Principles of Keystone Reconstruction

The principles of outlining the Keystone (Behan et al., ANZ J Surg 64(3):155–166, 1994; Behan, ANZ J Surg 78:116–117, 2008; Behan et al., J Plast Reconstr Aesthet Surg 62:427–562, 2008; Behan et al., J Plast Reconstr Aesthet Surg 62:551–553, 2009; Behan et al., J Plast Reconstr Aesthet Surg 63:739–745, 2010; Behan et al., ANZ J Surg 81:574–575, 2011; Behan et al., ANZ J Surg 81:650–652, 2011; Behan et al., The keystone perforator island flap concept. Elsevier Textbook Churchill Livingstone, Sydney, 2012; Behan et al., ANZ J Surg 82:381–382, 2012; Behan et al., ANZ J Surg 83:942–947, 2013; Behan, Surgical tips and skills illustrating the keystone principle. Elsevier, Sydney, 2014; Behan and Sizeland, World J Surg Surg Res 2021;4(1):1293; Behan, Austr J Plast Surg 4(2):105–107, 2021; Behan, Atlas of keystone reconstructive technique in the management of melanoma. Springer, Cham, 2024) design must sit within the dermatomal precinct, it must not be undermined, it must be fascial lined and any neurovascular structures (i.e. venous tributaries and cutaneous nerves) are all defined and preserved without any surgical division. Even venous tributaries can be repaired to preserve the venous drainage system because as McGregor from Canniesburn quoted years ago, more flaps die from venous stasis than arterial insufficiency. The closure of the defects under tension defies plastic surgical traditions but the hyperaemia, hypothetically a sympathectomy effect, allows one to close these island flaps under tension, compressing the surrounding muscular bellies which seem to facilitate this manoeuvre because of the hypervascularity, thus established based on the suprafascial and infrafascial circulation (Rodriguez-Unda et al., Clin Plast Surg 47(4):635–648, 2020). Hyperaemia is a contributing factor to this facial repair/healing which has important aesthetic applications. Yes, sensory recovery occurs in 6 weeks along the incision lines, with the resolution of oedema and swelling, again presumably a sympathectomy effect simply an observational finding as it occurs in all such Keystone designs.