Estimating the Population Burden of Lymphedema

KATP channels in lymphatic function

KATP channels function as negative regulators of active lymphatic pumping and lymph transport. This review summarizes and critiques the evidence for the expression of specific KATP channel subunits in lymphatic smooth muscle and endothelium, the roles that they play in normal lymphatic function, and their possible involvement in multiple diseases, including metabolic syndrome, lymphedema, and Cantú syndrome. For each of these topics, suggestions are made for directions for future research.

Outcomes of lipectomy in patients with advanced unilateral upper extremity lymphedema with regard to the difference in time required for indocyanine green to reach the axilla: A retrospective cohort study in a single center

This study aimed to compare and analyze the prognosis after lipectomy with respect to the difference in time required for indocyanine green (ICG) to reach the axilla in patients with advanced unilateral upper extremity lymphedema. The study population was divided into 2 groups, according to the time required by ICG to reach the axilla after injection, that is, <1 hour (<1 hour; n = 9) and over 1 hour (>1 hour; n = 8). The patient's arm volume was examined before surgery and up to 12 months after surgery. The volume difference between the 2 groups was compared using the excess volume ratio. Statistically significant differences were not observed before surgery (P = .847) and 1 month (P = .336), 3 months (P = .630), and 6 months after surgery (P = .124) between the excess volume ratio values of the < 1 hour and > 1 hour groups. A statistically significant difference was confirmed 12 months after surgery (P = .034). The difference in the time when ICG reached the axilla in patients with lymphedema was associated with prognosis after lipectomy. The difference in time could possibly be used as a variable to classify the progress of lymphedema in the future.

Correlation between Lymphatic Surgery Outcome and Lymphatic Image-Staging or Clinical Severity in Patients with Lymphedema

Lymphoscintigraphy and indocyanine green (ICG) lymphography reveal the severity of extremity lymphedema. Lower extremity lymphedema (LEL) index and NECST classification are related to the clinical severity of lymphedema. We aimed to investigate the correlation between lymphatic surgery, lymphatic imaging, and clinical severity in patients with lymphedema. Thirty-five patients with lower-extremity lymphedema who underwent lymphatic venous anastomosis (LVA) were evaluated. Ten of the thirty-five patients underwent multi-surgery (additional vascularized lymphatic transfer and/or liposuction). We investigated the correlation between the LEL index, NECST classification, lymphoscintigraphy staging, ICG lymphography staging, and rate of improvement (RI: [preoperative LEL index − postoperative LEL index]/[preoperative LEL index] × 100). The LEL index in 35 patients after LVA and all procedures decreased significantly compared to that of preoperative (272.4 vs. 256.2 vs. 243.5, p < 0.05). RI after LVA and all procedures showed positive correlations with the preoperative LEL index; however, there was no correlation with any other lymphatic image or clinical severity. LVA can reduce lymphedema circumference at any stage. Additional surgery improved the circumference. Hence, LVA as the first line of treatment, and vascularized lymphatic transfer and liposuction as additional procedures, should be considered as the standard treatment for lymphedema.

Clinical staging and genetic profiling of Korean patients with primary lymphedema using targeted gene sequencing

Lymphedema is a progressive disease caused by lymphatic flow blockage in the lymphatic pathway. Primary (hereditary) lymphedema is caused by genetic mutations without secondary causes. We performed clinical profiling on Korean primary lymphedema patients based on their phenotypes using lymphoscintigraphy and made genetic diagnoses using a next-generation sequencing panel consisting of 60 genes known to be related to primary lymphedema and vascular anomalies. Of 27 patients included in this study, 14.8% of the patients had lymphedema of the upper extremities, 77.8% had lymphedema of the lower extremities and 7.4% had 4-limbs lymphedema. Based on the International Society of Lymphology staging, 14, 10, and 3 patients had stage 3, 2, and 1 lymphedema, respectively. Only one family was genetically confirmed to harbor likely pathogenic variants in CELSR1. The proband was carrying two likely pathogenic variants in CELSR1, while her symptomatic mother was confirmed to carry only one of the variants. Furthermore, two other variants of uncertain significance in CELSR1 were detected in other patients, making CELSR1 the most commonly altered gene in our study. The clinical and genetic profile of hereditary lymphedema reported here is the first such data series reported for South Korea.

Visual analysis of global research output of lymphedema based on bibliometrics

Background

Globally, several generations of doctors in the field of lymphedema have created numerous publications. To date, no bibliometric analysis has been performed specifically on these publications. For the further promotion of research on lymphedema and to align with the international research frontiers, it is essential to understand the current state of Lymphedema research output.

Objective

This study aims to statistically and visually analyze the characteristics of publications output, distribution of contributions and development process of lymphedema, enriching the knowledge base of Lymphedema, and then seek potential research topics and collaborators.

Methods

Based on the Web of Science core collection database, we firstly analyzed the quantity and quality of publications in the field of lymphedema, secondly profiled the publishing groups in terms of country, institution, author's publication and cooperation network, and finally sorted out and summarized the hot topics of research.

Results

A total of 8569 papers were retrieved from 1900-2021. The top4 journals with the most publications were LYMPHOLOGY, LYMPHATIC RESEARCH AND BIOLOGY, PLASTIC AND RECONSTRUCTIVE SURGERY and ANNALS OF SURGICAL ONCOLOGY. The top 4 countries with the most publications were USA, Japan, UK, and China. The United States dominates the total number of publications and the international cooperation network. The most productive research institution is Harvard University, and the research institution with the most collaborating institutions is Memorial Sloan Kettering Cancer Center. Mortimer, Peter S contributes the most research in this field. The research achievements of Japanese scholars in this field are of great significance. The top 5 ranked keywords are "Breast Cancer", "Health-Related Quality Of Life", "Lymphscintigraphy", "Lymphovenous Anastomosis", and "Lymphangiogenesis".

Conclusion

More and more scholars are devoted to the research of cancer-related Lymphedema. It is foreseeable that breast cancer-related lymphedema and lymphangiogenesis will remain a focus of future research. Advances in Lymphatic vessel imaging and the development of lymphatic microsurgery will further play a role in the clinical workup of lymphedema. Meanwhile, This study can help researchers identify potential collaborators and partner institutions and contribute to further research.

Updates on Excisional Procedures for Lymphedema

Significance: Excisional procedures for lymphedema have been used for over a century, and many surgeons have abandoned the old techniques as improvements in nonsurgical management and microsurgery have limited their clinical utility. Nonetheless, excisional procedures remain relevant as an important tool in the comprehensive surgical management of lymphedema. Recent Advances: Modifications to the Charles procedure and other direct excisional procedures have improved the complication profile and patient outcomes. Moreover, the use of liposuction techniques for minimally invasive tissue excision has expanded the scope of excisional surgery to benefit patients with less severe lymphedema. Recent operations combining excisional and physiologic procedures may prove to have superior results to stand-alone procedures. Critical Issues: No standard protocol exists for the comprehensive surgical management of lymphedema. Proper patient selection for any procedure requires robust outpatient assessment, cooperation with physiotherapy treatment teams, careful patient stratification, and a clear understanding of the procedure's goal. Future Directions: Larger, prospective trials will be needed to elucidate the ideal timing and combinations of techniques to optimize outcomes for patients with late-stage lymphedema.

