Factors influencing Frey syndrome after parotidectomy with acellular dermal matrix

BACKGROUND Frey syndrome,also known as ototemporal nerve syndrome or gustatory sweating syndrome,is one of the most common complications of parotid gland surgery.This condition is characterized by abnormal sensations in the facial skin accompanied by episodes of flushing and sweating triggered by cognitive processes,visual stimuli,or eating.AIM To investigate the preventive effect of acellular dermal matrix(ADM)on Frey syndrome after parotid tumor resection and analyzed the effects of Frey syndrome across various surgical methods and other factors involved in parotid tumor resection.METHODS Retrospective data from 82 patients were analyzed to assess the correlation between sex,age,resection sample size,operation time,operation mode,ADM usage,and occurrence of postoperative Frey syndrome.RESULTS Among the 82 patients,the incidence of Frey syndrome was 56.1%.There were no significant differences in sex,age,or operation time between the two groups(P>0.05).However,there was a significant difference between ADM implantation and occurrence of Frey syndrome(P<0.05).ADM application could reduce the variation in the incidence of Frey syndrome across different operation modes.CONCLUSION ADM can effectively prevent Frey syndrome and delay its onset.

Randomized controlled trial of minimally invasive surgery using acellular dermal matrix for complex anorectal fistula

AIM: To compare the efficacy and safety of acellular dermal matrix (ADM) bioprosthetic material and endorectal advancement flap (ERAF) in treatment of complex anorectal fistula. METHODS: Ninety consecutive patients with complex anorectal fistulae admitted to Anorectal Surgical Department of First Affi liated Hospital, Xinjiang Medical University from March 2008 to July 2009, were enrolled in this study. Complex anorectal fistula was diagnosed following its clinical, radiographic, or endoscopic diagnostic criteria. Under spinal anesthesia, patients underwent identification and irrigation of the fistula tracts using hydrogen peroxide. ADM was securely sutured at the secondary opening to the primary opening using absorbable suture. Outcomes of ADM and ERAF closure werecompared in terms of success rate, fecal incontinence rate, anorectal deformity rate, postoperative pain time, closure time and life quality score. Success was defined as closure of all external openings, absence of drainage without further intervention, and absence of abscess formation. Follow-up examination was performed 2 d, 2, 4, 6, 12 wk, and 5 mo after surgery, respectively. RESULTS: No patient was lost to follow-up. The overall success rate was 82.22% (37/45) 5.7 mo after surgery. ADM dislodgement occured in 5 patients (11.11%), abscess formation was found in 1 patient, and fistula recurred in 2 patients. Of the 13 patients with recurrent fistula using ERAF, 5 (11.11%) received surgical drainage because of abscess formation. The success rate, postoperative pain time and closure time of ADM were significantly higher than those of ERAF (P < 0.05). However, no difference was observed in fecal incontinence rate and anorectal deformity rate after treatment with ADM and ERAF. CONCLUSION: Closure of fistula tract opening with ADM is an effective procedure for complex anorectal fistula. ADM should be considered a first line treatment for patients with complex anorectal fistula.

A novel porcine acellular dermal matrix scaffold used in periodontal regeneration

