3 Causes of Failed Fat Transfer — Correction Methods for Nodules, Resorption, and Asymmetry

3 Causes of Failed Fat Transfer — Correction Methods for Nodules, Resorption, and Asymmetry

Expected natural rejuvenation, but regretting nodules or irregularities? We explain the secrets to avoiding failure and correction methods.

• After fat transfer, there is a risk that approximately 47% of fat on average will be resorbed without establishing
• Nodules (fat necrosis), once formed, do not disappear naturally with massage, etc.
• The biggest cause of failure can be broadly divided into two categories: "physician injection technique" and "post-operative care"
• Even if failure occurs, it is entirely possible to restore your natural facial features with appropriate revision surgery

"Natural rejuvenation should have been achieved, but instead I ended up with an unnatural irregular face…"

Fat transfer utilizes your own fat to compensate for facial volume loss and restore a youthful appearance. Unlike artificial substances such as hyaluronic acid, it is an extremely popular aesthetic medical procedure expected to deliver natural results. However, it is also true that the internet and social media are filled with painful testimonies such as "unnatural nodules formed," "the fat was resorbed quickly and I returned to my original state," and "my facial balance became asymmetrical."

Did you know that on average, approximately 47% of fat is resorbed after fat transfer to the face?

Why does such a terrifying failure occur despite paying high fees and selecting a prestigious clinic?

In fact, the success rate of fat transfer changes dramatically with "one specific step." This article thoroughly explains the 3 causes of fat transfer failure and revision surgery methods, incorporating evidence from medically authoritative scientific papers worldwide so that general readers without medical knowledge can fully understand.

Why Does Fat Transfer Fail in the First Place? [The Fateful Crossroads Between Success and Failure]

Fat transfer failure is never merely a matter of "luck." There are clear reasons based on medical mechanisms. The main causes can be divided into the following 3 categories:

Variation in Resorption Rate: Why Does Fat Disappear?

The most common complaint about fat transfer is "the fat I had injected disappeared so quickly." As mentioned above, the overall volume retention rate (engraftment rate) in autologous fat transfer to the face is reported to be an average of 47% (95% confidence interval: 41–53%).
Whether fat establishes depends on how quickly new blood vessels connect to the injected fat cells and supply nutrients and oxygen. Fat cells that become nutrient-deficient before blood flow resumes are absorbed into the body and disappear. Regarding the fat engraftment rate 6 months after facial fat transfer, a significant improvement in engraftment rate is reported in groups using fat with impurities thoroughly removed and purity increased compared to standard technique groups. In other words, the quality of the fat purification process greatly influences the resulting engraftment rate.

Technical Issues: "Immature Injection" Producing Unnatural Irregularities

Be wary of physicians who say, "Let's inject more fat to increase the engraftment rate." This is an extremely dangerous approach.
When the fat particle (parcel) being injected exceeds 1/30–1/50 mL, oxygen and nutrients do not reach the center, increasing the risk of central necrosis (a phenomenon where oxygen and nutrients fail to reach the center of the injected fat particle, causing cell death) (Coleman 2006). When a large amount of fat is injected together in one location, only the surrounding fat (approximately 40% within a range of approximately 1.5±0.5 mm) can survive, and the center undergoes necrosis. This becomes the cause of nodules described later.

Impact of Post-operative Care: NG Behaviors That Lower Engraftment Rate

Even if the surgery is perfect, the transplanted fat can easily die depending on how you care for yourself after the procedure. You must absolutely avoid strongly rubbing the injection site or applying physical pressure such as massage. The newly formed delicate blood vessels can be torn by physical damage, cutting off the nutrient supply to the fat cells. Additionally, smoking constricts capillaries, making it the worst factor that significantly reduces engraftment rate.

The 3 Major Failure Patterns and Their Reality【The Terrifying Changes Happening to Your Face Right Now】

Fat injection failures can be broadly categorized into the following 3 patterns.

Excessive absorption (Volume deficiency and reversion)

A pattern where the volume gradually decreases over 1-3 months after surgery, leaving you feeling that "nothing has changed compared to before the operation." When excessive absorption occurs, it is standard practice to wait 3-6 months or more before re-injecting fat (touch-up) to approach the ideal volume. Since the vascular foundation (bed) is formed during the first injection, the second injection has the advantage of better engraftment.

Nodule formation (The terror of fat necrosis and calcium deposition)

The most troublesome failure is "nodule" formation. When fat necrosis (a phenomenon where fat cells die due to insufficient blood flow) occurs due to poor blood circulation, the body treats the dead fat as a foreign substance and encapsulates it with hard capsular tissue. If left untreated, it can lead to calcium deposition (a phenomenon where mineral components accumulate hard around the dead fat tissue), forming stone-like hard nodules that become palpable from the skin surface.
According to research data, while the incidence of nodules (fat necrosis) from the conventional single-point high-volume injection method was 14.5%, the micro-dispersed injection technique significantly reduced this to 2.3% (p<0.01).

Asymmetry between left and right (Facial balance collapse)

Although the human face is inherently asymmetrical, unnatural left-right differences can occur due to the physician's miscalculation of injection volume or differences in engraftment rate between the left and right sides.
According to the literature, for patients complaining of left-right asymmetry after fat injection, corrective surgery combining fineliposuctionand re-injection resulted in significant improvement in the patient's facial symmetry score from 45% pre-operatively to 89% post-operatively, demonstrating very high corrective effectiveness (p<0.001).

