An overview of clinical and experimental treatment modalities for port wine stains

532-nm potassium titanyl-phosphate laser versus 595-nm pulsed dye laser for port-wine birthmarks: A prospective, randomized, split-side study

BACKGROUND

Pulsed dye lasers (PDL) are currently the first-line treatment of port-wine birthmarks (PWB). Due to high maintenance costs and instable technology, alternative methods are needed.

OBJECTIVES

To compare clinical outcomes of a variable-sequenced, long-pulsed 532-nm potassium titanyl-phosphate (KTP) laser and PDL on treating PWB.

METHODS

A prospective, randomized, split-side study. Patients were treated with a KTP laser and PDL with 1 to 5 sessions at intervals of 6-8 weeks. A follow-up visit was scheduled 6 weeks post-treatment. Efficacy was evaluated through colorimetric analysis, area reduction measurements and clinical evaluations by two blinded investigators based on photo documentation. Subjects provided rating of pain intensity during treatment, post-treatment reactions and satisfaction. Safety was measured by adverse events. Maintenance issues of the laser systems were documented.

RESULTS

A total of 35 patients (mean age 42.1 years) were enrolled. 63% were female. Patients received 2.4 (SD 1.4; 1-5) treatment sessions. Colorimetric analysis indicated a comparable clearance effect in PWB of both KTP laser and PDL. Independent investigators rated clinical appearance to be significantly improved compared to baseline. No significant difference was observed between both laser systems. Regarding post-treatment reactions, the KTP laser caused less swelling, purpura and crusts. 96% would recommend both treatment modalities. Patients were satisfied with both laser systems. During the study, PDL systems malfunctioned for 6.6 months in total. For the KTP laser, we did not observe any system failures.

CONCLUSION

Our data indicate that the KTP laser of the latest generation with large-spot sizes, subpulse technology and cryogen cooling has a comparable efficacy to the PDL in treating PWB. In addition, KTP laser is associated with greater tolerability, fewer technical failures and lower repair costs. Further prospective studies are required to determine the true effectiveness of the KTP laser in PWB treatment. This study was preregistered in Clinicaltrials.gov (NCT05771298).

Real-World Data on the Use of Sirolimus in Asian Children with Vascular Malformations

OBJECTIVES

The management of vascular malformations is complex and challenging. This study aimed to explore efficacy, plasma trough concentrations of sirolimus, post-withdrawal conditions, and adverse reactions of sirolimus in treating complex vascular malformations.

METHODS

In our center, we analyzed vascular malformations treated with sirolimus (and corticosteroid) from August 2017 to June 2021. Meanwhile, we reviewed the medical records, the efficacy, side effects, and laboratory tests. Patients who had stopped taking sirolimus were followed up by telephone.

RESULTS

A total of 25 patients with complicated vascular malformations in our center, including 7 females and 18 males aged 4 months to 15 years, were enrolled. In all, 19 patients (76.0%) responded to sirolimus, and the plasma concentration of sirolimus fluctuated between 0.97 and 27.15 ng/ml. In all, 24 patients (96.0%) were in follow-up. A total of 15 patients (62.5%) stopped taking sirolimus during follow-up, and 2 patients (13.3%) discontinued the sirolimus due to side effects. A total of 3 patients (20.0%) restarted sirolimus treatment.

CONCLUSION

Starting dose of 1.5-2 mg/m2 sirolimus is effective and safe in vascular malformation treatment. The best treatment regimen and discontinuation indications needed more investigation. Most should be done about targeted therapy to improve effectiveness and reduce side effects.

Non-invasive efficacy assessment of pulsed dye laser and photodynamic therapy for port-wine stain

Port wine stain (PWS) is a congenital vascular malformation that commonly occurs on the face and neck. Currently, the main treatments for port wine stain are pulsed dye laser (PDL) and photodynamic therapy (PDT). However, the efficacy evaluation of PWS mostly relies on the subjective judgement of clinicians, and it is difficult to accurately respond to many small changes after treatment. Therefore, some non-invasive and efficient efficacy assessment methods are also needed. With the continuous development of technology, there are currently many visualisation instruments to evaluate PWS, including dermoscopy, VISIA-CR™ system, reflectance confocal microscopy (RCM), high-frequency ultrasound (HFUS), optical coherence tomography (OCT), Photoacoustic imaging (PAI), laser speckle imaging (LSI) and laser Doppler imaging (LDI). Among them, there are simple and low-cost technologies such as dermoscopy and the VISIA-CR™ system, but they may not be able to observe the deeper structures of PWS. At this time, combining techniques such as HFUS and OCT to increase penetration depth is crucial to evaluate PWS. In the future, the combination of these different technologies could help overcome the limitations of a single technology. This article provides a systematic overview of non-invasive methods for evaluating treatment efficacy in port wine stains and summarises their advantages and disadvantages.

Current clinical evidence is insufficient to support HMME-PDT as the first choice of treatment for young children with port wine birthmarks

BACKGROUND

Port wine birthmark (PWB) is a congenital vascular malformation of the skin. Pulsed dye laser (PDL) is the "gold standard" for the treatment of PWB globally. Hematoporphyrin monomethyl ether (HMME or hemoporfin)-mediated photodynamic therapy (HMME-PDT) has emerged as the first choice for PWB treatment, particularly for young children, in many major hospitals in China during the past several decades.

AIM

To evaluate whether HMME-PDT is superior to PDL by comparing the clinical efficacies of both modalities.

METHOD

PubMed records were searched for all relevant studies of PWB treatment using PDL (1988-2023) or HMME-PDT (2007-2023). Patient characteristics and clinical efficacies were extracted. Studies with a quartile percentage clearance or similar scale were included. A mean color clearance index (CI) per study was calculated and compared among groups. An overall CI (C0), with data weighted by cohort size, was used to evaluate the final efficacy for each modality.

RESULT

A total of 18 HMME-PDT studies with 3910 patients in China were eligible for inclusion in this analysis. Similarly, 40 PDL studies with 5094 patients from nine different countries were eligible for inclusion in this analysis. Over 58% of patients in the HMME-PDT studies were minors (<18 years old). A significant portion (21.3%) were young children (<3 years old). Similarly, 33.2% of patients in the PDL studies were minors. A small proportion (9.3%) was young children. The overall clearance rates for PDL were slightly, but not significantly, higher than those for HMME-PDT in cohorts with patients of all ages (C0, 0.54 vs. 0.48, p = 0.733), subpopulations with only minors (C0, 0.54 vs. 0.46, p = 0.714), and young children (C0, 0.67 vs. 0.50, p = 0.081). Regrettably, there was a lack of long-term data on follow-up evaluations for efficacy and impact of HMME-PDT on young children in general, and central nervous system development in particular, because their blood-brain barriers have a greater permeability as compared to adults.

CONCLUSION

PDL shows overall albeit insignificantly higher clearance rates than HMME-PDT in patients of all ages; particularly statistical significance is nearly achieved in young children. Collectively, current evidence is insufficient to support HMME-PDT as the first choice of treatment of PWBs in young children given: (1) overall inferior efficacy as compared to PDL; (2) risk of off-target exposure to meningeal vasculature during the procedure; (3) administration of steriods for mitigation of side effects; -and (4) lack of long-term data on the potential impact of HMME on central nervous system development in young children.

