Bilobed Flap on Nose After Mohs

A bilobed flap is a crucial technique in reconstructive surgery, used after Mohs surgery for nose skin cancer.

A bilobed flap is a specialized surgical technique used in reconstructive surgery, especially for the nose.

It's a random-pattern double transposition flap, which involves moving two adjacent skin patches to fill a defect.

The bilobed flap is versatile and can be used in various anatomical locations, but it is most commonly used for nasal tip defects.

What Is Mohs Surgery?

Mohs surgery is a precise technique used to treat some skin cancers. It effectively removes the cancer while preserving healthy skin and determining its margins.

During Mohs surgery, the surgeon removes thin layers of skin cancer one at a time, examining each layer under a microscope until all cancer cells are gone.

This allows the surgeon to pinpoint and remove only the minimum amount of tissue needed. By fully examining the tissue slices, Mohs surgery helps ensure no cancer cells remain and reduces the chances of recurrence.

How Is a Bilobed Flap Used in Nasal Reconstruction After Mohs Surgery?

The bilobed flap is commonly used in nasal reconstruction after Mohs surgery because it's a simple local flap technique that uses adjacent skin to improve closure outcomes.

The flap allows for more skin movement over a larger distance than a single transposition flap, which is beneficial for less mobile face areas, like the nasal tip.

This technique is often chosen for its ability to repair defects with skin that matches the color and consistency of the nasal area.

What Are the Key Characteristics of a Bilobed Flap?

The key characteristics of a bilobed flap are:

• Versatility: It can be used for various anatomical locations, not just the nose.
• Design: The flap has two lobes; the first fills the primary defect, and the second fills the secondary defect from moving the first.
• Blood Supply: It's a random transposition flap, meaning its blood supply is not from a specific artery segment but from musculocutaneous and cutaneous arteries.
• Geometry: The design can be complex due to the nose contour changes and precise measurements.
• Improvements: Since its original description in 1918, the bilobed flap has undergone modifications to increase its rotation arc and indications, with the Zitelli modification being most commonly used.

Why Is a Bilobed Flap Often Used After Mohs Surgery on the Nose?

The bilobed flap is often used after Mohs surgery on the nose for several reasons:

• Movement of Skin: It allows for a larger distance compared to a single transposition flap, crucial for nasal reconstruction.
• Matching Skin: Enables use of similar color and texture for nasal reconstruction, important for aesthetics.
• Reduced Tissue Distortion: The technique is indicated when adjacent tissue is not mobile enough to close the defect without causing distortion.
• Versatility: The bilobed flap is versatile and can be adapted to the specific needs of the nasal reconstruction following skin cancer removal.

What Is the Design Principle of a Bilobed Flap?

A bilobed flap is a double transposition flap used to cover small to moderate-sized defects, especially on the nose, using two lobes based on a single pedicle.

The design principle involves the 3-2-1 rule, measuring the defect and the flap geometry. The first lobe fills the primary defect, while the second lobe fills the secondary defect created by moving the first lobe.

The bilobed flap is versatile and can be modified to suit the defect and the patient's needs.

How Is a Bilobed Flap Applied During Surgery?

During surgery, the bilobed flap is designed so that the primary lobe is next to the defect and the second lobe fills the secondary defect. The lobes are rotated, usually 90°-100°, to cover the defects with minimal tension. 

The primary lobe is undermined above the perichondrium of the nasal cartilage, and the second lobe is elevated in the plane of the superficial fascia to preserve blood supply. The defects are closed under minimal tension, and the scars are typically inconspicuous.

What Are the Indications for Using a Bilobed Flap in Nasal Reconstruction?

The bilobed flap is used for nasal reconstruction when adjacent tissue can't close a defect without distortion. It's suitable for repairing defects on the nasal dorsum and tip, the lower third of the nose, the helix, and the posterior ear. The choice depends on the patient, defect size, and surgeon's preference.

What Are the Common Complications Associated With Bilobed Flaps?

Common complications of bilobed flaps include pincushioning, alar deformation, swelling, scarring, flap necrosis, infection, and bleeding. To minimize pincushioning, thin the flap and remove excess subcutaneous tissue. Wide undermining reduces tension and the pincushion effect.

How Have Bilobed Flap Designs Been Modified Over Time?

Since 1918, the bilobed flap has been modified to improve its design, increase rotation arc, and expand its indications.

The Zitelli modification is one of the most commonly used designs, with changes in size, form, angles, and length-to-width ratios to improve cosmetic results and reduce distal compromise risk.

