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.     

Use of external reservoirs in tissue expansion

The use of tissue expanders having external reservoirs is presented. Twenty-four patients had 36 tissue expanders placed in the scalp, face, neck, upper limbs, chest, and lower limbs. All patients, apart from one, were taken to completion. This patient had erosion of the skin over expander and was only partially completed after removal of the expander. Apart from one instance of deflation at the end of the expansion where the skin could still be used, there were no other complications, in particular, no infections. The advantages of this technique are reduced operating time, ease of injection into the reservoir, lack of pain for the patient, early detection of reservoir or filling tube junction leakage, and lack of complications associated with the reservoir. This procedure is not recommended on at least theoretical grounds for breast expansion, where a permanent implant is to be inserted.     

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.     

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.     

The role of tissue expanders in an anophthalmic animal model

A study of orbital bony expansion using a custom tissue expander was performed in the anophthalmic cat model. Twelve 6-week-old kittens underwent right unilateral enucleations. Six kittens had immediate insertion of a tissue expander into the orbit. The remaining six served as controls. Every 2 weeks 0.5 cc saline was injected into the expander to a maximum of 5 cc. External horizontal and vertical orbital dimensions were obtained by palpation technique weekly. All animals had preoperative and study conclusion head CT scans with three-dimensional reconstructions performed. Dry skull preparations were done at the study conclusion at 24 weeks. Results demonstrated that tissue expanders were successful in maintaining normal orbital growth and size relative to the contralateral control orbit. The animals with enucleation only had an average difference in vertical and horizontal orbital measurements of -27 and -13 percent when compared with the contralateral normal orbit. In contrast, the enucleation and tissue-expansion animals had vertical and horizontal measurements of +4 and +2 percent (p less than 0.05) when compared with the contralateral orbit. Head CT scans with three-dimensional reconstructions demonstrated normal orbital geometry and volume for the animals with tissue expanders, whereas animals with enucleation only had small hypoplastic orbits. In conclusion, orbital tissue expanders offer a promising new technique in the treatment of anophthalmos.     

Microvascular pressure and functional capillary density in extreme hemodilution with low- and high-viscosity dextran and a low-viscosity Hb-based O2 carrier

Blood losses are usually corrected initially by the restitution of volume with plasma expanders and subsequently by the restoration of oxygen-carrying capacity using either a blood transfusion or possibly, in the near future, oxygen-carrying plasma expanders. The present study was carried out to test the hypothesis that high-plasma viscosity hemodilution maintains perfused functional capillary density (FCD) by preserving capillary pressure. Microvascular pressure responses to extreme hemodilution with low- (LV) and high-viscosity (HV) plasma expanders and an exchange transfusion with a polymerized bovine cell-free Hb (PBH) solution were analyzed in the awake hamster window chamber model (n = 26). Systemic hematocrit was reduced from 50% to 11%. PBH produced a greater mean arterial blood pressure than the nonoxygen carriers. FCD was higher after a HV plasma expander (70 +/- 15%) vs. PBH (47 +/- 12%). Microvascular pressure spanning the capillary network was higher after a HV plasma expander (16-19 mmHg) compared with PBH (12-16 mmHg) and a LV plasma expander (11-14 mmHg) but lower than control (22-26 mmHg). FCD was found to be directly proportional to capillary pressure. The use of a HV plasma expander in extreme hemodilution maintained the number of perfused capillaries and tissue perfusion by comparison with a LV plasma expander due to increased mean arterial blood pressure and capillary pressure. The use of PBH increased mean arterial pressure but reduced capillary pressure due to vasoconstriction and did not maintain FCD.     

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.     

The modeling of skin expanders

In this paper we present mathematical models of tissue expanders of several shapes. Within the restrictions of the models, relations are given between surface-area gain and volume of the expanders. It is shown that for the most frequently used expander shapes, the relevant formulas are simple and do not require computer facilities. It is discussed that the approach unavoidably leads to considerable overestimation of the area gain but may serve as a necessary starting point for further research. Furthermore, the rate of overestimation appears to follow such a regular pattern that it can quite easily be compensated for by means of a correcting factor.     

