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At least 1,099 records · Page 61Linked to original sources
PubMed1994

Silicone breast implant rupture: comparison between three-point Dixon and fast spin-echo MR imaging.

OBJECTIVE: This study was designed to compare the three-point Dixon technique with our present MR protocol incorporating T2-weighted fast spin echo and fast spin echo with water suppression to detect ruptured silicone breast implants. SUBJECTS AND METHODS: Eighty-two symptomatic women with silicone breast implants were examined with both the three-point Dixon technique and fast spin-echo MR sequences. Of these patients, 41 had surgery to remove their implants. Four radiologists reviewed the images from only those patients who had surgery and graded each for rupture by using a scale of 1-5. Receiver-operating-characteristic analysis was performed. RESULTS: Of 81 implants removed, 18 were ruptured. Silicone implant ruptures were identified more frequently on the fast spin-echo sequence than on the three-point Dixon sequence, with areas under the ROC curves of .95 and .84, respectively. Although the difference was not statistically significant, the sensitivity for detecting silicone implant rupture was 89% for the fast spin-echo sequence and 61% for the three-point Dixon sequence. The specificity was 97% for both sequences. CONCLUSION: Silicone implant ruptures were detected more frequently with fast spin-echo MR sequences than with the three-point Dixon technique, although the difference was not significant. The greater spatial resolution used for the fast spin-echo sequence partially accounts for the difference in detection of implant ruptures in this study.

Breast↗
PubMed2003

Dose reduction in patients undergoing chest imaging: digital amorphous silicon flat-panel detector radiography versus conventional film-screen radiography and phosphor-based computed radiography.

OBJECTIVE: We sought to compare the radiation dose delivered to patients undergoing clinical chest imaging on a full-field digital amorphous silicon flat-panel detector radiography system with the doses delivered by a state-of-the-art conventional film-screen radiography system and a storage phosphor-based computed radiography system. Image quality was evaluated to ensure that the potential reduction in radiation dose did not result in decreased image acuity. SUBJECTS AND METHODS. Three groups of 100 patients each were examined using the amorphous silicon flat-panel detector, film-screen, or computed radiography systems. All patient groups were matched for body mass index, sex, and age. To measure the entrance skin dose, we attached 24 calibrated thermoluminescent dosimeters to every patient. The calculation of the effective dose, which represents the risk of late radiation-induced effects, was based on measurements on an anthropomorphic phantom. Image quality of all three systems was evaluated by five experienced radiologists, using the European Quality Criteria for Chest Radiology. In addition, a contrast-detail phantom study was set up to assess the low-contrast detection of all three systems. RESULTS: The amorphous silicon flat-panel detector radiography system allowed an important and significant reduction in both entrance skin dose and effective dose compared with the film-screen radiography (x 2.7 decrease) or computed radiography (x 1.7 decrease) system. In addition, image quality produced by the amorphous silicon flat-panel detector radiography system was significantly better than the image quality produced by the film-screen or computed radiography systems, confirming that the dose reduction was not detrimental to image quality. CONCLUSION: The introduction of digital flat-panel radiography systems based on amorphous silicon and cesium iodide is an important step forward in chest imaging that offers improved image quality combined with a significant reduction in the patient radiation dose.

Adult↗
PubMed1994

Adjuvant breast disease: an evaluation of 100 symptomatic women with breast implants or silicone fluid injections.

We evaluated 100 referred women with breast implants (n = 97) or silicone fluid injections (n = 3) into breasts who developed various symptoms. All reported symptoms occurred at a median latency period of 6 years (range 0-24 years) after implantation or injection of silicone. Commonest symptoms were weakness (95%), fatigability (95%), myalgia (90%), morning stiffness (89%), arthralgia (81%), memory loss (81%), sensory loss (77%), headache (73%) and dry eyes and dry mouth (72%). Laboratory results revealed abnormal levels of serum immunoglobulins or complement in 57% and autoantibodies in 78%. Sural nerve biopsy was abnormal in 80% with the major finding of loss of myelinated fibers in 79%. Biceps muscle biopsy was abnormal in 58% with the major finding of neurogenic atrophy in 27%. Ninety-six patients underwent implant removal; 60% of the patients were found to have one or both implants ruptured with silicone spilled into tissue. At time of removal, a pectoralis major muscle biopsy was taken which was abnormal in 89% with the major finding of neurogenic atrophy in 55%. Biopsy of implant capsule was abnormal in 94% showing foreign body giant cells containing refractile material consistent with silicone in 69% whether or not the elastomer shell was ruptured. Silicone can cause a systemic autoimmune disease with a variety of symptoms probably due to a global activation of the immune system. Since our patients had objective laboratory and histologic findings together with a high rate of mechanical implant failure, further investigations are necessary.

