Misconnection of Vitrectomy Handpieces and Vitrectomy Units
Hazard [Health Devices Feb 1995;24(2):86]
Two hospitals reported incidents in which eye injuries occurred when one
of the lines from a pneumatically driven vitrectomy handpiece was misconnected to the
vitrectomy unit's high-pressure actuator line. The Food and Drug Administration's (FDA)
Medical Device Reports (MDR) database contains two similar reports. Also, in 1993, one
manufacturer's vitrectomy handpiece was recalled because connectors on the actuator and
aspiration lines were reversed during manufacturing.
With this type of misconnection, a large blast of compressed air enters
the eye on activation of the handpiece. In most of the reported cases, eye damage
occurred, including an iris prolapse, dislocation of an implanted lens, and retinal
injury. Because vitrectomy equipment from many manufacturers and distributors share the
same actuator-line design, this problem could occur with any of the vitrectomy handpieces
that are pneumatically driven and that have aspiration- or irrigation-line connectors that
are compatible with the unit's actuator line.
Vitrectomy handpieces are connected to the vitrectomy unit by 1) an
aspiration line and 2) an actuator line. The actuator line is used to supply an
oscillating pulse of positive and negative pressure on the membrane in a chamber within
the vitrectomy handpiece; this oscillation of the membrane causes the cutting blade, which
is connected to the back side of the membrane, to move. Some handpieces also have an
irrigation line that may be integral to the handpiece or supplied as a separate irrigation
cannula that the user can slip over the handpiece.
All lines are connected using Luer connectors. In addition, a stopcock may
be used to allow connection of another handpiece. Depending on the particular
configuration, it will be possible to connect either the handpiece's irrigation line or
its aspiration line to the vitrectomy unit's actuator line. If this misconnection occurs,
oscillating air pressure will be forced into the patient's eye when the unit is operated.
To help prevent misconnections, most vendors use some sort of color coding for the Luer
connectors; in some instances, the tubing itself has some color identifier.
Every time lines are reconnected and before the device is used, the
handpiece should be inspected while outside the eye to detect misconnection. However,
because an anterior vitrectomy is usually performed only after a posterior capsule rupture
(i.e., emergency intervention), the operating room staff may be rushed and may not take
the time to check the handpiece before using it. Therefore, the only way to prevent
misconnections is to design the lines on the vitrectomy handpiece so that they can be
connected to the machine in only the correct manner (e.g., the manufacturer could provide
an actuator-line connector that is incompatible with other connectors).
- Notify all clinical staff who use pneumatic-powered
vitrectomy equipment of this hazard.
- Inform staff of the need to inspect every
ophthalmic handpiece after connecting the lines and before inserting it into
the patient's eye. Inspecting all ophthalmic handpieces just before using
them in the eye should already be a standard procedure, regardless of this
particular problem; however, inspection is especially important until
vendors incorporate design changes in their pneumatic vitrectomy systems.
- To check a vitrectomy handpiece before use, the scrub nurse should first
make the handpiece connections to the machine's actuator and aspiration
lines (and the irrigation line when present). The handpiece should then be
operated in a beaker of sterile water. Air bubbles coming from the handpiece
indicate that the actuator line is connected inappropriately to either the
aspiration or irrigation line.
- Vitrectomy Units [14-386]
- Cataract Extraction Units, Phacoemulsification [17-596]
Cause of Device-Related Incident
Device factors: Design/labeling error; Manufacturing error
User errors: Accidental misconnection; Failure to perform pre-use inspection
Support system failure: Lack or failure of
incoming and pre-use inspections
Mechanism of Injury or Death