One-step approach for full-thickness skin defect reconstruction in rats using minced split-thickness skin grafts with Pelnac overlay

Background:Split-thickness skin grafting is the current gold standard for the treatment of traumatic skin loss.However,for patients with extensive burns,split-thickness skin grafting is limited by donor skin availability.Grafting split-thickness skin minced into micrografts increases the expansion ratio but may reduce wound repair quality.Dermal substitutes such as Pelnac can enhance the healing of full-thickness skin wounds,but their application currently requires two surgeries.The present study investigated whether it is possible to repair full-thickness skin defects and improve wound healing quality in a single surgery using Pelnac as an overlay of minced split-thickness skin grafts in a rat model.Methods:A full-thickness skin defect model was established using male Sprague-Dawley rats of 10 weeks old.The animals were randomly divided into control and experimental groups in which Vaseline gauze and Pelnac,respectively,were overlaid on minced split-thickness skin grafts to repair the defects.Wound healing rate and quality were compared between the two groups.For better illustration of the quality of wound healing,some results were compared with those obtained for normal skin of rats.Results:We found that using Pelnac as an overlay for minced split-thickness skin grafts accelerated wound closure and stimulated cell proliferation and tissue angiogenesis.In addition,this approach enhanced collagen synthesis and increased the formation of basement membrane and dermis as well as the expression of growth factors related to wound healing while reducing scar formation.Conclusions:Using minced split-thickness skin grafts overlaid with Pelnac enables the reconstruction of fullthickness skin defects in a single step and can increase the healing rate while improving the quality of wound healing.

Effects of hyperbaric oxygen therapy on 32 cases of full-thickness skin grafting for the repair of defects on the hand and foot

Full-thickness skin grafting is one of the most commonly used repair methods for skin defects. It has the advantage of wear-resistant with less scar hyperplasia and less difficult to operate with no symptoms. Hyperbaric oxygen was used in this study after full-thickness skin grafting from September 2012 to August 2016 to achieve the best effect of skin survival after surgery.

Oxygen Penetration Through Full-Thickness Skin by Oxygen-Releasing Sutures for Skin Graft Transplantation

The transplantation of full-thickness skin grafts(FTSGs)is important for reconstructing skin barrier and promoting wound healing.Sufficient oxygen supply is closely related to the success of skin grafting.However,full-thickness oxygen delivery is limited by the poor oxygen permeability of skin.Oxygen-releasing sutures(O_(2)sutures)were developed to facilitate oxygen penetration through full-thickness skin.The O_(2)sutures delivered 100 times more oxygen than topical gaseous oxygen therapy at a 15 mm depth in the skin model.Under extreme hypoxia(<0.5%O_(2),v/v),O_(2)sutures could also promote endothelial cell proliferation.After the transplantation of FTSGs in mice,O_(2)sutures accelerated blood re-perfusion and increased the survival area of the skin graft.It is expected that O_(2)sutures will be adopted in clinical applications to increase the success rate of full-thickness skin transplantation.

Correction of Scar Contracture Deformity of Dorsal Hand by Invisible Full-thickness Mesh Skin Graft

Objective To investigate the effect of invisible full-thickness mesh skin graft in the treatment of scar contracture deformity of the dorsal hand.Methods From January 2016 to February 2019,25 patients with cicatricial contracture deformity of dorsal hand admitted to our hospital underwent full thickness skin graft.During the operation,the scar healed completely and the superficial fascia remained intact.The wound surface was transplanted with invisible mesh full thickness skin graft.The survival of the skin graft and the recovery of hand function and appearance in the later period were observed after the operation.Results The skin grafts of 20 patients survived with high quality,3 cases had partial epidermis exfoliation,and 2 cases had partial epidermis scattered in blisters.After intensive dressing change,all wounds healed and no complications occurred after the operation.The hand function and appearance of the patients were obviously improved.Conclusion The application of full thickness skin graft to correct scar deformity has the advantages of good functional and appearance recovery and difficult postoperative contracture.Invisible full-thickness mesh skin graft is one of the ideal methods to correct scar contracture deformity of the dorsal hand.

