Anatomic and functional evaluation of the lymphatics and lymph nodes in diagnosis of lymphatic circulation disorders with contrast magnetic resonance lymphangiography

Identifying Functional Lymph Nodes in Lower Extremity Lymphedema Patients: The Role of High-frequency Ultrasound

BACKGROUND

 Lymph nodes may play a potential role in lymphedema surgery. Radiologic evaluation of nodes may reveal the status of pathologic conditions but with limited accuracy. This study is the first to evaluate the efficacy of ultrasound in detecting functioning nodes in lymphedema patients and presents a criterion for determining the functionality of the lymph nodes.

METHODS

 This retrospective study reviews 30 lower extremity lymphedema cases which were candidates for lymph node to vein anastomosis. Lymphoscintigraphy and magnetic resonant lymphangiography (MRL) imaging were compared with ultrasound features which were correlated to intraoperative indocyanine green (ICG) nodal uptake as an indication of functionality.

RESULTS

 Majority were International Society of Lymphology stage 2 late (50.0%) and stage 3 (26.7%). ICG positive uptake (functioning nodes) was noted in 22 (73.3%), while 8 patients (26.6%) had negative uptake (nonfunctioning). Ultrasound had significantly the highest specificity (100%) for identifying functional nodes followed by lymphoscintigraphy (55%) and MRL (36%; p = 0.002, p < 0.001, respectively). This was associated with 100% positive predictive value compared against lymphoscintigraphy (44%) and MRL (36%; p < 0.001 for both). The identified ultrasound imaging criteria for functioning lymph node were oval lymph node shape (Solbiati Index), morphology, vascularity pattern, and vascularity quantification.

CONCLUSION

 The use of ultrasound in nodal evaluation was proven effective in different pathologic conditions and demonstrated the best prediction for functionality of the lymph node based on the new evaluation criteria.

Supermicrosurgical lymphovenous anastomosis

Lymphedema impairs patients' function and quality of life. Currently, supermicrosurgical lymphovenous anastomosis (LVA) is regarded as a significant and effective treatment for lymphedema. This article aims to review recent literature on this procedure, serving as a reference for future research and surgical advancements. Evolving since the last century, LVA has emerged as a pivotal domain within modern microsurgery. It plays a crucial role in treating lymphatic disorders. Recent literature discusses clinical imaging, surgical techniques, postoperative care, and efficacy. Combining advanced tools, precise imaging, and surgical skills, LVA provides a safer and more effective treatment option for lymphedema patients, significantly enhancing their quality of life. This procedure also presents new challenges and opportunities in the realm of microsurgery.

Optimal Cut-Off Value for Detecting Breast Cancer-Related Lymphedema Using Ultrasonography

Background: We previously devised an ultrasonographic evaluation to calculate subcutaneous tissue cross-sectional area (△CSA). The reliability and accuracy of this method were demonstrated in healthy individuals and in patients with lymphedema. The purpose of this study was to estimate the optimal cut-off value of the ratio of the △CSA of the involved side (lesion side) to the contralateral side for detecting breast cancer-related lymphedema (BCRL) using ultrasonography. Methods and Results: Ultrasonographic measurements were performed 290 times in 150 patients. BCRLD was defined as a confirmed difference of >2 cm in arm circumference. BCRL confirmed by a clinician (BCRLC) was defined as the patient group that included not only BCRLD but also patients with subcutaneous thickening and abnormal findings on lymphoscintigraphy, even if the difference in arm circumference was <2 cm. The △CSAs of both upper arms and forearms were calculated by measuring the thickness of the subcutaneous tissue at four locations using ultrasonography (superior, medial, inferior, lateral) at 10 cm above the elbow and 10 cm below the elbow. With a 1.35 △CSA ratio as the cut-off value for detecting BCRLD, the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were 0.88, 0.87, and 0.95, respectively. With a 1.20 △CSA ratio as the cut-off value for detecting BCRLC, the sensitivity, specificity, and AUC were 0.92, 0.89, and 0.97, respectively. Conclusions: Our findings suggest that a 1.20 △CSA ratio as determined using ultrasonography, corresponding to a tape measurement of 1.05 cm, can be considered as a diagnostic criterion for lymphedema.

MRI of Lymphedema

Lymphedema is a devastating disease that has no cure. Management of lymphedema has evolved rapidly over the past two decades with the advent of surgeries that can ameliorate symptoms. MRI has played an increasingly important role in the diagnosis and evaluation of lymphedema, as it provides high spatial resolution of the distribution and severity of soft tissue edema, characterizes diseased lymphatic channels, and assesses secondary effects such as fat hypertrophy. Many different MR techniques have been developed for the evaluation of lymphedema, and the modality can be tailored to suit the needs of a lymphatic clinic. In this review article we provide an overview of lymphedema, current management options, and the current role of MRI in lymphedema diagnosis and management. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 5.

Lymph Node Metastases Detection Using Gd2O3@PCD as Novel Multifunctional Contrast Imaging Agent in Metabolic Magnetic Resonance Molecular Imaging

Axillary lymph node detection is crucial to staging and prognosis of the lymph node metastatic spread in breast cancer. Currently, lymphoscintigraphy and blue dye, as the conventional methods to localize sentinel lymph nodes (SLNs), are invasive and can only be performed during surgery. This study has had a novel hybrid gadolinium oxide nanoparticle coating with Cyclodextrin-based polyester as a high-relaxivity T₁ magnetic resonance molecular imaging (MRMI) contrast agent (CA). Twelve female BALB/c mice were randomly divided into three groups of four mice; each group was injected with 4T₁ cells to obtain metastasis lymph nodes and diagnosed by using the 3D T₁W (VIBE) MRI (Siemens 3T, Prisma). The synthesized Gd₂O₃@PCD nanoparticles with a suitable particle size range of 20-40 nm have had much higher longitudinal relaxivity (r ₁) for Gd₂O₃@PCD and Gd-DOTA (Dotarem) with the values of 3.98 mM^-1·s^-1 ± 0.003 and 2.71 mM^-1·s^-1 ± 0.005, respectively. Identical MR images in coronal views were subsequently obtained to create time-intensity curves of the right axillary lymph nodes and to measure the contrast ratio (CR). The peak CR and qualitative assessment of axillary lymph nodes at five-time points were evaluated. After subcutaneous injection, the contrast ratio of axillary lymph node and tumor in mice exhibited CR peak of Gd₂O₃@PCD and Dotarem with the values of 2.21 ± 0.06 and 0.40 ± 0.004 for lymph node and 2.54 ± 0.04 and 1.21 ± 0.007 for the tumor, respectively. Furthermore, the lumbar-aortic lymph node is weakly visible in the original coronal image. In conclusion, the use of Gd₂O₃@PCD nanoparticles as novel MRMI CAs enables high resolution for the detection of lymph node metastasis in mice with the potential capability for breast cancer diagnostic imaging.

