Mathematical Guide to Minimize Donor Size in Full‐Thickness Skin Grafting

• Published in: Dermatologic surgery Vol. 35; no. 9; pp. 1364 - 1367
• Main Authors: WANG, QIANG, CAI, MEI, WU, YU‐LE, ZHANG, GUO‐CHENG
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.09.2009; by the American Society for Dermatologic Surgery, Inc; Wiley
• Subjects: Abdominal Wall - surgery; Aged; Biological and medical sciences; Biopsy; Bowen's Disease - pathology; Bowen's Disease - surgery; Dermatology; Humans; Male; Mathematical Computing; Medical sciences; Skin Neoplasms - pathology; Skin Neoplasms - surgery; Skin plastic surgery; Skin Transplantation - methods; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Suture Techniques; Tissue Donors; Human; Guide; Treatment; Donor; Dermatology; Surgery; Size; Skin
• ISSN: 1076-0512; 1524-4725
• DOI: 10.1111/j.1524-4725.2009.01242.x

BACKGROUND Full‐thickness skin grafting is a common repair option in dermatologic surgery. Generally, a 3:1 ellipse is designed for the donor area. This results in occasional large donor site defects. A new formula to guide donor site design would potentially create smaller donor defects. OBJECTIVE To design a mathematical formula to facilitate smaller donor incisions. METHODS A geometric analysis was undertaken to design a practical formula to create smaller defects. This strategy was then used in a case series of 23 patients with large (average 11 cm in diameter) defects [This sentence was corrected after online publication on June 29, 2009: (average 16 × 11 cm) changed to read (average 11 cm in diameter).]. A geometrical analysis was used to design the best way to divide donor grafts to minimize tissue loss. RESULTS A formula called for the diameter of the primary defect to be multiplied by 3/2 and 2/3 to design a donor ellipse length and width, respectively. The resulting graft was divided into two equal sizes, using a tangential acute angle. The width and the area of the donor were significantly smaller, so the donor site was repaired using a shorter and faster repair. CONCLUSION Skin graft harvest may be accomplished using a smaller donor graft than previously described using the formula reported here. This will probably reduce surgical morbidity, time, and expense.