A critical aspect of many cancer surgeries is the removal of nearby lymph nodes, which helps eliminate cancer cells that may have spread from the primary tumor. In some cases, however, removing these lymph nodes causes a debilitating side effect called lymphedema.
The lymphatic system is a network of tubes and filters that serves as the body’s waste-disposal system. Removing lymph nodes can create a blockage that prevents fluid waste from draining from the area. This condition involves swelling and stiffness in the arms or legs and causes discomfort, restricts mobility, and can lead to infections requiring hospitalization.
“Patients with lymphedema suffer tremendously — more than people realize,” says Memorial Sloan Kettering reconstructive surgeon Joseph Dayan. “They’ve survived cancer but find themselves stuck with a potentially permanent disability that may get worse over time. Many of these patients can’t wear their usual clothes and even find it difficult to go swimming or be in the sun because a burn can trigger swelling or infection.”
People with lymphedema can gain some relief through physical therapy or by wrapping their limbs in compression garments, but the condition gravely impairs day-to-day well-being and may never go away.
A new approach to treating lymphedema involves transplanting lymph nodes from elsewhere in the body to replace those removed as part of treatment. Although this technique has been investigated for years, there is a known risk of lymphedema developing at the site from which the nodes are taken.
Dr. Dayan has helped pioneer a method for selecting lymph nodes for transplant that could minimize this risk.
Reverse lymphatic mapping enables surgeons to ascertain which lymph nodes are appropriate for removal.
“The key was to find some way to identify which lymph nodes primarily drain the trunk — the middle of the body — as opposed to those that mainly drain the arms and legs,” he explains. “Removing lymph nodes that drain the trunk does not generally cause lymphedema. However, no clear guidelines have existed on how to do this operation.”Back to top
Mapping For Safe Removal
The new technique, called reverse lymphatic mapping, enables surgeons to ascertain which lymph nodes are appropriate for removal, reducing risk of lymphedema at the donor site.
“Assume we want to take lymph nodes from the groin and put them under the arm for a patient with breast cancer–related lymphedema,” Dr. Dayan says. “We inject one type of dye into the foot and a different type of dye into the lower abdomen. The first type of dye allows us to trace the location of lymph nodes draining the leg, so we know to avoid them. The second dye reveals the lymph nodes draining the lower abdomen, which can be removed without causing problems.”
Dr. Dayan says it is easy to tell apart the two dyes and the lymph nodes they have infiltrated to see which ones to avoid and which can be safely removed.
“The mapping has dramatically increased the safety of transplants because we can see the drainage pattern,” he says.
A recent study published in Plastic and Reconstructive Surgery by Dr. Dayan and colleagues bears this out. Thirty-five patients were transplanted with no lymphedema from the donor sites, whether the lymph nodes were taken from the groin or from the upper body.
In addition to lymph node transplant, there are other possible approaches to treating lymphedema. For example, MSK reconstructive surgeon Babak Mehrara is investigating drugs that could alleviate or reverse the condition.
“I don’t think we’re going to solve lymphedema by surgery alone,” Dr. Dayan says. “It’s going to take a lot of different minds and different perspectives.”Back to top