Fat grafting in rhinoplasty

What repeats

Five findings that hold across the literature.

About half the injected fat is gone within six months

Three studies in the systematic review measured retention. One reported under 50% at six months, one 44.54% at three months with a range of 21% to 74%, one 50.5% at six months. Of the 849 patients pooled, at least 158 had more than one injection, and the reinjection rate at one year is put at 19.27% or higher.

Elsewhere in the face the figure has been measured under randomisation. Sixty-three patients with facial asymmetry were randomised to one of three ways of processing the fat, and 30 completed a year of three-dimensional scanning. Volume held at 12 months was 41% after cotton pad filtration, 34% after centrifugation and 31% after sedimentation, and filtration beat the other two at every time point.

Rests on: Zeng and Tang, systematic review of fat injection for rhinoplasty · Wu et al., three fat-processing techniques compared.

What does survive is still visible on a scan a year later

One hundred and seven rhinoplasties used diced macrofat bonded with platelet-rich fibrin on the dorsum, with a mean follow-up of 14 months, no wound-healing problems, and graft survival confirmed by ultrasound and magnetic resonance imaging. A separate series of 21 patients with thin or scarred skin showed surviving fat in every patient at one year on both scans.

Rests on: Kovacevic et al., fat transfer with platelet-rich fibrin · Storck et al., characterization of the fat used.

The commonest reason to use it is the skin

Fat is placed as a thin layer between the framework and the skin, to hide small irregularities, to stop the skin shrinking onto a rebuilt dorsum, and to improve the quality of a thin or scarred envelope. Injectable fillers are inert. Fat carries living cells, which is the argument for using it instead.

That use was first described as a routine step in 2007. Three to five millilitres of fat were aspirated at the start of the operation, left to sediment, and 2 to 3 millilitres injected over the bone and cartilage after the incisions were closed and before the splint went on. Seventy-eight rhinoplasties were done that way, 61 of them first operations and 17 revisions, followed for up to 36 months, and the paper reports no minor irregularities in any of them.

Rests on: Cardenas and Carvajal, refinement of rhinoplasty with lipoinjection · Saadoun et al., the role of autologous fat grafting in rhinoplasty · Kovacevic et al. · thin skin and the dorsum.

Adding it to a primary open rhinoplasty reduces bruising

Sixty-two patients were compared. Thirty-three had fat grafted during a primary open rhinoplasty and 29 did not. In the first two weeks the fat group had 7.29 square centimetres less bruising, a difference that held at P below 0.001. The difference in swelling was 0.73 cc and did not reach significance, and by six weeks the bruising difference had gone.

Rests on: Gabrick et al., edema and ecchymoses in primary open rhinoplasty · recovery after rhinoplasty.

Mixed with diced cartilage it acts as glue and as padding

Two hundred and twenty-eight cases used diced cartilage mixed with fat on the dorsum. Mean settling of the dorsum after the first month was 1.4 mm, most of it between one month and six. Rhinoplasty Outcome Evaluation scores moved from 45 before surgery to 81.5 after. Chondrocyte viability in specimens from six patients measured between 85% and 90%.

Rests on: Firat et al., diced cartilage and fat graft combination · diced cartilage on the dorsum.

By what the fat is asked to do

One material, used for five different jobs.

Cover a framework under thin skin

Thin skin shows every edge underneath it. A layer of fat on the dorsum is the published answer, with platelet-rich fibrin added in both imaging series.

The same layer is used to correct a nose already operated on. Twenty patients had 1 to 6 cc of fat injected by the Coleman technique for dorsal irregularities, an inverted V, visible lateral osteotomies and saddle nose. Followed for 18 to 24 months, 18 had a satisfactory result after one session and two needed a second.

Rests on: Baptista et al., correction of rhinoplasty sequelae by lipofilling · Kovacevic et al. · Storck et al. · the inverted-V deformity.

