ASTM F647-94(2000)
(Practice)Standard Practice for Evaluating and Specifying Implantable Shunt Assemblies for Neurosurgical Application
Standard Practice for Evaluating and Specifying Implantable Shunt Assemblies for Neurosurgical Application
SCOPE
1.1 This practice covers requirements for the evaluation and specification of implantable shunts as related to resistance to flow, direction of flow, materials, radiopacity, mechanical properties, finish, sterility, and labeling of shunt assemblies.
1.2 Devices to which this practice is applicable include, but are not limited to, those that are temporarily implanted to effect external drainage; or permanently implanted to effect shunting of fluid from a cerebral ventricle, a cyst, the subarachnoid space to the peritoneal cavity, the venous circulation, or some other suitable internal delivery site, and intracranial bypass.
1.3 Limitations-- Although this practice includes a standard test method for the evaluation of pressure/flow characteristics of shunts or shunt components, it does not include specific pressure/flow requirements.
1.4 The following components, that individually or in combination comprise shunt assemblies, are considered to be within the scope of this practice: catheters (such as atrial, peritoneal, ventricular), connectors, implantable accessory devices (such as antisiphon devices and reservoirs), valved catheters and valves.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.Note 1--The following standards contain provisions that, through reference in this text, constitute provisions of this practice. At the time of publication, the editions indicated are valid. All standards are subject to revision, and parties to agreements based on this practice are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Devices or components, or both, whose structures are comparable to that outlined in these standards are acceptable.
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Designation:F647–94 (Reapproved 2000)
Standard Practice for
Evaluating and Specifying Implantable Shunt Assemblies for
Neurosurgical Application
This standard is issued under the fixed designation F 647; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
A hydrocephalus shunt assembly is a one-way pressure-activated or flow-controlling device or
combination of devices intended to be surgically implanted in the body of a patient with
hydrocephalusanddesignedtodivertcerebrospinalfluid(CSF)fromfluidcompartmentsinthecentral
nervous system (CNS) (the cerebral ventricles or other site within the cerebrospinal fluid system) to
an internal delivery site (internal shunt) in another part of the body or an external collection site
(external shunt), for the purpose of relieving elevated intracranial pressure or CSF volume.
A hydrocephalus shunt system typically consists of three basic elements: (1) an inflow (proximal)
catheter,whichdrainsCSFfromtheventricularsystem,lumbarsubarachnoidspaceorextraventricular
structureandtransmitsitto(2)anarrangementofoneormorevalveswhichregulate(s)thedifferential
pressure or controls flow through the system, and (3) an outflow (distal) catheter which drains CSF
into the cardiovascular system via the peritoneal cavity, heart or other suitable drainage site. In
addition, specialized accessory devices such as reservoirs, antisiphon devices and on-off valves and
filters are added at the discretion of the physician to modify performance or adapt the basic system to
the specialized needs of the patient.
Because of the considerable length of time over which a shunt or component may be required to
function after implantation, it is felt that it should be type-tested to ensure its durability. It has not yet
been found feasible to specify a test method of durability testing, but a test method is proposed in
Appendix X1.
1. Scope of shunts or shunt components, it does not include specific
pressure/flow requirements.
1.1 This practice covers requirements for the evaluation and
1.4 The following components, that individually or in com-
specification of implantable shunts as related to resistance to
bination comprise shunt assemblies, are considered to be
flow, direction of flow, materials, radiopacity, mechanical
within the scope of this practice: catheters (such as atrial,
properties, finish, sterility, and labeling of shunt assemblies.
peritoneal, ventricular), connectors, implantable accessory de-
1.2 Devices to which this practice is applicable include, but
vices (such as antisiphon devices and reservoirs), valved
arenotlimitedto,thosethataretemporarilyimplantedtoeffect
catheters and valves.
external drainage; or permanently implanted to effect shunting
1.5 This standard does not purport to address all of the
of fluid from a cerebral ventricle, a cyst, the subarachnoid
safety concerns, if any, associated with its use. It is the
space to the peritoneal cavity, the venous circulation, or some
responsibility of the user of this standard to establish appro-
other suitable internal delivery site, and intracranial bypass.
priate safety and health practices and determine the applica-
1.3 Limitations—Although this practice includes a standard
bility of regulatory limitations prior to use.
test method for the evaluation of pressure/flow characteristics
NOTE 1—The following standards contain provisions that, through
reference in this text, constitute provisions of this practice.At the time of
This practice is under the jurisdiction of ASTM Committee F04 on Surgical
publication, the editions indicated are valid. All standards are subject to
Materials and Devices and is the direct responsibility of Subcommittee F4.31 on
revision, and parties to agreements based on this practice are encouraged
Neurosurgical Standards.
to investigate the possibility of applying the most recent editions of the
Current edition approved June 15, 1994. Published August 1994. Originally
e1
published as F 647 – 79. Last previous edition F 647 – 85 (1993) .
