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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3733_Библиотеки_им_академика_М_И_Перельмана.pdf
Access to celiac trunk is performed with 4-Fr or 5-Fr support catheter,
usually a Cobra C2 or a Simmons 1 or 2. If possible, direct catheterization
and DSA of splenic artery should be performed first to save time and
contrast. A vascular lesion might appear as a PA, AVF, contrast
extravasation, artery transection, or splenic parenchymal deformation by
hematoma. Number, topography, and accessibility of lesions are assessed to
determine indication for proximal and/or distal splenic artery embolization
(see the section “Clinical Applications”). A 3-Fr or smaller microcatheter is
coaxially inserted to access embolization chosen site selectively. Splenic
artery diameter usually measures 7 to 8 mm, so proximal embolization of the
main splenic artery should be performed with 10- to 12-mm diameter coils.
Attention should be paid that hypovolemic patients have spastic arteries,
which can lead to underestimation of true lumen diameter. The superior polar
splenic artery can have a proximal origin and should be checked for
hemorrhage. Coils should be deployed between dorsal and magna pancreatic
arteries to keep collateral flow to spleen. Anchoring of the first coil in a small
branch is useful to avoid coil migration. The first coil must be long enough
(usually 10 to 14 cm long) to build a solid frame before packing with smaller
coils. The end point is stagnation of contrast upstream in splenic artery. For
distal embolization of the splenic artery, a 3-Fr or smaller microcatheter is
positioned as close as possible to the target lesion. PA should ideally be
embolized “front door and back door” with embolic material (coils or NBCA)
covering its neck. As intrasplenic collaterals are not numerous, if
catheterization of the “back door” is not possible, embolization of the “front
door” artery is often efficient and enough, especially if liquid embolic agent
such as glue is selected. Catheterization of the PA itself should be avoided to
minimize rupture risk. AVF are usually embolized with coils positioned in
the fistula or just proximal to it. Care should be taken to avoid coil migration
in venous flow. Active hemorrhage should embolized with coils, NBCA, or
Gelfoam. For multiple lesions in the same splenic segment, segmental artery
embolization with NBCA, gelfoam slurry, or coils is indicated. For lesions
that are in different segments, superselective embolization can be performed
if time and access are granted; otherwise, proximal embolization is efficient
(Fig. 26.3). PVA particles should usually be avoided as they may cause
profound parenchymal ischemia.
Iatrogenic Pulmonary Lesions
Because they are usually self-limiting, hemorrhagic complication of lung
biopsies are often treated conservatively. To avoid filling of the airways with
blood, patients presenting with hemoptysis after lung biopsy should be laid
on the punctured side. Close monitoring of blood oxygen level should be
performed as the main risk for these patients is suffocation. If blood oxygen
level drops, cleaning of the airways with rigid fibroscopy should be
performed promptly. Pulmonary artery PA from Swan-Ganz insertion or
RFA can be treated by coil embolization from a venous peripheral puncture.
CLINICAL APPLICATIONS
Iatrogenic Vascular Access Lesions
Patient-related risk factors for vascular complications are hypertension,
female gender, emergency procedures, high bifurcation of femoral artery, and
anticoagulation. Technical risk factors are left groin puncture, method of
puncture, arterial entry site, size of sheath, anticoagulation, and use of closure
device.
11,63–65
Hematoma of the groin is usually self-limiting. Small
hematomas are frequent, but in up to 2.8% of patients, blood transfusion or
invasive treatment is required.65 Clinically, immediate or delayed
tumefaction appears around the arterial puncture site and increases the
diameter of the thigh. Rarely, hematoma is hard to control even with manual
compression. US or angio-CT is needed to exclude PA.
Pseudoaneurysm
PAs are seen in 1.2% to 8% of femoral punctures.
63
,66
Clinical manifestation
is a palpable, painful, pulsatile, or thrilling mass, which can grow over time.
Complications related to PA are rupture, distal embolization of thrombus,
infection, skin necrosis, and nerve and vessel compression.67 Diagnosis is
confirmed with Doppler US.11 In symptomatic patients, PA must be treated
quickly. But in asymptomatic patients, it has been shown that most PAs less
than 1.8 cm diameter spontaneously thrombose in less than 2 months.