Effect of Lymphaticovenous Anastomosis on Muscle Edema, Limb, and Subfascial Volume in Lower Limb Lymphedema: MRI Studies

BACKGROUND

Although satisfactory volume reduction in secondary unilateral lower limb lymphedema after lymphaticovenous anastomosis (LVA) in the affected limb has been well reported, alleviation of muscle edema and the impact of LVA on the contralateral limb have not been investigated.

STUDY DESIGN

This retrospective cohort study enrolled patients who underwent supermicrosurgical LVA between November 2015 and January 2017. Pre- and post-LVA muscle edema were assessed using fractional anisotropy (FA) and apparent diffusion coefficient (ADC). The primary endpoint was changes in limb/subfascial volume assessed with magnetic resonance volumetry at least 6 months after LVA.

RESULTS

Twenty-one patients were enrolled in this study. Significant percentage reductions in post-LVA muscle edema were found in the affected thigh (83.6% [interquartile range = range of Q1 to Q3; 29.8-137.1] [FA], 53.3% [27.0-78.4] [ADC]) as well as limb (21.7% [4.4-26.5]) and subfascial (18.7% [10.7-39.1]) volumes. Similar findings were noted in the affected lower leg: 71.8% [44.0-100.1] (FA), 59.1% [45.8-91.2] (ADC), 21.2% [6.8-38.2], and 28.2% [8.5-44.8], respectively (all p < 0.001). Significant alleviation of muscle edema was also evident in the contralateral limbs (thigh: 25.1% [20.4-57.5] [FA]; 10.7% [6.6-17.7] [ADC]; lower leg: 47.1% [35.0-62.8] [FA]; 14.6% [6.5-22.1] [ADC]; both p < 0.001), despite no statistically significant difference in limb and subfascial volumes.

CONCLUSIONS

Our study found significant reductions in muscle edema and limb/subfascial volumes in the affected limb after LVA. Our findings regarding edema in the contralateral limb were consistent with possible lymphedema-associated systemic influence on the unaffected limb, which could be surgically relieved.

Current Overview of Obesity-Induced Lymphedema

Significance: Obesity affects one-third of the U.S. population and lymphedema is a chronic disorder without a cure. The relationship between obesity and lymphedema has important implications for public health. Recent Advances: Extreme obesity can cause lower extremity lymphedema, termed "obesity-induced lymphedema (OIL)." OIL is a form of secondary lymphedema that may occur once an individual's body mass index (BMI) exceeds 40. The risk of lymphatic dysfunction increases with elevated BMI and is almost universal once BMI exceeds 60. Patients with OIL also may develop areas of massive localized lymphedema (MLL). Critical Issues: Individuals with OIL are in an unfavorable cycle of weight gain and lymphatic injury. As BMI increases lymphedema worsens, ambulation becomes more difficult, and BMI further rises. The fundamental treatment for OIL is weight loss. Resection of areas of MLL and lower extremity volume reduction are performed when the BMI is lowered to <40 to reduce complications and recurrence. Future Directions: The mechanisms by which obesity causes lymphedema are still being elucidated. Although lymphatic function can improve following weight loss, it is unclear whether lymphedema may be completely reversed.

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.

Impact of retrograde anastomosis during supermicrosurgical lymphaticovenous anastomosis for cancer-related lower limb lymphedema: A retrospective cohort propensity-score-matched outcome analysis

BACKGROUND

In addition to antegrade anastomosis, retrograde anastomosis has been thought to offer further improvements after lymphaticovenous anastomosis (LVA) by bypassing the retrograde lymphatic flow. However, this concept has yet to be validated. The aim of this study was to determine the impacts on outcomes of performing both retrograde and antegrade anastomosis, as compared to antegrade-only anastomosis for treating lower limb lymphedema.

STUDY DESIGN

This was a retrospective cohort propensity score-matched study. Eighty-seven patients with gynecologic cancer-related lower limb lymphedema were enrolled, including 58 patients who had received both antegrade and retrograde anastomoses (Group I) and 29 patients who had received antegrade-only anastomoses (Group II) as the control group. LVA was the primary treatment. Patients who had previous LVA, liposuction, or excisional therapy were excluded. Patient characteristics, intraoperative findings, and functional parameters including the ratio of indocyanine green-enhanced and flow-positive lymphatic vessels were recorded. Magnetic resonance volumetry was used for outcome assessments. The primary endpoint was the volume change at 6 months after LVA.

RESULTS

After matching, a total of 26 patients have remained in each group. All parameters were matched except that Group I still had significantly more median LVA performed compared to Group II (8 [IQR: 5.3-10.0] vs. 5.5 [4.3-6.0], p = 0.001, respectively). Group II showed more post-LVA improvements at six-month and one-year follow-up compared to Group I but without statistically significant differences.

CONCLUSION

The use of supplementary retrograde anastomoses is discouraged since it may lead to inferior post-LVA outcome compared to antegrade-only anastomoses.

Lymphedema and Obesity

Lymphedema results from inadequate lymphatic function. Extreme obesity can cause lower extremity lymphedema, termed "obesity-induced lymphedema (OIL)." OIL is a form of secondary lymphedema that may occur once an individual's body mass index (BMI) exceeds 40. The risk of lymphatic dysfunction increases with elevated BMI and is almost universal once BMI exceeds 60. Obesity has a negative impact on lymphatic density in subcutaneous tissue, lymphatic endothelial cell proliferation, lymphatic leakiness, collecting-vessel pumping capacity, and clearance of macromolecules. Lymphatic fluid unable to be taken up by lymphatic vessels results in increased subcutaneous adipose deposition, fibrosis, and worsening obesity. Individuals with OIL are in an unfavorable cycle of weight gain and lymphatic injury. The fundamental treatment for OIL is weight loss.

Health-related Quality of Life Measurement Tools for Lymphedema: A Review of the Literature

Lymphedema can significantly affect patients' health-related quality of life (HRQoL). Various quality of life scales have been developed to assess the extent of the disease burden. The purpose of this study is to review various HRQoL instruments that have been used in lymphedema studies and compare their qualities against the COSMIN checklist.

Methods

A systematic literature review search was conducted for clinical lymphedema studies published between January 1, 1984, and February 1, 2020, using Pubmed database. All clinical lymphedema studies which used HRQoL instruments as outcome measures were identified.

Results

One thousand seventy-six studies were screened-of which, 288 studies were individually assessed. Thirty-nine HRQoL instruments were identified in these clinical lymphedema studies. Of these, there are eight lymphedema-specific questionnaires that cover all HRQoL domains, all of which have been validated for use in lymphedema. We contrasted the two most popular questionnaires [LYMQOL and Upper Limb Lymphedema (ULL)-27] and compared their features.