Regeneration of periodontal tissue is the most promising method for restoring periodontal structures.To find a suitable bioactive three- dimensional scaffold promoting cell proliferation and differentiation is critical in periodontal tissue engineering.The objective of this study was to evaluate the biocompatibility of a novel porcine acellular dermal matrix as periodontal tissue scaffolds both in vitro and in vivo.The scaffolds in this study were purified porcine acellular dermal matrix(PADM) and hydroxyapatite-treated PADM(HA-PADM). The biodegradation patterns of the scaffolds were evaluated in vitro.The biocompatibility of the scaffolds in vivo was assessed by implanting them into the sacrospinal muscle of 20 New Zealand white rabbits.The hPDL cells were cultured with PADM or HA-PADM scaffolds for 3,7,14,21 and 28 days.Cell viability assay,scanning electron microscopy(SEM),hematoxylin and eosin(H&E) staining, immunohistochemistry and confocal microscopy were used to evaluate the biocompatibility of the scaffolds.In vitro,both PADM and HA-PADM scaffolds displayed appropriate biodegradation pattern,and also,demonstrated favorable tissue compatibility without tissue necrosis,fibrosis and other abnormal response.The absorbance readings of the WST-1 assay were increased with the time course, suggesting the cell proliferation in the scaffolds.The hPDL cells attaching,spreading and morphology on the surface of the scaffold were visualized by SEM,H&E staining,immnuohjstochemistry and confocal microscopy,demonstrated that hPDL cells were able to grow into the HA-PADM scaffolds and the amount of cells were growing up in the course of time.This study proved that HA-PADM scaffold had good biocompatibility in animals in vivo and appropriate biodegrading characteristics in vitro.The hPDL cells were able to proliferate and migrate into the scaffold.These observations may suggest that HA-PADM scaffold is a potential cell carrier for periodontal tissue regeneration.

Differentiation of mesenchymal stem cells into neuronal cells on fetal bovine acellular dermal matrix as a tissue engineered nerve scaffold

The purpose of this study was to assess fetal bovine acellular dermal matrix as a scaffold for supporting the differentiation of bone marrow mesenchymal stem cells into neural cells fol-lowing induction with neural differentiation medium. We performed long-term, continuous observation of cell morphology, growth, differentiation, and neuronal development using several microscopy techniques in conjunction with immunohistochemistry. We examined speciifc neu-ronal proteins and Nissl bodies involved in the differentiation process in order to determine the neuronal differentiation of bone marrow mesenchymal stem cells. The results show that bone marrow mesenchymal stem cells that differentiate on fetal bovine acellular dermal matrix display neuronal morphology with unipolar and bi/multipolar neurite elongations that express neuro-nal-speciifc proteins, includingβIII tubulin. The bone marrow mesenchymal stem cells grown on fetal bovine acellular dermal matrix and induced for long periods of time with neural differen-tiation medium differentiated into a multilayered neural network-like structure with long nerve ifbers that was composed of several parallel microifbers and neuronal cells, forming a complete neural circuit with dendrite-dendrite to axon-dendrite to dendrite-axon synapses. In addition, growth cones with filopodia were observed using scanning electron microscopy. Paraffin sec-tioning showed differentiated bone marrow mesenchymal stem cells with the typical features of neuronal phenotype, such as a large, round nucleus and a cytoplasm full of Nissl bodies. The data suggest that the biological scaffold fetal bovine acellular dermal matrix is capable of supporting human bone marrow mesenchymal stem cell differentiation into functional neurons and the subsequent formation of tissue engineered nerve.

Application of acellular dermal matrix for intestinal elongation in animal models

AIM:To investigate the eff icacy of acellular dermal matrix(ADM) for intestinal elongation in animal models.METHODS:Japanese white big-ear rabbits(n = 9) and Wuzhishan miniature pigs(n = 5) were used in the study.Home-made and commercial ADM materials were used as grafts,respectively.A 3-cm long graft was interposed in continuity with the small bowel and a sideto-side anastomosis,distal to the graft about 3-4 cm,was performed.The animals were sacrificed at 2 wk,4 wk,8 wk and 3 mo after surgery and the histological changes were evaluated under light microscope and electron microscope.RESULTS:The animals survived after the operation with no evidence of peritonitis and sepsis.Severe ad-hesions were found between the graft and surrounding intestine.The grafts were completely absorbed within postoper ative two or three months except one.Histological observ ation showed inflammation in the grafts with fibrinoid necroses,infiltration of a large amount of neutrophils and leukomonocytes,and the degree varied in different stages.The neointestine with wellformed structures was not observed in the study.CONCLUSION:It is not suitable to use acellular dermal matrix alone as a scaffold for the intestinal elongation in animal models.

