RSNA: Unapproved Silicone Injections Carry Lethal Risk

CHICAGO, Dec. 1 -- Liquid silicone augmentation of the breasts or buttocks, an unapproved cosmetic procedure, risks pulmonary emboli, said researchers here.

A literature review of 44 cases found a mortality rate of 25%, radiologist Carlos S. Restrepo, M.D., of the University of Texas Health Science Center in San Antonio, reported at the Radiological Society of North America meeting.

He suggested that silicone-induced pulmonary emboli should be included in the differential diagnosis of "transsexual men who present with sudden onset of fever and respiratory distress."

Dr. Restrepo treated seven such men who arrived at his hospital's emergency department.

While conceding that it is difficult to estimate the true prevalence of the problem, he added that "given the high mortality rate, I felt it was important to bring this to the attention of both physicians and patients."

On chest radiographs, pulmonary emboli caused by silicone injections are characterized by diffuse parenchymal opacities and on CT scan there is a "peripheral distribution of opacities with dominant ground glass pattern," he said.

In addition to the seven cases treated at his hospital, Dr. Restrepo discussed 37 additional cases reported in the literature.

The FDA recently agreed to allow two companies to market encapsulated silicone implants for breast augmentation or reconstruction.

But liquid silicone, or polydimethylsiloxan fluid, is a popular product in the underground, illegal cosmetic industry, Dr. Restrepo said.

He said the potential for silicone leaking into the blood stream to form emboli might be increased by the practice of following the injection with a massage to "smooth out the appearance of the injection site."

Twenty-five of the 44 patients included in this report were transsexual males and 19 were females. The mean age of the patients was 31 and the most common site of injection was the breast followed by the buttocks.

Twenty-one of the patients, including one of the seven men treated in San Antonio, reported previous liquid silicone injections.

The onset of symptoms was rapid, usually within hours of injections, and the most common presenting symptom was respiratory distress followed by fever. Dr. Restrepo said, however, that bronchial lavage failed to identify any pathogens.

The mortality rate was 25% and the most significant finding at autopsy was alveolar hemorrhage.

Michael Brant-Zawadzki, M.D., medical director of radiology at Hoag Memorial Hospital Presbyterian in Newport Beach, Calif., who moderated the RSNA press conference where the results were discussed, said that any subcutaneous injection could increase the risk of pulmonary embolism.

"That's why injections need to be so carefully monitored," he said. For example, he said this is a recognized risk associated with vertebroplasty procedures in which joint cement is injected into the vertebral space.

"We guide those injections by ultrasound, but there have been reports of cement leaking into a blood vessel and causing a pulmonary embolism," he said.

If there is a recognized risk with carefully monitored procedures, it is logical to assume that the risk associated with the "illegal, underground cosmetic industry is likely to much greater," he said.