The effect of ambient temperature on capillary vascular malformations

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.

Does Topical Anesthesia Alter the Outcomes of Vascular Laser Procedures? Review of Vasodynamic Effects and Clinical Outcomes Data

BACKGROUND

Topical anesthesia has vasodynamic effects within the skin and therefore has the potential to change the presence of hemoglobin as a chromophore before intense pulsed light (IPL) and vascular laser treatments. It is unclear whether this is clinically relevant. Global consensus on the use of topical anesthetics in this context is lacking.

OBJECTIVE

Review the effects of topical anesthetics on the skin microvasculature and the clinical implications of such effects on vascular treatments.

METHODS

PubMed and Medline searches were performed to identify studies examining the vasodynamic effects of topical anesthesia on skin and evaluating differences in efficacy of IPL and vascular laser treatments with or without topical anesthetic use.

RESULTS

Published studies reveal variable effects of different topical anesthetic agents on skin microvasculature. Only 3 controlled studies that directly examined the effect of topical anesthesia on clinical outcomes for pulsed dye laser (PDL) treatment of vascular conditions were identified. They did not support a difference in clinical outcomes with or without the use of topical anesthesia before PDL treatment.

CONCLUSION

Although topical anesthetic agents have vasodynamic effects within the skin, there is currently insufficient evidence to advise against their use before light and laser-based vascular treatments.

Hematoporphyrin Monomethyl Ether Photodynamic Therapy of Port Wine Stain: Narrative Review

Port wine stain (PWS) is a congenital and progressive capillary malformation characterized by structural abnormalities of intradermal capillaries and postcapillary venules. The visible manifestation is often considered a disfigurement and the accompanying social stigma often causes serious emotional and physical impact. Hematoporphyrin monomethyl ether (HMME) is a newly authorized photosensitizer for treating PWS in China. Hematoporphyrin monomethyl ether photodynamic therapy (HMME-PDT) has successfully treated thousands of Chinese patients with PWS since 2017, and HMME-PDT may be one of the most promising strategies for the treatment of PWS. However, there are few reviews published about the clinical use of HMME-PDT. So in this article, we want to briefly review the mechanism, efficacy evaluation, effectiveness and influencing factors, and the common postoperative reactions and treatment suggestions of HMME-PDT in the treatment of PWS.

Laser Speckle Contrast Imaging for the Objective Assessment of Blood Perfusion in Keloids Treated With Dual-Wavelength Laser Therapy

BACKGROUND

Most of the widely used methods for the assessment of keloid treatment are subjective grading scales based on the opinion of an individual clinician or patient. There is a growing need for objective methods to evaluate keloid treatment.

OBJECTIVE

This study aimed to evaluate the value of laser speckle contrast imaging (LSCI) as an objective method for the assessment of dual-wavelength laser therapy for keloids.

METHODS

This prospective study included 21 patients with 54 keloids. All patients were treated with a combined 585-nm pulsed dye laser and 1,064 nm neodymium-doped yttrium aluminum garnet dual-wavelength laser at 4 weeks to 6 weeks intervals. Keloids were assessed using the Vancouver Scar Scale (VSS) and LSCI.

RESULTS

The total VSS score significantly decreased after 4 sessions of treatment (p < .05). Blood perfusion in keloids as measured by LSCI was significantly reduced after treatment (p < .05). The improvement of chest keloids in terms of the total VSS score and blood perfusion was significantly greater than that of scapular keloids (p < .05). There was a positive correlation between decreased perfusion and reduced total VSS score (R2 = 0.84).

CONCLUSION

Blood perfusion in keloids significantly decreased after dual-wavelength laser therapy. Laser speckle contrast imaging is a promising objective method for assessing the improvement of keloids treated with laser therapy.

Monitoring perfusion and oxygen saturation in port-wine stains during vascular targeted photodynamic therapy

Background

Vascular targeted photodynamic therapy (V-PDT) is a safe and effective therapeutic modality for port-wine stains (PWS) by targetedly damaging the dilated and malformed blood vessels. This study aims to monitor and quantify the changes in oxygen saturation (StO₂), blood volume fraction (BVF) and perfusion in PWS lesions before and during V-PDT.

