A Bent Infusion Cannula for Vitreous Surgery

Purpose: To modify an infusion cannula for vitreous surgery and decrease cannula-related complications.

Design: New surgical instrument.

Methods: A conventional 20-gauge infusion cannula was modified by forming a 135-degree angle at the joint of the flange between the cannula adapter and the needle. The sloped plane of the needle tip was opposite the bent adapter. The cannula was routinely fastened with a 7-0 absorbable suture after insertion into the eye.

Results: We used the modified infusion cannula in 50 consecutive phakic eyes (48 patients). Intraoperatively, the cannula remained attached to the globe surface; it did not tilt anteriorly and damage the lens when touched inadvertently. No suprachoroidal or subretinal infusion was observed. Neither the lens nor the retina was damaged. There were no cannula-related retinal detachments or breaks during follow-up.

Conclusions: The modified infusion cannula is more effective and safer during pars plana vitrectomy in phakic eyes compared with a conventional cannula.