Facial fat grafting — Processing, plane of infiltration and contraindicated territories
The four products obtained according to processing, the line separating the lifting from the volumising effect, the plane corresponding to each region, the two contraindicated territories and the biological basis of resorption.
Content intended for healthcare professionals. It does not replace clinical assessment and is not written as patient information.
Key points
- Adipose tissue does not constitute a single product: processing determines four distinct preparations, each with its plane of infiltration and its indication.
- Nanofat contains no viable adipocytes: it delivers the stromal vascular fraction and its mesenchymal stem cells, so its effect is on skin quality rather than volumetric.
- The ligament line delimits two opposite effects: lateral to it the product lifts, medial to it it adds volume.
- There are two contraindicated territories: the lower cheek with the sulci, and the anterior half of the mandibular border between the marionette line and the prejowl.
- Resorption of one third to one half of the volume within the first 6 to 12 months reflects the biological behaviour of a free graft and must be built into the planning.
The basis of the indication
The distribution of facial volume changes with age along a recognisable pattern: the youthful contour approximates a triangle with its base above and the aged contour a triangle with its base below. That change of shape summarises the findings that constitute the object of treatment: temporal atrophy, descent of the brow tail, tear trough and palpebral bags, descent of the malar compartment with accentuation of the nasolabial sulcus and prejowl, labial atrophy, submental accumulation with opening of the cervicomental angle and preauricular atrophy. Against these there are three tools of distinct mechanism: the facelift repositions, commercial fillers add volume of limited duration, and the fat graft adds autologous volume with regenerative capacity.
One qualification orders the indication and avoids unnecessary augmentation: three-dimensional analysis has documented that vertical traction of the midfacial SMAS by itself restores the volume of that region, without additional filling. The consequence is that not every finding interpreted as a volumetric deficit is one; part of it corresponds to displacement and is corrected by repositioning.
The line that determines the effect of the product
The same ligament line that in surgery indicates where to release determines, in aesthetic medicine, what effect the infiltrated material will produce. Its course runs from the temporal crest to the lateral canthus, follows the zygomatic ligament and reaches the mandibular ligament. Lateral to that line the product exerts a lifting effect; medial to it, a volumising effect. Two contraindications follow. The first concerns the lower cheek and the nasolabial and melolabial sulci: augmentation there produces a disproportionate fullness of the lower third that alters the facial contour as a whole. The second concerns the anterior half of the mandibular border, between the marionette line and the prejowl sulcus: volume in that zone masculinises the lower third and accentuates the very prejowl it was meant to correct.
The four products according to processing
The bore of the harvesting cannula and the subsequent treatment of the specimen determine particle size and, with it, both the plane in which it may be infiltrated and its behaviour over time. The relation is direct: the smaller the particle, the greater the contact surface with the recipient bed and the more superficial the plane it tolerates, to the extreme of nanofat, which no longer contains adipocytes.
Processing, characteristics and application
| Product | Preparation | Application |
|---|---|---|
| Macrofat | Cannulae with 2-3 mm ports | The traditional preparation. Particle size entails a risk of irregularity after infiltration |
| Microfat | Cannulae with 1 mm ports | Volumetric augmentation. It is the reference preparation for all deep planes |
| Emulsified, unfiltered | Microfat passed some 30 times between syringes through a connector, without filtration | Structured particles of under 0.5 mm, with greater capillary contact, lower resorption and no irregularity in the superficial plane. 23 G needle, dermal plane, for coarse perioral and glabellar rhytides |
| Nanofat | Microfat emulsified and then filtered, with double emulsification through a 2.4 mm and then a 1.2 mm connector, 40 passes each | Whitish suspension without viable adipocytes, carrying the stromal vascular fraction and mesenchymal stem cells. 27-30 G needle, dermal plane, for fine periocular and perioral rhytides and for the tear trough |
Harvesting the graft
- Donor sitesAbdominal flanks, lateral and medial thigh and, in selected cases, the buccal fat pad. A 5 mm incision with a number 11 blade, usually in the midline below the umbilical scar
- Tumescent solutionModified Klein solution: 400 ml of normal saline, one ampoule of adrenaline, 90 ml of 1 % lidocaine and 10 ml of 8.4 % bicarbonate. Waiting time of 10 minutes
- AspirationBlunt-tipped cannula on a 20 ml syringe, with in-and-out movements, pinching the fat deposit with the contralateral hand to control depth. The harvesting cannula is of larger bore than the infiltration cannula and has cutting ports
- Plane of aspirationHypodermis in all cases. The dermal plane is contraindicated for the risk of permanent irregularity at the donor site
- YieldOnly 30 % of the aspirate corresponds to adipocytes; the remainder is blood, infiltrated solution and other cellular elements. In practical terms, 120 ml infiltrated yields some 80 ml aspirated and around 40 ml of usable microfat
Rationale for two components of the solution
Two elements of the formula have a specific justification. Bicarbonate alkalinises the anaesthetic from a pH of 5 to close to 7, more physiological, which translates into greater analgesic effect and an appreciable reduction in pain during infiltration. There is a trade-off: alkalinisation favours precipitation of local anaesthetics; bupivacaine precipitates immediately, which is why it is not combined, whereas lidocaine takes days, making it safe in this mixture. As to the use of normal saline instead of lactated Ringer’s, the latter was employed to attenuate the metabolic acidosis derived from the anaesthetic, but has been associated with a greater risk of metabolic alkalosis with hypokalaemia and intracellular oedema.
