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330 Indications, techniques, and results of inferior vena cava filters
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(a) (b) (c) (d) (e)
(f) (g) (h) (i)
(j) (k)
Figure 26.2 Various available filters. (a) Stainless steel Greenfield (Boston Scientific/Medi-Tech); (b) Günther Tulip MREye
(Cook);
(c) Simon Nitinol (Bard); (d) VenaTech LGM (B. Braun); (e) low-profile VenaTech (B. Braun); (f) OptEase (Cordis);
(g)TrapEase (Cordis); (h) G2 Filter (Bard); (i) bird’s nest (Cook); (j) ALN (ALN); (k) Denali (Bard); (l) Crux (Volcano).
(Reprinted with permission from Getzen TM, Rectenwald JE. J Natl Compr Canc Netw 2006;4:881–8.)
(l)
26.6 Types of IVC filters 331
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26.6.4 VenaTech LGM and low-profile filter
This original LGM filter has a six-strut conical configuration with side rails containing hooklets that provide
caval centering and fixation, respectively. The filter is
designed for IVC diameters of 28 mm or less. The filter
is loaded in an injection syringe, with the orientation of
filter injection into the sheath determined by the access
route (femoral or jugular). The low-profile filter replaces
the LGM, and instead of six side struts as with the original VenaTech filter, this design uses eight Phynox wires
formed in a conventional conical configuration with
welded hooks, some oriented superiorly and others inferiorly. The lateral, side-rail configuration of these wires
allows for caval centering and stabilizing. The low-profile filter can be deployed from femoral, jugular, or antecubital routes, and the low-profile design uses a cartridge
injection system to properly orient the filter for femoral
or jugular uses.
26.6.5 Simon Nitinol filter
e conguration of the lter uses a conical array of six
struts with hooks at the base, and a daisy-wheel conguration of wires at the lter apex, in eect providing two levels
of ltration. e lter daisy wheel has seven overlapping
loops. e lter is manufactured from Nitinol (an alloy of
nickel and titanium), which has unique thermal–mechanical memory properties that allow the lter to exist in the
straightened but exible form at room temperatures (<27°C)
within the 7-Fr delivery carrier and reform into a predetermined designed lter shape at body temperatures. e lter
is designed for IVC diameters of 28 mm and smaller. e
lter can be deployed from femoral, jugular, or antecubital
routes.
26.6.6 TrapEase filter
e TrapEase lter is a signicant departure from the conical design introduced by Greeneld. It has a double-basket
symmetric conguration with cephalad and caudad baskets in a six-diamond or trapezoidal shape and the baskets
are then connected by six straight struts, which contain
proximal and distal hooks for xation within the IVC. e
lter can be inserted by femoral, jugular, or antecubital
approaches. e TrapEase IVC lter can be used in patients
with IVC diameters of 30 mm and smaller. Recent data suggest that the TrapEase—and by association the retrievable
version of this lter, the OptEase—may be associated with
an excessive rate of IVC thrombosis.
26.6.7 Bird’s nest filter
is lter consists of four stainless steel wires (25 cm long
by 0.18 mm) attached to two V-shaped struts. e V-shaped
struts have small barbs at the two ends to engage the IVC
wall. During insertion, the four wires are extruded from
the delivery system in a random distribution, simulating
a bird’s nest. e lter is approximately 7 cm long but, in
practice, the deployed length varies by the amount of overlap of the “V” struts. It can be placed in IVCs with diameters
as large as 40 mm. It can be placed by femoral or jugular
routes. e lter generates the largest magnetic resonance
imaging artifact of all the lter devices because of the stainless steel construction.
26.6.8 Optional retrievable filters
With optional retrievable IVC lters, the delivery system is
completely removed and the venous system is re-accessed
at a later date for retrieval of the lter if desired. e rst
retrievable lter to become commercially available was
the Amplatz device, but this lter was removed from the
market due to a high rate of IVC occlusion. Table 26.4 lists
the commercially available retrievable IVC lters available
in the United States. e time of retrieval for these lters
varies with device, and there are multiple case reports of
lter retrieval several months to years aer placement. In
general, retrieval of lters must be performed as soon aer
placement as clinically possible, because endothelialization
of lter struts to the IVC wall has been described to occur as
soon as 12 days aer lter placement.
35
26.6.9 Günther Tulip filter
is lter consists of four main struts congured as a cross
with 1-mm-long hooks at the inferior end for IVC xation. Each strut has an elongated wire loop that extends
inferiorly three-quarters of the length from the apex to
the hooked end of the four main cross struts. e lter is
30 mm in diameter and 50 mm long in the fully expanded
state. Whereas the lter can be placed from either femoral or jugular access sites, retrieval is performed from
the right jugular site with use of a retrieval snare and an
11-Fr sheath. It is recommended by the manufacturer that
the lter removal is done within 14days of implantation,
but “conventional wisdom” suggests that removal out to 8
weeks is possible. Data suggest that the Günther Tulip may
be safely removed at 30 days with minimal, if any, complications,
been reported.
