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.

Advances in our understanding of the prognosis of adrenal incidentaloma.

INTRODUCTION: As cross-sectional abdominal imaging is used increasingly, adrenal incidentaloma (AI) are being found frequently and present a clinical dilemma. The vast majority are benign and non-functioning, but a minority represent incidentally found functional or malignant tumours. In this review we summarise the current clinical, biochemical and radiological investigation of AI and discuss recent advances that differentiate clinically inconsequential lesions from functional and/or malignant AI. Areas covered: Prevalence, natural history, biochemical and radiological assessment, indications for surgery and surgical provision. Expert commentary: Well established work-up of AI usually enables benign, non-functioning lesions to be differentiated from functioning and/or malignant AI. In indeterminate lesions recent advances in work-up such as urine steroid profiles measured by gas chromatography /mass spectrometry and functional imaging with 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) in addition to standard investigations have improved characterisation of these lesions. The management of AI showing mild autonomous hypercortisolism without overt features of Cushing's syndrome remains controversial and is discussed in this review.

Effects of perforator number and location on the total pedicle flow and perfusion of zone IV skin and fat of DIEP flaps.

BACKGROUND: DIEP flaps are a popular choice for autologous breast reconstruction, though many surgeons routinely discard zone IV, limiting transferrable tissue. We investigated the effect of altering number and location of perforators supplying the flap on total pedicle flow and perfusion of skin and fat of zone IV. METHODS: 20 cranially-based abdominal epigastric perforator flaps were raised in rats on two perforators. The perforators were sequentially clamped and released in a randomised order and total pedicle flow measured using microvascular flow-probes, on the following perforator combinations: 13 DIEP flaps were raised in post-mastectomy patients requiring breast reconstruction on two perforators. These were clamped and released as before to assess perfusion of fat and skin in zone IV using SPY indocyanine-green-fluorescence-angiography scans on the same perforator combinations as in our animal study, listed above. RESULTS: All data were analysed using 2-way-ANOVA and revealed that vascular flow was significantly (p < 0.0001) greater on one perforator as opposed to two. These results were supported by our human study, revealing both zone IV fat and skin perfusion were significantly (p < 0.0001) greater when a single perforator was used. CONCLUSIONS: Our data suggests total pedicle flow and perfusion of zone IV fat and skin is significantly higher on a single perforating blood vessel as opposed to two. Reasons for these observed differences could be due to changing pressure gradients across a piece of tissue prone to venous congestion, with maintenance of flow better in a single lumen.

A direct comparison of pulsed dye, alexandrite, KTP and Nd:YAG lasers and IPL in patients with previously treated capillary malformations.

INTRODUCTION: Several studies have reported laser treatment of Capillary Malformations (CMs) using systems other than pulsed dye lasers (PDL). Few, however, have compared different systems in the same patients. This study aimed to directly compare CM fading using five different systems. METHODS: Eighteen previously PDL-treated patients were test-patched using the alexandrite, KTP, and Nd:YAG lasers and intense pulsed light (IPL) with additional PDL patches as a control. Pre- and post-treatment videomicroscopy, and colour measurements using Munsell colour charts were carried out. RESULTS: Four patients failed to respond to any test patches. The alexandrite laser test patches had the largest mean improvement in Munsell colour following treatment (P = 0.023) and resulted in CM fading in 10 patients, although 4 patients developed hyperpigmentation, and 1 patient scarring, following treatment. In addition, the alexandrite laser caused a significant decrease in mean post-treatment capillary diameter (P = 0.007), which was not mirrored by the other systems. The KTP and Nd:YAG lasers were least effective, with fading seen in two patients for both systems, whilst IPL patches resulted in CM fading in six patients. In addition, five patients had further CM fading using double-passed PDL treatment. Mean pre-treatment capillary diameter measurements were predictive of those patients likely to respond to laser treatment. CONCLUSIONS: Alexandrite laser treatment was the most effective, but resulted in hyperpigmentation and scarring in four patients, probably due to its deeper penetration and lower specificity for oxyhaemoglobin causing non-specific dermal damage. Double passing of the PDL can result in further CM fading even in previously treated patients. Videomicroscopy measurements of capillary diameter before treatment may be predictive of the likelihood for patient's to respond to laser treatment.

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.

The validation of the Depth Measurement Videomicroscope (DMV) as a noninvasive tool for the assessment of capillary vascular malformations.

The assessment of capillary vascular malformation (CM) morphology can be performed using videomicroscopy. Previously only the type of capillary pattern could be demonstrated. The Depth Measurement Videomicroscope (DMV) allows both depth and diameter of CM vessels to be measured. The aim of this study was to examine how videomicroscope recordings correlated with biopsy recordings and to investigate pressure-related changes in recordings when using the device. For the first part of the study, 10 patients with CMs resting in a temperature-controlled room were assessed with the DMV. Following this a 3mm punch biopsy of the area was taken. The depth and diameter measurements taken with the DMV were compared to those obtained histologically. For the second part of the study, pressure measurement was used to determine the amount of pressure required on the tip of the DMV to alter the results obtained. Five recordings were taken on the forearm of one volunteer. When the DMV and biopsy measurements are compared using a Bland and Altman Test to determine their relationship there is a close agreement with the diameter measurements and a correction factor of -0.100mm for the depth measurements. The pressure required to alter the skin microcirculation when placing the DMV on the skin surface was found to be 62mmHg. This corresponds closely with other studies of pressure effects on the skin microcirculation and exceeds the pressure used when using the DMV. The DMV thus provides a useful tool for assessing CM capillary structure.