Evaluating the clinical efficacy of pulsed dye laser with sirolimus for treatment of capillary malformations: A systematic review

Port-wine stains (PWS) are capillary vascular anomalies that are often treated with pulsed-dye laser (PDL). Revascularization limits persistent clearance; however, the anti-angiogenic effects of sirolimus (SIRO) may inhibit revascularization. This review aims to determine differences in PWS outcomes when treated with PDL monotherapy or in combination with SIRO. A systematic review was conducted using PubMed, Cochrane, and Embase databases. The following search terms were used: 'port wine stain PDL SIRO', 'port wine stain PDL', and 'port wine stain PDL and topical treatment' with (MeSH) and (Title/Abstract) limits. The search was limited to the English language and human-subject studies conducted between 1 January 2000 and 1 June 2023. Inclusion criteria included studies evaluating SIRO as an adjunct to PDL in patients with PWS. Data extraction and quality assessment were performed by two independent reviewers. A total of nine studies met the inclusion criteria, which included randomized controlled trials (3), case series (2), case reports (3), and a prospective intrapatient study (1), which represented a total of 58 patients. Five studies showed improvement of a measured post-treatment PDL parameter including shortening treatment time and less frequent dosing. A subset of studies (4/9) which did not demonstrate significant clinical improvements exhibited significant photographic evidence of improvement. Heterogeneity among the studies highlights the need for further research and standardization. While adjunctive SIRO shows promise, larger studies and comprehensive evaluation methods are required to establish conclusive safety and efficacy guidelines to shape clinical decision-making.

Ocular and orbital tumors in childhood

Pediatric tumors of the eye and orbit can be benign or malignant as well as congenital or acquired and are usually distinctively different than those seen in adults. Although most of these neoplasms are benign (eg, dermoid cyst, chalazion, molluscum), their location near and within a vital organ can result in serious dermatologic and ophthalmologic sequelae. Lesions discussed include vascular lesions, retinoblastomas (the most common primary pediatric intraocular malignancy), rhabdomyosarcoma (the most common primary pediatric orbital malignancy), Langerhans cell histiocytosis, and metastatic lesions to the orbit (neuroblastoma, Ewing sarcoma). Although cysts and ocular melanoma can occur within the pediatric population, these conditions are covered in other contributions in this issue of Clinics in Dermatology.

Efficacy and influential factors of hematoporphyrin monomethyl ether mediated photodynamic therapy in the treatment for port-wine stains

BACKGROUNDS

Hematoporphyrin monomethyl ether mediated photodynamic therapy (HMME-PDT) has emerged as an alternative approach for port-wine stain (PWS), which was primarily treated with pulsed dye laser (PDL). This study was aimed to evaluate the efficacy and safety of HMME-PDT for PWS and to explore influential factors on the efficacy.

METHODS

A total of 254 patients were enrolled. Patients received an intravenous injection of HMME at 5 mg/kg. Lesion areas were irradiated with 532-nm light for 20-25 min. Efficacy was assessed according to fading of lesions and graded as excellent (≥90 %), good (60 %-89 %), fair (20 %-59 %), or poor (<20 %). Adverse events were recorded. Clinical data were analyzed including gender, age, lesion sub-type, lesion location and number of treatments.

RESULTS

Overall, 72.4 % of patients achieved an effective response, with 27.6% showing excellent efficacy, 24.8 % showing good efficacy and 20.1 % showing fair efficacy. Only 27.6 % showed poor efficacy. Patients under the age of 18 obtained a better efficacy than adults. Lesions in face showed a better therapeutic outcome than those in neck or trunk and extremities. A more effective response was seen in pink type compared with nodular thickening type. Multiple HMME-PDT treatments could improve the clinical response. Lesion location, lesion sub-type, number of treatments were independent influential factors on efficacy. Adverse events included edema, blister, crust, hypopigmentation, hyperpigmentation, pain, itch and burning sensation. No severe systemic side events were observed.

CONCLUSIONS

HMME-PDT was effective for treating PWS and was safe and well-tolerated by patients. It is worth further investigation in efficacy and safety involving more patients from medical institutions in different regions in China. The optimal treatment parameters and treatment protocols are still being explored in the clinical treatment for PWS.

Updates in Genetic Testing for Head and Neck Vascular Anomalies

Vascular anomalies include benign or malignant tumors or benign malformations of the arteries, veins, capillaries, or lymphatic vasculature. The genetic etiology of the lesion is essential to define the lesion and can help navigate choice of therapy. . In the United States, about 1.2% of the population has a vascular anomaly, which may be underestimating the true prevalence as genetic testing for these conditions continues to evolve.

Cutaneous Hypervascularization Treatment Using Photo-Mediated Ultrasound Therapy

Photo-mediated ultrasound therapy (PUT) is a cavitation-based, highly selective antivascular technique. In this study, the effectiveness and safety of PUT on cutaneous vascular malformation was examined through in vivo experiments in a clinically relevant chicken wattle model, whose microanatomy is similar to that of port-wine stain and other hypervascular dermal diseases in humans. Assessed by optical coherence tomography angiography, the blood vessel density in the chicken wattle decreased by 73.23% after one session of PUT treatment in which 0.707 J/cm2 fluence laser pulses were applied concurrently with ultrasound bursts (n = 7, P < .01). The effectiveness of removing blood vessels in the skin at depth up to 1 mm was further assessed by H&E-stained histology at multiple time points, which included days 1, 3, 7, 14, and 21 after treatment. Additional immunohistochemical analyses with CD31, caspase-3, and Masson's trichrome stains were performed on day 3 after treatment. The results show that the PUT-induced therapeutic effect was confined and specific to blood vessels only, whereas unwanted collateral damage in other skin tissues such as collagen was avoided. The findings from this study demonstrate that PUT can efficiently and safely remove hypervascular dermal capillaries using laser fluence at a level that is orders of magnitude smaller than that used in conventional laser treatment of vascular lesions, thus offering a safer alternative technique for clinical management of cutaneous vascular malformations.

Assessment of the efficacy of 595 nm pulsed dye laser in the management of facial flat angiomas. Results of a case series

BACKGROUND

Studies on pulsed dye laser (PDL) have shown the best efficacy and safety data for treating vascular anomalies among the various lasers used and the 595-nm PDL has been used to treat cutaneous vascular anomalies for about 30 years. The purpose of this study was to assess the efficacy of 595 nm Pulsed Dye Laser in the management of facial flat angiomas present in the form of Port-Wine Stain.

MATERIALS AND METHODS

Seven cases of PWS in Fitzpatrick skin type ranged from I to III and colour ranging from pink to purple, were treated with 595 nm pulse Dye Laser. Patients underwent to 6-8 laser sessions at 20-30 days intervals. Results obtained were judged by dermatologist, by comparing pre-treatment and post-treatment photographs, 6 months after the last session and a quartile scale of lesion clearance (4-point Investigator Global Assessment scale): 1 = no or low results (0%-25% of the lesion area improved), 2 = slight improvement (25%-50% of the lesion area cleared), 3 = moderate-good improvement (50%-75%), and 4 = excellent improvement (75%-100%) was used. Possible side effects such as blisters, hyper/hypopigmentation, and scarring were monitored.

RESULTS

All patients observed global improvements. 71% of patients achieved excellent clearance and 29% patients achieved good-moderate clearance of their angioma. Patients were asked for a subjective evaluation of the results: 57% of patients were very satisfied, 29% were satisfied, and 14% patients were not very satisfied with the results. No patients were dissatisfied. No significant side effects were noted.

CONCLUSION

This research confirms the efficacy of the 595 nm PDL for flat angioma management, without considerable side effects.

Analysis of related factors affecting hemoporfin-mediated photodynamic therapy for port-wine stain: A retrospective study

BACKGROUND

Hemoporfin-mediated photodynamic therapy (HMME-PDT) is currently considered one of the most promising therapies for port-wine stain (PWS). However, the efficacy of this is very variable and needs further studies.

