An accelerated approach to tissue expansion for breast reconstruction: experience with intraoperative and rapid postoperative expansion in 370 reconstructions

Breast reconstruction with tissue expansion is a well-established technique that offers satisfactory aesthetic results with minimal patient morbidity. The traditional period of expansion, however, continues to be a significant source of patient inconvenience and dissatisfaction. The objective of this study was to develop and evaluate a protocol for rapid tissue expansion. A total of 370 breast reconstructions in 314 patients who underwent rapid tissue expansion were retrospectively reviewed. Contraindications to rapid expansion were considered to be previous radiation, mastectomy skin flaps of questionable viability, and an excessively tight skin envelope. All expanders were placed submuscularly and filled to 40 to 50 percent of tissue expander volume. Office expansion was undertaken within 10 to 14 days after the operation and continued on a weekly basis. Each expansion was limited by patient tolerance up to a maximal pressure of 40 mm of water or a volume of 120 cm3. Expansion was considered complete once the expanded breast was 30 to 50 percent larger than the contralateral breast. If required, postoperative chemotherapy was given during the expansion period. Mean patient age was 48 years (range, 23 to 73 years). Two hundred fifty-eight patients had unilateral reconstructions. Three hundred two patients had immediate reconstruction. Mean tissue expander size was 583 cm3 (SD, 108 cm3). Mean intraoperative expansion was 271 cm3, or 46 percent (SD, 9 percent) of the tissue expander size. The first expansion was started 12 days (SD, 3 days) after the operation. The mean volume of each expansion was 88 cm3 (SD, 23 cm3). Expansion was completed in 4.7 office visits (SD, one visit). Mean final expander volume was 672 cm3 (SD, 144 cm3). The expanders were overexpanded by 15.3 percent (SD, 8.4 percent). The mean time between expander placement and the final expansion was 6.6 weeks (SD, 3 weeks). The overall complication rate was 4 percent. Ten patients developed cellulitis, five patients had hematomas requiring drainage, and one expander became exposed. A total of eight expanders were removed: four for cellulitis, one for a hematoma, one because of locally recurrent disease, one because of expander exposure, and one at the patient's request for no medical reason. Intraoperative and rapid postoperative tissue expansion is a safe and reliable technique that offers a significant improvement over conventional techniques. In this accelerated protocol, expansion may be completed in less than 7 weeks. The result is decreased patient morbidity and delays in adjuvant therapy at no detriment to the final surgical outcome.     

Stretching and tissue expansion for rhytidectomy: an improved approach

Intraoperative expansion of the skin of the face supplies additional tissue that permits closure of the face lift incision with minimal tension. This paper presents the findings in rhytidectomy patients over the last 3 years using both intraoperative stretching and intraoperative stretching combined with tissue expansion utilizing the Man face lift expander. Sixty-seven patients underwent rhytidectomy surgery, of whom 50 were treated with stretching techniques alone and 17 were treated with the combined stretching and expansion method. The patients' ages ranged from 28 to 78 years. Results indicate that the patients treated with combined stretching and expansion had significantly more skin removed. This new technique appears to offer significant clinical advantages over usual face lifts.     

Continuous versus conventional tissue expansion: experimental verification of a new technique

Historically, tissue expansion is a prolonged process, typically requiring at least 6 weeks to complete. Recently, interest has increased in shortening this time period. In the current study, a continuous infusion device maintaining constant expander pressure less than capillary filling pressure was used in a canine model in seven dogs to minimize the time period needed to achieve significant expansion. There were no complications, except one device malfunction, corrected by changes in design. The process was shown to be a safe and effective means of producing amounts of expansion similar to traditional methods in approximately 72 hours, with expansion of 28 percent (n = 6) for continuous tissue expansion (CTE) versus 34 percent (n = 6) for a 2-week rapid expansion protocol. This expansion was derived from either stretch of preexisting tissue (46 percent for CTE, 35 percent for 2-week expansion) or recruitment of adjacent tissue. The clinical application of continuous tissue expansion could permit the advantages of tissue expansion to be obtained in many more situations than are currently available to traditional tissue expansion techniques.     

