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422 A.M. Papadopoulou and A. Platts
• Most commonly, the precise site of bleeding is not known. Bilateral IMA
embolization with particles is necessary in such cases because of the side-to-side
anastomoses that can be recruited to the bleeding nasal mucosa. The microcatheter should be advanced distal to branches with high potential for dangerous
anastomosis collaterals such as the middle meningeal, accessory meningeal, and
superficial temporal arteries to avoid non-target embolization.
• For patients with an anterior source of bleeding, particle embolization of the nasal
branches of the facial artery should also be performed carefully so that the distal
supply of the terminal alar artery, which supplies the skin of the nasal ala, is
preserved.
• Catheter-induced vasospasm is a common occurrence with superselective
catheterization of ECA branches. This significantly alters flow distally, even to
the point of stasis. Gentle microcatheter manipulation and minimal guidewire
manipulation can minimize vasospasm. Glycerine trinitrate (GTN 50–500 μg)
can be administered to treat vasospasm after the catheter has been retracted
proximal to the point of vasospasm.
• Liquid embolic agents (NBCA, Onyx
tinely because of the risk of non-target embolization or tissue necrosis. Their
use has been advocated in rare cases where a focal angiographic abnormality or
extravasation is demonstrated but the feeding vessel cannot be catheterized.
TM
) are not recommended for use rou-
Juvenile Nasal Angiofibroma
• PVA particles are the agent of choice in the pre-operative embolization of juvenile
nasal angiofibroma.
• The goal is to obliterate the capillary bed while preserving normal tissue.
Hereditary Hemorrhagic Telangiectasia
• Approach similar to that for spontaneous epistaxis with bilateral IMA
embolization.
• There is a higher recurrence rate and need for re-intervention.
Trauma Including Traumatic Pseudoaneurysms
• Coils or covered stents may be used in the case of pseudoaneurysms.
Aftercare
Arterial Puncture Site
• A closure device is useful when the patient has been anti-coagulated during the
procedure.
42 Epistaxis 423
Post-embolization
• No specific care is needed.
• Do not forget the following:
◦ To continue resuscitation/transfusion as necessary
◦ To manage risk factors
◦ That rebleeding is common
Follow-Up
No routine follow-up needed.
Keypoints
• Epistaxis can result from a multitude of causes, the commonest being the
spontaneous or idiopathic form.
• Embolotherapy in the management of spontaneous epistaxis is reserved for
cases refractory to topical or conservative measures.
• Embolotherapy is essential prior to some endoscopic tumor resection
procedures.
Safety
• Knowledge of the arterial anatomy, the angiographic and embolization
technique, and potential complications and how to avoid these are imperative for ensuring a good outcome.
Bibliography
Gifford TO, Capt MC, Orlandi, RR. Epistaxis. Otolaryngol Clin N Am 2008; 41: 525–536.
Mahadevia AA, Murphy KJ, Obray R, Gailloud P. Embolization for intractable epistaxis. Tech
Vasc Interventional Rad 2005; 8:134–138.
Nguyen QA. Epistaxis eMedicine http://www.emedicine.com/ent/TOPIC701.HTM
Smith T. E mbolization in the external carotid artery. J Vasc Interv Radiol 2006; 17:1897–1913.
Chapter 43
Meningiomas and Paragangliomas
H.L.D. Makalanda and Andrew Platts
Clinical Features
• Meningiomas are extra-axial brain tumors derived from arachnoid cells of neu-
ral crest origin. They comprise 20% of primary intra-cranial tumors and are
more common in older patients and women (M:F = 2:1). They also have some
syndromal associations.
• Paragangliomas (glomus tumors) arise from neural crest cells and typically arise
at four locations and are as follows:
Carotid body (caroticum)
Jugular foramen of the temporal bone (jugulare)
Tympanic plexus (tympanicum)
Vagal nerve (vagale)
◦ They are slow growing and most frequently found in women of the fifth and
sixth decade.
◦ May be multifocal in as many as 22% of patients.
• The optimal treatment for these tumors is complete resection where possible.
Pre-operative embolization reduces operative time and intra-operative blood loss
when resecting these vascular tumors. It provides a particularly useful adjunct
when the tumors exhibit hypervascularity or when they encase vital structures.
Diagnostic Evaluation
Laboratory
As for any angiographic examination (e.g., clotting and renal profiles).
Transcatheter Embolization and Therapy,
Techniques in Interventional Radiology, DOI 10.1007/978-1-84800-897-7_43,
C
Springer-Verlag London Limited 2010
425
426 H.L.D. Makalanda and A. Platts
Imaging
• Never start embolization until you have formally reviewed the pre-procedure
imaging.
• Use contrast-enhanced CT/MRI with multi-planar reformats to
◦ Establish diagnosis (differential diagnosis: hemangiopericytoma, angiosar-
coma).
◦ Demonstrate location and tumor extent.
◦ Assess operability.