Adult↗
PubMed2005

Liquid silicone for soft tissue augmentation.

BACKGROUND: The use of liquid silicone for soft tissue augmentation has been associated with a great deal of controversy and negative publicity. It is hoped that this monograph will clarify some of the substantive issues behind the controversy. OBJECTIVE: To outline and discuss the history, legal status, indications, contraindications, technique, and complications associated with the use of liquid silicone for soft tissue augmentation. METHODS: Impressions derived from a 22-year experience involving the treatment of over 3000 patients using liquid silicone are presented, along with data abstracted from the scientific and the lay literature. CONCLUSION: Pure liquid silicone may be superior to any currently available agent in properly selected patients for permanent correction of certain types of defects. Physicians who use it, however, must be advised that the misuse of this agent or other materials masquerading as liquid silicone have created a pervasive climate of distrust and a veritable minefield of extraordinarily unpleasant medicolegal possibilities.

Cicatrix↗
PubMed2005

Injectable silicone and the foot: a 41-year clinical and histologic history.

BACKGROUND: Since 1964, the author has investigated injectable liquid silicone as a soft tissue substitute for the loss of plantar fat. This form of fatty tissue depletion over the sole is closely linked to a common painful weight-bearing foot disorder, metatarsalgia, and to painless diabetic foot ulcers. OBJECTIVES: To present the history of injectable silicone, corporate interest, individuals who helped pursue approval, its misuses, and events that have delayed its availability. MATERIALS AND METHODS: Dow Corning Corporation's 360 Medical Fluid of 350 centistoke was injected beneath corns and calluses in 1585 patients. Diabetic neuropathic foot ulcers were injected after healing in an effort to prevent their recurrence. Surgical and postmortem specimens were gathered for histologic analysis. RESULTS: There was no evidence of significant adverse response in long-term clinical follow-up. Silicone specimens studied by two departments of pathology found no inflammation, infection, allergy, or granulomas. CONCLUSIONS: Medical Fluid silicone appears to be safe, effective, and stable biomaterial for treating weight-bearing loss of plantar fat. Trademarked PodiSil (Richard-James Inc., Peabody, MA, USA), a 350-centistoke injectable silicone has been approved for marketing in Europe for the prevention of diabetic foot ulcers.

Callosities↗
PubMed2005

Lip augmentation with liquid silicone.

BACKGROUND: Many fillers have been used to augment the lips. One of these that has provided long-term satisfactory results is liquid silicone. OBJECTIVE: To demonstrate the efficacy and safety of lip augmentation with liquid silicone. METHOD: Following a discussion of the benefits and risks of the procedure and the benefits and risks of alternatives and after answering all of the patients' questions, an informed consent form was signed. After obtaining anesthesia with a regional nerve block of the infraorbital and mental nerves, 0.25 to 0.5 cc of liquid silicone (1,000 centistokes) was injected using the microdroplet technique into the vermilion border of both the upper and lower lips. Depending on the desire of the patient, the procedure was repeated monthly. The augmentation of the lips was documented with histology, micrometry, and digital photography. RESULTS: Lip augmentation was achieved gradually during the months following liquid silicone injections into the vermilion border of the lips in the 608 patients studied. Most of the patients requested a second and third injection session. The results were most dramatic in the patients with type I and type II lips and less satisfactory in patients with type III lips. Bruising occurred in the majority of the patients. Eleven patients (2%) developed small palpable granulomas. These granulomas either required no treatment, responded to steroid injections, or were excised. CONCLUSION: The use of liquid silicone remains an effective method of lip augmentation. It returns the adolescent vermilion curl to the lips.

Cosmetic Techniques↗
PubMed2000

Efficacy of injected liquid silicone in the diabetic foot to reduce risk factors for ulceration: a randomized double-blind placebo-controlled trial.

