Ординатура / Офтальмология / Английские материалы / Atlas of Aesthetic Eyelid and Periocular Surgery_Spinelli, Lewis, Elahi_2004

THE MODIFIED LATERAL TARSAL STRIP PROCEDURE

The most useful procedure in addressing lower lid malposition and laxity is probably the lateral tarsal strip or tarsal tongue procedure. Although there is a shortening of the lower eyelid in this procedure, it differs from a wedge resection in that a tarsal strip is created, and this will serve as the new inferior crus of the lateral canthal tendon. It is also imperative that the tarsal strip be inserted at Whitnall’s tubercle, the insertion point for the superior crus of the lateral canthal tendon, which is described in detail in Chapter 1.

Unlike some classic descriptions of this procedure, I recommend division of the inferior crus of the lateral canthal tendon by means of a lateral canthotomy. Once the inferior crus is severed, it is most important to mobilize the lower lid. This is achieved by dividing the subcutaneous tissues, including the lower lid retractors and the orbital septum. It is only when these structures are divided that the lower eyelid can be mobilized almost to the eyebrow when placed on stretch. I believe the most significant error in failing to achieve adequate results with this procedure is by not completely mobilizing the lower lid by lysis of the lateral retinacular structures, despite all other aspects of the procedure being performed satisfactorily. Once the lower eyelid is mobilized, a tarsal strip is created by circumferentially de-epithelializing a lateral segment of the lower eyelid, which is back-cut below the tarsal plate. Approximately 3 mm of distal tarsal plate is isolated by carefully removing hair follicles superiorly, skin anteriorly, and mucous membrane posteriorly. The isolated tarsal strip will then serve as a neocanthal tendon that will be inserted into the lateral orbital rim. Proper insertion requires surgically isolating Whitnall’s tubercle. This involves lateral displacement of the lateral canthal soft tissue with digital or instrument retraction and medial retraction of the orbital soft tissue with superior dissection to the orbital rim. This serves to isolate the anterior orbital rim and then its internal aspect, at the level of Whitnall’s tubercle. This area can be readily discerned not only by its bony excrescence but also by

the insertion point of the superior crus of the lateral canthal tendon. The orbital rim periosteum is incised and then elevated from anterior to posterior within the orbital rim, without division or raising any flaps. I prefer to anchor the tarsal strip to the orbital rim periosteum utilizing a double-armed braided nonabsorbable 4-0 suture on a spatulated semicircular needle; however, other sutures, depending on the surgeon’s preference, are acceptable. The lateral tarsal strip is engaged with the double-armed suture, and each arm of the suture is brought through the internal orbital rim periosteum from Whitnall’s tubercle anteriorly. The path of the sutures will ride between the orbital rim periosteum and the internal orbital bony surface. If one were to visualize lower lid position without a corneal protector, the lower eyelid should ride 1.5 to 2 mm above the lower limbus once adequate positioning of the tarsal strip is achieved. The next step should involve refining the lateral commissure (commissuroplasty), and this is achieved by precisely aligning the analogous elements of the upper and lower eyelids (i.e., hair follicles or gray line) with a single small absorbable suture (i.e., 6-0 Vicryl). This can be brought through the upper and lower eyelids and tied subcutaneously just lateral to the eyelids. Mild degrees of lid rotation may be invoked with this technique, and it allows fine adjustments of the eyelids and orientation of lateral canthal elements. I have found it technically easier to pre-place the canthal suture (tarsus and periosteum) and, before tying it down, completing the commissuroplasty. Once the commissuroplasty is completed and the canthal suture tied down, the orbicularis muscle should be suspended with one or two absorbable sutures in a cephalolateral direction at the level of the lateral canthotomy. Closure of the skin can be achieved after desirable trimming, depending on the degree of redundancy and the desired results. Some skin tailoring, especially laterally, may be indicated when some form of cheek suspension is performed concomitantly. However, skin conservation should be the general rule, with secondary skin trimming always a viable option (Figs. 3-5 and 3-6). Periosteal flaps raised lateral to the orbital rim and based medially can serve as an excellent salvage canthal tendon for reconstruction and should be kept in mind should a tarsal strip be avulsed or excessively shortened (Fig. 3-7).

Figure 3-5 The canthus may be suspended by a lateral tarsal strip procedure. There are a few steps that when properly executed allow for this to be completed quickly and simply.

A, First, the lateral canthus is divided.

B, The inferior crus of the lateral canthal tendon is lysed, and the lateral retinacular elements are incised (arrows) to allow complete lower eyelid mobilization. C, A transverse back cut is made in the lateral tarsal plate, and epithelium is denuded circumferentially. It is especially important to remove hair follicles to avoid lateral distichiasis.

D, The lateral orbit is exposed and periosteum is engaged with a doublearmed suture that has already been passed through the tarsal strip. It is sometimes helpful to incise the periosteum vertically so as to engage the internal orbital reflection “deeply” (2 to 3 mm) within the orbit. A small amount of lateral orbicularis muscle may be trimmed. E, The muscle is suspended laterally and cephalad with a small absorbable suture. F, Alignment of the lateral commissure is achieved with a small absorbable suture (preferably double-armed) that is passed between the upper and lower eyelids at their most lateral aspects. I prefer to complete this step before tying down my suspension suture linked to the tarsal strip. The

tarsal strip procedure is well suited to the more senescent patient in whom lower lid and tarsal stretching has created relative redundancy in this structure.

