Indirect Cavernous Carotid Fistulas
♦ Preoperative
Operative Planning
- Diagnostic angiography should be performed with specific views that will provide excellent visualization of the fistula and help determine whether a transarterial or a transvenous approach should be used. Venous drainage patterns are extremely important for treatment planning.
- Manual vascular compression techniques may be required to define the shunt point of the fistula.
- High risk features for hemorrhage (cortical venous drainage, pseudoaneurysm, and cavernous sinus varix) should be identified.
Special Equipment
- As noted for retrograde percutaneous femoral artery puncture
- One 5 French (F) sheath possibly upsized to 6.5F if transarterial approach
- One 7.5F sheath if transvenous treatment employed
- One 5F diagnostic catheter, possibly 6F guiding catheter
- One 7F guiding catheter for transvenous treatment
- Size 18 microcatheters for fibered and nonfibered coils
- Size 10 to 14 microcatheters for liquid embolic agents
- Detachable and nondetachable latex or silicone balloons are no longer commercially available
- 0.035-inch guide wire and micro–guide wires
- Iohexol contrast
- Polyvinyl alcohol (PVA) particles
- Platinum coils of differing sizes with or without polyester fibers
- Polyvinyl alcohol (PVA) particles
Anesthetic Issues
- General anesthesia (GA) with endotracheal intubation is recommended (can start with monitored anesthesia care and convert to GA if a balloon test occlusion is contemplated).
- The anesthesiologist should be prepared to induce hypotension, if necessary.
Monitoring
- No special monitoring is needed beyond that used by the anesthesiologist
♦ Intraoperative
Positioning
- The patient is placed in the supine position.
- Intravenous antibiotics, if needed, are given.
- A Foley catheter is placed.
- The proper shielding is placed on the patient.
- Both inguinal areas are shaved and prepped with iodine solution.
- A sterile drape is placed over the prepped areas.
- The head is positioned in neutral position and gently taped in place.
Technique
- Femoral artery puncture is performed, and a 5F sheath is inserted in the right common femoral artery.
- Patient is kept well-heparinized throughout the procedure (activated clotting time ≥ 2.5 times baseline).
- A four-vessel diagnostic cerebral angiogram is performed.
- The exact location of the fistula site is determined.
- For a direct CCF, transarterial balloons are no longer available. Internal carotid artery (ICA) sacrifice may be required, and a balloon test occlusion of the ipsilateral ICA is recommended.
- If endovascular ICA sacrifice is planned, the occlusion should be performed across the fistulous opening in the ICA so as not to allow patency from retrograde flow into the ICA distal to the fistula.
- If coil occlusion of the direct fistula is planned either from the arterial or venous side, consider endovascular ICA stent placement to prevent coil protrusion/embolization into the parent artery.
- For an arterial approach, a 6.5F sheath is exchanged for the 5F sheath in the CFA using the technique as described.
- A 6 Fr guiding catheter is inserted through the 6.5F sheath, advanced into the affected carotid artery and connected to continuous heparinized saline flush.
- A roadmap of the parent vessel is obtained.
- The endovascular stent is navigated through the 6F guiding catheter across the site of the fistula and is deployed.
- A microcatheter is then navigated through the stent (or placed into the fistula prior to stent deployment, the so-called “trapping technique”).
- Coil embolization of the fistula is performed through the microcatheter.
- Surveillance angiograms are performed to confirm that the fistula has been obliterated and adjacent parent distal vessels are patent.
- Transvenous approach involves femoral vein puncture and placement of a 7F sheath inserted in the left common femoral vein. The right CFA sheath is still required for surveillance angiograms during embolization. This approach is commonly performed for indirect CCF treatment.
- A 7F guide catheter is navigated into the ipsilateral internal jugular vein under fluoroscopic guidance.
- An 18 microcatheter is navigated into the inferior petrosal sinus (IPS) and eventually the cavernous sinus and or superior ophthalmic vein (SOV), depending on the anatomy of the fistula. A facial vein approach or direct SOV cut down may be required.
- Arterial and venous roadmaps are performed for microcatheter navigation.
- Coil embolization of the SOV, cavernous sinus, and IPS are performed as required by the anatomy of the fistula with fibered microcoils.
- Surveillance angiograms are performed to confirm that the fistula has been obliterated and adjacent parent distal vessels are patent.
- Surveillance angiograms are performed to confirm that the fistula has been obliterated and adjacent parent distal vessels are patent.
Sheath Removal
- The sheaths are removed as described.
< div class='tao-gold-member'>
Only gold members can continue reading. Log In or Register to continue
Related posts:
