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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3869_Библиотеки_им_академика_М_И_Перельмана.pdf
316 G. Behrens and N.H. Patel
• Stent-graft deployment should be considered in large vessels as a method
to exclude the AVF while maintaining antegrade flow in the native
vessel.
Materials
Catheters and Microcatheters and Guidewires
• As in other chapters for the target organ—liver, kidney, lung.
Embolization Materials
• The best embolization agent to use may be the one with which you are most
familiar!
• There is usually a focal bleeding point which should be targeted as precisely
as possible whenever time allows. Proximal embolizations are generally not
warranted in this patient population.
• Coils and microcoils are often ideal; however, Gelfoam embolization can be
performed if a temporary occlusion is desired.
• In cases where speed is of the essence or the target vessel cannot be selectively
catheterized, consider proximal embolization with the following:
◦ Resorbable gelatin sponge (Gelfoam)
◦ Spherical polyvinyl alcohol particles (255 μ in size or larger) or tris-acryl
gelatin microspheres (300 μ in size or larger)
◦ N butyl cyanoacrylate and other glues
Medications
• Pain control: sedation and analgesia are recommended.
• Infection: prophylactic antibiotics are controversial.
• Hydration: intravenous normal saline.
Complications
• Fatal complications are rare.
• Major complications
◦ Non-target embolization
◦ Ischemia/tissue necrosis (usually asymptomatic)
32 Arterial Embolization Post-percutaneous Biopsy or Drainage 317
◦ Intraprocedural rupture of pseudoaneurysm; embolization needs to proceed
expeditiously
◦ Renal failure secondary to contrast-induced nephropathy
◦ Vascular dissection
• Minor complications
◦ Post-embolization syndrome
◦ Biliary stenosis due to ischemia/necrosis
◦ Groin hematoma
◦ Infection
Specific Organ Systems: Liver Embolization Post-percutaneous
Biopsy/Drainage
General Concept and Definitions
• Severe hemorrhage in the form of hemobilia, hematoma, and/or hemoperitoneum
that requires surgery or embolization is uncommon particularly when ultrasound
or CT guidance is used. The mortality of liver biopsy is 0.01–0.1%
• Bleeding occurs at the puncture sites and can result in subcapsular hematomas,
hemothorax, hemoperitoneum, arteriovenous fistulae, arterial–biliary or venous–
biliary fistulae, and arterial pseudoaneurysm.
• Ninety-six percent of such complications appear in the first 24 h and should be
suspected in any patient with falling blood pressure and rising pulse. If this is a
trend, image early.
• Percutaneous transhepatic biliary drainage (PTBD) carries a 3.7-fold higher risk
of arterial injury than other percutaneous transhepatic procedures.
Anatomy of the Lesion
Hematomas
• Post-biopsy/drainage hematomas and/or bleeding can arise from various
locations:
◦ Intraparenchymal or subcapsular: most common and usually self-limited
◦ Perihepatic or intraperitoneal
◦ Intraductal (hemobilia)
◦ Extra-abdominal (hemothorax) or at the puncture site
• Hematomas can be complex and associated with fistulae or pseudoaneurysms.
• The location of hematoma can help to identify the vessel injured.
318 G. Behrens and N.H. Patel
Arteriovenous, Arterioportal, or Arteriobiliary Fistulae
• Results from wall damage of two adjacent vascular structures or vascular
structure and bile ducts, resulting in abnormal communication.
◦ Arterioportal fistulae (see Chapter 16)
◦ Arteriovenous fistulae (see Chapter 16)
Pseudoaneurysm
• Extrahepatic
◦ Rare and potentially fatal due to severe bleeding when ruptured.
• Intrahepatic
◦ Most common type resulting from hepatic biopsy/drainage
◦ Strongly associated with fistulae and hematomas
◦ Majority of cases are asymptomatic and resolve spontaneously
Bile Leaks
• Primary bile leak after biopsy/drainage is extremely rare.
