The lymphatic system is a defense network of the body, closely related to the venous system. Although clinically important as the main route of the immune system, the lymphatic vessels provide also the major route of cancer metastasis and, unfortunately, our knowledge of the lymphatic system is very limited. Current understanding of the pattern of lymph channels is largely dependant on the anatomical studies of Sappey (1) in the 19th century when mercury was injected into human cadavers and the lymphatics were dissected. These studies have not been repeated because of the use of mercury is now prohibited because of its toxicity.

The aim of this study was to find a new reliable method of delineating lymph channels in human cadavers and to reappraise their gross anatomy and lymph node connections using a radiological technique. It took more than three years to develop this new method. It commenced as a pilot study using animal cadavers and then it was applied to various human body parts. The definitive technique utilized hydrogen peroxide to identify lymphatic vessels and to inflate them. The individual channels were injected with a radio-opaque lead oxide mixture and recorded on x-ray film. Each channel was meticulously dissected under the surgical microscope and its course examined in relation to the regional lymph modes. This method was then applied to a 14 human cadaver upper limbs obtained from ten different cadavers.

We found that the superficial lymphatic vessels course within the subcutaneous fat in close proximity to the main subcutaneous veins. Communication between the superficial and the deep lymphatic system was not identified in these studies. Most of lymph vessels were seen to flow into one main (sentry) lymph node in the axillary region, however, some of the lymph vessels ran along the posterior forearm, bypassing the “sentry” node to reach other smaller nodes.