METHODS

A total of 101 patients with PWS in the face, neck, or extremities who received at least 2 HMME-PDT sessions were included in the study, and correlations of efficacy with age, gender, locations, treatment sessions, and PDL treatment history were analyzed.

RESULTS

The efficacy of HMME-PDT in patients with different ages, locations, and different numbers of prior PDL treatment showed constantly significant differences after 1/2/last session (p < .05). The number of treatments was associated with efficacy, and patients who received more than two sessions had a better response than those who underwent two sessions only (p < .001). Ordinal logistic regression analysis confirmed the above-mentioned associations. Nevertheless, patients of different sex, subtype, and lesion size showed no significant differences.

CONCLUSIONS

Our studies demonstrated that HMME-PDT is effective in the treatment of PWS. The more prior PDL treatments, older age, lips involvement, PWS on limbs were adverse factors for Hemoporfin-PDT, while multiple HMME-PDT sessions can improve effective and response rate. Besides, ambient temperature and lesions temperature should be concerned, local cooling provides some relief from pain but may influence effect.

Clinical efficacy and safety of two different hematoporphyrin monomethyl ether-mediated photodynamic therapy regimen in Chinese children with port-wine stain

Hematoporphyrin monomethyl ether-photodynamic therapy (HMME-PDT) has achieved encouraging clinical outcomes in adult port-wine stain (PWS). Optimal treatment option for children with PWS was minimal. To compare whether the clinical effectiveness of HMME-PDT with the 5-min (fast) administration treatment regimen (FATR) was better than the 20-min (slow) administration treatment regimen (SATR) for PWS of children in vivo and in vitro. Thirty-four children with PWS were divided into two groups including FATR and SATR. The two groups received three times HMME-PDT, respectively. Treatment efficacy and safety were evaluated in vivo and in vitro. Erythema index (EI) was used to evaluate the clinical outcomes. Both FATR and SATR were effective and safe in children with PWS after HMME-PDT. There were significance differences between the two groups in reductions of EI after the second treatment (p < 0.001) and the third treatment (p < 0.001) with HMME-PDT. The serum HMME concentration reach the peak level at short time compare with SATR group. A significance increased superoxide levels were observed in FATR group compare to SATR groups in vitro (p < 0.05). Our study suggested that HMME-PDT was effective and safe for children with PWS, the therapy regimen with FATR was better in clinical efficacy than that of the SATR.

M-CSAFN: Multi-Color Space Adaptive Fusion Network for Automated Port-Wine Stains Segmentation

Automatic segmentation of port-wine stains (PWS) from clinical images is critical for accurate diagnosis and objective assessment of PWS. However, this is a challenging task due to the color heterogeneity, low contrast, and indistinguishable appearance of PWS lesions. To address such challenges, we propose a novel multi-color space adaptive fusion network (M-CSAFN) for PWS segmentation. First, a multi-branch detection model is constructed based on six typical color spaces, which utilizes rich color texture information to highlight the difference between lesions and surrounding tissues. Second, an adaptive fusion strategy is used to fuse complementary predictions, which address the significant differences within the lesions caused by color heterogeneity. Third, a structural similarity loss with color information is proposed to measure the detail error between predicted lesions and truth lesions. Additionally, a PWS clinical dataset consisting of 1413 image pairs was established for the development and evaluation of PWS segmentation algorithms. To verify the effectiveness and superiority of the proposed method, we compared it with other state-of-the-art methods on our collected dataset and four publicly available skin lesion datasets (ISIC 2016, ISIC 2017, ISIC 2018, and PH2). The experimental results show that our method achieves remarkable performance in comparison with other state-of-the-art methods on our collected dataset, achieving 92.29% and 86.14% on Dice and Jaccard metrics, respectively. Comparative experiments on other datasets also confirmed the reliability and potential capability of M-CSAFN in skin lesion segmentation.

Influential Factors in the Efficacy of Hemoporfin-Mediated Photodynamic Therapy for Port-wine Stains

Hemoporfin-mediated photodynamic therapy (HMME-PDT) is commonly used in the treatment of port-wine stains (PWS). However, the influential factors for the efficacy of the treatment are not well defined. This study intends to observe the influential factors for the efficacy of HMME-PDT in the treatment of port-wine stains (PWS). A total of 551 patients with PWS of head and neck was enrolled in this retrospective study. Further screening the patients of facial PWS, 484 patients were chosen. Patients were treated with HMME-PDT. All patients received 1~3 sessions of treatment with 2~3-month intervals. We photographed the lesions before each session and 2~3 months after the last session. Ages, sessions, lesion subtypes, and previous treatment history were related to the response of HMME-PDT (P =0.032, P<0.001, P=0.012, P=0.003 respectively). Treatment sessions were the independent factor correlated with efficacy after 3 sessions of treatment. Patients with no treatment history targeting PWS showed higher efficacy than those were treated with laser or other photodynamic treatment (P<0.05). The efficacy was higher by increasing the sessions of treatment. The efficacy was higher for lesion on maxillary prominence area and mandibular prominence area that on frontonasal prominence area and optic vesicle area (P<0.05). HMME-PDT is an effective in the treatment of PWS. Patients received no previous treatment for PWS, total treatment sessions and lesion on maxillary prominence area and mandibular prominence area are positive factors.

Hemoporfin-mediated photodynamic therapy with general anesthesia showed superior efficacy in the treatment of port-wine stains: a retrospective evaluation

Background

Hemoporfin-mediated photodynamic therapy (PDT) is an effective treatment for port-wine stains (PWS), and pain is the main adverse effect of this therapy. General anesthesia is commonly used for pain management during PDT, but the effect of general anesthetics on the subsequent treatment efficacy of PDT in PWS has not been reported.

Objectives

To assess the use of general anesthesia combined with PDT compared with PDT alone in 207 PWS patients, and to provide further safety and efficacy data on this combined therapy.

Methods

Propensity score matching (PSM) was used at a 2:1 ratio to create a general anesthetic group (n = 138) and a highly comparable nonanesthetic group (n = 69). The clinical outcomes were evaluated, and the treatment reactions and adverse effects were recorded after one treatment with PDT.

Results

After matching, there was no significant difference in the demographic data of the patients in the two groups (p > 0.05), while the treatment efficacy was significantly higher in the general anesthetic group than in the nonanesthetic group (76.81 vs. 56.52%, p < 0.05). Moreover, logistic regression analysis confirmed that patients receiving general anesthesia showed an association with a good response to PDT (OR = 3.06; 95% CI, 1.57-6.00; p = 0.0011). Purpura lasted longer in the general anesthetic group, but the other treatment reactions and adverse effects were similar in the two groups (p > 0.05). No serious systemic adverse reactions were observed.

Conclusion

We recommend this combined therapy, which is associated with painless, as a high efficacy treatment option for PWS patients, especially for patients with a poor response to multiple PDT alone treatments.

Mapping port wine stain in vivo by optical coherence tomography angiography and multi-metric characterization

Port wine stain (PWS) is a congenital cutaneous capillary malformation composed of ecstatic vessels, while the microstructure of these vessels remains largely unknown. Optical coherence tomography angiography (OCTA) serves as a non-invasive, label-free and high-resolution tool to visualize the 3D tissue microvasculature. However, even as the 3D vessel images of PWS become readily accessible, quantitative analysis algorithms for their organization have mainly remained limited to analysis of 2D images. Especially, 3D orientations of vasculature in PWS have not yet been resolved at a voxel-wise basis. In this study, we employed the inverse signal-to-noise ratio (iSNR)-decorrelation (D) OCTA (ID-OCTA) to acquire 3D blood vessel images in vivo from PWS patients, and used the mean-subtraction method for de-shadowing to correct the tail artifacts. We developed algorithms which mapped blood vessels in spatial-angular hyperspace in a 3D context, and obtained orientation-derived metrics including directional variance and waviness for the characterization of vessel alignment and crimping level, respectively. Combining with thickness and local density measures, our method served as a multi-parametric analysis platform which covered a variety of morphological and organizational characteristics at a voxel-wise basis. We found that blood vessels were thicker, denser and less aligned in lesion skin in contrast to normal skin (symmetrical parts of skin lesions on the cheek), and complementary insights from these metrics led to a classification accuracy of ∼90% in identifying PWS. An improvement in sensitivity of 3D analysis was validated over 2D analysis. Our imaging and analysis system provides a clear picture of the microstructure of blood vessels within PWS tissues, which leads to a better understanding of this capillary malformation disease and facilitates improvements in diagnosis and treatment of PWS.