36
and removal out to 126 days aer placement has
37
26.6.10 Celect
e Celect is a cobalt–chromium lter that also consists of
four main hooked struts for IVC xation, as well as eight
shorter secondary legs that provide additional outward support. e lter has a maximum diameter of 30 mm and is
45 mm long when deployed. It may be delivered via a jugular or femoral approach with a 7-Fr sheath, and retrieved
using a looped snare through an 11-Fr sheath.
332 Indications, techniques, and results of inferior vena cava filters
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Table 26.4 Retrievable inferior vena cava filters
Delivery
Year
Name Manufacturer
Gunther
Tulip
G2 Bard 2000 7.0 Fr Nitinol Compatible 60 days Currently
OptEase Cordis 2003 6.0 Fr Nitinol Compatible 23 days Approved
Cook 1992 (available
introduced
in the U.S.
since 2001)
26.6.11 Recovery filter/Generation
2 filter/G2X/Meridian filter/
Eclipse/Denali
e Bard series of retrievable lters started with the
Recovery Nitinol lter, which was the rst lter to have a
retrieval indication in the United States. e Recovery
Nitinol lter was subsequently replaced by the Generation 2
system
size Material
8.5 Fr Elgiloy Compatible 14 days Approved
26.6.12 Option
e Option is an over-the-wire Nitinol lter that consists of
six hooked struts for caval xation. is is the lowest-prole
lter currently available and utilizes a 5-Fr sheath that has
an outer diameter of 6.5 Fr. e Option also has an optional
100-cm delivery sheath, and is the only IVC lter approved
for popliteal access.
Magnetic
resonance
compatibility
Recommended
time for
retrieval
FDA approval
for retrievable
use
permanent
use only
(G2), which was later renamed the G2X. Both the Recovery
and the G2 lters have two levels of ltration, similar to
26.6.13 ALN
the Simon Nitinol lter. ese lters have six arms and six
legs (upper and lower ltering elements, respectively). e
Recovery lter was retrieved from the right jugular vein
approach with a retrieval cone that was fabricated from nine
metal claws covered with urethane material. e G2 lter
was modied by increasing its resting diameter, changing
the angulation of the wires forming the upper ltering elements, and changing the metallic composition of the hooks
attached to the lower ltering elements. Both the recovery
and G2 lters were reported to have high rates of strut fac-
e ALN is a cone-shaped lter with three long, curvilinear centering struts and six shorter anchoring struts with
curved hooks for xation. e struts are all variable in
length to prevent entanglement when loaded in the 7-Fr
delivery sheath. e ALN lter is approved for use in caval
diameters of up to 32 mm, and is available with or without
a hook on the lter base for retrieval. e hooked system
can be retrieved with a looped snare, while a pincer retrieval
system is used for the non-hooked lter.
ture. One study noted that strut fracture occurred in 25% of
Recovery lters and 12% of G2 lters, potentially leading to
26.6.14 OptEase filter
severe complications, including ventricular tachycardia and
tamponade.38 Both the Recovery and G2 lters were eventually removed from the market. Subsequent design changes
led to the Eclipse, Meridian, and nally the Denali lters.
Only the Eclipse and Denali are presently available for use
in theUnited States. e Eclipse lter consists of 12 Nitinol
wires originating from a central hooked nitinol ring. e
two sets of legs provide two levels of ltration, with the
longer legs providing xation and the shorter legs providing stabilization. e lter can be deployed via a jugular or
femoral approach in IVC diameters of up to 28 mm using
a 7-Fr sheath. e Denali is a Nitinol lter consisting of 12
legs with two levels of ltration, much like the Eclipse. is
e OptEase lter has a dual cone (symmetrical) design that
is nearly identical to the TrapEase. e OptEase lter has
been modied with the placement of unidirectional barbs
and an apical hook for removal, and can be inserted from
jugular or femoral routes with the same 6-Fr introducer
sheath (by reorienting the lter). is lter is retrieved from
the femoral vein only by snaring a small hook at the caudal end of the lter. Notably, in 2013, the Food and Drug
Administration (FDA) issued a class I recall on OptEase lters due to confusion with the labeling of the lter and to
avoid loading the lter backward. ere were no problems
with the device itself.
lter has two longer anchors and four midsized legs with
hooks and anchors that provide the rst level of ltration.
An additional six shorter legs stabilize the lter and provide
a second level of ltration. e lter comes preloaded in a
storage tube with a pusher. e delivery system uses an 8.4Fr sheath and can be deployed in an IVC with a maximum
diameter of 28 mm.
26.6.15 Crux
e Crux lter also varies signicantly from the traditional
conical lter design. e Crux is composed of a Nitinol
frame made of two sinusoidal wave forms connected
at the ends. When deployed, the lter forms a partially
26.8 Permanent or optionally retrievable? 333
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sandwiched gure of 8 within the IVC. One loop contains
a webbed expanded polytetrauoroethylene (ePTFE) mesh
to trap emboli. ere are ve tissue anchors along the outer
frame that secure the lter in place. ere are retrieval tails
at either end of the lter, so that bidirectional retrieval can
be performed.
