A New Approach to an Old Flap: A Technique to Augment Venous Drainage from the Paramedian Forehead Flap.

The paramedian forehead flap is commonly used in nasal reconstruction, and survival of the distal part of the flap is usually essential for a good cosmetic outcome. Venous congestion leading to tissue necrosis is a recognized complication with this flap. The standard paramedian forehead flap is designed with a number of aims. These are to include the supratrochlear artery, to maximize mobility of the flap pedicle, to maximize the reach of the flap, and to minimize cosmetic implications at the donor site. The supratrochlear artery does not possess sizable venae comitantes; thus, the main pathway for venous drainage of the paramedian forehead flap is through superficial veins. The pattern and location of the superficial veins varies and therefore a standard skin pedicle design cannot be expected to always include sufficient veins to prevent venous congestion and subsequent flap necrosis. This article demonstrates the superficial venous anatomy of the forehead using computed tomographic venography, clinical demonstration, and cadaveric dissection, and describes a technique that can be carried out to augment flap venous drainage by performing careful dissection to identify additional superficial veins at the margins of the flap skin pedicle. One or more veins can then be mobilized and included with the flap pedicle to augment its venous drainage. Use of this technique should lead to a lower incidence of flap necrosis secondary to venous congestion.

Depth data improves skin lesion segmentation.

This paper shows that adding 3D depth information to RGB colour images improves segmentation of pigmented and non-pigmented skin lesion. A region-based active contour segmentation approach using a statistical model based on the level-set framework is presented. We consider what kinds of properties (e.g., colour, depth, texture) are most discriminative. The experiments show that our proposed method integrating chromatic and geometric information produces segmentation results for pigmented lesions close to dermatologists and more consistent and accurate results for non-pigmented lesions.