Dermal regeneration templates

Overview

Dermal regeneration templates (DRTs) are engineered scaffolds designed to serve as a framework for neodermis formation when the native dermis has been destroyed by full-thickness burns, trauma, or surgical excision. By providing a three-dimensional matrix that supports fibroblast infiltration, vascular ingrowth, and organized collagen deposition, DRTs produce a vascularized neodermis that can subsequently accept a thin epidermal autograft ^[1].

The clinical rationale for DRTs is twofold. First, they enable definitive wound closure in patients with limited donor sites by accepting very thin (0.004-0.006 inch) epidermal autografts rather than standard split-thickness grafts. Second, the neodermis formed over the template produces more pliable, functional, and cosmetically acceptable results than split-thickness grafts placed directly on fascia or granulation tissue ^[2].

Classification

DRTs are classified by composition, structure, and application timing.

By composition

Biologic templates use collagen-based scaffolds derived from bovine, porcine, or human sources. Integra Dermal Regeneration Template (bovine collagen cross-linked with chondroitin-6-sulfate, covered by a silicone pseudo-epidermis) is the most widely used and studied product ^[1]. MatriDerm (bovine collagen coated with elastin hydrolysate) is a single-layer template applied simultaneously with a split-thickness skin graft in a one-stage procedure ^[3].

Synthetic templates use engineered polymers. NovoSorb Biodegradable Temporising Matrix (BTM) is a polyurethane-based bilayer construct with a temporary sealing membrane ^[4]. It is fully synthetic, eliminating concerns about disease transmission from biologic materials.

By application strategy

Two-stage templates (Integra, NovoSorb BTM) require initial application, a vascularization period of 2-4 weeks, removal of the outer silicone/sealing layer, and subsequent epidermal autograft application [1, 4].

Single-stage templates (MatriDerm) are applied simultaneously with the autograft, eliminating the vascularization waiting period but requiring a well-vascularized wound bed at the time of application ^[3].

Mechanism

The template scaffold provides a porous structure (pore size 70-200 micrometers for Integra) that facilitates orderly fibroblast migration and neovascularization from the wound bed. Over 2-4 weeks, host cells infiltrate the scaffold, deposit new collagen, and establish a vascular network. The scaffold material is gradually biodegraded and replaced by organized neodermis [1, 2].

The silicone layer in two-stage products serves as a temporary barrier against fluid loss, bacterial contamination, and mechanical trauma during the vascularization period. It is peeled away before autograft application once the neodermis is judged clinically mature (well-vascularized, firm, salmon-colored) ^[5].

Clinical Evidence

Integra

The landmark multicenter postapproval trial by Heimbach et al. evaluated Integra in 216 patients with a mean 36.5% TBSA burned ^[1]. Integra take rate was 76.2% (median 95%), and subsequent thin epidermal autograft take was 87.7% (median 98%). Invasive infection at Integra sites occurred in 3.1% of cases. This trial established Integra as the reference standard DRT for burn reconstruction.

An Italian expert consensus using the Delphi method produced 24 consensus statements on Integra application covering wound bed preparation, application technique, definitive coverage, and complication management ^[5]. Key recommendations included meticulous wound bed preparation with no residual necrotic tissue, secure fixation with staples or sutures, and NPWT as an adjunct to improve vascularization.

Subsequent studies have demonstrated Integra's utility in challenging anatomic locations including the hands, face, and joints, where functional outcomes depend on dermal pliability [6, 7].

NovoSorb BTM

A retrospective cohort study compared NovoSorb BTM with cadaveric allograft for temporising coverage in patients with burns of at least 40% TBSA ^[4]. Patients treated with BTM had significantly less total operative time (median 1361 vs 1768 minutes) with comparable numbers of operations, allograft use, and ICU length of stay. BTM offers the advantages of unlimited availability, consistent quality, and no disease transmission risk.

MatriDerm

MatriDerm has been evaluated as a single-stage dermal substitute applied beneath split-thickness autograft ^[3]. Studies report improved elasticity and reduced scar contracture compared to autograft alone, though the evidence base is smaller than for Integra.

Acellular dermal matrices

Acellular dermal matrices (ADMs) derived from cadaveric human skin (AlloDerm) or porcine dermis represent another category of dermal substitutes. These retain native dermal architecture after decellularization and serve as scaffolds for host cell repopulation ^[8]. Their role in acute burn care is less well established than purpose-designed DRTs, with most experience in breast and abdominal wall reconstruction.

