Meningeal lymphatic supporting cells govern the formation and maintenance of zebrafish mural lymphatic endothelial cells.

The meninges are critical for the brain functions, but the diversity of meningeal cell types and intercellular interactions have yet to be thoroughly examined. Here we identify a population of meningeal lymphatic supporting cells (mLSCs) in the zebrafish leptomeninges, which are specifically labeled by ependymin. Morphologically, mLSCs form membranous structures that enwrap the majority of leptomeningeal blood vessels and all the mural lymphatic endothelial cells (muLECs). Based on its unique cellular morphologies and transcriptional profile, mLSC is characterized as a unique cell type different from all the currently known meningeal cell types. Because of the formation of supportive structures and production of pro-lymphangiogenic factors, mLSCs not only promote muLEC development and maintain the dispersed distributions of muLECs in the leptomeninges, but also are required for muLEC regeneration after ablation. This study characterizes a newly identified cell type in leptomeninges, mLSC, which is required for muLEC development, maintenance, and regeneration.

[Imaging for displaying lymphatic vessels in whole-mount aorta adventitia of ApoE-/- mice by immunofluorescent histochemical staining].

Objective To explore a simple and feasible method for whole-mount immunofluorescence staining of lymphatic vessels in the ApoE-/- mouse model of atherosclerosis. Methods Aortic specimens were carefully excised from the ApoE-/- mouse model. Following immunostaining with specific antibodies against smooth muscle actin (SMA) and lymphatic vessel endothelial receptor 1 (LYVE1), the aortas, including the aortic root, were subjected to a 30-minute treatment with 5 g/L Sudan Black B solution. This step was instrumental in minimizing the autofluorescent background of the tissue. Thereafter, the aortas were processed through a clearing protocol and imaged within a purpose-built chamber under a fluorescence microscope. Results The pretreatment with 5 g/L Sudan Black B effectively suppressed the autofluorescent signals emanating from the vascular structures, thereby enhancing the contrast and clarity of the specific fluorescence signals associated with the lymphatic vessels. This enhancement in signal quality did not compromise the integrity or specificity of the immunofluorescent markers. Conclusion A facile, highly specific, and effective approach for the visualization of lymphatic vessels in whole-mount aortic preparations from ApoE-/- mice is established.

An arabinogalactan isolated from Cynanchum atratum promotes lymphangiogenesis and lymphatic vessel remodeling to alleviate secondary lymphedema.

Secondary lymphedema is a chronic and incurable disease lacking satisfactory therapeutic drugs. It primarily results from lymphatic vessel dysfunction resulting from factors such as tumor-related surgery, injury, or infection. Promoting lymphangiogenesis and lymphatic vessel remodeling is crucial for restoring tissue fluid drainage and treating secondary lymphedema. In this study, we discovered that the oral administration of a type-II arabinogalactan (CAPW-1, molecular weight: 64 kDa) significantly promoted lymphangiogenesis and alleviated edema in mice with secondary lymphedema. Notably, the tail diameter of the CAPW-1200 group considerably decreased in comparison to that of the lymphedema group, with an average diameter difference reaching 0.98 mm on day 14. CAPW-1 treatment also reduced the average thickness of the subcutaneous area in the CAPW-1200 group to 0.37 mm (compared with 0.73 mm in the lymphedema group). It also facilitated the return of injected indocyanine green (ICG) from the tail tip to the sciatic lymph nodes, indicating that CAPW-1 promoted lymphatic vessel remodeling at the injury site. In addition, CAPW-1 enhanced the proliferation and migration of lymphatic endothelial cells. This phenomenon was associated with the activation of the toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway, thereby promoting the expression of vascular endothelial growth factor-C (VEGF-C), which can be abolished using a TLR4 antagonist. Despite these findings, CAPW-1 did not alleviate the symptoms of lymphedema or restore lymphatic drainage in VEGFR3flox/flox/Prox1-CreERT2 mice. In summary, CAPW-1 alleviates secondary lymphedema by promoting lymphangiogenesis and lymphatic vessel remodeling through the activation of the TLR4/NF-κB/VEGF-C signaling pathway, indicating its potential as a therapeutic lymphangiogenesis agent for patients with secondary lymphedema.

Lymphatic vessel transit seeds cytotoxic resident memory T cells in skin draining lymph nodes.

