Soft-tissue augmentation with injectable alginate and syngeneic fibroblasts

Tissue engineering, a field that combines polymer scaffolds with isolated cell populations to create new tissue, may be applied to soft-tissue augmentation-an area in which polymers and cell populations have been injected independently. We have developed an inbred rat model in which the subcutaneous injection of a hydrogel, a form of polymer, under vacuum permits direct comparison of different materials in terms of both histologic behavior and their ability to maintain the specific shape and volume of a construct. Using this model, we compared three forms of calcium alginate, a synthetic hydrogel, over an 8-week period-standard alginate that was gelled following injection into animals (alginate post-gel), standard alginate that was gelled before injection into animals (alginate pre-gel) and alginate-RGD, to which the cell adhesion tripeptide RGD was linked covalently (RGD post-gel). Parallel groups that included cultured syngeneic fibroblasts suspended within each of these three gels were also evaluated (alginate post-gel plus cells, alginate pre-gel plus cells, and RGD post-gel plus cells). The study used 54 inbred Lewis rats (n = 9 for each of the six groups). Construct geometry was optimally maintained in the alginate post-gel group in which 58 percent of the original volume was preserved at 8 weeks and increased to 88 percent at 8 weeks when syngeneic fibroblasts were included within the gel. Volume was not as well preserved in the RGD post-gel group (25 percent of original volume at 8 weeks), but again increased when syngeneic fibroblasts were included (41 percent of original volume at 8 weeks). Maintenance of volume was poorest in the alginate pre-gel group (31 percent of original volume at 8 weeks) and failed to be augmented by the addition of fibroblasts (19 percent of original volume at 8 weeks). Histologically, the gel remained a uniform sheet surrounded by a fibrous capsule in the alginate post-gel groups. In the alginate pre-gel and RGD post-gel groups, there was significant ingrowth of a fibrovascular stroma into the gel with fragmentation of the construct. In constructs in which syngeneic fibroblasts were included, cells were visualized throughout the gel but did not extend processes or appear to contribute to new tissue formation. Material compression testing indicated that the alginate and RGD post-gel constructs became stiffer over a 12-week period, particularly in the cell-containing groups. Our results suggest that calcium alginate could be a suitable agent for soft-tissue augmentation when gelled subcutaneously following injection. The addition of syngeneic fibroblasts enhanced the ability of the gel to maintain the volume of a construct; this seems to be mediated by increased gel stiffness rather than by de novo tissue formation. Our animal model, in combination with material testing data, permits rigorous comparison of different materials used for soft-tissue augmentation.     

Historical review and present status of free fat graft autotransplantation in plastic and reconstructive surgery

Free fat graft autotransplantation for soft-tissue replacement has been a neglected subject in recent years. In a review of the literature, investigations of the various uses of free fat autotransplantation in animals and humans provide an understanding of the problems associated with the use of fat as a free graft. Results of free fat autotransplantation were found to be quite unpredictable, with wide variations in the resulting bulk of the graft. Microscopic studies of this behavior led to controversy as to whether the graft ultimately was made of surviving graft adipocytes (cell survival theory) or host adipocytes (host replacement theory). Studies revealed a "fibroblast-like" mesenchymal cell within adipose tissue that was believed to be an immature adipocyte precursor or preadipocyte. Further characterization of the preadipocyte and its complete differentiation was accomplished using tissue-culture techniques. These investigations provide evidence of the dynamic nature of adipose tissue that strongly supports the cell survival theory and gives explanation to the unpredictable behavior of free fat autografts. Many conditions treated by plastic surgeons require soft-tissue augmentation. Autogenous adipose tissue is the most appropriate and natural replacement material. With new culturing techniques, preadipocytes in a single cell suspension may provide an injectable soft-tissue replacement. This subject appears ripe for investigation.     

Foreign-body granuloma following bilateral facial reconstruction with an omental flap

Bilateral facial reconstruction using an omental free-flap transfer for soft-tissue augmentation was performed on a 23-year-old man who had undergone previous surgical resection of an embryonal-cell rhabdomyosarcoma followed by radiation and chemotherapy. Eight weeks following surgery, the patient presented with pain and edema from a foreign-body reaction documented by electron microscopy. This was successfully managed with a course of steroid administration. The patient has remained symptom-free for 5 years.     