3-D bioprinted human-derived skin organoids accelerate full-thickness skin defects repair

The healing of large skin defects remains a significant challenge in clinical settings.The lack of epidermal sources,such as autologous skin grafting,limits full-thickness skin defect repair and leads to excessive scar formation.Skin organoids have the potential to generate a complete skin layer,supporting in-situ skin regeneration in the defect area.In this study,skin organoid spheres,created with human keratinocytes,fibroblasts,and endothelial cells,showed a specific structure with a stromal core surrounded by surface keratinocytes.We selected an appropriate bioink and innovatively combined an extrusion-based bioprinting technique with dual-photo source cross-linking technology to ensure the overall mechanical properties of the 3D bioprinted skin organoid.Moreover,the 3D bioprinted skin organoid was customized to match the size and shape of the wound site,facilitating convenient implantation.When applied to full-thickness skin defects in immunodeficient mice,the 3D bioprinted human-derived skin organoid significantly accelerated wound healing through in-situ regeneration,epithelialization,vascularization,and inhibition of excessive inflammation.The combination of skin organoid and 3D bioprinting technology can overcome the limitations of current skin substitutes,offering a novel treatment strategy to address large-area skin defects.

Extensive full-thickness eyelid reconstruction with rotation flaps through "subcutaneous tunnel" and palatal mucosal grafts

· AIM: To reconstruct the extensive full-thickness defects of eyelids is a challenge for the plastic surgeon because of their complex anatomy and special functions.This article presents and discusses an improved surgical technique in which the orbicularis oculi myocutaneous flap is rotated through a "subcutaneous tunnel" in conjunction with a palatal mucosal graft employed for lining.·METHODS: Data from 22 eyes with extensive full-thickness eyelid defects from various causes between2009 and 2013 were analyzed in this study. After the different layers of eyelid were separated completely, a temporally based orbicularis oculi myocutaneous flap was designed following fishtail lines and was mobilized,leaving the base of the pedicle intact with a submuscular tissue attachment. The flap was then rotated through a "subcutaneous tunnel" to the defect, and the donor site was closed primarily. Posterior lamellar reconstruction was performed with a mucosal graft harvested from the hard palate.·RESULTS: All the flaps were survived without any healing problems. There was no corneal irritation, flap contraction, or significant donor-site morbidity in the follow-up period. The incision scars were almost invisible.The defects were repaired completely, and the evaluations showed satisfactory function and appearance.·CONCLUSION: This technique is an improved singlestage operation and can be applied to repair large, full-thickness eyelid defects from various causes. With our method, the functional and aesthetic results can be obtained in either the upper or lower eyelids.

Subcutaneous pedicle Limberg flap for repairing skin defects in the face

Objective:To investigate the effect of a subcutaneous pedicle Limberg flap for the reconstruction of medium-sized skin defects in the face following skin tumor or scar excision. Methods: From August 2002 to June 2004,the subcutaneous pedicle Limberg flap was designed to repair facial skin defects in 17 patients(19 flaps),and the size of the lesions ranged from 2.0 cm×1.9 cm to 5.0 cm×4.5 cm.The operation was performed under general anesthesia in 2 children,and under local anesthesia in the remaining 15 patients. Results: All flaps survived with primary healing postoperatively.With a follow-up from 1 to 22 months,neither short-term nor long-term postoperative complications such as flap necrosis,hematoma,infection,visible dog-ear and trap door deformity were found,and functionally and cosmetically satisfactory outcomes were achieved. Conclusion: This subcutaneous pedicle Limberg flap provides a competitive repair alternative for the treatment of medium-sized skin defects in the face.

Bipedicled Mini V-Y Advancement Flap for Skin Defect of the Face

In young patients, even small circular facial defects after the excision of benign skin tumors present a reconstructive challenge. The usefulness of a V-Y advancement flap for reconstructing such defects is well documented. We refined this technique as a mini V-Y advancement flap consisting of two subcutaneous pedicles that vascularize the skin island via subdermal plexus lateral bridges. This technique was used for 21 middle-aged or younger patients with a small benign skin lesion. None of them experienced any postoperative complications. Aesthetically excellent results were found in all patients. This small advancement flap could be attempted as an alternative to fusiform excision of small skin lesions, particularly in younger patients.

