Histomorphological observation of surgical debridement combined with negative pressure therapy in treatment of diabetic foot

Abstract

Purpose: To further study the mechanism of epithelization on the fascia side of the flap after surgical incision and the treatment of the negative pressure therapy.

Methods: With the patients' informed consent, parts of tissue samples were obtained from a 51-year-old diabetic patient who was suffering lower extremity ulcers. The samples were processed with hematoxylin and eosin (HE) staining and Masson trichrome staining. The keratin 19, keratin 15 and carcino-embryonic antigen (CEA) were immunohistochemically detected.

Results: The results of HE staining showed that the specimen was divided into two regions, newborn area and original epithelial area. There were more inflammatory cells infiltrating in the dermis in the newborn epithelial area, compared with the original epithelial area. Cells in newborn epithelial area were more active and many dinuclear and polynuclear cells were observed in newborn epithelial area. But there were more cuticular layers and obvious rete pegs in original epithelial area. In addition, the cells with keratin 19 and CEA positive were found around hair follicle, while keratin 15 was negative. Masson trichrome staining showed that there was a lot of de novo collagen in newborn epithelial area.

Conclusion: Epidermal cells on the fascia side of the flap could be derived from the stem cells. Negative pressure wound therapy would attract not only cells but also other elements such as growth factors, cytokines, some nutrients and extracellular matrix. With the formation of the appropriate microenvironment after debridement, the migrated cells can grow, differentiate and spread, eventually leading to the epithelization on the fascia side of the flap in diabetic foot.

Keywords: Diabetic foot; Epithelium; Negative-pressure wound therapy; Stem cells; Wound healing.

Fig. 1

A: On the 7th day after surgical incision, there were several scattered epithelial islands in the wound side of fascia flap. B: On the 8th day after surgical incision, epithelial islands were gradually broadened. C: On the 9th day after surgical incision, epithelial islands were almost confluent.

Fig. 2

HE staining on the 12th day after surgical incision showed that the specimen was divided into newborn epithelial area A and original epithelial area B.

Fig. 3

HE staining on the 12th day after surgical incision showed that there were more cuticular layers and obvious rete pegs in the original epithelial area B compared with the newborn epithelial area A.

Fig. 4

HE staining on the 12th day after surgical incision showed that there were a large number of inflammatory cells infiltrating in the dermis in the newborn epithelial area (A) compared with the original epithelial area (B).

Fig. 5

HE staining on the 12th day after surgical incision showed that cells in newborn epithelial area (A) were more active and there were many dinuclear and polynuclear cells in area A.

Fig. 6

Masson trichrome staining on the 12th day after surgical incision showed that there was much de novo collagen in area A and the collagen had progressive maturity from outer to inner layer in area B.

Fig. 7

Immunohistochemical staining on the 12th day after surgical incision showed that keratin 19 was a specific marker of hair follicle stem cells in corium slightly near area B.

Fig. 8

Immunohistochemical staining showed negative expression of keratin 15 on the 12th day after surgical incision.

Fig. 9

Immunohistochemical staining on the 12th day after surgical incision showed that the cells with carcino-embryonic antigen weakly positive were found in corium around hair follicle in area B, but also scattered in both regions (A and B).