Platelet-rich plasma as a scaffold for injectable soft-tissue augmentation

A recent paper in Cytotherapy presented an interesting soft-tissue augmentation technique that caught our attention. We believe that the method is creative but complicated to practice. We note that the authors used platelet-rich plasma (PRP) solely as the source of growth factors. In fact, PRP itself can serve as a scaffold to carry cells. Considering the unique properties of PRP, we propose an alternative technique that may not only simplify the procedure but also yield promising results. The specific reasons are explained in this letter. In addition, we comment on the use of heparin as an anticoagulant for PRP production.     

Human-derived and new synthetic injectable materials for soft-tissue augmentation: current status and role in cosmetic surgery

The recent development of human-derived and new synthetic filling agents heralds a new era in soft-tissue augmentation. Many of the disadvantages of xenogenic and prior exogenous materials have been overcome with the advent of these autologous, allogeneic, and inert synthetic alternatives. Early reports using human-derived and inert exogenous filling agents have demonstrated good results and prolonged correction. It is too early, however, to assess the long-term efficacy of these agents. Future investigations should include histologic examination after facial implantation to document long-term safety and efficacy.     

Augmentation rhinoplasty with dermal graft and review of the literature

Nasal augmentation required following a trauma or a rhinoplasty operation poses a challenging problem to many plastic surgeons. Currently, allografts and autologous tissues are used for nasal augmentation; however, an ideal technique has not yet been described. Although preferred for augmentation of different parts of the body, pure dermal graft use has not been described for nasal augmentation. The authors performed nasal augmentation using a dermal graft in 90 patients in their hospital between 1994 and 2000, and they followed up the patients for 6 months to 8 years. In this article, the early and late results of dermal grafts for nasal augmentation are presented, and their advantages and disadvantages are discussed with a review of the literature. It was concluded that the easily obtained dermal graft could be an appropriate alternative in nasal augmentation, though it has not been used widely for this purpose.     

Superficial circumflex iliac artery perforator flap for reconstruction of limb defects

The superficial circumflex iliac artery perforator (SCIP) flap differs from the established groin flap in that it is nourished by only a perforator of the superficial circumflex iliac system and has a short segment (3 to 4 cm in length) of this vascular system. Three cases in which free superficial circumflex iliac artery perforator flaps were successfully transferred for coverage of soft-tissue defects in the limb are described in this article. The advantages of this flap are as follows: no need for deeper and longer dissection for the pedicle vessel, a shorter flap elevation time, possible thinning of the flap with primary defatting, the possibility of an adiposal flap with customized thickness for tissue augmentation, a concealed donor site, minimal donor-site morbidity, and the availability of a large cutaneous vein as a venous drainage system. The disadvantages are the need for dissection for a smaller perforator and an anastomosing technique for small-caliber vessels of less than 1.0 mm.     

Free groin flap revisited

Reported herein are 130 consecutive cases of free groin flap transfer performed by one surgeon over a 19-year period. Transplantation was performed for soft-tissue cover or augmentation of contour defects involving the head and neck (68 cases), trunk (4 cases), upper limb (14 cases), and lower limb (44 cases). Indications for flap coverage/augmentation were classified broadly into tumor, trauma, radiation induced, and miscellaneous. Specific reconstructive problems included augmentation for Romberg's hemifacial atrophy, external ear canal reconstruction after tumor ablation, and coverage of lower limb defects. There were nine failures (total flap loss), seven cases of partial flap loss, and two cases were abandoned intraoperatively. Of 15 cases that were urgently re-explored, 9 flaps were salvaged. The failure rate for the groin flap series (130 cases) was 8.5 percent compared with the failure rate of 4.2 percent for the other 517 cases of microvascular transfer performed over the same period by the same surgeon. Donor-site complications occurred in 24 cases and included hematoma or seroma formation, hypertrophic scars, nerve paresthesiae, infection, and dehiscence. Secondary debulking procedures were performed in 26 cases. The free groin flap, contrary to some reports, is a reliable flap that provides relatively thin pliable soft-tissue cover or augmentation, with minimal donor-site morbidity. The specific indications for its use have undergone an evolution since first described in 1973.     

