Reconstruction of large full thickness defects of the lower eyelid |
Size and dimensions of lower eyelid defect |
Involvement of proximal canalicular system |
Eyelid laxity |
Prior eyelid, facial surgery or trauma |
Evaluation of donor site for full thickness skin graft (upper eyelid, pre-/retroauricular, supraclavicular, inner arm) |
Visual function of both eyes (monocular status) |
History of smoking/tobacco use |
Introduction
Total defects of the lower eyelid often result from wide excision of lower eyelid malignancies such as melanoma, squamous cell carcinoma, basal cell carcinoma and Merkel cell carcinoma. The resultant defects can encompass the entire lower eyelid and may involve the proximal lacrimal drainage system. Reconstruction of these defects is guided by the goal of reconstructing the bi-lamellar nature of the lower eyelid and lacrimal system if needed.
The size of the defect and degree of lower eyelid laxity dictate the reconstructive options. Small lower eyelid defects of less than 33% or slightly larger defects with significant lower eyelid laxity may be repaired by direct closure ( Chapter 37 ). An adjunctive lateral canthotomy and cantholysis can be performed to yield an additional 2–3 mm of laxity needed to close defects primarily. Larger defects greater than 50% can be closed with a semicircular flap ( Chapter 39 ). Lower eyelid defects greater than 80% usually require reconstruction with a tarsoconjunctival flap with full thickness skin graft or a Mustardé rotational flap for the anterior lamella ( Chapter 41 ).
Wendell Hughes originally described reconstruction of the lower eyelid using an upper eyelid tarsoconjunctival flap that was split at the eyelid margin. The anterior lamellar deficit was supplied by advancement of the cheek. At 3 months postoperatively, the flap was divided and inset. Hughes’ original tarsoconjunctival flap was complicated by upper eyelid retraction and entropion after division of the pedicle. Today, most surgeons perform a modification of Hughes’ original description by raising a tarsoconjunctival flap at least 4 mm from the eyelid margin and reconstructing the anterior lamella with a full thickness skin graft or adjacent pedicle-based flap. Preservation of the inferior 4 mm of the tarsus along with the eyelid margin maintains structural support of the upper eyelid. The blood supply for the full thickness skin graft is derived from the tarsoconjunctival flap of the upper eyelid and this can be augmented with an adjacent orbicularis flap. The tarsoconjunctival pedicle is typically separated at 4–6 weeks after the initial operation. Patients should be strictly advised to stop smoking.
In patients who are monocular, with the seeing eye on the reconstructed side, a Hughes’s tarsoconjunctival flap will effectively render the patient blind until the pedicle is severed. A non-eyelid sharing procedure such as a free tarsal graft with adjacent tissue flap, for example as a semicircular flap or Mustardé, may be more appropriate. Likewise, children under the age of 8 should undergo non-eyelid sharing procedures to minimize risk of occlusion amblyopia.