Diabetic foot ulceration is a complex pathology that even after healing may result in recurrence for 75% of the patients within five years. Various methods to augment the healed area and redistribute normal and shear stresses, especially in the plantar aspect of the foot, have been utilized with varying levels of success.
A novel, off-the-shelf ,natural soft-tissue augmentation matrix has been developed from allogeneic adipose tissue. This allograft adipose matrix (AAM) is processed to preserve the endogenous matrix proteins and growth factors necessary for cellular infiltration, angiogenesis, and adipogenesis. In vitro studies with adipose-derived stem cells seeded on hydrated AAM showcase cell attachment and infiltration followed by differentiation into functional adipocytes within 7-14 days, as evidenced histologically and with scanning electron microscopy. When injected subcutaneously in immunocompromised nude mice, the endogenous factors retained in AAM supported revascularization and adipogenesis. Hematoxylin and Eosin and Perilipin A staining showcased new vessel formation within the matrix and infiltration of fat cells starting at three weeks, with progressive increase in adipocyte density at six and 12 weeks. Clinical use of this matrix to augment the fat pad and delay ulcer reoccurrence of one diabetic patient had promising results within the first four months of treatment. Within 10 weeks post treatment, there was more than 70% decrease in mean peak pressure at the site of the postoperative callus as measured by a F-Scan pressure sensor and by two months the callus had resolved.
Thus, AAM is a novel, off-the-shelf, adipose-derived matrix representing a natural scaffold that supports host cell infiltration, adipogenesis, angiogenesis, and volume retention. We look forward to further evaluation with more patients and longer time points to confirm or refute the preliminary positive outcomes of AAM in augmenting atrophic fat pads and extending ulcer-free days for high-risk patients in diabetic foot remission.