Authors: Liv Schöllhammer, MD, Frederik Gulmark Hansen, med.stud. and Magnus Balslev Avnstorp, MD
In this chapter you will learn about the different types of advancement flaps, from the standard advancement flap to V-Y, Y-V, H, T and L-flaps.
Advancement flaps are flaps that are unidirectionally moved or advanced into a defect.
- Linear configuration
- Usually based on a random-pattern blood supply
- Must be located adjacent to the primary defect (local flap)
- One border of the defect must become the most distal and leading border of the flap. As a result the greatest wound closure tension is at this site
- Primary tissue movement: Advancement and stretching of the flap into the primary defect
- Secondary tissue movement: Movement of the skin peripheral to the primary defect being pulled toward the flap upon closure
- Often results in long, straight scars. Works best in anatomical sites where this is aesthetically viable, for example the forehead, lip and helical rim
- Works best in an area with high skin laxity
- Location next to a free margin (eyes, lips exc.) must be done very cautiously as to avoid any risk of feature distortion such as ectropion, lib eclabion
An advancement flap is a very versatile flap and can be designed in numerous ways. Described below are unipedicular, V-Y, Y-V and helical rim flaps.
Unilateral unipedicular advancement flap
- The width of the flap is determined by the width of the primary defect (A).
- The length of the flap should be 1,5-3 times the width (B).
- Undermining the entirety of the of the flap is necessary. Keep the subdermal plexus intact for sufficient blood supply.
- Undermining the tissue peripheral to the flap is recommended for better secondary tissue movement.
- A skin excision (Burows triangle) is often required in the peripheral tissue to eliminate a standing cutaneous deformity (C). Can be placed anywhere along the border of the flap but an excision of Burow triangles at the base of the flap is the most common choice
(Bilateral unipedicular advancement flap)
When skin laxity is lacking or the possible length of an unilateral flap is limited, a combination of bilateral advancement flaps, advancing from opposing sides can be used.
The principle for designing the flap are the same as described above for the unilateral advancement flap.
Two flap designs will be shown here. The H-plasty (Fig 4) and the T-plasty (Fig 5).
- The horizontal leg of the flap (A) should extend the width of the defect in each direction
- The vertical height of the flap (B) should equal twice the height of the primary defect
Island pedicle flap, V shaped. When drawn into the primary defect, closing of the secondary defect results in a Y shaped scar.
- Incised down to the subcutaneous tissue on all sides
- Blood supply to the flap comes from the underlying tissue in the center pedicle of the flap
- Undermining of the sides of the flap must be done very cautiously to leave enough capillaries to supply the entirety of the flap. At least one-third of the total flap area should remain untouched
- Undermine the peripheral tissue to maximize secondary tissue movement
- Work particularly well when placed along the nasolabial fold or the upper lip
- Can be design unilateral or bilateral
A primary Y shaped defect is excised and the resulting V shaped flap at the apex of the excision is advanced down into the defect.
- The peripheral tissue surrounding the flap is pushed outward in the secondary tissue movement, opposite other advancement flaps
- Works well in correction of scars with a need for release of tightness when tissue excess or good skin laxity exist in the opposing direction of the tightness
Helical Rim flap
The flap also known as the Antia-Buck flap is an advancement of the helical rim.
- Incision is made through skin and cartilage from the caudale border of the primary defect following the edge of the rim to the lobule
- A Burow triangle can be excised in the lobule to smoothen any standing cutaneous deformity if necessary
- Can cover a helical rim defect up to 2 cm
- Can also be designed bilaterally with an additional excision from the superior edge of the primary defect to the crus of the helix
Illustrations: Christian Kaare Paaskesen, med.stud