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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3722_Библиотеки_им_академика_М_И_Перельмана
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Fig. 7.10 Salvage of a
T-stent conguration:
The interstices of the
previously placed
iliocaval stent have been
crossed and dilated,
allowing for extension
of the contralateral stent,
forming the fenestrated,
inverted Y conguration
S. S. Ahmed et al.
4. Access site hematoma: This risk is mitigated
with ultrasound-guided access. Consider
purse string suture for venous access >16 Fr.
7.4 Reconstruction ofChronic
Iliocaval Occlusion
ShinMeiChan and KushDesai
7.4.1 Introduction
Deep venous obstruction is split into nonthrombotic, acute thrombotic, or post-thrombotic
etiologies; patients with the greatest disease
burden have involvement of the inferior vena
cava (IVC) and/or the iliac veins. In patients with
severe chronic venous insufciency presenting
with healed or active venous ulcers, more than
one-third have iliocaval obstructions of at least
50%, with about one-quarter having iliocaval
obstructions of greater than 80% [32]. In this
section, we will describe the clinical
characteristics of iliocaval obstructive disease,
followed by endovascular management.
7.4.2 Etiologies
There are a broad range of etiologies contributing
to iliocaval obstruction. Malignant caval obstructions are uncommon and occur secondary to
masses that compress or rarely invade the IVC or
iliac veins (Fig.7.11). Various cancers can result in
retroperitoneal nodal or direct tumoral involvement that can cause caval obstruction; metastases
from distant sites have been described as well [33].
• Patients may present with symptoms of lower
extremity pain, swelling, skin changes, or
lymphorrhea.
• Endovascular stent placement of unresectable
malignancies often provides immediate relief;
ab
7 Venous Interventions
Fig. 7.11 Malignant
obstruction of the IVC due
to cholangiocarcinoma
(Panel a). Panel (b)
Patency restoration
following deployment of
stents
269
however, recurrence in symptoms due to stent
occlusion or stenosis occurs in more than onethird of patients; thus, intervention should be
• Some degree of PTS develops in up to 50% of
DVT patients [35]; severe PTS, resulting in
ulceration, may occur in up to 10% [36].
considered as largely palliative [33].
• Similarly, retroperitoneal brosis due to therapeutic radiation or inammatory processes
can cause iliocaval obstruction.
Perhaps the most common cause of chronic
iliocaval obstruction, at least in the United
States, is thrombosis secondary to an in situ
IVC lter (Fig. 7.12). While there has been
Thrombotic causes of iliocaval obstruction are
often a result of deep vein thrombosis (DVT) and
subsequent post-thrombotic syndrome (PTS). PTS
increased awareness surrounding long-term
complications of IVC lters, retrieval rates
remain low [37].
results from chronic venous reux and obstruction, combining to result in ambulatory venous
hypertension, a potentially debilitating condition
characterized by edema refractory to compression,
severe pain with extended standing or walking,
permanent skin damage, and stasis ulceration [34].
• The prospective, randomized Prevention du
Risque d’Embolie Pulmonaire par Interruption
Cave (PREPIC) trial demonstrated that
patients who received permanent IVC lters
had a cumulative incidence of recurrent DVT
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S. S. Ahmed et al.
7.4.3 Clinical Presentation of
Iliocaval Disease
Overall, the symptomatology of chronic iliocaval
obstructions varies broadly. Presenting symptoms
of pain or swelling and venous claudication are
the most common, approaching 100% and 81%,
respectively [41].
• The venous CEAP (clinical, etiological, anatomical, pathophysiological) is widely used to
broadly classify lower extremity disease [42].
• The clinical severity score (VCSS) and Villalta
PTS are more precise in scoring disease severity. In a series of 120 patients with IVC thrombosis, 37% presented with class 3
symptomatology, whereas 26% presented
with class 4 and 19% presented with class 6
[43]. Similar distributions have been reported,
with clinical class 3 being the most common
[44, 45].
– In a series of 89 patients with non-
malignant obstructive iliocaval lesions, the
median presenting VCSS score was 9 prior
to stenting [44].
Fig. 7.12 Thrombosis secondary to an in situ lter
of 8.5% at 1year, which increased to 20.8% at
2years and 35.7% at 8years [38, 39].
• More recently, it has been shown that about
2% of indwelling IVC lters may result in
symptomatic iliocaval obstruction. Desai etal.
demonstrated in a study of 1582 lter-bearing
patients that male sex, central neurologic
disease, and implantation time greater than 6
or 12 months were signicantly associated
with IVC thrombosis [40].
