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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3733_Библиотеки_им_академика_М_И_Перельмана.pdf
can be cut through them for femoral access. Others are leather binders, which
may have to be undone before obtaining access. Most pelvic embolizations
can be performed via a single common femoral artery access site. If there is
known unilateral pelvic or lower extremity injury, contralateral femoral
access is preferred. If injuries or external devices preclude the preferred
femoral access, the procedure can be performed via a brachial or even
popliteal or radial artery access. More recently, dual access has been
advocated to allow placement of a temporary occlusion balloon within the
infrarenal abdominal aorta while pelvic or lower extremity hemorrhage is
treated.
7,11
We advocate the use of ultrasound guidance for all arterial
punctures. When used routinely, it adds little time to the procedure and
avoids the complications encountered with suboptimal access (e.g.,
retroperitoneal hematoma or arteriovenous fistula). This is especially
important when dealing with hemorrhagic shock, as these patients already
have little cardiovascular reserve and may not tolerate iatrogenic injury
superimposed on traumatic injury. Ultrasound guidance also increases the
likelihood that a closure device can be successfully used at the end of the
procedure.
Often in the acute setting, renal function has not yet been assessed, and
the risk of contrast nephropathy becomes a secondary concern. In a patient
with known renal insufficiency, nonselective and selective pelvic and lower
extremity angiography may be performed with carbon dioxide (CO2).
The procedure should start with nonselective angiography to quickly
localize sites of hemorrhage and serves as a road map for vessel selection.
Additionally, the initial imaging is useful in differentiating traumatic injury
from guidewire-induced vasospasm. Fractures should prompt selective
angiography at potential sites of vascular injury. For instance, the superior
gluteal artery is the most commonly injured vessel with a posterior fracture
pattern, and this is typically injured as it passes under the sciatic notch. It is
commonly injured with open book fractures.
19
Appropriate angiographic imaging of the internal iliac artery requires
orthogonal selective views. The anterior division is best imaged with a
contralateral oblique view of approximately 45 degrees. This can be thought
of as looking at the iliac wing en face. An ipsilateral anterior oblique view is
important to identify the superior gluteal artery and the internal pudendal
artery. It should be stressed that, although initial nonselective pelvic
angiogram is an important part of pelvic or extremity evaluation, selective
angiography is crucial to achieving appropriate angiographic sensitivity.
Hemorrhage from pelvic trauma is most often associated with the
internal iliac artery, but some have advocated that a selective angiogram of
the external iliac artery should also be obtained.41 Although the external iliac
artery is not usually a source of pelvic hemorrhage, the external pudendal,
deep iliac circumflex, inferior epigastric, and the circumflex femoral arteries
may be injured.
1,3,42
The more inferior lumbar arteries as well as the inferior
mesenteric or even the gonadal arteries are other rare sources of pelvic
bleeding.
Following completion of contralateral pelvic vessel evaluation, selection
of the ipsilateral common iliac artery should be obtained with a reverse curve
catheter or a tightly curved catheter such as the Rim catheter
(AngioDynamics, Latham, New York). Imaging of the bilateral iliac vessels
should always be obtained. This avoids continued hemorrhage resulting from
reperfusion of the injured vessel via anastomoses with the contralateral pelvic
arteries. It also rules out additional injury, which may have been occult on
initial CT imaging.
Pelvic Embolotherapy
The decision to embolize should be based on angiographic findings of vessel
injury but not limited to active extravasation. This aggressive approach may
even include embolization of potential sources of hemorrhage identified on
CT. Less selective or nonselective internal iliac embolization is
recommended by some if the patient is hemodynamically unstable or if
multiple sites of active extravasation are identified. Nonselective
embolization of the internal iliac arteries is performed with the injection of
Gelfoam, often followed by coils with the tip positioned in the internal iliac
artery. Nonselective embolization is probably not appropriate for most pelvic
trauma and is not appropriate for the profunda artery given the risk of
ischemia. At the very least, CT will usually direct the operator to
nonselectively embolize either the anterior or posterior division of the
internal iliac artery.
Gelfoam, widely considered the workhorse of trauma embolotherapy, is
a temporary agent that allows for potential recanalization within a few weeks.
