of care.

Experimental Study of the Prevention and Treatment of Lymphoedema in a Rat Hindlimb Model by Applying Cardioperitoneal Catheters and Lacrimal Intubation Tubes in the Inguinoperitoneal Region

OBJECTIVE

Secondary lymphoedema (LE) is a chronic condition with limited surgical treatment options for restoring extremity form and function. This study aimed to establish a reproducible model of secondary LE and evaluate the preventive and corrective effects of fenestrated catheters (FC) and capillary tubes (CT).

METHODS

Thirty-five rats underwent left hindlimb inguinal and popliteal lymph node dissection, followed by radiotherapy after two weeks. The right hindlimb served as the control. The rats were divided into five groups: sham, two preventive (Group 2 - EFC, Group 3 - ECT), and two corrective (Group 4 - LFC, Group 5 - LCT). Measurements of ankle circumference (AC) and paw thickness (PT) were taken weekly, and imaging modalities were performed. After a 16 week follow up, rats were euthanised for histological examination.

RESULTS

Data include paw thickness (PT) and ankle circumference (AC) ratios for hindlimbs. In the sham group, AC ratio was 1.08 (p = .002) and PT ratio was 1.11 (p = .020), confirming successful lymphoedema model establishment. Early catheter and tube placement in Groups 2 and 3 prevented AC and PT increase until the 16th week. Group 2: the AC ratio was 0.98 (p = .93), and the PT ratio was 0.98 (p = .61). Group 3: the AC ratio was 0.98 (p = .94) and the PT ratio was 0.99 (p = .11). From the 10th to the 16th week, Groups 4 and 5 exhibited reduced measurements after insertion of catheters and tubes. Computed tomography imaging as an objective examination supported the results obtained from the measurements. The histological findings confirmed the benefits of both FC and CT.

CONCLUSION

The insights gained from the present study provide a basis for further exploration and refinement of drainage system designs, ultimately leading to improved treatment approaches for individuals suffering from lymphoedema in the future.

The Axillary Lateral Vessel Thoracic Junction Is Not an Organ at Risk for Breast Cancer-Related Lymphedema

PURPOSE

Breast cancer-related lymphedema (BCRL) is a treatment complication that significantly reduces patient quality of life. Regional nodal irradiation (RNI) may increase the risk of BCRL. Recently, a region of the axilla known as the axillary-lateral thoracic vessel juncture (ALTJ) was identified as a potential organ at risk (OAR). Here, we set out to validate whether radiation dose to the ALTJ is associated with BCRL.

METHODS AND MATERIALS

We identified patients with stage II-III breast cancer treated with adjuvant RNI from 2013 to 2018, excluding those with BCRL preradiation. We defined BCRL as difference in arm circumference between the ipsilateral and contralateral limb >2.5 cm at any 1 encounter or ≥2 cm on ≥2 visits. All patients suspected of having BCRL at routine follow-up visits were referred to physical therapy for confirmation. The ALTJ was retrospectively contoured and dose metrics were collected. Cox proportional hazards regression models were used to test the association between clinical and dosimetric parameters with the development of BCRL.

RESULTS

The study population included 378 patients with a median age of 53 years, median body mass index of 28.4 kg/m2, and median of 18 axillary nodes removed; 71% underwent mastectomy. Median follow-up was 70 months (interquartile range, 55-89.7 months). BCRL developed in 101 patients at a median of 18.9 months (interquartile range, 9.9-32.4 months), with a corresponding 5-year cumulative incidence BCRL of 25.8%. On multivariate analysis, none of the ALTJ metrics were associated with BCRL risk. Only increasing age, increasing body mass index, and increasing number of nodes were associated with a higher risk of developing BCRL. The 6-year locoregional recurrence rate was 3.2%, the axillary recurrence rate was 1.7%, and the isolated axillary recurrence rate was 0%.

CONCLUSIONS

The ALTJ is not validated as a critical OAR for reducing BCRL risk. Until such an OAR is discovered, the axillary PTV should not be modified or dose reduced in efforts to reduce BCRL.