Methods

Microvascular parameters (i.e., StO₂ and BVF) and skin perfusion were measured noninvasively by using diffuse reflectance spectroscopy (DRS) and laser Doppler imaging (LDI), respectively. The change in StO₂, BVF and perfusion that occurred in the PWS lesions of 26 patients were monitored and investigated before and during V-PDT in vivo with the systematic administration of the porphyrin-based photosensitizer HiPorfin.

Results

The mean StO₂ (P<0.05), BVF (P<0.05), and perfusion (P<0.001) in PWS lesions of all subjects significantly increased by 6%, 34%, and 113%, respectively, 3 min after the initiation of V-PDT. The StO₂ increased first and fluctuated during V-PDT. The overall trend of BVF change was consistent with the perfusion change. The BVF and the perfusion of PWS lesions increased after the initiation of V-PDT, and then gradually decreased.

Conclusions

V-PDT is an effective therapeutic modality in treating PWS. Results showed that LDI and DRS permitted the noninvasive monitoring of the changes in StO₂, BVF, and perfusion in PWS lesions during V-PDT, and these methods can be useful in facilitating our understanding of the basic physiological mechanisms during V-PDT.

Application of different noninvasive diagnostic techniques used in HMME-PDT in the treatment of port wine stains

BACKGROUND

Hematoporphyrin monomethyl ether photodynamic therapy (HMME-PDT) is an effective method for treating port wine stains (PWS). However, methods to evaluate the treatment of HMME-PDT for PWS effectively and objectively are lacking.

OBJECTIVE

This study aimed to describe the different noninvasive diagnostic techniques used in the evaluation of treatment response to HMME-PDT for PWS.

METHODS

Thirty-one lesions of 22 patients with PWS were treated with HMME-PDT. Four noninvasive diagnostic techniques including VISIA-CR™ system, dermoscopy, high-frequency ultrasound (HFUS), and laser speckle contrast imaging (LSCI) were used to obtain standard radiographic data on skin color, skin thickness, blood vessel morphology, blood vessel distribution, and blood perfusion from lesions and surrounding normal skin before and after HMME-PDT.

RESULTS

The standard image pattern of VISIA-CR™ system showed color change in the lesions of PWS after HMME-PDT. RBX red image of VISIA-CR™ system showed that erythema was highly aggregated even in invisible lesions at baseline but decreased after HMME-PDT. The erythema index reduced value d was related to the efficacy rating (γ = 0.631, P < 0.05). Dermoscopy showed that the number of spot-like and irregular linear vessels increased, which was correlated with the increase in clinical classification. After HMME-PDT, vascular rupture was observed by dermoscopy. The response rate of lesions with vascular rupture was 100.00% (20/20). Moreover, the response rate of lesions without vascular rupture was 63.64% (7/11). Vascular rupture sign was correlated with better efficacy (P < 0.05). HFUS showed that the dermis of PWS thickened and was arranged loosely with scattered linear hypoechoic signal. After HMME-PDT, the dermal layer of the lesions became thinner with a decreased linear hypoechoic signal. The response rate of the lesions with linear hypoechoic signal was 76.92% (10/13), and that without linear hypoechoic signal was 94.44% (17/18). The lesions without linear hypoechoic signal in the dermis showed better efficacy (P < 0.05). In some lesions, LSCI showed high blood perfusion signal in PWS lesions and blood perfusion reduction after HMME-PDT.

CONCLUSION

VISIA-CR™ system can be used to observe not only visible but also invisible lesions of PWS. Moreover, lesions fading after HMME-PDT can be described objectively by VISIA-CR™ system. Dermoscopy played an important role in the clinical classification of PWS, including assessing vascular injury after HMME-PDT, guiding the adjustment of therapeutic dose, and selecting the end point of treatment. Both HFUS and LSCI can be used to assist treatment response evaluation of HMME-PDT.

