Novel expansion techniques for skin grafts

Abstract

The quest for skin expansion is not restricted to cover a large area alone, but to produce acceptable uniform surfaces, robust engraftment to withstand mechanical shear and infection, with a minimal donor morbidity. Ease of the technique, shorter healing period and reproducible results are essential parameters to adopt novel techniques. Significant advances seen in four fronts of autologous grafting are: (1) Dermal–epidermal graft expansion techniques, (2) epidermal graft harvests technique, (3) melanocyte-rich basal cell therapy for vitiligo and (4) robust and faster autologous cell cultures. Meek's original concept that the sum of perimeter of smaller grafts is larger than the harvested graft, and smaller the graft size, the greater is the potential for regeneration is witnessed in newer modification. Further, as graft size becomes smaller or minced, these micrografts can survive on the wound bed exudate irrespective of their dermal orientation. Expansion produced by 4 mm × 4 mm sized Meek micrografts is 10-folds, similarly 0.8 mm × 0.8 mm size micrografts produce 100-fold expansion, which becomes 700-fold with pixel grafts of 0.3 mm × 0.3 mm size. Fractional skin harvest is another new technique with 700 μ size full thickness graft. These provide instant autologous non-cultured graft to cover extensive areas with similar quality of engraftment surface as split skin grafts. Newer tools for epidermal blister graft harvest quickly, with uniform size to produce 7-fold expansions with reproducible results. In addition, donor area heals faster with minimal scar. Melanocyte-rich cell suspension is utilised in vitiligo surgery tapping the potential of hair root melanocytes. Further advances in the cell culture to reduce the cultivation time and provide stronger epidermal sheets with dermal carrier are seen in trials.

Validation of an implantable bioink using mechanical extraction of human skin cells: First steps to a 3D bioprinting treatment of deep second degree burn

“…We encountered difficulties to compare our result with other -few papers being published on skin cells mechanical extraction. Usually, when mechanical dissociation is involved in cell preparation from tissue, it is combined with an enzymatic digestion (He et al, 2016) and most of the time, enzyme digestion alone is use to obtain autologous cell suspensions (Kadam, 2016;van Geel, Goh, Wallaeys, De Keyser, & Lambert, 2011). For example, ReCell technique -a nonamplified cell suspension obtain with trypsin -is routinely used to treat wound (De Angelis, Migner, Lucarini, Agovino, & Cervelli, 2015) or vitiligo with a melanocytes enriched cell suspension (Kadam, 2016).…”

A Narrative Review of the History of Skin Grafting in Burn Care

“…Further, developing Hackl’s technique, Denesh Kadam an Indian surgeon from Karnataka, India developed a technique called “Pixel Grafting”. Similar to the Xpansion TM technique, skin grafts are minced into digital pixel sized grafts (0.3 mm × 0.3 mm) and are able to achieve expiation ratio of up to 700:1 [ 63 ].…”

Advances in keratinocyte delivery in burn wound care

“…Subsequently, many skin graft expansion techniques have been developed to reduce donor site size, these techniques include meshing of the graft (maximum expansion ratio of 1:9), modified meek technique (expansion ratio of 1:9), epidermal blister grafting (expansion ratio of 1:1) and several techniques of micro grafting such as epidermal CelluTome™ micro-grafting (expansion ratio: 1:6), or Xpansion® micro-grafting (maximum expansion ratio: 1:100). Developers of cellular based techniques claim to deliver even higher expansion rates, such as cultured epithelial sheets (expansion rate 1:1000) and uncultured cell suspensions (maximum expansion rate 1:100) [76] , [77] . However, to the knowledge of the authors no other studies have been able to support these findings.…”