Method to reroute lymphatic system may help lymphedema treatment

Researchers in California may have found a solution to lymphedema, a blockage of passages in the lymph system that can lead to painful swelling of the limbs in patients. A scaffolding composed of collagen nanofibers successfully helped new lymph vessels grow around blockages in pigs with lymphedema, giving researchers at Stanford University hope they have found an effective treatment for the condition.

The lymphatic system drains toxins and waste, using immune cell-containing lymph fluid as part of the filtration system. When a vessel in the system is blocked, the fluid backs up, causing painful swelling. In addition to some infections and genetic conditions, lymphedema is often seen in cancer patients whose lymph nodes have been affected.

Doctors can treat an infection causing it, but for the most part temporary relief with physical therapy and massage is the best patients can get. "Lymphedema is a chronic, debilitating disease with profound functional and psychosocial implications," Dr. Stanley Rockson, a professor in lymphatic research and medicine at Stanford University, said in a press release. "Current treatments are extremely limited.

While transplantation of healthy lymph nodes represents a theoretically viable treatment option for cancer survivors and others, the success rate of these procedures has been disappointing." For the study, published in the journal Biomaterials, researchers at Stanford worked with scientists at the company Fibralign, which has developed a collagen-based matrix meant to be used for soft tissue repair. The researchers used stretches of the company's BioBridge nanofibers coated with fragments of lymph nodes, which are known to stimulate new lymph vessel growth.

The fibers were then implanted in pigs with lymphedema. As hoped, the implants stimulated the growth along stretches of fibers around lymph blockages to bypass them, like a bridge, reducing fluid buildup in limbs over the course of three months. Although the researchers say the sample size for the study was not as big as they would have liked, there were no adverse health events among the animals six months after implantation.

This, they say, raises hope for success in a clinical trial in Latin America and another study with breast cancer patients planned for Stanford. "We were able to take a cue from nature about what molecules spur vessel growth, but also think outside the box and use this nanoscale scaffolding to bridge the blockages," said Dr. Ngan Huang, an assistant professor of cardiothoracic surgery at Stanford. "I think combining the two was really key."