The Top 100 Cited Articles in the Microsurgical Treatment for Lymphedema

BACKGROUND

 Evidence-based medicine uses the current best evidence for decisions about patient care. Lymphedema is a chronic debilitating medical condition caused by a dysfunctional lymphatic system. This study analyzes the most cited articles, including the levels of evidence, for the surgical treatment of lymphedema.

METHODS

 The Web of Science Sci-Expanded Index was utilized to search for surgical treatment of lymphedema. Articles were examined by three independent reviewers and the top 100 articles were determined. The corresponding author, citation count, publication year, topic, study design, level of evidence, journal, country, and institution were analyzed.

RESULTS

 Since 1970, the top 100 articles have been cited 7,300 times. The average citation count was 68 and standard deviation was 55. The majority was case series (71), followed by retrospective cohort (8), prospective cohort (7), retrospective case-control (5), and randomized controlled trials (2). Based on the "Level of Evidence Pyramid," 71 articles were level IV, 13 articles were level III, and 9 articles were level II. On the Grading of Recommendations Assessment, Development, and Evaluation Scale, there were 71 articles with "very low," 20 articles with "low," and 2 articles with "moderate" quality of evidence.

CONCLUSION

 The top 100 cited articles were mostly case series and lacked high levels of evidence. Most studies are retrospective case series with short-term outcomes. However, low level evidence for new surgical procedures is to be expected. Current trends suggest the treatment and understanding of lymphedema will continue to improve.

The utility of computed tomography venography in the routine evaluation of patients who present to a lymphedema center with lower extremity edema

OBJECTIVE

Computed tomography venography (CTV) is not routinely used to screen patients presenting with a presumed lower extremity lymphedema diagnosis for left iliac vein obstruction (IVO) or May-Thurner syndrome (MTS). The objective of this study is to determine the utility of routine CTV screening for these patients by evaluating the proportion presenting with clinically significant CTV-identified left IVO.

METHODS

We retrospectively reviewed 121 patients who had presented to our lymphedema center with lower extremity edema between November 2020 and May 2022. Information regarding demographics, comorbidities, lymphedema characteristics, and imaging reports was collected. Cases of IVO present on CTV were reviewed by a multidisciplinary team to determine the clinical significance of the CTV findings.

RESULTS

Of the patients with complete imaging studies, 49% (n = 25) had abnormal lymphoscintigraphy findings, 45% (n = 46) had reflux on ultrasound, and 11.4% (n = 9) had IVO on CTV. Seven patients (6%) had CTV findings of IVO and edema of either the isolated left (n = 4) or bilateral (n = 3) lower extremities. Cases of IVO on CTV were determined by the multidisciplinary team to be the predominant cause of lower extremity edema for three of these seven cases (43%; or 2.5% of all 121 patients).

CONCLUSIONS

Six percent of patients presenting to a lymphedema center with lower extremity edema had left-sided IVO on CTV suggestive of MTS. However, the cases of IVO were determined to be clinically significant <50% of the time or for 2.5% of all patients. CTV should be reserved for patients with isolated left-sided or bilateral lower extremity edema with a greater left-sided component and a history of findings that raise clinical suspicion for MTS.

Patient Experience of Photobiomodulation Therapy in Head and Neck Chronic Lymphedema

Purpose: Lymphedema is a common late effect of head and neck cancer treatment that causes various symptoms, functional impairment, and poor quality of life. We completed a pilot, prospective, single-arm clinical trial to determine the feasibility and potential efficacy of the use of photobiomodulation (PBM) therapy for head and neck lymphedema. In this study, we report patients' perceived treatment experience of PBM therapy and provide suggestions to better understand head and neck cancer survivors' experience of PBM therapy. Methods: Head and neck cancer patients who underwent PBM therapy completed face-to-face semi-structured interviews. Interviews were audio-recorded and then transcribed verbatim. Qualitative content analysis was used to analyze the transcriptions from the interviews. Results: Among 12 participants who consented for the study, 11 (91.7%) completed the PBM therapy. Participants described positive experiences and unique benefits about the PBM therapy, for example, decreased swelling, reduced tightness, increased range of motion, increased saliva production, and improved ability to swallow. Some participants (n = 5, 45.5%) delineated challenges related to traffic, travel time, and distance from study location. Many participants proposed suggestions for future research on PBM therapy, for example, research on internal edema and its relationship with swallowing, and indicated patients with severe lymphedema and fibrosis may be more likely to benefit. Conclusions: Findings from this study suggested the potential benefits of PBM therapy in treatment of chronic head and neck lymphedema. Rigorously designed clinical trials are needed to evaluate the effect of PBM therapy for head and neck cancer-related lymphedema. Trial Registration Number and Date of Registration: ClinicalTrials.gov Identifier: NCT03738332; date of registration: November 13, 2018.