• Small bile leaks after biopsy/drainage are treated conservatively with hydration.
• Embolization is usually not required.
Specific Indications for Liver Embolization
• Severe active hemobilia on endoscopy
• Pseudoaneurysms
◦ Extrahepatic pseudoaneurysm
◦ More than 10 mm in diameter
◦ Enlarging pseudoaneurysm
• Enlarging perihepatic or subhepatic hematoma
• Arterioportal, arteriovenous, or arteriobiliary fistulae
◦ Increased portal hypertension resulting in bleeding
◦ High-flow shunt resulting in CHF, portal hypertension, or persistent GI bleed
◦ Decreased liver function
Vascular Anatomy
Native Liver
• Anatomical variants are common (see Chapter 33).
• If selective hepatic artery angiography is negative, consider other arterial sources
including diaphragmatic, intercostal, or inferior phrenic arteries.
32 Arterial Embolization Post-percutaneous Biopsy or Drainage 319
Transplanted Livers
• Review of the operative note is recommended to delineate vascular anatomy.
• Post-transplant anatomy includes the following:
◦ End-to-end anastomosis using a branch patch technique
◦ Jump graft directly from the aorta
• Gastroduodenal artery is always absent.
Procedure/Steps
• CT of the abdomen: obtain a CT in hemodynamically stable patients to rule out
intrathoracic or intra-abdominal bleeding.
Embolization
• Coils
◦ In fistulae, the aim is to embolize the actual communication or place coils in
the feeding vessel across the entire site of communication.
◦ In pseudoaneurysms, the aim is to reduce the flow into the sac to per-
mit thrombosis. Coils may be used to fill the sac or the feeding artery
is embolized both proximal and distal to the site of the pseudoaneurysm. PROXIMAL EMBOLIZATION ONLY IS INSUFFICIENT,
SINCE THIS CAN PERMIT RETROGRADE (BACKDOOR)
BLEEDING.
• Gelfoam
◦ Gelfoam slurry
◦ Gelfoam pledgets
• Permanent particulate agents are usually avoided; however, they may become
helpful to obtain distal control of a bleeding vessel that cannot be crossed with
a microcatheter for standard distal coil embolization. Injecting large particles
(>500 microns) proximal to the injured vessel will help in preventing retrograde
(backdoor) bleeding.
• Percutaneous thrombin injection
◦ There are some case reports of direct percutaneous thrombin injection into
large pseudoaneurysm under ultrasound or CT guidance.
Results
• Technical success (blockage of bleeding vessel) rates range from 95 to 100%.
• Clinical success (cessation of bleeding) around 95%.
320 G. Behrens and N.H. Patel
• Liver infarction is rare after superselective embolization, especially in a patient
with normal portal circulation.
• In cases of slow rates of bleeding, especially if venous in origin, tube upsizing
will tamponade and halt the bleeding.
Complications
• Biliary stenosis due to ischemia/necrosis.
• Worsening of liver function.
Renal Embolization Post-percutaneous Biopsy/Drainage
General Concept and Definitions
• The prevalence of vascular complications after renal biopsy/drainage has been
reported between 3 and 5%. However, the rates of major complications are around
1–2% and usually related to bleeding, arteriovenous fistula (AVF), arteriocaliceal
fistula (ACF), or pseudoaneurysm.
• Most of these complications resolve spontaneously.
• Risk of significant bleeding can be decreased with embolization of the track at
the time of the procedure or simple correction of a coagulopathic state.
• Post-biopsy vascular embolization is often considered an emergency, especially
in transplanted kidneys.
Anatomy of the Lesion
Hematomas
• Post-biopsy/drainage hematomas can occur in four anatomic spaces and are as
follows:
◦ Collecting system: resulting in hematuria, possible ureteral obstruction, and
arteriocaliceal fistula.
◦ Intrarenal or subcapsular: resulting in arteriovenous fistula, tamponade, and
pain. In severe cases, hypertension due to subcapsular hematoma compressing
the renal parenchyma (“Page kidney”) can occur.
