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At least 955 records · Page 53Linked to original sources
PubMed1998

Reconstruction of nasal defects with implant-retained nasal prostheses.

Predictable biomechanical retention of nasal prostheses can now be achieved using Brånemark osseointegrated implants. These prostheses are tissue compatible, simple in design and easy to place, can be worn independently of spectacles and can in the majority of cases be provided soon after surgical excision. We have treated 14 patients (30 implants) 8 of whom had the implants placed at the time of surgical excision of the tumour. The longest survival so far has been 62 months (mean 38 months). Craniofacial osseointegration changes patients' perceptions of a nasal prosthesis and improves quality of life. Initial reconstructive surgery after radical nasal excision should be limited to reconstruction of the upper lip and preparation of the surgical defect for an implant-retained prosthesis.

Female↗
PubMed1992

Breast cancer diagnosis and prognosis in women following augmentation with silicone gel-filled prostheses.

62 healthy women were studied mammographically before and after augmentation mammoplasty. Postaugmentation mammograms were done using both the implant compression and implant displacement technique. The amount of visualisable tissue was measured in all films before and after augmentation. We concluded: State-of-the-art film-screen mammography is extremely difficult to obtain in most patients augmented with silicone-gel-filled prostheses. On average, there is a decrease in measurable visualised breast tissue after augmentation mammoplasty with silicone-gel-filled prostheses. The area of mammographically measurable tissue is no different whether smooth or textured implants are used. Textured implants are less likely to form an early capsular contracture and are therefore preferred. However, the cancer-causing potential of polyurethane in humans is currently unknown. Anterior breast tissue is generally seen better with displacement mammography; posterior breast tissue with compression mammography. Better films are generally obtained when the implant is in the subpectoral position rather than subglandular. The more severe the capsular contracture, the poorer the mammogram. In addition 42 previously augmented patients developed breast carcinomas an average of 8.4 years after augmentation with silicone-gel-filled implants; 95% had palpable lesions (only 60% of which could be seen on mammography), 90% had infiltrating carcinomas, 45% had metastases to axillary nodes, and 7 patients have recurred, 5 of whom have died. We concluded: Augmented women who develop breast cancer are similar, in terms of tumour size and nodal positivity, to non-augmented breast cancer patients who present with palpable masses. When compared with non-augmented women whose breast cancers are found with screening mammography, augmented patients with breast cancer present with a higher percentage of invasive lesions and involved axillary lymph nodes, resulting in a poorer prognosis. The 40% false negative rate for mammography in this series is unduly high and alarming. Augmentation mammoplasty with silicone-gel-filled implants should be discouraged in women with a high risk of developing breast cancer.

Adult↗
PubMed1993

Report on a conference on motor prostheses for workplace mobility of paraplegic patients in North America.

On May 18, 1992 a symposium at Case Western Reserve University in Cleveland, Ohio, USA had the goal of defining the tasks needed to reach clinical utility of investigational neural prosthetic ambulation devices. The characteristics and stage of development of four systems were detailed: the Louiiana State University reciprocating gait orthosis (LSU-RGO) with muscle stimulation; the modular hybrid functional neuromuscular stimulation (FNS) orthosis; the Cleveland VA-Case Western Reserve University (VA-CWRU) implant system; and the Parastep system. Multicenter clinical trials are underway for the Parastep system and are planned to start within the next 2 years for the LSU-RGO with muscle stimulation, the VA-CWRU 8-channel system, and the floor reaction orthosis component of the modular hybrid FNS system. Current investigational systems provide little advantage over the standing wheelchair in some occupations but they do expand social, recreational, and exercise capabilities. Disabled people and some leading rehabilitation physicians are willing to test basic ambulation devices but the regulatory approvals must first be obtained for multicenter clinical trials. Corporate partners are central to the development of devices, their clinical testing, and their subsequent marketing. A key requirement for developing and disseminating motor prostheses is the education of clinicians so that they will participate in trials and be prepared to prescribe the prostheses when they reach the market.

Electric Stimulation↗
PubMed2003

Comparative retrospective study on the use of plastic prostheses and self-expanding metal stents in the palliative treatment of malignant strictures of the esophagus and cardia.

