Efficacy of Nd:YAG Laser and Intralesional Triamcinolone Injection Combination Therapy in the Postoperative Management of Keloids

BACKGROUND

Keloids, characterized by protruding scars that extend beyond the original skin damage site, cause significant emotional stress and reduced quality of life. Their exact pathogenesis remains unclear, with various hypotheses including growth factor imbalances and extracellular matrix changes. No single treatment is universally accepted, but multiple modalities like triamcinolone acetonide injection (TAC), laser therapies, and surgery are commonly used.

METHODS

This retrospective study involved East Asian patients who underwent keloid scar excision between March 2019 and June 2022. Patients were divided into two groups: one receiving only TAC injections and the other a combination of TAC and Nd:YAG laser therapy. The efficacy of treatments was evaluated using the modified Vancouver Scar Scale (mVSS) and the Patient and Observer Scar Assessment Scale (POSAS), with follow-ups at six and twelve months after operation.

RESULTS

The study involved 111 patients. Both treatment groups showed significant improvements in mVSS and POSAS scores, but the combination therapy group demonstrated a statistically significant improvement in POSAS scores and lower recurrence rates at 12 months compared to the TAC-only group. However, there was no significant difference in patient satisfaction between the groups.

CONCLUSION

Dual therapy involving TAC injection and Nd:YAG laser treatment was more effective than TAC injection alone for managing keloid scars after surgery. This combination therapy showed better outcomes in preventing keloid recurrence and improving scar status at 12 months after operation, along with significant improvements in patient-reported outcomes.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Impaired collagen fibril assembly in keloids with enhanced expression of lumican and collagen V

Keloids are characterized by fibroblast activation and altered architecture of extracellular matrix (ECM). Excessive deposition of ECM molecules and irregular organization of collagen fibers have been observed in keloids. However, the ultrastructural alteration of collagen has not been fully investigated. In this study, the differences in tissue structure, collagen ultrastructure, matrix components, mechanical properties and collagen assembling molecules between keloids and their extra-lesional skins (ELSs) were explored using histology, transmission electron microscope (TEM), qPCR, Western blot, immunohistochemistry and bioinformatics. Histological evaluation showed thinner fibers in keloids with increased contents of collagen III and proteoglycans, which were supported by TEM findings of thinner collagen fibrils and less developed D-band periodicity in keloids than in ELSs (p < 0.05). In addition, total collagen and water contents were significantly increased (p < 0.05) along with richer proteoglycan production in keloids vs ELSs, which also led to increased stiffness and decreased maximal load in keloids compared with ELSs. Mechanism study showed that multiple molecules related to matrix assembly were significantly upregulated in keloids (p < 0.05). In particular, lumican and collagen V showed high degrees in co-expression analysis and their upregulation levels were revealed from microarray data, which were also verified in keloids at both gene and protein levels (p < 0.05). Nevertheless, siRNA knockdown of lumican failed to affect in vitro collagen assembly, but caused upregulated collagen V expression along with the upregulation of focal adhesion kinase, TGF-β1, TGF-β3 and PDGF, among which some are known for capable of enhancing collagen V expression. In conclusion, this study demonstrates impaired collagen assembly along with enhanced expression of lumican and collagen V, both are known for interfering with collagen fibril assembly.

Composition, structure and function of the corneal stroma

No other tissue in the body depends more on the composition and organization of the extracellular matrix (ECM) for normal structure and function than the corneal stroma. The precise arrangement and orientation of collagen fibrils, lamellae and keratocytes that occurs during development and is needed in adults to maintain stromal function is dependent on the regulated interaction of multiple ECM components that contribute to attain the unique properties of the cornea: transparency, shape, mechanical strength, and avascularity. This review summarizes the contribution of different ECM components, their structure, regulation and function in modulating the properties of the corneal stroma. Fibril forming collagens (I, III, V), fibril associated collagens with interrupted triple helices (XII and XIV), network forming collagens (IV, VI and VIII) as well as small leucine-rich proteoglycans (SLRP) expressed in the stroma: decorin, biglycan, lumican, keratocan, and fibromodulin are some of the ECM components reviewed in this manuscript. There are spatial and temporal differences in the expression of these ECM components, as well as interactions among them that contribute to stromal function. Unique regions within the stroma like Bowman's layer and Descemet's layer are discussed. To define the complexity of corneal stroma composition and structure as well as the relationship to function is a daunting task. Our knowledge is expanding, and we expect that this review provides a comprehensive overview of current knowledge, definition of gaps and suggests future research directions.

Small Leucine-Rich Proteoglycans in Skin Wound Healing

Healing of cutaneous wounds is a complex and well-coordinated process requiring cooperation among multiple cells from different lineages and delicately orchestrated signaling transduction of a diversity of growth factors, cytokines, and extracellular matrix (ECM) at the wound site. Most skin wound healing in adults is imperfect, characterized by scar formation which results in significant functional and psychological sequelae. Thus, the reconstruction of the damaged skin to its original state is of concern to doctors and scientists. Beyond the traditional treatments such as corticosteroid injection and radiation therapy, several growth factors or cytokines-based anti-scarring products are being or have been tested in clinical trials to optimize skin wound healing. Unfortunately, all have been unsatisfactory to date. Currently, accumulating evidence suggests that the ECM not only functions as the structural component of the tissue but also actively modulates signal transduction and regulates cellular behaviors, and thus, ECM should be considered as an alternative target for wound management pharmacotherapy. Of particular interest are small leucine-rich proteoglycans (SLRPs), a group of the ECM, which exist in a wide range of connecting tissues, including the skin. This manuscript summarizes the most current knowledge of SLRPs regarding their spatial-temporal expression in the skin, as well as lessons learned from the genetically modified animal models simulating human skin pathologies. In this review, particular focus is given on the diverse roles of SLRP in skin wound healing, such as anti-inflammation, pro-angiogenesis, pro-migration, pro-contraction, and orchestrate transforming growth factor (TGF)β signal transduction, since cumulative investigations have indicated their therapeutic potential on reducing scar formation in cutaneous wounds. By conducting this review, we intend to gain insight into the potential application of SLRPs in cutaneous wound healing management which may pave the way for the development of a new generation of pharmaceuticals to benefit the patients suffering from skin wounds and their sequelae.

High resolution B-scan ultrasound of hypertrophic scars

BACKGROUND

Ultrasonography has provided the means for objective and non-invasive monitoring of the dynamics of some skin diseases. The pathologic scars (keloids and hypertrophic scars) that have an increased content of collagen, and have been not analyzed by high-frequency ultrasound so far. The purpose of the present study was to determine the ecographic features of these scars with a view in developing a reliable method for assessing the effectiveness of different therapeutic approaches.

METHODS

Six pathological scars from five patients were examined by a 20 MHz B-Scanner and compared with healthy skin of the same region. Densitometry analysis was performed with the aid of a dedicated software.

RESULTS

All the pathologic scars studied showed an easily identified echo-poor image clearly demarcated from the surrounding not involved tissue. When they were analyzed by densitometry, the lesions had highly significant reduced densitometric values (7.6+/-4.7) compared with regional healthy skin (31.79+/-10.8).

CONCLUSION

The high-frequency ultrasonography is a suitable objective and non-invasive method for discriminating healthy from pathologic skin in hypertrophic scars and keloids.