A Lateral canthotomy

C Denude lateral tarsal strip

E Trim excess skin and/or orbicularis muscle

B Division of lower crus and wide lateral lysis

D Suture fixation of strip to internal periosteum of lateral orbital rim

F Commissuroplasty

Another method of tightening the lower eyelid without division of the lateral canthal tendon or its inferior crus is to plicate or tuck the lateral aspect of the tarsal plate. This can be performed transcutaneously and may be performed alone or in combination with other procedures (Fig. 3-8). It is effective only in mild degrees of lower lid laxity and in youthful patients who do not have attenuation of the lateral canthal complex.

This subgroup of patients will tolerate increased forces across the lower lid without foreshortening the intercommissure distance and other problems associated with procedures that do not suspend the lateral canthal complex. In the face of significant horizontal lower lid laxity, the tarsal plication will produce a buckled lower eyelid that does not appropriately appose the ocular surface.

Figure 3-8 The transcutaneous approach to the lower eyelid affords access to the inferior crus of the lateral canthal tendon and lateral tarsus. In mild cases of lower lid laxity, plication of the inferior crus can be performed (tarsal tuck). Because the lower eyelid is not shortened, buckling is created (central insert) in the lower eyelid, which can create spatial orientation problems in the lower eyelid (e.g., ectropion, anterior displacement from the globe). Therefore, it is only applicable in very mild cases of laxity. Fat may be transposed over the orbital rim. I prefer a supraperiosteal tunnel with transcutaneous fixation sutures. The access may be transcutaneous or transconjunctival. The amount of viable filler available is limited in all pedicled fat transposition procedures and usually promises more than is deliverable. The inserts depict the subtle changes in the lower lid that may be achieved with a tarsal tuck and fat transposition.

FAT REDISTRIBUTION AND TARSAL TUCK

Access incision–common canthopexy

Depressions that may be filled with orbital fat

Closeup of tarsal tuck

Access incision–tarsal tuck

Fat redistribution from lateral pocket

Fat redistribution from medial pocket

Completed canthopexy

An effective alternative approach to the inferior canthal or common canthal complex is by way of an upper lid approach. Access to the lateral canthal complex can always be achieved by way of an upper lateral eyelid incision, whether for cosmetic or reconstructive purposes. Through this route, the common canthal tendon may be suspended and anchored to the internal orbital rim periosteum in a method analogous to the tarsal strip procedure described previously. Again, cephalic and lateral pull or tension is the key to achieving satisfactory results. Using this route, I favor disinsertion of the entire lateral canthal tendon complex along with the inferolateral aspect of the lower lid retractors and orbital septum. This should allow complete mobilization of the entire lateral lid complex, including the lower eyelid. Significant degrees of elevation can be achieved without tension, and the entire complex can be anchored to the internal orbital rim at an appropriate position.

This procedure enables the surgeon to effectively increase the intercommissure distance, as well as significantly alter the angle of inclination of the lateral canthus relative to the medial canthus. Should inadequate periosteum or soft tissue be present for suspension, as in secondary or tertiary procedures, then a drill hole through the orbital rim at an appropriate level will suffice. In using this approach, care must be taken to avoid entrapping the lateral horn of the levator muscle in the suspension suture because lateral upper eyelid closure problems can result in this instance. Overelevation of the lateral canthus can create an unacceptable cosmetic appearance and/or impingement on the pupillary axis by the elevated lower eyelid. When this occurs, patients complain of obstruction of their vision in down gaze, for example when reading.

The upper lateral eyelid access incision may be used to approach the mid face for suspension procedures, but with slightly more difficulty than in approaching the mid face from the lower eyelid incision. I believe

that canthal and midface suspension is more easily and accurately achieved and the appropriate vector is more easily engendered with an upper lid approach. Because the surgeon is farther away from the structures to be addressed, he or she may be less comfortable initially.

I do not recommend lower eyelid incisions combined with upper lateral eyelid incisions for approaching the canthal complex when division, lysis, and suspension are to be performed. Generally, this requires significant dissection, and the small bipedicle bridge tends to be surgically compromised, leaving the lateral canthal soft tissue elements with at least an appearance of having had a surgical procedure and sometimes with severe contraction bands that are difficult to correct. Therefore, the ideal use for the upper lateral eyelid access incision to the lateral canthal complex is one in which there is complete lateral canthal dystopia and the surgeon would like to reposition the entire complex or in the case in which a lower eyelid incision will not be used other than a transconjunctival route, thereby avoiding compromise of skin and soft tissue bridges. In all these patients, the mid face may be effectively approached through this route should the surgeon choose not to utilize a preauricular facialplasty incision to access the mid face (Fig. 3-9).

The lateral canthopexy and canthoplasty can then be applied in a number of scenarios either alone or in consort with other procedures. I view canthal suspension as a procedure that should be liberally applied as a primary procedure for patients with frank lower lid laxity whether or not other procedures are being performed concomitantly. It should also be liberally applied when a patient has a tendency toward lower lid laxity, that is, he or she has normal or near-normal lower eyelid position and appearance but is undergoing a primary cosmetic or reconstructive procedure in which increased distraction forces will be applied to the lower eyelid, thereby tipping the balance of forces toward lower eyelid malposition.