Regenerative Medicine: A Review of Solutions in the Treatment of Skin Defects

The issue of skin defects is a major concern of almost every trauma surgeon after surgery. Despite numerous conventional methods and introduction of the reconstruction ladder, managing skin defects is still a challenge for the trauma surgeons. In recent years, parallel to the advances in the more conventional methods of skin repair, regenerative medicine has offered new and novel treatments. This article aims to explore these contemporary regenerative solutions as well as to review the conventional methods of treating skin defects.

Porocarcinoma in a palm reconstructed with a full thickness skin graft: A case report

BACKGROUND Porocarcinoma is a rare type of skin cancer that originates from sweat gland tumors.It is an aggressive malignant skin cancer that is difficult to diagnose clinically owing to its rarity and similarity to squamous cell carcinoma(SCC).CASE SUMMARY This case involved a 92-year-old woman,a farmer by profession,presented with an exophytic and verrucous mass on her left palm that had formed 2 years prior and caused chronic pain and frequent bleeding.Initially,the patient was diagnosed with SCC using a punch biopsy;however,a repeat biopsy with addi-tional immunohistochemical tests was performed for porocarcinoma.Ultimately,the patient was diagnosed with porocarcinoma and reconstruction was planned using a full-thickness skin graft.After treatment,the range of motion of the palm was preserved,and the aesthetic outcome was favorable.At 6 mo of follow-up,the patient was satisfied with the outcome.CONCLUSION Porocarcinoma is commonly misdiagnosed as SCC;therefore,clinicians should consider porocarcinomas when evaluating mass-like lesions on the hands.

Application of free vein skin flap on the anterior aspect of wrist in the case of finger injury with vessel and skin defect

Objective To introduce an effective reconstruction method for the finger injured with vessel and skin defect. Methods Free skin flap with skin vein was transplanted on the site of tissue defect, connecting by anastomosis the vein with artery or vein of the finger. Results Seven cases were treated with this method,among which 5 cases have sikin defect on the palm aspect of fingers, the rest have skin defect on the dorsal aspect skin of finger. All fingers survived with good shape and function. Conclusion This is a simple and effective method of finger reconstruction for the patients with defect of vessels and skin. 6 refs.

Repair of facial skin defect with a skin flap of SMAS pedicle

To report a method of repair facial skin defects with a skin flap of SMAS pedicle.Methods According to the size of defect of skin,design a skin flap with SMAS pedicle for repair of defect.Results The method has been successfully applied for skin defects of eyelid and lip in 14 cases with satisfied results.The area of the largest flap was 5 cm×3 cm.Conclusion Repairing facial defects such as eyelid skin defect or lip skin defect with skin flap of SMAS pedicle is a very good method.The flap has a good blood supporting and satisfactory color and flexibility.5 refs,6 figs.

