New concepts in fat grafting

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CHAPTER 61 New concepts in fat grafting

Ewaldo Bolivar de Souza Pinto, Paulo R. Carneiro, Leonora d’Ascensão Mansur, Rodrigo Federico

History

In the 1980s, an important step was taken in body contour surgery, resulting in the liposuction procedure. It was based on the introduction of a large caliber cannula and aspiration of fat tissue, previously marked. This technique was initially abandoned, because the medical community was not convinced that the technique produced good results; also, there were concerns about the aggressiveness of the procedure, as well as potential injury to adjacent tissues. However, with the technique’s evolution, diverse instrumentation was developed, particularly regarding the types of cannula. Changes were made to caliber and tip configuration.

Nowadays, two types of liposuction are known: the dry technique, using no infiltrate, with the intention of making the fat tissue undermining easier; and the humid technique, that uses the infiltration of physiological saline or Ringer’s lactate associated with other substances, with the intention of promoting a more turgid tissue and reducing blood loss.

Histologically, the presence of two different fat layers in some body areas enabled the development of two techniques of liposuction: (1) deep liposuction, that covers the lamellar layer; and (2) superficial liposuction, that reaches both the lamellar and areolar layers, leading to skin retraction and better results on the contour of the treated areas.

Fat grafting, currently a widely used procedure, has undergone important changes along with liposuction. It is known that the first fat graft was described by Neuber in 1893; another important contribution was given by Pier in 1956, reporting that 50% of the infiltrated fat remained.

The fat grafting performed by us since 1985 has evolved, along with the methods of obtaining fat, and processing of the tissue.

Histology of the fat tissue

The fat cells are also known as adipocytes. When a certain tissue is composed almost uniquely of fat cells, organized in lobes, it is termed adipose tissue.

The fat cell lobes are separated from each other by “walls”, divisions of loose conjunctive tissue that support them. We also observe blood vessels and nerves in the interior of the fat tissue.

Inside the lobe, the fat cells are supported by the stroma, which is comprised of collagen and reticular fibers, arranged in an interspersed net shape.

Technical steps

Method for obtaining fat

Many body areas can be used to obtain fat; however, as a standard pattern for small grafts, we recommend the inner part of the knees, with a volume varying between 5 and 10 mL of fat. Where there is a need for greater amounts of fat, we then opt for areas like the abdomen, “saddlebags”, and other areas with a high percentage of fat.

We use the superficial liposuction technique to collect fat, reaching both lamellar and areolar layers. The sequential method for obtaining and preparing the fat is described below.

The first step, after asepsis, no matter what kind of anesthesia is chosen, is to infiltrate saline solution with the following proportions:

• 500 mL of Ringer’s lactate or saline solution.

• 20 mL of lidocaine 2%.

• 1 mL of adrenaline 1 : 1000.

• 3 mL of sodium bicarbonate 8.4%.

We then proceed with the liposuction, using cannulas of 3 to 6 mm caliber. The obtained fat is aspirated with a pressure around 370 mmHg, with the intention of protecting the fat cell. Studies have shown that higher pressures can damage the fat cell (Fig. 61.1).

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Fig. 61.1 Obtaining fat.

We have evaluated the pressure variation and its effect on percentage of cell viability. We used five samples for each pressure value (between 370–590 mmHg):

1. Fat gathered with no special preparation.

2. Saline solution added to the fat and then sieved.

3. Fat that passed through the sieve (Fig. 61.2).

4. Fat retained in the sieve, injected with a 40 × 12 mm needle.

5. Fat injected with graft cannulae (Fig. 61.3).

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Fig. 61.2 Passing fat through sieve.

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Fig. 61.3 Injecting fat with cannulae.

Histological evaluation

The gathered material was stored in Formalin 10% with 3–4 mL of fat. The samples were analyzed with a microscope. The criterion of cell viability was established by the presence of cells with an intact nucleus and membrane. We observed the following results:

• 500 mBar pressure:

– Non-washed sample: viability around 50–60%; cellular rupture in central area.
– Washed sample: viability around 60–70%, with no or little cellular rupture (Fig. 61.4).
– Sample passed through the sieve: viability around 10–15%; small quantity of cellular integrity on the periphery.
– Sample used with needle: viability around 30–40% (Fig. 61.5).

• 800 mBar pressure:

– Non-washed sample: viability around 40–50%.
– Washed sample: viability around 50–60% (Fig. 61.6).
– Sample passed through the sieve: viability around 10–15%.
– Sample used with needle: viability around 25–30% (Fig. 61.7).
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Fig. 61.4 500 mBar pressure, washed, 60–70% cell viability.

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Fig. 61.5 500 mBar pressure, needle, 30–40% cell viability.

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Fig. 61.6 800 mBar pressure, washed, 50–60% cell viability.

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Fig. 61.7 800 mBar pressure, needle, 25–30% cell viability.

The samples obtained after passing through the 40 × 12 mm needle, with both 500 and 800 mBar pressure, showed a fat cell destruction of around 50% of the initial number, caused by the high pressure inside the needle.

We have also added a new variant for cellular integrity evaluation, based on the exposure time after fat harvesting. It is done using 500 mBar pressure.

