Effects Of Different Suture Methods On Scar Formation Under The Condition Of Simulated High Skin Tension

Objective: The purpose of this study is to explore the effects of three different suture methods,simple interrupted suture,vertical mattress suture,and returning needle in-situ vertical mattress suture on the formation of scars under the condition of continuous high tension.Methods:(1)A total of 18 healthy adult female SD rats were selected.After anesthesia,the 5cm×2mm full-thickness skin was cut off longitudinally on the back,and they were randomly divided into three groups to be sutured according to the following three suture methods: simple interrupted suture group-SIS,vertical mattress valgus suture group-VMS,in situ back stitch vertical mattress suture group-R-VMS;(2)The traction devices were installed for mechanical traction,and the traction distance was increased 2mm every day to form a high-tension suture wound;(3)The process of the wound healing and scar growth were observed continued and recorded by photos;(4)Scar tissue samples were collect from each group after 20 days,and HE staining performed to observe the morphology of scar tissue,Masson performed to calculate the collagen production rate;(5)Immunofluorescence staining was used to detect the expression of type I and III collagen;(6)Immunohistochemical staining performed to detect the expression of myofibroblast marker α-SMA;(7)RT-q PCR And Western blot was used to detect the expression of TGFβ1,TGFβ2,and TGFβ3.Results: Three different suture methods for continuous high-tension incision suture established successfully.The scar formation was observed at 0,5,10,and 20 days after operation.The incision healing speed in the R-VMS group was significantly faster than that of the SIS group and the VMS group;the incision line scars were seen in the SIS group and the VMS group after healing,and the incision disappeared in the R-VMS group.The results of HE staining showed that the scar dermis in the SIS group and the VMS group was flat,and the collagen fibers were wavy and dense.The dermal epidermis of the R-VMS group was thinner,and the collagen fibers were looser.The number of skin adnexities such as hair follicles and sweat glands in the R-VMS group was more than in SIS and VMS groups.Masson staining results showed that the collagen fibers in the R-VMS group were loose and the number of collagen fibers decreased.The quantitative results of collagen fraction showed that the collagen density of the R-VMS group was significantly lower than that of the SIS and the VMS group.Immunofluorescence results showed that the expression of type I collagen in the three groups was higher than that of type III collagen.The expression of type I collagen in the SIS group and the VMS group was significantly more than that in the R-VMS group,and the expression level of type III collagen was significantly lower than that in the R-VMS group.There was no significant difference between the SIS group and the VMS group.The results of immunohistochemistry showed that the expression level of the myofibroblast marker—α-SMA in the R-VMS group was lower than that in the SIS and VMS groups.RT-q PCR and Western blot results showed that the expression level of TGFβ1 in the R-VMS group was lower than that of the SIS group and the VMS group,and the expression of TGFβ2 and TGFβ3 did not change significantly in the three groups.Conclusions: In high-tension incisions,compared to simple interrupted suture and vertical mattress valgus suture,the returning needles in-situ vertical mattress suture has a better effect on reducing scar formation with the reduce of collagen formation,myofibroblast expression,and TGFβ1 expression.