D. Tuncali et F. Ozgur, Spontaneous autoinflation of saline-filled mammary implants: Postoperativevolume determination by magnetic resonance imaging, AES PLAS SU, 23(6), 1999, pp. 437-442
Autoinflation of saline-filled mammary implants has recently been reported
in the literature. Except for a few controversial hypotheses, the cause of
autoinflation has not been clarified. The need to remove implants for accur
ate measurement of fill volume has been a deterrent to studies of autoinfla
tion. To measure in situ Volumes of saline-filled mammary implants, a nonin
vasive technique using magnetic resonance imaging (MRI) was developed. Meas
urements were performed manually on every MRI slice by tracing the outline
of the implant with a hand-driven cursor. The accuracy of this MRI techniqu
e was assessed by measurements of tissue expanders containing known volumes
of saline. To evaluate for autoinflation in mammary implants, a prospectiv
e clinical study to compare initial fill volumes of saline-filled mammary i
mplants with 3- and 18-month postoperative volumes, calculated from magneti
c resonance imaging (MRI) studies, was designed. A total of 12 patients (23
breast implants) implanted between 1994 and 1996 was included in the study
. Volume data were compared by statistical analysis. MRI-determined volumes
3 months postoperatively were significantly larger than reported initial f
ill volumes, indicating that most saline-filled mammary implants included i
n the study autoinflated to some extent. Comparison of MRI-determined volum
es 3 and Is months postoperatively revealed no significant differences, ind
icating that saline-filled mammary implants remain stable and inflated betw
een 3 and 18 months postoperatively. As a result of this study we believe t
hat autoinflation of saline-filled mammary implants occurs more frequently
than previously thought.