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PubMed1989

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.

Adult↗
PubMed1998

Tissue culture surface characteristics influence the expansion of human bone marrow cells.

Human cell therapy applications in tissue engineering, such as the ex vivo production of hematopoietic cells for transplantation, have recently entered the clinic. Although considerable effort has been focused on the development of biological processes to generate therapeutic cells, little has been published on the design and manufacture of devices for implementation of these processes in a robust and reproducible fashion at a clinical scale. In this study, the effect of tissue culture surface chemistry and texture was assessed in human bone marrow (BM) mononuclear cell (MNC) and CD34-enriched cell cultures. Growth and differentiation was assessed by total, progenitor (CFU-GM), stromal (CFU-F), and primitive (LTC-IC) cell output. Tissue culture treated (TCT) plastic significantly increased MNC culture output as compared with non-TCT plastic, whereas CD34-enriched cell cultures gave lower output (than MNC cultures) that was unaffected by TCT plastic. Interestingly, the level of MNC culture output was significantly different on four commercial TCT surfaces, with the best performing surface giving output that was 1.6- to 2.8-fold greater than the worst one. The surface giving the highest output was the best at supporting development of a distinct morphological feature in the adherent layer (i.e. cobblestone area) indicative of primitive cells, and X-ray photoelectron spectroscopy (XPS) was used to characterize this surface. For custom injection molding of culture devices, the use of three different resins resulted in MNC culture output that was equivalent to commercial cultureware controls, whereas CD34-enriched cell cultures were highly sensitive to resins containing additives. When the texture of molded parts was roughened by sandblasting of the tool, MNC culture output was significantly reduced and higher spikes of IL-6 and G-CSF production were observed, presumably due to macrophage activation. In conclusion, the manufacture of BM MNC culture devices for clinical applications was optimized by consideration of plastic resin, surface treatment, and texture of the culture substratum. Although CD34-enriched cells were insensitive to surface treatment, they were considerably more sensitive to biocompatibility issues related to resin selection. The development of robust systems for BM MNC expansion will enable clinical trials designed to test the safety and efficacy of cells produced in this novel tissue engineering application.

Culture Media↗
PubMed1983

Ethylene-induced lateral expansion in etiolated pea stems : kinetics, cell wall synthesis, and osmotic potential.

Treatment of etiolated pea (Pisum sativum L.) internode tissue with ethylene gas inhibits elongation and induces lateral expansion. Precise kinetics of the induction of this altered mode of growth of excised internode segments were recorded using a double laser optical monitoring device. Inhibition of elongation and promotion of lateral expansion began after about 1 hour of treatment and achieved a maximum by 3 hours. Similar induction kinetics were observed after treating internodes with colchicine and 2,6-dichlorobenzonitrile, an inhibitor of cellulose synthesis. In sealed flask experiments, ethylene had no detectable effect on incorporation of label from [(14)C]glucose into any of the classical pectin, hemicellulose, or cellulose wall fractions. Ethylene inhibited fresh weight increase (total cell expansion) of both excised internode segments (in sealed flasks) and intact seedlings. Ethylene treatment resulted in an increase in cell sap osmolality in those tissues (intact and excised) which are inhibited by the gas. A model for ethylene-induced inhibition of elongation and induction of lateral expansion is presented.

Journal Article↗
PubMed2003

Fabrication of endothelial progenitor cell (EPC)-seeded intravascular stent devices and in vitro endothelialization on hybrid vascular tissue.

Rapid re-endothelialization at an atherosclerotic lesion after balloon inflation or stent deployment may be essential for reducing or preventing local thrombus formation and restenosis. In order to prevent these complications via enhanced rapid re-endothelialization, we fabricated two types of endothelial progenitor cell (EPC)-seeded intravascular stent devices. One was a photocured gelatin-coated metallic stent, and the other was a microporous thin segmented polyurethane (SPU) film-covered stent on which photocured gelatin was coated. Both devices were seeded with ex vivo expanded EPCs obtained from canine peripheral blood. Seeded EPCs formed confluent monolayers onto surfaces of both photocured gelatin-coated stent struts and SPU film, and a majority of cells remained on surfaces of stents after stent expansion. The EPC-seeded stent was expanded in a tubular hybrid vascular medial tissue composed of vascular smooth muscle cells and collagen as an arterial media mimic. After 7-day culture, EPCs, which migrated from the stent struts, proliferated and endothelialized the luminal surfaces of the hybrid vascular medial tissue. This in vitro pilot study prior to in vivo experiments suggests that on-stent cell delivery of EPCs may be novel therapeutic devices for re-endothelialization or endothelium lining or paving at an atherosclerotic arterial wall, resulting in the prevention of on-stent thrombus formation and in-stent restenosis, as well as the rapid formation of normal tissue architecture.