The Role of Escin as a Topical Agent for Lymphedema Treatment in a Rat Model

Escin, a naturally derived material isolated from horse chestnut, is used as an anti-inflammatory and anti-edema agent. This study aimed to evaluate its effects on lymphedema in a rat tail model. We divided the rats into five groups. The treatment groups received topical application of escin gel at concentrations of 20%, 10%, 2%, and 0.5% for 4 weeks. The fifth group served as a control. We performed volumetric (water displacement) tests, H&E staining, and LYVE-1 immunohistochemical staining, followed by statistical evaluation. All treatment groups showed significant volumetric reductions compared with the control group, but no significant differences were observed between the treatment groups. H&E staining showed a significant reduction in dermal thickness in the 20%, 10%, and 2% escin treatment groups compared to the control group. Within the treatment groups, the 2% escin group showed a significant difference compared with the 20% and 10% escin groups (p = 0.021 for both). LYVE-1 immunohistochemical staining revealed a significantly higher mean lymphatic vessel count in the 2% escin group compared with the 20%, 10%, and 0.5% escin-treated groups and the control group (p = 0.019, p = 0.025, p = 0.019, and p = 0.032 respectively). Topical escin applied to a rat tail model of acute lymphedema resulted in a significant reduction in tail volume, reduced dermal thickness, and increased lymphatic structures. The 2% escin concentration may be the optimal dose for improving lymphedema in this model. Further research is warranted to explore the clinical application of escin in patients with lymphedema.

Edematous Dermal Thickening on Magnetic Resonance Imaging as a Biomarker for Lymphatic Surgical Outcomes

Background and Objectives: One of the surgical treatments for breast cancer-related lymphedema (BCRL) is debulking lipectomy. The aim of this study is to investigate whether dermal thickness could be utilized as an objective indicator of post-operative changes following debulking. Materials and Methods: A retrospective review of BCRL patients who underwent debulking lipectomy was conducted. MRI-based dermal thickness was measured by two separate trained readers at 16 regions of the upper extremity. Pre- and post-operative reduction in dermal thickness was compared across the affected and unaffected (control) arms for each patient. The Wilcoxon rank sum test was used to assess for significant change. Univariate linear regression was used to assess the relationship between dermal thickness reduction and changes to LYMPH-Q scores, L-Dex scores, and relative volume change. Results: Seventeen patients were included in our analysis. There was significant reduction in dermal thickness at 5/16 regions in the affected arm. Dermal thickness change was significantly correlated with LYMPH-Q scores, L-Dex scores, and relative volume change in 2/16 limb compartments. There was predominant dermal thickening in the dorsal compartment of the upper arm and in the ventral and ulnar compartments of the forearm. Conclusions: Dermal thickness shows promising utility in tracking post-operative debulking procedures for breast cancer-related lymphedema. Further studies with larger patient populations and a variety of imaging modalities are required to continue to develop a clinically objective and reproducible method of post-surgical lymphedema staging and monitoring.

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.

Peripheral T cell profiling reveals downregulated exhaustion marker and increased diversity in lymphedema post-lymphatic venous anastomosis

Lymphedema is a progressive condition accompanying cellulitis and angiosarcoma, suggesting its association with immune dysfunction. Lymphatic venous anastomosis (LVA) can provide relief from cellulitis and angiosarcoma. However, the immune status of peripheral T cells during lymphedema and post-LVA remains poorly understood. Using peripheral blood T cells from lymphedema, post-LVA, and healthy controls (HCs), we compared the profile of T cell subsets and T cell receptor (TCR) diversity. PD-1⁺ Tim-3 ⁺ expression was downregulated in post-LVA compared with lymphedema. IFN-γ levels in CD4⁺PD-1⁺ T cells and IL-17A levels in CD4⁺ T cells were downregulated in post-LVA compared with lymphedema. TCR diversity was decreased in lymphedema compared with HCs; such TCR skewing was drastically improved in post-LVA. T cells in lymphedema were associated with exhaustion, inflammation, and diminished diversity, which were relieved post-LVA. The results provide insights into the peripheral T cell population in lymphedema and highlight the immune modulatory importance of LVA.

