Wound healing and dermal regeneration in severe burn patients treated with NovoSorb® Biodegradable Temporising Matrix: A prospective clinical study.

INTRODUCTION: For extensive burns, autologous donor skin may be insufficient for early debridement and grafting in a single stage. A novel, synthetic polyurethane dermal template (NovoSorb® Biodegradable Temporising Matrix, BTM) was developed to address this need. The aim of this study was to evaluate use of BTM for primary dermal repair after deep burn injury. METHODS: A multicentre, prospective, clinical study was conducted from September 2015 to May 2018. The primary endpoint was % split skin graft take over applied BTM at 7-10 days after grafting. Secondary endpoints included % BTM take, incidence of infection and adverse events, and scar quality to 12 months after BTM application. RESULTS: Thirty patients were treated with BTM and delayed split skin grafting. The % graft take had a mean of 81.9% and % BTM take had a mean of 88.6%, demonstrating effective integration of BTM. When managed appropriately, it was possible for BTM to integrate successfully despite findings suggestive of infection. Scar quality improved over time. DISCUSSION: These results provide additional clinical evidence on the safety and performance of BTM as an effective dermal substitute in the treatment of patients with deep burn injuries.

Early physiotherapy experience with a biodegradable polyurethane dermal substitute: Therapy guidelines for use.

OBJECTIVE: The purpose of this study was to investigate and develop range of motion (ROM) and mobilisation guidelines in adult patients where a newly developed synthetic dermal substitute was applied in our adult burn centre. METHOD: A retrospective case note audit was conducted on the first 20 acute burn injured patients who had a synthetic dermal substitute applied. Data collected included days to commencement of ROM, days to clearance for mobilisation, and joint ROM achieved after dermal substitute application (prior to delamination) and after split skin grafting (SSG) for the elbow, knee and shoulder joints. Scar assessments were completed at 12 months after injury using two scar assessment scales. RESULTS: Clearance to mobilise occurred at mean 10.4 and 4.9 days after dermal substitute and after skin graft application to lower limbs respectively. ROM commenced at a mean of 9.9 (upper limbs) and 12.7 (lower limbs) days after dermal substitute application. Following skin grafting, ROM commenced at a mean of 6.6 and 6.5 days for upper limbs and lower limbs respectively. Prior to dermal substitute delamination mean flexion at the knee (86.3°), elbow (114.0°) and shoulder (143.4°) was achieved. Mean ROM continued to improve after grafting with knee (133.2°), elbow (126.1°) and shoulder (151.0°) flexion approaching normal ROM in most cases. Mean extension of the elbow (-4.6°) was maintained close to normal levels after skin grafting. There were no recorded instances of knee extension contracture. Patient and Observer Scar Assessment Scale and Matching Assessment of Photographs of Scars scores indicated good cosmetic outcomes with relatively low levels of itch and minimal pain reported at 12 months after injury. CONCLUSION: A steep learning curve was encountered in providing therapy treatment for patients managed with this relatively new synthetic dermal substitute. Trends indicated that as experience with this new dermal substitute grew, patients progressed toward active therapy earlier. A guideline for therapy treatment has been developed but will continue to be evaluated and adjusted when required.

Mortality data 2004-2019: an audit of the Royal Adelaide Hospital Adult Burn Service.

BACKGROUND: Burns are complex, multifaceted injuries that can pose significant challenges to the treating team. The Royal Adelaide Hospital (RAH) Burns Service has undergone a major evolution over the past two decades, with perceived improvement in outcomes. We present here a longitudinal audit of the RAH Burns Service Mortality Data between 2004 and 2019. METHODS: An audit was conducted of all index admissions to the RAH Burns Unit from 1 January 2004 to 31 December 2019. Age at admission, total body surface area, burn depth, presence of inhalation injury and outcome were recorded. Baux and revised Baux Scores were calculated. Lethal Area 50% for different time points and age groups, Baux50/100 and Revised Baux50/100 values were then calculated using logistical regression. RESULTS: During 2004-2019, there were 5653 index admissions to the RAH Burns Unit. The mean total body surface area of burn injuries admitted was 5.1% and the survival rate was 99.17%. The Lethal Area 50% for the study period was 74%, with an improvement from 70% (2004-2011) to 80% (2012-2019). The Baux50 score for the time period was 120 and the Revised Baux50 was 129. CONCLUSION: The RAH results are comparable with other high-income country Burn Services and demonstrated significant improvement across the study period. The data also highlight areas for ongoing focus such as the elderly burns patient.

