Lipofilling
Over a couple of centuries ago, the use of autologous fat for filling deformities and reshaping body features was recorded. Czerny, who supplemented the breast with a lipoma taken from the patient's back, is widely credited as being the first to describe the use of autologous fat as a filler. In the early twentieth century, adipose tissue grafting was a well-documented operation. However, as questions were raised about the eventual loss of volume in these grafts, it went out of favor.
Lipofilling was first published by Bircoll, who presented a procedure that combined liposuction with autologous breast grafting of the collected fat. The presence of essentially endless soft and flexible donor tissue was recognized as a major benefit of this novel approach.
However, there were early fears that the treatment may result in breast scars, which would make breast screening challenging. The American Society of Plastic and Reconstructive Surgeons responded by issuing a statement criticizing the procedure's overuse.
However, about the same time, a significant amount of evidence emerged indicating that other breast techniques, such as reduction mammoplasties, can cause scarring in the breast that can be seen during breast screening. After lipofilling, scarring can be significantly more severe than one might imagine. Moreover, further research has revealed that these artifacts have little effect on screening.
In addition, over the years, a number of case reports and case studies have arisen which have failed to provide conclusive evidence to substantiate these and other issues. Since its original description, the process has undergone major modifications, resulting in improved assurance in its application, including for breast reconstruction and remodeling. The American Society of Plastic and Reconstructive Surgeons, now called the American Society of Plastic Surgeons, changed its previous advice against the treatment.
What is Lipofilling?
Lipofilling, also known as fat grafting, fat injections, or fat transfer, is a treatment that uses a person's own fat to fill creases and defects. This is now a well-established approach that was refined into a repeatable technique in the early 1990s.
Sunken cheekbones, the removal of fat from the cheeks, deep creases running from the nose to the corners of the mouth, and in certain cases, creases between the lower eyelids and the cheek are all cosmetic indications for lipofilling. It's also among the most popular lip augmentation procedures. Furthermore, lipofilling can be utilized to smooth out a variety of abnormalities, including those caused by inadequate liposuction or accidents.
A restricted liposculpture with one or more three to five mm cuts is used to acquire the appropriate fat. It's usually obtained from the thigh or the abdomen. Centrifugation, filtration, or rinsing are used to process the extracted fat. The end outcome is pure liquid fatty tissue suitable for injection.
The fat is then injected into the required areas. By introducing small amounts of fat into the tissues, the fat is equally dispersed throughout the area, and the injected fat is well surrounded by normal tissue. This keeps the grafted fat in contact with the surrounding tissues, which are responsible for supplying it with oxygen and nutrients.
Fat Tissue Harvesting
Fat cell vitality and graft survival are thought to be higher when less painful techniques of fat harvesting are used. Several approaches for fat harvesting have been developed, and the research is divided on whether the technique yields more live and functional adipose cells. Vacuum aspiration, syringe aspiration, and surgical excision are the most common procedures. Targeted fat excision is preferred over aspiration in current experimental and clinical trials. Fagrell et al. proposed the fat cylinder graft, in which fat is punched out in cylinders by a punching instrument, whereas Qin et al. suggested the core graft for block grafting because it preserves the architecture and vitality of harvested fat tissue by preventing fat cells injury. In comparison to fresh fatty tissue sections and syringe-aspirated adipose cells, Pu et al. discovered dramatically reduced fat cell function in traditional liposuction aspirates.
Fat Tissue Viability after Harvesting
When a substantial volume of fat is desired, such as in breast surgery, low negative-pressure lipoaspiration may deliver excess fat than syringe aspiration. Up to 91 percent of adipose tissues may be structurally disrupted by traditional liposuctions' high vacuum pressures. The survival of collected fat may also be affected by the size of the syringe. Excisional surgery and fat harvesting with large-bore cannula lessen the risk of cellular breakage and retain the tissue's natural structure. Campbell et al. discovered a negative connection between cellular damage and the diameter of the fat-extracting equipment. Erdim et al. found that lipo-aspirates acquired with a larger cannula had higher graft vitality than those obtained with a smaller cannula.
