Repair of Lip Defects With Karapandzic Flaps

Simon G. Talbot

Julian J. Pribaz

DEFINITION

Defects of the lips may occur from malignancy (most frequently squamous cell carcinoma followed by basal cell carcinoma), trauma, vascular malformations, or infections.
A Karapandzic flap is either a single/unilateral or a paired/bilateral innervated musculocutaneous rotation flap used to reconstruct subtotal lower lip defects.
A reverse Karapandzic flap can be used to reconstruct an upper lip defect. Combined upper and lower lip defects have been reconstructed with simultaneous upper and lower flaps.
Midline defects are preferred for this method of reconstruction; lateral or commissure defects may result in significant asymmetry.

ANATOMY

The unique anatomy of the lips make the use of adjacent “like” lip tissue ideal for reconstruction.
The lips include multiple layers of tissue: skin/subcutis, muscle, submucosa, and mucosa.
Karapandzic flaps maintain continuity and innervation of the orbicularis oris muscle. This is an advantage over flaps that replace a lip defect with cheek tissue excluding the orbicularis.
The vermilion forms a wide boundary between the skin and mucosa. Meticulous repair of the white roll (the external border of the vermilion and skin) is critical as defects in this border are easily noticed.
The original description of the Karapandzic flap references the robust labial artery circulation.¹
In the very old, irradiated, or those requiring bilateral flaps, the labial artery alone may be insufficient, hence the benefit of keeping an intact mucosa for additional vascularity when designing Karapandzic flaps.
The modiolus can be thought of as a circle, and a defect in this circle may be closed by rotating the remaining edges around the circumference to close the defect.
Reapproximation of the orbicularis oris and preservation of the buccinator along with maintenance of nerves allows for early intrinsic muscle function (FIG 1).
- Some authors recommend the use of a nerve stimulator to help protect native innervation.²

PATIENT HISTORY AND PHYSICAL FINDINGS

FIG 1 • Facial nerve anatomy and distribution of perioral facial nerve branches to be preserved in Karapandzic flap.

IMAGING

Imaging may be required for oncologic reasons but is not routinely required for flap planning.

SURGICAL MANAGEMENT

Preoperative Planning

Markings include a skin incision parallel to the lip margin; the vertical dimension of the flap is determined by the vertical dimension of the lip defect (FIG 2).
The flaps are extended laterally and vertically. Where possible, incisions are hidden in the melolabial folds and/or mental crease.