皮肤圆锥体结构损伤致增生性瘢痕的病理学观察

目的探讨皮肤圆锥体结构受损与增生性瘢痕(HS)形成的关系,寻找HS形成的原因及适合HS研究的动物模型。方法将2只雌性杜洛克猪(FRDP)背部去毛后,取正常皮肤1块, 行皮肤圆锥体结构观察;然后用气动取皮机造成皮肤缺损深度为0．38、0．76、1．14、1．52 mm的创面, 每个创面面积7．0 cm×7．0 cm,每只猪的背部共8个创面。根据上述创面深度将其分为4组,每组4 个创面。将0．38、0．76 mm组视为浅创面组;1．14、1．52 mm组视为深创面组。伤后不处理,让创面自然愈合。分别在伤后即刻(0)、10、30、60、90、150 d,切取创面组织标本行HE和弹性纤维(VVG)染色。行正常FRDP皮肤组织及受损圆锥体结构观察;大体观察不同深度FRDP创面愈合及瘢痕形成情况;用组织学方法观察HS的形态;VVG染色测定瘢痕组织的厚度并计分。结果正常FRDP背部皮肤存在圆锥体结构,与人类的皮肤圆锥体结构相似。浅创面组伤后3周内愈合,愈合的创面较为平整,无瘢痕组织形成;深创面组伤后4周以上愈合,愈合的创面较厚,无毛发,挛缩,质地坚硬,局部色素变浅或加深。浅创面组皮肤圆锥体结构的上半部分受损,但脂肪穹隆及腺体完好;深创面组皮肤圆锥体结构的下半部分受损,伤及脂肪穹隆及腺体。伤后150 d浅创面组的组织学结构与正常皮肤相似;深创面组圆锥体结构消失,并被大量堆积、没有特定方向、排列紊乱的胶原纤维束充盈。深创面组瘢痕组织厚度评分可见时间越长瘢痕越厚,伤后150 d瘢痕增生达高峰。结论皮肤圆锥体结构受损可导致HS的形成,FRDP可作为HS研究的动物模型。

Pathomorphological observation of the hypertrophic scar induced by injury to conical structure in female red Duroc pig

To further explore the relationship between hypertrophic scar and injury to conical structure of skin and the pathogenesis of hypertrophic scar, and to reproduce an optimal animal model of hypertrophic scar. METHODS: The back of two FRDP pigs were shaved, and a piece of normal skin was harvested for the observation of conical structure of skin. Skin wounds with depth of 0.38 mm, 0.76 mm, 1.14 mm and 1.52 mm, respectively, were created by gas-driven dermatome. Eight wounds measuring 7.0 cm x 7.0 cm were created on each pig. The wounds were divided into 4 groups according to the wound depth with 4 wounds in each group, i.e. 0.38 mm group, 0.76 mm group, 1.14 mm group and 1.52 mm group. The 0.38 mm and 0.76 mm groups were designated as superficial wound groups and 1.14 mm and 1.52 mm groups as deep wound groups. The wounds were allowed to heal without treatment. Tissue samples from the wound were harvested on 0, 10, 30, 60, 90 and 150 post injury day (PID) , and they were sectioned for HE staining and staining for elastic fibers (VVG). The wound healing and the scar formation were observed with naked eye. The skin conical structures in normal and injured skin were also observed. The morphology of hypertrophic scar was observed, and the thickness of the scar tissue was determined and scored. RESULTS: The wounds in superficial wound groups healed within 3 weeks with flat surface without scar formation. The wounds in deep wound groups healed later than 4 weeks with thick, hairless, hard in texture, with depigmentation or pigmentation, finally forming contracture. The skin conical structure could be found on the back of FRDP with HE and VVG staining, and it was similar to that of human in terms of the structure. In superficial wound groups, the upper part of the skin conical structure was injured, but fat fornix and glands were intact. In deep wound groups, the lower part of the skin cone, together with the fat fornix and gland were all injured. On the 150th post injury day, the histological picture of the tissue in superficial wound groups was similar to that of normal skin. But the skin conical structure could not be found in deep wound groups, and the wounds were filled by a large accumulation of disarrayed and irregularly arranged collagen fibers. With passage of time, the scar became thicker and thicker, and the scar hypertrophy reached the zenith in 150th PID. CONCLUSION: The injury of skin conical structure can lead to the formation of hypertrophic scar. FRDP can be used to reproduce and ideal model of hypertrophic scar.