26.7 TEMPORARY FILTERS
Temporary lters, by denition, remain attached to the
delivery system. is facilitates retrieval, but the external
portion increases the risk of infection. Temporary lters
are not clinically available in the United States and are
associated with poor outcomes in small European stud-
39,40
ies.
Two of the earliest caval interruption devices were
designed for temporary use. ese include the Eichelter
sieve and the Moser balloon. ese were soon abandoned
in response to concern regarding the fate of trapped
embolus.
4
26.8 PERMANENT OR OPTIONALLY
RETRIEVABLE?
e development of optional retrieval devices was largely
driven by the results of the Prévention du Risque d’Embolie
Pulmonaire par Interruption Cave (PREPIC) trial. e
PREPIC trial was the rst of only two randomized controlled trials involving IVC lters. e study was a multiinstitutional trial of 400 patients with conrmed acute
proximal DVT that were randomized to receive either
anticoagulation alone or anticoagulation and a permanent
IVC lter. e initial 2-year results from the PREPIC found
that at 12 days there were two PEs (1.1%) in the lter group
compared to nine (4.8%) in the no-lter group (P = 0.03),
resulting in an odds ratio (OR) of 0.22 (95% CI: 0.05–0.90).
Aer 2 years, there were six PEs in the lter group compared to 12 in the no-lter group (P = 0.16). e overall
incidence of recurrent DVT in the lter group was 20.8%
compared to 11.6% in the no-lter group (P = 0.02), for an
OR of 1.87 (95% CI: 1.10–3.20), although there was no signicant dierence in recurrent DVT at 1 year aer enroll-
41
ment.
e 8-year follow-up of the PREPIC trial found nine
PEs (6.2%) in the lter group compared to 24 (15.1%) in
the no-lter group (P = 0.008), resulting in an OR of 0.37
(95% CI: 0.17–0.79). Recurrent DVT occurred in 35.7% in
the lter group, compared to 27.4% in the no-lter group
(P = 0.042). At 8 years, there was no signicant dierence
in mortality between the lter and no-lter groups, and no
signicant dierence in incidence of post-thrombotic syndrome.42 e results from PREPIC study suggested that IVC
lters provide a reduction in risk of the development of PE
when combined with anticoagulation, but no improvement
in mortality. Furthermore, the benet in terms of reduced
risk of PE comes at the expense of an increased risk of recurrent DVT, although this did not translate to a higher risk of
post-thrombotic syndrome.
While the PREPIC trial was heralded as the rst randomized controlled trial to explore the benets of IVC lter use
in patients with DVT, the study had several notable aws in
its design and analysis. First, study participants were randomized using a 2 × 2 factorial design, so individuals were
randomized to receive either enoxaparin or unfractionated
heparin in addition to either an IVC lter or no lter. With
enrollment of 400 patients, the study was underpowered for
43
such an analysis.
Additionally, the PREPIC trial evaluated
IVC lters only in patients who were concomitantly receiving anticoagulation, thus the population in which lters are
most frequently deployed (patients who cannot be anticoagulated) was not examined.44 Finally, the selection of the
lter device was le up to the discretion of the physician,
such that four dierent lter types were used in the trial.45
Despite these weaknesses, the PREPIC study highlighted
the fact that permanent IVC lter placement carries certain
risks that could potentially be avoided with lter removal.
Expanding on the results of the PREPIC trial, the recently
published PREPIC2 trial focused only on optional retrievable lters utilized over a narrow therapeutic window. In
this study, 398 patients were randomized to receive either
6 months of anticoagulation alone or anticoagulation and
an IVC lter. ose randomized to the lter group had the
lter removed aer 3 months, and then received an additional 6 months of anticoagulation. At 3 months, there was
no signicant dierence in incidence of PE (3% with lter
vs. 1.5% with no lter, P = 0.50), and at 6 months, there was
no signicant dierence in mortality, PE, or recurrent DVT
between the two groups.46 e authors concluded that the
use of retrievable IVC lters in addition to anticoagulation
oers no benet over anticoagulation alone.
e PREPIC2 study design was improved over the original PREPIC trial in that anticoagulation and lter type were
standardized. However, the trial again failed to address the
potential benet of IVC lters in the population for which
they are most frequently utilized: patients with VTE who
cannot be anticoagulated. Furthermore, the study was not
designed to address the issue of whether lter retrieval
oered improved morbidity and fewer complications over
permanent lter placement, since there was no study arm
that included permanent lter placement. Additionally,
the 6-month study period was not long enough to provide
sucient data for evaluating rates of recurrent DVT aer
retrieval, thus nothing can be inferred from the data regarding the incidence of recurrent DVT at this time.
e retrospective data available comparing permanent
and optionally retrievable devices is equivocal at best. A
cohort study of 702 patients found similar rates of recurrent
PE in patients who received both permanent and optionally retrievable lters, suggesting that both types of lters
are similarly eective. While no dierence in incidence of
recurrent DVT was noted, the mean follow-up in this study
was only 11.5 months, and only 15.5% of the optionally
retrievable group had the lters removed.