• Causes are likely multifactorial. IVC lters
trap thrombus, which may predispose further
propagation. Additionally, the type of lter
may play a role due to geometric variability
resulting in differential ow dynamics and
subsequent clot entrapment. Lastly, there may
be inherent thrombogenicity of the lter itself
as a foreign object.
7.4.4 Endovascular Management of
Chronic Iliocaval Occlusion
Venous stent placement was rst described in the
late 1980s to address low patency rates following
surgical bypass [46]. Since then, it has been
recognized that stent placement is safe and can
lead to signicant improvement in symptoms
[47–49]. Despite common practice, the
development of dedicated venous stents has
lagged behind arterial stents, though several
venous-specic designs are now available.
Elgiloy-braided stents have the greatest
breadth of experience for venous obstruction
[50]. Neglén etal. demonstrated that among 982
femoro-iliocaval veins, primary patency was
57% and assisted-primary patency rates were
80% in thrombotic lesions [49]. In a series of 115
patients undergoing bilateral stenting for iliocaval
obstruction, primary patency rates at 4 years
7 Venous Interventions
271
were demonstrated to be 61% using Wallstents
[51].
Contemporary studies have focused on the uti-
lization of dedicated venous stents in the IVC.
• In a series of 59 patients with IVC obstruction, endovascular reconstruction using the
Vici Venous Stent (Veniti, Fremont, CA)
resulted in primary patency rates of 91.2%,
71.0%, and 24.1% at 1, 3, and 5years, respectively [52].
• For patients in this cohort presenting with
PTS, Villalta scores decreased from 14.2 to
8.1 at 1 year follow-up and 6.8 at 2 years
[52].
7.4.5 Pre-procedural Considerations
Successful iliocaval reconstruction is dependent
on thorough imaging review. Duplex ultrasound
is a noninvasive imaging modality that provides
information about the inow, the degree of
obstruction, and the presence of concomitant
supercial venous disease.
• When considering endovascular intervention,
this is crucial to adequately assess the status of
common femoral vein (CFV) inow and
profunda femoris vein to conrm inow
adequacy and ultimately determine whether
stents can be supported.
• Axial imaging, including computed tomographic venography (CTV), is very useful in
assessing the IVC and iliac anatomy, as well
as for the presence of causative factors such as
an IVC lter.
Access sites depend on the extent and ana-
tomic location of vascular disease and should be
selected to ensure that the inow can be fully
assessed during a procedure, and that a stent can
be placed into the CFV should it be signicantly
compromised. Femoral and popliteal vein access
are most common followed by greater saphenous
vein. Internal jugular venous access may be
helpful in the event adjunctive access is
necessary.
7.4.6 Intra-procedural Considerations
Successful venous stent placement requires full
consideration of the natural history of venous
disease, pathophysiologic processes, and the
mechanical properties of veins. Due to the elastic
properties of the vein wall, pre-dilation of longstanding occlusions should be done prior to
deploying a stent to overcome any brous
retraction resulting from chronic post-thrombotic
material [53].
• When more than one stent is deployed along
the vessel, it is necessary to overlap the
stents to ensure a stent separation does not
occur.
– Uncovered portions may result in recurrent
stenosis in that area [51].
• The cranial and caudal ends of the venous
stent should be placed in “healthy” venous
segments, ensuring adequate inow and
outow. Intraprocedurally, intravascular
ultrasound (IVUS) is an adjunct imaging
technique that should be employed to
determine cranial and caudal landing zones.
IVUS is also helpful in determining the size of
the vessel, degree of obstruction, and can also
provide information on the chronicity of clot
based on echogenicity.
For patients that require bilateral stent place-
ment, various techniques may be used including
a “double-barrel” method, inverted Y stenting
(requiring fenestration), and apposition
(Fig.7.13). It has been suggested that the doublebarrel technique results in superior patency rates
and the lowest re-intervention rates [51]. In most
cases, a 14-mm double-barrel stent extending
into single 14mm stents in each iliac vein may be
used.
• Lastly, while placing stents across the inguinal
ligament is controversial in arterial lesions,
venous stents can safely be deployed over this
region; indeed, it is frequently required if
there is an inow/CFV lesion [54].
• When crossing the ligament, a 12-mm stent is
used.
