Specialized Local Facial Flaps for the Eyelids and Lips

Robert W. Dolan and Susan M. Tucker

Lahey Clinic Medical Center, Burlington, Massachusetts, U.S.A.

EYELID RECONSTRUCTION

The goals of eyelid reconstruction are to:

Restore nonkeritanized internal lining Provide form and rigidity to the eyelid margin Re-establish fixation at the medial and lateral canthi Provide corneal protection

Restore the thin and supple skin over the eyelids for proper function and cosmesis

Provide appropriate elevation of the upper eyelid by the action of the levator muscle

Eyelid Anatomy

Knowledge of eyelid anatomy is essential to planning periocular reconstruction. Both anterior and posterior lamellae of the eyelid must be replaced to maximize structural integrity and function. The anterior lamella consists of the skin and orbi-cularis oculi muscle with its associated vascular elements. The posterior lamella consists of the levator muscle and aponeurosis (upper eyelid), Muller's muscle, tarsus, and conjunctiva. The gray line, visible along the middle of each eyelid margin, -g denotes the junction of the anterior and posterior lamella of the eyelid (Fig. 1). The | openings of the meibomian glands mark the mucocutaneous junction and lie just posterior to the gray line.

The tissue layers in the upper eyelid over the tarsus are skin, pretarsal orbicu-laris muscle, levator aponeurosis, tarsus, and conjunctiva. Above the tarsus the tis- >3

sue layers are skin, preseptal orbicularis muscle, orbital septum, orbital fat, levator muscle and aponeurosis, Muller's muscle, and conjunctiva. In the lower eyelid the o capsulopalpebral fascia is equivalent to the levator of the upper eyelid and the infer- §

ior tarsal (Horner's) muscle is the counterpart of Muller's muscle in the upper eyelid. @

201 f

Palpebral Tarsal Conjunctiva Pics

The orbicularis oculi muscle encircles the palpebral aperture and is organized into concentric zones: orbital and palpebral. The palpebral zone is divided into pre-tarsal and preseptal components. These components possess deep and superficial heads as they pass medially, forming the medial canthal tendon. The superficial head of the medial canthal tendon merges with the superior and inferior tarsal plates and inserts medially onto the frontal process of the maxilla, just anterior to the anterior lacrimal crest. The deep head of the medial canthal tendon inserts posterior to the lacrimal sac on the lacrimal bone (the posterior lacrimal crest). The lateral canthal tendon arises from the periosteum over the lateral orbital rim and also from Whitnall's tubercle located 5 mm behind the lateral rim; medially it splits to merge with the upper and lower eyelid tarsal plates.

The orbital septum is an effective barrier to the spread of infection from the more superficial parts of the eye (preseptal) to the deeper parts of the eye (postsep-tal). The orbital septum originates at the bony orbital rim as a thickening called the arcus marginalis. The facial periosteum also attaches at this point forming a trifur-cation of fascias consisting of the facial fascia, periorbital fascia, and the orbital septum. The septum attaches onto the levator complex 2-4 mm above the tarsal border in whites. In Asians, the septum inserts more inferiorly onto the tarsal border. Beneath the septum lies the orbital fat pads; hence the fullness of the Asian eyelid -g is a result of the more inferior extension of the septum and underlying fat (see the chapter on Blepharoplasty). In surgery, identification of the orbital fat is an important landmark because just below it lies the levator complex in the upper eyelid and the capsulopalpebral fascia in the lower eyelid.

The levator muscle arises from the roof of the orbit above the superior rectus muscle. It continues forward for about 40 mm where it ends just behind the septum |

as an aponeurosis. Close to the origin of the aponeurosis the muscle sheath is thick- o ened to form a sleeve referred to as Whitnall's ligament (1) (Fig. 2). This fascial § sleeve attaches to the trochlear fascia medially and the fascia of the orbital lobe of

Levator Aponeurosis And Whitnall
Figure 2 Whitnall's ligament.

the lacrimal gland laterally and acts as a fulcrum for the action of the levator. The aponeurosis inserts onto the lower anterior two-thirds of the tarsal plate and sends fibers to the orbicularis and skin. MUller's muscle is a nonstriated, sympathetically innervated elevator of the upper eyelid that arises from the undersurface of the levator muscle close to the junction of striated muscle and aponeurosis. It descends between the levator aponeurosis and the conjunctiva for 5-20 mm to insert into the superior edge of tarsus. In the lower eyelid, the capsulopalpebral fascia (the levator equivalent) is a fibrous tissue retinaculum, attached to and powered by the inferior rectus muscle that depresses the eyelid in downgaze (2). The inferior tarsal muscle (Muller's muscle equivalent) also arises from the sheath of the inferior rectus muscle and lies between the capsulopalpebral fascia and conjunctiva.

