Lymphatic Territories (Lymphosomes) in a Canine: An Animal Model for Investigation of Postoperative Lymphatic Alterations

Abstract

BackgroundLymph node dissection is often performed as a part of surgical treatment for breast cancer and malignant melanoma to prevent malignant cells from traveling via the lymphatic system. Currently little is known about postoperative lymphatic drainage pattern alterations. This knowledge may be useful for management of recurrent cancer and prevention of breast cancer related lymphedema. We mapped the complete superficial lymphatic system of a dog and used this canine model to perform preliminary studies of lymphatic architectural changes in postoperative condition.MethodsLymphatic territories (lymphosomes) were mapped with 4 female mongrel carcasses using an indocyanine green (ICG) fluorescent lymphography and a radiographic microinjection technique. Two live dogs were then subjected to unilateral lymph node dissection of lymph basins of the forelimb, and ICG lymphography and lymphangiogram were performed 6 months after the surgery to investigate lymphatic changes. Lymphatic patterns in the carcass were then compared with postoperative lymphatic patterns in the live dogs.ResultsTen lymphosomes were identified, corresponding with ten lymphatic basins. Postoperative fluorescent lymphographic images and lymphangiograms in the live dogs revealed small caliber lymphatic network fulfilling gaps in the surgical area and collateral lymphatic vessels arising from the network connecting to lymph nodes in the contralateral and ipsilateral neck in one dog and the ipsilateral subclavicular vein in another dog.ConclusionOur canine lymphosome map allowed us to observe lymphatic collateral formations after lymph node dissection in live dogs. This canine model may help clarify our understanding of postoperative lymphatic changes in humans in future studies.

Diphtheria toxin–mediated ablation of lymphatic endothelial cells results in progressive lymphedema

“…In addition, in an interesting recent article, Ogata and colleagues used a mouse model of lymphatic injury to show that macrophages play a key role in the early regulation of lymphangiogenesis and that this process may be regulated by interactions with Th1 and Th17 cells (33). Our findings are also supported by lymphangiographic studies in a canine model of axillary lymphadenectomy demonstrating resolution of edema concurrent with development of hyperplastic collateral lymphatics that bypassed the zone of lymphatic injury (34). In the current study, in contrast to that by Ogata and colleagues, we found that macrophage depletion tended to accelerate development of progressive lymphedema, suggesting that the degree of lymphatic stasis is a major regulator of chronic inflammation and pathology.…”

Lymphatic Territories (Lymphosomes) in the Rat: An Anatomical Study for Future Lymphatic Research

“…Unlike our previous studies in large animals, the lymph nodes in rats were located more superficially, less than 1cm below the surface of the skin. 16,17 We could specify all the sentinel nodes once we cut the skin and used ICG lymphography to follow the course of each lymphatic vessel back to the node (Fig 2). The skin lymphatics connected to six groups of sentinel lymph nodes: superficial cervical, brachial, axillar, inguinal, gluteal and popliteal.…”

“…16-19 The brachial lymph node was located outside the axillary fossa, caudal from the triceps brachii and lateral from the lattismus dorsi. The lymphatic vessels in the forelimb and cranial part of the dorsal upper torso connected to this node.…”

“…16 -18 In the rat, a lymphatic vessel sometimes converged with other lymphatic vessels within a lymphosome, but connected to a single sentinel node only. This anatomical characteristic enabled us to delineate the borders of the lymphosomes (Fig 3 and 4).…”

Metastasis of Mammary Carcinoma in Bitches: Evaluation of the Sentinel Lymph Node Technique

“…Despite awareness regarding mammary lymphosomes, which are regional lymph drainage sites, several studies have shown that the presence of tumors may significantly alter the lymphatic direction as animals carrying mammary neoplasia undergo lymphatic reconfiguration due largely to the presence of prolymphangiogenic cytokines in the tumor's location [2]- [4].…”