Comparison of 20-, 23- and 25-Gauge Cannulas Air Infusion Forces

Abstract

Purpose: : To evaluate and compare total force and impact pressure (force/area) of 20-, 23- and 25-gauge infusion air injection.

Methods: : The present study was executed in an experimental laboratory setting. Original vitrectomy 20-, 23- and 25-gauge Alcon cannulas (Forth Worth, TX) were connected to a compressed air system with growing levels of infusion pressure (from 0 to 0.08 atm, or 0 to 60.8 mmHg). Each of the cannulas was positioned in front of a pendulum device in order to measure the force. The impact pressure (force/area) was calculated using fluid dynamics formulas.

Results: : The 20-gauge cannula showed similar force values as the 23-gauge cannula for most of the infusion pressure readings (from 0 to 0.05 atm or 0 to 38 mmHg). Both showed higher results than 25-gauge cannula. Regarding the impact pressure (force/area), 23- and 25-gauge cannulas showed highest results in the majority of the experiment (from 0.025 to 0.08 atm or 19 to 61 mmHg), owing to their smaller area of impact.

Conclusions: : Both 23- and 25- gauge cannulas showed higher impact pressure values, compared to 20-gauge system. This could be a concern regarding air infusion toxicity during small gauge vitrectomy. Future experimental and clinical studies should corroborate these findings.

Keywords: vitreoretinal surgery • retinal detachment