Porcine dermal matrix sandwich graft for lower eyelid reconstruction

Engineered Skin Substitutes in Dermatologic Surgery: A Systematic Review

BACKGROUND

Artificial skin substitutes are a flexible alternative to autografting in Mohs micrographic surgery (MMS), but the characteristics and clinical outcomes of skin substitutes are not well defined.

OBJECTIVE

Summarize clinical data of skin substitutes in MMS for cutaneous malignancy.

METHODS

A MEDLINE/Embase/Web of Science search was conducted. Articles with original data on outcomes after skin substitute use in MMS for cutaneous malignancy were included. Articles not in English or without original data were excluded. Bias was assessed using the Oxford CEBM Levels of Evidence Table. Outcomes were synthesized using weighted averages. This study was prospectively registered in PROSPERO.

RESULTS

Of 1,007 articles, 40 met eligibility for inclusion. In total, 898 patients who underwent MMS and received a skin substitute were included. Xenografts were most commonly used ( n = 613). Semi-synthetic grafts (∼$<1/cm 2 ) and xenografts (∼$10/cm 2 ) are most affordable. Overall, outcomes were excellent for all skin substitutes, with a small proportion of patients experiencing correctable complications.

CONCLUSION

Skin substitutes are highly effective in MMS, with enormous potential. While the data demonstrate positive outcomes, they predominately draw from small, retrospective studies or case reports. There is also a scarcity of data comparing skin substitutes with each other or controls. Prospective studies are recommended.

Bioengineering autologous cartilage grafts for functional posterior lamellar eyelid reconstruction: A preliminary study in rabbits

The reconstruction of posterior lamellar eyelid defects remains a significant challenge in clinical practice due to anatomical complexity, specialized function, and aesthetic concerns. The ideal substitute for the posterior lamellar should replicate the native tarsoconjunctival tissue, providing both mechanical support for the eyelids and a smooth surface for the globe after implantation. In this study, we present an innovative approach utilizing tissue-engineered cartilage (TEC) grafts generated from rabbit auricular chondrocytes and a commercialized type I collagen sponge to reconstruct critical-sized posterior lamellar defects in rabbits. The TEC grafts demonstrated remarkable mechanical strength and maintained a stable cartilaginous phenotype both in vitro and at 6 months post-implantation in immunodeficient mice. When employed as autografts to reconstruct tarsal plate defects in rabbits' upper eyelids, these TEC grafts successfully restored normal eyelid morphology, facilitated smooth eyelid movement, and preserved the histological structure of the conjunctival epithelium. When applied in bilayered tarsoconjunctival defect reconstruction, these TEC grafts not only maintained the normal contour of the upper eyelid but also supported conjunctival epithelial cell migration and growth from the defect margin towards the centre. These findings highlight that auricular chondrocyte-based TEC grafts hold great promise as potential candidates for clinical posterior lamellar reconstruction. STATEMENT OF SIGNIFICANCE: The complex structure and function of the posterior lamellar eyelid continue to be significant challenges for clinical reconstructive surgeries. In this study, we utilized autologous auricular chondrocyte-based TEC grafts for posterior lamellar eyelid reconstruction in a preclinical rabbit model. The TEC grafts exhibited native cartilaginous histomorphology and comparable mechanical strength to those of the native human tarsal plate. In rabbit models with either tarsal plate defects alone or bilayered tarsoconjunctival defects, TEC grafts successfully restored the normal eyelid contour and movement, as well as supported preservation and growth of conjunctival epithelium. This is the first study to demonstrate autologous TEC grafts can be employed for repairing tarsal plate defects, thereby offering an alternative therapeutic approach for treating posterior lamellar defects in clinic settings.