Overview of Lymphedema for Physicians and Other Clinicians: A Review of Fundamental Concepts

Lymphedema has historically been underrated in clinical practice, education, and scholarship to the detriment of many patients with this chronic, debilitating condition. The mechanical insufficiency of the lymphatic system causes the abnormal accumulation of protein-rich fluid in the interstitium, which triggers a cascade of adverse consequences such as fat deposition and fibrosis. As the condition progresses, patients present with extremity heaviness, itchiness, skin infections, and, in later stages, dermal fibrosis, skin papillomas, acanthosis, and other trophic skin changes. Correspondingly, lymphedema results in psychological morbidity, including anxiety, depression, social avoidance, and a decreased quality of life, encompassing emotional, functional, physical, and social domains. For this review, we conducted a literature search using PubMed and EMBASE and herein summarize the evidence related to the fundamental concepts of lymphedema. This article aims to raise awareness of this serious condition and outline and review the fundamental concepts of lymphedema.

Using the Indocyanine Green (ICG) Lymphography to Screen Breast Cancer Patients at High Risk for Lymphedema

Background: Indocyanine green (ICG) lymphography is a newer technique for diagnosing lymphedema. Our study aimed to find whether the abnormality of ICG lymphography can predict the occurrence of early lymphedema and then select candidates at high risk of developing lymphedema. Methods: Postoperative breast cancer patients who visited the lymphedema clinic of Peking University People’s Hospital from December 2016 to September 2019 were consecutively enrolled and received ICG lymphography and circumference measurement. Data were collected on the patients’ characteristics and correlation between ICG lymphography and the occurrence of lymphedema. Results: The analysis included 179 patients. There were 91 patients in the lymphedema group and 88 patients in the non-lymphedema group. By multivariate analysis, age, axillary surgery, radiotherapy, and time since breast cancer surgery were regarded as risk factors for lymphedema (p < 0.05). According to the results of ICG lymphography, patients in the non-lymphedema group (n = 88) were divided into ICG-positive (n = 47) and ICG-negative (n = 41) groups. The incidence of lymphedema in the ICG-positive group was significantly higher than that in the ICG-negative group (19.1% vs. 2.4%, p = 0.027). Conclusion: Lymphatic disorder can be detected before circumference change using ICG lymphography. Abnormal ICG lymphography is an independent risk factor for lymphedema. Patients with abnormal dermal backflow patterns are considered to be a high-risk group for lymphedema and should undergo early interventions to prevent lymphedema.

In Vitro Studies Regarding the Safety of Chitosan and Hyaluronic Acid-Based Nanohydrogels Containing Contrast Agents for Magnetic Resonance Imaging

The aim of this study was to investigate the biocompatibility of contrast agents, such as gadolinium 1, 4, 7, 10 tetraazacyclo-dodecane tetraacetic acid (GdDOTA) and gadolinium dioctyl terephthalate (GdDOTP), encapsulated in a polymeric matrix containing chitosan and hyaluronic acid using RAW264.7 murine macrophages and human blood samples. The cell viability and cytotoxicity were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays, while cell cycle analysis was determined in RAW264.7 cells using flow cytometry. The mitochondrial membrane potential (MMP), hemolytic index, complement activation, and thrombogenic potential of gadolinium (Gd) containing nanohydrogels were measured by fluorometric and spectrophotometric methods. Taken together, our results demonstrate the good bio- and hemocompatibility of chitosan-based nanohydrogels with the RAW264.7 cell line and human blood cells, suggesting that these could be used as injectable formulations for the magnetic resonance imaging diagnostic of lymph nodes.

Multimodality Approach to Lymphedema Surgery Achieves and Maintains Normal Limb Volumes: A Treatment Algorithm to Optimize Outcomes

Surgical treatment of advanced lymphedema is challenging and outcomes are suboptimal. Physiologic procedures including lymphaticovenous anastomosis (LVA) and vascularized lymph node transfer (VLNT) improve lymphatic flow but cannot reverse fibrofatty tissue deposition, whereas liposuction removes fibrofatty tissue but cannot prevent disease progression. The adjunctive use of nanofibrillar collagen scaffolds (BioBridge^TM) can promote lymphangiogenesis. We report a treatment algorithm utilizing a multimodality approach to achieve sustained normal limb volumes in patients with stage II-III lymphedema. A retrospective review of late stage II-III lymphedema patients treated with liposuction, physiologic procedures, and BioBridge^TM from 2016 through 2019 was conducted. Treatment outcome in the form of excess volume reduction is reported. Total of 14 patients underwent surgical treatment of late stage II and III lymphedema according to our triple therapy algorithm. Patients had a baseline median volume excess of 29% (19.8, 43.3%). The median volume excess was improved to 0.5% (−4.3, 3.8%) at 14.4 months from the first stage surgery (p < 0.05) and further improved to −1.0% (−3.3, 1.3%) after triple therapy with BB placement at 24.6 months. A triple therapy surgical treatment algorithm can optimize outcomes and achieve sustained normalization of limb volume in late stage II-III lymphedema. The incorporation of nanofibrillar collagen scaffold technology allows for improved and sustained volume reduction.

Comparison of normal hindlimb lymphatic systems in rats with detours present after lymphatic flow blockage

In the present study, we aimed to identify the normal hindlimb lymphatic systems in rats and compare them with the detours after lymphatic flow blockage. The lymphatic systems of the hindlimbs of normal rats were investigated via lymphography using a near-infrared fluorescence imaging system. The lymphatic vessels were stained using Evans Blue. The lymphatic flow was blocked through lymphatic vessel ligation combined with inguinal and popliteal lymph node dissection. Detours that appeared after 30 days were visualized using lymphography and immunostaining with anti-podoplanin antibodies. Three main results were obtained in the present study. First, the deep medial system, the superficial medial system, a connection between the superficial and deep medial lymphatic systems, and the superficial lateral system, were elucidated. Second, three types of detours, namely the detour of the lateral abdomen, the detour to the lymphatic vessel near the midline of the abdomen, and the detour to the contralateral inguinal lymph node, were identified after lymphatic flow blockage. Lastly, detours were located in the fatty layer above the panniculus carnosus muscle and their lumina were wide. The histology suggested that the detour was a pre-collecting lymphatic vessel. Lymphatic routes in the rat hindlimbs after lymphatic flow blockage were different from those of the normal rat lymphatic system. It was suggested that the detour is a pre-collecting lymphatic vessel and that encouraging its development may be a new method of simple lymphatic drainage.

Visualization of Both the Superficial and Deep Lymphatic System of the Upper Extremity Using Magnetic Resonance Lymphography

Background: The lymphatic system consists of the superficial and deep lymphatic system. Several diagnostic methods are used to assess the lymphatic system. Lymphoscintigraphy and indocyanine green lymphography are widely applied, both showing disadvantages, such as a poor resolution and lack of field of view. Magnetic resonance lymphography (MRL) shows satisfactory temporal and spatial resolution. The aim of this study was to assess both the superficial and deep lymphatic system in the upper extremity of healthy subjects, using an MRL protocol. Methods and Results: Ten healthy volunteers underwent an MRL examination, using a three Tesla MRI unit. Water-soluble gadolinium was used as a contrast agent. MRL images were evaluated by an experienced radiologist on image quality, enhancement of veins and lymphatic vessels, and characteristics of the latter. Overall image quality was good to excellent. In all subjects, veins and lymphatic vessels could be distinguished. Superficial and deep lymphatic vessels were seen in 9 out of 10 subjects. Lymphatic vessels with a diameter between 0.9 and 4.3 mm were measured. Both veins and lymphatic vessels showed their characteristic appearance. Enhancement of veins was seen directly after contrast agent injection, which decreased over time. Lymphatic vessel enhancement slowly increased over time. Mean total MRL examination (room) time was 110 minutes (81 minutes scan time). Conclusions: The MRL protocol accurately visualizes both deep and superficial lymphatic vessels showing their characteristic appearances with high spatial resolution, indicating the MRL can be of value in diagnosing and staging peripheral lymphedema.

