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Results for “Tissue Expansion”

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At least 685 records · Page 38Linked to original sources

PubMed1992

[Histomorphologic findings in human expanded tissue].

Forty biopsies from 22 patients undergoing tissue expansion were examined histologically. Expanded skin demonstrated a generally unconspicious morphology of the epidermis, dermis and subcutis. Adnexal organs of the skin were preserved. Mean epidermal thickness was increased to 710 +/- 240 microns compared to 624 +/- 215 microns in the controls. The tissue expanders were bordered by a richly vascularized connective tissue capsule with a very variable mean thickness of 795 +/- 712 microns. These histologic findings in human tissues support experimental evidence for a real increase in tissue by expansion.

Adolescent↗

PubMed1994

Synovial metaplasia of a periprosthetic breast capsule.

A 48-year-old woman presented for reconstruction mammoplasty 5 years after undergoing a mastectomy for breast carcinoma. She underwent tissue expansion, with subsequent placement of a permanent silicone implant, removal of the permanent implant because of asymmetry, and further tissue expansion for another attempt at permanent silicone implant placement. The periprosthetic breast capsule surrounding the initial permanent implant consisted of a lining intima, subintima, and fibrous capsule consistent with synovium on light microscopy, immunohistochemical studies, transmission electron microscopy, and scanning electron microscopy. Silicone was localized intracellularly within the lining cells and extracellularly within the fibrous capsule by electron probe microanalysis. We believe that this case represents synovial metaplasia of a periprosthetic breast capsule that was most likely induced by repeated manipulation and silicon exposure from silicone gel leakage and the prosthetic Silastic shell.

Breast↗

PubMed1989

Tissue expanders in surgery.

The technique of tissue expansion using inflatable expanders has gained widespread attention in the surgical literature. We give two examples of its use and emphasise possible complications which may arise. The search for methods to close complex wounds, often associated with radiation-damaged tissue or exposed bone, has resulted in a progression from random skin flaps to axial pattern flaps with a longer length to breadth ratio guaranteed by anatomically constant vessels. Musculocutaneous, fasciocutaneous and free flaps have been described over the body surface allowing complex reconstruction at local and distant sites. The use of expansion is of particular value in allowing local tissue to fill defects with minimal functional and aesthetic disturbance. In the face and scalp, in particular, tissue expansion appears to be a promising method of at least partially removing disfiguring lesions and is useful in reconstruction following traumatic loss. The concept of tissue expansion in medicine is not new. During pregnancy the abdominal skin becomes gradually stretched over the expanding uterus. Large skin excisions can be carried out in abdominoplasty following weight loss. Skin and mucosa can be seen to expand rapidly over benign enlarging neoplasms. The serial excision of large naevi has been practised for many years by plastic surgeons. Skin grafts placed over fasciotomy wounds to obtain tension-free closure can be subsequently excised in stages to obtain a minimally stretched linear scar.

Adult↗

PubMed2004

Verifying surgical results and risk factors of the lateral thoracodorsal flap.

In 1986, the combined use of the lateral thoracodorsal flap and an implant was introduced as an alternative method of delayed reconstruction of small to medium-size breasts for postmastectomy patients who are reluctant or unable to consider reconstruction by tissue expansion or by more extensive autologous tissue transplantation. So far, the technique has only been proven reproducible in Sweden. Postmastectomy radiotherapy has been proven to increase the risk of wound-healing complications after lateral thoracodorsal transplantation, and additional risk factors such as advanced age, obesity, smoking, and some general health characteristics have been indicated. The authors initiated a prospective study to assess the reproducibility of this technique outside Sweden and to confirm the proven risk factor, prove or refute the alleged ones, and possibly identify additional factors. Additionally, they applied the technique for immediate breast reconstruction and tried to expand the indications and applications of the lateral thoracodorsal flap even further. The authors report on their initial experience with 60 lateral thoracodorsal flaps and conclude that the use of this flap is a well-reproducible technique for breast reconstruction, with few complications leading to failure. Using the lateral thoracodorsal flap in combination with tissue expanders allows for reconstruction of breasts of larger than medium size. Moreover, the authors successfully applied fully deepithelialized lateral thoracodorsal flaps for additional indications. The statistical significance of postmastectomy radiotherapy as a risk factor could not be confirmed, but some general health characteristics were found to be significant patient-related risk factors. Out of five procedure-related characteristics, only increased flap length was proven to negatively influence the outcome of the procedure.