Intraoperative monitoring of blood perfusion in port wine stains by laser Doppler imaging during vascular targeted photodynamic therapy: A preliminary study

OBJECTIVE

The objective of this study was to monitor blood perfusion dynamics of port wine stains (PWS) during vascular targeted photodynamic therapy (V-PDT) with laser Doppler imaging (LDI).

METHODS

The PWS lesions of 30 facial PWS patients received V-PDT, while the normal skins on the forearm of 5 healthy subjects were treated as light-only controls for comparison. Furthermore, two different PWS lesions in the same individual from each of 3 PWS patients successively received laser irradiation only and V-PDT, respectively. LDI was used to monitor intraoperative blood perfusion dynamics.

RESULTS

During V-PDT, the blood perfusion (278±96 PU) in PWS lesions for 31 of 33 PWS patients significantly increased after the initiation of V-PDT treatment, then reached a peak (638±105 PU) within 10min, followed by a slow decrease to a relatively lower level (515±100 PU). Furthermore, the time for reaching peak and the subsequent magnitude of decrease in blood perfusion varied with different patients. For light-only controls, an initial perfusion peak at 3min followed by a nadir and a secondary increase were found not only in normal skin, but also in PWS lesions.

CONCLUSION

The preliminary results showed that the LDI permits non-invasive monitoring blood perfusion changes of PWS lesions during V-PDT. There was a clear trend in blood perfusion responses during V-PDT and laser irradiation. The blood perfusion changes during treatment were due to V-PDT effects as well as local temperature increase induced by laser irradiation.

Topical anaesthetic effects on skin vasculature with potential implications for laser treatment

Laser treatment of vascular lesions is affected by parameters including the diameter and depth of the vessels and flow within the vessels. Topical anaesthetics are in common use prior to laser treatment but may have effects on vessel parameters and, subsequently, the efficacy of laser treatment. Eleven patients with capillary vascular malformations were investigated for vessel diameter before and after elective application of a topical anaesthetic, Eutectic Mixture of Local Anaesthetics (EMLA) (AstraZeneca) or Ametop (S&N Health), prior to pulsed dye laser treatment. EMLA contains 2.5% lidocaine ad 2.5% prilocaine, and Ametop gel contains 4% tetracaine. Patients' capillary malformations were assessed using confocal laser scanning microscopy (CLSM) (Vivascope 1500 Mavig GmbH, Munich). Six of the 11 patients recruited had EMLA topical anaesthetic, and five had Ametop. Four hundred twenty-one diameters were measured. The mean vessel diameter was 50.87 μm. Previous laser treatments undergone by each patient were noted to exclude this as a confounding variable, and no significant difference was found between topical anaesthetic groups. Statistical calculations were made using GenStat and Minitab. There is no evidence that Ametop affects mean diameter (p value is 0.361). EMLA reduces the mean diameter of vessels (p = 0.002), with a 27% reduction in post-EMLA diameter. This study demonstrates that the use of EMLA cream has a statistically significant reduction vessel diameter. As it is known that vessel diameter is important for the response of laser treatment, the use of EMLA may affect outcome.

Early depth assessment of local burns by videomicroscopy: a novel proposed classification

PURPOSE

Videomicroscopy is very useful for burn depth assessment in an early phase; however, there is no practical classification that includes complicated anatomic, pathologic, and morphologic findings of burn wounds. The aim of this study was to propose a novel classification to assess burn depth in its early phase easily and reliably by videomicroscopy.

METHODS

Forty-four patients with 56 intermediate-depth burn wounds were included. Burn depth was divided into each grade according to our proposed classification, which is composed of five categories based on dermal capillary integrity patterns. The intrarater and interrater reliabilities of the assessment by the second and third authors were evaluated by Cohen's unweighted κ-value.

