RESUMO
Objective To study the pathological mechanism of aseptic necrosis of breast tissue after long-term breast augmentation injected with polyacrylamide hydrogel (PAHG).Methods We included patients who had no obvious clinical symptoms and underwent surgical removal of the PAHG in our hospital,excluding patients with a history of breast prosthesis implantation.Extracts were collected,and then underwent a careful gross observation and serial sections followed by HE,Mallory,and toluidine blue staining,to observe the histological structure of collagen fibers and inflammatory cells.Immunohistochemistry for CD31 and a-smooth muscle actin (a-SMA) antibody was used to further identify vascular endothelial cells and vascular smooth muscle cells,respectively.Analysis of the correlation between injection time and the incidence of different pathological changes were done.Results We included 22 females (mean age 39.14 years,range 22-55 years) who requested surgical removal of the PAHG.The mean duration of PAHG injection was 9.27 years (range 4-14 years).They had no clinical symptoms or only had induration,deformation and displacement.The basic pathological changes of local tissue included foreign body reaction and chronic inflammation,fibrosis and tissue necrosis;and half of the tissue had also histological changes,such as small vascular smooth muscle layer thickening,lumen stenosis,etc.No significant correlation was found between the pathological changes and the duration of the disease and the clinical symptoms.Conclusions Patients with PAHG injection for augmentation mammoplasty can histopathological changes of local tissues even without experiencing discomfort.The tissue necrosis in some patients may be caused by foreign body reaction and inflammatory reaction.It may also be due to local ischemia caused by small vascular smooth muscle hyperplasia,luminal stenosis etc.