Lymphatic transport shapes the homeostatic immune repertoire of lymph nodes (LNs). LN-resident memory T cells (TRMs) play an important role in site-specific immune memory, yet how LN TRMs form de novo after viral infection remains unclear. Here, we tracked the anatomical distribution of antiviral CD8+ T cells as they seeded skin and LN TRMs using a model of vaccinia virus-induced skin infection. LN TRMs localized to the draining LNs (dLNs) of infected skin, and their formation depended on the lymphatic egress of effector CD8+ T cells from the skin, already poised for residence. Effector CD8+ T cell transit through skin was required to populate LN TRMs in dLNs, a process reinforced by antigen encounter in skin. Furthermore, LN TRMs were protective against viral rechallenge in the absence of circulating memory T cells. These data suggest that a subset of tissue-infiltrating CD8+ T cells egress from tissues during viral clearance and establish a layer of regional protection in the dLN basin.

Pedicled SCIP-based vascularized lymphnode and lymphatic vessels transfer (VLNT and VLVT) for deep lymphatic system reconstruction and dead space obliteration after medial thigh sarcoma resection: A case report.

Soft-tissue sarcomas represent a cohort of rare and heterogeneous malignant tumors that could affect various body parts, with a higher incidence in the lower extremity. When these tumors are surgically removed, both the superficial and deep lymphatic pathways could also be damaged and might require immediate reconstruction to prevent lymphatic complications. In the present report, we describe a case of a patient affected by a high-grade (G3) spindle cell pleomorphic rhabdomyosarcoma of the upper medial thigh. A 22 × 20 cm mass was removed with exposure of the deep femoral vessels and the great saphenous vein. After intraoperative indocyanine green lymphography, it was determined that the superficial lymphatic vessels were intact, but the deep lymphatic system was unavoidably damaged. As a reconstructive procedure, we performed a pedicled SCIP-based vascularized lymphatic vessel transfer and vascularized lymph node transfer to restore the deep lymphatic system and dead space obliteration. The procedure was successful, and no signs of lymphatic impairment were observed during the two-year follow-up period. We believe that this novel approach might be helpful in cases of large and profound defects that involve the deep lymphatic system. The combination of these two techniques could help restore deep lymph drainage, minimizing the risk of superficial system overload and lymphatic dysfunction. No other cases have been described so far employing the same approach. Considering the obtained results, this procedure might be worth further investigation.

Combination of tumor antigen drainage and immune activation to promote a cancer-immunity cycle against glioblastoma.

While conventional cancer modalities, such as chemotherapy and radiotherapy, act through direct killing of tumor cells, cancer immunotherapy elicits potent anti-tumor immune responses thereby eliminating tumors. Nevertheless, promising outcomes have not been reported in patients with glioblastoma (GBM) likely due to the immune privileged status of the central nervous system and immunosuppressive micro-environment within GBM. In the past years, several exciting findings, such as the re-discovery of meningeal lymphatic vessels (MLVs), three-dimensional anatomical reconstruction of MLV networks, and the demonstration of the promotion of GBM immunosurveillance by lymphatic drainage enhancement, have revealed an intricate communication between the nervous and immune systems, and brought hope for the development of new GBM treatment. Based on conceptual framework of the updated cancer-immunity (CI) cycle, here we focus on GBM antigen drainage and immune activation, the early events in driving the CI cycle. We also discuss the implications of these findings for developing new therapeutic approaches in tackling fatal GBM in the future.

Congenital Vascular and Lymphatic Diseases.

Over the past several centuries, the integration of contemporary medical techniques and innovative technologies, like genetic sequencing, have played a pivotal role in enhancing our comprehension of congenital vascular and lymphatic disorders. Nonetheless, the uncommon and complex characteristics of these disorders, especially considering their formation during the intrauterine stage, present significant obstacles in diagnosis and treatment. Here, we review the intricacies of these congenital abnormalities, offering an in-depth examination of key diagnostic approaches, genetic factors, and therapeutic methods.

Preliminary report of a thoracic duct-to-pulmonary vein lymphovenous anastomosis in swine: A novel technique and potential treatment for lymphatic failure.

