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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3733_Библиотеки_им_академика_М_И_Перельмана.pdf
endovascular embolization. Embolization is the process of inducing blood
clots or embolus to occlude blood flow. In 1974, Sokoloff et al.9 reported the
first successful percutaneous embolization of the internal maxillary artery
causing nasal hemorrhage. A later study conducted in 1995 by Elahi et al.
7
demonstrated a 96% success rate in treating patients with intractable epistaxis
using embolization. Embolization is a relatively short procedure, which
increases both safety and accuracy.7 Moreover, a patient who has undergone
embolization is able to remove his or her posterior nasal pack earlier, which
allows for a reduced hospital stay and increased patient comfort.7 The
technique has since then been widely accepted and its efficacy confirmed.
10
Nevertheless, in some institutions and in case the of conservative treatment
failure, angiographic embolization remains the procedure of first choice.
11
DEVICE/MATERIAL DESCRIPTION
Once a year, our group is asked to review strokes that occur during epistaxis
embolizations. Usually, this happens in a procedure performed by a wellintentioned interventional radiologist who uses a 5-Fr glide catheter to close
the internal maxillary. This is a recipe for disaster. Strict guiding catheter and
microcatheter technique must be used. Embolization is a procedure that can
be conducted using various techniques or materials, for example, microcoils,
gelfoam, glue, and polyvinyl alcohol (PVA) foam. Microcoils are overused
by inexperienced practitioners and are a major problem in patients with
recurrent bleeding as they recanalize, allowing reperfusion but obstructing
embolization access. In transarterial embolization, physicians will use 6-Fr
guiding catheters, microcatheters, and microwires to access the
sphenopalatine branch of the internal maxillary artery.12 As it is difficult to
reach areas in the nasal cavity, microcatheters are often preshaped in a 30- to
45-degree angle.12 The materials mentioned earlier are sometimes used in
combination with one another. Patients should be heparinized during
procedures to decrease the risk of periprocedural stroke.
PVA particles with a diameter of 300 to 500 μm are used for
embolization of epistaxis.13 Particles with a smaller diameter should be
avoided as they can navigate through the skull base extracranial–intracranial
dangerous anastomosis and cause stroke. On the other hand, a larger diameter
can clump and block the microcatheter. To balance the benefit of
embolization therapy and the risk of complications, it is recommended that
the range in diameter is between 300 and 500 μm.
4,14
N-butyl cyanoacrylate (NBCA), detachable balloons, and microcoil
embolization should be reserved for massive bleeding, when it is necessary to
sacrifice internal carotid artery for epistaxis caused by internal carotid artery
lesion such as a gunshot wound.15 For arteriovenous malformation (AVM) or
dural arteriovenous fistula (DAVF), NBCA or Onyx (Covidien, Irvine,
California) can be employed for embolization.
16–18
TECHNIQUE
Transarterial embolization therapy should be conducted under conscious
sedation, but in an agitated patient, general anesthesia (GA) should be
used.
19,20
Embolization under GA is recommended for patients with major
blood loss, especially for cases of epistaxis caused by trauma, which are
usually accompanied with a major blood loss and of higher risk for
aspiration. Confused patients move and you lose your road map guidance. In
that situation, it is harder to detect excessive reflux of embolic material
retrograde from the catheter tip and potentially into the carotid bifurcation
and hence internal carotid artery and cause stroke.
Complete common carotid and bilateral internal and external carotid
arterial angiography should be conducted before embolization
19,21
(Fig.
15.1). Preembolization angiography should be performed to indentify lesions
such as AVMs, DAVF, and pseudoaneurysms. Preembolization diagnostic
angiography can identify if extracranial–intracranial dangerous anastomosis
exist. The key dangerous anastomosis exists between the middle meningeal
artery and the ophthalmic artery. Due to anatomical variation, dangerous
anastomoses exist between external and internal carotid arteries and their
ophthalmic artery branches. Even if there is no extracranial–intracranial
dangerous anastomosis detected by conventional angiography, potentially
dangerous anastomosis will still open with an increase in the injection
pressure during the embolization process. Internal and external carotid artery
anastomoses can occur with vidian artery, artery of the foramen rotundum,
the ascending pharyngeal artery, branches of middle meningeal artery and
accessory meningeal artery, sphenopalatine artery, and branches between
sphenopalatine artery and ophthalmic artery (Fig. 15.2).
4,19
If embolic
materials traverse through these anastomosis from external carotid artery to
internal carotid artery or ophthalmic artery, it may cause cranial nerve palsy,
loss of vision from retinal artery embolization, or even stroke.
19,22
The internal carotid artery angiography could directly reveal if the
ophthalmic artery branches out from the internal carotid artery and if there is
development of choroidal blush. The blood supply to the ophthalmic artery
from the branches of the middle meningeal artery should be closely watched
for. The recommended sequence for performing angiography is to start from
the common carotid and internal carotid artery, followed by external carotid
artery of the diseased side. Then the same procedure is repeated on the other
side.
