CHAPTER 12 Fat Injections to the Breast

The Lipomodeling Technique

Introduction

Transferring fat from parts of the body where it is in excess to the breast for cosmetic and esthetic purposes has been a long-lasting objective, and probably also a long-lasting dream.

This approach has been considered since the very beginning of liposuction, particularly after the publication of the works of Illouz ¹ and Fournier.² However, it remained controversial and was not widely used until the development of more precise tools and techniques. It was feared that autologous fat transfer would generate fat necrosis and calcifications which, at that time, were not readily assessable because of the limitations of existing imaging modalities.

The final blow came in 1987. After the presentation of a case by Bircoll,³ the American Society of Plastic and Reconstructive Surgeons recommended to stop using fat tissue injections for breast augmentation. The technique regained popularity after confirmation by Coleman⁴^,⁵ that fat tissues could be transplanted safely provided that adequate care is given to the preparation and transfer of fat cells. In 1998, given the proven efficacy of fat transfer to the face for facial rejuvenation or post-surgery reconstruction, we developed a research program aimed at evaluating the efficacy of the procedure for thoracomammary reconstruction. We developed the technique named ‘lipomodeling’,⁶^,⁷ then assessed its efficacy and tolerability in patients and demonstrated the absence of clinical or radiological signs of adverse effects.

The objective of the present chapter is to examine the history and illustrate the progression of knowledge about the lipomodeling technique used in our unit, to describe indications, contraindications, as well as potential complications associated with its use, and finally to provide input regarding the most effective means of preventing or resolving these problems.

History of the Technique and Progression of Ideas

First attempts

Fat grafting for breast plastic surgery has long been advocated by prominent surgeons. In 1895, at the German Congress of Surgery, Czerny described the first clinical case of breast reconstruction by transplantation of a giant lipoma of the lumbar region to the breast. Adipose cells were used to fill the void left in the breast after tumor resection in a patient with a fibroadenoma.⁸^,⁹ Some surgeons thereafter performed breast reconstruction or augmentation using fascio-cutaneous flaps,¹⁰ gluteus fat implants,¹¹ or local pedicle flaps.¹² Injections of fat either directly into the breast^1,^2,¹³ or into previously inserted implants¹⁴ have also been reported. Some authors have even described the cases of women undergoing augmentation mammaplasty by cadaver fat allografts.¹⁵^,¹⁶

Liposuction experiments published by Illouz ¹ contributed to the development of the technique and to the worldwide generalization of the concept. It became tempting to use autologous fatty tissues collected by liposuction for breast augmentation, as primarily done by Illouz. Similarly, in 1991, Fournier described the fat-grafting technique which he used only in patients who refused prostheses and who desired only moderate breast augmentation.² The quantity of fat grafted to the patients was between 100 and 250 ml in each breast, injected in the retroglandular space, not in the mammary parenchyma.

At the time, many surgeons viewed the new procedure with skepticism. The technique had not been standardized and it was not possible to guarantee the absence of fat necrosis following fat transfer. Breast imaging techniques were not as accurate as they are today; any mammary tumefaction could cause mammographic changes and give rise to diagnostic confusion, and there was a fear that areas of fat necrosis might interfere with breast cancer detection.

The controversy

Fat grafting to the breasts has been highly controversial since the presentation by Bircoll, first in Bangkok in 1984, then at the California Society of Plastic Surgeons in 1985, of a case undergoing breast augmentation by injection of fat cells obtained by liposuction. The patient was a 20-year-old woman who requested a moderate augmentation of her breast while undergoing fat grafting to repair the damages caused by a dog bite. Bircoll ³ considered the technique should only be used for women requesting moderate augmentation because of the potential risk of necrosis when grafting large quantities of fat. He reported the main advantages of the procedure: simplicity, absence of scar, early recovery, avoidance of prosthesis use and thereby of prosthesis-related complications, as well as the positive slimming impact at the site of fat removal. In April 1987,¹⁷ Bircoll reported the case of a patient undergoing bilateral fat grafting after unilateral reconstruction by transverse rectus abdominis myocutaneous (TRAM; improved aesthetic results and symmetry). The two papers triggered controversial reactions from the medical community¹⁸^–²¹ who deplored that autologous fat injections in the breasts could generate microcalcifications and cysts, possibly interfering with the detection of early breast carcinoma. Bircoll argued²²^,²³ that cancer-related calcifications and those consecutive to fat transplantation occur in different sites and have different radiological aspects, and therefore cannot be mistaken, and that breast reduction surgery also is responsible for microcalcifications, but the American Society of Plastic and Reconstructive Surgeons stated:

The committee is unanimous in deploring the use of autologous fat injection in breast augmentation, much of the injected fat will not survive, and the known physiological response to necrosis of this tissue is scarring and calcification. As a result, detection of early breast carcinoma through xerography and mammography will become difficult and the presence of disease may go undiscovered.

