Figure 1 Healing progression of Wagner Grade 4 diabetic foot ulcer in a 95-year-old female (Case 1) A-E: images show the second toe of the left foot on different days. A: day 0 (initial presentation with red circle indicating the affected area); B: day 4 (the debridement has selectively removed necrotic tissue while viable tissue has simultaneously begun regenerating, red arrow indicates the primary treatment area where the Heiyu Gao A continues to be applied. The black material seen is the medicinal paste Heiyu Gao A or B, not eschar.); C: day 7 (progressive healing with granulation tissue); D: day 14 (continued healing with almost 100% wound closure including nail regeneration, but insufficient keratinization of the epidermis); E: day 27 (completely healed with no scarring, resulting in skin that seems to have never experienced gangrene).

Figure 2 Healing progression of left lower limb in a 94-year-old male (Case 2) A-D: images show the left lower limb on different days. A: day 0 (initial presentation with multiple ulcerations, redness, edema and exudate); B: day 8 (Significant reduction in inflammation and edema. Autolytic debridement and regeneration occur simultaneously, with the main wound area approximately 3 cm × 13 cm.); C: day 12 (Most of the wounds healed); D: day 32 (complete healing with no residual scarring).

Figure 3 Healing progression of Wagner Grade 4 diabetic foot ulcer of left foot in a 94-year-old male (Case 2) A-G: images show multiple toe ulcers of the left foot on different days. A: day 0 (initial presentation with dark purplish discoloration of second toe); B: day 4 (the distal phalanx of the second toe including the nail had undergone autolytic debridement, demonstrating that despite appearing merely discolored at Day 0, the distal portion of the second toe was actually completely necrotic and non-viable. The black material visible is the medicinal paste.); C-F: days 11, 19, 24 and 48 respectively (progressive selective autolytic debridement with necrotic tissue reduction and continuing tissue regeneration. The demarcation between viable and non-viable tissue is becoming more distinct.); G: day 105 (complete healing with autolytic amputation of the first phalanx of the second toe with no scarring, resembling a surgical amputation outcome but achieved non-invasively.). Red arrows highlight the transformation process from necrotic tissue to autolytic amputation in the primary lesion area.

Figure 4 Healing progression of Wagner Grade 4 diabetic foot ulcers of left foot in a 96-year-old male (Case 3). A-E: images show two ulcers of the left foot on different days. A: day 0 (initial presentation with rapidly progressed carbonized gangrene of the left foot's dorsum, 3.5cm × 2cm, and the left fifth toe, 2 cm × 1.5 cm); B: day 12 (the vast majority of gangrene scabs disappearing by autolytic debridement with a small amount remaining on the outer side of the fifth toe, meanwhile healthy granulation tissue growing along the margin of the wound bed.); C: day 34 (significant healing response with continued treatment. The black material seen outside of the wound is the residual medicinal paste, not new onset necrotic scabs.); D: day 69 (almost 100% wound closure of the fifth toe but insufficient keratinization of the epidermis, only a small central area of the wound not closed on the foot's dorsum); E: day 96 (complete wound closure with no scarring).