Use of a collagen-elastin matrix for hard to treat soft tissue defects

Use of a collagen-elastin matrix with split-thickness skin graft for defect coverage in complex wounds

OBJECTIVE

Severe soft tissue damage with destruction of the dermis requires plastic reconstructive treatment. For multimorbid patients or patients unable to undergo major reconstructive surgery, use of dermal substitutes, such as a collagen-elastin matrix (CEM) with a split-thickness skin graft (STSG), instead of local or free flap surgery, may be a valid and easy treatment option. We aimed to investigate and compare the outcomes and rate of successful defect reconstruction using CEM plus STSG, using either a one-step approach (simultaneous CEM and STSG) or a two-step approach (CEM and negative wound pressure therapy (NPWT), with secondary STSG transplantation).

METHOD

A single-centre, retrospective follow-up study of patients who had received CEM was conducted. Wounds had been treated with an STSG transplantation covering a CEM (MatriDerm, MedSkin Solutions Dr. Suwelack AG, Germany). Previous attempts at wound closure with conventional methods had failed in the selected patient population, which would usually have resulted in flap surgery.

RESULTS

Overall, 46 patients were included (mean age 60.9±20.0 years), with a total of 49 wound sites. We analysed 38 patients with wounds that did not require flap coverage; 18 patients received the one-step approach and 20 patients received the two-step approach. The mean follow-up in these patients was 22±11.5 months, and one patient was lost to follow-up. Overall, 29 (78.4%) wounds remained closed. Wounds which did not successfully heal were related to comorbidities, such as diabetes, alcohol misuse and smoking. Using the one-step approach, long-term defect coverage was achieved in 13 (76.5%) wounds and 16 (80.0%) wounds were closed using the two-step approach. However, there was no statistically significant differences between the one- or two-step approaches regarding the rate of development of a wound healing disorder.

CONCLUSION

Wound closure was achieved in 38 complex wounds using CEM plus STSG, while 11 wounds needed secondary flap coverage. In the flap-free wounds, there were no statistically significant differences between the one-step versus two-step approach. Using a simple defect reconstruction algorithm, we successfully used CEM plus STSG to treat complex wounds.

Preventing postoperative adhesions after hand tendon repair using acellular dermal matrix

AIMS

Postoperative tendon adhesions contribute to functional disability and reconstructive failure. In this study, we present the long-term outcomes of a prospective study in which acellular dermal matrix (ADM) was used to prevent postoperative adhesion after tendon injury.

METHODS

The study was conducted between March 2014 and February 2017. Patients, aged 19-65 years, with an acute single flexor tendon injury in zones 1 or 2, distal to the palmar digital crease were candidates for the study. Patients were allocated to either an ADM treatment group or a control group without ADM treatment.

RESULTS

A total of 37 patients were enrolled in the study: 21 patients in the ADM group and 16 patients in the control group. At six months after surgery, the range of motion in the proximal interphalangeal joint was 81.0±5.1 degrees in the ADM group and 75.8±6.9 degrees in the control group. The range of motion in the distal interphalangeal joint was 79.9±7.1 in the ADM group and 71.2±5.7 degrees in the control group, with significant difference (p=0.03 and p<0.05, respectively). In addition, the total active motion was higher in the ADM group than in the control group. The patients' scores on the Patient Satisfaction Questionnaire were also significantly different, with higher satisfaction scores in the ADM group (p=0.02). The minimal follow-up period was six months.

CONCLUSION

The use of ADM after tendon repair has the potential to significantly improve the outcome of tendon surgery in terms of range of motion.

DECLARATION OF INTEREST

None of the authors has any financial interest in the products, devices, or drugs mentioned in this article.

The Role of Complex Treatment in Mixed Leg Ulcers - A Case Report of Vascular, Surgical and Physical Therapy

BACKGROUND:

Leg ulcers are a burden to patients, their families and society. The second most common cause of chronic leg ulcers is the mixed arterio-venous type. An 80-year-old female patient presented to our department due to painful enlarging chronic leg ulcer of mixed arteriovenous origin on her left lower leg. She suffered from peripheral arterial occlusive disease stage I and chronic venous insufficiency Widmer grade IIIa, and a number of comorbidities.

AIM:

The aim of our ulcer treatment was a complete and stable wound closure that was hampered by arterial occlusion, exposed tendon, and renal insiffuciency.

CASE REPORT:

To improve the prognosis for ulcer surgery, we performed percutaneous transluminal angioplasty, transcutaneous CO₂ and deep ulcer shaving. The wound was closed by sandwich transplantation using elastin-collagen dermal template and meshed split skin graft. She had a 100% graft take with rapid reduction of severe wound pain.

CONCLUSION:

Complex approaches are necessary, to gain optimum results in leg ulcer therapy in mixed leg ulcers. Therapeutic nihilism should be abandonend.