Animals↗
PubMed2007

Vertical expandable prosthetic titanium rib for thoracic insufficiency syndrome: a new method to treat an old problem.

PURPOSE: The vertical expandable prosthetic titanium rib (VEPTR) thoracoplasty is a new technique devised for the treatment children with thoracic insufficiency syndrome. This study describes our initial experience with this device. METHODS: This is a retrospective chart review of all children undergoing VEPTR placement between October 2001 and December 2005. RESULTS: Twenty-two patients had 36 VEPTR devices placed. Two patients had Jeune syndrome, 19 had scoliosis, and 1 had a chest wall resection for tumor. Most had associated carbon dioxide retention, pulmonary restrictive disease, or respiratory failure. Eleven patients had multiple fused ribs requiring opening thoracostomy. All but the most recent patients have undergone sequential VEPTR expansion. All children had intraoperative spinal cord monitoring (somatosensory evoked potential). Four experienced intraoperative somatosensory evoked potential changes that resolved with decreased VEPTR expansion. Seven VEPTR devices required revision for erosion through the bone or dislodgment and 3 were removed. Five were outgrown and removed or replaced. One eroded soft tissue causing superficial infection that resolved with operative revision. Postoperative ventilation/perfusion scans improved most in younger children. Two of three children with carbon dioxide retention pre-VEPTR had carbon dioxide reduction post-VEPTR. CONCLUSIONS: Vertical expandable prosthetic titanium rib (VEPTR) is a new and safe method to treat children with thoracic insufficiency syndrome. The VEPTR may decrease carbon dioxide retention in some patients and may be most beneficial in younger children.

Adolescent↗
PubMed1992

Testing of dielectric properties of biological tissues in microwave range for solving matching problems.

Since the employment of microwave energy for defrosting biological tissues and for microwave-aided diagnosis in cryosurgery is very promising, the problem of ensuring the match between the contact antennas (applicators) and the frozen biological object has become a pressing one. It is for this reason that investigations were aimed at the study of the dielectric properties of the dog's muscular and fatty tissues in a temperature range of +20 to -30 degrees C including the phase transition of the samples to the solid state. The investigations were performed in a waveguide device using a short-circuit method. During the investigation possible error was estimated. The experiment provides for the reduction of the error caused by the waveguide linear expansion.

Adipose Tissue↗
PubMed1993

Increased sensitivity in objective monitoring of tissue expansion.

The end point for incremental filling of any tissue expander normally may reliably be assessed using subjective parameters, especially pain, as a guideline. However, in unusual circumstances, such as within denervated areas, the presence of marginal skin circulation, or if rapid expansion is required, an objective monitor may be beneficial to ensure safer expansion. We have previously examined the role of serial measurement of transcutaneous oxygen in this regard. In an effort to refine this sometimes cumbersome approach, a comparison using laser Doppler flowmetry as well has been undertaken in 13 consecutive patients. Both monitoring devices demonstrated a progressive impediment to blood flow with increased expansion. At the pain threshold, both techniques recorded values consistent with adequate skin circulation, thereby proving in general the relative safety of subjective evaluation during the usual course of tissue expansion. Greater sensitivity was noted for the laser Doppler as a monitor, though, via the recording of earlier changes in flow characteristics and more rapid identification of critical thresholds for nonviability. From a more practical standpoint, immediate application without a period for equilibration is another major asset of laser Doppler flowmetry as a system for objective monitoring.

Adolescent↗
PubMed1989

Trends and prospects of bio-medical electron microscopy.