68,69
PA
bigger than 1.8 cm and PA in anticoagulated patients, regardless of the size,
must be treated.
68,69
Due to its noninvasiveness, US-guided compression is
considered as the first-line treatment. US-guided thrombin injection can be a
valuable adjunct to US-guided compression (see “Tips and Tricks”) and has a
success rate of 90% to 100%.2 However, surgery remains indicated in case of
failure of other techniques.
Arteriovenous Fistulas
AVF between the femoral artery and vein is seen in less than 1% of inguinal
punctures.
63,64
The risk increases with low femoral artery puncture. AVFs are
rarely symptomatic, but they can present with high-output cardiac failure,
limb edema, claudication, or aneurysmal dilatation of femoral and iliac artery
and veins. Diagnosis is confirmed by Doppler US.11 AVF should be treated
because they tend to increase with time and can cause complications such as
venous hypertension in the affected limb or high-output cardiac failure.
2
They are usually treated by US-guided compression as first-line treatment.
Covered stent placement and surgical repair are options in case of failure.
There is concern about long-term patency of those stents and their resistance
in a flexure point such as the groin, so this option might be interesting in
older patients and in patients with contraindication to surgery, but surgical
repair is preferred for younger patients.
Retroperitoneal Hemorrhage
Retroperitoneal hemorrhage occurs generally when arterial puncture is
performed above the inguinal ligament. This complication can be lifethreatening as there is no exteriorization of blood. Clinical signs (tachycardia,
hypotension, abdominal pain, confusion, agitation) might appear only late
after intervention. Incidence is low, less than 1% of femoral punctures.
Noncontrast CT must be performed to make diagnosis and guide treatment.
11
Retroperitoneal bleeding is usually self-limited, but in some cases, such
as in patients with toubled coagulation status, it should be treated if size of
hematoma is increasing.
Iatrogenic Renal Lesions
Clinical manifestations are related to hemodynamic consequences of blood
loss and urinary obstruction: hematuria, flank pain, and hypovolemia. AVF
can also lead to progressive renal failure or to new or uncontrollable
hypertension as a consequence of blood steal and relative ischemia of renal
parenchyma. Cardiac failure caused by high-flow shunting is also
possible.
70,71
These symptoms may be delayed for years after an
intervention.
72,73
Lesion types are artery transection with active bleeding, PA,
arteriocalyceal fistula, AVF, or an association of these.23 Superselective
embolization is the treatment of choice. The procedure is safe and effective,
with a technical success rate of over 90% and clinical success rate over
80%.
20,22,23,74–79
Surgery remains indicated in case of failure of endovascular
treatment. The right timing for embolization is unclear. Hemorrhage is
usually self-limiting. For mildly symptomatic, stable, and well-responding
transfused patients, it is acceptable to wait 72 hours after intervention before
going to embolization. For persisting or uncontrollable hematuria,
retroperitoneal hemorrhage, deteriorating renal function, and unstable
patients, emergency embolization is required.
74,76,80
CT with contrast and US
can categorize lesion types and help to plan embolization but are not
mandatory before angiography. The approach is different in asymptomatic
patients. Some older series with a limited number of patients have reported a
spontaneous closure of AVF up to 75% and of PA up to 100% a few weeks
postintervention.
81–84
The risk of spontaneous enlargement and rupture of
AVF and PA, and the fact that TAE is a safe procedure, should make this
technique the first-line treatment in the management of these types of
lesions.
74
Iatrogenic Liver Lesions
Clinical manifestations include hemobilia, systemic hypotension,
gastrointestinal bleeding, and perihepatic hematoma.
1,8
Hemobilia has 94%
positive predictive value for arterial injury1 and is the most frequent clinical
sign, but its classic triad of abdominal pain, jaundice, and gastrointestinal
bleeding is present in only 22% of patients.6 Clinical presentation may be
delayed from days to months after intervention, but approximately 80% of
vascular complications are discovered within 2 weeks after an intervention.