Soften a nose that has contracted after previous surgery

Twenty-four patients with severe nasal contracture were split three ways: eight had shuffled lipoaspirated fat with manual stretching before revision, eight had stretching alone, eight had revision alone. The combined group gained the most nasal length and tip projection. In a separate trial, 40 patients had adipose-derived stromal vascular fraction injected around a revision septorhinoplasty, and nasal length went from 4.2 cm to 5.1 cm at 18 months against a saline control.

Rests on: An et al., shuffled fat with mechanical stretch · Ahn et al., adipose-derived stromal vascular fraction · revision rhinoplasty.

Add bulk instead of an implant

Fat injection has been proposed as an alternative to an operation for augmenting the nose. The systematic review concludes that it is safe and effective, and that resorption means further injections where the deformity is obvious.

The competing injection is a manufactured filler. A systematic review of 30 studies covering 9657 nonsurgical rhinoplasty patients, 96.76% of them treated with hyaluronic acid, records satisfaction of 99.08%, complications in 39.11%, erythema and swelling in 27.95%, and arterial occlusion in 0.27%. The severe events behind that last figure are blindness, skin necrosis and stroke.

Rests on: Song et al., nonsurgical rhinoplasty systematic review · Zeng and Tang · Saadoun et al..

Carry cells alongside cartilage

Thirty secondary rhinoplasty patients had diced cartilage enriched with mesenchymal stem cells. On the Global Aesthetic Improvement Scale at about one year, 80% were rated improved and twenty percent were not satisfied. Stem cells, nanofat, platelet-rich plasma and exosomes are reviewed together as adjuncts for scarred and poorly vascularised noses.

Nanofat is the extreme of that idea. It was described in 2013 as lipoaspirate emulsified and filtered until it passes through a needle as fine as 27 gauge, used in 67 cases for fine wrinkles, scars and dark lower eyelids. Analysis of the three preparations showed no viable fat cells left in the nanofat sample, while the stem cells were still richly present and grew as well as those from macrofat and microfat.

Rests on: Tonnard et al., nanofat grafting · Unlu et al., stem cells with diced cartilage · Jones and Toriumi, regenerative biologics.

Balance the nose against the rest of the face

Twenty patients had rhinoplasty and full-face fat transfer in one sitting, followed for a mean of 10.2 months. Nasal length and protrusion rose, the nasolabial angle moved from 106 degrees to 101, and volume increased at the forehead, temples, inner cheeks and chin.

Rests on: An et al., simultaneous full-face fat transfer · chin augmentation with rhinoplasty.

What to ask about fat grafting to the nose

Questions the evidence supports asking.

How much will still be there in a year, and how many sessions

Retention is the whole argument. Ask what proportion the surgeon expects to keep and whether they have measured it. The three published measurements sit at or below half, and at least 158 of the 849 pooled patients had more than one injection. Ask what happens if the first session under-fills, and what a second one costs.

Rests on: Zeng and Tang · the cost of rhinoplasty.

Where is the fat taken from, and what is mixed into it

The published series harvest from around the navel or from the rib area at the time of a cartilage harvest. Ask whether platelet-rich fibrin, stromal vascular fraction or anything else is added, and what evidence there is for it. The one randomised test of platelet-rich fibrin grafted 18 patients' temples, fibrin on one side and the same volume of saline on the other. Three-dimensional reconstruction found no difference in the volume that survived. The treated side recovered faster.

Rests on: Zhang et al., platelet-rich fibrin split-face trial · Kovacevic et al. · Storck et al. · Ahn et al..

What can go wrong, and is this instead of surgery or alongside it

Complications reported in the pooled series are uncommon, and swelling and bruising are named most often. Ask what the surgeon does about an over-filled area, since fat that survives has to be removed. Ask also which proposition this is: fat as a substitute for an operation and fat as a layer added during one carry different evidence.