The use of multifolded pericranial flaps as "plugs" and "pads"

Pericranial flaps are thin and, hence, their volumes are small. Therefore, their use for soft-tissue augmentation has not been popular. In this article, the author introduces a new concept: the use of a multifolded pericranial flap as a "plug" or a "pad" for localized contour defects. Eight patients were included in the study. In all cases, an anteriorly based pericranial flap was used, and the flap was folded on itself several times to increase its bulk. The results were satisfactory in all patients. The literature on the topic is reviewed, and the blood supply of pericranial flaps is discussed.     

Dual plane breast augmentation: optimizing implant-soft-tissue relationships in a wide range of breast types

In breast augmentation, surgeons usually choose a pocket location for the implant behind breast parenchyma (retromammary), partially behind the pectoralis major muscle (partial retropectoral), or totally behind pectoralis major and serratus (total submuscular). Each of these implant pocket locations has specific indications, but each also has a unique set of tradeoffs. When applied to a wide range of breast types, each pocket location has limitations. Glandular ptotic and constricted lower pole breasts offer unique challenges that often are not solved without tradeoffs when using a strictly retromammary, partial retropectoral, or total submuscular pocket. This article describes specific indications and techniques for a dual plane approach to breast augmentation in several different breast types, introducing techniques that combine retromammary and partial retropectoral pocket locations in a single patient to optimize the benefits of each pocket location while limiting the tradeoffs and risks of a single pocket location. A total of 468 patients had dual plane augmentation between January of 1992 and March of 1998 using the specific techniques of dual plane augmentation described in this article. All patients were treated as outpatients and received general anesthesia. Indications, operative techniques, results, and complications for this series of patients are presented. Dual plane augmentation mammaplasty adjusts implant and tissue relationships to ensure adequate soft-tissue coverage while optimizing implant-soft-tissue dynamics to offer increased benefits and fewer tradeoffs compared with a single pocket location in a wide range of breast types.     

Nasal augmentation with Surgicel-wrapped diced cartilage: a review of 67 consecutive cases

Cartilage grafting has been used extensively to correct both the functional and aesthetic aspects of the nasal framework. The technique described by Erol ( 105: 2229, 2000) uses Surgicel-wrapped diced cartilage grafts in rhinoplasties. The advantages include its ease of preparation, the large volume of graft substrate available for use, and the avoidance of contour irregularities in the areas of placement. A retrospective case review of 67 consecutive patients who were treated with a Surgicel-wrapped diced cartilage graft as part of an aesthetic and/or functional rhinoplasty, in a 5-year period between 1995 and 2000, was performed in this study. All cases of congenital nasal deformities or deformities caused by trauma or tumors in which the technique was used were excluded. The charts were reviewed to determine demographic variables, the surgical procedures performed, prior operations, the rhinoplasty approach used, and the graft donor and recipient sites. Preoperative and postoperative photographs were examined, and the results were assessed. Data on the donor and recipient sites, complications, and the necessity for revisionary procedures were tabulated. There were two complications, namely, an infection, which resolved with aspiration and oral antibiotic therapy, and a recurrence of a dorsal depression, which necessitated repeated augmentation within 6 months. The technique of using Surgicel-wrapped diced cartilage proved to be effective for the augmentation of various areas of the nose. The complication and revision rates were acceptable and comparable to those of other techniques. Patient satisfaction with the aesthetic results was rated highly, with no reports of graft extrusion or contour irregularities. This technique is recommended for nasal augmentation and contouring for selected rhinoplasty patients.     

