Your skin and glands of the eyelids are inclined to growth and development of benign and malignant neoplasms. There is a higher preponderance of eyelid tumors in the lower eyelids (90% vs. 10% in upper eyelids). The most typical malignant eyelid tumor is basal cell carcinoma. Squamous cell carcinoma of the eyelid is rare. Basal cell carcinoma has a high recurrence rate after excision and should be treated aggressively.
Malignant melanoma in situ (lentigo maligna), though rare, also warrants wide excision; 5 mm margin is recommended. Eyelid reconstruction after surgical excision of tumors should be delayed until final pathological diagnosis and evaluation of margins is finished. The surgeon treats outdoors wound with dressings during this period.
Partial-thickness defects from the lower eyelid may involve just skin or a combination of skin and orbicularis muscle. The reconstructive options for these defects include primary closure, local flap, full-thickness graft and split-thickness graft. Small defects usually can be closed primarily thereby avoiding excessive tension that can lead to ectropion (eversion of the eyelid). Larger defects may require one of the wide variety of local flaps that are available for lower eyelid reconstruction.
The bipedicled Tripier flap and medial/lateral skin-muscle flaps rely on ipsilateral upper eyelid tissue that provides excellent color match. The cheek flap also provides a good match in color and quality. The Fricke temporal brow flap, nasolabial flap and midline forehead flap are now and again useful but provide mediocre color and texture matches.
If local flap coverage of a defect isn't feasible, the surgeon may use a full-thickness or split-thickness graft. Full-thickness grafts can be better than split-thickness grafts for eyelid reconstruction; they provide little or no contracture with better color and texture match.
A full-thickness graft from the upper lid can cover small defects with excellent graft take and minimal donor site scar. For larger defects, skin from both upper eyelids can be used. For defects that involve skin and orbicularis muscle, a composite graft in the upper eyelids usually heals well. Full-thickness grafts can also be harvested from behind the ear and above the clavicle. Full-thickness defects from the lower eyelid involve the skin, orbicularis muscle, tarsus and conjunctiva. The reconstructive hierarchy for these defects is really as follows:
Primary closure usually can be performed for defects one-fourth to one-third from the lid margin. Parallel excision of the tarsal plates should be performed to avoid notching. Absorbable sutures approximate the tarsus and nonabsorbable sutures approximate the skin. If a gap of some millimeters prevents primary closure, a lateral canthotomy with cantholysis and closure is required.
The lateral palpebral fissure is incised and also the lower limb from the lateral canthal ligament is detached, thus allowing relaxation from the lateral part of the lower lid. The lateral canthotomy incision is often carried superolaterally to create a semicircular flap for more mobility. An extra few millimeters may also be gained by adding a Z-plasty to the lateral incision. All of these described techniques provide lining, structural support and cilia-bearing skin cover.
These maneuvers are often not adequate for large defects (>50%). In such cases, lining, support and cover are required via other means. Two options exists for lining and support: top of the eyelid tarsoconjunctival flap (modified Hughes) and chondromucosal composite grafts. The tarsoconjunctival flap (modified Hughes) involves harvesting a flap of conjunctiva with attached tarsus from the upper eyelid (leaving 3-4 mm of inferior tarsal edge intact and separating the levator and Müller's muscles) and advancing this superiorly-based flap towards the lower eyelid defect.
These flaps can cover up to 50% of lower eyelid posterior lamella defects. Coverage is obtained using a skin graft, local skin-muscle flap, or large cheek advancement flap (Mustarde). Larger lower lid defects prohibit borrowing from the upper lid for fear of upper lid distortion.
Cartilage, mucosal, or composite (chondromucosal) grafts really are a better option for lining and support in larger defects. Options for these grafts include auricular cartilage grafts, mucosal grafts in the mouth (hard palate or buccal mucosa) and nasal septal chondromucosal grafts. Selection of graft is dictated by size defect and the surgeon's familiarity with the strategy. Ear cartilage grafts are generally used in larger defects. Thin cartilage in the scaphoid fossa is strong yet pliable, donor site morbidity is low, and also the exposed surface of the cartilage becomes epithelialized by surrounding conjunctiva over several weeks.
Hard palate mucosal grafts are advantageous due to intrinsic support and mucosal lining. In contrast, buccal mucosal grafts are too thin for support and their primary uses are for lining and lid margin reconstruction. Nasal septal chondromucosal grafts are advantageous because they provide significant structural support in addition to mucosal lining.
Availability and convenience allows these grafts to be commonly used for reconstruction of total or near-total lid loss. Chondromucosal grafts need flap coverage (by having an adequate vascular bed) to outlive. Skin cover choices for large lower lid defects include medial/lateral skin-muscle flaps, large cheek advancement flaps or bipedicled Tripier flaps. These well-vascularized flaps can provide nourishment for primary chondromucosal grafts while covering large lower eyelid defects (>75%).
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Note: This article was sent to us by: Keith Hayes at 02142011
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