◦ Perinephric space: hematoma formation and possibly severe hemorrhage.
“Page kidney” can also occur in this space.
◦ Pararenal/extra fascial space: resulting in large retroperitoneal or intraperi-
toneal hematoma.
• Location of hematoma can help to identify the vessel injured.
◦ Intrarenal branch
32 Arterial Embolization Post-percutaneous Biopsy or Drainage 321
◦ Main renal artery
◦ Extrarenal (e.g., lumbar artery) (see fig 32.1, 32.2 and 32.3)
Arteriovenous Fistula (see Chapter 16)
Pseudoaneurysm
• Caused by trauma to an artery, resulting in bleeding that is contained by the
adventitial layer.
• Most post-biopsy/drainage pseudoaneurysms are asymptomatic and resolve
spontaneously.
◦ Decision to treat asymptomatic pseudoaneurysms is controversial due to the
unclear and variable natural history of pseudoaneurysms. However, treatment is recommended for pseudoaneurysms larger than 10 mm or in cases
of persistent hematuria.
Specific Indications for Renal Embolization
• Renal or perirenal hematoma
◦ Severe bleeding
◦ Symtomatic bleeding
◦ Bleeding persisting for more than 72 h
• Pseudoaneurysms
◦ More than 10 mm in diameter
◦ Enlarging pseudoaneurysm
◦ Symptomatic patients
◦ Hematuria for more than 72 h
• Arteriovenous fistula
◦ Persistent AVF for more than 1 month after biopsy/drainage
◦ High-flow shunt resulting in CHF
◦ Decreased renal function
◦ Creatinine elevation
◦ Decreased GFR
• The criteria for embolization in transplant recipients remain unclear.
Vascular Anatomy
Native Kidneys
• Accessory renal arteries (polar arteries) originating from the aorta and iliac
arteries are common.
322 G. Behrens and N.H. Patel
• If selective renal artery angiogram is negative, consider other arterial sources
including lumbar, adrenal, phrenic, or mesenteric vessels.
• Ectopic kidneys and horseshoe kidneys may have very unusual arterial supplies.
Transplanted Kidneys
• Generally there is a single arterial anastomosis.
• Type of anastomosis determines angiographic approach.
Procedure/Steps
Native Kidneys
Access
• Plan according to pre-operative imaging.
• Brachial approach is recommended in patients with severe peripheral vascular
disease with aortoiliac occlusion.
Angiography
• Non-selective arteriogram
◦ Always recommended in order to identify other arterial sources of
extravasation.
◦
◦ 15
LAO aortography can be helpful to define blood supply and anatomical
variants.
• Selective arteriogram
◦ Tip of the catheter within the proximal renal artery.
• Superselective angiogram
Transplant Kidneys
Access
• Plan according to the type of anastomosis.
◦ End-to-end anastomosis: contralateral femoral approach.
◦ End-to-side anastomosis: ipsilateral femoral approach.
Angiography
• Non-selective arteriogram is recommended to exclude other arterial sources of
extravasation.
• Selective arteriogram
◦ Tip of the catheter within the proximal renal artery.
32 Arterial Embolization Post-percutaneous Biopsy or Drainage 323
◦ 20–40◦contralateral anterior oblique arteriogram with the tip of the catheter
in the proximal renal artery.
• Superselective angiogram
Angiographic Appearance
• Active bleeding: active extravasation visualized as expanding and persistent
contrast that changes morphology on delayed images.
• Pseudoaneurysm: persistent or stagnant contrast material in venous phase with
round shape (see fig 32.3).
• Arteriovenous fistula: early visualization of the renal veins.
Results
• Success rates (technical and clinical) range from 80 to 100%.
• Despite superselective embolization, renal infarctions of more than 10% of the
kidney volume are often noted.
• Infarctions of less than 30% are usually asymptomatic in native kidneys.
