Superior Capsule Reconstruction Using Fascia Lata Allograft Compared With Double- and Single-Layer Dermal Allograft: A Biomechanical Study.

PURPOSE: To biomechanically characterize superior capsule reconstruction (SCR) using fascia lata allograft, double-layer dermal allograft, and single-layer dermal allograft for a clinically relevant massive irreparable rotator cuff tear involving the entire supraspinatus and 50% of the infraspinatus tendons. METHODS: Eight cadaveric specimens were tested in 0°, 30°, and 60° abduction for (1) intact, (2) massive rotator cuff tear, (3) SCR using fascia lata, (4) SCR using double-layer dermis, and (5) SCR using single-layer dermis. Superior translation and subacromial contact pressure were measured. Statistical analysis was conducted using repeated measures ANOVA or paired t test with P < .05. RESULTS: Massive rotator cuff tear significantly increased superior translation of the humeral head at all abduction angles (P < .05). At 0° abduction, all SCR conditions significantly decreased superior translation compared with the massive tear but did not restore translation (P < .05) to intact. Fascia lata and double-layer dermis SCR restored superior translation to intact at 30° and 60° of abduction, but single-layer dermis did not. Subacromial contact pressure at 0° of abduction significantly decreased with SCR with fascia lata and double-layer dermis compared with tear. At 30°, all SCR conditions significantly decreased subacromial contact pressure. Single-layer dermis graft thickness significantly decreased more than fascia lata during testing (P = .02). CONCLUSION: For SCR tensioned at 20° glenohumeral abduction, all 3 graft types may restore superior translation and subacromial contact pressure depending on the glenohumeral abduction angle; fascia lata and double-layer dermis may be more effective than single-layer dermis. CLINICAL RELEVANCE: If a dermal graft is to be used for SCR, consideration should be given to doubling the graft for increased thickness and better restorative biomechanical properties, which may improve clinical outcomes following SCR.

Superior Capsular Reconstruction Using Dermal Allograft Is a Safe and Effective Treatment for Massive Irreparable Rotator Cuff Tears: 2-Year Clinical Outcomes.

PURPOSE: To evaluate functional, symptomatic, and diagnostic imaging outcomes after arthroscopic superior capsular reconstruction (SCR) using dermal allograft in patients with massive irreparable rotator cuff tears. METHODS: From 2015 to 2017, this multicenter study retrospectively evaluated patients undergoing arthroscopic SCR for treatment of symptomatic massive rotator cuff tears. Study criteria included the presence of a massive irreparable rotator cuff tear with retraction to the glenoid without diffuse bipolar cartilage loss, Grade 4 or 5 Hamada classification, and subscapularis pathology that could not be addressed. All SCR procedures were performed with neutral abduction of the arm at the time of implantation. Outcome measures included visual analog pain scale (VAS) score, the American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE) score, and active forward elevation (FE) through 2 years postoperatively. Imaging analyses included radiographs, ultrasound, and magnetic resonance imaging at 6 months and 1 year. RESULTS: Fourteen patients met all study criteria including required follow-up. There were statistically significant improvements in VAS pain (3.3-0.6, P = .001), ASES (55.0-86.5, P < .0001), SANE (33.1-71.5, P < .0001), and active FE (128-172, P = .0005) with mean follow-up of 2.1 years. Twelve patients (86%) met the minimum clinically important difference in VAS pain, ASES, and SANE. Thirteen grafts (93%) had ultrasonographic evidence for vascularity by 1 year postoperatively. There were 2 graft complications (14%) with one (7%) requiring revision to reverse total shoulder arthroplasty. CONCLUSIONS: Arthroscopic SCR using dermal allograft can be a safe and effective treatment option for patients with massive irreparable rotator cuff tears with statistically significant improvements in VAS pain, ASES, SANE, and active FE at 2-years postoperatively, with 93% of grafts demonstrating vascularity at 1-year postoperatively. Neutral abduction of the arm at the time of implantation resulted in positive clinical outcomes and may decrease graft failure rate. LEVEL OF EVIDENCE: Level IV, case series.

Preliminary studies of hair follicle regeneration by injections of epidermal stem cells and dermal papilla cells into nude mice.

