sistence, or even worsening by rerouting of the venous drainage that is associated with increased risk of intracranial hemorrhage. At the end of the procedure, occluding the IPS itself should be avoided as it may be needed as an access route in a subsequent session. Secondly, an occlusion of the IPS may, if it serves as drainage for the CS, compromise the normal cerebral circulation of the posterior fossa. Although a 4-F or 5-F guiding catheter can be advanced into the IPS, one should remember that, especially in cases with cortical venous drainage, such a maneuver may elevate venous pressure sufficent enough to cause intracerebral hemorrhage as recently reported (Theaudin et al. 2007).

The angiographic endpoint of the endovascular procedure is either subtotal or complete occlusion of the fistula. If there is a minimal residual AV shunt visible, the procedure can usually be stopped, because the postoperative normalization of the ACT will further promote ongoing thrombosis within the CS. Ongoing thrombosis in the CS may be impeded by the heparinization of the patient during the procedure. Subtotal occlusion is often sufficient and will lead to complete occlusion within a few days or even 24 h when the coagulation system is normalized (Case Reports II and IV). Whenever possible, it is advisable to avoid overpacking the CS.

Additional particulate embolization using PVA or Embospheres after TVO, although performed by some investigators, has rarely been necessary in the author’s experience. After extubation, the patients are usually transferred to a post-anesthesia care unit, and then to a normal unit. Only if adverse effects or signs of visual deterioration are observed, will the patient be heparinized for 48 h. Some operators suggest reversal of systemic heparinization with protamine sulfate (10 mg per 1000 U) (Vinuela et al. 1997). In order to avoid post-procedural complications, the additional use of a closure device such as Angio-SealTM (St. Jude Medical Inc.) is increasingly practiced by many operators.

Postoperative headaches due to mechanical pressure induced by the coils can usually be controlled with analgesics (300 mg ASA daily). If postoperative CN palsy occurs, additional corticosteroids can be administered (e.g. Decadron 4–8 mg every 6). Every patient should undergo an ophthalmological exam a few days after the procedure. Many times, symptoms improve during the first 24 h. The patient may be discharged either the next day or after 2–3 days, and is then seen for clinical follow-up after 3 months with at least one angiographic follow-up after 6–9 months.

8.1.2

Alternative Approaches to the Cavernous Sinus

8.1.2.1

Transfemoral Superior Ophthalmic Vein Approach (Case Report IV)

When the ipsior contralateral IPS approach clearly fails, a transfemoral SOV approach may be performed during the same or a subsequent session. This is done in the following way: A 4-F guiding catheter (0.038s inner lumen) is introduced into the facial vein and navigated as distally as possible. The closer the tip of this catheter is placed to the angular vein, the easier the catheterization of the SOV will be with a microcatheter. A too proximally placed guide often requires more microcatheter manipulations in the facial and angular veins. These veins tend to become more mobile within the subcutaneous soft tissue, making advancing the microcatheter through a tortuous SOV difficult. A slightly stiffer microcatheter, such as the braided Rapid Transit 18, may be feasible. The use of a triaxial catheter systems (8 F-4 F-2 F), although never employed by the author, can also be helpful (Suzuki et al. 2006).

8.1.2.2

Transcutaneous Superior Ophthalmic Vein Approach (Cannulation, Case Report V)

This approach is chosen if both the IPS and the transfemoral SOV approach fail to provide access. Under general anesthesia, the patient gets prepared in the surgical OR, or (under sterile conditions) in the angiography suite. An experienced ophthalmic surgeon, ophthalmologist or, as in the author’s practice, a max- illo-facial surgeon should perform an upper-lid or sub-brow cut to mobilize the angular vein. The vessel is then gently held with a suture and cannulated with a 20or 21-G thin or ultra-thin wall needle (e.g. Terumo UTW 21). A small microguidewire, preferably a 0.010s wire, is carefully introduced and navigated into the distal SOV. The the blunt plastic cannula is stabilized with a suture until the end of the procedure. Then, the patient may be transferred to the OR (if not already prepared in the angiography suite). A small 0.010s microcatheter (Tracker-10, Excelsior SL-10) is introduced and navigated into the proximal SOV or CS, which is usually possible without difficulties.

Some operators suggest a slightly different technique, where the microcatheter is directly introduced into the vein, which has been ligated proximally and