OBJECTIVE: To investigate the effectiveness of injecting liquid silicone in the diabetic foot to reduce risk factors for ulceration in a randomized double-blind placebo-controlled trial. RESEARCH DESIGN AND METHODS: A total of 28 diabetic neuropathic patients without peripheral vascular disease were randomized to active treatment with 6 injections of 0.2 ml liquid silicone in the plantar surface of the foot or to treatment with an equal volume of saline (placebo). No significant differences were evident regarding age or neuropathy status between the 2 groups. All injections were under the metatarsal heads at sites of calluses or high pressures. Barefoot plantar pressures (pedobarography) and plantar tissue thickness under the metatarsal heads (Planscan ultrasound device) were measured at baseline and at 3, 6, and 12 months after the first injection. Injection sites were photographed at all stages, and callus formation was scored as a change from baseline. Throughout the study, patients were treated by the same podiatrist for all podiatry treatment. RESULTS: Patients who received silicone treatment had significantly increased plantar tissue thickness at injection sites compared with the placebo group (1.8 vs. 0.1 mm) (P < 0.0001) and correspondingly significantly decreased plantar pressures (-232 vs. -25 kPa) (P < 0.05) at 3 months, with similar results at 6 and 12 months. A trend was noted toward a reduction of callus formation in the silicone-treated group compared with no change in the placebo group. CONCLUSIONS: The results confirm the efficacy of plantar silicone injections in reducing recognized risk factors associated with diabetic foot ulceration.

Aged↗
PubMed1996

Quality of the capsule in reconstructions with textured or smooth silicone implants after mastectomy.

Many women desire some kind of reconstruction after mastectomy for breast cancer to improve the cosmetic result. Since the introduction of silicone breast implants, capsular contracture has been the most common complication of breast augmentation or reconstruction. The aim of the present study was to evaluate the capsule quality in patients with breast cancer who had undergone reconstructions with either textured (rough) or smooth silicone implants after simple or modified radical mastectomy. Forty-three consecutive patients had reconstructions with textured silicone implants (49 implants) and were evaluated 32 months post-operatively in a prospective clinical trial. The last 43 consecutive patients who had reconstructions with bilumen smooth silicone implants (49 implants) acted as controls. The results were graded by Baker's classification. Among the patients with textured implants only 9% (4/47) was graded as having moderate or severe capsular contracture in contrast to 24% (11/46) in patients with bilumen smooth-surface implants (p < 0.05). These results confirm previous reports that favour textured silicone implants in breast augmentation and reconstruction.

Breast Implants↗
PubMed2002

Reconstruction of the superior sagittal sinus with silicone tubing.

OBJECT: The authors conducted a study to develop a safe and effective intracranial venous sinus reconstruction for extensive clinical use. METHODS: After resecting the superior sagittal sinus (SSS), it was reconstructed in eight dogs by performing either a tube-insertion technique or end-to-end anastomosis procedure, in both of which a thin-walled silicone tube was used for repair. The patency of the SSS reconstruction was observed on digital subtraction angiography and transcranial Doppler ultrasonography, preoperatively and at 1, 2, 4, and 8 weeks postoperatively. Histological and ultrastructural changes were observed using light and electron microscopy. In five dogs the reconstructed SSS was patent, in one it was narrowed, in one it was completely occluded at the proximal site of the anastomosis, and one dog escaped from the laboratory 1 week postoperatively. The authors found no evidence of any additional neurological deficits, signs of toxicity, or side effects. Histological and ultrastructural studies generally showed vascular endothelial proliferation. No thrombosis occurred in the inner surface, at the site of anastomosis, or in the lumen of silicone tube nor in the sagittal sinus at up to 8 weeks postoperatively. CONCLUSIONS: The use of a thin-walled silicone tube as an artificial substitute for intracranial dural venous sinus reconstruction seems to be a valuable technique. The silicone tubes were found to have good biological compatibility, nonthrombogenic effects, and a high patency rate. The method was found to be simple and effective as well as practicable in the clinic for the short term (8 weeks). The authors emphasize that Phase I clinical trials involving silicone tube-assisted SSS reconstruction require further research.

Anastomosis, Surgical↗
PubMed2001

Comparison of the short-term clinical results of silicone and acrylic intraocular lens in patients with diabetes mellitus.

In order to compare the clinical results of silicone intraocular lenses (IOLs) and acrylic IOLs in patients with diabetes mellitus (DM), we reviewed the records of 69 diabetic patients (79 eyes--40 eyes; silicone IOLs, 39 eyes; acrylic IOLs) who had undergone phacoemulsifications and posterior chamber intraocular lens (PCI) implantations between January 1994 and January 1999. Postoperative ocular examinations included measurements of uncorrected and best corrected visual acuity tests and recording any complication one day, one week and two months after surgery. There was no statistically significant difference in visual acuity between the eyes with silicone IOLs and those with acrylic IOLs. Additionally, there was no difference in visual acuity according to the method of blood sugar level control. The rate of posterior capsular opacity (PCO) was significantly lower in the patients with acrylic IOLs than in those with silicone IOLs (p<0.05). These results suggest that there is no difference in visual outcome between acrylic IOLs and silicone IOLs in patients with DM. However in view of the lower rates of PCO with acrylic IOLs, they may be a better choice for eyes in diabetic patients.

