Delay Techniques for Local Flaps in Dermatologic Surgery
September 2012 | Volume 11 | Issue 9 | Original Article | 1108 | Copyright © September 2012
AbstractLocal flaps may be required to reconstruct defects on the face, neck, and scalp. Occasionally, delay techniques are indicated to reduce the risk for flap ischemia and subsequent necrosis. Delay may be employed before the flap is raised, as done to improve blood supply to a random flap when length to breadth proportions are not ideal, or after the flap is raised and before separation of the pedicle in the final reconstructive step to improve vascularity in the distal end of an interpolation flap. We present our techniques and results of delay procedures for interpolation and similar flaps.
J Drugs Dermatol. 2012;11(9):1108-1110.
Flap viability depends on adequate blood flow in relation to the tissue-specific metabolic demands. Severed nutrient blood vessels and surgical denervation result in immediate reduction in perfusion pressure and spillage of vasoconstricting catecholamines, which leads to acute peripheral ischemia. The flap then undergoes a process of hemodynamic, anatomic, and metabolic changes until blood flow is completely reestablished after about 4 weeks.1-8 If arterial inflow is inadequate flap failure will ensue, leaving the distal flap tissues particularly vulnerable as ischemia physiologically triggers compensatory vasodilation.4-5,9
In interpolation flaps the distal end is advanced over a bridge of normal tissue to be sutured to the distal border of a defect, leaving the base of the flap (vascular pedicle) attached as the only source of blood inflow. After a delay period of a few weeks to allow the sutured distal end to re-vascularize, the base of the flap is cut and advanced to cover the remaining portion of the defect. Practically, this step transforms the (previously) proximal end of the flap into a "neo-distal" end, which now relies on blood flow in a reverse direction—from the previously delayed, sutured end. This places the newly separated portion of the flap in increased jeopardy for necrosis because it is dependent on how successful the initial delay was. Thus, if the distal end, now the primary source of blood supply to the flap, does not generate adequate perfusion in the proximal portion of the flap, separation of that end as part of the final reconstructive step will result in ischemia and necrosis (Figure 1). To improve flap survival in such and similar circumstances an additional delay procedure may be sought. We present our delay techniques for preconditioning of interpolation and hinge flaps.
From 2002 to 2012, forty-six patients (average age of 61.7 years, range of 8 to 84 years) underwent reconstruction of facial defects with an interpolation flap. Twenty patients (43%) were reconstructed with an interpolation postauricular "page" flap and 26 (57%) with a forehead flap. All flaps were delayed by intermittent pressure techniques described hereafter or surgically. There was no partial or complete flap necrosis in any of the flaps and all patients were satisfied with their final aesthetic result.