Fat Harvesting with a Syringe
Coleman et al. described a fat harvesting procedure that caused the least amount of harm to the adipose tissues. Fat is manually vacuumed with a small, harsh, 2-hole cannula linked to a syringe by withdrawing the plunger. The surgeon utilizes digital manipulation to pull back on the plunger of the syringe and provide a moderate negative pressure as the cannula is inserted into the harvest area. Fat packages pass through the cannula and Leuer-Lok hole into the barrel of the syringe due to a mixture of slight negative pressure and the curetting movement of the cannula through the tissues. When the syringe is full, it is detached from the cannula and substituted with a plug that closes the syringes' Leuer-Lok end. Before placing the syringe into a centrifuge, the plunger is withdrawn.
Wet and Dry Techniques
There are several natural fat deposits throughout the body; surgeons should determine the best location after a thorough assessment of the patient. The most popular location for fat harvesting is the belly, followed by the trochanteric area and the inside of the thighs and knees. Fat grafts can be harvested using either a wet or a dry technique. Klein et al. described the wet technique, which includes injecting a fluid solution comprising 0.9 percent NaCl, epinephrine, and a local anesthetic into the donor area. Illouz and de Villers pointed out that the wet approach produces hydro-dissection and enlargement of the targeted fat tissue, making aspiration easier with less discomfort and petechiae.
Low shear strain forcing has been found to promote graft survival; in fact, shear force applied to collected fat has been identified as a determinant impacting fat cell viability. A dry technique without the tumescent liquid could be utilized instead. The dry technique, on the other hand, may result in a larger need for painkillers.
Micro-fat and Nano-fat Techniques
Micro- and nano-fat grafts can be utilized to repair delicate parts of the face like the eyelids and lips, with cannulas as small as 0.6 mm in diameter. In comparison to macro-fat, Tonnard et al. highlighted the therapeutic use of micro-fat and nano-fat transfer. A cannula with a small diameter was used to extract micro-fat nanoparticles from the abdomen. Using a Leuer-to-Leuer coupler and two small syringes, a portion of the micro-fat was shredded into finer particles. Following that, the nanoparticles were processed and collected. To serve as standards, macro-fat particles were extracted using a conventional cannula. For both macro-fat and micro-fat particles, the study gave micrographs that demonstrated normal cellular structure and sparse nonviable cells. The original structure was altered because the nano-fat grafts were lacking adipose tissues.
However, the nano-grafts preserved a large number of adipose-derived stem cells, which were identical in terms of proliferation and differentiation to the adipose-derived stem cells in the macro-fat and micro-fat tissues. The use of nano-fat grafts has led to enhanced skin quality seven months after surgery in numerous clinical cases. While nano-grafts do not include functional adipose cells, the high amount of stem cells in these grafts may be clinically effective for skin rejuvenation.
Fat Tissue Processing
Sedimentation, filtering, rinsing, and centrifugation are the most frequent procedures for preparing fat grafts. Because the lipoaspirate comprises not only adipose tissues but also collagen fibers, plasma, and debris, fat processing is performed. These changes can cause inflammatory reactions at the grafts' recipient location, which can be harmful to the fat graft. Blood must be taken since it hastens the deterioration of the fat that has been transplanted. Furthermore, because the debris will be absorbed after a few hours, the injection of debris offers a false view of the volume of correction. There were no significant variations in the weight or structure of fat grafts prepared using centrifugation, filtration, or sedimentation procedures in animal trials. In contrast, investigations in patients have shown that centrifugation, rather than gravity separation, produces better results.
Studies comparing fat processing methods such as centrifugation, washing, and filtration found no significant changes in fat preservation; nevertheless, filtration caused nodulation, whereas centrifugation did not. Ferraro et al. found that centrifugation with a force higher than 50g damaged adipose tissue's mechanical stability, increased cell death and apoptosis, and reduced adipogenic differentiation capability and tubular formation. Tubule formation during angiogenesis supplies blood and nutrients to adipose tissue, allowing the fat grafts to last for a long time. Higher centrifugation velocities have also been linked to an increase in fluid component, a decrease in injectable tissue volume, and an increase in oil component, all of which are linked to adipocyte destruction. Coleman proposed a fat-transfer processing approach that has gained traction and is now used in many clinical fat-transfer methods.