Optimal Bioprinting Parameters and Experimental Investigation of Acellular Dermal Matrix Scaffold

Acellular dermal matrix(ADM)as a biomaterial is currently believed to be promising tissue repair improvement.With the development of tissue engineering,ADM is increasingly used as biological scaffolds.We explored the feasibility and performance of ADM biological scaffolds that fabricated by 3D printing.This paper presented our study on the printability of 3D printed ADM scaffolds,with a focus on identifying the influence of printing parameters/conditions on printability.To characterize the printability,we examined the fiber morphology,pore size,strand diameter,and mechanical property of the printed scaffolds.Our results revealed that the printability could be affected by a number of factors and among them,the most considerable one was related to the nozzle diameter and the composition of ADM.We then evaluated the biocompatibility in terms of cytotoxicity,cell proliferation and vivisection.In vitro evaluation of the ADM scaffolds was carried out and the experimental results indicated that cells were viable and proliferative during the period of study.In vivo results also indicated that the defect area was well repaired without any noticeable infection,hematoma and other conditions.In conclusion,ADM could be reconstructed with 3D printing technology and ADM biological scaffold has potential applications for tissue engineering.

Treatment of oral lichen planus by surgical excision and acellular dermal matrix grafting:Eleven case reports and review of literature

BACKGROUND Oral lichen planus(OLP)is a chronic inflammatory disorder,and it can affect normal oral function.The conventional treatments for OLP are not always effective,and relapse easily occurs.Therefore,treatment of OLP is difficult and challenging.In this study,we evaluated over a long period the clinical efficacy of surgical excision and acellular dermal matrix(ADM)grafting in patients with refractory OLP.CASE SUMMARY Eleven patients with refractory OLP underwent a standardized protocol of surgical excision and ADM grafting.The condition of the area of the grafted wound,the intraoperative maximum mouth opening,pain,and clinical healing were assessed at postoperative follow-up visits.All patients had a flat surgical area with similar mucosal tissue coverage and local scar formation.Patients had no irritation and pain in their mucous membranes when eating acidic and spicy food.All patients’mouth openings returned to normal within 2-6 mo after surgery.During follow-up,none of the patients had recurrence of OLP after surgery.The longest follow-up was 11 yr and the shortest was 6 mo,and none of the patients relapsed during follow-up.CONCLUSION Surgical excision and ADM grafting could be an effective method to treat refractory OLP.

Effects of allogeneic mouse adipose-derived mesenchymal stem cell-microporous sheep acellular dermal matrix on healing of wound with full-thickness skin defect in mouse and the related mechanism

