nerve. Appropriate discussion with the patient preceding surgery in this area is again essential.

The most important vascular structure encountered during Mohs surgery of the face is the angular artery, which courses superiorly along the nasal sidewall. Transection of this structure requires effective and aggressive hemostatic maneuvers. Nasolabial transposition and advancement flaps in this area are especially prone to damaging this vascular structure.

Free margins of the face include the eyelids and lips. Reconstruction of Mohs micrographic surgery defects above or below the eyelid or lip can result in ectropion or eclabion, respectively, if the tension vector is oriented parallel to the free margin. It is, therefore, imperative to orient the tension vector perpendicular to the free margin to avoid these complications.

6.8.2Other Considerations

Several consequences of head and neck procedures may have disturbing, though not dangerous, consequences, of which Mohs surgeons should be aware. Excisions of scalp tumors carry the risk of hair loss which can be due to either superficial undermining or scar spreading. It is therefore recommended to undermine within the deep subgaleal plane on the scalp to avoid transaction of the follicular units. Closure should be oriented to reduce wound tension and scar spreading, which can result in an alopecic patch.

Not infrequently, reconstruction of Mohs surgery defects requires a full-thickness skin graft. Tissue

matching between the donor and recipient sites is essential to long-term cosmesis of the graft. The general appearance, thickness, as well as hair and sebaceous density are all considerations in this process. Common donor sites include posterior auricular skin, the conchal bowl, and the supraclavicular sulcus. However, in cases where a better match is needed, the nasolabial fold, upper eyelid, and upper forehead skin may be considered as donor sites for a full-thickness skin graft.

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