Impact of Magnetic Resonance Lymphography on Lymphaticolvenular Anastomosis for Lower-Limb Lymphedema

BACKGROUND

 Although several investigations have described the safety, utility, and precision of magnetic resonance lymphography (MRL) as a preoperative examination for lymphaticovenular anastomosis (LVA), it is unclear how much MRL assistance impacts LVA results. The present study aimed to clarify the outcome of MRL-assisted LVA for leg lymphedema using body water measurements obtained by bioelectrical impedance analysis.

METHODS

 The water reductive effect of MRL-assisted LVA in female secondary leg lymphedema patients was compared with that of non-MRL-assisted controls in this retrospective study. In the MRL-assisted group, all LVA candidates underwent MRL prior to surgery, and the lymphatic vessels to be anastomosed were primarily determined by MRL findings. The body water composition of the treated legs was assessed before LVA and at 6 months postoperatively using a multi-frequency bioelectrical impedance analyzer.

RESULTS

 Twenty-three patients in the MRL-assisted study group and an equal number in the non-MRL-assisted control group were analyzed. Although mean leg water volume before LVA, mean excess water volume of the affected leg before LVA, and number of anastomoses created were comparable between the groups, the water volume reduction (1.02 L versus 0.49 L; 95% confidence interval [CI]: 0.03-1.03, p < 0.05) and edema reduction rate (46.7% versus 27.2%; 95% CI: 3.7-35.5%, p < 0.05) in the MRL-assisted group were significantly greater than in controls.

CONCLUSION

 Preoperative MRL-assisted lymph vessel visualization and selection appeared to significantly enhance the water reductive effect of LVA for International Society of Lymphology classification stage 2 leg lymphedema. MRL also helped to reliably identify lymphatic vessels for anastomosis. Without increasing the number of anastomoses, LVA could be performed more effectively by better detecting stagnant lymphatic vessels using MRL.

Systematic Review of Magnetic Resonance Lymphangiography From a Technical Perspective

BACKGROUND

Clinical examination and lymphoscintigraphy are the current standard for investigating lymphatic function. Magnetic resonance imaging (MRI) facilitates three-dimensional (3D), nonionizing imaging of the lymphatic vasculature, including functional assessments of lymphatic flow, and may improve diagnosis and treatment planning in disease states such as lymphedema.

PURPOSE

To summarize the role of MRI as a noninvasive technique to assess lymphatic drainage and highlight areas in need of further study.

STUDY TYPE

Systematic review.

POPULATION

In October 2019, a systematic literature search (PubMed) was performed to identify articles on magnetic resonance lymphangiography (MRL).

FIELD STRENGTH/SEQUENCE

No field strength or sequence restrictions.

ASSESSMENT

Article quality assessment was conducted using a bespoke protocol, designed with heavy reliance on the National Institutes of Health quality assessment tool for case series studies and Downs and Blacks quality checklist for health care intervention studies.

STATISTICAL TESTS

The results of the original research articles are summarized.

RESULTS

From 612 identified articles, 43 articles were included and their protocols and results summarized. Field strength was 1.5 or 3.0 T in all studies, with 25/43 (58%) employing 3.0 T imaging. Most commonly, imaging of the peripheries, upper and lower limbs including the pelvis (32/43, 74%), and the trunk (10/43, 23%) is performed, including two studies covering both regions. Imaging protocols were heterogenous; however, T2 -weighted and contrast-enhanced T1 -weighted images are routinely acquired and demonstrate the lymphatic vasculature. Edema, vessel, quantity and morphology, and contrast uptake characteristics are commonly reported indicators of lymphatic dysfunction.

DATA CONCLUSION

MRL is uniquely placed to yield large field of view, qualitative and quantitative, 3D imaging of the lymphatic vasculature. Despite study heterogeneity, consensus is emerging regarding MRL protocol design. MRL has the potential to dramatically improve understanding of the lymphatics and detect disease, but further optimization, and research into the influence of study protocol differences, is required before this is fully realized.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.

Combined Liposuction and Physiologic Treatment Achieves Durable Limb Volume Normalization in Class II-III Lymphedema: A Treatment Algorithm to Optimize Outcomes

INTRODUCTION

Outcomes of surgical lymphedema treatment are currently suboptimal. Physiologic procedures including lymphovenous anastomosis (LVA) and vascularized lymph node transfer (VLNT) reestablish lymphatic flow but cannot correct fibroadipose deposition, whereas liposuction alone cannot prevent disease progression. We propose a treatment algorithm combining liposuction with LVA or VLNT that can achieve normal limb volumes and prevent disease progression in stage II-III lymphedema.

METHODS

We performed a retrospective chart review of patients undergoing liposuction and physiologic lymphedema operations at our institution between January 2016 and June 2019. Patients were assigned to treatment groups according to their clinical presentation: physiologic first, followed by no further treatment (physiologic only) or liposuction (physiologic then liposuction); liposuction then physiologic; or simultaneous. Preoperative patient characteristics and sequence of operations were recorded. Compression garment usage was self-reported. Limb volumes were approximated as a truncated cone.

RESULTS

Twenty-one patients met the inclusion criteria. The liposuction then physiologic group had significantly higher stage and excess limb volume at baseline, whereas the physiologic first groups had lower excess volume. While the physiologic only group had predominantly stage I disease, the patients who later required liposuction (physiologic then liposuction group) all had stage II disease. All groups achieved 82% to 106% mean excess volume reduction, and volume reduction was maintained for up to 2.4 years. Compression garment class was not reduced, but mean postoperative compression duration decreased from 12.5 to 7.5 h/d (P = 0.003). Ten of 11 patients with history of cellulitis had no further recurrence.

CONCLUSION

Lymphedema represents a continuum of fluid and fibroadipose disease. Accurate staging and timely treatment with physiologic procedures and liposuction can normalize limb volume. We propose a treatment algorithm to optimize outcomes. Patients with predominantly nonpitting presentation benefit from liposuction to maximize removal of fibroadipose tissue and optimize postoperative compression, followed by LVA or VLNT to improve lymphatic drainage. Patients with primarily pitting edema are best treated with physiologic procedures initially, reserving selective liposuction as a second stage. Patients with mixed presentation are best served by single-stage combination procedures.

The application of indocyanine green (ICG) and near-infrared (NIR) fluorescence imaging for assessment of the lymphatic system in reconstructive lymphaticovenular anastomosis surgery

INTRODUCTION

Lymphedema has traditionally been managed through noninvasive means with complete decongestive therapy. However, complete decongestive therapy is an intensive program that requires lifelong adherence by patients with lymphedema. More recently, reconstructive surgical procedures have shown promise in improving lymphedema by physiologically restoring lymphatic function. One of these types of procedures, lymphaticovenular anastomosis, relies on technological advances in imaging, particularly indocyanine green lymphangiography.

AREAS COVERED

This article reviews indocyanine green and near-infrared fluorescence imaging. In addition, this article discusses the application of this imaging to the preoperative, intraoperative, and postoperative assessment of the lymphatic system in the setting of lymphaticovenular anastomosis surgery.

