The posterior lamella is reconstructed by vertically augmenting the mucosal surface with the spacer graft.

Different materials have been used as spacer grafts throughout time. Desirable qualities of a spacer graft include easy accessibility and storage, affordability, short preparation time, and good handling properties allowing intraoperative manipulation, sizing, shaping, placement, and fixation. The graft should also induce minimal inflammation after implantation and permit native tissue ingrowth without shrinkage. With time, the implant should become virtually incorporated in the native tissues and provide long lasting support. For the purpose of eyelid reconstruction, the ideal material should mimic a tarso-conjunctival composite in thickness, surface quality, and resilience. Many different materials have been used, including autogenous, allogenic, and synthetic grafts. Commonly used autogenous grafts are hard palate, ear cartilage, temporalis fascia, fascia lata, buccal mucosa, nasal septal cartilage, tarsus, and periosteum [4, 5, 8, 10, 11, 29–39]. Allogenic donor sclera and, more recently, bioengineered grafts such as Alloderm (LifeCell, Branchburg, NJ), tarSys (IOP, Costa Mesa, CA), Enduragen (Porex, Newnan, GA), and DermaMatrix (Synthese, West Chester, PA) have also been used [40–47]. Although promising results with the use of each one of these grafts have been reported, none of them is perfect. Scleral grafts are not permanent and tend to be degraded by the body, resulting in graft shrinkage over time [40]. Temporalis fascia grafts do not replace the conjunctiva, which can lead to ocular irritation initially and contraction of the graft later on [32]. Auricular cartilage grafts, on the other hand, are much stiffer than the tarsus and do not replace the conjunctiva [31, 34]. Composite grafts such as the palate and nasal septum have the distinct advantage of replacing both tarsus and conjunctiva. Unfortunately, some of these techniques have the inconvenience of poor access, limited tissue availability, and donor site morbidity.

The gold standard spacer for lower eyelid reconstruction remains, however, the hard palate graft, which is harvested from an area between the gingiva and the palatine raphe. The use of hard palate mucosal grafts in lower eyelid reconstruction was first described by Siegel in 1985 for repair after tumor excision [35]. Its use as a spacer graft was subsequently reported for patients with cicatricial entropion, eyelid retraction secondary to thyroid eye disease, postblepharoplasty lower eyelid retraction, lagophthalmos after surgery for paralytic ptosis, and contracted socket [4, 5, 8, 10, 11, 29, 35, 39]. Hard palate mucosa serves as an ideal material for posterior lamella replacement for many reasons. It is a composite tissue that provides both structural support and mucous membrane replacement. Its mucosal surface nicely replaces conjunctiva, whereas its stiff structure provides eyelid support similar to that of tarsus. The dense concentration of collagen fibers in the lamina propria of the hard palate gives this tissue its stability and firmness, but at the

same time it has enough flexibility to allow it to maintain its contour and act as a tarsal replacement with excellent eyelid appearance and function, unlike ear or nasal cartilage. Acting as an internal splint, the palate mucosal graft also prevents shifting of the overlying layers. The eyelid remains stable, and therefore comfortable, for many years. In addition, hard palate mucosa is abundant, easily obtained, easy to handle, and it takes reliably with minimal shrinkage following grafting because of quick vascularization. Furthermore, being an autograft, it is not at risk for rejection. The rule of thumb for determining the vertical height of the spacer graft is to add one millimeter to the amount of vertical inadequacy between the existing and the desired eyelid margin positions. In the more proptotic patient, an additional 1 or even 2 mm of vertical height may be added to compensate for the inferior force exerted by the globe and for the anticipated loss of support due to the lesser horizontal tension that must be used when the globe is prominent.

Hard palate grafts have unfortunately their own disadvantages, including donor site morbidity (postoperative discomfort or bleeding, oral candidiasis, and oronasal fistula), increased operating time for graft harvesting, and occasional keratinization of the mucosal surface with potential ocular surface irritation [4, 5, 8, 11, 29].