Conclusion

There is currently no ideal lymphedema HRQoL measurement tool available based on the COSMIN criteria. However, our review suggested that LYMQOL and ULL-27 are the most used and most validated instruments at present, but each has their own limitations. We recommend the use of LYMQOL and ULL-27 for future studies to allow direct HRQoL comparison to current literature. Further research is required to develop an optimal HRQoL questionnaire that can ultimately become the gold standard HRQoL instrument for lymphedema.

Lymphatic Collecting Vessel: New Perspectives on Mechanisms of Contractile Regulation and Potential Lymphatic Contractile Pathways to Target in Obesity and Metabolic Diseases

Obesity and metabolic syndrome pose a significant risk for developing cardiovascular disease and remain a critical healthcare challenge. Given the lymphatic system's role as a nexus for lipid absorption, immune cell trafficking, interstitial fluid and macromolecule homeostasis maintenance, the impact of obesity and metabolic disease on lymphatic function is a burgeoning field in lymphatic research. Work over the past decade has progressed from the association of an obese phenotype with Prox1 haploinsufficiency and the identification of obesity as a risk factor for lymphedema to consistent findings of lymphatic collecting vessel dysfunction across multiple metabolic disease models and organisms and characterization of obesity-induced lymphedema in the morbidly obese. Critically, recent findings have suggested that restoration of lymphatic function can also ameliorate obesity and insulin resistance, positing lymphatic targeted therapies as relevant pharmacological interventions. There remain, however, significant gaps in our understanding of lymphatic collecting vessel function, particularly the mechanisms that regulate the spontaneous contractile activity required for active lymph propulsion and lymph return in humans. In this article, we will review the current findings on lymphatic architecture and collecting vessel function, including recent advances in the ionic basis of lymphatic muscle contractile activity. We will then discuss lymphatic dysfunction observed with metabolic disruption and potential pathways to target with pharmacological approaches to improve lymphatic collecting vessel function.

Evaluation of the External Jugular Vein Overlying the Sternocleidomastoid Muscle as Venous Lymph-Node Flap

Background: Until recently, vascularized lymph-node flaps were based on arterial and venous donor vessels. Now, venous lymph-node flaps form a novel promising concept in the treatment of advanced-stage lymphedema. In preliminary studies, the external jugular vein has shown promising results as a venous lymph-node flap. However, nothing is known about the number of lymph nodes adjacent to the external jugular vein. Methods: Standardized specimens of the external jugular vein and surrounding fatty tissue directly overlying the sternocleidomastoid muscle were obtained during routine neck dissection. Histologic evaluation was performed in order to evaluate for the presence of lymph nodes within the tissue. Results: A total of 20 specimens were evaluated. There was no vein in 4 of the samples. We found lymph nodes in 9 of the remaining 16 samples. In 7 samples, lymph nodes were absent. Conclusion: Our results suggest that the vein directly overlying the sternocleidomastoid muscle may not be the ideal candidate for a venous lymph-node flap.

Drug-Related Lymphedema: Mysteries, Mechanisms, and Potential Therapies

The lymphatic circulation is an important component of the circulatory system in humans, playing a critical role in the transport of lymph fluid containing proteins, white blood cells, and lipids from the interstitial space to the central venous circulation. The efficient transport of lymph fluid critically relies on the rhythmic contractions of collecting lymph vessels, which function to "pump" fluid in the distal to proximal direction through the lymphatic circulation with backflow prevented by the presence of valves. When rhythmic contractions are disrupted or valves are incompetent, the loss of lymph flow results in fluid accumulation in the interstitial space and the development of lymphedema. There is growing recognition that many pharmacological agents modify the activity of ion channels and other protein structures in lymph muscle cells to disrupt the cyclic contraction and relaxation of lymph vessels, thereby compromising lymph flow and predisposing to the development of lymphedema. The effects of different medications on lymph flow can be understood by appreciating the intricate intracellular calcium signaling that underlies the contraction and relaxation cycle of collecting lymph vessels. For example, voltage-sensitive calcium influx through long-lasting ("L-type") calcium channels mediates the rise in cytosolic calcium concentration that triggers lymph vessel contraction. Accordingly, calcium channel antagonists that are mainstay cardiovascular medications, attenuate the cyclic influx of calcium through L-type calcium channels in lymph muscle cells, thereby disrupting rhythmic contractions and compromising lymph flow. Many other classes of medications also may contribute to the formation of lymphedema by impairing lymph flow as an off-target effect. The purpose of this review is to evaluate the evidence regarding potential mechanisms of drug-related lymphedema with an emphasis on common medications administered to treat cardiovascular diseases, metabolic disorders, and cancer. Additionally, although current pharmacological approaches used to alleviate lymphedema are largely ineffective, efforts are mounting to arrive at a deeper understanding of mechanisms that regulate lymph flow as a strategy to identify novel anti-lymphedema medications. Accordingly, this review also will provide information on studies that have explored possible anti-lymphedema therapeutics.

Modelling the coupling of the M-clock and C-clock in lymphatic muscle cells

Chronic dysfunction of the lymphatic vascular system results in fluid accumulation between cells: lymphoedema. The condition is commonly acquired secondary to diseases such as cancer or the associated therapies. The primary driving force for fluid return through the lymphatic vasculature is provided by contractions of the muscularized lymphatic collecting vessels, driven by electrochemical oscillations. However, there is an incomplete understanding of the molecular and bioelectric mechanisms involved in lymphatic muscle cell excitation, hampering the development and use of pharmacological therapies. Modelling in silico has contributed greatly to understanding the contributions of specific ion channels to the cardiac action potential, but modelling of these processes in lymphatic muscle remains limited. Here, we propose a model of oscillations in the membrane voltage (M-clock) and intracellular calcium concentrations (C-clock) of lymphatic muscle cells. We modify a model by Imtiaz and colleagues to enable the M-clock to drive the C-clock oscillations. This approach differs from typical models of calcium oscillators in lymphatic and related cell types, but is required to fit recent experimental data. We include an additional voltage dependence in the gating variable control for the L-type calcium channel, enabling the M-clock to oscillate independently of the C-clock. We use phase-plane analysis to show that these M-clock oscillations are qualitatively similar to those of a generalised FitzHugh-Nagumo model. We also provide phase plane analysis to understand the interaction of the M-clock and C-clock oscillations. The model and methods have the potential to help determine mechanisms and find targets for pharmacological treatment of lymphoedema.