The ultimate goal of organ regenerative therapy is to reproduce fully functional organs to replace which have been damaged as a result of diseases or injury. Although several studies claimed that using different types of cells in some animal models promote hair follicles regeneration, more researches can be done to develop a sufficient and efficient protocol to induce hair generation from different animal models. In this study, we investigated the therapeutic potentials for hair follicle formation by injecting a mixture of epidermal stem cells and dermal papilla cells. Those cells were isolated and culture-expanded. Then we randomly allocated 8 nude mice into two groups. The experiment group received an injection of a mixture that containing of epidermal stem cells and dermal papilla cells. The control group received injection of keratinocyte serum-free medium. The hair follicles regeneration was observed and the injection area was harvested for HE staining. 14 day later, the regenerated hair shafts were observed and HE staining indicated that the newly hair follicle formed the correct structures in experiment group. Furthermore, the mixture injection induced a regular and multilayered stratified epidermis and the epidermis contained of hair follicle-likes structures. Our data showed that injection of a mixture of epidermal stem cells and dermal papilla cells could induce hair follicles regeneration and well-ordered epidermis formation. This study emphasized that the rearrangement of the interactions during seed cells and the niches of the seed cells is essential and necessary for tissue-engineered construct success.

Filling Up the Valleys

Man has tried and sought to erase wrinkles and scars for millennia. Sadly, however, the most effective and permanent techniques have fallen into disuse and neglect due to lack of training in universities, lack of awareness on the part of both physicians and patients, and heavy mass marketing of injectable fillers. Dermal grafting is a standard, time honored method for permanent correction of deep facial defects. Our goal as dermatologists is to generate the best results for our patients, and also to develop our personal skills and talents to the utmost.

Impact of human mesenchymal cells of different body site origins on the maturation of dermo-epidermal skin substitutes.

AIM OF THE STUDY: The use of autologous bio-engineered dermo-epidermal skin substitutes (DESS) yields a pivotal opportunity to cover large skin defects in human patients. These skin grafts consist of both epidermal and dermal compartments necessary for robust and permanent functional wound closure. In this study, we investigated the impact of mesenchymal cells derived from different body site origins on the expression pattern of diverse markers within DESS. METHODS: Human keratinocytes were obtained from interfollicular epidermis, and mesenchymal cells were isolated from foreskin, palmar skin, fat tissue, and tonsils. After expansion, epidermal cells were seeded on collagen I hydrogels containing stromal cells. These human DESS were transplanted on the back of immune-incompetent rats. After 3 weeks, transplants were excised and analyzed using immunohistology techniques. MAIN RESULTS: The macroscopic appearance of skin grafts containing tonsil, fat tissue, or palmar derived mesenchymal cells, was similar to substitutes with foreskin derived dermal fibroblasts. All skin grafts had a strong membrane-localized expression of Lingo-1 in the epidermis. Additionally, we observed an intense expression of transglutaminase 5 in upper epidermal cell layers of the skin grafts confirming a proper keratinocyte differentiation. Tropoelastin was localized throughout the dermal compartments and tightly in contact with the dermo-epidermal junction suggesting an advanced maturation of all skin grafts. CONCLUSIONS: Our data implicate that stromal cells derived from tonsil, fat tissue, and palmar skin can assume fibroblast functions supporting keratinocyte proliferation and differentiation. These findings indicate that distinct types of mesenchymal cells can be clinically used for skin engineering purposes.

Induction of angiogenic and inflammation-associated dermal biomarkers following acute UVB exposure on bio-engineered pigmented dermo-epidermal skin substitutes in vivo.