47
While option-
ally retrievable devices likely oer protection from PE that
334 Indications, techniques, and results of inferior vena cava filters
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is similar to permanent lters, it is unclear whether early
retrieval oers any improvement in complication rate. In
fact, there is some concern that optionally retrievable lters may be prone to higher device failure rates. In 2010,
the FDA released a safety communication stating that from
2005 to 2010, over 900 adverse event reports were received,
including IVC perforation, lter migration, lter fracture,
and component embolization. e FDA statement, which
was updated in 2014, recommended removal of retrievable
lters as soon protection from PE is no longer required. A
subsequent analysis of the FDA Manufacturer and User
Facility Device Experience (MAUDE) database supported
this statement, noting a signicantly higher number of
adverse events reported for retrievable lters compared to
permanent lters from 2009 to 2012.
48
In summary, optionally retrievable lters oer similar
benets to permanent lters and in general are associated
with low morbidity. e selection of a permanent or an
optionally retrievable lter should be considered on a caseby-case basis. Given the concern for a higher device failure
rate, patients who receive an optionally retrievable device
should have appropriate follow-up and the lters should
be removed as soon as safely allowable. Optionally retrievable lters should only be considered in certain populations, including younger patients, patients with temporary
contraindications to anticoagulation, and for prophylactic
indications.
26.9 TECHNIQUES OF IVC
FILTERPLACEMENT
Placement techniques for each of the lters dier, and the
most appropriate step-by-step guide for placement can be
found in the operator’s instructions provided by the manufacturers. ese directions should be reviewed prior to
placement and followed carefully to ensure the safety of
the patient. e usual steps involved in percutaneous lter
placement are described in Table 26.5.
26.9.1 Venous access
e choice depends on the patency of the vein access site
and sometimes operator preference. e right common
femoral vein is the most common access site and aords a
relatively straight course to the IVC. is is the preferred
access site unless there is evidence of clot in the right femoral or iliac veins. e right jugular vein is another common
access site through which most of the available lters can
be deployed. Le femoral, jugular, antecubital, and more
recently popliteal veins have all been used depending on the
anatomy and type of the lter that is planned to be deployed.
Placement of IVC lters through the le femoral and jugular approaches have been associated with a greater incidence
of lter “tilt” with respect to the course of the IVC. Filters
with low-prole delivery systems such as the TrapEase and
Simon Nitinol lters (6 Fr) can be placed via the antecubital
Table 26.5 Steps involved in radiological inferior vena
cava filter placement
1. Pre-procedural evaluation:
• Review indication and risk versus benefits of
inferior vena cava (IVC) filter placement, including
needed
• Review available duplex ultrasound/computed
tomography/magnetic resonance imaging to
evaluate presence of IVC, iliac, or femoral vein
thrombus
• Evaluate coagulation status
2. Preparation for filter placement:
• Choose access based on the above evaluation
• Perform inferior venacavogram; evaluate for IVC
thrombus; identify level of renal veins; measure IVC
diameter; detect venous anomalies
3. Choose appropriate filter and deploy according to
operator’s instructions provided by the manufacturer
4. Perform post-deployment radiographs
5. Follow-up recommendations
vein.49 Alternative access sites have been described and are
limited only by the surgeon’s or interventionist’s ingenuity. For example, the authors have placed Simon Nitinol lters through the right greater saphenous vein in morbidly
obese patients, and Günther Tulip lters through a brachial
approach with success in patients with bilateral femoral and
jugular thrombosis.
26.9.2 Inferior venacavogram
Either iodine-based contrast or carbon dioxide is used
to obtain a venogram via a marking pigtail catheter
(Figure 26.3). A venacavogram is used to identify venous
anomalies, measure caval diameter, exclude thrombus in
the IVC, and identify the level of the renal veins. e opacication of the renal veins may be enhanced by the Valsalva
maneuver. Except for bird’s nest and the VenaTech lowprole lters, most of the commercially available lters are
recommended for IVC diameters of 30 mm or less. When
placing a lter in a patient with a megacava, two options for
treatment exist: placement of a bird’s nest or other lter type
that is approved for a large vena cava, or placement of bilateral common iliac vein lters with devices that are approved
for a vena cava of 28 mm in diameter or less.
ree major venous anomalies are of particular interest when placing an IVC lter. ese are duplication of the
IVC, circumaortic le renal vein, and le-sided IVC. ese
anomalies must be assessed prior to placing an IVC lter.
Duplication of the IVC is seen in 0.2%–3.8% of the population and occurs due to persistence of both right and le
cardinal veins. e cavae may be of equal size, although the
right cava is usually larger. e le cava joins the right at
26.9 Techniques of IVC filterplacement 335
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(a) (b) (c)
Figure 26.3 Inferior venacavogram performed prior to
inferior vena cava filter placement showing normal caliber
of the inferior vena cava and location of renal veins.