There was no explicit reference to scientific findings and the report only expressed the opinion of the members of the committee. Despite the paucity of scientific information and although it had long been recognized that any mammary surgery can be responsible for the occurrence of fatty cysts or mammographic changes, the injection of fat into the breasts became taboo among surgeons. The ASPRS banning put an end to any research or experimentation on the subject.

Ironically, in 1987, a retrospective study of the mammographic changes after breast reduction published in the same journal ²⁴ reported that calcifications were detectable in 50% of all mammograms at 2 years from surgery. The author insisted that in most cases these benign calcifications were easily distinguishable from cancer. Despite this high incidence and the risk for mammography abnormalities to interfere with cancer detection, there was no discussion of discontinuing breast reductions.

Progressive lifting of the taboo

The demonstration of the efficacy of fat transfer, based on atraumatic fat harvesting and injection, for facial rejuvenation and for the correction of facial deformities ⁴^,⁵ prompted us to adapt the technique to breast reconstruction. The contribution of fat grafting to the thorax and the breast for breast reconstruction has been one of our principal research topics over the past ten years. First, we used fat grafting along with autologous latissimus dorsi flap reconstruction. This method, previously developed by our surgical unit,²⁵^–²⁷ allowed satisfactory reconstruction in 70% of the cases. However, the other 30% resulted in insufficient breast volume and reduction of the contralateral breast was needed, or else insertion of a prosthesis; in this case, the procedure was no longer autologous and the patients suffered the drawbacks of prostheses (unnatural shape and texture, and obligation to change the prosthesis after a while). We started using fat grafting in breast cancer patients undergoing autologous latissimus dorsi flap reconstruction who were at low risk of local recurrence. We named the technique ‘lipomodeling,’ from the Greek root lipo for fat, and the Latin word modello which means to give shape or volume, which is exactly the objective of this procedure. At first, only volunteer patients who agreed to undergo strict follow-up were operated on. Then, after the demonstration of the efficacy of the technique, we proposed it to almost all patients treated by latissimus dorsi flap reconstruction. Fat grafting provides them with optimal breast shape and texture as well as a natural cleavage. The study of mammography, computed tomography (CT)-scan and magnetic resonance imaging (MRI) findings conducted in parallel²⁸ demonstrated that the impact of lipomodeling on the patient’s images was far from negative. It was thus progressively extended to other indications of breast reconstruction, then to the correction of breast deformities, to the treatment of sequelae of conservative treatment and, more recently, to breast cosmetic surgery.

Our first presentations ²⁸^,²⁹ raised considerable controversy, similar to criticisms made in 1987. Point-by-point debate gradually won over the hostility of the clinical community and fat grafting has now become a standard procedure in breast reconstruction.^7,^30,³¹

Operative Technique ^6,^7,³¹

Preparation

The patients are given information about the technique and about possible risks and complications. Each patient receives one of four information leaflets corresponding to her situation: ‘Lipomodeling in breast reconstruction,’ ‘Lipomodeling for the correction of breast conservative treatment sequelae,’ ‘Lipomodeling for the correction of breast malformations,’ and ‘Aesthetic breast lipomodeling.’

It is essential that the patient be at her ideal weight at the time of lipomodeling. Fat cells have a memory of their origin and, if the patient loses weight after the procedure, grafted cells may not survive.

Careful clinical examination of the breast areas to be treated is required. They are identified and marked on the skin before the operation (Fig. 12.1). In addition to commonly used two-dimensional images, three-dimensional morphological images are taken and compared to evaluate the quantity of fat that should be grafted and estimate fat resorption.

Fig. 12.1 Marking of the area to be treated.

The various fatty areas in the patient’s body are examined to identify and locate natural fat deposits. Usually, the fat cells used for lipomodeling are those taken from the abdominal region. The patients are satisfied with the local thinning effect; and also, the procedure is easy for the surgeons since it is not necessary to change the patient’s position between collection and grafting. The second most frequent site for fat harvest is the trochanter (flabby thighs), and the inner side of the thighs and knees. Areas of fat harvest are visualized and marked with skin-marking pen (Fig. 12.2).

Fig. 12.2 Marking of harvest sites. A Harvest site: abdomen. B Harvest site: thigh.

Anesthesia

Successful breast reconstruction requires sufficient quantities of fat cells and the harvesting procedure is somewhat long. This is why most patients undergoing lipomodeling are placed under general anesthesia. In breast cancer patients undergoing postmastectomy reconstruction, the procedure is associated with nipple–areola reconstruction and contralateral breast symmetry. As is generally recommended in our unit for patients undergoing plastic surgery, perioperative antibiotic prophylaxis is given to all patients. No lipomodeling-specific antibiotic treatment is given.

Local anesthesia is considered only for patients requiring moderate lipomodeling, generally for secondary management of a residual scar.