◦ Assess tumor vascularity.
◦ Delineate tumor extension to
◦ Major arteries
◦ Major veins
◦ Cranial nerves
◦ Dural venous sinuses
◦ Calvarium
Use angiography to
• Plan embolization by identifying feeding vessels (dural and pial) and assess
feasibility and safety of embolization.
• Detect arterio-arterial anastamoses, abnormal branches, or trans-osseous
supply.
• Assess the collateral circulation to the brain.
• Assess the intensity of tumor staining and flow characteristics.
• Acquire information about the venous drainage, any cortical venous changes, and
patency of adjacent major dural venous sinuses.
Indications
• Pre-operative embolization: making the tumors smaller, softer, and less bloody
allowing easier manipulation and removal at surgery. Embolization of the ECA
branches controls deep hemorrhagic sites. Pial bleeding is usually easy to control
surgically.
• Stand-alone embolotherapy of tumors has been reported in a small series, but is
rarely performed.
Contraindications
• Renal insufficiency and coagulopathy are relative contraindications, and should
ideally be corrected before this semi-elective procedure is performed.
43 Meningiomas and Paragangliomas 427
• Gadolinium may be used in patients with a true allergic reaction to iodinated
contrast.
Alternative Therapies
Direct injection of liquid embolic agents into hypervascular paragangliomas has
TM
been proven safe and efficacious in some studies. Both NBCA and Onyx
have
been used.
Specific Complications
These include non-target embolization causing the following:
• Stroke
• Blindness
• Cranial nerve palsy
Anatomy
Assess the vascular supply on the pre-procedural imaging. Multiple vessels supplying the tumor indicate that the case will take longer to perform. The anatomy is
markedly variable depending upon tumor location.
Normal Anatomy
• Commonly supplied by the dural arteries. These include the following:
◦ External carotid artery branches
Middle meningeal (MMA)
Accessory meningeal
Ascending pharyngeal—of particular importance in paragangliomas
Occipital transmastoid
◦ Internal carotid artery (ICA) branches
Tentorial
Inferolateral trunk
◦ Vertebral artery branches
Posterior meningeal
• All these branches need to be assessed to exclude aberrant anatomy. However,
the feeding arteries can often be deduced from the tumor location (Tables 43.1
and 43.2).
428 H.L.D. Makalanda and A. Platts
Table 43.1 Meningioma location and supply
Meningioma l ocation Supply
Falx/parasagittal/convexity MMA—usually ECA occasionally from ICA—ophthalmic
Sphenoid wing MMA—usually ECA occasionally from ICA—ophthalmic
Olfactory
groove/planum
sphenoidale
Parasellar/pertroclinoid/
petrous apex
Tentorium Tentorial artery—ICA branch
Infratentorial Tentorial artery—ICA branch
Abbreviations: MMA—middle meningeal artery; ECA—external carotid artery; ICA—internal
carotid artery; VA—vertebral artery
Anterior falx artery—usually from ICA –ophthalmic
Superficial temporal artery –ECA
Anterior ethmoidal branches—usually from ICA –ophthalmic
Direct supply from pial branches of ICA
Meningo-hypophyseal artery—from cavernous ICA
Middle cranial fossa meningeal branches from ophthalmic
Usually from ICA—ophthalmic, anterior, and posterior ethmoidal
branches.
MMA—usually ECA occasionally from ICA –ophthalmic
MMA—usually ECA occasionally from ICA –ophthalmic
Dorsal meningeal from VA
Occipital artery from ECA
Ascending pharyngeal from ECA
MMA—usually ECA occasionally from ICA –ophthalmic
Occipital artery from ECA
MMA—usually ECA occasionally from ICA—ophthalmic
Occipital artery from ECA
Ascending pharyngeal from ECA
Dorsal meningeal from VA
Cerebellar branches from vertebral and basilar arteries
Table 43.2 Paraganglioma location and supply
Glomus caroticuum ICA and ECA supply
Glomus vagale ICA and ECA supply particularly ascending pharyngeal
Glomus jugulare VA branches
Glomus tympanicum VA branches
ECA branches occipital, post-auricular, MMA, posterior
division of ascending pharyngeal
ECA branches occipital, post-auricular, MMA, posterior
division of ascending pharyngeal
Aberrant Anatomy
Secondary supply may be derived from pial branches and are as follows:
• Anterior cerebral artery (ACA)
• Middle cerebral artery (MCA)
• Posterior cerebral artery (PCA)
43 Meningiomas and Paragangliomas 429
Strategy
• The goal is to reduce the tumor vascularity, thereby reducing surgical blood loss
and dissection time.
• The most important vessels to devascularize are those that feed the tumor deep
to the surgical approach. There is little point in embolizing the middle meningeal
or superficial temporal supply to a convexity meningioma when the surgical
exposure will result in these branches being clipped early during the surgical
approach.
• Pial branches from the ICA are not normally embolized, since the risk of nontarget embolization and stroke is unacceptably high.
