The Effect Of Steel Knife, Electrotome And Radiofrequency On The Healing Of Skin Incision

Objective:Maxillofacial region is located in the exposed parts of human body and is related to the oral-facial aesthetics. With the improvement of living standards, patients are paying more attention to the healing quality of skin incision after operation. Healing quality of skin incision has become a research hotspot in oral and maxillofacial surgery and plastic surgery fields. There are various types of scalpels, including steel knife, electrotome and radiofrequency. Steel knife, regarded as a traditional scalpel, is widely applied in skin incision. Electrotome is widely used in subcutaneous soft tissue and occasionally in skin incision. Radiofrequency can be directly used to the incision of skin and deep soft tissue. Up till now there is little research on the effect of three kinds of knife on the healing of skin incision. The study aim at observing the effect of three kinds of knife on the healing of rat skin incision and providing a guide for the selecting of different scalpel by using HE staining and Picrosirius-red staining.Methods:1 Experimental animals and groupsTwelve healthy female Wistar rats with age of four month and weights from 250 to 300 gram were selected for the study. There were six incisions on the back of each rat with self-contrast and there were 72 incisions in the experiment. The animal samples were divided into three groups: steel group, electrotome group, and radiofrequency group. Each group included 24 samples.2 Operation processUnder general anesthesia, steel knife, electrotome and radiofrequency were used to cut back skin for two times, respectively. The length of the incisions was 1.5cm and the incisions were parallel to the spine. The depth of the incisions included skin, subcutaneous tissue, and muscle. All incisions were sutured with 3-0 silk thread.3 Collection of samplesOn the 1st, 2nd, 3rd, 4th weeks after the surgery, 3 rats were sacrificed at each time point and specimens were collected according to different groups. Every specimen included the full-thickness skin with the area 2.0×1.5cm2. All specimens were fixed in the 10% formaldehyde solution. The specimens were made 4um tissue slice after dehydrated in ethanol,cleared in xylene, and embedded in waxing. Finally the tissue slices were stained by hematoxylin-eosin and Picrosirius-red.4 Observation indexGeneral observation:(1) bleeding and charring during operation;(2) postoperative healing line and the texture of surrounding skin. HE stainning: the healing time of epidermis; the thickness of epidermal; and the arrangement of the dermis collagen fiber. The Picrosirius-red staining: the contents, distribution, and ratio of collagen type I and type Ⅲ.5 Statistical analysisStatistical analysis was performed by SPSS 21.0 software and repeated measure was used. All data are presented as Mean±SD Valus for P < 0.05 were considered significant difference.Results:1 Bleeding and charring during operationThere was a little bleeding on the wound in steel knife group. There was no bleeding but a little charring on the wound in electrotome group. There was no bleeding and charring on the wound in radiofrequency group.2 General observationsOne week and two weeks after the operation: there was more obvious healing line and a little tough skin in steel knife group. There was obvious healing line and tougher skin in electrotome group. There was not obvious healing line and softer skin in radiofrequency group.Three weeks and four weeks after the operation: there was a little obvious healing line and a little tough skin in steel knife group. There was obvious healing line and tougher skin in electrotome group. There was not obvious healing line and softer skin like normal skin in radiofrequency group.3 Histological changesOne week after the operation: there was healing epidermal layer on incisions in three groups. There was healing dermis and thinner keratinized layer on incisions in steel knife group. There was incomplete healing dermis and thicker keratinized layer on incisions in electrotome group. There was healing dermis and the thinnest keratinized layer on incisions in radiofrequency group.Two weeks after the operation: there was the looser collagen fiber arranged in bundles in Steel knife group. There were a large number of newborn fibroblasts and thicker and denser fiber in bundles in electrotome group. There was looser fiber in small bundles in radiofrequency group.Three weeks after the operation: the collagen in steel knife group was more regular and looser than that in electrotome group. The collagen in electrotome group was larger, denser, and in a mess while the collagen in radiofrequency group was regular and loose.Four weeks after the operation: The collagen in steel knife group and electrotome group was similar to that of the third week. The epidermal layer in radiofrequency group was thin, flat, and loose while the collagen was arranged in small bundles.4 Quantitative analysis of the skin collagen fiberThe amount of collagen fiber: with the extension of healing time, the total amount of collagen fiber in three groups was increasing. At one week and two weeks after operation, the total amount of collagen fiber in radiofrequency group was the most, the amount in steel knife group the second, and the amount in electrotome group the lest. There was significant difference among steel knife group, electrotome group and radiofrequency group(P < 0.05). At three weeks and four weeks after operation, the total amount of collagen fiber in electrotome group was the most, the amount in steel knife group the second, and the amount in radiofrequency group the lest. There was significant difference among steel knife group, electrotome group and radiofrequency group(P < 0.05).The amount of collagen type Ⅰ: with the extension of healing time, the amount of collagen type in three groups was increasing. At one week, two Ⅰweeks, three weeks, and four weeks after operation, the amount of collagen type in electrotome group was theⅠ most, the amount in steel knife group the second, and the amount in radiofrequency group the lest. There was significant difference among steel knife group, electrotome group and radiofrequency group(P < 0.05).The amount of collagen type Ⅲ: with the extension of healing time, the amount of collagen type Ⅲ in three groups was decreasing. But at two weeks after operation the amount of collagen type Ⅲ in steel knife and electrotome group was increasing. At one week, two weeks, three weeks, and four weeks after operation, the amount of collagen type Ⅲ in radiofrequency group was the most, the amount in steel knife group the second, and the amount in electrotome group the lest. There was significant difference among steel knife group, electrotome group and radiofrequency group(P < 0.05).The ratio of collagen Ⅰ/Ⅲ: with the extension of healing time, the ratio of collagen Ⅰ/Ⅲ in three groups was increasing. But at two weeks after operation the ratio of collagen Ⅰ/Ⅲ in electrotome group was decreasing. At one week, two weeks, three weeks, and four weeks after operation, the ratio of collagen Ⅰ/Ⅲ in electrotome group was the most, the amount in steel knife group the second, and the amount in radiofrequency group the lest. There was significant difference among steel knife group, electrotome group and radiofrequency group(P < 0.05).Conclusions:1 There is effect of steel knife, electrotome, radiofrequency on the healing quality of skin incision.2 Compared with steel knife and radiofrequency, electrotome has more effect on healing of skin incision and electrotome had better not to cut directly the skin.3 Compared with steel knife, radiofrequency generates less scar in the healing of skin incision.