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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3869_Библиотеки_им_академика_М_И_Перельмана.pdf
262 O. van Delden
• The “metastable” patient: this is the situation when hemodynamic stability can
be maintained by continuous fluid resuscitation. “Metastability” is not a contraindication to imaging or intervention when the CT and angiography suites are
appropriately equipped to deal with such situations.
Imaging (See Also Chapter 10)
Abdominal Ultrasound (FAST)
• Is often performed in the emergency department by emergency physicians or
trauma surgeons.
• First and quickest test for abdominal injury.
• Has reasonable sensitivity for the detection of intraperitoneal blood.
• Has only moderate sensitivity for the detection of solid organ injury, retroperi-
toneal, and pelvic hematoma.
• Blood can be echogenic and therefore easily missed by inexperienced operator.
• Should be followed by CT in patients who are stable enough to undergo CT.
◦ In all patients with a positive FAST.
◦ In patients with a negative FAST but ongoing clinical suspicion of injury.
• Some would suggest that there is little logic in performing FAST if CT is
available and any other imaging is required.
Contrast-Enhanced CT
• Most accurate and comprehensive test for assessment of abdominal injury, partic-
ularly good at grading injuries of liver, spleen, and kidneys. MDCT preferred as
thin slices and multi-planar reformats provide a good road-map for angiography.
• IV contrast is mandatory.
• Detects both active arterial hemorrhage and false aneurysm.
• Contrast “blush” indicates arterial hemorrhage and should be followed by
angiography in most cases.
• Late phase helpful in patients with renal injury to differentiate perinephric
hemorrhage from urinary leakage.
• CT in patients with liver injuries is often helpful in differentiating arterial hem-
orrhage from hemorrhage from the major liver veins or inferior vena cava (which
can be a lethal injury!).
• Has only moderate sensitivity for detecting injuries to pancreas, mesentery, and
bowel.
27 Solid Organ Embolization in Trauma 263
Imaging Findings: The Following Predict the Need for Intervention
• Contrast extravastion or false aneurysm on contrast-enhanced CT. This is the
most reliable predictor for the presence of active bleeding on an angiogram and
the most practical imaging feature to use.
• High-grade (>grade 3) injury to liver, spleen or kidney.
• Large hemoperitoneum or increasing hemoperitoneum on sequential CTs.
Indications
Indications to perform angiography and embolization are clinical signs of ongoing
bleeding, imaging findings consistent with arterial hmorrhage or a combination of
clinical signs and imaging findings. The goal of arterial embolization in patients
with blunt trauma of liver, spleen or kidney is as follows:
• Treatment of ongoing bleeding of liver, spleen, and kidneys
◦ Reducing the need for blood transfusions
◦ Avoiding surgery altogether
◦ Allowing elective rather than emergency surgery
• Treatment of a false aneurysm or contained hemorrhage, thereby preventing
delayed rupture and increasing the splenic salvage rate and the success rate of
non-operative management.
• Treatment of perinephric bleeding or hematuria in renal injury.
Alternative Therapies
Surgery
• Operative management is indicated when there is suspicion of injury to mesentery
and/or bowel. Laparotomy should be performed in such cases.
• For splenic injury, surgery is usually splenectomy.
• For renal injury, partial or complete nephrectomy.
• For liver injury, packing with gauze. Acute partial hepatectomy is associated with
a high mortality and is usually avoided. As bleeding from liver vessels may not
be controlled by packing with gauze alone, angiography and embolization should
be considered as additional treatment directly following damage-control surgery.
Contraindications
• The only contraindication is incorrectable hemodynamic instability: these
patients must have immediate laparotomy.
264 O. van Delden
• Renal insufficiency and coagulopathy do not constitute contraindications in an
emergency setting.
Complications
All complications that are associated with angiography may occur and are probably
more common.
• Systemic complications (allergic reaction, contrast-induced nephropathy)
• Puncture-site complications (groin hematoma, false aneurysm, thrombosis,
dissection)
Specific complications are covered under separate headings for liver, spleen, and
kidney.