Adult↗

PubMed1989

The activity of phosphoenolpyruvate carboxykinase throughout the lactation cycle of the guinea pig mammary gland.

The enzyme phosphoenolpyruvate carboxykinase (PEPCK) has been measured in the guinea pig mammary gland throughout the pregnancy-lactation cycle. This is of interest since the primary importance of PEPCK is thought to be its role in gluconeogenesis and it is questionable whether or not gluconeogenesis occurs in the mammary gland. The enzyme activity, present in both the cytosol and mitochondria, was shown to follow the lactation profile. During the transition into lactation, cytosolic PEPCK activity increases 11-fold and mitochondrial PEPCK activity 43-fold while tissue weight increases 4-fold. Fructose 1,6-bisphosphatase was found to increase at a rate only slightly greater than that of the tissue weight. The increase in mitochondrial PEPCK activity is thus about 10 times greater than that of general tissue expansion, whereas the cytosolic PEPCK activity increase is only 2-fold greater. The activity of fructose 1,6-bisphosphatase appears to be merely keeping pace with general tissue expansion. The mitochondrial enzyme constitutes 59 +/- 3% of the total gland PEPCK activity in the prepartum state and 86 +/- 2% at midlactation. Therefore, mitochondrial PEPCK is the isoenzyme undergoing the greater increase during the transition into lactation in the guinea pig mammary gland and thus would appear to play the more important role in the conversion of oxalacetate to phosphoenolpyruvate in this tissue.

Animals↗

PubMed2000

Subfascial expansion and expanded two-flap method for microtia reconstruction.

This article presents an improved two-flap method for microtia reconstruction. In the first stage of this method, a tissue expander is inserted in the mastoid region through a subfascial pocket, after which the overlying fascia and skin are expanded simultaneously with saline infusion for about 5 months. In the second stage, the expanded fascial and skin layers are split and prepared as anteriorly based skin and fascial flaps defined by their vascularity. An erect, three-dimensional, contour-accentuated ear framework fabricated with autogenous rib cartilage is inserted between the two flaps. The anteroauricular surface of the framework is draped with the thin, expanded skin, and the postauricular surface is draped with the thin, expanded fascia and overlying grafted skin. In the third stage, remnant auricular cartilage is removed and the crus helicis, tragus, intertragic notch, conchal floor, and a hollow mimicking the external auditory meatus are shaped. In this study, 146 microtias were reconstructed consecutively using the improved two-flap method. The final results were promising--major complications were minimal and most patients showed consistently favorable aesthetic results. This method married a two-flap procedure with a gradual tissue expansion, conveniently exploiting the advantages of both methods, but without the disadvantages.

Adolescent↗

PubMed1992

Reconstruction of avulsed scalp after go-cart injury.

Scalp avulsion is a rare injury that has significant physical and psychological consequences. It may require emergency replantation or late, challenging surgical reconstruction, or both. The authors describe two patients who had scalp avulsion. Each patient got long hair entangled in the uncovered engine of a go-cart. One underwent unsuccessful replantation without vascular repair; the other had a large segment of scalp successfully replanted with microvascular repair. Both patients required late reconstruction with tissue expansion. The final results were good. When feasible, microvascular replantation is the treatment of choice. If replantation is not possible, temporary cover by skin grafts followed by later reconstruction with tissue expansion can be effective.

Child↗

PubMed1993

Scalp extension.

