Session Title: Vitreoretinal Surgery III
Session Date/Time: Friday 18/09/2015 | 14:30-16:00
Paper Time: 15:26
First Author: : P.Dugel UNITED STATES
Co Author(s): : D. Abulon T. Wang
PURPOSE:During pars plana vitrectomy, surgical maneuvers in the far periphery may bend the probes and halt cutter actuation. This laboratory study simulates vitrectomy probe bending during surgery and investigates the cutter functionality during probe needle deflection.
This is a laboratory study done with ultra-high speed video camera image capture at 500 frames per second.
Using an Instron machine with a 50N load cell, a load was applied 23.5mm from the base of probe, with constant loading rate of 20mm/min, and maximum deflection of 5mm. A Keyence digital high speed video camera (Model VW-9000) captured cutter actuation at 7500cuts per minute and probe bending at a frame rate of 500 frames per second. The maximum deflection at which the probe stopped actuating was determined from the video recordings and Instron data. A total of 18 UltraVit® vitrectomy probes were tested; N=6 for each 27+, 25, and 23gauge size. Differences in deflection among the three gauges were determined using an analysis of variance (ANOVA) with a statistical significance level of p<0.05.
The 25+ gauge probe could withstand the highest amount of deflection before cutter actuation stopped (2.27±0.28mm). Maximum deflection with 23 gauge probes occurred at 1.79±0.13mm. The lowest maximum deflection The 25+ gauge probe could withstand the highest amount of deflection before cutter actuation stopped (2.27±0.28mm). Maximum deflection with 23 gauge probes occurred at 1.79±0.13mm. The lowest maximum deflection occurred with 27+ probes at 1.25±0.25mm. ANOVA revealed that maximum deflection for all three gauges were statistically significantly different (P<0.0001).
The 25+ vitrectomy cutters were able to withstand the most deflection before cutter actuation failed and may be a robust selection for vitrectomy surgery handlings.