Dr. Barry Seibel is a cataract surgeon and sole author and illustrator of the critically acclaimed cataract surgery textbook, Phacodynamics. He is an expert in applying engineering principles to facilitate customized surgery for each patient.
Dr. Seibel is a proponent of vacuum control. “With the vacuum pump, there is an advancement of the whole surgical platform into a mechanism for more intuitively translating surgical skill, thought, and knowledge base into executed movements.” He noted that Bausch + Lomb has overcome early misconceptions about vacuum control with the innovative Stellaris Elite® system. However, based on some early experiences, myths about vacuum-based phaco still exist.
Through adaptive fluidics, fluidic resistors and dual-liner control, the vacuum pump has evolved into what I think is really the ideal modality for cataract surgery.
“Through adaptive fluidics, fluidic resistors and dual-liner control, the vacuum pump has evolved into what I think is really the ideal modality for cataract surgery.”
MYTH: Vacuum-based machines are too fast, and the vacuum level is too high.
REALITY: With vacuum-based machines, the surgeon is in control.
While some surgeons may misperceive vacuum-based systems as being faster and therefore riskier to use vacuum-based phaco machines provide more control.1 With vacuum-based machines, increased aspiration only occurs when the surgeon is requesting higher vacuum with the foot control when the aspiration port is not occluded, and vacuum will not exceed maximum vacuum set by the surgeon for the machine. When the surgeon feels anterior chamber outflow and current is too fast, the surgeon simply reduces the vacuum with the foot control. Additionally, the surgeon can program decreased vacuum rise time, so even fast motion of the foot control will result in slower, more graceful changes in the eye.
MYTH: Vacuum-based machines are risky to use.
REALITY: Post-occlusion surges are extremely rare with the Stellaris Elite® system.
Some perceived risk is related to the perception of excessively fast flow rates, a myth which was dispelled above. Also, with vacuum-based machines, increased vacuum pressure only occurs when the surgeon is requesting higher vacuum, so that they can easily manage it. Thus, post-occlusion surges are extremely rare with the vacuum-based Stellaris Elite® system.1 A potential issue with older pumps is the risk of post-occlusion surge with higher vacuum levels. The Adaptive Fluidics™ in the Stellaris Elite® system proactively monitors and responds to commanded vacuum.1
MYTH: It is complicated to adjust vacuum.
REALITY: With vacuum-based machines, adjusting vacuum is simple.
With a flow pump, there are two controls – maximum vacuum limit and flow rate – and adjustments are complicated because each control impacts other parameters. Vacuum is indirectly adjusted by modifying the vacuum limit. In this case, the surgeon needs to consider the link between vacuum limit and flow rate.
Using phacodynamic principles with vacuum-based machines, vacuum can be adjusted directly with (dual) linear pedal control. Thus, if the surgeon’s microscope view indicates vacuum is too high and abrupt because occluded material is deforming too quickly, the vacuum (deformational force) can be directly and ergonomically adjusted.
With the Stellaris Elite® system, the surgeon adjusts only a single parameter with the linear foot pedal–commanded vacuum – and the machine responds accordingly in a clinically relevant manner: grip in proportion to commanded vacuum when the aspiration port is occluded, and current/flow strength in proportion to commanded vacuum when the aspiration port is occluded.1 The surgeon uses commanded vacuum to direct the machine to the desired vacuum level, and the machine can proactively increase infusion pressure on its own via Adaptive Fluidics using a pressurized infusion bottle.
MYTH: Longitudinal cutting is inefficient.
REALITY: The Stellaris Elite® system delivers powerful cutting efficiency with longitudinal action at the tip.
With use of the proper techniques with vacuum systems, the longitudinal cutting action of the Stellaris Elite® system is powerful for efficient surgeries. Attune® Energy is employed to optimize cutting efficiency without using excess energy. Furthermore, vacuum-based surgery (especially with dual linear pedal control) with longitudinal action lends itself to chop techniques, which demands less phaco energy.
When the tip is occluded most of the time, efficiency of the chop technique and the fluid turnover in the eye is reduced compared with sculpting, which is the least efficient mode of phacoemulsification. Recall that as commanded vacuum is increased, Adaptive Fluidics proactively increases infusion pressure to help mitigate potential post-occlusion surge.
Proactively increases infusion pressure as more vacuum is commanded in order to maintain chamber stability as aspiration outflow increases.
Dr. Barry Seibel is the author of the textbook Phacodynamics, published in 4 editions and 5 languages, and he has invented more than 20 surgical instruments for cataract and LASIK surgery. Dr. Seibel is on the clinical faculty at UCLA Geffen School of Medicine and practices in the Los Angeles area.
Financial disclosure: consultant to Bausch + Lomb