The role of tissue expansion in the treatment of atypical facial clefting

Tissue expansion can be a valuable tool in the reconstruction of soft-tissue defects in craniofacial clefts. To our knowledge, there have been no reports in the literature of the use of tissue expanders to help solve this problem. We report the case of a child with an atypical Tessier no. 3 craniofacial cleft who had a forehead tissue expander placed, inflated, and thus used to provide sufficient local facial skin for repair of the soft-tissue defect.     

Long-term effects of tissue expansion on cranial and skeletal bone development in neonatal miniature swine: clinical findings and histomorphometric correlates

Progressive tissue expansion induces significant gross, histologic, and bony changes in skulls and long bones of neonatal miniature swine. These bony changes consist of erosion underlying tissue expanders, with bony lipping and bone deposition at the periphery of the expander. Cranial suture lines underneath expanders appear effaced and convoluted. Serial CT scans reveal decreased bone thickness and volume (p less than 0.02) but identical bone density (p = 0.60) beneath expanders. Increased bone volume and thickness occur at the periphery of expanders (p less than 0.02). Bone density (CT number) is unaffected by tissue expansion in both cranial and long bones. These findings have histomorphometric correlates: Osteoclastic bone resorption occurs underneath expanders with periosteal reaction at the periphery of expanders. Cranial sutures are similarly affected, but no cranial synostosis results. No changes to the inner table of the skull or stigmata of increased intracranial pressure were observed either in CT scans or in behavioral changes in long-term animals. The pathophysiology of bony changes is a remodeling effect, not one of simple pressure deformation. Increased bone resorption and complete inhibition of bone formation occur until the pressure is removed. Cranial bone is significantly more affected than long bone. After removal of the expanders, reparative bone remodeling begins within 5 days and nearly complete healing of the cranial defects occurs within 2 months (p less than 0.02). No plagiocephaly results despite early coronal suture changes. On the basis of this study, we conclude that tissue expansion causes significant but reversible effects, readily monitored by high-resolution CT scans, on neonatal and infant cranial and long bones.     

Enhancement of Tissue Expansion by Calcium Channel Blocker: A preliminary study

BACKGROUND: Reconstruction of the defects after surgical resection of tumors is one of the important issues in surgical oncology. It is essential that the defect should be covered with a tissue quite similar to the original one and is best achieved by harvesting tissue from an area adjacent to the defect. Tissue expansion is one of the most frequently used reconstructive techniques. A number of studies evaluated blood circulation, capsule formation, tissue tolerance, histomorphological changes and complications of expander placement. However, only a few attempted to enhance tissue expansion. This study we aimed to evaluate verapamil, a calcium channel blocker, to enhance tissue expansion. MATERIAL AND METHOD: Twelve New Zealand rabbits weighing between 900 gm and 1200 gm were assigned into study and control groups. High volume expanders (100, 200 or 300 cc) were placed into the subcutaneous tissue. Rabbits in the study group received verapamil. Expanders in the control group were inflated every three days to achieve same pressure as the study group. The size of the flaps was assessed by applying pressure on tip of the flap to demonstrate the contraction. Histopathological examinations were performed. RESULTS: By administering liquid earlier and more quickly less flap retraction was observed in the study group. In the control group expanders were exposed in two rabbits while no complication occurred in the study group. Following extraction of the expanders, the flaps were elevated and less retraction was observed in the study group compared to controls. CONCLUSION: Verapamil is safe when used topically and provides less retracted flaps. It can be suggested that verapamil acts on the myofibroblasts in the capsule around tissue expanders and thus increases efficiency of the expanders.     

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.     

In vivo diffusion of lidocaine through tissue expanders.

