Carotid cavernous fistula

1. Carotid Cavernous
Fistula – Neurovascular
Management
Dr Vaishal Shah
Senior Resident
Neurology department, GMC Kota

2. Introduction
▪ CCFs are abnormal communications between the
carotid arterial system and the cavernous sinus.
▪ Acquired.
▪ Most commonly seen in trauma involving skull
base fracture.
▪ Dural CCF are spontaneous is common in elderly
females

3. Classification
▪ Etiology (traumatic or spontaneous)
▪ Hemodynamic features (high vs low flow)
▪ Angiographic arterial architecture (direct or indirect)

4. Barrow et al. anatomical
classification
▪ Type A - direct communications between ICA and the cavernous
sinus. High flow rates.
▪ Type B fistulas have dural ICA branches to the cavernous sinus.
Uncommon.
▪ Type C fistulas are supplied solely by the dural branches of the ECA.
▪ Type D fistula that has dural ICA and ECA branches to the cavernous
sinus. Most prevalent.

6. Type A CCFs
▪ 80% are secondary to trauma.
▪ 20% are spontaneous.
Ehlers-danlos syndrome
Fibromuscular dysplasia
Pseudoxanthoma elasticum
Rupture of either a cavernous segment aneurysm of ICA

7. Type A CCFs
▪ High-flow shunts
▪ Flow rates in type A fistulas are variable and depend on the size of the
ostium and venous drainage.
▪ Complete steal - 5% of patients at diagnosis.
▪ Bilateral traumatic CCFs - 1%-2% of patients. Bilateral symptoms can
occur in unilateral CCF.

8. Indirect CCFs = Dural CCFs –
Type B, C, D CCFs
▪ Low flow rates.
▪ The major arterial supply is from the internal maxillary, middle
meningeal, accessory meningeal and ascending pharyngeal branches of
the ECA & cavernous segment branches of the ICA.
▪ R/F - HTn, DM, pregnancy, atherosclerotic disease, cavernous sinus
thrombosis, sinusitis, collagen vascular disease, trauma.

9. Pathophysiology and symptoms

10. High flow CCF
▪ Highly pressurized arterial blood gets transmitted directly into the
cavernous sinus, draining veins, leading to venous hypertension.
▪ Direction of the venous drainage is multidirectional.
▪ Onset is abrupt and rapidly progressive.
▪ Classic presentation for a direct, high-flow CCF is Dandy’s triad:
exophthalmos, bruit, and conjunctival chemosis.

12. Direct CCF
▪ Proptosis (90%)
▪ Chemosis (90%)
▪ Cephalic bruit (80%)
▪ Diplopia (50%)
▪ Pain (25%)
▪ Trigeminal nerve dysfunction
▪ Elevated intraocular pressure, and visual loss (up to 50%).

13. ▪ Intracranial haemorrhage develops in 5% of patients
▪ External haemorrhage such as otorrhagia and epistaxis can be seen in
nearly 3% of cases in CCF.
▪ Pseudoaneurysm or venous pouch that entered the sphenoid sinus via a
communication through a basal skull fracture

16. Indirect CCF
▪ Indirect CCFs often do not demonstrate the classic triad.
▪ The onset of symptoms of indirect CCFs is not as drastic as in direct
CCFs.
▪ Progressive glaucoma, proptosis or conjunctival injection (red eye)
▪ Spontaneous resolution without treatment occurs in 30%-60% of cases

17. ▪ Exacerbation and remission of signs and symptoms are the hallmark of
dural CCFs.
▪ Cavernous sinus thrombosis and rerouting of venous flow in various
directions.

18. Diagnostic imaging
1) CT scan
Proptosis.
Enlargement of the extraocular muscles.
Dilatation and tortuosity of the superior ophthalmic vein (sov).
Enlargement of the ipsilateral cavernous sinus.
2) MRI

21. 3) CT angiography
First-line diagnostic tool.
Rarely depicts small feeding arteries in dural CCFs.
The exact site of fistulous communication in direct CCFs is sometimes
difficult to locate.

22. 4) Cerebral angiography
Size and location of the fistula
Differentiation of direct from indirect lesions
Presence of any associated cavernous carotid aneurysm
Presence of complete or partial steal phenomena
Assessment of the global cortical arterial circulation and collateral
flow through the circle of willis.

23. Identification of high-risk features (e.g., Cortical venous drainage,
pseudoaneurysm, cavernous sinus varix)
Venous drainage patterns
Determination of therapeutic route
Associated vascular injuries (e.g., Traumatic pseudoaneurysm, arterial
dissection)
Evaluation of carotid bifurcation before compression therapy.

