Prospective Stage-Stratified Histopathologic Study and Proposed Disease-Evolution Model of Gluteal Permanent Synthetic Filler Complications
brief summary
This prospective biospecimen cohort will collect and analyze tissue from adults undergoing clinically indicated surgery for gluteal permanent synthetic filler disease. Two blinded pathologists will score foreign material burden, inflammation, fibrosis, necrosis, vascular and lymphatic injury, and deep-tissue involvement. Histopathologic severity will be compared across clinical-radiologic stages and time since injection. The study will propose a cross-sectional disease-evolution framework and assess the reproducibility of the scoring system.
detailed description
Participants will be enrolled before clinically indicated biopsy or filler-removal surgery. Exposure history, symptoms, physical findings, and MRI stage will be recorded using standardized forms. During surgery, samples from mapped tissue planes will be collected without extending the planned excision. Two pathologists blinded to clinical stage will independently grade eight tissue-injury domains and generate a composite severity score. Disagreements will undergo adjudication. The study will evaluate associations between tissue findings, time since injection, and clinical-radiologic stage and will use exploratory clustering to identify histopathologic phenotypes. Because participants are sampled at one operation, the resulting model will be described as a proposed cross-sectional natural-history framework.