外源性碱性成纤维细胞生长因子促进大鼠创面愈合的机制

背景:深入揭示外源性碱性成纤维细胞生长因子促进创面愈合的分子机制。目的:探讨外源性碱性成纤维细胞生长因子对大鼠创面修复中巨噬细胞表型转换和肉芽再生的影响。方法:(1)体外细胞实验:分为正常对照组、低剂量碱性成纤维细胞生长因子组、高剂量碱性成纤维细胞生长因子组以及碱性成纤维细胞生长因子+丙戊酸组,其中低、高剂量碱性成纤维细胞生长因子组细胞培养基中分别添加100,200μg/L碱性成纤维细胞生长因子,碱性成纤维细胞生长因子+丙戊酸组细胞培养基中添加200μg/L碱性成纤维细胞生长因子和20 mmol/L Notch1/Jagged1激动剂丙戊酸。通过EdU实验、划痕实验、小管生成实验检测碱性成纤维细胞生长因子对人脐静脉内皮细胞增殖、迁移和血管新生的影响。(2)体内动物实验:SD大鼠按照随机数字表法分为模型组、低剂量碱性成纤维细胞生长因子组、高剂量碱性成纤维细胞生长因子组以及碱性成纤维细胞生长因子+丙戊酸组,构建大鼠全层皮肤缺损开放性创面模型,其中低、高剂量碱性成纤维细胞生长因子组皮下注射100,200μg/L碱性成纤维细胞生长因子,碱性成纤维细胞生长因子+丙戊酸组大鼠皮下注射200μg/L碱性成纤维细胞生长因子的同时腹腔注射10 mg/kg丙戊酸。给药7,14 d检测大鼠创面的愈合率;TUNEL检测创面组织中的细胞凋亡情况;酶联免疫吸附实验检测大鼠血清中丙二醛、超氧化物歧化酶、肿瘤坏死因子α和白细胞介素10水平;免疫荧光检测创面组织中巨噬细胞的表型转换情况;免疫组化检测创面组织中增殖细胞核抗原、CD31和血管内皮生长因子的表达;Western blot法检测创面组织中Notch1、Jagged1的表达。结果与结论:(1)与正常对照组相比,碱性成纤维细胞生长因子能明显促进人脐静脉内皮细胞的增殖、迁移和血管新生,并且具有剂量依赖性;(2)与模型组相比,碱性成纤维细胞生长因子能明显促进创面的愈合,下调创面组织中的细胞凋亡率;降低大鼠血清中丙二醛和肿瘤坏死因子α水平,升高超氧化物歧化酶和白细胞介素10水平;促使创面组织中巨噬细胞向M2型转换,上调创面组织中增殖细胞核抗原、CD31和血管内皮生长因子的表达;抑制创面组织中Notch1、Jagged1的表达,并且均具有剂量依赖性。丙戊酸可部分逆转碱性成纤维细胞生长因子对创面愈合的促进作用。结果表明,碱性成纤维细胞生长因子能明显促进创面愈合与肉芽再生以及诱导巨噬细胞向M2型转换,这可能与调控Notch1/Jagged1信号有关。

脱细胞皮肤基质/聚氨酯混纺纤维支架促进大鼠皮肤缺损的修复

背景:研究证实,将脱细胞基质与聚合物进行混合纺丝不仅可改善纤维的结构性质,还可保存脱细胞基质的生物学活性,但是目前将聚氨酯与脱细胞皮肤基质进行静电纺丝制备皮肤组织工程支架还没有相关报道。目的:观察脱细胞皮肤基质/聚氨酯混纺纤维支架对大鼠皮肤缺损的修复作用。方法:利用静电纺丝技术分别制备聚氨酯静电纺丝纤维支架和脱细胞皮肤基质/聚氨酯混纺纤维支架。扫描电镜下观察纤维结构;将大鼠脂肪间充质干细胞分别接种于两组支架上,扫描电镜下观察支架上的细胞形态。取10只SD大鼠,在每只大鼠背部制作3个1 cm×1 cm的全层皮肤缺损,其中2处缺损分别植入聚氨酯静电纺丝纤维支架(对照组)、脱细胞皮肤基质/聚氨酯混纺纤维支架(实验组),剩余缺损处不植入任何材料(空白对照组)。术后第1,2,3周,观察皮肤创面愈合情况;植入后第3周,进行创面苏木精-伊红染色,计算创面瘢痕面积。结果与结论:①扫描电镜下可见两种静电纺丝纤维均为网状结构,并且大鼠脂肪间充质干细胞在两种支架上沿纤维附着,黏附良好。②随着术后时间的延长,各组皮肤创面逐渐愈合,至术后第3周,实验组、对照组皮肤创面基本愈合,空白对照组创面可见小溃疡形成。皮肤创面苏木精-伊红染色显示,对照组、实验组创面表皮覆盖基本完整,真皮层内可见成纤维细胞长入和炎症细胞浸润,并且实验组创面胶原纤维较为丰富、排列规则有序,与表皮面基本平行;空白对照组创面表皮仍有缺损。实验组创面瘢痕面积小于其他两组(P<0.05,P<0.01)。③结果表明,脱细胞皮肤基质/聚氨酯混纺纤维支架可以有效修复大鼠全层皮肤缺损、改善创面瘢痕形成。