The effect of varying pulse duration, wavelength, spot size, and fluence on the response of previously treated capillary vascular malformations to pulsed-dye laser treatment.

Modern lasers allow different parameters to be altered in an effort to gain further improvement in otherwise resistant capillary vascular malformations (CMs). The aim of this study was to examine the effect of changing the pulse duration, wavelength, spot size, and fluence on the color and capillary architecture of 585-nm pulsed-dye, laser-resistant CMs. Eighteen patients were assessed with a depth measurement videomicroscope (DMV) before and after 12 test patches with ScleroPlus and V-Beam lasers at specified parameters. In the majority of the test patch areas, there was little improvement after treatment. However, 44% of patients had greater than 75% clearance in at least 1 test patch site. This study demonstrates that both lasers can achieve further lightening in 585 nm 0.45 msec pulsed-dye laser-resistant CMs. However, in CMs consisting of small-diameter deep vessels, further improvement is unlikely.

Noninvasive in vivo assessment of vessel characteristics in capillary vascular malformations exposed to five pulsed dye laser treatments.

BACKGROUND: The treatment of capillary vascular malformations by pulsed dye laser results in fading of these disfiguring lesions in the majority of patients. In only a minority, however, is full clearance of the lesion achieved. It is believed that the capillary composition of a capillary vascular malformation is an important determinant of whether it will respond to further laser treatment. Moreover, by determining the type, size, and depth of the ectatic capillaries within a capillary vascular malformation, it may be possible to target these vessels with specific laser parameters. METHODS: The noninvasive technique of depth measurement videomicroscopy was used to delineate the capillary structure of 22 previously untreated capillary vascular malformations and examine how this structure changes after five treatments with a 0.45-msec pulse duration using a 585-nm pulsed dye laser. RESULTS: After one and five treatments, there was a statistically significant lightening (p < 0.02 and p < 0.001, respectively) of the lesions, as seen on Munsell Color Chart testing. Before any laser treatment, the majority (59 percent) of capillary vascular malformations displayed a superficial type 1 or mixed capillary pattern, whereas after five laser treatments, the majority displayed a deep type 2 pattern (81 percent). After five laser treatments, there was a statistically significant increase in the depth of the remaining capillaries within the lesion compared with normal skin (p < 0.02) and a statistically significant reduction in the vessel diameters (p < 0.001). CONCLUSIONS: The authors found that vessels with a diameter greater than 50 mum were adequately treated, whereas those smaller than 50 microm appeared resistant to laser treatment. These data would suggest that pulse durations longer than 0.45 msec are not required to treat large ectatic capillary vascular malformation vessels. The authors suggest that the failure to treat very-small-diameter vessels is attributable to thermal dissipation from the target vessels, whose thermal relaxation time is much shorter than the pulse duration of the laser used.

The relationship between location, color, and vessel structure within capillary vascular malformations.

The treatment of capillary vascular malformations by laser is well established. Despite this, only a minority of patients obtain full clearance of their lesion after treatment. Both anatomic location and color have been proposed as prognostic factors determining the amount of improvement seen after laser treatment. This study uses the technique of depth measuring video microscopy to examine the hypothesis that smaller and more deeply placed capillaries may be responsible for the poorer response seen in certain anatomic locations. Fifty sites on 44 previously untreated patients were examined resting in a temperature-controlled room at 28 degrees C. No statistically significant correlation was found between color, based on a Munsell color chart recording and capillary depth or diameter. Also, no correlation was found between diameter, depth, or type of capillary ectasia and anatomic site. The authors believe that other factors, such as alteration in blood flow between different anatomic regions, and not vessel morphology alone, may be responsible for this variation in response.

The depth measuring videomicroscope (DMV): a non-invasive tool for the assessment of capillary vascular malformations.

BACKGROUND AND OBJECTIVES: The response of capillary vascular malformations (CVMs) to laser treatment is believed to be due to the pattern of capillary ectasia, the depth, diameter, and flow through these capillaries and the amount of competing chromophores within the skin. Videomicroscopy has successfully been used to determine CVM capillary pattern and diameter of vessels. The depth measuring videomicroscope (DMV) allows the depth of capillaries to be measured also. The aim of this study is to examine how capillary depths within a CVM are affected by dye laser treatment using DMV. STUDY DESIGN/MATERIALS AND METHODS: Thirteen previously untreated patients were examined in a temperature-controlled room. A DMV examination was carried out prior to and 6 weeks following a treatment with pulsed dye laser. A further cohort of 11 resistant CVM patients, who had all received over five treatments, was also examined for comparison. RESULTS: Using a Wilcoxon Signed rank test, the results showed that the remaining vessels within the CVM as measured using DMV were more deeply located and smaller (P < 0.01 and P < 0.02 respectively), following the laser treatment. Also in the resistant patients the vessels were again more deeply placed and smaller. CONCLUSIONS: The hypothesis that smaller and more deeply placed CVM vessels respond poorest to laser treatment is supported by these findings. Moreover, the DMV provides a simple non-invasive technique for demonstrating this.