Prognostic ideas of the development of the bio-medical electron microscopy in the forthcoming decades to the 21st century include following points: 1. Development and improvement of electron microscopes with which one and the same point of a tissue section can be analysed in a wide spectrum of magnifications ranging from optical light microscopic to molecular level. 2. Element analysis on a large scale and 3-dimensional analysis of a wide range of electron microscopes, including the 100 kV standard model, high-voltage electron microscopes as well as intermediary electron microscopes of 200 kV to 400 kV with complementary devices. 3. Expansion of procedures for computerised image analysis for representation, modelling, and stimulation of macromolecules and other particles. 4. Improvement of both the chemical and physical aspects of fixation and embedding methods (freezing procedures) for the purpose of getting closer to in situ conditions of cells and tissues. 5. Persistent enhancement of methods of immunocytochemistry and genetic engineering at supramolecular and molecular levels, including their combination with appropriate hardware configurations for analysis of normal and pathological life processes. 6. The electron microscope will continue to keep its established position in medical diagnosis as well as in the assessment of ultrastructural alterations in the course of diseases. This position will be strengthened and expanded, and the electron microscope will thus play a role in scientifically substantiated therapy.

Clinical Laboratory Techniques↗
PubMed1995

[Full-load expansion techniques and preliminary clinical application].

For accelerating the inflation process of soft tissue expansion, a continuous inflation protocol regarding pain as the criterion of over-inflation, the full-load expansion technique, was introduced. It is carried out by restricting persistently the pressure in the expander near the pain threshold in a state of dynamic equilibrium between the infusing rate and the skin expansion velocity, with a simple and practical assembled device. This inflation is neither at a uniform infusing rate nor at a constant filing pressure. 19 expanders in 13 patients were inflated following this protocol. Their inflations were respectively fulfilled in 5 to 20 days, depending individually on their anatomic regions, total volumes of infusion, areas of the overlying skin and the patient susceptibilities.

Alopecia↗
PubMed1998

[Mandibular reconstruction of gunshot wounds by progressive bone distraction. Report of five cases].

Five adult patients with gunshot wound defect underwent bilateral mandibular lengthening by an extraoral device. All patients presented with interrupting mandibular defect of 50 to 100 mm. Distraction of bone fragments led to mandibular reconstruction without bone grafting and simultaneous expansion of soft tissues, avoiding free or pedicled myocutaneous flaps for soft tissue reconstruction of the lower third of the face. Mandibular distraction also recreated the alveolar ridge with its attached mucosa which is equivalent to the gingiva. It can be used for dental rehabilitation by osseointegrated implants. Avoiding the morbidity and functional problems of classical flaps, mandibular distraction accelerates facial reconstruction, and social reinsertion of these patients.

Adult↗
PubMed2001

[Distraction osteogenesis for the premaxillary reconstruction. Report of 3 cases].

Reconstructing the premaxillary is well-known for being difficult and usually requires a bone implant, in grafts or flaps. This technique has a high morbidity rate and its middle or long term results remain uncertain. Thanks to their experience and to the results they achieved in mandible and maxillary osteogenic distraction, the authors suggest applying the principle of distraction osteogenesis to the premaxillary reconstruction. Three patients have been treated: first, two hypoplasias of the premaxillary, sequelae of a cleft palate and of a former traumatic loss of teeth; secondly one premaxillary defect following a gunshot wound. The first two were women, the other one was man, all adults. For premaxillary distraction, an intraoral extramucosa device is made-up for each individual case before the surgical operation itself and after an orthognathic analysis. The surgical operation consists in a classical segmental maxillary osteotomy which respects the palatal periosteum, and also in fitting a distractor device with transmucosa screws into the palatal bone. In each of the three cases, with a follow-up from 24 to four months, the reconstruction of the premaxillary by distraction osteogenesis is considered satisfactory and stable as regards both bone and soft tissues. This achieves particularly a very good expansion of the fibrous mucosa of the palate which makes it possible to re-insert false teeth, with or without implants into the bone. The principle of distraction osteogenesis applied to premaxillary reconstruction has shown, in our cases, very good functional and aesthetic results. Yet the techniques we used are simple and have a low morbidity rate; secondly the distraction device is easy to design and little expansive.