Equipment
• Roadmap capability
• Non-selective catheters: none required.
• Selective catheters: vertebral, Sidewinder 2. Microcatheter for selective emboli-
zation.
• Guide catheter: 6Fr with 0.067 lumen allowing guiding contrast injections,
as well as constant flush by attaching to a pressurized heparinized saline bag
via a rotating hemostatic valve. This ensures that the dead space around the
microcatheter is flushed and clot accumulation is prevented.
Embolic Agents
• Polyvinyl alcohol (PVA) particles—300–500 μm, unless shunting or very large
vascular tumor are present in which case larger particles should be used.
• Acrylic polymer microspheres (Embospheres)—300–500 μm unless shunting or
very large vascular tumor when larger particles may be used.
• Coils – may be placed within the MMA proximal to the tumor bed, allowing
easier surgical transection of the artery.
Medication
• General anesthesia: addresses both patient compliance and analgesic require-
ment during the procedure. If provocative testing is to be employed, the procedure
must be performed under local anesthetic with mild sedation.
• Heparin: 5000 IU bolus with 1000 IU per hour thereafter during the embolization
procedure.
430 H.L.D. Makalanda and A. Platts
• Lidocaine: can be used as a provocative test to ensure safe catheter placement
prior to embolization. Inject 1 ml of 1% plain lidocaine and check that the patient
does not develop a cranial nerve palsy or facial sensory change.
• Pain control: analgesia should be prescribed for the recovery period.
• Sickness control: anti-emetics should also be prescribed to control symptoms of
post-embolization syndrome.
Procedure
Access
• Plan according to the pre-operative imaging.
• Almost always approached from the common femoral artery
Angiography
• Selective six-vessel angiography (both ICA, ECA, and vertebrals) can be helpful
in patients with large tumors when the blood supply may not derive exclusively from a single branch, and when the exact supply is unclear from the
pre-procedure imaging.
• The following must be identified and examined to avoid potentially disastrous
complications.
• The distal internal maxillary artery (potential communication with the ICA).
• The neuromeningeal trunk of the ascending pharyngeal artery (supply to 9th,
10th, and 11th cranial nerves).
• The odontoid branch of the ascending pharyngeal artery (potential vertebral
artery anastamosis).
• Meningolacrimal branch of the MMA (potential retinal supply).
• Pre-embolization testing by injection of a small-dose of lidocaine (1 ml 1% plain
lidocaine without epinephrine or buffer) may be used to identify that the blood
supply to cranial nerves is not jeopardized.
• Temporary cranial nerve deficit increases the risk of embolization.
• After the microcatheter has been properly and safely positioned, embolic
material is injected under constant, real-time digital-subtraction fluoroscopy
(road map). This optimizes visualization of tumor staining and filling of nontarget vessels to allow penetration of the material into the tumor bed thereby
producing devascularization and subsequent necrosis.[/l1]
• The pial supply is generally not embolized pre-operatively (due to the risk of
CVA).
43 Meningiomas and Paragangliomas 431
Assessing the Lesion
Location
• The location of the tumor should be known from the pre-operative imaging.
a
c
b
d
Fig. 43.1 (a) External carotid artery DSA images demonstrating a hypervascular left middle cra-
nial fossa meningioma supplied by enlarged posterior ethmoidal and middle meningeal arteries.
Note the typical DSA sunburst tumor blush pre-embolization. (b) Corresponding CT image. (c)
Post-embolization. Tumor vascularity is markedly reduced post-embolization. (d) CT illustrates
the tumor necrosis post-embolization and prior to surgery
432 H.L.D. Makalanda and A. Platts
Fig. 43.2 DSA images of
right common carotid artery
angiograms demonstrating a
right glomus jugulare tumor
(white arrowheads)(a)pre-
(b) post (right) embolization.
Note the pruning of
peripheral vessels
post-embolization
a
b
Angiographic Appearance
• A typical starburst blush pattern identifies the tumor (Figs. 43.1 and 43.2).
Treatment Plan and Technique
The treatment plan and embolic agent depends on the tumor anatomy and operator
experience.
• The goal is to obliterate the tumor capillary bed to produce devascularization of
the tumor while preserving normal tissue. Occluding the feeding artery confers
little benefit over surgical ligation of these vessels intra-operatively.
• When the flow of embolic particle begins to slow, embolization is halted to
prevent reflux of particles into non-target territories.
• Always try and embolize as selectively as possible using microcatheters to navigate into each feeding vessel. PVA particles or acrylic microspheres are used to
embolize as distally as possible.
• The catheter must not be wedged. Flow around the microcatheter delivers the
embolic agent to the target without undue pressurization.
• Embolization is complete when the majority of tumor flow has been obliterated—
remember that the goal is to try to make the surgery simpler by reducing blood
supply from branches of the ECA. Benefit vs. risk of embolizing a particular
vessel should always be considered.