A Synthetic Biodegradable Temporising Matrix in Degloving Lower Extremity Trauma Reconstruction: A Case Report.

Presented is the case of an obese, 72 year-old diabetic man with a dorsal foot de-gloving injury. Whilst the tendons of extensor hallucis longus, extensor digitorum longus to all digits, and extensor digitorum brevis to hallux and second toe were intact after surgical debridement, none had any covering paratenon. The joint between the medial cuneiform and first metatarsal was open. Reconstructive options were limited by his age and co-morbidities. A novel, completely synthetic dermal matrix (NovoSorb BTM) was applied, after which the patient was discharged home to attend for dressings and review of integration progress as an outpatient. He was allowed to mobilise without limitation. Because of the poor quality of the wound bed (and patient), the material integrated slowly over 9 weeks. Delamination of the matrix, and definitive closure by application of sheet split skin autograft, produced a robust, soft, mobile and excellent aesthetic result, over which he could wear footwear immediately. Clinically, the paratenon-denuded tendons glided under the neo-dermis without tethering to the overlying integrated matrix, allowing a full range of digital movement. This was confirmed on ultrasound examination, which also demonstrated no inflammation or oedema. Already proven in extensive burns, necrotising fasciitis and complex surgical wounds, BTM represents a useful addition to the reconstructive surgeon's toolbox.

A Novel Biodegradable Polyurethane Matrix for Auricular Cartilage Repair: An In Vitro and In Vivo Study.

Auricular reconstruction poses a challenge for reconstructive and burns surgeons. Techniques involving cartilage tissue engineering have shown potential in recent years. A biodegradable polyurethane matrix developed for dermal reconstruction offers an alternative to autologous, allogeneic, or xenogeneic biologicals for cartilage reconstruction. This study assesses such a polyurethane matrix for this indication in vivo and in vitro. To evaluate intrinsic cartilage repair, three pigs underwent auricular surgery to create excisional cartilage ± perichondrial defects, measuring 2 × 3 cm in each ear, into which acellular polyurethane matrices were implanted. Biopsies were taken at day 28 for histological assessment. Porcine chondrocytes ± perichondrocytes were cultured and seeded in vitro onto 1 × 1 cm polyurethane scaffolds. The total culture period was 42 days; confocal, histological, and immunohistochemical analyses of scaffold cultures were performed on days 14, 28, and 42. In vivo, the polyurethane matrices integrated with granulation tissue filling all biopsy samples. Minimal neocartilage invasion was observed marginally on some samples. Tissue composition was identical between ears whether perichondrium was left intact, or not. In vitro, the polyurethane matrix was biocompatible with chondrocytes ± perichondrocytes and supported production of extracellular matrix and Type II collagen. No difference was observed between chondrocyte culture alone and chondrocyte/perichondrocyte scaffold coculture. The polyurethane matrix successfully integrated into the auricular defect and was a suitable scaffold in vitro for cartilage tissue engineering, demonstrating its potential application in auricular reconstruction.

Free Flap Donor Site Reconstruction: A Prospective Case Series Using an Optimized Polyurethane Biodegradable Temporizing Matrix.

INTRODUCTION: We recently published a 10-patient case series where free flap donor site reconstruction was performed as a 2-stage procedure using an integrating biodegradable polyurethane matrix (to form a neodermis), followed by definitive closure with an autologous split-skin graft. Two issues were revealed by this pilot study that led to further modification of the biodegradable temporizing matrix. This involved alterations to the seal thickness and bonding to the foam matrix and the introduction of fenestrations to the seal. OBJECTIVE: This article documents a second cohort of patients requiring free flap (fibular and radial forearm) donor site reconstruction with this optimized material. METHODS: The biodegradable temporizing matrix was implanted when the free flap was detached from its donor site. Subsequent integration was monitored closely. Five weeks was the usual time of integration before delamination (seal removal), dermabrasion, and definitive closure with autograft. RESULTS: Integration was complete and uncomplicated in every case, delamination occurred in 1 piece in 1 action, and subsequent graft take was 100% for every patient. Long-term scar outcomes improved compared with the pilot group. Degradation is complete by 12 months, other than occasional microscopic remnants undergoing phagocytosis. CONCLUSION: This study has reiterated that the biodegradable temporizing matrix can be implanted into humans, followed by neovascularization and integration. No infection was observed, and split-skin overgrafting was successful and uncomplicated.

A biodegradable polyurethane dermal matrix in reconstruction of free flap donor sites: a pilot study.

