Fat transfer also referred to as fat grafting is a procedure is a common and important adjunct to many face and body treatments performed in plastic surgery today. Fat grafting is a simple technique that involves taking fat from one part of the body, purifying it, and then reinjecting it into another targeted treatment area.
Though transplantation is a relatively recent development in plastic surgery, the concept of fat transfer is not new. As early as 1893, free fat autografts were used to fill a soft tissue defect. Throughout the early part of the 20th century, attempts were made to correct other conditions, including hemifacial atrophy and breast defects, but modern fat grafting did not develop until the early 1980s with the popularity of liposuction.Illouz reported the transfer of liposuction aspirate fat in 1984. In 1986, Ellenbogen reported the use of free pearl fat autografts in a variety of atrophic and posttraumatic facial deficits. With refinements in technique, fat grafting has become the procedure of choice for an array of problems.
The areas of the face that are most common for fat injections are the lips, nasolabial folds (smile lines), corners of the mouth, chin, and under the eyes. In addition, fat grafting can be an excellent option for rejuvenating the backs of the hands.Older patients may present for correction of specific areas or for overall facial rejuvenation. The anatomic areas not addressed by traditional rhytidectomy, or facial resurfacing often are ideal for fat grafting.
While 30–40% of the harvested cells will be reabsorbed by the body when the fat is reinjected, the remaining fat cells take root in their new location, obtain a blood supply, and become a permanent “filler” in that particular area. To achieve an ideal contour improvement, multiple fat transfer sessions may be necessary.An ideal substance would be readily available, inexpensive, long-lasting, natural-feeling, and would not cause adverse immunologic reactions.
Types of Fat Used for Fat Injections
There are three “types” of fat used for fat grafting: macrofat, microfat, and nanofat. Macrofat is mainly utilized for the augmentation and/or enhancement of larger areas like the buttocks and breasts. On the other hand, microfat and nanofat consist of smaller fat particle sizes, enabling them to be injected into more delicate areas of the body like the face or hands without theappearance of lumpiness that may occur when larger fat particles are injected via bigger instruments.
Apart from fat several types of tissue can be transferred such as Fascia and dermis. Ideally, dermis can be harvested from the area of a previous incision, such as a caesarean delivery or abdominal scar, to avoid a new donor site defect. Strips of these tissues can be useful for larger areas and deeper defects but do not have the flexibility of a liquid or semiliquid substance.
Fat on the other hand can be harvested through inconspicuous stab incisions. The harvesting does not leave a defect, and the removal of fat is often desirable. Fat tissue is soft and feels natural. Despite early views that fat is a relatively inert and isolated tissue, fat has been demonstrated to be a well-vascularized tissue with high metabolic activity. In addition to its structural role, fat tissue serves as a reservoir for energy storage. Once adolescence is attained, any changes in the volume of fatty tissue relate to the size of the cells and their overall lipid content. Cells removed by liposuction or other surgical procedures do not regenerate. Cells shrink with overall weight loss and, in fact, may dedifferentiate. However, subsequent weight gain causes redifferentiation of the cells with an increase in volume.
What can Fat transfer correct
- Facial scarring,post surgical defects including deep acne scars
- Hemifacial atrophy
- Lip augmentation
- Signs of facial aging also can be improved. Rhytides that are too deep to be addressed by resurfacing modalities and areas poorly addressed by traditional lifting procedures (eg, nasolabial folds, glabellar creases, tear troughs) can be treated with grafted fat.
- Buttockand Breast Augmentation
- Body Contour abnormalities resulting from trauma, surgery or biopsy.
The First Consultation
An important part of the first meeting is an extensive discussion identifying areas to be treated. Your needs and goals will be understood and a surgical plan formulated to address them. In addition, details of the procedure, postoperative care, expectations, and possible adverse outcomes will be discussed.Photographic documentation is critical to planning and evaluation of this surgery. The patient should not wear makeup for preoperative or postoperative photographic documentation.
General Guidelines prior to Fat Grafting
- Detailed examination and measurements will be done
- Pre-Operative Photographs for medical record keeping
- Obtain laboratory testing or a medical evaluation
- Pre-operative Anaesthetic assessment for fitness for surgery
- Sign an informed Consent Form
- Stop smoking prior to surgery
- Take certain medications or adjust your current medications
- Avoid taking aspirin, anti-inflammatory drugs and herbal supplements as they increaserisk of bleeding.
- Maintain a stable weight for 3 months prior to the date of surgery
Fat grafting is a procedure done under general anesthesia in a Hospital. Almost any site can be used for harvesting. The abdomen is easily accessible and fatty and therefore most often used. The stab incisions can be hidden within the umbilicus or in the hair-bearing skin of the pubic area.Other donor areas are the buttock lateral thighs arms and knees. The procedure can last from 1 to 3 hours depending on the requirement. The recipient site must be marked out with the patient’s agreement while he or she is in the upright position preoperatively.