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F647–94 (2000)
standards indicated below. Devices or components, or both, whose
3.1.4 chambered valve—an element of a hydrocephalus
structures are comparable to that outlined in these standards are accept-
shunt containing one or more valve mechanisms that is to
able.
facilitate selective flushing in the proximal or distal direction.
3.1.5 connector—a device intended for the joining and
2. Referenced Documents
fixation of implantable shunt components at operation.
2.1 ASTM Standards:
3.1.6 distal (outflow) catheter—that part of a hydrocephalus
F 55 Specification for Stainless Steel Bar and Wire for
shunt assembly that provides a passive outflow pathway for the
Surgical Implants
diversion of fluid from a compartment of the central nervous
F 56 Specification for Stainless Steel Sheet and Strip for
system to the peritoneal cavity, venous circulation, or other
Surgical Implants
internal delivery site. The outflow catheter may or may not
F 67 Specification for Unalloyed Titanium for Surgical
contain a pressure/flow regulating device.
Implant Applications
3.1.7 flow-impedance device—those components of a shunt
F 75 Specification for Cast Cobalt-ChromiumMolybdenum
3 assembly which, by virtue of their resistance properties,
Alloy for Surgical Implant Applications
provide the principal means of controlling intracranial pressure
F 90 Specification for Wrought Cobalt-Chromium-
3 or flow of cerebrospinal fluid, or both. Flow-impedance de-
Tungsten-Nickel Alloy for Surgical Implant Applications
vices include valved catheters and valves and the relevant
F 138 Specification for Stainless Steel Bar and Wire for
3 constituent parts thereof.
Surgical Implants (Special Quality)
3.1.8 fluid compartment—the portion of the central nervous
F 469 Practice for Assessment of Compatibility of Nonpo-
system (CNS) including the ventricles and subdural space, and
rous Polymeric Materials for Surgical Implants with Re-
extraventricular structures such as cysts and hygromas.
gard to Effect of Materials on Tissue
F 604 Classification for Silicone Elastomers Used in Medi- 3.1.9 functional range—the representative pressure/flow
cal Use characteristics of a shunt or shunt element usually expressed in
F 640 Test Methods for Radiopacity of Plastics for Medical graphical form.
Use
3.1.10 hydrocephalus—the state of excessive accumulation
F 897 Practice for Measuring Fretting Corrosion of Osteo-
of cerebrospinal fluid (CSF) within the ventricular system of
synthesis Plates and Screws
the head due to a disturbance of secretion, flow or absorption,
2.2 ISO Standard:
usually resulting in a pathological increase in intracranial
pressure (ICP).
NOTE 2—AsuggestedmethodofdurabilitytestingisgiveninAppendix
X2. 3.1.11 hydrocephalus shunt—a one-way pressure-activated
or flow-controlling device or combination of devices intended
3. Terminology
to be surgically implanted in the body of a patient with
hydrocephalus and designed to divert cerebrospinal fluid from
3.1 Definitions of Terms Specific to This Standard:
a fluid compartment in the central nervous system or CNS (the
3.1.1 antisiphon device—a device implanted to counteract
cerebral ventricles or other site within the cerebrospinal fluid
the affects of the hydrostatic column of the outflow catheter.
system) to an internal delivery site in another part of the body
Thisistominimizethegravity(alsotermed“siphoning”)effect
(internal shunt) or an external collection site (external shunt),
of a hydrostatic pressure that may be created by the elevation
forthepurposeofrelievingelevatedintracranialpressure(ICP)
of the proximal (inflow) catheter in relation to the distal
or CSF volume.
(outflow) catheter thus preventing the excessive drainage of
CSF caused by gravity. 3.1.12 hydrocephalus shunt assembly—a complete hydro-
3.1.1.1 Discussion—The Committee adopted the terms si-
cephalus shunt comprising all the components necessary for
phon effect and antisiphon device for this practice because they clinical use.
are used in the medical literature. However, such devices are
3.1.13 implantable accessory device—component intended
designed to counteract the effects of gravity on the fluid in the
to facilitate the treatment of hydrocephalus by: providing
distal catheter when the patient is standing.
access to the shunt (such as reservoirs, antechambers, flushing
3.1.2 batch—a quantity of material that consists of a homo-
devices) or; modifying the performance characteristics of the
geneous mixture of common ingredients or a quantity of
shunt (such as on/off and antisiphon devices) or; reducing
devices processed and controlled as an integral production run.
hazards attendant to the presence of the shunt assembly (such
3.1.3 calibration—the act of fixing, checking, or correcting
as in-line filters).
on a schedule, the accuracy and precision of a measuring
3.1.14 implantable external drainage catheter—that ele-
instrument and maintaining records of these activities.
ment of an external drainage device which provides access to
a fluid compartment of the central nervous system.
