Aquafilling Infiltration into the Pectoralis Major Muscle with Obliterative Phlebitis: A Case Report with Histopathological Findings

Aquafilling® (Biomedica, spol. s r.o., Czech Republic) was introduced as an absorbable soft-tissue filler; however, complications similar to those of polyacrylamide hydrogel have been increasingly reported. A 37-year-old woman requested the removal of Aquafilling previously injected for breast augmentation. Magnetic resonance imaging demonstrated extensive foreign material in the plane between the mammary gland and the pectoralis major muscle. Intraoperatively, Aquafilling was identified within both tissues. Despite pulsed saline irrigation under direct visualization, substantial gel remained, necessitating partial excision of the mammary gland and the pectoralis major muscle. Histopathological examination revealed Aquafilling within the interfascicular spaces of the pectoralis major, confirming intramuscular infiltration, and elastic-van Gieson staining demonstrated obliterative phlebitis. To our knowledge, venous lesions associated with Aquafilling have not been previously reported. This case highlights that Aquafilling infiltrating glandular or muscular tissue is unlikely to be removed adequately by conservative procedures, supporting open surgical removal as the more reliable option.