19
The main blood supply to the nasal cavity is from the sphenopalatine
artery, which is branched from the internal maxillary artery. The normal
embolization method is through a superselective microcatheter to the distal
end of internal maxillary artery for angiography before embolization. In some
cases, it can be difficult to place a catheter into the distal end of the internal
maxillary artery or the inside of sphenopalatine artery or if the parent artery is
extremely tortuous.
The operator should always bear in mind that the purpose of treating
epistaxis is not to devascularize the nose but rather to reduce the blood flow
pressure in certain areas so as to facilitate the formation of local thrombus
and self-healing of the hemorrhage area. Thus, it is recommended that the
diameter of embolization particles should not be less than 150 μm to avoid
the possibility that a smaller particle could go intracranial through dangerous
anastomosis and cause catastrophic consequences. Before embolization, it is
important that a wedged catheter position is avoided and there is still forward
blood flow in the distal end of the microcatheter. If a wedged catheter
position and complete cutoff of forward blood flow occurs, the injection
pressure can increase during the embolization process, incurring the risk of
opening potential extracranial–intracranial dangerous anastomosis. It would
also increase the risk of reflux of embolic materials into nontargeted vessels.
In addition, it is very important to keep the microcatheter stable during the
embolization process. This is especially true in the later stages of the process
to avoid displacement of the microcatheter, which can be caused by increased
injection pressure. During the embolization, a suspension of embolic and
contrast material is subsequently injected under fluoroscopic control until
significant flow reduction is noted in the target vessel (Figs. 15.3 to 15.5).
19
CLINICAL INDICATIONS
Idiopathic Epistaxis
At least 70% of epistaxis cases are idiopathic.
10,23
In this situation, there is
often no characteristic angiography manifestations, and even otolaryngologist
are unsure which side is the cause of bleeding. There is an extensive branch
anastomosis among blood vessels of the two sides of nasal cavity, and thus
the bilateral sphenopalatine artery may sometimes need to be embolized.
Normally, successful hemostasis is achieved with internal maxillary route
embolization alone, although rarely, it is necessary to embolize both facial
artery branches. This has an additional risk of minor complications such as
skin or mucosal necrosis, particularly if very small embolic material is used
(50 to 199 μm).
4,20,24
PVA particles with sizes 300 to 500 μm are the material
of choice. It is not recommended to use microcoils to occlude main vessels as
these become road blocks if a reembolization is needed in the future.
Compared with other cases of epistaxis, the success rate of embolization
therapy for idiopathic epistaxis is higher, and the long-term success rates
could reach as high as 93.5%.
20
Trauma or Iatrogenic Injury
For epistaxis caused by trauma or iatrogenic injury, bleeding usually occur
immediately after the injury or medical procedure but can be delayed.15 Most
would happen within 3 weeks after injury.15 For epistaxis caused by trauma
or iatrogenic injury, diagnostic angiography may reveal a pseudoaneurysm of
internal or external carotid artery, and in an active situation, you may see
contrast media extravasation. For epistaxis caused by external carotid artery
injury, the treatment method is similar to that for spontaneous epistaxis.
However, trauma patients in shock may have injured vessels that are
constricted or in spasm. Although bleeding can be controlled temporarily
with embolization, blood pressure will increase once bleeding has stopped,
the peripheral vascular bed will reopen, and the chances of bleeding
reoccurring can be high. Using particles for embolizing diseased vessels,
gelfoam pledgets, or microcoil for embolizing main branches of diseased
vessels could be considered to consolidate the embolization effect and reduce
the rate of bleeding. In urgent cases, NBCA is an excellent tool to achieve
instant closure of a rapidly bleeding vessel. NBCA is, however, a complex
material to use and should not be used by the inexperienced.
Pseudoaneurysm induced by injury of the internal maxillary or proximal
external carotid can be difficult to handle. This is usually either traumatic or a
complication of an endoscopic approach.25 Permanent vessel occlusion is the
best solution.
Infectious Aneurysm
The wall of infectious aneurysm is thin; direct embolization of an aneurysm
could possibly cause rerupture due to the fragile nature of the aneurysmal
wall. Principally, treating infectious aneurysm of branches of external carotid
artery is done to embolize the parent artery. The operational procedure is the
same as previously described. For treatments of infectious aneurysm of the
internal carotid artery, the principle is similar to that for traumatic
pseudoaneurysm. In cases where a balloon occlusion test is tolerated,
sacrificing the internal carotid artery of the diseased side can be considered
for treatment. Another alternative therapy is a stent graft.
Hereditary Hemorrhagic Telangiectasia
The treatment of epistaxis in patients with hereditary hemorrhagic
telangiectasia (HHT) is initially conservative. The success rate of
embolization for treating HHT-induced epistaxis is only 20% to 25%,
whereas the rate is as high as 90% for idiopathic epistaxis.