EXPERT OPINION

Indocyanine green lymphangiography offers significant advantages over other types of imaging of the lymphatic system. In the future, it is hopeful that additional options for these imaging devices will become available which may increase their accessibility by centers interested in performing reconstructive lymphatic surgery, including in relation to cost. Finally, more studies with higher levels of evidence are needed to better define the long-term outcomes associated with lymphatic surgery including LVA. In this regard, practitioners should fully harness the information conferred by ICG lymphangiography as both a clinical and research tool.

Lymph Flow Before and After Lymphaticovenous Anastomosis Measured Using Transonic Transit-Time Ultrasound Microvascular Flowprobe

Background: Assessment of lymph flow has proven challenging. Transit-time ultrasound technique (TTUT) is the first technique that provides real-time quantitative lymphatic flow values. In cardiothoracic surgery and neurosurgery, this technique has tremendous clinical value in assessing surgery quality and predicting outcomes. The objective of this study was to measure lymph flow before and after lymphaticovenous anastomosis (LVA), using TTUT. Methods and Results: Consecutive patients with peripheral lymphedema undergoing LVA were included. Preoperative workup was performed using indocyanine green (ICG) lymphangiography. Perioperatively, the Transonic^® Microvascular Flowprobe was used to measure lymph flow before and after anastomosis. Twenty-five patients with International Society of Lymphology stage IIA (68%) and stage IIB (32%) peripheral lymphedema were included. Lymph flow velocities ranged from 0.02 to 0.80 mL/min (mean 0.25 ± 0.19) before anastomosis and from 0.02 to 0.86 mL/min (mean 0.27 ± 0.22) after anastomosis (p = 0.340). Mean flow values were significantly higher in the upper extremities compared with the lower extremities. Furthermore, there was a decrease in flow in patients with ICG stage IV in comparison with ICG stage III. Clinical outcomes could not be directly correlated with flow values in these individual cases. Conclusion: TTUT micro-flowprobe is a suitable instrument to measure real-time quantitative lymphatic flow in both lymphatics and LVA. It can confirm patency of lymphatic collectors and LVA peroperatively. Significantly higher lymph flow velocities were found in upper extremities in comparison with lower extremities, both before and after LVA. Further studies should be performed to evaluate lymph flow values and clinical correlation.

The Clinical Usefulness of Lymphedema Measurement Technique Using Ultrasound

Background: We previously invented a new technique to measure the cross-sectional area of soft tissue of a limb (ΔCSA) with lymphedema using ultrasonography. The measurement correlated strongly with both circumference and volumetry in normal subjects. The purpose of this study was to measure the reliability and accuracy of the method in patients with lymphedema. Methods and Results: Ultrasonography was performed on both arms of 69 female patients diagnosed with stage ≥1 lymphedema related to advanced breast cancer. At 10 cm above elbow (AE) and below elbow (BE), soft-tissue thicknesses at various locations were measured by two examiners. Subcutaneous tissue stiffness was also obtained by measuring thickness differences of soft tissue when applying minimal and maximal pressure to the skin (compliance) and its ratio to the initial thickness (compliance ratio). ΔCSA showed a strong positive correlation with circumference (r = 0.758 to 0.951), and a moderate negative correlation with Z at 5 Hz (r = -0.326 to -0.486). Intra- and interclass coefficients of all ultrasonography measurements were moderate to excellent (0.623-0.990). Compliance measured at 10 cm BE on the lesion side was significantly higher than on the normal side (p < 0.001), and compliance measured at 10 cm AE showed no difference between the two sides (p = 0.653). Conversely, compliance ratios measured at 10 cm AE and BE on the lesion side were significantly lower than on the normal side (p < 0.001). Conclusion: Thus, ΔCSA using ultrasonography could be a particularly viable option for determining status in lymphedema patients.

Magnetic resonance lymphography as three-dimensional navigation for lymphaticovenular anastomosis in patients with leg lymphedema

BACKGROUND

Precise mapping of functional lymphatic vessels is essential for successful lymphaticovenular anastomosis (LVA). This study aimed to clarify the precision of magnetic resonance lymphography (MRL) in detecting lymphatic vessels prior to LVA.

METHODS

Eighteen patients with leg lymphedema were recruited for this prospective study. All patients underwent MRL before LVA to obtain three-dimensional coordinates of lymphatic vessels from MRL images. The precision of MRL for detecting lymphatic vessels was evaluated and compared with those of other contrast techniques.

RESULTS

Twenty legs from 18 patients were analyzed. A total of 40 skin incisions were made, 32 of which were determined by MRL. The precision of MRL to detect lymphatic vessels was 94%. With the addition of MRL, the number of lymphatic vessels identified preoperatively was increased as compared with indocyanine green lymphography (ICG-L) alone. Assuming a detection sensitivity of MRL for lymphatic vessels of 1, those of other contrast techniques were 0.90 for ICG-L under microscopy, 0.73 for patent blue staining, and 0.43 for ICG-L before incision. Whereas ICG-L before incision could not detect lymphatic vessels at depths greater than 17.0 mm, all deeper anastomosed lymphatic vessels were identified by MRL.

CONCLUSION

Lymphatic vessels enhanced on MRL can be reliably identified intraoperatively. MRL is a promising preoperative examination in LVA that can selectively depict suitable lymphatic vessels even in deep tissue layers.

Mathematical Modelling of the Structure and Function of the Lymphatic System

This paper presents current knowledge about the structure and function of the lymphatic system. Mathematical models of lymph flow in the single lymphangion, the series of lymphangions, the lymph nodes, and the whole lymphatic system are considered. The main results and further perspectives are discussed.

A Novel Approach to Subcutaneous Collecting Lymph Ducts Using a Small Diameter Wire in Animal Experiments and Clinical Trials

Background: While performing microsurgery, including lymphaticovenous anastomosis (LVA) for chronic limb lymphedema, it is a common procedure to identify the subcutaneous collecting lymph ducts with near-infrared fluorescence lymphangiography (NIR) using indocyanine green. However, due to limitations such as minimum observable depth, only a few lymphatic ducts can be identified with this procedure. Hence, we developed a new smaller-diameter "lymphatic wire" (LW) that could be inserted directly into lymphatic collecting ducts of the limbs, enabling accurate identification and localization. Methods and Results: First, used the LW on the hind limbs of 6 swine, and 36 porcine lymphatic collecting ducts were identified, the outer diameter of which varied from 0.3-0.7 mm (mean 0.41 ± 0.11 mm). We could insert the LW after creating a side opening in 30 of these ducts. We encountered no difficulties during the procedure. In the pathological examination, adverse events such as valve dysfunction and perforation were not identified. Based on the results, a clinical evaluation of the LW was performed in two patients with lower extremity lymphedema, and the LW helped us identify lymphatic ducts in the subcutaneous layer, even at the sites where the NIR had proved ineffective. Conclusion: Based on our results, we suggest that the procedure for identifying lymphatic vessels using the newly developed LW is a useful technique that can be utilized before performing a LVA for lymphedema. However, further clinical study is required to develop this device and technique, for wider clinical application in the future.