The Future of Lymphedema: Potential Therapeutic Targets for Treatment

Purpose of Review

This review aims to summarize the current knowledge regarding the pharmacological interventions studied in both experimental and clinical trials for secondary lymphedema.

Recent Findings

Lymphedema is a progressive disease that results in tissue swelling, pain, and functional disability. The most common cause of secondary lymphedema in developed countries is an iatrogenic injury to the lymphatic system during cancer treatment. Despite its high incidence and severe sequelae, lymphedema is usually treated with palliative options such as compression and physical therapy. However, recent studies on the pathophysiology of lymphedema have explored pharmacological treatments in preclinical and early phase clinical trials.

Summary

Many potential treatment options for lymphedema have been explored throughout the past two decades including systemic agents and topical approaches to decrease the potential toxicity of systemic treatment. Treatment strategies including lymphangiogenic factors, anti-inflammatory agents, and anti-fibrotic therapies may be used independently or in conjunction with surgical approaches.

Structural and functional analysis of the newt lymphatic system

Regeneration competent vertebrates such as newts and salamanders possess a weakened adaptive immune system characterized by multiple connections between the lymphatic system and the blood vascular system called lymphatic hearts. The role of lymphatic vasculature and these lymphaticovenous connections in regeneration is unknown. We used in-vivo near-infrared lymphangiography, ultra-high frequency ultrasonography, micro-CT lymphangiography, and histological serial section 3-dimentional computer reconstruction to evaluate the lymphatic territories of Cynops pyrrhogaster. We used our model and supermicrosurgery to show that lymphatic hearts are not essential for lymphatic circulation and limb regeneration. Instead, newts possess a novel intraosseous network of lymphatics inside the bone expressing VEGFR-3, LYVE-1 and CD-31. However, we were unable to show Prox-1 expression by these vessels. We demonstrate that adult newt bone marrow functions as both a lymphatic drainage organ and fat reservoir. This study reveals the fundamental anatomical differences between the immune system of urodeles and mammals and provides a model for investigating lymphatics and regeneration.

Therapeutic Lymphangiogenesis Is a Promising Strategy for Secondary Lymphedema

Secondary lymphedema is caused by lymphatic insufficiency (lymphatic drainage failure) following lymph node dissection during the surgical treatment or radiation therapy of breast or pelvic cancer. The clinical problems associated with lymphedema are reduced quality of life in terms of appearance and function, as well as the development of skin ulcers, recurrent pain, and infection. Currently, countermeasures against lymphedema are mainly physical therapy such as lymphatic massage, elastic stockings, and skin care, and there is no effective and fundamental treatment with a highly recommended grade. Therefore, there is a need for the development of a fundamental novel treatment for intractable lymphedema. Therapeutic lymphangiogenesis, which has been attracting attention in recent years, is a treatment concept that reconstructs the fragmented lymphatic network to recover lymphatic vessel function and is revolutionary to be a fundamental cure. This review focuses on the translational research of therapeutic lymphangiogenesis for lymphedema and outlines the current status and prospects in the development of therapeutic applications.

Effect of valve spacing on peristaltic pumping

Peristaltic fluid pumping due to a periodically propagating contraction wave in a vessel fitted with one-way elastic valves is investigated numerically. It is concluded that the valve spacing within the vessel relative to the contraction wavelength plays a critical role in providing efficient pumping. When the valve spacing does not match the wavelength, the valves open asynchronously and the volume of the vessel segments bounded by two consecutive valves changes periodically, thereby inducing volumetric fluid pumping. The volumetric pumping leads to higher pumping flowrate and efficiency against an adverse pressure gradient. The optimum pumping occurs when the ratio of valve spacing to contraction wavelength is about2/3. This pumping regime is characterized by a longer period during which the valves are open. The results are useful for further understanding the pumping features of lymphatic system and provide insight into the design of biomimetic pumping devices.