The authors commonly use the DermaMatrix allograft, a non-crosslinked acellular human dermis that is processed to allow for fast vascular and cellular ingrowth. We have found that DermaMatrix becomes covered with conjunctiva within several weeks after implantation. Although not a rigid composite graft like the hard palate, DermaMatrix obviates the problems related to donor site morbidity, limited tissue availability, and prolonged operative time. DermaMatrix also comes in a thin and a thick version, with the thick version giving more support when placed in the lower eyelid.

A critical step in the reconstruction process of any retracted lower eyelid is vertical eyelid splinting at the end of surgery using a Frost-type suspension suture. This allows the three reconstructed layers of the lower eyelid to fuse in the desired configuration and preserves the vertical dimension of the spacer graft in the early postoperative period.

18.7Surgical Technique

18.7.1 Scar Lysis and Mobilization

Before making the incision, the lower eyelid margin is grasped with a forceps and pulled superiorly to determine the amount of restriction to superior movement. In the case of scarring of the middle or posterior lamella, this test will be positive. This superior traction test is repeated frequently throughout the procedure. An incision is made centrally through the conjunctiva and lower eyelid retractors at the

inferior tarsal margin with Stevens scissors. The incision is extended medially and laterally all the way to the caruncle and the lateral canthus, respectively. Care is taken to avoid damaging the inferior canaliculus and the semilunar fold medially. Injury to the canaliculus may result in epiphora, and injury to the semilunar fold may result in diplopia. Superiorly directed lower eyelid traction is again performed. If scarring is present, this usually shows persistent restriction, because only the posterior lamellar attachments to the inferior tarsal margin have been divided. Now, the posterior lamella (conjunctiva and lower lid retractors) is grasped at its leading edge and pulled superiorly to assess its vertical adequacy. A 4.0 silk traction suture passed through the conjunctiva and lower lid retractors can be used to put superior tension on the posterior lamella. At this point, the posterior lamella should be entirely free and should stretch superiorly without restriction. If it does not, the surgeon will find a cicatrix between the lower lid retractors and inferior orbital rim. Dissection is continued in the preseptal plane as far inferiorly as the arcus marginalis at the inferior orbital rim. At this point, superior traction is limited by middle lamellar tether, anterior lamellar inadequacy, or both. To further determine the cause of restriction, the cheek (anterior lamella) is digitally pushed superiorly. If this fully relieves the retraction, then the restriction is in the anterior lamella. In contrast, if the eyelid is still tethered, then most likely the restriction is midlamellar in which case the cicatrix in the plane of the septum that tethers the lower eyelid retractors to the inferior orbital rim has to be lysed. The conjunctiva and lower lid retractors are then pulled superiorly again. If the procedure did not fully release the entire middle lamellar cicatrix, the septum can be dissected free from the arcus marginalis along the inferior orbital rim to provide further release.

The orbitomalar ligament is then incised sharply with Stevens scissors and the orbicularis oculi muscle is elevated from the orbital rim, in a preperiosteal plane, using a vertical spreading technique with Stevens scissors followed by a Sayre elevator. The orbitomalar ligament is released all across the inferior and infero-lateral orbital rim to allow for superior mobilization of the orbicularis oculi muscle, in preparation for the midface lift.

18.7.2 Midface Elevation

The authors’ current thinking on midface elevation focuses less on SOOF lifting and more on repositioning of the orbicularis oculi muscle. In our hands, a preperiosteal midface elevation technique performed through an upper eyelid blepharoplasty or lateral skin crease incision is the procedure of choice. A large preperiosteal myocutaneous flap is created first that extends all the way from the brow to the cheek.

Dissection initiates in the lateral brow area, where an incision is made with Stevens scissor through the posterior leaf of the deep galea to elevate the brow fat pad from the periosteum (Fig. 18.8). To mobilize the brow, dissection continues for 2 cm above the superior-lateral orbital rim, between the posterior leaf of the deep galea and the periosteum, using a vertical spreading technique. To break into the midface and the lower eyelid, a sharp incision is made with Stevens scissors at the supero-lateral orbital rim beneath the orbicularis oculi muscle to expose the preperiosteal plane. The orbicularis oculi is elevated by releasing the orbitomalar and the zygomaticomalar ligaments using a vertical spreading technique with Stevens scissors (Fig. 18.9). The lateral raphae and the

