Abstract
BACKGROUND: Hypertrophic scars and keloids can develop from surgical incisions. These pathologic scars grow progressively due to chronic dermal inflammation, which is exacerbated by skin tension. Postsurgical wound tension can be mitigated by various surgical tactics. One underrecognized aspect is surgical incision orientation. Here, we discuss the principles underlying existing surgical incision line systems, including Langer and Pinkus lines, and propose a new system based on our observations of pathological scar growth. METHODS: We review the biological mechanisms that drive pathological scar growth, describe existing surgical incision line systems and their limitations, and propose our "ideal surgical incision line" system. RESULTS: Keloids grow in the direction of predominant skin-stretching tension. The main surgical incision line systems are those of Borges (relaxed skin tension lines caused by anatomical features), Kraissl (dynamic lines driven by muscle contraction), and Lemperle (striae distensae). Borges lines only consist of static lines; Kraissl lines are generally not accurate for dynamic wrinkles caused by multidirectional or multilayered muscle contraction; and not every patient bears striae distensae. Our experience with pathologic scars led us to develop an "ideal surgical incision" system for the face and entire body that incorporates static wrinkles, dynamic wrinkles caused by simple and multidirectional muscle contraction, and classical folds/creases/grooves. We also propose that when ideal lines cannot be used for practical reasons, Z-incisions and Z-plasties can mitigate skin tension. CONCLUSIONS: Our ideal surgical incision line system may help guide surgeons in their choice of surgical incision lines, thus reducing the risk of pathological scarring.