Non-invasive monitoring of compression therapy: a report of three cases with venous insufficiency.

Sir, Skin oedema is believed to have a negative effect on wound healing and to contribute to skin necrosis and the development of leg ulceration (1, 2). To understand the pathologic signi® cance of oedema, it is important to be able to determine the quantity of ̄ uid content and its localization in the skin. High-frequency ultrasonography visualizes oedema as areas of reduced echogenicity in skin images (3, 4). In the post-thrombotic syndrome and lipodermatosclerosis, the drop in echogenicity is present mainly in the subepidermal region; in lymphoedema, echogenicity decreases in the entire dermis, whereas in cardiac insuf® ciency echogenicity decreases in the lower portion of the dermis (5, 6). Since the upper part of the dermis is a site of intensive metabolism (7), oedema localized in this layer might be particularly deleterious. In this study, we used high-frequency ultrasonography to quantify the reduction of dermal oedema after use of two types of compression bandages in three patients with venous insuf® ciency.