8
At laboratory, arterial injuries should be suspected particularly if there is a
5% decrease of hematocrit level or abnormality/worsening of the hepatic tests
after the intervention.
1,48
It should also be noted that a large proportion of
vascular injuries may remain clinically silent.
6,45
TAE is currently the
treatment of choice for these lesions, with a technical and clinical success rate
of 75% to 100%.
8,10,42,48,85–87
Surgery remains available in cases of failure of
TAE, but has a higher morbidity and mortality. Embolization in transplanted
liver and after pancreatico-biliary operation should be evaluated very
carefully as liver are and particularly bile ducts become very sensitive to
ischemia, as they are primarily vascularized by hepatic arteries.
48
Angiographic findings are active bleeding, PA, APF, AHF (rare),
arteriobiliary fistula, and nonspecific lesions.45 Complex injuries are defined
by a mix of more than one lesion type.88 Symptomatic APF requires
embolization. Estimation of the hemodynamic consequences of the fistula
with Doppler US should be made.
43,48
A significant shunt is defined by a low
arterial resistive index (RI) or a drop of RI ≥ 0.10 compared to previous
examinations and by reversal of flow in portal vein or first-order branch, with
or without arterialization of spectral flow.
43,48
Angiography confirms
presence and estimates shunt during intervention. APF is considered
significant if contrast flows back to portal vein or first-order branch.
44,49
In
conclusion, in asymptomatic patients with large and hemodynamically
significant APF, embolization is required, whereas in others, surveillance is
probably enough.
43,44,48,49
Hepatic artery PAs have a reported rupture rate
50
as high as 76% and a mortality rate of 16% to 43%.
50,89
In consequence,
treatment is required regardless of symptomatology. However, in
transplanted liver and after pancreatico-biliary surgery if PA is small,
asymptomatic, and nonevoluting, a conservative attitude may be indicated.
43
Arteriobiliary fistulas are managed as PA.
Iatrogenic Spleen Lesions
Splenic TAE has a high technical success rate close to 100% and a high
clinical success rate of around 91.1%.12 The natural evolution of splenic PA
is unclear. It appears that an unknown proportion of PA spontaneously
thromboses.
51,90,91
As PAs have a high rupture and mortality risk,
recommendation is embolization of all PA independently of
symptomatology.51 The spontaneous evolution of AVFs is also unclear. It
seems logical to embolize them, unless they are present for a long time and
are asymptomatic.
Regardless the lesion types, proximal embolization of the splenic artery
is indicated when the splenic artery is too tortuous to allow
microcatheterization of the spleen, when bleeding is diffuse or multifocal, or
when hemodynamic instability is severe and time is lacking. Distal
embolization is indicated when bleeding is unifocal or paucifocal.92 After
proximal TAE of the splenic artery, the spleen remains vascularized through
short gastric, gastroepiploic, and pancreatic collaterals, but pressure in the
splenic artery is reduced by a factor of 2, allowing coagulation to occur
naturally.
93–95
COMPLICATIONS
Iatrogenic Vascular Access Lesions
Thrombus leakage during thrombin percutaneous injection through PA neck
with distal nontarget embolization is a known complication. So, in lesions
with wide neck, a balloon can be used to cover the PA neck during thrombin
injection (see the section “Clinical Applications”). In case of AVF,
embolization material may flow directly to the right atrium and lungs or even
the left atrium in case of patent foramen ovale. This is why US-guided
compression, surgical repair, and, in selected patients, covered-stent
placement is preferred when neck is wide. Stent graft deformation and
fracture can occur if deployed in flexure points. Care should also be taken
before stent graft deployment because of risk of occlusion of unwanted
vessels (typically deep femoral artery).
2
Iatrogenic Renal Lesions
Ischemic parenchymal territory after embolization is estimated from less than
50% in older series23 to less than 10% in recent ones.76 Moreover, there is a
partial reperfusion of the ischemic territory after some time due to collateral
vascular supply.
20,76
Studies have failed to demonstrate any effect of
embolization on worsening of renal function and blood
pressure.