It has been suggested that the addition of lidocaine to the saline used to fill tissue expanders will reduce the pain often associated with the expansion process. In vitro experiments have shown that lidocaine as it is normally supplied will diffuse through an expander only at a very slow rate, which would probably be inadequate for a clinical effect. We found that the addition of sodium bicarbonate resulted in a substantial increase in the rate of diffusion. Studies in rabbits demonstrated that at a pH of 8.0, 75 percent of the lidocaine dose crossed the silicone elastomer membrane at 24 hours and greater than 95 percent had left the expander at 1 week. We have concluded that intraluminal lidocaine can be effective only when the pH is close to the pKa of lidocaine.     

Influence of the Presence of Tissue Expanders on Energy Deposition for Post-Mastectomy Radiotherapy

An increasing number of studies have shown that post-mastectomy radiotherapy presents benefits associated with the patients survival and a significant fraction of the treated patients makes use of tissue expanders for breast reconstruction. Some models of tissue expanders have a magnetic disk on their surface that constitutes heterogeneity in the radiation field, which can affect the dose distribution during the radiotherapy treatment. In this study, the influence of a metallic heterogeneity positioned in a breast tissue expander was evaluated by means of Monte Carlo simulations using the MCNPX code and using Eclipse treatment planning system. Deposited energy values were calculated in structures which have clinical importance for the treatment. Additionally, the effect in the absorbed energy due to backscattering and attenuation of the incident beam caused by the heterogeneity, as well as due to the expansion of the prosthesis, was evaluated in target structures for a 6 MV photon beam by simulations. The dose distributions for a breast treatment were calculated using a convolution/superposition algorithm from the Eclipse treatment planning system. When compared with the smallest breast expander volume, underdosage of 7% was found for the largest volume of breast implant, in the case of frontal irradiation of the chest wall, by Monte Carlo simulations. No significant changes were found in dose distributions for the presence of the heterogeneity during the treatment planning of irradiation with an opposed pair of beams. Even considering the limitation of the treatment planning system, the results obtained with its use confirm those ones found by Monte Carlo simulations for a tangent beam irradiation. The presence of a heterogeneity didńt alters the dose distributions on treatment structures. The underdosage of 7% observed with Monte Carlo simulations were found for irradiation at 0°, not used frequently in a clinical routine.     

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.     

Fungal growth inside saline-filled implants and the role of injection ports in fungal translocation: in vitro study

Infection is a serious complication of breast augmentation and tissue expansion with inflatable devices. Several reports have shown that fungi may be able to survive, colonize, and even cause infection in saline-filled devices. The mechanism of how they penetrate, spread, and colonize inside the inflatable implants is not exactly understood. The authors assessed both the expander membrane and the port in terms of leakage and penetration of Candida albicans and Aspergillus niger in an in vitro model. Thirty saline-filled expanders connected to the injection port were placed in sterile containers filled with tryptic soy broth culture medium to simulate the clinical situation in phases I and II. Intact and multipunctured ports were used in the first and second phases of the study, respectively. Either the container or the implant was inoculated with one of these fungi, and six implants in containers without fungal inoculation served as controls. As a third phase, intraluminal survival of fungi was investigated in saline-filled containers (n = 12) in 21 days. The silicone membrane, with its intact connecting tube and port, was impermeable to these fungi, whereas both fungi were able to diffuse inside-out or outside-in through the punctured ports. C. albicans did not survive beyond 18 days in saline, whereas A. niger continued to multiply at day 21. Chemical analyses of the implant fluids revealed that the contents of the culture medium diffused into the implants in phases I and II. The data show that an intact silicone membrane is impermeable to fungi, and punctured ports allow translocation of fungi into the implants. Fungi can grow and reproduce in a saline-only environment, and their survival periods differ among the species. Furthermore, their survival may be enhanced by the influx of substances through the implant shell.     