甲基丙烯酰化改性真皮细胞外基质水凝胶促进腹壁缺损修复

背景:目前用于填充腹壁缺损部位的合成高分子材料(如聚丙烯或聚酯)不仅缺乏可降解性和生物活性,还难以适应复杂形状伤口需求,因此,找到免疫原性低、组织相容性好的生物活性材料成为腹壁缺损修复研究的热点。目的:制备甲基丙烯酰化改性真皮细胞外基质水凝胶,探讨其在腹壁缺损中的潜在应用价值。方法:(1)依次用0.25%胰蛋白酶、1%Triton X-100对猪真皮进行脱细胞处理,获得真皮细胞外基质;胃蛋白酶消化真皮细胞外基质,经甲基丙烯酸酐改性后光交联形成甲基丙烯酰化改性真皮细胞外基质水凝胶,扫描电镜观察水凝胶的微观形貌,测试其流变学性能、溶胀性等理化性质;(2)将L929成纤维细胞接种到甲基丙烯酰化改性的真皮细胞外基质水凝胶中,检测细胞相容性;(3)将12只SD大鼠随机分为2组(n=6),创建保留腹膜的腹壁缺损模型,聚丙烯组缺损部位填充聚丙烯材料,水凝胶组缺损部位填充甲基丙烯酰化改性真皮细胞外基质水凝胶,两组创面皮肤均用聚丙烯材料覆盖,观察创面愈合情况并进行组织学分析。结果与结论:(1)采用酶解法对猪真皮进行脱细胞后具有良好的脱细胞效果,并且原有的糖胺聚糖及胶原蛋白保留较好。扫描电镜下可见甲基丙烯酰化改性真皮细胞外基质水凝胶为疏松多孔结构,孔径在70-120μm之间,该水凝胶的溶胀比为(16.88±3.24)%,吸水率为(94.24±1.11)%,流变学性能测试表明该水凝胶状态稳定且具有剪切变稀特点,具备可注射性;(2)CCK-8检测与Live/Dead染色结果显示,甲基丙烯酰化改性真皮细胞外基质水凝胶具有良好的细胞相容性;(3)动物实验结果显示,实验组术后7,10,14 d的皮肤创面愈合率高于对照组(P <0.05);皮肤与肌层组织苏木精-伊红、Masson染色显示,与聚丙烯组比较,水凝胶组术后14 d的皮肤创面上皮化情况、毛囊生成、胶原纤维排列及新生血管情况更好,术后28 d的皮肤创面新生组织结构与正常组织相近,并且瘢痕增生较少,术后28 d时可见少量肌肉组织再生;(4)结果表明,甲基丙烯酰化改性真皮细胞外基质水凝胶可促进腹壁缺损大鼠的皮肤创面愈合和肌肉组织再生。

Role of adipose-derived stromal cells in pedicle skin flap survival in experimental animal models

The use of skin flaps in reconstructive surgery is the first-line surgical treatment for the reconstruction of skin defects and is essentially considered the starting point of plastic surgery. Despite their excellent usability, their application includes general surgical risks or possible complications, the primary and most common is necrosis of the flap. To improve flap survival, researchers have used different methods, including the use of adiposederived stem cells, with significant positive results. In our research we will report the use of adipose-derived stem cells in pedicle skin flap survival based on current literature on various experimental models in animals.

Prediction of shear-related defect locations in semi-solid casting using numerical flow models

Contaminated surfaces of the feedstock materials in aluminum alloy casting processes often produce various types of defects which can affect the tensile properties of the final products as well as their fatigue reliabilities.Semi-solid processing takes advantage of a much higher apparent viscosity of the die cast materials by limiting the risk of oxides formed at the free surfaces to become incorporated into the casting when the material is injected into the die.Most of existing semi-solid processes that use billets as feedstock material are however tied up with a different type of contaminated surface.During the injection phase,the external-skin on the periphery of the billet,which has been in contact with air and lubricant during the transfer in the shot sleeve,can be incorporated into the casting.When subjected to a heat treatment,the lubricant is decomposed and produces lens shape porosities.This might be a cause of reject for most structural parts.To avoid this kind of defects,the paths along which the billet skin evolves must be controlled during filling.In order to investigate the possibility of skin inclusion into cast parts during injection of the billet,a two-phase finite element mixture model is employed to model the metal flow.The formation of a skin on the periphery of the billet is modeled by setting an initial solid phase concentration profile in the radial direction.Microscopic observations of the real castings show that the approach is able to model the shear layers and to predict the paths along which the"lens porosity"defects could be formed.An Arbitrary Eulerian-Lagangian(ALE) method is also investigated and appears to be very promising to follow the skin movement in the casting.