20,21,74,75,77–79,96,97
Other complications are nontarget embolization,
coil migration, artery dissection, thrombosis, postembolization syndrome,
abdominal compartment syndrome, and renal abscess.
98
Iatrogenic Liver Lesions
Usually, the complication rate after TAE in the liver is low because of the
dual vascularization of liver by portal vein and hepatic artery. Moreover,
intraparenchymal arterial collaterals are opening immediately after
embolization.99 So, in the native liver, parenchymal necrosis is rare,
occurring only in 4.2% of patients after TAE.8 Transitory ischemia of liver
parenchyma is reflected by transient increase of liver enzymes and explains
part of the postembolization syndrome, which is seen in 20% of patients.
3,8,42
Patients who have undergone pancreatic, biliary, or hepatic surgery or liver
transplantation, as well as those with underlying liver disease, have a higher
risk of liver necrosis and failure.
100
Embolization is contraindicated in
patients with portal vein thrombosis because of the risk of ischemia.44 As the
bile ducts are vascularized by the hepatic artery, ischemia after TAE may
lead to wall necrosis with stenosis or fistulas. As consequence, there is an
increased risk of biloma, cholangitis, hepatic abscess, or peritonitis.5 A small
series shows 6.7% hepatic abscess formation after TAE for hepatic arterial
injuries.87 Nontarget embolization may lead to gallbladder, pancreas, or
spleen ischemia or inflammation.
Celiac trunk and hepatic artery dissection with or without occlusion may
occur, especially in patients with arcuate ligament syndrome and
fibromuscular dysplasia, both infrequent entities.
Iatrogenic Spleen Lesions
Postembolization syndrome occurs in 30% of patients with fever, abdominal
pain, slowed transit, and sometimes pancreatitis.
101
Other complications such
as abscess formation, spleen infarction, and abnormal fluid collections are
seen in 3.8% to 7%, 10% to 43%, and 43% of patients, respectively.
12,102–104
TIPS AND TRICKS
Minimally Invasive Treatment of Vascular Access Complications
• US-guided compression of PA: The probe is positioned over the neck
of the PA and a pressure is applied until flow disappearance inside the
PA. Pressure is maintained until complete thrombosis. This method is
not invasive and has few complications but also has drawbacks. It
takes time as the compression should be applied during at least 20–30
min and can be very painful; the failure rate is between 30% and 40%
in anticoagulated patients.
105
Strong analgesia with intravenous
opioids should be considered.
• Direct percutaneous thrombin injection: Under US guidance, a small-
diameter needle (19–21 gauge) is inserted in the PA and positioned at
its center. Color Doppler US should show the needle tip in the part of
the PA with blood flowing away from the neck to minimize
thromboembolic risks. 500–1,000 International Units of thrombin
should be injected in small pushes. This dose is usually enough to
completely embolize the PA. If the PA is multiloculated,
embolization should begin with the farthest loculus from PA neck.
The coagulation status of the patient does not seem to affect thrombin
injection efficacy. The risk of thrombin leakage in the femoral artery
and distal embolization is low.
106
To protect the limb from distal
thromboembolic event, in PAs with large and short neck or complex
PA, an occlusion balloon can be inserted from a contralateral arterial
access. It should be inflated to occlude the neck of the PA during
thrombin injection.
107
The balloon should stay inflated for 10–15 min
afterward. US Doppler should be used to confirm disappearance of
flow in the aneurysm before and after thrombin injection. Neck width
larger than 3 mm in diameter has been proposed as the minimal
diameter for this technique (Fig. 26.4).
108
Renal and Splenic Pseudoaneurysms
• PA in the renal and splenic vasculature can usually be treated with
proximal embolization only because parenchymal vascularization is
almost terminal with few collaterals.
Arterial Embolization in the Liver
• Before performing embolization in the native liver, care should be
taken to verify permeability of the portal vein and direction of the
portal vein flow because of the risk of ischemia. It is particularly
important in liver to embolize front door and back door vessels
because liver has many intraparenchymal collaterals and there is a
risk of recanalization of lesion.87 Embolization with coils or thrombin
of a PA through a direct percutaneous transhepatic approach has been
described in cases where TAE was not feasible.
109