Skin defects of the hand due to trauma are common injuries which are often accompanied by exposure of tendon, bone, nerve, and blood vessels [4]. The treatment methods vary widely due to different range of possible injuries which should be individualized considered both to the patients and to the injuries [14, 15]. Typical treatment of skin defects of hand is focusing on autologous skin grafts and flaps, while this kind of traditional treatment methods cannot overcome the vital demerit of the second injury to the donor side where the skin or graft harvested and other demerits including color mismatch, contour and volume mismatch, and texture mismatch, etc. [6]. Moreover, the consequent sensorimotor function recovery of both the donor and the recipient areas is still a problem that not only affects the treatment effect but also brings up the associated burden to the patients and family.
The search for an ideal “synthetic” or “artificial” skin graft, which could be found without using skin tissues from elsewhere in the body to avoid donor-site morbidity during reconstructing the soft tissue defect, is still a formidable task for surgeons [3]. In 1981, O’Connor et al. [16,17,18] first reported the successful use of autologous cultured human epithelium in the repair of the wounds of 2 burn patients. Subsequent animal-derived artificial skin, Integra® Matrix Wound Dressing (Integra Life Sciences, Plainsboro, NJ), was successfully developed as a skin substitute to promote the repair of damaged tissue. With rapid development of biological tissue engineering technologies, tissue engineering of skin now employs one of three distinct approaches including tissue constructed and cultured in vitro using seeded cells and scaffold materials, tissue composed of cells only, and tissue engineering of scaffold materials to promote epithelialization [19,20,21]. Meanwhile, xenogeneic tissues, which are not limited by the autologous source required of current approaches, are becoming a focal area of research.
The ideal artificial skin coverage should be easy to obtain, convenient to use, bioactive, and protective. Since SIS patch has been used more than 3 decades in the field of medicine, it has been shown to help tissue regeneration and angiogenesis, such as in skull base reconstruction [22, 23], upper airway tissue remodeling [24], tympanic membrane repair [25], cardiovascular diseases [26]. The natural three-dimensional ECM framework composed of collagen I, III, and IV and a variety of bioactive substances it contains makes it helpful during wound healing [7, 8], and this kind of particular composition enables it rapid the rate of angiogenesis and does not activate immune system [9, 10]. The natural three-dimensional structure of the collagen framework could facilitate cell migration, and cells in the wound bed could secrete endogenous regulatory factors, which can stimulate the growth of new tissue, regulate immune function, and transport stem cells to the affected area at the same time [10]. This kind of crosstalk makes adequate preparations for the healing of the wound. Meanwhile, the ECM could protect these growth factors from inactivation and prolong their half-life [27], which enables the biological factors and polysaccharides in the ECM keep playing their roles in the affected area, including promoting tissue regeneration, vascular growth, and neuronal differentiation [28]. The SIS patch has been reported useful in musculoskeletal reconstructions of the foot and ankle due to its characteristics of augmentation effect on cellular and vascular in-growth [29], while another report of Hodde et al. [30] showed SIS patch did not improve the rate of tendon healing or the clinical outcome scores. The treatment effect of SIS patch in glenohumeral arthritis is also ambiguous [31]. Whether SIS patch is superiorly useful in hand skin reconstruction is still unclear. Our group had used SIS patch to cure hand skin defects, and the preliminary effects seems satisfying. Here, we conducted this retrospective investigation to report the results.
The initial principal aims of any type soft tissue reconstruction are to restore the form, function, and sensation of the hand [6]. Color mismatch, contour and volume mismatch, texture mismatch, donor-recipient tissue interface, hair growth and the following scar location and development of skin contractures, and overall appearance of the donor site are all issues that need to be considered preoperation. The novel soft tissue repair patch used in this study can supply adequate strength to be sutured and is also soft enough to cover the wound bed to provide a barrier against the outside pathogen environment [32, 33]. The last follow-up results in this study show that this novel SIS patch is really helpful in skin defect that it could supply stable coverage until the new growth of the skin tissue. Further evaluation of the newborn skin shows that the SCAR scale of the novel patch group is superior to the autologous skin graft group, while the BMRC grading of sensation assessment has no significant difference between them. These results may indicate that in situ regeneration could better mimic the surrounding affected skin during wound healing, which may be the ideal of skin regeneration process. It is inseparable that the coverage of the novel SIS patch could supply a perfect microenvironment during this process. In the meantime, without sacrifice of other skin tissue of the body could be treated as another advantage of the novel SIS patch, which could eliminate the corresponding risk of the donor side, while the financial burden of the patients and society of patch used should be a potential issue to be reconsidered. The sensation recovery of the new skin tissue still needs further research to be verified.
This study also presents some limitations. First, the sample size of the current study is small, and larger number of patients and prospective study are needed to support the advantages of the novel SIS patch and perfect the indications. This trial includes adults and children could be treated as another limitation, as many potential differences may exist between them. Further research that can differentiate this issue is needed in the future to confirm the results. Meanwhile, advanced research on the mechanisms of the novel SIS patch during tissue recovery is also needed to explore more evidence on the fueling tissue growth. Last, we focused on the treatment of full-thickness hand skin defects, which may be an underlying limitation of the study. As hand injuries always accompanied by multiple tissue injuries (such as bone or nerve tissue), whether this novel SIS patch is still effective in this complex tissue reconstruction procedure must be further validated, which could be the direction of future study.