Reconstruction of massive skin avulsion of the scrota and penis by combined application of dermal regeneration template(Pelnac) and split-thickness skin graft with vacuum-assisted closure: A case report

BACKGROUND Although skin avulsions to male external genitalia are rare, they can be both physically and psychologically traumatic. Thus, the necessity for judicious management poses significant challenges to surgeons in order to avoid potential permanent disabilities. We report a case of massive penoscrotal skin avulsion and a composite graft was creatively applied to cover the defect which achieved good results. We believe that this case is of great reference value for fellow surgeons.CASE SUMMARY A 52-year-old male presented with massive traumatic avulsion of the penile and scrotal skin following mishandling of an electric drill. The avulsed skin was missing. The patient was diagnosed with massive skin avulsion of external genitalia. Following initial complete debridement of devitalized or infected tissues, Pelnac dermal substitute was secured to the defect with the assistance of negative-pressure wound closure. In the final step, the silicone layer of Pelnac was removed and a split-thickness skin graft was applied. The defect had healed at the two-month follow-up. The patient now has normal erections and satisfactory sexual function.CONCLUSION Our experience with this wound repair demonstrated that the combination of a dermal regeneration template and a split-thickness skin graft with vacuumassisted closure is a safe, well-tolerated and efficient solution for the reconstruction of massive penoscrotal skin defects.

Facial Reconstruction with Combined Facial,Neck and Occipital Skin Flap Transplantation

To treat large facial defect (more than 6 cm×4 cm in diameter ) or a wound with bone exposure to atmosphere by less traumatic, easier healing reconstruction method, a pedicle flap including facial, neck, posterior auricle and occipital skin flap was designed and transferred, one by one, to repair facial defect as well as other flap donor sites, but occipital skin flap was only used to cover posterior auricle area. After 2-3 years follow up, well healed skin flaps with good color, elasticity and sensation were observed in all 16 patients. It is concluded that this method is effective and practical.

Feasibility and efficacy of endoscopic purse-string suture-assisted closure for mucosal defects induced by endoscopic manipulations

BACKGROUND Large or transmural defects induced by gastrointestinal endoscopic manipulations are difficult to close,although complete closure is recommended for better recovery.Endoscopic purse-string assisted suturing(EPSS)has been used in clinical practice and has proven to be an effective and safe technique for the closure of large mucosal defects.However,details regarding the efficacy of endoscopic pre-purse-string suture(P-EPSS)are unknown,especially that it offers several advantages over conventional EPSS(C-EPSS).AIM To elucidate the outcomes of EPSS-assisted closure in different clinical situations,and evaluate the efficacy of P-EPSS.METHODS This retrospective observational study included a total of 180 patients who underwent closure assisted by P-EPSS(n=63)or C-EPSS(n=117)between July 2014 and June 2020.The P-EPSS and C-EPSS groups were compared and the intergroup differences in aspects such as the lesion size,location,and morphology,incidence of complete closure,intraoperative perforation,and delayed adverse events were evaluated.Data on the features and clinical course of cases with adverse events were collected for further analysis.RESULTS Patients with lesion size larger than 3 cm,lesions located at the fundus of stomach,or submucosal tumors originating from the deep mucosa were more likely to undergo P-EPSS-assisted closure.The P-EPSS group showed a significantly higher proportion of intraoperative perforation(56%vs 17%)and a much shorter procedure time(9.06±6.14 min vs 14.84±7.25 min).Among adverse events,the incidence of delayed perforation(5%vs 4%;P=0.82)and delayed bleeding(3%vs 4%;P=0.96)did not differ significantly between the groups.Multivariate analysis revealed that lesions with incomplete closure[odds ratio(OR)=21.33;95%confidence interval(CI):5.45-83.45;P<0.01]or size greater than 3 cm(OR=3.14;95%CI:1.08-9.18;P=0.039)showed a statistical tendency to result in an increase in delayed adverse events.CONCLUSION The present study revealed that EPSS could achieve secure complete closure of mucosal defect.PEPSS could shorten the procedure and yield complete closure of mucosal defects.Rather than closure-type selection,incomplete closure or lesion size larger than 3 cm were associated with worse outcomes.