Polymers and Biomaterials for Posterior Lamella of the Eyelid and the Lacrimal System

The application of biopolymers in the reconstruction of the posterior lamella of the eyelid and the lacrimal system marks a significant fusion of biomaterial science with clinical advancements. This review assimilates research spanning 2015 to 2023 to provide a detailed examination of the role of biopolymers in reconstructing the posterior lamella of the eyelid and the lacrimal system. It covers the anatomy and pathophysiology of eyelid structures, the challenges of reconstruction, and the nuances of surgical intervention. This article progresses to evaluate the current gold standards, alternative options, and the desirable properties of biopolymers used in these intricate procedures. It underscores the advancements in the field, from decellularized grafts and acellular matrices to innovative natural and synthetic polymers, and explores their applications in lacrimal gland tissue engineering, including the promise of 3D bioprinting technologies. This review highlights the importance of multidisciplinary collaboration between material scientists and clinicians in enhancing surgical outcomes and patient quality of life, emphasizing that such cooperation is pivotal for translating benchtop research into bedside applications. This collaborative effort is vital for restoring aesthetics and functionality for patients afflicted with disfiguring eyelid diseases, ultimately aiming to bridge the gap between innovative materials and their clinical translation.

Safety and Efficacy of Mucograft Porcine Collagen Bioengineered Acellular Dermal Matrix as a Spacer Graft in Lower Eyelid Elevation Surgery

Background

Recent regulatory changes have limited the access to a widely used commercially available bioengineered acellular dermal matrix (BADM) product as a spacer graft in the surgical correction of lower eyelid retraction. We report our off-label usage of Mucograft, a porcine BADM, as an alternative BADM.

Methods

A retrospective review was conducted of patients undergoing bilateral lower lid surgery with Mucograft (12 eyes) at a single institution.

Results

For the six patients, there was a mean lower lid elevation of 1.93 mm, without any serious complications. There was greater elevation of the lower lid position for the Mucograft group compared with four septo-retractor control patients (1.93 versus 0.94mm, P = 0.008).

Conclusion

Mucograft performed satisfactorily, and further investigation is warranted regarding its longer-term safety and efficacy.

Use of biomaterials in the reconstruction of posterior lamellar eyelid defects: a systematic review and meta-analysis

Eyelid defects can occur secondary to tumours, trauma, burns, and congenital factors. Among the most challenging aspects of eyelid reconstruction is the rebuilding of a tarsal substitute due to its delicate and multi-layered tissue composition. Attempts to use biomaterials for posterior lamellar reconstruction are intended to provide an alternative to traditional autograft reconstructions. In this review, we aimed to assess the types of biomaterials used for the reconstruction of the posterior lamella associated with eyelid defects and the associated clinical outcomes. A literature search was conducted on Pubmed, Prospero, Dynamed, DARE, EMBASE, and COCHRANE databases. A total of 15 articles fulfilled the inclusion criteria, and 129 patients with 142 eyelids reconstructed, using artificial grafts, were included in the review. Acellular dermis allograft (AlloDerm®, LifeCell) (n = 49) was the most common artificial graft used. A meta-analysis was performed, which demonstrated a pooled success rate of artificial grafts of 99% (95% CI 96-100, p = 0.05; I2 = 40%, total complications seen 39% (95% CI 96-100, p = 0.05; I2 = 40%) and re-operation rates of 5.6% (n = 8). The biomaterials used demonstrated an overall success rate of 99%, which is similar if not greater than that reported with the use of traditional autograft reconstruction techniques, with similar complications and fewer re-operations than autografts. This suggests that clinicians should consider the clinical use of artificial grafts for posterior lamellar reconstruction.

Acellular dermal matrix in reconstructive surgery: Applications, benefits, and cost