Psychometric Properties of Quality of Life Questionnaires for Patients with Breast Cancer-Related Lymphedema: A Systematic Review

Backgrounds: Assessing quality of life (QoL) using a well-developed and validated questionnaire is an essential part of a breast cancer-related lymphedema (BCRL) treatment. However, a QoL questionnaire with the best psychometric properties is so far unknown. The aim of this systematic review is to evaluate the psychometric properties of the questionnaires measuring the QoL of patients with BCRL. Methods: A thorough search was performed to identify published studies in electronic databases such as Medline (via Ovid), EBSCOhost, PubMed, Scopus, and Web of Science, on 8 February 2022, by using search terms as follows: ‘quality of life’; ‘breast cancer’; ‘upper limb’; ‘lymphedema’; ‘questionnaire’; and ‘measurement properties.’ Two reviewers conducted article selection, data extraction, and quality assessment independently. The third reviewer helped solve any possible disagreements between the two reviewers. The COSMIN checklist and manual were used to assess the quality of included studies. Results: A total of nineteen articles with nine questionnaires were included and assessed using the COSMIN Risk of Bias checklist. Most studies only assessed content validity, structural validity, internal consistency, reliability, and construct validity. Lymph-ICF-UL showed the most ‘sufficient’ and ‘high’ quality of evidence ratings for its measurement properties. Conclusion: The most appropriate questionnaire for use based on our assessment is Lymph-ICF-UL.

Development of a diffusion-weighed mathematical model for intradermal drainage quantification

The quantitative assessment of lymphatic dermal clearance using NIR fluorescent tracers is particularly important for the early diagnosis of several potential disabling diseases. Currently, half-life values are computed using a mono-exponential mathematical model, neglecting diffusion of the tracer within the dermis after injection. The size and position of the region of interest are subjectively manually selected around the point of injection on the skin surface where the fluorescence signal intensity is averaged, neglecting any spatial information contained in the image. In this study we present and test a novel mathematical model allowing the objective quantification of dermal clearance, taking into consideration potential dermal diffusion. With only two parameters, this "clearance-diffusion" model is simple enough to be applied in a variety of settings and requires almost no prior information about the system. We demonstrate that if dermal diffusion is low, the mono-exponential approach is suitable but still lacking objectivity. However, if dermal diffusion is substantial, the clearance-diffusion model is superior and allows the accurate calculation of half-life values.

Efficacy of Microsurgical Treatment of Primary Lymphedema: A Systematic Review

INTRODUCTION

Treatment of lymphedema remains a challenging clinical problem. Lymphatic surgery has recently gained momentum as an effective method to treat both early- and late-stage disease. In particular, "physiologic" microsurgical techniques including vascularized lymph node transplant and lymphovenous bypass/anastomosis have been shown to be effective in treating even advanced lymphedema. Most published reports describe techniques and success in secondary lymphedema. Traditionally, physiologic surgery was not believed to be useful in the treatment of primary lymphedema where baseline lymphatic function is abnormal. However, recent studies have shown a benefit in these cases. The objective of this study is to evaluate outcomes and complications of physiologic microsurgical treatment for primary lymphedema.

METHODS

The electronic databases of PubMed, Scopus, and MEDLINE were searched using key words "primary lymphedema" and "surgery" (also vascularized lymph node transplant, lymphovenous bypass, microsurgery). Only human studies published between 2000 and 2021 were included. Studies that only included ablative or resection surgeries were excluded.

RESULTS

A total of 10 studies comprising 254 patients with primary lymphedema who underwent 357 physiologic microsurgical operations were included. Lymphovenous bypass comprised 88% of cases, and in the patients who underwent vascularized lymph node transplant, all but 1 flap survived. Regardless of type of operative intervention, all studies showed a statistically significant improvement in lymphedema, through either reduction in limb circumference or edema volume or improvement in quality of life.

DISCUSSION

Physiologic lymphatic surgery has shown success and improvement for patients with primary lymphedema. Based on current literature, physiologic surgical treatment of primary lymphedema should be considered when treating this patient population.

Pharmacological Treatment of Secondary Lymphedema

Lymphedema is a chronic disease that results in swelling and decreased function due to abnormal lymphatic fluid clearance and chronic inflammation. In Western countries, lymphedema most commonly develops following an iatrogenic injury to the lymphatic system during cancer treatment. It is estimated that as many as 10 million patients suffer from lymphedema in the United States alone. Current treatments for lymphedema are palliative in nature, relying on compression garments and physical therapy to decrease interstitial fluid accumulation in the affected extremity. However, recent discoveries have increased the hopes of therapeutic interventions that may promote lymphatic regeneration and function. The purpose of this review is to summarize current experimental pharmacological strategies in the treatment of lymphedema.

Genetic Predisposition in Cancer-Related Lymphedema: A Systematic Review

Background: Lymphedema is a debilitating and progressive clinical entity characterized by abnormal accumulation of lymph and fluid in the extracellular space. Most of the cases in western population are related to cancer treatment. Research on cancer-related lymphedema (CRL) is mounting for potential risk factors associated to disease, treatment, or patient. However, only a few cancer survivors with the same risk factors will develop lymphedema, giving rise to the hypothesis that inherited genetic susceptibility may play a role in CRL pathophysiology. This systematic review aimed to identify, critically appraise, and summarize the results of individual studies that have examined the genetic predisposition to CRL. Methods and Results: A comprehensive literature search in MEDLINE, Cochrane, and Scopus was conducted from inception to February 2021. Screening of available studies and quality of the included studies were carried out by two reviewers independently. Eight studies fulfilled eligibility criteria, involving 573 women with breast-cancer related lymphedema (BCRL) among 1,481 participants. Associations between the development of CRL and genetic factors were observed for variations in 23 genes in patients with BCRL. Conclusions: The present systematic review is the first examining specifically the genetic predisposition in CRL. Statistically significant genetic variations were found in 23 genes in patients with BCRL. These preliminary findings highlight the importance of genetic susceptibility in the development of CRL, altering the traditional perception of its iatrogenic etiology. Additional well-designed research, aiming toward the confirmation of previously performed genetic analyses and functional assessment of the genetic variations, is required.

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

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

Intracellular calcium dynamics of lymphatic endothelial and muscle cells co-cultured in a Lymphangion-Chip under pulsatile flow

A Lymphangion-Chip consisting an endothelial lumen co-cultured with muscle cells was exposed to step or pulsatile flow. The real-time analyses of intracellular calcium dynamics reveal the coupling of signaling between these cells under complex flows.

Nanofibrillar Collagen Scaffold Enhances Edema Reduction and Formation of New Lymphatic Collectors after Lymphedema Surgery

BACKGROUND

Treatment of secondary lymphedema remains challenging, with suboptimal rates of edema reduction following physiologic procedures (i.e., lymphaticovenous anastomosis and vascularized lymph node transfer). The objective of this study was to investigate the long-term effect of a nanofibrillar collagen scaffold on edema reduction in lymphedema patients treated with lymphaticovenous anastomosis or vascularized lymph node transfer.

METHODS

A retrospective cohort study was performed, comparing stage 1 to 3 lymphedema patients who underwent lymphaticovenous anastomosis and/or vascularized lymph node transfer with or without delayed implantation of nanofibrillar collagen scaffold (BioBridge) from 2016 to 2019. The primary endpoint was excess volume reduction. Indocyanine green lymphatic mapping was performed to evaluate superficial lymphatic flow.