Palliative treatment of malignant strictures of the esophagus and cardia is usually carried out by the endoscopic placement of a prosthesis. The aim of this retrospective study was to evaluate short- and long-term outcomes of the use of expandable stents, compared with conventional plastic prostheses. One hundred and thirteen endoscopic intubations were carried out in 120 patients affected by malignant stenosis of the esophagus and cardia using plastic prosthesis and self-expanding metal stents. Dysphagia was scored according to Atkinson and Ferguson's classification and the preoperative median score (3.6) was comparable in both groups. The technical success rate was 94.4% with plastic prosthesis and 93.7% with self-expanding metal stent while the functional success rate was, respectively, 85.2% and 88.8%. Three deaths occurred with plastic prostheses (4.4%), while no deaths were observed with metal stents. A comparative analysis of the results of this study suggests that the endoscopic placement of self-expanding metal stents is effective and safe and has to be preferred to the conventional plastic prosthesis for easier implantation and lower morbidity.

Adenocarcinoma↗
PubMed2002

Closed-field titanium magnets for the retention of complex craniofacial prostheses.

Where reconstruction with autogenous tissue is contraindicated in craniofacial reconstruction, or declined by the patient, a prosthesis may be used. Originally made from latex, cellulose or acrylic resins, prostheses are now largely made of silicone. These prostheses were traditionally retained using adhesives, natural undercuts at retention sites or spectacles. However, these methods were unsatisfactory because of frequent loss of retention, skin reactions to adhesives or unnatural movements of the prosthesis. Osseointegration became a popular method of prosthesis retention, initially using a bar-and-clip device. The use of a bar attached to the implant has certain shortcomings, however, including rigidity of the prosthesis and the difficulty in maintaining hygiene at the implant site. We present our experience with the use of magnets to hold the prosthesis in place, which allows ease of use, improved hygiene and a more natural mobility of the prosthesis.

Adolescent↗
PubMed2005

[Electronic visual prostheses].

BACKGROUND: Currently, no treatment is available for progressive retinal dystrophies. The fabrication of an implantable visual prosthesis seems to be possible now as a result of advances in the fabrication of extremely small micro-systems and their encapsulation in biocompatible materials. MATERIALS AND METHODS: The development of implantable visual prostheses is based on the fabrication of remotely controlled microelectrode arrays which have to be implanted in different target regions of the visual system. Prototypes of such systems have already been implanted in animal experiments and also in pilot trials in humans. RESULTS: Four concepts are pursued: 1. epiretinal implant -- fixation onto the inner retinal surface; 2. subretinal implant -- implantation within the subretinal space; 3. optic nerve stimulator -- cuff electrode placed around the optic nerve; 4. cortical prosthesis -- implantation of surface electrodes in the region of the visual cortex. All these concepts have already been applied in pilot trials in humans. The results show some promising visual perception. CONCLUSIONS: The use of implantable electronic visual prostheses will become a possible option in the treatment of currently untreatable retinal dystrophies. Further basic research initiatives are necessary as well as further human trials to characterize the stimulation parameters and to improve the currently available devices.

Animals↗
PubMed1988

Optimal palliation of malignant bile duct obstruction: experience with endoscopic 12 French prostheses.

Large-caliber prostheses, 11.5-12 French, were placed in 167 patients (183 attempts, 91% success) presenting with obstructive jaundice. Thirty-three patients had additional prostheses placed to selectively decompress intrahepatic ducts obstructed by cholangiocarcinoma. In this prospective unrandomized series, there were 43 lesions of the common hepatic duct, 123 of the common bile duct (96 pancreas, 27 cholangiocarcinoma) and 17 ampullary. Transient fever responding to parenteral antibiotics occurred in 11 patients who did not receive prophylaxis, whereas only 2 patients who received antibiotics prior to the procedure developed fever subsequently. Four patients bled subsequent to sphincterotomy, 1 requiring a 2-unit transfusion. Pancreatitis occurred in only 1 patient. The mean hospital stay was only 3 days, range 1-10 days, with most patients being discharged within 48 hours. No procedural deaths occurred. The patency rate of this new, larger 12 Fr. prosthesis is significantly longer than that for the 10 Fr. stent, 190 days for 12 Fr., 150 days for 10 Fr. Given the advantages of the larger prosthesis, i. e., increased patency and function and decreased rehospitalization rate, the authors recommend this method of palliation for obstructive jaundice.