PURPOSE: Ultraviolet (UV) radiation adversely affects skin health at cellular and molecular levels. Hence, UV radiation can directly induce inflammatory responses in the dermis by inducing erythema, edema, inflammation, dermal fibroblasts alterations, and extracellular matrix modifications. METHODS: Human keratinocytes, melanocytes, and fibroblasts were isolated from skin biopsies, cultured, and expanded in vitro. Fibroblasts were seeded into collagen type I hydrogels that were subsequently covered by keratinocytes and melanocytes. These pigmented dermo-epidermal skin substitutes (pigmDESS) were transplanted for 5 weeks onto full-thickness skin wounds on the back of immuno-incompetent rats, exposed to a single UVB dose of 250 mJ/cm2 or unexposed and excised after 1 week. The effects onto the dermis were assessed regarding cell number, cell phenotype, and cell proliferation. Local inflammation by granulocytes (HIS48) or macrophages (CD11b, iNOS) was analyzed by immunohistochemistry staining. RESULTS: We observed a significantly enhanced ingrowth rate of blood capillaries, but not of lymphatic capillaries at 1 week post-irradiation. Moreover, the enhanced vascularization of pigmDESS after UVB exposure was concomitant with a high infiltration of granulocytes and monocytes/macrophages to the dermal part of grafts. In addition, a heterogeneous expression of HIF-1α and TNFα was detected at this early phase after UVB exposure. In local cellular response examination, results only show a moderate cell proliferation in the dermis. CONCLUSIONS: We were able to define early markers of UVB-induced effects in the dermis of pigmDESS. Overall, a single UVB dose induces temporary acute angiogenic and immune responses during the early post-irradiation phase in vivo.

Microdermal Grafting for Color Regeneration of White Scars.

White scars are defined in this study as mature hypopigmented surgical or traumatic scars whose color is much lighter than surrounding skin, to the extent that they appear white. These scars are often obvious and very difficult to treat or mask. This 3-year retrospective study reports the outcomes from 38 recipients of a new microdermal grafting surgery we developed, which introduces melanocytes into the white scar lesion to regenerate skin color. The study shares 18 years of experience with this procedure, describes the surgical steps, offers videos of the procedures, and presents 4 cases. Between September 2013 and December 2016, 38 patients (30 females; 8 males) underwent microdermal grafting for color regeneration of white scars in our plastic surgery clinic. Most patients, 78.9%, received 1 treatment, 15.8% received 2 treatments, and 5.3% received 3 treatments. Three lay judges were asked to assess percentage pigmentation recovery by comparing photographic images of patients' preoperative and postoperative scars. Patients were also asked to assess, via a questionnaire, satisfaction and percentage improvement 1 year after surgical treatment. Lay judges found an average of 49% improvement after 1 session, 75% after 2 sessions, and 90% after 3 sessions. In total, 71.1% of the patients completed the questionnaire 1 year after the surgery. Average subjective improvement was 55% after 1 session, 88% after 2 sessions, and 95% after 3 sessions. The patient satisfaction rate was high. Microdermal grafting provides adequate treatment of white scars by regenerating melanocytes, although more than 1 session treatment may be needed.

[Use of the autologous dorsal dermis in reconstruction of the posterior palpebral lamella in blepharopoiesis]. / Utilisation du derme dorsal autologue en reconstruction lamellaire palpébrale postérieure en blépharopoïèse.

OBJECTIVES: Blepharopoiesis represents a double aesthetic and functional challenge. If anterior lamellar reconstruction is less discussed, the variety of posterior lamellar substitutes testifies that none is ideal. We report here our experience of the use of autologous dermal dermis as posterior lamellar substitutes in bilamellar blepharopoiesis. PATIENTS AND METHOD: We performed a single-center retrospective observational study of seven patients undergoing blepharopoiesis using dorsal dermal autograft as posterior lamellar substitute. RESULTS: Between September 2011 and January 2017, seven patients aged of 80.9 years on average were cared for. The defect, affecting in 6 cases on 7 the lower eyelid, concerned almost three-quarter of the length of the eyelid. These defects followed the excision of basal cell carcinomas. Procedures performed under local anesthesia have simple follow-up without complications of the donor site. The superficial surface of the graft in contact with eyeball was covered in 2.4 months with a non-keratinized squamous epithelium like the conjunctiva. Two patients presented ocular functional signs during 2 months without keratitis. Two patients required a second correction procedure. CONCLUSION: The use of the dorsal dermis seems reliable, simple, fast, possible under local anesthesia and sedation, achievable in one operative time, outpatient, without temporary tarsorraphy. The graft is available in large quantities and its removal is not morbid. The good functional and esthetic results suggest that the autologous dermal dermis could represent the main alternative to palatal fibromucosa as a posterior lamellar substitute in old population.

