Special Equipment

• 5 French (F) or 6F sheath
  
• 5 or 6F guiding catheter
  
• Tuohy Borst adaptor for continuous heparinized flush system
  
• Two-tip marker 14 or 10 microcatheter
  
• Soft-tip 14 or 10 micro–guide wire
  
• Various coil types, sizes, and configurations
  
• Some cases, neurovascular stent
  
• Some cases, compliant balloon catheter

Operating Room Set-up

• The surgeon is positioned at the patient’s groin with the viewing monitors directly facing the surgeon
  
• Lead shields should be positioned between the C-arm and the surgeon
  
• The anesthesiologist is usually positioned cross-table from the surgeon

Anesthetic Issues

• General endotracheal anesthesia is strongly recommended for best possible digital road map imaging during microcatheter and coil placement, and for patient management
  
• In certain circumstances with a very compliant patient, conscious sedation may be utilized

Miscellaneous

• For unruptured aneurysms, full heparinization (activated clotting times [ACT] two times baseline) can be administered after the sheath is placed, pretreatment with clopidogrel (75 mg by mouth every day) and aspirin (325 mg by mouth every day) for at least 5 days preprocedure if use of a neurovascular stent is anticipated
  
• For ruptured aneurysms, full heparinization (ACT two times baseline) can be administered after the aneurysm is “protected”
  
• Protamine should be readily available in the angiography suite before heparinization is initiated
  
• For unruptured and ruptured aneurysms, continuous heparinization (partial thromboplastin time [PTT] goal 60 to 80 second) is maintained for 24 hours postprocedure, and patient remains on aspirin (325 mg by mouth every day), with additional clopidogrel (75 mg by mouth every day) if a neurovascular stent is used

Positioning

• The patient is positioned supine on the angiography table
  
• A Foley catheter is placed
  
• Both inguinal areas are shaved and prepped with sterilizing solution
  
• A sterile drape is placed over the prepped areas
  
• The head is positioned in neutral position in a head holder

Technique

• Femoral artery puncture is performed and a 5 or 6F sheath is inserted
  
• A 5 or 6F guiding catheter is advanced through the sheath into the parent internal carotid artery at a stable position well below the skull base
  
• The guiding catheter should be connected to a continuous heparinized flush system using a Tuohy Borst adaptor
  
• Pretreatment angiograms are performed
  
• Optimal working projections of the aneurysm dome, neck, and all adjacent vessels must be obtained; rotational three-dimensional (3D) angiography reconstructions are extremely helpful in providing the best visualization
  
• The origin of the ophthalmic artery should be well visualized
  
• The aneurysm is measured; it is important to measure three dimensions of the aneurysm dome as well as measuring the aneurysm neck
  
• The microcatheter is steam-shaped, or there are also commercially available pre-shaped microcatheters
  
• A road map image is obtained
  
• The two-tip microcatheter is advanced over a soft tip micro–guide wire into the aneurysm to a stable position using road map guidance; the microcatheter should not be positioned directly into the wall of the dome
  
• Choose the largest possible 3D conformation “basket” coil that safely fit into the aneurysm
  
• The coil is checked on the prep table before it is inserted into the patient
  
• The coil is gently advanced through the microcatheter into the aneurysm until the markers demonstrate that the detachment zone is within the aneurysm and out of the microcatheter
  
• An angiogram is performed via the guiding catheter before coil detachment to confirm optimal position of the coil, patency of adjacent vessels (i.e., ophthalmic artery), and no thrombus formation
  
• If the angiogram demonstrates optimal position of the coil and patency of adjacent vessels, the coil can be detached (electrolytic or mechanical)
  
• A new road map image is obtained and further coils are placed in the same fashion
  
• Typically, one or two 3D conformation “basket” coils are placed to frame the aneurysm, followed by two-dimensional “filling” coils
  
• The final coils are usually ultra-soft “finishing” coils to occlude the neck of the aneurysm
  
• A neurovascular stent or balloon catheter may be necessary to buttress the coil mass if the aneurysm is wide-necked
  
• A final post-coiling angiogram is obtained

• The sheath is removed as described for a heparinized patient
  
• For unruptured and ruptured aneurysms, continuous heparinization (PTT goal 60 to 80 second) is maintained for 24 hours postprocedure, and patient remains on aspirin (325 mg by mouth every day), with additional clopidogrel (75 mg by mouth every day) if a neurovascular stent is used