Selecting appropriate compression for lymphedema patients: American Vein and Lymphatic Society position statement

BACKGROUND

Lymphedema is a significant and disabling disorder affecting millions of people worldwide. Compression therapy is an important component of lifelong treatment but the specifics of appropriate compression garment selection and prescribing is not always well understood by practitioners and payers.

METHOD

An expert panel of the American Vein and Lymphatic Society was convened to write a Position Statement with explanations and recommendations for the appropriate compression therapy to be used in the treatment of lymphedema patients.

RESULT

A Position Statement was produced by the expert panel with recommendations for documentation and compression therapy treatment. Their recommendations were reviewed, edited, and approved by the Guidelines Committee of the society.

CONCLUSION

This societal Position Statement provides a useful document for reference for medical care providers for the appropriate compression therapy selection and treatment of patients with lymphedema.

Adipose Tissue in Lymphedema: A Central Feature of Pathology and Target for Pharmacologic Therapy

Lymphedema is a chronic condition of impaired lymphatic flow that results in limb swelling and debilitation. The pathophysiology of lymphedema is characterized by lymphatic stasis that triggers inflammation, fibrosis, and adipose tissue deposition in the extremities. Most often, this condition occurs in cancer survivors in the years after treatment with combinations of surgery, radiation, or chemotherapy, with the major risk factor being lymph node dissection. Interestingly, obesity and body mass index are independent risk factors for development of lymphedema, suggesting interactions between adipose and lymphatic tissue biology. Currently, treatment of lymphedema involves palliative approaches, including compression garments and physical therapy, and surgical approaches, including liposuction, lymphovenous bypass, and vascularized lymph node transfer. Emerging lymphedema therapies that focus on weight loss or reducing inflammation have been tested in recent clinical trials, yielding mixed results with no effect on limb volumes or changes in bioimpedance measurements. These studies highlight the need for novel therapeutic strategies that target the driving forces of lymphedema. In this light, animal models of lymphedema demonstrate a role of adipose tissue in the progression of lymphedema and suggest these processes may be targeted in the treatment of lymphedema. Herein, we review both conventional and experimental therapies for lymphedema as well as the defining characteristics of its pathophysiology. We place emphasis on the aberrant fibroadipose tissue accumulation in lymphedema and propose a new approach to experimental treatment at the level of adipocyte metabolism.

Lymphatic Microsurgical Preventive Healing Approach for the Primary Prevention of Lymphedema: A 4-Year Follow-Up

BACKGROUND

Axillary lymph node dissection (ALND) remains the leading cause of lymphedema nationally, and there is still no cure for the disease. The lymphatic microsurgical preventive healing approach (LYMPHA) is a promising option for lymphedema prophylaxis in patients undergoing ALND, but long-term outcomes of the LYMPHA are not well established.

METHODS

The authors conducted a retrospective review of patients undergoing ALND at their center from November of 2012 to November of 2016 and assembled two cohorts, those who received the LYMPHA and those who did not (non-LYMPHA). Patient data were collected to evaluate lymphedema risk and long-term lymphedema incidence of each group.

RESULTS

Forty-five women were included in both our LYMPHA and non-LYMPHA cohorts. Mean body mass index (27.7 kg/m2 versus 29.9 kg/m2; P = 0.15) and radiation therapy rates (60.0% versus 68.9%; P = 0.51) did not differ between groups. Non-LYMPHA patients underwent complete mastectomy more frequently than LYMPHA patients (97.8% versus 77.8%; P = 0.007), but had a similar number of nodes removed during ALND (14.4 versus 15.8; P = 0.32). Median follow-up time was greater than 4 years for both LYMPHA and non-LYMPHA groups (57.0 months versus 63.0 months; P = 0.07). Overall, lymphedema incidence was 31.1% in the LYMPHA group and 33.3% in the non-LYMPHA group (P > 0.99). No significant differences in lymphedema incidences were observed between the LYMPHA and non-LYMPHA groups for patients with obesity, patients who received radiation therapy, or patients with obesity who also received radiation therapy (P > 0.05 for all subgroups).