20,26
It is difficult
for embolization therapy to achieve radical treatment of HHT, and the
purpose of the treatment is mainly to reduce the frequency of epistaxis
occurrence and lessen the severity of each episode.27 Due to the fact that
abnormal angiogenesis constantly exists, it is very difficult to conduct
permanent embolization therapy for diseased vessels caused by HHT.26 In
considering the refractory nature and high rate of recurrence for epistaxis
induced by HHT, it is not recommended to use such permanent embolic
materials as microcoil to embolize the main branches of diseased vessels so
as to preserve the interventional approach for future treatment.
27
POTENTIAL COMPLICATIONS
The complication of embolism therapy for epistaxis fall into two categories:
minor transient adverse event and major complications. Major complications
can be further categorized as major transient or persistent.19 Patients with
minor transient adverse event such as headache, facial pain, jaw pain,
trismus, facial edema, or facial numbness are able to recover quickly without
any disturbing aftereffects. Major transient complications include skin
slough, temporary hemiparesis, temporary monocular visual field loss, and
mucosal necrosis.19 Persistent complications include facial scarring following
ischemia, monocular blindness, peripheral facial nerve paralysis, cerebral
infarction, and ischemic sialadenitis requiring surgery.19 Larger series report
minor transient complications in 25% to 59%, major transient in 0% to 1%,
and persistent in 2% of cases.19 Smith4 retrospectively analyzed 15 clinical
studies on embolism therapy for epistaxis and found that the occurrence rate
of serious complication was 0% to 8% and the average rate was 3%.
TIPS AND TRICKS
• Create a separate table for the embolization materials and keep the
bowls with the PVA, the contrast used for control injections, and all
other equipment that have contact with embolic material. Do not
cross-contaminate your diagnostic equipment.
• Do not do a final control injection with the guiding catheter in a
common carotid ever. Most strokes occur from clot in the guide
around the microcatheter.
• Use a negative road map. Foot on road map. Inject nothing, then use
that image as the guide for the embolization. It allows you see
dangerous anastomosis easier.
• Some of our patients have been elderly women with left-sided
nosebleeds and a horrible ecstatic aortic arch. Keep a few Simmons 2
(Cook Medical Inc., Bloomington, Indiana) Envoy guide catheters on
your shelf for this situation. If that is not working for you, look at
some of the cardiology internal mammary guide catheters.
• Control the patient’s blood pressure.
• Heparinize the patient for the embolization. You can always give
blood. You cannot give gray cells if you have a procedural stroke.
The last thing you want to do is to give recombinant tissue
plasminogen activator to someone with epistaxis.
• With a diagnostic catheter, do a complete preembolization
angiography, common carotid to look for atheroma, then internal and
external carotid arteries to identify extracranial–intracranial
dangerous anastomosis.
• Appropriate range for diameter of PVA particles is 300–500 μm.
Smaller particles increase the risk of skin necrosis and stroke.
• Do not wedge the catheter in the vessel and always maintain the
forward flow of blood during embolization process; pay attention to
the change of injection pressure or increase in resistance.
• If you block the microcatheter with PVA delivered by a 3-mL
syringe, carefully unblock it using a contrast-filled 1-mL syringe or
consider pulling the microcatheter out and recanalize it on the
procedure table.
• Have a system to identify the syringes used in the embolization. We
use 3-mL Luer lock syringes. We use Steri-Strips (3M, St. Paul,
Minnesota) to identify the three different syringes, and they draw up
from three different bowls. The syringes used for saline are bare, that
is, no Steri-Strip; the contrast syringes have one Steri-Strip; and the
PVA syringes have two Steri-Strips. The bowls have Steri-Strips that
match this. The embolization space is self-sufficient. You never ever
draw up saline or contrast from your diagnostic system with any
syringe that came from the embolization table as a PVA particle can
contaminate the clean system and cause a stroke.
REFERENCES
1. Shukla PA, Chan N, Duffis EJ, et al. Current treatment strategies for
epistaxis: a multidisciplinary approach. J Neurointerv Surg.
2013;5(2):151–156.
2. Small M, Murray JA, Maran AG. A study of patients with epistaxis
requiring admission to hospital. Health Bull (Edinb). 1982;40(1):20–29.
3. Fatakia A, Winters R, Amedee RG. Epistaxis: a common problem.
Ochsner J. 2010;10(3):176–178.
4. Smith TP. Embolization in the external carotid artery. J Vasc Interv
Radiol. 2006;17(12):1897–1912; quiz 1913.
5. Schlosser RJ. Clinical practice: epistaxis. N Engl J Med.
2009;360(8):784–789.
6. Breda SD, Choi IS, Persky MS, et al. Embolization in the treatment of