Adult↗
PubMed2001

Immunohistochemical study of clinical skin-penetrating titanium implants for orthopaedic prostheses compared with implants in the craniofacial area.

The technique of using osseointegrated bone-anchored percutaneous titanium implants in the rehabilitation of patients with amputated limbs has recently been introduced at the Brånemark Osseointegration Centre in Göteborg. The new method is based on an implantation technique that is well-established for anchorage of bone-conductive hearing aids and craniofacial prostheses. The soft tissues around skin-penetrating titanium implants used to anchor orthopaedic prostheses were evaluated histochemically using quantitative analyses. The implants had been in clinical use for between 6 to 24 months. The number of inflammatory cells was higher in the area close to the interface than in the area distant from the skin-penetrating site, and higher than in the corresponding controls. The current data was also compared with corresponding data from tissue around skin-penetrating craniofacial implants. The number of inflammatory cells was lower in the orthopaedic samples than in the craniofacial specimens. We conclude that skin-penetration of orthopaedic implants is as safe as when titanium implants are used for craniofacial rehabilitation, which is a clinically well-established procedure.

Adult↗
PubMed2004

Neutron dose from prostheses material during radiotherapy with protons and photons.

The purpose of this investigation is to measure the impact of Ti-alloy-prostheses on the neutron dose during proton and photon radiotherapy. Such unwanted neutron dose to the patient should be kept as low as possible (ALARA principle), as such additional dose can create secondary malignancies. For this purpose we performed neutron dose measurements using etch track detectors under the same conditions on a proton and a photon beam line used for radiotherapy. We found no influence of the prostheses material on the neutron dose both for proton and photon treatment.

Alloys↗
PubMed1994

Evaluation of staples and prostheses for use in laparoscopic inguinal hernia repair.

With the increasing popularity of laparoscopic prosthetic inguinal hernia repair, it was decided to compare the various staples and prostheses currently in use. A twofold increase in breaking or opening strength was required to disrupt the Endoscopic Multifeed Staple (31.2 Newtons vs 15.6 Newtons) compared with the Multifire Endo Hernia Staple. A linear relationship existed between the number of staples used and the maximum load tolerated. No significant difference was found between the breaking strength of the prostheses evaluated. Further research into the biomechanics of laparoscopic inguinal hernia repair is necessary to determine how important staple and prosthesis strength is for the success of the repair.

Hernia, Inguinal↗
PubMed1984

Reconstruction of breasts following mastectomy with polyurethane-covered, gel-filled prostheses.

This article describes a simple, one-stage procedure to reconstruct breasts following radical and subcutaneous mastectomy by using subcutaneous placement of Natural-Y prostheses (polyurethane-covered, gel-filled implants with an internal Y-shaped septum). Breast reconstruction after mastectomy or immediately following subcutaneous mastectomy was performed in 36 patients using 62 Natural-Y prostheses. All patients still had implants in place six months to five years later. Neither spherical capsular contractures, infection, nor skin necrosis developed around any implants. Transfer of pedicle flaps was not required in any patient and the reconstructive procedures resulted in minimal scarring. Wrinkling of skin and a palpable implant edge in the superior quadrant were noticeable in some breast reconstructions following subcutaneous mastectomy but rarely in breasts reconstructed following mastectomy because the taut skin conformed to the implant.

Breast↗
PubMed1993

Biointegrated hydroxylapatite-coated implant fixation of facial prostheses.

This pilot study reports the 2-year follow-up on hydroxylapatite-coated nonscrew titanium implants (Integral) used for fixation of auricular and orbital prostheses. Fifty-four implants have been inserted in a two-stage procedure for auricular reconstruction in 12 patients and orbital reconstruction in 2 patients. Clinically solid integration has occurred with 51 implants in 13 patients, three implants being lost in previously irradiated bone where soft tissue coverage was never adequate. Early soft tissue reaction occurred in those younger patients and where multiple previous surgery had occurred in the same area. Conservative local treatment produced resolution of this in all patients. Stable retention of cosmetically acceptable orbital prostheses was achieved with bar-clip assembly or magnet arrangements.

Durapatite↗
PubMed1993

Fine needle aspiration biopsy in patients with augmentation prostheses and a palpable mass.