Three layers are visible after centrifugation: the first layer contains lipids, which can be drained out using an absorbent pad; the second layer contains adipose tissue; and the third layer comprises blood, extracellular fluid, and local anesthesia, which is pushed from the syringes' base. Adipose tissue grafting is commonly performed on the middle layer. Finding the best processing procedure will enhance the amount of living cells, which will lead to better fat engraftment and preservation over time.
Fat Tissue Injection
Despite a lengthy history of therapeutic use and the development of lipofilling procedures, there is no agreement on the best approach and the duration of outcomes, despite the fact that fat reimplantation concepts are based on ideal recipient-site vasculature for greater fat retention. The fat graft is placed at the level of the anatomical region damaged through a skin incision of a size that corresponds to the diameter of the cannula. Small cannulas are expected to lessen recipient site injury, lowering the likelihood of bleeding, hematoma development, and poor graft oxygen supply. Because revascularization begins at the periphery, the reperfusion time in the graft's center is longer. As a result, many small-volume procedures of fat reinjection are favored over a single large-volume injection. Several holes are primarily produced on insertion through multiple access points, but fat is injected only when the cannula is withdrawn in a fanning-out pattern.
To minimize increased interstitial pressure at the recipient site and congestion of the transplanted adipose tissues, fat grafts are disseminated in small replicates and fanned out to different depths in the soft tissue. Mobile parts of the face, such as the glabella and lips, are less receptive to repair than less-mobile parts, such as the malar and lateral face regions, according to studies on fat-graft preservation. Several publications employ different caliber cannulas for fat infusion, and the nature of the recipient site is the most important driver in cannula size selection. Ozsoy et al. discovered that infiltrating fat cells with cannulas of at least 2.5 mm in diameter increased the survival of the tissue. Erdim et al., on the other hand, reported no significant changes in cell viability when the needle was adjusted.
Lipofilling Applications
Breast Reconstructive Surgery
In reconstructive breast surgery, autologous fat transplantation (lipofilling) is routinely performed. Cosmetic surgeons and patients considering reconstructive surgery may have very unique opinions about what makes a breast shape beautiful, natural, and perfect. After breast reconstruction, lipofilling is a straightforward way to restore the right look of the breast. In fact, subsequent shape abnormalities of the reconstructed breast can arise in the early or late postoperative period. Indeed, there are crucial landmarks in the woman's breasts; for example, achieving a satisfactory cosmetic result following breast reconstruction requires the formation of a well-defined inframammary crease. Lipofilling can be employed following implant or muscle flap repair, with or without tissue expansion.
For breast reconstruction, adequate tissue expansion enables the use of autologous flaps or the placement of final artificial implants. This could be done with the help of computer software to assist the surgeon in selecting the appropriate tissue stretcher for breast reconstruction. Autologous fat injection (lipofilling) appears to be a particularly helpful treatment for filling the sub-clavicular and anterior axillary folds abnormalities in Poland syndrome of the chest wall and breast. Fat injection is seldom utilized as a stand-alone procedure; rather, it is frequently used in conjunction with other common breast surgery procedures. Fat tissue that isn't perfused can die, resulting in necrotic lesions and even calcification; nevertheless, this problem can occur during any surgical breast surgery. Fat grafting to the breast has the ability to impede breast cancer detection; however, no substantial evidence has been discovered to support this claim. The biggest disadvantage of lipofilling, according to early research, was graft re-absorption, which resulted in 50 to 90 percent graft loss.
Liquefaction, necrosis, and cysts formation are more common in large grafts, whereas resorption is more common in small grafts. Many doctors use multiple transfers to ensure optimal take.
Scars
Patients who have retractile and uncomfortable scars that are interfering with their normal daily activities/mobility of the affected joint can benefit from lipofilling treatment. In fact, fat transplantation can be utilized as a regenerative alternative to conventional surgical treatments not only to replace atrophic scars but also to minimize scar contracture. The presence of adipose-derived stem cells in the fat tissue enables this. Histologically, autologous fat grafts (lipofilling) have the regenerative capacity of the dermis and subcutaneous fat, as well as strengthen dermal and dermo-hypodermic freshness in scar regions, by adjusting the quantity of fat layer - which is significantly damaged during thermal insults and inadequately regenerated during tissue regeneration after any type of trauma - new collagen fibers, and local neo-angiogenesis.