Extended Application of Fractional Carbon Dioxide Laser in the Treatment of Port Wine Stain Birthmarks with Hypertrophy: A Case Report

Background: Conventional treatments of port wine stain birthmarks often do not achieve the desired outcome in patients with hypertrophy. Potential reasons include deeper and larger blood vessels, abnormal arrangement of blood vessels, and darker or thicker epidermis. However, these factors may not significantly limit the efficacy of fractional carbon dioxide (CO2) laser. The aim of this case report was to examine the extended application of fractional CO2 laser in treating patients with hypertrophic port wine stain birthmarks. Methods: Two cases with hypertrophic port wine stain birthmarks treated with fractional CO2 laser for 5 years are described in this case report. Results: When compared with conventional treatment, both cases reported better outcomes, including a reduced risk of infection, pigmentation, and scarring, a decrease of clinical erythema, and much less pain. Conclusions: The findings demonstrate that fractional CO2 laser has the potential to be an effective modality for the treatment of patients with hypertrophic port wine stains.

Carbon monoxide combined with artificial blood cells acts as an antioxidant for tissues thermally-damaged by dye laser irradiation

Artificial red blood cells [i.e., hemoglobin vesicles (HbVs)] can be used as photosensitizers in pulsed-dye laser (PDL) treatment for port wine stains in animal models. Small HbVs are distributed in the vicinity of the endothelial cells of the blood vessels. In our previous in vivo experiments, both HbVs and red blood cells absorbed photons of the laser and generated heat, contributing to removal of very small blood vessels and large deeper subcutaneous blood vessels with PDL irradiation. Herein, we tested carbon monoxide-bound HbVs (CO-HbVs) that would produce heat energy while releasing CO in vessels after dye laser irradiation in a rabbit auricle model. We conducted this experiment to confirm secondary progression of thermal injury being reduced with the antioxidative property of CO. We histopathologically evaluated the damages to the large vessels and surrounding dermal tissue following PDL irradiation alone or subsequent to the intravenous injection of the qualified HbVs. The soft tissue damages were graded on a five-point scale and compared statistically. Intravenous CO-HbVs significantly reduced damage to the surrounding tissue after subsequent PDL irradiation; however, the degree of damage to the larger vessel wall resulted in a variety of changes, including a slight increase in our histopathological grades. This beneficial effect in dye laser treatment for port wine stains may be the result of the antioxidative property of CO against free radicals in the zone of stasis that may still be theoretically viable in burns. This effect of CO protecting tissues from thermal damage is consistent with previous reports of CO as a reducing agent. If the reducing agent can be delivered directly to the affected area immediately after the burn injury, even in a small amount, the complex inflammatory cascade may be reduced and unnecessary inflammation after laser treatment that lowers the patient's quality of life can be avoided.

Three-dimensional image-guided topical photodynamic therapy system with light dosimetry dynamic planning and monitoring

Photodynamic therapy (PDT) has shown significant potential for skin disease treatment. As a key element, light is critical to influencing its treatment outcome, and light dosimetry is an issue of much concern for researchers. However, because of three-dimensional irregularity in shape and patient's movement during the therapy, irradiance hardly keeps uniform on the lesion and flux measurement remains a challenge. In this work, we report the development of a three-dimensional image-guided PDT system, and the method of dynamic irradiance planning and flux monitoring for lesions in different poses. This system comprises a three-dimensional camera for monitoring patients' movement during therapy, a computer for data analysis and processing, and a homemade LED array for forming uniform irradiance on lesions. Simulations on lesions of the face and arm show that the proposed system significantly increases effective therapy area, enhances irradiance uniformity, is able to visualize flux on the lesion, and reduces risks of burns during PDT. The developed PDT system is promising for optimizing procedures of PDT and providing better treatment outcomes by delivering controllable irradiance and flux on lesions even when a patient is moving.

High speed photo-mediated ultrasound therapy integrated with OCTA

Photo-mediated Ultrasound Therapy (PUT), as a new anti-vascular technique, can promote cavitation activity to selectively destruct blood vessels with a significantly lower amount of energy when compared to energy level required by other laser and ultrasound treatment therapies individually. Here, we report the development of a high speed PUT system based on a 50-kHz pulsed laser to achieve faster treatment, decreasing the treatment time by a factor of 20. Furthermore, we integrated it with optical coherence tomography angiography (OCTA) for real time monitoring. The feasibility of the proposed OCTA-guided PUT was validated through in vivo rabbit experiments. The addition of OCTA to PUT allows for quantitative prescreening and real time monitoring of treatment response, thereby enabling implementation of individualized treatment strategies.

Initial research on the effect and mechanism of Tivozanib on pulsed dye laser induced angiogenesis

INTRODUCTION

Pulsed dye laser (PDL) is the main treatment for port wine stain (PWS), but a considerable number of patients show low clearances. The reason for the poor efficacy is related to PDL-induced angiogenesis. Vascular endothelial growth factor (VEGF) plays an important role in PDL-induced angiogenesis and can activate the tyrosine kinase activity of VEGF receptor (VEGFR) in endothelial cells. It triggers a full range of responses, and then participates in the regulation of angiogenesis. Tivozanib is an inhibitor of VEGFR tyrosine kinase activity, which can block the pro-angiogenic effect of VEGF and reduce vascular permeability.

METHOD

Different energy densities of PDL were used to irradiate the abdominal skin of rats. According to the general and pathological changes of the irradiated area, the energy density of 8 J/cm² with smaller scab and stronger vascular effect was selected for follow-up experiments. Divided the rat abdomen skin into four areas, irradiated three of them uniformly with an energy density of 8 J/cm² , and applied different concentrations of Tivozanib coating agent to the laser irradiation area, and grouped them as follows: (1) vacant group, (2) control group, (3) 0.5% Tivozanib group, (4) 1% Tivozanib group. Camera and dermoscopy were used to observe skin changes. Hematoxylin-eosin staining, immunohistochemical staining, and blood vessels were counted to detect dermal vascular regeneration. Transcriptome sequencing and real-time polymerase chain reaction (PCR) were conducted to elucidate the mechanism and validate the reliability.

RESULTS

The number of blood vessels in the 0.5% Tivozanib group and 1% Tivozanib group was significantly reduced on the 7, 10, and 14 days compared with the control group. The number of blood vessels in the 1% Tivozanib group was significantly reduced compared with the 0.5% Tivozanib group, indicating that Tivozanib successfully inhibited PDL-induced angiogenesis, and the inhibitory effect of 1% Tivozanib was more significant than that of 0.5% Tivozanib. Transcriptome sequencing results showed a total of 588 significantly differentially expressed genes, including 90 upregulated genes and 498 downregulated genes. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that the significantly differentially expressed genes were mainly enriched in the metabolic pathways which were closely related to angiogenesis. Finally, real-time PCR was used to verify the genes with higher expression differences, the top ranking and closely related to angiogenesis, namely, Cxcl1, Cxcl2, Cxcl3, Cxcl6, Ccl3, Csf3, IL1β, iNOS, Mmp9, Mmp13, Plau, Ets1, Spp1, Nr4a1. The results were consistent with the trend of transcriptome sequencing results, which proved the reliability of this study.

