Optical coherence tomography-measured blood vessel characteristics of port-wine birthmarks by depth: A cross-sectional study.

BACKGROUND: Port-Wine Birthmarks (PWB) are congenital capillary malformations requiring multiple treatments. Optical coherence tomography (OCT), a noninvasive imaging technique, characterizes vessels in cutaneous vascular lesions, including PWBs. OBJECTIVE: To assess variability in blood vessel characteristics within and between individual PWBs. METHODS: OCT was used to measure blood vessel density (%) and modal vessel diameter (micrometers) at increments of 0.05 mm from the skin surface to a depth of 0.50 mm at several adjacent spots of single PWBs in this cross-sectional study. Average ratios of vessel density and diameter in affected to control skin were obtained for each PWB by averaging data for all spots within a lesion. Statistical analysis was performed with a linear mixed effects model using SPSS software (IBM Corporation). RESULTS: There was great variability in vessel density and diameter within and between PWBs. Depths where average ratios of vessel density were consistently greater in affected to control skin were shallow, between 0.15 mm and 0.2 mm deep from the skin surface. LIMITATIONS: Small sample size and device's inability to measure diameters smaller than 20 micrometers. CONCLUSION: There is variability in vessel density and diameter within and between PWBs. Individualized treatment planning guided by OCT mapping should be studied further.

Pulsed dye laser and adjuvant topical therapies for the treatment of port-wine stains: A systematic review.

OBJECTIVES: The current gold standard treatment for port-wine stains (PWS) is pulsed dye laser (PDL). However, multiple treatment sessions may be necessary and complete resolution is often not achieved. Neoangiogenesis can occur soon after treatment and is thought to be a major factor contributing to treatment failure. Adjuvant antiangiogenic topical therapies may therefore improve the efficacy of pulsed dye laser treatment of port-wine stains. MATERIAL AND METHODS: Following PRISMA guidelines, we searched PubMed, Embase, Web of Science, and clinicaltrials.gov using "port-wine stain," "nevus flammeus," "capillary malformation," "sturge weber," and "pulsed dye laser" as keywords and medical subject heading (MeSH) terms. Articles were included if they (1) were a randomized controlled trial (RCT); (2) studied patients with PWS; and (3) investigated topical adjuvant therapies with PDL. Bias was assessed using the Critical Appraisal Skills Programme (CASP) Randomized Controlled Trial Standard Checklist. RESULTS: 1835 studies were identified, with six studies meeting inclusion criteria. The total number of patients studied was 103 (range: 9-23), with 8-36 week follow-up. The average age ranged from 11 to 33.5 years old. Three studies examined adjuvant topical sirolimus (n = 52), two examined timolol (n = 29), and one studied imiquimod (n = 22). Two of three RCTs reported no improvement through colorimetric analysis with topical sirolimus; however, one of these studies did show a significant improvement through Investigator Global Assessment (IGA) score. The last sirolimus study showed significant improvement through digital photographic image scoring (DPIA). Studies examining topical timolol reported no change in PWS appearance compared to placebo. The addition of 5% adjuvant imiquimod cream did lead to significant improvement. A variety of outcome measures were used. Imiquimod and sirolimus led to mild cutaneous adverse events, while timolol caused no side effects. None of the adverse events led to treatment discontinuation. Study quality was moderate in three, high in two, and low in one. CONCLUSION: The efficacy of adjuvant topical therapy was unclear. Limitations included variation in concentration and duration of adjuvant therapies, differences in follow-up time, and inconsistent outcome measure reporting. Given their potential clinical promise, larger prospective studies examining topical adjuvant therapies should be considered.

Capillary malformations in a child caused by a novel HRAS mutation.

A 6-year-old boy with multiple capillary malformations of the port-wine birthmark (PWB) type on the right leg since birth presented with a varicose vein and segmental overgrowth of the affected leg. Genetic testing on affected skin confirmed the presence of a somatic novel pathogenic HRAS 30 bp in-frame duplication/insertion in the switch II domain. This case illustrates the phenotypic overlap of different genotypes and shows that somatic HRAS pathogenic variants, especially in-frame duplications/insertions, must be added to the list of the underlying causes in capillary malformations.