RESULTS

The results of the measurements according to the proposed classification showed an accuracy of 92.9%, sensitivity of 81.8%, and specificity of 100.0%. The intrarater reliability of the second and third authors showed substantial agreement (κ=0.719 and 0.729, respectively). The interrater reliability of the sum of each observer's variable also showed substantial agreement (κ=0.636).

CONCLUSION

This pattern analysis system is easy to use even for inexperienced personnel, and is reliable with high accuracy and specificity. Intrarater and interrater statistics also support its reliability and reproducibility.

Early depth assessment of local burns by videomicroscopy: 24 h after injury is a critical time point

PURPOSE

Videomicroscopy has simple and prompt operability, and useful in the burn depth assessment in its early phase. A burn wound is, however, a dynamic environment in the first few days and the critical time to assess a burn wound by videomicroscopy has not been investigated. The aim of this study is to investigate the critical time point to assess the burn depth by videomicroscopy.

METHODS

Forty one patients with 44 intermediate depth burns admitted within 7 days after injury were included. Accuracies were assessed by comparison with clinical outcome: healing within 21 days after injury or not with conservative treatment. We prospectively evaluated and compared the accuracy of the videomicroscopy measurements with the clinical assessments. All findings were serialized in order of time after injury and divided into three groups, and we compared the appreciation of burn depth by videomicroscopy findings among groups.

RESULTS

The videomicroscopy measurements is significantly accurate compared with clinical assessments (p=0.001). The accuracy of videomicroscopy measurements was significantly lower in the post-injury <24 h group compared with post-injury ≥24 h group (p=0.004).

CONCLUSION

Videomicroscopy is effective tool in assessment of early burn depth and the critical time point to assess the burn depth by videomicroscopy is 24 h after injury.

Blood flow dynamics after laser therapy of port wine stain birthmarks

BACKGROUND AND OBJECTIVE

During laser therapy of port wine stain (PWS) birthmarks, regions of perfusion may persist. We hypothesize that such regions are not readily observable even when laser surgery is performed by highly experienced clinicians. The objective of this study was to use objective feedback to assess the acute vascular response to laser therapy.

STUDY DESIGN/MATERIALS AND METHODS

A clinic-friendly laser speckle imaging (LSI) instrument was developed to provide the clinician with real-time images of blood flow during laser therapy. Images were acquired from patients undergoing laser therapy of PWS birthmarks at Scripps Clinic and the Beckman Laser Institute and Medical Clinic. Blood flow maps were extracted from the acquired imaging data. Histogram-based analysis was applied in grading the degree of heterogeneity present in the blood flow maps after laser therapy.

RESULTS

Collectively, two types of patient responses were observed in response to laser exposure: (1) an immediate increase in perfusion within minutes after laser therapy; and (2) an overall decrease in blood perfusion approximately 1 hour after laser therapy, with distinct regions of persistent perfusion apparent in the majority of post-treatment blood-flow images. A comparison of blood flow in PWS and adjacent normal skin demonstrated that PWS blood flow can be greater than, or sometimes equivalent to, that of normal skin.

CONCLUSION

In general, a decrease in skin perfusion is observed during pulsed laser therapy of PWS birthmarks. However, a heterogeneous perfusion map was frequently observed. These regions of persistent perfusion may be due to incomplete photocoagulation of the targeted vessels. We hypothesize that immediate retreatment of these regions identified with LSI, will result in enhanced removal of the PWS vasculature. Lasers Surg. Med. 41:563-571, 2009. (c) 2009 Wiley-Liss, Inc.

Noninvasive blood flow imaging for real-time feedback during laser therapy of port wine stain birthmarks

BACKGROUND AND OBJECTIVES

During laser therapy of port wine stain (PWS) birthmarks, regions of persistent perfusion may exist. Immediate retreatment of such regions may improve PWS laser therapeutic outcome. To address this need, we propose use of laser speckle imaging (LSI) to provide real-time, quantitative feedback during laser surgery. Herein, we present in vitro and in vivo data collected with a clinic-based LSI instrument.