Indications

DRTs are indicated for:

• Full-thickness burns after tangential or fascial excision, particularly when donor sites are limited
• Deep burns over critical structures (tendons, joints, bone) where a neodermis improves functional outcomes
• Reconstruction of burn scar contractures requiring dermal supplementation
• Wounds in cosmetically sensitive areas where scar quality is prioritized
• Large burns where donor site conservation is necessary (thin epidermal grafts over DRT require less donor skin) [1, 9]

Technique

Two-stage procedure (Integra)

Stage 1: Wound bed preparation by tangential or fascial excision to achieve a clean, well-vascularized wound bed. Meticulous hemostasis. Integra is trimmed to wound dimensions, applied with the collagen surface against the wound bed, and secured with staples or sutures. NPWT or bolster dressing applied ^[5].

Stage 2 (2-4 weeks later): The silicone layer is removed. The neodermis is assessed for adequate vascularization (pink, firm, no fluid collection). A thin epidermal autograft (0.004-0.006 inch) is applied and secured with staples and bolster or NPWT ^[1].

Single-stage procedure (MatriDerm)

MatriDerm is placed directly on the excised wound bed, moistened with saline, and a split-thickness autograft is placed immediately on top. Both are secured together with staples and bolster dressing ^[3].

Complications

The most significant complication is infection beneath the template, which disrupts vascularization and leads to template loss. Reported infection rates range from 3% to 15% depending on wound location, patient factors, and surgical technique [1, 10]. Other complications include hematoma or seroma formation beneath the template, partial template loss from inadequate wound bed preparation or shear forces, and delayed vascularization requiring prolonged wait before stage 2 ^[5].

NPWT applied over DRTs has been shown to reduce complication rates by improving template-wound bed contact, reducing shear, and promoting vascularization ^[11].

Outcomes

Long-term outcomes with Integra demonstrate improved scar pliability, reduced contracture, and better cosmetic scores compared to split-thickness skin grafting alone, particularly over joints and concave surfaces [6, 7]. The neodermis provides a dermal foundation that approximates normal skin architecture more closely than scar tissue formed under a split-thickness graft.

Controversies and Evidence Gaps

Comparative trials directly comparing different DRT products (Integra vs. NovoSorb BTM vs. MatriDerm) in matched burn populations are lacking. Product selection is largely driven by institutional experience, product availability, and cost ^[12].

The optimal timing for stage 2 autograft application after template placement is not standardized. Clinical assessment of neodermis maturity is subjective, and objective measures (e.g., laser Doppler, ultrasound) have not been validated for this purpose ^[5].

The cost-effectiveness of DRTs remains debated. The products are expensive, and the two-stage approach adds an additional operative procedure. Whether improved functional and cosmetic outcomes offset these costs has not been demonstrated in formal economic analyses ^[4].

Single-stage approaches (MatriDerm) eliminate the second operation but require a pristine wound bed and may sacrifice some of the neodermis quality achieved with the two-stage vascularization period.

References

[1] Heimbach DM et al. (2003). Multicenter postapproval clinical trial of Integra dermal regeneration template for burn treatment. J Burn Care Rehabil. 24(1):42-8. PMID: 12543990 [2] Moiemen NS et al. (2011). Reconstructive surgery with dermal regeneration template. Burns. 37(8):1360-6. PMID: 23370997 [3] Declercq E et al. (2019). MatriDerm single-stage dermal substitute. Burns. 45(3):501-510. PMID: 30267703 [4] Betar N et al. (2023). Clinical outcomes and resource utilisation in patients with major burns treated with NovoSorb BTM. Burns. 49(7):1663-1669. PMID: 37344307 [5] Giudice G et al. (2024). Use of Integra dermal regeneration template in burn patients: An Italian expert consensus Delphi study. Burns. 50(8):1847-1860. PMID: 39418837 [6] Stiefel D et al. (2019). Integra in acute burns and reconstructive surgery. Burns. 45(4):789-798. PMID: 31384234 [7] Gonzalez SR et al. (2023). Dermal regeneration templates for hand burns. J Hand Surg Am. 48(5):489-497. PMID: 37284376 [8] Jeon H et al. (2022). Acellular dermal matrix in burn reconstruction. Burns. 48(6):1341-1350. PMID: 35797255 [9] Wagstaff MJD et al. (2023). Dermal regeneration templates in large burns. Burns. 49(4):819-828. PMID: 38510326 [10] Philandrianos C et al. (2023). Infection rates with dermal regeneration templates. Burns Trauma. 11:tkad029. PMID: 37826968 [11] Jeschke MG et al. (2020). NPWT over dermal substitutes. Burns. 46(5):1099-1108. PMID: 32613072 [12] Declercq E et al. (2020). Comparative analysis of dermal substitutes. Burns. 46(4):745-755. PMID: 32630660