Porcine Dermis Patch Augmentation of Supraspinatus Tendon Repairs: A Pilot Study Assessing Tendon Integrity and Shoulder Function 2 Years After Arthroscopic Repair in Patients Aged 60 Years or Older.

PURPOSE: To investigate the 2-year postoperative clinical and subjective outcomes after arthroscopic rotator cuff repair (ARCR) with xenologous porcine dermal patch augmentation compared with ARCR alone. METHODS: Patients aged 60 years or older with a complete supraspinatus (SSP) tendon tear underwent primary ARCR with a transosseous-equivalent technique. By use of a matched-pair comparative trial design, a consecutive series of 20 patients receiving additional xenologous porcine dermal patch augmentation (patch group) was matched by tear location with 20 patients who received ARCR only (control group). Prior conservative treatment failed in all patients. Patients with concomitant pathologies precluding accurate repair assessment, partial or open reconstruction, or a latissimus dorsi and/or pectoralis major muscle transfer were excluded. Patients reported daily pain levels for 10 days after surgery. Clinical parameters and various patient-reported outcome scores were documented preoperatively and at 3, 6, and 24 months after surgery. Repair integrity was determined by magnetic resonance imaging or ultrasound at 24 months. Adverse events were recorded. Group outcome differences were analyzed with t tests, Fisher exact tests, and mixed models. RESULTS: Patients in both groups were aged 67 years on average (range, 60-74 years), and 70% of patients were men. Patients in the patch group had slightly more SSP fatty infiltration preoperatively. Patch surgical procedures were on average 22 minutes longer than control interventions (P = .003). At 24 months, 4 patients and 9 patients were diagnosed with a recurrent SSP tendon defect in the control group (n = 20) and patch group (n = 19), respectively (relative risk, 2.4; P = .096). Of 11 defects (85%) identified as medial cuff failure, 8 occurred in the patch group. Pain rated by all patients decreased from postoperative day 1 to day 10 without any significant group difference (P = .348). No significant group differences were noted for other outcome parameters, and recurrent defects had no relevant effect on functional outcomes. Local complications (including recurrent defects) occurred in 8 patients in the control group and 12 in the patch group (P = .343). CONCLUSIONS: Our pilot study supports the view that an SSP tear repair with porcine dermal xenograft augmentation does not benefit patients in terms of reducing the risk of a recurrent tendon defect or improving shoulder function up to 24 months after surgical repair. LEVEL OF EVIDENCE: Level III, therapeutic study, retrospective comparative trial.

The expression pattern of keratin 24 in tissue-engineered dermo-epidermal human skin substitutes in an in vivo model.

AIMS AND OBJECTIVES: The use of autologous tissue-engineered skin substitutes is a promising approach to cover large skin defects in patients. Preclinical investigation is pivotal to test and improve the quality of these bio-engineered substitutes. In the skin, the epidermis, formed mainly by keratinocytes, provides the first physical barrier protecting from the environment. Proper keratinocyte differentiation and, thus, formation of a stratified epidermis is essential for this function. Keratins, the main structural support of keratinocytes, play a vital role regarding differentiation of keratinocytes. Here, we examined the expression pattern of a recently described keratinocyte differentiation marker, namely Keratin 24, in our skin substitutes. MATERIALS AND METHODS: Human epidermal keratinocytes, melanocytes, dermal fibroblasts, palmar fibroblasts or sweat gland cells were used to prepare skin substitutes. Fibroblast-containing collagen hydrogels were prepared, and keratinocytes or sweat gland cells and melanocytes were seeded onto the hydrogels. The generated tissue-engineered dermo-epidermal skin analogs were transplanted onto full-thickness skin wounds created on the back of immuno-incompetent rats. The skin substitutes were excised at different time points and histologically examined with regard to Keratin 24 expression. RESULTS: We observed the expression of Keratin 24 in keratinocytes of the upper stratum spinosum of the epidermis. In particular, we observed an intensified expression of Keratin 24 13 weeks after transplantation compared to 4 weeks after transplantation. Importantly, we noticed a markedly higher presence of Keratin 24 in more spinous layers if we used palmar fibroblasts or sweat gland cells in our skin substitutes compared non-palmar fibroblasts or epidermal keratinocytes. CONCLUSION: Our observations prove that the keratinocyte differentiation marker Keratin 24 is expressed in our dermo-epidermal skin substitutes in a normal pattern. This highlights that our bio-engineered skin analogs mature and reach homeostasis in an in vivo assay. These findings harbor favorable implications regarding future clinical application.