Six patients with augmentation prostheses presented with a firm, painless, breast mass that could not be visualized by mammography. One lesion was demonstrated to be solid by ultrasound, and the remaining sonograms were nondiagnostic. The lesions were indistinguishable from carcinoma, by physical examination. All of the patients had fine needle aspiration biopsy despite close proximity to the implant. The patients all had silicone granulomas related to silicone leakage. Our experience suggests that fine needle aspiration biopsy is a useful technique to evaluate palpable breast masses that are not visualized by mammography in patients with augmentation prostheses.

Biopsy, Needle↗
PubMed1994

Magnetic resonance imaging of in situ mammary prostheses.

A study was conducted at the University of Virginia Health Sciences Center to examine the effectiveness of magnetic resonance imaging in detecting rupture or deflation of in situ mammary prostheses. Thirty-three women with 59 prostheses were included in the study. Fifteen of the 33 patients had undergone surgery for removal or replacement of 21 implants. Positive findings for rupture were accurately predicted for 15 implants and confirmed at surgery. Negative findings for rupture were accurately predicted in the remaining 6 implants and confirmed at surgery. Although it is a more costly procedure than either mammography or ultrasonography, we believe that magnetic resonance imaging is also more accurate in detecting damaged implants, particularly when they are contained within an intact capsule or when the implants are stacked. Unlike mammography, magnetic resonance imaging requires no ionizing radiation or breast compression. Magnetic resonance imaging of the in situ breast prosthesis may be a useful adjunct when other modalities yield inconclusive results or when a contained rupture is suspected.

Adolescent↗
PubMed1986

Use of sutureless intraluminal aortic prostheses in traumatic rupture of the aorta.

Despite wide acceptance of use of sutureless intraluminal prosthetic grafts in surgical management of acute and chronic aortic dissection, their use in traumatic aortic rupture appears not to have been specifically addressed. This report describes the use of intraluminal prostheses in two cases of aortic disruption due to blunt trauma. Aortic cross-clamp times were 21 and 28 minutes, respectively. Both patients have recovered without sequelae from their aortic injuries. Although not all traumatic aortic disruptions are suitable for repair with intraluminal prostheses, the ease and safety with which this device may be employed recommends consideration of their use in appropriate cases of traumatic rupture of the aorta.

Accidents, Traffic↗
PubMed1977

Experimental study of tissue response to ruptured gel-filled mammary prostheses.

Miniature "soft gel" filled breast prostheses were implanted into rats, and half of these were purposefully ruptured upon insertion. At sacrifice of the animals later, the position of the exuded gel, the variability of the capsule thickness, and the extent of the capsule formation were evaluated. The capsule thickness was significantly increased around the ruptured prostheses, in response to the exuded gel. Also, the gel migrated through the fibrous capsule and into the surrounding tissue, eliciting an inflammatory response there to produce capsule thickening.

Animals↗
PubMed1981

Clinical experience with polyurethane-covered gel-filled mammary prostheses.

We have used 104 low-profile polyurethane-covered gel-filled mammary prostheses in 54 patients. Only one patient has developed capsular contracture. Foreign-body reaction to polyurethane was clinically significant in only one patient. Other complications have been few and of the type that can accompany any type of mammary prosthesis. Of the 54 patients studied, 51 still have their implants in place and have soft, compressible breasts. The superior wrinkling and palpable implant edge that is occasionally present when the implant is placed subcutaneously has been of some concern to patients and can be eliminated by submuscular placement. The use of polyurethane-covered low-profile gel-filled prostheses for breast reconstruction has greatly improved our results, and the satisfaction of both surgeon and patient has been gratifying.

Breast↗
PubMed1984

Reconstruction of the breast using polyurethane-coated prostheses.

We have inserted 302 Natural-Y polyurethane-coated implants in 92 patients. Follow-up time for the cases studied ranges from 6 months to 41/2 years after reconstruction. None of our patients was observed to develop capsular contracture, and the foreign-body reaction to the polyurethane was of no clinical significance when the implants were placed in a total muscle pocket. Four cases of ruptured prostheses were observed. Overall, the excellent aesthetic results of the polyurethane-coated prostheses were encouraging, resulting in soft, natural-feeling, and aesthetically pleasing breasts.

Breast↗