Objective:To explore the effects of allogeneic mouse adipose-derived mesenchymal stem cell(ADSC)-microporous sheep acellular dermal matrix(ADM)on wound healing of full-thickness skin defect in mice and the related mechanism.Methods:One Kunming mouse was sacrificed by cervical dislocation to collect adipose tissue from the inguinal region.Mouse ADSCs were isolated from the adipose tissue and cultured in vitro.Cells in the third passage were identified by cell adipogenic and osteogenic differentiation.The expressions of CD34,CD73,CD90,and CD105 were analyzed by flow cytometer.After one sheep was sacrificed with the skin of its back cut off,microporous sheep ADM was prepared by using acellular processing and freeze-thaw method.A round and full-thickness skin defect wound,with a diameter of 12 mm,was made on the back of each of 36 Kunming mice.The wounds were covered by microporous sheep ADM.The mice were divided into ADSC group and control group with 18 mice in each group according to the random number table method after surgery.A volume of 0.2 ml of DMEM/F12 culture medium containing 1×10^(6)ADSCs was injected between microporous sheep ADM and the wound of each mouse in ADSC group,while 0.2 ml of DMEM/F12 culture medium was injected between microporous sheep ADM and the wound of each mouse in control group.At post-surgery day(PSD)12 and 17,the wound healing rate in each group was calculated respectively;wound vascularization in 2 groups of mice was observed under the reverse irradiation of back light;and the granulation tissue in the wound in ADSC group was observed by means of hematoxylin-eosin staining.At PSD 7,the thickness of the granulation tissue in the wound was measured in each group of mice.At PSD 12 and 17,the immunohistochemical method was used to detect the expression of VEGF in each group of mice.The number of samples was 6 in each group at each time point in the above experiments.The data obtained were processed with t-test and factorial design ANOVA.Results:(1)After 7 days of adipogenic induction,red lipid droplets were observed in the cytoplasm with oil red O staining.After 21 days of osteogenic induction,black calcium deposition was observed in the medium stained with silver nitrate.The expression levels of CD73,CD90,CD 105 and CD34 in cells were 97.82%,99.32%,97.35%and 5.88%respectively.The cells were identified as ADSCs.(2)The wound healing rates of ADSC group at PSD 12 and 17[(78±6)%,(98±3)%]were significantly higher than those of control group at PSD 12 and 17[(60±9)%,(90±4)%,t=4.26,4.46,p<.01].(3)At PSD 7,no vessels obviously grew into the center of the wound in both groups of mice,while the granulation tissue already covered the wound in ADSC group.At PSD 12,the wound in ADSC group was more well-perfused than control group.At PSD 17,it was observed that large vessels were crossing through the whole wound in ADSC group,while large vessels were observed without crossing through the whole wound in control group.(4)In ADSC group,at PSD 7,the wound was covered with thin granulation tissue,and the granulation tissue was obviously thickened at PSD 12.At PSD 17,the granulation tissue was covered by epidermis.At PSD 7,the thickness of the granulation tissue in the wound in ADSC group[(0.62±0.05)mm]was significantly greater than that in control group[(0.31±0.04)mm,t=12.27,p<.01].(5)At PSD 12 and 17,the expression levels of VEGF in the wound in ADSC group[(80.7±2.2),(102.8±2.6)/mm^(2)]were significantly than those in control group[(59.5±2.4),(81.5±2.6)/mm^(2),t=15.95,14.14,p<.01].Conclusions:Allogeneic mouse ADSC-microporous sheep ADM can promote angiogenesis and the growth of granulation tissue in the wound with full-thickness skin defect in mice,thus accelerating wound healing.The mechanism is probably related with the increase in the expression of VEGF.

Histologic analysis and long-term effect of acellular dermal matrix combined with autologous thin split-thickness skin graft

Objective To evaluate the long-term therapeutic effect and histologic result of ADM combined with autologous thin split-thickness skin graft.Methods 23 patients were treated with acellalar dermal matrix(ADM) combined with autoiogous

Reconstruction of the abdominal wall by using a combination of the human acellular dermal matrix implant and an interpositional omentum flap after extensive tumor resection in patients with abdominal wall neoplasm: A preliminary result

AIM:To present our trial using a combination of the human acellular dermal matrix (HADM) implant and an interpositional omentum flap to repair giant abdominal wall defects after extensive tumor resection. METHODS:Between February and October of 2007, three patients with giant defects of the abdominal wall after extensive tumor resection underwent reconstruction with a combination of HADM and omentum flap. Postoperative morbidities and signs of herniation were monitored. RESULTS:The abdominal wall reconstruction was successful in these three patients, there was no severe morbidity and no signs of herniation in the follow-up period. CONCLUSION:The combination of HADM and omentum flap offers a new, safe and effective alternative to traditional forms in the repair of giant abdominal wall defects. Further analysis of the long-term outcome and more cases are needed to assess the reliability of this technique.

