Role of Ultrathin Skin Graft in Early Healing of Diabetic Foot Ulcers

A Randomized Controlled Trial in Comparison With Conventional Methods

Rahul Shetty, MBBS, MS, MCh, DNB; BS Giridhar, MBBS, MS; Ankush Potphode, MBBS, DNB

Disclosures

Wounds. 2022;34(2):57-67. 

In This Article

Discussion

Wound care for those with diabetes is a significant financial and resource burden on the health care system, which signifies a need to further optimize current wound coverage strategies.[22,23] Epidermal grafting for wound healing is not a new concept. Several case reports have indicated good wound healing outcomes; however, it is unknown whether the healing rate is comparable to that of STSG, a mainstay of treatment for wounds that cannot be closed primarily.[24–26] The usefulness of a novel epidermal harvesting system was first demonstrated in Port-au-Prince, Haiti, where insufficient resources and lack of clinical training limited wound care options.[27]

The use of epidermal graft in managing vitiligo and chronic wounds has been widely reported, but its use is limited because of the lack of reproducible and efficient harvesting techniques.[28,29] The present study demonstrated the feasibility of using the Watson dermatome for harvesting UTSG to achieve definitive wound coverage of DFUs.

Similarly, automated epidermal graft also proved useful when STSG was contraindicated because of concern for poor wound healing at the donor site, such as in the case of pyoderma gangrenosum.[26] Molecular studies of the epidermal graft using an automated epidermal harvesting tool showed that epidermal micrografts formed at the dermal-epidermal junction secrete various growth factors essential to wound healing, including platelet-derived growth factor, VEGF, and granulocyte colony-stimulating factor,[19,30] thereby encouraging the wound bed to regenerate and initiate keratinocyte migration from the edges of the wound. The migrating keratinocytes also deposit a variety of extracellular matrix components, such as laminin, fibronectin, and type IV collagen.[31]

These findings are consistent with the observation of the authors of the current study that when the epidermal graft was transplanted, wound healing occurred simultaneously within the wound bed and margins. These islands of reepithelialization eventually merged to form a confluent structure, which suggests a unique molecular mechanism of epidermal grafts and warrants further investigation.

Wound healing and healing time were key outcomes measured, and the results demonstrate that 84.61% of the wounds in the test group fully healed. More than 50% of wound healing was achieved within 6 weeks, and complete wound closure was achieved within a mean of 6.2 weeks. Of the wounds that were not healed in the study population, the majority (75%) were in the control group, which may imply that the epidermal grafts stimulate the healing process in hard-to-heal wounds.

Ultrathin skin graft donor site complications can be avoided, such as infection, pain, and hypertrophic scarring.[32] None of these donor site-related complications occurred in the current study.

As with all new technologies, the costs of intervention and follow-up time must be assessed; these factors may also be important determinants of patient adherence. In the present study, the mean frequency of hospital visits was 9 among 84.6% of the study population in the test group, whereas 50% of the patients in the control group required more than 12 visits. This would mean patients in the control group are associated with a higher number of hospital visits, thus adding further health care costs to the group that did not receive the UTSG. The probable reason for it may be that the extra added cost of UTSG is compensated by multiple dressings, more hospital visits for a longer period, and more cost to the patients in the control group.

In the current study, the effect of the growth factors on the wound bed and the edges of the wound was further confirmed by histopathological examination. The incisional biopsy taken from the center of the wound was used to identify increased granulation tissue and tiny blood vessels, which are signs of wound healing probably due to a defect of growth factor.

Also, in patients with DFUs with mild PVD being managed conservatively, the current study demonstrated the efficacy of UTSG by improving wound healing in terms of improved granulation tissue and hyperemia of the wound bed. The primary aim was to demonstrate an improved wound bed, which was easily accomplished, after which the wound was covered with STSG, and complete wound closure was achieved.

Ultrathin skin grafting serves an important role in improving the healing process of the wound bed and acting as a primary cover for wound closure in most cases. Some cases may require additional STSG for definitive wound closure, which shows promising results due to enhanced healing process by prior UTSG. In the authors' opinion, most wounds healed with UTSG, but in some cases, an additional STSG may be necessary. However, the use of UTSG prior to definitive STSG would help to increase granulation tissue and help with STSG uptake.

Ultrathin skin grafting has advantages over STSG; UTSG allows contact between the growth factor-secreting basal epidermal layer and the wound bed and improves the healing process, which is not exposed as it is in STSG. Ultrathin skin grafting was associated with fewer harvesting site complications than other various modalities used in the treatment of DFUs, which was a consistent finding in the current study.

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