Laser-Induced Koebner-Related Skin Reactions: A Clinical Overview.

The Koebner phenomenon (KP), also known as the isomorphic response, describes the process by which new lesions that are clinically and histologically identical to a patient's existing skin disease develop following trauma. Many skin diseases exhibit this characteristic, with variations that include possible, questionable, and pseudo-Koebner reactions, with the latter category occurring due to infectious agents seeding at a trauma site. Laser application, a type of controlled skin injury used for improving cutaneous lesions and skin rejuvenation, is also considered a form of trauma. This raises the question of whether controlled thermal injury can be regarded as a type of mechanical trauma capable of producing Koebner-related reactions. We conducted a literature review of cases or studies to identify laser-induced dermatoses that correspond to Koebner-related or pathergy reaction categories. As a whole, we identified nine case reports on true KPs, two cases on possible KPs, seventeen cases on laser-induced questionable KPs comprising cases of vasculitis, eczema or Meyerson reactions, and eruptive squamous atypia cases (ESA) as well as two pseudo-Koebner cases involving wart occurrences at laser application sites. Laser-induced Koebner reactions highlight several aspects of the KP. Firstly, the type of mechanical damage influences disease promotion, as different lasers are associated with different KPs. For example, hair removal lasers are linked with true and questionable KPs such as vasculitis while resurfacing lasers were found to be more connected with ESA occurrence. Secondly, the laser target is significant, with vascular laser application for port-wine stains tending to result in eczematous reactions, while hair follicle destruction can frequently lead to true KPs. Thirdly, the number of sessions matters; true KPs and eruptive squamous atypia questionable KPs typically appear after one to two sessions, whereas eczematous reactions require more sessions (at least four). Additionally, skin phototype is crucial, with darker phototypes showing a higher KP frequency as laser treatment for hypertrichosis relies on melanin absorption in the hair bulge or bulb for follicle destruction, as chromophore competes with the abundant melanin in the epidermis. Further research with larger-scale studies into trauma-specific Koebner reactions is vital for refining treatment protocols, minimizing post-laser adverse effects, and improving dermatological care outcomes.

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.

Endothelial GNAQ p.R183Q Increases ANGPT2 (Angiopoietin-2) and Drives Formation of Enlarged Blood Vessels.

OBJECTIVE: Capillary malformation (CM) occurs sporadically and is associated with Sturge-Weber syndrome. The somatic mosaic mutation in GNAQ (c.548G>A, p.R183Q) is enriched in endothelial cells (ECs) in skin CM and Sturge-Weber syndrome brain CM. Our goal was to investigate how the mutant Gαq (G-protein αq subunit) alters EC signaling and disrupts capillary morphogenesis. Approach and Results: We used lentiviral constructs to express p.R183Q or wild-type GNAQ in normal human endothelial colony forming cells (EC-R183Q and EC-WT, respectively). EC-R183Q constitutively activated PLC (phospholipase C) ß3, a downstream effector of Gαq. Activated PLCß3 was also detected in human CM tissue sections. Bulk RNA sequencing analyses of mutant versus wild-type EC indicated constitutive activation of PKC (protein kinase C), NF-κB (nuclear factor kappa B) and calcineurin signaling in EC-R183Q. Increased expression of downstream targets in these pathways, ANGPT2 (angiopoietin-2) and DSCR (Down syndrome critical region protein) 1.4 were confirmed by quantitative PCR and immunostaining of human CM tissue sections. The Gαq inhibitor YM-254890 as well as siRNA targeted to PLCß3 reduced mRNA expression levels of these targets in EC-R183Q while the pan-PKC inhibitor AEB071 reduced ANGPT2 but not DSCR1.4. EC-R183Q formed enlarged blood vessels in mice, reminiscent of those found in human CM. shRNA knockdown of ANGPT2 in EC-R183Q normalized the enlarged vessels to sizes comparable those formed by EC-WT. CONCLUSIONS: Gαq-R183Q, when expressed in ECs, establishes constitutively active PLCß3 signaling that leads to increased ANGPT2 and a proangiogenic, proinflammatory phenotype. EC-R183Q are sufficient to form enlarged CM-like vessels in mice, and suppression of ANGPT2 prevents the enlargement. Our study provides the first evidence that endothelial Gαq-R183Q is causative for CM and identifies ANGPT2 as a contributor to CM vascular phenotype.