The beginning of a new era in tissue expansion: self-filling osmotic tissue expander--four-year clinical experience

The osmotic tissue expander is a new device made of a hydrogel expanding skin that does not require external fillings. Once implanted, it absorbs body fluids, which leads to a gradual swelling of the device. The swelling phase is completed in 6 to 8 weeks and results in skin gain. Different shapes and sizes are available, and the devices can be used in almost every area of the body. Over a 4-year period, the osmotic tissue expander was used in 58 patients in different areas of the body. A round osmotic tissue expander was mainly used in breast reconstruction, and a rectangular expander was used for defect coverage after excision (i.e., of scars and tumors). The mean age of the patients was 49.34 years (range, 4 to 76 years). During the expansion phase, the patients noted only a little discomfort and pain for the first few days. Without a silicone membrane in the first-generation expander, the rate of successful explantation and good final result was 81.5 percent. In a few cases, rapid swelling of the device led to the introduction of a silicone membrane that encloses the expander and leads to a slower, more gradual, and consistent swelling. After introduction of the silicone envelope, the success rate improved to 91 percent. The expander is now used with a silicone membrane in every case. The osmotic tissue expander has many advantages compared with the conventional expander: there is no need for painful external fillings and the risk of external infections is avoided. The expander is 10 percent of its final volume and only requires a short incision and a small pocket. An operation can easily be performed under local anesthesia, with minimal tissue mobilization in older children and compliant patients.     

Intraoperative tissue expansion in rhytidectomy revisited

Intraoperative tissue expansion is an adjunct that has been used during rhytidectomy to rejuvenate the face and neck. This technique has been thought to allow for additional skin resection and, thus, increased skin tightening during rhytidectomy. The stretch of the skin by expansion should allow for additional skin resection before closure. Also, when the force of the underlying expander is removed, the expanded skin would recoil and the advancement of the flap should become tighter, with improved results. The technique achieved some popularity a few years ago but has received little recent attention. In this study, the authors attempted to compare face-lift results of adjunctive intraoperative tissue expansion during rhytidectomy with similar techniques without intraoperative expansion. The results of 50 female patients who underwent rhytidectomy for midface rejuvenation by a single operating surgeon composed the study group. Twenty-five of the patients had undergone rhytidectomy that addressed the cheek, chin, and neck areas without expansion (nonexpanded rhytidectomy group). The other 25 patients (expanded rhytidectomy group) had adjunctive intraoperative tissue expansion performed with the rhytidectomy. A tissue expander was temporarily placed beneath the rhytidectomy flaps on each side and expanded in a standard manner before final skin resection and closure. Frontal and lateral photographs were evaluated by 54 examiners. Preoperative and postoperative photographs of the 50 patients were viewed side-by-side by the examiners. The patients were presented in blind fashion and random order. The examiners graded the results of each patient on a scale of improvement from 1 to 10, with 10 being the maximum level of improvement. The scores were recorded and statistically evaluated by using the two-sample test. Evaluation of the examiners' scores showed that the mean rating given to patients in the expanded rhytidectomy group was 5.07 (SD = 1.12). The mean rating for the nonexpanded rhytidectomy group was 5.27 (SD = 1.57). When the two groups were compared using the two-sample test, the difference between the two was not statistically significant (p = 0.6127). Intraoperative tissue expansion as an adjunct to rhytidectomy did not result in improved facial rejuvenation in this patient series. The authors' impression is that the benefits of tissue expansion do not justify the added expense, time, and risks associated with using tissue expansion during rhytidectomy.     

