The nasolabial flap is a hardy flap that finds its use in the everyday reconstruction of various defects in the head and neck. The flap may be superiorly or inferiorly based. The choice between the two will depend on the location of the defect and the arc of rotation needed to reach it with the least amount of tension.
The use of the nasolabial flap varies. In broad terms, it is commonly used as a superiorly based flap to reconstruct nasal defects and oral defects located in the upper sulcus or palate. When it is raised as an inferiorly based flap, it is used most commonly to address lower lip defects or intraoral defects such as floor of mouth, lower gingival sulcus, and buccal mucosa defects.1 The nasolabial flap has found a unique role as one of the go-to flaps in the reconstruction of buccal defects such as those encountered after the excision of scar bands and or fibrosis secondary to betel nut chewing.2 Prior to the establishment of microvascular transfer as a routine option in the reconstruction of head and neck defects, the nasolabial flap was very popular for the repair of floor of mouth defects created after excision of squamous cell carcinomas.
The main advantages of using the nasolabial flap for reconstruction of external skin defects are the color and texture match to the defect site.3 Because of the proximity of the donor site to the defect site, the use of this flap allows for a near imperceptible reconstruction for these two factors.
The main disadvantage of the nasolabial flap is the scar at the donor site. The location of the scar renders its use less than favorable to many patients. In some cases, when the flap is utilized in younger patients and only on one side, there is a potential for postoperative facial asymmetry. Lastly, in cases where the flap is needed for the reconstruction of floor of mouth defects, the remaining dentition needs to be evaluated to see if it will traumatize the flap when the patient is chewing and the reconstruction is carried out in stages.
The regional anatomy relevant to the nasolabial flap extends from about 5 mm inferior to the medial canthus and extends inferiorly towards the inferior border of the mandible.
The bulk of tissue available for use in a nasolabial flap is found along the area of the nasolabial fold as it extends lateral to the ala of the nose to a few millimeters below the lateral aspect of the oral commissure. The common design of the nasolabial flap would include the tissues in the nasolabial fold and lateral to it and as it extends inferiorly, it would include a small quantity of tissue just medial to the fold but with a greater quantity on the lateral aspect.
The vascular anatomy of the periorbital and perinasal region comes mainly from the facial artery, angular artery, and the nasal arteries.
The facial artery travels in a superior oblique direction once it emerges above the mandible. Along its path it gives off a number of branches, those being the inferior and superior labial arteries, and the lateral nasal artery before it becomes confluent with the angular artery.4
The angular artery is a branch of the ophthalmic artery that joins the facial artery as it descends inferiorly along the superior lateral aspect of the nose.
In the superior aspect of the nose, the ophthalmic artery also gives off the dorsal nasal artery.
All of these arteries give off perforators to the skin, which are responsible for the perfusion to the nasolabial flap. The main perfusion to the flap comes from the perpendicular vessels originating from the facial artery and angular artery.
The venous supply to the flap is based on the accompanying veins.
The nasolabial flap may be raised as an axial flap, a random flap, or as an island flap.5 An inferiorly based nasolabial flap has been raised in patients where the ipsilateral facial artery has been ligated either at the time of surgery or in a previous surgical encounter5.
- Once the decision has been made to raise a superiorly based flap, the next decision is to determine its width and length, and therefore the reach of the flap.
- The flap should be designed so that the inferior tip of the flap narrows down to a point. This design will allow for the closure of the donor site with the least amount of undermining and excision of dog ear. Equally, the flap design should place the final scar within the nasolabial groove. The placement of the scar within this region will give the least conspicuous evidence of the surgery.
- The flap is elevated from the distal tip towards the base by first making an incision deep to the dermis along the marked width of the flap.
- The flap is elevated in a plane superficial to the muscles.
- Care should be taken to identify and avoid injury to the perpendicular branches of the facial artery as they penetrate the muscle on their way to perfuse the overlying skin.
- The surrounding area is undermined to improve the rotation of the flap without causing distortion of the tissues around the base of the flap.
- In cases where the flap is to be used along the nasal sidewalls, the flap is rotated to insure the reach is adequate and without tension.
- The flap is contoured to the defect and inset by placing one to two deep sutures along the base to recreate the groove and the rest of the flap is inset in the usual fashion as per the surgeon’s routine.
- The inferiorly based flap is designed with the superior medial border of the flap running in the nasolabial fold and widening to incorporate the desired width of the flap laterally along the cheek.
- In the inferior region of the flap, around the upper lip and towards the commissure, the medial incision should extend about 4 mm medial to the crease.
- The inferior width of the flap should be about 1.5 cm in order to capture enough of the perforating vessels and to allow for adequate perfusion to the distal tip of the flap.
- The incision is made superiorly/>