Inferior venacavogram using iodinated contrast media
b)
in digital subtraction mode and with bone landmarks to
facilitate inferior vena cava filter placement.
venacavogram using carbon dioxide as the contrast
medium in a patient with renal insufficiency.
(c) Inferior
(a and
the level of the le renal vein. is IVC variant can be safely
excluded if contrast lls the le iliac vein on cavogram. If
the le iliac vein is not seen on venogram and the le renal
vein appears prominent, then a duplicated IVC should be
actively ruled out prior to lter placement. If a duplicated
cava is identied, then two options exist: two lters may
be placed in both cavae or a suprarenal lter can be placed.
Circumaortic renal vein occurs in 8.7% of the population,
and the posterior component of the le renal vein is usually lower than the anterior one. e lter should be placed
below the entry of all renal vein branches. Le-sided IVC is
rare, with a prevalence of 0.2%–0.5%. e le cava crosses
at the level of the renal vein to the right side, and the lter is
deployed in the infrarenal location in such patients.
26.9.3 Intravascular ultrasound and
transabdominal duplex ultrasoundguided placement of IVC filters
Bedside placement of IVC lters by using either transabdominal duplex or intravascular ultrasound (IVUS) guidance has been shown to be safe and eective.
techniques are preferred and are especially useful in critically ill patients, those who are pregnant, those who have
a contraindication to iodinated contrast media and CO2 is
not available, or those who exceed the safe weight limits of
standard radiographic equipment.
50, 51
ese
placement. Important ndings to be noted on pre-procedural ultrasound include IVC diameter, absence of venous
thrombosis, absence of venous anomalies, and the patency
of the intended femoral vein access site. e IVC must be
adequately visualized at the renal vein junction in both
the transverse and the longitudinal axes. Identication
oftheright renal vein is critical because this usually represents the lowest renal vein. If venous anomalies or iliofemoral venous thrombosis is suspected, contrast venography
is preferred to more precisely dene the venous anatomy
before lter placement.
e procedure is usually performed under local anesthesia. e femoral vein access is obtained and a 0.035-inch
guidewire is advanced into the IVC. e lter introducer
sheath is advanced over this wire to just above the renal
vein conuence. e guidewire is removed to enable adequate visualization of the tip of the delivery catheter. e
lowest renal vein/IVC junction is visualized transversely
as the lter delivery catheter and sheath are slowly pulled
back. When the tip of the lter delivery catheter disappears
from the ultrasound view, the intended deployment position has been reached. is is visualized on longitudinal
view, and under direct visualization, the lter is deployed.
Full deployment is conrmed with dedicated duplex imaging and plain abdominal radiographs.
26.9.5 IVUS technique
Under local anesthesia, femoral vein access is obtained and a
9-Fr (longer than 25 cm) sheath is placed into the IVC over a
0.035-inch guidewire. An IVUS probe (15 MHz) is inserted
over the guidewire to the level of the right atrium. With
pullback technique, the level of renal veins, caval diameter,
caval anomalies, caval thrombosis, and conuence of the
iliac veins are identied. If the conuence of iliac veins is
not clear, contralateral femoral vein access is obtained and
IVUS is performed again to identify the above venous landmarks. Single or dual venous access techniques can be used
for lter placement.
In the dual venous access technique, the IVUS probe
is positioned just below the renal veins. Filter deployment
is performed through a separate venous access, preferably through the contralateral femoral vein to reduce the
incidence of access site thrombosis by dual puncture at a
single common femoral vein. e lter delivery catheter
and sheath are inserted to a level above the renal veins and
pulled back to just below the renal veins. Correct placement
is then conrmed by IVUS. Once the position is conrmed,
the IVUS probe is pulled back and the lter is deployed.
In the single-vein, single-puncture technique, the IVUS
26.9.4 Transabdominal duplex
ultrasoundtechnique
Transabdominal duplex ultrasonography is performed
to determine the technical feasibility of bedside lter
length of the IVUS probe is then premeasured against the
length of the lter delivery catheter that corresponds to the
position of the lter delivery catheter when fully loaded in
the sheath. Measurement guides on the IVUS probe mark
this distance. e IVUS probe is then inserted into the
336 Indications, techniques, and results of inferior vena cava filters
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sheath up to this premeasured length, which represents the
distance that the lter delivery catheter extends beyond the
length of the sheath. e IVUS probe and sheath are pulled
back together to a level just below the lowest renal vein as
visualized by IVUS. In this regard, IVUS is guiding sheath
positioning, which, because of the premeasured length, indirectly guides the intended lter position. Finally, the IVUS
probe is removed, the lter delivery catheter is loaded into
the sheath, and the IVC lter is deployed. Post-procedure
abdominal X-rays are obtained to conrm the placement,
position, and alignment of the lter.