Burn injury: Challenges and advances in burn wound healing, infection, pain and scarring

Severe burn injuries are the most traumatic and physically debilitating injuries affecting nearly every organ system and leading to significant morbidity and mortality. Early burn wound excision and skin grafting are common clinical practices that have significantly improved the outcomes for severe burn injured patients by reducing mortality rate and days of hospital stay. However, slow wound healing, infection, pain, and hypertrophic scarring continue to remain a major challenge in burn research and management. In the present article, we review and discuss issues in the current treatment of burn injuries; the advances and novel strategies developed in the past decade that have improved burn management; and also, pioneer ideas and studies in burn research which aims to enhance burn wound care with a focus on burn wound infection, pain management, treatments for scarring and skin tissue engineering.

Shotgun label-free proteomic analysis for identification of proteins in HaCaT human skin keratinocytes regulated by the administration of collagen from soft-shelled turtle

Soft‐shelled turtles (Pelodiscus sinensis) are widely distributed in some Asian countries, and we previously reported that soft‐shelled turtle tissue could be a useful material for collagen. In the present study, we performed shotgun liquid chromatography (LC)/mass spectrometry (MS)‐based global proteomic analysis of collagen‐administered human keratinocytes to examine the functional effects of collagen from soft‐shelled turtle on human skin. Using a semiquantitative method based on spectral counting, we were able to successfully identify 187 proteins with expression levels that were changed more than twofold by the administration of collagen from soft‐shelled turtle. Based on Gene Ontology analysis, the functions of these proteins closely correlated with cell–cell adhesion. In addition, epithelial–mesenchymal transition was induced by the administration of collagen from soft‐shelled turtle through the down‐regulation of E‐cadherin expression. Moreover, collagen‐administered keratinocytes significantly facilitated wound healing compared with nontreated cells in an in vitro scratch wound healing assay. These findings suggest that collagen from soft‐shelled turtle provides significant benefits for skin wound healing and may be a useful material for pharmaceuticals and medical care products. © 2017 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2403–2413, 2018.

The effect of a collagen-elastin matrix on adhesion formation after flexor tendon repair in a rabbit model

PURPOSE

The outcome of flexor tendon surgery is negatively affected by the formation of adhesions which can occur during the healing of the tendon repair. In this experimental study, we sought to prevent adhesion formation by wrapping a collagen-elastin scaffold around the repaired tendon segment.

METHODS

In 28 rabbit hind legs, the flexor tendons of the third and fourth digits were cut and then repaired using a two-strand suture technique on the fourth digit and a four-strand technique on the third digit. Rabbits were randomly assigned to study and control groups. In the control group, the operation ended by closing the tendon sheath and the skin. In the study group, a collagen-elastin scaffold was wrapped around the repaired tendon segment in both digits. After 3 and 8 weeks, the tendons were harvested and processed histologically. The range of motion of the digits and the gap formation between the repaired tendon ends were measured. The formation of adhesions, infiltration of leucocytes and extracellular inflammatory response were quantified.

RESULTS

At the time of tendon harvesting, all joints of the operated toes showed free range of motion. Four-strand core sutures lead to significantly less diastasis between the repaired tendon ends than two-strand core suture repairs. The collagen-elastin scaffold leads to greater gapping after 3 weeks compared to the controls treated without the matrix. Within the tendons treated with the collagen-elastin matrix, a significant boost of cellular and extracellular inflammation could be stated after 3 weeks which was reflected by a higher level of CAE positive cells and more formation of myofibroblasts in the αSMA stain in the study group. The inflammatory response subsided gradually and significantly until the late stage of the study. Both the cellular and extracellular inflammatory response was emphasized with the amount of material used for the repair.

CONCLUSION

The use of a collagen-elastin matrix cannot be advised for the prevention of adhesion formation in flexor tendon surgery, because it enhances both cellular and extracellular inflammation. Four-strand core sutures lead to less gapping than two-strand core sutures, but at the same time, the cellular and extracellular inflammatory response is more pronounced.

Optimization of Method to Extract Collagen from "Emperor" Tissue of Soft-shelled Turtles

Soft-shelled turtles (Pelodiscus sinensis) are widely distributed in some Asian countries, and parts of this turtle contain abundant collagen. In this study, we optimized a method for extracting collagen from the soft-shelled turtle. We used three types of solvent and four extraction conditions to determine an effective collagen extraction method, which was extraction at 37°C with acetic acid after hydrochloric acid pretreatment. Next, we extracted collagen from three regions in the soft-shelled turtle: muscle, skin, and an area of soft tissue in the periphery of the turtle shell known in Japan and China as the "emperor." We determined that emperor tissue yielded the highest concentration and purity of collagen. We then optimized the pretreatment method for extraction from emperor tissue by using formic acid instead of hydrochloric acid, and the amount of extracted collagen increased by approximately 1.3-fold. Finally, we identified the optimal solvent out of four types of organic acid for collagen extraction from emperor tissue; the amount of extracted collagen from emperor tissue increased approximately 3-fold when citric acid was used as the extraction solvent instead of acetic acid. Emperor tissue can regenerate; thus, it is possible to obtain collagen from the emperor repeatedly without killing the turtle. Our findings suggest that the emperor tissue of softshelled turtles may be a good source of collagen for pharmaceutical and cosmetic applications.