This may allow for reclaimed tissue perfusion once the acute injury has had
time to heal. It is also inexpensive and readily available. Gelfoam is typically
delivered as slurry. This is mixed in a three-way stopcock with a half-strength
mixture of contrast and normal saline. More agitation will create a Gelfoam
mixture that is less coarse. If the target of embolization with Gelfoam is
distal, the Gelfoam mixture should be kept coarse. This achieves hemostasis
through occlusion proximal to the end capillary bed, thereby mitigating
against the complication of tissue necrosis.
6,43
Gelfoam can also be delivered
in the form of 2- to 3-mm pledgets termed torpedoes. This is achieved by
front-loading a 2- to 3-mm piece of Gelfoam into the tip of a 1-mL syringe of
half-strength contrast. The torpedoes may be soaked in contrast before
injection. This can be used to achieve occlusion of larger caliber vessels and
may reduce the risk of ischemia. The delivery of Gelfoam should be followed
with a contrast injection after every few 0.1- to 0.3-mL injections of slurry or
every few torpedoes, with the goal of sluggish flow and not complete stasis
of contrast.
19,29
This technique helps limit reflux of embolic agents into other
branches.
The administration of Gelfoam into internal iliac artery branches is
typically followed by selective branch occlusion with coils (Fig. 24.2). The
theory is that the coils prevent very early recanalization of the vessel but are
proximal enough to not cause ischemia. The problem with coils is that they
may block access to bleeding vessels if repeat embolization is needed. If a 4Fr or 5-Fr catheter has been advanced to the target vessel, then 0.035-in coils
such as a Nester or Tornado (Cook Medical, Inc., Bloomington, Indiana) can
be used. These 0.035-in coils have Dacron fibers to promote thrombogenesis.
The 0.035-in coils should be pushed and not injected. Superselective
catheterization of the target vessel is typically accomplished with a 0.021-in
lumen 3-Fr microcatheter (e.g., Cantata; Cook Medical, Inc., Bloomington,
Indiana). A high-flow microcatheter, which typically has a 0.025-in lumen,
such as the Progreat Omega (Terumo Medical Corporation, Somerset, New
Jersey), provides the ability to perform rapid power injection. The slightly
larger inner lumen introduces concerns with compatibility of 0.018-in
microcoils (e.g., Nester or Tornado) with high-flow microcatheters because
coils can fold over and become wedged within larger lumen microcatheters.
This will potentially make arterial branch access difficult for the operator to
obtain.
Microcoils can be deployed conventionally by using a pushing wire such
as the TruPush (Cordis Corporation, Bridgewater, New Jersey). Microcoils
can also be injected, which may expedite the procedure, but the safety of this
technique requires a stable delivery location (i.e., not close to the origin of the
vessel) and low risk of refluxing Gelfoam.
The proximity of the microcatheter to the vessel origin during
embolization influences the choice of embolization materials. If the catheter
is near the origin of the accessed vessel, detachable coils (e.g., the Axiom
Concerto coil; Covidien, Irvine, California), although often more expensive,
may be considered to help prevent herniation of the coil into the parent
vessel.
Attempts should always be made to advance the microcatheter distal to
the site of injury. This allows for coils first to be deployed distal to the injury,
followed by Gelfoam, and then additional coils proximally (the so-called
Gelfoam sandwich technique) (Fig. 24.3). Gelfoam, or in very select
circumstances glue or Onyx, and proximal coils without distal coiling can be
used if the lesion cannot be crossed. If a traumatic pseudoaneurysm begins
expanding subsequent to proximal coiling, endovascular treatment options
are limited to percutaneous embolization of the additional branches that are
backfilling the pseudoaneurysm. Coils should not be used directly within a
traumatic pseudoaneurysm sac due to the potential for rupture as well as
reexpansion.18 However, if the anatomy of the pseudoaneurysm allows,
coiling can be performed across the neck of a pseudoaneurysm.