26.10 FOLLOW-UP OF IVC FILTERS
Patients with vena caval lters should undergo follow-up on
an annual basis until removed if retrievable, and indenitely
if permanent. e purpose of the examination is to evaluate
the mechanical stability of the lter. In addition, the condition of the lower extremities is evaluated to monitor the
ongoing risk for recurrent thrombosis. Because so many of
these devices are placed by radiologists, it is important that
the information about the lter placement is passed along
to the patient’s local physician so that arrangements for the
appropriate studies can be made.
Patients with optionally retrievable lters placed for
temporary risk of PE should be followed more rigorously.
Although the recommended retrieval window varies by
device, the FDA issued a safety statement in 2010 and again
in 2014 recommending that retrievable lters be removed
as soon as protection from PE is no longer required. ese
patients should be reassessed at 1–3-month intervals aer
lter deployment to determine whether ongoing protection
from PE is warranted. A standardized surveillance program
is highly recommended, as patients are otherwise much less
likely to have the lter removed when appropriate.
Traditionally, follow-up aer IVC lter placement has
included physical examination of the lower extremities to
observe for edema, hyperpigmentation, skin ulceration,
and other signs of post-thrombotic syndrome. In the past,
anteroposterior and lateral radiographs of the lter were
obtained at intervals and compared to previous studies for
IVC lter follow-up to demonstrate the mechanical stability and physical integrity of the device. is practice is
currently controversial as the long-term complications of
established IVC lters are low. Newer lters, with fewer
long-term data on fracture and migration rates, may be candidates for this more rigorous follow-up until these issues
are rmly resolved.
Emergent follow-up should be obtained if the patient
develops new bilateral lower extremity edema. Should this
occur, a duplex scan of the vena cava is performed to look
for thrombus in the lter or IVC. If the results of the ultrasound study are indeterminate, the patient should undergo
a venacavogram to evaluate for caval obstruction. If occlusion is documented and felt to be of recent origin (less than 7
days), and the patient’s medical condition allows, thrombolytic therapy may be attempted in order to treat the current
52,53
symptoms and prevent later post-thrombotic syndrome.
Patients who present with signs or symptoms of PE should
also undergo venacavogram to determine the patency of the
lter and the presence of trapped or propagating emboli.
Rare propagation of thrombus above the level of the lter
may be an indication for a second (suprarenal) lter rather
than thrombolytic therapy.
26.11 COMPLICATIONS OF IVC FILTERS
Complications of IVC lter placement include those related
directly to the procedure for placement or removal, and
those related to the length of time the lter stays inside the
IVC.54 e incidence of complications varies and depends
not only on lter type, but more importantly on the methods used to assess complications and the duration of followup. Table 26.6 lists the common complications associated
with IVC lter placement. Fortunately, most of the complications associated with IVC lters are minor or infrequent.
Access site thrombosis is the most common complication.
With newer, smaller-sized delivery systems, the incidence
of occlusive thrombosis of the access vein is low (2%–10%),
although a non-occlusive femoral vein thrombus is seen
more oen (25%). IVC thrombosis is a serious and potentially fatal complication requiring emergent diagnosis and
treatment. rombus may extend above the level of the
lter, causing major PE and necessitating placement of an
additional lter in the suprarenal IVC. IVC thrombosis
may also cause phlegmasia cerulea dolens, a limb-threatening condition. While small clot burden may be treated
with anticoagulation, large to complete caval thrombosis
causing symptoms may need thrombolysis or stent placement in the IVC to restore patency and treat associated
phlegmasia.
Table 26.6 Complications of inferior vena cava filter
placement
Incidence
Complication
1. Procedure-related complications:
• Puncture site complications: bleeding,
infection, thrombosis, or air embolism
• Delivery system complications: filter
malposition, tilting, or incomplete
opening
• Inferior vena cava wall penetration
• Death
2. Filter migration to renal vein, heart, or
pulmonary artery
3. Filter fracture <1
4. New or worsened deep venous
thrombosis
5. Inferior vena cava thrombosis 6–30
6. Recurrent/fatal pulmonary embolism 2–5
7. Venous insufficiency 10–30
(%)
4–11
3–69
6–30
26.12 Comparison of performance between IVC filters 337
SIEMENS
https://t.me/med1917
05.10.12–12:14:60-D...
10/12/2005
12:22:16 PM
VF7-3
VENOUS
7fps
THI/3.3 MHz
2dB/DR65
MapG/VEO
RS4/SC3
VEL/3.3 MHz
Flow Gen
–11dB/P2
PRF867/F2
PW/3.3 MHz
72dB/DR55
MapE/F47Hz
PRF1563
GS2.0/60°
21 mm
60°
ART_
RT
PARK LENOX SURGICAL P. C.
SUBCL CHRONIC THROMBUS
LSH
4 cm
7fps
Fr424
10
cm/s
20
cm/s
–20
10
Figure 26.4 Results of experimental thromboembolism to the bird’s nest, Simon Nitinol, and VenaTech filters in sheep,
allowing sufficient time (30 days) for thrombus resolution. All filters show fibrous webbing.