Anatomy
Most anatomic variants will be apparent on the contrast-enhanced CT, which is
preferably obtained prior to angiography.
Normal Anatomy and Common Variations
• Common variations of celiac anatomy such as replaced right hepatic artery from
the superior mesenteric artery or left hepatic artery originating from the left
gastric artery are frequently seen. Variations such as a common hepatic artery
originating from the aorta or superior mesenteric artery are seen much less
frequently, but are not exceedingly rare.
• Splenic artery anatomy is usually classic.
• Accessory renal arteries arise from a variety of positions on the aorta and iliac
arteries.
• Bleeding may also occur from the adrenal glands or diaphragm; so also assess
adrenal branches and inferior phrenic arteries.
Equipment
• Sheath: a 5-French sheath suffices in most cases. The sheath may be left in
(sutured to the skin) after the procedure when
◦ An arterial line is required
◦ There is coagulopathy
• Non-selective catheters: Pigtail or straight catheter for flush aortogram if CT does
not indicate the site of bleeding.
• Selective catheters: 5-French cobra and celiac-type catheters will suffice in
the vast majority of cases. 4-French hydrophylic catheters may be useful for
superselective catheterization.
27 Solid Organ Embolization in Trauma 265
• Micro-catheters and appropriate guidewires are mandatory for selective
embolization. When using micro-catheters, the use of a Tuohy Borst adaptor is
recommended.
• Guiding catheters: not usually required.
• Closure devices.
Embolic Agents
The choice of agent depends on the situation, but the vast majority of cases can be
performed using the following:
• Coils (diameters 3–12 mm): accurate placement is safe and easy. Associated
with low risk of ischemic complications in both liver, spleen, and kidneys.
Require at least some degree of clotting in order to induce occlusion of a
vessel and may therefore be insufficient in patients with severe coagulopathy. In such cases, a combination of coils and gelfoam or gelfoam alone may
be used.
• Micro-coils (3–8 mm): same as above. Micro-coils usually required when per-
forming selective embolization of the liver, spleen or segmental renal branches.
Micro-coils usually not required for proximal splenic artery embolization or large
renal branches.
• Gelfoam: gelfoam pledgets can be cut to the preferred size and mixed to a slurry
using a three-way stop-cock and two 1-ml Luer-lock syringes. Gelfoam pledgets
can be used for a more proximal occlusion and can be injected through both
regular 5-French diagnostic and micro-catheters.
The availability of both coils and gelfoam are mandatory for trauma
embolization.
Rarely Required
• Amplatzer vascular plug may be useful in rare instances.
• Poly-vinyl alcohol particles 300–500 μ may also be useful in rare instances.
Medication
Patients with major injury require physiological support during imaging and
embolization—this is not the role of the interventional radiologist and must be
provided by emergency physicians, anesthetists, and other appropriately trained
staff.
266 O. van Delden
Angiography
Access
• Almost always approached from the femoral artery.
• In the presence of a pelvic fracture, the sheet wrap or pelvic binder may some-
times need to be displaced somewhat in order to expose the groin. The presence
of an external pelvic fixation device usually poses no problem.
• If embolization is required for a pelvic fracture, then it may be practical to punc-
ture the contralateral side. Puncture the side which lends itself to the most rapid
catheterization of the target artery.
Angiography
• Flush aortography is usually only helpful to assess for the presence of accessory
renal arteries in case of renal injury or when doubt exists about the anatomy of
the visceral vasculature (variations of celiac axis or superior mesenteric artery).
However, when a good contrast-enhanced CT is performed prior to intervention, a
flush aortogram can usually be left out all together. Moreover, a flush aortogram
only adds to the contrast load which will often be significant when a contrastenhanced CT is followed by angiography.
• Selective injections should be performed of all suspected vessels. Cobra or
sidewinder type catheters will allow rapid selection of all relevant vessels
including the renal arteries in most cases.
• Repeated, forceful hand injections may sometimes be helpful, when extravasation
is expected (from the CT) but not seen on the initial angiogram.
Angiographic Appearance
Vascular abnormalities that should actively be sought for and embolized include the
following:
• Extravasation of contrast medium.