Fig. 18.8 Intraoperative clinical photograph showing the release of deep galea from the arcus marginalis at the superior orbital rim with Stevens scissors. A plane is created between deep galea and periosteum to elevate and mobilize the brow fat pad

Fig. 18.9 Intraoperative clinical photograph showing elevation of orbicularis oculi muscle at the lateral orbital rim using a vertical spreading technique with Stevens scissors in the preperiosteal plane. The orbitomalar and the zygomaticomalar ligaments are released to create a large myocutaneous flap and mobilize the brow, the lateral canthus, and the cheek as one unit

Fig. 18.10 Intraoperative clinical photograph of preperiosteal midface elevation where the (a) lateral orbicularis oculi muscle and the fibrous suborbicularis oculi fat (SOOF) (tissues engaged with suture) are (b) resuspended to the periosteum overlying the lateral orbital rim with 6.0 Prolene sutures

lateral orbital thickening (LOT) are elevated from the periosteum. However, the posterior limb of the lateral canthal tendon is left attached to the Witnall’s tubercle. The dissection is then extended downwards in a plane between the zygomaticus muscles and the SOOF. The planes of dissection created via the transconjunctival lower eyelid incision and the upper lid blepharoplasty incision are united. The midface is then resuspended with one or two 4.0 Prolene sutures. The sutures are passed through the infero-lateral portion of the orbital orbicularis oculi muscle and the fibrous SOOF and attached to the dense periosteum overlying the lateral orbital rim. This creates an orbicularis oculi muscle sling that lifts the cheek superiorly (Fig. 18.10).

18.7.3 Graft Placement

The chosen spacer graft is cut to fit the horizontal lower eyelid defect. As mentioned previously, we use roughly a 1:1 ratio plus 1–2 mm for the vertical dimension, especially with the hard palate mucosal grafts or the rigid synthetic grafts such as tarSys or thick Alloderm. The graft is sutured to the lower border of the tarsal plate with a running 6.0 chromic suture with the knots externalized to the skin. The lower

border of the spacer graft is usually left unattached although it can be sutured to the conjunctiva inferiorly with a running 6.0 chromic suture.

18.7.4 Lateral Canthal Resuspension

In our hands, the LCR-SC is the procedure of choice for the majority of patients. To resuspend the lower eyelid, a 4.0 Prolene suture on a P3 needle is passed through the upper eyelid blepharoplasty incision, beneath the orbicularis oculi muscle but above the lateral canthal tendon, and externalized through the apex of the lateral canthal angle at the muco-cutaneous junction (Fig. 18.11a). The suture is then passed back through the same hole in the canthal angle created by the forward pass, but this time inferior and deep to the lateral canthal tendon, and externalized through the blepharoplasty incision (Fig. 18.11b). The suture is then secured to periosteum just inside the lateral orbital rim at the desired height (Fig. 18.11c). This procedure combined with a midface lift can be the only intervention necessary in patients that present with lower lid laxity without vertical shortening of the eyelid. However, in patients with vertical eyelid insufficiency, the LCR-SC and the mid-face lift performed through an upper eyelid incision can lead to complete restoration of the eyelid anatomy only when combined with a lower eyelid transconjunctival scar lysis and spacer graft placement. On occasion, an LTS canthoplasy-type procedure is required to correct an advanced lower lid laxity [15–17].

18.7.5 Eyelid Splinting and Casting

In patients with vertical eyelid insufficiency, to ensure adequate anatomical fixation of the reconstructed lower eyelid and to prevent reattachment of the middle lamella to the periosteum and the inferior orbital rim, the eyelid is placed on upward traction for a couple of days. After a bandage contact lens is placed in the eye, a 6.0 Prolene horizontal mattress Frost-type suture is passed vertically through the brow and upper eyelid tarsus and then horizontally through the lower eyelid tarsus and back the same route to the brow. The suture is tied above the brow to place the lower eyelid on an upward stretch. Either one single central suture or two sutures, one medial and one lateral, are placed in this fashion. A tight patch is then placed over the eye using Mastisol® liquid adhesive (Eloquest Healthcare, Ferndale, MI) to act as a cast and prevent postoperative hematoma formation and movement between the lower eyelid lamellae. The patch and the Frost suture are left in place for 3–5 days.