OBJECTIVE: The thoracic duct is the largest lymphatic vessel in the body, and carries fluid and nutrients absorbed in abdominal organs to the central venous circulation. Thoracic duct obstruction can cause significant failure of the lymphatic circulation (i.e., protein-losing enteropathy, plastic bronchitis, etc.). Surgical anastomosis between the thoracic duct and central venous circulation has been used to treat thoracic duct obstruction but cannot provide lymphatic decompression in patients with superior vena cava obstruction or chronically elevated central venous pressures (e.g., right heart failure, single ventricle physiology, etc.). Therefore, this preclinical feasibility study sought to develop a novel and optimal surgical technique for creating a thoracic duct-to-pulmonary vein lymphovenous anastomosis (LVA) in swine that could remain patent and preserve unidirectional lymphatic fluid flow into the systemic venous circulation to provide therapeutic decompression of the lymphatic circulation even at high central venous pressures. METHODS: A thoracic duct-to-pulmonary vein LVA was attempted in 10 piglets (median age 80 [IQR 80-83] days; weight 22.5 [IQR 21.4-26.8] kg). After a right thoracotomy, the thoracic duct was mobilized, transected, and anastomosed to the right inferior pulmonary vein. Animals were systemically anticoagulated on post-operative day 1. Lymphangiography was used to evaluate LVA patency up to post-operative day 7. RESULTS: A thoracic duct-to-pulmonary vein LVA was successfully completed in 8/10 (80.0%) piglets, of which 6/8 (75.0%) survived to the intended study endpoint without any complication (median 6 [IQR 4-7] days). Initially, 2/10 (20.0%) LVAs were aborted intraoperatively, and 2/10 (20.0%) animals were euthanized early due to post-operative complications. However, using an optimized surgical technique, the success rate for creating a thoracic duct-to-pulmonary vein LVA in six animals was 100%, all of which survived to their intended study endpoint without any complications (median 6 [IQR 4-7] days). LVAs remained patent for up to seven days. CONCLUSION: A thoracic duct-to-pulmonary vein LVA can be completed safely and remain patent for at least one week with systemic anticoagulation, which provides an important proof-of-concept that this novel intervention could effectively offload the lymphatic circulation in patients with lymphatic failure and elevated central venous pressures.

Lymphaticovenous anastomosis map established using lymphatic ultrasound and multi-lymphosome indocyanine green lymphography.

BACKGROUND: Although the usefulness of lymphaticovenous anasotmosis (LVA) for lymphedema has been reported, it is difficult to determine where the LVA is to be performed, especially for inexperienced surgeons. This study aimed to establish a map of the LVA site. METHOD: A total of 105 limbs from 64 patients who underwent lower limb LVA were retrospectively reviewed. Multi-lymphosome indocyanine green (ICG) lymphography (in 35 patients) and lymphatic ultrasound (in all patients) were performed preoperatively and the incision site was determined where dilated lymph vessels and appropriate veins were located in close proximity. The LVA location was identified using a post-operative photograph. Additionally, the degree of lymphatic degeneration at the LVA site was recorded based on the normal, ectasis, contraction, and sclerosis type (NECST) classification. RESULT: A total of 206 skin incisions were analyzed. Among them, 161 (75.9%) were medial and 45 (21.2%) were lateral. Among the 85 sites on the calf, 52 (61.2%) were medial and 33 (38.8%) were lateral. Among the 117 sites on the thigh, 106 (90.6%) were medial and 11 (9.4%) were lateral. As the severity of lymphedema progressed, the probability of performing LVA on the lateral calf increased. Among the 202 locations where LVA was performed on the thigh and lower leg, ectasis type was found in 164 sites (81.2%). CONCLUSION: We established an LVA map of the legs based on multi-lymphosome ICG lymphography and lymphatic ultrasound data. Using this LVA map, surgeons can easily predict the location of lymph vessels, thereby improving the success rate of LVA.

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

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

Zmiz1 is a novel regulator of lymphatic endothelial cell gene expression and function.