The rare event is an arterial one, and it is reported for fat as well as for filler. A systematic review collected 61 patients with arterial embolism after facial fat injection, mean volume injected 21.5 ml, most often at the glabella, the temples or the forehead. Visual symptoms appeared in 41.4% and the ophthalmic artery was the vessel blocked in 43.3%. Every one of the 26 patients with an ophthalmic artery occlusion lost vision permanently. Six patients died. A separate review of every reported case of vision loss after an injectable found 98 of them, with autologous fat the commonest material at 47.9% and hyaluronic acid next at 23.5%, and the nose the second commonest site at 25.5%.

Rests on: Moellhoff et al., arterial embolism after facial fat grafting · Beleznay et al., blindness from fillers · Zeng and Tang · Saadoun et al. · Gabrick et al. · the clinical practice guideline.

The terms, defined

The words used about fat in the nose.

• Autologous fat grafting: the patient's own fat, moved from one part of the body to another. [36100254]
• Lipoaspirate: the fat as it comes out of the liposuction cannula, before processing. [35606536]
• Retention: the share of injected volume still present at a stated time. [39751904]
• Stromal vascular fraction: the cell-rich fraction separated from fat and injected on its own. [33620926]
• Platelet-rich fibrin: a preparation spun from the patient's blood and mixed with the fat. [33636740]
• Nanofat: mechanically emulsified fat used for its cells rather than its volume. [42091333] [23783059]
• Microfat: fat taken through a small-hole cannula, for injection through fine needles. [23783059]
• Arterial embolism: fat forced into an artery and blocking it, the cause of vision loss after an injection. [37563433]
• Soft tissue envelope: the skin and the layer under it that covers the nasal framework. [38688299]
• Diced cartilage: cartilage cut into small pieces, often mixed with fat on the dorsum. [33683385]
• Rhinoplasty Outcome Evaluation: the patient-completed score used as the endpoint in these series. [33683385]

Where else this is documented

Sources outside the journals, each one free to read.

The national guideline

The American Academy of Otolaryngology published a clinical practice guideline on nasal form and function after rhinoplasty, with a plain language summary written for patients. It sets what should be discussed and recorded before surgery, whatever material is used.

Rests on: the clinical practice guideline · the plain language summary.

The surgeons' own textbook chapter

Rhinoplasty Archive, the free online rhinoplasty textbook edited by Daniel G. Becker, has no chapter on fat, and its nearest chapter covers the same job done with cartilage.

• The use of crushed cartilage grafts for camouflage and contouring in rhinoplasty

The reference summaries

• Autologous Fat Grafting for Facial Rejuvenation in StatPearls, covering harvest, processing and the survival problem.
• Nonsurgical Rhinoplasty Using Fillers in StatPearls, the injectable alternative, with its vascular complications.

The societies

• American Academy of Facial Plastic and Reconstructive Surgery, fat transfer patient information.
• American Society of Plastic Surgeons, rhinoplasty patient information.

The trials in progress

• 3D Facial Scanning for Evaluating Autologous Fat Grafting in Craniofacial Deformities, recruiting, 100 participants.
• Autologous Fresh Fat Grafting Followed by Autologous Cryopreserved Fat Grafting, recruiting, 22 participants.

What is not settled

• Retention is measured three different ways at two different time points, and the systematic review reports the figures separately because they cannot be pooled. [39751904]
• No randomised trial compares fat against a cartilage graft for the same job on the dorsum. The imaging series that show survival have no control group. [33636740] [38688299]
• Platelet-rich fibrin has been tested once against saline in a split-face trial and made no difference to the volume that survived. Whether stromal vascular fraction or stem cells add anything over fat alone is untested. The regenerative adjuncts are reviewed as emerging. [35495758] [42091333] [39444535]
• Vision loss after injection is counted from case reports, not from a denominator. Neither review can say how often it happens per thousand procedures. [37563433] [26356847]
• The bruising benefit rests on one comparison at one centre, and the swelling difference in the same study was not significant. [30868159]
• Long-term shape after fat on the dorsum is reported at 14 months at most. [33636740] [33683385]