Enhancing cartilage regeneration and repair through bioactive and biomechanical modification of 3D acellular dermal matrix

Acellular dermal matrix(ADM)shows promise for cartilage regeneration and repair.However,an effective decellularization technique that removes cellular components while preserving the extracellular matrix,the transformation of 2D-ADM into a suitable 3D scaffold with porosity and the enhancement of bioactive and biomechanical properties in the 3D-ADM scaffold are yet to be fully addressed.In this study,we present an innovative decellularization method involving 0.125%trypsin and 0.5%SDS and a 1%Triton X-100 solution for preparing ADM and converting 2D-ADM into 3D-ADM scaffolds.These scaffolds exhibit favorable physicochemical properties,exceptional biocompatibility and significant potential for driving cartilage regeneration in vitro and in vivo.To further enhance the cartilage regeneration potential of 3D-ADM scaffolds.we incorporated porcine-derived small intestinal submucosa(SIS)for bioactivity and calcium sulfate hemihydrate(CSH)for biomechanical reinforcement.The resulting 3D-ADM+SIS scaffolds displayed heightened biological activity,while the 3D-ADM+CSH scaffolds notably bolstered biomechanical strength.Both scaffold types showed promise for cartilage regeneration and repair in vitro and in vivo,with considerable improvements observed in repairing cartilage defects within a rabbit articular cartilage model.In summary,this research introduces a versatile 3D-ADM scaffold with customizable bioactive and biomechanical properties,poised to revolutionize the field of cartilageregeneration.

Application of acellular dermal matrix in breast reconstruction

In the past 10 years, acellular dermal matrix （ADM） has .been widely used in various fields of surgery, includingcleft palate repair, abdominal wall repair, tendon repair, hernia repair, facial and eyelid soft tissue augmentation surgery, ulcer repair, and vaginal sling repair, among others.1-3 ADM not only provides initial structural strength and bulk, but also allows relatively rapid vascular growth and serves as a scaffold for ＂new＂ tissue formation.4 These properties have led to its application to resolving surgical problems where tissue deficiency remains an issue. Many surgeons have begun to use ADM-assisted breast reconstruction techniques. Compared with ADM, the traditional method of implant-based breast reconstruction is more straightforward but is more prone to postoperative complications. Generally speaking, breast revision surgery procedures are complex, challenging, and unpredictable as the potential for the development of serious complications, such as capsular contracture （CC）, must be addressed. CC has plagued plastic surgeons as the most common complication of reconstructive breast surgery for many yearsY The application of ADM addresses these problems, and as a result, its popularity is growing： in the United States 73% of surgeons have some experience in the use of xenogeneic or allogeneic ADM in breast reconstruction.8 Furthermore, the use of ADM in nipple and areola reconstruction can achieve a more natural appearance and avoids complications of other more traditional techniques.~ In cases of breast reconstruction, techniques that incorporate the use of ADM have been used to treat and reduce the incidence of CC, determine the position of the inframammary fold and final breast contour, enhance the use of available mastectomy skin, and increase the thickness of the soft tissue to reduce implant visibility or palpability. These goals can be achieved by replacing or extending the tissue with ADM or using ADM as a supplement. In addition to the advantages afforded by the use of ADM, the safety and efficacy of these techniques have been widely reported.1-1 Tissue expander breast reconstruction consists of three major surgical steps： placement of the expander after mastectomy, exchange of the expander for an implant, and nipple-areola complex reconstruction. This article summarizes the main methods and different aspects of ADM-assisted breast reconstruction.

MRI tracking of human Wharton’s jelly stem cells seeded onto acellular dermal matrix labeled with superparamagnetic iron oxide nanoparticles in burn wounds

