En Bloc Technique

Use a caliper and marking pen to delineate an ellipse of skin representing the millimeter-for- millimeter difference between preoperative and proposed eyelid margin levels. The superior edge of the ellipse should correspond to the existing eyelid crease. Segmental eyelid margin contour deformities may be accounted for in the same manner as in the lamellar technique, with the only difference being that the segmental borders of excision are drawn on the skin surface (Fig. 22.4a, b).

After infiltrating the upper eyelid with local anesthetic, insert a bone plate or similar device beneath the eyelid to protect the globe during eyelid tissue excision (Fig. 22.5). Then, use a #15 blade to make a full-thickness incision along the premarked ellipse (Fig. 22.6a, b). Stevens scissors may be used to complete the excision (Fig. 22.7a, b).

With the en bloc full-thickness eyelid resection technique, tissue layers are not dissected free, making it somewhat more difficult to identify the cut edge of the tarsal plate inferiorly and the cut edge of the levator aponeurosis superiorly. In fact, the edges of the incision may not show any tarsus in cases where a prior tarsectomy was performed and only dense scar tissues remain. Thus, interrupted simple vertical sutures should be passed in very deep lamellar fashion to incorporate near full-thickness eyelid tissue on

either cut edge (Fig. 22.8). Again, care is taken to avoid penetration of the conjunctiva. As described with the lamellar technique, sutures may be tied temporarily while intraoperative adjustments are made by sitting the patient upright. Use several interrupted or a continuous running suture to close the skin, incorporating levator aponeurosis to reestablish a harsh eyelid crease as desired (Fig. 22.9a, b).

Challenges and Solutions

The techniques described above apply to cases in which the MCD is greater in the ptotic eyelid when compared to the fellow nonptotic eyelid. In cases where the eyelid crease in the ptotic eyelid is symmetric with the fellow eyelid, lower than the fellow eyelid, or nonexistent, the initial incision should follow a line that is drawn superior to the eyelid margin at a vertical distance that is equal to the MCD of the fellow nonptotic eyelid plus the amount of desired blepharoptosis correction. Full-thickness eyelid resection is then carried inferior to this incision using either the lamellar or en bloc technique. At the completion of surgery, bilaterally symmetric tarsal platform show should be achieved.

In patients with a contour deformity isolated to one segment of the eyelid, full-thickness tissue resection may be performed in only that

segment of the eyelid (Fig. 22.10a–c). If the area of tissue to be excised fits entirely within the head of a very large chalazion clamp, surgery may be performed with the aid of this clamp. To do so, place the clamp with the solid plate against the globe and the ring entirely encompassing the tissue marked for excision. The clamp now serves several purposes: to facilitate manipulation of the eyelid, to provide a firm surface against which the incision is made, and to protect the globe. The remainder of the surgery may be completed using either the lamellar or en bloc technique. If the area of tissue to be excised does not fit entirely within the head of the chalazion

clamp, the clamp may be still be placed and the initial full thickness incision made centrally with the stability afforded by the clamp. The clamp can then be removed and the full thickness excisions extended medially and laterally with scissors.

In cases of severe eyelid margin contour deformities, the excised tarsus from one eyelid segment may be used to augment and thus lower another eyelid segment. This is a complicated eyelid reconstruction and should be reserved for use by surgeons with experience in full-thickness eyelid resection as well as eyelid reconstruction.

Fig. 22.9 (a) Skin closure is accomplished with interrupted sutures, incorporating underlying levator aponeurosis to create a harsh eyelid crease. (b) Artist schematic

of intraoperative photograph. Reprinted with permission from Henry Baylis, MD

Pearls

It is the authors’ suggestion to use the lamellar technique when teaching residents or in particularly challenging cases where added precision is required. Layer-by-layer dissection allows for direct visualization of tissues and avoids potential inaccuracies associated with simultaneously cutting through multiple layers of tissue. The en bloc technique is a good alternative in severely scarred eyelids or in eyelids that have undergone prior tarsectomy. In these cases, it may be impossible to separate tissue layers. Or, even if dissection is carried down to bare tarsus, vertical tarsus length may be insufficient to perform the necessary

amount of millimeter-for-millimeter resection and still preserve the ideally desired 4 mm of vertical tarsal height at the eyelid margin.

The ability to achieve predictable results remains the elusive goal of any blepharoptosis surgery. One major reason for this unpredictability is the variable healing associated with surgery on thin, distensible, and fluid tissue layers. When multioperated eyelids become scarred such that formerly fluid tissue layers adhere into a single cicatricial mass continuum, this variability is removed. Fullthickness surgery then offers an opportunity to achieve predictable amounts of blepharoptosis correction.