RESULTS

Edema reduction was significantly greater for the BioBridge cohort (12-month follow-up, n = 18) compared to controls (18.2-month follow-up, n = 11) (111.5 ± 34.5 percent versus 70.0 ± 19.0 percent; p = 0.0004). This held true in lymphaticovenous anastomosis and vascularized lymph node transfer subgroup analysis. The average rate of edema reduction increased by 3.5-fold in lymphaticovenous anastomosis and 7.6-fold in vascularized lymph node transfer following BioBridge placement. Eighty-eight percent of patients with concurrent liposuction and BioBridge implantation maintained normal volumes at 13 months postoperatively. Lymphatic mapping following BioBridge placement showed significantly more new lymphatic collectors and decreased dermal backflow. The majority of patients (77.8 percent) achieved and maintained normal limb volume at an average total follow-up of 29 months.

CONCLUSION

Nanofibrillar collagen scaffold implantation enhances overall effectiveness of physiologic procedures, even in the presence of liposuction, and is a promising adjunct therapy for treatment of lymphedema.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Advances in surgical treatment of lymphedema

An estimated 250 million people worldwide suffer from lymphedema. In the past, the firstline option for treatment was nonsurgical management, either in the form of compression garments or wrapping, or comprehensive decongestive therapy, with debulking surgery reserved for the more advanced cases. However, with improvements in microsurgical techniques and imaging modalities, surgical intervention is increasingly being utilized. This review highlights recent advancements in the surgical treatment of lymphedema, specifically focusing on improvements in imaging, surgical techniques, and prevention of lymphedema.

Outcomes analysis of microsurgical physiologic lymphatic procedures for the upper extremity from the United States National Surgical Quality Improvement Program

INTRODUCTION

Physiologic microsurgical procedures to treat lymphedema include vascularized lymph node transfer (VLNT) and lymphovenous bypass (LVB). The purpose of this study was to assess 30-day outcomes of VLNT and LVB using the National Surgical Quality Improvement Program (NSQIP) database.

METHODS

NSQIP was queried (2012-2018) for lymphatic procedures for upper extremity lymphedema after mastectomy. Prophylactic lymphatic procedures and those for lower extremity lymphedema were excluded. Outcomes were assessed for three groups: LVB, VLNT, and patients who had procedures simultaneously (VLNA+LVB). Primary outcomes measured were operative time, 30-day morbidities, and hospital length of stay.

RESULTS

The study included 199 patients who had LVB (n = 43), VLNT (n = 145), or VLNT+LVB (n = 11). There was no difference in co-morbidities between the groups (p = 0.26). 30-day complication rates including unplanned reoperation (6.9% VLNT vs. 2.3% LVB) and readmission (0.69% VLNT vs. none in LVB) were not statistically significant (p = 0.54). Surgical site infection, wound complications, deep vein thromboembolism, and cardiac arrest was also similar among the three groups. Postoperative length of stay for VLNT (2.5 days± 2.3), LVB (1.9 days± 1.9), and VLNT+LVB (2.8 days± 0.3) did not differ significantly (p = 0.20). Operative time for LVB (305.4 min ± 186.7), VLNT (254 min ± 164.4), and VLNT+LVB (295.3 min ± 43.2) was not significantly different (p = 0.21).

CONCLUSIONS

Our analysis of the NSQIP data revealed that VLNT and LVB are procedures with no significant difference in perioperative morbidity. Our results support that choice of VLNT versus LVB can be justifiably made per the surgeon's preference and experience as the operations have similar complication rates.

A Soft Robotic Sleeve for Compression Therapy of the Lower Limb

'We present the development of a soft robotic-inspired device for lower limb compression therapy with application in the treatment of lymphedema. This device integrates the control capabilities of pneumatic devices with the wearability and low cost of compression garments. The design consists of a three-layered soft robotic sleeve that ensures safe skin contact, controls compression, and secures the device to the patient limb. The expandable component is made of interconnected pockets of various heights, which passively create a graduated compression profile along the lower limb. The system is inflated by a pump and a microcontroller-actuated valve, with force sensors embedded in the sleeve that monitor the pressure applied to the limb. Testing on healthy individualsq demonstrated the ability to reach clinically relevant target pressures (30, 40, 50 mmHg) and establish a distal-to-proximal descending pressure gradient of approximately 40 mmHg. Device function was shown to be robust against variations in subject anatomy.Clinical Relevance- This system provides controllable, graduated, compression therapy to lymphedema patients in an economical, portable, and customizable package.

A case report of RASA1-associated inherited lymphoedema with recurrent life-threatening lymphangitis

Background

Most cases of lymphoedema are secondary to other causes, while cases of primary lymphoedema, in particular that of congenital origin, are uncommon. Limited genetic disorders are so far known to be associated with lymphatic malformation including mutations in RASA1. This clinical case highlights the possible complications of RASA1-associated lymphatic malformation in a female suffering from recurrent life-threatening septic lymphangitis.

Case summary

A 23-year-old female patient presented with congenital lymphoedema of the lower right extremity. At the age of eight, she first suffered from an episode of lymphangitis. Thereafter, she developed recurrent episodes of lymphangitis predominately occurring during menstruation and culminating into severe and life-threatening septicaemias. Due to the menstrual association, endometriosis was suspected but could not be confirmed. Furthermore, angiography could not detect any sign of arteriovenous fistula. Single-Photon-Emission-Computed-Tomography confirmed absent major lymphatics of the right leg with severely impaired and prolonged dermal lymphatic backflow. Genetic testing identified a disease-causing variant in the RASA1 gene.

Discussion

To our knowledge, this is the first case of recurrent septic lymphangitis with close relation to menstruation in a female with RASA1-associated lymphatic malformation. Due to the possible de novo or somatic origin of a pathogenic variant, a genetic disease should be considered in spite of an unremarkable family history or a localized lymphoedema. Although there is no curative therapy available yet, the knowledge of the underlying genetic defect is important for interdisciplinary patient care and might be crucial for individual molecular therapies in the future.

Posttraumatic Lymphedema after Open Fractures of the Lower Extremity-A Retrospective Cohort Analysis

Secondary lymphedema is a very common clinical issue with millions of patients suffering from pain, recurrent skin infections, and the constant need for a decongestive therapy. Well-established as a consequence of oncologic procedures, secondary lymphedema is also a well-known phenomenon after trauma. However, precise epidemiological data of lymphedema progress upon severe extremity injuries are still missing. In the present work, we analyzed a patient cohort of 94 individuals who suffered open fractures of the lower extremity and soft tissue injury, of 2nd and 3rd grade according to Tscherne classification, between 2013 and 2019. Typical symptoms of lymphedema have been obtained via interviews and patient medical records in a retrospective cohort analysis. Of all patients, 55% showed symptoms of secondary lymphedema and 14% reported recurrent skin infections, indicating severe lymphedema. Furthermore, comparing patients with and without lymphedema, additional parameters, such as obesity, total number of surgeries, infections, and compartment syndrome, related to lymphedema progress could be identified. According to these data, posttraumatic secondary lymphedema has a highly underestimated clinical prevalence. Further prospective studies are needed to validate this first observation and to identify high-risk groups in order to improve patient’s health care.