Background:In vivo cell tracking after transplantation in regenerative medicine remains an unmet challenge and limits current understanding of the wound healing mechanism through cell-based therapies.This study investigated tracking of human Wharton’s jelly stem cells(hWJSCs)seeded onto an acellular dermal matrix(ADM)and labeled with superparamagnetic iron oxide nanoparti-cles(SPIONs)by magnetic resonance imaging(MRI)in burn injury.Method:The hWJSCs were characterized and assessed for growth kinetics.A total of 30 rats were enrolled in three equal groups.Group 1 underwent scald burn injury left without treatment,the group 2 was treated by an ADM that was prepared from cosmetic surgery skin samples and the group 3 received hWJSCs labeled with SPIONs seeded onto an ADM.Tensile strength was evaluated before and after interventions,real time PCR assessed apoptosis,and Prussian blue staining,scanning electron microscopy(SEM)and MRI were used for the tracking of labeled cells.Results:The hWJSCs exhibited mesenchymal stem cell properties.Population doubling time was 40.1 hours.SPIONs did not show any toxic effect.The hWJSCs seeded onto an ADM decreased Bax and increased Bcl-2 gene expression.Internalization of SPIONs within hWJSCs was confirmed by Prussian blue staining,SEM and MRI until day 21.There was a significant difference between the Young’s moduli of normal skin and the group receiving hWJSCs seeded onto an ADM.Histological observations and SEM imaging confirmed that MRI is an accurate method to track SPION-labeled hWJSCs in vivo.Conclusions:This study showed that SPION labeling coupled with MRI can be used to further understand the fate of stem cells after transplantation in a burn model.

Frozen bean curd-inspired xenogeneic acellular dermal matrix with triple pretreatment approach of freeze–thaw,laser drilling and ADSCs pre-culture for promoting early vascularization and integration

Xenogeneic acellular dermal matrix(ADM)is widely used in clinical practice given its good biocompatibility and biomechanical properties.Yet,its dense structure remains a hindrance.Incorporation of laser drilling and pre-culture with Adipose-derived stem cells(ADSCs)have been attempted to promote early vascularization and integration,but the results were not ideal.Inspired by the manufacturing procedure of frozen bean curd,we proposed a freeze–thaw treatment to enhance the porosity of ADM.We found that the ADM treated with-80℃3Rt-30℃3R had the largest disorder of stratified plane arrangement(deviation angle 28.6%)and the largest porosity(96%),making it an optimal approach.Human umbilical vein endothelial cells on freeze–thaw treated ADM demonstrated increased expression in Tie-2 and CD105 genes,proliferation,and tube formation in vitro compared with those on ADM.Combining freeze–thaw with laser drilling and pre-culture with ADSCs,such tri-treatment improved the gene expression of proangiogenic factors including IGF-1,EGF and vascular endothelial growth factor,promoted tube formation,increased cell infiltration and accelerated vascularization soon after implantation.Overall,freeze–thaw is an effective method for optimizing the internal structure of ADM,and tri-treatments may yield clinical significance by promoting early cell infiltration,vascularization and integration with surrounding tissues.

Meshed acellular dermal matrix:technique and application in implant based breast reconstruction

Alloderm was the first acellular dermal matrix used and remains a popular choice among plastic surgeons.However,while the overall surgical outcome of breast reconstruction using alloderm has been a success,the economic burden on the health care system makes it a subject of frequent re-evaluations in cost-effectiveness.Prompted by the high price of$3,700 USD for a 6 cm×16 cm area,our group proposes the meshing of AlloDerm to decrease the total amount needed for breast reconstruction,while achieving comparable surgical outcomes as using unmeshed alloderm.

The Versatility of Acellular Fetal Bovine Dermal Matrix for Head and Neck Surgical Reconstruction in Children