CONCLUSIONS

The LYMPHA may not prevent lymphedema long-term in patients who undergo ALND. More long-term studies are needed to determine the true potential of the procedure.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Influencing factors associated with lymph node status in patients with cutaneous melanoma: An Asian population study

BACKGROUND

Sentinel lymph node (SLN) status is the predominant prognostic factor in patients diagnosed with clinically localized melanoma. The significance of completion lymph node dissection in patients with SLN metastasis is debatable. Not many studies have been conducted on acrallentiginous melanoma (ALM). This study aimed to characterize the prognostic factors of nodal positive ALM and confirm whether ALM patients can undergo the same treatment strategy as non-ALM patients in the Asian population.

METHODS

This is a retrospective review of patients who underwent surgery for cutaneous melanoma (CM) at Taipei Veterans General Hospital between January 1993 and December 2019. We investigated the risk factors for lymph node status. The association between clinicopathological factors and lymph node status of ALM and non-ALM patients was analyzed. Outcomes of completion lymph node dissection (CLND) performed following sentinel lymph node biopsy (SLNB) in the CM and ALM groups were compared.

RESULTS

A total of 197 patients were included in this study. ALM was the most common histological subtype, accounting for 66.5% of all the cases. Patients in the CM and ALM subgroups with metastatic SLN ( p = 0.012) or lymph nodes ( p < 0.001 and p = 0.001) exhibited higher mortality rate. Multivariate analysis showed that patients with clinical presentation of T4 category tumor ( p = 0.012) and lymphovascular invasion ( p = 0.012) had a significantly higher risk of positive lymph nodes. The overall survival of patients with lymph nodes metastasis was not associated with the performance of CLND.

CONCLUSION

Patients in the CM or ALM subgroups with metastatic SLNs or lymph nodes exhibited significantly poorer overall survival. Advanced Breslow thickness and lymphovascular invasion were independent predictive factors for CM and ALM patients with positive lymph node status. There was no significant difference in survival between CM and ALM patients following SLNB, regardless of CLND being performed.

Identification of lymph vessels using an indocyanine green camera-integrated operative microscope for lymphovenous anastomosis in the treatment of secondary lymphedema

OBJECTIVE

Lymphedema is a debilitating disease that impairs a patient's quality of life. Although lymphovenous anastomosis (LVA) can cure lymphedema, successful LVAs rely on the precise identification of the lymph vessels. In the present study, we assessed the use of a near-infrared camera-integrated operating microscope for preoperative mapping of the lymphatic vessels and evaluated the outcome of LVAs in patients with secondary lymphedema of a limb.

METHODS

We retrospectively reviewed patients with secondary unilateral lymphedema who had undergone LVA surgery with the lymph vessels identified using a near-infrared camera-integrated operating microscope (Moller 3-1000; Möller-Wedel Optical GmbH, Wedel, Germany) between 2020 and 2021. The lymph vessels identified using near-infrared fluorescence lymphography, diameter of the vessels used for anastomosis, anastomosis configuration, and perioperative limb circumference were recorded.

RESULTS

Overall, 35 LVAs were performed in six patients with secondary lymphedema, with a mean number of 5.8 LVAs per limb. The anastomotic configurations were end-to-end in 26 LVAs, side-to-end in 2 LVAs, and end-to-side in 7 LVAs. The diameter of the lymph vessels ranged from 0.3 to 0.9 mm (mean, 0.62 ± 0.18 mm) and that of the vein from 0.4 to 1.2 mm (mean, 0.75 ± 0.21 mm). The changes in the lymphedema index and estimated limb volume indicated a postoperative decrease in edema.

CONCLUSIONS

We found a near-infrared camera-integrated operating microscope useful for the preoperative identification of functional lymph vessels. Our results have shown that microsurgical LVAs can be performed using an integrated indocyanine green camera without an independent indocyanine green detector.

Water-based exercise for upper and lower limb lymphedema treatment

BACKGROUND

Lymphedema is a debilitating illness caused by insufficient lymph drainage, which can have serious physical and psychological consequences. Although water-based exercise can be useful, at present, little evidence is available regarding the outcomes of aquatic treatment for patients with lymphedema. Therefore, the aim of the present scoping review was to evaluate, from reported studies, the effects of water-based exercise on pain, limb motor function, quality of life (QoL), and limb volume among patients affected by primary and secondary upper and lower limb lymphedema.

