Evidence of stage progression in a novel, validated fluorescence-navigated and microsurgical-assisted secondary lymphedema rodent model

Abstract

Secondary lymphedema (SL)is a frequent and devastating complication of modern oncological therapy and filarial infections. A lack of a reliable preclinical model to investigate the underlying mechanism of clinical stage progression has limited the development of new therapeutic strategies. Current first line treatment has shown to be merely symptomatic and relies on lifetime use of compression garments and decongestive physiotherapy. In this study, we present the development of a secondary lymphedema model in 35 rats using preand intraoperative fluorescence-guided mapping of the lymphatics and microsurgical induction. In contrast to the few models reported so far, we decided to avoid the use of radiation for lymphedema induction. It turned out, that the model is nearly free of complications and capable of generating a statistically significant limb volume increase by water displacement measurements, sustained for at least 48 days. A translational, accurate lymphatic dysfunction was visualized by a novel VIS-NIR X-ray ICG-Clearance-Capacity imaging technology. For the first-time SL stage progression was validated by characteristic histological alterations, such as subdermal mast cell infiltration, adipose tissue deposition, and fibrosis by increased skin collagen content. Immunofluorescence confocal microscopy analysis suggested that stage progression is related to the presence of a characteristic α SMA + /HSP-47 + /vimentin + fibroblast subpopulation phenotype. These findings demonstrate that the invivo model is a reliable and clinically relevant SL model for the development of further secondary lymphedema therapeutic strategies and the analysis of the veiled molecular mechanisms of lymphatic dysfunction.

Establishment of a Simple, Reproducible, and Long-lasting Hind Limb Animal Model of Lymphedema

“…Most published lymphedema animal models have incorporated a combination of circumferential incision of the skin with fascia fixation, ligation or ablation of lymphatic vessels, lymph node dissection, and/or irradiation. 1,2,[11][12][13][14][15][16] Although these measures are potent and critical for induction of lymphedema, few publications reported maintaining lymphedema for over a month without irradiation or dressing. We therefore aimed to develop a simple but reliable and long-lasting hind limb lymphedema model that would reflect the dynamics of foot lymphedema induced by surgery for malignant diseases such as uterine and ovarian cancer 18 and be easy to reproduce and apply widely.…”

“…Although lymphedema is generally not life-threatening, management of this condition is crucial because it impairs the quality of life of affected individuals. The current standard therapy for lymphedema is a combination of decompression therapies 1 ; however, the therapeutic effects are unsatisfactory. 2 The potentially useful radical therapy of mesenchymal stem cell (MSC) transplantation has been discussed.…”

“… 7 Furthermore, irradiation injures healthy soft tissue and skin, interfering with tissue repair. 1 , 8 Therefore, a better animal model with long-lasting lymphedema that can be created by a simple procedure would contribute to establishing curative and radical therapy for this disease and alleviate many patients’ troublesome symptoms. In this study, we aimed to establish a simple and reproducible mouse model of long-lasting lymphedema.…”

Evidenz der modernen Diagnostik, der konservativen und chirurgischen Therapie des sekundären Lymphödems

“…Die frühzeitige Diagnose und Therapie des SL hat zum Ziel, klinisch die trophischen Veränderungen und bildgebend die direkten Schädigungen des Lymphgefäßsystems zu erkennen und stadienabhängig zu therapieren, um den Krankheitsverlauf des Gewebeumbaus zu verzögern zum Stillstand zu bringen oder sogar reversible Mechanismen zu initiieren [13]. Die progrediente Umgestaltung von Haut und Unterhaut ist in lymphödemspezifischen Tiermodellen bis hin zu Patientenproben grundlegend charakterisiert worden und zeigt Fibrosierung, Anreicherung von Fettgewebe und selektive Akkumulation von Immunzell-Subpopulationen [14]. Das klinische Bild geht einher mit diesem Gewebeveränderungen und fließt in die Klassifikation der Stadien ein [2] (▶ Abb.…”

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

“…Furthermore, long-term lymphedema can induce angiosarcoma, a malignant tumor derived from vascular and lymphatic endothelial cells (LECs) 7 . The current standard therapy for lymphedema is a combination of decompression therapies, including skin care, manual lymphatic drainage, compression using elastic stockings, and exercise 8 . However, these therapies are only palliative, and the therapeutic effects are unsatisfactory 9 .…”