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.

A retrospective 10 years- experience overview of dye laser treatments for vascular pathologies.

INTRODUCTION: The Flash-lamp pulsed dye laser (FPDL) is nowadays considered the most precise laser currently on the market for treating superficial vascular lesions. In this study, we gathered data from 10 years of experience regarding dye laser treatment of patients presenting vascular malformations such as telangiectasia, rhinophyma, port-wine stain, cherry and spider angioma and vascular tumours. METHODS: Subjects were enrolled from 2013 to 2023 based on the vascular anomalies they presented. They underwent different treatment sessions with the FPDL device. RESULTS: The age-range distribution by vascular anomaly confirmed that haemangiomas are typical in children while rhinophyma is a condition very common in older adults. A difference in sex distribution showed that pathologies such as telangiectasias typically affect women whereas rhinophyma is more frequent in men. Most of the treatments interested the face area but no permanent side effects were registered. CONCLUSIONS: Our 10 years of experience with FPDL demonstrated good results in a wide range of applications for the treatment of different vascular anomalies. The absence of long-term side effects and bearable pain during the treatment makes it a valuable solution for the resolution of benign tumours also in very young patients.

Feasibility of photoacoustic-guided ultrasound treatment for port wine stains.

BACKGROUND AND OBJECTIVES: Port wine birthmark, also known as port wine stain (PWS) is a skin discoloration characterized by red/purple patches caused by vascular malformation. PWS is typically treated by using lasers to destroy abnormal blood vessels. The laser heating facilitates selective photothermolysis of the vessels and attenuates quickly in the tissue due to high optical scattering. Therefore, residual abnormal capillaries deep in the tissue survive and often lead to the resurgence of PWS. Ultrasound (US) has also been proposed to treat PWS, however, it is nonselective with respect to the vasculature but penetrates deeper into the tissue. We aim to study the feasibility of a hybrid PWS treatment modality combining the advantages of both modalities. MATERIALS AND METHODS: In this manuscript, we propose a photoacoustic (PA) guided US focusing methodology for PWS treatment which combines the optical contrast-based selectivity with US penetration to focus the US energy onto the vasculature. The PA signals collected by the transducers, when time-reversed, amplified, and transmitted, converge onto the PWS, thus minimally affecting the neighboring tissue. We performed two- and three-dimensional simulations that mimic realistic transducers and medium properties in this proof of concept study. RESULTS: The time-reversed PA signals when transmitted from the transducers converged onto the vasculature, as expected, thus reducing the heating of the neighboring tissue. We observed that while the US focus is indeed affected due to experimental factors such as limited-view, large detector separation and finite detection bandwidth, and so forth, the US did focus completely or partially onto the vasculature demonstrating the feasibility of the proposed methodology. CONCLUSION: The results demonstrate the potential of the proposed methodology for PWS treatment. This treatment method can destroy the deeper capillaries while minimally heating the neighboring tissue, thus reducing the chances of the resurgence of PWS and as well as cosmetic scarring.

A case of large airway and orbital hemangiomas with facial capillary malformation.

Infantile hemangiomas (IHs) are the most common pediatric vascular tumors, although their genetic etiology is largely unknown. Congenital capillary malformations (CMs) are associated with known somatic pathogenic variants, including GNAQ, GNA11, PIK3CA, and PIK3R1. Co-occurrence of a facial CM such as port wine stain and IH is not associated with any recognized vascular anomaly syndromes and rarely reported in the literature. We describe a case of a 5-week-old female patient with a large facial CM and extensive IHs of the lower lip, airway, and orbit who presented with airway compromise and responded to propranolol therapy.