METHODS

We performed a scoping review to examine clinical studies and randomized controlled trials reported in English from 2000 to 2021 by screening the MEDLINE (PubMed) and PEDro databases.

RESULTS

The search produced a total of 88 studies. Eight randomized controlled trials and one clinical study of patients with primary or secondary lymphedema of upper or lower limbs who had undergone water-based treatment were included in the present study. Most trials had focused on breast cancer-related lymphedema. The shoulder range of flexion, external rotation, and abduction have been shown to improve after performing a water-based exercise protocol. Some evidence has also demonstrated that the lymphedematous limb strength can improve. Moreover, water-based exercise seemed to improve pain perception and QoL for patients with upper or lower limb lymphedema. In contrast, in the control groups, the QoL showed a tendency to worsen over time. Although some studies had not reported beneficial effects on the lymphedematous limb volume, most of the studies examined had reported a reduction in volume, especially in the short term. No adverse events were reported in the included studies.

CONCLUSIONS

The findings from the present review have shown the potential for aquatic exercise in lymphedema management. However, at the same time, the findings underline the multiple limitations resulting from the heterogeneity in the study populations and related physical activity protocols. The role of aquatic exercise in the conservative treatment of lymphedema requires further investigation in the future to define specific protocols of application.

Lymphatic/blood vessel plasticity: motivation for a future research area based on present and past observations

The lymphatic system plays a significant role in homeostasis and drainage of excess fluid back into venous circulation. Lymphatics are also associated with a number of diseases including lymphedema, tumor metastasis, and various lymphatic malformations. Emerging evidence suggests that lymphatics might have a bigger connection to the blood vascular system than originally presumed. As these two systems are often studied in isolation, several knowledge gaps exist surrounding what constitutes lymphatic vascular plasticity, under what conditions it arises, and where structures characteristic of plasticity can form. The objective of this review is to overview current structural, cell lineage-based, and cell identity-based evidence for lymphatic plasticity. These examples of plasticity will then be considered in the context of potential clinical and surgical implications of this evolving research area. This review details our current understanding of lymphatic plasticity, highlights key unanswered questions in the field, and motivates future research aimed at clarifying the role and therapeutic potential of lymphatic plasticity in disease.

Triple mapping for axillary staging after neoadjuvant therapy: Axillary reverse mapping with indocyanine green and dual agent sentinel lymph node biopsy

Axillary staging is 1 of the major issues of current breast cancer management after neoadjuvant systemic therapy (NST). Sentinel lymph node biopsy (SLNB) is an option for clinically node negative patients. Axillary reverse mapping (ARM) was introduced to identify and preserve the lymphatic drainage from the arm. The aim of the presented study is to employ triple mapping (radiocolloid, blue dye and indocyanine green [ICG]) to assess the crossover rate and metastatic involvement of ARM nodes after NST. Clinically node positive patients before NST who were converted to N0 and scheduled for targeted axillary dissection were included. sentinel lymph node (SLN) mapping was performed via dual agent mapping. ICG was used for ARM procedure. Blue, hot and fluorescent nodes and lymphatics were visualized in the axilla using infrared camera system and dual opto-nuclear probe (Euoroprobe3). Fifty-two patients underwent targeted axillary dissection and ARM procedures 12 out of whom had axillary node dissection. 45 of the 52 patients had at least 1 hot or blue SLN identified intraoperatively. Of these, 61.5% cases had hot SLNs, 42.3% had hot and blue, 15.4% had hot/blue/fluorescent, 7.7% had blue/fluorescent, 6 11.5% had hot/fluorescent and 7 13.5% had only clipped nodes. The overall identification rate of ARM-nodes by means of ICG technique was 86.5%. Overall crossover of ARM nodes with SLNs was determined in 36.5%. The ICG intensity was found to be higher in both hot and blue SLNS (8 out of 18 ICG positive cases, 44.4%). In 3 of 52 patients (5.7%) metastatic SLNs were hot or blue but fluorescent which predicts metastatic involvement of the ARM-nodes. More than 1-third of the patients revealed a crossover between arm and breast draining nodes. The higher observed rate of overlap might partially explain why more patients develop clinically significant lymphedema after NST even after sentinel lymph node biopsy alone. The triple mapping provides valuable data regarding the competency of lymphatic drainage and would have the potential to serve selecting patients for lymphovenous by-pass procedures at the index procedure. NST reduces the metastatic involvement of the ARM nodes. However, conservative axillary staging with sparing ARM nodes after NST necessitates further studies with larger sample size and longer follow-up.

