INTRODUCTION
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.
METHODS
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.