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ab c
S. S. Ahmed et al.
Fig. 7.13 (Panel a) The double-barrel technique involves
the deployment of two parallel stents in the IVC, extending
into the iliac veins. (Panel b) The apposition technique
involves a stent extending into the ipsilateral iliac vein,
7.4.6.1 IVC Filter Management
The presence of an IVC lter in the vessel may
pose a unique challenge as it may be difcult to
retrieve the lter; the predominant approach had
been stent placement across a chronic IVC lter;
this technique is further described below:
• Neglén etal. demonstrated that patency rates
at 54 months are 32% with this technique;
early stent occlusion within 30days occurred
in 12% of patients [55].
More recent data, however, suggests that
removal of the IVC lter whenever possible is
favored. Single-session IVC lter removal,
recanalization, and endovascular reconstruction
has been shown to result in excellent early
patency rates, with 96% of patients maintaining
iliocaval stent patency at 1–3months (Fig.7.14).
• This technique has demonstrated improvement in VCSS edema and pain subscores by
1.4 and 0.6, respectively [56].
• At 1-year follow-up, primary, primaryassisted, and secondary patency by limb is
94%, 96%, and 100%, respectively; at 2
years it is 91%, 95%, and 100%, respectively
[56].
with the contralateral stent deployed with the proximal
end adjacent to the ipsilateral stent. (Panel c) In the
fenestration technique, the contralateral limb penetrates
through the ipsilateral stent
• Thus, antecedent removal of IVC lters prior
to recanalization demonstrates high rates of
durable clinical success and is encouraged
when possible.
7.4.6.2 Stenting Across Filters
In lters that cannot be removed, stenting across
the lter is one approach to treat lter-related IVC
thrombosis. This is done by crossing the obstructed
area with a guidewire, followed by dilating with a
balloon. This either displaces or attens the lter
against the vessel wall to allow for the deployment
of the stent. There are several considerations when
stenting through IVC lters, although most published studies have reported overall feasibility,
safety, and efcacy with this method.
• Neglén etal. published a series suggesting that
primary and secondary patency following IVC
stenting is not inuenced by the presence of
an IVC lter, even at 54 months (32% and
75%, respectively) [55].
• However, there was a signicant association
between patency and the extent of disease
(occlusive vs. non-occlusive) [55].
Reports of retroperitoneal hemorrhage, back
pain, and IVC perforation with stent placement
7 Venous Interventions
ab c
273
Fig. 7.14 (Panel a) Example of extensive IVC thrombus
secondary to a permanent inferior vena cava lter (arrow).
(Panel b) Retrieval of IVC lter using foreign body
retrieval device and photothermal ablation with a 14 Fr
across IVC lters are limited [57]. However,
there are numerous hypothetical risks associated with this method include deformity or
fracture of the lter that theoretically may penetrate the IVC, although this has not been denitively supported by the literature [56]. Another
concern is whether displacement of the lter
impacts patency of the stent by precluding
complete stent expansion [55]. Renal vein
thrombosis is another rare but reported complication [57].
7.4.6.3 Advanced Recanalization
Techniques
In iliocaval occlusions that cannot be traversed
with standard wire/catheter technique, advanced
recanalization techniques including sharp
recanalization and radiofrequency guidewires
may be used.
• There is a risk of damage to adjacent struc-
tures, particularly arteries, and familiarity
excimer laser sheath. (Panel c) Completion venogram
demonstrating restored patency throughout the IVC and
common iliac veins
with the technique, preparedness for intraprocedural complications, correlation with preand intraprocedural imaging are key to
limiting the risk of these procedures.
For sharp recanalization, a balloon or snare
can be placed distal to the occlusion via a separate
access site, to serve as a target. A sheath is
employed close to the occlusion and a needle is
carefully advanced under direct visualization.
• Sharps including the stiff end of a 0.035″
guidewire, straight needles, trans-septal
needles, or Rosch-Uchida needles may be
used [58].
• In a retrospective review of central venous
occlusions, outcomes for sharp recanalization
include a 90–95% technical success rate with
minimal adverse effects (2–3%) [59, 60]. Prior
stenting or length of occlusion is not
signicantly associated with the probability of
technical success [59].
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S. S. Ahmed et al.
– Long-term patency data is further promis-
ing, with 79% of reconstructions remaining
patent following sharp recanalization [59].
RF wires have also been described as another
option for traversing vessel obstructions. The
PowerWire RF Guidewire (Baylis Medical,
Montreal, Quebec) is the most reported in the
literature. RF wires have a technical success of
crossing and resolving the occlusion ranging
from 69 to 100% [61–64].