Combined effects of artificial dermis and vascular endothelial growth factor concentration gradient on wound healing in diabetic porcine model.

Wounds in patients with diabetes mellitus are one of the most prevalent impaired wounds in the world. Vascular endothelial growth factor (VEGF) is one of the most important proangiogenic mediators. Artificial dermal (AD) such as Pelnac® has been shown, in humans and animal models, a great therapeutic potential in full-thickness skin wounds. We attempt to promote the wound healing in diabetic porcine models through combined use of AD and constant concentration of VEGF or VEGF concentration gradient. We created full-thickness excisional wounds in diabetic animal models. Analyzed the healing process through images, histology and immunohistochemistry. Results show that the combination of AD and concentration gradient of VEGF could provide an appropriate angiogenesis, improve granulation formation, increase epithelization and maintain the VEGF levels of the wound bed. Eventually accelerate the direct healing of diabetic wounds or make good preparation for secondary skin graft.

Accelerated epithelialization and improved wound healing metrics in porcine full-thickness wounds transplanted with full-thickness skin micrografts.

Split-thickness skin grafting (STSG) is the current gold standard for treatment of extensive burn and traumatic skin injuries. However, STSG is limited by donor-site morbidity and availability, and often leads to scarring and wound contracture. Furthermore, these thin grafts lack dermal elements such as nerves and adnexa which are important in recapitulating normal skin function. Methods of fractional skin replacement either as minced STSGs or microscopic skin tissue columns have been proposed, though these techniques have not been fully characterized and lack evidence of regenerated adnexal structures. Here, we describe an alternative method of fractional skin replacement using full-thickness skin micrografts containing deep dermal components and intact adnexa. Full-thickness wounds measuring 3 cm in diameter and 2 cm apart were created on adult female Yorkshire swine. Full-thickness skin tissue columns (FTSTCs) 1.5 mm in diameter with intact adnexa and subcutaneous tissue were obtained using a suction-assisted device. Explant culture was initiated to demonstrate the capacity of FTSTCs to act as reservoirs of viable and proliferative epidermal and dermal cells. FTSTCs were applied directly to excisional wounds at three different expansion ratios (1:16, 1:40, 1:100) in fibrin sealant. Biopsies were collected at defined time points postwounding and processed for histology and immunohistochemistry. Wounds grafted with FTSTCs showed enhanced reepithelialization and epidermal differentiation over untreated control wounds in a dosage dependent manner. Adnexal structures such as hair follicles and sweat glands were only evident in FTSTC-treated wounds. Furthermore, whereas ungrafted wounds were marked by extensive infiltration of α-Smooth Muscle Actin+ (α-SMA+ ) myofibroblasts at POD 60, α-SMA expression was sparse and largely limited to perivascular cells in FTSTC-treated wounds. The number of Ki67+ cells was also greatly reduced in FTSTC-treated wounds. Transplantation of FTSTCs containing intact adnexa improved wound healing parameters in porcine full-thickness wounds and may have implications for the treatment of large, traumatic wounds.

Novel Application of Cultured Epithelial Autografts (CEA) with Expanded Mesh Skin Grafting Over an Artificial Dermis or Dermal Wound Bed Preparation.

