The Role of Dermal Regenerative Templates in Complex Lower Extremity Wounds

The Use of Integra Dermal Regeneration Template in Exposed Bone Reconstruction: A Case Report with Systematic Literature Review

Background/Objectives: Integra Dermal Regeneration Template (IDRT) has emerged as a viable reconstructive option in exposed avascular structures, such as exposed bone devoid of periosteum. This systematic review aimed at examining success rates by comparing different wound types and their characteristics, as well as the surgical methods involved. Methods: A systematic review was conducted to identify studies using IDRT in the reconstruction of defects with exposed bone devoid of periosteum. Primary outcomes of interest were IDRT and skin graft success rates, followed by patient and wound characteristics, and different surgical methods used. The results were accompanied by an illustrative case report of IDRT-based hand reconstruction after a deep burn injury. Results: The review included 40 studies, with a total of 202 individual defects. The primary indication for IDRT-based reconstruction was post-oncologic defects in the elderly population. Although surgeons mostly used burring/fenestration as a bone preparation method prior to IDRT placement, decorticated bones showed faster grafting time (23.8 vs. 27.9 days). The average success rate of IDRT was 87.54% (±25.9), with an excellent IDRT take rate (100%) observed in more than 50% of cases. In the majority of cases (95.5%), the skin graft acceptance rate was deemed to be higher than 95%, with an average graft take of 98.8%. Conclusions: The results of this review support the use of IDRT in managing complex defects involving exposed bone, offering fast coverage with good functional restoration, without any donor site morbidity. Additionally, bone preparation methods also play an important role in IDRT-based reconstruction by shortening the grafting time.

Use of Dermal Substitute Matrices for Coverage of Exposed Limb Vascular Repairs: A Literature Review

Background

Prompt coverage of vascular repairs in the extremities is needed to protect from desiccation and trauma. In the absence of local soft tissues to provide early coverage pending demarcation of the tissues and the zone of injury, there is no clear data in the literature on the ideal coverage method. This article is the first to review the use of dermal substitutes for temporary coverage of extremity vascular repairs pending definitive coverage.

Methods

We conducted a review of the literature to identify previous articles indexed in PubMed and Ovid using these search terms: [(skin) OR (artificial skin) OR (Integra) OR (dermal substitute) OR (dermal substitute matrix) OR (dermal regeneration) OR (dermal regeneration matrix) OR (dermal regeneration template)] AND [(bypass) OR (graft) OR (vascular surgery) OR (revascularization) OR (salvage) OR (limb salvage) OR (vascular repair) OR (artery repair) OR (arterial repair)] AND [(limb) OR (extremity) OR (leg) OR (arm) OR (vascular injury) OR (amputation)].

Results

Of the 32 articles retrieved for initial review, five case reports with six patients of dermal substitute use for direct coverage of extremity repairs were identified. In all cases, the dermal substitute was able to provide stable coverage pending definitive coverage or was allowed to heal secondarily.

Conclusions

Dermal substitute matrices are a potential means of temporary coverage of exposed extremity vascular repairs when there is a paucity of local soft tissues pending more definitive coverage.

A Model to Study Wound Healing Over Exposed Avascular Structures in Rodents With a 3D-Printed Wound Frame

BACKGROUND

Soft tissue defects with exposed avascular structures require reconstruction with well-vascularized tissues. Extensive research is ongoing to explore tissue engineered products that provide durable coverage. However, there is a lack of controlled and affordable testbeds in the preclinical setting to reflect this challenging clinical scenario. We aimed to address this gap in the literature and develop a feasible and easily reproducible model in rodents that reflects an avascular structure in the wound bed.

METHODS

We created 20 × 20 mm full thickness wounds on the dorsal skin of Lewis rats and secured 0.5-mm-thick silicone sheets of varying sizes to the wound bed. A 3D-printed wound frame was designed to isolate the wound environment. Skin graft and free flap survival along with exposure of the underlying silicone was assessed. Rats were followed for 4 weeks with weekly dressing changes and photography. Samples were retrieved at the endpoint for tissue viability and histologic analysis.