Effect of radiation on skin expansion and skin flap viability in pigs

The aim of the present study was to investigate the effect of radiation treatment both on skin tissue expansion with the chronic inflation of subcutaneous expanders and on skin flap viability in surgically delayed and expanded skin in the pig. One flank in each of six pigs (initially weighing 17 +/- 1.8 kg) was randomly assigned for radiation treatment, and the contralateral flank served as a nonirradiated control. Three mirror-image, 8 x 10 cm, rectangular templates were marked on each flank; these templates were randomly assigned to the construction of a delayed skin flap (group A), a skin flap raised on expanded skin (group B), or a skin flap raised on expanded skin with a capsulectomy before flap surgery (group C). Radiation treatment was performed using sequential radiation with three fractions per week (810 cGy/fraction) for 2 weeks, with a total dose of 4,860 cGy. Twelve weeks after radiation treatment, skin expanders (8 x 10 cm) were installed subcutaneously in the locations assigned for skin expansion. Skin expansion by the inflation of subcutaneous skin expanders with saline twice weekly was started 8 weeks later and lasted for 3 weeks. Two weeks after surgical delay and the last skin expansion, 8 x 20 cm skin flaps were raised on the locations assigned for delayed skin flaps, expanded skin flaps, and expanded skin flaps with a capsulectomy. Skin flap viability was assessed 24 hours later using a fluorescein dye-staining technique. Skin expansion by the inflation of subcutaneous expanders with saline was slower (p < 0.05) in the radiated skin (39 +/- 6 ml/filling) than in the nonirradiated control skin (51 +/- 6 ml/filling). Radiation reduced the overall area of expanded skin by 23 percent (p < 0.05) compared with the control. Radiation treatment also reduced skin viability by 36 percent (p < 0.05) in the delayed skin flaps, 27 percent (p = 0.10) in the expanded skin flaps, and 36 percent (p < 0.05) in the expanded skin flaps with a capsulectomy when compared with their contralateral, nonirradiated controls. There were no significant differences in skin viability among these three types of skin flaps within the radiated and nonirradiated groups. Taken together, these observations indicate that radiation treatment reduced the effectiveness of the surgical delay procedure, the amount of subcutaneous skin expansion (by an increase in skin area), and skin flap viability. However, a capsulectomy alone did not affect the viability of skin flaps raised on expanded skin.     

The premature removal of tissue expanders in breast reconstruction.

The role of tissue expanders in breast reconstruction is well established. Little information exists, however, regarding the incidence and etiology of premature removal of the tissue expander before planned exchange to a permanent breast implant. The purpose of this study was to review our 10-year experience with tissue expander breast reconstruction and identify factors relating to the premature removal of the tissue expander. This study is a retrospective review of 770 consecutive patients who underwent breast reconstruction with tissue expanders over the past 10 years. Breast reconstruction was immediate in 90 percent of patients. Patients were expanded weekly, and adjuvant chemotherapy was begun during the expansion process when required. Factors potentially affecting premature expander removal (chemotherapy, diabetes, obesity, radiation therapy, and smoking) were evaluated. Fourteen patients (1.8 percent) with a mean age of 47 years (range, 38 to 62 years) required premature removal of their tissue expander. Expanders were removed a mean of 3.2 months (0.1 to 8 months) after insertion. Causes for premature removal of the tissue expander included infection (7 patients), exposure (2), skin necrosis (2), patient dissatisfaction (2), and persistent breast cancer (1). Positive wound cultures were obtained in four of the seven infected patients (57 percent), requiring expander removal for infection. Tissue expanders were removed in 11 patients for complications directly related to the expander. Among these, six (55 percent) were receiving adjuvant chemotherapy, and one was a smoker. Diabetes, obesity, other concomitant medical illnesses, and prior mantle irradiation were not associated with expander removal. Premature removal of the tissue expander was required in only 1.8 percent of the patients in this series. Infection was the most common complication necessitating an unplanned surgical procedure to remove the expander. This study demonstrates that the use of tissue expanders in breast reconstruction is reliable, with the vast majority of patients completing the expansion process.     

An Axisymmetric Computational Model of Skin Expansion and Growth

Skin expansion is the principal technique used in plastic surgery to repair large cutaneous defects, typically after tumour removal, burn care, craniofacial surgery and post-mastectomy breast reconstruction. It allows a gain of new tissue by means of gradual expansion of a prosthesis, surgically implanted beneath the patient’s skin. Nevertheless, wide clinical use is not supported by a deep quantitative knowledge of the phenomena occurring during the expansion. A finite element model of the skin expansion was developed to evaluate the stresses and the strains of the skin due to the expander inflation and validated by proper in vitro experiments; furthermore, a growth model based on the mechanical stimulus was implemented to estimate the skin area gain. The developed computational approach, composed of the skin expansion model interaction and the growth law, proved its validity to investigate skin expansion phenomena: its use suggests a new predictive tool to optimize clinical procedures and the expander devices’ design.     