Analysis of collateral lymphatic circulation in patients with lower limb lymphedema using magnetic resonance lymphangiography

OBJECTIVE

Although the development of lymphatic collaterals is expected following lymphedema, little is known about the anatomic details of such compensatory pathways or their association with symptoms. Magnetic resonance lymphangiography (MRL) has been shown to be superior to lymphoscintigraphy and indocyanine green lymphography in visualizing lymphatics. This study aimed to analyze MRL images of lower limbs to elucidate the patterns of lymphatic collateral formation and their association with the clinical stages of lymphedema.

METHODS

We enrolled 56 consecutive patients (112 lower limbs) with lymphedema who underwent MRL. Two radiologists performed a consensus reading of MRL images for the presence or absence of collateral lymphatic pathways, and the results were compared with the clinical stages. Furthermore, the frequency of abnormal MRL findings in 43 asymptomatic lower limbs of patients with unilateral lymphedema was analyzed and compared with that in the 69 symptomatic lower limbs of the patients. The imaging findings were also compared with the cause of lymphedema.

RESULTS

All three collateral pathways (anterolateral, deep, and posteromedial lymphatics) were visualized at a higher (P < .05) frequency in stage II than in stage 0 lower limbs. The frequency of visualization of the three collaterals was significantly higher in symptomatic (stages I-III) lower limbs than in asymptomatic (stage 0) lower limbs. Most (76.8%) of the symptomatic limbs exhibited at least one of these collaterals, and the frequency was significantly higher than in the asymptomatic limbs (P < .001). Most (81.4%) of the asymptomatic (stage 0) lower limbs had at least one abnormal finding in terms of lymphatic circulation, although this proportion was significantly lower compared with the symptomatic limbs (98.6%). The collaterals tended to appear less frequently in primary lymphedema than in secondary lymphedema, reaching statistical significance in the posteromedial lymphatics.

CONCLUSIONS

These results suggested that the two superficial lymphatic groups and the deep lymphatic system act as major collaterals of the lower limbs in patients with lymphedema. Furthermore, MRL of most patients with unilateral lymphedema demonstrated abnormal findings, including collateral formation, not only in the affected lower limb but also in the asymptomatic lower limb. In primary lymphedema, the collaterals may appear less frequently than in secondary lymphedema. Collaterals should be taken into consideration in planning the site of lymphaticovenous anastomosis and assessing disease progression. MRL can visualize preclinical alterations in lymphatic flow and compensatory pathways; therefore, we expect that it will be useful for the early diagnosis of lymphedema.

Anatomical Theories of the Pathophysiology of Cancer-Related Lymphoedema

Lymphoedema is a well-known concern for cancer survivors. A crucial issue in lymphoedema is that we cannot predict who will be affected, and onset can occur many years after initial cancer treatment. The variability of time between cancer treatment and lymphoedema onset is an unexplained mystery. Retrospective cohort studies have investigated the risk factors for lymphoedema development, with extensive surgery and the combination of radiation and surgery identified as common high-risk factors. However, these studies could not predict lymphoedema risk in each individual patient in the early stages, nor could they explain the timing of onset. The study of anatomy is one promising tool to help shed light on the pathophysiology of lymphoedema. While the lymphatic system is the area least investigated in the field of anatomical science, some studies have described anatomical changes in the lymphatic system after lymph node dissection. Clinical imaging studies in lymphangiography, lymphoscintigraphy and indocyanine green (ICG) fluorescent lymphography have reported post-operative anatomical changes in the lymphatic system, including dermal backflow, lymphangiogenesis and creation of alternative pathways via the deep and torso lymphatics, demonstrating that such dynamic anatomical changes contribute to the maintenance of lymphatic drainage pathways. This article presents a descriptive review of the anatomical and imaging studies of the lymphatic system in the normal and post-operative conditions and attempts to answer the questions of why some people develop lymphoedema after cancer and some do not, and what causes the variability in lymphoedema onset timing.

A systematic review of magnetic resonance lymphography for the evaluation of peripheral lymphedema

OBJECTIVE

Visualization of the lymphatic system is necessary for both early diagnosis and associated treatments. A promising imaging modality is magnetic resonance lymphography (MRL). The aim of this review was to summarize different MRL protocols, to assess the clinical value in patients with peripheral lymphedema, and to define minimal requirements necessary for visualization of lymphatics.

METHODS

A systematic literature search was conducted in PubMed, Embase, and the Cochrane Library in December 2018. Studies performing MRL in patients with peripheral lymphedema or healthy participants were included. Study design, population, etiology, duration of lymphedema, clinical staging, contrast agent, dose, injection site, and technical magnetic resonance imaging details were analyzed. No meta-analyses were performed because of different study aims and heterogeneity of the study populations.

RESULTS

Twenty-five studies involving 1609 patients with both primary lymphedema (n = 669) and secondary lymphedema (n = 657) were included. Upper and lower limbs were examined in 296 and 602 patients, respectively. Twenty-two studies used a gadolinium-based contrast agent that was injected intracutaneously or subcutaneously in the interdigital web spaces. Contrast-enhanced T1-weighted combined with T2-weighted protocols were most frequently used. T1-weighted images showed lymphatics in 63.3% to 100%, even in vessels with a diameter of ≥0.5 mm. Dermal backflow and a honeycomb pattern were clearly recognized.

CONCLUSIONS

MRL identifies superficial lymphatic vessels with a diameter of ≥0.5 mm with high sensitivity and specificity and accurately shows abnormal lymphatics and lymphatic drainage patterns. Therefore, MRL could be of clinical value in both early and advanced stages of peripheral lymphedema. Minimum requirements of an MRL protocol should consist of a gadolinium-based contrast-enhanced T1-weighted gradient-recalled echo sequence combined with T2-weighted magnetic resonance imaging, with acquisition at least 30 minutes after injection of contrast material.

Quantification of Thoracic Lymphatic Flow Patterns Using Dynamic Contrast-enhanced MR Lymphangiography

Background Dynamic contrast material-enhanced MR lymphangiography has recently emerged as a technique to image the lymphatic anatomy and identify lymphatic flow abnormalities; however, a method to quantify lymphatic flow in health and disease is needed. Purpose To develop a method to quantify thoracic lymphatic flow patterns using dynamic contrast-enhanced MR lymphangiography. Materials and Methods The following patients with dynamic contrast-enhanced MR lymphangiography images collected in 2015 and 2016 were retrospectively identified: group A, neonates with chylothorax; group B, children with heart failure complicated by plastic bronchitis; and group C, adults with lymphatic plastic bronchitis and without heart failure. An automated image segmentation method was developed for segmenting the contrast-enhanced lymphatic flow in spatiotemporal domains from the dynamic contrast-enhanced MR lymphangiography images. The lymphatic flow rates were quantified for individual patients on the basis of their spatiotemporal dynamic contrast-enhanced MR lymphangiography segmentation results, and the flow rates were compared among the three patient groups by using Wilcoxon rank sum tests. Results Twenty-two patients were evaluated: seven neonates (mean age, 49 days ± 71 [standard deviation]; three boys, four girls), 10 children (mean age, 8 years ± 3; seven boys, three girls), and five adults (mean age, 46 years ± 10; three men, two women). The proposed method was used to obtain lymphatic flow segmentation results with Dice scores of 0.80, 0.82, and 0.83 for patients from groups A, B, and C, respectively. The mean flow rates for groups A, B, and C were 1.8 mL/min ± 1.4, 4.0 mL/min ± 1.8, and 12.5 mL/min ± 3.8, respectively. The flow rate differed significantly between groups A and B (P = .002), groups A and C (P = .01), and groups B and C (P = .01). Conclusion An automatic spatiotemporal segmentation method was used to determine thoracic lymphatic flow rates in individual patients based on their dynamic contrast-enhanced MR lymphangiographic images. © RSNA, 2020 Online supplemental material is available for this article.