Objectives: To describe the versatility of acellular fetal bovine dermal matrix as an alternative to human cadaveric allograft for head and neck reconstructive procedures in children. Study Design: Case series with chart review. Methods: A database of pediatric operative procedures was queried for the use of acellular fetal bovine dermal matrix over a 16-month period. Indications for reconstruction were assessed and initial parental and surgeon satisfaction with the product were noted. Results: During the time period of 3/2012 and 7/2013 a total of 8 reconstructive procedures were performed on pediatric patients using acellular fetal bovine dermal matrix. Indications for use varied and included open and transnasal endoscopic repair of encephaloceles and soft tissue reconstructions including lateral pharyngeal wall repair, cleft palate repair, and facial recontouring operations. Acellular fetal bovine dermal matrix had a subjectively increased ease of use as compared to the surgeon’s prior experience with human cadaveric acellular dermis. Every parent vocalized a greater comfort level with the use of a bovine product over the alternative of human cadaveric tissue. The cost of acellular fetal bovine dermal matrix is slightly lower than the cost of human cadaveric acellular dermis. Conclusions: Acellular fetal bovine dermal matrix appears to be an acceptable alternative to human cadaveric acellular dermis for various forms of head and neck soft tissue reconstruction in children. Further prospective studies are warranted to assess for any differences in the long-term efficacy of this product as compared to other forms of allograft reconstruction.

Lessons Learned from Three Different Acellular Dermal Matrices in Direct-to-Implant Breast Reconstruction

The aim of the study was to show significant differences regarding postoperative complications and outcomes using three different Acellular Dermal Matrices (ADM), namely Epiflex®, Strattice® and Braxon®, in immediate implant-based subpectoral breast reconstruction cases. Background: The use of Acellular Dermal Matrices for implant-based breast reconstruction cases continues to evolve. There is a wide variety of products which differ significantly in their biological features. It remains unclear if and how these differences manifest in clinical practice. Methods: 82 cases of primary breast reconstruction in the Department of Plastic and Aesthetic Surgery of HELIOS Clinics Schwerin, Germany between 2010 and 2018 were analyzed. 25 patients received Strattice® acellular dermal matrix (SADM), 22 cases Epiflex® acellular dermal matrix (EADM) and the remaining 35 cases Braxon® acellular dermal matrix (BADM). The mean follow-up was 1.8 years. Cases were analyzed regarding minor or major complications and rate of capsular contracture grade III or IV (Baker Classification). Results: The overall complication rate was 34.1% for all groups (SADM = 40%, EADM = 50%, BADM = 20%, p-value = 0.051). Of all cases, 6 patients underwent implant exchange or secondary autologous reconstruction due to capsular contracture (7.3%). The mean time between revision due to capsular contracture and reconstruction was 35.8 ± 14.4 months. 50% of patients, who developed capsular contracture, received postoperative radiation. Mean hospitalization time was 8.2 ± 3 days (SADM = 8 ± 3.2 days, EADM = 10 ± 2.8 days, BADM = 6 ± 1.3 days). There were no significant differences between all three groups for demographics, overall complication rate or capsular contracture. However, patients receiving Braxon® matrix showed significantly fewer minor complications (p-value = 0.01). Moreover, patients receiving Braxon® ADM showed a significantly lower time of hospitalization (p < 0.001). Conclusion: No significant differences regarding the overall complication rate were found between the three groups. Different biological features of ADM showed a weak influence on overall results. However, patients receiving Braxon® ADM showed significantly lower minor complication rates and hospitalization time. In addition, these matrices showed a trend towards lower capsular contracture rates. The low rate of capsular contracture hints at possible advantages of ADM-use in direct-to-implant cases.

Macrophage phenotypes correspond with remodeling outcomes of various acellular dermal matrices

