The non-invasive assessment of vascular anomalies

• Main Author: Sivarajan, Vivek
• Published: University of Edinburgh 2007
• Subjects: 616.5
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.662004

Capillary Vascular Malformations (CMs) or Port Wine Stains are a congenital abnormality of the dermal vasculature that results in the skin having a pink to purple colouration. This thesis examines the development of the videomicroscopy as a non-invasive tool to examine the vessel structure of CMs in vivo. A number of studies have been undertaken including: 1. the use of colour filtering as an adjunct to videomicroscopy; 2. the development and validation through a biopsy study of a Depth Measuring Videomicroscope (DMV); 3. the description of vessel change following a single laser treatment using DMV; 4. the relationship between location and colour of a CM and vessel structure; 5. the effect of prolonged laser treatment on vessel structure; and 6. the effect of using new generation Pulsed dye lasers on CM vessel structure and their efficacy. Colour filtering appears to reduce the artefact from the reflection of light from the skin surface. The development of the Depth Measuring Videomicroscope (DMV), however, reduces this reflection and colour filtering is not required. The DMV can be used to measure the diameter and depth of Capillary Vascular Malformations (CM) in vivo and this has been validated against biopsy measurements using a Bland and Altman Test. Following laser treatment the larger and more superficial capillaries are successfully treated leaving the deeper (p<0.02) and smaller vessels (p<0.001).This occurs both after a single laser treatment and prolonged treatment. To improve the treatment of CMs resistance to standard pulsed dye laser treatment the capillary characteristics of resistant CMs were studied prior to treatment were newer generation pulsed dye lasers. Although, the optimum treatment parameters for a particular malformation could not be predicted from this study, 595nm wavelength, 1.5 ms pulse duration and 14 j/sqcm fluence appeared to be the most successful settings.