Surgical reconstruction of primary genital lymphedema-long term therapeutic efficacy

Background

Primary genital lymphedema is caused by congenital lymphatic dysplasia, which is often accompanied by lymphedema of the lower extremities. A lack of effective diagnostics and treatments are available in clinical practice. The purpose of this study is to present the experience of surgical treatment of genital lymphedema and follow-up magnetic resonance lymphangiography (MRL) examinations.

Methods

The clinical records of 40 patients diagnosed with primary genital lymphedema between 2010 and 2019 were retrospectively reviewed. The surgical management of all patients consisted of complete excision of the edematous subcutaneous tissue and plastic reconstruction of the penis or scrotum. This involved excision of the affected tissue while retaining the scrotal septum, preserving the subcutaneous lymphatic tissue flap, turnover of the perididymis, and primary closure. All patients were examined by MRL to assess the extent of lymphedema pre- and postoperatively. The cosmetic results, recovery of sexual function, patient satisfaction, and complications are discussed.

Results

A total of 40 patients underwent surgical treatment. Scrotal hematoma (2.5%) and poor wound healing (5%) were encountered postoperatively. During follow-up period, no recurrence of edema occurred. The appearance of the scrotum and penis, as well as the sexual function was improved. MRL confirmed tissue edema and lymphatic malformation in the enlarged penis and scrotum preoperatively. In follow-up MRL, new formation or reopen of lymphatic drainage can be detect in 25 (62.5%) patients. All patients showed decreased area of dermal backflow.

Conclusions

Surgical treatment is necessary for genital lymphedema when swelling develops. The use of a retained scrotal septum and subcutaneous lymphatic tissue flaps can achieve improved morphology and function. MRL is a safe and accurate diagnostic imaging method for pre- and postoperative evaluation of lymphedema in patients undergoing lymphatic surgery.

MR Lymphangiography

림프부종의 수술적 치료는 최근 늘어나고 있으며 그에 따른 림프관 평가를 위해 자기공명영상 획득이 증가하고 있다. 전통적인 T2 강조영상에서부터 삼차원 영상에 이르기까지 많은 발전이 이루어지고 있는 분야이다. 삼차원 영상으로는 spoiled gradient echo 영상이 있고 그 변형기법들이 시행되고 있으며 영상에 필수적인 지방억제기법은 최근 mDixon 기법이 각광받고 있다.

Meningeal Lymphatics: A Review and Future Directions From a Clinical Perspective

The recent discovery of lymphatic vessels in the meningeal layers calls into question the known mechanisms of fluid and macromolecule homeostasis and immunoregulation within the central nervous system. These meningeal lymphatic vessels and their potential role in the pathophysiology of neurological disease have become a rapidly expanding area of research, with the hopes that they may provide a novel therapeutic target in the treatment of many devastating conditions. This article reviews the current state of knowledge surrounding the anatomical structure of the vessels, their functions in fluid and solute transport and immune surveillance, as well as their studied developmental biology, relationship with the novel hypothesized “glymphatic” system, and implications in neurodegenerative disease in animal models. Furthermore, this review summarizes findings from the human studies conducted thus far regarding the presence, anatomy, and drainage patterns of meningeal lymphatic vessels and discusses, from a clinical perspective, advancements in both imaging technologies and interventional methodologies used to access ultrafine peripheral lymphatic vessels.

Correlation between superficial and deep lymphatic systems using magnetic resonance lymphangiography in breast cancer-related lymphedema: Clinical implications

BACKGROUND

Magnetic resonance lymphangiography (MRL) has increased our knowledge of lymphatic anatomy and lymphedema pathophysiology and improved the efficacy of microsurgical procedures to manage peripheral lymphedema. The aim of this study is to investigate the ability of MRL to detect communications between superficial and deep lymphatic systems in breast cancer-related lymphedema (BRCL) and to investigate whether these communications could preserve lymphatic drainage of the hand.

METHODS

Between 2008 and 2017 we used MRL imaging in 59 women with BCRL. Lymphedema of the arm and hand was detected in 30 patients while the hand was spared in 29. Using axial and coronal MRL reconstruction images we investigated the existence of any communication between the superficial and deep lymphatic systems.

RESULTS

Among the 29 patients with spared hand, MRL revealed that 24 had at least one communicating lymphatic perforator at the wrist region (p < 0.001). Lymphatic flow at the axilla was clearly visualized in 16 of the 29 patients (55.2%), no perforating lymphatic vessels were detected in the group with lymphedema in the hand (30 patients).

CONCLUSIONS

Communications between the deep and superficial lymphatic systems at the wrist region in BCRL patients without hand lymphedema should be considered when planning microsurgical lymphatic procedures at the wrist and in postoperative compression therapy.

Development and Themes of Diagnostic and Treatment Procedures for Secondary Leg Lymphedema in Patients with Gynecologic Cancers

Patients with leg lymphedema sometimes suffer under constraint feeling leg heaviness and pain, requiring lifelong treatment and psychosocial support after surgeries or radiation therapies for gynecologic cancers. We herein review the current issues (a review of the relevant literature) associated with recently developed diagnostic procedures and treatments for secondary leg lymphedema, and discuss how to better manage leg lymphedema. Among the currently available diagnostic tools, indocyanine green lymphography (ICG-LG) can detect dermal lymph backflow in asymptomatic legs at stage 0. Therefore, ICG-LG is considered the most sensitive and useful tool. At symptomatic stage ≥1, ultrasonography, magnetic resonance imaging-lymphography/computed tomography-lymphography (MRI-LG/CT-LG) and lymphosintiography are also useful. For the treatment of lymphedema, complex decongestive physiotherapy (CDP) including manual lymphatic drainage (MLD), compression therapy, exercise and skin care, is generally performed. In recent years, CDP has often required effective multi-layer lymph edema bandaging (MLLB) or advanced pneumatic compression devices (APCDs). If CDP is not effective, microsurgical procedures can be performed. At stage 1–2, when lymphaticovenous anastomosis (LVA) is performed, lymphaticovenous side-to-side anastomosis (LVSEA) is principally recommended. At stage 2–3, vascularized lymph node transfer (VLNT) is useful. These ingenious procedures can help maintain the patient’s quality of life (QOL) but unfortunately cannot cure lymphedema. The most important concern is the prevention of secondary lymphedema, which is achieved through approaches such as skin care, weight control, gentle limb exercises, avoiding sun and heat, and elevation of the affected leg.

Magnetic Resonance Lymphography of Lymphatic Vessels in Upper Extremity With Breast Cancer-Related Lymphedema

BACKGROUND

Magnetic resonance lymphangiography (MRL) has been proven to be able to visualize pathological lymphatic networks and accompanying complications through subcutaneous injection of commonly used contrast agents. However, no comprehensive prior studies have previously been reported regarding MRL for the evaluation of upper extremity lymphedema in patients with breast cancer-related lymphedema (BCRL). In this study, we establish a novel MRL protocol to characterize the normal and abnormal characteristics of different clinical stages of BCRL in patients using high-spatial-resolution MRL.