Minor degrees of lter migration are of little concern.
However, lter migration to the heart or pulmonary artery
may be fatal due to the development of associated arrhythmias, acute myocardial infarction, pericardial tamponade,
and cardiac valvular injury. Percutaneous retrieval or repo-
shown the ecacy of lters in the prevention of PE, irrespective of the lter design.
60
Five major reports of objectively documented Greeneld lter patient outcomes have
been published.
61–65
e follow-up included abdominal
radiographs to determine the position of the lter and either
sitioning can be performed in these situations in an attempt
to avoid emergent thoracotomy.
26.12 COMPARISON OF PERFORMANCE
BETWEEN IVC FILTERS
Despite large numbers of clinical studies describing the
eectiveness and safety of IVC lters, there are no studies
that prospectively compare dierent lter designs. ere is a
misconception that because the published data for vena caval
lters are similar, thus they are equivalent. Outcomes from
in vivo animal studies demonstrated that this is not true.
Figure 26.4 shows that thrombus resolution in the bird’s
nest, Simon Nitinol, and VenaTech lters results in heavy
layers of brin webbing, while Figure 26.5 demonstrates the
absence of webbing associated with the stainless steel and
titanium Greeneld lters and an investigational device.
Comparing dierent designs is dicult due to variations
in the populations studied, evaluation criteria, associated
treatments, and the types and durations of follow-up.
55–57
erefore, several guidelines have been published concern-
58,59
ing reporting standards for lters.
Meta-analyses have
Figure 26.5 Results of experimental thromboembolism
to the experimental filter, the percutaneous stainless
steel Greenfield filter, and the titanium Greenfield filter in
sheep with the same protocol as in Figure 26.4. All filters
were clear of any residual fibrous tissue.
338 Indications, techniques, and results of inferior vena cava filters
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Table 26.7 Performance of different inferior vena cava filters
Mean
follow-up
Filter Number
Stainless-steel Greenfield 3184 18 2.6 5.9 3.6 19
Titanium Greenfield 511 5.8 3.1 22.7 6.5 14.4
Stainless steel over-the-wire
Greenfield
Simon Nitinol 319 16.9 3.8 8.9 7.7 12.9
Bird’s nest 1426 14.2 2.9 6 3.9 14
VenaTech/LGM 1050 12 3.4 32 11.2 41
Low-profile VenaTech 30 2.3 0 10.3 0 Not reported
TrapEase 65 6 0 45.7 2.8 Not reported
Gunther Tulip 83 4.5 3.6 Not reported 9.6 Not reported
Source: Angel LF etal. J Vasc Interv Radiol 2011;22(11):1522–30.e3; Hann CL and Streiff MB. Blood Rev 2005;19(4):179–202.
599 26 2.6 7.3 1.7 2
(months)
venographic or ultrasound studies to determine the patency
Recurrent
pulmonary
embolism (%)
26.14 CONCLUSION
Deep venous
thrombosis
(%)
Inferior
venacava
thrombosis (%)
Post-
phlebitic
syndrome
of the lter. In addition, reports on subgroups of patients
have also been published.
66,67
ese reports have covered 27
years of experience with the stainless steel and the titanium
Greeneld lters. In all, the patency rate has remained at
96% and the rate of recurrent PE has been between 3% and
5%.4 e comparative ecacies and complications of dierent IVC lters are detailed in Table 26.7.
Vena caval lters provide protection against PE without the
signicant morbidity and mortality associated with surgical interruption. ey are intended for use in patients who
are at risk of PE, but for whom anticoagulation is contraindicated or thought to be insucient. IVC lter placement
is a technically straightforward and safe procedure with an
associated low morbidity and mortality. Multiple studies
26.13 SUPRARENAL IVC AND SUPERIOR
VENACAVA FILTERS
Indications for suprarenal IVC lter placement are listed
in Table 26.8. e ecacy and safety of Greeneld lters
placed in a suprarenal position appear similar to those of
lters placed conventionally in an infrarenal location.
e role of a superior vena cava (SVC) lter in preventing
PE is controversial. A few reports have described the benets
of such lter placement.
71–74
SVC thrombosis and guidewire entrapment during central line placement are potential
complications of SVC lter placement. One recent systematic review reported serious, life-threatening complications
(including SVC perforations, cardiac tamponade, aortic perforation, and recurrent pneumothorax) in 3.8% of SVC lters
deployed. e rates of PE and associated mortality in patients
with upper extremity DVT were 5.6% and 0.7%, respec-
75
erefore, the risks associated with SVC lter place-
tively.
ment may outweigh any potential benets in PE prevention.