Genital Lymphedema after Cancer Treatment: A Narrative Review

Genital lymphedema may affect males and females after cancer treatment (gynecological, such as cervical, uterine or ovarian, melanoma, prostate, anus…). It is frequently associated with lower limb lymphedema, and is responsible for discomfort, cosmetic disfigurement and functional disturbances. Impacts on body image, sexual function and quality of life are major, and difficult to explore because cancer treatment itself and lymphedema are so closely interwoven. Local complications, e.g., papillomatosis, warty growth, lymph vesicles with embarrassing lymph oozing and cellulitis, may occur. Usual lymphedema therapies, like bandaging and elastic compression, are poorly adapted to these sites. Surgery, essentially based on cutaneous resection techniques, is the primary symptomatic treatment; it achieves good efficacy, in adults and children, with possible recurrence requiring reintervention.

Doxycycline for the treatment of breast cancer-related lymphedema

Purpose: Secondary lymphedema is a common complication of cancer treatment for which no effective drug treatments yet exist. Level I clinical data suggests that doxycycline is effective for treating filariasis-induced lymphedema, in which it decreases tissue edema and skin abnormalities; however, this treatment has not been tested for cancer-related lymphedema. Over the past year, we used doxycycline in an off-label manner in patients with breast cancer-related secondary lymphedema. The purpose of this report was to retrospectively analyze the efficacy of this treatment. Methods: Patients who presented to our lymphedema clinic between January 2021 and January 2022 were evaluated, and barring allergies or contraindications to doxycycline treatment, were counseled on the off-label use of this treatment. Patients who wished to proceed were treated with doxycycline (200 mg given orally once daily) for 6 weeks. After IRB approval of this study, lymphedema outcomes were retrospectively reviewed. Results: Seventeen patients with a mean follow-up of 17.0 ± 13.2 weeks were identified in our retrospective review. Although doxycycline treatment had no significant effect on relative limb volume change or L-Dex scores, we found a significant improvement in patient-reported quality of life. Analysis of patient responses to the Lymphedema Life Impact Scale showed a significant improvement in the total impairment score due to improvements in the physical and psychological well-being subscales (p = 0.03, p = 0.03, p = 0.04, respectively). Conclusion: This small, retrospective study did not show significant improvements in limb volume or L-Dex scores in patients with breast cancer-related lymphedema treated with doxycycline. However, our patients reported improvements in quality-of-life measures using a validated lymphedema patient-reported outcome instrument. Our results suggest that doxycycline may be of use in patients with breast cancer-related lymphedema; however, larger and more rigorous studies are needed.

Soft-Tissue Considerations in Shoulder Surgery in the Patient With Lymphedema

Lymphedema is a chronic, progressive, and often debilitating condition that results in swelling of the affected tissue. Secondary lymphedema is most commonly recognized by unilateral swelling of the ipsilateral extremity after the treatment of cancer. It is estimated that nearly 1.45 million women suffer from breast cancer-related lymphedema in the United States. The number of patients suffering from upper extremity lymphedema is expected to increase because multimodal treatment of breast cancer increases the long-term survival after diagnosis. Because this population ages, the likelihood of encountering a patient with concurrent lymphedema and shoulder pathology requiring orthopaedic intervention is likely to rise. A patient with an already edematous arm and/or impaired drainage of that arm is likely to have different and more complex intraoperative and postoperative courses than patients with normal lymphatic drainage. Although a lymphedematous arm should not preclude surgical intervention, there are considerations when approaching shoulder surgery in the setting of upper extremity lymphedema that may help mitigate complications and aid the patient in their orthopaedic recovery.