The tarsal plates are fibroelastic structures extending across the margin of each eyelid. The upper tarsus is 10-12 mm in height centrally, tapering to 6 mm laterally and medially extending from the superior punctum to approximately 3 mm from the lateral canthal angle. The lower tarsus is 3-5 mm in height.

Branches of the ophthalmic artery (from the internal carotid artery) give rise to the palpebral vessels: laterally from the lacrimal artery and medially from the terminal branches of the ophthalmic artery (Fig. 3). The peripheral arcade of the upper -g eyelid courses beneath the levator aponeurosis at the superior border of the tarsus, and the marginal arcade courses 2-4 mm above the lid margin deep to the pretarsal » orbicularis oculi muscle. The inferior marginal arcade supplies the lower eyelid and courses 2-3 mm below the lid margin deep to the pretarsal orbicularis oculi muscle.

Important contributions from the external carotid system occur via branches of the infraorbital, anterior deep temporal, and superficial temporal arteries (3).

The normal position of the upper eyelid margin in primary gaze is 1-2 mm o below the superior limbus. The highest point is just nasal to the center of the pupil in whites, and at the midpoint of the eyelid in Asians. The lower eyelid should @

Eyelid Anatomy

Figure 3 Vascular anatomy of the eyelids. (Courtesy Dr. Susan Tucker, Lahey Clinic Burlington, MA.)

slightly overlap the inferior limbus and the lowest point is just temporal to the pupil. The upper eyelid crease in whites 8-12 mm above the eyelid margin formed by the insertion of fibers from the levator aponeurosis into the orbicularis muscle and skin. The perceived fullness of the Asian eyelid is a result of the more inferior insertion of the orbital septum (onto the tarsus compared with 2-3 mm superior to it), and the low skin crease is due to the low and less prominent subcutaneous insertions of the levator aponeurosis.

Partial-Thickness Lid Defects

Both the anterior and posterior lamellae must be adequately restored, and at least one must be vascularized to support nonvascularized grafts, if needed. Anterior lamellar defects may be reconstructed with a basic local flap or a full-thickness skin graft; split-thickness skin grafts should be avoided due to excess contraction that could lead to ectropion or lagophthalmos. The order of preferred donor sites for full-thickness skin grafts is upper eyelid, retroauricular, and supraclavicular. It is acceptable to orient scars vertically (against the resting skin tension lines [RSTLs]) to avoid displacement of the lid margin in the process of skin recruitment in closing an elliptical defect. Eyelid skin generally heals with minimal cicatrization and postoperative pulling on the eyelid margin in the direction of the scar is minimal. Posterior lamellar defects may be repaired with free autogenous composite grafts (e.g., tarsoconjunctival, septal cartilage-mucosa, hard palate mucosa), advancement or rotational conjunctival flaps, and periosteal strips.

Full-Thickness Lid Defects

The method of closure for full-thickness eyelid defects depends upon the location and shape of the wound. The vast majority of defects from cancer resection will be located on the lower eyelid, most often in the shape of a wedge. Wedged-shaped 3

defects involving up to 50% of the lid margin may be closed primarily in older |

patients. However, a lateral cantholysis is necessary if the edges of the defect cannot o be brought together easily. The edges of the defect must be perpendicular to the lid margin along the full height of the tarsus to avoid notching. Marginal horizontally @

shaped defects of this extent may be converted into a wedged-shaped defect to facilitate primary closure. Advancing the lateral cheek facilitated by wide undermining and release of the lateral eyelid remnant by cantholysis may close wedged-shaped defects of the lower eyelid involving move than 50% of the lid margin. Flaps for this purpose include the Tenzel and the Mustarde cheek rotation flaps. For marginal horizontally shaped defects of this size, upper eyelid tissue can be used in the form of a full-thickness unipedicle flap, a bipedicled flap, or a Hughes tarsoconjunctival flap. Flaps for extensive defects of the upper eyelid include the Abbe;-type full-thickness flap from the lower eyelid (switch flap) and the Cutler-Beard flap.

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