Lipostructure for the facial skeleton

Introduction

Autologous fat grafting has taken various applications since its inception in the 1800s from aesthetic to reconstructive purposes. Fat grafting was initially used in the face to improve tuberculosis-induced facial contour changes. Subsequently, it was trialed to obliterate the frontal sinus which still remains the gold standard today. But it was only in the 1980s and early 1990s that fat grafts were used as cosmetic fillers; however, the resorption rate was very variable and it was not widely used. Dr. Coleman popularized fat grafting with a reproducible technique. The tenets are aspiration of small aliquots of fat, processing the fat using centrifugation, separating out the unwanted components of the lipoaspirate (local anesthetic, oil, blood, and other noncellular material), and injecting the fat as tiny aliquots with each pass of the cannula. As research in the field increased, the indications and quoted graft retention rates also increased (as high as 90%), but the great variation persisted.

Youthful facial fullness is presumed to result from colloidal fluid held in place by a combination of hyaluronic acid, proteins, hormones, and other factors. These are gradually lost in the natural process of aging, and as a person approaches middle age, the fat deposits in the eyelids, cheeks, above the nasolabial folds, and the jowl become more visible as the surrounding fullness disappears. These changes also make underlying structures, such as submandibular glands and the facial skeleton, more obvious. As discussed in previous chapters, the aging face is universally characterized by fat atrophy as well as descent of the skin, muscles, and fat due to gravity and loss of elastic properties caused by time. González-Ulloa et al. have extensively discussed fat atrophy as the primary factor in aging and challenged surgeons to find ways of facial augmentation to reverse fat atrophy. Fat grafting allows us to address the atrophic changes caused by aging in a minimally invasive, yet very effective, manner. The transfer of fat from one part of the body to the face has proven to be a very powerful, effective, and longer-lasting treatment, especially compared with the increasing use of resorptive fillers, which can be a useful tool for temporary correction of facial defects. Furthermore, fat grafting will restore not only the youthful contours of the face but also its intrinsic qualities of skin texture, elasticity, and color return. Stem cells have been identified in large quantities in the harvested lipoaspirate and have been shown by our group to induce angiogenesis, skin thickening, and elasticity restoration.

Age-related atrophy is also associated with skin changes, excess skin laxity, and ptosis. Therefore fat grafting to the face is not only used as a stand-alone therapy, but often it is also used as an adjunct to other facial rejuvenation surgical procedures, such as rhytidectomy or blepharoplasty, to ensure an improved contour and smoother-appearing skin surface. This is to avoid an unnatural, overfilled, and unfeminine look caused by excess filling of the face. The potential aesthetic and surgical complications of fat grafting to the face warrant careful planning and attention to maximize the rejuvenation effect of lipofilling. This chapter examines the practical aspects involved in decision-making and in the technique of fat grafting to improve the contour of the facial skeleton.

Patient evaluation

As with any plastic surgery procedure, a thorough history and physical examination are the basis for a successful surgical strategy and a happy patient. The first step is to understand the patient’s concerns and goals to ensure that expectations can be met with fat grating alone and to determine whether other procedures are needed. The patient should be allowed to express what aspects of the face cause concern and what he or she hopes to achieve with surgery. Patients should be asked about recent weight changes and plans for future weight loss or gain. Evaluation of the patient’s preoperative medical status must include conditions that can affect the survival of fat grafting, such as smoking and tobacco use and history of prior infection (including methicillin-resistant Staphylococcus aureus ) or postsurgical infection. A surgical history, including prior surgeries, adverse events to anesthesia, and prior cosmetic medical or surgical procedures, should be taken. Patients should be specifically asked about prior liposuction or fat grafting procedures because these procedures can greatly affect the quantity and quality of fat that can be harvested from a donor site. A personal or family history of clotting or bleeding disorders, previous miscarriages, and deep vein thrombosis or pulmonary embolism should be noted. Allergies should be known, and lidocaine should be avoided if the patient is allergic to it. A thorough medication history should be obtained to determine whether the patient takes anticoagulants, such as enoxaparin, coumadin, aspirin, nonsteroidal antiinflammatory drugs, and certain vitamins and supplements known to affect clotting (e.g., vitamin K).