Accelerated tissue expansion with the "overfilling" technique

Temporary overexpansion of the tissues at each filling session increased the actual inflation volume by about 59 percent. This shortened the process of tissue expansion considerably. "Overexpansion" means that the pressure in the expander is increased to a point where the dermal capillary flow is zero or the patient experiences so much discomfort that inflation cannot be carried out any further. The pressure in the expander is thereafter gradually decreased by taking out saline until both the capillary refill and all other clinical criteria are sufficient for safe dermal circulation. Comparison of the expander volume at the final pressure to the initial filling volume at the same pressure before the "overfilling" confirmed an average gain of about 59 percent in 14 patients.     

Physical, biomechanical, histologic, and biochemical effects of rapid versus conventional tissue expansion

Clinical tissue expansion has been quite successful but takes 2 to 3 months. This study compares the effects of a conventional tissue expansion regimen of 6 weeks with an accelerated regimen of 2 weeks in the dog model, which is biomechanically similar to the human. In 22 dogs, the skin expanded 34.4 percent in the 2-week and 35.8 percent in the 6-week protocol, excluding stretch and recruitment. There was thinning of the panniculus carnosus in the 6-week group and otherwise no significant decrease in dermal thickness in either group. The biomechanical properties of elasticity and creep did not differ in expanded skin from both groups, while stress/relaxation mildly decreased from a control value of 53.5 percent to 48.8 percent in the 6-week group (p less than 0.05). Collagen activity was increased in both the 6-week and the 2-week groups (p less than 0.001) over nonexpanded skin, and immunohistochemical staining with a monoclonal procollagen antibody demonstrated collagen synthesis by dermal fibroblasts in both groups. We conclude that rapid tissue expansion did not demonstrate any deleterious effects when compared with a conventional regimen.     

Increased survival and vascularity of random-pattern skin flaps elevated in controlled, expanded skin

Controlled clinical tissue expansion, a new technique of providing donor tissue, results in an increase in surface area of expanded skin. The aim of the present study was to determine the effect of controlled tissue expansion on the surviving lengths of random-pattern skin flaps elevated in expanded tissue. In five pigs the surviving lengths of flaps raised in skin expanded for 5 weeks using a 250-cc rectangular Radovan-type tissue expander were compared with the survival lengths of flaps elevated in tissue in which a similar prosthesis was not expanded, bipedicle flaps delayed for 5 weeks, and control acutely raised random-pattern flaps. The expanded flaps had a mean increase in surviving length of 117 percent over control flaps, which was statistically significant. The delay flaps had an increase in survival of 73 percent over control flaps, which was also statistically significant. There was no significant difference in survival between expanded flaps and delayed flaps. Morphologic studies using radiographic techniques on one pig demonstrated increased vascularity with tissue expansion. The results of this work demonstrate that in addition to providing increased surface area with controlled expansion, flaps raised in expanded skin have a significantly augmented surviving length. The mechanism for this increased vascularity with expansion is not known at this time, but it may be due to physical forces associated with expansion acting as a stimulus for angiogenesis.     

A method of reconstructing a pendulous breast utilizing the tissue expander

It is possible to reconstruct a breast mound of almost any size by utilizing tissue expansion. In order to produce a pendulous breast which is also ptotic, the tissue-expansion technique has been combined with two other procedures. A new technique is being introduced. It is that of elevating the lower third of the mature breast capsule surrounding the tissue expander at the time the permanent prosthesis is to be exchanged for the expander. The established techniques of inframammary fold reconstruction of Pennisi and Ryan are used to provide pedicle skin coverage for the undersurface of the breast and the bed of the elevated capsule. Internal and external surgical approaches are described, and two examples of each are illustrated. Breasts reconstructed in this manner have remained pendulous structures. Some loss of the initial degree of ptosis has been noted in some cases.     

