Effects of a Fibrin Sealant on Skin Graft Tissue Adhesion in a Rodent Model

Safeguarding Skin Grafts: An Evidence-Based Summary of Fixation Techniques

BACKGROUND

Effective skin graft fixation is vital in preventing sheering forces, seroma, and hematoma from compromising graft take. Yet, selecting the ideal technique for securing skin grafts remains a contentious subject, with significant variation in practice existing between surgeons. There is, therefore, benefit to be derived from assessing the literature for evidence-based recommendations to guide the decision-making process.

METHODS

A search of Medline and Embase was performed using appropriate key terms, yielding 419 articles. Reference lists were analyzed. Inclusion and exclusion criteria were composed. Level I to III studies, as defined by the Centre for Evidence-Based Medicine, that compared skin graft fixation methods were analyzed. Rayyan QCRI was used for abstract and title screening. After full text screening, 41 studies were included for qualitative analysis. All included randomized control trials (RCTs) were assessed for risk of bias using the Cochrane Risk-of-Bias 2 (ROB2) tool.

RESULTS

We identified 4 groups of fixation technique: "tie-over bolster" (TOB), "no TOB," "adhesive glues," and "negative pressure wound therapy" (NPWT). Twelve studies compared TOB with no TOB, with no difference in graft take demonstrated. Sixteen studies compared adhesive glues with traditional methods, with no difference in graft take demonstrated. Thirteen studies compared NPWT with traditional methods, with enhanced graft take demonstrated. Risk of bias was deemed low in 1 of 13 RCTs.

CONCLUSIONS

Based on the current evidence, only NPWT is associated with enhanced graft take. However, there is a scarcity of robust level I evidence comparing different fixation techniques, meaning that strong recommendations cannot be made. We propose examples of hypothesis-driven RCTs, in predetermined clinical settings, based on the theoretical benefits of the techniques that would add value to clinical practice.

To Glue or Not to Glue? Analysis of Fibrin Glue for Split-thickness Skin Graft Fixation

Background:

Split-thickness skin grafting (STSG) is a commonly used tool in the plastic surgeon’s reconstructive armamentarium. Fibrin glue (FG) consists of a combination of clotting factors and thrombin whose key properties include adherence and hemostasis. This preliminary study aimed to assess clinical outcomes and cost of FG for STSG fixation in a general wound reconstruction.

Methods:

A retrospective review was conducted in all patients undergoing STSG placement by a single surgeon (JPF) from January 2016 to March 2018. Twenty patients were identified and matched by wound location and wound size. Patients were then divided into 2 groups based on the method of STSG fixation: FG (n = 10) or suture only (SO) (n = 10).

Results:

In patients with FG fixation, we observed trends of decreased adjusted operative times (34.9 versus 49.4 minutes, P = 0.612), a similar length of stay (2.8 versus 3.5 days, P = 0.306), and liberation from the use of negative pressure wound therapy (0 versus 10 wounds, P < 0.0001). There were no observed differences between the 2 groups in terms of graft-related complications at 180 days (1 complication FG versus 0 complications SO). Time to 100% graft take was also not different (20.2 versus 29.4 days, P = 0.405). Additionally, total direct cost ($16,542 FG versus $24,266 SO; P = 0.545) and total charges ($120,336 FG versus $183,750 SO; P = 0.496) were not statistically different between the FG and SO groups.

Conclusions:

In this preliminary comparative assessment, FG for STSG fixation has shown no difference in clinical outcomes to SO fixation, trends of decreased operative time, and afforded complete liberation from negative pressure wound therapy dressings.

Handheld skin printer: in situ formation of planar biomaterials and tissues

We present a handheld skin printer that enables the in situ formation of biomaterial and skin tissue sheets of different homogeneous and architected compositions. When manually positioned above a target surface, the compact instrument (weight <0.8 kg) conformally deposits a biomaterial or tissue sheet from a microfluidic cartridge. Consistent sheet formation is achieved by coordinating the flow rates at which bioink and cross-linker solution are delivered, with the speed at which a pair of rollers actively translate the cartridge along the surface. We demonstrate compatibility with dermal and epidermal cells embedded in ionically cross-linkable biomaterials (e.g., alginate), and enzymatically cross-linkable proteins (e.g., fibrin), as well as their mixtures with collagen type I and hyaluronic acid. Upon rapid crosslinking, biomaterial and skin cell-laden sheets of consistent thickness, width and composition were obtained. Sheets deposited onto horizontal, agarose-coated surfaces were used for physical and in vitro characterization. Proof-of-principle demonstrations for the in situ formation of biomaterial sheets in murine and porcine excisional wound models illustrate the capacity of depositing onto inclined and compliant wound surfaces that are subject to respiratory motion. We expect the presented work will enable the in situ delivery of a wide range of different cells, biomaterials, and tissue adhesives, as well as the in situ fabrication of spatially organized biomaterials, tissues, and biohybrid structures.