Fat tissue transfer, according to Mojallal et al., promotes the neo-synthesis of fibrous tissue at the recipient location and thickens the dermis, increasing skin quality. Fat's healing effect in damaged areas is assumed to be due to the release of numerous nerve entrapments, resulting in reduced neuropathic pain. Furthermore, to minimize the recurrence of scar contracture, the reduction in neurogenic pain can be sustained by inserting fat grafts around the nerve. Lipofilling was used to repair scars in several individuals. They noticed an improvement in the quality of all healed scars, both in terms of aesthetics and functionality. All patients experienced pain control and increased scar flexibility, which could be scientifically measured.
The first outcomes were seen two weeks after the treatment; pain alleviation and improved scar flexibility were noticed at 3 months, and all patients maintained these improvements until one year. Skin becomes smoother, more flexible, and extensible due to autologous fat grafts, and the color is frequently identical to the adjacent unaffected skin. Another benefit of scar removal, both superficial and deep, is increased mobility of the affected body part, particularly the damaged joints, eyelids, and mouth, as well as the potential of partial facial expression restitution for the patient. Scar removal by autologous fat grafting (lipofilling) generally addresses volume deficiencies in patients with severe skin depression, resulting in great aesthetic outcomes and a positive impact on the patient's self-image.
Burns
A burn injury is a life-changing event with far-reaching implications. Burn injury remains a major difficulty in the field of cutaneous wound healing, despite improving survival rates. Patients with significant burns do not have enough skin to cover the burns, and the currently available cutaneous replacements and cultured epithelial autografts are inefficient and ineffective. Due to transplant rejection, grafted skin from donations is presently not a choice; however, increasing immune tolerance through stem cell treatment may be able to solve this problem. Because of the restoration of skin appendages and the reduced risks of hypertrophic scars, regenerative medicine employing stem cells is an effective, low-morbidity, and high-quality treatment for skin covering in burns. In over 74 percent of white individuals with third-degree burns, hypertrophic scars develop. Because of aesthetic and functional questions, as well as worries about the patient's psychological and social life, burn consequences continue to be a problem.
Sub-scar and intra-scar fat grafting are relatively new scar-improvement procedures. Burn scarring, even old ones, cannot be termed inactive scars, according to Bruno et al., who found that they are marked by maturation blockage as well as an inflammatory and hyper-vascularized status. Lipofilling provides for a substantial change in this condition, with the tissue becoming considerably more histologically similar to normal tissue. Brongo et al. reported on their results with lipofilling to repair burn marks in another investigation. A questionnaire, as well as physical and histological investigations, were used to assess the scars' progression one year following therapy. All patients reported an improvement in their clinical state during the one-year period. In the light of emerging tissue, histopathological findings revealed new collagen deposits, neo-angiogenesis, and dermal proliferation, showing tissue regeneration.
Clinically, the treated skin's structure, smoothness, thickness, color, and flexibility were better, and scar retraction was reduced. Gal et al., on the other hand, addressed eight burned children and adolescents with a single lipofilling and found no difference in scarring when compared to a control group given saline injections. The results recommend that the findings could be attributed to the fact that they only did one lipofilling procedure. Serial lipofilling treatments, according to Strong et al., may be necessary to repair damaged recipient locations.
Conclusion
The use of lipofilling as a safe reconstructive procedure has been validated by practice over the previous two decades. While more research is needed, the use of this approach has not been linked to an increase in the risk of tumorigenesis or the general risk of recurrence in patients with initial invasive breast cancer. Patients with intra-epithelial lesions such as ductal carcinoma in situ, particularly those under the age of 55 who are undergoing a breast-conserving surgical procedure for high-grade ductal carcinoma in situ with a high proliferation score, should be informed of the concerns raised about a possible increased risk of local recurrence and the need for more research on the subject.
The most substantial body of evidence supports cell-assisted lipofilling, which is one of the Coleman technique's modifications. More research is needed, however, to get a reasonable agreement on the best technique.