CONCLUSION

This study explored the inhibitory effect of Tivozanib on PDL-induced angiogenesis, and provided a new idea for the treatment of clinical PWS. Transcriptome sequencing explored the mechanism and provided reliable clues for later in-depth research.

The application of photodynamic therapy in plastic and reconstructive surgery

Photodynamic therapy (PDT) is a modern clinical treatment paradigm with the advantages of high selectivity, non-invasiveness, rare side-effect, no obvious drug resistance and easy combination with other therapies. These features have endowed PDT with high focus and application prospects. Studies of photodynamic therapy have been expanded in a lot of biomedical and clinical fields, especially Plastic and Reconstructive Surgery (PRS) the author major in. In this review, we emphasize the mechanism and advances in PDT related to the PRS applications including benign pigmented lesions, vascular malformations, inflammatory lesions, tumor and others. Besides, combined with clinical data analysis, the limitation of PDT and current issues that need to be addressed in the field of PRS have also been discussed. At last, a comprehensive discussion and outlooking represent future progress of PDT in PRS.

Whole-Genome Sequencing Identified KCNJ12 and SLC25A5 Mutations in Port-Wine Stains

Port-wine stains (PWSs) are a congenital capillary malformed disorder and are caused by a number of somatic mutations that disrupt vascular development. However, the underlying genetic mutations in the pathogenesis of PWS have not yet been fully elucidated. To understand PWS genetic variations and investigate novel genetic mutations, we extracted genomic DNA from four sporadic PWS patients and then performed whole-genome sequencing (WGS). Using Sorting Intolerant from Tolerant (SIFT), PolyPhen2, Mutation Assessor, MetaSVM to identify candidate genetic mutations and whole-exome sequencing (WES) to confirm the identified variants. We found a previously reported G protein subunit alpha q (GNAQ) mutation c.548G &gt; A, p.Arg183Gln in one case, whereas no such mutation was found in the other three samples. Moreover, six novel somatic mutations in three genes, including KCNJ12, SLC25A5, POTEE, were found in these four samples. Importantly, WES also verified the KCNJ12 (c.433G &gt; A, p.Gly145Ser) and SLC25A5 (c.413G &gt; A, p.Arg138His) mutations in other five sporadic PWS patients, with the frequency of 60% (3 of 5) and 40% (2 of 5), respectively. Thus, we reveal in this study two novel somatic mutations, KCNJ12 and SLC25A5, in the sporadic PWS patients for the first time. These findings highlight the genetic polymorphism of PWS and provide potential clinical prediction targets for this disease.

Efficacy and influential factors analysis in hemoporfin-mediated photodynamic therapy in the treatment of port-wine stains: a retrospective analysis

BACKGROUND

Hemoporfin-mediated photodynamic therapy (Hemoporfin-PDT) is a safe and effective treatment modality for port-wine stain (PWS). However, there is still no consensus about the influential factors for the efficacy of the treatment. This study investigated the influential factors associated with the efficacy of Hemoporfin-PDT.

METHODS

We retrospectively analyzed 321 PWS patients who underwent Hemoporfin-PDT at our center from August 2017 to July 2021. The correlation between efficacy versus sex, age, location, type of PWS, treatment numbers, and the lesion size were analyzed.

RESULTS

The numbers of treatment sessions undertaken were associated with the response to therapy, and compared with patients who received one session, patients who received two or more sessions showed a better response (ORadj=2.46, 95%CI, 1.49-4.07; ORadj=6.01, 95%CI, 3.38-10.70, P<0.001). The effect on central face, peripheral face, and neck was superior to the extremity and trunk, respectively (P<0.001). The lesion size smaller than and equal to 25 cm² showed a better effect than those whose lesion size was larger than 64 cm² (ORadj=1.92, 95%CI, 1.03-3.57, P=0.040). However, other variables, including sex and age, were not associated with the efficacy of the treatment.

CONCLUSIONS

Hemoporfin-PDT is an effective and safe treatment for PWS. The number of treatments was a favorable factor for Hemoporfin-PDT, smaller lesion sizes showed a better effect than the larger one, and the location of extremity and trunk was a negative factor.

A New Nonlinear Photothermal Iterative Theory for Port-Wine Stain Detection

The development of appropriate photothermal detection of skin diseases to meet complex clinical demands is an urgent challenge for the prevention and therapy of skin cancer. An extensive body of literature has ignored all high-order harmonics above the second order and their influences on low-order harmonics. In this paper, a new iterative numerical method is developed for solving the nonlinear thermal diffusion equation to improve nonlinear photothermal detection for the noninvasive assessment of the thickness of port-wine stain (PWS). First, based on the anatomical and structural properties of skin tissue of PWS, a nonlinear theoretical model for photothermal detection is established. Second, a corresponding nonlinear thermal diffusion equation is solved by using the new iterative numerical method and taking into account harmonics above the second-order and their effects on lower-order harmonics. Finally, the thickness and excitation light intensity of PWS samples are numerically simulated. The simulation results show that the numerical solution converges fasterand the physical meaning of the solution is clearerwith the new method than with the traditional perturbation method. The rate of change in each harmonic with the sample thickness for the new method is higher than that for the conventional perturbation method, suggesting that the proposed numerical method may provide greater detection sensitivity. The results of the study provide a theoretical basis for the clinical treatment of PWS.

Histological Characteristics of Port-Wine Stains with Complete Regression After Photodynamic Therapy Treatment: A 7-Year Follow-Up

Background: Vascular-targeted photodynamic therapy (PDT) is an effective alternative treatment choice for port-wine stains (PWSs). The histological characteristics of PWSs after PDT treatment have not yet been reported. Objective: To investigate the morphological features of PWSs treated by PDT and define the histopathological characteristics of PWS that achieve clinical cure. Methods: Thirteen patients with facial PWSs, who presented with complete regressive PWS lesions after a mean of 4.38 (standard deviation = 4.907) sessions of PDT. Post-treatment biopsy samples were obtained from each patient. The number of blood vessels, vascular diameter, and depth were measured and compared in all samples of PDT-regressive sites, PDT-resistant sites, and normal skin. Results: Within the 7-year follow-up after PDT, there was no recurrence in the regression area of PDT. In the PDT-regressive sites, within 800 μm of the dermal-epidermal junction, the dilated vessels were occluded and remained fissure-like after PDT. Conclusions: When the vascular lesions within 800 μm of the dermal-epidermal junction were closed after PDT, a stable clinical cure (no recurrence) was achieved.

Generating multiple optical vortices in orange beams induced by selectively pumped frequency-doubled solid-state Raman lasers with mode conversion

We employ a selectively pumped solid-state laser with stimulated Raman scattering and second-harmonic generation to generate frequency-doubled lasing modes (FDLMs) at 588 nm. The FDLMs are transformed by using an external cylindrical mode converter to generate various structured beams with multiple optical vortices. Theoretical analyses clearly reveal the relationship between the mode components in the laser emission and the transverse displacement of the off-center pumping. We further verify that the experimental results for the transformed FDLMs can be numerically reconstructed with a theoretical model. By analyzing the phase structures of the converted beams, it can be demonstrated that the number of vortices rises from 2 to 19 with increasing off-center displacement.

