Nasal Reconstruction With Banner Flaps, Bilobed Flaps, and Nasolabial Flaps
Michael V. Chiodo
Pierre Saadeh
DEFINITION
Banner and bilobed flaps are local rotation and transposition flaps that provide well-matched color and textured skin for small (0.7-1.2 and 0.5-1.5 cm, respectively) nasal cutaneous defects.
When compared with banner or single transposition flaps, bilobed or “double transposition” flaps can move tissue over a longer distance from the mobile soft tissue of the upper nose to the nasal tip.
Although full-thickness skin grafts may aid in reconstructing small defects of the upper two-thirds of the nose, they are often too thin to mimic the native contours of the nasal tip.
The nasolabial crease is one of the most important boundaries in facial aesthetics. It is the delineation between the cheek and the lips and the cheek and the nose.
Because of its proximity to the nose and lips, flaps from this region have a critical role in nasal and cutaneous lip reconstruction.
Nasolabial flaps are cheek flaps harvested from the strip of prominent cheek fat just lateral to the nasolabial crease referred to as the nasolabial fold.
These flaps are most useful for small to medium-sized full-thickness skin defects of the nasal alae, caudal nasal sidewall, and upper cutaneous lip.
They take advantage of the redundant nature of the skin of the nasolabial fold and its reliable underlying blood supply to achieve transfer of sizeable flaps and ability for primary closure of donor defects with favorable scar placement along aesthetic unit borders.
Nasolabial flaps are largely classified as transposition, advancement, or interpolated flaps. By definition, the base of an interpolated flap is not continuous with the defect of question, so the pedicle must cross over or under intervening tissue. Therefore, interpolated nasolabial flaps ultimately require division and inset of the flap’s pedicle in a secondstage procedure, whereas transposition and advancement flaps can be done as single-stage operations.
ANATOMY
The nose can be divided into nine aesthetic subunits with three paired units (alar base, alar wall, dorsal sidewall) and three central subunits (tip, columella, and dorsum) (FIG 1A).
These units are separated by nasal contour lines between areas of different skin texture and thickness.
Additionally, the nose can be broken into thirds based on skeletal support: proximal third is supported by the nasal bones, middle third by the upper lateral cartilages, and distal third by lower lateral cartilages (FIG 1B).
The nose should be thought of as a trilaminate structure with external skin and muscle (nasalis) supported by a skeleton of cartilage and bone and an internal lining.
Banner and bilobed flaps are random pattern cutaneous flaps dependent on the subdermal plexus for blood supply.
The nasalis muscle, which is often included in these flaps, consists of transverse and alar parts that overlie the nasal sidewalls with an aponeurosis extending across the nasal dorsum.
The anatomic basis for the nasolabial crease is controversial. There are two prevailing theories: a muscular theory and a fascial theory.
Supporters of the muscular theory discuss a “fold muscle,” which originates from the upper lip elevators and progresses through the nasolabial fold and crease on its way to the upper lip vermillion.
Proponents of the fascial theory suggest the nasolabial crease is not created by muscular insertion, but rather developed by the fascial insertion of the end portion of the superficial musculoaponeurotic system (SMAS) into the skin at the junction between the upper and lower cutaneous lips and the cheek.
There is an abundance of subcutaneous fat directly lateral to the nasolabial crease, referred to as the nasolabial fold. The skin of the cheek in this area is loosely adherent to the deeper fascia, allowing for excellent mobility.1,2
The arterial supply to this region of the cheek is provided by facial and angular artery perforating vessels.
Venous drainage parallels the arterial system.
The blood supply of this region is robust to support both superiorly and inferiorly based flaps.
PATIENT HISTORY AND PHYSICAL FINDINGS
Given its prominence, the nose is the facial structure most susceptible to trauma as well as photodamage, which can lead to cutaneous malignancies, making it a common site for reconstruction.
The size, depth, composition (skin, skeletal support, internal lining), and location of the defect or anticipated defect must be evaluated in addition to the surrounding skin quality, tone, and texture.
FIG 1 • A. Aesthetic subunits of the nose. B. “Thirds” of the nose.