Complication rates and safety of pulsed dye laser treatment for port-wine stain: a systematic review and meta-analysis.

Pulsed dye laser (PDL) is the most commonly used method for port-wine stain (PWS); however, no studies have reported the safety of PDL. This review aimed to collect and summarize complications reported in relevant literature, assess complication rates in treating PWS with PDL, and explore the relevant influencing factors. A systematic review and meta-analysis were conducted to search for related studies in PubMed, Embase, and the Cochrane Library until August 2022. Two reviewers independently evaluated the risk of bias of included studies. Stata Software version 17.0 was used for the analysis. All complications reported in the literature are divided into acute phase complications and long-term complications. Overall pooled purpura, edema, crusting, blistering, hyperpigmentation, hypopigmentation, and scarring rates were 98.3%, 97.6%, 21.5%, 8.7%, 12.8%, 0.9%, and 0.2%, respectively. Although the acute adverse reactions were found to be common, the long-term permanent complications clearly have a lower frequency, and the occurrence of scarring is much lower than that initially thought. This indicates that effective protective measures after treatment are very important for preventing scar formation. Overall, PDL treatment for PWS shows a high level of safety and low chances of causing long-term complications.

Efficacy and safety of 595-nm pulsed dye laser treating port wine stains in Vietnamese patients: analysis of 124 cases and optimal treatment regimens.

The purpose of this study is to determine the efficacy and safety of 595-nm pulsed dye laser (PDL) for port wine stains (PWS) treatment in Vietnamese patients. The study also analyzed the association between the response to treatment and the characteristics of patients and treatment regimens. Parallelly, the study contributed to further optimal treatment sessions for different subjects based on the data collected. One hundred twenty-five patients who underwent 595-nm PDL to treat PWS were included in the study, in which data from 124 patients was retrospectively analyzed. Data on demographic characteristics of patients, treatment regimens, and clinical improvement were collected. SPSS version 25 was used to analyze the relationship between associated factors and the response rate. The overall response rate of Vietnamese patients who had Fitzpatrick skin classification type III and IV was 73.4%. Age, gender, treatment sessions, and lesion positions were generally not associated with the response rate. The lesion grade was the sole element that affected the clinical improvement. The lesion grade 1 had the best response (100%) even after a short duration of treatment (six to ten treatments). Lesion grade 4 demanded over 16 treatments to reach > 60% of improvement. The lesion grades 1 and 2 could be blanched with regimen < 10 treatments while regimens exceeding 15 treatments should be carefully considered for lesions at grade 3 after evaluating associated conditions. Lesions at grade 4 demanded ≥ 16 treatments to reach acceptable outcomes. These results could help physicians establish a reasonable treatment strategy for patients.

Topical metformin suppresses angiogenesis pathways induced by pulsed dye laser irradiation in animal models.

Pulsed dye laser (PDL) is the first-line treatment for port-wine stain (PWS). However, only a small portion of the lesions could be completely cleared by PDL treatment, which might be related to the regeneration and revascularization of the vascular structures after laser irradiation. Recently, it is believed that the suppression of regeneration and revascularization of photocoagulated blood vessels can achieve a better therapeutic outcome. We use rabbit ear and SD rat as the animal models to investigate whether PDL-induced angiogenesis can be suppressed by topical metformin. Our results showed that topical application of metformin can effectively suppress the PDL-induced early stage of angiogenesis via inhibition of the AKT/mTOR/P70S6K pathway in animal models.

GNA11-mutated Sturge-Weber syndrome has distinct neurological and dermatological features.

