The EVA surgical system can switch between flow and vacuu, modes and accommodate small-gauge instruments.
Switching from vacuum to flow mode during vitrectomy without changing pumps is something that retina specialists could only imagine in their wildest dreams, but with the EVA surgical system, they now have that capability literally at their fingertips, says Gaurav K. Shah, MD, co-director of retina fellowship at The Retina Institute and professor at Washington University in St. Louis.

Dr. Shah, who discloses that he is an advisory board member for Dutch Ophthalmic Research Center (DORC), the maker and distributor of EVA, has performed around 50 vitrectomies with EVA. Its VacuFlow VTI (for valve timing intelligence) pump system provides both flow and vacuum fluidics.

Fast Cutting, Even Suction

For Dr. Shah, the TDC cutting system, which stands for two-dimensional cutting, is well suited to the smaller-port 27-gauge surgery that more retina specialists are adopting. The TDC vitrectrome cuts at speeds of up to 16,000 cycles per minute and has vacuum control that maintains even suction.

“With this technology you can do flow control that allows precision control with less movement of the retina, which is especially evident during retinal detachment,” Dr. Shah says. “In flow control, the flow pushes individual pieces into the cutter; it gives you precision and you have to go to it, it doesn’t come to you.”

Flow control provides a higher level of accuracy when cutting the vitreous close to the retina surface. “That allows you to do very meticulous, precise shaving of the vitreous base,” he says. The TDC vitrectrome also cuts forward and backward without closing, Dr. Shah says. “This is a very different cutter.”

Flow and Vacuum Modes

The ability to change between flow and vacuum modes also has its advantages, as Dr. Shah explains. “If you want to do entire case in vacuum you can. If you want to do an entire case in in flow, you can, or you can do a combination,” he says. “Typically, I do a core vitrectomy with vacuum mode and then as I move into the periphery, I will do that in flow mode.”

The system does allow faster operative times. “But to me that’s really not relevant whether it’s three or five minutes less,” Dr. Shah says. “We all want to look at outcomes of patients as more important than times.”

EVA at a Glance

EVA is for both vitreoretinal and cataract surgery. The company says the flow mode can complete the fluid-air exchange without the drop in intraocular pressure that can occur because of the variation in viscosity between the balanced-salt solution and air. The vitrectome is available in 20 through 27 gauge. It uses LED illumination to minimize UV light exposure. A green 532-nm laser with a wireless foot pedal is optional.  RS