3.1.15 kit—a number of components in a common package
2 to be used for a single purpose on the same occasion.
Discontinued; see 1991 Annual Book of ASTM Standards, Vol 13.01.
Annual Book of ASTM Standards, Vol 13.01.
3.1.16 magnetizable—a metal that has the capacity to ac-
Discontinued; see 1987 Annual Book of ASTM Standards, Vol 13.01.
quire magnetic properties of sufficient force to become dan-
Discontinued; see 2000 Annual Book of ASTM Standards, Vol 13.01.
gerous due to movement or thermal effects, or both, or to
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036. degrade the MRI image to the point of making it diagnostically
F647–94 (2000)
or therapeutically useless.Ashunt system that is magnetizable 3.1.26 pressure/flow graph—a graphic representation of the
is not MRI-compatible. composite performance characteristics of a population of flow
impedance devices.
3.1.17 modifiable connection—a portion of the shunt as-
sembly in which components are intended to be modified by 3.1.27 production line bench flow test—a test method used
by the manufacturer to verify that the pressure/flow character-
the surgeon during a surgical procedure (for example, the
length of a tube can be adjusted to accommodate the height of istics of each individual flow impedance device conforms to its
the patient). functional range.
3.1.18 multipiece hydrocephalus shunt assembly—a com- 3.1.28 proximal (inflow) catheter—thatpartofahydroceph-
plete sterile, single-use hydrocephalus shunt, supplied either alus shunt assembly that is inserted into the cerebral ventricles
assembled by the manufacturer or in kit form for assembly by or any other site in the craniospinal axis to provide access to a
fluid compartment of the central nervous system (for example,
the physician typically consisting of an inflow catheter,
pressure-activatedorflow-controllingdeviceorcombinationof into a lateral ventricle) and therefore constitutes the inflow
pathway for the diversion of fluid through a shunt system.
devices and an outflow catheter with requisite connectors
required for assembly.
3.1.29 radiopacity—the X-ray absorption properties that
3.1.19 nominal category—the generic performance cat- allow a shunt component to have clear and permanent visual-
egoryofthepressure/flowcharacteristicsoftheshuntassembly ization fluoroscopically or on X-ray film after implantation.
typicallydefinedas“low,”“medium,”“high,”etc.,thelimitsof (See Annex Annex A1).
which are defined by the manufacturer.
3.1.30 referee test method—the methods in the published
3.1.20 nonmodifiable connection—see preassembled con- standard for the device. The method and the corresponding
requirements will be invoked when the performance of the
nection.
medical device will be questioned. The manufacturer need not
3.1.21 one-piece hydrocephalus shunt assembly—complete
use this referee test method in the usual inspection and quality
sterile, single-use hydrocephalus shunt consisting of an inflow
control.
catheter integral with a pressure-activated or flow-controlling
3.1.31 reflux—a flow of fluid within a hydrocephalus shunt
device or combination of devices and an integral outflow
catheter. towards the cerebral ventricles or cerebrospinal fluid system.
3.1.32 shunt, v—to drain CSF from the CNS.
3.1.22 on-off device—an accessory component specifically
designed to permit alternate opening and closing of the shunt
3.1.33 shunt assembly—any device or combination of de-
system upon external activation. vices that functions to divert CSF from a fluid compartment of
the central nervous system to an internal delivery site (internal
3.1.23 packaging—the protective wrapping of shunt sys-
shunt) or an external collection site (external shunt).
tems or components:
3.1.34 shunt element—any component of a hydrocephalus
3.1.23.1 inner container—the packaging that is in direct
contact with the implant. shunt.
3.1.35 shunt filter—a device intended to remove particulate
3.1.23.2 multiple pack—a pack containing a number of unit
matter from the CSF before it passes through the shunt.
packs.
3.1.23.3 outer container or shelf container—a package, 3.1.36 sterile—in microbiology, free from all living organ-
isms; in practice, the condition of a product that has been
carton, or other container that may contain one or more unit
containers. The packaging that envelopes the inner container subjected to a validated sterilization process and maintained in
this state by suitable protection.
such that sterility and the integrity of that container is main-
tained.
3.1.37 sterilized—term used to denote an object that has
been subjected to a validated sterilization process.
3.1.23.4 sterile pack—a pack intended to maintain the
sterility of the contents and comprising an inner and outer 3.1.38 test specimen—a device or sample of devices repre-
container. sentative of the population of devices.
3.1.23.5 transit container—a package, carton, or other con- 3.1.39 tip valve—an element of a hydrocephalus shunt
tainer that may contain one or more unit containers used to
located at the distal catheter tip that controls pressure or
protect the contents during shipping of the product from the establishes flow of cerebrospinal fluid and resists reflux of
manufacturer to the end user.
blood or other fluids into the
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