The most important principle in the surgical management is the atraumatic transfer of fat. Trauma to fat in the process of harvesting or placing fat affects the survival of the graft. While a nonviable graft initially may appear to have corrected the problem, eventual resorption of the tissue negates the result. Any blood that remains in the harvested fat also facilitates rapid degradation of the transplanted lipograft.
Obtaining Microfat and Nanofat for Fat Transfer
Patient’s own fat tissue is first harvested from a donor area, such as the hips, abdomen, or back. The collected fat is centrifuged to isolate a concentrated volume of healthy, fat cells. This process helps to significantly improve the survival rate of transferred fat. Next, the isolated fat is passed through a sequential series of devices designed to break down the size of the fat particles until microfat or nanofat is attained. (The difference between the two is that nanofat is filtered through an ultra-fine mesh.)
This all-natural microfat or nanofat is then reinjected into targeted treatment areas using very fine injection cannulas to either rejuvenate, smoothen, or volumize the skin with exceptionally natural-looking results.
Microfat due to its smaller particle size compared to conventional macrofat, can be anremarkable option for restoring lost volume and/or improving contour in areas that require absolute precision and finesse, such as the under eye hollows the temples, cheeks, brows, lips and back of the hands.
Nanofat particles on the other hand are too small to provide a notable “volumizing” effect, but studies suggest that the stem cells present in nanofat help to rebuild dermal support structures like collagenand regenerate healthier, more youthful-appearing skin. Some of the most common aesthetic skin concerns that can be improved with nanofat grafting include Fine lines, texture irregularities, sun damage, poor skin elasticity and superficial scarring.
The technique is designed to harvest the fat in parcels of readily transferable size. Common donor sites include periumbilical, lower abdomen, buttock and lateral thigh areas and occasionally the knees and arms. The donor site is anesthetized with tumescent solution through a small stab incision.The same site serves as the access for harvesting. A standard tumescent solution consists of 1 mg of epinephrine, 200 mg of lidocaine, and 5 mEq of sodium bicarbonate in 1 L of Ringers lactate or Normal Saline. Dosages of lidocaine up to 35 mg/kg can be used for the tumescent technique, although substantially less is required for simple fat harvesting.Following infiltration,fat is harvested manually via a small aspiration cannula connected to a negative pressure syringe. Small syringes are recommended to avoid creation of negative pressures greater than 1 atm which could harm the fat cells.
Transfer and Purification of Fat
Once harvesting is complete, the aspirate is then transferred in a sterile manner through multiple syringes using the tulip connections to injection syringes. An alternative to gentle hand tipping is use of the centrifuge. The aspirate divides into 3 layers. The top layer is free oil from ruptured fat cells. This layer is decanted or blotted gently. The bottom layer contains variable amounts of tumescent fluid and blood and is drained. The middle layer consists of fat cells for grafting. Multiple washes of lactated Ringer’s solution rinses local anaesthetic solution and blood away from the fat.
Placement of Fat in Recipient site
For the recipient siteregional nerve blocks are the most useful because adequate anaesthesia can be provided without obscuring the defect to be treated.The goal with any grafting procedure is to gently place the graft in a well-vascularized bed to maximize graft take. Every part of the graft should be within 1.5 mm of living, vascularized tissue. If a large area is grafted, the central area, which is most removed from the blood supply, may not survive.Creating small tracks for the grafts helps keep the grafted fat adherent to the recipient site. The fat is injected with a needle or cannula or gun in a controlled method while withdrawing. Slight overcorrection is important because some absorption will occur. Fat grafting is done from the deep to the superficial layer.
Generally, for areas with large defects or volumerequirement 3 procedures should be anticipated. Even distribution of the injection is crucial. Excess bulk in a particular area may isolate the fat in the central region from the new blood supply.For visible tear-trough or naso labial fold improvements, a combination of pearl fat grafting and sparse fat injection may provide optimal results. This technique uses small pearls (5-8 mm) excised from fat and placed in saline. These pearls are then stacked on top of each other through an incision in the depressed area.
Patients are typically discharged from hospital after a day on antibiotics and pain medication. They need to wear a elastic compression garment for the donor areas for smoother recovery and a light support garment for the recipient area to prevent fat migration. If the fat has been placed in an appropriate tunnel, minimal concern about migration should exist. Ice compresses are applied for 24-48 hours to minimize inflammation.Massage and excessive facial or body animation are discouraged immediately following fat grafting. These restrictions are to prevent migration of fat away from the desired areas of treatment. Swelling and bruising are expected and are mitigated with the help of ice packs etc.
Patients should be seen in the first week postoperatively to check the donor and recipient sites. Some edema and a minimal amount of bruising may be apparentwhich will go away.An additional follow-up appointment should be made for approximately 6-8 weeks. At this point, most of the edema has subsided, and early results can be assessed.
If a repeat procedure is to be performed, a waiting period of 3 months is prudent to allow the first graft to revascularize and to allow any edema to resolve.