After a general examination, a thorough analysis of the face and potential fat harvesting donor sites should be conducted. Care should be taken to identify prior liposuction deformities to avoid worsening of those sites during harvesting. Facial analysis should be conducted in a methodical manner by using the basic principles of facial aesthetics. The texture and quality of the skin should be assessed. Special attention should be given to the supraorbital area, temporal area, nasolabial folds, lips, and neck. A youthful face is fuller, thanks to the underlying fat, which also helps to soften the contour of deep structures, such as bones, muscles, cartilage, and glands. The sequelae of facial skeletonization due to aging is more prominent in the upper third of the face than in the rest of the face, usually with a greater degree of hollowing instead of sagging, which is more characteristic of the middle and lower thirds. With aging, the shapes of the skull and the supraorbital bony rims become more prominent; the temples become hollowed; blood vessels are no longer hidden within the fat and stand out more; and the muscles of facial expression are more visible, creating a frowning or scowling appearance because of an increase in lines and folds in the forehead and glabellar regions. The eyebrows appear ptotic because of the loss of forehea d, temple, and brow fullness and loss of lateral support of the brow. The overall effect is that the lateral eyebrows can no longer be seen from the front giving an illusion of eyebrow shortening and lateral descent. The eyes may also become more deep set and eventually skeletal with a sunken look due to loss of fullness in the eyelids, eventually leading to dermatochalasis. Similarly, the inferior orbital rim becomes more prominent because of fat atrophy and tissue descent, leading to elongation of the lid–cheek junction and deepening of the tear trough and the nasolabial and marionette folds. The zygomatic arches become more prominent because of malar fat pad deflation. Lips deflate predominantly in the subvermilion and subcutaneous regions, leading to the orbicularis oris muscle coming more in contact with the vermilion and the mucosa, which results in perioral wrinkling, and significant changes in the upper and lower lips. Upper lip changes are more variable and include inversion, loss of visible vermilion, increase in maxillary incisor show, and illusion of overall lip narrowing. Lower lip changes include deflation, inversion, central depression loss, flattening of the central pout, and descent with associated mandibular incisors exposure. The contour of the mandible is also affected because of fat atrophy and skin ptosis. The jawline becomes less defined because of the relative ascent of the anterior and posterior jawline and the descent of the jowl, leading to the appearance of excess jowls.

Indications/contraindications

Fat grafting is a very powerful minimally invasive procedure to treat cosmetic and reconstructive deformities. Although the procedure is very well-tolerated, there are some contraindications, including hematologic abnormalities and anticoagulant medication use (e.g., coumadin, aspirin, clopidogrel). Care should be taken in patients who have unrealistic expectations or have body dysmorphic disorder. Lidocaine should not be used for infiltration or tumescence if the patient is allergic to it. As with other surgical procedures, patients should be medically stable.

Preoperative planning

Preoperative planning is critical for fat grafting. Patients should be adequately assessed, as described previously, and should undergo medical clearance. The appropriate laboratory tests should be performed before surgery. Patients should be instructed to stop all medications that interfere with platelet function 2 weeks before surgery to avoid bleeding complications. Patients should be encouraged to stop smoking at least 1 month before surgery. Photographs of the face and the donor sites should be taken from various angles. Photographs are helpful to plan the surgery, trace the amount and location of planned fat harvesting and grafting, plan the cannula entry points, and critically assess the results postoperatively. Anesthesia type should be discussed preoperatively with the patient and the anesthesia team because both the harvesting and grafting of fat can be performed under general anesthesia or local anesthesia (or regional block), with or without intravenous sedation, depending on the amount of planned fat transfer and the surgical site. Informed consent should be obtained after discussing the procedure, alternatives, and complications. The surgeons should discuss postoperative care and prepare the patient on what to expect during the recovery period. The surgical plan, risks, and benefits should be reviewed again on the day of surgery to address any remaining patient concerns. Throughout preoperative planning, the surgeon should gauge the goals of the patient to ensure that the expectations are realistic and that the patient is ready for the surgery.