Morris D E, Wu L, Zhao L L, Bolton L, Roth S I, Ladin D A, Mustoe T A
Department of Surgery, Northwestern University Hospital Medical School, Chicago, Ill., USA.
Plast Reconstr Surg. 1997 Sep;100(3):674-81. doi: 10.1097/00006534-199709000-00021.
Excessive scarring in the form of keloids and hypertrophic scars continues to be a clinical problem for some patients. The lack of an animal model for such scarring has been an obstacle to studying the cellular and molecular biology of these entities. Previous observations made by the authors that some surgical scars in the rabbit ear remain raised for months after wounding prompted us to investigate whether the rabbit ear might provide a model by which to study excessive dermal scarring. After establishing the model in preliminary study, 40 excisional wounds, 6 mm in diameter, were created over the ventral surface of rabbit ears. Elevated scars were treated with either intralesional triamcinolone acetonide or saline at day 16 postwounding. On day 22, 25 scar wounds were used for thorough histomorphometric analysis, 15 wounds were eliminated prior to analysis because of invagination of epithelial tissue, which made analysis difficult. Total area of scar and Hypertrophic Index, a ratio comparing scar prominence with the thickness of adjacent unwounded tissue, were measured for 25 (62 percent) of the resulting scars. Both total area of scar and Hypertrophic Index were found to be significantly decreased in the steroid-treated group (p < 0.02 and < 0.03, respectively). In a chronic form of this model, in which larger excisions were taken, an excessive accumulation of both new collagen and cartilage over 9 months was observed. An animal model for excessive dermal scarring that allows quantitation of scar formation and, at an early stage, can be modulated in a predictable way with intralesional corticosteroid treatment is presented. This model may parallel hypertrophic scarring in humans and thus might provide a tool by which to study its pathophysiology and objectively evaluate therapeutic modalities.
瘢痕疙瘩和增生性瘢痕形式的过度瘢痕形成，对一些患者来说仍然是一个临床问题。缺乏针对此类瘢痕形成的动物模型一直是研究这些病变的细胞和分子生物学的障碍。作者之前观察到，兔耳上的一些手术瘢痕在受伤后数月仍会隆起，这促使我们研究兔耳是否能提供一个研究过度皮肤瘢痕形成的模型。在初步研究中建立该模型后，在兔耳腹侧制造了40个直径6毫米的切除伤口。在受伤后第16天，对隆起的瘢痕用曲安奈德或生理盐水进行病灶内注射治疗。在第22天，选取25个瘢痕伤口进行全面的组织形态计量学分析，另外15个伤口因上皮组织内陷导致分析困难，在分析前被剔除。对25个（62%）形成的瘢痕测量瘢痕总面积和增生指数（增生指数是瘢痕突出度与相邻未受伤组织厚度的比值）。结果发现，类固醇治疗组的瘢痕总面积和增生指数均显著降低（分别为p < 0.02和< 0.03）。在该模型的慢性形式中，即进行更大范围的切除时，观察到在9个月的时间里新胶原蛋白和软骨都过度积累。本文介绍了一种用于过度皮肤瘢痕形成的动物模型，该模型能够对瘢痕形成进行定量，并且在早期阶段可以通过病灶内皮质类固醇治疗以可预测的方式进行调节。这个模型可能与人类的增生性瘢痕相似，因此可能提供一种研究其病理生理学并客观评估治疗方式的工具。