The 3 Major Failure Patterns of Fat Injection | Corrective Surgery Comparison Table

※The figures are based on evidence from medical literature (Coleman 2006, et al.)

How Far Can Corrective Surgery Go【The Final Resort to Recover Your Original Face from Despair】

There is no need to despair thinking "Will I be stuck with this face forever if it fails?" With a specialist physician possessing advanced technique, recovery through corrective surgery is possible.

• Steroid injection:For relatively soft nodules in the early stage or excessive volume, steroid injection can cause tissue atrophy and make them less noticeable. However, careful judgment is required due to the risk of over-depression.
• Fine liposuction:To remove overly engrafted fat or nodules, fat is precisely aspirated using an ultrafine cannula (suction tube).
• Incisional nodule removal:Hard, stone-like nodules accompanied by calcium deposits cannot be removed by injection or aspiration. A small incision is made from an inconspicuous location, such as behind the lower eyelid or inside the mouth, and the nodule is directly extracted.
• Re-injection into depressions:After nodule removal or in areas that have become depressed due to fat aspiration, minute amounts of fat are carefully injected in multiple layers to reconstruct a smooth contour.

Criteria for choosing a surgeon and clinic without failure【Absolute conditions to never regret again】

The most important factor in fat injection is the surgeon's technical skill in "how finely and in how many layers the fat can be dispersed and injected."
When selecting a clinic, confirm whether they employ MAFT (Micro-Autologous Fat Transfer: a technique that injects fat in extremely fine units to increase engraftment rate). Clinics using specialized equipment that controls each injection volume to 0.01 mL or less are demonstrating their effort to minimize nodule risk.
Additionally, whether they offer techniques to increase engraftment rate by adding SVF (Stromal Vascular Fraction: a cell group rich in stem cells and other cells contained in adipose tissue that promotes angiogenesis) is also a point to assess their level of expertise. Most importantly, choose a surgeon who has published numerous before-after case photos of past "revision surgeries" and possesses the anatomical knowledge and technical skill to address failures from other clinics—this is the absolute condition for never regretting your decision.

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Summary of this article【To stop repeating failures】

• Fat injection failures concentrate in 3 patterns: "excessive absorption, nodules (fat necrosis), and asymmetry."
• The greatest cause of failure is "immature technique"—injecting fat all at once in large chunks.
• Even if nodules or asymmetry occur, appropriate revision surgery such as fat aspiration or incisional removal can improve the condition.
• Selecting a surgeon with advanced techniques such as micro-injection (MAFT) based on scientific evidence is extremely important.

FAQ (Frequently Asked Questions)

Q1. Can I self-massage nodules (fat necrosis) to make them go away?
A. No, they will not. In fact, it has the opposite effect. Forceful massage with strong pressure can damage surrounding healthy tissue, triggering inflammation or fibrosis (a phenomenon where damaged tissue is replaced by hard fibrous tissue), making nodules even harder and more noticeable. Please consult a specialist experienced in revision treatment as soon as possible.

Q2. If fat is absorbed without engraftment, when can re-injection be performed?
A. Generally, 3 to 6 months after surgery is the guideline. During the months following surgery, angiogenesis and remodeling (reconstruction) occur within the tissue, and the condition is unstable. It is safest and most reliable to perform the second injection (touch-up) only after the condition has completely stabilized and the volume of remaining fat is confirmed.

Q3. Are there ways to improve the retention rate of fat grafting, even slightly?
A. Yes, there are. From the medical institution's perspective, established evidence-based methods include MAFT (microfat autologous fat injection), which disperses fat in units smaller than a grain of rice for fine distribution, and the simultaneous injection of SVF (stromal vascular fraction) extracted from adipose tissue to powerfully promote angiogenesis. As for what patients can do themselves, it is extremely important to absolutely avoid compressing the treated area post-operatively, and to completely refrain from smoking before and after the procedure, as it impairs blood flow.

References

1. Coleman SR. "Structural Fat Grafting: More Than a Permanent Filler." Plastic & Reconstructive Surgery, 2006. DOI: 10.1097/01.prs.0000234610.81672.e7
2. Azoury SC et al.. "Modern Fat Grafting Techniques to the Face and Neck." Plastic & Reconstructive Surgery, 2021. DOI: 10.1097/PRS.0000000000008405
3. Vizcay M et al.. "Current Fat Grafting Practices and Preferences: A Survey from Members of ISPRES." Plastic and Reconstructive Surgery - Global Open, 2023. DOI: 10.1097/GOX.0000000000004849
4. Firriolo JM et al.. "Fat Grafting as Regenerative Surgery: A Current Review." Plastic & Reconstructive Surgery, 2022. DOI: 10.1097/PRS.0000000000009710

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Supervising Physician for This Article

Hiromitsu Nakamura (中村 仁光)

Director of Zettis Beauty Clinic. Certified Specialist in Plastic Surgery. Member of the Japan Society for Aesthetic Plastic Surgery (JSAPS). He actively incorporates the latest evidence from domestic and international conferences and performs precision procedures tailored to each individual's skeletal structure and tissues.