43 Dermis Fat Graft
In the surgical management of the anophthalmic socket, dermis fat grafts serve an important function. The dual nature of this compound graft provides volume augmentation to the socket (fat) as well as a scaffold for conjunctiva to increase the surface area of the socket (dermis). Additionally, dermis fat grafts promote orbital growth when used in children. Complications include fat atrophy, ulceration, graft hirsutism, keratinization, and infection. The surgical technique is straightforward; however, there is a second surgical site at the donor site.
To increase orbital soft-tissue volume as well as conjunctivalized surface area in the anophthalmic socket. If there is volume deficiency in the orbit with an orbital implant already present, the dermis fat graft may be placed on top of the implant. If an exposed or infected orbital implant is present, this implant is first removed, and the dermis fat graft is used to replace the lost volume from the implant.
To optimize the fit and cosmesis of an ocular prosthesis.
To promote orbital bone development in pediatric anophthalmic sockets, as the graft has the potential to expand paralleling the child’s growth, unlike a static sized synthetic implant. 1 , 2 , 3 , 4
To reconstruct the anophthalmic socket in special circumstances: previous orbital implant exposure or infection, multiple prior surgeries, and in settings where the cost or access to alloplastic implants precludes their use.
To augment eyelid or anterior orbit volume in cases of superior sulcus deformity or lower lid fat atrophy from a variety of atrophic or pathologic processes.
Harvesting and transplanting a dermis fat graft is a fundamental oculoplastic surgery skill. There are numerous indications, which will be discussed in detail later. Dermis fat grafts may be used as a primary implant, to augment a preexisting implant, or as a secondary implant. One unique advantage of the dermis fat graft is augmentation of the “bulbar” surface area of the anophthalmic socket, necessary for the creation of adequate fornices. If there is inadequate conjunctiva and Tenon’s capsule to create a watertight closure without tension over an orbital implant, the risk of implant exposure and infection is significant. Additionally, if closure is forced under tension, the conjunctiva will be recruited from the fornices, which as a result become too shallow to retain a prosthesis. In such instances, the surgeon can use a dermis fat graft to replace orbital volume with the dermis segment appropriately sized to fill the defect on the “bulbar” conjunctival surface.
Although dermis fat grafts in adults undergo predictable mild atrophy, in children there can be growth of the graft and occasional hypertrophy. This is a useful feature of the dermis fat graft because placing it in the anophthalmic socket of a child can stimulate growth of the bony orbit that would not occur with a static sized implant. This bony expansion may minimize disfiguring facial asymmetry.
Alloplastic orbital implants have been adopted by the majority of ophthalmic plastic surgeons for primary implants after enucleation or evisceration in the United States. However, in developing nations, there may be a lack of availability of such implants. Dermis fat grafts are a cost-effective means of reconstructing the anophthalmic socket and optimizing the patient’s appearance. Dermis fat grafts add sufficient volume to the orbit and permit use of an ocular prosthesis despite the lack of alloplastic orbital implants.
Epithelialization of the dermis in 8 to 10 weeks for primary grafts; 12 to 16 weeks for secondary grafts or traumatized sockets. 7
43.4 Key Principles
The dermis fat graft is a composite graft that provides both dermis, a scaffold for surface epithelialization, and fat for volume augmentation. Free fat grafts in the orbit were largely abandoned due to significant and unpredictable atrophy. The inclusion of dermis allows for better vascularization and survival of the graft than seen in free fat grafts. Graft vascularization is key to preventing atrophy. To promote vascularization, one must avoid excessive handling of the graft, cautery to the recipient bed, and optimize systemic patient factors.
Secondary implant after implant exposure, extrusion, or infection.
Secondary implant to augment orbital volume on top of a preexisting implant.
Primary orbital implant in pediatric anophthalmic patients.
Primary implant in traumatized sockets that are unlikely to retain an alloplastic implant due to insufficient conjunctiva for closure.
Primary orbital implant if alloplastic implants are not available.
Volume augmentation for superior sulcus deformity or other volume deficiencies.
Patient unwilling or unable to undergo orbital surgery with a second surgical site (donor site).
Active orbital infection.
Previous radiation to the socket is a relative contraindication.