The lip is comprised of skin, fat, muscle, minor salivary glands, and mucosa. It begins superiorly beneath the nasal sill and passes inferiorly to the chin. The lateral borders are the nasolabial folds and marionette lines. The vermilion is the red part of the lip and has wet and dry components based on the presence or absence of surface keratinization. The red line is the junction between the wet and dry vermilion. The philtral column forms part of the upper central area where the superficial muscle inserts into the dermis. The philtral columns frame the central philtral dimple. Cupid’s bow lies at the base of the philtral dimple between the two philtral columns. The white roll marks the interface between the skin and vermilion (Fig. 44.1). The orbicularis oris forms the muscular component of the lips and has both deep and superficial components. The superficial component is involved with speech and facial expression, whereas the deep portion is involved with oral competence. The oral commissure is the point where the upper and lower lips join. Lateral to this is the modiolus, where muscle fibers from other mimetic muscles attach, such as the depressor anguli oris, levator anguli oris, risorius, and zygomaticus major.1,2 Fig. 44.1 The anatomy of the lip. Philtral dimple Philtral columns White roll Cupid’s bow Tubercle Commissure Vermilion
2. Williams PL, Warwick R, eds. Gray’s Anatomy, 36th British ed. Philadelphia: WB Saunders; 1980 The upper and lower lips differ in their vascular supply, sensory nerve supply, and their lymphatic drainage. However, orbicularis oris is innervated by the buccal branches of the facial nerve irrespective of whether the upper or lower lip is considered. The sensory innervation to the upper lip is from the second part of the trigeminal nerve (CN V2) and the lower lip from the third part (CN V3). The upper lip receives its main blood supply from the superior labial artery and the lower lip from the inferior labial artery. Each of these is a branch of the facial artery. The lower lip lymphatics drain to either the ipsilateral submandibular region (lateral part of the lip) or the submental and submandibular nodes (medial part of the lip). Drainage can be to either side so tumor spread can involve bilateral neck disease. In contrast, the upper lip primarily drains to the ipsilateral submandibular nodes and tends not to cross the midline. Drainage occasionally passes to the preauricular or parotid nodes. Although the upper lip has three subunits (right, left, and philtral dimple), the lower lip is a single unit. This is relevant to lip surgery because it can increase the technical difficulty of upper lip reconstruction.1,2
Malalignments of the white roll as small as 1 mm can be visualized at conversational distances. This highlights the importance of accurate lip repair after trauma or tumor resection. A good technical tip is to mark the white roll with ink before local anesthetic infiltration to ensure accurate alignment during reconstruction or repair. Clear contemporaneous documentation before and after lip repair surgery is really important to set patient expectations at a realistic level, whether having lip repair following tumor resection or trauma.1
Smaller vermilion defects may be reconstructed using axial myovermilion advancement flaps, V-Y advancement flaps, or a two-stage (not single-stage) lip switch procedure. Defects that are larger than 50% require either a tongue flap or advancement of the buccal mucosa. Aesthetic outcomes after a tongue flap are suboptimal compared with those of vermilion or oral mucosa flaps. The blood supply to an axial myovermilion flap is the labial artery; therefore, these flaps are elevated with the muscle deep to the arterial supply.1–3
Perialar crescenteric flaps are useful for reconstructing a range of defect sizes, particularly when combined with other procedures such as Abbe or Bernard-Burow flaps (Fig. 44.2).1 Although lower lip defects of less than a third are closed directly, the same is not true for upper lip defects because their reconstruction depends on the anatomic site. For example, lateral defects of the upper lip may be closed directly, but central defects may require perialar crescenteric excision, an Abbe flap, or both. Similarly, reconstruction of upper or lower lip defects that are larger than a half depends on the location of the defect. Some will require a two-stage procedure using an Abbe flap, but others can be reconstructed with single-stage techniques such as Estlander or Karapandzic flaps. The first choice for reconstruction of a commissure defect that involves the lower lip is usually an Estlander flap (not a V-Y flap). Local flaps can be used in combination to reconstruct defects that are larger than two-thirds of either lip. Free flaps are usually required in total lip reconstruction after radiation therapy or failed local flap reconstruction. However, free tissue transfer for lip reconstruction tends to give suboptimal functional and aesthetic results.