We have developed a biodegradable temporizing matrix (BTM) capable of supporting secondary split-skin graft-take in animal studies. We report its first long-term implantation and use as a dermal scaffold in humans. This preliminary study assesses its ability to integrate, its ease of delamination, its ability to sustain split-skin graft in complex wounds, the degree of wound contraction, and ultimately the quality of the scar at 1 year postimplantation. Ten patients were recruited, each requiring elective free flap reconstruction. Free flap donor sites created were anterolateral thigh flaps, fibular osseocutaneous flaps, or radial/ulnar forearm (RF/UF) flaps. The BTM was implanted when the flap was detached from its donor site. Dressing changes were performed twice weekly. The time elapsed between implantation and delamination depended on the type of flap and thus the wound bed left. Once integrated, the BTMs were delaminated in theatre, and the surface of the "neodermis" was refreshed by dermabrasion, prior to application of a split-skin graft. The BTM integration occurred in all patients (100% in 6 patients, with 90%, 84%, 76%, and 60% integration in the remainder). Integrated BTM sustained successful graft-take in all patients. Complete take was marred in 2 patients, over areas of BTM that had not integrated and graft application was performed too early. The BTM can be applied into wounds in humans and can integrate, persist in the presence of infection, and sustain split-skin overgrafting, despite the trial group presenting with significant comorbidities.

Performing two DIEP flaps in a working day: an achievable and reproducible practice.

BACKGROUND: While the deep inferior epigastric artery perforator (DIEP) flap is a reliable technique for autologous breast reconstruction, the meticulous dissection of perforators may require lengthy operative times. In our unit, we have performed 600 free flaps for breast reconstruction over 8 years and have reduced operative times with a combination of preoperative computed tomographic angiography (CTA), various anastomotic techniques and the Cook-Swartz implantable Doppler probe for perfusion monitoring. We sought to assess the feasibility of performing two DIEP flaps within the working hours of a single day. METHODS: A review of 101 consecutive patients undergoing DIEP flap breast reconstruction in a 12-month period was performed, comparing one DIEP flap per day (n=43) to two DIEP flaps per day (n=58). Complications, outcomes and techniques used were critically analysed. For cases of two DIEP flaps per day, a comparison was made between the use of two separate operating theatres (n=44) and a single consecutive theatre (n=14). RESULTS: Complications did not increase when two DIEP flaps were performed in a single working day. The use of vascular closure staple (VCS) sutures and ring couplers resulted in statistically significant reductions in anastomotic times. The use of two separate theatres for performing two DIEP flaps resulted in a reduction of 59min in operative time per case (p=0.004). CONCLUSION: Two DIEP flaps can be safely and routinely performed within the hours of a single working day. By minimising operative times, these techniques can improve productivity and substantially decrease surgeon fatigue.

Perineal and posterior vaginal wall reconstruction with superior and inferior gluteal artery perforator flaps.

Perineal and posterior vaginal wall reconstruction following abdominoperineal and local cancer resection entails replacement of volume between the perineum and sacrum and restoration of a functional vagina. Ideal local reconstructive options include those which avoid functional muscle sacrifice, do not interfere with colostomy formation, and avoid the use of irradiated tissue. In avoiding the donor site morbidity of other options, we describe a fasciocutaneous option for the reconstruction of the perineum and posterior vaginal wall. We present our technique of superior and inferior gluteal artery perforator (SGAP or IGAP) flaps to reconstruct such defects. Fourteen patients between 2004 and 2008 underwent 11 SGAP and three IGAP flaps. There were no flap failures or partial flap losses and no postoperative hernias. All female patients reported resumption of sexual intercourse following this procedure. Our experience in both the immediate and delayed setting is that this technique produces a good functional outcome with low donor-site morbidity.

A reliable and aesthetic technique for cephalic vein harvest in DIEP flap surgery.

The need for a secondary source of venous drainage in deep inferior epigastric artery perforator flaps is common, with the cephalic vein commonly utilized as an alternative venous recipient vessel. In using the cephalic vein, previous studies have described the deltopectoral groove or the infraclavicular fossa as the site for harvest. We describe the use of an anterior axillary skin crease, which can improve aesthetic outcome, reduce the time needed for harvest, enable a greater length of vein to be transposed, and minimize surgical insult to the upper breast/chest wall. An anterior axillary-line skin fold can be used as the site for cephalic vein harvest, and using the methodology described, the technique can be fast and highly reliable and result in a final scar that is barely visible.