丝线线结在小鼠腹壁不同解剖层次异物炎症反应的组织学观察研究

Morphological observations of knot-induced inflammation at different anatomic levels in mouse abdominal wall

目的小儿腹腔镜监视下经腹壁腹膜外内环结扎后有时会出现线结反应。本研究旨在探索腹壁不同层次打结与线结炎症反应的相关性。方法Balb/C小鼠随机分组，在同一小鼠腹壁左向右分别纵向剪开3个皮肤切口（0.5 cm长），分别经切口处用无菌平镊提起全腹壁，采用4-0带针慕斯线进针贯穿腹壁至壁腹膜内，经切口直视下经原针孔采用钩针将带针丝线折返钩出，经原线道出针，分别打结于皮下、肌层内和腹膜外间隙。术后7 d、14 d取材打结部位腹壁标本，连续冷冻切片用于组织学观察和分析。结果HE染色显示各组线结位于腹壁不同解剖层次内（皮下、肌层和腹膜外间隙组）。免疫组织化学和半定量检测显示术后14 d标本皮下组线结周围巨噬细胞、IL-6和TNF-α的表达，异物巨细胞浸润，以及纤维化最显著，腹膜外间隙组线结周围巨噬细胞、IL-6和TNF-α的表达，异物巨细胞浸润，以及纤维化最轻微。结论丝线用于腹壁打结深度与线结异物反应呈相关性；线结位于腹膜外间隙引起异物炎症反应轻微，皮下线结异物炎症反应明显。提示对于腹腔镜监视下经腹壁腹膜外内环结扎术，将线结打在腹膜外间隙有利于降低线结炎症反应和线结反应相关并发症的发生率。

ObjectiveKnot-induced inflammatory response is noted in percutaneous extracorporeal knotting for laparoscopic inguinal inner ring closure in children.The present study was intended to explore the correlation between knot-induced inflammation and different knot locations in mouse abdominal wall.MethodsThree vertical and parallel incisions with a length of 0.5 cm were created in abdominal wall in the same Balb/C mice, followed by saturation with 1mm stitch using MERSILK ？ non-absorbable suture.The knots were located in subcutaneous, intramuscular and extra peritoneal space in abdominal wall.Knot segments of each group were harvested at Day 7 and 14 post operatively.Hematoxylin ＆ eosin, immunohistochemical and Masson stains were conducted to examine the location of knots in each group and degree of inflammation by inflammatory cell infiltration and expression of pro-cytokines, as well as collagen deposition around knots in each group.ResultsHematoxylin ＆ eosin staining indicated that knot was located in subcutaneous, intramuscular and extra peritoneal space of abdominal wall.Immunohistochemical staining and quantitative evaluations revealed less macrophage infiltration and decreased production of interleukin-6 （IL-6） and tumor necrosis factor alpha （TNF-α） in extra peritoneal space.On the contrary, there were more macrophage infiltration and increased production of IL-6 and TNF-α in subcutaneous layer.The significant biological difference of the above cytokines among three groups further confirmed a correlation between knot-induced inflammation and differential knot location in murine abdominal wall.Masson staining showed relative less collagen deposition and fibrosis in subcutaneous layer as compared with intramuscular layer and extra peritoneal space.ConclusionsThere is a correlation between knot-induced inflammation and differential knot location in murine abdominal wall.Knot in extra peritoneal space induced slight inflammation in abdominal wall as compared with other subcutaneous and intramuscular layers.Knot in extra peritoneal space is more likely to lower knot-induced inflammation and potential complications caused by extracorporeal knotting for laparoscopic inguinal inner ring closure in children.Long-term clinical trials are still required for further confirmations.