Cultured epithelial autografts (CEA) with highly expanded mesh skin grafts were used for extensive adult burns covering more than 30% of the total body surface area. A prospective study on eight patients assessed subjective and objective findings up to a 12-month follow-up. The results of wound healing for over 1:6 mesh plus CEA, gap 1:6 mesh plus CEA, and 1:3 mesh were compared at 3, 6, and 12 months using extensibility, viscoelasticity, color, and transepidermal water loss by a generalized estimating equation (GEE) or generalized linear mixed model (GLMM). No significant differences were observed among the paired treatments at any time point. At 6 and 12 months, over 1:6 mesh plus CEA achieved significantly better expert evaluation scores by the Vancouver and Manchester Scar Scales (p < 0.01). Extended skin grafting plus CEA minimizes donor resources and the quality of scars is equal or similar to that with conventional low extended mesh slit-thickness skin grafting such as 1:3 mesh. A longitudinal analysis of scars may further clarify the molecular changes of scar formation and pathogenesis.

Comparison of Efficacy and Complications Among Various Spacer Grafts in the Treatment of Lower Eyelid Retraction: A Systematic Review.

BACKGROUND: Lower eyelid retraction is a difficult problem to treat, but it is a prevalent condition and a common complication of blepharoplasty. The use of spacer grafts to increase eyelid height and improve symptoms has been described for a long time, but the optimal choice of spacer graft material is unknown. OBJECTIVES: The authors reviewed the currently available evidence to determine the best available spacer graft material in terms of efficacy and complications. METHODS: A systematic review of all available literature published between 1985 and the present was performed using the Pubmed, Ovid MEDLINE, and Cochrane library databases. Inclusion criteria were that the studies contain original content assessing the treatment of lower eyelid retraction in humans using a spacer graft and provide quantitative outcomes data. RESULTS: One hundred and twelve articles were reviewed following an initial screen using titles, and 19 articles were chosen for inclusion in this systematic review. Analysis of these articles revealed no spacer graft material that is clearly superior to others. CONCLUSIONS: Due to a lack of high quality evidence, this review did not reveal one spacer graft material that is clearly superior to others. However, a narrative summary of the available evidence reveals unique sets of advantages and disadvantages associated with the various materials currently available. Further research in the form of well-designed studies will be necessary to further clarify advantages of certain spacer graft materials over others. LEVEL OF EVIDENCE: 5.

Cell therapy for full-thickness wounds: are fetal dermal cells a potential source?

The application of autologous dermal fibroblasts has been shown to improve burn wound healing. However, a major hurdle is the availability of sufficient healthy skin as a cell source. We investigated fetal dermal cells as an alternative source for cell-based therapy for skin regeneration. Human (hFF), porcine fetal (pFF) or autologous dermal fibroblasts (AF) were seeded in a collagen-elastin substitute (Novomaix, NVM), which was applied in combination with an autologous split thickness skin graft (STSG) to evaluate the effects of these cells on wound healing in a porcine excisional wound model. Transplantation of wounds with NVM+hFF showed an increased influx of inflammatory cells (e.g., neutrophils, macrophages, CD4(+) and CD8(+) lymphocytes) compared to STSG, acellular NVM (Acell-NVM) and NVM+AF at post-surgery days 7 and/or 14. Wounds treated with NVM+pFF presented only an increase in CD8(+) lymphocyte influx. Furthermore, reduced alpha-smooth muscle actin (αSMA) expression in wound areas and reduced contraction of the wounds was observed with NVM+AF compared to Acell-NVM. Xenogeneic transplantation of NVM+hFF increased αSMA expression in wounds compared to NVM+AF. An improved scar quality was observed for wounds treated with NVM+AF compared to Acell-NVM, NVM+hFF and NVM+pFF at day 56. In conclusion, application of autologous fibroblasts improved the overall outcome of wound healing in comparison to fetal dermal cells and Acell-NVM, whereas application of fetal dermal fibroblasts in NVM did not improve wound healing of full-thickness wounds in a porcine model. Although human fetal dermal cells demonstrated an increased immune response, this did not seem to affect scar quality.

Collagen structural alterations contribute to stiffening of tissue after split-thickness skin grafting.