• False aneurysms: these represent contained hemorrhage, embolization prevents
delayed rupture and free extravasation into the peritoneal space.
• AV- fi s tu l a (particularly in renal and splenic injuries): these are associated with
ongoing hemorrhage and hematuria. AV fistulae often present days or weeks
following the initial trauma.
• Vessel occlusions “cut-offs”: occlusions represent vessels that have been dis-
sected or completely transected. The vessel is typically occluded by spasm and
or superimposed thrombus. When the blood pressure of the patient normalizes
during resuscitation, such vessels are prone to start hemorrhaging again. They
should be embolized.
27 Solid Organ Embolization in Trauma 267
Clinical Scenarios
Embolization
• Generally speaking, embolization should be performed as selectively as possi-
ble. However, in practice the way embolization is performed is often dictated by
the clinical circumstances. Although salvage of the organ involved is desirable,
saving the patients life is paramount.
• In most situations, embolization can be performed using coils, particularly when
one or at the most a few focal bleeding vessels are identified. When many bleeding points are identified or when there is diffuse bleeding, the use of gelfoam is
more appropriate.
Liver
• Due to its dual vascularization (75% of total flow supplied by portal vein, 25%
by hepatic artery), the liver is able to tolerate occlusion of part of its arterial
inflow. However, the bile ducts and gallbladder are fully dependent on hepatic
arterial blood flow. Occlusion of the cystic artery should therefore be avoided.
The cystic artery usually originates from the proper hepatic artery, but may also
originate from the right hepatic artery. This vessel should always be identified
prior to embolization; occlusion of the cystic artery should be avoided if possible
(Fig. 13.1).
• Embolizing as selectively as possible is recommended as intra- and extra-hepatic
collateral arteries may cause bleeding to persist when embolization has not been
performed selectively enough.
• Hepatic vessels are prone to developing spasm during manipulation: for selective
catheterization of hepatic vessels, the liberal use of micro-catheters is recommended. Micro-coils are usually adequate for inducing hemostasis of liver
hemorrhage.
• When a large subcapsular hematoma has disrupted the liver capsule, torn capsular
vessels may cause many bleeding points and this is best treated by more proximal
embolization gelfoam or particles (“shotgun embolization”).
Complications of Hepatic Embolization
• The biliary system is dependent on arterial blood supply. Bile duct ischemia
leading to liver abscess may develop after embolization.
• Abscess can usually be managed with percutaneous drainage.
• Biliary drainage is rarely required.
• Remember that liver abscess, infected hematoma, and infected biloma are fre-
quently seen after high-grade injuries to the liver in both patients who did and
who did not undergo embolization.
• Occlusion of the cystic artery may lead to gallbladder necrosis, which should
subsequently be treated with cholecystectomy. However, flow to the gallbladder
268 O. van Delden
may also remain preserved as a result of collaterals, and occlusion of the cystic
artery should not automatically lead to cholecystectomy.
Figs. 27.1 (a–d) (Liver Case)
a
c
b
d
Fig. 27.1 (a) CT scan with intravenous contrast in hemodynamically unstable patient who sus-
tained blunt abdominal trauma shows a deep liver laceration with extravasation of contrast medium
into the peritoneal cavity. (b and c) The hypotensive patient was immediately transferred to the
angio-suite and a selective angiogram of the common hepatic artery shows a so-called “cut-off”
sign of the hepatic artery branch that had been severely bleeding on the preceding CT scan. As
there is a high chance for this branch to start bleeding again once normal blood pressure has been
restored, coil embolization of this branch was subsequently performed (Fig. 27.3c). (d) CT scan
performed 2 weeks after the trauma shows large inhomogenous fluid collection in the liver with
hyperdense areas consistent with a hematoma. This collection showed no signs of infection and
was treated conservatively
Spleen
• Splenic salvage is preferred to splenectomy because it avoids the risk of
overwhelming post-splenectomy sepsis.
27 Solid Organ Embolization in Trauma 269
• For splenic embolization, two different techniques are available; proximal
embolization of the splenic artery and distal or selective embolization. Neither
of these two techniques has proved superior in the literature.