Elevated magnetic resonance imaging measures of adipose tissue deposition in women with breast cancer treatment-related lymphedema

PURPOSE

Breast cancer treatment-related lymphedema (BCRL) is a common co-morbidity of breast cancer therapies, yet factors that contribute to BCRL progression remain incompletely characterized. We investigated whether magnetic resonance imaging (MRI) measures of subcutaneous adipose tissue were uniquely elevated in women with BCRL.

METHODS

MRI at 3.0 T of upper extremity and torso anatomy, fat and muscle tissue composition, and T₂ relaxometry were applied in left and right axillae of healthy control (n = 24) and symptomatic BCRL (n = 22) participants to test the primary hypothesis that fat-to-muscle volume fraction is elevated in symptomatic BCRL relative to healthy participants, and the secondary hypothesis that fat-to-muscle volume fraction is correlated with MR relaxometry of affected tissues and BCRL stage (significance criterion: two-sided p < 0.05).

RESULTS

Fat-to-muscle volume fraction in healthy participants was symmetric in the right and left sides (p = 0.51); in BCRL participants matched for age, sex, and BMI, fat-to-muscle volume fraction was elevated on the affected side (fraction = 0.732 ± 0.184) versus right and left side in controls (fraction = 0.545 ± 0.221, p < 0.001). Fat-to-muscle volume fraction directly correlated with muscle T₂ (p = 0.046) and increased with increasing level of BCRL stage (p = 0.041).

CONCLUSION

Adiposity quantified by MRI is elevated in the affected upper extremity of women with BCRL and may provide a surrogate marker of condition onset or severity.

CLINICAL TRIAL

NCT02611557.

Primary lymphoedema

Lymphoedema is the swelling of one or several parts of the body owing to lymph accumulation in the extracellular space. It is often chronic, worsens if untreated, predisposes to infections and causes an important reduction in quality of life. Primary lymphoedema (PLE) is thought to result from abnormal development and/or functioning of the lymphatic system, can present in isolation or as part of a syndrome, and can be present at birth or develop later in life. Mutations in numerous genes involved in the initial formation of lymphatic vessels (including valves) as well as in the growth and expansion of the lymphatic system and associated pathways have been identified in syndromic and non-syndromic forms of PLE. Thus, the current hypothesis is that most cases of PLE have a genetic origin, although a causative mutation is identified in only about one-third of affected individuals. Diagnosis relies on clinical presentation, imaging of the structure and functionality of the lymphatics, and in genetic analyses. Management aims at reducing or preventing swelling by compression therapy (with manual drainage, exercise and compressive garments) and, in carefully selected cases, by various surgical techniques. Individuals with PLE often have a reduced quality of life owing to the psychosocial and lifelong management burden associated with their chronic condition. Improved understanding of the underlying genetic origins of PLE will translate into more accurate diagnosis and prognosis and personalized treatment.

Predictors of severity of lymphosclerosis in extremity lymphedema

BACKGROUND

Lymphovenous anastomosis (LVA) is an accepted method for treating lymphedema, and its efficacy could be greatly affected by the severity of lymphosclerosis. In the present study, we analyzed the intraoperative findings of lymphatic ducts in our patients who had undergone LVA to find predictive factors for the severity of lymphosclerosis.

METHODS

The medical records of the patients who had undergone LVA for managing extremity lymphedema from September 2017 to December 2020 were reviewed. The severity of lymphosclerosis was evaluated intraoperatively under a surgical microscope and stratified using the NECST (normal, ectasia, contraction, sclerosis type) classification. Patient age, gender, body mass index (BMI), lymphoscintigraphy stage, and lymphatic duct locations were included for analysis.

RESULTS

Multivariate linear regression analysis showed that location in a lower extremity (regression coefficient, -0.38; P = .03) and more advanced Taiwan lymphoscintigraphy stage (regression coefficient, 0.27; P < .001) were associated with more severe lymphosclerosis. In a subgroup analysis of lower extremity lymphedema, in addition to the Taiwan lymphoscintigraphy stage (regression coefficient, 0.24; P < .001), age (regression coefficient, 0.02; P = .001), and BMI (regression coefficient, 0.04; P = .005) were also associated with the severity of lymphosclerosis.

CONCLUSIONS

The severity of lymphosclerosis in extremity lymphedema correlated positively with the Taiwan lymphoscintigraphy stage and was more severe in lower limb lymphedema. In lower limb lymphedema, a higher BMI and older age also contributed to more severe lymphosclerosis.

A systematic review of pharmacologic and cell-based therapies for treatment of lymphedema (2010-2021)

BACKGROUND

Lymphedema describes the accumulation of interstitial fluid that results from lymphatic failure. Lymphedema can be of primary or secondary origin and has been estimated to affect 200 million people worldwide. Secondary lymphedema is commonly due to damage to the lymphatic vessels after surgical procedures. Treatments include compression bandaging and exercise regimens. However, at present, no pharmacologic therapy has been approved. We performed a systematic review of randomized controlled trials (RCTs) that had investigated pharmacologic and cell-based therapies for secondary lymphedema.

METHODS

We searched the databases MEDLINE, Embase, and ClinicalTrials.gov from January 2010 to May 2021. Only RCTs that had investigated pharmacologic and/or cell-based therapies for secondary lymphedema were eligible for inclusion. Those studies that had examined only active filarial infection were excluded. Two of us (J.W., S.T.) independently screened the studies for eligibility.

RESULTS

We identified eight RCTs that met the inclusion criteria. Overall, the studies were of poor quality with a high risk of bias. Ketoprofen demonstrated promising improvements in skin thickness and tissue histopathologic scores. Some evidence was found to suggest that doxycycline might be beneficial for nonfilarial secondary lymphedema, and a single, small RCT demonstrated that selenium might also confer some benefit. Neither synbiotics nor platelet-rich plasma resulted in reduced lymphedema volumes or symptom severity. Also, although bone marrow-derived stem cells resulted in improved symptom scores, no significant volume reduction was detected. Although positive results were demonstrated in trials investigating benzopyrones, previous meta-analyses have cast doubt on their efficacy. No two studies assessed the same intervention; thus, we could not perform a meta-analysis.

CONCLUSIONS

Although the results from some studies appeared promising, the available evidence at present is insufficient for any pharmacologic or cell-based therapy for patients with secondary lymphedema. Furthermore, large, high-quality RCTs are required before treatment recommendations will be possible.