The effect of breast implants on the radiographic detection of microcalcification and soft-tissue masses

Current implants for breast augmentation containing silicone gel, saline, or both can totally obscure mammographic detection of microcalcifications and soft-tissue masses. To investigate the possibility of developing a more radiolucent implant, radiographs were obtained of silicone shells that contained silicone gel, saline, silicone gel and saline, polyurethane-covered silicone gel, gelatin, sunflower oil, and peanut oil. All radiographs were obtained using a Siemens Mammomat by placing the implant over an American College of Radiology mammography phantom. Results were measured by the ability to visualize or resolve the artifacts in the mammography phantom. The silicone shell alone minimally altered artifact resolution. Silicone shells filled with silicone gel, silicone gel and saline, saline alone, polyurethane-covered silicone gel, and gelatin were equal in radiodensity and completely obscured all phantom artifacts. Silicone shells filled with peanut oil and sunflower oil had equal radiodensity and allowed visualization of large microcalcifications and some soft-tissue masses. Current implants used for augmentation mammaplasty can totally obscure mammographic detection of microcalcifications and soft-tissue masses. A more radiolucent breast implant is possible, and further research is needed to define the best filler material and test its biocompatibility.     

Cryopreservation of adipose tissue

The main obstacle to achieving favorable outcome of soft-tissue augmentation after autologous fat transplantation is unpredictable long-term results due to the high rate of absorption in the grafted site. At the present time, adipose aspirates can only be used for immediate autologous fat grafting during the same procedure in which liposuction is performed; therefore adipose aspirates obtained from the procedure are usually discarded. It has been a strong desire of both surgeons and patients to be able to preserve the adipose aspirates, if an optimal technique were available, for potential future applications. For the last several years, cryopreservation of adipose tissue has been studied extensively in the author’s laboratory. Several findings from this exciting translational research will lead to develop a reliable method for long-term preservation of adipose tissue in the future. In addition, successful long-term preservation of adipose tissue may open a new era in adipose tissue related tissue regeneration.     

A system for breast implant selection based on patient tissue characteristics and implant-soft tissue dynamics

Primary breast augmentation patients have widely varying characteristics of their breast envelope, parenchyma, and adjacent tissues. When preoperative breast implant selection does not specifically address critical soft-tissue parameters individual to each patient, risks of complications increase. Complications that occur from failure to reconcile a patient's wishes for breast size with her individual tissue characteristics include skin stretch and thinning, ptosis, atrophy of parenchyma, implant edge or shell visibility, implant edge or shell palpability, visible traction rippling, "bottoming" deformities, and lateral implant displacement with widening of the intermammary distance. Previous dimensional systems address implant parenchyma base width relative to implant base width, but no published system adequately addresses or attempts to quantitate the third dimension, tissue stretch, that is critical to estimate amount of fill necessary in a wide range of breast and tissue types. This system addresses the tissue characteristics (T) of the envelope (E), the parenchyma (P), and the implant (I), and the dynamics (D) of implant and filler distribution that affect soft tissues. The acronym TEPID summarizes the key factors that determine aesthetic results and occurrence of problems and reoperations following breast augmentation. This simple, efficient, and clinically practical system focuses on only three tissue measurements to estimate implant volume required to fill each patient's existing breast envelope, on the basis of her individual tissue characteristics: base width of the parenchyma, anterior pull skin stretch, and areola- and/or nipple-to-inframammary-fold distance measured under maximal stretch. The surgeon then adjusts initial volume to address differences in degree of skin stretch (anterior pull skin stretch) and contribution of the patient's existing parenchyma to stretched envelope fill, and to address differences in implant dimensions and filler distribution dynamics. To base decisions of implant pocket location on quantifiable soft-tissue coverage thickness, the system measures soft-tissue pinch thickness of the upper pole and at the inframammary fold. Surgeon time required to measure, estimate, and make preoperative implant selection decisions is less than 5 minutes. This system evolved from compiling and reviewing measurements and results from 330 primary breast augmentations from 1996 to 1999, including round and anatomic implant types with smooth shells and two different textured shells. The TEPID system was then used concurrently with the previous dimensional system for patient tissue evaluation and preoperative implant selection in 627 consecutive primary augmentation cases over a 3-year period from January of 1998 to January of 2001. Implant selection that did not comply with the parameters of the system was necessary in only eight cases. The TEPID system is a simple, efficient, and clinically practical method that allows surgeons to base implant selection on clinically quantifiable, individual patient tissue characteristics.     