• Proximal embolization is performed by coil occlusion of the proximal splenic
artery. The Amplatzer vascular plug may also be used for this purpose, although it
requires a larger delivery system than coils. As a result of this, the pressure in the
splenic artery is lowered causing hemorrhage to cease. Splenic perfusion is preserved via collateral flow through the short gastric, gastroepiploic, and pancreatic
branches. This technique is especially appropriate when
◦ there is diffuse splenic injury with multiple bleeding vessels or when
◦ selective embolization is difficult and time-consuming.
• Distal or selective splenic embolization is performed by embolizing a bleeding
vessel as selectively as possible. This typically requires the use of microcatheters. This technique is especially appropriate when one focal bleeding vessel
is identified.
• Distal embolization is associated with a higher chance for developing splenic
infarction compared to proximal embolization, but such infarcts are usually
clinically silent.
• Delayed rupture of the spleen and subsequent life-threatening hemorrhage may
occur days after the initial trauma and poses the biggest threat to the success of
non-operative management.
Figs. 27.2 (a–d) (Splenic Case, Proximal Embolization)
Complications of Splenic Embolization
• Infarcts are commonly seen after distal or selective embolization of splenic
injuries. These are often noted on follow-up CT and generally produce no clinical
sequelae.
• DO NOT OCCLUDE the distal main splenic artery beyond the short gastric
vessels, as this may cause massive splenic infarction!
• Splenic abscesses can usually be treated percutaneously.
• Air in a splenic infarct as seen on follow-up CT is not a specific sign for infection
and should not lead to aspiration or drainage unless clinical signs of infection
exist.
Figs. 27.3 (a–d) (Splenic Case, Distal Embolization)
Kidney
• Always assess for accessory renal arteries (pre-embolization CT or flush aor-
togram).
270 O. van Delden
a
c
b
d
Fig. 27.2 (a) CT scan with intravenous contrast in hemodynamically unstable patient who sus-
tained blunt abdominal trauma shows blood around the liver and spleen and active extravasation
of contrast medium into the peritoneal cavity from the ruptured spleen. (b and c) The patient was
immediately transferred to the angio-suite and a selective angiogram of the splenic artery shows
brisk extravasation of contrast medium from a large branch of the splenic artery at the level of
the splenic hilum. As the patient was hemodynamically unstable, no attempt was made to perform
superselective catheterization and coil embolization of the proximal splenic artery was done (Fig.
27.1c). (d) CT scan performed 1 week after the embolization shows a small peripheral hypodense
area in the spleen, caused by the laceration, but no significant area of infarction
• Renal pedicle injury may cause complete occlusion of the proximal renal artery.
In such cases, embolization of the proximal renal artery may prevent recurrent
hemorrhage when normal blood pressure is restored.
• When superselective embolization is impossible or too time-consuming, emboliz-
ing somewhat proximal to the bleeding point may suffice. Renal artery branches
are end-arteries and bleeding will not persist or recur, as there is no collateral
flow.
27 Solid Organ Embolization in Trauma 271
a
c
d
b
Fig. 27.3 (a) CT scan with intravenous contrast in hemodynamically stable patient who sus-
tained blunt abdominal trauma shows focal area of contrast pooling in the spleen consistent with
a pseudoaneurysm. No contrast extravasation outside the spleen is noted. (b and c) The patient
was transferred to the angio-suite and a selective angiogram of the splenic artery shows a 1.5cm pseudoaneurysm in the spleen with an associated traumatic AV fistula (not shown in this
image). The small feeding branch was subsequently selected using a co-axial micro-catheter and
coil embolization was performed (Fig. 27.2c). (d) CT scan performed 1 week after embolization shows a small splenic infarction in the area, which was embolized. A small air bubble
is also noted in the infarcted area, but there were no signs of infection and the patient was
asymptomatic
Complications of Renal Embolization
• As renal arteries are end-arteries, embolization of kidney injury will lead to
infarction of part of the kidney. This seldomly leads to clinical sequelae.
• Infected hematoma or urinoma may occur and can be treated by percutaneous
drainage.