Incisions

Fat is harvested by making incisions with a No. 15 blade: four periumbilical incisions are performed for collecting abdominal deposits, and two lateral incisions (one on each side) for lateroabdominal or suprailiac deposits. Fat cells in the thighs are removed through incisions in the buttock fold (one on each side), and frequently also in the inner side of the knees.

When the patient requiring lipomodeling has had previous surgery to the breast, the procedure can be performed through the same incisions. In total, five or six incisions are made to reduce the convergence of graft tunnels: at least two in the inframammary fold and one in the upper breast quadrant. To keep scars to a minimum, incisions are generally made with the beveled edge of a cutting blade.

Fat harvesting

Recent work in the field has contributed to the standardization of the methods to be used for fat harvesting and grafting, and for the limitation of hazards at each step of the procedure. Only a strict observation of the rules at the different steps can ensure satisfactory median and long-term fat cell survival.⁴^–⁷ ⁹ Fat is harvested using a disposable cannula or a Coleman harvesting cannula. These blunt-tipped cannulas are inserted through 4 mm incisions made with a No. 15 blade, and directly attached to a 10 ml Luer-lock syringe. Fat cells are collected by moderate aspiration (Fig. 12.3) to minimize trauma on the adipocytes and improve the number of viable transplanted cells. The volume of fat aspirates must be enhanced to account for the cell loss incurred by centrifugation, refinement and transplantation.

Fig. 12.3 Fat cell collection. A Disposable harvest cannula. B Fat cell collection using a disposable harvest cannula attached to a 10 ml Luer-lock syringe.

For better cosmetic results, the areas where fat cells have been harvested are smoothed by classical liposuction with a 4 mm cannula. Skin incisions are sutured with absorbable stitches.

Conditioning of the graft

During fat harvesting, a surgical assistant prepares the cells for centrifugation by placing a screw cap on the extremity of each syringe (Fig. 12.4), then syringes are subjected to 3-minute centrifugation at 3200 rpm (Fig. 12.4). Six syringes can be processed at a time.

Fig. 12.4 Preparation of the fat cells.

A Placement of a screw cap on top of the syringe. B Centrifugation of syringes (six syringes at a time). C Centrifugation separates the graft into three layers. Only the layer containing purified fat cells is reinjected to the patient. D Elimination of the bottom layer (serum and residues) by opening the cap.E Elimination of the upper layer (oily supernatant). F Transfer from one syringe to another using a three-way tap; 10 ml of pure fat cells are collected.

During centrifugation, harvested fat cells are separated into three layers (Fig. 12.4C):

• the top layer contains oil (oily supernatant rich in chylomicrons and triglycerides) resulting from cell lysis;

• the bottom layer contains blood residues and serum, as well as infiltration solution when harvesting is performed under local anesthesia;

• finally, the intermediate layer contains purified fat cells suitable for transplantation. Only cells contained in this intermediate layer are ultimately transplanted to the patient. Other layers are eliminated: the bottom layer is removed by opening the cap (Fig. 12.4D) and the upper layer by pouring out the oily supernatant that has formed above the intermediate layer (Fig. 12.4E).

Careful planning is necessary to ensure efficient and rapid preparation of the fat graft. Fat cells are transferred from one syringe to the other using a three-way stopcock, then collected into 10 ml fractions (Fig. 12.4F).

Placement of the fat graft

When all fat samples have been processed, a number of 10 ml syringes of purified fat aspirates are available. The fat is then transferred directly from the 10 ml syringes to the breast area by adapting specific disposable cannulas of 2 mm diameter. These cannulas (Fig. 12.5A) are slightly longer and more resistant than those used for fat grafting to the face because higher mechanical constraints are associated with injection of fat into more solid and more fibrous tissues.

Fig. 12.5 Placement of the fat graft.

A Disposable transplantation cannula specific for lipomodeling. B Breast incision with a 17G needle knife. C Modalities of fat transfer: injection of small, spaghetti-like strips of fat while pulling the cannula back. D Fat transfer to the breast.

Incisions to the breast are performed using a 17 gauge needle knife (Fig. 12.5B). These small incisions allow for the passage of the cannula while limiting the impact of scarring and preserving the cosmetic results of the procedure which becomes almost invisible with time. Multiple small incisions, positioned to allow accurate placement of graft tunnels in different radial directions are required to ensure correct shaping.

It is recommended to inject the fat in small spaghetti strips (Fig. 12.5C), in multiple layers and multiple directions, from deep to superficial tissues (Fig. 12.5D), following a three-dimensional grid pattern. A good spatial representation of the area is required to avoid injecting large fat clumps potentially responsible for fat cell necrosis. On the contrary, each aliquot must be injected in a well-vascularized area, at a distance from other injection sites, and under low pressure (while gently pulling the cannula back).

The volume of fat transferred to the patient must be overestimated (whenever possible) to account for 30% fat resorption after injection. As a rule, one must graft at least 140 ml of fat cells to obtain a final volume of 100 ml.

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