Tissue expansion using osmotically active hydrogel systems for direct closure of the donor defect of the radial forearm flap.

Although widely used, the radial forearm flap has been criticized for the poor quality of its donor site. Attempts to avoid donor-site problems have concentrated on the elaboration of the split-thickness and full-thickness skin graft methods of reconstruction. Skin grafts frequently fail over the flexor carpi radialis tendon, leading to chronic skin breakdown or, at best, tendon adhesion. Tissue expansion appears to be a good alternative that allows the use of local tissues to ultimately improve the forearm donor-site appearance. To avoid the disadvantages of traditional silicone balloon expanders (such as pressure peaks, infection, the valve at a distance from the expander, postoperative fillings), an osmotically active system was used. In an 18-month prospective study, 10 osmotically active hydrogel tissue expanders were placed on the forearms of 10 patients. The radial forearm flap was performed for intraoral reconstruction after surgical resection of oral cavity malignancies. The study showed that, in nine out of 10 patients, the expanded skin achieved was sufficient to cover the donor site after raising the forearm flap. Additionally, the expansion-related swelling pressure was well tolerated by the patients, the cosmetic results were very satisfactory, and the incidence of complications was very low. By using osmotically active hydrogel tissue expanders, there is no postoperative filling and no risk of complications arising from defective balloon expanders, filling valves, or missing ports.     

Breast reconstruction with implants and expanders

Breast reconstruction with expanders and implants provides an excellent option in the properly selected patient. Techniques for reconstruction have evolved significantly over the past 30 years with the development of more sophisticated devices and improvement in surgical procedures. Several options exist, each with its own advantages and disadvantages. Two-stage breast reconstruction using a textured device with an anatomic shape and integrated valve seems to provide the most consistent and reproducible results in most patients. Those patients with small, minimally ptotic breasts may be candidates for either single-stage implant reconstruction or reconstruction with an adjustable device. Advantages of expander and implant reconstruction over other techniques include relative ease of the procedure; no distant donor-site morbidity; use of tissue of similar color, texture, and sensation; reduced operative time; and more rapid postoperative recovery.     

Three-dimensional assessment of transverse dentoskeletal mandibular dimensions after utilizing two designs of fixed mandibular expansion appliance: A prospective clinical investigation

The aim of this clinical study was to evaluate and compare the dentoskeletal transverse mandibular arch dimensions following the use of two designs of fixed mandibular expanders using cone beam computed tomography (CBCT). Twenty orthodontic patients, 12 females and 8 males, with mean age of 13.4 ± 0.5 years were selected and randomly divided into two equivalent groups; group A consisted of 10 patients (4 boys, 6 girls) who were treated with modified Williams expander and group B consisted of 10 patients (4 boys, 6 girls) who were treated with a two-arm fixed expander. Consistent expansion instructions were given to all patients according to a standardized slow protocol of one quarter turn twice/week for both expanders. Routine orthodontic records as well as mandibular CBCTs were obtained before (T1) and immediately after expansion (T2) to estimate changes in dentoskeletal mandibular transverse dimensions. The data was statistically analyzed and the significance level was set at p ≤ 0.05. Mandibular intercanine, inter-premolar, intermolar widths; and arch perimeter were significantly increased (p ≤ 0.05) following expansion with both fixed expanders. However, the changes in inter-premolar width, intercanine width, and arch perimeter were significantly augmented in two-arm fixed expander group than modified Williams’s group. In contrast, their effects on the skeletal mandibular body width were non-significant (p > 0.05). Both expanders yielded significant and equivalent dentoalveolar effects that were more evident with two-arm fixed expander than the William one. Both fixed designs enhanced mandibular transverse dental dimensions; however, they were unsuccessful to create any considerable skeletal effects.     

Maximizing gain from rectangular tissue expanders.

Three different options are proposed to cut the flap after expansion of rectangular tissue expanders. Each method, when used effectively, allows the expander to deliver the full punch of the expansion process.