Abbé1 first described this flap for lip reconstruction in patients with double-hairlip deformities in 1898. It is particularly well suited for use in central defects of the upper lip. An Abbe flap is full thickness but not sensate and is not used for commissure defects. This flap is usually designed to be half the width of the original defect. It requires a two-stage process that requires division of the pedicle at 2–3 weeks. The flap receives its blood supply from the ipsilateral labial artery, which is within the orbicularis oris just deep to the white roll. To ensure safe preservation of the blood supply, a cuff of muscle should be maintained around the artery (see Fig. 44.2). Fig. 44.2 The Abbe flap for upper lip reconstruction. The flap is designed to be smaller than the defect which it is reconstructing. The vascularity is maintained by elevating the flap full thickness but retaining a cuff of muscle around the ipsilateral labial artery. Division is performed at 3 weeks. A B C D
Estlander1 originally described this flap in 1872 (Fig. 44.3). It is a good choice for reconstruction of defects of the oral commissure. The flap receives blood supply from the contralateral labial artery of the opposite lip and reconstruction is accomplished in a single stage, unlike the Abbe flap. The flap can be used for defects of up to two-thirds the lip width but does distort the lip and blunts the oral commissure. Fig. 44.3 Estlander flap for upper lip reconstruction. A, The lower lip flap is designed to be no more than half the size of the upper lip defect. B, The flap is rotated about the vermilion, which harbors its blood supply from the contralateral labial artery. C, Three-layer closure of the inset flap and donor site. (From Jackson IT. Local Flaps in Head and Neck Reconstruction. St Louis: Quality Medical Publishing, 2007.) A B C
The Karapandzic1 flap may be used to reconstruct large central defects of either the upper or lower lips. A Karapandzic flap usually involves full-thickness dissection a short distance lateral to the defect. The remaining dissection is partial thickness with preservation of the neurovascular pedicle and oral mucosa. Hence, all branches of the facial nerve should be preserved. This is achieved with gentle scissor dissection of the orbicularis oris fibers in the direction in which the nerves and vessels course. Oral competence is usually well maintained but microstomia is likely with larger defects following reconstruction with a Karapandzic flap (Fig. 44.4). This may be particularly troublesome for patients who normally wear dentures as they may be unable to use them.1
The Karapanzic flap is a single-stage advancement flap that is useful for reconstruction of one-third to two-thirds of the central upper or lower lip defects. The main advantage of this flap over the Bernard-Burow flap is that muscular continuity of the orbicularis oris is maintained so sphincter continence is superior with this flap. It also preserves the philtrum and modeolus. In contrast, the Bernard-Burow technique can be used to reconstruct central lower lip defects greater than one-third of the lower lip; however, this is at the cost of oral sphincter competence with little or no muscle function afterwards. Furthermore, this flap is insensate. Both flaps can result in microstomia and this has important consequences especially in edentulous patients where mouth opening may be too little to allow them to use their dentures. The Karapandzic flap is drawn as circumoral flaps passing into the nasolabial folds. Dissection is full thickness on either side of the defect and then partial thickness thereafter in order to preserve muscle, mucosa, and muscle innervation. The Bernard-Burow flap and the Webster modification of this use lateral cheek flaps to advance into the defect and require Burow’s triangle excisions in the cheek and chin to facilitate this. These techniques will also need involve reconstruction of the vermilion with buccal mucosal flaps (see Figs. 44.4 and 44.5).1–5 Fig. 44.4 Lower lip reconstruction with a Karapandzic flap. A, The width of the circumoral incision must be equal to the height of the defect at all points of the flap. B, The labial arteries and buccal nerve branches are identified and preserved bilaterally. C, Three-layer closure following medial advancement of the flaps. A B C
Total lower lip reconstruction can be achieved with a free radial forearm flap and a palmaris longus graft to support lip height. Unfortunately, although the radial forearm remains the best reconstructive option for total lower lip reconstruction overall, the aesthetics and function remain less than ideal; the color match tends to be poor and it can be difficult to achieve aesthetically good reconstruction of specific lip landmarks. Sensory innervation can be provided with branches of the lateral or medial antebrachial cutaneous nerves, providing a suitable recipient nerve can be identified in the face. Because the radial forearm flap is a fasciocutaneous flap, and does not involve harvesting of the flexor carpi radialis muscle, the reconstruction represents a static sling arrangement (albeit that upper lip movement may be intact) rather than a functional muscle transfer, so poor oral competence is generally observed. The clinical relevance of the flexor carpi radialis muscle is that it guides elevation of the flap from the forearm as the vascular pedicle lies between this and brachioradialis. The gracilis muscle has been used as an alternative to the radial forearm flap in order to provide functional muscle for the lip, but the aesthetic outcomes when using this flap still tend to be inferior to other reconstructive options such as the radial forearm and it is less commonly used because of this and its short vascular pedicle. One more alternative option to the radial flap is to utilize the soft tissues of the chin and advance this in a hinge fashion to the lower lip. The soft tissues of the submental region will however then need reconstruction due to the defect which is created by this transfer. The advantage here is that the skin match and hair growth (if in a male patient) for the lip is good, but there will still be functional impairment and the vermilion will still need separate reconstruction. When planning a radial forearm flap, a preoperative Allen’s test is required to assess the integrity of the radial and ulnar arterial supply to the hand. Flap elevation should only proceed where there is clear evidence of good ulnar artery flow. The benefit of importing new tissue into the lip with a radial forearm or other free flap is particularly apparent in irradiated fields.1–7
This defect is approximately 70% of the lower lip and of the options listed, it is best reconstructed with a Karapandzic flap. This flap will allow reconstruction of defect this size with rotation/advancement of the residual lower and upper lip components in a single stage. The flap may cause microstomia in cases such as this and should be discussed with patients preoperatively. Due to the design of the flap, sensation and motor innervation are retained (see Fig. 44.4).1 The Abbe flap could be used to reconstruct a smaller defect of the lower lip but in general, it is preferable to avoid using the Abbe flap from the upper lip for lower lip reconstruction to avoid tissue distortion.2 The Estlander flap would be better suited to lateral/commissure defects than the scenario described (see Fig. 44.3). The Bernard- Burow flap is a complex flap reserved for reconstruction of larger defects than described in this scenario and is best avoided due to the poor functional outcome. Direct closure in this case would not be a suitable option and even if it is technically possible to close the defect there would be significant tissue distortion as a result (see Fig. 44.5).
The Abbe flap is well suited for reconstruction of the upper lip in two stages. In general, this works best for central or lateral defects that do not involve the commissure as in this case. The Abbe flap alone can be used to reconstruct defects of around one-third of lip width. By incorporating a perialar crescenteric excision, additional soft tissue advancement is possible, without compromising function or aesthetics. The scars around the alar base are well disguised and this flap lends itself well to reconstruction of the midline upper lip. In contrast, allowing large facial defects like this to heal by secondary intention will lead to significant tissue distortion and poor functional and aesthetic results. The nasolabial flap can be used for lip reconstruction and in large defects bilateral flaps may be used in unison. These flaps are versatile and can be used for internal lining or skin reconstruction. However, they do not provide any muscle for functional support. The Estlander flap is a single-stage flap indicated for lateral defects involving the commissure rather than central defects as in this case.1–3