A study on patients treated with polyacrylamide hydrogel injection for facial corrections.

Polyacrylamide hydrogel (PAAG) has been used as a tissue filler in facial corrective surgery and for breast augmentation in Kiev, Ukraine, for more than 10 years with reportedly very good results. These results, however, have not been published in peer-reviewed journals. A Danish/Swedish group of plastic surgeons with special interest in facial corrective surgery did a retrospective, systematic, pre-planned investigation of 104 patients treated at the center in Kiev. All data were entered into a pre-programmed database for data processing. The mean age of this population was 37.4 years and the mean time since the gel injection was 3.9 years. An average of 5.7 ml of PAAG was injected prior to the investigation. The gel was well tolerated and assessment of the outcome was judged to be very good by 78% and good by 22%, by both physicians and patients. It is concluded that PAAG is well tolerated and seems to be a promising product for facial corrective surgery. Currently, the product (Aquamid) is being studied in several prospective clinical trials, one of which is completed and in the process of preparation for publication.

Long-term effects of polyacrylamide hydrogel on human breast tissue.

Polyacrylamide hydrogel is an atoxic, stable, nonresorbable sterile watery gel consisting of approximately 2.5% cross-linked polyacrylamide and nonpyrogenic water. Polyacrylamide hydrogel is widely used in ophthalmic operations, drug treatment, food packaging products, and water purification. In the former Soviet Union, polyacrylamide hydrogel has been used in plastic and aesthetic surgery for more than 10 years, and Kiev City Hospital treats approximately 300 women a year for breast augmentation using the polyacrylamide hydrogel Interfall (Contura SA, Montreux, Switzerland). Capsule shrinkage following these injections has never been observed. The authors examined breast tissue samples from a total of 27 women who had polyacrylamide hydrogel injected at Kiev City Hospital up to 8 years and 10 months earlier. Age at operation, duration of polyacrylamide hydrogel implantation, history of possible side effects to the gel injection, other intercurrent diseases, the reason for present open breast operation, and breast palpation findings before operation were in each case compared with the histological findings on samples taken from breast tissue bordering the gel. The gel presented itself as a dark violet, homogenous mass with a rounded or ragged outline in large or medium-size deposits and as elongated strands, which mimicked the extracellular matrix, in small deposits. Histological findings of the breast tissue bordering the gel showed three different patterns: large collections of gel gave rise to a thick, soft-looking cellular membrane of macrophages and foreign-body giant cells; medium-size deposits were surrounded by just a thin layer of macrophages; and small deposits were not associated with any reaction in the surrounding tissue. Projections of the cellular soft membrane, known as granulomas, were seen in six patients. The granulomas were composed of macrophages, foreign-body giant cells, lymphocytes, and blood cells. A thin layer of fibrous connective tissue was occasionally present around the foreign-body membrane, but the thick fibrous capsule, which has been described in connection with silicone implants, was completely absent. The gel changes could be correlated to neither time since gel injection nor a history of recent injury or inflammation. It is concluded that the polyacrylamide hydrogel Interfall, which has been used in the former Soviet Union, is stable over time, nondegradable, confined to the breast, and diffusion and migration resistant. When the hydrogel is injected in medium-size or large quantities a cellular foreign-body reaction occurs, but in small amounts it is capable of splitting up individual connective tissue fibers and fat cells, substituting for the extracellular connective tissue matrix without eliciting any foreign-body reaction. As far as these data are concerned, polyacrylamide hydrogel is well tolerated by the breast and does not give rise to severe fibrosis, pain, or capsule shrinkage. However, to determine safety with more certainty, a larger sample size would be necessary.