Zinc Finger MIZ-Type Containing 1 (Zmiz1), also known as ZIMP10 or RAI17, is a transcription cofactor and member of the Protein Inhibitor of Activated STAT (PIAS) family of proteins. Zmiz1 is critical for a variety of biological processes including vascular development. However, its role in the lymphatic vasculature is unknown. In this study, we utilized human dermal lymphatic endothelial cells (HDLECs) and an inducible, lymphatic endothelial cell (LEC)-specific Zmiz1 knockout mouse model to investigate the role of Zmiz1 in LECs. Transcriptional profiling of ZMIZ1-deficient HDLECs revealed downregulation of genes crucial for lymphatic vessel development. Additionally, our findings demonstrated that loss of Zmiz1 results in reduced expression of proliferation and migration genes in HDLECs and reduced proliferation and migration in vitro. We also presented evidence that Zmiz1 regulates Prox1 expression in vitro and in vivo by modulating chromatin accessibility at Prox1 regulatory regions. Furthermore, we observed that loss of Zmiz1 in mesenteric lymphatic vessels significantly reduced valve density. Collectively, our results highlight a novel role of Zmiz1 in LECs and as a transcriptional regulator of Prox1, shedding light on a previously unknown regulatory factor in lymphatic vascular biology.

Prognostic significance and value of further classification of lymphovascular invasion in invasive breast cancer: a retrospective observational study.

PURPOSE: To investigate the prognostic significance of lymphovascular invasion in invasive breast cancer and the value of using specific vascular endothelial markers to further classify lymphovascular invasion. METHODS: We collected 2124 patients with invasive breast cancer who were hospitalized at the First Hospital of Dalian Medical University from 2012 to 2020. Statistical methods were used to investigate the relationship between lymphovascular invasion and clinicopathological characteristics of breast cancer, and the correlation between lymphovascular invasion on overall survival (OS) and disease-free survival (DFS) of various categories of breast cancers. Immunohistochemical staining of breast cancer samples containing lymphovascular invasion using specific vascular endothelial markers D2-40 and CD34 was used to classify lymphovascular invasion and to investigate the relationship between lymphovascular invasion and breast cancer progression. RESULTS: There was a high correlation between lymphovascular invasion and T stage, N stage and nerve invasion. Survival analyses showed that patients with lymphovascular invasion, especially luminal B, triple-negative, and Her-2 overexpression breast cancer patients, had poorer OS and DFS prognosis, and that lymphovascular invasion was an independent prognostic factor affecting OS and DFS in breast cancer. The immunohistochemical staining results showed that positive D2-40 staining of lymphovascular invasion was linked to the N stage and localized recurrence of breast cancer. CONCLUSION: Lymphovascular invasion is associated with aggressive clinicopathological features and is an independent poor prognostic factor in invasive breast cancer. Breast cancer localized recurrence rate and lymph node metastases are influenced by lymphatic vessel invasion. Immunohistochemical techniques should be added to the routine diagnosis of lymphovascular invasion.

Borneol regulates meningeal lymphatic valve plasticity to clear Aß aggregates in the prevention of AD-like symptoms.

BACKGROUND: Meningeal lymphatic vessels (mLVs) have great potential to be the therapeutic target for ß Amyloid protein (Aß) clearing in Alzheimer's disease (AD), but the regulatory methods of the mLVs are limited. The lymphatic valve, marked by FOXC2, is the fundamental structure for maintaining stable lymphatic drainage function. Preliminary evidence suggested that borneol (BO) as the classical phytochemicals could enhance the expression of FOXC2 in the mLVs of healthy mice. PURPOSE: This study aims to explore the regulatory ability of BO on lymphatic valves of mLVs in the AD model mice. STUDY DESIGN: We used the intracerebroventricular injection of Aß42 oligomers to construct the AD-like symptoms model induced by toxic protein deposition. We administered BO nano micelles(BO-Ms) orally before and after to simulate the AD prevention and treatment strategy. METHODS: Herein, this study characterized the efficacy and pathways of BO-Ms for regulating mLVs in AD model by Rt-PCR, WB and confocal microscopy, and determined the effects of BO-Ms on Aß clearance, behavior and safety of AD mice. RESULTS: The AD modeling process severely impaired the expression of lymphatic valves. However, after oral administering BO-Ms for prevention and treatment, an increase in the lymphatic valves of the transverse sinus was observed, which derived from the up-regulation of the transcription factor (FOXC2 and Akt) and the down-regulation of the transcription inhibitors (FOXO1 and PRDM1). Furthermore, the effects of BO-Ms on the lymphatic valves could enhance the lymphatic drainage of the mLVs in AD-like mice, promoting the clearance of toxicity aggregates, protecting neurons, and alleviating AD-like symptoms. Simultaneously, continuous oral BO-Ms for 30 days didn't show any significant organ toxicity. The most important thing was that the preventive effect of BO administration was superior to therapeutic administration in all data. CONCLUSION: In summary, our research indicated that BO is a promoter of lymphatic valve formation in the mLVs, and could prevent or repair damage caused by toxic Aß42. BO was the only bioactive natural product with the ability to regulate mLVs valves. Thus, BO has the potential to become phytochemicals for alleviating AD symptoms by enhancing the drainage function of mLVs.

