NTTS 2017

To address the limitations of current treatments for secondary lymphedema, our study group developed an experimental surgical procedure based on Autologous Lymph Node Fragment (ALNF) transfer supplemented by nanofibrillar collagen scaffold with and without autologous Adipose Derived Stromal Cells (ADSCs). The efficacy of this scaffold was demonstrated before by histological, functional and imaging analyses in a porcine model of secondary lymphedema. The use of ADSCs has major potential demonstrated in preclinical and clinical studies, but their use is often hampered due to difficulties in harvesting and delivery. The cell injections require large dosages and still have limited effect due to poor survival and migration from the target site. We address these challenges by using ADSC-seeded scaffolds to deliver the cells, support cell survival, maintenance and function precisely at the targeted site. The ongoing pilot study has 8 patients currently enrolled. The ALNF transfer was performed in all patients and additionally 6 patients received the collagen scaffolds alone and 2 patients received the ADSC-seeded scaffolds. Lymphoscintigraphy was conducted before the treatment, 6 and 12 months after the surgery. Volume and bioimpedance measurements (L-Dex U400) were conducted for 0, 3, 6, and 12 months after surgery. A portable closed-loop Mini-Stem system was used for extraction of ADSCs from patient lipoaspirate. Also, a 1.7 ml trocar was used for cell seeding on the scaffolds (~2 hours in incubator) and for subcutaneous delivery to bridge the area of impaired lymphatics. While this is a small ongoing study, safety has been demonstrated as there has been no complications reported over the 12 months. The affected/unaffected limb volume ratio was reduced on average 20%. For two patients, the affected/unaffected limb volume ratio was reduced to nearly normal level. More data will be presented at the time of the conference. While vascularized lymph node transfer is considered to be a more advanced technique than ALNF transfer, there is a great interest in developing countries to have a simpler surgery that could help patients with lymphedema. On the other hand, if the current treatment improves lymphedema, the concept of guiding lymphangiogenesis with collagen scaffolds could potentially improve the efficiency of established vascularized lymph node procedures.