Reconstruction Requiring Contour Preservation
Central Face
The hinge flap is optimal for reconstruction of deep central facial defects (Figure 1). The hinge flap is planned at a site contiguous with a margin of the defect and can include the dermis, subcutaneous tissue, muscle, or a combination of these. The desired tissue is folded over on the pedicle to fill the defect. Cutaneous coverage is accomplished through a primary closure, separate flap, or skin graft. In addition to restoring contour and therefore the cosmetic subunit, the hinge flap is performed in a single stage, resists wound contracture, and provides a well-vascularized wound bed resulting in a low incidence of graft failure.13,14 Muscular hinge flaps have been described for reconstruction of forehead defects with exposed bone based on the frontalis muscle.15
Figure 1. Subcutaneous hinge flap. The defect at the alar-cheek junction was too deep for immediate graft placement (A). Superior and inferolateral incisions from the defect were made (B)(white arrows). The cheek advancement was undermined in the subcutaneous plane, effectively deepithelializing the underlying tissue (blue arrow). A deepithelialized hinge flap was elevated from underneath the undermined cheek from the right malar fat pad and transposed into the right nasal ala defect to restore alar volume (black arrow). The Burow triangle along the superior aspect of the primary closure was excised as a full-thickness skin graft (red arrow) and was defatted and inset into the right nasal ala defect (C)(black arrow).
Lower Lip
A variant of a V-Y advancement flap has been described for reconstruction of defects greater than one-third the length of the lower lip. The top of the “V” is deepithelialized and the flap is advanced such that the top of the “V” abuts the inferior border of the defect. The “V” flap is inset at its advanced position, converting the “V”-shaped wound into a “Y.” An overlying buccal mucosal graft provides reconstruction of the lower red lip and labial mucosa.16
Helix of the Ear
Large defects of the scapha and helix of the ear can be reconstructed with the use of a staged interpolated postauricular flap. The postauricular flap is elevated into a subcutaneous plane. A full-thickness incision is made medial to the helical rim, and the flap is tunneled through and sutured into place. The pedicle is later divided, and the distal aspect of the flap is deepithelialized and inset into the helical rim for volume restoration.17
Reconstruction Involving Free Margins
Nasal Ala
For large defects involving the upper cutaneous lip with adjacent alar base involvement, a partially deepithelialized V-Y flap is a useful reconstructive option (Figure 2).
Figure 2. Partially deepithelialized V-Y flap (A). The defect involved the alar base, medial cheek, and white lip with collapse of the ala and external nasal valve dysfunction. The diagonal purple lines indicate the planned deepithelialization. The flap was raised from the adjacent tissue and undermined (B). The superior deepithelialized aspect of the flap was sutured into the soft tissue void under the remnant ala. The native alar position was restored and the external nasal valve dysfunction was corrected. The free alar margin was preserved at 12 weeks’ follow-up (C).
Infraorbital Region
A deepithelialized variant of a V-Y advancement flap can be used for closure of infraorbital defects. The limbs of the V-Y flap are deepithelialized and anchored to the medial and lateral canthal tendons or periosteum. Ectropion prevention is the primary advantage of this flap.18
APPLICATION OF DEEPITHELIALIZED GRAFTS
Deepithelialized grafts may be considered for volume replacement, reconstruction requiring contour preservation, and restoration of mechanical integrity in areas of high mechanical tension.3,19-21
Reconstruction Requiring Contour Preservation
Deepithelialized grafts are used to improve depressed nasal scars and restore volume in deep nasal wounds. One method involves deepithelialization of 2 postauricular punch biopsies. An 18-gauge needle is used to make a small hole in the depressed nasal scar, the dermal grafts are inserted, and the defect is closed primarily.19 Dermal grafts may be harvested from excess full-thickness skin grafts (FTSGs) or dog-ear tissue. When used under flaps, the dermal graft is trimmed to the size of the defect. When used under FTSGs, thin dermal graft strips are placed in a gridlike pattern to allow for revascularization. A study of 15 patients with contour deformities reconstructed with dermal graft insertions demonstrated that 14 (94%) patients had no significant complications and improvement of scar depression was achieved.20
Reconstruction in Areas of High Mechanical Tension
Plantar Foot
A combined dermal and full-thickness sandwich graft has been described for reconstruction of plantar foot defects.3 The graft is created by obtaining a FTSG twice the size of the wound defect and deepithelializing half of the graft. The graft is then defatted and the deepithelialized portion is folded beneath the other half, allowing the papillary dermis to make contact with the wound surface.
Scalp
Dermal graft reconstruction for scalp defects may be accomplished with a split-thickness skin flap. The flap is harvested using an electronic dermatome that ensures the proximal aspect is still attached to adjacent skin. The dermis is removed from the area underneath the back-folded split-thickness skin flap. The dermal graft is meshed and sutured into the recipient site. The split-thickness skin flap is replaced over the donor site. Meshed reversed dermal grafts have excellent survival rates, even with direct placement on bone without periosteum. Querings et al21 reported graft survival with no complications in 19 of 21 (90.4%) patients undergoing scalp or plantar sole reconstruction.
CONCLUSION
With the widespread adoption of the fresh-tissue technique for Mohs micrographic surgery and the establishment of the American Society for Dermatologic Surgery in 1970, the depth and scope of techniques used by dermatologic surgeons has dramatically expanded. Although the use of dermal flaps and grafts is not as widespread in dermatology as other reconstructive techniques, their unique advantages should be considered. Deepithelialized flaps and grafts should be considered when the following reconstructive goals are desired: (1) conversion of a 2-stage interpolation flap to a single-stage tunneled flap, (2) contour and cosmetic subunit preservation of deep defects through volume augmentation, (3) reconstruction in areas of high mechanical tension, and (4) free margin preservation. The multiple applications of deepithelialized flaps and grafts as described in this review demonstrate their continued applicability in dermatologic surgery.