24. ▪ Exact location can be challenging.
▪ Specific maneuvers
Angiographic high frame rate imaging (> 5 frames/s) and rapid
contrast injection rates (7 or 8 ml/s)
The mehringer-hieshima maneuver
Double-lumen balloon catheter
Heuber maneuver

25. Pretherapeutic evaluation
▪ Tolerance for ICA occlusion
▪ Balloon test occlusion is the currently accepted technique.
▪ Use of sodium nitroprusside.
▪ Use of SPECT.

26. Differential diagnosis
▪ Primary intracranial tumour
▪ Lymphoma or local or distant metastatic tumour
▪ Carotid dissection
▪ Cavernous sinus thrombosis
▪ Orbital pseudotumor
▪ Tolosa hunt syndrome
M/C
D/D

27. Indication of emergency
treatment
Angiographic findings
▪ Pseudoaneurysm
▪ Large varix of cavernous sinus
▪ Venous drainage to cortical
veins
▪ Thrombosis of distal venous
outflow pathways
Clinical signs & symptoms
▪ Increased ICP
▪ Rapidly progressive proptosis
▪ ICH,SAH & external
haemorrhage
▪ TIA

28. Treatment modalities
▪ Conservative management
▪ Manual compression therapy and medical therapy
▪ Surgical management
▪ Stereotactic radiosurgery
▪ Endovascular management

29. Endovascular management
Direct fistula
Transarterial treatment
(preferred approach for direct
CCF)
▪ Detachable balloon occlusion
▪ Transarterial coil embolization
▪ Covered stent graft placement
▪ Parent artery occlusion
Transvenous treatment
▪ Transvenous detachable coil embolization
▪ Liquid embolizing agents (n-bca, onyx)
Indirect fistula
Transvenous treatment (preferred
approach for indirect CCF)
▪ Transvenous detachable coil embolization
▪ Liquid embolizing agents (n-bca, onyx)
Transarterial treatment
▪ Transarterial coil embolization

30. Conservative management
▪ Higher risk fistulas – aggressive approach.
▪ Low-risk fistulas – conservative.
▪ Spontaneous resolution – Days to months.
▪ Prism therapy.
▪ Lubrication.
▪ Beta blockers and acetazolamide.

31. Manual external carotid-jugular
compression
▪ For indirect CCFs. 10 s while sitting or lying down, 4 to 6 times each
hour.
▪ Cure in 30% of patients with spontaneous CCF.
▪ Prerequisite – status of carotid atherosclerosis & cortical venous
drainage

32. Surgical management
▪ Limited role. A/w morbidity from cranial nerve deficits and residual
fistulous communications.
▪ Indications
Compromised proximal arterial access
Failed endovascular treatments
▪ Preoperative
Complete angiographic documentation of the fistula and BTO.
Appearance and condition of the superficial temporal artery.

33. Radiosurgery
▪ Gamma knife radiosurgery.
▪ For indirect CCF.
▪ Alone or as an adjunct therapy before/after endovascular intervention.
▪ 22 month average lag period.

34. Endovascular management
▪ It has evolved as the primary treatment option
▪ Method of endovascular treatment are often significantly different in
direct and indirect CCF

35. Direct CCF treatment
▪ The goal of treatment - occlude the tear between the ICA and the
cavernous sinus while preserving the patency of the ICA.
1. Detachable balloon
2. Coils or other embolic material
3. Covered stent

36. Detachable balloon occlusion
▪ Accepted since the 1980s
▪ Large fistulous tract & large cavernous sinus - prerequisite
▪ Transfemoral access to the proximal cca with a 7-french guide
catheter.
▪ Uninflated balloon is advanced to the distal end of the guide catheter

37. ▪ Advantage of being able to be flow directed through the fistula and
into the cavernous sinus.
▪ Inflated to a volume larger than the orifice of the fistula.
▪ Multiple balloons in the setting of a large tear in the ica.

39. ▪ Advantage – Procedure is rapid, cheaper if goes smooth
▪ Complications –
Inadequate embolization early balloon detachment.
deflation or rupture by contact with a bony fragment.
Long term – recurrent fistula, protrude/shift into parent artery.

40. Coil and material embolization
▪ Mainstay for high-flow direct CCFs
Detachable platinum coils
N-butyl cyanoacrylate (N-BCA)
Ethylene-vinylalcohol copolymer (EVOH)
▪ Detachable platinum coils are preferred because of their reliable and
controlled deployment

41. ▪ Placing a guiding catheter in the cervical ICA.
▪ Microcatheter is superselectively advanced into the cavernous
segment of the ica and through the tear into the cavernous sinus.
▪ Through this microcatheter, embolic material is placed into the
cavernous sinus.

42. ▪ Advantage
Ease of access and availability of a variety of sizes of the embolic
device
▪ Disadvantage
Slower gradual occlusion of the fistula, which increases procedure
time

43. ▪ Complication
ICA compromise by protruding coil mass and ICA dissection.
▪ balloon-assist technique (preventing the retrograde herniation of the
embolic material)

45. Covered stent graft placement
▪ Recent advances
▪ Immediate obliteration of a direct CCF, while preserving ica patency.
▪ PTFE- covered stents have created alternatives to ICA sacrifice in
traumatic arterial damage.
▪ In the setting of an unsuccessful balloon test occlusion study.