Transumbilical endoscopic breast augmentation: submammary and subpectoral

Endoscopic techniques have recently been applied to aesthetic cosmetic surgery procedures. Endoscopic bilateral augmentation mammaplasty through a transumbilical approach ("TUBA") has recently been advocated as an alternative technique. The purpose of this article is to describe the author's transumbilical technique, to identify procedural limitations and special considerations, and to retrospectively analyze preliminary results. Five hundred thirteen patients (n = 1026 breasts) who underwent submammary transumbilical augmentation from January of 1993 through December of 1998 were evaluated. In 1997, the technique was further developed to permit subpectoral placement of implants; an additional 140 patients (n = 280 breasts) who underwent subpectoral transumbilical augmentation from September of 1997 through February of 1999 will also be presented. Success of the technique was based upon a number of criteria, including completion of the operation without conversion to an inframammary incision or reoperation, normal nipple-areola sensation, absence of hematoma formation, absence of infection, no umbilical scar revision, and patient satisfaction. Complications included hematoma (n = 2 breasts), conversion to inframammary incision (n = 5 breasts), and required secondary corrective procedure (n = 3 breasts). The majority of these complications occurred early in the learning curve. The successful augmentation rate in 1306 breasts was 99.2 percent. Based upon these results, transumbilical endoscopic breast augmentation is believed to be a safe alternative technique with excellent results.     

Cryopreservation of adipose tissue

The main obstacle to achieving favorable outcome of soft-tissue augmentation after autologous fat transplantation is unpredictable long-term results due to the high rate of absorption in the grafted site. At the present time, adipose aspirates can only be used for immediate autologous fat grafting during the same procedure in which liposuction is performed; therefore adipose aspirates obtained from the procedure are usually discarded. it has been a strong desire of both surgeons and patients to be able to preserve the adipose aspirates, if an optimal technique were available, for potential future applications. For the last several years, cryopreservation of adipose tissue has been studied extensively in the author''s laboratory. Several findings from this exciting translational research will lead to develop a reliable method for long-term preservation of adipose tissue in the future. in addition, successful long-term preservation of adipose tissue may open a new era in adipose tissue related tissue regeneration.     

Dispelling the myths and misconceptions about transumbilical breast augmentation

Since its invention in 1991, the transumbilical breast augmentation (TUBA) technique has gained popularity, and it has been proven safe and effective. In addition, the technique has several advantages over other methods of breast augmentation. Nevertheless, the method has often been the subject of a great variety of criticisms. Careful examination of those criticisms reveals that most are, in fact, untrue; they are misconceptions at best and falsehoods at worst. In this article, the author examines the 20 most common misconceptions about this procedure, clarifies or corrects them as appropriate, and suggests possible reasons for their having arisen in the first place. In addition, the actual drawbacks of the technique are reviewed. The author also outlines what he considers to be the criteria necessary for a surgeon to criticize any technique being used successfully by others: the surgeon must have proper plastic surgical training and certification, have completed training in the specific technique, and have a personal experience with performing a minimum number of cases.     

Induction of interferon and activation of NK cells and macrophages in mice by oral administration of Ge-132, an organic germanium compound

After oral administration of an organic germanium compound, Ge-132 (300 mg/kg), a significant level of interferon (IFN) activity was detected in the sera of mice at 20 hr and it reached a maximum of 320 U/ml at 24 hr. This IFN activity was lost after heat- or acid-treatment, suggesting that the induced IFN is of gamma-nature. The molecular weight of this IFN was estimated to be 50,000 daltons by gel filtration. The NK activity of spleen cells was increased 24 hr after the oral administration of Ge-132, and cytotoxic macrophages were induced in the peritoneal cavity by 48 hr. In the mice receiving an intraperitoneal (ip) injection of trypan blue or carrageenan 2 days before oral administration of Ge-132, neither induction of IFN nor augmentation of NK activity occurred, and X-ray irradiation of mice also rendered the mice incapable of producing IFN, all indicating that both macrophages and lymphocytes are required for this IFN induction. Both NK and cytotoxic macrophages appeared 18 hr after ip administration of the induced IFN with a titer as low as 20 U/ml. These facts suggest that both the augmentation of NK activity and activation of macrophages in mice after oral administration of Ge-132 are mediated by the induced IFN.     

