Authors: Liv Schöllhammer, MD, Frederik Gulmark Hansen, med.stud. and Magnus Balslev Avnstorp, MD
- A series of two transposition flaps, sharing a single base, rotated into a primary defect
- Allows for movement of skin laxity over greater distance than a single transposition flap
- Often used in nasal reconstruction
- The first lobe is located directly adjacent to the primary defect and must equal in size to the defect
- The secondary defect after the second lobe is closed by direct suturing
- The angles of the flap design may vary. The greater angles between flaps = greater distance = larger standing cutaneous defects
Bilobe flap in nasal reconstruction
- Best used to cover defect on the central or lateral nasal tip of up to 1,5cm in size
- Optimal blood supply when based laterally
- The skin quality of the nasal tip requires a precisely designed flap as skin laxity is sparse. See fig 3
Step 1: Measuring
The radius of the defect is measured
Step 2: Marking of base
A point at the base of the lobe is marked at the distance equal to 1 x radius
Step 3: Drawing of first arch
An arc is drawn from this point equal to 2 x radius. This arc marks the center of the lobes.
Step 4: Drawing of second arch
A second arc is drawn from the same point equal to 3xradius. This arc marks the height of the second lobe
Step 5: Drawing of first lobe
The first lobe is drawn (1). Width equals width of primary defect. Angle at base point should be approximately 45° from center of primary defect to center of first lobe.
Step 7: Drawing of second lobe
Second lobe is drawn (2). Height of second lobe is twice the height of first lobe. The width is the same or slightly smaller than first lobe.
Step 8: Flap elevation and undermining
The flap is elevated in the plane between the nasal muscle fibers and perichondrium/periosteum. The entire flap and adjacent skin is undermined.
Step 9: Excision and closure
Standing cutaneous defect is excised and second lobe is trimmed to fit defect.
Illustrations: Christian Kaare Paaskesen, med.stud