46. ▪ Disadvantage
Limited longitudinal flexibility – making it difficult to navigate
Periprocedural vasospasms
Endoleak, coverage of vital perforators, dissection.
Limited due to lack of configurations compatible with intracranial use

49. Parent artery occlusion
▪ Arterial sacrifice may be required as a life-saving emergency
treatment.
Extensive traumatic vessel wall damage.
Active haemorrhage or a rapidly expanding hematoma of the soft
tissues.

50. ▪ Assessment of the collateral flow and patient’s ability to
tolerate ICA occlusion,
In cases of complete steal presenting without any ischemic symptom,
If ACOM and PCOM collaterals are found to be patent,
▪ Collateral flow is confirmed
Balloon occlusion test

51. ▪ Coil [ Hydrocoil embolization system (HES) ]
▪ Balloon
▪ Vascular plug embolization
▪ Distal to proximal approach to prevent the retrograde arterial filling of
the fistula.

52. Indirect (type B, C, D) CCFs
▪ Transvenous embolization
▪ Alternative technique in direct CCFs but preferred treatment for
indirect CCFs
Simplicity
Lower ischemic risk
Higher success rates
Capability to cure the fistula in a single session.

53. ▪ Aim – to catheterize the abnormal cavernous sinus superselectively
and to occlude the fistula.
▪ Navigation through the venous system and mechanical perforation are
technical challenges.
▪ Via multiple routes but most common is via IPS.

54. IPS approach
▪ From a posterior direction through IJV IPS Pathologic
shunts of the cavernous sinus
▪ Feasible in the great majority (99%) of cases
▪ Accessibility of the cavernous sinus through the IPS becomes
technically difficult due to occlusion of the IPS due to longstanding
venous hypertension.

55. SOV approach
• Orbital haemorrhage
• Nerve damage
• Laceration of the ICA
resulting in direct CCF
• Globe puncture, and
infection

56. Less commonly used transvenous approaches
▪ Lateral pterygoid plexus
▪ Superior petrosal sinus
▪ The inferior ophthalmic vein
▪ Contralateral IPS

57. ▪ Following successful catheterization of the cavernous sinus
Coils
N-BCA
EVOH
▪ Can be used either alone or in combination.

58. Coil embolisation
▪ coil advantage – radiopaque, easily removable
▪ Coil disadvantages
Difficulty in achieving adequate volumetric packing or complete
occlusion.
Reported rates of cranial nerve paresis due to their mass effect.
▪ Transvenous liquid embolic agents are commonly used - either alone
or in combination with platinum coils.

59. EVOH
▪ Nonadhesive nature – decreases the risk of microcatheter retention.
▪ Propensity for retrograde filling of arterial feeders.

60. N-BCA
▪ n-BCA has the advantages of rapid polymerization and permanent
occlusion of the injected feeders.
▪ Prolonged injections are not possible and as they may risk gluing the
catheter because of the adhesive nature of N-BCA
▪ Catheter repositioning, reinjection during embolization cannot be
performed.

61. Transarterial embolization
▪ Cumbersome because of the small size, complex anatomy, and
multiplicity of arterial feeders.
▪ Multiple staged sessions may be necessary.
▪ Transarterial embolization is typically used
Only to reduce arterial inflow before transvenous occlusion for
highflow indirect CCFs.
As a viable alternative after failure of transvenous attempts.

62. Follow-up
▪ Ocular symptoms resolve rapidly following successful treatment.
▪ “Paradoxical worsening phenomenon”
Transiently more symptomatic due to propagation of thrombus
throughout the cavernous sinus and extending into the SOV
▪ Resolve spontaneously over time. A brief course of corticosteroids
may help.

63. ▪ Severe progression of the ocular manifestations in the early
postoperative period suggest recurrent CCF.
▪ Stent-graft patency should be followed carefully as long-term safety
data are lacking

64. Dural CCF-after 6 months of treatment

66. References
▪ Endovascular treatment of carotid cavernous sinus fistula:A
systematic review, Bora Korkmazer et al., World J Radiol 2013
April 28; 5(4): 143-155
▪ Advances in the endovascular treatment of direct carotid-
cavernous fistulas, Guilherme Brasileiro de Aguiar et al.,Rev
Assoc Med Bras 2016; 62(1):78-84
▪ Traumatic carotid-cavernous fistulas treated with covered
stents: experience of 12 cases, jin li et al., World
neurosurgery 2010 73 [5]:514-519
▪ www.uptodate.com
▪ Practical Neuroangiography by Pearse Morris

67. THANK YOU