Andrographolide promotes lymphangiogenesis and lymphatic vessel remodeling to alleviate secondary lymphedema.

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

Hyaluronic Acid as a LYVE-1 Receptor Ligand in the Lymphatic System of Healthy Human Skin.

Immunohistochemical detection of the LYVE-1 marker in healthy human full-thickness skin (the epidermis and the dermis) was carried out. LYVE-1 expression was found in the endothelium of lymphatic capillaries located in the papillary dermis, in the endothelium of larger lymphatic vessels of the reticular dermis, and in fibroblasts, which indicates their joint participation in hyaluronan metabolism. LYVE-1+ staining detected for the first time in cells of the stratum basale, the stratum spinosum, and the stratum granulosum of healthy human epidermis indicates their participation in hyaluronan metabolism and allows us to consider the spaces between epidermis cells as prelimphatics.

Quantification of Lymphangiogenesis in the Murine Lymphedema Tail Model Using Intravital Microscopy.

Background: Lymphedema is chronic limb swelling resulting from lymphatic dysfunction. It affects an estimated five million Americans. There is no cure for this disease. Assessing lymphatic growth is essential in developing novel therapeutics. Intravital microscopy (IVM) is a powerful imaging tool for investigating various biological processes in live animals. Tissue nanotransfection technology (TNT) facilitates a direct, transcutaneous nonviral vector gene delivery using a chip with nanochannel poration in a rapid (<100 ms) focused electric field. TNT was used in this study to deliver the genetic cargo in the murine tail lymphedema to assess the lymphangiogenesis. The purpose of this study is to experimentally evaluate the applicability of IVM to visualize and quantify lymphatics in the live mice model. Methods and Results: The murine tail model of lymphedema was utilized. TNT was applied to the murine tail (day 0) directly at the surgical site with genetic cargo loaded into the TNT reservoir: TNTpCMV6 group receives pCMV6 (expression vector backbone alone) (n = 6); TNTProx1 group receives pCMV6-Prox1 (n = 6). Lymphatic vessels (fluorescein isothiocyanate [FITC]-dextran stained) and lymphatic branch points (indicating lymphangiogenesis) were analyzed with the confocal/multiphoton microscope. The experimental group TNTProx1 exhibited reduced postsurgical tail lymphedema and increased lymphatic distribution compared to TNTpCMV6 group. More lymphatic branching points (>3-fold) were observed at the TNT site in TNTProx1 group. Conclusions: This study demonstrates a novel, powerful imaging tool for investigating lymphatic vessels in live murine tail model of lymphedema. IVM can be utilized for functional assessment of lymphatics and visualization of lymphangiogenesis following gene-based therapy.

Immediate lymphatic reconstruction: Lessons learned over eight years.

Immediate lymphatic reconstruction (ILR) is recognized as a surgical approach used to reduce the risk of developing secondary lymphedema, and evidence demonstrating the efficacy of ILR is favorable. Our Lymphatic Center has become a centralized location offering ILR for the risk-reduction in breast cancer-related lymphedema (BCRL) in New England. Over the course of our experience, we made several modifications and adapted our approach to enhance the operative success of this procedure. These include advancements in our use of indocyanine green (ICG) imaging to identify baseline lymphatic anatomical variation, utilization of fluorescein isothiocyanate for lymphatic vessel visualization, application of the lymphosome concept to guide arm injection sites, verification of anastomotic patency (using ICG), localization of reconstruction to guide radiation therapy, incorporation of intraoperative tools to facilitate better anatomic visualization of the axilla, and addition of a lower extremity vein graft to mitigate venous-related complications. Collecting information from each surgery in a standardized manner, including intraoperative lymphatic channel measurements, and deploying clips for possible future radiation exposure, enables future studies on ILR patient outcomes. In this contribution, we aimed to share our institutional modifications with the surgical community to facilitate further adoption, conversation, and advancement of ILR for the risk-reduction in BCRL.

Lymphaticovenous anastomosis in rabbits: A novel live experimental animal model for supermicrosurgical training.