Superiorly-based bilobed flaps have been developed to move the terminal donor site of the nose and decrease the risk of lower nasal distortion. Bilobed islanded flaps have been designed to increase rotation up to 180° and address dog ears without compromising blood supply.

How Does a Bilobed Flap Compare To Other Types of Flaps Used in Nasal Reconstruction?

The bilobed flap is favored in nasal reconstruction over other flaps due to its ability to distribute wound closure tension over a larger surface area using two lobes. 

This is beneficial for repairing defects in the less elastic caudal portion of the nose. Compared to single transposition flaps like the rhomboid flap, the bilobed flap allows for the movement of more skin over a greater distance, advantageous for nasal tip defects. It also provides a better color and texture match using nearby skin.

What Are the Advantages of a Bilobed Flap Over Other Types of Flaps?

The bilobed flap is ideal for defects up to 1.5 cm, especially in the central or lateral nasal tip, and is better than skin grafts for deeper defects. 

Its design also minimizes the risk of lower nasal distortion. It's versatile and can be used in various anatomical locations, not just the nose.

How Does the Zitelli Modification of the Bilobed Flap Differ From the Original Design?

The Zitelli modification of the bilobed flap, now the most commonly used variant, limits the pivotal arc to 90° to 110°, with an approximately 45° arc between each lobe, reducing cutaneous deformity. 

The original design by Esser used a 180-degree rotational arc, but Zitelli's 1989 methodization refined the technique for better outcomes.

How Does the Use of a Bilobed Flap Compare To Other Methods of Nasal Reconstruction After Mohs Surgery?

After Mohs surgery, a bilobed flap is often used for nasal reconstruction due to its effective tension distribution and ability to match the original area's color and texture. It is useful for defects needing depth, which skin grafts can't achieve. 

The flap's design principles, like the 3-2-1 rule, allow precise geometric planning to cover the defect with minimal distortion. It's versatile, applicable to other areas, and associated with a low complication rate.

How Does the Size and Location of the Nasal Defect Influence the Effectiveness of a Bilobed Flap?

The size and location of the nasal defect are critical in determining the effectiveness of a bilobed flap, which is most practical for defects less than 1.5 cm in diameter. 

Studies show successful use for intermediate or larger defects, suggesting flexibility. It's particularly suitable for repairing nasal dorsum and tip defects and is employed more frequently than trilobed flaps. 

The flap's design allows for skin movement over a longer distance, useful when adjacent tissue can't close the defect without distortion.

How Does the Patient’s Skin Characteristics Impact the Success of a Bilobed Flap?

The patient's skin characteristics, such as thickness, elasticity, and sebaceous glands, can impact the success of a bilobed flap. 

For example, the thick, dense, and sebaceous gland-rich skin of the distal nose is similar to the nasolabial region, making it suitable for flap design and ensuring better texture matching. 

The choice of flap design, such as the modified bilobed flap, can provide satisfying outcomes with lower morbidity and inconspicuous scarring, influenced by the donor site's skin characteristics.

How Does the Use of a Bilobed Flap Influence the Need for Revision Surgery?

Using a bilobed flap can minimize the need for revision surgery when executed properly. A retrospective study indicated that thinning a bilobed flap by removing excess subcutaneous tissue could reduce poor aesthetic results, revision surgery, and pincushioning in nasal reconstruction. 

The modified Zitelli bilobed flap has been associated with good aesthetic results and preserved function, with no reported infections or major complications, which may reduce the need for further surgical intervention.

In What Practical Scenarios Is a Bilobed Flap Most Commonly Used?

Bilobed flaps are commonly used to repair defects on the nose, dorsum and tip, and temporal forehead. 

They are the first choice for closing various defects, even in areas with low skin compliance. The flap is versatile and widely used in plastic surgery for oncologic reconstructions, with a high success rate in the cephalic segment.

How Is the Decision Made To Use a Bilobed Flap in a Specific Case?

The decision to use a bilobed flap in a specific case is based on factors including defect size and location, tissue mobility, and patient's skin. The flap is indicated when adjacent tissue mobility is insufficient to close the defect without distortion. 

The surgeon considers potential complications and the patient's outcomes. The bilobed flap's versatility, reliability, and ability to provide good functional and aesthetic results make it a preferred choice. 

Modified designs, like the Zitelli modification, improve cosmetic results and are selected based on defect requirements and desired outcomes.