STUDY DESIGN/MATERIALS AND METHODS

Prior to clinical implementation, we first investigated three aspects of LSI deemed important for clinical imaging: (1) instrument depth of field (DOF); (2) effects of laser irradiance on speckle flow index (SFI) values; and (3) measurement repeatability. Clinical measurements were acquired from the lesions of PWS patients immediately prior to and after laser therapy at the Beckman Laser Institute.

RESULTS

Our preclinical data suggest the following: (1) instrument DOF was approximately 1 cm; (2) quantitative flow characterization with LSI was practically unaffected at normalized irradiance values between 0.06 and 0.5; and (3) our LSI instrument was capable of highly reproducible SFI values. From our clinical measurements, we found that the relative difference between blood perfusion in PWS lesions and adjacent normal skin was highly variable. Based on SFI images, the perfusion of PWS skin is sometimes indistinguishable from that of adjacent normal skin. With laser therapy, we measured a global decrease in blood perfusion, and we frequently observed distinct regions of persistent perfusion.

CONCLUSIONS

Our results demonstrate the potential role of image-guided laser therapy of PWS birthmarks. LSI is a promising tool for noninvasive blood flow characterization during laser therapy due to its relative simplicity and low cost.

Assessment of burn depth: a prospective, blinded comparison of laser Doppler imaging and videomicroscopy

INTRODUCTION AND AIMS

There is a need, both in clinical and research settings, for an affordable, objective method of assessing burn depth. This study compares burn depth assessment by videomicroscopy with laser Doppler imaging (LDI) in patients with dermal burns. The videomicroscope is inexpensive compared to LDI, and can visualise the dermal capillary structure, therefore potentially allowing objective assessment of dermal burn injuries.

METHODS

Patients admitted <72 h post-injury were included in the trial. Blinded LDI and videomicroscopy assessments were carried out. The patients were then followed up to one of three end-points: primary healing without surgery; early surgery; delayed healing and subsequent split skin grafting. The incidence of infection was also noted.

RESULTS

Twenty-seven burn wounds were examined. In superficial partial thickness injuries, the videomicroscope reliably demonstrated an intact or nearly intact dermal vascular structure, progressing through to large amounts of capillary destruction and haemoglobin deposition in deep partial thickness injuries and complete destruction in full thickness injuries. The videomicroscope findings correlated strongly with both those of the LDI (p<0.001) and with clinical outcome (p<0.001).

DISCUSSION

The videomicroscope is capable of accurately and objectively assessing burn depth. The results correlated well with both the clinical outcome and the laser Doppler findings. In addition, videomicroscopy is significantly cheaper than LDI and avoids several of the disadvantages of LDI.

Capillary Vascular Malformation Response to Increased Ambient Temperature Is Dependent Upon Anatomical Location

BACKGROUND

It has been documented that capillary malformations (CMs) located on the limbs tend to respond less well to laser treatment than those sited on the head and neck. However, there is little evidence available to explain this observation.

OBJECTIVES

To investigate potential differences between CMs located on the head and neck with those on the limbs, by comparing their response to increasing ambient temperature.

METHODS

Fifteen previously untreated subjects with CMs were compared as the ambient temperature was increased from 20 degrees C to 28 degrees C. These included 10 with head and neck CMs and 5 with limb CMs. The following measurements were taken at 2 degrees C intervals: cutaneous blood flow, capillary diameter, density and depth, CM color, skin and core temperatures.

RESULTS

There were no statistically significant differences in mean capillary depth, diameter, density, or CM color between groups. Cutaneous blood flow increased with ambient temperature in the head and neck CMs (P = 0.009) and was significantly higher than that in the limb CMs at all temperatures (P < 0.001), while the limb CMs did not demonstrate any increase in cutaneous blood flow with temperature.

CONCLUSIONS

These results suggest a possible reason for the poorer response to laser treatment seen in limb CMs: since cutaneous blood flow is a product of the blood flow velocity and hemoglobin concentration, malformations with lower blood perfusion would have less chromophore available and therefore be less suitable for laser destruction.