BACKGROUND: Lymphaticovenous anastomosis is widely used in lymphedema management. Although its effectiveness in reducing edema in patients can be clinically observed, evaluating the long-term outcomes of this technique can be complex. This study established an animal model to assess the outcomes of lymphaticovenous anastomosis technique at 15 and 30-days post-surgery using indocyanine green lymphography, Patent Blue V dye injection, and histopathological examination. METHODS: An experimental model was established in the hindlimbs of 10 rabbits using the popliteal vein and afferent lymphatic vessels in the popliteal area. The subjects were divided into two groups: the first group (n = 5) underwent patency assessment at 0 and 15 days, and the second group (n = 5) at 0 and 30-days, resulting in 20 anastomoses. Patency was verified at 0, 15, and 30-days using indocyanine green lymphography and Patent Blue V injection. Histopathological examinations were performed on the collected anastomosis samples. RESULTS: The patency rate was 90% (19/20) initially, 60% (6/10) at 15 days post-surgery, and 80% (8/10) at 30-days. The average diameter of lymphatic vessels and veins was 1.0 mm and 0.8 mm, respectively. The median number of collateral veins was 3; the median surgical time was 65.8 min. Histopathology revealed minimal endothelial damage and inflammatory responses due to the surgical sutures, with vascular inflammation and thrombosis in a single case. Local vascular neoformations were observed. CONCLUSION: This study highlights the reliability and reproducibility of using rabbits as experimental models for training in lymphaticovenous anastomosis technique owing to the accessibility of the surgical site and dimensions of their popliteal vasculature.

Robot-assisted lymphovenous anastomosis surgery for lymphocele in the groin.

We present the first-in-human robot-assisted microsurgery on a lymphocele in the groin involving a man in his late 60s who had been coping with the condition for 12 months. Despite numerous efforts at conservative treatment and surgical intervention, the lymphocele persisted, leading to a referral to our clinic.Diagnostic techniques, including indocyanine green lymphography and ultrasound, identified one lymphatic vessel draining into the lymphocele. The surgical intervention, conducted with the assistance of a robot and facilitated by the Symani Surgical System (Medical Microinstruments, Calci, Italy), involved a lymphovenous anastomosis and excision of the lymphocele. An end-to-end anastomosis was performed between the lymphatic and venous vessels measuring 1 mm in diameter, using an Ethilon 10-0 suture.The surgery was successful, with no postoperative complications and a prompt recovery. The patient was discharged 3 days postoperatively and exhibited complete recovery at the 14-day follow-up. This case marks the first use of robot-assisted microsurgical lymphovenous anastomosis to address a groin lymphocele, highlighting the benefit of advanced robotic technology in complex lymphatic surgeries.

Analysis on efficacy of magnetic resonance lymphangiography using INV-001 in healthy beagle dogs.

We aimed to conduct a proof-of-concept study of INV-001 in visualizing lymphatic vessels and nodes without venous contamination and to determine the optimal dose condition of INV-001 for magnetic resonance lymphangiography (MRL) in healthy beagles. MRL was performed using a 3.0-Tesla (T) whole body clinical magnetic resonance imaging (MRI) scanner. A dose-finding study of INV-001 for MRL in beagles (N = 6) was carried out according to an adaptive optimal dose finding design. For the reproducibility study (N = 6), MRL was conducted at selected INV-001 doses (0.056 and 0.112 mg Fe/kg) with a 15 mM concentration. Additionally, an excretion study (N = 3) of INV-001 was conducted by analyzing T1, T2, and T2* maps of the liver and kidney 48 h post-administration. INV-001 administration at doses of 0.056 and 0.112 mg Fe/kg (concentration: 15 mM) consistently demonstrated the visualization of contrast-enhanced lymphatic vessels and nodes without venous contamination in the beagles. The contrast enhancement effect was highest at 30 min after INV-001 administration, then gradually decreasing. No toxicity-related issues were identified during the study. After 48 h, the T1, T2, and T2* values in the liver and both kidneys were found to be comparable to the pre-administration values, indicating thorough INV-001 excretion. The optimal dosing conditions of INV-001 for MRL for contrast-enhanced visualization of lymphatic vessels and nodes exclusively with no venous contamination in beagles was determined to be 0.056 mg Fe/kg with a 15 mM concentration.