• Infarctions of more than 50% can be followed by renal failure, especially in
transplanted kidneys.
Complications
Fatal Complication
• Rare.
Procedural Complication
• Major complications
◦ Non-target embolization: coils can dislodge and migrate. In the case of AVF, a
small coil can travel through the fistulous communication to the lung.
◦ Ischemia/tissue necrosis: usually asymptomatic.
◦ Intraprocedural rupture of the pseudoaneurysm; embolization needs to proceed
expeditiously.
◦ Renal failure secondary to contrast-induced nephropathy.
◦ Renal artery dissection.
• Minor complications
◦ Post-embolization syndrome.
◦ Groin hematoma.
◦ There is no evidence to show that the incidence of renal hypertension increases
after superselective renal embolization.
324 G. Behrens and N.H. Patel
Lung Embolization Post-percutaneous Biopsy/Drainage
General Concept and Definitions
• The definition of massive hemoptysis varies widely in the literature, with blood
loss volumes ranging from 200 to 1000 ml per day.
• Pulmonary hemorrhage manifesting as trace hemoptysis occurs in 5–10% of
cases after lung biopsies; the vast majority are self-limited.
• Massive intraparenchymal hemorrhage requiring intervention is extremely rare
(0.01%), but the mortality rate can be as high as 75% if untreated. Death
results from massive tracheobronchial aspiration and asphyxia rather than
exanguination.
• Majority of massive bleeds arise from the bronchial circulation.
• Bleeding as a result of drainage catheter placement is classically a result of injury
to intercostal arteries rather than intraparenchymal vessels.
Anatomy of the Lesion
Source of Bleeding
• Massive intraparenchymal bleeding usually arises from the bronchial circulation
(90%).
Imaging Findings
• Tortuous bronchial vessel (especially in the setting of chronic pulmonary dis-
eases)
• Neovascularity and/or hypervascularity
• Shunting to pulmonary arterial circulation
• Active extravasation of contrast material
• Bronchial artery pseudoaneurysm
Specific Indications for Lung Embolization
• Massive hemoptysis (see Chapters 35 and 36)
• Unstable patients
◦ Requiring immediate ventilatory assistance
◦ Requiring blood transfusions
◦ Hypotensive
◦ Progressive deterioration in ventilation
• Ongoing hemorrhage despite adequate resuscitation and correction of coagulopa-
thy/thrombocytopenia
32 Arterial Embolization Post-percutaneous Biopsy or Drainage 325
Vascular Anatomy
(see Chapters 15, 35, and 36)
Procedure/Steps
Procedure Preparation
• The first step in the management of post-biopsy/drainage bleeding is to stabilize
and secure the airway!
• Chest CT scans have been reported to be superior to bronchoscopy in the
evaluation of hemoptysis by
◦ Localizing bleeding region/lobe.
◦ Defining intraparenchymal bleed versus pleural hemorrhage.
• General anesthesia may be preferred in order to protect the airway.
• Complete patient resuscitation with correction of any coagulopathy.
Angiography
• Non-selective arteriogram
◦ Always recommended to define anatomy. The tip of the flush catheter is
positioned near the left subclavian artery.
• Selective and superselective arteriogram
◦ Classic angiographic findings in patients with bronchial artery bleeding
includes the following:
• Bronchial artery enlargement (>3 mm).
• Hypervascularity.
• Parenchymal stain.
• Bronchial to pulmonary artery shunting.
• Frank extravasation is rarely seen and is not necessary to proceed with
embolization.
• After the bronchial arteries are evaluated, the potential non-bronchial systemic
collateral vessels may be interrogated.
Embolization
• Particles are the agent of choice. However, they should be used with superselective technique due to high risk of complication.
• Coils should not be used in bronchial artery embolization, because they cause
proximal occlusion and preclude re-embolization.
• Contributions from collaterals from non-bronchial arteries represent an important
cause of recurrent hemoptysis.