Acrylic Resins↗
PubMed2005

[Glaucoma secondary to silicone oil in the anterior chamber].

CASE REPORT: A 53-year-old woman, with a history of a right retinal detachment treated by vitrectomy and silicone oil injection, who subsequently had the oil removed. She presented to us with a hypertensive anterior uveitis, which could not be controlled with medical treatment. On examination, micro-bubbles of emulsified silicone oil were evident in the anterior chamber simulating tyndall. A secondary glaucoma to emulsified silicone oil in the anterior chamber was diagnosed, and surgical treatment was proposed. DISCUSSION: Although secondary glaucoma is a frequent complication after oil silicone injection in vitreo-retinopathy surgery, the presence of emulsified silicone oil in the anterior chamber simulating tyndall is uncommon.

Anterior Chamber↗
PubMed2006

[Cholesterol, alpha-tocopherol, and retinoid concentrations in silicone oil used as a vitreous substitute].

OBJECTIVE: To verify the existence of organic lipophylic compounds in silicone oil extracted from human eyes following its use for previous retinal detachment, and to determine the intraocular permanence time of these substances in the oil. METHODS: Concentrations of retinoic acid, retinol, retinal, cholesterol and alpha-tocopherol were detected by HPLC in 23 samples of silicone oil extracted from patients with complicated retinal detachments. The time interval between the time of injection of the silicone oil and the subsequent assessment varied from 3 to 50 months (the permanence time). RESULTS: All tested compounds were found in the samples, but these were most commonly cholesterol and less frequently alpha-tocopherol. There was an inverse relationship between retinoic acid concentration and age (p=0.023), and a direct relationship between cholesterol concentration and permanence time (p=0.0008) at least up to 20 months. CONCLUSIONS: These findings confirm that silicone oil is not an inert substance but is capable of extracting lipophylic compounds from the intraocular tissues. There is a clear linear elevation of cholesterol levels with increased intraocular permanence time. This finding could be used to further establish a safe permanence time for intraocular silicone oil used in ophthalmologic surgery. More studies with larger samples are warranted to evaluate this further.

Adolescent↗
PubMed2003

[Postoperative evaluation of surgically treated cases with temporary silicone implant in temporomandibular joint].

We have carried out temporary silicone implants after diskectomies or arthroplasties in temporomandibular joint surgeries to avoid postoperative adhesion and to maintain articular space. We evaluated 19 joints in 15 patients who had received dacron-reinforced silicone implant after silicone sheet removal through follow-up for at least 6 months. The cases included temporomandibular joint disorder (10 joints in 9 patients), psoriatic arthritis (2 joints in 1 patient), ankylosis (4 joints in 3 patients) and synovial chondromatosis (2 joints in 2 patients). On the basis of the criteria of temporomandibular dysfunction for the results, they were classified as bad (4 patients). It is thought that factors other than the implant are related to the bad results in the postoperative evaluation. In this study, lymphadenopathy induced by exfoliated silicone debris could not be confirmed. The temporary silicone implant in the temporomandibular joint was thought to be useful.

Adolescent↗
PubMedDate not supplied

The histologic host response to liquid silicone injections for prevention of pressure-related ulcers of the foot: a 38-year study.

This study analyzed the histologic effects of and host response to subdermally injected liquid silicone to augment soft-tissue cushioning of the bony prominences of the foot. A total of 148 postmortem and surgical specimens of pedal skin with attached soft tissue were obtained from 49 patients between July 1, 1974, and November 30, 2002. The longest period that silicone was in vivo was 38 years. The specimens were then processed into paraffin blocks and examined for specific findings. The variables considered included distribution of silicone within the tissue, host response, migration to regional lymph nodes, and viability of the host tissue after treatment. The host response to silicone therapy consisted primarily of delicate-to-robust fibrous deposition and histiocytic phagocytosis, with eventual formation of well-formed elliptic fibrous pads. The response in the foot appears different from that in the breast and other areas of the body previously studied. No examples of granulomas, chronic lymphoplasmacytic inflammation, or granulation tissue formation were seen, with only rare foreign-body giant cells present. Silicone injections in fat pads for the treatment of atrophy and loss of viable tissue show a histologically stable and biologically tolerated host response that is effective, with no evidence of any systemic changes.