Defects caused by tumor extirpation are often the result of Mohs micrographic surgery; once margins are confirmed negative by frozen section (same day), reconstruction can proceed.
Prior nasal operations, scars, and the effect of radiation therapy must also be taken into account when applicable.
SURGICAL MANAGEMENT
Preoperative Planning
In the senior author’s practice, nasal banner and bilobed flaps and nasolabial flaps are most commonly performed under local anesthesia. Patient preference should be considered regarding the method of anesthesia.
Assess the mobility and laxity of the skin surrounding the defect. Cranial nasal skin is thinner and more mobile than the caudal skin and must be considered when planning flap choice and orientation.
With proper flap planning of nasolabial flaps, scars will recreate the nasolabial crease.
The alar facial sulcus is a crucial facial aesthetic boundary representing the convexity between the nose, cheek, and upper lip.
Preservation of this boundary is of critical importance in flap design and should be a primary focus during initial nasolabial flap planning.
Secondary revision of this region should be avoided as recreation of this convexity is challenging.1
Positioning
The patient is positioned supine on the operative table with their head turned to the contralateral side from the defect. Some reverse Trendelenburg with the neck in slight extension can be useful to decrease venous bleeding.
The entire midface, at minimum, is prepped into the field to assess symmetry intraoperatively.
Approach
Banner and bilobed flaps
The choice between banner and bilobed flaps is mainly dependent on defect size and location.
Smaller defects of the upper nasal sidewall and dorsum (0.5-1.0 cm diameter) are typically more amenable to banner flap closure. Donor-site scars are minimal, and medial canthus distortion is avoided. Banner flaps for nasal tip reconstruction often result in mismatched skin thickness resulting in unnatural topography. Larger banner flaps involve wider dissections and undermining, resulting in nasal distortion and significant standing cutaneous deformity at the pivot point.
Although bilobed flaps require a more extensive scar pattern, the geometrically precise design recruits mobile skin from the mid-dorsum and sidewall to enable greater flap rotation. Better skin thickness match with less nasal contour distortion and standing cutaneous deformity is achieved at the pivot point. They are more useful for larger defects (1.0-1.5 cm diameter), particularly on the central or lateral nasal tip, ala, and caudal sidewall. Defects on the upper half of the nose are typically not suited for bilobed reconstruction due to medial canthus distortion.
Banner and bilobed flaps include skin, subcutaneous fat, and nasalis muscle elevated in the areolar tissue plane directly over the perichondrium (if flap is raised laterally over cartilage) or periosteum (if raised over the nasal bones). Including the nasalis makes both banner and bilobed flaps myocutaneous, adding reliable vascularity.
Cutaneous nasal defects larger than 1.5 to 2 cm are best reconstructed with other modalities (forehead flap, dorsonasal flap, or nasolabial flap) as larger banner or bilobed flaps often leave scars that violate multiple aesthetic subunits and can result in nasal contour distortion.
Nasolabial flaps
Depending on the size and location of the defect, decisions must be made regarding plane of flap elevation (cutaneous, subcutaneous, or fascial) and need for cartilaginous support for the nasal alae.1
These flaps can be elevated as peninsular flaps in the cutaneous plane or island flaps when elevated in the subcutaneous plane.
We prefer elevation in the subcutaneous or fascial planes, taking advantage of the rich network of perforating vessels from the facial and angular artery in this area.
TECHNIQUES
▪ Banner Flap
The defect is outlined, with additional areas of excision determined in order to place scars along the borders of aesthetic subunits.
Most often, the inferior border of the anticipated banner flap is marked tangential to the superior border of the defect and oriented in a horizontal fashion across the dorsum of the nose.
The distance between a and c determines flap base width and can be designed 1 to 2 mm smaller than the diameter of the defect (TECH FIG 1).
Point b represents the tip of the flap, and when possible, this landmark is placed along a subunit border to help hide the donor-site scar.
The length of raised tissue (ab) is longer than the defect size, making the flap a long and thin triangle, facilitating easy and primary closure of the donor site.Related posts:
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