Opera ve Emulsifica on of Perfluorocarbon Liquid associated with 23

Intra-­‐<strong>Opera</strong>*<strong>ve</strong> <strong>Emulsifica</strong>*on of
Perfluorocarbon Liquid associated with 23-­‐
Guage Vitrectomy
Roxane J. Hillier FRCOphth, David T. Wong FRCSC
St Michael’s Hospital, Toronto, Canada
Contact: roxanehillier@gmail.com

Introduc*on & purpose
• Contemporary 23-­‐guage vitrectomy systems offer enhanced efficiency of
vitreous clearance and beLer intra-­‐operaM<strong>ve</strong> intra-­‐ocular pressure (IOP)
control. Key advances ha<strong>ve</strong> been made in terms of trocar cannula design and
IOP regulated infusion technology. Howe<strong>ve</strong>r, without appropriate
modificaMons to surgical technique, these features may predispose to intra-­‐
operaM<strong>ve</strong> perfluorocarbon liquid emulsificaMon and other surgical difficulMes.
• The purpose of this poster is to illustrate a no<strong>ve</strong>l intra-­‐operaM<strong>ve</strong> challenge and
suggest ways to avoid it.
Methods
• We report on our personal experience using the Alcon CONSTELLATION®
Vision System and Alcon 23G standard (val<strong>ve</strong>less) and val<strong>ve</strong>d cannula entry
systems.

Results
Standard (val<strong>ve</strong>less) 23G cannula entry system
• Upon removal of instrument from port, excessi<strong>ve</strong> and immediate emulsificaMon of
intra-­‐ocular perfluorocarbon liquid may be seen to occur (fig 1)
• When val<strong>ve</strong>less cannulas are used in conjuncMon with IOP regulated infusion, vast
fluctuaMons in infusion pressure occur when a port is open. The resultant high
<strong>ve</strong>locity fluid currents through the vitreous cavity ser<strong>ve</strong> to o<strong>ve</strong>rcome the surface
tension of the tamponade agent.
• <strong>Emulsifica</strong>Mon of perfluorocarbon liquid presents an increased risk of incurring
sub-­‐reMnal perfluorocarbon liquid droplets.
Figure 1: <strong>Emulsifica</strong>+on of perfluorocarbon liquid upon
removal of instrument (val<strong>ve</strong>less 23G cannula system).
Direc+on of infusion current (white arrows) and
impression on surface of tamponade agent (asterisk).

Results
Val<strong>ve</strong>d 23G cannula entry system (Alcon Labs Inc.) (fig 2a and b)
• Reduced incidence of perfluorocarbon liquid emulsificaMon upon removal of
instrument
• StabilisaMon of infusion pressure whilst port is open
• Lower incidence of sub-­‐reMnal perfluorocarbon liquid droplets
Figure 2a: Alcon 23G val<strong>ve</strong>d Figure 2b: Alcon 23G val<strong>ve</strong>d cannula (note
cannula entry system setup external silicone membranous val<strong>ve</strong>)

Conclusions
• Certain features of contemporary 23G vitrectomy systems, such as val<strong>ve</strong>less trocar
cannulas in conjuncMon with IOP regulated infusion, promote increased flow of
fluid across the vitreous cavity and predispose to emulsificaMon of perfluorocarbon
liquid during instrument removal/exchange. Awareness of this phenomenon is
parMcularly important when operaMng on eyes which are at increased risk of
incurring sub-­‐reMnal perfluorocarbon liquid droplets (e.g. giant reMnal tears and
proliferaM<strong>ve</strong> vitreoreMnopathy). We suggest the following steps to reduce intra-­‐
operaM<strong>ve</strong> perfluorocarbon liquid emulsificaMon:
– Use of val<strong>ve</strong>d trocar cannula system
– ReducMon of infusion rate (where val<strong>ve</strong>less cannulas are used)
– Opt to o<strong>ve</strong>r-­‐ride IOP regulated infusion feature (where val<strong>ve</strong>less cannulas are used)
• We suggest that the advantages of IOP regulated infusion may only be fully
realized when used in conjunc1on with newer val<strong>ve</strong>d cannula entry systems. We
ha<strong>ve</strong> found that val<strong>ve</strong>d cannulas offer se<strong>ve</strong>ral addiMonal advantages (Box 1), and
highlight unique issues regarding surgical technique when adopMng a val<strong>ve</strong>d
cannula entry system (Box 2)