Post-procedural Management
andPharmacotherapy
There is no consensus on anticoagulation following iliocaval reconstruction of chronic
obstructions. Dual antiplatelet therapy with
clopidogrel and aspirin may be used in the short
term, with indenite use of aspirin [65]. It is
noted, however, that there is a paucity of randomized-controlled data that supports the use of
dual antiplatelet therapy [66–68]. In patients
with extensive occlusions, thrombophilia, and a
history of long-term anticoagulation, warfarin or
direct oral anticoagulants may be efcacious following endovascular treatment. The length of
treatment remains at the providers’ discretion,
although it generally varies between 6 and
12months for patients with a single DVT episode [68]. For all patients, compression stockings should be continued post-operatively along
with continued ambulation and exercise recommendations [66].
7.4.6.4 Conclusion
Iliocaval obstruction can result in severe symptoms secondary to venous stasis and signicantly impact the quality of life. Contemporary
treatment involves endovascular stent placement. Current techniques and devices allow for
relatively immediate symptom relief, although
high rates of re-intervention remain an ongoing
concern. In patients with IVC lters, removal of
the lter is favored and may be associated with
improved patency. In complex recanalizations,
where the obstruction cannot be traversed with
standard technique, advanced techniques using
sharp recanalization or RF wires may be necessary. Robust pre-procedural planning, familiarity with the array of endovascular devices
needed to perform such procedures, and diligent
follow-up are essential to maintaining good
long-term outcomes.
7.5 Surgical Options
JordanC.Tasse
In the current era, surgical approaches to venous
obstructive disease are extremely limited, and
often mostly historically described due to the
growth of endovenous success. Of note, surgical
venous bypass is mostly reserved for possible
fem-fem surgical bypass known as the Palma
procedure, using saphenous vein conduit. Other
options include PTFE and or addition of
arteriovenous stula creation to increase the
venous inow as the low-pressure ow can be
prone to early or recurrent thrombosis.
Interestingly completely percutaneous common femoral to common femoral vein prosthetic
stent graft bypass creation has been performed,
with long-term success. Due to the limited sample size, it is reserved for extreme situations
only and is soon to be published.
7.6 Compression Therapy
GrifnMcnamara, JillianDrogin,
and KeithPereira
7.6.1 Compression Therapy
inWound Care: Why andHow
Compression therapy is essential in the treatment of edema secondary to both venous insufciency and lymphedema. Generally, these
therapies are required for patients with CEAP of
3–6 and patients with symptomatic lymphedema. Though this treatment is relatively
straightforward, providers must consider the
7 Venous Interventions
275
benets and risks of different forms of compression therapies. The minimum tolerable compression pressure tailored to the patient’s
requirement should be ensured to maximize
compliance. The most efcacious therapy is the
one that the patient can tolerate, and time should
be spent counseling patients to ensure compliance with these therapies. This chapter will
focus on the rationale of compression therapy,
available options and their indications, proper
use, and contraindications.
7.6.2 Why Compression Therapy?
Optimal wound care and compression therapy
will heal most small venous ulcers of short duration. There is Level A evidence showing that
venous ulcers heal faster with compression when
compared to no compression [69].
• Compression narrows veins, restores valve
competence, and reduces ambulatory venous
pressure, thus reducing venous reux.
• It alleviates limb edema by decreasing inammatory cytokines, accelerating capillary ow,
and lowering capillary uid leakage.
• It also softens lipodermatosclerosis, improves
lymphatic ow and function, and enhances
brinolysis [70].
• Goals of compression therapy are ulcer healing, reduction of pain and edema, and prevention of recurrence [71].
7.6.3 Types of Compression Therapies
Compression therapies are split into broad categories based on static vs. dynamic and elastic vs.
inelastic.
• Static therapies maintain compression and
shape.
• Dynamic therapies administer intermittent
compression.
• Elastic therapies stretch before applying the
desired pressure.
• Non-elastic is less pliable and often used as
wraps or bandages.
The type of compression therapy for a patient
is dependent on many factors, some of which
include the etiology (Venous vs Lymphedema),
presence of ulcer, and body habitus. Figure7.15
illustrates a owchart of the optimal use of compression therapies.
The most common and efcacious options are
static and elastic garments such as compression
stockings. These are available in numerous
lengths and pressures. Most studies recommend a
pressure of at least 20–30mmHg in patients with
chronic venous insufciency [72–74]. Higher
pressures of 40–50 mmHg may be used in the
treatment of severe chronic venous insufciency,
but 50–60mmHg is typically reserved for patients
with severe lymphedema or burn scars. Variation
in length can be utilized to target disease with
options ranging from knee-high, which is ideal
for most patients, to the top of the thigh which
may be required after venous surgery. However,
these options still have their limitations.