Use of a permanent tissue expander for breast reconstruction

The use of tissue expansion in breast reconstruction is a recognized alternative surgical approach. The second generation of tissue-expanding prostheses is the permanent reverse double-lumen expander. In a series of 100 breast reconstructions using a permanent tissue expander, the clinical benefits of producing a moderate degree of mound ptosis along with observed reduction in pain during expansion are discussed. Additional advantages to the use of the device are the cost savings realized, elimination of a second procedure and a second anesthetic exposure, and a high degree of patient acceptance and satisfaction. This study includes breast reconstruction following mastectomies for malignant and premalignant disease, as demonstrated in 75 delayed and 25 immediate reconstructions, with the longest follow-up being 3 years. Complications of infection (3 percent), significant capsular contracture (4 percent), and implant failure (3 percent) are the most frequent and major complications observed yet. In no instance was breast reconstruction rendered unachievable in the face of these complications. The demonstrated results achieved with permanent tissue-expanding prosthesis, complemented by the obvious benefits and a low rate of significant complications, endorse this method as a viable alternative approach in reconstructive breast surgery.     

Treatment of burn alopecia with tissue expanders in children

During the past 18 months, 60 tissue expanders were utilized in the reconstruction of 42 children with burn alopecia of the scalp not amenable to a single excision and primary closure at the Shriners Burns Institute in Galveston, Texas. The children were grouped according to the degree of alopecia. All patients with defects of 15 percent or less of the total hair-bearing scalp were able to obtain complete closure of their defects with two operations, i.e., one to place the expander and the second to remove the expander and advance the flaps. Some patients with defects up to 40 percent were closed with serial expansion. Patients with even larger defects had a significant reduction in the percentage of alopecia and benefited from re-creation of anterior hairlines. We have encountered a postoperative complication rate of 10 percent. When compared to previous methods of treating burn alopecia, tissue expansion allows a more rapid closure, fewer operations and coincident anesthetics, and decreased total length of hospitalization.     

Patient-activated controlled expansion for breast reconstruction with controlled carbon dioxide inflation: a feasibility study

This feasibility study represents the first report of a new carbon dioxide-based tissue expander designed to allow gradual controlled expansion and to eliminate the need for percutaneous injections. Seven patients underwent implantation with a total of 10 (three bilateral) tissue expanders. After intraoperative filling by the surgeon and wound healing, small doses of carbon dioxide were administered on a daily basis by the patient by means of a hand-held dosage controller leading to gradual, incremental expansion. Rapid expansion during the active dosing phase and flexibility to meet individual patient needs during expansion were demonstrated with all subjects. These patients achieved full expansion in an average of 15 days. All seven patients were able to use the device safely and with ease at home, leading to successful tissue expansion and permanent breast reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.     

Irradiation after immediate tissue expander/implant breast reconstruction: outcomes, complications, aesthetic results, and satisfaction among 156 patients

Chest wall irradiation is becoming increasingly common for mastectomy patients who have opted for immediate breast reconstruction with tissue expanders and implants. The optimal approach for such patients has not yet been defined. This study assesses the outcomes of a reconstruction protocol for patients who require irradiation after tissue expander/implant reconstruction. The charts of all patients who underwent immediate tissue expander/implant reconstruction at Memorial Sloan-Kettering Cancer Center between January of 1995 and June of 2001 and who had not previously undergone irradiation were retrospectively reviewed. A subgroup of patients who required chest wall irradiation after mastectomy and reconstruction was identified. Those patients were treated according to the following treatment algorithm: (1) reconstruction with tissue expander placement at the time of mastectomy , (2) tissue expansion during postoperative chemotherapy, (3) exchange of the tissue expander for a permanent implant approximately 4 weeks after the completion of chemotherapy, and (4) chest wall irradiation beginning 4 weeks after the exchange. All irradiated patients with at least 1 year of follow-up monitoring after the completion of radiotherapy were evaluated with respect to aesthetic outcomes, capsular contracture, and patient satisfaction. A control group of nonirradiated patients was randomly selected from the cohort of patients treated during the study period. During the 5-year study period, a total of 687 patients underwent immediate reconstruction with tissue expanders. Eighty-one patients underwent postoperative irradiation after placement of the final implant. A total of 68 patients who received postoperative chest wall irradiation underwent at least 1 year of follow-up monitoring after the completion of radiotherapy, with a mean follow-up period of 34 months. Seventy-five nonirradiated patients were evaluated as a control group. Overall, 68 percent of the irradiated patients developed capsular contracture, compared with 40 percent in the nonirradiated group (p = 0.025). Eighty percent of the irradiated patients demonstrated acceptable (good to excellent) aesthetic results, compared with 88 percent in the nonirradiated group (p = not significant). Sixty-seven percent of the irradiated patients were satisfied with their reconstructions, compared with 88 percent of the nonirradiated patients (p = 0.004). Seventy-two percent of the irradiated patients stated that they would choose the same form of reconstruction again, compared with 85 percent of the nonirradiated patients. The results of this study suggest that tissue expander/implant reconstruction is an acceptable surgical option even when followed by postoperative radiotherapy and should be considered in the reconstruction algorithm for all patients, particularly those who may not be candidates for autogenous reconstruction.     