The Use of Neodymium-Doped Yttrium Aluminum Garnet Laser for Treatment of Hypertrophic Port-Wine Stain

Port-wine stains (also called nevus flammeus) are congenital malformations of the capillaries and postcapillary venules. They occur in 0.1–2% of newborns without sex predilection. Although PWS lesions are flat early in life, with age, they become hypertrophic and darker. Pulsed dye laser therapy is the standard of care for treating these lesions, although other laser wavelengths have been utilized with varying degrees of success. We present the case of a gentleman with a hypertrophic PWS who had an excellent response to Nd:YAG laser treatment. The increased tissue penetration of longer laser wavelengths may be of benefit to patients with hypertrophic PWS, and further research into this concept is warranted.

Analysis of port-wine birthmark vascular characteristics by location: Utility of optical coherence tomography mapping

INTRODUCTION

Port-wine birthmarks (PWBs) are congenital capillary malformations that can be located on any area of the body. Vascular features include vessel size, depth, and density, which can greatly differ between patients, individual lesions, and even sites within the same lesion. Previous studies have determined that the location of PWB lesions has impacted their clinical response to laser treatment.

OBJECTIVE

We utilized dynamic optical coherence tomography (D-OCT) to measure in vivo vessel diameter, density, and superficial plexus depth in patients of all ages with PWB on various sites of the body. We hypothesized that these vascular characteristics would differ according to body location.

MATERIALS AND METHODS

Patients who had a PWB and presented to clinic at three sites for treatment with the pulsed dye laser (PDL) were enrolled into the study. A D-OCT scanner was utilized for noninvasive, in vivo imaging of PWB lesions. The depth of the top portion of the superficial vascular plexus was estimated as the depth at which the vessel density reaches 50% of the maximum. Vessel diameter and density were calculated by incorporated software algorithm.

RESULTS

A total of 108 patients were enrolled into the study. There was a total of 204 measurements of PWB lesions. Of all patients, 56.5% (n = 61) reported having a previous treatment with PDL. Of all D-OCT scans, 62.3% (n = 127) were located on the head, 14.2% (n = 29) the upper extremities, 8.3% (n = 17) the lower extremities, 7.8% (n = 16) the trunk, and 7.8% (n = 15) the neck. All locations were compared for each vascular characteristic. For superficial plexus depth, lesions on the head were significantly shallower than those on the upper extremities (217 vs. 284 µm; p < 0.001) and lower extremities (217 vs. 309 µm; p < 0.001). For vessel diameter, lesions on the head had significantly larger vessels than those on the upper extremities (100 vs. 72 µm; p = 0.001). For vessel density, lesions on the head had significantly denser vessels than those on the trunk (19% vs. 9.6%; p = 0.039) and upper extremities (19% vs. 9.3%; p < 0.001) CONCLUSIONS: PWB lesions have distinct vascular characteristics, which can be associated with their body location. This includes superficial vascular plexus depth as well as vessel diameter and density.

Quantitative assessment of vascular features in port wine stains through optical coherence tomography angiography

BACKGROUND

Vascular lesions such as port wine stains (PWS) lead to facial and psychological problems, which require careful and precise treatments. The key point of treating PWS is to selectively destroy the abnormal blood vessels. Hence, the in vivo monitoring of targeted vessels is crucial. Optical coherence tomography angiography (OCTA), an emerging label-free imaging tool, facilitates the evaluation of skin structure and vasculature at a high resolution. In this study, we utilised OCTA to capture the structural and vascular morphology in patients with PWS. Moreover, we quantitatively characterised the morphological features of different types of PWS.

METHODS

This observational clinical study was conducted on 3 patients with flat PWS and 3 patients with thickened PWS. The age range was 4-27 years, and all of them had not received any treatment before this study. The OCTA images of the PWS lesions and contralateral skin were compared. Vascular morphology was characterized, and ectatic vessel depth was quantified according to the OCTA images.

RESULTS

The blood vessels of the PWS lesions tend to had larger diameters and higher densities than those in the contralateral normal skin. The vessel diameters of PWS lesions were 73 ± 14 μm, with high heterogeneity ranging from 10 to >150 μm, however, the vessel diameters of normal skin were 28 ± 2 μm, ranging from 10 μm to 60 μm. In terms of different PWS lesions, the thickened type showed a trend of larger vessel diameter and higher density than those of the purplish red type. The ectatic vessels were located at the depth of 216 ± 13 μm in the PWS skin.

CONCLUSIONS

OCTA can facilitate the in vivo three-dimensional visualization of structure and vasculature for PWS lesions. Various quantitative analysis parameters, such as vessel diameter, density, and depth, are typically measured using OCTA. This fact demonstrates the superior capability of OCTA for the precise and comprehensive assessment of PWS lesions.

Efficacy and safety of hemoporfin photodynamic therapy for port-wine stains in paediatric patients: A retrospective study of 439 cases at a single centre

BACKGROUND

Although hemoporfin photodynamic therapy is a promising treatment approach for port-wine stains, its efficacy in children has not been sufficiently assessed. We aimed to evaluate the efficacy and safety of this approach in a paediatric population.

METHODS

We retrospectively analysed the medical records of 439 children with port-wine stains receiving hemoporfin photodynamic therapy at our institution from July 2017 to January 2020. They received intravenous hemoporfin (hematoporphyrin monomethyl ether, 5 mg/kg), followed by lesion irradiation with a 532-nm green LED light for 20-25 min. The stains' blanching degree and occurrence of adverse events were registered.

RESULTS

Overall, 95.2% of patients showed an 'effective response' (>20% fading) and 74.3% showed almost-complete resolution and great improvement (≥60% fading). Red and pink lesions showed better response than purple lesions (P < 0.05). Neck and facial lesions showed better response than the trunk and extremity lesions (P < 0.05). The response of the patients to the PDT showed a cumulative effect of the treatment session. No photosensitivity or systemic adverse reactions were observed. Transient local adverse effects included swelling, purpura, crusts, and pigmentation, which resolved without treatment. Only 2% of children had permanent scars, likely related to scratching crusts.

CONCLUSIONS

Hemoporfin photodynamic therapy was well tolerated and effective in paediatric Chinese patients with port-wine stains. It could be recommended as the first choice, over pulsed-dye laser therapy, for treating port-wine stains, particularly for large lesions. This should be evaluated in direct clinical trials.

Quantitative and anatomical imaging of dermal angiopathy by noninvasive photoacoustic microscopic biopsy

The ability to noninvasively acquire the fine structure of deep tissues is highly valuable but remains a challenge. Here, a photoacoustic microscopic biopsy (PAMB) combined switchable spatial-scale optical excitation with single-element depth-resolved acoustic detection mode was developed, which effectively coordinated the spatial resolution and the penetration depth for visualizations of skin delamination and chromophore structures up to reticular dermis depth, with the lateral resolution from 1.5 to 104 μm and the axial resolution from 34 to 57 μm. The PAMB obtained anatomical imaging of the pigment distribution within the epidermis and the vascular patterns of the deep dermal tissue, enabling quantification of morphological abnormalities of angiopathy without the need for exogenous contrast agents. The features of healthy skin and scar skin, and the abnormal alteration of dermal vasculature in port wine stains (PWS) skin were first precisely displayed by PAMB-shown multi-layered imaging. Moreover, the quantitative vascular parameters evaluation of PWS were carried out by the detailed clinical PAMB data on 174 patients, which reveals distinct differences among different skin types. PAMB captured the PWS changes in capillary-loop depth, diameter, and vascular volume, making it possible to perform an objective clinical evaluation on the severity of PWS. All the results demonstrated the PAMB can provide vascular biopsy and new indexes deep into the dermal skin noninvasively, which should be meaningful to timely evaluate the pathological types and treatment response of skin diseases. This opens up a new perspective for label-free and non-invasive biopsies of dermal angiopathy.