The gold standard treatment for full thickness injuries of the skin is autologous split-thickness skin grafting. This involves harvesting the epidermis and superficial dermis from healthy skin and transplanting it onto the prepared wound bed. The donor site regenerates spontaneously, but the appendages and cellular components from the dermal layer are excluded from the graft. As a result, the new tissue is inferior; the healed graft site is dry/itchy, has decreased elasticity, increased fragility, and altered sensory function. Because this dermal layer is composed of collagen and other extracellular matrix proteins, the aim was to characterize the changes in the dermal collagen after split thickness grafting that could contribute to a deficit in functionality. This will serve as a baseline for future studies designed to improve skin function using pharmacological or cell-based therapies for skin repair. A xenograft model whereby human split-thickness grafts were implanted into full-thickness defects on immunocompromised (athymic Nu/Nu) mice was used. The grafts were harvested 4 and 8 weeks later. The collagen microstructure was assessed with second harmonic generation with dual-photon microscopy and light polarization analysis. Collagen fiber stiffness and engagement stretch were estimated by fitting the results of biaxial mechanical tensile tests to a histo-mechanical constitutive model. The stiffness of the collagen fibril-proteoglycan complex increased from 682 ± 226 kPa/sr to 1016 ± 324 kPa/sr between 4 and 8 weeks postgrafting. At the microstructural level there were significant decreases in both thickness of collagen fibers (3.60 ± 0.34 µm vs. 2.10 ± 0.27 µm) and waviness ratio (2.04 ± 0.17 vs. 1.43 ± 0.08) of the collagen fibers postgrafting. The decrease of the macroscopic engagement stretch from 1.19 ± 0.11 to 1.09 ± 0.08 over time postgrafting mirrored the decrease in waviness measured at the microscopic level. This suggested that the integrity of the collagen fibers was compromised and contributed to the functional deficit of the skin postgrafting.

Transvaginal rectocele repair with human dermal allograft interposition and bilateral sacrospinous fixation with a minimum eight-year follow-up.

BACKGROUND: Human dermal allografts have been used for over a decade for interpositional repair of rectoceles. How do dermal allografts perform with regards to success rate and complications with 8 years' minimum follow-up? METHODS: We retrospectively reviewed 41 consecutive patients undergoing dermal allograft interposition procedures between October 2001 and December 2005 (Repliform, Boston Scientific, Natick, MA, USA) for stage two, three, and four International Continence Society (ICS) symptomatic rectocele repairs with bilateral sacrospinous fixation. Failure was defined as recurrent stage two International Continence Society prolapse (Ap ≥ -1 and/or Bp ≥ -1). All questionnaires were completed 1 week before surgery and at follow-up (September 2014 through December 2014). RESULTS: The mean preoperative and postoperative A(p) were 0.95 ± 0.70,-1.90 ± 0.52 and B(p) 1.30 ± 0.84,-2.13 ± 0.51 (p < 0.001). With a mean follow-up of 116.5 ± 18.9 months, a success rate of 73 % (30/41) was achieved, with anatomical reduction of prolapse. For splinting and digitations, an 82 % cure rate was realized. The Pelvic Floor Distress Inventory (PFDI) pre- and post-operative results showed significant improvement (p < 0.001). There were two incisional exposures (5 %). Seventy percent of patients were secondary repairs while 30 % were primary repairs (81 % success rate, p < 0.36). One patient experienced nerve entrapment and subsequent unilateral takedown. Patient satisfaction was 77 %. CONCLUSIONS: Our retrospective study approaching long-term results demonstrated that symptomatic rectocele procedures with human dermal allograft interposition provide an effective anatomical and functional repair with acceptable complication rates.

Dermis-Fat Graft in Children as Primary and Secondary Orbital Implant.

PURPOSE: To report the experience with the use of dermis-fat graft in the pediatric population and to evaluate the outcome of this procedure as a primary or secondary orbital implant. METHODS: Case series. Analysis of the clinical charts of 22 patients. Age at the time of surgery ranged from 2.1 to 13 years. Three patients affected were submitted to evisceration with primary dermis-fat graft. Six patients had explantation of exposed implants and a replacement with a dermis-fat graft. Three patients had a dermis-fat graft to repair contracted sockets. Ten patients were affected by congenital anophthalmia: 4 patients had a primary dermis-fat graft, 6 patients had a removal of a socket expander, or an orbital spherical expander, or pellet expanders and a replacement with a dermis-fat graft. This study adheres to the principles outlined in the Declaration of Helsinki. RESULTS: The patients' follow up ranged between 2.5 and 8 years. Only 1 child who had a primary dermis-fat graft experienced excessive growth of the implant, managed by surgical debulking. In the end, all the patients showed satisfactory orbital volume along with adequate fornices. CONCLUSIONS: The dermis-fat graft as a primary implant may be useful in children with severe scleromalacia or following ocular trauma. It is a suitable option in children affected by congenital anophthalmia as it helps continued socket expansion. It can also be considered in the pediatric population to address the volume deficit following explantation of exposed implants and in contracted sockets.

