目的观察超脉冲CO_2激光手术创口愈合过程中成纤维细胞的病理和超微结构特点,探讨超脉冲CO_2激光手术创口延迟愈合的机理。方法采用6 W功率超脉冲CO_2激光及常规机械方法(常规组)对大鼠背部皮肤致创,随机分成术后9个时相点对组织进行病理观察,并计数成纤维细胞;同时,对其中6个时相点的创缘成纤维细胞进行超微结构观察。结果创口愈合时间常规组于术后8.96 d愈合,6 W激光组愈合延迟至术后12.81 d,两组间有明显差异(P<0.01)激光组创伤愈合过程中成纤维细胞细胞增殖受抑制,术后5 d时成纤维细胞数量少于对照组(P<0.05);常规组成纤维细胞计数高峰为术后第7天,6 W激光组成纤维细胞计数高峰为术后第10天,7 d以后激光组成纤维细胞数量持续超过常规组。电镜观察结果显示,激光组伤口成纤维细胞增殖出现滞后,持续时间长。结论激光引起了创伤周围组织的热损伤,导致了愈合过程中的成纤维细胞增殖的时相改变、早期成纤维细胞增值功能受抑制等,从而使激光创口愈合延迟。

Objective To compare the histologic appearance and the ultrastructure of fibroblast in the healing of ultrapulsed CO_2 laser and scalpel incisions of rats.To explore the mechanism of the ultrapulsed CO_2 laser in the delayed the wound healing;and that to provide a theoretical support for its clinical application.Methods Six W power levels ultrapulsed CO_2 laser and a scalpel were performed in the skin to form two incisions on each of the total seventy two male SD rats.Wounds were harvested at 0,1,2,3,5,7,10,15 and 20 days schedules.Each specimen was prepared for staining with haematoxylin and eosin.Fibroblast of every sections were counted and evaluated independently;and observed the ultrastructure of the fibroblast at 3,5,7,10,15 and 20 days schedules by electron-microscope.Results The average time for the incisions closure of the ultrapulsed CO_2 laser at 6 W level was 12.81 days when the parallel scalpel incisions which healed significant earlier(P<0.01),which healed at 8.94 days.The generation of fibroblasts was inhibited at 5 days,the number of the laser group at 6 W level was(76.625 0±7.153 92),which was less then the scalpel group(101.406 3±20.557 82). There was statistically significant difference(P<0.05).In different periods of wound healing,there were different distribution of different types of fibroblasts by electron microscope.Conclusion The ultrapulsed CO_2 laser may delay the wound healing, due to power setting-dependent tissue thermal damage which lead to the change of the phase on the generation of fibroblast, ultrastructural changes and the inhibition of fibroblasts.