Atypical Hyaluronic Acid-Induced Vascular Occlusion Masked by a Hematoma: Ultrasound-Guided Diagnosis and Management.

Hyaluronic acid (HA) fillers are widely used in aesthetic practice as they are generally considered safe and effective. However, vascular occlusions remain a rare but serious complication that can cause tissue ischemia and necrosis if they are missed. Recently, with the challenges of early diagnosis, ultrasound has emerged as a valuable tool in identifying vascular compromise through Doppler flow assessment and visualization of filler deposits, supporting both the diagnosis and management of these events. We present a case of vascular occlusion following HA filler injection to the nasolabial fold and the upper lip, presenting with swelling, blanching, and an atypical, exaggerated hematoma. Initial management at the referring clinic including high-dose hyaluronidase and lidocaine administration was insufficient, followed by the development of a hematoma, which raised the concern for an incomplete resolution of symptoms and complicated accurate assessment of progression and severity. Further evaluation using ultrasound precisely confirmed vascular occlusion of the left angular and left superior labial arteries and guided targeted hyaluronidase administration, allowing for immediate restoration of vascular flow and progressive clinical improvement, resulting in a highly effective approach compared to blind, high-dose treatments. This case highlights the importance of accurately diagnosing vascular occlusions, even when the presentation is not classic. Early recognition and careful monitoring after filler injections are essential to prevent progression and reduce complications. Effective management can significantly improve outcomes, and the use of ultrasound adds a great advantage by improving visualization of vascular structures and enabling more precise and targeted treatments.