Therapeutic Strategies for Untreated Capillary Malformations of the Head and Neck Region: A Systematic Review and Meta-Analyses

Background

Capillary malformations of the head and neck region often cause psychological and physical burden. As the effectiveness of modern laser and light therapies is still suboptimal, patients often seek different therapeutic strategies. Other recognized, but not routinely proposed therapies include cosmetic camouflage, surgery, and medical tattooing. Information on therapeutic outcomes is currently lacking for patients to adequately participate in the treatment decision-making process.

Objective

The objective of this systematic review was to review the effectiveness and safety of recognized therapies for untreated capillary malformations of the head and neck: laser and light treatment modalities, photodynamic therapy, cosmetic camouflage, medical tattooing, and surgery.

Methods

PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched up to 16 December, 2020 for observational and experimental studies examining recognized therapies for untreated capillary malformations of the head and neck. Two reviewers independently evaluated the risk of bias of included studies. Predefined treatment and safety outcomes of pooled data were scored using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

Results

We included 48 observational and three randomized studies (totaling 3068 patients), evaluating nine different therapies. No studies on surgery or cosmetic camouflage matched our inclusion criteria. The pooled proportion of patients reaching a ≥75% clearance was 43% (95% confidence interval 24–64%; I² = 55%) for the pulsed dye laser after three to eight treatment sessions (GRADE score: very low). Other therapies were less effective. Hyperpigmentation was most frequently described after the pulsed dye laser (incidences up to 40%). Pain was most common after photodynamic therapy, yet the intensity was unreported. Substantial heterogeneity among studies as to patient characteristics and outcomes limited pooling and data comparisons.

Conclusions

The pulsed dye laser seems preferable for treatment-naive capillary malformations of the head and neck region, yet demonstrates greater hyperpigmentation rates compared with other therapies. Our results are, however, based on low-quality evidence. Future studies using uniform outcome measures and validated metrics are warranted for study comparability. Based on this systematic review, clinicians and patients should be aware of the limited evidence about the available options when making (shared) treatment decisions for capillary malformations.

Trial Registration

Review registration number PROSPERO database: CRD42020199445.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40257-021-00616-5.

Does Double-Pass Pulsed-Dye Laser With Long and Short Pulse Duration Increase Treatment Efficacy of Port-Wine Stain? A Randomized Clinical Trial

BACKGROUND

Although pulsed-dye laser (PDL) 595 nm is known as the gold standard for treatment of port-wine stains (PWS), complete clearance of lesions occurs in a minority of cases.

OBJECTIVE

To compare the efficacy and safety of double-pass pulsed-dye laser (DPL), long pulse duration (20 m/s) followed by short pulse duration (1.5 m/s) within 20 minutes interval, with single-pass pulsed-dye laser (SPL) for (1.5 m/s) in the treatment of PWS.

METHODS

Twenty-four patients with PWS underwent 3 sessions of PDL. Each lesion was randomly divided into 2 portions to receive DPL or SPL. Colorimetric and dermoscopic evaluations were used to determine the response objectively. In addition, improvement was scored subjectively using the visual analog scale (VAS).

RESULTS

According to colorimetric analysis, the mean blanching rates for DPL and SPL treated sites were 48% (SD = 0.215) and 37% (SD = 0.213), respectively (p = .001). With VAS, 3.79 (SD = 0.93) and 3.33 (SD = 0.91) improvement scores were reported in the DPL and SPL treated areas, respectively (p = .008). Dermoscopic images showed that larger deep vessels were the most common remnant vessels in both treatment areas.

CONCLUSION

Compared with SPL, DPL with 20 minutes interval seems to be a more effective and safe method for the treatment of PWS.

Vascular characteristics of port wine birthmarks as measured by dynamic optical coherence tomography

BACKGROUND

Port wine birthmarks (PWBs) are congenital capillary malformations. Vessel characteristics, such as diameter and depth, may impact presentation and outcomes. They can be imaged using dynamic optical coherence tomography, a high-resolution, noninvasive imaging method.

PURPOSE

We conducted a cross-sectional observational study to measure in vivo vascular characteristics as a function of PWB color.

METHODS

Patients undergoing treatment for PWB were recruited from 3 sites. PWBs were classified by color. Dynamic optical coherence tomography images with calculations were obtained.

RESULTS

One hundred eight patients were enrolled. Mean age correlated with PWB color, with birthmarks being lighter in younger patients and darker in older patients (P < .01). Mean superficial plexus depth was significantly shallower in purple PWBs than in pink PWBs. Color was not associated with significant differences in mean superficial vessel density or diameter. Among pink PWBs, each 10-year increase in age was associated with a 10.6-μm increase in superficial plexus depth. Among purple PWBs, each 10-year increase in age was associated with a 16.2-μm reduction in superficial plexus depth. In lesions without prior treatment, vessel density was 12.7% lower in purple PWBs than in pink PWBs.

CONCLUSION

Superficial vessels of purple PWBs were significantly closer to the epidermis than those of pink PWBs, which might impact optimal laser parameters.

Efficacy of influential factors in hemoporfin-mediated photodynamic therapy for facial port-wine stains

Hemoporfin-mediated photodynamic therapy (HMME-PDT) is a vascular-targeted treatment for port-wine stains (PWS). However, the efficacy of this has varied and is difficult to predict. The objective of this study was to evaluate the efficacy of influential factors associated with HMME-PDT and provide a suitable method for predicting the efficacy. Patients with facial PWS who underwent HMME-PDT were retrospective analyzed. A total of 212 patients (93 males) with mean age of 13.01 ± 12.67 years (range, 1-51) years were included. There were 143 cases with red, 56 cases with purple, and 13 cases with hypertrophic-type PWS. The number of HMME-PDT sessions ranged 1-6. The excellent response rate after 1-4 PDT sessions was 9.4%, 17.6%, 32.7%, and 42.9%, respectively. The number of PDT treatments is associated with efficacy, and patients who underwent treatment with more than three sessions had response better than those who underwent treatment with less than three sessions (p = 0.003). Response to HMME-PDT in patients of different ages, previous treatment history, lip involvement, and vessels morphology showed significant differences after two treatment sessions (p = 0.001, 0.03, 0.014, and 0.001, respectively), while patients of different sex, subtype, lesion size, location (medial, lateral, or mixed), or non-vascular morphology showed no significant differences. Logistic regression analysis confirmed that the patients with lip hypertrophy (p = 0.002), history of more than five times prior treatment (p = 0.003), fewer PDT sessions (<3) (p = 0.000002), linear vessels (p = 0.007), and reticular vessels (p = 0.0003) showed association with poor response of HMME-PDT. In conclusion, HMME-PDT is an effective treatment for PWS. Patients who had underwent treatment for more than five times prior, lip hypertrophy, and linear vessels or reticular vessels under dermoscope showed association with poor efficacy.

Hypoxia-Induced Cyr61/CCN1 Production in Infantile Hemangioma

BACKGROUND

Hypoxia may play a role in the pathogenesis of infantile hemangioma. Cysteine-rich angiogenic inducer 61 (Cyr61), or CCN1, can be induced under hypoxic conditions in several types of cells. However, whether CCN1 has any impact on infantile hemangioma remains unknown. This study aims to explore the expression of CCN1 in infantile hemangioma and to investigate the effect of hypoxia on CCN1 and vascular endothelial growth factor-A (VEGF-A) production.