Eighty-four consecutive breast reconstructions using a textured silicone tissue expander.

Breast reconstruction utilizing smooth-surface silicone tissue expanders is associated with certain problems. Significant capsular contracture may develop around the expander with subsequent expander displacement necessitating repositioning or capsulectomy at the time of expander removal. Infection, pain on expansion, chest-wall compression, and complications related to the remote fill valve also have been reported. A textured-surface silicone expander with an integrated fill valve was developed to address these issues. Eighty-four consecutive breast reconstructions were performed by a single surgeon using textured expanders in 55 patients. Intraexpander pressures were measured during expansion for a group of these patients, and both initial and postinflation pressure readings were quite low (average initial pressure 2.88 mmHg; average postinflation pressure 12.87 mmHg). Eighty-one of the reconstructions have been completed without any expander losses and with minimal complications. Tissue expander volume averaged 580 cc, and the expansion duration averaged 5.6 months. Various types and configurations of permanent implants were used to complete the reconstructions. Eighty-four percent of our patients' completed reconstructions (including nippleareola reconstruction and opposite breast alteration, when necessary) were accomplished with just two procedures. Seventeen long-term adjustable textured-surface expander/implants with anatomic breast shape are still in place, all after only one operation. The inframmary fold has generally been established passively by the expansion process alone. Textured-surface silicone expanders have stayed where positioned, have expanded easily with minimal patient pain, and have created a noncontractile soft-tissue cover for the final implant. The textured expander with an integrated fill valve has simplified breast reconstruction by helping to limit the problems encountered with smooth silicone expanders. The resulting reconstructions have remained soft with a very acceptable aesthetic appearance. The patient office and hospital charts and photographs of this consecutive series were notarized and submitted to the Editor of this Journal, whose biostatistician randomly selected the cases illustrated.     

Stretching skin: undermining is more important than intraoperative expansion

The efficacy of intraoperative expansion in reducing the tension of wound closure was tested in young pigs. The young piglet as a model for studying human skin was characterized by finding a close similarity between the modulus of elasticity of young piglet skin and human abdominoplasty and mammaplasty skin (range 12.8 to 23.7 N/mm2 for piglet skin, 14.3 to 19 N/mm2 for human skin). The tension required to close a standardized wound was determined before undermining, after undermining, and finally after intraoperative expansion. These measurements were performed in 10 young pigs with an average weight of 11.5 kg. Undermining the wound edges resulted in a significant decrease in the force required to close the wounds (p less than 0.0001). Intraoperative expansion did not significantly decrease the tension. Previous work showing the importance of site and direction of pull on the tension for wound closure was confirmed in this study. Analysis of variance demonstrated that the tension required to close a standard wound is greater high on the pig's back than near the belly and near the shoulder as opposed to the hip for midflank wounds (p less than 0.0001). Increasing the extent of undermining from 62 to 136 cm2 significantly decreased the tension for wound closure (p less than 0.05). Further undermining did not result in a significant decrease in wound closure tension. In this model, intraoperative expansion offers no advantage over simple undermining. We suggest that the benefit reported by clinicians using intraoperative expansion may derive from an increase in the extent of undermining required to place expanders under the wound margins.     

Breast reconstruction using tissue expanders and implants in Hodgkin's patients with prior mantle irradiation.