METHODS

Fifty females with unilateral upper extremity BCRL underwent MRL. Lymphatic vessel morphology in normal and affected limbs was compared. The appearance, distribution pattern, morphologic characteristics, and maximum transversal diameter of the lymphatic vessels, dermal backflow, and regeneration of lymphatic vessels were analyzed.

RESULTS

Lymph fluid was retained in the subcutis of the affected limbs, and no edema was observed in the subfascial compartment. In stage 1, tortuous and dilated lymphatic vessels exhibited a beaded appearance, and their diameters were larger than those in the contralateral forearm (P < 0.05). In stage 2, the dilated lymphatic vessels exhibited larger diameters. "Dermal backflow" and tiny regenerated lymphatic vessels appeared. The thickened subcutaneous tissue showed a honeycomb pattern induced by soft tissue fibrosis and adipose hypertrophy. In stage 3, disordered and unrecognizable affected lymphatic vessels were observed with many small regenerated lymphatics and confluent dermal backflow; the tissue fibrosis was more serious.

CONCLUSIONS

Each stage presents different characteristics, and the deformity degree of the lymphatic network is consistent with the severity of the disease. Magnetic resonance lymphangiography could provide adequate information for clinical staging in patients with BCRL.

[The set of International Classification of Functioning, Disability and Health categories for the study of the effectiveness of rehabilitation of breast cancer patients with the main late complications of the surgical treatment]

The author selected the set of ICF (International Classification of Functioning, Disability and Health) categories selected for breast cancer patients presenting with the major late complications of the surgical treatment, such as upper limp lymphedema, pain syndrome, and mobility limitation in the shoulder joint on the side of the intervention. The problems associated with each component of ICF are described including the body functions - 26 categories, body structures - 15, activities and participation - 49, environmental factors - 31 categories. The author's original classifications are adapted to the ICF terminology. The criteria for estimating the determinants of the structure of spinal nerves, lymph nodes and vessels, veins, the mammary gland, upper extremities, muscles of the trunk, the skin and the related structures have been developed. All the changes in the body functions are described and the methods are proposed for the evaluation of the determinants or the mental and sensory functions, the cardiovascular, immune and respiratory systems, neuromuscular and skeletal functions, the functions of the skin and the related structures. The principles of coding for the components of activity and participation are illustrated (general tasks and requirements, mobility, self-service, everyday life, interpersonal interactions and relationships, main spheres of life, community life, social and civil life) and the environmental factors. The coding is presented in the form of detailed and readily intelligible tables with the explanatory remarks.

Preoperative planning of lymphaticovenous anastomosis: The use of magnetic resonance lymphangiography as a complement to indocyanine green lymphography

BACKGROUND

Lymphaticovenous anastomosis (LVA) is a surgical treatment for lymphedema that requires identification and mapping of functional lymphatic channels. This technique was performed blindly for years because of the lack of suitable methods of study. Progress in imaging techniques and the introduction of Indocyanine green lymphography (ICG-L) represented a significant advancement in lymphedema management. Magnetic resonance lymphangiography (MRL) has also helped improve knowledge about lymphedema anatomy and pathophysiology. We now present our protocol based on both ICG-L and MRL for optimal LVA preoperative planning.

METHODS

A prospective study between April 2010 and June 2015 was conducted in 82 patients (77 females, mean age 45.5 years) with stage I (9.8%), II (73.2%), and III (17.0%) lymphedema. All patients underwent lymphedema surgical treatment with LVA. Surgery was planned based on preoperative information from ICG- L and MRL.

RESULTS

We obtained a mean of 6.87 lymphatic locations per extremity from MRL and selected a mean of 4.04 for LVA. When MRL data coincided with ICG-L data, we found a functional lymphatic vessel in 96.9% of cases and performed LVA successfully in 91.4%.

CONCLUSIONS

ICG-L and MRL are noninvasive techniques that provide images of the lymphatic system with sufficient temporal and spatial resolution to depict functional lymphatic vessels. Such knowledge is essential for preoperative planning of LVA microsurgery. We present our protocol for the approach of surgical treatment of lymphedema. This protocol represents a step forward in unifying patient selection criteria and achieving safe, effective, and rational surgery.

A Review of Lymphedema for the Hand and Upper-Extremity Surgeon

Secondary lymphedema of the upper limb is frequently seen in Western countries after cancer treatment (most often breast in women). It is a chronic disease that affects quality of life and functioning. In its extreme form, it may be debilitating. A review is given of the pathology, nonsurgical treatment, and surgical treatment with a protocol.

Patterns of lymphatic drainage after axillary node dissection impact arm lymphoedema severity: A review of animal and clinical imaging studies

Upper extremity lymphoedema after axillary node dissection is an iatrogenic disease particularly associated with treatment for breast or skin cancer. Anatomical studies and lymphangiography in healthy subjects identified that axillary node dissection removes a segment of the lymphatic drainage pathway running from the upper limb to the sub-clavicular vein, creating a surgical break. It is reasonable to infer that different patterns of lymphatic drainage may occur in the upper limb following surgery and contribute to the various presentations of lymphoedema from none to severe. Firstly, we reviewed animal imaging studies that investigated the repair of lymphatic drainage pathways from the limb after lymph node dissection. Secondly, we examined clinical imaging studies of lymphatic drainage pathways after axillary node dissection, including lymphangiography, lymphoscintigraphy and indocyanine green fluorescence lymphography. Finally, based on the gathered data, we devised a set of general principles for the restoration of lymphatic pathways after surgery. Lymphoscintigraphy shows that restoration of the original lymphatic pathway to the axilla after its initial disruption by nodal dissection was not uncommon and may prevent lymphoedema. We found that regenerated lymphatic vessels and dermal backflow (the reflux of lymph to the skin) contributed to either restoration of the original pathway or rerouting of the lymphatic pathway to other regional nodes. Variation in the lymphatic drainage pathway and the mechanisms of fluid drainage itself are the foundation of new lymphatic drainage patterns considered to be significant in determining the severity with which lymphoedema develops.

MR lymphography in patients with upper limb lymphedema: The GPS for feasibility and surgical planning for lympho-venous bypass

BACKGROUND AND OBJECTIVES

Lymphedema is caused by insufficient lymphatic drainage leading to abnormal accumulation of interstitial fluid within soft tissues. Lympho-venous anastomosis (LVA), as a surgical option for selected patients, is widely applied. Through preoperative localization of functional lymphatics with indocyanine green, real time visualization of functioning lymphatic vessels is possible. This examination is time consuming and operator dependant and is not suitable to differentiate the ratio of fat hypertrophy to liquid edema. We investigated whether MR lymphangiography is accurate for imaging functional lymphatics and adjacent veins in arms. Furthermore, we investigated the accuracy and predictability of preoperative mapping for the feasibility of performing LVA and the preoperative decision making in lymphedema surgery.

METHODS

A prospective study was performed in which 25 patients suffering from lymphedema of the upper extremity were examined. MR lymphography with contrast agent injection in a deep dermal plane was performed.

RESULTS

Precise localization of lymphatic vessels crossing a vein was achieved in 18 of 25 arms. In 16 of the 18 patients in whom functional lymphatics were localized with an adjacent vein on MRI an LVA was performed successfully.

CONCLUSIONS

MR lymphangiography is an accurate and reproducible method for imaging and mapping of lymphatic channels in the lymphedemateous limb.

