Spontaneous dislocation of fluocinolone acetonide implant pellets from their suture struts

To characterize spontaneous dislocation of the fluocinolone acetonide sustained release implant (Retisert; Bausch & Lomb) drug pellet from its strut.

Retrospective, observational case series.

The medical records of 224 patients in whom 407 fluocinolone acetonide implants were placed by either of 2 surgeons between 1998 and 2012 were reviewed for drug pellet-suture strut separation, observed before surgery in clinic or occurring at the time of implant replacement.

Seventeen (4.2%) of 407 drug pellets spontaneously dislocated away from the suture strut at a mean postimplantation time of 77.4 months (range, 33 to 132 months). The rate of spontaneous dislocation increased from 1 dislocation per 262 person years (95% confidence interval, 1 per 1269 to 1 per 89.6 person-years) before 60 months to 1 dislocation per 13.3 person-years (95% confidence interval, 1 per 24.4 to 1 per 7.9 person-years) afterward. Fourteen of 17 dislocated pellets were removed surgically. Of 77 exchanged fluocinolone acetonide implants without dislocated pellets, 11 (14.2%) pellets had separated, but not dislocated away, from the strut; time to exchange of dislocated or dissociated pellets was significantly longer than time to exchange of intact fluocinolone acetonide implants (70.5 vs 44.9 months; P < .001).

The fluocinolone acetonide drug pellet can dislocate spontaneously from the suture strut as a late event that typically occurs after 3 years. Pellets also may be dissociated from the strut without dislocation, when separation occurs at the time of surgical replacement. Removal of the dislocated pellet can be achieved safely. Time was the major risk factor identified for both events.