Traumatic arteriovenous fistula may occur when a vein and artery are
injured simultaneously, either in the pelvis or extremities. Angiographically,
this is appreciated as abnormal early venous return concurrent with the
opacification of the arteries. Treatment is similar to pseudoaneurysms, with
distal and proximal coil embolization of the artery, but rarely, treatment may
require access through both the arterial and venous systems. Although coils
can be used in this situation, there is a risk of coil migration in the venous
system and subsequent migration centrally. Other options include exclusion
of the fistulous connection with an arterial stent graft or use of an Amplatzer
Vascular Plug.44 The Amplatzer Vascular Plug can be particularly useful for
the treatment of AVF because of its low risk of migration. The Amplatzer 4
device has a 5-Fr delivery profile. It is the authors’ opinion that the use of
detachable coils with simultaneous balloon occlusion of venous outflow
carries a risk of massive coil migration when the balloon is deflated.
Extremity Embolotherapy
Preprocedural assessment with CT may be obtained but is not necessarily
commonplace. CTA of the extremity and runoff vessels is reliably sensitive
for evaluation of traumatic vascular injury and can be obtained with a single
contrast bolus used for concurrent CT imaging of the chest, abdomen, and
pelvis.
Although the upper and lower extremities do not differ significantly in
terms of the specific methods of treatment, a few differences bear
mentioning. First, a double flush technique should be used whenever the
catheter is proximal to the cerebral circulation, including the vertebral and
thyrocervical trunk. This is accomplished by first aspirating the catheter with
a 20-mL syringe hooked up to a stopcock and then using a second 20-mL
syringe to make an additional aspiration of a few milliliters. The catheter is
then flushed with the second 20-mL syringe, with the stopcock turned off
while actively injecting to prevent any blood accumulation in the catheter tip.
Second, CO2 should not be used during evaluation of the upper extremity due
to the risk of reflux in the cerebral vasculature.
The distal anastomoses of the radial and ulnar arteries via the deep and
superficial palmar arches can allow embolization of an upper extremity
runoff vessel. Although this is a rare clinical situation where surgical options
are usually preferred, perfusion of the hand can be maintained if either the
radial artery or ulnar artery is sacrificed so long as the palmar arches are
sufficient. Patency of the palmar arches and collateral circulation (with Allen
test) should be confirmed on physical exam as well as with angiography
before intervention. If the distal anastomoses are satisfactory, embolotherapy,
such as with the Gelfoam sandwich technique, can be undertaken within the
radial or ulnar artery for the purpose of treating traumatic injury. Coil
occlusion distal to site of hemorrhage is critical to prevent Gelfoam
embolization to the digits. A single runoff vessel to the lower extremity may
be sacrificed in a similar fashion so long as the other two runoff vessels are
patent and there are no confounding factors such as multifocal flow-limiting
stenoses in the setting of peripheral vascular disease.
Angiographic evaluation should begin with nonselective angiography
through a sidehole catheter positioned within the aortic arch for the upper
extremity or within the infrarenal abdominal aorta for the lower extremity.
Subsequent angiographic evaluation should then be obtained in the proximal
vessel, either the axillary artery or external iliac artery. As with the pelvis,
initial diagnostic angiographic imaging should be carefully scrutinized for the
presence of variant anatomy, vascular injury in areas predicted by
preprocedure imaging, and also for potential additional sites of injury, which
may have been occult on initial imaging or physical examination. Selective
angiography is typically obtained with the use of a glidewire and an angletipped catheter such as a Kumpe catheter (AngioDynamics, Latham, New
York). A Headhunter catheter (AngioDynamics, Latham, New York) is often
used in the selection of the upper extremity.
Trauma is complicated by decreased cardiac output, hypovolemia, and
vasospasm, but paradoxically, the injection rate and volume of contrast
within the extremity may need to be increased over what is normally used.
Slow flow may indicate vascular injury and vasospasm or, in the lower leg,
raise suspicion for compartment syndrome.
Large vessel injury, such as the brachial artery, even if diagnosed
angiographically, may be preferentially treated surgically depending on the
institution. Endovascular treatment within the larger vessels is typically
limited to stent graft placement. The use of stent grafts for the purpose of
excluding the focal site of traumatic injury is being used more frequently.
36
Embolotherapy of side branches near or in the site of injury may be required
to prevent endoleak.
The branches of the profunda femoral arteries, muscular branches, and
geniculate arteries are an ideal application of embolotherapy for trauma
within the extremity.18 Treatment here can often be accomplished without
compromising perfusion of the treated extremity. The endovascular treatment
of traumatic injury within the extremity is approached in much the same way
as treatment within the pelvis, but with careful attention to primary or
accidental embolization of the runoff vessels.
