The spectrum of microscopic and macroscopic fat embolism following aesthetic procedures: updated definitions, diagnosis, and clinical implications.

Fat embolism following aesthetic procedures such as fat grafting and liposuction is a rare but potentially fatal complication. Traditionally classified by symptom timing into macroscopic fat embolism (MAFE) and microscopic fat embolism (MIFE), recent evidence challenges this dichotomy due to overlapping clinical features and variable presentations. This review synthesizes data from systematic analyses of 172 reported cases to propose updated definitions that exclude symptom timing as a primary criterion. We emphasize the need for a multifactorial diagnostic approach incorporating clinical findings, imaging, and histopathology to distinguish MAFE, characterized by large fat globules causing vascular obstruction, from MIFE, a systemic inflammatory syndrome induced by microscopic fat particles. Recognizing mixed MAFE-MIFE presentations further complicates diagnosis and management but is critical for guiding therapeutic strategies and improving outcomes. The review highlights significant knowledge gaps and advocates for standardized reporting protocols and prospective studies to refine diagnostic criteria and treatment modalities to enhance patient safety in aesthetic medicine.