Imaging lymphatics in human normal and lymphedema limbs-Usefulness of various modalities for evaluation of lymph and edema fluid flow pathways and dynamics

The human lymphatic system morphology and function still remain largely unknown to clinicians and biologists. How does the lymphatic vascular system look like in comparison to the blood transport system, how does lymph flow, where does capillary filtrate accumulate in cases with lymphatic obstruction caused by inflammation, trauma, and cancer therapy, remain as basic questions. Visualization of the lymphatic pathways and dynamics of lymph flow, and in cases of obstruction, the localization of the capillary filtrate/edema fluid accumulation becomes indispensable. The contemporary methods only partly meet these requirements. Since the early 1950s of the 20th century only few specific clinical methods of imaging of limb lymphatics are being used in human clinic. Each of the applied modalities provides different images due to different physical chemistry and distribution of tracer, methods used for its detection in tissues, their sensitivity and specificity and clinical type of lymph vessel pathology. Here, the advantages and disadvantages of the most commonly used 3 methods of imaging: the iodinated oil X-ray, isotopic, and fluorescent lympangiographies are presented. The study is based on retrospective and recent collections of lymphangiograms from large cohorts of patients. Imaging of lymph nodes has not been included as it is requiring different interpretation compared with vessels. Composite evaluation of X-ray, isotopic, and fluorescent lymphographic images or, as it is practiced now the isotope and indocyanine green near infrared lymphographies, provide most clinically important information. Special attention was directed at methods enabling early diagnosis of imminent lymphedema especially in cases with cancer therapy-related lymphedema. Groups of typical images obtained with the 3 methods are presented.

Primary lower limb lymphoedema: classification with non-contrast MR lymphography

PURPOSE

The purpose of the present study was to analyse the performance of non-contrast MR lymphography for the classification of primary lower limb lymphoedema in 121 consecutive patients with 187 primary lower limb lymphoedemas.

MATERIALS AND METHODS

121 consecutive patients with clinically diagnosed primary lower limb lymphoedema underwent non-contrast MR lymphography with a free-breathing 3D fast spin-echo sequence with a very long TR/TE (4000/884 ms). MR examinations were retrospectively reviewed for severity of lymphoedema (absent, mild, moderate, severe) and characteristics of inguinal lymph nodes and iliac and inguinal lymphatic trunks graded as aplasic (no lymph nodes or lymphatic trunks), hypoplasic (less lymph nodes or lymphatic trunks), normal and hyperplasic (more lymph nodes or more and/or dilated trunks).

RESULTS

There was an excellent correlation between clinical stage and severity of lymphoedema (Cramer's V of 0,73 (p < 0.001)). Differentiation was feasible between inguinal lymphatic vessel aplasia (21%), hypoplasia (15%), normal pattern (53%) and hyperplasia (11%). Severe lymphoedema was observed in 46% of aplasic patterns and in 37% of hyperplasic patterns, but in only 15% of hypoplasic patterns and never observed in normal patterns (p < 0.001).

CONCLUSION

Non-contrast MR lymphography is able to classify primary lower limb lymphoedemas into hyperplasic, aplasic, hypoplasic and normal patterns.

KEY POINTS

• Non-contrast MR lymphography is able to classify primary lower limb lymphoedemas. • Lymphoedema can be classified in hyperplasic, aplasic, hypoplasic and normal patterns. • Non-contrast MR lymphography can optimize clinical management of primary lower limb lymphoedemas.

MR Lymphangiography: A Practical Guide to Perform It and a Brief Review of the Literature from a Technical Point of View

We propose a practical approach for performing high-resolution MR lymphangiography (MRL). We shall discuss and illustrate the technical approach for the visualization of lymphatic vessels in patients suffering from lymphedema, how to distinguish lymphatic vessels from veins, and MRL role in supermicrosurgery treatment planning. A brief review of literature, from a technical point of view, is also reported.

Peripheral Magnetic Resonance Lymphangiography: Techniques and Applications

Peripheral lymphedema is a chronic progressive and debilitating disorder that results from abnormal lymphatic drainage. Advances in microsurgical techniques have led to the development of new treatment options for lymphedema that benefit from preoperative imaging to select the most appropriate surgical repair. Magnetic resonance (MR) lymphangiography is a noninvasive imaging modality capable of providing high-resolution 3D images of the lower extremities to define the severity and extent of lymphedema and depict individual lymphatic channels. The MR examination consists of 2 primary sequences. The first is a 3D heavily T2-weighted sequence to depict the severity and extent of the lymphedema. The second is a fat-suppressed 3D spoiled gradient-echo sequence performed after the intracutaneous injection of an extracellular gadolinium-based MR contrast agent. As venous enhancement almost always occurs, one of the interpretative challenges is differentiating enhancing lymphatic channels from superficial veins. MR techniques that can help with venous contamination include the addition of a contrast-enhanced MR venogram to the examination protocol, or the use of an iron-based blood-pool contrast agent to selectively suppress venous enhancement.

Assessment of The Lymphatic System of the Genitalia Using Magnetic Resonance Lymphography Before and After Treatment of Male Genital Lymphedema

Treatment for chronic male genital lymphedema (GL) is limited. No standard treatment or validated instrument to assess GL is available. The aim of this study was to explore whether magnetic resonance lymphography (MRL) could be used to assess GL, select proper treatment for patients, and monitor postoperative progress.This is a retrospective analysis of a prospectively acquired cohort of men with GL presenting for MRL over a 7-year period. Thirty-six of 47 eligible men were included. All men were offered preoperative and postoperative MRL and assigned a morphology and function classification. Men with mild, moderate, and severe nodal dysfunction underwent complex decongestive physiotherapy (CDP), lymphoveneous microsurgery, and surgical excision, respectively. The volume reductions in the genitalia of patients with mild and moderate nodal dysfunction were recorded and compared using Student t test.The abnormal superficial and deep lymphatic vessels in the lymphedematous genitalia were detected by MRL, and inguinal lymph node dysfunction was classified by MRL. Seven patients with mild dysfunction who underwent CDP showed a more significant mean volume reduction in the genitalia than did 9 patients with moderate dysfunction. Three patients with hyperplasia and moderate dysfunction who underwent microsurgical operations and 17 patients with hypoplasia and moderate or severe nodal dysfunction who underwent surgical excision had excellent cosmetic results with no lymphedema at the 3- to 5-year follow-up.MRL can be used to assess morphological and functional lymphatic abnormalities in GL, preoperatively select appropriate treatment, and postoperatively evaluate treatment outcomes.

Lymphatic mapping and preoperative imaging in the management of post-mastectomy lymphoedema

Early detection and diagnosis of upper extremity lymphoedema in patients after mastectomy and axillary lymph node clearance is important in order to treat disease before it is too advanced to achieve favourable outcomes. Patients with disease refractory to conservative management can be efficiently assessed for diagnosis and surgical intervention using advanced lymphatic imaging techniques. The current paper highlights the more readily available of these: lymphoscintigraphy, indocyanine green (ICG) lymphangiography and immunofluorescence, magnetic resonance lymphangiography (MRL) and computed tomographic lymphangiography in combination or individually. With such techniques, both diagnosis and treatment of lymphoedema has become more readily achieved, with lymphatico-venous and lymphatico-lymphatic anastomosis, and lymph node transfer now increasingly common undertakings.