Adult↗
PubMed1991

Development of a new culture system for human lymphokine-activated killer cells: comparison with a conventional static culture method.

We recently developed a new culture system based on dialysis perfusion (designated JCC-device) for the generation and expansion of human lymphokine-activated killer (LAK) cells (Murata et al., 1990). More recently we have scaled up the volume of the culture vessel of the JCC-device from 100 ml to 400 ml for clinical use. In the present study, using this new 400 ml JCC-device, we cultured human lymph node lymphocytes (LNL) obtained from 8 surgical patients with primary lung cancer, and investigated the cellular characteristics in comparison with a conventional batchwise culture system using tissue culture dishes. With the JCC-device, the cell density reached a maximum 2.7 x 10(7) cells/ml with greater than 90% viability by the appropriate exchange of perfusion medium and by making additions at the appropriate intervals for recombinant interleukin-2 (rIL-2). The expansion fold of LNL with the JCC-device, ranging 6.6- to 19.2-fold (mean 13.8-fold), was not significantly different from that in dish cultures. There was no marked difference in cell surface phenotypes between the two culture systems in 7 out of 8 cases. As for LAK activity of LNL, the JCC culture was either superior or equal in 4 out of 8 cases, but inferior in the other 4 cases to the conventional dish cultures. In the latter cases, the usage of serum for the JCC culture was limited, which might have resulted in the low LAK activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Count↗
PubMed1978

Technical note: an improved McCutchen miniviscometer for connective tissue fluids.

McCutchen's miniviscometer is a Couette-type instrument that requires only 0.2 ml of synovial or other test fluid. The modification described here adds to the capabilities of the original: control of temperature good to +/- 0.2 degrees C; increase of the maximum measureable viscosity at low shear rates (20 sec-1) to 3000 centipoise; and expansion of the usable range of shear rates to (20--1500 sec-1. The device is rugged and data are reproducible to +/- 1.2% (S.D.) of the mean over the full range of shear rates.

Body Fluids↗
PubMed2001

Cranial distraction osteogenesis in sheep using a totally implantable hydraulic mechanism: early results.

Conventional distraction osteogenesis has been performed by using either percutaneous pins attached to a thread and screw mechanism, or a thread and screw mechanism that is implanted but still requires turning by a percutaneous instrument or device. In these situations there is always the risk of infection passing to the bone via the percutaneous connection. We have developed a totally implantable hydraulic mechanism, which is activated in much the same way as injection into the port of a tissue expander. Preliminary in vitro testing has suggested that our mechanism can produce sufficient force at appropriate rates of distraction to have a promising role in distraction osteogenesis. We examined the effect of osseous distraction on the cranial vault. Expansion of the cranial vault by distraction osteogenesis is not widespread in clinical practice, in part because of the risk of infective complications of the extra-dural space. We were, therefore, presented with an ideal opportunity both to test the new distraction device and to examine the effect of distraction osteogenesis on the cranial vault. A sheep animal model was used in a pilot study to test the plausibility and examine the physiology of cranial-vault distraction osteogenesis using a totally implantable hydraulic device. Two sheep had a device implanted in the temporal fossa so as to push the craniotomised cranial cap upwards. Distraction was performed for 13 days beginning 1 week after craniotomy. After 9 weeks of consolidation, 5.5 mm and 7.4 mm of new woven bone of normal cranial thickness were demonstrated.

Animals↗
PubMed2000

Nonsurgical breast enlargement using an external soft-tissue expansion system.