Myelinated and unmyelinated nerve fibers reinnervate tissue-engineered dermo-epidermal human skin analogs in an in vivo model.

PURPOSE: The clinical application of autologous tissue-engineered skin analogs is an important strategy to cover large skin defects. Investigating biological dynamics, such as reinnervation after transplantation, is essential to improve the quality of such skin analogs. Previously, we have examined that our skin substitutes are reinnervated by host peripheral nerve fibers as early as 8 weeks after transplantation. Here, we wanted to investigate the presence and possible differences regarding myelinated and unmyelinated host nerve fibers 15 weeks after the transplantation of light and dark human tissue-engineered skin analogs. METHODS: Human epidermal keratinocytes, melanocytes, and dermal fibroblasts were isolated from human light and dark skin biopsies. Keratinocytes and melanocytes were seeded on fibroblast-containing collagen type I hydrogels after expansion in culture. After additional culturing, the tissue-engineered dermo-epidermal skin analogs were transplanted onto full-thickness skin wounds created on the back of immuno-incompetent rats. Skin substitutes were excised and analyzed 15 weeks after transplantation. Histological sections were examined with regard to the ingrowth pattern of myelinated and unmyelinated nerve fibers into the skin analogs using markers, such as Substance P, NF200, and S100-Beta. RESULTS: We found myelinated and unmyelinated peripheral host nerve fibers 15 weeks after transplantation in the dermal part of our human skin substitutes. In particular, we identified large-diameter-myelinated Aß- and Aδ-fibers, and small-diameter C-fibers. Furthermore, we observed myelinated nerves in close proximity to CD31-positive blood capillaries. In the long run, both types of ingrown host fibers showed an identical pattern in both light and dark skin analogs. CONCLUSION: Our data suggest that myelinated and unmyelinated peripheral nerves reinnervate human skin substitutes in a long-term in vivo transplantation assay. Our tissue-engineered skin analogs attract A- and C-fibers to supply both light and dark skin analogs. Potentially, this process restores skin sensitivity and has, therefore, a significant relevance with regard to future application of autologous pigmented dermo-epidermal skin substitutes onto patients.

Adhesion of Neisseria meningitidis to dermal vessels leads to local vascular damage and purpura in a humanized mouse model.

Septic shock caused by Neisseria meningitidis is typically rapidly evolving and often fatal despite antibiotic therapy. Further understanding of the mechanisms underlying the disease is necessary to reduce fatality rates. Postmortem samples from the characteristic purpuric rashes of the infection show bacterial aggregates in close association with microvessel endothelium but the species specificity of N. meningitidis has previously hindered the development of an in vivo model to study the role of adhesion on disease progression. Here we introduced human dermal microvessels into SCID/Beige mice by xenografting human skin. Bacteria injected intravenously exclusively associated with the human vessel endothelium in the skin graft. Infection was accompanied by a potent inflammatory response with the secretion of human inflammatory cytokines and recruitment of inflammatory cells. Importantly, infection also led to local vascular damage with hemostasis, thrombosis, vascular leakage and finally purpura in the grafted skin, replicating the clinical presentation for the first time in an animal model. The adhesive properties of the type IV pili of N. meningitidis were found to be the main mediator of association with the dermal microvessels in vivo. Bacterial mutants with altered type IV pili function also did not trigger inflammation or lead to vascular damage. This work demonstrates that local type IV pili mediated adhesion of N. meningitidis to the vascular wall, as opposed to circulating bacteria, determines vascular dysfunction in meningococcemia.