BACKGROUND: Surgery to correct extensive alopecia requires increasing the surface of hair-bearing scalp and removing bald scalp. Two commonly used methods, scalp expansion and scalp reduction, have disadvantages. OBJECTIVE: To describe a new method, scalp extension, that employs a thin sheet of bioplastic (an extender) stretched and attached with hooks to the galea after scalp reduction. METHODS: The surgical technique is described and the results compared with those of patients who have undergone scalp reduction and scalp expansion. A study of the first fifteen cases treated is presented. RESULTS: During the few weeks that the extender is implanted, the constant tension it exerts on the galea causes a progressive stretching of the scalp. Data from the first fifteen cases treated reveal eradication of more extensive bald areas than with scalp reduction, making it possible to cut the number of operations necessary in half while considerably shortening total treatment time. The absence of major side effects, along with the absence of any deformation of the scalp (unlike scalp expansion), explains the excellent acceptability of the instrument by patients. CONCLUSION: Scalp extension appears to be a useful adjunctive technique in hair replacement and reconstructive surgery, and has distinct advantages over standard scalp reduction and tissue expansion techniques.

Alopecia↗

PubMed1988

Puncture threshold prior to leakage from tissue expander reservoirs.

An ex vivo study was devised to ascertain the maximum number of needle punctures possible prior to onset of leakage from remote-type tissue expansion reservoirs. At least 10 standard valves obtained from all major manufacturers were analyzed using various needle gauges. An 18-gauge beveled needle was determined to be the maximum size that could be safely employed for all vendors within a usual course for tissue expansion. No significant difference was found in comparison of Dacron-reinforced versus plain silicone membrane-type valves.

Equipment Failure↗

PubMed1988

An approach to excision of congenital giant pigmented nevi in infancy and early childhood.

This paper presents a timely coordinated approach to complete excision of congenital giant pigmented nevi in infancy and early childhood based on a review of 78 patients with giant pigmented nevi of the head and neck, trunk, and/or extremity. Giant pigmented nevi in those selected for review measured from a minimum of 2 percent up to 45 percent total body surface (TBS). Giant nevi of the scalp were treated most effectively using tissue expansion, beginning as early as 3 months of age. Expanded forehead and neck flaps in combination with expanded full-thickness skin grafts were used in early excision of giant pigmented nevi of the face. Giant nevi of the trunk were treated using a combination of abdominoplasty technique, tissue expansion, and split-thickness skin graft, with early "large segment" excision and grafting being the most effective treatment of giant nevi covering the posterior trunk. Giant nevi of the extremities were treated most effectively with excision and graft. Expanded full-thickness skin grafts gave excellent coverage on the hands and feet.

Child, Preschool↗

PubMed2006

Nevus sebaceus of Jadassohn.

The nevus sebaceus of Jadassohn (SNJ) is a hamartomatous disorder of the skin and its adnexa pertaining to the group of "organoid nevi,'' most frequently involving the face and scalp. During adulthood, patients with SNJ have a 10% to 20% risk of the development of cutaneous or adnexal neoplasia, so that prophylactic excision before puberty is recommended by most authors, and tissue expansion is considered to be the best method of reconstruction. It has been largely demonstrated in literature that most of the lesions that have been interpreted as basal cell carcinoma (BCC) are actually examples of primitive follicular induction or trichoblastomas, not authentic BCCs. A literature review on histopathologic findings associated with SNJ and a retrospective chart review of two cases occurring in young females are presented. In one case, the lesion was treated by intraoperative expander-assisted reduction and scalp graft (Case 1); in the other one, a primary closure with adjacent tissue was performed (Case 2). No signs of malignant degeneration or residual pathology have been found. For treatment of the biggest lesions, when preoperative tissue expansion cannot be performed, intraoperative one, transfer of a scalp graft has been shown to be a good reconstructive method. For the smallest lesions, a primary closure with adjacent tissue is sufficient.

Adult↗

PubMed2005

Human chondrocytes differentially express matrix modulators during in vitro expansion for tissue engineering.