Surgical Therapy by Sandwich Transplantation using a Dermal Collagen-Elastin Matrix and Full Thickness Split Grafts and Gait Rehabilitation with Individualized Orthesis

Painful callosities of the feet (PCOF) are a rare complaint in children with severe impairment of mobility and quality of life. There is no medical treatment available. We investigated the usefulness of a recently developed combined transplant technique-the sandwich transplantation with dermal collagen-elastin template in this rare condition. A 14-year-old boy suffered from PCOF for several years without any improvement by topical therapy, dermabrasion, and oral retinoids. He was unable to walk normally and suffered from severe pain. We performed a complete deep excision of the hyperkeratotic plantar tissue in general anaesthesia in combination with sandwich transplantation in the same setting. Dry sheets of collagen-elastin matrix (1 mm thickness) were placed on the soft tissue defects and covered by full-thickness mesh graft transplants from the upper leg. An individualized orthosis was produced for gait rehabilitation. Two weeks after surgery the gait-related pain was reduced remarkably. Using the orthosis, the boy was able to walk pain-free even on staircase. Surgery of PCOF with sandwich transplantation and gait rehabilitation appears to be a promising strategy for this rare condition.

One-stage Reconstruction of Soft Tissue Defects with the Sandwich Technique: Collagen-elastin Dermal Template and Skin Grafts

Background:

A full-thickness soft tissue defect closure often needs complex procedures. The use of dermal templates can be helpful in improving the outcome.

Objective:

The objective was to evaluate a sandwich technique combining the dermal collagen–elastin matrix with skin grafts in a one-stage procedure.

Materials and Methods:

Twenty-three patients with 27 wounds were enrolled in this prospective single-centre observational study. The mean age was 74.8 ± 17.2 years. Included were full-thickness defects with exposed bone, cartilage and/ or tendons. The dermal collagen–elastin matrix was applied onto the wound bed accomplished by skin transplants, i.e. ‘sandwich’ transplantation. In six wounds, the transplants were treated with intermittent negative pressure therapy.

Results:

The size of defects was ≤875 cm². The use of the dermal template resulted in a complete and stable granulation in 100% of wounds. Seventeen defects showed a complete closure and 19 achieved a complete granulation with an incomplete closure. There was a marked pain relief. No adverse events were noted due to the dermal template usage.

Conclusions:

Sandwich transplantation with the collagen–elastin matrix is a useful tool when dealing with full-thickness soft tissue defects with exposed bone, cartilage or tendons.

Giant epithelial malignancies (Basal cell carcinoma, squamous cell carcinoma): a series of 20 tumors from a single center

Background:

Among nonmelanoma skin cancer (NMSC), basal cell carcinoma (BCC), and squamous cell carcinoma (SCC) are the most common. Giant NMSCs have occasionally reported in the medical literature with particular problems related to diagnosis and treatment. The aim of this study was to analyze patients, treatment, and outcome with giant BCC/SCC.

Materials and Methods:

We analyzed our files between January 1, 2008, and December 31, 2011, of an academic teaching hospital in the dermatology department. Patients were analyzed according to demographic factors, clinical presentation, histopathology, treatment, and outcome. American Society of Anesthesiology physical status system was used to assess the fitness of patients before surgery.

Results:

The frequency of giant NMSC was estimated as 0.4% for both tumor entities. 80% of giant BCC patients were female and 100% of giant SCC patients were male. The mean age was 81.5 ± 8.5 years for BCC) and 79.5 ± 11.4 years for SCC. The major anatomical site was the scalp. Four of 10 BCCs were classified metatypic (basosquamous). Perineural infiltration was seen in 5 NMSCs. Seventy percent of patients had an ASA score ≥3. Surgery was performed in general anaesthesia in 5 (BCC) and 6 (SCC) patients, respectively. All other patients were operated in local or tumescence anesthesia. Blood transfusions were necessary in five patients. The primary treatment was delayed Mohs technique. Defect closure was realized with rotational flaps in most cases. Neoadjuvant chemoimmune therapy and adjuvant combined cetuximab/radiotherapy have been performed in three patients. We observed three deaths, all unrelated to NMSC. 75% of patients achieved complete remission.

Conclusions:

Giant NMSC is uncommon but not rare. These tumors are high-risk subtypes. Treatment needs an interdisciplinary approach.