METHODS

Hemangioma-derived endothelial cells and hemangioma-derived stem cells were isolated from surgical specimens of proliferative infantile hemangioma. RNA extracted from infantile hemangioma tissue, hemangioma-derived endothelial cells, and hemangioma-derived stem cells was used to analyze gene expression by real-time polymerase chain reaction. The effects of CCN1 blockade were examined in hemangioma-derived stem cells. Immunostaining, immunoblotting, and enzyme-linked immunosorbent assays were used to assess protein expression.

RESULTS

By double-label immunofluorescence staining, the authors first identified that CCN1 was abundant in proliferative infantile hemangioma lesions and colocalized well with immature microvessels. The authors found that the mRNA level of CCN1 in proliferative infantile hemangioma was significantly higher than in healthy controls, as was involuting infantile hemangioma. Treatment with the hypoxia inducer cobalt chloride dramatically increased CCN1 production in hemangioma-derived endothelial cells in a time-dependent manner. Furthermore, blocking or knockdown of CCN1 expression reduced the expression of VEGF-A in hemangioma-derived stem cells. Lastly, the signaling pathway study showed that CCN1 up-regulation of VEGF-A synthesis in hemangioma-derived stem cells depends on nuclear factor-κB and JNK activation.

CONCLUSIONS

These findings provide new evidence that CCN1 participates in the crosstalk between hemangioma-derived endothelial cells and hemangioma-derived stem cells through promoting VEGF-A expression in the hypoxic environment of infantile hemangioma angiogenesis and vasculogenesis. Targeting of CCN1 might be a novel therapeutic strategy for infantile hemangioma.

Extraction of the Structural Properties of Skin Tissue via Diffuse Reflectance Spectroscopy: An Inverse Methodology

For the laser treatment of vascular dermatosis, the blood vessel morphology and depth in skin tissue is essential to achieve personalized intelligent therapy. The morphology can be obtained from the laser speckle imaging, and vessel depth was extracted by an inverse methodology based on diffuse reflectance spectrum. With optimized spot size of 0.5 mm and known optical properties, the proposed method was experimentally validated via the spectral measurement of microcapillary with known size and depth embedded in an epoxy resin-based skin phantom. Results prove that vessel depth can be extracted with an average relative error of 5%, thereby providing the foundation for a personalized, precise, and intelligent laser treatment of vascular dermatosis.

Noninvasive diagnostic techniques of port wine stain

Port-wine stain (PWS) is a benign capillary malformation that most commonly occurs in the head and neck. It is present at birth and progresses over time. It is formed by progressive dilatation of post-capillary venules and is associated with hypertrophy and nodularity with increasing age, leading to cosmetic disfigurement and psychological aggravation. It is caused by genetic mosaicism in GNAQ and GNA11 genes. Histopathology is the gold standard for assessment of PWS but it is invasive and may cause scarring. Inadequate characterization of the lesions may predispose to inadequate treatment protocols as well as higher treatment dosages. Clinical evaluation of treatment efficacy is subjective and may not be a representative of actual results. Therefore, an objective visualization modality is required. With evolving technology, numerous optical instruments have been developed for objective evaluation and visualization of subsurface structures. These include VISIA-CR™ system, videodermoscopy, high-frequency ultrasound (HFUS), laser speckle contrast imaging (LSCI), reflectance spectrophotometers and tristimulus colorimeter, laser Doppler flowmetry (LDF), cross-polarized diffuse reflectance imaging system (CDR), reflectance confocal microscopy (RCM), optical coherence tomography (OCT), and spatial frequency domain imaging (SFDI). These semi-quantitative modes of diagnosis are complementary to each other. Some can be used in the clinical setting while others, due to high instrument cost, are limited to the research settings. In this review, we bring to you a brief overview of noninvasive diagnostic modalities in PWS.

Blue Laser (450 nm) in the Treatment of Port Wine Stains and Telangiectasia

This study aimed to test a blue light source for the treatment of port wine stains (PWS) and telangiectasia and to compare this with the application of green and yellow lasers based on data in the literature. A total of 22 patients with PWS were treated with radiation from a novel, high-power 450 nm blue laser that was created for this project. The group contained 15 patients with red PWS and 7 with pink PWS. The best results were achieved for red PWS, using 15–20 ms light pulses and 47 W power. For patients with pink malformations, the results were unsatisfactory. The group with telangiectasia consisted of six patients with facial lesions and three with leg lesions. The recovery was completed for all patients with facial telangiectasia, while the blue laser therapy was ineffective for patients with leg telangiectasia. This study shows that, in some cases, the use of a blue laser may be an alternative to the use of green and yellow lasers.

Light-based treatment of pediatric port-wine birthmarks

Port-wine birthmarks (PWBs) are progressive vascular malformations with significant disfigurement and psychosocial morbidity; early light-based treatment has shown improved outcomes in the pediatric population. Somatic mosaic mutations underly the progressive nature of PWBs and explain the significant differences in response and heterogeneity of vessel architecture in the pediatric population when compared to the adult cohort. Here, we summarize a review of pediatric specific literature on the various light-based treatment modalities, including pulsed dye laser, near-infrared lasers, and intense pulsed light, providing the various indications, tips, advantages, and disadvantages for the pediatric dermatologist.

Artificial red blood cells increase large vessel wall damage and decrease surrounding dermal tissue damage in a rabbit auricle model after subsequent flashlamp-pumped pulsed-dye laser treatment

Artificial red blood cells (i.e. hemoglobin [Hb] vesicles [Hb-Vs]) function effectively as photosensitizers in flashlamp-pumped pulsed-dye laser (PDL) treatment for port-wine stains in animal models. Hb-Vs deliver more Hb to the vicinity of the endothelial cells. Both Hb-Vs and red blood cells absorb the laser energy and generate heat, supporting the removal of very small blood vessels and deeper subcutaneous blood vessels with PDL irradiation in in vivo experiments. Here, we analyzed the photosensitizing effect of Hb-Vs in PDL irradiation on large blood vessels and surrounding soft tissues. We histopathologically analyzed markers of damage to the large vessels and surrounding dermal tissue in a rabbit auricle model following PDL irradiation alone or subsequent to the addition of intravenous Hb-V injection. Markers were graded on a five-point scale and statistically compared. The changes in laser light absorption and reflection in a human skin model caused by the administration of Hb-Vs were evaluated using Monte Carlo light-scattering programs. Histological markers of damage to blood vessels were significantly greater in Hb-V-injected arteries and veins measuring 1-3 mm in diameter as compared with the controls. However, Hb-V injection significantly reduced PDL-induced necrosis and hemorrhage in the surrounding tissues. During computer simulation, photon absorption increased within the vessel layer and decreased around the layer. Intravenous Hb-Vs increase the extent of damage in larger vessel walls but significantly reduce damage to the surrounding skin after subsequent PDL irradiation. These beneficial effects are the result of improving vessel selectivity by Hb-Vs in vessels. Hb-V administration prior to PDL irradiation therapy could mechanically improve the outcomes and safety profiles of port-wine stain treatment protocols.

Highly efficient solid-state Raman yellow-orange lasers created by enhancing the cavity reflectivity

A new, to the best of our knowledge, output coupler (OC) with enhancement of the cavity reflectivity is proposed to remarkably elevate the output powers and efficiencies of diode-pumped Nd:GdVO₄/KGW Raman yellow-orange lasers. The cavity reflectivity is effectively increased by using the double-sided dichroic coating on the OC. In comparison with the conventional single-sided coating, the conversion efficiency can be boosted from 15% to 26.3% in the experiment of a yellow laser at 578.8 nm, and the maximum output power can be increased from 5.7 to 10.5 W in the quasi-continuous-wave mode with 50% duty cycle and frequency of 500 Hz. Furthermore, in the operation of an orange laser at 588 nm, the maximum output power can be improved from 5.6 to 7.0 W by replacing the conventional OC with the new one.