Analysis Of Factors Affecting The Effects Of Artificial Dermis On Hand External Injury

Objective: Artificial dermis is a kind of membrane-like structure that has non cellular bilayer and can be substituted for skin tissue.The structure of the inner layer is made of 6-collagen and chondroitin sulfate,the surface is a temporary substitute for silicone skin cover.The inner structure allows the migration of fibroblast like cells,macrophages,and lymphocytes,and capillaries to the surface,thereby providing a biological condition for the regeneration of the skin.At first,artificial dermis was used to treat third-degree burn wounds of threaten lives.Artificial dermis has different sizes and different shapes for clinicians to choose from.In addition,there are two types of surface covering with or without silicone resin skin substitutes.For artificial dermis with no silicone resin skin substitute,it can be directly transplanted on the surface of the wounds and can make new skin close wounds,and reduce the number of migratory muscle fibroblasts.This can reduce the adhesion of superficial tissues under the artificial dermis to the joints,tendons,and nerves below.Artificial dermis has been successfully used in the treatment of burns,tumor resection,avulsion,congenital malformations and other diseases,and has achieved satisfactory results.The purpose of this study is to investigate the clinical efficacy of artificial dermis treatment for hand trauma and to analyze the factors that influence its recovery.Method:From April 2013 to December 2015,25 cases of hand trauma patients with hand skin defects were given artificial dermis cover to close their wounds after debridement.After 2 ~ 3 weeks' time,pink dermoid tissues were found to be formed on the wounds,and the wounds with bone and tendon exposure were found to be covered by dermoid tissues.Phase II transplantation of autologous thin skin onto the wounds were administered after the removal of artificial dermis silicone membrane.While some of the wounds had no autosomatic transplantation,the surface of the wounds had become naturally epithelialized.The study has obtained approval from the Ethics Committee of the PLA 252 Hospital.Before the operation,all patients were informed of the purpose and significance of the study and signed their agreement to participate.Out of the 25 patients,18 were males and were 7 females,averaging about 35.2 years(age from 16 to 59 years old).The artificial dermis was cut according to the shape and area of the patients' skin defect of hand trauma.The average area of skin wound defect was 2.0cm ×1.5 cm~9.0cm ×6.5cm.The factors that affect the therapeutic effects were determined by a statistical analysis of the patients' recovery,and the therapeutic effect was assessed utilizing the Vancouver Scar Scale(VSS)and Hand Score.Result:Of the 25 patients in the study,artificial dermis transplanted showed no complications such as infection,hematoma,bleeding,etc.While the artificial dermis of 17 patients had 100% grown into the surrounding tissues and fused well,2%~5% area of the artificial dermis in 6 patients was not fused with the surrounding tissues,and the artificial dermis in 2 patients still had 5%~10% area which had not fused with the surrounding tissues.The wounds healed well,in which 20 patients newborn dermal tissue grew well,and the wounds were repaired by skin graft and 5 patients wounds healed on its own.All patients were followed up for 3 ~19months.Through a multiple regression analysis,the factors that affect the treatment outcome were revealed,which include: the cause of the injury,the area of the defect,whether the injury was associated with the exposure of bone and tendon,and the blood supply of the wounds and their surrounding areas.Conclusion:There are some advantages for the use of artificial dermis to treat skin defect of hand injury,especially for patients with bone and tendon exposure of hand injury.The advantages are: 1.3D mesh stent like structure is conducive to the growth of induced dermoid tissues,and can treat complex wounds with bone and tendon exposure with good results;2.the operation itself is simple with short operation time and low risks,thus can be easily popularized;3.during operation Phase II,it only needs the patients' own skin graft to repair the skin flap wounds,thus reducing damage to the donor site and contributing to postoperative wound healing;4.After the operation,the patients' healing wounds demonstrates flexible texture,good wear resistance and have no obvious pigmentation and scars,and the appearance of the wounds is not bloated.The patients' sensation and function are better recovered as well;5.it needs no special nursing care after the operation and the patients can have early postoperative functional exercise.At the same time,the treatment of traumatic hand skin defect with artificial dermis may also has some limitations: 1.it would take 2 ~ 3 weeks for pink dermoid tissues to be formed after the implantation of artificial demis,and during Phase II of the operation,it needs autologous skin graft to repair the wounds,prolonging the treatment of the patients in the hospital and causing new injury at the skin graft's donor site;2.artificial dermis itself has no resistance to infection,so after the surgery,debridement,hemostasis and drainage should be thoroughly conducted,and postoperative conditions of the patients should be closely observed to prevent infection;3.The high medical cost of the operation is another obvious limitation,and it may depend on the size of the artificial dermis needed;4.although we believe that skin graft can restore good appearance and function,the requirements of the relevant medical ethics of certain units may limit the use of artificial dermis graft,making it difficult to carry out the relevant clinical treatment.The main factors that may influence the therapeutic effect are: 1.injury types.In terms of treatment effect for different injury types,degloving injury was the worst,crush injury was the second,and contusion and abrasion was better,and cutting injury was the best.2.injury area.The larger the injury area,the worse the treatment effect of the operation,and vice versa.3.whether the injury is associated with bone and tendon exposure.The effect of the operation to treat injuries with bone and tendon exposure was poor,while the effect of the operation to treat injuries without bone or tendon exposure can be satisfactory;4.the condition of blood supply of the wounds and surrounding areas.The therapeutic effect for wounds that have poor blood supply at the wound base and surrounding areas was poor,while the effect for patients with good blood supply at the wound base and surrounding areas can be satisfactory.