• Patients with severe obesity or edema may not
be able to t into stockings.
• In addition, chronic lipodermatosclerosis may
prevent the stockings from applying pressure
due to subcutaneous brosis and hardening of
the skin.
• When using stockings, it is important to perform ulcer care prior to placement and put
them on before getting out of bed in the
morning when edema is minimal.
Static inelastic stockings such as the Unna
boot, a disposable wrap applied to the lower
extremities, rely on muscle contraction to apply
pressure [75]. Benets of this option include low
price, disposability, ease of application,
antimicrobial properties, and ability to be
changed in patients with draining ulcers [76].
Nonetheless, these options are typically less
effective than elastic bandages as pressure is
dependent on muscle contraction and patients
may require frequent dressing changes [75].
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S. S. Ahmed et al.
Fig. 7.15 Flowchart illustrating the optimal use of compression therapy
7 Venous Interventions
277
Multilayer dressings are static dressings that
combine elastic and inelastic components in up
to four layers. These are the most labor-intensive
dressings but report similar efcacy to compression stockings when used properly [74].
• The base is a protruding padding layer that
ofoads compression from high-pressure
areas such as bony prominences that are sus-
ceptible to developing ischemic changes.
• The next layer, the crepe bandage, is an absor-
bent layer that smooths the padded layer.
• The third layer is an elastic bandage that can
provide signicant pressure with stretch and
overlap [76, 77].
• Finally, a cohesive elastic bandage is placed
for an even greater level of compression.
Together, the layers can add up to 40mmHg
of pressure [76].
Dynamic therapies deliver intermittent pneumatic compression via a compression pump or
sleeve. These are used in patients with lymphedema and to promote brinolysis in patients
with chronic ulcers [78–80]. Pneumatic compression is efcacious for patients with stage 1
lymphedema on the ISL staging scale, while
stage 2 lymphedema requires additional
assistance from healthcare providers to maintain
this efcacy [81]. This option, like the other
therapies, is heavily dependent on patient
compliance [82].
Finally, there are adjustable therapies, e.g.,
Circaid, that are used primarily for lymphedema.
These therapies utilize overlapping and
intertwining straps secured by Velcro. They are
well tolerated and promote good compliance.
Further, compression with adjustable bandages is
more effective at 40 mmHg than 60 mmHg,
highlighting the importance of patient tolerance
and compliance in these therapies [83].
7.6.3.1 Contraindications to
Compression Therapy
Compression stockings are only efcacious in
the treatment of venous ulceration and
lymphedema. Some of the contraindications
include:
1. Arterial ulceration and signicant peripheral
arterial disease (PAD) are absolute
contraindications to compression stocking
use. The recommended ankle-brachial index
(ABI) cutoff for absolute contraindication is
an ABI <0.5, however, careful consideration
must be taken in patients with any level of
PAD [9, 84–86].
(a) For patients with PAD, studies suggest
that up to 40mmHg of compression is
safe if the absolute ankle pressure in
extremities is greater than 60 mmHg
[87].
2. Supercial and deep venous thrombosis, in
patients without current anticoagulation therapy, are contraindications for compression
therapy due to the theoretical risk of dislodged
clots causing a pulmonary embolism.
3. Chronic heart failure with reduced ejection
fraction may be exacerbated by these therapies because of uid volume shifts. A study
that examined the use of inelastic bandages in
patients with heart failure demonstrated that
ejection fraction was further reduced by 72%
when under pressure of 21–30 mmHg and
103% at 31–40mmHg [87].
4. Cellulitis, infection, or skin necrosis are additional contraindications for compression therapy. Conversely, for patients with recurrent
cellulitis, compression therapy may help to
prevent future infections [88].
7.6.3.2 Complications
fromCompression Therapies
Most complications from these therapies stem
from improper use. Skin necrosis may occur
when bandages are applied too tightly, or necessary padding layers are not placed on highpressure areas. Due to the location of these
bandages, fungal infections may occur when
dressings are not changed at proper intervals.
Further, fungal infections are more common in
patients with exudate accumulation, and this factor should be taken into consideration during
wound care planning. Finally, contact dermatitis
may occur from the zinc in Unna boots or the
latex in elastic wraps and the type of bandage
should be changed accordingly.
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