Experimental Study On The MR Interstitial Lymphangiography In Experimental Monkey Upper Limb Secondary Lymphedema

Background and ObjectiveLymphedema is a systemic,chronic,progressing,debilitating condition that always been seen as refractory or incurable. Lymphedema can be divided into Primary lymphedema and Secondary lymphedema.Primary lymphedema is the result of the lymphatic malformations at the later stage of lymphatic generation. The Primary lymphedema is a lymphedema that also not been fully identified and also includes other types of causes. Most people think that Primary lymphedema is congenital.Because the majority of Primary lymphedema patients has the birth defects of the lymphatic system, including lymphatic channels and lymph node defects. However, not all Primary lymphedema lymphatic system have defects in the anatomical structure. Secondary lymphedema is due to the obstruction or interruption of the lymphatic system, which occur in the tumor, surgery, trauma, infection, inflammation and radiation therapy.Lymphedema has important implications on the limb function, the quality of life. The incidence of breast cancer increased year by year, postmastectomy upper limb lymphedema gradually become the focus of current research. Secondary lymphedema is a type of lymphedema and is a progressive pathological state of the lymphatic system. In clinical cancer(breast cancer, pelvic cancer), because of the cleaning of the lymphatic drainage area, the drainage of the limb lymphatic is blocked, so a large number of protein-containing lymph fluid retention in the tissue spaces which causes swelling of the limb. High concentration of proteins stimulate connective tissue dysplasia.The fat is replaced by the large number of fibrous tissue, thickening of the skin and subcutaneous tissue, so the surface of the skin keratosis. rough, verrucous hyperplasia. Lymphocytes and macrophages circulation are blocked and cell-mediated immunity become weakened.Once the skin is damaged, the protein-rich media may easy result secondary infections. Secondary lymphedema seriously affect the work and life of the patients. Because there are not really effective treatments, so how to early detection has become a priority of secondary lymphedema. The early check methods contain:direct injection of lipiodol lymphangiography method (direct method),subcutaneous injection of X-ray contrast agent indirect lymphangiography method (indirect method) and radionuclide lymphography(lymphoscintigraphy, LSG).Direct method is time-consuming, invasive procedures and has potential side effects. Indirect method may overcome these shortcomings, but shows the limited range and requires special instruments and can not be3D imaging. LSG resolution can not clearly show the lymphatic vessels in the anatomical context and lymph nodes, and can not be3D imaging. In recent years, MR interstitial lymphography start for the clinical evaluation of the limb lymphatic edema. We use this method to investigate the diagnostic value of the morphology and function of the lymphatic vessels in monkey upper limb secondary lymphedema model, so as to explore the value of MR interstitial lymphography at limb lymphedema.MethodsSecondary lymphedema was created in the right upper limb of3monkeys with2weeks before surgery irradiation+axillary lymph node dissection+6weeks after irradiation combined. Left upper limb of each monkey was used as the normal control. After7weeks、10weeks and16weeks of the surgery, Between the upper limb palm linger web, intradermal injection of gadolinium-DTPA (Gd-DTPA), the palm of your hand on each side of each finger web0.2ml contrast agent. And use Magnetic resonance interstitial lymphoscintigraphy to observe the change in the different periods of the lymphatic system lymphedema.Results1.Successful make the right upper limb secondary lymphedema model of the three monkeys.2. MR interstitial lymphoscintigraphy clearly show changes in the macaque edema limbs skin and subcutaneous tissue of the lymphatic system.3.Early lesions, from the MRL interstitial lymphoscintigraphy, we mainly find that the subcutaneous tissue’s exudative change. Lesions interim, we can see that some irregular network structure appear in the subcutaneous tissue, beaded expansion of the lymphatic vessels, and because of the Contrast agent leaking, the cloudy or pine-like changes appear the outside of the lymphatic vessels. Late lesions, we can see that proliferation of fibrous connective tissue of the skin and subcutaneous tissue, body diameter was significantly widened, and lymphatic presented pouch pocket expansion from the MRL interstitial.Conclusion1. Combination of irradiation and axillary lymph node dissection, can create monkey upper limb secondary lymphedema model.2. MR interstitial lymphoscintigraphy can be used to detect the change of limb lymphedema of the lymphatic system.