BACKGROUND AND PURPOSE: Sturge-Weber syndrome (SWS) is a neurocutaneous disorder characterized by clinical manifestations involving the brain, eye and skin. SWS is commonly caused by somatic mutations in G protein subunit Alpha Q (GNAQ). Five cases of subunit Alpha 11 (GNA11) mutations have been reported. We studied phenotypic features of GNA11-SWS and compared them with those of classic SWS. METHODS: Within two European multidisciplinary centers we looked for patients with clinical characteristics of SWS and a GNA11 mutation. Clinical and radiological data were collected retrospectively and prospectively. RESULTS: We identified three patients with SWS associated with a somatic GNA11 mutation. All had disseminated capillary malformation (CM) and hyper- or hypotrophy of an extremity. At birth, the CMs of the face, trunk and limbs were pink and patchy, and slowly darkened with age, evolving to a purple color. Two of the patients had glaucoma. All had neurological symptoms and moderate brain atrophy with a lower degree of severity than that classically associated with SWS. Susceptibility-weighted imaging (SWI) and contrast-enhanced fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging demonstrated the best sensitivity to reveal the pial angiomas. CONCLUSIONS: We have differentiated two distinct clinical/radiological phenotypes of SWS; GNAQ- and GNA11-SWS. The classic GNAQ-SWS is characterized by a homogeneous dark-red CM, commonly associated with underlying soft tissue hypertrophy. The CM in GNA11-SWS is more reticulate and darkens with time, and the neurological picture is milder. SWI and post-contrast FLAIR sequences appear to be necessary to demonstrate leptomeningeal angiomatosis. Anti-epileptic medication or future targeted therapies may be useful, as in classic SWS.

Hematoporphyrin monomethyl ether photodynamic therapy for the treatment of Sturge-Weber syndrome and large segmental facial port-wine stain.

Hematoporphyrin monomethyl ether (HMME) is a newly authorized photosensitizer for the treatment of port-wine stain (PWS) in China. However, no research on its efficacy for treating PWS lesions of Sturge-Weber syndrome (SWS) has been made. To assess the efficacy and safety of HMME-photodynamic therapy (PDT) in the treatment of SWS and simple large segmental facial PWS. Medical records of patients with SWS and large segmental facial PWS were reviewed. Efficacy was evaluated according to color blanching and graded as excellent (≥75%), good (50%-74%), fair (25%-49%), and poor (≤24%). Adverse events were analyzed. Nineteen patients with SWS and 33 patients with large segmental facial PWS were analyzed. 52.6% SWS and 69.7% PWS patients (p > .05) achieved at least 25% improvement. Common adverse events included short-term pain, edema, pruritus, exudation, and scab. No severe adverse event occurred. HMME-PDT was effective and safe for SWS and large segmental facial PWS.

Clinical characteristics of infants with port-wine stain and glaucoma secondary to Sturge-Weber Syndrome.

BACKGROUND: Sturge-Weber Syndrome (SWS) is a rare disease involving the eye, skin, and brain. Port-wine stain (PWS) and glaucoma are common clinical manifestations. This study analysed the clinical characteristics of infants with PWS and glaucoma secondary to SWS. METHODS: Children with PWS and glaucoma secondary to SWS were enrolled. Data were extracted from ophthalmic and systemic examination findings. Ocular examinations included intraocular pressure, anterior segment and fundus examination, and ocular A-scan and B-scan ultrasonography. RESULTS: Fifty-seven patients were included, with a mean age of 9.9 ± 11.9 months, and 34 (59.6%) patients were male. In all, 61 eyes were diagnosed with glaucoma. Forty-one patients (71.9%) had unilateral facial PWS and glaucoma occurred on the same side. Eight patients (14.0%) had Mongolian spots and ten patients (17.5%) had epilepsy. Corneal changes included corneal oedema (n = 36 eyes, 59.0%), corneal opacity (n = 15 eyes, 24.6%), and Haab lines (n = 13 eyes, 21.3%). Mean corneal diameter and thickness in the eyes with glaucoma was larger than those in the unaffected eyes (12.2 ± 0.7 mm vs 10.8 ± 0.6 mm, P < 0.001; 681.2 ± 106.4 µm vs 578.2 ± 58.2 µm, P < 0.001). The eyes with glaucoma had higher IOP and larger axial length and C/D ratio (19.3 ± 6.2 mmHg vs 11.6 ± 4.2 mmHg, P < 0.001; 21.23 ± 1.93 mm vs 19.68 ± 1.61 mm, P < 0.001; and 0.57 ± 0.18 vs 0.24 ± 0.15, P < 0.001). Thirty-three (57.9%) and 25 (43.9%) patients showed diffuse choroidal haemangioma (DCH) and conjunctival/episcleral haemangiomas, respectively. Ten patients (17.5%) showed iris anterior insertion or hyperpigmentation in the anterior chamber angles. Six of them had Mongolian spots at the same time. CONCLUSIONS: Monocular glaucoma, DCH, and conjunctival/episcleral haemangiomas are common in SWS patients with PWS and glaucoma. Glaucomatous eyes have larger corneal diameter and axial length and thicker cornea. Patients with Mongolian spots have higher incidence of iris anterior insertion or hyperpigmentation in anterior chamber angle.