Methods of separating the aspirate
| Method | Procedure | Assessment |
|---|---|---|
| Centrifugation | Tubes at 1,000 rpm for 2 minutes | Of declining use: it has been shown to damage adipocytes |
| Closed-system lipodialysis | The fat is introduced through a port and washed with an equivalent volume of solution | Preferred for the lesser adipocyte damage. Around 50 % of the aspirate is recovered |
| Decantation and gauze | Syringes held vertically for 10 minutes to separate three phases — oil, fat and fluid — removal of the lower phase and decanting of the remainder onto gauze to eliminate the oil | A valid alternative when no closed system is available, requiring no specific equipment |
Infiltration pressure and syringe calibre
The processed fat is transferred from the 20 ml syringes to 1 ml syringes through a connector, and the reason is haemodynamic rather than one of handling. The smaller the syringe volume, the lower the pressure exerted during infiltration, and it is pressure that ruptures adipocytes and that may displace material into a vessel. The same rationale applies to commercial fillers. For the same reason infiltration is performed on withdrawal and in linear passes, rather than depositing static boluses.
Plane of infiltration by region
| Region | Plane | Caution |
|---|---|---|
| Temporal | Between the two laminae of the deep temporal fascia or intramuscular, beneath it. Entry is felt as a click and the cannula ceases to be visible through the skin | Avoid the subcutaneous plane: it produces irregularity and exposes to embolisation of the temporal vessels |
| Upper eyelid | Retro-orbicular without perforating the septum, preperiosteal, depositing the material below the supraorbital rim | Do not perforate the orbital septum under any circumstances |
| Malar | All planes over the malar eminence, including the supraperiosteal | Avoid the lower cheek and the sulci, a contraindicated territory |
| Tear trough | Suborbicular, in the suborbital fat compartment: passage through the orbicularis is felt | A region at high risk of irregularity and persistent oedema. Reduced volume and deliberate undercorrection |
| Mandibular angle and border | Supraperiosteal only | Avoid the anterior half of the mandible, between the prejowl sulcus and the marionette line |
| Chin | Supraperiosteal, for volume and projection | Keep to the midline to avoid creating deviation |
| Lip | Submucosal, in three stages: upper vermilion adjacent to the white roll, wet line and finally the roll itself | The upper lip has three tubercles and the lower two; preserving them is difficult with nanofat |
| Perioral | Subdermal with blanching technique, associated with subsequent CO₂ laser | Overcorrection in this region becomes visible early |
The five entry points
- Lateral to the lateral canthus: access to the tear trough and the malar eminence, and optionally to the upper eyelid and brow tail.
- Over the malar eminence, at the intersection of the ala-tragus line with the lateral canthus-commissure line: access to the tear trough.
- Lateral to the oral commissure: access to the nasolabial sulcus and the malar eminence, and optionally to the lips and melolabial sulcus.
- Mandibular angle: access to the mandibular border and the preauricular region.
- Intersection of the hairline with the zygomatic arch: access to the temporal region.
Sequence in relation to the facelift
There is an anatomical argument for performing fat grafting before rhytidectomy: with the planes intact, infiltration respects the anatomical spaces and the inflammatory response is lesser, allowing more precise placement of the material. From this follows an exception to the contraindication described: the region between the melolabial sulcus and the marionette line is contraindicated for hyaluronic acid because it accentuates the prejowl, but with fat grafting and prior to a facelift it does admit volumetric augmentation of the mandibular border, since subsequent traction redistributes the infiltrated material. The exception is confined to that specific sequence.
The biological basis of resorption
Expected resorption is one third to one half of the material within the first 6 to 12 months, and reflects a precisely described mechanism. After infiltration the graft organises into three zones according to distance from the vessels of the recipient bed: in the superficial zone both adipocytes and stem cells survive; in the intermediate zone the adipocytes die and the stem cells regenerate them; and in the deep zone neither population survives. From this model follow the technical recommendations: fine, widely distributed passes maximise the contact surface with the bed, which explains the lower resorption of preparations emulsified into particles under half a millimetre. In oncological patients with an irradiated bed, deficient vascularity increases overall resorption, so it is preferable to infiltrate a smaller volume and repeat the procedure at six months.
Postoperative care and patient information
- Donor site: compressive dressing for 48 hours followed by a girdle or elastic stocking for one week continuously and a second week at night.
- Recipient site: antibiotic and anti-inflammatory cover, with local cold for the first 48 hours.
- Inform of swelling, bruising and transient irregularity as expected postoperative findings.
- Establish that the result is assessed at six months: the immediate volume includes oedema and a fraction of the material that will resorb.
References
- 1.Coleman SR. Structural fat grafting: more than a permanent filler. Plast Reconstr Surg. 2006;118(3 Suppl):108S-120S.
- 2.Tonnard P, Verpaele A, Peeters G, Hamdi M, Cornelissen M, Declercq H. Nanofat grafting: basic research and clinical applications. Plast Reconstr Surg. 2013;132(4):1017-1026.
- 3.Eto H, Kato H, Suga H, et al. The fate of adipocytes after nonvascularized fat grafting: evidence of early death and replacement of adipocytes. Plast Reconstr Surg. 2012;129(5):1081-1092.
- 4.Suga H, Eto H, Aoi N, et al. Adipose tissue remodeling under ischemia: death of adipocytes and activation of stem/progenitor cells. Plast Reconstr Surg. 2010;126(6):1911-1923.
- 5.Rohrich RJ, Pessa JE. The fat compartments of the face: anatomy and clinical implications for cosmetic surgery. Plast Reconstr Surg. 2007;119(7):2219-2227.
- 6.Jacono AA, Malone MH, Talei B. Three-dimensional analysis of long-term midface volume change after vertical vector deep-plane rhytidectomy. Aesthet Surg J. 2015;35(5):491-503.
- 7.Klein JA. Tumescent technique chronicles: local anesthesia, liposuction, and beyond. Dermatol Surg. 1995;21(5):449-457.
Related specialty: Facial Lifting & Rejuvenation