2.2. AHSC preparation, application, and follow‐up

Harvests were performed at initial patient visit. Before the harvest procedure, the subject's clinical and wound history were recorded. A 1 × 2 cm full‐thickness harvest of healthy skin was taken from the proximal calf of the affected limb of each patient using sterile technique and local anaesthesia. Harvest sites were sutured closed. The harvest was mailed overnight to a Food and Drug Administration–registered biomedical manufacturing facility (PolarityTE, Salt Lake City, Utah), where the AHSC (SkinTE, PolarityTE) was created from the tissue. The AHSC was returned to the provider within 48 hours of tissue harvest, per provider discretion, and was applied to the wound bed 3 days after the harvesting procedure.

For the application procedure, the wound was cleaned and sharply debrided. The AHSC was topically spread evenly across the wound bed and covered with a silicone dressing, then covered by an absorbent foam dressing (DermaFoam, DermaRite, North Bergen, New Jersey), followed by a 3‐layer compression bolster (DYNA‐FLEX, Acelity, 3M Corporation, Minnesota). Dressings were changed weekly, and wounds were offloaded with a diabetic offloading boot. The silicone dressing was replaced by a nonadherent contact layer (Adaptic Touch, KCI, 3M Corporation) at the third dressing change, and covered by the aforementioned 3‐layer compression bolster. Standard of care wound management was maintained until wound closure.

Patients had weekly follow‐up visits and dressing changes until closure was confirmed for up to 12 weeks. A DFU was deemed closed if it remained completely epithelialised without drainage 2 weeks after it was first determined to be closed by the treating provider, and closure was confirmed by consensus of three blinded plastic surgeons through review of high‐resolution digital photography. At each visit, the provider assessed graft take (yes/no), assessed the wound for infection, recorded patient‐reported pain using a VAS, and wound measurements were recorded by a wound imaging system (Insight, eKare Inc, Fairfax, Virginia).