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.

Theoretical and in vivo investigations of morphology and concentration of gold nanoparticles for laser surgery.

BACKGROUND AND OBJECTIVE: Precise control of the thermal damage is critical during thermal therapy with the assistance of gold nanoparticles, which depends on the laser parameters and characteristics of gold nanoparticles. However, the current understanding of the relationship between the gold nanoparticles/incident laser light and the efficiency of photothermal therapy is limited, which should be studied systematically. MATERIALS AND METHODS: In this study, theoretical simulations were conducted to investigate the influence of laser wavelength, the size and shape of gold nanoparticles, and the distance of the particle in complex nanostructures on the optical properties and temperature distribution after laser irradiation, aiming to achieve maximum photothermal conversion efficiency and therapeutic effect during the laser treatment of port wine stains. Thereafter, gold nanoparticles were prepared and in vivo experiments were conducted to evaluate the effect on thermal damage of blood vessels. RESULTS: For the laser wavelength at 532 nm, gold nanospheres with diameters of 20 nm are ideal in terms of temperature rise. The optimized particle distance is 5 nm and the corresponding concentration is 0.26 mg/ml. For Nd:YAG laser at 1064 nm, gold nanorods with an aspect ratio of 6.3 and an effective radius of 12.7 nm are the most effective photothermal agents. The optimized particle distance is 4 nm, yielding the optimal concentration of 0.017 mg/ml. In vivo results demonstrated that using gold nanoparticles following our simulations as photothermal agents can greatly enhance the thermal damage of diseased blood vessels, reducing the laser energy and laser pulses required for the obvious thermal response of blood vessels. CONCLUSION: For different laser wavelengths used in clinics in the near future, theoretical models presented in this study can be employed to obtain the morphology of single gold nanoparticle and the concentration of nanoparticles solutions, thereby obtaining the optimal photothermal conversion and enhanced thermal damage assisted by gold nanoparticles.

Morphea mimicking facial capillary malformations: Two new cases and review of the literature.

Morphea and facial capillary malformations (port-wine stains) are distinct conditions that can affect the pediatric population. Early localized morphea mimicking a capillary malformation is an uncommon clinical presentation. We present two new cases of girls, aged 2 and 3 years, who presented with erythematous patches, initially diagnosed as capillary malformations, which were later diagnosed as morphea. We also performed a literature review, yielding 12 additional cases that underscore that the unusual presentation of morphea may delay correct diagnosis. Although early management of morphea reduces long-term sequelae, it is important to delay laser treatment for selected acquired vascular malformations, until the diagnosis of morphea is excluded.

Experimental study of combined photodynamic and photothermal therapy in the treatment of port wine stain.

Laser therapy has become the golden standard of port wine stain (PWS), but complete clearance of resistant PWSs is still difficult. The application of photodynamic therapy (PDT) in the treatment of PWS shows potential in clinical practice, especially for large-area and deep lesions. In this work, in vivo animal experimental investigation on the coupling effect of PDT with multi-pulse laser (MPL) irradiation on the treatment of PWS was conducted by using a dorsal skin window chamber model. Through visualization of the thermal response of blood vessels and damage evaluation, it is found that the combination of PDT with MPL results in 96.2% more vascular injury than PDT alone and 90% more than MPL alone, thus reducing side effects such as purpura after treatment. The combined therapy also has the benefit of large treatment area, uniform fading effect, shortened light duration, and reduced photosensitizer admit.