Macrophages have recently been characterized as having an M1 or M2 phenotype based on receptor expression, mechanism of activation and function. The effects of macrophage phenotype upon tissue remodeling following implantation of an acellular dermal matrix (ADM) is largely unknown. The purpose of this study was to compare the macrophage phenotype and tissue remodeling elicited by four different ADMs (DermaMatrix, AlloDerm, Integra and Der mACELL). ADM samples were wrapped around the inferior epigastric vessels of a rat and were harvested on 7, 14, 21 and 42 days post implantation. Immunohistologic methods were used to identify macrophage surface markers CD68 (pan macrophage), CCR7 (M1 profile), and CD206 (M2 profile). All human derived ADMs showed a bell shaped curve for distribution of CD68+ macrophages with peaks for DermaMatrix occurring at day 14 and peak influx for AlloDerm occurring on day 21. In contrast, bovine derived Integra showed an increasing trend of macrophages with time. DermACELL had the highest influx of macro- phages while Integra had the lowest. A quantitative analysis of phenotype of macrophages in AlloDerm showed that the cells were predominantly M1 at 7, 14, 21 and 42 days post implantation. In contrast, Integra showed a mixed M1/M2 population of macrophages at all time points. The histopathologic evaluation showed that a predominantly M1 macrophage response was associated with a more inflamematory type tissue remodeling outcome in AlloDerm while a mixed M1/M2 macrophage response was associated with a more constructive tissue remodeling response seen in the other substrates.

不同软组织替代物在比格犬尖牙唇侧区域移植后附着龈的厚度和组织学变化

背景:上皮下结缔组织移植被认为是软组织增量术的金标准,然而,自体移植需要开辟第二术区,延长手术时间,增加患者的疼痛感,这也使得软组织替代物成为研究热点。目的:比较不同软组织替代物在比格犬尖牙唇侧区域移植后移植区附着龈厚度和组织学变化。方法:在3只比格犬尖牙唇侧附着龈区域,分别用双层同种异体脱细胞真皮基质膜(allograft acellular dermal matrix,AADM)、牛源性脱细胞真皮基质(bovine acellular dermal matrix,BADM)联合浓缩生长因子膜以及BADM联合胶原蛋白海绵进行附着龈增厚。分别在术前和术后1,2,3,4个月测量附着龈厚度,术后4个月进行组织学观察。结果与结论:①术后第1-4个月,双层AADM组附着龈厚度及附着龈厚度增量均值高于其他2组(均P<0.05);②术后1个月3组附着龈厚度显著增加,而后呈下降趋势;术后3个月,BADM联合胶原蛋白海绵组与BADM联合浓缩生长因子组移植区附着龈厚度变化较术前差异无显著性意义(P>0.05);术后4个月,双层AADM组附着龈厚度均值较术前仍显著增加(P<0.05);第1-4个月双层AADM组附着龈厚度值最高,其次为BADM联合胶原蛋白海绵组,BADM联合浓缩生长因子组最低;③双层AADM组真皮基质与宿主牙龈组织良好的结合在一起,并可见新生纤维结缔组织和成纤维细胞长入基质内,另外两组移植物已经完全吸收,增量区域改建成与周围宿主组织一致的结构;④结果说明,AADM在牙龈增厚方面优于BADM联合浓缩生长因子膜和BADM联合胶原蛋白海绵。

复合皮移植联合VSD修复碾压伤致肘关节外露

目的:探讨复合皮移植联合负压封闭引流(Vacuum sealing drainage,VSD)在碾压伤伴关节外露创面修复中的临床应用效果及可行性。方法:2020年12月,笔者科室收治1例因左上肢车祸伤致皮肤坏死伴肿胀1 d的患者,入院时查体左上肢肿胀,左前臂、肘部可见约15.0 cm×20.0 cm皮肤坏死,左手感觉功能减退,桡动脉尚可触及,急诊手术探查见肘关节外露、脱位,肱三头肌自肱骨大范围撕脱,尺神经外露、移位,肘关节、尺骨外露范围约3.0 cm×5.0 cm。根据患者病史、临床表现、左上肢X线片及手术探查体征诊断左上肢碾压伤,肘关节外露。应用复合皮移植两步法联合VSD覆盖创面,自体中厚皮片移植修复皮肤缺损。结果:患者左上肢皮肤缺损处愈合良好,术后4个月复查,肘关节屈曲、伸直、旋转功能均恢复良好。结论:对于此例肘关节、骨外露创面,应用复合皮移植后可覆盖骨外露创面,大大降低了手术难度及患者的痛苦,为以后相对小面积骨外露创面的修复提供了新思路。