Fat Graft Survival After a BBL or Fat Transfer: What Affects It and What the Evidence Says

Some of the fat transferred in a BBL, a breast fat transfer, or a facial fat transfer does not survive. A 2021 meta-analysis of 27 facial fat grafting studies covering 1,011 patients found that the retained volume ranged from 26% to 83%, with a pooled average of 47%. The result you see in the first weeks is not the result you keep. This article covers why grafted fat is lost, what affects how much stays, and where the Hyperbaric Oxygen Therapy (HBOT) evidence stands. That evidence is preclinical: two small animal studies with mixed results and one human trial that has not reported.

Why transferred fat is lost

Grafted fat arrives with no blood supply of its own. In the first days it survives on oxygen and nutrients diffusing in from the surrounding tissue, and it only gains a lasting supply once new capillaries grow into it. Fat cells farthest from a vessel are the first to die, and the body absorbs them over the following months. The StatPearls entry on autologous fat grafting  describes graft survival and volume retention as the primary problem of the procedure.

What affects how much stays

The meta-analysis by Lv et al. (2021)  found that the measurement method significantly changed the reported retention rate, and that secondary grafting procedures trended toward better retention than first procedures. Its authors concluded that the exact percentage retained is currently unpredictable. The factors surgeons control are the ones StatPearls lists: recipient site preparation, how the fat is harvested and processed, how it is placed, and the pre-operative and post-operative management around it. Your surgeon's instructions on pressure over the grafted area, on compression garments, and on smoking are part of that management and take priority over anything below.

Where the HBOT evidence stands

No human study has measured fat graft retention with and without HBOT. The rationale is the diffusion window described above: at 2.0 ATA, substantially more oxygen dissolves into blood plasma, and the hypothesis is that grafted cells waiting for a blood supply survive longer when the surrounding tissue carries more oxygen. What has been tested is listed below.

• Shoshani et al. (2000) : human fat placed in 40 immunodeficient mice, with daily 90-minute sessions at 2 ATA for 5, 10, or 15 days. Graft weight and volume did not differ significantly between groups at 15 weeks. Tissue integrity on microscopy was better in the 5-day group, and the 15-day group had the worst results. Longer courses trended worse.

• Liang et al. (2023) : 90 rats with 1 ml fat grafts, given one hour of HBOT a day, two hours a day, or none, for 10 days. At six weeks the one-hour group retained 0.473 ml against 0.169 ml in the untreated group, and the two-hour group retained less than the one-hour group. The abstract does not state the chamber pressure or p-values.

• Yoshinoya et al. (2020) : human adipose-derived stem cells in culture, exposed to 2 and 3 atmospheres. The 3-atmosphere exposure increased cell viability and proliferation and pushed the cells toward fat-forming differentiation. This is a cell study and says nothing about graft retention in a person.

• NCT07140198 : a randomized crossover trial at University Hospital Geneva of 16 breast reconstruction patients after radiotherapy, with five 90-minute sessions at 2.5 ATA in the first three days after fat transfer and MRI volume retention at six months as the primary outcome. It has been recruiting since March 2026 and has no results.

Two figures that circulate on clinic websites do not hold up. A 2022 rat study reporting improved survival and new vessel growth was retracted in December 2023  for manipulation of the peer-review process, so it is not cited here. The "90% or better retention" claim traces to a narrative review  describing one surgeon's own practice, with no comparison group and no measurement method. The one consistent signal across the animal work is that more HBOT was not better than less.

Timing around a fat transfer

For surgical clients, a 6-session package is typically structured as one session before surgery and five as soon as possible after, sometimes the same day if your doctor allows. The animal courses that did best were short, and the Geneva trial concentrates its five sessions in the first three days after surgery, which is close to the shape of that package. The pre-surgery session follows the pre-conditioning rationale described in HBOT before surgery. Inside the chamber you sit or recline, and your surgeon's rules on pressure over the grafted area apply there as anywhere else, so tell us which areas were grafted before your first session.

HBOT in Los Angeles

HBOT is not FDA-cleared for fat graft retention or cosmetic surgery recovery. At OxyRenew in West Hollywood, sessions run in a private 2.0 ATA hard-shell chamber with a Certified Hyperbaric Technician monitoring from start to finish, and you breathe concentrated oxygen through a mask or cannula.

Book your first session online, or contact us to speak directly with a Certified Hyperbaric Technician about timing around your procedure date. You can also read about capsular contracture after breast augmentation and more about HBOT for surgery recovery.