The effect of hyperbaric oxygenation on the viability of human fat injected into nude mice

Autologous free-fat injection for the correction of soft-tissue defects has become a common procedure in plastic surgery. The main shortcoming of this method for achieving permanent soft-tissue augmentation is the partial absorption of the injected fat, an occurrence that leads to the need for both overcorrection and repeated fat reinjection. Improving the oxygenation of the injected fat has been suggested as a means of helping to overcome the initial critical phase that occurs postinjection (when the fat cells are nourished by osmosis), increasing phagocyte activity, accelerating fibroblast activity and collagen formation, and enhancing angiogenesis. In addition, the hyperbaric oxygen-mediated decrement in endothelial leukocyte adhesion will decrease cytokine release, thereby reducing edema and inflammatory responses. The purpose of the present study was to examine the effect of hyperbaric oxygenation on improving the viability of injected fat. Adipose tissue obtained from human breasts by suction-assisted lipectomy was injected into the subcuticular nuchal region in nude mice. The mice were then exposed to daily hyperbaric oxygen treatments, breathing 100% oxygen at 2 atmospheres absolute (ATA) for 90 minutes. The duration of the administered hyperbaric oxygen therapy was 5, 10, or 15 days, according to the study group. Mice exposed to normobaric air alone served as the control group, and each group included 10 animals. The rats were killed 15 weeks after fat injection. The grafts were dissected out, weight and volume were measured, and histologic evaluation was performed. In all of the study groups, at least part of the injected fat survived, giving the desired clinical outcome. No significant differences could be found between the groups regarding fat weight and volume. Histopathologic examination of the dissected grafts demonstrated a significantly better integrity of the fat tissue in the group that received hyperbaric oxygen for 5 days (p = 0.047). This finding was manifested by the presence of well-organized, intact fat cells, along with a normal appearance of the fibrous septa and blood vessels. The worst results were found in animals treated by hyperbaric oxygenation for 15 consecutive days. An inverse correlation was found between an increased dose of the high-pressure oxygen and fat tissue integrity (r = -0.87, p = 0.076). The toxic effects of highly reactive oxygen species on fat cells might explain the failure of an excessively high dose of hyperbaric oxygen to provide any beneficial outcome. The clinical relevance of these results should be further investigated.     

The effect of interleukin-8 on the viability of injected adipose tissue in nude mice

Adipose tissue injection as a free graft for the correction of soft-tissue defects is a widespread procedure in plastic surgery. The main problem in achieving long-term soft-tissue augmentation is partial absorption of the injected fat and hence the need for overcorrection and re-injection. The purpose of this study was to improve the viability of the injected fat by the use of interleukin-8. The rationale for the use of interleukin-8 was its abilities to accelerate angiogenesis and attract inflammatory cells and fibroblasts, providing the injected adipocytes more feeding vessels and a well-established graft bed to enhance their viability. Human adipose tissue, obtained by suction-assisted lipectomy, was re-injected into the subcutis in the scalp of nude mice. Interleukin-8 (0.25 ng) was injected subcutaneously to the scalp as a preparation of the recipient site 24 hours before the fat injection and was added to the fat graft itself (25 ng per 1 cc of injected fat). In the control group, pure fat without interleukin-8 was injected and no interleukin-8 was added for the preparation of the recipient site. One cubic centimeter of fat was injected in each animal in both the study and control groups. There were 10 animals in each group. The animals were euthanized 15 weeks after the procedure. Graft weight and volume were measured and histologic evaluation was performed. In addition, triglyceride content and adipose cell sizes were measured as parameters for fat cells viability. Histologic analysis demonstrated significantly less cyst formation in the group treated with interleukin-8. No significant differences were found between the groups with regard to graft weight and volume or the other histologic parameters investigated. No significant differences were demonstrated in adipose cell sizes and their triglyceride content. In conclusion, less cyst formation, indicating improved quality of the injected fat, can be obtained by the addition of interleukin-8. Further studies of various dosages of interleukin-8 and their long-term effect are required before these encouraging results could be applied clinically.