Laser Doppler perfusion imaging of the normal and diseased vulva

Vulval lichen sclerosus (LS) and high-grade intraepithelial neoplasia (VIN 3) are two common and distressing diseases. Significant morbidity is caused by symptoms of persistent pruritus and surgical treatment of skin areas suspicious of malignancy. The risk of developing cancer in a background of LS...

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Bibliographic Details
Main Author: Saravanamuthu, J.
Published: University College London (University of London) 2007
Subjects:
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.644413
Description
Summary:Vulval lichen sclerosus (LS) and high-grade intraepithelial neoplasia (VIN 3) are two common and distressing diseases. Significant morbidity is caused by symptoms of persistent pruritus and surgical treatment of skin areas suspicious of malignancy. The risk of developing cancer in a background of LS and VIN 3 is poorly defined. The methods currently available for clinical assessment of the vulva are limited. There is abundant research on the application of the LASER Doppler technique - laser Doppler Flowmetry (LDF) - showing changes in perfusion within the small blood vessels of the skin as a useful parameter for more accurate disease classification. There is also research on immunohistochemical microvessel density (MVD) studies showing increases in blood supply in tissues prone to develop cancer or as a prognostic marker of cancer outcome. The Laser Doppler perfusion imager (LDPI) provides a rapid, real time, non-invasive and non-contact method to measure skin blood flow in an area as opposed to a single point by the LDF, making the LDPI more suitable for application to the vulva. This thesis reports for the first time, the application of the LDPI to the vulva. Initially the LDPI was applied to the clinically normal vulva to study perfusion variance related to menstrual cycle, age and local skin temperature provocation. The application was then extended to vulval disease, LS and VIN 3, and validated against morphological differences in MVD. The LDPI and MVD studies suggest that in VIN 3 there is an actual increase in skin perfusion. In LS the situation is more complex and suggests that the LDPI measured perfusion at a greater depth than the MVD. Studies on base line perfusion variance of vulval LS to topical therapy show that there is no overall difference in baseline perfusion in spite of symptom improvement. Temperature provocation studies suggest differences in skin blood flow response in diseased compared to the normal vulva.