audiomaniac a écrit:l'hydrogel il est injecté dans le muscle ?
je t'ai trouvé un résumé sympa si tu veux te lancer
What Is PMMA & How Does It Work?Made famous by Youtube bodybuilder Rich Piana this product is secretly being used by bodybuilders in the United States to enhance body parts. They fly to Tijuana, Mexico to see Dr Luis Casavantes. Many have gotten their chest, biceps, triceps, calves, and buttocks enhanced. PMMA is approved in the United States as the brand name Artefill but it is too expensive to be used in larger volumes required for enhancing body parts.
The use of PMMA for medical uses dates to 1936 in as a bone cement. PMMA has presented a good degree of bio-compatibility and as a result it has been extensively used as a soft tissue filler, bone cement, component of denture materials and tooth bond, housing for pacemakers and intra-ocular and contact lenses. The material itself was chemically synthesized in 1904.
Dr. Gottfried Lemperle developed the concept of using PMMA micro-spheres for tissue augmentation in Germany in 1989. PMMA has been available in Germany since as sub-dermal injections used to reduce wrinkles, scars and for certain larger soft tissue deficits.
PMMA as a tissue filler was first introduced to Europe in 1991 as Arteplast and marketed as a non absorbable injected material. It was composed of microspheres suspended in a gelatin solution. It was observed that the gelatin material was reabsorbed and replaced by native collagen. Not fully recognized at the time was that PMMA itself was stimulating the deposition of new healthy collagen around the individual microspheres without causing fibrotic reactions seen in the implant of foreign materials such as siloxane. Arteplast has since been superseded by newer generations of PMMA of greater consistency in granule size and surface smoothness. Dr Lemperle said: “because of the extensive fibrous network associated with PMMA related granulomas, intralesional corticosteroid injections are considered the best treatment. We saw an Arteplast® granuloma develop as late as 10 years after injection, which responded well to high doses of local steroids and a pulse light therapy. After sieving and washing, the second generation Artecoll in Europe caused a significant lower number of foreign body granuloma.”
There are several PMMA injectable products available. Among the approved and registered PMMA based products are Artecoll and Artesense®, manufactured in Holland and approved in Mexico and Canada since 1998. Both are formulated with 20% PMMA in a vehicle composed of 79.7% bovine collagen and 0.3% lidocaine. Metracryl and BioPlastic are two other PMMA products widely used in Mexico, Brazil, Argentina and Europe.
Published safety and efficacy studies of PMMA in the United States done for FDA review dealt with PMMA use for the cosmetic correction of nasolabial deficits and concluded that “PMMA is the first soft tissue filler that demonstrates continued improvement and persistence of correction over a 5-year period post-treatment”. PMMA is now manufactured in the United States and was approved by the FDA in October 2006; marketed as ArteFill® (a new formulation of Artecoll), a compound of 20% PMMA in 80% bovine collagen and a small amount of lidocaine.
However, Artefill is extremely expensive for facial or buttock lipoatrophy correction. ArteFill® costs medical providers $720.00 per ml prepackaged in a box containing 4 syringes of 0.8 ml of product. The professional services of the provider are often sold to the patient for double the cost of the product, thus making it impractical as a corrective for large volume tissue loss. Calculations for the cost-of-treatment climbs astronomically since quite common in the faces or buttocks of people with HIV tissue loss are deficits which can require from 30 ml to 400 ml of filler to correct. A severely atrophied buttock requiring 300 to 400 ml of ArteFill® would cost in the range of $ 200,000 to $ 300,000.
Dr Lemperle has shown that the reported complication appearing in clinical trial results of Arte-Fill has been a small number of tiny palpable nodules. The clinical experience suggests that nodules tend to develop in thin skin areas or when the product is dermally injected in a too superficial manner. These nodules often respond to treatment with Kenalog 40, a cortico-steroid and in many cases also spontaneously remiss. ArteFill was developed and purified over several generations from the original Arteplast, the appearance of granuloma have decreased dramatically after the micro sphere surface was cleaned up of any imperfections that may have caused macrophages to attack them as foreign objects.
Dr. Luis Casavantes said that based on his experience in the past 5 years of experience with NewPlastic, a PMMA product produced in Brazil and widely used in Mexico and worldwide, does not appear to produce either palpable nodules or true foreign body granuloma, when
grafted underneath the muscle fascia. NewPlastic seems to be a lot cheaper than Artefill. A moderate to severe facial lipoatrophy correction would cost from 2500 to 3500 depending on the volume needed. Buttocks require a lot more volume, with costs running from $4000 to $8000 depending on the severity of wasting.