Cartilage tissue engineering plays an important role in the generation of grafts for reconstructive surgery. In cultured chondrocytes, the dedifferentiation of cells seems unavoidable for multiplication. Dedifferentiated cells produce matrix of less quality, and the molecular basis is still not well understood. Therefore, the aim of our study was to investigate the expression of matrix modulators in human chondrocytes during expansion. Human chondrocytes were isolated from septal cartilage (n=32) and held in primary cell culture. Cells were harvested after 1, 6 and 21 days. The differentiation of cells using light microscopy, the expression patterns of various proteins (MMPs, BMPs, and TIMPs) using immunohistochemistry, and the expression of distinct genes using microarray technique, were investigated. The chondrocytes showed strong in vitro proliferation. After 6 and 21 days, BMP-5 and -8 were up-regulated, BMP-2 was down-regulated and BMP-6 was inactivated. Other BMPs were not expressed. The expression of MMP-2, -3 and -13 was up-regulated from day 1 to 21, and MMP-12 and -20 were down-regulated. Other MMPs were not expressed. TIMP-1 was up-regulated and TIMP-3 was down-regulated during expansion. Differential expression of matrix modulators might influence the matrix composition of engineered cartilage. Improving the basic knowledge in this area may ultimately help clinicians to identify and proactively intervene in an attempt to prevent bioartificial cartilage from losing stability.

Bone Morphogenetic Protein 2↗

PubMed1996

Aesthetic breast reconstruction using a combination of free transverse rectus abdominis musculocutaneous flaps and breast implants.

Some women electing immediate bilateral postmastectomy breast reconstruction have inadequate autologous tissue to achieve an aesthetic result and also wish to avoid tissue expansion or a back scar. These patients are candidates for reconstruction using free transverse rectus abdominis musculocutaneous (TRAM) flaps and breast implants. Since November 1993, 5 women have been reconstructed bilaterally with a combination of free TRAM flaps and adjustable saline breast implants. Each patient was young (age, 29-47 years) and of slender body habitus. During the procedure, the implants were placed in a submuscular pocket formed by the pectoralis major, the serratus anterior, and the muscular portion of the TRAM flap. Careful approximation of the serratus anterior to the lateral border of the pectoralis major muscle created a reliable layer of tissue to protect the vascular pedicle of the TRAM flap from contact with the implant. The saline chambers of the implants were filled to 60% to 80% capacity at the time of surgery. TRAM flap skin was tailored to precisely replace missing breast envelope, and subcutaneous fat increased implant coverage, creating a mound with normal-appearing ptosis. There were no occurrences of microvascular thrombosis. Three patients experienced prolonged formation of serous fluid, with 2 patients requiring late aspiration of a serosa after drain removal. Although there were no documented infections, 1 patient experienced postoperative erythema of the mastectomy skin flaps and was treated empirically with antibiotics with resolution of the erythema. All breasts have remained soft and appear natural. Using free TRAM flaps and adjustable saline breast implants allows selected women to undergo immediate breast reconstruction without the need for prolonged tissue expansion or back scars. Aesthetic results are excellent and the immediate use of an implant does not appear to pose a risk to the success of the free tissue transfer.

Adult↗

PubMed2001

Pre-expanded arterialised venous free flaps for burn contracture of the cervicofacial region.

Despite the fact that arterialised venous flaps provide thin good-quality tissue to repair defects of the face and neck, their clinical applications have been limited by an unstable postoperative course and variable flap necrosis. In an effort to resolve these problems, a tissue-expansion technique has been applied to the arterialised venous flap before flap transfer. Three pre-expanded arterialised venous free flaps have been used to treat post-burn scar contracture of the cervicofacial region. The donor site was confined to the forearm in each case. A rectangular expander was usually placed over the fascia of the flexor muscles in the proximal two-thirds of the forearm. The mean expansion period, volume and flap size were 44 days, 420 cm(3)and 147 cm(2), respectively. There were no complications caused by insertion and expansion. The cervicofacial region was successfully reconstructed, after excision of the post-burn contractures, with pre-expanded arterialised venous flaps, with no marginal necrosis or postoperative instability. Large thin arterialised venous flaps are well matched with the recipient defect in the cervicofacial area and the colour and texture match obtained with forearm tissue produced an aesthetically favourable result. Pre-expanded arterialised venous flaps are another new option for free flap reconstruction of the face and neck.

Adult↗

PubMed2001

Breast reconstruction using a deepithelialized rectus abdominis musculocutaneous flap.