Less than 1 percent of the women interested in having larger breasts elect to have surgical augmentation mammaplasty with insertion of breast implants. The purpose of this report is to describe and test the efficacy of a nonsurgical method for breast enlargement that is based on the ability of tissues to grow when subjected to controlled distractive mechanical forces. Seventeen healthy women (aged 18 to 40 years) who were motivated to achieve breast enlargement were enrolled in a single-group study. The participants were asked to wear a brassiere-like system that applies a 20-mmHg vacuum distraction force to each breast for 10 to 12 hours/day over a 10-week period. Breast size was measured by three separate methods at regular intervals during and after treatment. Breast tissue water density and architecture were visualized before and after treatment by magnetic resonance imaging scans obtained in the same phase of the menstrual cycle. Twelve subjects completed the study; five withdrawals occurred due to protocol noncompliance. Breast size increased in all women over the 10-week treatment course and peaked at week 10 (final treatment); the average increase per woman was 98 +/- 67 percent over starting size. Partial recoil was seen in the first week after terminating treatment, with no significant further size reduction after up to 30 weeks of follow-up. The stable long-term increase in breast size was 55 percent (range, 15 to 115 percent). Magnetic resonance images showed no edema and confirmed the proportionate enlargement of both adipose and fibroglandular tissue components. A statistically significant decrease in body weight occurred during the course of the study, and scores on the self-esteem questionnaire improved significantly. All participants were very pleased with the outcome and reported that the device was comfortable to wear. No adverse events were recorded during the use of the device or after treatment. We conclude that true breast enlargement can be achieved with the daily use of an appropriately designed external expansion system. This nonsurgical and noninvasive alternative for breast enlargement is effective and well tolerated.

Adult↗
PubMed1998

A nerve distraction model in the rat.

Segmental loss of a peripheral nerve has been a challenging reconstructive problem. Management of the nerve gap has been accomplished classically with nerve grafting. However, autogenous nerve grafts are not always available for bridging large nerve gaps, and clinical results of large nerve cable grafts have been disappointing. Newer techniques concentrate on nerve lengthening with different methods. Tissue expansion of peripheral nerves has been producing promising results. Since the introduction of the Ilizarov external fixator, much attention has turned to limb-lengthening techniques and studies investigating the results of nerve and soft tissues lengthened during the course of this procedure. Primary nerve distraction may be an alternative to nerve elongation, by expansion or nerve grafting to repair the peripheral nerve gap. This study describes a device and a model for peripheral nerve distraction in a rat. Primary nerve distraction will need to be subjected to vigorous studies before clinical application.

Animals↗
PubMed1986

Tissue expansion in the treatment of alopecia.

Tissue expanders have been used in multiple body sites. We successfully used the Radovan tissue expander in the scalp of patients with cicatricial alopecia and in hair replacement surgery for male pattern alopecia. The expander is placed in the subgaleal plane beneath a hairbearing area and is inflated over a six- to eight-week period. In a second procedure, the device is removed and the bald area is excised. Closure of the defect is accomplished, with the stretched hairbearing scalp replacing the area of alopecia. Scalp reduction and pedicle scalp flap procedures have benefited by preliminary scalp expansion.

Adolescent↗
PubMed1995

Mechanisms of lumen enlargement after excimer laser coronary angioplasty. An intravascular ultrasound study.

BACKGROUND: The mechanisms of excimer laser coronary angioplasty (ELCA) have never been studied in human coronary arteries in vivo. METHODS AND RESULTS: ELCA was used to treat 202 lesions in 190 patients. Forty-nine lesions in 48 patients were studied by use of sequential (before and after ELCA and after adjunctive device therapy) intravascular ultrasound (IVUS). External elastic membrane (EEM), lumen, and plaque+media (P+M = EEM-lumen) cross-sectional areas (CSAs) and lesion arcs of calcium were measured before and after ELCA and after adjunct device use. Lumen improvement after ELCA (1.4 +/- 0.5 to 2.7 +/- 0.8 mm2) was the result of both tissue ablation (decrease in P+M CSA from 16.8 +/- 7.1 to 15.9 +/- 6.7 mm2, P < .0001) and vessel expansion (increase in EEM CSA from 18.2 +/- 7.1 to 18.6 +/- 6.8 mm2, P = .0245), with no change in calcium. The decrease in P+M CSA was 39% of the CSA of the laser catheter used. Dissections were present in 39% of lesions, 84% within superficial calcium; fibrocalcific deposits developed a "fragmented" appearance. CONCLUSIONS: ELCA increased lumen CSA by both atheroablation and vessel expansion without calcium ablation. Superficial fibrocalcific deposits developed a characteristic fragmented appearance. These findings support both photoablation and forced vessel expansion as mechanisms of lumen enlargement and plaque dissection after ELCA.

Angioplasty, Balloon, Coronary↗