Pilot Study of Anti-Th2 Immunotherapy for the Treatment of Breast Cancer-Related Upper Extremity Lymphedema

Recent studies suggest that Th2 cells play a key role in the pathology of secondary lymphedema by elaborating cytokines such as IL4 and IL13. The aim of this study was to test the efficacy of QBX258, a monoclonal IL4/IL13 neutralizing antibody, in women with breast cancer-related lymphedema (BCRL). We enrolled nine women with unilateral stage I/II BCRL and treated them once monthly with intravenous infusions of QBX258 for 4 months. We measured limb volumes, bioimpedance, and skin tonometry, and analyzed the quality of life (QOL) using a validated lymphedema questionnaire (Upper Limb Lymphedema 27, ULL-27) before treatment, immediately after treatment, and 4 months following treatment withdrawal. We also obtained 5 mm skin biopsies from the normal and lymphedematous limbs before and after treatment. Treatment was well-tolerated; however, one patient with a history of cellulitis developed cellulitis during the trial and was excluded from further analysis. We found no differences in limb volumes or bioimpedance measurements after drug treatment. However, QBX258 treatment improved skin stiffness (p < 0.001) and improved QOL measurements (Physical p < 0.05, Social p = 0.01). These improvements returned to baseline after treatment withdrawal. Histologically, treatment decreased epidermal thickness, the number of proliferating keratinocytes, type III collagen deposition, infiltration of mast cells, and the expression of Th2-inducing cytokines in the lymphedematous skin. Our limited study suggests that immunotherapy against Th2 cytokines may improve skin changes and QOL of women with BCRL. This treatment appears to be less effective for decreasing limb volumes; however, additional studies are needed.

Magnetic resonance lymphangiography: with or without contrast?

Lymphedema is an important medical issue around the world, caused by an anomalous collection of fluid in soft tissue due to congenital malformations or stenosis or obstruction of lymphatic vessels. Magnetic resonance lymphangiography (MRL) is an emerging technique focused on noninvasive or minimally invasive imaging of lymphatics with the goal to diagnose and treat lymphedema. This review will briefly discuss lymphatic imaging starting with lymphography and radionuclide lymphoscintigraphy up to the newest methods, focusing on MRL, a rising technique, and highlighting the technical aspects fundamental for achieving high-resolution MRL.

[Multidisciplinary approach in the lymphedema patient: From rehabilitation to microsurgery]

Lymphedema is a chronic disease with a high incidence in our society. In this paper, we present a review with the latest advances in imaging techniques and surgical reconstructive treatment of lymphedema (lymphovenous anastomosis, vascularized lymph node transfer, and prophylactic lymphedema surgery). In addition, a protocol is established based on a multidisciplinary team (composed of physiatrists, plastic surgeons, radiologists and nuclear medicine radiologists) to optimize the treatment of these patients.

Sentinel Lymph Node Biopsy, Lymph Node Dissection, and Lymphedema Management Options in Melanoma

Melanoma tumor thickness and ulceration are the strongest predictors of nodal spread. The recommendations for sentinel lymph node biopsy (SLNB) have been updated in recent American Joint Committee on Cancer and National Comprehensive Cancer Network guidelines to include tumor thickness ≥0.8 mm or any ulcerated melanoma. Mitotic rate is no longer considered an indicator for determining T category. Improvements in disease-specific survival conferred from SLNB were demonstrated through level I data in the Multicenter Selective Lymphadenectomy Trial (MSLT) I. The role for completion lymph node dissection has evolved to less surgery in lieu of recent domestic (MSLT II) and international (Dermatologic Cooperative Oncology Group Selective Lymphadenectomy Trial [DeCOG-SLT]) level I data having similar melanoma-specific survival. Treatment options for the prevention of treatment of lymphedema have progressed to include immediate lymphatic reconstruction, lymphovenous anastomosis, and vascularized lymph node transfer.

Feasibility of arm-draining lymph node-sparing radiotherapy of breast cancer: A pilot planning study

INTRODUCTION

Lymphoedema following axillary radiotherapy for breast cancer causes significant morbidity. Our goal was to evaluate the feasibility of sparing the lymph node that drains the arm's lymphatics (ARM node) while achieving standard dose constraints for whole breast and comprehensive lymph node irradiation.

METHODS

Six patients underwent lymphoscintigraphy and SPECT CT to identify the breast sentinel node (SN) and ARM node. The ARM node was contoured on the SPECT CT and deformably registered to the radiotherapy treatment planning CT. Radiotherapy plans (50 Gy in 25 fractions) with VMAT technique were generated, with the aim to spare the ARM node (Mean dose <25 Gy) and achieve adequate coverage to the remaining axilla. The plan required the breast SN site (clip + 10 mm surrounding the clip) to achieve D98% > 47.5 Gy, and axillary nodal CTV excluding ARM node to achieve D90% > 45 Gy.

RESULTS

In one patient, the ARM node was within the volume of breast SN site and sparing was not possible. For the remaining 5 patients, an ARM node-sparing plan could be successfully generated; the mean dose to the ARM node ranged from 11.2 to 23.1 Gy (median 13.8 Gy). In these 5 subjects, D90% > 45 Gy of axillary nodal CTV (range, 44.9-48.5 Gy, median 46.2 Gy) and D98% > 47.5 Gy of breast SN site were achieved.

CONCLUSION

In this planning study, ARM node-sparing VMAT of the breast and lymph nodes was feasible, while maintaining adequate dosimetric coverage. However, in some individuals, localization of the ARM node in close proximity to breast SN site precluded the generation of an ARM node-sparing treatment plan.

Breast Cancer related upper limb lymphedema: approach and surgical management

Lymphedema of the upper extremities in a common, chronic, progressive and debilitating disease, that affects the increasing population of cancer survivors. The gold standard is nowadays an integrated approach, including conservative and surgical treatment. Lymphatic surgery, particularly the physiologic procedures including lymphaticovenous anastomosis and vascularised lymph node transfer, should be offered to lymphedema patients as soon as possible, aimed to ameliorate the subjective symptoms and also to interrupt the degeneration cascade that makes this condition progressive over time. Indications for surgery, patient selection, and diagnostic tools will be discussed.

Outcomes of Lymphovenous Anastomosis for Upper Extremity Lymphedema: A Systematic Review

BACKGROUND

Lymphovenous anastomosis (LVA) is an accepted microsurgical treatment for lymphedema of the upper extremity (UE). This study summarizes and analyzes recent data on the outcomes associated with LVA for UE lymphedema at varying degrees of severity.

METHODS

A literature search was conducted in the PubMed database to extract articles published through June 19, 2020. Studies reporting data on postoperative improvement in limb circumference/volume or subjective improvement in quality of life for patients with primary or secondary lymphedema of the UE were included. Extracted data consisted of demographic data, number of patients and upper limbs, duration of symptoms before LVA, surgical technique, follow-up, and objective and subjective outcomes.

RESULTS

A total of 92 articles were identified, of which 16 studies were eligible for final inclusion comprising a total of 349 patients and 244 upper limbs. The average age of patients ranged from 38.4 to 64 years. The duration of lymphedema before LVA ranged from 9 months to 7 years. The mean length of follow-up ranged from 6 months to 8 years. Fourteen studies reported an objective improvement in limb circumference or volume measurements following LVA, ranging from 0% to 100%. Patients included had varying severity of lymphedema, ranging from Campisi stage I to IV. The maximal improvement in objective measurements was found in patients with lower stage lymphedema.

