Barcelona, Spain — Researchers here have found that polyalkylimide implants may lead to potentially severe, immune-related adverse effects that appear months after the procedure is performed, reports news source Medical News Today.
The study, conducted by a research team at Vall d’Hebron University Hospital and Autonomous University of Barcelona, appears in a recent issue of the Archives of Dermatology.
Polyalkylimide implants are used to augment lips, cheeks, the forehead and nasolabial folds. In their study, the researchers note that “According to the manufacturer’s information, polyalkylimide structures do not change over time and do not move or migrate. In the early reports on polyalkylimide implant injections for cosmetic purposes, there were no significant signs of bioincompatibility. However, more recent evidence refutes these statements, and so the complete safety of polyalkylimide implant gels can no longer be assured.”
For their study, the researchers assessed 25 patients who had polyalkylimide implant injections and presented adverse effects at one year or longer post-procedure. The patients showed a variety of reactions: swelling, hardening and swollen or tender nodules around the injection site, and systemic events such as fever, arthritis and dry eyes or mouth.
“Tender inflammatory nodules were seen in 24 patients, systemic or distant manifestations appeared in six cases [and] laboratory abnormalities were found in 20 cases,” the study authors write. “After an average of 21.3 months of follow-up, 11 patients appeared to be free of adverse effects and 10 still had recurrent bouts.”
The study, however, does not discuss precisely how prevalent these tardy adverse effects are. One reason for this lack of knowledge, write the authors, is that many physicians fail to report negative events, leaving researchers without complete information about patients who underwent similar procedures in the same time period.
“Although [they are] infrequent, delayed, moderate to severe immune-mediated adverse effects may be caused by polyalkylimide implants, occasionally with systemic manifestations,” the authors write. “Perhaps in predisposed hosts, the use of more than one source of dermal filler may increase the risk of the onset of delayed immune-mediated reactions related to bioimplants.”
The authors conclude that given the increased use of polyalkylimide implants in European countries and in the United States, “physicians should be aware that intermediate or delayed adverse effects can occur with polyalkylimide implants just as they can with collagen, polyacrylamide, polylactic acid or methacrylate.”
