Hesheep, for lymphedema studies is that lymphatic function can be measured
Hesheep, for lymphedema studies is that lymphatic function can be measured, something that is extremely difficult to achieve in a small species. In sheep, the pre- and postnodal popliteal ducts are easy to identify, and some of these are of sufficient size for cannulation. In thisBaker et al. Breast Cancer Research 2010, 12:R70 http://breast-cancer-research.com/content/12/5/RPage 13 ofFigure 8 Relationship between lymphatic functionality and edema magnitude. Functionality data (AUC at 2 hr) were plotted versus their corresponding edema values at 6 wk, n = 36. The trend shows a negative correlation, suggesting that as lymphatic functionality increases, edema magnitude at 6 wk decreases. Linear regression analysis revealed this trend to be significant, P = 0.001.regard, the ability to transport a known mass of radiolabeled albumin to plasma provides a useful measure of the lymph transport effectiveness of a given lymphatic network. Therefore, following the injection of 125I-BSA into prenodal lymphatic vessels, one would expect that the mass transport rate of this protein tracer to plasma PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/25112874 would reflect the integrity of the lymphatic network in question, a notion that PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/27797473 is supported by the data in this report. In humans, lymph-venous anastomoses can form with long-term lymphatic obstruction [19,20]. If such connections were to exist in our sheep experiments, the labeled BSA would be diverted into the limb vasculature and would not pass through the nodal excision site. However, over the many years we have used the sheep model, we have never observed these connections in the popliteal region. Presumably, the level of impediment caused by nodal excision in the animal model is relatively benign compared to that which occurs in humans with cancer. In the human case, the surgical procedures related to the removal of the cancer and lymph nodes are much more extensive and likely provide a significantly greater insult to the lymphatic system than that occurring in our experiments. In the latter case,relatively robust lymphangiogenesis occurs and some degree of fluid continuity is restored relatively quickly so that the stimulus for lymph-venous connections in the leg may not be as great as is the case with some lymphedema patients. In cancer patients, the removal of one or more lymph nodes often gives rise to acute edema which resolves successfully. It is, of course, the chronic form of edema that occurs in a subgroup of purchase JNJ-26481585 patients that is most problematic. The exact conditions that drive the formation of this subgroup are unknown. It has been suggested that women with greater than average peripheral lymph flow are more likely to develop lymphedema following breast cancer surgery [21]. The authors postulated that this predisposing factor might explain why lymphedema develops in patients in which only a few nodes have been removed. In all likelihood, lymphedema is the result of a complex interplay between many factors (surgery, lymph node removal, radiation, injury and predisposing characteristics) that lead to the development of this condition. It should be noted that we are not attempting to replicate the complex conditions experienced by cancer patients in our model. Instead, our model permits us to examine the properties of a singleBaker et al. Breast Cancer Research 2010, 12:R70 http://breast-cancer-research.com/content/12/5/RPage 14 oflymphatic network in order to develop basic therapeutic principles that could be applicable to the human condition.