Filler Migration: A Number of Mechanisms to Consider

To report 3 representative cases of soft tissue filler identified in locations other than their intended injected sites (possible migration) and review the literature on pathogenesis of filler migration.

Soft tissue fillers are continuing to increase in popularity throughout North America and worldwide as a means of volume restoration and contour enhancement. With increasing recognition of their value in restoring a more youthful appearance and the ease of office injection, soft tissue fillers have become one of the most commonly performed nonsurgical cosmetic procedures. Soft tissue fillers are also foreign bodies in our system and therefore have the potential for a myriad of complications both immediately after the injection and potentially months or years later. Filler migration is one such complication and has a number of potential mechanisms.

The authors reviewed the medical records of 3 patients with filler located in areas other than their intended injected sites possibly as a result of migration. All patients were from the practice of 1 individual (DRJ). A MEDLINE search of the English-language literature on filler migration was conducted to investigate the various causes responsible for migration of filler.

Clinical manifestations of the possible filler migration in the 3 cases included eyelid swelling in 2 patients and a noninflammatory mass adjacent to the area of filler injection in the third patient. Surgery was performed on 1 patient, and filler was visualized in the tissue and dissolved with hyaluronidase. Hyaluronidase was also used to dissolve the suspected filler in a second patient, and the third patient has elected to continue with observation.

Filler migration is one of the potential complications associated with the injection of soft tissue fillers. It is important all physicians assessing nodules/masses/swelling in the facial area be aware that soft tissue fillers may migrate to a location away from their intended site of injection by several mechanisms and persist in the tissue even years later. A delayed reaction to the filler may occur months to years later and at times subject the patient to unnecessary investigations in attempt to identify it.