CONCLUSION

LVA is a safe, effective technique for the treatment of UE lymphedema refractory to decompressive treatment. Results of LVA indicate greater efficacy in earlier stages of lymphedema before advanced lymphatic sclerosis.

Lower Limb Lymphedema Patients Can Still Benefit from Supermicrosurgical Lymphaticovenous Anastomosis (LVA) after Vascularized Lymph Node Flap Transfer (VLNT) as Delayed Lymphatic Reconstruction-A Retrospective Cohort Study

Background: For lymphedema patients who received a vascularized lymph node flap transfer (VLNT) as their primary treatment, what are the treatment options when they seek further improvement? With recent publications supporting the use of lymphaticovenous anastomosis (LVA) for treating severe lymphedema, we examined whether LVA could benefit post-VLNT patients seeking further improvement. Methods: This retrospective cohort study enrolled eight lymphedema patients with nine lymphedematous limbs (one patient suffered from bilateral lower limb lymphedema) who had received VLNT as their primary surgery. Patients with previous LVA, liposuction, excisional therapy, or incomplete data were excluded. LVA was performed on nine lower lymphedematous limbs. Demographic data and intraoperative findings were recorded. Preoperative and postoperative limb volumes were measured with magnetic resonance volumetry. The primary outcome was the limb volume measured 6 months post-LVA. Results: The median duration of lymphedema before LVA was 10.5 (4.9–15.3) years. The median waiting time between VLNT and LVA was 41.4 (22.3–97.9) months. The median volume gained in the lymphedematous limb was 3836 (2505–4584) milliliters (mL). The median post-LVA follow-up period was 18 (6–30) months. Significant 6-month and 1-year post-LVA percentage volume reductions were found compared to pre-LVA volume (both p < 0.001). Conclusion: Based on the results from this study, the authors recommend the use of LVA as a secondary procedure for post-VLNT patients seeking further improvement.

Lower limb lymphedema staging based on magnetic resonance lymphangiography

OBJECTIVE

Dermal backflow (DBF) and reduced lymphatic visualization are common findings of lymphedema on various imaging modalities. However, there is a lack of knowledge about how these findings vary with the anatomic location and severity of lymphedema, and previous reports using indocyanine green lymphography or lymphoscintigraphy show variable results. Magnetic resonance lymphangiography (MRL) is expected to clarify this clinical question due to its superior ability for lymphatic visualization. This retrospective study aimed to investigate the following: (1) Are there any characteristic patterns for DBF and lymphatics' visualization, depending on the anatomic location within lower limbs and severity of lymphedema? (2) Is it possible to classify the severity of lymphedema based on MRL findings?

METHODS

Two radiologists performed consensus readings of MRL of 56 patients (112 limbs) with lower-limb lymphedema. The frequency of visualized DBF and lymphatics was analyzed in six regions in each lower limb. The results were compared with the International Society of Lymphology clinical stages and etiology of lymphedema. Characteristic findings were categorized and compared with the clinical stage and duration of lymphedema.

RESULTS

DBF and lymphatics were observed more frequently in the distal regions than the proximal regions of lower limbs. DBF appeared more frequently as the clinical stage increased, reaching statistical significance (P < 10^-3) between stages 0 or I and II. DBF above the knee joint was rarely observed (0.48%) in early stages (0 and I) but appeared more frequently (13.5%, P < 10^-5) in stage II. Lymphatics appeared less frequently as the stage progressed, with significant differences (P < .05) between stages I and II and between II and III. The frequency of lymphatics above the knee joint decreased significantly (P < .05) between stages I and II and between II and III as the stage progressed, reaching 0% in stage III. An MRL staging was proposed and showed significant positive correlations with the clinical stage (r = 0.79, P < .01) and the duration of lymphedema (r = 0.57, P < .01).

CONCLUSIONS

MRL-specific patterns of DBF and lymphatics that depended on the site within the lower limb and clinical stage were shown. The DBF pattern differed from those observed in previous studies with other imaging techniques. The proposed MRL staging based on these characteristic findings allows new stratification of patients with lymphedema. Combined with its excellent ability to visualize lymphatic anatomy, MRL could enable a more detailed understanding of individual patient's pathology, useful for determining the most appropriate treatment.

Advances in Lymphedema

Lymphedema is a common, complex, and inexplicably underappreciated human disease. Despite a history of relative neglect by health care providers and by governmental health care agencies, the last decade has seen an explosive growth of insights into, and approaches to, the problem of human lymphedema. The current review highlights the significant advances that have occurred in the investigative and clinical approaches to lymphedema, particularly over the last decade. This review summarizes the progress that has been attained in the realms of genetics, lymphatic imaging, and lymphatic surgery. Newer molecular insights are explored, along with their relationship to future molecular therapeutics. Growing insights into the relationships among lymphedema, obesity, and other comorbidities are important to consider in current and future responses to patients with lymphedema.

Vascularized lymph node transfer for surgical treatments of upper versus lower extremity lymphedema

OBJECTIVE

The purpose of this study was to compare clinical outcomes after vascularized lymph node transfer (VLNT) for the treatment of lymphedema performed on the upper and lower extremities.

METHODS

Between April 2015 and January 2020, 71 patients with advanced-stage lymphedema, categorized as International Society of Lymphology late stage 2 or 3, who underwent VLNT in upper and lower extremities were included in this study. Thirty-seven and 34 patients underwent VLNT in upper and lower extremities, respectively. The circumference of the affected and unaffected extremities was measured at baseline, follow-up visits, and at the last visit. The circumference was measured in six places on the extremities, and the circumference and volume percent differences between the affected and unaffected extremities were calculated. First, we compared preoperative and postoperative extremity circumferences in the overall, upper, and lower extremity groups. Second, we compared circumference and volume percent differences between the affected and unaffected extremities calculated at the last visit to identify the degree of improvement by VLNT in the upper and lower extremity groups.

RESULTS

The results of the comparative analysis between the preoperative and postoperative extremity circumferences showed that all postoperative extremity circumferences measured at the last visit were decreased compared with the preoperative values in the overall, upper, and lower extremity groups. In the upper extremity group, the circumference percent difference measured at the elbow was 23.1% before surgery and decreased to 13.4% at the last visit (P < .001). In the lower extremity group, the circumference percent difference measured at the knee was 24.4% before surgery and decreased to 17.4% at the last visit (P = .003). In the results of comparative analysis between the upper and lower extremity groups, there was a statistically significant difference in the postoperative circumference percent differences at the elbow/knee calculated at the last visit (P = .048). Similarly, there were statistically significant differences in circumference percent differences in two of six measurement sites at the last visit between the upper and lower extremity groups. However, there was no statistically significant difference in the volume percent difference calculated at the last visit between the upper and lower extremity groups.

CONCLUSIONS

These results demonstrate that VLNT may be effective in treating patients with advanced-stage lymphedema. However, patients with upper extremity lymphedema demonstrate superior outcomes compared with those with lower extremity lymphedema.