Modern tissue engineering has made substantial advancements that have revolutionized plastic surgery. Acellular dermal matrix (ADM) is an example that has gained considerable attention recently. ADM can be made from humans, bovines, or porcine tissues. ADM acts as a scaffold that incorporates into the recipient tissue. It is gradually infiltrated by fibroblasts and vascularized. Fortunately, many techniques have been used to remove cellular and antigenic components from ADM to minimize immune system rejection. ADM is made of collagen, fibronectin, elastin, laminin, glycosaminoglycans, and hyaluronic acid. It is used in critical wounds (e.g., diabetic wounds) to protect soft tissue and accelerate wound healing. It is also used in implant-based breast reconstruction surgery to improve aesthetic outcomes and reduce capsule contracture risk. ADM has also gained attention in abdominal and chest wall defects. Some studies have shown that ADM is associated with less erosion and infection in abdominal hernias than synthetic meshes. However, its higher cost prevents it from being commonly used in hernia repair. Also, using ADM in tendon repair (e.g., Achilles tendon) has been associated with increased stability and reduced rejection rate. Despite its advantages, ADM might result in complications such as hematoma, seroma, necrosis, and infection. Moreover, ADM is expensive, making it an unsuitable option for many patients. Finally, the literature on ADM is insufficient, and more research on the results of ADM usage in surgeries is needed. This article aims to review the literature regarding the application, Benefits, and costs of ADM in reconstructive surgery.

Skin substitutes for the management of mohs micrographic surgery wounds: a systematic review

The data on skin substitute usage for managing Mohs micrographic surgery (MMS) wounds remain limited. This systematic review aimed to provide an overview of skin substitutes employed for MMS reconstruction, summarize clinical characteristics of patients undergoing skin substitute-based repair after MMS, and identify advantages and limitations of skin substitute implementation. A systematic review of Ovid MEDLINE, EMBASE, Cochrane Library, and Web of Science databases, from inception to April 7, 2021, identified all cases of MMS defects repaired using skin substitutes. A total of 687 patients were included. The mean patient age was 70 years (range: 6-98 years). Commonly used skin substitutes were porcine collagen (n = 397), bovine collagen (n = 78), Integra (n = 53), Hyalofill (n = 43), amnion/chorion-derived grafts (n = 40), and allogeneic epidermal-dermal composite grafts (n = 35). Common factors influencing skin substitute selection were cost, healing efficacy, cosmetic outcome, patient comfort, and ease of use. Some articles did not specify patient and wound characteristics. Skin substitute usage in MMS reconstruction is not well-guided. Blinded randomized control trials comparing the efficacy of skin substitutes and traditional repair methods are imperative for establishing evidence-based guidelines on skin substitute usage following MMS.

Lower eyelid margin reconstruction: results of five different techniques

PURPOSE

This retrospective study was performed to examine surgical results of five different techniques for lower eyelid margin reconstruction after Mohs surgery: primary closure, semicircular flap, dermal matrix graft, sliding tarsal flap, and tarsoconjunctival flap.

METHODS

Medical records were reviewed in 178 patients undergoing surgery between 2005 and 2020. Outcomes were evaluated (photographic review) by three oculoplastic observers masked to procedure type, both with and without knowledge of the eyelid defect.

RESULTS

All patients achieved a good-excellent functional result and 90.4% were asymptomatic after surgery. Tarsoconjunctival flaps were associated with greater need for subsequent interventions (p < .001) and anterior lamellar deformities (p < .001). Semicircular flaps had a higher incidence of lateral canthal deformity (p < .001), but less eyelash disruption than other flap/graft techniques (p < .001). Mean cosmetic ratings (defect masked) were similar for dermal matrix grafts, semicircular, and sliding tarsal flaps; with each grading higher than tarsoconjunctival flaps (p ≤ .05). Among patients with 9-15 mm wide defects, results were better for semicircular and sliding tarsalflaps, than dermal matrix grafts (p ≤ .005) and tarsoconjunctival flaps (p ≤ .02).

CONCLUSIONS

All patients achieved a good-excellent functional result and 87.1% a good-excellent cosmetic result. The semicircular flap was effective for repairing medium sized wounds that could not be closed primarily, creating a continuous lash line, although with a higher incidence of lateral canthal deformities. The sliding tarsal flap was effective for shallow wounds of varying widths. The single-staged dermal matrix graft provided similar results as the tarsoconjunctival flap. Subsequent interventions were more frequent after the tarsoconjunctival flap than other methods.