6,6 8–70
have demonstrated the ecacy of lters for preventing PE,
although rarely IVC lters may cause progression or recurrence of DVT in lower extremities and IVC thrombosis.
e rates of these complications are device specic, and it
is important for physicians placing IVC lters to be familiar with the thrombosis, migration, and complication rates
associated with the lter chosen for placement. ere has
been a recent surge in the placement of retrievable lters for
the prophylaxis of PE in patients with time-limited contraindications to anticoagulation. e patient benet associated with this practice is largely theoretical and needs to be
objectively studied. e type of lter used should be tailored
to each patient, with particular attention to the indication
and the long-term results associated with the IVC lter chosen. e recent increase in the use of retrievable IVC lters
is notable, and additional studies are required to document
their safety and ecacy.
As improved techniques for the delivery of these devices,
and new materials and designs, are developed, it is essential to keep in focus the indications and appropriate uses
Table 26.8 Indications for suprarenal inferior vena cava
filter placement
of these devices, including retrievable lters. Rather than
focusing on the dierences between the various devices
(which will sort themselves out over time), the major eort
• Renal vein or infrarenal vena cava or ovarian vein
thrombosis
• During pregnancy or in women anticipating pregnancy
• Thrombus propagating proximal to a previously
placed filter in an infrarenal location
Source: Caplin DM et al. J Vasc Interv Radiol 2011;22(11):
1499–506.
ought to be directed toward identifying those patients who
are at highest risk of signicant PE. Eorts must also continue to be directed toward improving methods of thromboprophylaxis, since no lter can inuence the development
or course of the underlying disorder. is is clearly a case in
which a well-planned oense is the best defense against this
unnecessary source of morbidity and mortality.
References 339
https://t.me/med1917
Guidelines 3.10.0 of the American Venous Forum on the indications, techniques, and results of inferior vena cava filters
Grade of evidence
(A: high quality;
B:moderate
quality; C: low or
very low quality)
No. Guideline
3.10.1 We recommend placement of inferior vena cava (IVC) filters: in
Grade of
recommendation
(1: strong;
2:weak)
1 A
patients with deep venous thrombosis (DVT) and/or pulmonary
embolism (PE) and a baseline contraindication to anticoagulation;
in patients who suffer a complication from anticoagulation; in
patients who develop recurrent DVT or PE despite adequate
anticoagulation; and in patients who previously have had a massive
PE and cannot tolerate further cardiopulmonary insult that would
be associated with an additional PE.
3.10.2 We suggest placement of an IVC filter in patients with a free-floating
2 B
thrombus greater than 5 cm in length within an iliac vein or the IVC.
3.10.3 We suggest prophylactic filters to patients if their associated medical
2 B
conditions (malignancy or traumatic injuries) predispose them to
DVT or PE.
3.10.4 We suggest caution in special situations prior to filter placement for
2 C
patients with untreated or uncontrolled bacteremia, pediatric
patients, and pregnant women, due to the uncertain long-term
effects and durability of the filters.
3.10.5 We suggest bedside placement of IVC filters by using either
2 B
transabdominal duplex or intravascular ultrasound guidance. Both
have been shown to be safe and effective.
3.10.6 We suggest performing additional studies to document the safety
2 B
and efficacy of the placement of retrievable filters in patients with
time-limited contraindications to anticoagulation.
3.10.7 We suggest follow-up examination annually for patients with vena
2 B
caval filters to evaluate the mechanical stability of the filter. In
addition, the condition of the lower extremities is to be evaluated
in order to monitor the ongoing risk for recurrent thrombosis.
REFERENCES
●
= Key primary paper
★
= Major review article
◆
= Guideline
1. Homans J. Thrombosis of the deep veins of the
lower leg, causing pulmonary embolism. N Engl J
Med 1934;211(22):993–7.
2. Collins CG and Nelson EW. Ligation of the vena
cava; a critical evaluation based on a study of 22
cases. New Orleans Med Surg J 1947;99(10):488–96.
3. Homans J. Diseases of the veins. N Engl J Med
194 6 ; 2 3 5 (5):163 – 7.
4. Greenfield LJ and Wakefield TW. Prevention of
venous thrombosis and pulmonary embolism. Adv
Surg 1989;22:301–23.
5. Mansour M, Chang AE, and Sindelar WF. Interruption
of the inferior vena cava for the prevention of recurrent pulmonary embolism. Am Surg 1985;51(7):375–80.
6. Greenfield LJ, Proctor MC, and Fischer DFJ.
Suprarenal filter placement. J Vasc Surg 1998;28(3):
432–8.
7. Duszak R, Parker L, Levin DC, and Rao VM. Placement
and removal of inferior vena cava filters: National
trends in the Medicare population. J Am Coll Radiol
2011;8(7):483–9.
◆
8. Kearon C, Akl EA, Comerota AJ etal. Antithrombotic
therapy for VTE disease: Antithrombotic Therapy
and Prevention of Thrombosis, 9th ed: American
College of Chest Physicians evidence-based clinical
practice guidelines. Chest 2012;141(2 Suppl.):
419–96.
◆
9. Jaff MR, McMurtry MS, Archer SL etal.
Managementof massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary
hypertension: Ascientific statement from
the american heart association. Circulation
2011;123(16):178 8 – 3 0.
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