Two cases of accidental dislocation of the silicone sleeve of an extrusion cannula into the vitreous cavity

Abstract

Background: fluid-air exchange during vitreoretinal surgery is often used as a tool for subretinal fluid endodrainage. Soft-tipped flexible extrusion cannulas are commonly used to aspirate the posterior subretinal fluid. Methods: this is an observational two-case series describing two patients who underwent 20-G pars plana vitrectomy complicated by the accidental fall of the silicone sleeve of a soft-tipped extrusion cannula into the vitreous cavity. In the first case, the cannula had inadvertently been subjected to sterilization process. Results: while withdrawing the soft-tipped extrusion cannula from the eye, following internal drainage of transvitreal and subretinal fluid, the loose silicone sleeve probably got entangled at the inner lip of the sclerotomy and finally fell on the retinal surface. In both cases, the silicone sleeve was held and removed with an intraocular forceps. Conclusions: this rare complication has been reported in the literature only once previously. Sterilization of disposable subretinal fluid cannulas is not advisable because of the risk of dislocation of the silicone sleeve into the eye. Besides this, it is important to check the integrity of the silicone sleeve before and after surgery.