Following embolization, the success of the procedure should be assessed
with both postembolization angiography and examination of the extremities.
Any change in the peripheral vascular exam should be further interrogated,
with possible angiography of the involved limb. Routine postprocedure care
includes keeping the accessed extremity steady, which can sometimes be
challenging in a patient going to the operating room or suffering
disorientation.
DEVICE AND MATERIALS
• Nonselective multi-sidehole catheters: Pigtail (AngioDynamics, Latham,
New York) or Sos-Omni (AngioDynamics, Latham, New York)
• Selective catheters: Cobra (AngioDynamics, Latham, New York),
multipurpose (AngioDynamics, Latham, New York), Bernestein
(AngioDynamics, Latham, New York), JB1 (AngioDynamics, Latham,
New York), or Headhunter for the upper extremity; Cobra, multipurpose,
Bernestein, Rim, Kumpe, or Sos-Omni for the lower extremity
• Microcatheters: Cantata, Renegade (Boston Scientific Corporation, Natick,
Massachusetts), high-flow Renegade, Direxion (Boston Scientific
Corporation, Natick, Massachusetts), Progreat, Progreat Omega, Prowler
(Cordis Corporation, Bridgewater, New Jersey)
• Embolization materials: Gelfoam in slurry or torpedo form (Gelfoam
particles are not used), Nester coils and microcoils, Tornado coils and
microcoils, Amplatzer occlusion devices
POTENTIAL COMPLICATIONS
Rebleeding after pelvic TAE should be considered the most important
adverse event because it occurs in 15% to 20% of patients and is associated
with mortality increasing from 15% to 30%.2 Predictors of recurrent pelvic
arterial hemorrhage include hemoglobin less than 7.5 g/dL before the
procedure, more than 6 units of packed red blood cells (PRBCs) after the
procedure, or a superselective embolization.2 This last predictor of rebleeding
is contrary to the authors’ opinion on the advantages of superselective
embolization.2 Injured vessels may be in vasospasm or otherwise go
undetected during angiography. These missed arterial injuries can manifest as
delayed hemorrhage after resuscitation restores intravascular volume.
Vasospasm or delayed migration/packing of Gelfoam may also contribute to
rebleeding. We continue to advocate superselective embolization but also
recommend aggressive embolization of occluded vessels, which may be due
to traumatic thrombosis or vasospasm. Leaving the vascular sheath in place
should also be considered when there is concern the embolization is
incomplete or the patient still needs resuscitation.
Complication directly related to embolization is tissue ischemia within
the treatment vascular bed or other territories secondary to nontarget
embolization. This uncommon complication is manifested in pelvic
embolizations as gluteal muscle necrosis, sacral skin breakdown, ischemic
necrosis of the bladder wall and rectum, or necrosis of the femoral
head.
42
,43,45–47
Nerve injury following TAE for trauma has been reported, but
shear injury from the trauma itself rather than procedure-related ischemic
changes may account for many of these reported pelvic TAE complications.
42
Impotence in the male patient is likewise usually considered a consequence
of the initial traumatic injury rather than nerve injury caused by pelvic
TAE.
48,49
Because of the possibility of inducing tissue necrosis, selective
embolization should be performed if the patient’s hemodynamic status
permits, and the patient should be adequately observed for signs of ischemic
changes in the days that follow. Long-term follow-up is also required as
buttock claudication may be associated with pelvic TAE but not be observed
until patient is well into rehabilitation exercises.
50
The most important step in reducing the risk of tissue ischemia is the
appropriate choice of embolic agent. This should be small enough to
effectively occlude the site of bleeding but large enough to avoid the terminal
capillary bed. The use of nonpermanent embolic agents (Gelfoam) may
potentially aid in reducing the risk of tissue necrosis by allowing for
recanalization of the vessel over the course of a few weeks.
Nontarget embolization most often occurs when the rate of embolization
is too fast and embolic material refluxes proximal to the catheter tip.
Anastomotic vessels not appreciated on angiography can also contribute to
nontarget embolization. Nontarget embolization of unintended pelvic vessels
is typically well tolerated secondary to pelvic collateral vessels. In contrast,
embolic material introduced into the outflow vessels of the extremity, or used