Duration of open wound management can contribute to patient morbidity and increased cost. Hyaluronic acid (HA) functions as a passive structural component of the extracellular matrix and acts as a signaling molecule by interacting with cell surface receptors. HA appears to regulate cell proliferation, migration, and differentiation. A prospective, controlled, experimental study compared a cross-linked hyaluronic acid-based gel (CMHA-S) with a standard wound management protocol. Bilateral 2×2 cm wounds were surgically created on either side of the trunks of 10 dogs; each side was randomized to either treatment (CMHA-S) or control (CON) groups. The first appearance of granulation tissue, total wound area, percent contraction, percent epithelialization, and histologic variables of inflammation and repair were compared. Subjective wound evaluations showed smoother granulation tissue surfaces with CON compared with CMHA-S. Second intention healing initially appeared to be slower in CMHA-S wounds, which were consistently exuberant on day 7. CON wounds contracted significantly more than did CMHA-S wounds from days 9–18 and epithelialized significantly more from day 11. These findings suggest that CMHA-S may not be indicated in the acute inflammatory period; however, it may be beneficial for treating more advanced wounds (ie, wounds in the mid-to-late repair stage with established granulation bed), as by study end the CMHA-S wounds had contracted more, resulting in smaller total wound area and a less obvious scar.

Commentary
Wound-healing products that accelerate wound resolution have been of interest both for veterinarians and physicians. Typically these products have promoted the rapid formation of granulation tissue. The unique feature of HA may be helpful later in healing after granulation tissue has formed. Subjectively, changing wound-healing stimulants periodically during wound healing may accelerate the process. This product could be beneficial in accelerating the final phase of wound healing; affecting this late phase would be useful, given the paucity of products that fill this void.—Kristy Broaddus, DVM, MS, DACVS

Source
Effects of a cross-linked hyaluronic acid based gel on the healing of open wounds in dogs. Hadley HS, Stanley BJ, Fritz MC, et al. VET SURG 42:161-169, 2013.