Women treated for Hodgkin's disease with mantle irradiation have an increased risk for developing breast cancer. Typically, breast malignancy in Hodgkin's patients presents bilaterally in a younger age group. Skin flap ischemia, poor skin expansion, implant extrusion, capsular contracture, and poor cosmesis are common sequelae of tissue expander/implant breast reconstruction after breast irradiation for failed breast conservation therapy. This has led most surgeons to favor autologous tissue reconstruction in this setting. This study was performed to determine the efficacy of tissue expander/implant breast reconstruction in breast cancer patients who have been treated with prior mantle irradiation for Hodgkin's disease. A retrospective analysis of all breast cancer patients with a history of Hodgkin's disease and mantle irradiation treated with mastectomy and tissue expander/implant reconstruction between 1992 and 1999 was performed. There were seven patients, with a mean age of 35 years (range, 28 to 42 years). The average interval between mantle irradiation and breast cancer diagnosis was 16 years (range, 12 to 23 years). All patients underwent two-stage reconstruction. Textured surface tissue expanders were placed in a complete submuscular position at the time of mastectomy. Expansion was initiated 2 weeks after insertion and continued on a weekly basis until completion. Expanders were replaced with textured surface saline-filled implants as a second stage. Patients were evaluated for skin flap ischemia, infection, quality of skin expansion, implant extrusion, capsular contracture, rippling, symmetry, and final aesthetic outcome. Breast cancer was bilateral in five patients and unilateral in two. Two patients did not undergo simultaneous bilateral breast reconstruction because of metachronous cancer development. One of the patients had an initial transverse rectus abdominis muscle flap breast reconstruction, followed by a tissue expander/implant reconstruction of the opposite breast. The average follow-up was 3 years. Complications were limited to one case of cellulitis after implant placement that resolved with intravenous antibiotics. There were no cases of skin flap ischemia, poor skin expansion, or implant extrusion. Overall patient satisfaction was high and revisions were not requested or required. Symmetry was best achieved with bilateral implants. This study demonstrates the efficacy of tissue expander/implant breast reconstruction in patients treated with prior mantle irradiation. In this series, tissue expansion was reliable with low morbidity. Second-stage placement of permanent implants yielded good aesthetic results without significant capsular contracture. Mantle irradiation did not appear to compromise the prosthetic breast reconstruction. Tissue expander/implant breast reconstruction should remain a viable option in this category of irradiated patients.     

Balloon expansion of the pectoralis major muscle flap in sternoplasty: a biomechanical and histologic study in a rat model

The pectoralis major advancement flap is currently the most popular technique for reconstruction of the anterior chest in patients with sternotomy wounds. Recently, the SpaceMaker balloon was introduced for rapid expansion of the pectoralis major muscle intraoperatively. The aim of the present study was to investigate the biomechanical and histologic effects of this expansion technique in a rat model. The upper 2 cm of the sternum was resected in 54 male rats. Reconstruction with balloon-assisted pectoralis muscle expansion was performed in 24 rats (study group). Another 24 rats underwent reconstruction with simple muscle advancement without expansion. Submuscular insertion of a catheter for expansion, without inflation, was performed in the remaining six rats (sham group). Rats were killed either immediately or 2 to 4 weeks after surgery. Thirty-eight rats, including 16 after reconstruction with expansion, 16 after reconstruction without expansion, and six in the sham group, were killed immediately after surgery. Sixteen rats were killed 2 to 4 weeks after surgery, eight rats for each reconstruction technique. Before the animals were killed, the biomechanical properties of the muscles were tested with weights to calculate stiffness (in newtons per meter) and compliance gain (in percent). After the animals were killed, biopsy specimens were obtained for histologic analysis. Results indicated significantly lower muscle stiffness in the study group compared with the others immediately after surgery (p = 0.0000), although the difference failed to achieve statistical significance 2 to 4 weeks later (p = 0.76). In the study group, the compliance gain was 74.4 percent immediately after surgery but only 3.4 percent 2 weeks to 1 month postoperatively. Histologic examinations in all groups immediately and 2 to 4 weeks after surgery revealed regular muscle striation with no signs of inflammation. The elastic stiffness of the rat pectoralis major muscle is significantly reduced following rapid intraoperative expansion and returns to normal 2 to 4 weeks later.