RESULTS

The total wound surface area was constant throughout the duration of the experiment in all groups and the wound frames were well tolerated. The portion of the skin graft without underlying silicone demonstrated integration with the underlying fascia and a histologically intact epidermis. Gradual necrosis of the portion of the skin graft overlying the silicone sheet was observed with varying sizes of the silicone sheet. When the size of the silicone sheet was reduced from 50% of the wound surface area, the portion surviving over the silicone sheet increased at the 4-week timepoint. The free flap provided complete coverage over the silicone sheet.

CONCLUSION

We developed a novel model of rodent wound healing to maintain the same wound size and isolate the wound environment for up to 4 weeks. This model is clinically relevant to a complex wound with an avascular structure in the wound bed. Skin grafts failed to completely cover increasing sizes of the avascular structure, whereas the free flap was able to provide viable coverage. This cost-effective model will establish an easily reproducible platform to evaluate more complex bioengineered wound coverage solutions.

The Future of Microsurgery: Vascularized Composite Allotransplantation and Engineering Vascularized Tissue

Background

Microsurgical techniques have revolutionized the field of reconstructive surgery and are the mainstay for complex soft tissue reconstruction. However, their limitations have promoted the development of viable alternatives. This article seeks to explore technologies that have the potential of revolutionizing microsurgical reconstruction as it is currently known, reflect on current and future vascularized composite allotransplantation (VCA) practices, as well as describe the basic science within emerging technologies and their potential translational applications.

Methods

A literature review was performed of the technologies that may represent the future of microsurgery: vascularized tissue engineering (VCA) and flap-specific tissue engineering.

Results

VCA has shown great promise and has already been employed in the clinical setting (especially in face and limb transplantation). Immunosuppression, logistics, cost, and regulatory pathways remain barriers to overcome to make it freely available. Vascularized and flap-specific tissue engineering remain a laboratory reality but have the potential to supersede VCA. The capability of creating an off-the-shelf free flap matching the required tissue, size, and shape is a significant advantage. However, these technologies are still at the early stage and require significant advancement before they can be translated into the clinical setting.

Conclusion

VCA, vascularized tissue engineering, and flap-specific bioengineering represent possible avenues for the evolution of current microsurgical techniques. The next decade will elucidate which of these three strategies will evolve into a tangible translational option and hopefully bring a paradigm shift of reconstructive surgery.

Dermal Regeneration Template in the Management and Reconstruction of Burn Injuries and Complex Wounds: A Review

Background

Dermal scaffolds have created a paradigm shift for burn and wound management by providing improved healing and less scarring, while improving cosmesis and functionality. Dermal regeneration template (DRT) is a bilayer membrane for dermal regeneration developed by Yannas and Burke in the 1980s. The aim of this review is to summarize clinical evidence for dermal scaffolds focusing on DRT for the management and reconstruction of burn injuries and complex wounds.

Methods

A comprehensive search of PubMed was performed from the start of indexing through November 2022. Articles reporting on DRT use in patients with burns, limb salvage, and wound reconstruction were included with focus on high-level clinical evidence.

Results

DRT has become an established alternative option for the treatment of full-thickness and deep partial-thickness burns, with improved outcomes in areas where cosmesis and functionality are important. In the management of diabetic foot ulcers, use of DRT is associated with high rates of complete wound healing with a low risk of adverse outcomes. DRT has been successfully used in traumatic and surgical wounds, showing particular benefit in deep wounds and in the reconstruction of numerous anatomical sites.

Conclusions

Considerable clinical experience has accrued with the use of DRT beyond its original application for thermal injury. A growing body of evidence from clinical studies reports the successful use of DRT to improve clinical outcomes and quality of life across clinical indications at a number of anatomical sites.

Dermal Regenerative Templates in Orthopaedic Surgery

Management of soft-tissue injuries is a critical principle in the treatment of orthopaedic trauma. Understanding the options for soft-tissue reconstruction is vital for successful patient outcomes. Application of dermal regenerative templates (DRTs) in traumatic wounds has created a new rung in the reconstructive ladder bridging the gap between skin graft and flap coverage. There are multiple DRT products with specific clinical indications and mechanisms of action. This review outlines the up-to-date specifications and uses of DRT in commonly seen orthopaedic injuries.