A novel subcision technique for effective treatment of depressed facial scars

Although there are many treatment methods for depressed scars, most of them are complex, with longer downtime and certain adverse effects. Subcision is a commonly used minimally invasive surgical treatment for depressed scars, with the advantages of being simple, effective, and cost-efficient (Figures S1 and S2).1 However, traditional subcision technique has disadvantages of narrow indications and obvious sensation of pain during the operation. In this study, we made a comprehensive and innovative improvement of the subcision technique, including the tool and the method. In this study, we conducted a clinical trial on 102 patients who had depressed facial scars of different types, and treated them using this new subcision technique. This study was approved by the Ethics Committee. In terms of treatment tools, we chose the relatively small 26G needle rather than 18G needles or blunt knives. Compared with traditional tools, it can facilitate the precision of subcision without damaging the normal tissues around the scar, and greatly reduce the feeling of pain during the treatment.2 Another key point of this new technique is the selection of the subcision layer according to the atrophy degree of the scar. For scars with smaller atrophy degrees, such as rolling scars and icepick scars, the subcision layer was selected in the middle and lower dermis. This type of scars retains the structure of normal skin at its base, and its depression is mainly caused by dermal tethering of otherwise normal skin.3 While the layer close to the skin surface was selected as the subcision layer for scars with a deeper atrophy degree, such as chickenpox scars and boxcar scars. The basal structure of this kind of scar is different from that of normal skin, and there is no standard structure of various layers, which makes the surgeon unable to effectively identify the dermis layer. Traditional subcision technique can easily damage deeper tissues and fail to achieve good effects. According to observations and statistics, the overall postoperative scar grade was significantly lower than the preoperative scar grade (1.32 ± 0.50 vs. 3.69 ± 0.47, p < 0.001), as evaluated by two independent physicians using the Goodman and Baron scale (Figure 1). By group, there were no significant differences in the baseline data of these groups, such as age, scar existence time, and preoperative scar grade. The postoperative scar grades of patients who suffered from chickenpox scars or boxcar scars were significantly lower than those of patients who suffered from icepick scars and rolling scars (Table 1). We speculate that the differences in treatment outcomes of different types of facial depressed scars may be related to the structure of the scars. Chickenpox scars and boxcar scars share a similar morphology with vertical and neat edges because the level and extent of the cutaneous involvement are consistent, and often involve all layers of the skin.4 It is easier to precisely control the depth of subcision layer during the operation. By contrast, rolling scars and icepick scars are variable and irregular in morphology because of the different cutaneous involvement. Our study shows that this novel subcision technique has a good effect on the treatment of depressed facial scars, which is simple and effective. It is a good option for patients who are unwilling to undergo complex or expensive therapies and pursue short downtime. This technique is particularly suitable for the treatment of chickenpox scars and boxcar scars. Due to the impact of prevalence, we were unable to recruit more types of patients with depressed facial scars, and the effectiveness of this technique on depressed facial scars caused by other causes needs to be further investigated. Yueheng Zhu developed the idea and provided the methodology for the study. Yueheng Zhu and Jintian Hu performed the operation and collected the data. Zehui Li collected the data, analyzed the data, and wrote the paper. The remaining authors contributed to refining the ideas，discussing the results, and revising the manuscript. We are grateful to every staff member and patient who provided support for this study. The authors have no financial interest to declare in relation to the content of this article. This study complies with the Declaration of Helsinki, and all patients signed informed consent forms. Figure S1 Figure S2 Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.