Five different measures were taken: right after harvest; 30 min; 60 min; 90 min and 120 min, with both washed and non-washed fat. The findings were:

• From 0 to 60 min: fat cells were preserved with good shape and well-distinguished nucleus.

• After 60 min: fat cell destruction varied from 30% to 70%, with high tissue alteration.

Based on these findings, we suggest that the time of exposure from zero to 60 minutes offers better quality of fat cells for grafting, when the fat is washed with saline solution.

After 60 minutes we notice major changes within the fat cell, which vary from a simple modification on the contour to the complete destruction of the cell.

Here we show some cases to illustrate the results and to exemplify the procedure after grafting with a 40 × 12 mm needle and with an infiltration cannula (Fig. 61.8).

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Fig. 61.8 Syringe and graft cannulae.

Conclusion

• We conducted microscopic experimental studies and established some concepts that can be applied to enhance clinical practice. These are: (1) a defined pressure of 370 mmHg and (2) a preparation time of 60 minutes.

• Regarding the cannula diameter, we have established that 3 to 6 mm allows us to collect a more even material and fat cells with greater vitality.

• We also established that the fat must be washed with saline solution, so that we can remove those cells with less viability, in other words, the fat cells that would be destroyed by the liposuction process. This fat, when prepared and filtered as described above, is presented in a more homogeneous form. Using this standard pattern, we achieve an average time of 60 minutes between the harvest and the injection of the fat.

• Through histological evaluation, we observed that the cells suffered damage over time, and after 120 minutes considerable morphological modifications occur which jeopardize the fat grafting procedure.

• The goal of fat grafting is the augmentation by fat tissue integration at the recipient site, and not via a fibrosis reaction as described in some papers. We prefer the technique described here to ensure the graft’s viability (Figs 61.9–61.15).

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Fig. 61.9 Fat graft in shoulder after 2 years.

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Fig. 61.10 Fat graft in shoulder, preoperative.

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Fig. 61.11 Saddle bag, preoperative.

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Fig. 61.12 Saddle bag, after 3 years.

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Fig. 61.13 Gluteus correction, preoperative.

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Fig. 61.14 Gluteus correction postoperative, after 4 years.

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Fig. 61.15 A&B, Pre- and post-nasolabial fat grafting using needle.

Further reading

Aboudib Júnior JH, De Castro CC, Gradel J. Hand rejuvenescence by fat filling. Ann Plast Surg. 1992;28(6):559–564.

Carpaneda CA, Ribeiro MT. Study of the histologic alterations and viability of the adipose graft in humans. Aesthet Plast Surg. 1993;17(1):43–47.

Collins PC, Field LM, Narins RS. Liposuction surgery and fat transplantation. Clin Dermatol. 1992;10(3):365–372.

Curi M, Singer MJ, Iaconelli LM, et al. Transplante autógeno de gordura em ratos. Ver Paul Med. 1991;109(1):24–26.

Eppley BL, Sadove AM. A physicochemical to improving free fat graft survival: Preliminary observations. Aesthet Plast Surg. 1991;15(3):215–258.

Eppley BL, Synders RV, Jr., Winkelman T, Delfino JJ. Autologous facial fat transplantation: Improve graft maintenance by microbead bioactivation. J Oral Maxillofac Surg. 1992;50(5):477–482. discussion 482–483 –

Guerrerosantos J, Flores M, De-Leon O. Free fat autografting for cervico-facial augmentation: A 5-year study. Plastic Surgery Forum. 1988;11:216.

Ham AW, Cormack DH. Histologia, 8th edn. Amsterdam: G. Koogan; 1983. pp. 222–228

Illiouz YG. Present results of fat injection. Aesthet Plast Surg. 1988;12:175.

Lam A, Moy R. The potential for fat transplantation. J Dermatol Surg Oncol. 1992;18(5):432–434.

Lewis CM. The correction of deep gluteal depression by autologous fat grafting. Aesthet Plast Surg. 1992;16(3):247–250.

Loeb R. Nasolabial fold undermining and fat grafting based on histological study. Aesthet Plast Surg. 1991;15(1):61–66.

Neuber G. Asepsis und kunstiche Bluteere. Verhandl d Deutsch Gesellsch F Chir, Berlin. 1910;22:159.

Peer LA. The neglected “free fat graft,” its behavior and clinical use. Am J Surg. 1956;92:40.

Queiroz Filho W, De Souza Pinto EB. Estudo comparativo da lipoaspiração ultra-sônica e lipoaspiração superficial. Revista Catarinense. Jornada Sul Brasileira de Cirurgia Plástica, 1993.

Smahel J. Adipose tissue in plastic surgery. Ann Plast Surg. 1986;16:444.

Wertheimer E, Shapiro B. The physiology of adipose tissue. Physiol Rev. 1948;28:451.

Souza Pinto EBS. Superficial liposuction and fat graft. Cellulitis. RAPS International. The VI Annual Meeting; Beverly Hills, CA, July 20–21, 1991.

De Souza Pinto EB. Lipoaspiração dos membros inferiores. Anais do XII Congresso Brasileiro de Cirurgia Plástica; 10 a 14 de novembro de 1985; Gramado RS, pp. 640–641.

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