Filling The Unit; Accessories; Operating Principles; Treatment/Clinical Application - Cortex Cryopro Gebrauchsanweisung

the EU member state in which the user and/or patient is established. For
users outside the EU: local distributor and relevant competent authorities
must be informed.

FILLING THE UNIT

The CryoPro® unit is to be filled with liquid nitrogen only. Fill the unit by
slowly pouring liquid nitrogen into the bottle or by using a standard low
pressure withdrawal device from a storage tank (dewar). Depending on
the number of lesions to be treated and the duration of the individual
treatments the unit should be filled to at least one third of its maximum
capacity. After filling a warm unit, the liquid will boil for approx. 30 secs.
Hereafter, the lid can be mounted and tightened firmly. A weak but audible
hissing sound from the pressure relief valve indicates that normal working
pressure has been reached inside the unit. This is normal operation and
the pressure relief valve should never be blocked or tigtened. Various
factors influence the time it takes from the lid is closed until the device is
ready for use. Please see recommendations in the section "Performance
characteristics".
Caution should be taken when refilling a CryoPro® containing residual
fluid as the unit is pressurized at 0.8 bar. Slowly unscrewing the lid
will allow the unit to depressurize before the top comes off. This is
accompanied by an audible hissing sound until it is fully depressurized.
Evaporized nitrogen may escape and hit the hand.
NB: When handling liquid nitrogen (LN2) it is recommended to take
appropriate precautions as prescribed in the Safety Data Sheet (SDS)
from the LN2-supplier. As a minimum, it is recommended to use protec-
tive gloves and safety goggles or similar.

ACCESSORIES

Before use, attach a spray apperture or contact probe, as the CryoPro®
cannot perform its intended use without an attached spray aperture or
contact probe.
The CryoPro® is supplied with a set of standard open spray apertures.
Optional accessories comprise a variety of spray tips, contact probes,
rubber/plastic covers (cones), and other attachments. A table listing the
accessories are found in the section "Accessories".
NB: The contact probes are semi-critical items that come into contact
with non-intact skin. It is important to inspect them as they must be
discarded if they have any signs of a compromised surface. Scratches
or defects in the gold coating may bring the patient into contact with
underlaying materials or debris.
NB: The CryoPro® is only intended for use with Cortex manufactured
spray tips, contact probes, and accessories.
OPERATING PRINCIPLE
When the device is pressurized and the trigger handle is activated, the
flow of LN2 will start. The nitrogen flow will stop when the trigger handle is
released. Adjustment of the LN2 flow rate is not possible using the trigger
handle. The nitrogen flow rate is adjusted by selecting the appropriate
spray aperture. A continuous flow of LN2 without pressing the handle
can be achieved by pushing the handle forward and to the side. For left-
handed users, the trigger handle can be placed on the left side of the
main valve.
NB: To avoid contamination and cold burn, it is recommended to use
protective gloves and safety goggles or similar.

TREATMENT/CLINICAL APPLICATION

All probes and spray apertures are mounted into the permanently affixed
knurled nut with fingertight firmness. Do not apply excessive force.
Anesthetic cream may be applied to im-prove tolerability of the procedure
and reduce posttreatment pain.
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NB: When left on the table between uses, there will be an audible,
constant, or intermittent hissing sound from the pressure relief valve. This
is normal and should not be prevented.
Spray freezing ( OS A, B, C, D, SS, BS, SOFT, LL)
The spray apertures include: A (1 mm opening), B (0.75 mm opening), C
(0.55 mm opening), D (0.45 mm opening) as well as Bent Spray aperture
(BS, 0.55 mm opening) and Straight Spray (SS, 0.55 mm opening) both
for areas difficult to reach like behind the ears, lip and outer nose (to avoid
nitrogen gas into the airways).
Select a spray aperture providing an LN2 output appropriate for the lesion
to be treated. In-depth freezing is best obtained when the spray aperture
is close to the lesion (5 - 10 mm distance) as the liquid content of the
spray is higher close to the aperture. When possible, raised warts should
be approached tangientally from at least two sides. This allows the ice
ball to move down through the wart while sparing the surrounding tissue.
Spraying directly at the lesion (perpendicular to the surface) will cause
more lateral spread with less penetration. To avoid this apply the spray
intermittently or use a smaller spray aperture.
The Soft Spray aperture is for freezing larger areas at greater distance
(up to approx. 5 cm) with higher vapor content. Move the aperture slowly
back and forth thus "painting" the surface with vaporized nitrogen.
The Luer Lock adapter facilitates the use of a hypodermic needle as a
spray aperture and the diameter of the needle determines the LN2 flow
rate. The flow rate must be adjusted according to the lesion to be treated.
NB: The use of hyperdermic needles is not intended for intralesional
treatment.
If the spray is clogged or liquid nitrogen flows slowly, it might be due to an
impurity in the liquid nitrogen. Take off the lid and let it thaw completely. To
clean the spray aperture, use the cleaning adapter or an air compressor.
Contact freezing ( CP SP, CP 1mm-30mm)
Closed contact probes provide in-depth freezing with minimal lateral
spread.
Select a probe size fitting the size of the lesion. Make the lesion wet with
a drop of water or contact gel prior to freezing to facilitate the thermal
transfer between skin and probe tip. Apply the contact probe when still
warm applying light pressure and pull the trigger handle. Keep freezing
until a 1-5 mm halo is seen around the probe tip. Then stop the freezing
and allow a few seconds for the probe tip to be released from the skin.
Freeze time varies according to the aperture or probe used, the size
and type of the lesion and the freezing distance (spray only). The user
is encouraged to familiarize him/her-self with the available literature on
cryosurgery using liquid nitrogen. A table showing the recommended
treatment times for the indicated skin lesions is seen in the section
"Recommended treatment times".
After treatment, the treated area must be protected (normal wound care).

DECONTAMINATION

The main CryoPro® unit is not intended to be autoclaved, but may be
cleaned using alcohol (isopropyl or ethanol).
Normally, spray apertures need no cleaning as they are not in contact
with the patient.
The CryoPro® contact probes are semi-critical reusable devices that
may get in contact with non-intact skin during the intended use. For this
reason, a manual cleaning process together with a moist heat sterilization
process have been validated as being able to prepare the device for
reuse. See section "Cleaning and sterilization of CryoPro® contact
probes".