Adipose Tissue↗
PubMed1998

Ultrasound interactions with free silicone in a tissue-mimicking phantom.

This study attempts to explain the physical basis for the sonographic appearance of different stages of free silicone in breast tissue by laboratory simulations. A tissue-mimicking breast phantom was constructed, into which silicone inclusions were introduced, to simulate various forms of silicone leakage within the body. These simulations suggest that silicone leakage into surrounding body tissues can cause three primary physical interactions with an ultrasound beam: (1) distortions due to changes in speed of sound; (2) refraction, causing a "lens" effect; and (3) multiple scattering, producing the "snowstorm" effect described previously as a signature pattern for detection of silicone migration in breast tissue.

Breast Implants↗
PubMed2001

Moisture permeability of the total surface bearing prosthetic socket with a silicone liner: is it superior to the patella-tendon bearing prosthetic socket?

The purpose of this study was to examine the moisture permeability properties of materials used for total surface bearing (TSB) socket with a silicone liner, a combination of Silicone Suction Socket or Icelandic Roll-On Silicone Socket (ICEROSS) and an acrylic plastic sheet (Degaplast), patella-tendon bearing (PTB) socket, a combination of Pe-Lite and Degaplast, and wooden socket made of poplar. Moisture permeability of the socket materials was measured as the diminution of water in a container after 12 hours in a climatic chamber. Eight containers with their open, top side were uncovered (no material) or sealed with one of the socket materials; the experiment was repeated four times. One-way analysis of variance followed by Bonferroni's test was applied to examine the differences in moisture permeability. Moisture permeability levels were as follows: no material, 85.9 +/- 1.3 g; poplar, 4.3 +/- 0.4 g; Silicone Suction Socket, 1.1 +/- 0.2 g; ICEROSS, 1.0 +/- 0.2 g; Pe-Lite, 0.8 +/- 0.1 g; 3S + Degaplast, 0.8 +/- 0.1 g; ICEROSS + Degaplast, 0.8 +/- 0.2 g; and Pe-Lite + Degaplast, 0.8 +/- 0.1 g. There were significant differences between the uncovered container and the others, and between poplar and the others (P < 0.05). We concluded that the TSB socket with a silicone liner is not superior to the PTB socket with regard to moisture permeability, and that it is necessary to develop a new prosthetic socket that allows heat release and drainage of sweat.

Artificial Limbs↗
PubMedDate not supplied

Silicone oil emulsification of the retinal surface.

A 35-year-old patient with cytomegalovirus (CMV) retinitis secondary to acquired immunodeficiency syndrome (AIDS) underwent pars plana vitrectomy and fluid-gas-silicone exchange for retinal detachment. Three weeks following surgery and additional laser photocoagulation, extensive retinal surface emulsification was noted. It masked the retinal surface and demonstrated shifting in subsequent examinations. This case stresses the importance of careful and close follow-up after pars plana vitrectomy and silicone oil injection. Silicone oil emulsification may in some cases require removal of the emulsified fluid or silicone oil exchange, but in others such as our case, shifting of the emulsified silicone oil may allow evaluation of the nonobscured retina.

AIDS-Related Opportunistic Infections↗
PubMed2000

Effects of a silicone-coated polyamide net dressing and calcium alginate on the healing of split skin graft donor sites: a prospective randomised trial.

An open randomised prospectively controlled trial was performed to assess the healing efficacy, slippage rate and degree of discomfort on removal of calcium alginate and a silicone-coated polyamide net dressing on split skin graft donor sites. Sixteen patients were randomised to the calcium alginate group and 14 to the silicone-coated group. The donor sites were assessed at days 7, 10, 14 and up to day 21. The mean time to healing in the calcium alginate group was 8.75 +/- 0.78 days (range 7 to 14 days) compared to 12 +/- 0.62 days (range 7 to 16 days) for the silicone-coated group (p < 0.01). Although more silicone-coated dressings slipped (5 versus 1), the difference was not statistically significant. Pain during the first dressing change was assessed using a visual analogue pain scale. Although no significant differences were found between the groups, it was necessary to change the dressing protocol in the silicone-coated arm of the trial after entering the first two patients. Overlaid absorbent gauze adhered to the donor site through the fenestrations in the dressing necessitating the placement of paraffin gauze between the experimental dressing and the overlying cotton gauze. There was one infection in the study, occurring in the alginate group. Based on these results we recommend calcium alginate as the dressing of choice for split skin graft donor sites.

Adult↗