What Is A Blow Out Deformity?

What a Blow Out Deformity Is

A blow out deformity is a swollen bulge of dead fat. It forms when a large volume of fat is placed in a single space and those cells never reconnect to a blood supply. A Brazilian butt lift transfers fat from another area of the body into the buttocks. That transfer is fat grafting. It is done to add fullness, roundness, and projection. The bulge from dead fat is not that planned projection. It is a lake of cells that swells out of the shape the graft was meant to create.

The medical name for dead grafted fat is fat necrosis. Fat necrosis can follow a large bolus placed where the blood supply is thin, and the dead fat may harden. If only a small volume of fat cells die, they become firm and calcified, and the body can remove them. If a large volume dies in one region, the body cannot reabsorb the cells. They collect, irritate the surrounding tissue, and can become infected. The area becomes inflamed, and the skin bows outward. The change in shape can be dramatic, and it has to be treated.

Why the Grafted Fat Dies

Grafted fat cells have to reconnect to blood vessels. Arteries bring in oxygen and nutrients. Veins carry away carbon dioxide and waste. That blood supply is called vascularity. If the cells do not establish vascularity, they die. A living graft depends on that new connection. Without it, the transferred fat cannot stay as living tissue.

The size of each deposit matters as much as the total volume. Fat placed as one thick mass has cells in the center that sit far from the nearest vessel. Those central cells fail first. The same amount of fat, divided into many small packs, gives each pack tissue on every side from which it can pick up a blood supply. This is why the deformity tracks back to bulk. A thin, even layer of graft does not create the same lake of dead cells.

A small calcified spot and a swollen collection are not the same problem. The firm, small spot may be one the body can clear over time. The swollen collection is the lake. It stays because the volume of dead fat is too large to be carried away. Once that lake is inflamed, or once it becomes infected, the outward bulge is what patients and surgeons see.

How the Fat Is Placed

The fat is harvested with liposuction before it is grafted. On a Brazilian butt lift, that harvest often includes the waist and flanks, the back, and the outer thigh. Liposuction of the waist narrows the midsection while it collects the fat that will be moved. The harvested fat is then placed into the buttocks. The graft belongs in the soft tissue of the glute, in the tight space between the skin and the muscle. It does not belong inside the muscle.

Fat in the muscle can cause a fat embolism. For that reason the injecting cannula stays in the soft tissue above the gluteus maximus. Ultrasound is used so the surgeon can see that the cannula has not entered the muscle. The fat stays between the skin and the muscle, where it can meet small blood vessels, and it stays out of the deeper veins.

The receiving space is narrow even when the cannula is in the right plane. A buttock that is already full has less room for a new graft. Packs that are forced into that tight space press on one another and on the vessels that would feed them. Placement is therefore a matter of where the fat sits, how it is divided, and how much the tissue can accept.

How Small Packs Prevent a Lake of Dead Fat

During buttock fat transfer, each pack of fat is kept small. The fat cells are placed in packs no greater than 0.5 cc. They are injected from different directions, through more than one port site, so the packs are cross-hatched across different planes instead of sitting in one straight line. A single tunnel of fat behaves like a bolus. Cross-hatching breaks that tunnel into separate deposits.

The surgeon has to picture the buttock in three dimensions so those packs are not piled on one another. Two packs that look separate on the skin can still meet under the surface if they were injected along the same deep line. Changing the entry site and the angle is what keeps the deposits apart. That three-dimensional spread is the practical form of the rule that fat should not collect in one space.

Expansion vibratory lipofilling, or EVL, can widen the tight space so more fat can be grafted safely. EVL uses a micro vibratory cannula called PALS, which stands for power-assisted liposuction. The cannula expands the soft tissue just enough to hold each 0.5 cc pack. The expansion does not move the graft into the muscle. The packs still sit between the skin and the muscle, and each pack is still no greater than 0.5 cc.

How Much Fat Is Too Much

The most common cause of this deformity is overfilling. As a general rule, avoid more than 1,000 cc of fat in each buttock. Past that volume, separate packs are more likely to merge into one bulk, and the tissue has less room to supply them with blood. A smaller graft that is spread through the soft tissue is safer than a larger graft that is stacked in one area.

The intended result is projection of the buttock and a smooth line through the hip. Filling the lateral hip is part of shaping the side of the buttock, and it is still fat grafting into soft tissue, not a license to overfill the center. Adding volume until the skin is tight does not create a better shape. Tight skin means the space for blood flow has already been used up. That is the setting in which dead fat collects and swells.

Patients sometimes ask for the largest change the waist and the buttock can show at one operation. The safer plan is the volume the tissue can feed. A graft that lives will still be there after swelling resolves. A graft that dies becomes the collection that has to be removed later. Conservative volume is therefore part of the technique, not a compromise added at the end.

How to Correct a Blow Out Deformity

A blow out deformity is difficult to correct. The pool of dead cells has to be removed, and a liposuction cannula cannot simply suck them out. Living fat can be removed with liposuction because it is soft and still in separate deposits. Dead fat that has formed a lake is not the same material. It does not travel up a cannula the way living fat does. The treatment is an incision and drainage.

The cavity is then washed with an antibiotic solution so leftover dead cells are cleared and the field is clean. Any skin redundancy is removed with a formal excision. The extra skin is the cover that stretched over the lake. If that skin is left behind, the contour stays uneven even after the fluid and the dead fat are gone. Drainage, irrigation, and excision are the three parts of the correction, and they are done together.

A small, firm, calcified spot may still be one the body can clear. A swollen lake that is inflamed or infected is not a spot to watch. Once the collection has formed, a compression garment does not empty it. The operation is what removes the dead fat and the stretched skin.

Care After Fat Grafting

After an uncomplicated fat graft, a compression garment is worn and strenuous activity is limited for two weeks. Weight should stay stable so the new contour does not shift as the body changes. Those steps support living fat while it establishes vascularity. They are the ordinary care after buttock fat transfer. They are not the treatment of a lake of dead fat.

Pressure on the grafted buttock is also limited while the cells are picking up a blood supply. Sitting fully on the central buttock presses the packs. Positions that keep weight off that central area give the graft a better chance to survive. None of that aftercare replaces incision and drainage if a blow out has already formed. It is how a healthy graft is protected, not how a formed collection is repaired.

A Blow Out Deformity in Brief

Dead fat collects when a large bulk of grafted cells never establishes blood flow. If the body cannot reabsorb those cells, they irritate the tissue and often become infected. Small packs, placement in the soft tissue of the glute, and a volume under 1,000 cc in each buttock are what keep the graft from becoming that lake. Once the deformity has formed, correction means incision and drainage, an antibiotic wash, and excision of the extra skin.

Please see this 26-year-old female who had a maximized BBL while avoiding a blow out deformity.