There are many methods for breast reconstruction. Using implants can achieve good results without conspicuous scarring, but this method has disadvantages, such as infection, exposure, and capsular contracture. The rectus abdominis musculocutaneous (RAM) flap has become a standard technique because of its safety and abundant volume, but its main problem is the lack of a color and texture match between the skin paddle and the skin around the flap. To overcome such shortcomings, the authors perform breast reconstruction using tissue expansion and a RAM flap. First a tissue expander is inserted superficially to the pectoralis major muscle at the time of or after mastectomy, and is expanded to a size larger than the contralateral breast. The expander is replaced with the deepithelialized RAM flap. Scar revision is performed if the expander is inflated satisfactorily. The authors used this technique in 11 patients and obtained good results without severe complications.

Adult↗

PubMed1997

Obtaining maximal use of expanded scalp rotation flaps via an experimental model.

The relative inelasticity of scalp skin and the irregular convexity of the cranial vault necessitate careful planning in the design and mobilization of scalp flaps. Rotation flaps adapt particularly well to the curves of the cranial vault. An experimental model has enabled us to study the design and mobilization of expanded scalp rotation flaps and to obtain maximal efficiency from the tissue expansion process. The use of a round tissue expander situated immediately adjacent to a scalp defect is an excellent method for the creation of a rotation flap. To optimize the use of the expanded tissues, the flap should be designed so that its border passes along the periphery of these expanded tissues. In cases in which it is advisable to separate the expander from the defect, such as when the defect is highly contaminated, efficient use of the expanded tissues can still be obtained by placing the expander at the site of a rotation flap backcut. Furthermore, although this study focuses on rotation flaps only, this same model can be used to examine and compare different closure methods using other types of flaps as well.

Child, Preschool↗

PubMedDate not supplied

Surgical reconstruction of lentigo maligna defects.

OBJECTIVE: To review our experience with lentigo maligna, a melanoma in situ that occurs primarily on the head and neck in older adults, and reconstructive efforts applied in managing the large defects following lentigo maligna excision that are not amenable to primary closure. METHODS: We reviewed the records of 23 patients who underwent serial excision of lentigo maligna using a modified Mohs technique. We compared the sizes of the initial lesion and postexcision defect, examined photographs taken before and after surgery, and studied techniques used in reconstruction. RESULTS: The final surgical defect after staged Mohs excision of lentigo maligna lesions ranged from 2 to 10 times the original lesion size. Invasive melanoma was identified in 2 surgical specimens on pathologic evaluation. We reviewed successful reconstructive techniques including local flaps and tissue expansion. CONCLUSIONS: Surgical excision remains the standard of care for lentigo maligna. Because of the subclinical spread and extensive radial growth characteristic of these lesions, patients are often left with large defects that are not amenable to primary closure. Appropriate preoperative patient counseling includes preparation for the possibility of a large surgical defect that requires staged reconstruction. Creative techniques, including local flaps and tissue expansion, must be in the head and neck reconstructive surgeon's armamentarium for the management of defects following lentigo maligna excision.

Adult↗

PubMed2003

Autologous fat graft in nipple reconstruction.

Reconstruction of the nipple is the penultimate step in breast reconstruction after mastectomy. A number of reconstructive techniques have been described for nipple reconstruction including skin grafts, composite grafts, and various local flaps. The authors' preferred reconstructive technique is the local C-V or modified star flap. This flap produces an excellent reconstruction, but it is dependent on underlying subcutaneous fat to provide bulk to the reconstructed nipple. In most instances, the subcutaneous tissue is adequate. However, under certain circumstances, the subcutaneous fat may be insufficient to produce a nipple of adequate projection. Two cases of bilateral nipple reconstruction after soft-tissue expansion and implant placement and subsequent nipple reconstruction with local flaps provided inadequate nipple projection. These instances, as well as a retrospective review of reconstructed nipples after mound restoration using a variety of techniques, led the authors to conclude that a more predictable alternative to sustain nipple projection was necessary. The authors identified two broad categories of breast reconstruction patients in whom this new technique would be beneficial. In the first category of patients, breast mounds are reconstructed with tissue expansion and implant insertion, and in the second category, breast mounds are reconstructed by any technique in which the nipple reconstruction subsequently flattens. This article describes the indications, techniques, and experience in 13 patients treated over a 10-month period with fat grafting for nipple reconstruction.

Adipose Tissue↗